From 6c29291112b6b767e98ce3fb93dd4752d0ef1469 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 24 Apr 2014 05:46:08 +0300 Subject: Start on gawk manual updating. --- doc/gawk.info | 1156 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 581 insertions(+), 575 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 8a26992f..589ac015 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -127,7 +127,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * One-shot:: Running a short throwaway `awk' program. * Read Terminal:: Using no input files (input from - terminal instead). + the keyboard instead). * Long:: Putting permanent `awk' programs in files. * Executable Scripts:: Making self-contained `awk' @@ -791,6 +791,10 @@ and other `awk' implementations. * Perform simple network communications + * Profile and debug `awk' programs. + + * Extend the language with functions written in C or C++. + This Info file teaches you about the `awk' language and how you can use it effectively. You should already be familiar with basic system commands, such as `cat' and `ls',(2) as well as basic shell facilities, @@ -799,13 +803,12 @@ such as input/output (I/O) redirection and pipes. Implementations of the `awk' language are available for many different computing environments. This Info file, while describing the `awk' language in general, also describes the particular implementation -of `awk' called `gawk' (which stands for "GNU awk"). `gawk' runs on a -broad range of Unix systems, ranging from Intel(R)-architecture -PC-based computers up through large-scale systems, such as Crays. -`gawk' has also been ported to Mac OS X, Microsoft Windows (all -versions) and OS/2 PCs, and VMS. (Some other, obsolete systems to -which `gawk' was once ported are no longer supported and the code for -those systems has been removed.) +of `awk' called `gawk' (which stands for "GNU `awk'"). `gawk' runs on +a broad range of Unix systems, ranging from Intel(R)-architecture +PC-based computers up through large-scale systems. `gawk' has also +been ported to Mac OS X, Microsoft Windows (all versions), and OpenVMS. +(Some other, obsolete systems to which `gawk' was once ported are no +longer supported and the code for those systems has been removed.) * Menu: @@ -822,7 +825,7 @@ those systems has been removed.) ---------- Footnotes ---------- - (1) The 2008 POSIX standard is online at + (1) The 2008 POSIX standard is accessable online at `http://www.opengroup.org/onlinepubs/9699919799/'. (2) These commands are available on POSIX-compliant systems, as well @@ -892,20 +895,21 @@ The `awk' language has evolved over the years. Full details are provided in *note Language History::. The language described in this Info file is often referred to as "new `awk'" (`nawk'). - Because of this, there are systems with multiple versions of `awk'. -Some systems have an `awk' utility that implements the original version -of the `awk' language and a `nawk' utility for the new version. Others -have an `oawk' version for the "old `awk'" language and plain `awk' for -the new one. Still others only have one version, which is usually the -new one.(1) - - All in all, this makes it difficult for you to know which version of -`awk' you should run when writing your programs. The best advice we -can give here is to check your local documentation. Look for `awk', -`oawk', and `nawk', as well as for `gawk'. It is likely that you -already have some version of new `awk' on your system, which is what -you should use when running your programs. (Of course, if you're -reading this Info file, chances are good that you have `gawk'!) + For some time after new `awk' was introduced, there were systems +with multiple versions of `awk'. Some systems had an `awk' utility +that implemented the original version of the `awk' language and a +`nawk' utility for the new version. Others had an `oawk' version for +the "old `awk'" language and plain `awk' for the new one. Still others +only had one version, which is usually the new one. + + Today, only Solaris systems still use an old `awk' for the default +`awk' utility. (A more modern `awk' lives in `/usr/xpg6/bin' on these +systems.) All other modern systems use some version of new `awk'.(1) + + It is likely that you already have some version of new `awk' on your +system, which is what you should use when running your programs. (Of +course, if you're reading this Info file, chances are good that you +have `gawk'!) Throughout this Info file, whenever we refer to a language feature that should be available in any complete implementation of POSIX `awk', @@ -914,7 +918,7 @@ specific to the GNU implementation, we use the term `gawk'. ---------- Footnotes ---------- - (1) Often, these systems use `gawk' for their `awk' implementation! + (1) Many of these systems use `gawk' for their `awk' implementation!  File: gawk.info, Node: This Manual, Next: Conventions, Prev: Names, Up: Preface @@ -1168,11 +1172,10 @@ significant note for this edition was *note Debugger::. the major new additions are *note Arbitrary Precision Arithmetic::, and *note Dynamic Extensions::. - `GAWK: Effective AWK Programming' will undoubtedly continue to -evolve. An electronic version comes with the `gawk' distribution from -the FSF. If you find an error in this Info file, please report it! -*Note Bugs::, for information on submitting problem reports -electronically. + This Info file will undoubtedly continue to evolve. An electronic +version comes with the `gawk' distribution from the FSF. If you find +an error in this Info file, please report it! *Note Bugs::, for +information on submitting problem reports electronically. ---------- Footnotes ---------- @@ -1199,14 +1202,17 @@ something more broad, I acquired the `awk.info' domain. contributed code: the archive did not grow and the domain went unused for several years. - Fortunately, late in 2008, a volunteer took on the task of setting up -an `awk'-related web site--`http://awk.info'--and did a very nice job. + Late in 2008, a volunteer took on the task of setting up an +`awk'-related web site--`http://awk.info'--and did a very nice job. If you have written an interesting `awk' program, or have written a `gawk' extension that you would like to share with the rest of the world, please see `http://awk.info/?contribute' for how to contribute it to the web site. + As of this writing, this website is in search of a maintainer; please +contact me if you are interested. +  File: gawk.info, Node: Acknowledgments, Prev: How To Contribute, Up: Preface @@ -1297,7 +1303,7 @@ to take advantage of those opportunities. Arnold Robbins Nof Ayalon ISRAEL -May, 2013 +May, 2014  File: gawk.info, Node: Getting Started, Next: Invoking Gawk, Prev: Preface, Up: Top @@ -1375,7 +1381,7 @@ variations of each. * One-shot:: Running a short throwaway `awk' program. -* Read Terminal:: Using no input files (input from terminal +* Read Terminal:: Using no input files (input from the keyboard instead). * Long:: Putting permanent `awk' programs in files. @@ -1425,7 +1431,7 @@ following command line: awk 'PROGRAM' `awk' applies the PROGRAM to the "standard input", which usually means -whatever you type on the terminal. This continues until you indicate +whatever you type on the keyboard. This continues until you indicate end-of-file by typing `Ctrl-d'. (On other operating systems, the end-of-file character may be different. For example, on OS/2, it is `Ctrl-z'.) @@ -2381,7 +2387,7 @@ The following list describes options mandated by the POSIX standard: `--debug=[FILE]' Enable debugging of `awk' programs (*note Debugging::). By default, the debugger reads commands interactively from the - terminal. The optional FILE argument allows you to specify a file + keyboard. The optional FILE argument allows you to specify a file with a list of commands for the debugger to execute non-interactively. No space is allowed between the `-D' and FILE, if FILE is supplied. @@ -2586,7 +2592,7 @@ having to be included into each individual program. (As mentioned in *note Definition Syntax::, function names must be unique.) With standard `awk', library functions can still be used, even if -the program is entered at the terminal, by specifying `-f /dev/tty'. +the program is entered at the keyboard, by specifying `-f /dev/tty'. After typing your program, type `Ctrl-d' (the end-of-file character) to terminate it. (You may also use `-f -' to read program source from the standard input but then you will not be able to also use the standard @@ -5111,7 +5117,7 @@ File: gawk.info, Node: Getline, Next: Read Timeout, Prev: Multiple Line, Up: ================================= So far we have been getting our input data from `awk''s main input -stream--either the standard input (usually your terminal, sometimes the +stream--either the standard input (usually your keyboard, sometimes the output from another program) or from the files specified on the command line. The `awk' language has a special built-in command called `getline' that can be used to read input under your explicit control. @@ -5560,8 +5566,8 @@ File: gawk.info, Node: Read Timeout, Next: Command line directories, Prev: Ge 4.10 Reading Input With A Timeout ================================= -You may specify a timeout in milliseconds for reading input from a -terminal, pipe or two-way communication including, TCP/IP sockets. This +You may specify a timeout in milliseconds for reading input from the +keyboard, pipe or two-way communication including, TCP/IP sockets. This can be done on a per input, command or connection basis, by setting a special element in the `PROCINFO' array: @@ -5579,8 +5585,8 @@ from the server after a certain amount of time: else if (ERRNO != "") print ERRNO - Here is how to read interactively from the terminal(1) without -waiting for more than five seconds: + Here is how to read interactively from the user(1) without waiting +for more than five seconds: PROCINFO["/dev/stdin", "READ_TIMEOUT"] = 5000 while ((getline < "/dev/stdin") > 0) @@ -5591,7 +5597,7 @@ after waiting for the timeout period, return failure and set the `ERRNO' variable to an appropriate string value. A negative or zero value for the timeout is the same as specifying no timeout at all. - A timeout can also be set for reading from the terminal in the + A timeout can also be set for reading from the keyboard in the implicit loop that reads input records and matches them against patterns, like so: @@ -5644,7 +5650,7 @@ writing. ---------- Footnotes ---------- - (1) This assumes that standard input is the keyboard + (1) This assumes that standard input is the keyboard.  File: gawk.info, Node: Command line directories, Prev: Read Timeout, Up: Reading Files @@ -21173,7 +21179,7 @@ need it. arbitrary precision arithmetic. The easiest way to find out is to look at the output of the following command: - $ ./gawk --version + $ gawk --version -| GNU Awk 4.1.1, API: 1.1 (GNU MPFR 3.1.0-p3, GNU MP 5.0.2) -| Copyright (C) 1989, 1991-2014 Free Software Foundation. ... @@ -26263,8 +26269,8 @@ Various `.c', `.y', and `.h' files PC Installation::, for details). `vms/*' - Files needed for building `gawk' under VMS (*note VMS - Installation::, for details). + Files needed for building `gawk' under Vax/VMS and OpenVMS (*note + VMS Installation::, for details). `test/*' A test suite for `gawk'. You can use `make check' from the @@ -26748,8 +26754,8 @@ translation of `"\r\n"', since it won't. Caveat Emptor!  File: gawk.info, Node: VMS Installation, Prev: PC Installation, Up: Non-Unix Installation -B.3.2 How to Compile and Install `gawk' on VMS ----------------------------------------------- +B.3.2 How to Compile and Install `gawk' on Vax/VMS and OpenVMS +-------------------------------------------------------------- This node describes how to compile and install `gawk' under VMS. The older designation "VMS" is used throughout to refer to OpenVMS. @@ -31677,7 +31683,7 @@ Index * git, use of for gawk source code: Derived Files. (line 6) * GMP: Gawk and MPFR. (line 6) * GNITS mailing list: Acknowledgments. (line 52) -* GNU awk, See gawk: Preface. (line 49) +* GNU awk, See gawk: Preface. (line 53) * GNU Free Documentation License: GNU Free Documentation License. (line 7) * GNU General Public License: Glossary. (line 306) @@ -32023,7 +32029,7 @@ Index * namespace issues <1>: Library Names. (line 6) * namespace issues: Arrays. (line 18) * namespace issues, functions: Definition Syntax. (line 20) -* nawk utility: Names. (line 17) +* nawk utility: Names. (line 10) * negative zero: Unexpected Results. (line 34) * NetBSD: Glossary. (line 616) * networks, programming: TCP/IP Networking. (line 6) @@ -32103,7 +32109,7 @@ Index * numeric, output format: OFMT. (line 6) * numeric, strings: Variable Typing. (line 6) * o debugger command (alias for option): Debugger Info. (line 57) -* oawk utility: Names. (line 17) +* oawk utility: Names. (line 10) * obsolete features: Obsolete. (line 6) * octal numbers: Nondecimal-numbers. (line 6) * octal values, enabling interpretation of: Options. (line 207) @@ -33094,529 +33100,529 @@ Index  Tag Table: Node: Top1292 -Node: Foreword40821 -Node: Preface45166 -Ref: Preface-Footnote-148219 -Ref: Preface-Footnote-248315 -Node: History48547 -Node: Names50921 -Ref: Names-Footnote-152398 -Node: This Manual52470 -Ref: This Manual-Footnote-158244 -Node: Conventions58344 -Node: Manual History60500 -Ref: Manual History-Footnote-163948 -Ref: Manual History-Footnote-263989 -Node: How To Contribute64063 -Node: Acknowledgments65207 -Node: Getting Started69401 -Node: Running gawk71780 -Node: One-shot72966 -Node: Read Terminal74191 -Ref: Read Terminal-Footnote-175841 -Ref: Read Terminal-Footnote-276117 -Node: Long76288 -Node: Executable Scripts77664 -Ref: Executable Scripts-Footnote-179497 -Ref: Executable Scripts-Footnote-279599 -Node: Comments80146 -Node: Quoting82613 -Node: DOS Quoting87236 -Node: Sample Data Files87911 -Node: Very Simple90426 -Node: Two Rules95077 -Node: More Complex96975 -Ref: More Complex-Footnote-199905 -Node: Statements/Lines99990 -Ref: Statements/Lines-Footnote-1104453 -Node: Other Features104718 -Node: When105646 -Node: Invoking Gawk107793 -Node: Command Line109256 -Node: Options110039 -Ref: Options-Footnote-1125417 -Node: Other Arguments125442 -Node: Naming Standard Input128100 -Node: Environment Variables129194 -Node: AWKPATH Variable129752 -Ref: AWKPATH Variable-Footnote-1132533 -Ref: AWKPATH Variable-Footnote-2132578 -Node: AWKLIBPATH Variable132838 -Node: Other Environment Variables133556 -Node: Exit Status136519 -Node: Include Files137194 -Node: Loading Shared Libraries140763 -Node: Obsolete142127 -Node: Undocumented142824 -Node: Regexp143066 -Node: Regexp Usage144455 -Node: Escape Sequences146480 -Node: Regexp Operators152149 -Ref: Regexp Operators-Footnote-1159529 -Ref: Regexp Operators-Footnote-2159676 -Node: Bracket Expressions159774 -Ref: table-char-classes161664 -Node: GNU Regexp Operators164187 -Node: Case-sensitivity167910 -Ref: Case-sensitivity-Footnote-1170878 -Ref: Case-sensitivity-Footnote-2171113 -Node: Leftmost Longest171221 -Node: Computed Regexps172422 -Node: Reading Files175759 -Node: Records177761 -Ref: Records-Footnote-1187284 -Node: Fields187321 -Ref: Fields-Footnote-1190277 -Node: Nonconstant Fields190363 -Node: Changing Fields192569 -Node: Field Separators198528 -Node: Default Field Splitting201230 -Node: Regexp Field Splitting202347 -Node: Single Character Fields205689 -Node: Command Line Field Separator206748 -Node: Full Line Fields210090 -Ref: Full Line Fields-Footnote-1210598 -Node: Field Splitting Summary210644 -Ref: Field Splitting Summary-Footnote-1213743 -Node: Constant Size213844 -Node: Splitting By Content218451 -Ref: Splitting By Content-Footnote-1222200 -Node: Multiple Line222240 -Ref: Multiple Line-Footnote-1228087 -Node: Getline228266 -Node: Plain Getline230482 -Node: Getline/Variable232577 -Node: Getline/File233724 -Node: Getline/Variable/File235065 -Ref: Getline/Variable/File-Footnote-1236664 -Node: Getline/Pipe236751 -Node: Getline/Variable/Pipe239450 -Node: Getline/Coprocess240557 -Node: Getline/Variable/Coprocess241809 -Node: Getline Notes242546 -Node: Getline Summary245333 -Ref: table-getline-variants245741 -Node: Read Timeout246653 -Ref: Read Timeout-Footnote-1250394 -Node: Command line directories250451 -Node: Printing251081 -Node: Print252712 -Node: Print Examples254049 -Node: Output Separators256833 -Node: OFMT258849 -Node: Printf260207 -Node: Basic Printf261113 -Node: Control Letters262652 -Node: Format Modifiers266464 -Node: Printf Examples272473 -Node: Redirection275185 -Node: Special Files282159 -Node: Special FD282692 -Ref: Special FD-Footnote-1286317 -Node: Special Network286391 -Node: Special Caveats287241 -Node: Close Files And Pipes288037 -Ref: Close Files And Pipes-Footnote-1295020 -Ref: Close Files And Pipes-Footnote-2295168 -Node: Expressions295318 -Node: Values296450 -Node: Constants297126 -Node: Scalar Constants297806 -Ref: Scalar Constants-Footnote-1298665 -Node: Nondecimal-numbers298847 -Node: Regexp Constants301847 -Node: Using Constant Regexps302322 -Node: Variables305377 -Node: Using Variables306032 -Node: Assignment Options307756 -Node: Conversion309631 -Ref: table-locale-affects315131 -Ref: Conversion-Footnote-1315755 -Node: All Operators315864 -Node: Arithmetic Ops316494 -Node: Concatenation318999 -Ref: Concatenation-Footnote-1321787 -Node: Assignment Ops321907 -Ref: table-assign-ops326895 -Node: Increment Ops328226 -Node: Truth Values and Conditions331660 -Node: Truth Values332743 -Node: Typing and Comparison333792 -Node: Variable Typing334585 -Ref: Variable Typing-Footnote-1338482 -Node: Comparison Operators338604 -Ref: table-relational-ops339014 -Node: POSIX String Comparison342562 -Ref: POSIX String Comparison-Footnote-1343518 -Node: Boolean Ops343656 -Ref: Boolean Ops-Footnote-1347726 -Node: Conditional Exp347817 -Node: Function Calls349549 -Node: Precedence353143 -Node: Locales356812 -Node: Patterns and Actions357901 -Node: Pattern Overview358955 -Node: Regexp Patterns360624 -Node: Expression Patterns361167 -Node: Ranges364948 -Node: BEGIN/END368052 -Node: Using BEGIN/END368814 -Ref: Using BEGIN/END-Footnote-1371550 -Node: I/O And BEGIN/END371656 -Node: BEGINFILE/ENDFILE373938 -Node: Empty376852 -Node: Using Shell Variables377169 -Node: Action Overview379454 -Node: Statements381811 -Node: If Statement383665 -Node: While Statement385164 -Node: Do Statement387208 -Node: For Statement388364 -Node: Switch Statement391516 -Node: Break Statement393670 -Node: Continue Statement395660 -Node: Next Statement397453 -Node: Nextfile Statement399843 -Node: Exit Statement402498 -Node: Built-in Variables404914 -Node: User-modified406009 -Ref: User-modified-Footnote-1414367 -Node: Auto-set414429 -Ref: Auto-set-Footnote-1427494 -Ref: Auto-set-Footnote-2427699 -Node: ARGC and ARGV427755 -Node: Arrays431609 -Node: Array Basics433114 -Node: Array Intro433940 -Node: Reference to Elements438257 -Node: Assigning Elements440527 -Node: Array Example441018 -Node: Scanning an Array442750 -Node: Controlling Scanning445064 -Ref: Controlling Scanning-Footnote-1450151 -Node: Delete450467 -Ref: Delete-Footnote-1453232 -Node: Numeric Array Subscripts453289 -Node: Uninitialized Subscripts455472 -Node: Multidimensional457099 -Node: Multiscanning460192 -Node: Arrays of Arrays461781 -Node: Functions466421 -Node: Built-in467240 -Node: Calling Built-in468318 -Node: Numeric Functions470306 -Ref: Numeric Functions-Footnote-1474138 -Ref: Numeric Functions-Footnote-2474495 -Ref: Numeric Functions-Footnote-3474543 -Node: String Functions474812 -Ref: String Functions-Footnote-1497770 -Ref: String Functions-Footnote-2497899 -Ref: String Functions-Footnote-3498147 -Node: Gory Details498234 -Ref: table-sub-escapes499913 -Ref: table-sub-posix-92501267 -Ref: table-sub-proposed502618 -Ref: table-posix-sub503972 -Ref: table-gensub-escapes505517 -Ref: Gory Details-Footnote-1506693 -Ref: Gory Details-Footnote-2506744 -Node: I/O Functions506895 -Ref: I/O Functions-Footnote-1513885 -Node: Time Functions514032 -Ref: Time Functions-Footnote-1525015 -Ref: Time Functions-Footnote-2525083 -Ref: Time Functions-Footnote-3525241 -Ref: Time Functions-Footnote-4525352 -Ref: Time Functions-Footnote-5525464 -Ref: Time Functions-Footnote-6525691 -Node: Bitwise Functions525957 -Ref: table-bitwise-ops526519 -Ref: Bitwise Functions-Footnote-1530740 -Node: Type Functions530924 -Node: I18N Functions532075 -Node: User-defined533702 -Node: Definition Syntax534506 -Ref: Definition Syntax-Footnote-1539420 -Node: Function Example539489 -Ref: Function Example-Footnote-1542138 -Node: Function Caveats542160 -Node: Calling A Function542678 -Node: Variable Scope543633 -Node: Pass By Value/Reference546596 -Node: Return Statement550104 -Node: Dynamic Typing553085 -Node: Indirect Calls554016 -Node: Library Functions563703 -Ref: Library Functions-Footnote-1567216 -Ref: Library Functions-Footnote-2567359 -Node: Library Names567530 -Ref: Library Names-Footnote-1571003 -Ref: Library Names-Footnote-2571223 -Node: General Functions571309 -Node: Strtonum Function572337 -Node: Assert Function575267 -Node: Round Function578593 -Node: Cliff Random Function580134 -Node: Ordinal Functions581150 -Ref: Ordinal Functions-Footnote-1584227 -Ref: Ordinal Functions-Footnote-2584479 -Node: Join Function584690 -Ref: Join Function-Footnote-1586461 -Node: Getlocaltime Function586661 -Node: Readfile Function590402 -Node: Data File Management592241 -Node: Filetrans Function592873 -Node: Rewind Function596942 -Node: File Checking598329 -Node: Empty Files599423 -Node: Ignoring Assigns601653 -Node: Getopt Function603207 -Ref: Getopt Function-Footnote-1614510 -Node: Passwd Functions614713 -Ref: Passwd Functions-Footnote-1623691 -Node: Group Functions623779 -Node: Walking Arrays631863 -Node: Sample Programs633999 -Node: Running Examples634673 -Node: Clones635401 -Node: Cut Program636625 -Node: Egrep Program646476 -Ref: Egrep Program-Footnote-1654249 -Node: Id Program654359 -Node: Split Program658008 -Ref: Split Program-Footnote-1661527 -Node: Tee Program661655 -Node: Uniq Program664458 -Node: Wc Program671887 -Ref: Wc Program-Footnote-1676153 -Ref: Wc Program-Footnote-2676353 -Node: Miscellaneous Programs676445 -Node: Dupword Program677633 -Node: Alarm Program679664 -Node: Translate Program684471 -Ref: Translate Program-Footnote-1688858 -Ref: Translate Program-Footnote-2689106 -Node: Labels Program689240 -Ref: Labels Program-Footnote-1692611 -Node: Word Sorting692695 -Node: History Sorting696579 -Node: Extract Program698418 -Ref: Extract Program-Footnote-1705921 -Node: Simple Sed706049 -Node: Igawk Program709111 -Ref: Igawk Program-Footnote-1724268 -Ref: Igawk Program-Footnote-2724469 -Node: Anagram Program724607 -Node: Signature Program727675 -Node: Advanced Features728775 -Node: Nondecimal Data730661 -Node: Array Sorting732244 -Node: Controlling Array Traversal732941 -Node: Array Sorting Functions741225 -Ref: Array Sorting Functions-Footnote-1745094 -Node: Two-way I/O745288 -Ref: Two-way I/O-Footnote-1750720 -Node: TCP/IP Networking750802 -Node: Profiling753646 -Node: Internationalization761149 -Node: I18N and L10N762574 -Node: Explaining gettext763260 -Ref: Explaining gettext-Footnote-1768328 -Ref: Explaining gettext-Footnote-2768512 -Node: Programmer i18n768677 -Node: Translator i18n772879 -Node: String Extraction773673 -Ref: String Extraction-Footnote-1774634 -Node: Printf Ordering774720 -Ref: Printf Ordering-Footnote-1777502 -Node: I18N Portability777566 -Ref: I18N Portability-Footnote-1780015 -Node: I18N Example780078 -Ref: I18N Example-Footnote-1782716 -Node: Gawk I18N782788 -Node: Debugger783409 -Node: Debugging784380 -Node: Debugging Concepts784813 -Node: Debugging Terms786669 -Node: Awk Debugging789266 -Node: Sample Debugging Session790158 -Node: Debugger Invocation790678 -Node: Finding The Bug792011 -Node: List of Debugger Commands798498 -Node: Breakpoint Control799832 -Node: Debugger Execution Control803496 -Node: Viewing And Changing Data806856 -Node: Execution Stack810212 -Node: Debugger Info811679 -Node: Miscellaneous Debugger Commands815661 -Node: Readline Support820837 -Node: Limitations821668 -Node: Arbitrary Precision Arithmetic823920 -Ref: Arbitrary Precision Arithmetic-Footnote-1825569 -Node: General Arithmetic825717 -Node: Floating Point Issues827437 -Node: String Conversion Precision828318 -Ref: String Conversion Precision-Footnote-1830023 -Node: Unexpected Results830132 -Node: POSIX Floating Point Problems832285 -Ref: POSIX Floating Point Problems-Footnote-1836110 -Node: Integer Programming836148 -Node: Floating-point Programming837887 -Ref: Floating-point Programming-Footnote-1844218 -Ref: Floating-point Programming-Footnote-2844488 -Node: Floating-point Representation844752 -Node: Floating-point Context845917 -Ref: table-ieee-formats846756 -Node: Rounding Mode848140 -Ref: table-rounding-modes848619 -Ref: Rounding Mode-Footnote-1851634 -Node: Gawk and MPFR851813 -Node: Arbitrary Precision Floats853224 -Ref: Arbitrary Precision Floats-Footnote-1855667 -Node: Setting Precision855983 -Ref: table-predefined-precision-strings856669 -Node: Setting Rounding Mode858814 -Ref: table-gawk-rounding-modes859218 -Node: Floating-point Constants860405 -Node: Changing Precision861834 -Ref: Changing Precision-Footnote-1863231 -Node: Exact Arithmetic863405 -Node: Arbitrary Precision Integers866543 -Ref: Arbitrary Precision Integers-Footnote-1869558 -Node: Dynamic Extensions869705 -Node: Extension Intro871163 -Node: Plugin License872428 -Node: Extension Mechanism Outline873113 -Ref: load-extension873530 -Ref: load-new-function875008 -Ref: call-new-function876003 -Node: Extension API Description878018 -Node: Extension API Functions Introduction879305 -Node: General Data Types884232 -Ref: General Data Types-Footnote-1889927 -Node: Requesting Values890226 -Ref: table-value-types-returned890963 -Node: Memory Allocation Functions891917 -Ref: Memory Allocation Functions-Footnote-1894663 -Node: Constructor Functions894759 -Node: Registration Functions896517 -Node: Extension Functions897202 -Node: Exit Callback Functions899504 -Node: Extension Version String900753 -Node: Input Parsers901403 -Node: Output Wrappers911160 -Node: Two-way processors915670 -Node: Printing Messages917878 -Ref: Printing Messages-Footnote-1918955 -Node: Updating `ERRNO'919107 -Node: Accessing Parameters919846 -Node: Symbol Table Access921076 -Node: Symbol table by name921590 -Node: Symbol table by cookie923566 -Ref: Symbol table by cookie-Footnote-1927698 -Node: Cached values927761 -Ref: Cached values-Footnote-1931251 -Node: Array Manipulation931342 -Ref: Array Manipulation-Footnote-1932440 -Node: Array Data Types932479 -Ref: Array Data Types-Footnote-1935182 -Node: Array Functions935274 -Node: Flattening Arrays939110 -Node: Creating Arrays945962 -Node: Extension API Variables950687 -Node: Extension Versioning951323 -Node: Extension API Informational Variables953224 -Node: Extension API Boilerplate954310 -Node: Finding Extensions958114 -Node: Extension Example958674 -Node: Internal File Description959404 -Node: Internal File Ops963495 -Ref: Internal File Ops-Footnote-1975004 -Node: Using Internal File Ops975144 -Ref: Using Internal File Ops-Footnote-1977497 -Node: Extension Samples977763 -Node: Extension Sample File Functions979287 -Node: Extension Sample Fnmatch987772 -Node: Extension Sample Fork989541 -Node: Extension Sample Inplace990754 -Node: Extension Sample Ord992532 -Node: Extension Sample Readdir993368 -Node: Extension Sample Revout994900 -Node: Extension Sample Rev2way995493 -Node: Extension Sample Read write array996183 -Node: Extension Sample Readfile998066 -Node: Extension Sample API Tests999166 -Node: Extension Sample Time999691 -Node: gawkextlib1001055 -Node: Language History1003836 -Node: V7/SVR3.11005429 -Node: SVR41007749 -Node: POSIX1009191 -Node: BTL1010577 -Node: POSIX/GNU1011311 -Node: Feature History1016910 -Node: Common Extensions1029886 -Node: Ranges and Locales1031198 -Ref: Ranges and Locales-Footnote-11035815 -Ref: Ranges and Locales-Footnote-21035842 -Ref: Ranges and Locales-Footnote-31036076 -Node: Contributors1036297 -Node: Installation1041678 -Node: Gawk Distribution1042572 -Node: Getting1043056 -Node: Extracting1043882 -Node: Distribution contents1045574 -Node: Unix Installation1051279 -Node: Quick Installation1051896 -Node: Additional Configuration Options1054342 -Node: Configuration Philosophy1056078 -Node: Non-Unix Installation1058432 -Node: PC Installation1058890 -Node: PC Binary Installation1060189 -Node: PC Compiling1062037 -Node: PC Testing1064981 -Node: PC Using1066157 -Node: Cygwin1070325 -Node: MSYS1071134 -Node: VMS Installation1071648 -Node: VMS Compilation1072412 -Ref: VMS Compilation-Footnote-11073664 -Node: VMS Dynamic Extensions1073722 -Node: VMS Installation Details1075095 -Node: VMS Running1077346 -Node: VMS GNV1080180 -Node: VMS Old Gawk1080903 -Node: Bugs1081373 -Node: Other Versions1085291 -Node: Notes1091375 -Node: Compatibility Mode1092175 -Node: Additions1092958 -Node: Accessing The Source1093885 -Node: Adding Code1095325 -Node: New Ports1101370 -Node: Derived Files1105505 -Ref: Derived Files-Footnote-11110826 -Ref: Derived Files-Footnote-21110860 -Ref: Derived Files-Footnote-31111460 -Node: Future Extensions1111558 -Node: Implementation Limitations1112141 -Node: Extension Design1113393 -Node: Old Extension Problems1114547 -Ref: Old Extension Problems-Footnote-11116055 -Node: Extension New Mechanism Goals1116112 -Ref: Extension New Mechanism Goals-Footnote-11119477 -Node: Extension Other Design Decisions1119663 -Node: Extension Future Growth1121769 -Node: Old Extension Mechanism1122605 -Node: Basic Concepts1124345 -Node: Basic High Level1125026 -Ref: figure-general-flow1125298 -Ref: figure-process-flow1125897 -Ref: Basic High Level-Footnote-11129126 -Node: Basic Data Typing1129311 -Node: Glossary1132666 -Node: Copying1157897 -Node: GNU Free Documentation License1195453 -Node: Index1220589 +Node: Foreword40825 +Node: Preface45170 +Ref: Preface-Footnote-148303 +Ref: Preface-Footnote-248410 +Node: History48642 +Node: Names51016 +Ref: Names-Footnote-152480 +Node: This Manual52553 +Ref: This Manual-Footnote-158327 +Node: Conventions58427 +Node: Manual History60583 +Ref: Manual History-Footnote-164013 +Ref: Manual History-Footnote-264054 +Node: How To Contribute64128 +Node: Acknowledgments65367 +Node: Getting Started69561 +Node: Running gawk71940 +Node: One-shot73130 +Node: Read Terminal74355 +Ref: Read Terminal-Footnote-176005 +Ref: Read Terminal-Footnote-276281 +Node: Long76452 +Node: Executable Scripts77828 +Ref: Executable Scripts-Footnote-179661 +Ref: Executable Scripts-Footnote-279763 +Node: Comments80310 +Node: Quoting82777 +Node: DOS Quoting87400 +Node: Sample Data Files88075 +Node: Very Simple90590 +Node: Two Rules95241 +Node: More Complex97139 +Ref: More Complex-Footnote-1100069 +Node: Statements/Lines100154 +Ref: Statements/Lines-Footnote-1104617 +Node: Other Features104882 +Node: When105810 +Node: Invoking Gawk107957 +Node: Command Line109420 +Node: Options110203 +Ref: Options-Footnote-1125581 +Node: Other Arguments125606 +Node: Naming Standard Input128264 +Node: Environment Variables129358 +Node: AWKPATH Variable129916 +Ref: AWKPATH Variable-Footnote-1132697 +Ref: AWKPATH Variable-Footnote-2132742 +Node: AWKLIBPATH Variable133002 +Node: Other Environment Variables133720 +Node: Exit Status136683 +Node: Include Files137358 +Node: Loading Shared Libraries140927 +Node: Obsolete142291 +Node: Undocumented142988 +Node: Regexp143230 +Node: Regexp Usage144619 +Node: Escape Sequences146644 +Node: Regexp Operators152313 +Ref: Regexp Operators-Footnote-1159693 +Ref: Regexp Operators-Footnote-2159840 +Node: Bracket Expressions159938 +Ref: table-char-classes161828 +Node: GNU Regexp Operators164351 +Node: Case-sensitivity168074 +Ref: Case-sensitivity-Footnote-1171042 +Ref: Case-sensitivity-Footnote-2171277 +Node: Leftmost Longest171385 +Node: Computed Regexps172586 +Node: Reading Files175923 +Node: Records177925 +Ref: Records-Footnote-1187448 +Node: Fields187485 +Ref: Fields-Footnote-1190441 +Node: Nonconstant Fields190527 +Node: Changing Fields192733 +Node: Field Separators198692 +Node: Default Field Splitting201394 +Node: Regexp Field Splitting202511 +Node: Single Character Fields205853 +Node: Command Line Field Separator206912 +Node: Full Line Fields210254 +Ref: Full Line Fields-Footnote-1210762 +Node: Field Splitting Summary210808 +Ref: Field Splitting Summary-Footnote-1213907 +Node: Constant Size214008 +Node: Splitting By Content218615 +Ref: Splitting By Content-Footnote-1222364 +Node: Multiple Line222404 +Ref: Multiple Line-Footnote-1228251 +Node: Getline228430 +Node: Plain Getline230646 +Node: Getline/Variable232741 +Node: Getline/File233888 +Node: Getline/Variable/File235229 +Ref: Getline/Variable/File-Footnote-1236828 +Node: Getline/Pipe236915 +Node: Getline/Variable/Pipe239614 +Node: Getline/Coprocess240721 +Node: Getline/Variable/Coprocess241973 +Node: Getline Notes242710 +Node: Getline Summary245497 +Ref: table-getline-variants245905 +Node: Read Timeout246817 +Ref: Read Timeout-Footnote-1250556 +Node: Command line directories250614 +Node: Printing251244 +Node: Print252875 +Node: Print Examples254212 +Node: Output Separators256996 +Node: OFMT259012 +Node: Printf260370 +Node: Basic Printf261276 +Node: Control Letters262815 +Node: Format Modifiers266627 +Node: Printf Examples272636 +Node: Redirection275348 +Node: Special Files282322 +Node: Special FD282855 +Ref: Special FD-Footnote-1286480 +Node: Special Network286554 +Node: Special Caveats287404 +Node: Close Files And Pipes288200 +Ref: Close Files And Pipes-Footnote-1295183 +Ref: Close Files And Pipes-Footnote-2295331 +Node: Expressions295481 +Node: Values296613 +Node: Constants297289 +Node: Scalar Constants297969 +Ref: Scalar Constants-Footnote-1298828 +Node: Nondecimal-numbers299010 +Node: Regexp Constants302010 +Node: Using Constant Regexps302485 +Node: Variables305540 +Node: Using Variables306195 +Node: Assignment Options307919 +Node: Conversion309794 +Ref: table-locale-affects315294 +Ref: Conversion-Footnote-1315918 +Node: All Operators316027 +Node: Arithmetic Ops316657 +Node: Concatenation319162 +Ref: Concatenation-Footnote-1321950 +Node: Assignment Ops322070 +Ref: table-assign-ops327058 +Node: Increment Ops328389 +Node: Truth Values and Conditions331823 +Node: Truth Values332906 +Node: Typing and Comparison333955 +Node: Variable Typing334748 +Ref: Variable Typing-Footnote-1338645 +Node: Comparison Operators338767 +Ref: table-relational-ops339177 +Node: POSIX String Comparison342725 +Ref: POSIX String Comparison-Footnote-1343681 +Node: Boolean Ops343819 +Ref: Boolean Ops-Footnote-1347889 +Node: Conditional Exp347980 +Node: Function Calls349712 +Node: Precedence353306 +Node: Locales356975 +Node: Patterns and Actions358064 +Node: Pattern Overview359118 +Node: Regexp Patterns360787 +Node: Expression Patterns361330 +Node: Ranges365111 +Node: BEGIN/END368215 +Node: Using BEGIN/END368977 +Ref: Using BEGIN/END-Footnote-1371713 +Node: I/O And BEGIN/END371819 +Node: BEGINFILE/ENDFILE374101 +Node: Empty377015 +Node: Using Shell Variables377332 +Node: Action Overview379617 +Node: Statements381974 +Node: If Statement383828 +Node: While Statement385327 +Node: Do Statement387371 +Node: For Statement388527 +Node: Switch Statement391679 +Node: Break Statement393833 +Node: Continue Statement395823 +Node: Next Statement397616 +Node: Nextfile Statement400006 +Node: Exit Statement402661 +Node: Built-in Variables405077 +Node: User-modified406172 +Ref: User-modified-Footnote-1414530 +Node: Auto-set414592 +Ref: Auto-set-Footnote-1427657 +Ref: Auto-set-Footnote-2427862 +Node: ARGC and ARGV427918 +Node: Arrays431772 +Node: Array Basics433277 +Node: Array Intro434103 +Node: Reference to Elements438420 +Node: Assigning Elements440690 +Node: Array Example441181 +Node: Scanning an Array442913 +Node: Controlling Scanning445227 +Ref: Controlling Scanning-Footnote-1450314 +Node: Delete450630 +Ref: Delete-Footnote-1453395 +Node: Numeric Array Subscripts453452 +Node: Uninitialized Subscripts455635 +Node: Multidimensional457262 +Node: Multiscanning460355 +Node: Arrays of Arrays461944 +Node: Functions466584 +Node: Built-in467403 +Node: Calling Built-in468481 +Node: Numeric Functions470469 +Ref: Numeric Functions-Footnote-1474301 +Ref: Numeric Functions-Footnote-2474658 +Ref: Numeric Functions-Footnote-3474706 +Node: String Functions474975 +Ref: String Functions-Footnote-1497933 +Ref: String Functions-Footnote-2498062 +Ref: String Functions-Footnote-3498310 +Node: Gory Details498397 +Ref: table-sub-escapes500076 +Ref: table-sub-posix-92501430 +Ref: table-sub-proposed502781 +Ref: table-posix-sub504135 +Ref: table-gensub-escapes505680 +Ref: Gory Details-Footnote-1506856 +Ref: Gory Details-Footnote-2506907 +Node: I/O Functions507058 +Ref: I/O Functions-Footnote-1514048 +Node: Time Functions514195 +Ref: Time Functions-Footnote-1525178 +Ref: Time Functions-Footnote-2525246 +Ref: Time Functions-Footnote-3525404 +Ref: Time Functions-Footnote-4525515 +Ref: Time Functions-Footnote-5525627 +Ref: Time Functions-Footnote-6525854 +Node: Bitwise Functions526120 +Ref: table-bitwise-ops526682 +Ref: Bitwise Functions-Footnote-1530903 +Node: Type Functions531087 +Node: I18N Functions532238 +Node: User-defined533865 +Node: Definition Syntax534669 +Ref: Definition Syntax-Footnote-1539583 +Node: Function Example539652 +Ref: Function Example-Footnote-1542301 +Node: Function Caveats542323 +Node: Calling A Function542841 +Node: Variable Scope543796 +Node: Pass By Value/Reference546759 +Node: Return Statement550267 +Node: Dynamic Typing553248 +Node: Indirect Calls554179 +Node: Library Functions563866 +Ref: Library Functions-Footnote-1567379 +Ref: Library Functions-Footnote-2567522 +Node: Library Names567693 +Ref: Library Names-Footnote-1571166 +Ref: Library Names-Footnote-2571386 +Node: General Functions571472 +Node: Strtonum Function572500 +Node: Assert Function575430 +Node: Round Function578756 +Node: Cliff Random Function580297 +Node: Ordinal Functions581313 +Ref: Ordinal Functions-Footnote-1584390 +Ref: Ordinal Functions-Footnote-2584642 +Node: Join Function584853 +Ref: Join Function-Footnote-1586624 +Node: Getlocaltime Function586824 +Node: Readfile Function590565 +Node: Data File Management592404 +Node: Filetrans Function593036 +Node: Rewind Function597105 +Node: File Checking598492 +Node: Empty Files599586 +Node: Ignoring Assigns601816 +Node: Getopt Function603370 +Ref: Getopt Function-Footnote-1614673 +Node: Passwd Functions614876 +Ref: Passwd Functions-Footnote-1623854 +Node: Group Functions623942 +Node: Walking Arrays632026 +Node: Sample Programs634162 +Node: Running Examples634836 +Node: Clones635564 +Node: Cut Program636788 +Node: Egrep Program646639 +Ref: Egrep Program-Footnote-1654412 +Node: Id Program654522 +Node: Split Program658171 +Ref: Split Program-Footnote-1661690 +Node: Tee Program661818 +Node: Uniq Program664621 +Node: Wc Program672050 +Ref: Wc Program-Footnote-1676316 +Ref: Wc Program-Footnote-2676516 +Node: Miscellaneous Programs676608 +Node: Dupword Program677796 +Node: Alarm Program679827 +Node: Translate Program684634 +Ref: Translate Program-Footnote-1689021 +Ref: Translate Program-Footnote-2689269 +Node: Labels Program689403 +Ref: Labels Program-Footnote-1692774 +Node: Word Sorting692858 +Node: History Sorting696742 +Node: Extract Program698581 +Ref: Extract Program-Footnote-1706084 +Node: Simple Sed706212 +Node: Igawk Program709274 +Ref: Igawk Program-Footnote-1724431 +Ref: Igawk Program-Footnote-2724632 +Node: Anagram Program724770 +Node: Signature Program727838 +Node: Advanced Features728938 +Node: Nondecimal Data730824 +Node: Array Sorting732407 +Node: Controlling Array Traversal733104 +Node: Array Sorting Functions741388 +Ref: Array Sorting Functions-Footnote-1745257 +Node: Two-way I/O745451 +Ref: Two-way I/O-Footnote-1750883 +Node: TCP/IP Networking750965 +Node: Profiling753809 +Node: Internationalization761312 +Node: I18N and L10N762737 +Node: Explaining gettext763423 +Ref: Explaining gettext-Footnote-1768491 +Ref: Explaining gettext-Footnote-2768675 +Node: Programmer i18n768840 +Node: Translator i18n773042 +Node: String Extraction773836 +Ref: String Extraction-Footnote-1774797 +Node: Printf Ordering774883 +Ref: Printf Ordering-Footnote-1777665 +Node: I18N Portability777729 +Ref: I18N Portability-Footnote-1780178 +Node: I18N Example780241 +Ref: I18N Example-Footnote-1782879 +Node: Gawk I18N782951 +Node: Debugger783572 +Node: Debugging784543 +Node: Debugging Concepts784976 +Node: Debugging Terms786832 +Node: Awk Debugging789429 +Node: Sample Debugging Session790321 +Node: Debugger Invocation790841 +Node: Finding The Bug792174 +Node: List of Debugger Commands798661 +Node: Breakpoint Control799995 +Node: Debugger Execution Control803659 +Node: Viewing And Changing Data807019 +Node: Execution Stack810375 +Node: Debugger Info811842 +Node: Miscellaneous Debugger Commands815824 +Node: Readline Support821000 +Node: Limitations821831 +Node: Arbitrary Precision Arithmetic824083 +Ref: Arbitrary Precision Arithmetic-Footnote-1825732 +Node: General Arithmetic825880 +Node: Floating Point Issues827600 +Node: String Conversion Precision828481 +Ref: String Conversion Precision-Footnote-1830186 +Node: Unexpected Results830295 +Node: POSIX Floating Point Problems832448 +Ref: POSIX Floating Point Problems-Footnote-1836273 +Node: Integer Programming836311 +Node: Floating-point Programming838050 +Ref: Floating-point Programming-Footnote-1844381 +Ref: Floating-point Programming-Footnote-2844651 +Node: Floating-point Representation844915 +Node: Floating-point Context846080 +Ref: table-ieee-formats846919 +Node: Rounding Mode848303 +Ref: table-rounding-modes848782 +Ref: Rounding Mode-Footnote-1851797 +Node: Gawk and MPFR851976 +Node: Arbitrary Precision Floats853385 +Ref: Arbitrary Precision Floats-Footnote-1855828 +Node: Setting Precision856144 +Ref: table-predefined-precision-strings856830 +Node: Setting Rounding Mode858975 +Ref: table-gawk-rounding-modes859379 +Node: Floating-point Constants860566 +Node: Changing Precision861995 +Ref: Changing Precision-Footnote-1863392 +Node: Exact Arithmetic863566 +Node: Arbitrary Precision Integers866704 +Ref: Arbitrary Precision Integers-Footnote-1869719 +Node: Dynamic Extensions869866 +Node: Extension Intro871324 +Node: Plugin License872589 +Node: Extension Mechanism Outline873274 +Ref: load-extension873691 +Ref: load-new-function875169 +Ref: call-new-function876164 +Node: Extension API Description878179 +Node: Extension API Functions Introduction879466 +Node: General Data Types884393 +Ref: General Data Types-Footnote-1890088 +Node: Requesting Values890387 +Ref: table-value-types-returned891124 +Node: Memory Allocation Functions892078 +Ref: Memory Allocation Functions-Footnote-1894824 +Node: Constructor Functions894920 +Node: Registration Functions896678 +Node: Extension Functions897363 +Node: Exit Callback Functions899665 +Node: Extension Version String900914 +Node: Input Parsers901564 +Node: Output Wrappers911321 +Node: Two-way processors915831 +Node: Printing Messages918039 +Ref: Printing Messages-Footnote-1919116 +Node: Updating `ERRNO'919268 +Node: Accessing Parameters920007 +Node: Symbol Table Access921237 +Node: Symbol table by name921751 +Node: Symbol table by cookie923727 +Ref: Symbol table by cookie-Footnote-1927859 +Node: Cached values927922 +Ref: Cached values-Footnote-1931412 +Node: Array Manipulation931503 +Ref: Array Manipulation-Footnote-1932601 +Node: Array Data Types932640 +Ref: Array Data Types-Footnote-1935343 +Node: Array Functions935435 +Node: Flattening Arrays939271 +Node: Creating Arrays946123 +Node: Extension API Variables950848 +Node: Extension Versioning951484 +Node: Extension API Informational Variables953385 +Node: Extension API Boilerplate954471 +Node: Finding Extensions958275 +Node: Extension Example958835 +Node: Internal File Description959565 +Node: Internal File Ops963656 +Ref: Internal File Ops-Footnote-1975165 +Node: Using Internal File Ops975305 +Ref: Using Internal File Ops-Footnote-1977658 +Node: Extension Samples977924 +Node: Extension Sample File Functions979448 +Node: Extension Sample Fnmatch987933 +Node: Extension Sample Fork989702 +Node: Extension Sample Inplace990915 +Node: Extension Sample Ord992693 +Node: Extension Sample Readdir993529 +Node: Extension Sample Revout995061 +Node: Extension Sample Rev2way995654 +Node: Extension Sample Read write array996344 +Node: Extension Sample Readfile998227 +Node: Extension Sample API Tests999327 +Node: Extension Sample Time999852 +Node: gawkextlib1001216 +Node: Language History1003997 +Node: V7/SVR3.11005590 +Node: SVR41007910 +Node: POSIX1009352 +Node: BTL1010738 +Node: POSIX/GNU1011472 +Node: Feature History1017071 +Node: Common Extensions1030047 +Node: Ranges and Locales1031359 +Ref: Ranges and Locales-Footnote-11035976 +Ref: Ranges and Locales-Footnote-21036003 +Ref: Ranges and Locales-Footnote-31036237 +Node: Contributors1036458 +Node: Installation1041839 +Node: Gawk Distribution1042733 +Node: Getting1043217 +Node: Extracting1044043 +Node: Distribution contents1045735 +Node: Unix Installation1051456 +Node: Quick Installation1052073 +Node: Additional Configuration Options1054519 +Node: Configuration Philosophy1056255 +Node: Non-Unix Installation1058609 +Node: PC Installation1059067 +Node: PC Binary Installation1060366 +Node: PC Compiling1062214 +Node: PC Testing1065158 +Node: PC Using1066334 +Node: Cygwin1070502 +Node: MSYS1071311 +Node: VMS Installation1071825 +Node: VMS Compilation1072621 +Ref: VMS Compilation-Footnote-11073873 +Node: VMS Dynamic Extensions1073931 +Node: VMS Installation Details1075304 +Node: VMS Running1077555 +Node: VMS GNV1080389 +Node: VMS Old Gawk1081112 +Node: Bugs1081582 +Node: Other Versions1085500 +Node: Notes1091584 +Node: Compatibility Mode1092384 +Node: Additions1093167 +Node: Accessing The Source1094094 +Node: Adding Code1095534 +Node: New Ports1101579 +Node: Derived Files1105714 +Ref: Derived Files-Footnote-11111035 +Ref: Derived Files-Footnote-21111069 +Ref: Derived Files-Footnote-31111669 +Node: Future Extensions1111767 +Node: Implementation Limitations1112350 +Node: Extension Design1113602 +Node: Old Extension Problems1114756 +Ref: Old Extension Problems-Footnote-11116264 +Node: Extension New Mechanism Goals1116321 +Ref: Extension New Mechanism Goals-Footnote-11119686 +Node: Extension Other Design Decisions1119872 +Node: Extension Future Growth1121978 +Node: Old Extension Mechanism1122814 +Node: Basic Concepts1124554 +Node: Basic High Level1125235 +Ref: figure-general-flow1125507 +Ref: figure-process-flow1126106 +Ref: Basic High Level-Footnote-11129335 +Node: Basic Data Typing1129520 +Node: Glossary1132875 +Node: Copying1158106 +Node: GNU Free Documentation License1195662 +Node: Index1220798  End Tag Table -- cgit v1.2.3 From 4e4446794686a101e0c64ff7242a44a646c56d7e Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 29 Apr 2014 06:13:23 +0300 Subject: Working on documentation edits. --- doc/gawk.info | 1630 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 831 insertions(+), 799 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 589ac015..1d5f496d 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1652,6 +1652,23 @@ knowledge of shell quoting rules. The following rules apply only to POSIX-compliant, Bourne-style shells (such as Bash, the GNU Bourne-Again Shell). If you use the C shell, you're on your own. + Before diving into the rules, we introduce a concept that appears +throughout this Info file, which is that of the "null", or empty, +string. + + The null string is character data that has no value. In other +words, it is empty. It is written in `awk' programs like this: `""'. +In the shell, it can be written using single or double quotes: `""' or +`'''. While the null string has no characters in it, it does exist. +Consider this command: + + $ echo "" + +Here, the `echo' utility receives a single argument, even though that +argument has no characters in it. In the rest of this Info file, we use +the terms "null string" and "empty string" interchangeably. Now, on to +the quoting rules. + * Quoted items can be concatenated with nonquoted items as well as with other quoted items. The shell turns everything into one argument for the command. @@ -1892,7 +1909,7 @@ different ways to do the same things shown here: awk 'length($0) > 80' data The sole rule has a relational expression as its pattern and it - has no action--so the default action, printing the record, is used. + has no action--so it uses the default action, printing the record. * Print the length of the longest line in `data': @@ -1949,9 +1966,9 @@ File: gawk.info, Node: Two Rules, Next: More Complex, Prev: Very Simple, Up: The `awk' utility reads the input files one line at a time. For each line, `awk' tries the patterns of each of the rules. If several -patterns match, then several actions are run in the order in which they -appear in the `awk' program. If no patterns match, then no actions are -run. +patterns match, then several actions execture in the order in which +they appear in the `awk' program. If no patterns match, then no +actions run. After processing all the rules that match the line (and perhaps there are none), `awk' reads the next line. (However, *note Next @@ -2027,12 +2044,12 @@ contains the file name.(1) The `$6 == "Nov"' in our `awk' program is an expression that tests whether the sixth field of the output from `ls -l' matches the string -`Nov'. Each time a line has the string `Nov' for its sixth field, the -action `sum += $5' is performed. This adds the fifth field (the file's -size) to the variable `sum'. As a result, when `awk' has finished -reading all the input lines, `sum' is the total of the sizes of the -files whose lines matched the pattern. (This works because `awk' -variables are automatically initialized to zero.) +`Nov'. Each time a line has the string `Nov' for its sixth field, +`awk' performs the action `sum += $5'. This adds the fifth field (the +file's size) to the variable `sum'. As a result, when `awk' has +finished reading all the input lines, `sum' is the total of the sizes +of the files whose lines matched the pattern. (This works because +`awk' variables are automatically initialized to zero.) After the last line of output from `ls' has been processed, the `END' rule executes and prints the value of `sum'. In this example, @@ -2084,15 +2101,15 @@ We have generally not used backslash continuation in our sample programs. `gawk' places no limit on the length of a line, so backslash continuation is never strictly necessary; it just makes programs more readable. For this same reason, as well as for clarity, we have kept -most statements short in the sample programs presented throughout the -Info file. Backslash continuation is most useful when your `awk' -program is in a separate source file instead of entered from the -command line. You should also note that many `awk' implementations are -more particular about where you may use backslash continuation. For -example, they may not allow you to split a string constant using -backslash continuation. Thus, for maximum portability of your `awk' -programs, it is best not to split your lines in the middle of a regular -expression or a string. +most statements short in the programs presented throughout the Info +file. Backslash continuation is most useful when your `awk' program is +in a separate source file instead of entered from the command line. +You should also note that many `awk' implementations are more +particular about where you may use backslash continuation. For example, +they may not allow you to split a string constant using backslash +continuation. Thus, for maximum portability of your `awk' programs, it +is best not to split your lines in the middle of a regular expression +or a string. CAUTION: _Backslash continuation does not work as described with the C shell._ It works for `awk' programs in files and for @@ -2213,14 +2230,15 @@ those that it has are much larger than they used to be. If you find yourself writing `awk' scripts of more than, say, a few hundred lines, you might consider using a different programming -language. Emacs Lisp is a good choice if you need sophisticated string -or pattern matching capabilities. The shell is also good at string and -pattern matching; in addition, it allows powerful use of the system -utilities. More conventional languages, such as C, C++, and Java, offer -better facilities for system programming and for managing the complexity -of large programs. Programs in these languages may require more lines -of source code than the equivalent `awk' programs, but they are easier -to maintain and usually run more efficiently. +language. The shell is good at string and pattern matching; in +addition, it allows powerful use of the system utilities. More +conventional languages, such as C, C++, and Java, offer better +facilities for system programming and for managing the complexity of +large programs. Python offers a nice balance between high-level ease +of programming and access to system facilities. Programs in these +languages may require more lines of source code than the equivalent +`awk' programs, but they are easier to maintain and usually run more +efficiently.  File: gawk.info, Node: Invoking Gawk, Next: Regexp, Prev: Getting Started, Up: Top @@ -2350,11 +2368,11 @@ The following list describes options mandated by the POSIX standard: treated as single-byte characters. Normally, `gawk' follows the POSIX standard and attempts to process - its input data according to the current locale. This can often - involve converting multibyte characters into wide characters - (internally), and can lead to problems or confusion if the input - data does not contain valid multibyte characters. This option is - an easy way to tell `gawk': "hands off my data!". + its input data according to the current locale (*note Locales::). + This can often involve converting multibyte characters into wide + characters (internally), and can lead to problems or confusion if + the input data does not contain valid multibyte characters. This + option is an easy way to tell `gawk': "hands off my data!". `-c' `--traditional' @@ -2368,8 +2386,8 @@ The following list describes options mandated by the POSIX standard: Print the short version of the General Public License and then exit. -`-d[FILE]' -`--dump-variables[=FILE]' +`-d'[FILE] +`--dump-variables'[`='FILE] Print a sorted list of global variables, their types, and final values to FILE. If no FILE is provided, print this list to the file named `awkvars.out' in the current directory. No space is @@ -2383,8 +2401,8 @@ The following list describes options mandated by the POSIX standard: particularly easy mistake to make with simple variable names like `i', `j', etc.) -`-D[FILE]' -`--debug=[FILE]' +`-D'[FILE] +`--debug'[`='FILE] Enable debugging of `awk' programs (*note Debugging::). By default, the debugger reads commands interactively from the keyboard. The optional FILE argument allows you to specify a file @@ -2392,16 +2410,16 @@ The following list describes options mandated by the POSIX standard: non-interactively. No space is allowed between the `-D' and FILE, if FILE is supplied. -`-e PROGRAM-TEXT' -`--source PROGRAM-TEXT' +`-e' PROGRAM-TEXT +`--source' PROGRAM-TEXT Provide program source code in the PROGRAM-TEXT. This option allows you to mix source code in files with source code that you enter on the command line. This is particularly useful when you have library functions that you want to use from your command-line programs (*note AWKPATH Variable::). -`-E FILE' -`--exec FILE' +`-E' FILE +`--exec' FILE Similar to `-f', read `awk' program text from FILE. There are two differences from `-f': @@ -2434,37 +2452,41 @@ The following list describes options mandated by the POSIX standard: Print a "usage" message summarizing the short and long style options that `gawk' accepts and then exit. -`-i SOURCE-FILE' -`--include SOURCE-FILE' +`-i' SOURCE-FILE +`--include' SOURCE-FILE Read `awk' source library from SOURCE-FILE. This option is completely equivalent to using the `@include' directive inside your program. This option is very similar to the `-f' option, but there are two important differences. First, when `-i' is used, - the program source will not be loaded if it has been previously - loaded, whereas the `-f' will always load the file. Second, - because this option is intended to be used with code libraries, - `gawk' does not recognize such files as constituting main program - input. Thus, after processing an `-i' argument, `gawk' still - expects to find the main source code via the `-f' option or on the + the program source is not loaded if it has been previously loaded, + whereas with `-f', `gawk' always loads the file. Second, because + this option is intended to be used with code libraries, `gawk' + does not recognize such files as constituting main program input. + Thus, after processing an `-i' argument, `gawk' still expects to + find the main source code via the `-f' option or on the command-line. -`-l LIB' -`--load LIB' - Load a shared library LIB. This searches for the library using the - `AWKLIBPATH' environment variable. The correct library suffix for - your platform will be supplied by default, so it need not be - specified in the library name. The library initialization routine - should be named `dl_load()'. An alternative is to use the `@load' - keyword inside the program to load a shared library. - -`-L [value]' -`--lint[=value]' +`-l' EXT +`--load' EXT + Load a dynamic extension named EXT. Extensions are stored as + system shared libraries. This option searches for the library + using the `AWKLIBPATH' environment variable. The correct library + suffix for your platform will be supplied by default, so it need + not be specified in the extension name. The extension + initialization routine should be named `dl_load()'. An + alternative is to use the `@load' keyword inside the program to + load a shared library. This feature is described in detail in + *note Dynamic Extensions::. + +`-L'[VALUE] +`--lint'[`='VALUE] Warn about constructs that are dubious or nonportable to other - `awk' implementations. Some warnings are issued when `gawk' first - reads your program. Others are issued at runtime, as your program - executes. With an optional argument of `fatal', lint warnings - become fatal errors. This may be drastic, but its use will - certainly encourage the development of cleaner `awk' programs. + `awk' implementations. No space is allowed between the `-D' and + VALUE, if VALUE is supplied. Some warnings are issued when `gawk' + first reads your program. Others are issued at runtime, as your + program executes. With an optional argument of `fatal', lint + warnings become fatal errors. This may be drastic, but its use + will certainly encourage the development of cleaner `awk' programs. With an optional argument of `invalid', only warnings about things that are actually invalid are issued. (This is not fully implemented yet.) @@ -2495,23 +2517,26 @@ The following list describes options mandated by the POSIX standard: Force the use of the locale's decimal point character when parsing numeric input data (*note Locales::). -`-o[FILE]' -`--pretty-print[=FILE]' +`-o'[FILE] +`--pretty-print'[`='FILE] Enable pretty-printing of `awk' programs. By default, output - program is created in a file named `awkprof.out'. The optional - FILE argument allows you to specify a different file name for the - output. No space is allowed between the `-o' and FILE, if FILE is - supplied. + program is created in a file named `awkprof.out' (*note + Profiling::). The optional FILE argument allows you to specify a + different file name for the output. No space is allowed between + the `-o' and FILE, if FILE is supplied. + + NOTE: Due to the way `gawk' has evolved, with this option + your program is still executed. This will change in the next + major release such that `gawk' will only pretty-print the + program and not run it. `-O' `--optimize' Enable some optimizations on the internal representation of the - program. At the moment this includes just simple constant - folding. The `gawk' maintainer hopes to add more optimizations - over time. + program. At the moment this includes just simple constant folding. -`-p[FILE]' -`--profile[=FILE]' +`-p'[FILE] +`--profile'[`='FILE] Enable profiling of `awk' programs (*note Profiling::). By default, profiles are created in a file named `awkprof.out'. The optional FILE argument allows you to specify a different file name @@ -2544,15 +2569,15 @@ The following list describes options mandated by the POSIX standard: data (*note Locales::). If you supply both `--traditional' and `--posix' on the command - line, `--posix' takes precedence. `gawk' also issues a warning if - both options are supplied. + line, `--posix' takes precedence. `gawk' issues a warning if both + options are supplied. `-r' `--re-interval' Allow interval expressions (*note Regexp Operators::) in regexps. This is now `gawk''s default behavior. Nevertheless, this option remains both for backward compatibility, and for use in - combination with the `--traditional' option. + combination with `--traditional'. `-S' `--sandbox' @@ -2602,25 +2627,25 @@ input as a source of data.) source file and command-line `awk' programs, `gawk' provides the `--source' option. This does not require you to pre-empt the standard input for your source code; it allows you to easily mix command-line -and library source code (*note AWKPATH Variable::). The `--source' -option may also be used multiple times on the command line. +and library source code (*note AWKPATH Variable::). As with `-f', the +`--source' and `--include' options may also be used multiple times on +the command line. If no `-f' or `--source' option is specified, then `gawk' uses the first non-option command-line argument as the text of the program source code. If the environment variable `POSIXLY_CORRECT' exists, then `gawk' -behaves in strict POSIX mode, exactly as if you had supplied the -`--posix' command-line option. Many GNU programs look for this -environment variable to suppress extensions that conflict with POSIX, -but `gawk' behaves differently: it suppresses all extensions, even -those that do not conflict with POSIX, and behaves in strict POSIX -mode. If `--lint' is supplied on the command line and `gawk' turns on -POSIX mode because of `POSIXLY_CORRECT', then it issues a warning -message indicating that POSIX mode is in effect. You would typically -set this variable in your shell's startup file. For a -Bourne-compatible shell (such as Bash), you would add these lines to -the `.profile' file in your home directory: +behaves in strict POSIX mode, exactly as if you had supplied `--posix'. +Many GNU programs look for this environment variable to suppress +extensions that conflict with POSIX, but `gawk' behaves differently: it +suppresses all extensions, even those that do not conflict with POSIX, +and behaves in strict POSIX mode. If `--lint' is supplied on the +command line and `gawk' turns on POSIX mode because of +`POSIXLY_CORRECT', then it issues a warning message indicating that +POSIX mode is in effect. You would typically set this variable in your +shell's startup file. For a Bourne-compatible shell (such as Bash), +you would add these lines to the `.profile' file in your home directory: POSIXLY_CORRECT=true export POSIXLY_CORRECT @@ -2672,18 +2697,18 @@ begins scanning the argument list. The variable values given on the command line are processed for escape sequences (*note Escape Sequences::). (d.c.) - In some earlier implementations of `awk', when a variable assignment -occurred before any file names, the assignment would happen _before_ -the `BEGIN' rule was executed. `awk''s behavior was thus inconsistent; -some command-line assignments were available inside the `BEGIN' rule, -while others were not. Unfortunately, some applications came to depend -upon this "feature." When `awk' was changed to be more consistent, the -`-v' option was added to accommodate applications that depended upon -the old behavior. + In some very early implementations of `awk', when a variable +assignment occurred before any file names, the assignment would happen +_before_ the `BEGIN' rule was executed. `awk''s behavior was thus +inconsistent; some command-line assignments were available inside the +`BEGIN' rule, while others were not. Unfortunately, some applications +came to depend upon this "feature." When `awk' was changed to be more +consistent, the `-v' option was added to accommodate applications that +depended upon the old behavior. The variable assignment feature is most useful for assigning to variables such as `RS', `OFS', and `ORS', which control input and -output formats before scanning the data files. It is also useful for +output formats, before scanning the data files. It is also useful for controlling state if multiple passes are needed over a data file. For example: @@ -2718,7 +2743,7 @@ with `getline' (*note Getline/File::). In addition, `gawk' allows you to specify the special file name `/dev/stdin', both on the command line and with `getline'. Some other versions of `awk' also support this, but it is not standard. (Some -operating systems provide a `/dev/stdin' file in the file system, +operating systems provide a `/dev/stdin' file in the file system; however, `gawk' always processes this file name itself.)  @@ -2757,9 +2782,9 @@ colons(1). `gawk' gets its search path from the `AWKPATH' environment variable. If that variable does not exist, `gawk' uses a default path, `.:/usr/local/share/awk'.(2) - The search path feature is particularly useful for building libraries -of useful `awk' functions. The library files can be placed in a -standard directory in the default path and then specified on the + The search path feature is particularly helpful for building +libraries of useful `awk' functions. The library files can be placed +in a standard directory in the default path and then specified on the command line with a short file name. Otherwise, the full file name would have to be typed for each file. @@ -2776,7 +2801,7 @@ filename. NOTE: To include the current directory in the path, either place `.' explicitly in the path or write a null entry in the path. (A null entry is indicated by starting or ending the path with a - colon or by placing two colons next to each other (`::').) This + colon or by placing two colons next to each other [`::'].) This path search mechanism is similar to the shell's. However, `gawk' always looks in the current directory _before_ @@ -2785,8 +2810,8 @@ filename. If `AWKPATH' is not defined in the environment, `gawk' places its default search path into `ENVIRON["AWKPATH"]'. This makes it easy to -determine the actual search path that `gawk' will use from within an -`awk' program. +determine the actual search path that `gawk' used from within an `awk' +program. While you can change `ENVIRON["AWKPATH"]' within your `awk' program, this has no effect on the running program's behavior. This makes @@ -2810,13 +2835,13 @@ File: gawk.info, Node: AWKLIBPATH Variable, Next: Other Environment Variables, ------------------------------------------- The `AWKLIBPATH' environment variable is similar to the `AWKPATH' -variable, but it is used to search for shared libraries specified with -the `-l' option rather than for source files. If the library is not -found, the path is searched again after adding the appropriate shared -library suffix for the platform. For example, on GNU/Linux systems, -the suffix `.so' is used. The search path specified is also used for -libraries loaded via the `@load' keyword (*note Loading Shared -Libraries::). +variable, but it is used to search for loadable extensions (stored as +system shared libraries) specified with the `-l' option rather than for +source files. If the extension is not found, the path is searched +again after adding the appropriate shared library suffix for the +platform. For example, on GNU/Linux systems, the suffix `.so' is used. +The search path specified is also used for extensions loaded via the +`@load' keyword (*note Loading Shared Libraries::).  File: gawk.info, Node: Other Environment Variables, Prev: AWKLIBPATH Variable, Up: Environment Variables @@ -2833,7 +2858,7 @@ used by regular users. traditional and GNU extensions. *Note Options::. `GAWK_SOCK_RETRIES' - Controls the number of time `gawk' will attempt to retry a two-way + Controls the number of times `gawk' attempts to retry a two-way TCP/IP (socket) connection before giving up. *Note TCP/IP Networking::. @@ -2876,6 +2901,11 @@ change. The variables are: supposed to be differences, but occasionally theory and practice don't coordinate with each other.) +`GAWK_NO_PP_RUN' + If this variable exists, then when invoked with the + `--pretty-print' option, `gawk' skips running the program. This + variable will not survive into the next major release. + `GAWK_STACKSIZE' This specifies the amount by which `gawk' should grow its internal evaluation stack, when needed. @@ -2955,7 +2985,7 @@ enclosed in double quotes. NOTE: Keep in mind that this is a language construct and the file name cannot be a string variable, but rather just a literal string - in double quotes. + constant in double quotes. The files to be included may be nested; e.g., given a third script, namely `test3': @@ -3010,19 +3040,19 @@ and this also applies to files named with `@include'.  File: gawk.info, Node: Loading Shared Libraries, Next: Obsolete, Prev: Include Files, Up: Invoking Gawk -2.8 Loading Shared Libraries Into Your Program -============================================== +2.8 Loading Dynamic Extensions Into Your Program +================================================ This minor node describes a feature that is specific to `gawk'. - The `@load' keyword can be used to read external `awk' shared -libraries. This allows you to link in compiled code that may offer -superior performance and/or give you access to extended capabilities -not supported by the `awk' language. The `AWKLIBPATH' variable is used -to search for the shared library. Using `@load' is completely -equivalent to using the `-l' command-line option. + The `@load' keyword can be used to read external `awk' extensions +(stored as system shared libraries). This allows you to link in +compiled code that may offer superior performance and/or give you +access to extended capabilities not supported by the `awk' language. +The `AWKLIBPATH' variable is used to search for the extension. Using +`@load' is completely equivalent to using the `-l' command-line option. - If the shared library is not initially found in `AWKLIBPATH', another + If the extension is not initially found in `AWKLIBPATH', another search is conducted after appending the platform's default shared library suffix to the filename. For example, on GNU/Linux systems, the suffix `.so' is used. @@ -3037,7 +3067,7 @@ This is equivalent to the following example: For command-line usage, the `-l' option is more convenient, but `@load' is useful for embedding inside an `awk' source file that requires -access to a shared library. +access to an extension. *note Dynamic Extensions::, describes how to write extensions (in C or C++) that can be loaded with either `@load' or the `-l' option. @@ -3108,8 +3138,8 @@ A regular expression can be used as a pattern by enclosing it in slashes. Then the regular expression is tested against the entire text of each record. (Normally, it only needs to match some part of the text in order to succeed.) For example, the following prints the -second field of each record that contains the string `li' anywhere in -it: +second field of each record where the string `li' appears anywhere in +the record: $ awk '/li/ { print $2 }' mail-list -| 555-5553 @@ -3194,8 +3224,8 @@ apply to both string constants and regexp constants: A literal backslash, `\'. `\a' - The "alert" character, `Ctrl-g', ASCII code 7 (BEL). (This - usually makes some sort of audible noise.) + The "alert" character, `Ctrl-g', ASCII code 7 (BEL). (This often + makes some sort of audible noise.) `\b' Backspace, `Ctrl-h', ASCII code 8 (BS). @@ -3330,20 +3360,21 @@ sequences and that are not listed in the table stand for themselves: at the beginning of the string. It is important to realize that `^' does not match the beginning of - a line embedded in a string. The condition is not true in the - following example: + a line (the point right after a `\n' newline character) embedded + in a string. The condition is not true in the following example: if ("line1\nLINE 2" ~ /^L/) ... `$' This is similar to `^', but it matches only at the end of a string. For example, `p$' matches a record that ends with a `p'. The `$' - is an anchor and does not match the end of a line embedded in a - string. The condition in the following example is not true: + is an anchor and does not match the end of a line (the point right + before a `\n' newline character) embedded in a string. The + condition in the following example is not true: if ("line1\nLINE 2" ~ /1$/) ... -`. (period)' +`.' (period) This matches any single character, _including_ the newline character. For example, `.P' matches any single character followed by a `P' in a string. Using concatenation, we can make a @@ -3355,7 +3386,7 @@ sequences and that are not listed in the table stand for themselves: Otherwise, NUL is just another character. Other versions of `awk' may not be able to match the NUL character. -`[...]' +`['...`]' This is called a "bracket expression".(1) It matches any _one_ of the characters that are enclosed in the square brackets. For example, `[MVX]' matches any one of the characters `M', `V', or @@ -3363,7 +3394,7 @@ sequences and that are not listed in the table stand for themselves: square brackets of a bracket expression is given in *note Bracket Expressions::. -`[^ ...]' +`[^'...`]' This is a "complemented bracket expression". The first character after the `[' _must_ be a `^'. It matches any characters _except_ those in the square brackets. For example, `[^awk]' matches any @@ -3379,7 +3410,7 @@ sequences and that are not listed in the table stand for themselves: The alternation applies to the largest possible regexps on either side. -`(...)' +`('...`)' Parentheses are used for grouping in regular expressions, as in arithmetic. They can be used to concatenate regular expressions containing the alternation operator, `|'. For example, @@ -3406,8 +3437,8 @@ sequences and that are not listed in the table stand for themselves: This symbol is similar to `*', except that the preceding expression must be matched at least once. This means that `wh+y' would match `why' and `whhy', but not `wy', whereas `wh*y' would - match all three of these strings. The following is a simpler way - of writing the last `*' example: + match all three. The following is a simpler way of writing the + last `*' example: awk '/\(c[ad]+r x\)/ { print }' sample @@ -3416,9 +3447,9 @@ sequences and that are not listed in the table stand for themselves: expression can be matched either once or not at all. For example, `fe?d' matches `fed' and `fd', but nothing else. -`{N}' -`{N,}' -`{N,M}' +`{'N`}' +`{'N`,}' +`{'N`,'M`}' One or two numbers inside braces denote an "interval expression". If there is one number in the braces, the preceding regexp is repeated N times. If there are two numbers separated by a comma, @@ -3698,7 +3729,9 @@ works in any POSIX-compliant `awk'. Another method, specific to `gawk', is to set the variable `IGNORECASE' to a nonzero value (*note Built-in Variables::). When `IGNORECASE' is not zero, _all_ regexp and string operations ignore -case. Changing the value of `IGNORECASE' dynamically controls the +case. + + Changing the value of `IGNORECASE' dynamically controls the case-sensitivity of the program as it runs. Case is significant by default because `IGNORECASE' (like most variables) is initialized to zero: @@ -3721,9 +3754,6 @@ dynamically turn case-sensitivity on or off for all the rules at once. `IGNORECASE' from the command line is a way to make a program case-insensitive without having to edit it. - Both regexp and string comparison operations are affected by -`IGNORECASE'. - In multibyte locales, the equivalences between upper- and lowercase characters are tested based on the wide-character values of the locale's character set. Otherwise, the characters are tested based on @@ -3785,7 +3815,8 @@ The righthand side of a `~' or `!~' operator need not be a regexp constant (i.e., a string of characters between slashes). It may be any expression. The expression is evaluated and converted to a string if necessary; the contents of the string are then used as the regexp. A -regexp computed in this way is called a "dynamic regexp": +regexp computed in this way is called a "dynamic regexp" or a "computed +regexp": BEGIN { digits_regexp = "[[:digit:]]+" } $0 ~ digits_regexp { print } @@ -3833,8 +3864,8 @@ constants," for several reasons: Using `\n' in Bracket Expressions of Dynamic Regexps - Some commercial versions of `awk' do not allow the newline character -to be used inside a bracket expression for a dynamic regexp: + Some versions of `awk' do not allow the newline character to be used +inside a bracket expression for a dynamic regexp: $ awk '$0 ~ "[ \t\n]"' error--> awk: newline in character class [ @@ -4517,7 +4548,7 @@ letter): > { print $2 }' -| a -In this case, the first field is "null" or empty. +In this case, the first field is null, or empty. The stripping of leading and trailing whitespace also comes into play whenever `$0' is recomputed. For instance, study this pipeline: @@ -5993,11 +6024,11 @@ width. Here is a list of the format-control letters: the first byte of a string or to numeric values within the range of a single byte (0-255). -`%d, %i' +`%d', `%i' Print a decimal integer. The two control letters are equivalent. (The `%i' specification is for compatibility with ISO C.) -`%e, %E' +`%e', `%E' Print a number in scientific (exponential) notation; for example: printf "%4.3e\n", 1950 @@ -6028,7 +6059,7 @@ width. Here is a list of the format-control letters: The `%F' format is a POSIX extension to ISO C; not all systems support it. On those that don't, `gawk' uses `%f' instead. -`%g, %G' +`%g', `%G' Print a number in either scientific notation or in floating-point notation, whichever uses fewer characters; if the result is printed in scientific notation, `%G' uses `E' instead of `e'. @@ -6044,7 +6075,7 @@ width. Here is a list of the format-control letters: use, because all numbers in `awk' are floating-point; it is provided primarily for compatibility with C.) -`%x, %X' +`%x', `%X' Print an unsigned hexadecimal integer; `%X' uses the letters `A' through `F' instead of `a' through `f' (*note Nondecimal-numbers::). @@ -8264,7 +8295,7 @@ to avoid the problem the expression can be rewritten as `$($0++)--'. This table presents `awk''s operators, in order of highest to lowest precedence: -`(...)' +`('...`)' Grouping. `$' @@ -8285,7 +8316,7 @@ precedence: `+ -' Addition, subtraction. -`String Concatenation' +String Concatenation There is no special symbol for concatenation. The operands are simply written side by side (*note Concatenation::). @@ -9684,7 +9715,7 @@ automatically on certain occasions in order to provide information to your program. The variables that are specific to `gawk' are marked with a pound sign (`#'). -`ARGC, ARGV' +`ARGC', `ARGV' The command-line arguments available to `awk' programs are stored in an array called `ARGV'. `ARGC' is the number of command-line arguments present. *Note Other Arguments::. Unlike most `awk' @@ -9713,7 +9744,7 @@ with a pound sign (`#'). are any of `awk''s command-line options. *Note ARGC and ARGV::, for information about how `awk' uses these variables. (d.c.) -`ARGIND #' +`ARGIND' # The index in `ARGV' of the current file being processed. Every time `gawk' opens a new data file for processing, it sets `ARGIND' to the index in `ARGV' of the file name. When `gawk' is @@ -9746,7 +9777,7 @@ with a pound sign (`#'). `ENVIRON["AWKPATH"]', *note AWKPATH Variable:: and `ENVIRON["AWKLIBPATH"]', *note AWKLIBPATH Variable::). -`ERRNO #' +`ERRNO' # If a system error occurs during a redirection for `getline', during a read for `getline', or during a `close()' operation, then `ERRNO' contains a string describing the error. @@ -9792,7 +9823,7 @@ with a pound sign (`#'). create or remove fields from the current record. *Note Changing Fields::. -`FUNCTAB #' +`FUNCTAB' # An array whose indices and corresponding values are the names of all the user-defined or extension functions in the program. @@ -9806,7 +9837,7 @@ with a pound sign (`#'). beginning of the program's execution (*note Records::). `NR' is incremented each time a new record is read. -`PROCINFO #' +`PROCINFO' # The elements of this array provide access to information about the running `awk' program. The following elements (listed alphabetically) are guaranteed to be available: @@ -9939,7 +9970,7 @@ with a pound sign (`#'). of the string where the matched substring starts, or zero if no match was found. -`RT #' +`RT' # This is set each time a record is read. It contains the input text that matched the text denoted by `RS', the record separator. @@ -9947,7 +9978,7 @@ with a pound sign (`#'). implementations, or if `gawk' is in compatibility mode (*note Options::), it is not special. -`SYMTAB #' +`SYMTAB' # An array whose indices are the names of all currently defined global variables and arrays in the program. The array may be used for indirect access to read or write the value of a variable: @@ -11195,7 +11226,7 @@ brackets ([ ]): Return the positive square root of X. `gawk' prints a warning message if X is negative. Thus, `sqrt(4)' is 2. -`srand([X])' +`srand('[X]`)' Set the starting point, or seed, for generating random numbers to the value X. @@ -11262,8 +11293,8 @@ pound sign (`#'): `&' with `sub()', `gsub()', and `gensub()'. -`asort(SOURCE [, DEST [, HOW ] ]) #' -`asorti(SOURCE [, DEST [, HOW ] ]) #' +`asort('SOURCE [`,' DEST [`,' HOW ] ]`)' # +`asorti('SOURCE [`,' DEST [`,' HOW ] ]`)' # These two functions are similar in behavior, so they are described together. @@ -11313,7 +11344,7 @@ pound sign (`#'): `asort()' and `asorti()' are `gawk' extensions; they are not available in compatibility mode (*note Options::). -`gensub(REGEXP, REPLACEMENT, HOW [, TARGET]) #' +`gensub(REGEXP, REPLACEMENT, HOW' [`, TARGET']`)' # Search the target string TARGET for matches of the regular expression REGEXP. If HOW is a string beginning with `g' or `G' (short for "global"), then replace all matches of REGEXP with @@ -11366,7 +11397,7 @@ pound sign (`#'): `gensub()' is a `gawk' extension; it is not available in compatibility mode (*note Options::). -`gsub(REGEXP, REPLACEMENT [, TARGET])' +`gsub(REGEXP, REPLACEMENT' [`, TARGET']`)' Search TARGET for _all_ of the longest, leftmost, _nonoverlapping_ matching substrings it can find and replace them with REPLACEMENT. The `g' in `gsub()' stands for "global," which means replace @@ -11395,7 +11426,7 @@ pound sign (`#'): It is a fatal error to use a regexp constant for FIND. -`length([STRING])' +`length('[STRING]`)' Return the number of characters in STRING. If STRING is a number, the length of the digit string representing that number is returned. For example, `length("abcde")' is five. By contrast, @@ -11435,7 +11466,7 @@ pound sign (`#'): array argument is not portable. If `--posix' is supplied, using an array argument is a fatal error (*note Arrays::). -`match(STRING, REGEXP [, ARRAY])' +`match(STRING, REGEXP' [`, ARRAY']`)' Search STRING for the longest, leftmost substring matched by the regular expression, REGEXP and return the character position, or "index", at which that substring begins (one, if it starts at the @@ -11522,7 +11553,7 @@ pound sign (`#'): compatibility mode (*note Options::), using a third argument is a fatal error. -`patsplit(STRING, ARRAY [, FIELDPAT [, SEPS ] ]) #' +`patsplit(STRING, ARRAY' [`, FIELDPAT' [`, SEPS' ] ]`)' # Divide STRING into pieces defined by FIELDPAT and store the pieces in ARRAY and the separator strings in the SEPS array. The first piece is stored in `ARRAY[1]', the second piece in `ARRAY[2]', and @@ -11544,7 +11575,7 @@ pound sign (`#'): The `patsplit()' function is a `gawk' extension. In compatibility mode (*note Options::), it is not available. -`split(STRING, ARRAY [, FIELDSEP [, SEPS ] ])' +`split(STRING, ARRAY' [`, FIELDSEP' [`, SEPS' ] ]`)' Divide STRING into pieces separated by FIELDSEP and store the pieces in ARRAY and the separator strings in the SEPS array. The first piece is stored in `ARRAY[1]', the second piece in @@ -11617,7 +11648,7 @@ pound sign (`#'): assigns the string `pi = 3.14 (approx.)' to the variable `pival'. -`strtonum(STR) #' +`strtonum(STR)' # Examine STR and return its numeric value. If STR begins with a leading `0', `strtonum()' assumes that STR is an octal number. If STR begins with a leading `0x' or `0X', `strtonum()' assumes that @@ -11637,7 +11668,7 @@ pound sign (`#'): `strtonum()' is a `gawk' extension; it is not available in compatibility mode (*note Options::). -`sub(REGEXP, REPLACEMENT [, TARGET])' +`sub(REGEXP, REPLACEMENT' [`, TARGET']`)' Search TARGET, which is treated as a string, for the leftmost, longest substring matched by the regular expression REGEXP. Modify the entire string by replacing the matched text with @@ -11710,7 +11741,7 @@ pound sign (`#'): into a string, and then the value of that string is treated as the regexp to match. -`substr(STRING, START [, LENGTH])' +`substr(STRING, START' [`, LENGTH' ]`)' Return a LENGTH-character-long substring of STRING, starting at character number START. The first character of a string is character number one.(3) For example, `substr("washington", 5, 3)' @@ -11967,7 +11998,7 @@ File: gawk.info, Node: I/O Functions, Next: Time Functions, Prev: String Func The following functions relate to input/output (I/O). Optional parameters are enclosed in square brackets ([ ]): -`close(FILENAME [, HOW])' +`close('FILENAME [`,' HOW]`)' Close the file FILENAME for input or output. Alternatively, the argument may be a shell command that was used for creating a coprocess, or for redirecting to or from a pipe; then the @@ -11982,7 +12013,7 @@ parameters are enclosed in square brackets ([ ]): not matter. *Note Two-way I/O::, which discusses this feature in more detail and gives an example. -`fflush([FILENAME])' +`fflush('[FILENAME]`)' Flush any buffered output associated with FILENAME, which is either a file opened for writing or a shell command for redirecting output to a pipe or coprocess. @@ -12189,7 +12220,7 @@ enclosed in square brackets ([ ]): If DATESPEC does not contain enough elements or if the resulting time is out of range, `mktime()' returns -1. -`strftime([FORMAT [, TIMESTAMP [, UTC-FLAG]]])' +``strftime(' [FORMAT [`,' TIMESTAMP [`,' UTC-FLAG ]]]`)'' Format the time specified by TIMESTAMP based on the contents of the FORMAT string and return the result. It is similar to the function of the same name in ISO C. If UTC-FLAG is present and is @@ -12507,23 +12538,23 @@ again with `10111001' and shift it left by three bits, you end up with `11001000'. `gawk' provides built-in functions that implement the bitwise operations just described. They are: -`and(V1, V2 [, ...])' +``and(V1, V2' [`,' ...]`)'' Return the bitwise AND of the arguments. There must be at least two. -`compl(VAL)' +``compl(VAL)'' Return the bitwise complement of VAL. -`lshift(VAL, COUNT)' +``lshift(VAL, COUNT)'' Return the value of VAL, shifted left by COUNT bits. -`or(V1, V2 [, ...])' +``or(V1, V2' [`,' ...]`)'' Return the bitwise OR of the arguments. There must be at least two. -`rshift(VAL, COUNT)' +``rshift(VAL, COUNT)'' Return the value of VAL, shifted right by COUNT bits. -`xor(V1, V2 [, ...])' +``xor(V1, V2' [`,' ...]`)'' Return the bitwise XOR of the arguments. There must be at least two. @@ -12639,7 +12670,7 @@ descriptions here are purposely brief. *Note Internationalization::, for the full story. Optional parameters are enclosed in square brackets ([ ]): -`bindtextdomain(DIRECTORY [, DOMAIN])' +``bindtextdomain(DIRECTORY' [`,' DOMAIN ]`)'' Set the directory in which `gawk' will look for message translation files, in case they will not or cannot be placed in the "standard" locations (e.g., during testing). It returns the @@ -12649,13 +12680,13 @@ brackets ([ ]): the null string (`""'), then `bindtextdomain()' returns the current binding for the given DOMAIN. -`dcgettext(STRING [, DOMAIN [, CATEGORY]])' +``dcgettext(STRING' [`,' DOMAIN [`,' CATEGORY ]]`)'' Return the translation of STRING in text domain DOMAIN for locale category CATEGORY. The default value for DOMAIN is the current value of `TEXTDOMAIN'. The default value for CATEGORY is `"LC_MESSAGES"'. -`dcngettext(STRING1, STRING2, NUMBER [, DOMAIN [, CATEGORY]])' +``dcngettext(STRING1, STRING2, NUMBER' [`,' DOMAIN [`,' CATEGORY ]]`)'' Return the plural form used for NUMBER of the translation of STRING1 and STRING2 in text domain DOMAIN for locale category CATEGORY. STRING1 is the English singular variant of a message, @@ -17577,10 +17608,10 @@ are several cases of interest: programming trick. Don't worry about it if you are not familiar with `sh'.) -`-v, -F' +`-v', `-F' These are saved and passed on to `gawk'. -`-f, --file, --file=, -Wfile=' +`-f', `--file', `--file=', `-Wfile=' The file name is appended to the shell variable `program' with an `@include' statement. The `expr' utility is used to remove the leading option part of the argument (e.g., `--file='). (Typical @@ -17589,10 +17620,10 @@ are several cases of interest: sequences in their arguments, possibly mangling the program text. Using `expr' avoids this problem.) -`--source, --source=, -Wsource=' +`--source', `--source=', `-Wsource=' The source text is appended to `program'. -`--version, -Wversion' +`--version', `-Wversion' `igawk' prints its version number, runs `gawk --version' to get the `gawk' version information, and then exits. @@ -19067,7 +19098,7 @@ internationalization: for translation at runtime. String constants without a leading underscore are not translated. -`dcgettext(STRING [, DOMAIN [, CATEGORY]])' +``dcgettext(STRING' [`,' DOMAIN [`,' CATEGORY ]]`)'' Return the translation of STRING in text domain DOMAIN for locale category CATEGORY. The default value for DOMAIN is the current value of `TEXTDOMAIN'. The default value for CATEGORY is @@ -19084,7 +19115,7 @@ internationalization: be simple and to allow for reasonable `awk'-style default arguments. -`dcngettext(STRING1, STRING2, NUMBER [, DOMAIN [, CATEGORY]])' +``dcngettext(STRING1, STRING2, NUMBER' [`,' DOMAIN [`,' CATEGORY ]]`)'' Return the plural form used for NUMBER of the translation of STRING1 and STRING2 in text domain DOMAIN for locale category CATEGORY. STRING1 is the English singular variant of a message, @@ -19095,7 +19126,7 @@ internationalization: The same remarks about argument order as for the `dcgettext()' function apply. -`bindtextdomain(DIRECTORY [, DOMAIN])' +``bindtextdomain(DIRECTORY' [`,' DOMAIN ]`)'' Change the directory in which `gettext' looks for `.gmo' files, in case they will not or cannot be placed in the standard locations (e.g., during testing). Return the directory in which DOMAIN is @@ -20276,16 +20307,16 @@ from a file. The commands are: `prompt' The debugger prompt. The default is `gawk> '. - `save_history [on | off]' + `save_history' [`on' | `off'] Save command history to file `./.gawk_history'. The default is `on'. - `save_options [on | off]' + `save_options' [`on' | `off'] Save current options to file `./.gawkrc' upon exit. The default is `on'. Options are read back in to the next session upon startup. - `trace [on | off]' + `trace' [`on' | `off'] Turn instruction tracing on or off. The default is `off'. `save' FILENAME @@ -20414,7 +20445,7 @@ categories, as follows: accidentally type `q' or `quit', to make sure you really want to quit. -`trace' `on' | `off' +`trace' [`on' | `off'] Turn on or off a continuous printing of instructions which are about to be executed, along with printing the `awk' line which they implement. The default is `off'. @@ -24281,8 +24312,8 @@ create a GNU/Linux shared library: } The `AWKLIBPATH' environment variable tells `gawk' where to find -shared libraries (*note Finding Extensions::). We set it to the -current directory and run the program: +extensions (*note Finding Extensions::). We set it to the current +directory and run the program: $ AWKLIBPATH=$PWD gawk -f testff.awk -| /tmp @@ -24355,7 +24386,7 @@ File: gawk.info, Node: Extension Sample File Functions, Next: Extension Sample The `filefuncs' extension provides three different functions, as follows: The usage is: -`@load "filefuncs"' +@load "filefuncs" This is how you load the extension. `result = chdir("/some/directory")' @@ -24364,7 +24395,7 @@ follows: The usage is: success or less than zero upon error. In the latter case it updates `ERRNO'. -`result = stat("/some/path", statdata [, follow])' +`result = stat("/some/path", statdata' [`, follow']`)' The `stat()' function provides a hook into the `stat()' system call. It returns zero upon success or less than zero upon error. In the latter case it updates `ERRNO'. @@ -30049,8 +30080,8 @@ Index * ! (exclamation point), !~ operator <6>: Case-sensitivity. (line 26) * ! (exclamation point), !~ operator: Regexp Usage. (line 19) * " (double quote) in shell commands: Read Terminal. (line 25) -* " (double quote), in regexp constants: Computed Regexps. (line 28) -* " (double quote), in shell commands: Quoting. (line 37) +* " (double quote), in regexp constants: Computed Regexps. (line 29) +* " (double quote), in shell commands: Quoting. (line 54) * # (number sign), #! (executable scripts): Executable Scripts. (line 6) * # (number sign), commenting: Comments. (line 6) @@ -30068,15 +30099,15 @@ Index (line 6) * ' (single quote): One-shot. (line 15) * ' (single quote) in gawk command lines: Long. (line 33) -* ' (single quote), in shell commands: Quoting. (line 31) +* ' (single quote), in shell commands: Quoting. (line 48) * ' (single quote), vs. apostrophe: Comments. (line 27) -* ' (single quote), with double quotes: Quoting. (line 53) +* ' (single quote), with double quotes: Quoting. (line 70) * () (parentheses), in a profile: Profiling. (line 146) -* () (parentheses), regexp operator: Regexp Operators. (line 79) +* () (parentheses), regexp operator: Regexp Operators. (line 80) * * (asterisk), * operator, as multiplication operator: Precedence. (line 55) * * (asterisk), * operator, as regexp operator: Regexp Operators. - (line 87) + (line 88) * * (asterisk), * operator, null strings, matching: Gory Details. (line 164) * * (asterisk), ** operator <1>: Precedence. (line 49) @@ -30090,7 +30121,7 @@ Index * + (plus sign), ++ operator: Increment Ops. (line 11) * + (plus sign), += operator <1>: Precedence. (line 95) * + (plus sign), += operator: Assignment Ops. (line 82) -* + (plus sign), regexp operator: Regexp Operators. (line 102) +* + (plus sign), regexp operator: Regexp Operators. (line 103) * , (comma), in range patterns: Ranges. (line 6) * - (hyphen), - operator: Precedence. (line 52) * - (hyphen), -- operator <1>: Precedence. (line 46) @@ -30100,7 +30131,7 @@ Index * - (hyphen), filenames beginning with: Options. (line 59) * - (hyphen), in bracket expressions: Bracket Expressions. (line 17) * --assign option: Options. (line 32) -* --bignum option: Options. (line 201) +* --bignum option: Options. (line 205) * --characters-as-bytes option: Options. (line 68) * --copyright option: Options. (line 88) * --debug option: Options. (line 108) @@ -30120,22 +30151,22 @@ Index * --gen-pot option: Options. (line 147) * --help option: Options. (line 154) * --include option: Options. (line 159) -* --lint option <1>: Options. (line 182) +* --lint option <1>: Options. (line 185) * --lint option: Command Line. (line 20) -* --lint-old option: Options. (line 288) +* --lint-old option: Options. (line 295) * --load option: Options. (line 173) * --non-decimal-data option <1>: Nondecimal Data. (line 6) -* --non-decimal-data option: Options. (line 207) +* --non-decimal-data option: Options. (line 211) * --non-decimal-data option, strtonum() function and: Nondecimal Data. (line 36) -* --optimize option: Options. (line 228) -* --posix option: Options. (line 247) -* --posix option, --traditional option and: Options. (line 266) -* --pretty-print option: Options. (line 220) +* --optimize option: Options. (line 237) +* --posix option: Options. (line 254) +* --posix option, --traditional option and: Options. (line 273) +* --pretty-print option: Options. (line 224) * --profile option <1>: Profiling. (line 12) -* --profile option: Options. (line 235) -* --re-interval option: Options. (line 272) -* --sandbox option: Options. (line 279) +* --profile option: Options. (line 242) +* --re-interval option: Options. (line 279) +* --sandbox option: Options. (line 286) * --sandbox option, disabling system() function: I/O Functions. (line 94) * --sandbox option, input redirection with getline: Getline. (line 19) @@ -30143,9 +30174,9 @@ Index (line 6) * --source option: Options. (line 117) * --traditional option: Options. (line 81) -* --traditional option, --posix option and: Options. (line 266) -* --use-lc-numeric option: Options. (line 215) -* --version option: Options. (line 293) +* --traditional option, --posix option and: Options. (line 273) +* --use-lc-numeric option: Options. (line 219) +* --version option: Options. (line 300) * --with-whiny-user-strftime configuration option: Additional Configuration Options. (line 35) * -b option: Options. (line 68) @@ -30158,29 +30189,29 @@ Index * -f option: Options. (line 25) * -F option: Options. (line 21) * -f option: Long. (line 12) -* -F option, -Ft sets FS to TAB: Options. (line 301) +* -F option, -Ft sets FS to TAB: Options. (line 308) * -F option, command line: Command Line Field Separator. (line 6) -* -f option, multiple uses: Options. (line 306) +* -f option, multiple uses: Options. (line 313) * -g option: Options. (line 147) * -h option: Options. (line 154) * -i option: Options. (line 159) -* -L option: Options. (line 288) +* -L option: Options. (line 295) * -l option: Options. (line 173) -* -M option: Options. (line 201) -* -N option: Options. (line 215) -* -n option: Options. (line 207) -* -O option: Options. (line 228) -* -o option: Options. (line 220) -* -P option: Options. (line 247) -* -p option: Options. (line 235) -* -r option: Options. (line 272) -* -S option: Options. (line 279) +* -M option: Options. (line 205) +* -N option: Options. (line 219) +* -n option: Options. (line 211) +* -O option: Options. (line 237) +* -o option: Options. (line 224) +* -P option: Options. (line 254) +* -p option: Options. (line 242) +* -r option: Options. (line 279) +* -S option: Options. (line 286) * -v option: Assignment Options. (line 12) -* -V option: Options. (line 293) +* -V option: Options. (line 300) * -v option: Options. (line 32) * -W option: Options. (line 46) -* . (period), regexp operator: Regexp Operators. (line 43) +* . (period), regexp operator: Regexp Operators. (line 44) * .gmo files: Explaining gettext. (line 41) * .gmo files, converting from .po: I18N Example. (line 62) * .gmo files, specifying directory of <1>: Programmer i18n. (line 47) @@ -30232,8 +30263,8 @@ Index * ? (question mark), ?: operator: Precedence. (line 92) * ? (question mark), regexp operator <1>: GNU Regexp Operators. (line 59) -* ? (question mark), regexp operator: Regexp Operators. (line 111) -* [] (square brackets), regexp operator: Regexp Operators. (line 55) +* ? (question mark), regexp operator: Regexp Operators. (line 112) +* [] (square brackets), regexp operator: Regexp Operators. (line 56) * \ (backslash): Comments. (line 50) * \ (backslash) in shell commands: Read Terminal. (line 25) * \ (backslash), \" escape sequence: Escape Sequences. (line 76) @@ -30281,8 +30312,8 @@ Index * \ (backslash), in escape sequences: Escape Sequences. (line 6) * \ (backslash), in escape sequences, POSIX and: Escape Sequences. (line 112) -* \ (backslash), in regexp constants: Computed Regexps. (line 28) -* \ (backslash), in shell commands: Quoting. (line 31) +* \ (backslash), in regexp constants: Computed Regexps. (line 29) +* \ (backslash), in shell commands: Quoting. (line 48) * \ (backslash), regexp operator: Regexp Operators. (line 18) * ^ (caret), ^ operator: Precedence. (line 49) * ^ (caret), ^= operator <1>: Precedence. (line 95) @@ -30436,7 +30467,7 @@ Index * asterisk (*), * operator, as multiplication operator: Precedence. (line 55) * asterisk (*), * operator, as regexp operator: Regexp Operators. - (line 87) + (line 88) * asterisk (*), * operator, null strings, matching: Gory Details. (line 164) * asterisk (*), ** operator <1>: Precedence. (line 49) @@ -30450,7 +30481,7 @@ Index * awf (amazingly workable formatter) program: Glossary. (line 25) * awk debugging, enabling: Options. (line 108) * awk language, POSIX version: Assignment Ops. (line 136) -* awk profiling, enabling: Options. (line 235) +* awk profiling, enabling: Options. (line 242) * awk programs <1>: Two Rules. (line 6) * awk programs <2>: Executable Scripts. (line 6) * awk programs: Getting Started. (line 12) @@ -30555,8 +30586,8 @@ Index * backslash (\), in escape sequences: Escape Sequences. (line 6) * backslash (\), in escape sequences, POSIX and: Escape Sequences. (line 112) -* backslash (\), in regexp constants: Computed Regexps. (line 28) -* backslash (\), in shell commands: Quoting. (line 31) +* backslash (\), in regexp constants: Computed Regexps. (line 29) +* backslash (\), in shell commands: Quoting. (line 48) * backslash (\), regexp operator: Regexp Operators. (line 18) * backtrace debugger command: Execution Stack. (line 13) * Beebe, Nelson H.F. <1>: Other Versions. (line 78) @@ -30617,14 +30648,14 @@ Index * braces ({}), actions and: Action Overview. (line 19) * braces ({}), statements, grouping: Statements. (line 10) * bracket expressions <1>: Bracket Expressions. (line 6) -* bracket expressions: Regexp Operators. (line 55) +* bracket expressions: Regexp Operators. (line 56) * bracket expressions, character classes: Bracket Expressions. (line 30) * bracket expressions, collating elements: Bracket Expressions. (line 69) * bracket expressions, collating symbols: Bracket Expressions. (line 76) -* bracket expressions, complemented: Regexp Operators. (line 63) +* bracket expressions, complemented: Regexp Operators. (line 64) * bracket expressions, equivalence classes: Bracket Expressions. (line 82) * bracket expressions, non-ASCII: Bracket Expressions. (line 69) @@ -30665,6 +30696,7 @@ Index * Brian Kernighan's awk, extensions: BTL. (line 6) * Brian Kernighan's awk, source code: Other Versions. (line 13) * Brini, Davide: Signature Program. (line 6) +* Brink, Jeroen: DOS Quoting. (line 10) * Broder, Alan J.: Contributors. (line 88) * Brown, Martin: Contributors. (line 82) * BSD-based operating systems: Glossary. (line 616) @@ -30710,14 +30742,14 @@ Index * CGI, awk scripts for: Options. (line 125) * changing precision of a number: Changing Precision. (line 6) * character classes, See bracket expressions: Regexp Operators. - (line 55) + (line 56) * character lists in regular expression: Bracket Expressions. (line 6) -* character lists, See bracket expressions: Regexp Operators. (line 55) +* character lists, See bracket expressions: Regexp Operators. (line 56) * character sets (machine character encodings) <1>: Glossary. (line 133) * character sets (machine character encodings): Ordinal Functions. (line 45) * character sets, See Also bracket expressions: Regexp Operators. - (line 55) + (line 56) * characters, counting: Wc Program. (line 6) * characters, transliterating: Translate Program. (line 6) * characters, values of as numbers: Ordinal Functions. (line 6) @@ -30861,7 +30893,7 @@ Index * cosine: Numeric Functions. (line 15) * counting: Wc Program. (line 6) * csh utility: Statements/Lines. (line 44) -* csh utility, POSIXLY_CORRECT environment variable: Options. (line 348) +* csh utility, POSIXLY_CORRECT environment variable: Options. (line 355) * csh utility, |& operator, comparison with: Two-way I/O. (line 44) * ctime() user-defined function: Function Example. (line 73) * currency symbols, localization: Explaining gettext. (line 103) @@ -31043,7 +31075,7 @@ Index * debugger, read commands from a file: Debugger Info. (line 96) * debugging awk programs: Debugger. (line 6) * debugging gawk, bug reports: Bugs. (line 9) -* decimal point character, locale specific: Options. (line 263) +* decimal point character, locale specific: Options. (line 270) * decrement operators: Increment Ops. (line 35) * default keyword: Switch Statement. (line 6) * Deifik, Scott <1>: Bugs. (line 70) @@ -31132,7 +31164,7 @@ Index * directories, command line: Command line directories. (line 6) * directories, searching: Igawk Program. (line 368) -* directories, searching for shared libraries: AWKLIBPATH Variable. +* directories, searching for loadable extensions: AWKLIBPATH Variable. (line 6) * directories, searching for source files: AWKPATH Variable. (line 6) * disable breakpoint: Breakpoint Control. (line 69) @@ -31153,8 +31185,8 @@ Index * dollar sign ($), regexp operator: Regexp Operators. (line 35) * double precision floating-point: General Arithmetic. (line 21) * double quote (") in shell commands: Read Terminal. (line 25) -* double quote ("), in regexp constants: Computed Regexps. (line 28) -* double quote ("), in shell commands: Quoting. (line 37) +* double quote ("), in regexp constants: Computed Regexps. (line 29) +* double quote ("), in shell commands: Quoting. (line 54) * down debugger command: Execution Stack. (line 21) * Drepper, Ulrich: Acknowledgments. (line 52) * dump all variables of a program: Options. (line 93) @@ -31470,7 +31502,7 @@ Index * FS variable, --field-separator option and: Options. (line 21) * FS variable, as null string: Single Character Fields. (line 20) -* FS variable, as TAB character: Options. (line 259) +* FS variable, as TAB character: Options. (line 266) * FS variable, changing value of: Field Separators. (line 35) * FS variable, running awk programs and: Cut Program. (line 68) * FS variable, setting from command line: Command Line Field Separator. @@ -31560,7 +31592,7 @@ Index (line 138) * gawk, ERRNO variable in: Getline. (line 19) * gawk, escape sequences: Escape Sequences. (line 124) -* gawk, extensions, disabling: Options. (line 247) +* gawk, extensions, disabling: Options. (line 254) * gawk, features, adding: Adding Code. (line 6) * gawk, features, advanced: Advanced Features. (line 6) * gawk, field separators and: User-modified. (line 77) @@ -31591,7 +31623,7 @@ Index (line 13) * gawk, interpreter, adding code to: Using Internal File Ops. (line 6) -* gawk, interval expressions and: Regexp Operators. (line 139) +* gawk, interval expressions and: Regexp Operators. (line 140) * gawk, line continuation in: Conditional Exp. (line 34) * gawk, LINT variable in: User-modified. (line 98) * gawk, list of contributors to: Contributors. (line 6) @@ -31609,7 +31641,7 @@ Index (line 26) * gawk, regular expressions, operators: GNU Regexp Operators. (line 6) -* gawk, regular expressions, precedence: Regexp Operators. (line 161) +* gawk, regular expressions, precedence: Regexp Operators. (line 162) * gawk, RT variable in <1>: Auto-set. (line 266) * gawk, RT variable in <2>: Multiple Line. (line 129) * gawk, RT variable in: Records. (line 132) @@ -31621,7 +31653,7 @@ Index * gawk, TEXTDOMAIN variable in: User-modified. (line 162) * gawk, timestamps: Time Functions. (line 6) * gawk, uses for: Preface. (line 36) -* gawk, versions of, information about, printing: Options. (line 293) +* gawk, versions of, information about, printing: Options. (line 300) * gawk, VMS version of: VMS Installation. (line 6) * gawk, word-boundary operator: GNU Regexp Operators. (line 63) @@ -31722,7 +31754,7 @@ Index * help debugger command: Miscellaneous Debugger Commands. (line 66) * hexadecimal numbers: Nondecimal-numbers. (line 6) -* hexadecimal values, enabling interpretation of: Options. (line 207) +* hexadecimal values, enabling interpretation of: Options. (line 211) * history expansion, in debugger: Readline Support. (line 6) * histsort.awk program: History Sorting. (line 25) * Hughes, Phil: Acknowledgments. (line 43) @@ -31832,7 +31864,7 @@ Index * internationalizing a program: Explaining gettext. (line 6) * interpreted programs <1>: Glossary. (line 357) * interpreted programs: Basic High Level. (line 15) -* interval expressions, regexp operator: Regexp Operators. (line 116) +* interval expressions, regexp operator: Regexp Operators. (line 117) * inventory-shipped file: Sample Data Files. (line 32) * invoke shell command: I/O Functions. (line 72) * isarray: Type Functions. (line 11) @@ -31935,9 +31967,9 @@ Index * lint checking, array subscripts: Uninitialized Subscripts. (line 43) * lint checking, empty programs: Command Line. (line 16) -* lint checking, issuing warnings: Options. (line 182) +* lint checking, issuing warnings: Options. (line 185) * lint checking, POSIXLY_CORRECT environment variable: Options. - (line 332) + (line 340) * lint checking, undefined functions: Pass By Value/Reference. (line 88) * LINT variable: User-modified. (line 98) @@ -31948,10 +31980,10 @@ Index * list debugger command: Miscellaneous Debugger Commands. (line 72) * list function definitions, in debugger: Debugger Info. (line 30) -* loading, library: Options. (line 173) +* loading, extensions: Options. (line 173) * local variables, in a function: Variable Scope. (line 6) * locale categories: Explaining gettext. (line 80) -* locale decimal point character: Options. (line 263) +* locale decimal point character: Options. (line 270) * locale, definition of: Locales. (line 6) * localization: I18N and L10N. (line 6) * localization, See internationalization, localization: I18N and L10N. @@ -32035,13 +32067,13 @@ Index * networks, programming: TCP/IP Networking. (line 6) * networks, support for: Special Network. (line 6) * newlines <1>: Boolean Ops. (line 67) -* newlines <2>: Options. (line 253) +* newlines <2>: Options. (line 260) * newlines: Statements/Lines. (line 6) * newlines, as field separators: Default Field Splitting. (line 6) * newlines, as record separators: Records. (line 20) -* newlines, in dynamic regexps: Computed Regexps. (line 58) -* newlines, in regexp constants: Computed Regexps. (line 68) +* newlines, in dynamic regexps: Computed Regexps. (line 59) +* newlines, in regexp constants: Computed Regexps. (line 69) * newlines, printing: Print Examples. (line 12) * newlines, separating statements in actions <1>: Statements. (line 10) * newlines, separating statements in actions: Action Overview. @@ -32081,7 +32113,7 @@ Index * null strings <3>: Regexp Field Splitting. (line 43) * null strings: Records. (line 122) -* null strings in gawk arguments, quoting and: Quoting. (line 62) +* null strings in gawk arguments, quoting and: Quoting. (line 79) * null strings, and deleting array elements: Delete. (line 27) * null strings, as array subscripts: Uninitialized Subscripts. (line 43) @@ -32112,7 +32144,7 @@ Index * oawk utility: Names. (line 10) * obsolete features: Obsolete. (line 6) * octal numbers: Nondecimal-numbers. (line 6) -* octal values, enabling interpretation of: Options. (line 207) +* octal values, enabling interpretation of: Options. (line 211) * OFMT variable <1>: User-modified. (line 115) * OFMT variable <2>: Conversion. (line 55) * OFMT variable: OFMT. (line 15) @@ -32192,7 +32224,7 @@ Index * P1003.1 POSIX standard: Glossary. (line 454) * parent process ID of gawk process: Auto-set. (line 186) * parentheses (), in a profile: Profiling. (line 146) -* parentheses (), regexp operator: Regexp Operators. (line 79) +* parentheses (), regexp operator: Regexp Operators. (line 80) * password file: Passwd Functions. (line 16) * patsplit: String Functions. (line 291) * patterns: Patterns and Actions. @@ -32213,7 +32245,7 @@ Index * percent sign (%), % operator: Precedence. (line 55) * percent sign (%), %= operator <1>: Precedence. (line 95) * percent sign (%), %= operator: Assignment Ops. (line 129) -* period (.), regexp operator: Regexp Operators. (line 43) +* period (.), regexp operator: Regexp Operators. (line 44) * Perl: Future Extensions. (line 6) * Peters, Arno: Contributors. (line 85) * Peterson, Hal: Contributors. (line 39) @@ -32230,7 +32262,7 @@ Index * plus sign (+), ++ operator: Increment Ops. (line 11) * plus sign (+), += operator <1>: Precedence. (line 95) * plus sign (+), += operator: Assignment Ops. (line 82) -* plus sign (+), regexp operator: Regexp Operators. (line 102) +* plus sign (+), regexp operator: Regexp Operators. (line 103) * pointers to functions: Indirect Calls. (line 6) * portability: Escape Sequences. (line 94) * portability, #! (executable scripts): Executable Scripts. (line 33) @@ -32256,7 +32288,7 @@ Index * portability, NF variable, decrementing: Changing Fields. (line 115) * portability, operators: Increment Ops. (line 60) * portability, operators, not in POSIX awk: Precedence. (line 98) -* portability, POSIXLY_CORRECT environment variable: Options. (line 353) +* portability, POSIXLY_CORRECT environment variable: Options. (line 360) * portability, substr() function: String Functions. (line 510) * portable object files <1>: Translator i18n. (line 6) * portable object files: Explaining gettext. (line 36) @@ -32296,26 +32328,26 @@ Index * POSIX awk, functions and, gsub()/sub(): Gory Details. (line 54) * POSIX awk, functions and, length(): String Functions. (line 173) * POSIX awk, GNU long options and: Options. (line 15) -* POSIX awk, interval expressions in: Regexp Operators. (line 135) +* POSIX awk, interval expressions in: Regexp Operators. (line 136) * POSIX awk, next/nextfile statements and: Next Statement. (line 45) * POSIX awk, numeric strings and: Variable Typing. (line 6) * POSIX awk, OFMT variable and <1>: Conversion. (line 55) * POSIX awk, OFMT variable and: OFMT. (line 27) -* POSIX awk, period (.), using: Regexp Operators. (line 50) +* POSIX awk, period (.), using: Regexp Operators. (line 51) * POSIX awk, printf format strings and: Format Modifiers. (line 159) -* POSIX awk, regular expressions and: Regexp Operators. (line 161) +* POSIX awk, regular expressions and: Regexp Operators. (line 162) * POSIX awk, timestamps and: Time Functions. (line 6) * POSIX awk, | I/O operator and: Getline/Pipe. (line 55) -* POSIX mode: Options. (line 247) +* POSIX mode: Options. (line 254) * POSIX, awk and: Preface. (line 23) * POSIX, gawk extensions not included in: POSIX/GNU. (line 6) * POSIX, programs, implementing in awk: Clones. (line 6) -* POSIXLY_CORRECT environment variable: Options. (line 332) +* POSIXLY_CORRECT environment variable: Options. (line 340) * PREC variable <1>: Setting Precision. (line 6) * PREC variable: User-modified. (line 134) * precedence <1>: Precedence. (line 6) * precedence: Increment Ops. (line 60) -* precedence, regexp operators: Regexp Operators. (line 156) +* precedence, regexp operators: Regexp Operators. (line 157) * print debugger command: Viewing And Changing Data. (line 36) * print statement: Printing. (line 16) @@ -32403,13 +32435,13 @@ Index * question mark (?), ?: operator: Precedence. (line 92) * question mark (?), regexp operator <1>: GNU Regexp Operators. (line 59) -* question mark (?), regexp operator: Regexp Operators. (line 111) +* question mark (?), regexp operator: Regexp Operators. (line 112) * QuikTrim Awk: Other Versions. (line 134) * quit debugger command: Miscellaneous Debugger Commands. (line 99) * QUIT signal (MS-Windows): Profiling. (line 214) * quoting in gawk command lines: Long. (line 26) -* quoting in gawk command lines, tricks for: Quoting. (line 71) +* quoting in gawk command lines, tricks for: Quoting. (line 88) * quoting, for small awk programs: Comments. (line 27) * r debugger command (alias for run): Debugger Execution Control. (line 62) @@ -32467,8 +32499,8 @@ Index * regexp constants, as patterns: Expression Patterns. (line 34) * regexp constants, in gawk: Using Constant Regexps. (line 28) -* regexp constants, slashes vs. quotes: Computed Regexps. (line 28) -* regexp constants, vs. string constants: Computed Regexps. (line 38) +* regexp constants, slashes vs. quotes: Computed Regexps. (line 29) +* regexp constants, vs. string constants: Computed Regexps. (line 39) * register extension: Registration Functions. (line 6) * regular expressions: Regexp. (line 6) @@ -32486,10 +32518,10 @@ Index (line 57) * regular expressions, dynamic: Computed Regexps. (line 6) * regular expressions, dynamic, with embedded newlines: Computed Regexps. - (line 58) + (line 59) * regular expressions, gawk, command-line options: GNU Regexp Operators. (line 70) -* regular expressions, interval expressions and: Options. (line 272) +* regular expressions, interval expressions and: Options. (line 279) * regular expressions, leftmost longest match: Leftmost Longest. (line 6) * regular expressions, operators <1>: Regexp Operators. (line 6) @@ -32501,7 +32533,7 @@ Index * regular expressions, operators, gawk: GNU Regexp Operators. (line 6) * regular expressions, operators, precedence of: Regexp Operators. - (line 156) + (line 157) * regular expressions, searching for: Egrep Program. (line 6) * relational operators, See comparison operators: Typing and Comparison. (line 9) @@ -32573,7 +32605,7 @@ Index (line 68) * sample debugging session: Sample Debugging Session. (line 6) -* sandbox mode: Options. (line 279) +* sandbox mode: Options. (line 286) * save debugger options: Debugger Info. (line 84) * scalar or array: Type Functions. (line 11) * scalar values: Basic Data Typing. (line 13) @@ -32588,7 +32620,7 @@ Index * search paths <1>: VMS Running. (line 58) * search paths <2>: PC Using. (line 10) * search paths: Igawk Program. (line 368) -* search paths, for shared libraries: AWKLIBPATH Variable. (line 6) +* search paths, for loadable extensions: AWKLIBPATH Variable. (line 6) * search paths, for source files <1>: VMS Running. (line 58) * search paths, for source files <2>: PC Using. (line 10) * search paths, for source files <3>: Igawk Program. (line 368) @@ -32687,7 +32719,7 @@ Index (line 145) * sidebar, Understanding $0: Changing Fields. (line 134) * sidebar, Using \n in Bracket Expressions of Dynamic Regexps: Computed Regexps. - (line 56) + (line 57) * sidebar, Using close()'s Return Value: Close Files And Pipes. (line 128) * SIGHUP signal, for dynamic profiling: Profiling. (line 211) @@ -32706,9 +32738,9 @@ Index * single precision floating-point: General Arithmetic. (line 21) * single quote ('): One-shot. (line 15) * single quote (') in gawk command lines: Long. (line 33) -* single quote ('), in shell commands: Quoting. (line 31) +* single quote ('), in shell commands: Quoting. (line 48) * single quote ('), vs. apostrophe: Comments. (line 27) -* single quote ('), with double quotes: Quoting. (line 53) +* single quote ('), with double quotes: Quoting. (line 70) * single-character fields: Single Character Fields. (line 6) * single-step execution, in the debugger: Debugger Execution Control. @@ -32754,7 +32786,7 @@ Index * sprintf() function, print/printf statements and: Round Function. (line 6) * sqrt: Numeric Functions. (line 78) -* square brackets ([]), regexp operator: Regexp Operators. (line 55) +* square brackets ([]), regexp operator: Regexp Operators. (line 56) * square root: Numeric Functions. (line 78) * srand: Numeric Functions. (line 82) * stack frame: Debugging Terms. (line 10) @@ -32783,7 +32815,7 @@ Index (line 46) * strftime: Time Functions. (line 48) * string constants: Scalar Constants. (line 15) -* string constants, vs. regexp constants: Computed Regexps. (line 38) +* string constants, vs. regexp constants: Computed Regexps. (line 39) * string extraction (internationalization): String Extraction. (line 6) * string length: String Functions. (line 164) @@ -32892,7 +32924,7 @@ Index * translate string: I18N Functions. (line 22) * translate.awk program: Translate Program. (line 55) * treating files, as single records: Records. (line 219) -* troubleshooting, --non-decimal-data option: Options. (line 207) +* troubleshooting, --non-decimal-data option: Options. (line 211) * troubleshooting, == operator: Comparison Operators. (line 37) * troubleshooting, awk uses FS not IFS: Field Separators. (line 30) @@ -32919,7 +32951,7 @@ Index * troubleshooting, quotes with file names: Special FD. (line 68) * troubleshooting, readable data files: File Checking. (line 6) * troubleshooting, regexp constants vs. string constants: Computed Regexps. - (line 38) + (line 39) * troubleshooting, string concatenation: Concatenation. (line 26) * troubleshooting, substr() function: String Functions. (line 497) * troubleshooting, system() function: I/O Functions. (line 94) @@ -33013,7 +33045,7 @@ Index * version of gawk extension API: Auto-set. (line 229) * version of GNU MP library: Auto-set. (line 215) * version of GNU MPFR library: Auto-set. (line 211) -* vertical bar (|): Regexp Operators. (line 69) +* vertical bar (|): Regexp Operators. (line 70) * vertical bar (|), | operator (I/O) <1>: Precedence. (line 65) * vertical bar (|), | operator (I/O): Getline/Pipe. (line 9) * vertical bar (|), |& operator (I/O) <1>: Two-way I/O. (line 44) @@ -33033,7 +33065,7 @@ Index * Wall, Larry <1>: Future Extensions. (line 6) * Wall, Larry: Array Intro. (line 6) * Wallin, Anders: Contributors. (line 103) -* warnings, issuing: Options. (line 182) +* warnings, issuing: Options. (line 185) * watch debugger command: Viewing And Changing Data. (line 67) * watchpoint: Debugging Terms. (line 42) @@ -33046,7 +33078,7 @@ Index * whitespace, as field separators: Default Field Splitting. (line 6) * whitespace, functions, calling: Calling Built-in. (line 10) -* whitespace, newlines as: Options. (line 253) +* whitespace, newlines as: Options. (line 260) * Williams, Kent: Contributors. (line 34) * Woehlke, Matthew: Contributors. (line 79) * Woods, John: Contributors. (line 27) @@ -33075,7 +33107,7 @@ Index * {} (braces): Profiling. (line 142) * {} (braces), actions and: Action Overview. (line 19) * {} (braces), statements, grouping: Statements. (line 10) -* | (vertical bar): Regexp Operators. (line 69) +* | (vertical bar): Regexp Operators. (line 70) * | (vertical bar), | operator (I/O) <1>: Precedence. (line 65) * | (vertical bar), | operator (I/O) <2>: Redirection. (line 57) * | (vertical bar), | operator (I/O): Getline/Pipe. (line 9) @@ -33127,502 +33159,502 @@ Ref: Executable Scripts-Footnote-179661 Ref: Executable Scripts-Footnote-279763 Node: Comments80310 Node: Quoting82777 -Node: DOS Quoting87400 -Node: Sample Data Files88075 -Node: Very Simple90590 -Node: Two Rules95241 -Node: More Complex97139 -Ref: More Complex-Footnote-1100069 -Node: Statements/Lines100154 -Ref: Statements/Lines-Footnote-1104617 -Node: Other Features104882 -Node: When105810 -Node: Invoking Gawk107957 -Node: Command Line109420 -Node: Options110203 -Ref: Options-Footnote-1125581 -Node: Other Arguments125606 -Node: Naming Standard Input128264 -Node: Environment Variables129358 -Node: AWKPATH Variable129916 -Ref: AWKPATH Variable-Footnote-1132697 -Ref: AWKPATH Variable-Footnote-2132742 -Node: AWKLIBPATH Variable133002 -Node: Other Environment Variables133720 -Node: Exit Status136683 -Node: Include Files137358 -Node: Loading Shared Libraries140927 -Node: Obsolete142291 -Node: Undocumented142988 -Node: Regexp143230 -Node: Regexp Usage144619 -Node: Escape Sequences146644 -Node: Regexp Operators152313 -Ref: Regexp Operators-Footnote-1159693 -Ref: Regexp Operators-Footnote-2159840 -Node: Bracket Expressions159938 -Ref: table-char-classes161828 -Node: GNU Regexp Operators164351 -Node: Case-sensitivity168074 -Ref: Case-sensitivity-Footnote-1171042 -Ref: Case-sensitivity-Footnote-2171277 -Node: Leftmost Longest171385 -Node: Computed Regexps172586 -Node: Reading Files175923 -Node: Records177925 -Ref: Records-Footnote-1187448 -Node: Fields187485 -Ref: Fields-Footnote-1190441 -Node: Nonconstant Fields190527 -Node: Changing Fields192733 -Node: Field Separators198692 -Node: Default Field Splitting201394 -Node: Regexp Field Splitting202511 -Node: Single Character Fields205853 -Node: Command Line Field Separator206912 -Node: Full Line Fields210254 -Ref: Full Line Fields-Footnote-1210762 -Node: Field Splitting Summary210808 -Ref: Field Splitting Summary-Footnote-1213907 -Node: Constant Size214008 -Node: Splitting By Content218615 -Ref: Splitting By Content-Footnote-1222364 -Node: Multiple Line222404 -Ref: Multiple Line-Footnote-1228251 -Node: Getline228430 -Node: Plain Getline230646 -Node: Getline/Variable232741 -Node: Getline/File233888 -Node: Getline/Variable/File235229 -Ref: Getline/Variable/File-Footnote-1236828 -Node: Getline/Pipe236915 -Node: Getline/Variable/Pipe239614 -Node: Getline/Coprocess240721 -Node: Getline/Variable/Coprocess241973 -Node: Getline Notes242710 -Node: Getline Summary245497 -Ref: table-getline-variants245905 -Node: Read Timeout246817 -Ref: Read Timeout-Footnote-1250556 -Node: Command line directories250614 -Node: Printing251244 -Node: Print252875 -Node: Print Examples254212 -Node: Output Separators256996 -Node: OFMT259012 -Node: Printf260370 -Node: Basic Printf261276 -Node: Control Letters262815 -Node: Format Modifiers266627 -Node: Printf Examples272636 -Node: Redirection275348 -Node: Special Files282322 -Node: Special FD282855 -Ref: Special FD-Footnote-1286480 -Node: Special Network286554 -Node: Special Caveats287404 -Node: Close Files And Pipes288200 -Ref: Close Files And Pipes-Footnote-1295183 -Ref: Close Files And Pipes-Footnote-2295331 -Node: Expressions295481 -Node: Values296613 -Node: Constants297289 -Node: Scalar Constants297969 -Ref: Scalar Constants-Footnote-1298828 -Node: Nondecimal-numbers299010 -Node: Regexp Constants302010 -Node: Using Constant Regexps302485 -Node: Variables305540 -Node: Using Variables306195 -Node: Assignment Options307919 -Node: Conversion309794 -Ref: table-locale-affects315294 -Ref: Conversion-Footnote-1315918 -Node: All Operators316027 -Node: Arithmetic Ops316657 -Node: Concatenation319162 -Ref: Concatenation-Footnote-1321950 -Node: Assignment Ops322070 -Ref: table-assign-ops327058 -Node: Increment Ops328389 -Node: Truth Values and Conditions331823 -Node: Truth Values332906 -Node: Typing and Comparison333955 -Node: Variable Typing334748 -Ref: Variable Typing-Footnote-1338645 -Node: Comparison Operators338767 -Ref: table-relational-ops339177 -Node: POSIX String Comparison342725 -Ref: POSIX String Comparison-Footnote-1343681 -Node: Boolean Ops343819 -Ref: Boolean Ops-Footnote-1347889 -Node: Conditional Exp347980 -Node: Function Calls349712 -Node: Precedence353306 -Node: Locales356975 -Node: Patterns and Actions358064 -Node: Pattern Overview359118 -Node: Regexp Patterns360787 -Node: Expression Patterns361330 -Node: Ranges365111 -Node: BEGIN/END368215 -Node: Using BEGIN/END368977 -Ref: Using BEGIN/END-Footnote-1371713 -Node: I/O And BEGIN/END371819 -Node: BEGINFILE/ENDFILE374101 -Node: Empty377015 -Node: Using Shell Variables377332 -Node: Action Overview379617 -Node: Statements381974 -Node: If Statement383828 -Node: While Statement385327 -Node: Do Statement387371 -Node: For Statement388527 -Node: Switch Statement391679 -Node: Break Statement393833 -Node: Continue Statement395823 -Node: Next Statement397616 -Node: Nextfile Statement400006 -Node: Exit Statement402661 -Node: Built-in Variables405077 -Node: User-modified406172 -Ref: User-modified-Footnote-1414530 -Node: Auto-set414592 -Ref: Auto-set-Footnote-1427657 -Ref: Auto-set-Footnote-2427862 -Node: ARGC and ARGV427918 -Node: Arrays431772 -Node: Array Basics433277 -Node: Array Intro434103 -Node: Reference to Elements438420 -Node: Assigning Elements440690 -Node: Array Example441181 -Node: Scanning an Array442913 -Node: Controlling Scanning445227 -Ref: Controlling Scanning-Footnote-1450314 -Node: Delete450630 -Ref: Delete-Footnote-1453395 -Node: Numeric Array Subscripts453452 -Node: Uninitialized Subscripts455635 -Node: Multidimensional457262 -Node: Multiscanning460355 -Node: Arrays of Arrays461944 -Node: Functions466584 -Node: Built-in467403 -Node: Calling Built-in468481 -Node: Numeric Functions470469 -Ref: Numeric Functions-Footnote-1474301 -Ref: Numeric Functions-Footnote-2474658 -Ref: Numeric Functions-Footnote-3474706 -Node: String Functions474975 -Ref: String Functions-Footnote-1497933 -Ref: String Functions-Footnote-2498062 -Ref: String Functions-Footnote-3498310 -Node: Gory Details498397 -Ref: table-sub-escapes500076 -Ref: table-sub-posix-92501430 -Ref: table-sub-proposed502781 -Ref: table-posix-sub504135 -Ref: table-gensub-escapes505680 -Ref: Gory Details-Footnote-1506856 -Ref: Gory Details-Footnote-2506907 -Node: I/O Functions507058 -Ref: I/O Functions-Footnote-1514048 -Node: Time Functions514195 -Ref: Time Functions-Footnote-1525178 -Ref: Time Functions-Footnote-2525246 -Ref: Time Functions-Footnote-3525404 -Ref: Time Functions-Footnote-4525515 -Ref: Time Functions-Footnote-5525627 -Ref: Time Functions-Footnote-6525854 -Node: Bitwise Functions526120 -Ref: table-bitwise-ops526682 -Ref: Bitwise Functions-Footnote-1530903 -Node: Type Functions531087 -Node: I18N Functions532238 -Node: User-defined533865 -Node: Definition Syntax534669 -Ref: Definition Syntax-Footnote-1539583 -Node: Function Example539652 -Ref: Function Example-Footnote-1542301 -Node: Function Caveats542323 -Node: Calling A Function542841 -Node: Variable Scope543796 -Node: Pass By Value/Reference546759 -Node: Return Statement550267 -Node: Dynamic Typing553248 -Node: Indirect Calls554179 -Node: Library Functions563866 -Ref: Library Functions-Footnote-1567379 -Ref: Library Functions-Footnote-2567522 -Node: Library Names567693 -Ref: Library Names-Footnote-1571166 -Ref: Library Names-Footnote-2571386 -Node: General Functions571472 -Node: Strtonum Function572500 -Node: Assert Function575430 -Node: Round Function578756 -Node: Cliff Random Function580297 -Node: Ordinal Functions581313 -Ref: Ordinal Functions-Footnote-1584390 -Ref: Ordinal Functions-Footnote-2584642 -Node: Join Function584853 -Ref: Join Function-Footnote-1586624 -Node: Getlocaltime Function586824 -Node: Readfile Function590565 -Node: Data File Management592404 -Node: Filetrans Function593036 -Node: Rewind Function597105 -Node: File Checking598492 -Node: Empty Files599586 -Node: Ignoring Assigns601816 -Node: Getopt Function603370 -Ref: Getopt Function-Footnote-1614673 -Node: Passwd Functions614876 -Ref: Passwd Functions-Footnote-1623854 -Node: Group Functions623942 -Node: Walking Arrays632026 -Node: Sample Programs634162 -Node: Running Examples634836 -Node: Clones635564 -Node: Cut Program636788 -Node: Egrep Program646639 -Ref: Egrep Program-Footnote-1654412 -Node: Id Program654522 -Node: Split Program658171 -Ref: Split Program-Footnote-1661690 -Node: Tee Program661818 -Node: Uniq Program664621 -Node: Wc Program672050 -Ref: Wc Program-Footnote-1676316 -Ref: Wc Program-Footnote-2676516 -Node: Miscellaneous Programs676608 -Node: Dupword Program677796 -Node: Alarm Program679827 -Node: Translate Program684634 -Ref: Translate Program-Footnote-1689021 -Ref: Translate Program-Footnote-2689269 -Node: Labels Program689403 -Ref: Labels Program-Footnote-1692774 -Node: Word Sorting692858 -Node: History Sorting696742 -Node: Extract Program698581 -Ref: Extract Program-Footnote-1706084 -Node: Simple Sed706212 -Node: Igawk Program709274 -Ref: Igawk Program-Footnote-1724431 -Ref: Igawk Program-Footnote-2724632 -Node: Anagram Program724770 -Node: Signature Program727838 -Node: Advanced Features728938 -Node: Nondecimal Data730824 -Node: Array Sorting732407 -Node: Controlling Array Traversal733104 -Node: Array Sorting Functions741388 -Ref: Array Sorting Functions-Footnote-1745257 -Node: Two-way I/O745451 -Ref: Two-way I/O-Footnote-1750883 -Node: TCP/IP Networking750965 -Node: Profiling753809 -Node: Internationalization761312 -Node: I18N and L10N762737 -Node: Explaining gettext763423 -Ref: Explaining gettext-Footnote-1768491 -Ref: Explaining gettext-Footnote-2768675 -Node: Programmer i18n768840 -Node: Translator i18n773042 -Node: String Extraction773836 -Ref: String Extraction-Footnote-1774797 -Node: Printf Ordering774883 -Ref: Printf Ordering-Footnote-1777665 -Node: I18N Portability777729 -Ref: I18N Portability-Footnote-1780178 -Node: I18N Example780241 -Ref: I18N Example-Footnote-1782879 -Node: Gawk I18N782951 -Node: Debugger783572 -Node: Debugging784543 -Node: Debugging Concepts784976 -Node: Debugging Terms786832 -Node: Awk Debugging789429 -Node: Sample Debugging Session790321 -Node: Debugger Invocation790841 -Node: Finding The Bug792174 -Node: List of Debugger Commands798661 -Node: Breakpoint Control799995 -Node: Debugger Execution Control803659 -Node: Viewing And Changing Data807019 -Node: Execution Stack810375 -Node: Debugger Info811842 -Node: Miscellaneous Debugger Commands815824 -Node: Readline Support821000 -Node: Limitations821831 -Node: Arbitrary Precision Arithmetic824083 -Ref: Arbitrary Precision Arithmetic-Footnote-1825732 -Node: General Arithmetic825880 -Node: Floating Point Issues827600 -Node: String Conversion Precision828481 -Ref: String Conversion Precision-Footnote-1830186 -Node: Unexpected Results830295 -Node: POSIX Floating Point Problems832448 -Ref: POSIX Floating Point Problems-Footnote-1836273 -Node: Integer Programming836311 -Node: Floating-point Programming838050 -Ref: Floating-point Programming-Footnote-1844381 -Ref: Floating-point Programming-Footnote-2844651 -Node: Floating-point Representation844915 -Node: Floating-point Context846080 -Ref: table-ieee-formats846919 -Node: Rounding Mode848303 -Ref: table-rounding-modes848782 -Ref: Rounding Mode-Footnote-1851797 -Node: Gawk and MPFR851976 -Node: Arbitrary Precision Floats853385 -Ref: Arbitrary Precision Floats-Footnote-1855828 -Node: Setting Precision856144 -Ref: table-predefined-precision-strings856830 -Node: Setting Rounding Mode858975 -Ref: table-gawk-rounding-modes859379 -Node: Floating-point Constants860566 -Node: Changing Precision861995 -Ref: Changing Precision-Footnote-1863392 -Node: Exact Arithmetic863566 -Node: Arbitrary Precision Integers866704 -Ref: Arbitrary Precision Integers-Footnote-1869719 -Node: Dynamic Extensions869866 -Node: Extension Intro871324 -Node: Plugin License872589 -Node: Extension Mechanism Outline873274 -Ref: load-extension873691 -Ref: load-new-function875169 -Ref: call-new-function876164 -Node: Extension API Description878179 -Node: Extension API Functions Introduction879466 -Node: General Data Types884393 -Ref: General Data Types-Footnote-1890088 -Node: Requesting Values890387 -Ref: table-value-types-returned891124 -Node: Memory Allocation Functions892078 -Ref: Memory Allocation Functions-Footnote-1894824 -Node: Constructor Functions894920 -Node: Registration Functions896678 -Node: Extension Functions897363 -Node: Exit Callback Functions899665 -Node: Extension Version String900914 -Node: Input Parsers901564 -Node: Output Wrappers911321 -Node: Two-way processors915831 -Node: Printing Messages918039 -Ref: Printing Messages-Footnote-1919116 -Node: Updating `ERRNO'919268 -Node: Accessing Parameters920007 -Node: Symbol Table Access921237 -Node: Symbol table by name921751 -Node: Symbol table by cookie923727 -Ref: Symbol table by cookie-Footnote-1927859 -Node: Cached values927922 -Ref: Cached values-Footnote-1931412 -Node: Array Manipulation931503 -Ref: Array Manipulation-Footnote-1932601 -Node: Array Data Types932640 -Ref: Array Data Types-Footnote-1935343 -Node: Array Functions935435 -Node: Flattening Arrays939271 -Node: Creating Arrays946123 -Node: Extension API Variables950848 -Node: Extension Versioning951484 -Node: Extension API Informational Variables953385 -Node: Extension API Boilerplate954471 -Node: Finding Extensions958275 -Node: Extension Example958835 -Node: Internal File Description959565 -Node: Internal File Ops963656 -Ref: Internal File Ops-Footnote-1975165 -Node: Using Internal File Ops975305 -Ref: Using Internal File Ops-Footnote-1977658 -Node: Extension Samples977924 -Node: Extension Sample File Functions979448 -Node: Extension Sample Fnmatch987933 -Node: Extension Sample Fork989702 -Node: Extension Sample Inplace990915 -Node: Extension Sample Ord992693 -Node: Extension Sample Readdir993529 -Node: Extension Sample Revout995061 -Node: Extension Sample Rev2way995654 -Node: Extension Sample Read write array996344 -Node: Extension Sample Readfile998227 -Node: Extension Sample API Tests999327 -Node: Extension Sample Time999852 -Node: gawkextlib1001216 -Node: Language History1003997 -Node: V7/SVR3.11005590 -Node: SVR41007910 -Node: POSIX1009352 -Node: BTL1010738 -Node: POSIX/GNU1011472 -Node: Feature History1017071 -Node: Common Extensions1030047 -Node: Ranges and Locales1031359 -Ref: Ranges and Locales-Footnote-11035976 -Ref: Ranges and Locales-Footnote-21036003 -Ref: Ranges and Locales-Footnote-31036237 -Node: Contributors1036458 -Node: Installation1041839 -Node: Gawk Distribution1042733 -Node: Getting1043217 -Node: Extracting1044043 -Node: Distribution contents1045735 -Node: Unix Installation1051456 -Node: Quick Installation1052073 -Node: Additional Configuration Options1054519 -Node: Configuration Philosophy1056255 -Node: Non-Unix Installation1058609 -Node: PC Installation1059067 -Node: PC Binary Installation1060366 -Node: PC Compiling1062214 -Node: PC Testing1065158 -Node: PC Using1066334 -Node: Cygwin1070502 -Node: MSYS1071311 -Node: VMS Installation1071825 -Node: VMS Compilation1072621 -Ref: VMS Compilation-Footnote-11073873 -Node: VMS Dynamic Extensions1073931 -Node: VMS Installation Details1075304 -Node: VMS Running1077555 -Node: VMS GNV1080389 -Node: VMS Old Gawk1081112 -Node: Bugs1081582 -Node: Other Versions1085500 -Node: Notes1091584 -Node: Compatibility Mode1092384 -Node: Additions1093167 -Node: Accessing The Source1094094 -Node: Adding Code1095534 -Node: New Ports1101579 -Node: Derived Files1105714 -Ref: Derived Files-Footnote-11111035 -Ref: Derived Files-Footnote-21111069 -Ref: Derived Files-Footnote-31111669 -Node: Future Extensions1111767 -Node: Implementation Limitations1112350 -Node: Extension Design1113602 -Node: Old Extension Problems1114756 -Ref: Old Extension Problems-Footnote-11116264 -Node: Extension New Mechanism Goals1116321 -Ref: Extension New Mechanism Goals-Footnote-11119686 -Node: Extension Other Design Decisions1119872 -Node: Extension Future Growth1121978 -Node: Old Extension Mechanism1122814 -Node: Basic Concepts1124554 -Node: Basic High Level1125235 -Ref: figure-general-flow1125507 -Ref: figure-process-flow1126106 -Ref: Basic High Level-Footnote-11129335 -Node: Basic Data Typing1129520 -Node: Glossary1132875 -Node: Copying1158106 -Node: GNU Free Documentation License1195662 -Node: Index1220798 +Node: DOS Quoting88093 +Node: Sample Data Files88768 +Node: Very Simple91283 +Node: Two Rules95933 +Node: More Complex97828 +Ref: More Complex-Footnote-1100760 +Node: Statements/Lines100845 +Ref: Statements/Lines-Footnote-1105300 +Node: Other Features105565 +Node: When106493 +Node: Invoking Gawk108641 +Node: Command Line110104 +Node: Options110887 +Ref: Options-Footnote-1126699 +Node: Other Arguments126724 +Node: Naming Standard Input129386 +Node: Environment Variables130480 +Node: AWKPATH Variable131038 +Ref: AWKPATH Variable-Footnote-1133816 +Ref: AWKPATH Variable-Footnote-2133861 +Node: AWKLIBPATH Variable134121 +Node: Other Environment Variables134880 +Node: Exit Status138045 +Node: Include Files138720 +Node: Loading Shared Libraries142298 +Node: Obsolete143681 +Node: Undocumented144378 +Node: Regexp144620 +Node: Regexp Usage146009 +Node: Escape Sequences148042 +Node: Regexp Operators153709 +Ref: Regexp Operators-Footnote-1161189 +Ref: Regexp Operators-Footnote-2161336 +Node: Bracket Expressions161434 +Ref: table-char-classes163324 +Node: GNU Regexp Operators165847 +Node: Case-sensitivity169570 +Ref: Case-sensitivity-Footnote-1172462 +Ref: Case-sensitivity-Footnote-2172697 +Node: Leftmost Longest172805 +Node: Computed Regexps174006 +Node: Reading Files177355 +Node: Records179357 +Ref: Records-Footnote-1188880 +Node: Fields188917 +Ref: Fields-Footnote-1191873 +Node: Nonconstant Fields191959 +Node: Changing Fields194165 +Node: Field Separators200124 +Node: Default Field Splitting202826 +Node: Regexp Field Splitting203943 +Node: Single Character Fields207284 +Node: Command Line Field Separator208343 +Node: Full Line Fields211685 +Ref: Full Line Fields-Footnote-1212193 +Node: Field Splitting Summary212239 +Ref: Field Splitting Summary-Footnote-1215338 +Node: Constant Size215439 +Node: Splitting By Content220046 +Ref: Splitting By Content-Footnote-1223795 +Node: Multiple Line223835 +Ref: Multiple Line-Footnote-1229682 +Node: Getline229861 +Node: Plain Getline232077 +Node: Getline/Variable234172 +Node: Getline/File235319 +Node: Getline/Variable/File236660 +Ref: Getline/Variable/File-Footnote-1238259 +Node: Getline/Pipe238346 +Node: Getline/Variable/Pipe241045 +Node: Getline/Coprocess242152 +Node: Getline/Variable/Coprocess243404 +Node: Getline Notes244141 +Node: Getline Summary246928 +Ref: table-getline-variants247336 +Node: Read Timeout248248 +Ref: Read Timeout-Footnote-1251987 +Node: Command line directories252045 +Node: Printing252675 +Node: Print254306 +Node: Print Examples255643 +Node: Output Separators258427 +Node: OFMT260443 +Node: Printf261801 +Node: Basic Printf262707 +Node: Control Letters264246 +Node: Format Modifiers268066 +Node: Printf Examples274075 +Node: Redirection276787 +Node: Special Files283761 +Node: Special FD284294 +Ref: Special FD-Footnote-1287919 +Node: Special Network287993 +Node: Special Caveats288843 +Node: Close Files And Pipes289639 +Ref: Close Files And Pipes-Footnote-1296622 +Ref: Close Files And Pipes-Footnote-2296770 +Node: Expressions296920 +Node: Values298052 +Node: Constants298728 +Node: Scalar Constants299408 +Ref: Scalar Constants-Footnote-1300267 +Node: Nondecimal-numbers300449 +Node: Regexp Constants303449 +Node: Using Constant Regexps303924 +Node: Variables306979 +Node: Using Variables307634 +Node: Assignment Options309358 +Node: Conversion311233 +Ref: table-locale-affects316733 +Ref: Conversion-Footnote-1317357 +Node: All Operators317466 +Node: Arithmetic Ops318096 +Node: Concatenation320601 +Ref: Concatenation-Footnote-1323389 +Node: Assignment Ops323509 +Ref: table-assign-ops328497 +Node: Increment Ops329828 +Node: Truth Values and Conditions333262 +Node: Truth Values334345 +Node: Typing and Comparison335394 +Node: Variable Typing336187 +Ref: Variable Typing-Footnote-1340084 +Node: Comparison Operators340206 +Ref: table-relational-ops340616 +Node: POSIX String Comparison344164 +Ref: POSIX String Comparison-Footnote-1345120 +Node: Boolean Ops345258 +Ref: Boolean Ops-Footnote-1349328 +Node: Conditional Exp349419 +Node: Function Calls351151 +Node: Precedence354745 +Node: Locales358414 +Node: Patterns and Actions359503 +Node: Pattern Overview360557 +Node: Regexp Patterns362226 +Node: Expression Patterns362769 +Node: Ranges366550 +Node: BEGIN/END369654 +Node: Using BEGIN/END370416 +Ref: Using BEGIN/END-Footnote-1373152 +Node: I/O And BEGIN/END373258 +Node: BEGINFILE/ENDFILE375540 +Node: Empty378454 +Node: Using Shell Variables378771 +Node: Action Overview381056 +Node: Statements383413 +Node: If Statement385267 +Node: While Statement386766 +Node: Do Statement388810 +Node: For Statement389966 +Node: Switch Statement393118 +Node: Break Statement395272 +Node: Continue Statement397262 +Node: Next Statement399055 +Node: Nextfile Statement401445 +Node: Exit Statement404100 +Node: Built-in Variables406516 +Node: User-modified407611 +Ref: User-modified-Footnote-1415969 +Node: Auto-set416031 +Ref: Auto-set-Footnote-1429098 +Ref: Auto-set-Footnote-2429303 +Node: ARGC and ARGV429359 +Node: Arrays433213 +Node: Array Basics434718 +Node: Array Intro435544 +Node: Reference to Elements439861 +Node: Assigning Elements442131 +Node: Array Example442622 +Node: Scanning an Array444354 +Node: Controlling Scanning446668 +Ref: Controlling Scanning-Footnote-1451755 +Node: Delete452071 +Ref: Delete-Footnote-1454836 +Node: Numeric Array Subscripts454893 +Node: Uninitialized Subscripts457076 +Node: Multidimensional458703 +Node: Multiscanning461796 +Node: Arrays of Arrays463385 +Node: Functions468025 +Node: Built-in468844 +Node: Calling Built-in469922 +Node: Numeric Functions471910 +Ref: Numeric Functions-Footnote-1475744 +Ref: Numeric Functions-Footnote-2476101 +Ref: Numeric Functions-Footnote-3476149 +Node: String Functions476418 +Ref: String Functions-Footnote-1499421 +Ref: String Functions-Footnote-2499550 +Ref: String Functions-Footnote-3499798 +Node: Gory Details499885 +Ref: table-sub-escapes501564 +Ref: table-sub-posix-92502918 +Ref: table-sub-proposed504269 +Ref: table-posix-sub505623 +Ref: table-gensub-escapes507168 +Ref: Gory Details-Footnote-1508344 +Ref: Gory Details-Footnote-2508395 +Node: I/O Functions508546 +Ref: I/O Functions-Footnote-1515542 +Node: Time Functions515689 +Ref: Time Functions-Footnote-1526682 +Ref: Time Functions-Footnote-2526750 +Ref: Time Functions-Footnote-3526908 +Ref: Time Functions-Footnote-4527019 +Ref: Time Functions-Footnote-5527131 +Ref: Time Functions-Footnote-6527358 +Node: Bitwise Functions527624 +Ref: table-bitwise-ops528186 +Ref: Bitwise Functions-Footnote-1532431 +Node: Type Functions532615 +Node: I18N Functions533766 +Node: User-defined535418 +Node: Definition Syntax536222 +Ref: Definition Syntax-Footnote-1541136 +Node: Function Example541205 +Ref: Function Example-Footnote-1543854 +Node: Function Caveats543876 +Node: Calling A Function544394 +Node: Variable Scope545349 +Node: Pass By Value/Reference548312 +Node: Return Statement551820 +Node: Dynamic Typing554801 +Node: Indirect Calls555732 +Node: Library Functions565419 +Ref: Library Functions-Footnote-1568932 +Ref: Library Functions-Footnote-2569075 +Node: Library Names569246 +Ref: Library Names-Footnote-1572719 +Ref: Library Names-Footnote-2572939 +Node: General Functions573025 +Node: Strtonum Function574053 +Node: Assert Function576983 +Node: Round Function580309 +Node: Cliff Random Function581850 +Node: Ordinal Functions582866 +Ref: Ordinal Functions-Footnote-1585943 +Ref: Ordinal Functions-Footnote-2586195 +Node: Join Function586406 +Ref: Join Function-Footnote-1588177 +Node: Getlocaltime Function588377 +Node: Readfile Function592118 +Node: Data File Management593957 +Node: Filetrans Function594589 +Node: Rewind Function598658 +Node: File Checking600045 +Node: Empty Files601139 +Node: Ignoring Assigns603369 +Node: Getopt Function604923 +Ref: Getopt Function-Footnote-1616226 +Node: Passwd Functions616429 +Ref: Passwd Functions-Footnote-1625407 +Node: Group Functions625495 +Node: Walking Arrays633579 +Node: Sample Programs635715 +Node: Running Examples636389 +Node: Clones637117 +Node: Cut Program638341 +Node: Egrep Program648192 +Ref: Egrep Program-Footnote-1655965 +Node: Id Program656075 +Node: Split Program659724 +Ref: Split Program-Footnote-1663243 +Node: Tee Program663371 +Node: Uniq Program666174 +Node: Wc Program673603 +Ref: Wc Program-Footnote-1677869 +Ref: Wc Program-Footnote-2678069 +Node: Miscellaneous Programs678161 +Node: Dupword Program679349 +Node: Alarm Program681380 +Node: Translate Program686187 +Ref: Translate Program-Footnote-1690574 +Ref: Translate Program-Footnote-2690822 +Node: Labels Program690956 +Ref: Labels Program-Footnote-1694327 +Node: Word Sorting694411 +Node: History Sorting698295 +Node: Extract Program700134 +Ref: Extract Program-Footnote-1707637 +Node: Simple Sed707765 +Node: Igawk Program710827 +Ref: Igawk Program-Footnote-1725998 +Ref: Igawk Program-Footnote-2726199 +Node: Anagram Program726337 +Node: Signature Program729405 +Node: Advanced Features730505 +Node: Nondecimal Data732391 +Node: Array Sorting733974 +Node: Controlling Array Traversal734671 +Node: Array Sorting Functions742955 +Ref: Array Sorting Functions-Footnote-1746824 +Node: Two-way I/O747018 +Ref: Two-way I/O-Footnote-1752450 +Node: TCP/IP Networking752532 +Node: Profiling755376 +Node: Internationalization762879 +Node: I18N and L10N764304 +Node: Explaining gettext764990 +Ref: Explaining gettext-Footnote-1770058 +Ref: Explaining gettext-Footnote-2770242 +Node: Programmer i18n770407 +Node: Translator i18n774634 +Node: String Extraction775428 +Ref: String Extraction-Footnote-1776389 +Node: Printf Ordering776475 +Ref: Printf Ordering-Footnote-1779257 +Node: I18N Portability779321 +Ref: I18N Portability-Footnote-1781770 +Node: I18N Example781833 +Ref: I18N Example-Footnote-1784471 +Node: Gawk I18N784543 +Node: Debugger785164 +Node: Debugging786135 +Node: Debugging Concepts786568 +Node: Debugging Terms788424 +Node: Awk Debugging791021 +Node: Sample Debugging Session791913 +Node: Debugger Invocation792433 +Node: Finding The Bug793766 +Node: List of Debugger Commands800253 +Node: Breakpoint Control801587 +Node: Debugger Execution Control805251 +Node: Viewing And Changing Data808611 +Node: Execution Stack811967 +Node: Debugger Info813434 +Node: Miscellaneous Debugger Commands817428 +Node: Readline Support822606 +Node: Limitations823437 +Node: Arbitrary Precision Arithmetic825689 +Ref: Arbitrary Precision Arithmetic-Footnote-1827338 +Node: General Arithmetic827486 +Node: Floating Point Issues829206 +Node: String Conversion Precision830087 +Ref: String Conversion Precision-Footnote-1831792 +Node: Unexpected Results831901 +Node: POSIX Floating Point Problems834054 +Ref: POSIX Floating Point Problems-Footnote-1837879 +Node: Integer Programming837917 +Node: Floating-point Programming839656 +Ref: Floating-point Programming-Footnote-1845987 +Ref: Floating-point Programming-Footnote-2846257 +Node: Floating-point Representation846521 +Node: Floating-point Context847686 +Ref: table-ieee-formats848525 +Node: Rounding Mode849909 +Ref: table-rounding-modes850388 +Ref: Rounding Mode-Footnote-1853403 +Node: Gawk and MPFR853582 +Node: Arbitrary Precision Floats854991 +Ref: Arbitrary Precision Floats-Footnote-1857434 +Node: Setting Precision857750 +Ref: table-predefined-precision-strings858436 +Node: Setting Rounding Mode860581 +Ref: table-gawk-rounding-modes860985 +Node: Floating-point Constants862172 +Node: Changing Precision863601 +Ref: Changing Precision-Footnote-1864998 +Node: Exact Arithmetic865172 +Node: Arbitrary Precision Integers868310 +Ref: Arbitrary Precision Integers-Footnote-1871325 +Node: Dynamic Extensions871472 +Node: Extension Intro872930 +Node: Plugin License874195 +Node: Extension Mechanism Outline874880 +Ref: load-extension875297 +Ref: load-new-function876775 +Ref: call-new-function877770 +Node: Extension API Description879785 +Node: Extension API Functions Introduction881072 +Node: General Data Types885999 +Ref: General Data Types-Footnote-1891694 +Node: Requesting Values891993 +Ref: table-value-types-returned892730 +Node: Memory Allocation Functions893684 +Ref: Memory Allocation Functions-Footnote-1896430 +Node: Constructor Functions896526 +Node: Registration Functions898284 +Node: Extension Functions898969 +Node: Exit Callback Functions901271 +Node: Extension Version String902520 +Node: Input Parsers903170 +Node: Output Wrappers912927 +Node: Two-way processors917437 +Node: Printing Messages919645 +Ref: Printing Messages-Footnote-1920722 +Node: Updating `ERRNO'920874 +Node: Accessing Parameters921613 +Node: Symbol Table Access922843 +Node: Symbol table by name923357 +Node: Symbol table by cookie925333 +Ref: Symbol table by cookie-Footnote-1929465 +Node: Cached values929528 +Ref: Cached values-Footnote-1933018 +Node: Array Manipulation933109 +Ref: Array Manipulation-Footnote-1934207 +Node: Array Data Types934246 +Ref: Array Data Types-Footnote-1936949 +Node: Array Functions937041 +Node: Flattening Arrays940877 +Node: Creating Arrays947729 +Node: Extension API Variables952454 +Node: Extension Versioning953090 +Node: Extension API Informational Variables954991 +Node: Extension API Boilerplate956077 +Node: Finding Extensions959881 +Node: Extension Example960441 +Node: Internal File Description961171 +Node: Internal File Ops965262 +Ref: Internal File Ops-Footnote-1976771 +Node: Using Internal File Ops976911 +Ref: Using Internal File Ops-Footnote-1979258 +Node: Extension Samples979524 +Node: Extension Sample File Functions981048 +Node: Extension Sample Fnmatch989535 +Node: Extension Sample Fork991304 +Node: Extension Sample Inplace992517 +Node: Extension Sample Ord994295 +Node: Extension Sample Readdir995131 +Node: Extension Sample Revout996663 +Node: Extension Sample Rev2way997256 +Node: Extension Sample Read write array997946 +Node: Extension Sample Readfile999829 +Node: Extension Sample API Tests1000929 +Node: Extension Sample Time1001454 +Node: gawkextlib1002818 +Node: Language History1005599 +Node: V7/SVR3.11007192 +Node: SVR41009512 +Node: POSIX1010954 +Node: BTL1012340 +Node: POSIX/GNU1013074 +Node: Feature History1018673 +Node: Common Extensions1031649 +Node: Ranges and Locales1032961 +Ref: Ranges and Locales-Footnote-11037578 +Ref: Ranges and Locales-Footnote-21037605 +Ref: Ranges and Locales-Footnote-31037839 +Node: Contributors1038060 +Node: Installation1043441 +Node: Gawk Distribution1044335 +Node: Getting1044819 +Node: Extracting1045645 +Node: Distribution contents1047337 +Node: Unix Installation1053058 +Node: Quick Installation1053675 +Node: Additional Configuration Options1056121 +Node: Configuration Philosophy1057857 +Node: Non-Unix Installation1060211 +Node: PC Installation1060669 +Node: PC Binary Installation1061968 +Node: PC Compiling1063816 +Node: PC Testing1066760 +Node: PC Using1067936 +Node: Cygwin1072104 +Node: MSYS1072913 +Node: VMS Installation1073427 +Node: VMS Compilation1074223 +Ref: VMS Compilation-Footnote-11075475 +Node: VMS Dynamic Extensions1075533 +Node: VMS Installation Details1076906 +Node: VMS Running1079157 +Node: VMS GNV1081991 +Node: VMS Old Gawk1082714 +Node: Bugs1083184 +Node: Other Versions1087102 +Node: Notes1093186 +Node: Compatibility Mode1093986 +Node: Additions1094769 +Node: Accessing The Source1095696 +Node: Adding Code1097136 +Node: New Ports1103181 +Node: Derived Files1107316 +Ref: Derived Files-Footnote-11112637 +Ref: Derived Files-Footnote-21112671 +Ref: Derived Files-Footnote-31113271 +Node: Future Extensions1113369 +Node: Implementation Limitations1113952 +Node: Extension Design1115204 +Node: Old Extension Problems1116358 +Ref: Old Extension Problems-Footnote-11117866 +Node: Extension New Mechanism Goals1117923 +Ref: Extension New Mechanism Goals-Footnote-11121288 +Node: Extension Other Design Decisions1121474 +Node: Extension Future Growth1123580 +Node: Old Extension Mechanism1124416 +Node: Basic Concepts1126156 +Node: Basic High Level1126837 +Ref: figure-general-flow1127109 +Ref: figure-process-flow1127708 +Ref: Basic High Level-Footnote-11130937 +Node: Basic Data Typing1131122 +Node: Glossary1134477 +Node: Copying1159708 +Node: GNU Free Documentation License1197264 +Node: Index1222400  End Tag Table -- cgit v1.2.3 From 2535d8a18e8c0d328fe6d1d8ae015320eeec6b5d Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 30 Apr 2014 06:06:06 +0300 Subject: Editing progress through chapter 5. --- doc/gawk.info | 1344 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 696 insertions(+), 648 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 1d5f496d..57fdc3d4 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -651,15 +651,15 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Basic High Level:: The high level view. * Basic Data Typing:: A very quick intro to data types. - To Miriam, for making me complete. + To my parents, for their love, and for the wonderful example they +set for me. - To Chana, for the joy you bring us. + To my wife Miriam, for making me complete. Thank you for building +your life together with me. - To Rivka, for the exponential increase. + To our children Chana, Rivka, Nachum and Malka, for enrichening our +lives in innumerable ways. - To Nachum, for the added dimension. - - To Malka, for the new beginning.  File: gawk.info, Node: Foreword, Next: Preface, Prev: Top, Up: Top @@ -3939,8 +3939,19 @@ started. Another built-in variable, `NR', records the total number of input records read so far from all data files. It starts at zero, but is never automatically reset to zero. - Records are separated by a character called the "record separator". -By default, the record separator is the newline character. This is why +* Menu: + +* awk split records:: How standard `awk' splits records. +* gawk split records:: How `gawk' splits records. + + +File: gawk.info, Node: awk split records, Next: gawk split records, Up: Records + +4.1.1 Record Splitting With Standard `awk' +------------------------------------------ + +Records are separated by a character called the "record separator". By +default, the record separator is the newline character. This is why records are, by default, single lines. A different character can be used for the record separator by assigning the character to the built-in variable `RS'. @@ -4060,16 +4071,22 @@ affected. After the end of the record has been determined, `gawk' sets the variable `RT' to the text in the input that matched `RS'. - When using `gawk', the value of `RS' is not limited to a -one-character string. It can be any regular expression (*note -Regexp::). (c.e.) In general, each record ends at the next string that -matches the regular expression; the next record starts at the end of -the matching string. This general rule is actually at work in the -usual case, where `RS' contains just a newline: a record ends at the -beginning of the next matching string (the next newline in the input), -and the following record starts just after the end of this string (at -the first character of the following line). The newline, because it -matches `RS', is not part of either record. + +File: gawk.info, Node: gawk split records, Prev: awk split records, Up: Records + +4.1.2 Record Splitting With `gawk' +---------------------------------- + +When using `gawk', the value of `RS' is not limited to a one-character +string. It can be any regular expression (*note Regexp::). (c.e.) In +general, each record ends at the next string that matches the regular +expression; the next record starts at the end of the matching string. +This general rule is actually at work in the usual case, where `RS' +contains just a newline: a record ends at the beginning of the next +matching string (the next newline in the input), and the following +record starts just after the end of this string (at the first character +of the following line). The newline, because it matches `RS', is not +part of either record. When `RS' is a single character, `RT' contains the same single character. However, when `RS' is a regular expression, `RT' contains @@ -4132,8 +4149,10 @@ use for `RS' in this case: BEGIN { RS = "\0" } # whole file becomes one record? `gawk' in fact accepts this, and uses the NUL character for the -record separator. However, this usage is _not_ portable to most other -`awk' implementations. +record separator. This works for certain special files, such as +`/proc/environ' on GNU/Linux systems, where the NUL character is in +fact the record separator. However, this usage is _not_ portable to +most other `awk' implementations. Almost all other `awk' implementations(1) store strings internally as C-style strings. C strings use the NUL character as the string @@ -4144,10 +4163,9 @@ terminator. In effect, this means that `RS = "\0"' is the same as `RS as a record separator. However, this is a special case: `mawk' does not allow embedded NUL characters in strings. - The best way to treat a whole file as a single record is to simply -read the file in, one record at a time, concatenating each record onto -the end of the previous ones. - + *Note Readfile Function::, for an interesting, portable way to read +whole files. If you are using `gawk', see *note Extension Sample +Readfile::, for another option. ---------- Footnotes ---------- @@ -4172,7 +4190,7 @@ to these pieces of the record. You don't have to use them--you can operate on the whole record if you want--but fields are what make simple `awk' programs so powerful. - A dollar-sign (`$') is used to refer to a field in an `awk' program, + You use a dollar-sign (`$') to refer to a field in an `awk' program, followed by the number of the field you want. Thus, `$1' refers to the first field, `$2' to the second, and so on. (Unlike the Unix shells, the field numbers are not limited to single digits. `$127' is the one @@ -4195,8 +4213,9 @@ the last one (such as `$8' when the record has only seven fields), you get the empty string. (If used in a numeric operation, you get zero.) The use of `$0', which looks like a reference to the "zero-th" -field, is a special case: it represents the whole input record when you -are not interested in specific fields. Here are some more examples: +field, is a special case: it represents the whole input record. Use it +when you are not interested in specific fields. Here are some more +examples: $ awk '$1 ~ /li/ { print $0 }' mail-list -| Amelia 555-5553 amelia.zodiacusque@gmail.com F @@ -4228,11 +4247,11 @@ File: gawk.info, Node: Nonconstant Fields, Next: Changing Fields, Prev: Field 4.3 Nonconstant Field Numbers ============================= -The number of a field does not need to be a constant. Any expression in -the `awk' language can be used after a `$' to refer to a field. The -value of the expression specifies the field number. If the value is a -string, rather than a number, it is converted to a number. Consider -this example: +A field number need not be a constant. Any expression in the `awk' +language can be used after a `$' to refer to a field. The value of the +expression specifies the field number. If the value is a string, +rather than a number, it is converted to a number. Consider this +example: awk '{ print $NR }' @@ -4249,7 +4268,7 @@ another example of using expressions as field numbers: number of the field to print. The `*' sign represents multiplication, so the expression `2*2' evaluates to four. The parentheses are used so that the multiplication is done before the `$' operation; they are -necessary whenever there is a binary operator in the field-number +necessary whenever there is a binary operator(1) in the field-number expression. This example, then, prints the type of relationship (the fourth field) for every line of the file `mail-list'. (All of the `awk' operators are listed, in order of decreasing precedence, in *note @@ -4268,6 +4287,12 @@ Variables::). The expression `$NF' is not a special feature--it is the direct consequence of evaluating `NF' and using its value as a field number. + ---------- Footnotes ---------- + + (1) A "binary operator", such as `*' for multiplication, is one that +takes two operands. The distinction is required, since `awk' also has +unary (one-operand) and ternary (three-operand) operators. +  File: gawk.info, Node: Changing Fields, Next: Field Separators, Prev: Nonconstant Fields, Up: Reading Files @@ -4293,11 +4318,11 @@ three minus ten: `$3 - 10'. (*Note Arithmetic Ops::.) Then it prints the original and new values for field three. (Someone in the warehouse made a consistent mistake while inventorying the red boxes.) - For this to work, the text in field `$3' must make sense as a -number; the string of characters must be converted to a number for the -computer to do arithmetic on it. The number resulting from the -subtraction is converted back to a string of characters that then -becomes field three. *Note Conversion::. + For this to work, the text in `$3' must make sense as a number; the +string of characters must be converted to a number for the computer to +do arithmetic on it. The number resulting from the subtraction is +converted back to a string of characters that then becomes field three. +*Note Conversion::. When the value of a field is changed (as perceived by `awk'), the text of the input record is recalculated to contain the new field where @@ -4362,7 +4387,7 @@ even when you assign the empty string to a field. For example: -| a::c:d -| 4 -The field is still there; it just has an empty value, denoted by the +The field is still there; it just has an empty value, delimited by the two colons between `a' and `c'. This example shows what happens if you create a new field: @@ -4987,7 +5012,7 @@ affects field splitting with `FPAT'. deal with this. Since there is no formal specification for CSV data, there isn't much more to be done; the `FPAT' mechanism provides an elegant solution for the majority of cases, and the - `gawk' maintainer is satisfied with that. + `gawk' developers are satisfied with that. As written, the regexp used for `FPAT' requires that each field have a least one character. A straightforward modification (changing @@ -5037,8 +5062,8 @@ doesn't start until the first nonblank line that follows--no matter how many blank lines appear in a row, they are considered one record separator. - There is an important difference between `RS = ""' and `RS = -"\n\n+"'. In the first case, leading newlines in the input data file + However, there is an important difference between `RS = ""' and `RS += "\n\n+"'. In the first case, leading newlines in the input data file are ignored, and if a file ends without extra blank lines after the last record, the final newline is removed from the record. In the second case, this special processing is not done. (d.c.) @@ -5310,9 +5335,9 @@ are changed, resulting in a new value of `NF'. `RT' is also set. According to POSIX, `getline < EXPRESSION' is ambiguous if EXPRESSION contains unparenthesized operators other than `$'; for example, `getline < dir "/" file' is ambiguous because the -concatenation operator is not parenthesized. You should write it as -`getline < (dir "/" file)' if you want your program to be portable to -all `awk' implementations. +concatenation operator (not discussed yet; *note Concatenation::) is +not parenthesized. You should write it as `getline < (dir "/" file)' if +you want your program to be portable to all `awk' implementations.  File: gawk.info, Node: Getline/Variable/File, Next: Getline/Pipe, Prev: Getline/File, Up: Getline @@ -5517,10 +5542,10 @@ in mind: testing the new record against every pattern. However, the new record is tested against any subsequent rules. - * Many `awk' implementations limit the number of pipelines that an - `awk' program may have open to just one. In `gawk', there is no - such limit. You can open as many pipelines (and coprocesses) as - the underlying operating system permits. + * Some very old `awk' implementations limit the number of pipelines + that an `awk' program may have open to just one. In `gawk', there + is no such limit. You can open as many pipelines (and + coprocesses) as the underlying operating system permits. * An interesting side effect occurs if you use `getline' without a redirection inside a `BEGIN' rule. Because an unredirected @@ -5559,9 +5584,9 @@ in mind: file is encountered, before the element in `a' is assigned? `gawk' treats `getline' like a function call, and evaluates the - expression `a[++c]' before attempting to read from `f'. Other - versions of `awk' only evaluate the expression once they know that - there is a string value to be assigned. Caveat Emptor. + expression `a[++c]' before attempting to read from `f'. However, + some versions of `awk' only evaluate the expression once they know + that there is a string value to be assigned. Caveat Emptor.  File: gawk.info, Node: Getline Summary, Prev: Getline Notes, Up: Getline @@ -5597,10 +5622,12 @@ File: gawk.info, Node: Read Timeout, Next: Command line directories, Prev: Ge 4.10 Reading Input With A Timeout ================================= -You may specify a timeout in milliseconds for reading input from the -keyboard, pipe or two-way communication including, TCP/IP sockets. This -can be done on a per input, command or connection basis, by setting a -special element in the `PROCINFO' array: +This minor node describes a feature that is specific to `gawk'. + + You may specify a timeout in milliseconds for reading input from the +keyboard, a pipe, or two-way communication, including TCP/IP sockets. +This can be done on a per input, command or connection basis, by +setting a special element in the `PROCINFO' (*note Auto-set::) array: PROCINFO["input_name", "READ_TIMEOUT"] = TIMEOUT IN MILLISECONDS @@ -5623,10 +5650,10 @@ for more than five seconds: while ((getline < "/dev/stdin") > 0) print $0 - `gawk' will terminate the read operation if input does not arrive -after waiting for the timeout period, return failure and set the -`ERRNO' variable to an appropriate string value. A negative or zero -value for the timeout is the same as specifying no timeout at all. + `gawk' terminates the read operation if input does not arrive after +waiting for the timeout period, returns failure and sets the `ERRNO' +variable to an appropriate string value. A negative or zero value for +the timeout is the same as specifying no timeout at all. A timeout can also be set for reading from the keyboard in the implicit loop that reads input records and matches them against @@ -5690,14 +5717,21 @@ File: gawk.info, Node: Command line directories, Prev: Read Timeout, Up: Read ==================================== According to the POSIX standard, files named on the `awk' command line -must be text files. It is a fatal error if they are not. Most -versions of `awk' treat a directory on the command line as a fatal -error. +must be text files; it is a fatal error if they are not. Most versions +of `awk' treat a directory on the command line as a fatal error. By default, `gawk' produces a warning for a directory on the command -line, but otherwise ignores it. If either of the `--posix' or -`--traditional' options is given, then `gawk' reverts to treating a -directory on the command line as a fatal error. +line, but otherwise ignores it. This makes it easier to use shell +wildcards with your `awk' program: + + $ gawk -f whizprog.awk * Directories could kill this progam + + If either of the `--posix' or `--traditional' options is given, then +`gawk' reverts to treating a directory on the command line as a fatal +error. + + *Note Extension Sample Readdir::, for a way to treat directories as +usable data from an `awk' program.  File: gawk.info, Node: Printing, Next: Expressions, Prev: Reading Files, Up: Top @@ -5741,9 +5775,9 @@ File: gawk.info, Node: Print, Next: Print Examples, Up: Printing ========================= The `print' statement is used for producing output with simple, -standardized formatting. Specify only the strings or numbers to print, -in a list separated by commas. They are output, separated by single -spaces, followed by a newline. The statement looks like this: +standardized formatting. You specify only the strings or numbers to +print, in a list separated by commas. They are output, separated by +single spaces, followed by a newline. The statement looks like this: print ITEM1, ITEM2, ... @@ -5810,8 +5844,8 @@ Here is the same program, without the comma: To someone unfamiliar with the `inventory-shipped' file, neither example's output makes much sense. A heading line at the beginning would make it clearer. Let's add some headings to our table of months -(`$1') and green crates shipped (`$2'). We do this using the `BEGIN' -pattern (*note BEGIN/END::) so that the headings are only printed once: +(`$1') and green crates shipped (`$2'). We do this using a `BEGIN' +rule (*note BEGIN/END::) so that the headings are only printed once: awk 'BEGIN { print "Month Crates" print "----- ------" } @@ -6050,7 +6084,8 @@ width. Here is a list of the format-control letters: On systems supporting IEEE 754 floating point format, values representing negative infinity are formatted as `-inf' or `-infinity', and positive infinity as `inf' and `infinity'. The - special "not a number" value formats as `-nan' or `nan'. + special "not a number" value formats as `-nan' or `nan' (*note + General Arithmetic::). `%F' Like `%f' but the infinity and "not a number" values are spelled @@ -6250,11 +6285,12 @@ string, like so: This is not particularly easy to read but it does work. - C programmers may be used to supplying additional `l', `L', and `h' -modifiers in `printf' format strings. These are not valid in `awk'. -Most `awk' implementations silently ignore them. If `--lint' is -provided on the command line (*note Options::), `gawk' warns about -their use. If `--posix' is supplied, their use is a fatal error. + C programmers may be used to supplying additional modifiers (`h', +`j', `l', `L', `t', and `z') in `printf' format strings. These are not +valid in `awk'. Most `awk' implementations silently ignore them. If +`--lint' is provided on the command line (*note Options::), `gawk' +warns about their use. If `--posix' is supplied, their use is a fatal +error.  File: gawk.info, Node: Printf Examples, Prev: Format Modifiers, Up: Printf @@ -6295,7 +6331,7 @@ they are last on their lines. They don't need to have spaces after them. The table could be made to look even nicer by adding headings to the -tops of the columns. This is done using the `BEGIN' pattern (*note +tops of the columns. This is done using a `BEGIN' rule (*note BEGIN/END::) so that the headers are only printed once, at the beginning of the `awk' program: @@ -6346,7 +6382,7 @@ commands, except that they are written inside the `awk' program. There are four forms of output redirection: output to a file, output appended to a file, output through a pipe to another command, and output -to a coprocess. They are all shown for the `print' statement, but they +to a coprocess. We show them all for the `print' statement, but they work identically for `printf': `print ITEMS > OUTPUT-FILE' @@ -6427,7 +6463,7 @@ work identically for `printf': FILE or COMMAND--it is not necessary to always use a string constant. Using a variable is generally a good idea, because (if you mean to refer to that same file or command) `awk' requires - that the string value be spelled identically every time. + that the string value be written identically every time. `print ITEMS |& COMMAND' This redirection prints the items to the input of COMMAND. The @@ -6539,7 +6575,7 @@ run from a background job, it may not have a terminal at all. Then opening `/dev/tty' fails. `gawk' provides special file names for accessing the three standard -streams. (c.e.). It also provides syntax for accessing any other +streams. (c.e.) It also provides syntax for accessing any other inherited open files. If the file name matches one of these special names when `gawk' redirects input or output, then it directly uses the stream that the file name stands for. These special file names work @@ -6732,14 +6768,15 @@ end-of-file return status from `getline'), the child process is not terminated;(1) more importantly, the file descriptor for the pipe is not closed and released until `close()' is called or `awk' exits. - `close()' will silently do nothing if given an argument that does -not represent a file, pipe or coprocess that was opened with a -redirection. + `close()' silently does nothing if given an argument that does not +represent a file, pipe or coprocess that was opened with a redirection. +In such a case, it returns a negative value, indicating an error. In +addition, `gawk' sets `ERRNO' to a string indicating the error. Note also that `close(FILENAME)' has no "magic" effects on the implicit loop that reads through the files named on the command line. -It is, more likely, a close of a file that was never opened, so `awk' -silently does nothing. +It is, more likely, a close of a file that was never opened with a +redirection, so `awk' silently does nothing. When using the `|&' operator to communicate with a coprocess, it is occasionally useful to be able to close one end of the two-way pipe @@ -6753,9 +6790,9 @@ I/O::, which discusses it in more detail and gives an example. Using `close()''s Return Value - In many versions of Unix `awk', the `close()' function is actually a -statement. It is a syntax error to try and use the return value from -`close()': (d.c.) + In many older versions of Unix `awk', the `close()' function is +actually a statement. It is a syntax error to try and use the return +value from `close()': (d.c.) command = "..." command | getline info @@ -30772,7 +30809,7 @@ Index * close() function, portability: Close Files And Pipes. (line 81) * close() function, return value: Close Files And Pipes. - (line 130) + (line 131) * close() function, two-way pipes and: Two-way I/O. (line 77) * Close, Diane <1>: Contributors. (line 20) * Close, Diane: Manual History. (line 41) @@ -30817,7 +30854,7 @@ Index * common extensions, func keyword: Definition Syntax. (line 83) * common extensions, length() applied to an array: String Functions. (line 194) -* common extensions, RS as a regexp: Records. (line 135) +* common extensions, RS as a regexp: gawk split records. (line 6) * common extensions, single character fields: Single Character Fields. (line 6) * comp.lang.awk newsgroup: Bugs. (line 38) @@ -30918,7 +30955,7 @@ Index (line 43) * dark corner, break statement: Break Statement. (line 51) * dark corner, close() function: Close Files And Pipes. - (line 130) + (line 131) * dark corner, command-line arguments: Assignment Options. (line 43) * dark corner, continue statement: Continue Statement. (line 43) * dark corner, CONVFMT variable: Conversion. (line 40) @@ -30934,7 +30971,7 @@ Index * dark corner, format-control characters: Control Letters. (line 18) * dark corner, FS as null string: Single Character Fields. (line 20) -* dark corner, input files: Records. (line 118) +* dark corner, input files: awk split records. (line 110) * dark corner, invoking awk: Command Line. (line 16) * dark corner, length() function: String Functions. (line 180) * dark corner, locale's decimal point character: Conversion. (line 77) @@ -30948,7 +30985,7 @@ Index * dark corner, regexp constants, as arguments to user-defined functions: Using Constant Regexps. (line 43) * dark corner, split() function: String Functions. (line 359) -* dark corner, strings, storing: Records. (line 210) +* dark corner, strings, storing: gawk split records. (line 83) * dark corner, value of ARGV[0]: Auto-set. (line 35) * data, fixed-width: Constant Size. (line 10) * data-driven languages: Basic High Level. (line 85) @@ -31143,19 +31180,23 @@ Index * differences in awk and gawk, print/printf statements: Format Modifiers. (line 13) * differences in awk and gawk, PROCINFO array: Auto-set. (line 133) -* differences in awk and gawk, record separators: Records. (line 132) +* differences in awk and gawk, read timeouts: Read Timeout. (line 6) +* differences in awk and gawk, record separators: awk split records. + (line 124) * differences in awk and gawk, regexp constants: Using Constant Regexps. (line 43) * differences in awk and gawk, regular expressions: Case-sensitivity. (line 26) -* differences in awk and gawk, RS/RT variables: Records. (line 187) +* differences in awk and gawk, RS/RT variables: gawk split records. + (line 58) * differences in awk and gawk, RT variable: Auto-set. (line 266) * differences in awk and gawk, single-character fields: Single Character Fields. (line 6) * differences in awk and gawk, split() function: String Functions. (line 347) * differences in awk and gawk, strings: Scalar Constants. (line 20) -* differences in awk and gawk, strings, storing: Records. (line 206) +* differences in awk and gawk, strings, storing: gawk split records. + (line 77) * differences in awk and gawk, SYMTAB variable: Auto-set. (line 274) * differences in awk and gawk, TEXTDOMAIN variable: User-modified. (line 162) @@ -31214,7 +31255,7 @@ Index * empty array elements: Reference to Elements. (line 18) * empty pattern: Empty. (line 6) -* empty strings: Records. (line 122) +* empty strings: awk split records. (line 114) * empty strings, See null strings: Regexp Field Splitting. (line 43) * enable breakpoint: Breakpoint Control. (line 73) @@ -31256,7 +31297,7 @@ Index * ERRNO variable: Auto-set. (line 73) * ERRNO variable, with BEGINFILE pattern: BEGINFILE/ENDFILE. (line 26) * ERRNO variable, with close() function: Close Files And Pipes. - (line 138) + (line 139) * ERRNO variable, with getline command: Getline. (line 19) * error handling: Special FD. (line 16) * error handling, ERRNO variable and: Auto-set. (line 73) @@ -31335,7 +31376,7 @@ Index * extensions, common, func keyword: Definition Syntax. (line 83) * extensions, common, length() applied to an array: String Functions. (line 194) -* extensions, common, RS as a regexp: Records. (line 135) +* extensions, common, RS as a regexp: gawk split records. (line 6) * extensions, common, single character fields: Single Character Fields. (line 6) * extensions, in gawk, not in POSIX awk: POSIX/GNU. (line 6) @@ -31349,7 +31390,6 @@ Index * FDL (Free Documentation License): GNU Free Documentation License. (line 7) * features, adding to gawk: Adding Code. (line 6) -* features, advanced, See advanced features: Obsolete. (line 6) * features, deprecated: Obsolete. (line 6) * features, undocumented: Undocumented. (line 6) * Fenlason, Jay <1>: Contributors. (line 18) @@ -31589,7 +31629,7 @@ Index * gawk, ERRNO variable in <2>: Auto-set. (line 73) * gawk, ERRNO variable in <3>: BEGINFILE/ENDFILE. (line 26) * gawk, ERRNO variable in <4>: Close Files And Pipes. - (line 138) + (line 139) * gawk, ERRNO variable in: Getline. (line 19) * gawk, escape sequences: Escape Sequences. (line 124) * gawk, extensions, disabling: Options. (line 254) @@ -31644,7 +31684,7 @@ Index * gawk, regular expressions, precedence: Regexp Operators. (line 162) * gawk, RT variable in <1>: Auto-set. (line 266) * gawk, RT variable in <2>: Multiple Line. (line 129) -* gawk, RT variable in: Records. (line 132) +* gawk, RT variable in: awk split records. (line 124) * gawk, See Also awk: Preface. (line 36) * gawk, source code, obtaining: Getting. (line 6) * gawk, splitting fields and: Constant Size. (line 88) @@ -32047,6 +32087,7 @@ Index * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) * monetary information, localization: Explaining gettext. (line 103) +* Moore, Duncan: Getline Notes. (line 40) * MPFR: Gawk and MPFR. (line 6) * msgfmt utility: I18N Example. (line 62) * multiple precision: Arbitrary Precision Arithmetic. @@ -32071,7 +32112,7 @@ Index * newlines: Statements/Lines. (line 6) * newlines, as field separators: Default Field Splitting. (line 6) -* newlines, as record separators: Records. (line 20) +* newlines, as record separators: awk split records. (line 12) * newlines, in dynamic regexps: Computed Regexps. (line 59) * newlines, in regexp constants: Computed Regexps. (line 69) * newlines, printing: Print Examples. (line 12) @@ -32112,7 +32153,7 @@ Index * null strings <2>: Truth Values. (line 6) * null strings <3>: Regexp Field Splitting. (line 43) -* null strings: Records. (line 122) +* null strings: awk split records. (line 114) * null strings in gawk arguments, quoting and: Quoting. (line 79) * null strings, and deleting array elements: Delete. (line 27) * null strings, as array subscripts: Uninitialized Subscripts. @@ -32274,7 +32315,8 @@ Index (line 112) * portability, close() function and: Close Files And Pipes. (line 81) -* portability, data files as single record: Records. (line 194) +* portability, data files as single record: gawk split records. + (line 65) * portability, deleting array elements: Delete. (line 56) * portability, example programs: Library Functions. (line 42) * portability, functions, defining: Definition Syntax. (line 99) @@ -32473,17 +32515,18 @@ Index * reading input files: Reading Files. (line 6) * recipe for a programming language: History. (line 6) * record separators <1>: User-modified. (line 143) -* record separators: Records. (line 14) -* record separators, changing: Records. (line 93) -* record separators, regular expressions as: Records. (line 132) +* record separators: awk split records. (line 6) +* record separators, changing: awk split records. (line 85) +* record separators, regular expressions as: awk split records. + (line 124) * record separators, with multiline records: Multiple Line. (line 10) * records <1>: Basic High Level. (line 73) * records: Reading Files. (line 14) * records, multiline: Multiple Line. (line 6) * records, printing: Print. (line 22) * records, splitting input into: Records. (line 6) -* records, terminating: Records. (line 132) -* records, treating files as: Records. (line 219) +* records, terminating: awk split records. (line 124) +* records, treating files as: gawk split records. (line 92) * recursive functions: Definition Syntax. (line 73) * redirect gawk output, in debugger: Debugger Info. (line 72) * redirection of input: Getline/File. (line 6) @@ -32510,7 +32553,8 @@ Index (line 6) * regular expressions, as patterns <1>: Regexp Patterns. (line 6) * regular expressions, as patterns: Regexp Usage. (line 6) -* regular expressions, as record separators: Records. (line 132) +* regular expressions, as record separators: awk split records. + (line 124) * regular expressions, case sensitivity <1>: User-modified. (line 82) * regular expressions, case sensitivity: Case-sensitivity. (line 6) * regular expressions, computed: Computed Regexps. (line 6) @@ -32542,7 +32586,7 @@ Index (line 54) * return statement, user-defined functions: Return Statement. (line 6) * return value, close() function: Close Files And Pipes. - (line 130) + (line 131) * rev() user-defined function: Function Example. (line 53) * revoutput extension: Extension Sample Revout. (line 11) @@ -32587,14 +32631,14 @@ Index (line 6) * ROUNDMODE variable: User-modified. (line 138) * RS variable <1>: User-modified. (line 143) -* RS variable: Records. (line 20) +* RS variable: awk split records. (line 12) * RS variable, multiline records and: Multiple Line. (line 17) * rshift: Bitwise Functions. (line 52) * RSTART variable: Auto-set. (line 259) * RSTART variable, match() function and: String Functions. (line 221) * RT variable <1>: Auto-set. (line 266) * RT variable <2>: Multiple Line. (line 129) -* RT variable: Records. (line 132) +* RT variable: awk split records. (line 124) * Rubin, Paul <1>: Contributors. (line 15) * Rubin, Paul: History. (line 30) * rule, definition of: Getting Started. (line 21) @@ -32644,8 +32688,9 @@ Index * separators, field, FPAT variable and: User-modified. (line 45) * separators, field, POSIX and: Fields. (line 6) * separators, for records <1>: User-modified. (line 143) -* separators, for records: Records. (line 14) -* separators, for records, regular expressions as: Records. (line 132) +* separators, for records: awk split records. (line 6) +* separators, for records, regular expressions as: awk split records. + (line 124) * separators, for statements in actions: Action Overview. (line 19) * separators, subscript: User-modified. (line 156) * set breakpoint: Breakpoint Control. (line 11) @@ -32712,7 +32757,7 @@ Index * sidebar, Piping into sh: Redirection. (line 140) * sidebar, Portability Issues with #!: Executable Scripts. (line 31) * sidebar, Recipe For A Programming Language: History. (line 6) -* sidebar, RS = "\0" Is Not Portable: Records. (line 192) +* sidebar, RS = "\0" Is Not Portable: gawk split records. (line 63) * sidebar, So Why Does gawk have BEGINFILE and ENDFILE?: Filetrans Function. (line 83) * sidebar, Syntactic Ambiguities Between /= and Regular Expressions: Assignment Ops. @@ -32721,7 +32766,7 @@ Index * sidebar, Using \n in Bracket Expressions of Dynamic Regexps: Computed Regexps. (line 57) * sidebar, Using close()'s Return Value: Close Files And Pipes. - (line 128) + (line 129) * SIGHUP signal, for dynamic profiling: Profiling. (line 211) * SIGINT signal (MS-Windows): Profiling. (line 214) * signals, HUP/SIGHUP, for profiling: Profiling. (line 211) @@ -32829,7 +32874,7 @@ Index * strings, converting: Conversion. (line 6) * strings, converting letter case: String Functions. (line 520) * strings, converting, numbers to: User-modified. (line 28) -* strings, empty, See null strings: Records. (line 122) +* strings, empty, See null strings: awk split records. (line 114) * strings, extracting: String Extraction. (line 6) * strings, for localization: Programmer i18n. (line 14) * strings, length limitations: Scalar Constants. (line 20) @@ -32875,7 +32920,7 @@ Index * tee utility: Tee Program. (line 6) * tee.awk program: Tee Program. (line 26) * temporary breakpoint: Breakpoint Control. (line 90) -* terminating records: Records. (line 132) +* terminating records: awk split records. (line 124) * testbits.awk program: Bitwise Functions. (line 70) * testext extension: Extension Sample API Tests. (line 6) @@ -32923,7 +32968,7 @@ Index * traceback, display in debugger: Execution Stack. (line 13) * translate string: I18N Functions. (line 22) * translate.awk program: Translate Program. (line 55) -* treating files, as single records: Records. (line 219) +* treating files, as single records: gawk split records. (line 92) * troubleshooting, --non-decimal-data option: Options. (line 211) * troubleshooting, == operator: Comparison Operators. (line 37) @@ -32988,7 +33033,7 @@ Index * Unix awk, backslashes in escape sequences: Escape Sequences. (line 124) * Unix awk, close() function and: Close Files And Pipes. - (line 130) + (line 131) * Unix awk, password files, field separators and: Command Line Field Separator. (line 64) * Unix, awk scripts and: Executable Scripts. (line 6) @@ -33116,7 +33161,7 @@ Index * | (vertical bar), |& operator (I/O) <3>: Redirection. (line 102) * | (vertical bar), |& operator (I/O): Getline/Coprocess. (line 6) * | (vertical bar), |& operator (I/O), pipes, closing: Close Files And Pipes. - (line 118) + (line 119) * | (vertical bar), || operator <1>: Precedence. (line 89) * | (vertical bar), || operator: Boolean Ops. (line 57) * ~ (tilde), ~ operator <1>: Expression Patterns. (line 24) @@ -33132,529 +33177,532 @@ Index  Tag Table: Node: Top1292 -Node: Foreword40825 -Node: Preface45170 -Ref: Preface-Footnote-148303 -Ref: Preface-Footnote-248410 -Node: History48642 -Node: Names51016 -Ref: Names-Footnote-152480 -Node: This Manual52553 -Ref: This Manual-Footnote-158327 -Node: Conventions58427 -Node: Manual History60583 -Ref: Manual History-Footnote-164013 -Ref: Manual History-Footnote-264054 -Node: How To Contribute64128 -Node: Acknowledgments65367 -Node: Getting Started69561 -Node: Running gawk71940 -Node: One-shot73130 -Node: Read Terminal74355 -Ref: Read Terminal-Footnote-176005 -Ref: Read Terminal-Footnote-276281 -Node: Long76452 -Node: Executable Scripts77828 -Ref: Executable Scripts-Footnote-179661 -Ref: Executable Scripts-Footnote-279763 -Node: Comments80310 -Node: Quoting82777 -Node: DOS Quoting88093 -Node: Sample Data Files88768 -Node: Very Simple91283 -Node: Two Rules95933 -Node: More Complex97828 -Ref: More Complex-Footnote-1100760 -Node: Statements/Lines100845 -Ref: Statements/Lines-Footnote-1105300 -Node: Other Features105565 -Node: When106493 -Node: Invoking Gawk108641 -Node: Command Line110104 -Node: Options110887 -Ref: Options-Footnote-1126699 -Node: Other Arguments126724 -Node: Naming Standard Input129386 -Node: Environment Variables130480 -Node: AWKPATH Variable131038 -Ref: AWKPATH Variable-Footnote-1133816 -Ref: AWKPATH Variable-Footnote-2133861 -Node: AWKLIBPATH Variable134121 -Node: Other Environment Variables134880 -Node: Exit Status138045 -Node: Include Files138720 -Node: Loading Shared Libraries142298 -Node: Obsolete143681 -Node: Undocumented144378 -Node: Regexp144620 -Node: Regexp Usage146009 -Node: Escape Sequences148042 -Node: Regexp Operators153709 -Ref: Regexp Operators-Footnote-1161189 -Ref: Regexp Operators-Footnote-2161336 -Node: Bracket Expressions161434 -Ref: table-char-classes163324 -Node: GNU Regexp Operators165847 -Node: Case-sensitivity169570 -Ref: Case-sensitivity-Footnote-1172462 -Ref: Case-sensitivity-Footnote-2172697 -Node: Leftmost Longest172805 -Node: Computed Regexps174006 -Node: Reading Files177355 -Node: Records179357 -Ref: Records-Footnote-1188880 -Node: Fields188917 -Ref: Fields-Footnote-1191873 -Node: Nonconstant Fields191959 -Node: Changing Fields194165 -Node: Field Separators200124 -Node: Default Field Splitting202826 -Node: Regexp Field Splitting203943 -Node: Single Character Fields207284 -Node: Command Line Field Separator208343 -Node: Full Line Fields211685 -Ref: Full Line Fields-Footnote-1212193 -Node: Field Splitting Summary212239 -Ref: Field Splitting Summary-Footnote-1215338 -Node: Constant Size215439 -Node: Splitting By Content220046 -Ref: Splitting By Content-Footnote-1223795 -Node: Multiple Line223835 -Ref: Multiple Line-Footnote-1229682 -Node: Getline229861 -Node: Plain Getline232077 -Node: Getline/Variable234172 -Node: Getline/File235319 -Node: Getline/Variable/File236660 -Ref: Getline/Variable/File-Footnote-1238259 -Node: Getline/Pipe238346 -Node: Getline/Variable/Pipe241045 -Node: Getline/Coprocess242152 -Node: Getline/Variable/Coprocess243404 -Node: Getline Notes244141 -Node: Getline Summary246928 -Ref: table-getline-variants247336 -Node: Read Timeout248248 -Ref: Read Timeout-Footnote-1251987 -Node: Command line directories252045 -Node: Printing252675 -Node: Print254306 -Node: Print Examples255643 -Node: Output Separators258427 -Node: OFMT260443 -Node: Printf261801 -Node: Basic Printf262707 -Node: Control Letters264246 -Node: Format Modifiers268066 -Node: Printf Examples274075 -Node: Redirection276787 -Node: Special Files283761 -Node: Special FD284294 -Ref: Special FD-Footnote-1287919 -Node: Special Network287993 -Node: Special Caveats288843 -Node: Close Files And Pipes289639 -Ref: Close Files And Pipes-Footnote-1296622 -Ref: Close Files And Pipes-Footnote-2296770 -Node: Expressions296920 -Node: Values298052 -Node: Constants298728 -Node: Scalar Constants299408 -Ref: Scalar Constants-Footnote-1300267 -Node: Nondecimal-numbers300449 -Node: Regexp Constants303449 -Node: Using Constant Regexps303924 -Node: Variables306979 -Node: Using Variables307634 -Node: Assignment Options309358 -Node: Conversion311233 -Ref: table-locale-affects316733 -Ref: Conversion-Footnote-1317357 -Node: All Operators317466 -Node: Arithmetic Ops318096 -Node: Concatenation320601 -Ref: Concatenation-Footnote-1323389 -Node: Assignment Ops323509 -Ref: table-assign-ops328497 -Node: Increment Ops329828 -Node: Truth Values and Conditions333262 -Node: Truth Values334345 -Node: Typing and Comparison335394 -Node: Variable Typing336187 -Ref: Variable Typing-Footnote-1340084 -Node: Comparison Operators340206 -Ref: table-relational-ops340616 -Node: POSIX String Comparison344164 -Ref: POSIX String Comparison-Footnote-1345120 -Node: Boolean Ops345258 -Ref: Boolean Ops-Footnote-1349328 -Node: Conditional Exp349419 -Node: Function Calls351151 -Node: Precedence354745 -Node: Locales358414 -Node: Patterns and Actions359503 -Node: Pattern Overview360557 -Node: Regexp Patterns362226 -Node: Expression Patterns362769 -Node: Ranges366550 -Node: BEGIN/END369654 -Node: Using BEGIN/END370416 -Ref: Using BEGIN/END-Footnote-1373152 -Node: I/O And BEGIN/END373258 -Node: BEGINFILE/ENDFILE375540 -Node: Empty378454 -Node: Using Shell Variables378771 -Node: Action Overview381056 -Node: Statements383413 -Node: If Statement385267 -Node: While Statement386766 -Node: Do Statement388810 -Node: For Statement389966 -Node: Switch Statement393118 -Node: Break Statement395272 -Node: Continue Statement397262 -Node: Next Statement399055 -Node: Nextfile Statement401445 -Node: Exit Statement404100 -Node: Built-in Variables406516 -Node: User-modified407611 -Ref: User-modified-Footnote-1415969 -Node: Auto-set416031 -Ref: Auto-set-Footnote-1429098 -Ref: Auto-set-Footnote-2429303 -Node: ARGC and ARGV429359 -Node: Arrays433213 -Node: Array Basics434718 -Node: Array Intro435544 -Node: Reference to Elements439861 -Node: Assigning Elements442131 -Node: Array Example442622 -Node: Scanning an Array444354 -Node: Controlling Scanning446668 -Ref: Controlling Scanning-Footnote-1451755 -Node: Delete452071 -Ref: Delete-Footnote-1454836 -Node: Numeric Array Subscripts454893 -Node: Uninitialized Subscripts457076 -Node: Multidimensional458703 -Node: Multiscanning461796 -Node: Arrays of Arrays463385 -Node: Functions468025 -Node: Built-in468844 -Node: Calling Built-in469922 -Node: Numeric Functions471910 -Ref: Numeric Functions-Footnote-1475744 -Ref: Numeric Functions-Footnote-2476101 -Ref: Numeric Functions-Footnote-3476149 -Node: String Functions476418 -Ref: String Functions-Footnote-1499421 -Ref: String Functions-Footnote-2499550 -Ref: String Functions-Footnote-3499798 -Node: Gory Details499885 -Ref: table-sub-escapes501564 -Ref: table-sub-posix-92502918 -Ref: table-sub-proposed504269 -Ref: table-posix-sub505623 -Ref: table-gensub-escapes507168 -Ref: Gory Details-Footnote-1508344 -Ref: Gory Details-Footnote-2508395 -Node: I/O Functions508546 -Ref: I/O Functions-Footnote-1515542 -Node: Time Functions515689 -Ref: Time Functions-Footnote-1526682 -Ref: Time Functions-Footnote-2526750 -Ref: Time Functions-Footnote-3526908 -Ref: Time Functions-Footnote-4527019 -Ref: Time Functions-Footnote-5527131 -Ref: Time Functions-Footnote-6527358 -Node: Bitwise Functions527624 -Ref: table-bitwise-ops528186 -Ref: Bitwise Functions-Footnote-1532431 -Node: Type Functions532615 -Node: I18N Functions533766 -Node: User-defined535418 -Node: Definition Syntax536222 -Ref: Definition Syntax-Footnote-1541136 -Node: Function Example541205 -Ref: Function Example-Footnote-1543854 -Node: Function Caveats543876 -Node: Calling A Function544394 -Node: Variable Scope545349 -Node: Pass By Value/Reference548312 -Node: Return Statement551820 -Node: Dynamic Typing554801 -Node: Indirect Calls555732 -Node: Library Functions565419 -Ref: Library Functions-Footnote-1568932 -Ref: Library Functions-Footnote-2569075 -Node: Library Names569246 -Ref: Library Names-Footnote-1572719 -Ref: Library Names-Footnote-2572939 -Node: General Functions573025 -Node: Strtonum Function574053 -Node: Assert Function576983 -Node: Round Function580309 -Node: Cliff Random Function581850 -Node: Ordinal Functions582866 -Ref: Ordinal Functions-Footnote-1585943 -Ref: Ordinal Functions-Footnote-2586195 -Node: Join Function586406 -Ref: Join Function-Footnote-1588177 -Node: Getlocaltime Function588377 -Node: Readfile Function592118 -Node: Data File Management593957 -Node: Filetrans Function594589 -Node: Rewind Function598658 -Node: File Checking600045 -Node: Empty Files601139 -Node: Ignoring Assigns603369 -Node: Getopt Function604923 -Ref: Getopt Function-Footnote-1616226 -Node: Passwd Functions616429 -Ref: Passwd Functions-Footnote-1625407 -Node: Group Functions625495 -Node: Walking Arrays633579 -Node: Sample Programs635715 -Node: Running Examples636389 -Node: Clones637117 -Node: Cut Program638341 -Node: Egrep Program648192 -Ref: Egrep Program-Footnote-1655965 -Node: Id Program656075 -Node: Split Program659724 -Ref: Split Program-Footnote-1663243 -Node: Tee Program663371 -Node: Uniq Program666174 -Node: Wc Program673603 -Ref: Wc Program-Footnote-1677869 -Ref: Wc Program-Footnote-2678069 -Node: Miscellaneous Programs678161 -Node: Dupword Program679349 -Node: Alarm Program681380 -Node: Translate Program686187 -Ref: Translate Program-Footnote-1690574 -Ref: Translate Program-Footnote-2690822 -Node: Labels Program690956 -Ref: Labels Program-Footnote-1694327 -Node: Word Sorting694411 -Node: History Sorting698295 -Node: Extract Program700134 -Ref: Extract Program-Footnote-1707637 -Node: Simple Sed707765 -Node: Igawk Program710827 -Ref: Igawk Program-Footnote-1725998 -Ref: Igawk Program-Footnote-2726199 -Node: Anagram Program726337 -Node: Signature Program729405 -Node: Advanced Features730505 -Node: Nondecimal Data732391 -Node: Array Sorting733974 -Node: Controlling Array Traversal734671 -Node: Array Sorting Functions742955 -Ref: Array Sorting Functions-Footnote-1746824 -Node: Two-way I/O747018 -Ref: Two-way I/O-Footnote-1752450 -Node: TCP/IP Networking752532 -Node: Profiling755376 -Node: Internationalization762879 -Node: I18N and L10N764304 -Node: Explaining gettext764990 -Ref: Explaining gettext-Footnote-1770058 -Ref: Explaining gettext-Footnote-2770242 -Node: Programmer i18n770407 -Node: Translator i18n774634 -Node: String Extraction775428 -Ref: String Extraction-Footnote-1776389 -Node: Printf Ordering776475 -Ref: Printf Ordering-Footnote-1779257 -Node: I18N Portability779321 -Ref: I18N Portability-Footnote-1781770 -Node: I18N Example781833 -Ref: I18N Example-Footnote-1784471 -Node: Gawk I18N784543 -Node: Debugger785164 -Node: Debugging786135 -Node: Debugging Concepts786568 -Node: Debugging Terms788424 -Node: Awk Debugging791021 -Node: Sample Debugging Session791913 -Node: Debugger Invocation792433 -Node: Finding The Bug793766 -Node: List of Debugger Commands800253 -Node: Breakpoint Control801587 -Node: Debugger Execution Control805251 -Node: Viewing And Changing Data808611 -Node: Execution Stack811967 -Node: Debugger Info813434 -Node: Miscellaneous Debugger Commands817428 -Node: Readline Support822606 -Node: Limitations823437 -Node: Arbitrary Precision Arithmetic825689 -Ref: Arbitrary Precision Arithmetic-Footnote-1827338 -Node: General Arithmetic827486 -Node: Floating Point Issues829206 -Node: String Conversion Precision830087 -Ref: String Conversion Precision-Footnote-1831792 -Node: Unexpected Results831901 -Node: POSIX Floating Point Problems834054 -Ref: POSIX Floating Point Problems-Footnote-1837879 -Node: Integer Programming837917 -Node: Floating-point Programming839656 -Ref: Floating-point Programming-Footnote-1845987 -Ref: Floating-point Programming-Footnote-2846257 -Node: Floating-point Representation846521 -Node: Floating-point Context847686 -Ref: table-ieee-formats848525 -Node: Rounding Mode849909 -Ref: table-rounding-modes850388 -Ref: Rounding Mode-Footnote-1853403 -Node: Gawk and MPFR853582 -Node: Arbitrary Precision Floats854991 -Ref: Arbitrary Precision Floats-Footnote-1857434 -Node: Setting Precision857750 -Ref: table-predefined-precision-strings858436 -Node: Setting Rounding Mode860581 -Ref: table-gawk-rounding-modes860985 -Node: Floating-point Constants862172 -Node: Changing Precision863601 -Ref: Changing Precision-Footnote-1864998 -Node: Exact Arithmetic865172 -Node: Arbitrary Precision Integers868310 -Ref: Arbitrary Precision Integers-Footnote-1871325 -Node: Dynamic Extensions871472 -Node: Extension Intro872930 -Node: Plugin License874195 -Node: Extension Mechanism Outline874880 -Ref: load-extension875297 -Ref: load-new-function876775 -Ref: call-new-function877770 -Node: Extension API Description879785 -Node: Extension API Functions Introduction881072 -Node: General Data Types885999 -Ref: General Data Types-Footnote-1891694 -Node: Requesting Values891993 -Ref: table-value-types-returned892730 -Node: Memory Allocation Functions893684 -Ref: Memory Allocation Functions-Footnote-1896430 -Node: Constructor Functions896526 -Node: Registration Functions898284 -Node: Extension Functions898969 -Node: Exit Callback Functions901271 -Node: Extension Version String902520 -Node: Input Parsers903170 -Node: Output Wrappers912927 -Node: Two-way processors917437 -Node: Printing Messages919645 -Ref: Printing Messages-Footnote-1920722 -Node: Updating `ERRNO'920874 -Node: Accessing Parameters921613 -Node: Symbol Table Access922843 -Node: Symbol table by name923357 -Node: Symbol table by cookie925333 -Ref: Symbol table by cookie-Footnote-1929465 -Node: Cached values929528 -Ref: Cached values-Footnote-1933018 -Node: Array Manipulation933109 -Ref: Array Manipulation-Footnote-1934207 -Node: Array Data Types934246 -Ref: Array Data Types-Footnote-1936949 -Node: Array Functions937041 -Node: Flattening Arrays940877 -Node: Creating Arrays947729 -Node: Extension API Variables952454 -Node: Extension Versioning953090 -Node: Extension API Informational Variables954991 -Node: Extension API Boilerplate956077 -Node: Finding Extensions959881 -Node: Extension Example960441 -Node: Internal File Description961171 -Node: Internal File Ops965262 -Ref: Internal File Ops-Footnote-1976771 -Node: Using Internal File Ops976911 -Ref: Using Internal File Ops-Footnote-1979258 -Node: Extension Samples979524 -Node: Extension Sample File Functions981048 -Node: Extension Sample Fnmatch989535 -Node: Extension Sample Fork991304 -Node: Extension Sample Inplace992517 -Node: Extension Sample Ord994295 -Node: Extension Sample Readdir995131 -Node: Extension Sample Revout996663 -Node: Extension Sample Rev2way997256 -Node: Extension Sample Read write array997946 -Node: Extension Sample Readfile999829 -Node: Extension Sample API Tests1000929 -Node: Extension Sample Time1001454 -Node: gawkextlib1002818 -Node: Language History1005599 -Node: V7/SVR3.11007192 -Node: SVR41009512 -Node: POSIX1010954 -Node: BTL1012340 -Node: POSIX/GNU1013074 -Node: Feature History1018673 -Node: Common Extensions1031649 -Node: Ranges and Locales1032961 -Ref: Ranges and Locales-Footnote-11037578 -Ref: Ranges and Locales-Footnote-21037605 -Ref: Ranges and Locales-Footnote-31037839 -Node: Contributors1038060 -Node: Installation1043441 -Node: Gawk Distribution1044335 -Node: Getting1044819 -Node: Extracting1045645 -Node: Distribution contents1047337 -Node: Unix Installation1053058 -Node: Quick Installation1053675 -Node: Additional Configuration Options1056121 -Node: Configuration Philosophy1057857 -Node: Non-Unix Installation1060211 -Node: PC Installation1060669 -Node: PC Binary Installation1061968 -Node: PC Compiling1063816 -Node: PC Testing1066760 -Node: PC Using1067936 -Node: Cygwin1072104 -Node: MSYS1072913 -Node: VMS Installation1073427 -Node: VMS Compilation1074223 -Ref: VMS Compilation-Footnote-11075475 -Node: VMS Dynamic Extensions1075533 -Node: VMS Installation Details1076906 -Node: VMS Running1079157 -Node: VMS GNV1081991 -Node: VMS Old Gawk1082714 -Node: Bugs1083184 -Node: Other Versions1087102 -Node: Notes1093186 -Node: Compatibility Mode1093986 -Node: Additions1094769 -Node: Accessing The Source1095696 -Node: Adding Code1097136 -Node: New Ports1103181 -Node: Derived Files1107316 -Ref: Derived Files-Footnote-11112637 -Ref: Derived Files-Footnote-21112671 -Ref: Derived Files-Footnote-31113271 -Node: Future Extensions1113369 -Node: Implementation Limitations1113952 -Node: Extension Design1115204 -Node: Old Extension Problems1116358 -Ref: Old Extension Problems-Footnote-11117866 -Node: Extension New Mechanism Goals1117923 -Ref: Extension New Mechanism Goals-Footnote-11121288 -Node: Extension Other Design Decisions1121474 -Node: Extension Future Growth1123580 -Node: Old Extension Mechanism1124416 -Node: Basic Concepts1126156 -Node: Basic High Level1126837 -Ref: figure-general-flow1127109 -Ref: figure-process-flow1127708 -Ref: Basic High Level-Footnote-11130937 -Node: Basic Data Typing1131122 -Node: Glossary1134477 -Node: Copying1159708 -Node: GNU Free Documentation License1197264 -Node: Index1222400 +Node: Foreword40832 +Node: Preface45177 +Ref: Preface-Footnote-148310 +Ref: Preface-Footnote-248417 +Node: History48649 +Node: Names51023 +Ref: Names-Footnote-152487 +Node: This Manual52560 +Ref: This Manual-Footnote-158334 +Node: Conventions58434 +Node: Manual History60590 +Ref: Manual History-Footnote-164020 +Ref: Manual History-Footnote-264061 +Node: How To Contribute64135 +Node: Acknowledgments65374 +Node: Getting Started69568 +Node: Running gawk71947 +Node: One-shot73137 +Node: Read Terminal74362 +Ref: Read Terminal-Footnote-176012 +Ref: Read Terminal-Footnote-276288 +Node: Long76459 +Node: Executable Scripts77835 +Ref: Executable Scripts-Footnote-179668 +Ref: Executable Scripts-Footnote-279770 +Node: Comments80317 +Node: Quoting82784 +Node: DOS Quoting88100 +Node: Sample Data Files88775 +Node: Very Simple91290 +Node: Two Rules95940 +Node: More Complex97835 +Ref: More Complex-Footnote-1100767 +Node: Statements/Lines100852 +Ref: Statements/Lines-Footnote-1105307 +Node: Other Features105572 +Node: When106500 +Node: Invoking Gawk108648 +Node: Command Line110111 +Node: Options110894 +Ref: Options-Footnote-1126706 +Node: Other Arguments126731 +Node: Naming Standard Input129393 +Node: Environment Variables130487 +Node: AWKPATH Variable131045 +Ref: AWKPATH Variable-Footnote-1133823 +Ref: AWKPATH Variable-Footnote-2133868 +Node: AWKLIBPATH Variable134128 +Node: Other Environment Variables134887 +Node: Exit Status138052 +Node: Include Files138727 +Node: Loading Shared Libraries142305 +Node: Obsolete143688 +Node: Undocumented144385 +Node: Regexp144627 +Node: Regexp Usage146016 +Node: Escape Sequences148049 +Node: Regexp Operators153716 +Ref: Regexp Operators-Footnote-1161196 +Ref: Regexp Operators-Footnote-2161343 +Node: Bracket Expressions161441 +Ref: table-char-classes163331 +Node: GNU Regexp Operators165854 +Node: Case-sensitivity169577 +Ref: Case-sensitivity-Footnote-1172469 +Ref: Case-sensitivity-Footnote-2172704 +Node: Leftmost Longest172812 +Node: Computed Regexps174013 +Node: Reading Files177362 +Node: Records179364 +Node: awk split records180099 +Node: gawk split records184957 +Ref: gawk split records-Footnote-1189478 +Node: Fields189515 +Ref: Fields-Footnote-1192479 +Node: Nonconstant Fields192565 +Ref: Nonconstant Fields-Footnote-1194795 +Node: Changing Fields194997 +Node: Field Separators200951 +Node: Default Field Splitting203653 +Node: Regexp Field Splitting204770 +Node: Single Character Fields208111 +Node: Command Line Field Separator209170 +Node: Full Line Fields212512 +Ref: Full Line Fields-Footnote-1213020 +Node: Field Splitting Summary213066 +Ref: Field Splitting Summary-Footnote-1216165 +Node: Constant Size216266 +Node: Splitting By Content220873 +Ref: Splitting By Content-Footnote-1224623 +Node: Multiple Line224663 +Ref: Multiple Line-Footnote-1230519 +Node: Getline230698 +Node: Plain Getline232914 +Node: Getline/Variable235009 +Node: Getline/File236156 +Node: Getline/Variable/File237540 +Ref: Getline/Variable/File-Footnote-1239139 +Node: Getline/Pipe239226 +Node: Getline/Variable/Pipe241925 +Node: Getline/Coprocess243032 +Node: Getline/Variable/Coprocess244284 +Node: Getline Notes245021 +Node: Getline Summary247825 +Ref: table-getline-variants248233 +Node: Read Timeout249145 +Ref: Read Timeout-Footnote-1252972 +Node: Command line directories253030 +Node: Printing253912 +Node: Print255543 +Node: Print Examples256884 +Node: Output Separators259663 +Node: OFMT261679 +Node: Printf263037 +Node: Basic Printf263943 +Node: Control Letters265482 +Node: Format Modifiers269336 +Node: Printf Examples275363 +Node: Redirection278070 +Node: Special Files285042 +Node: Special FD285575 +Ref: Special FD-Footnote-1289199 +Node: Special Network289273 +Node: Special Caveats290123 +Node: Close Files And Pipes290919 +Ref: Close Files And Pipes-Footnote-1298057 +Ref: Close Files And Pipes-Footnote-2298205 +Node: Expressions298355 +Node: Values299487 +Node: Constants300163 +Node: Scalar Constants300843 +Ref: Scalar Constants-Footnote-1301702 +Node: Nondecimal-numbers301884 +Node: Regexp Constants304884 +Node: Using Constant Regexps305359 +Node: Variables308414 +Node: Using Variables309069 +Node: Assignment Options310793 +Node: Conversion312668 +Ref: table-locale-affects318168 +Ref: Conversion-Footnote-1318792 +Node: All Operators318901 +Node: Arithmetic Ops319531 +Node: Concatenation322036 +Ref: Concatenation-Footnote-1324824 +Node: Assignment Ops324944 +Ref: table-assign-ops329932 +Node: Increment Ops331263 +Node: Truth Values and Conditions334697 +Node: Truth Values335780 +Node: Typing and Comparison336829 +Node: Variable Typing337622 +Ref: Variable Typing-Footnote-1341519 +Node: Comparison Operators341641 +Ref: table-relational-ops342051 +Node: POSIX String Comparison345599 +Ref: POSIX String Comparison-Footnote-1346555 +Node: Boolean Ops346693 +Ref: Boolean Ops-Footnote-1350763 +Node: Conditional Exp350854 +Node: Function Calls352586 +Node: Precedence356180 +Node: Locales359849 +Node: Patterns and Actions360938 +Node: Pattern Overview361992 +Node: Regexp Patterns363661 +Node: Expression Patterns364204 +Node: Ranges367985 +Node: BEGIN/END371089 +Node: Using BEGIN/END371851 +Ref: Using BEGIN/END-Footnote-1374587 +Node: I/O And BEGIN/END374693 +Node: BEGINFILE/ENDFILE376975 +Node: Empty379889 +Node: Using Shell Variables380206 +Node: Action Overview382491 +Node: Statements384848 +Node: If Statement386702 +Node: While Statement388201 +Node: Do Statement390245 +Node: For Statement391401 +Node: Switch Statement394553 +Node: Break Statement396707 +Node: Continue Statement398697 +Node: Next Statement400490 +Node: Nextfile Statement402880 +Node: Exit Statement405535 +Node: Built-in Variables407951 +Node: User-modified409046 +Ref: User-modified-Footnote-1417404 +Node: Auto-set417466 +Ref: Auto-set-Footnote-1430533 +Ref: Auto-set-Footnote-2430738 +Node: ARGC and ARGV430794 +Node: Arrays434648 +Node: Array Basics436153 +Node: Array Intro436979 +Node: Reference to Elements441296 +Node: Assigning Elements443566 +Node: Array Example444057 +Node: Scanning an Array445789 +Node: Controlling Scanning448103 +Ref: Controlling Scanning-Footnote-1453190 +Node: Delete453506 +Ref: Delete-Footnote-1456271 +Node: Numeric Array Subscripts456328 +Node: Uninitialized Subscripts458511 +Node: Multidimensional460138 +Node: Multiscanning463231 +Node: Arrays of Arrays464820 +Node: Functions469460 +Node: Built-in470279 +Node: Calling Built-in471357 +Node: Numeric Functions473345 +Ref: Numeric Functions-Footnote-1477179 +Ref: Numeric Functions-Footnote-2477536 +Ref: Numeric Functions-Footnote-3477584 +Node: String Functions477853 +Ref: String Functions-Footnote-1500856 +Ref: String Functions-Footnote-2500985 +Ref: String Functions-Footnote-3501233 +Node: Gory Details501320 +Ref: table-sub-escapes502999 +Ref: table-sub-posix-92504353 +Ref: table-sub-proposed505704 +Ref: table-posix-sub507058 +Ref: table-gensub-escapes508603 +Ref: Gory Details-Footnote-1509779 +Ref: Gory Details-Footnote-2509830 +Node: I/O Functions509981 +Ref: I/O Functions-Footnote-1516977 +Node: Time Functions517124 +Ref: Time Functions-Footnote-1528117 +Ref: Time Functions-Footnote-2528185 +Ref: Time Functions-Footnote-3528343 +Ref: Time Functions-Footnote-4528454 +Ref: Time Functions-Footnote-5528566 +Ref: Time Functions-Footnote-6528793 +Node: Bitwise Functions529059 +Ref: table-bitwise-ops529621 +Ref: Bitwise Functions-Footnote-1533866 +Node: Type Functions534050 +Node: I18N Functions535201 +Node: User-defined536853 +Node: Definition Syntax537657 +Ref: Definition Syntax-Footnote-1542571 +Node: Function Example542640 +Ref: Function Example-Footnote-1545289 +Node: Function Caveats545311 +Node: Calling A Function545829 +Node: Variable Scope546784 +Node: Pass By Value/Reference549747 +Node: Return Statement553255 +Node: Dynamic Typing556236 +Node: Indirect Calls557167 +Node: Library Functions566854 +Ref: Library Functions-Footnote-1570367 +Ref: Library Functions-Footnote-2570510 +Node: Library Names570681 +Ref: Library Names-Footnote-1574154 +Ref: Library Names-Footnote-2574374 +Node: General Functions574460 +Node: Strtonum Function575488 +Node: Assert Function578418 +Node: Round Function581744 +Node: Cliff Random Function583285 +Node: Ordinal Functions584301 +Ref: Ordinal Functions-Footnote-1587378 +Ref: Ordinal Functions-Footnote-2587630 +Node: Join Function587841 +Ref: Join Function-Footnote-1589612 +Node: Getlocaltime Function589812 +Node: Readfile Function593553 +Node: Data File Management595392 +Node: Filetrans Function596024 +Node: Rewind Function600093 +Node: File Checking601480 +Node: Empty Files602574 +Node: Ignoring Assigns604804 +Node: Getopt Function606358 +Ref: Getopt Function-Footnote-1617661 +Node: Passwd Functions617864 +Ref: Passwd Functions-Footnote-1626842 +Node: Group Functions626930 +Node: Walking Arrays635014 +Node: Sample Programs637150 +Node: Running Examples637824 +Node: Clones638552 +Node: Cut Program639776 +Node: Egrep Program649627 +Ref: Egrep Program-Footnote-1657400 +Node: Id Program657510 +Node: Split Program661159 +Ref: Split Program-Footnote-1664678 +Node: Tee Program664806 +Node: Uniq Program667609 +Node: Wc Program675038 +Ref: Wc Program-Footnote-1679304 +Ref: Wc Program-Footnote-2679504 +Node: Miscellaneous Programs679596 +Node: Dupword Program680784 +Node: Alarm Program682815 +Node: Translate Program687622 +Ref: Translate Program-Footnote-1692009 +Ref: Translate Program-Footnote-2692257 +Node: Labels Program692391 +Ref: Labels Program-Footnote-1695762 +Node: Word Sorting695846 +Node: History Sorting699730 +Node: Extract Program701569 +Ref: Extract Program-Footnote-1709072 +Node: Simple Sed709200 +Node: Igawk Program712262 +Ref: Igawk Program-Footnote-1727433 +Ref: Igawk Program-Footnote-2727634 +Node: Anagram Program727772 +Node: Signature Program730840 +Node: Advanced Features731940 +Node: Nondecimal Data733826 +Node: Array Sorting735409 +Node: Controlling Array Traversal736106 +Node: Array Sorting Functions744390 +Ref: Array Sorting Functions-Footnote-1748259 +Node: Two-way I/O748453 +Ref: Two-way I/O-Footnote-1753885 +Node: TCP/IP Networking753967 +Node: Profiling756811 +Node: Internationalization764314 +Node: I18N and L10N765739 +Node: Explaining gettext766425 +Ref: Explaining gettext-Footnote-1771493 +Ref: Explaining gettext-Footnote-2771677 +Node: Programmer i18n771842 +Node: Translator i18n776069 +Node: String Extraction776863 +Ref: String Extraction-Footnote-1777824 +Node: Printf Ordering777910 +Ref: Printf Ordering-Footnote-1780692 +Node: I18N Portability780756 +Ref: I18N Portability-Footnote-1783205 +Node: I18N Example783268 +Ref: I18N Example-Footnote-1785906 +Node: Gawk I18N785978 +Node: Debugger786599 +Node: Debugging787570 +Node: Debugging Concepts788003 +Node: Debugging Terms789859 +Node: Awk Debugging792456 +Node: Sample Debugging Session793348 +Node: Debugger Invocation793868 +Node: Finding The Bug795201 +Node: List of Debugger Commands801688 +Node: Breakpoint Control803022 +Node: Debugger Execution Control806686 +Node: Viewing And Changing Data810046 +Node: Execution Stack813402 +Node: Debugger Info814869 +Node: Miscellaneous Debugger Commands818863 +Node: Readline Support824041 +Node: Limitations824872 +Node: Arbitrary Precision Arithmetic827124 +Ref: Arbitrary Precision Arithmetic-Footnote-1828773 +Node: General Arithmetic828921 +Node: Floating Point Issues830641 +Node: String Conversion Precision831522 +Ref: String Conversion Precision-Footnote-1833227 +Node: Unexpected Results833336 +Node: POSIX Floating Point Problems835489 +Ref: POSIX Floating Point Problems-Footnote-1839314 +Node: Integer Programming839352 +Node: Floating-point Programming841091 +Ref: Floating-point Programming-Footnote-1847422 +Ref: Floating-point Programming-Footnote-2847692 +Node: Floating-point Representation847956 +Node: Floating-point Context849121 +Ref: table-ieee-formats849960 +Node: Rounding Mode851344 +Ref: table-rounding-modes851823 +Ref: Rounding Mode-Footnote-1854838 +Node: Gawk and MPFR855017 +Node: Arbitrary Precision Floats856426 +Ref: Arbitrary Precision Floats-Footnote-1858869 +Node: Setting Precision859185 +Ref: table-predefined-precision-strings859871 +Node: Setting Rounding Mode862016 +Ref: table-gawk-rounding-modes862420 +Node: Floating-point Constants863607 +Node: Changing Precision865036 +Ref: Changing Precision-Footnote-1866433 +Node: Exact Arithmetic866607 +Node: Arbitrary Precision Integers869745 +Ref: Arbitrary Precision Integers-Footnote-1872760 +Node: Dynamic Extensions872907 +Node: Extension Intro874365 +Node: Plugin License875630 +Node: Extension Mechanism Outline876315 +Ref: load-extension876732 +Ref: load-new-function878210 +Ref: call-new-function879205 +Node: Extension API Description881220 +Node: Extension API Functions Introduction882507 +Node: General Data Types887434 +Ref: General Data Types-Footnote-1893129 +Node: Requesting Values893428 +Ref: table-value-types-returned894165 +Node: Memory Allocation Functions895119 +Ref: Memory Allocation Functions-Footnote-1897865 +Node: Constructor Functions897961 +Node: Registration Functions899719 +Node: Extension Functions900404 +Node: Exit Callback Functions902706 +Node: Extension Version String903955 +Node: Input Parsers904605 +Node: Output Wrappers914362 +Node: Two-way processors918872 +Node: Printing Messages921080 +Ref: Printing Messages-Footnote-1922157 +Node: Updating `ERRNO'922309 +Node: Accessing Parameters923048 +Node: Symbol Table Access924278 +Node: Symbol table by name924792 +Node: Symbol table by cookie926768 +Ref: Symbol table by cookie-Footnote-1930900 +Node: Cached values930963 +Ref: Cached values-Footnote-1934453 +Node: Array Manipulation934544 +Ref: Array Manipulation-Footnote-1935642 +Node: Array Data Types935681 +Ref: Array Data Types-Footnote-1938384 +Node: Array Functions938476 +Node: Flattening Arrays942312 +Node: Creating Arrays949164 +Node: Extension API Variables953889 +Node: Extension Versioning954525 +Node: Extension API Informational Variables956426 +Node: Extension API Boilerplate957512 +Node: Finding Extensions961316 +Node: Extension Example961876 +Node: Internal File Description962606 +Node: Internal File Ops966697 +Ref: Internal File Ops-Footnote-1978206 +Node: Using Internal File Ops978346 +Ref: Using Internal File Ops-Footnote-1980693 +Node: Extension Samples980959 +Node: Extension Sample File Functions982483 +Node: Extension Sample Fnmatch990970 +Node: Extension Sample Fork992739 +Node: Extension Sample Inplace993952 +Node: Extension Sample Ord995730 +Node: Extension Sample Readdir996566 +Node: Extension Sample Revout998098 +Node: Extension Sample Rev2way998691 +Node: Extension Sample Read write array999381 +Node: Extension Sample Readfile1001264 +Node: Extension Sample API Tests1002364 +Node: Extension Sample Time1002889 +Node: gawkextlib1004253 +Node: Language History1007034 +Node: V7/SVR3.11008627 +Node: SVR41010947 +Node: POSIX1012389 +Node: BTL1013775 +Node: POSIX/GNU1014509 +Node: Feature History1020108 +Node: Common Extensions1033084 +Node: Ranges and Locales1034396 +Ref: Ranges and Locales-Footnote-11039013 +Ref: Ranges and Locales-Footnote-21039040 +Ref: Ranges and Locales-Footnote-31039274 +Node: Contributors1039495 +Node: Installation1044876 +Node: Gawk Distribution1045770 +Node: Getting1046254 +Node: Extracting1047080 +Node: Distribution contents1048772 +Node: Unix Installation1054493 +Node: Quick Installation1055110 +Node: Additional Configuration Options1057556 +Node: Configuration Philosophy1059292 +Node: Non-Unix Installation1061646 +Node: PC Installation1062104 +Node: PC Binary Installation1063403 +Node: PC Compiling1065251 +Node: PC Testing1068195 +Node: PC Using1069371 +Node: Cygwin1073539 +Node: MSYS1074348 +Node: VMS Installation1074862 +Node: VMS Compilation1075658 +Ref: VMS Compilation-Footnote-11076910 +Node: VMS Dynamic Extensions1076968 +Node: VMS Installation Details1078341 +Node: VMS Running1080592 +Node: VMS GNV1083426 +Node: VMS Old Gawk1084149 +Node: Bugs1084619 +Node: Other Versions1088537 +Node: Notes1094621 +Node: Compatibility Mode1095421 +Node: Additions1096204 +Node: Accessing The Source1097131 +Node: Adding Code1098571 +Node: New Ports1104616 +Node: Derived Files1108751 +Ref: Derived Files-Footnote-11114072 +Ref: Derived Files-Footnote-21114106 +Ref: Derived Files-Footnote-31114706 +Node: Future Extensions1114804 +Node: Implementation Limitations1115387 +Node: Extension Design1116639 +Node: Old Extension Problems1117793 +Ref: Old Extension Problems-Footnote-11119301 +Node: Extension New Mechanism Goals1119358 +Ref: Extension New Mechanism Goals-Footnote-11122723 +Node: Extension Other Design Decisions1122909 +Node: Extension Future Growth1125015 +Node: Old Extension Mechanism1125851 +Node: Basic Concepts1127591 +Node: Basic High Level1128272 +Ref: figure-general-flow1128544 +Ref: figure-process-flow1129143 +Ref: Basic High Level-Footnote-11132372 +Node: Basic Data Typing1132557 +Node: Glossary1135912 +Node: Copying1161143 +Node: GNU Free Documentation License1198699 +Node: Index1223835  End Tag Table -- cgit v1.2.3 From 0ceab11e44cac45f8653fa79510726cc121719f4 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 30 Apr 2014 21:29:18 +0300 Subject: Edits, into chapter 7. --- doc/gawk.info | 1082 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 543 insertions(+), 539 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 57fdc3d4..8c13d181 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -6921,7 +6921,8 @@ codes. (1) The internal representation of all numbers, including integers, uses double precision floating-point numbers. On most modern systems, -these are in IEEE 754 standard format. +these are in IEEE 754 standard format. *Note Arbitrary Precision +Arithmetic::, for much more information.  File: gawk.info, Node: Nondecimal-numbers, Next: Regexp Constants, Prev: Scalar Constants, Up: Constants @@ -7054,8 +7055,8 @@ the contents of the current input record. Constant regular expressions are also used as the first argument for the `gensub()', `sub()', and `gsub()' functions, as the second argument -of the `match()' function, and as the third argument of the -`patsplit()' function (*note String Functions::). Modern +of the `match()' function, and as the third argument of the `split()' +and `patsplit()' functions (*note String Functions::). Modern implementations of `awk', including `gawk', allow the third argument of `split()' to be a regexp constant, but some older implementations do not. (d.c.) This can lead to confusion when attempting to use regexp @@ -7248,29 +7249,28 @@ use when printing numbers with `print'. `CONVFMT' was introduced in order to separate the semantics of conversion from the semantics of printing. Both `CONVFMT' and `OFMT' have the same default value: `"%.6g"'. In the vast majority of cases, old `awk' programs do not -change their behavior. However, these semantics for `OFMT' are -something to keep in mind if you must port your new-style program to -older implementations of `awk'. We recommend that instead of changing -your programs, just port `gawk' itself. *Note Print::, for more -information on the `print' statement. - - And, once again, where you are can matter when it comes to converting -between numbers and strings. In *note Locales::, we mentioned that the -local character set and language (the locale) can affect how `gawk' -matches characters. The locale also affects numeric formats. In -particular, for `awk' programs, it affects the decimal point character. -The `"C"' locale, and most English-language locales, use the period -character (`.') as the decimal point. However, many (if not most) -European and non-English locales use the comma (`,') as the decimal -point character. +change their behavior. *Note Print::, for more information on the +`print' statement. + + Where you are can matter when it comes to converting between numbers +and strings. The local character set and language--the "locale"--can +affect numeric formats. In particular, for `awk' programs, it affects +the decimal point character and the thousands-separator character. The +`"C"' locale, and most English-language locales, use the period +character (`.') as the decimal point and don't have a thousands +separator. However, many (if not most) European and non-English +locales use the comma (`,') as the decimal point character. European +locales often use either a space or a period as the thousands +separator, if they have one. The POSIX standard says that `awk' always uses the period as the decimal point when reading the `awk' program source code, and for command-line variable assignments (*note Other Arguments::). However, when interpreting input data, for `print' and `printf' output, and for number to string conversion, the local decimal point character is used. -(d.c.) Here are some examples indicating the difference in behavior, -on a GNU/Linux system: +(d.c.) In all cases, numbers in source code and in input data cannot +have a thousands separator. Here are some examples indicating the +difference in behavior, on a GNU/Linux system: $ export POSIXLY_CORRECT=1 Force POSIX behavior $ gawk 'BEGIN { printf "%g\n", 3.1415927 }' @@ -7475,9 +7475,9 @@ example: print (a " " (a = "panic")) } -It is not defined whether the assignment to `a' happens before or after -the value of `a' is retrieved for producing the concatenated value. -The result could be either `don't panic', or `panic panic'. +It is not defined whether the second assignment to `a' happens before +or after the value of `a' is retrieved for producing the concatenated +value. The result could be either `don't panic', or `panic panic'. The precedence of concatenation, when mixed with other operators, is often counter-intuitive. Consider this example: @@ -7550,9 +7550,9 @@ that the assignment stores in the specified variable, field, or array element. (Such values are called "rvalues".) It is important to note that variables do _not_ have permanent types. -A variable's type is simply the type of whatever value it happens to -hold at the moment. In the following program fragment, the variable -`foo' has a numeric value at first, and a string value later on: +A variable's type is simply the type of whatever value was last assigned +to it. In the following program fragment, the variable `foo' has a +numeric value at first, and a string value later on: foo = 1 print foo @@ -7625,9 +7625,10 @@ The indices of `bar' are practically guaranteed to be different, because the `rand()' function haven't been covered yet. *Note Arrays::, and see *note Numeric Functions::, for more information). This example illustrates an important fact about assignment operators: the lefthand -expression is only evaluated _once_. It is up to the implementation as -to which expression is evaluated first, the lefthand or the righthand. -Consider this example: +expression is only evaluated _once_. + + It is up to the implementation as to which expression is evaluated +first, the lefthand or the righthand. Consider this example: i = 1 a[i += 2] = i + 1 @@ -7640,14 +7641,14 @@ converted to a number. Operator Effect -------------------------------------------------------------------------- -LVALUE `+=' INCREMENT Adds INCREMENT to the value of LVALUE. -LVALUE `-=' DECREMENT Subtracts DECREMENT from the value of LVALUE. -LVALUE `*=' Multiplies the value of LVALUE by COEFFICIENT. +LVALUE `+=' INCREMENT Add INCREMENT to the value of LVALUE. +LVALUE `-=' DECREMENT Subtract DECREMENT from the value of LVALUE. +LVALUE `*=' Multiply the value of LVALUE by COEFFICIENT. COEFFICIENT -LVALUE `/=' DIVISOR Divides the value of LVALUE by DIVISOR. -LVALUE `%=' MODULUS Sets LVALUE to its remainder by MODULUS. +LVALUE `/=' DIVISOR Divide the value of LVALUE by DIVISOR. +LVALUE `%=' MODULUS Set LVALUE to its remainder by MODULUS. LVALUE `^=' POWER -LVALUE `**=' POWER Raises LVALUE to the power POWER. (c.e.) +LVALUE `**=' POWER Raise LVALUE to the power POWER. (c.e.) Table 6.2: Arithmetic Assignment Operators @@ -7670,8 +7671,8 @@ A workaround is: awk '/[=]=/' /dev/null - `gawk' does not have this problem, nor do the other freely available -versions described in *note Other Versions::. + `gawk' does not have this problem; Brian Kernighan's `awk' and +`mawk' also do not (*note Other Versions::).  File: gawk.info, Node: Increment Ops, Prev: Assignment Ops, Up: All Operators @@ -7686,13 +7687,13 @@ they are convenient abbreviations for very common operations. The operator used for adding one is written `++'. It can be used to increment a variable either before or after taking its value. To -pre-increment a variable `v', write `++v'. This adds one to the value -of `v'--that new value is also the value of the expression. (The +"pre-increment" a variable `v', write `++v'. This adds one to the +value of `v'--that new value is also the value of the expression. (The assignment expression `v += 1' is completely equivalent.) Writing the -`++' after the variable specifies post-increment. This increments the -variable value just the same; the difference is that the value of the -increment expression itself is the variable's _old_ value. Thus, if -`foo' has the value four, then the expression `foo++' has the value +`++' after the variable specifies "post-increment". This increments +the variable value just the same; the difference is that the value of +the increment expression itself is the variable's _old_ value. Thus, +if `foo' has the value four, then the expression `foo++' has the value four, but it changes the value of `foo' to five. In other words, the operator returns the old value of the variable, but with the side effect of incrementing it. @@ -7839,10 +7840,12 @@ The 1992 POSIX standard introduced the concept of a "numeric string", which is simply a string that looks like a number--for example, `" +2"'. This concept is used for determining the type of a variable. The type of the variable is important because the types of two variables -determine how they are compared. The various versions of the POSIX -standard did not get the rules quite right for several editions. -Fortunately, as of at least the 2008 standard (and possibly earlier), -the standard has been fixed, and variable typing follows these rules:(1) +determine how they are compared. + + The various versions of the POSIX standard did not get the rules +quite right for several editions. Fortunately, as of at least the 2008 +standard (and possibly earlier), the standard has been fixed, and +variable typing follows these rules:(1) * A numeric constant or the result of a numeric operation has the NUMERIC attribute. @@ -7899,10 +7902,9 @@ comparison is performed. characters, and so is first and foremost of STRING type; input strings that look numeric are additionally given the STRNUM attribute. Thus, the six-character input string ` +3.14' receives the STRNUM attribute. -In contrast, the eight-character literal `" +3.14"' appearing in -program text is a string constant. The following examples print `1' -when the comparison between the two different constants is true, `0' -otherwise: +In contrast, the eight characters `" +3.14"' appearing in program text +comprise a string constant. The following examples print `1' when the +comparison between the two different constants is true, `0' otherwise: $ echo ' +3.14' | gawk '{ print $0 == " +3.14" }' True -| 1 @@ -8045,9 +8047,10 @@ File: gawk.info, Node: POSIX String Comparison, Prev: Comparison Operators, U .......................................... The POSIX standard says that string comparison is performed based on -the locale's collating order. This is usually very different from the -results obtained when doing straight character-by-character -comparison.(1) +the locale's "collating order". This is the order in which characters +sort, as defined by the locale (for more discussion, *note Ranges and +Locales::). This order is usually very different from the results +obtained when doing straight character-by-character comparison.(1) Because this behavior differs considerably from existing practice, `gawk' only implements it when in POSIX mode (*note Options::). Here @@ -8199,7 +8202,7 @@ not. *Note Arrays::, for more information about arrays. continued simply by putting a newline after either character. However, putting a newline in front of either character does not work without using backslash continuation (*note Statements/Lines::). If `--posix' -is specified (*note Options::), then this extension is disabled. +is specified (*note Options::), this extension is disabled.  File: gawk.info, Node: Function Calls, Next: Precedence, Prev: Truth Values and Conditions, Up: Expressions @@ -8216,6 +8219,8 @@ available in every `awk' program. The `sqrt()' function is one of these. *Note Built-in::, for a list of built-in functions and their descriptions. In addition, you can define functions for use in your program. *Note User-defined::, for instructions on how to do this. +Finally, `gawk' lets you write functions in C or C++ that may be called +from your program: see *note Dynamic Extensions::. The way to use a function is with a "function call" expression, which consists of the function name followed immediately by a list of @@ -8255,11 +8260,12 @@ which is a way to choose the function to call at runtime, instead of when you write the source code to your program. We defer discussion of this feature until later; see *note Indirect Calls::. - Like every other expression, the function call has a value, which is -computed by the function based on the arguments you give it. In this -example, the value of `sqrt(ARGUMENT)' is the square root of ARGUMENT. -The following program reads numbers, one number per line, and prints the -square root of each one: + Like every other expression, the function call has a value, often +called the "return value", which is computed by the function based on +the arguments you give it. In this example, the return value of +`sqrt(ARGUMENT)' is the square root of ARGUMENT. The following program +reads numbers, one number per line, and prints the square root of each +one: $ awk '{ print "The square root of", $1, "is", sqrt($1) }' 1 @@ -8472,10 +8478,10 @@ summary of the types of `awk' patterns: A single expression. It matches when its value is nonzero (if a number) or non-null (if a string). (*Note Expression Patterns::.) -`PAT1, PAT2' +`BEGPAT, ENDPAT' A pair of patterns separated by a comma, specifying a range of records. The range includes both the initial record that matches - PAT1 and the final record that matches PAT2. (*Note Ranges::.) + BEGPAT and the final record that matches ENDPAT. (*Note Ranges::.) `BEGIN' `END' @@ -8485,7 +8491,7 @@ summary of the types of `awk' patterns: `BEGINFILE' `ENDFILE' Special patterns for you to supply startup or cleanup actions to be - done on a per file basis. (*Note BEGINFILE/ENDFILE::.) + done on a per-file basis. (*Note BEGINFILE/ENDFILE::.) `EMPTY' The empty pattern matches every input record. (*Note Empty::.) @@ -8605,7 +8611,7 @@ record. When a record matches BEGPAT, the range pattern is "turned on" and the range pattern matches this record as well. As long as the range pattern stays turned on, it automatically matches every input record read. The range pattern also matches ENDPAT against every input -record; when this succeeds, the range pattern is turned off again for +record; when this succeeds, the range pattern is "turned off" again for the following record. Then the range pattern goes back to checking BEGPAT against each record. @@ -8737,10 +8743,10 @@ File: gawk.info, Node: I/O And BEGIN/END, Prev: Using BEGIN/END, Up: BEGIN/EN 7.1.4.2 Input/Output from `BEGIN' and `END' Rules ................................................. -There are several (sometimes subtle) points to remember when doing I/O -from a `BEGIN' or `END' rule. The first has to do with the value of -`$0' in a `BEGIN' rule. Because `BEGIN' rules are executed before any -input is read, there simply is no input record, and therefore no +There are several (sometimes subtle) points to be aware of when doing +I/O from a `BEGIN' or `END' rule. The first has to do with the value +of `$0' in a `BEGIN' rule. Because `BEGIN' rules are executed before +any input is read, there simply is no input record, and therefore no fields, when executing `BEGIN' rules. References to `$0' and the fields yield a null string or zero, depending upon the context. One way to give `$0' a real value is to execute a `getline' command without a @@ -8808,10 +8814,10 @@ tasks that would otherwise be difficult or impossible to perform: entirely. Otherwise, `gawk' exits with the usual fatal error. * If you have written extensions that modify the record handling (by - inserting an "input parser"), you can invoke them at this point, - before `gawk' has started processing the file. (This is a _very_ - advanced feature, currently used only by the `gawkextlib' project - (http://gawkextlib.sourceforge.net).) + inserting an "input parser," *note Input Parsers::), you can invoke + them at this point, before `gawk' has started processing the file. + (This is a _very_ advanced feature, currently used only by the + `gawkextlib' project (http://gawkextlib.sourceforge.net).) The `ENDFILE' rule is called when `gawk' has finished processing the last record in an input file. For the last input file, it will be @@ -8863,15 +8869,15 @@ to get the value of the shell variable into the body of the `awk' program. The most common method is to use shell quoting to substitute the -variable's value into the program inside the script. For example, in -the following program: +variable's value into the program inside the script. For example, +consider the following program: printf "Enter search pattern: " read pattern awk "/$pattern/ "'{ nmatches++ } END { print nmatches, "found" }' /path/to/data -the `awk' program consists of two pieces of quoted text that are +The `awk' program consists of two pieces of quoted text that are concatenated together to form the program. The first part is double-quoted, which allows substitution of the `pattern' shell variable inside the quotes. The second part is single-quoted. @@ -8883,7 +8889,7 @@ quotes when reading the program. A better method is to use `awk''s variable assignment feature (*note Assignment Options::) to assign the shell variable's value to an `awk' -variable's value. Then use dynamic regexps to match the pattern (*note +variable. Then use dynamic regexps to match the pattern (*note Computed Regexps::). The following shows how to redo the previous example using this technique: @@ -8945,9 +8951,9 @@ Control statements well as a few special ones (*note Statements::). Compound statements - Consist of one or more statements enclosed in curly braces. A - compound statement is used in order to put several statements - together in the body of an `if', `while', `do', or `for' statement. + Enclose one or more statements in curly braces. A compound + statement is used in order to put several statements together in + the body of an `if', `while', `do', or `for' statement. Input statements Use the `getline' command (*note Getline::). Also supplied in @@ -9210,7 +9216,8 @@ File: gawk.info, Node: Switch Statement, Next: Break Statement, Prev: For Sta 7.4.5 The `switch' Statement ---------------------------- -This minor node describes a `gawk'-specific feature. +This minor node describes a `gawk'-specific feature. If `gawk' is in +compatibility mode (*note Options::), it is not available. The `switch' statement allows the evaluation of an expression and the execution of statements based on a `case' match. Case statements @@ -9261,9 +9268,6 @@ is executed and then falls through into the `default' section, executing its `print' statement. In turn, the -1 case will also be executed since the `default' does not halt execution. - This `switch' statement is a `gawk' extension. If `gawk' is in -compatibility mode (*note Options::), it is not available. -  File: gawk.info, Node: Break Statement, Next: Continue Statement, Prev: Switch Statement, Up: Statements @@ -9276,15 +9280,15 @@ divisor of any integer, and also identifies prime numbers: # find smallest divisor of num { - num = $1 - for (div = 2; div * div <= num; div++) { - if (num % div == 0) - break - } - if (num % div == 0) - printf "Smallest divisor of %d is %d\n", num, div - else - printf "%d is prime\n", num + num = $1 + for (div = 2; div * div <= num; div++) { + if (num % div == 0) + break + } + if (num % div == 0) + printf "Smallest divisor of %d is %d\n", num, div + else + printf "%d is prime\n", num } When the remainder is zero in the first `if' statement, `awk' @@ -9299,17 +9303,17 @@ Statement::.) # find smallest divisor of num { - num = $1 - for (div = 2; ; div++) { - if (num % div == 0) { - printf "Smallest divisor of %d is %d\n", num, div - break - } - if (div * div > num) { - printf "%d is prime\n", num - break + num = $1 + for (div = 2; ; div++) { + if (num % div == 0) { + printf "Smallest divisor of %d is %d\n", num, div + break + } + if (div * div > num) { + printf "%d is prime\n", num + break + } } - } } The `break' statement is also used to break out of the `switch' @@ -9420,7 +9424,7 @@ rules. *Note BEGINFILE/ENDFILE::. According to the POSIX standard, the behavior is undefined if the `next' statement is used in a `BEGIN' or `END' rule. `gawk' treats it -as a syntax error. Although POSIX permits it, some other `awk' +as a syntax error. Although POSIX permits it, most other `awk' implementations don't allow the `next' statement inside function bodies (*note User-defined::). Just as with any other `next' statement, a `next' statement inside a function body reads the next record and @@ -9524,12 +9528,12 @@ with a nonzero status. An `awk' program can do this using an `exit' statement with a nonzero argument, as shown in the following example: BEGIN { - if (("date" | getline date_now) <= 0) { - print "Can't get system date" > "/dev/stderr" - exit 1 - } - print "current date is", date_now - close("date") + if (("date" | getline date_now) <= 0) { + print "Can't get system date" > "/dev/stderr" + exit 1 + } + print "current date is", date_now + close("date") } NOTE: For full portability, exit values should be between zero and @@ -27797,7 +27801,7 @@ Item Limit -------------------------------------------------------------------------- Characters in a character 2^(number of bits per byte) class -Length of input record `MAX_INT ' +Length of input record `MAX_INT' Length of output record Unlimited Length of source line Unlimited Number of fields in a record `MAX_LONG' @@ -27810,9 +27814,9 @@ Number of pipe redirections min(number of processes per user, number of open files) Numeric values Double-precision floating point (if not using MPFR) -Size of a field `MAX_INT ' -Size of a literal string `MAX_INT ' -Size of a printf string `MAX_INT ' +Size of a field `MAX_INT' +Size of a literal string `MAX_INT' +Size of a printf string `MAX_INT'  File: gawk.info, Node: Extension Design, Next: Old Extension Mechanism, Prev: Implementation Limitations, Up: Notes @@ -30129,7 +30133,7 @@ Index * $ (dollar sign), regexp operator: Regexp Operators. (line 35) * % (percent sign), % operator: Precedence. (line 55) * % (percent sign), %= operator <1>: Precedence. (line 95) -* % (percent sign), %= operator: Assignment Ops. (line 129) +* % (percent sign), %= operator: Assignment Ops. (line 130) * & (ampersand), && operator <1>: Precedence. (line 86) * & (ampersand), && operator: Boolean Ops. (line 57) * & (ampersand), gsub()/gensub()/sub() functions and: Gory Details. @@ -30150,9 +30154,9 @@ Index * * (asterisk), ** operator <1>: Precedence. (line 49) * * (asterisk), ** operator: Arithmetic Ops. (line 81) * * (asterisk), **= operator <1>: Precedence. (line 95) -* * (asterisk), **= operator: Assignment Ops. (line 129) +* * (asterisk), **= operator: Assignment Ops. (line 130) * * (asterisk), *= operator <1>: Precedence. (line 95) -* * (asterisk), *= operator: Assignment Ops. (line 129) +* * (asterisk), *= operator: Assignment Ops. (line 130) * + (plus sign), + operator: Precedence. (line 52) * + (plus sign), ++ operator <1>: Precedence. (line 46) * + (plus sign), ++ operator: Increment Ops. (line 11) @@ -30164,7 +30168,7 @@ Index * - (hyphen), -- operator <1>: Precedence. (line 46) * - (hyphen), -- operator: Increment Ops. (line 48) * - (hyphen), -= operator <1>: Precedence. (line 95) -* - (hyphen), -= operator: Assignment Ops. (line 129) +* - (hyphen), -= operator: Assignment Ops. (line 130) * - (hyphen), filenames beginning with: Options. (line 59) * - (hyphen), in bracket expressions: Bracket Expressions. (line 17) * --assign option: Options. (line 32) @@ -30260,11 +30264,11 @@ Index * / (forward slash) to enclose regular expressions: Regexp. (line 10) * / (forward slash), / operator: Precedence. (line 55) * / (forward slash), /= operator <1>: Precedence. (line 95) -* / (forward slash), /= operator: Assignment Ops. (line 129) +* / (forward slash), /= operator: Assignment Ops. (line 130) * / (forward slash), /= operator, vs. /=.../ regexp constant: Assignment Ops. - (line 147) + (line 148) * / (forward slash), patterns and: Expression Patterns. (line 24) -* /= operator vs. /=.../ regexp constant: Assignment Ops. (line 147) +* /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) * /dev/... special files: Special FD. (line 46) * /dev/fd/N special files (gawk): Special FD. (line 46) * /inet/... special files (gawk): TCP/IP Networking. (line 6) @@ -30354,7 +30358,7 @@ Index * \ (backslash), regexp operator: Regexp Operators. (line 18) * ^ (caret), ^ operator: Precedence. (line 49) * ^ (caret), ^= operator <1>: Precedence. (line 95) -* ^ (caret), ^= operator: Assignment Ops. (line 129) +* ^ (caret), ^= operator: Assignment Ops. (line 130) * ^ (caret), in bracket expressions: Bracket Expressions. (line 17) * ^ (caret), in FS: Regexp Field Splitting. (line 59) @@ -30399,7 +30403,7 @@ Index * amazing awk assembler (aaa): Glossary. (line 12) * amazingly workable formatter (awf): Glossary. (line 25) * ambiguity, syntactic: /= operator vs. /=.../ regexp constant: Assignment Ops. - (line 147) + (line 148) * ampersand (&), && operator <1>: Precedence. (line 86) * ampersand (&), && operator: Boolean Ops. (line 57) * ampersand (&), gsub()/gensub()/sub() functions and: Gory Details. @@ -30431,7 +30435,7 @@ Index * arguments, command-line <2>: Auto-set. (line 11) * arguments, command-line: Other Arguments. (line 6) * arguments, command-line, invoking awk: Command Line. (line 6) -* arguments, in function calls: Function Calls. (line 16) +* arguments, in function calls: Function Calls. (line 18) * arguments, processing: Getopt Function. (line 6) * ARGV array, indexing into: Other Arguments. (line 12) * arithmetic operators: Arithmetic Ops. (line 6) @@ -30510,14 +30514,14 @@ Index * asterisk (*), ** operator <1>: Precedence. (line 49) * asterisk (*), ** operator: Arithmetic Ops. (line 81) * asterisk (*), **= operator <1>: Precedence. (line 95) -* asterisk (*), **= operator: Assignment Ops. (line 129) +* asterisk (*), **= operator: Assignment Ops. (line 130) * asterisk (*), *= operator <1>: Precedence. (line 95) -* asterisk (*), *= operator: Assignment Ops. (line 129) +* asterisk (*), *= operator: Assignment Ops. (line 130) * atan2: Numeric Functions. (line 11) * automatic displays, in debugger: Debugger Info. (line 24) * awf (amazingly workable formatter) program: Glossary. (line 25) * awk debugging, enabling: Options. (line 108) -* awk language, POSIX version: Assignment Ops. (line 136) +* awk language, POSIX version: Assignment Ops. (line 137) * awk profiling, enabling: Options. (line 242) * awk programs <1>: Two Rules. (line 6) * awk programs <2>: Executable Scripts. (line 6) @@ -30763,7 +30767,7 @@ Index * call stack, display in debugger: Execution Stack. (line 13) * caret (^), ^ operator: Precedence. (line 49) * caret (^), ^= operator <1>: Precedence. (line 95) -* caret (^), ^= operator: Assignment Ops. (line 129) +* caret (^), ^= operator: Assignment Ops. (line 130) * caret (^), in bracket expressions: Bracket Expressions. (line 17) * caret (^), regexp operator <1>: GNU Regexp Operators. (line 59) @@ -30844,7 +30848,7 @@ Index * commenting: Comments. (line 6) * commenting, backslash continuation and: Statements/Lines. (line 76) * common extensions, ** operator: Arithmetic Ops. (line 30) -* common extensions, **= operator: Assignment Ops. (line 136) +* common extensions, **= operator: Assignment Ops. (line 137) * common extensions, /dev/stderr special file: Special FD. (line 46) * common extensions, /dev/stdin special file: Special FD. (line 46) * common extensions, /dev/stdout special file: Special FD. (line 46) @@ -30948,7 +30952,7 @@ Index * dark corner: Conventions. (line 38) * dark corner, "0" is actually true: Truth Values. (line 24) * dark corner, /= operator vs. /=.../ regexp constant: Assignment Ops. - (line 147) + (line 148) * dark corner, ^, in FS: Regexp Field Splitting. (line 59) * dark corner, array subscripts: Uninitialized Subscripts. @@ -30974,14 +30978,14 @@ Index * dark corner, input files: awk split records. (line 110) * dark corner, invoking awk: Command Line. (line 16) * dark corner, length() function: String Functions. (line 180) -* dark corner, locale's decimal point character: Conversion. (line 77) +* dark corner, locale's decimal point character: Conversion. (line 75) * dark corner, multiline records: Multiple Line. (line 35) * dark corner, NF variable, decrementing: Changing Fields. (line 107) * dark corner, OFMT variable: OFMT. (line 27) * dark corner, regexp constants: Using Constant Regexps. (line 6) * dark corner, regexp constants, /= operator and: Assignment Ops. - (line 147) + (line 148) * dark corner, regexp constants, as arguments to user-defined functions: Using Constant Regexps. (line 43) * dark corner, split() function: String Functions. (line 359) @@ -31365,7 +31369,7 @@ Index * extensions, Brian Kernighan's awk <1>: Common Extensions. (line 6) * extensions, Brian Kernighan's awk: BTL. (line 6) * extensions, common, ** operator: Arithmetic Ops. (line 30) -* extensions, common, **= operator: Assignment Ops. (line 136) +* extensions, common, **= operator: Assignment Ops. (line 137) * extensions, common, /dev/stderr special file: Special FD. (line 46) * extensions, common, /dev/stdin special file: Special FD. (line 46) * extensions, common, /dev/stdout special file: Special FD. (line 46) @@ -31523,9 +31527,9 @@ Index * forward slash (/) to enclose regular expressions: Regexp. (line 10) * forward slash (/), / operator: Precedence. (line 55) * forward slash (/), /= operator <1>: Precedence. (line 95) -* forward slash (/), /= operator: Assignment Ops. (line 129) +* forward slash (/), /= operator: Assignment Ops. (line 130) * forward slash (/), /= operator, vs. /=.../ regexp constant: Assignment Ops. - (line 147) + (line 148) * forward slash (/), patterns and: Expression Patterns. (line 24) * FPAT variable <1>: User-modified. (line 45) * FPAT variable: Splitting By Content. @@ -31803,7 +31807,7 @@ Index * hyphen (-), -- operator <1>: Precedence. (line 46) * hyphen (-), -- operator: Increment Ops. (line 48) * hyphen (-), -= operator <1>: Precedence. (line 95) -* hyphen (-), -= operator: Assignment Ops. (line 129) +* hyphen (-), -= operator: Assignment Ops. (line 130) * hyphen (-), filenames beginning with: Options. (line 59) * hyphen (-), in bracket expressions: Bracket Expressions. (line 17) * i debugger command (alias for info): Debugger Info. (line 13) @@ -32285,7 +32289,7 @@ Index * PC operating systems, gawk on, installing: PC Installation. (line 6) * percent sign (%), % operator: Precedence. (line 55) * percent sign (%), %= operator <1>: Precedence. (line 95) -* percent sign (%), %= operator: Assignment Ops. (line 129) +* percent sign (%), %= operator: Assignment Ops. (line 130) * period (.), regexp operator: Regexp Operators. (line 44) * Perl: Future Extensions. (line 6) * Peters, Arno: Contributors. (line 85) @@ -32308,7 +32312,7 @@ Index * portability: Escape Sequences. (line 94) * portability, #! (executable scripts): Executable Scripts. (line 33) * portability, ** operator and: Arithmetic Ops. (line 81) -* portability, **= operator and: Assignment Ops. (line 142) +* portability, **= operator and: Assignment Ops. (line 143) * portability, ARGV variable: Executable Scripts. (line 42) * portability, backslash continuation and: Statements/Lines. (line 30) * portability, backslash in escape sequences: Escape Sequences. @@ -32345,10 +32349,10 @@ Index * positional specifiers, printf statement, mixing with regular formats: Printf Ordering. (line 57) * positive zero: Unexpected Results. (line 34) -* POSIX awk <1>: Assignment Ops. (line 136) +* POSIX awk <1>: Assignment Ops. (line 137) * POSIX awk: This Manual. (line 14) * POSIX awk, ** operator and: Precedence. (line 98) -* POSIX awk, **= operator and: Assignment Ops. (line 142) +* POSIX awk, **= operator and: Assignment Ops. (line 143) * POSIX awk, < operator and: Getline/File. (line 26) * POSIX awk, arithmetic operators and: Arithmetic Ops. (line 30) * POSIX awk, backslashes in string constants: Escape Sequences. @@ -32538,7 +32542,7 @@ Index (line 102) * regexp constants <2>: Regexp Constants. (line 6) * regexp constants: Regexp Usage. (line 57) -* regexp constants, /=.../, /= operator and: Assignment Ops. (line 147) +* regexp constants, /=.../, /= operator and: Assignment Ops. (line 148) * regexp constants, as patterns: Expression Patterns. (line 34) * regexp constants, in gawk: Using Constant Regexps. (line 28) @@ -32735,7 +32739,7 @@ Index * side effects, conditional expressions: Conditional Exp. (line 22) * side effects, decrement/increment operators: Increment Ops. (line 11) * side effects, FILENAME variable: Getline Notes. (line 19) -* side effects, function calls: Function Calls. (line 54) +* side effects, function calls: Function Calls. (line 56) * side effects, statements: Action Overview. (line 32) * sidebar, A Constant's Base Does Not Affect Its Value: Nondecimal-numbers. (line 64) @@ -32761,7 +32765,7 @@ Index * sidebar, So Why Does gawk have BEGINFILE and ENDFILE?: Filetrans Function. (line 83) * sidebar, Syntactic Ambiguities Between /= and Regular Expressions: Assignment Ops. - (line 145) + (line 146) * sidebar, Understanding $0: Changing Fields. (line 134) * sidebar, Using \n in Bracket Expressions of Dynamic Regexps: Computed Regexps. (line 57) @@ -32909,7 +32913,7 @@ Index * switch statement: Switch Statement. (line 6) * SYMTAB array: Auto-set. (line 274) * syntactic ambiguity: /= operator vs. /=.../ regexp constant: Assignment Ops. - (line 147) + (line 148) * system: I/O Functions. (line 72) * systime: Time Functions. (line 66) * t debugger command (alias for tbreak): Breakpoint Control. (line 90) @@ -32981,7 +32985,7 @@ Index * troubleshooting, fatal errors, printf format strings: Format Modifiers. (line 159) * troubleshooting, fflush() function: I/O Functions. (line 60) -* troubleshooting, function call syntax: Function Calls. (line 28) +* troubleshooting, function call syntax: Function Calls. (line 30) * troubleshooting, gawk: Compatibility Mode. (line 6) * troubleshooting, gawk, bug reports: Bugs. (line 9) * troubleshooting, gawk, fatal errors, function arguments: Calling Built-in. @@ -33309,400 +33313,400 @@ Node: Values299487 Node: Constants300163 Node: Scalar Constants300843 Ref: Scalar Constants-Footnote-1301702 -Node: Nondecimal-numbers301884 -Node: Regexp Constants304884 -Node: Using Constant Regexps305359 -Node: Variables308414 -Node: Using Variables309069 -Node: Assignment Options310793 -Node: Conversion312668 -Ref: table-locale-affects318168 -Ref: Conversion-Footnote-1318792 -Node: All Operators318901 -Node: Arithmetic Ops319531 -Node: Concatenation322036 -Ref: Concatenation-Footnote-1324824 -Node: Assignment Ops324944 -Ref: table-assign-ops329932 -Node: Increment Ops331263 -Node: Truth Values and Conditions334697 -Node: Truth Values335780 -Node: Typing and Comparison336829 -Node: Variable Typing337622 -Ref: Variable Typing-Footnote-1341519 -Node: Comparison Operators341641 -Ref: table-relational-ops342051 -Node: POSIX String Comparison345599 -Ref: POSIX String Comparison-Footnote-1346555 -Node: Boolean Ops346693 -Ref: Boolean Ops-Footnote-1350763 -Node: Conditional Exp350854 -Node: Function Calls352586 -Node: Precedence356180 -Node: Locales359849 -Node: Patterns and Actions360938 -Node: Pattern Overview361992 -Node: Regexp Patterns363661 -Node: Expression Patterns364204 -Node: Ranges367985 -Node: BEGIN/END371089 -Node: Using BEGIN/END371851 -Ref: Using BEGIN/END-Footnote-1374587 -Node: I/O And BEGIN/END374693 -Node: BEGINFILE/ENDFILE376975 -Node: Empty379889 -Node: Using Shell Variables380206 -Node: Action Overview382491 -Node: Statements384848 -Node: If Statement386702 -Node: While Statement388201 -Node: Do Statement390245 -Node: For Statement391401 -Node: Switch Statement394553 -Node: Break Statement396707 -Node: Continue Statement398697 -Node: Next Statement400490 -Node: Nextfile Statement402880 -Node: Exit Statement405535 -Node: Built-in Variables407951 -Node: User-modified409046 -Ref: User-modified-Footnote-1417404 -Node: Auto-set417466 -Ref: Auto-set-Footnote-1430533 -Ref: Auto-set-Footnote-2430738 -Node: ARGC and ARGV430794 -Node: Arrays434648 -Node: Array Basics436153 -Node: Array Intro436979 -Node: Reference to Elements441296 -Node: Assigning Elements443566 -Node: Array Example444057 -Node: Scanning an Array445789 -Node: Controlling Scanning448103 -Ref: Controlling Scanning-Footnote-1453190 -Node: Delete453506 -Ref: Delete-Footnote-1456271 -Node: Numeric Array Subscripts456328 -Node: Uninitialized Subscripts458511 -Node: Multidimensional460138 -Node: Multiscanning463231 -Node: Arrays of Arrays464820 -Node: Functions469460 -Node: Built-in470279 -Node: Calling Built-in471357 -Node: Numeric Functions473345 -Ref: Numeric Functions-Footnote-1477179 -Ref: Numeric Functions-Footnote-2477536 -Ref: Numeric Functions-Footnote-3477584 -Node: String Functions477853 -Ref: String Functions-Footnote-1500856 -Ref: String Functions-Footnote-2500985 -Ref: String Functions-Footnote-3501233 -Node: Gory Details501320 -Ref: table-sub-escapes502999 -Ref: table-sub-posix-92504353 -Ref: table-sub-proposed505704 -Ref: table-posix-sub507058 -Ref: table-gensub-escapes508603 -Ref: Gory Details-Footnote-1509779 -Ref: Gory Details-Footnote-2509830 -Node: I/O Functions509981 -Ref: I/O Functions-Footnote-1516977 -Node: Time Functions517124 -Ref: Time Functions-Footnote-1528117 -Ref: Time Functions-Footnote-2528185 -Ref: Time Functions-Footnote-3528343 -Ref: Time Functions-Footnote-4528454 -Ref: Time Functions-Footnote-5528566 -Ref: Time Functions-Footnote-6528793 -Node: Bitwise Functions529059 -Ref: table-bitwise-ops529621 -Ref: Bitwise Functions-Footnote-1533866 -Node: Type Functions534050 -Node: I18N Functions535201 -Node: User-defined536853 -Node: Definition Syntax537657 -Ref: Definition Syntax-Footnote-1542571 -Node: Function Example542640 -Ref: Function Example-Footnote-1545289 -Node: Function Caveats545311 -Node: Calling A Function545829 -Node: Variable Scope546784 -Node: Pass By Value/Reference549747 -Node: Return Statement553255 -Node: Dynamic Typing556236 -Node: Indirect Calls557167 -Node: Library Functions566854 -Ref: Library Functions-Footnote-1570367 -Ref: Library Functions-Footnote-2570510 -Node: Library Names570681 -Ref: Library Names-Footnote-1574154 -Ref: Library Names-Footnote-2574374 -Node: General Functions574460 -Node: Strtonum Function575488 -Node: Assert Function578418 -Node: Round Function581744 -Node: Cliff Random Function583285 -Node: Ordinal Functions584301 -Ref: Ordinal Functions-Footnote-1587378 -Ref: Ordinal Functions-Footnote-2587630 -Node: Join Function587841 -Ref: Join Function-Footnote-1589612 -Node: Getlocaltime Function589812 -Node: Readfile Function593553 -Node: Data File Management595392 -Node: Filetrans Function596024 -Node: Rewind Function600093 -Node: File Checking601480 -Node: Empty Files602574 -Node: Ignoring Assigns604804 -Node: Getopt Function606358 -Ref: Getopt Function-Footnote-1617661 -Node: Passwd Functions617864 -Ref: Passwd Functions-Footnote-1626842 -Node: Group Functions626930 -Node: Walking Arrays635014 -Node: Sample Programs637150 -Node: Running Examples637824 -Node: Clones638552 -Node: Cut Program639776 -Node: Egrep Program649627 -Ref: Egrep Program-Footnote-1657400 -Node: Id Program657510 -Node: Split Program661159 -Ref: Split Program-Footnote-1664678 -Node: Tee Program664806 -Node: Uniq Program667609 -Node: Wc Program675038 -Ref: Wc Program-Footnote-1679304 -Ref: Wc Program-Footnote-2679504 -Node: Miscellaneous Programs679596 -Node: Dupword Program680784 -Node: Alarm Program682815 -Node: Translate Program687622 -Ref: Translate Program-Footnote-1692009 -Ref: Translate Program-Footnote-2692257 -Node: Labels Program692391 -Ref: Labels Program-Footnote-1695762 -Node: Word Sorting695846 -Node: History Sorting699730 -Node: Extract Program701569 -Ref: Extract Program-Footnote-1709072 -Node: Simple Sed709200 -Node: Igawk Program712262 -Ref: Igawk Program-Footnote-1727433 -Ref: Igawk Program-Footnote-2727634 -Node: Anagram Program727772 -Node: Signature Program730840 -Node: Advanced Features731940 -Node: Nondecimal Data733826 -Node: Array Sorting735409 -Node: Controlling Array Traversal736106 -Node: Array Sorting Functions744390 -Ref: Array Sorting Functions-Footnote-1748259 -Node: Two-way I/O748453 -Ref: Two-way I/O-Footnote-1753885 -Node: TCP/IP Networking753967 -Node: Profiling756811 -Node: Internationalization764314 -Node: I18N and L10N765739 -Node: Explaining gettext766425 -Ref: Explaining gettext-Footnote-1771493 -Ref: Explaining gettext-Footnote-2771677 -Node: Programmer i18n771842 -Node: Translator i18n776069 -Node: String Extraction776863 -Ref: String Extraction-Footnote-1777824 -Node: Printf Ordering777910 -Ref: Printf Ordering-Footnote-1780692 -Node: I18N Portability780756 -Ref: I18N Portability-Footnote-1783205 -Node: I18N Example783268 -Ref: I18N Example-Footnote-1785906 -Node: Gawk I18N785978 -Node: Debugger786599 -Node: Debugging787570 -Node: Debugging Concepts788003 -Node: Debugging Terms789859 -Node: Awk Debugging792456 -Node: Sample Debugging Session793348 -Node: Debugger Invocation793868 -Node: Finding The Bug795201 -Node: List of Debugger Commands801688 -Node: Breakpoint Control803022 -Node: Debugger Execution Control806686 -Node: Viewing And Changing Data810046 -Node: Execution Stack813402 -Node: Debugger Info814869 -Node: Miscellaneous Debugger Commands818863 -Node: Readline Support824041 -Node: Limitations824872 -Node: Arbitrary Precision Arithmetic827124 -Ref: Arbitrary Precision Arithmetic-Footnote-1828773 -Node: General Arithmetic828921 -Node: Floating Point Issues830641 -Node: String Conversion Precision831522 -Ref: String Conversion Precision-Footnote-1833227 -Node: Unexpected Results833336 -Node: POSIX Floating Point Problems835489 -Ref: POSIX Floating Point Problems-Footnote-1839314 -Node: Integer Programming839352 -Node: Floating-point Programming841091 -Ref: Floating-point Programming-Footnote-1847422 -Ref: Floating-point Programming-Footnote-2847692 -Node: Floating-point Representation847956 -Node: Floating-point Context849121 -Ref: table-ieee-formats849960 -Node: Rounding Mode851344 -Ref: table-rounding-modes851823 -Ref: Rounding Mode-Footnote-1854838 -Node: Gawk and MPFR855017 -Node: Arbitrary Precision Floats856426 -Ref: Arbitrary Precision Floats-Footnote-1858869 -Node: Setting Precision859185 -Ref: table-predefined-precision-strings859871 -Node: Setting Rounding Mode862016 -Ref: table-gawk-rounding-modes862420 -Node: Floating-point Constants863607 -Node: Changing Precision865036 -Ref: Changing Precision-Footnote-1866433 -Node: Exact Arithmetic866607 -Node: Arbitrary Precision Integers869745 -Ref: Arbitrary Precision Integers-Footnote-1872760 -Node: Dynamic Extensions872907 -Node: Extension Intro874365 -Node: Plugin License875630 -Node: Extension Mechanism Outline876315 -Ref: load-extension876732 -Ref: load-new-function878210 -Ref: call-new-function879205 -Node: Extension API Description881220 -Node: Extension API Functions Introduction882507 -Node: General Data Types887434 -Ref: General Data Types-Footnote-1893129 -Node: Requesting Values893428 -Ref: table-value-types-returned894165 -Node: Memory Allocation Functions895119 -Ref: Memory Allocation Functions-Footnote-1897865 -Node: Constructor Functions897961 -Node: Registration Functions899719 -Node: Extension Functions900404 -Node: Exit Callback Functions902706 -Node: Extension Version String903955 -Node: Input Parsers904605 -Node: Output Wrappers914362 -Node: Two-way processors918872 -Node: Printing Messages921080 -Ref: Printing Messages-Footnote-1922157 -Node: Updating `ERRNO'922309 -Node: Accessing Parameters923048 -Node: Symbol Table Access924278 -Node: Symbol table by name924792 -Node: Symbol table by cookie926768 -Ref: Symbol table by cookie-Footnote-1930900 -Node: Cached values930963 -Ref: Cached values-Footnote-1934453 -Node: Array Manipulation934544 -Ref: Array Manipulation-Footnote-1935642 -Node: Array Data Types935681 -Ref: Array Data Types-Footnote-1938384 -Node: Array Functions938476 -Node: Flattening Arrays942312 -Node: Creating Arrays949164 -Node: Extension API Variables953889 -Node: Extension Versioning954525 -Node: Extension API Informational Variables956426 -Node: Extension API Boilerplate957512 -Node: Finding Extensions961316 -Node: Extension Example961876 -Node: Internal File Description962606 -Node: Internal File Ops966697 -Ref: Internal File Ops-Footnote-1978206 -Node: Using Internal File Ops978346 -Ref: Using Internal File Ops-Footnote-1980693 -Node: Extension Samples980959 -Node: Extension Sample File Functions982483 -Node: Extension Sample Fnmatch990970 -Node: Extension Sample Fork992739 -Node: Extension Sample Inplace993952 -Node: Extension Sample Ord995730 -Node: Extension Sample Readdir996566 -Node: Extension Sample Revout998098 -Node: Extension Sample Rev2way998691 -Node: Extension Sample Read write array999381 -Node: Extension Sample Readfile1001264 -Node: Extension Sample API Tests1002364 -Node: Extension Sample Time1002889 -Node: gawkextlib1004253 -Node: Language History1007034 -Node: V7/SVR3.11008627 -Node: SVR41010947 -Node: POSIX1012389 -Node: BTL1013775 -Node: POSIX/GNU1014509 -Node: Feature History1020108 -Node: Common Extensions1033084 -Node: Ranges and Locales1034396 -Ref: Ranges and Locales-Footnote-11039013 -Ref: Ranges and Locales-Footnote-21039040 -Ref: Ranges and Locales-Footnote-31039274 -Node: Contributors1039495 -Node: Installation1044876 -Node: Gawk Distribution1045770 -Node: Getting1046254 -Node: Extracting1047080 -Node: Distribution contents1048772 -Node: Unix Installation1054493 -Node: Quick Installation1055110 -Node: Additional Configuration Options1057556 -Node: Configuration Philosophy1059292 -Node: Non-Unix Installation1061646 -Node: PC Installation1062104 -Node: PC Binary Installation1063403 -Node: PC Compiling1065251 -Node: PC Testing1068195 -Node: PC Using1069371 -Node: Cygwin1073539 -Node: MSYS1074348 -Node: VMS Installation1074862 -Node: VMS Compilation1075658 -Ref: VMS Compilation-Footnote-11076910 -Node: VMS Dynamic Extensions1076968 -Node: VMS Installation Details1078341 -Node: VMS Running1080592 -Node: VMS GNV1083426 -Node: VMS Old Gawk1084149 -Node: Bugs1084619 -Node: Other Versions1088537 -Node: Notes1094621 -Node: Compatibility Mode1095421 -Node: Additions1096204 -Node: Accessing The Source1097131 -Node: Adding Code1098571 -Node: New Ports1104616 -Node: Derived Files1108751 -Ref: Derived Files-Footnote-11114072 -Ref: Derived Files-Footnote-21114106 -Ref: Derived Files-Footnote-31114706 -Node: Future Extensions1114804 -Node: Implementation Limitations1115387 -Node: Extension Design1116639 -Node: Old Extension Problems1117793 -Ref: Old Extension Problems-Footnote-11119301 -Node: Extension New Mechanism Goals1119358 -Ref: Extension New Mechanism Goals-Footnote-11122723 -Node: Extension Other Design Decisions1122909 -Node: Extension Future Growth1125015 -Node: Old Extension Mechanism1125851 -Node: Basic Concepts1127591 -Node: Basic High Level1128272 -Ref: figure-general-flow1128544 -Ref: figure-process-flow1129143 -Ref: Basic High Level-Footnote-11132372 -Node: Basic Data Typing1132557 -Node: Glossary1135912 -Node: Copying1161143 -Node: GNU Free Documentation License1198699 -Node: Index1223835 +Node: Nondecimal-numbers301952 +Node: Regexp Constants304952 +Node: Using Constant Regexps305427 +Node: Variables308497 +Node: Using Variables309152 +Node: Assignment Options310876 +Node: Conversion312751 +Ref: table-locale-affects318187 +Ref: Conversion-Footnote-1318811 +Node: All Operators318920 +Node: Arithmetic Ops319550 +Node: Concatenation322055 +Ref: Concatenation-Footnote-1324851 +Node: Assignment Ops324971 +Ref: table-assign-ops329954 +Node: Increment Ops331271 +Node: Truth Values and Conditions334709 +Node: Truth Values335792 +Node: Typing and Comparison336841 +Node: Variable Typing337634 +Ref: Variable Typing-Footnote-1341534 +Node: Comparison Operators341656 +Ref: table-relational-ops342066 +Node: POSIX String Comparison345614 +Ref: POSIX String Comparison-Footnote-1346698 +Node: Boolean Ops346836 +Ref: Boolean Ops-Footnote-1350906 +Node: Conditional Exp350997 +Node: Function Calls352724 +Node: Precedence356482 +Node: Locales360151 +Node: Patterns and Actions361240 +Node: Pattern Overview362294 +Node: Regexp Patterns363971 +Node: Expression Patterns364514 +Node: Ranges368295 +Node: BEGIN/END371401 +Node: Using BEGIN/END372163 +Ref: Using BEGIN/END-Footnote-1374899 +Node: I/O And BEGIN/END375005 +Node: BEGINFILE/ENDFILE377290 +Node: Empty380226 +Node: Using Shell Variables380543 +Node: Action Overview382826 +Node: Statements385171 +Node: If Statement387025 +Node: While Statement388524 +Node: Do Statement390568 +Node: For Statement391724 +Node: Switch Statement394876 +Node: Break Statement396979 +Node: Continue Statement399034 +Node: Next Statement400827 +Node: Nextfile Statement403217 +Node: Exit Statement405872 +Node: Built-in Variables408274 +Node: User-modified409369 +Ref: User-modified-Footnote-1417727 +Node: Auto-set417789 +Ref: Auto-set-Footnote-1430856 +Ref: Auto-set-Footnote-2431061 +Node: ARGC and ARGV431117 +Node: Arrays434971 +Node: Array Basics436476 +Node: Array Intro437302 +Node: Reference to Elements441619 +Node: Assigning Elements443889 +Node: Array Example444380 +Node: Scanning an Array446112 +Node: Controlling Scanning448426 +Ref: Controlling Scanning-Footnote-1453513 +Node: Delete453829 +Ref: Delete-Footnote-1456594 +Node: Numeric Array Subscripts456651 +Node: Uninitialized Subscripts458834 +Node: Multidimensional460461 +Node: Multiscanning463554 +Node: Arrays of Arrays465143 +Node: Functions469783 +Node: Built-in470602 +Node: Calling Built-in471680 +Node: Numeric Functions473668 +Ref: Numeric Functions-Footnote-1477502 +Ref: Numeric Functions-Footnote-2477859 +Ref: Numeric Functions-Footnote-3477907 +Node: String Functions478176 +Ref: String Functions-Footnote-1501179 +Ref: String Functions-Footnote-2501308 +Ref: String Functions-Footnote-3501556 +Node: Gory Details501643 +Ref: table-sub-escapes503322 +Ref: table-sub-posix-92504676 +Ref: table-sub-proposed506027 +Ref: table-posix-sub507381 +Ref: table-gensub-escapes508926 +Ref: Gory Details-Footnote-1510102 +Ref: Gory Details-Footnote-2510153 +Node: I/O Functions510304 +Ref: I/O Functions-Footnote-1517300 +Node: Time Functions517447 +Ref: Time Functions-Footnote-1528440 +Ref: Time Functions-Footnote-2528508 +Ref: Time Functions-Footnote-3528666 +Ref: Time Functions-Footnote-4528777 +Ref: Time Functions-Footnote-5528889 +Ref: Time Functions-Footnote-6529116 +Node: Bitwise Functions529382 +Ref: table-bitwise-ops529944 +Ref: Bitwise Functions-Footnote-1534189 +Node: Type Functions534373 +Node: I18N Functions535524 +Node: User-defined537176 +Node: Definition Syntax537980 +Ref: Definition Syntax-Footnote-1542894 +Node: Function Example542963 +Ref: Function Example-Footnote-1545612 +Node: Function Caveats545634 +Node: Calling A Function546152 +Node: Variable Scope547107 +Node: Pass By Value/Reference550070 +Node: Return Statement553578 +Node: Dynamic Typing556559 +Node: Indirect Calls557490 +Node: Library Functions567177 +Ref: Library Functions-Footnote-1570690 +Ref: Library Functions-Footnote-2570833 +Node: Library Names571004 +Ref: Library Names-Footnote-1574477 +Ref: Library Names-Footnote-2574697 +Node: General Functions574783 +Node: Strtonum Function575811 +Node: Assert Function578741 +Node: Round Function582067 +Node: Cliff Random Function583608 +Node: Ordinal Functions584624 +Ref: Ordinal Functions-Footnote-1587701 +Ref: Ordinal Functions-Footnote-2587953 +Node: Join Function588164 +Ref: Join Function-Footnote-1589935 +Node: Getlocaltime Function590135 +Node: Readfile Function593876 +Node: Data File Management595715 +Node: Filetrans Function596347 +Node: Rewind Function600416 +Node: File Checking601803 +Node: Empty Files602897 +Node: Ignoring Assigns605127 +Node: Getopt Function606681 +Ref: Getopt Function-Footnote-1617984 +Node: Passwd Functions618187 +Ref: Passwd Functions-Footnote-1627165 +Node: Group Functions627253 +Node: Walking Arrays635337 +Node: Sample Programs637473 +Node: Running Examples638147 +Node: Clones638875 +Node: Cut Program640099 +Node: Egrep Program649950 +Ref: Egrep Program-Footnote-1657723 +Node: Id Program657833 +Node: Split Program661482 +Ref: Split Program-Footnote-1665001 +Node: Tee Program665129 +Node: Uniq Program667932 +Node: Wc Program675361 +Ref: Wc Program-Footnote-1679627 +Ref: Wc Program-Footnote-2679827 +Node: Miscellaneous Programs679919 +Node: Dupword Program681107 +Node: Alarm Program683138 +Node: Translate Program687945 +Ref: Translate Program-Footnote-1692332 +Ref: Translate Program-Footnote-2692580 +Node: Labels Program692714 +Ref: Labels Program-Footnote-1696085 +Node: Word Sorting696169 +Node: History Sorting700053 +Node: Extract Program701892 +Ref: Extract Program-Footnote-1709395 +Node: Simple Sed709523 +Node: Igawk Program712585 +Ref: Igawk Program-Footnote-1727756 +Ref: Igawk Program-Footnote-2727957 +Node: Anagram Program728095 +Node: Signature Program731163 +Node: Advanced Features732263 +Node: Nondecimal Data734149 +Node: Array Sorting735732 +Node: Controlling Array Traversal736429 +Node: Array Sorting Functions744713 +Ref: Array Sorting Functions-Footnote-1748582 +Node: Two-way I/O748776 +Ref: Two-way I/O-Footnote-1754208 +Node: TCP/IP Networking754290 +Node: Profiling757134 +Node: Internationalization764637 +Node: I18N and L10N766062 +Node: Explaining gettext766748 +Ref: Explaining gettext-Footnote-1771816 +Ref: Explaining gettext-Footnote-2772000 +Node: Programmer i18n772165 +Node: Translator i18n776392 +Node: String Extraction777186 +Ref: String Extraction-Footnote-1778147 +Node: Printf Ordering778233 +Ref: Printf Ordering-Footnote-1781015 +Node: I18N Portability781079 +Ref: I18N Portability-Footnote-1783528 +Node: I18N Example783591 +Ref: I18N Example-Footnote-1786229 +Node: Gawk I18N786301 +Node: Debugger786922 +Node: Debugging787893 +Node: Debugging Concepts788326 +Node: Debugging Terms790182 +Node: Awk Debugging792779 +Node: Sample Debugging Session793671 +Node: Debugger Invocation794191 +Node: Finding The Bug795524 +Node: List of Debugger Commands802011 +Node: Breakpoint Control803345 +Node: Debugger Execution Control807009 +Node: Viewing And Changing Data810369 +Node: Execution Stack813725 +Node: Debugger Info815192 +Node: Miscellaneous Debugger Commands819186 +Node: Readline Support824364 +Node: Limitations825195 +Node: Arbitrary Precision Arithmetic827447 +Ref: Arbitrary Precision Arithmetic-Footnote-1829096 +Node: General Arithmetic829244 +Node: Floating Point Issues830964 +Node: String Conversion Precision831845 +Ref: String Conversion Precision-Footnote-1833550 +Node: Unexpected Results833659 +Node: POSIX Floating Point Problems835812 +Ref: POSIX Floating Point Problems-Footnote-1839637 +Node: Integer Programming839675 +Node: Floating-point Programming841414 +Ref: Floating-point Programming-Footnote-1847745 +Ref: Floating-point Programming-Footnote-2848015 +Node: Floating-point Representation848279 +Node: Floating-point Context849444 +Ref: table-ieee-formats850283 +Node: Rounding Mode851667 +Ref: table-rounding-modes852146 +Ref: Rounding Mode-Footnote-1855161 +Node: Gawk and MPFR855340 +Node: Arbitrary Precision Floats856749 +Ref: Arbitrary Precision Floats-Footnote-1859192 +Node: Setting Precision859508 +Ref: table-predefined-precision-strings860194 +Node: Setting Rounding Mode862339 +Ref: table-gawk-rounding-modes862743 +Node: Floating-point Constants863930 +Node: Changing Precision865359 +Ref: Changing Precision-Footnote-1866756 +Node: Exact Arithmetic866930 +Node: Arbitrary Precision Integers870068 +Ref: Arbitrary Precision Integers-Footnote-1873083 +Node: Dynamic Extensions873230 +Node: Extension Intro874688 +Node: Plugin License875953 +Node: Extension Mechanism Outline876638 +Ref: load-extension877055 +Ref: load-new-function878533 +Ref: call-new-function879528 +Node: Extension API Description881543 +Node: Extension API Functions Introduction882830 +Node: General Data Types887757 +Ref: General Data Types-Footnote-1893452 +Node: Requesting Values893751 +Ref: table-value-types-returned894488 +Node: Memory Allocation Functions895442 +Ref: Memory Allocation Functions-Footnote-1898188 +Node: Constructor Functions898284 +Node: Registration Functions900042 +Node: Extension Functions900727 +Node: Exit Callback Functions903029 +Node: Extension Version String904278 +Node: Input Parsers904928 +Node: Output Wrappers914685 +Node: Two-way processors919195 +Node: Printing Messages921403 +Ref: Printing Messages-Footnote-1922480 +Node: Updating `ERRNO'922632 +Node: Accessing Parameters923371 +Node: Symbol Table Access924601 +Node: Symbol table by name925115 +Node: Symbol table by cookie927091 +Ref: Symbol table by cookie-Footnote-1931223 +Node: Cached values931286 +Ref: Cached values-Footnote-1934776 +Node: Array Manipulation934867 +Ref: Array Manipulation-Footnote-1935965 +Node: Array Data Types936004 +Ref: Array Data Types-Footnote-1938707 +Node: Array Functions938799 +Node: Flattening Arrays942635 +Node: Creating Arrays949487 +Node: Extension API Variables954212 +Node: Extension Versioning954848 +Node: Extension API Informational Variables956749 +Node: Extension API Boilerplate957835 +Node: Finding Extensions961639 +Node: Extension Example962199 +Node: Internal File Description962929 +Node: Internal File Ops967020 +Ref: Internal File Ops-Footnote-1978529 +Node: Using Internal File Ops978669 +Ref: Using Internal File Ops-Footnote-1981016 +Node: Extension Samples981282 +Node: Extension Sample File Functions982806 +Node: Extension Sample Fnmatch991293 +Node: Extension Sample Fork993062 +Node: Extension Sample Inplace994275 +Node: Extension Sample Ord996053 +Node: Extension Sample Readdir996889 +Node: Extension Sample Revout998421 +Node: Extension Sample Rev2way999014 +Node: Extension Sample Read write array999704 +Node: Extension Sample Readfile1001587 +Node: Extension Sample API Tests1002687 +Node: Extension Sample Time1003212 +Node: gawkextlib1004576 +Node: Language History1007357 +Node: V7/SVR3.11008950 +Node: SVR41011270 +Node: POSIX1012712 +Node: BTL1014098 +Node: POSIX/GNU1014832 +Node: Feature History1020431 +Node: Common Extensions1033407 +Node: Ranges and Locales1034719 +Ref: Ranges and Locales-Footnote-11039336 +Ref: Ranges and Locales-Footnote-21039363 +Ref: Ranges and Locales-Footnote-31039597 +Node: Contributors1039818 +Node: Installation1045199 +Node: Gawk Distribution1046093 +Node: Getting1046577 +Node: Extracting1047403 +Node: Distribution contents1049095 +Node: Unix Installation1054816 +Node: Quick Installation1055433 +Node: Additional Configuration Options1057879 +Node: Configuration Philosophy1059615 +Node: Non-Unix Installation1061969 +Node: PC Installation1062427 +Node: PC Binary Installation1063726 +Node: PC Compiling1065574 +Node: PC Testing1068518 +Node: PC Using1069694 +Node: Cygwin1073862 +Node: MSYS1074671 +Node: VMS Installation1075185 +Node: VMS Compilation1075981 +Ref: VMS Compilation-Footnote-11077233 +Node: VMS Dynamic Extensions1077291 +Node: VMS Installation Details1078664 +Node: VMS Running1080915 +Node: VMS GNV1083749 +Node: VMS Old Gawk1084472 +Node: Bugs1084942 +Node: Other Versions1088860 +Node: Notes1094944 +Node: Compatibility Mode1095744 +Node: Additions1096527 +Node: Accessing The Source1097454 +Node: Adding Code1098894 +Node: New Ports1104939 +Node: Derived Files1109074 +Ref: Derived Files-Footnote-11114395 +Ref: Derived Files-Footnote-21114429 +Ref: Derived Files-Footnote-31115029 +Node: Future Extensions1115127 +Node: Implementation Limitations1115710 +Node: Extension Design1116958 +Node: Old Extension Problems1118112 +Ref: Old Extension Problems-Footnote-11119620 +Node: Extension New Mechanism Goals1119677 +Ref: Extension New Mechanism Goals-Footnote-11123042 +Node: Extension Other Design Decisions1123228 +Node: Extension Future Growth1125334 +Node: Old Extension Mechanism1126170 +Node: Basic Concepts1127910 +Node: Basic High Level1128591 +Ref: figure-general-flow1128863 +Ref: figure-process-flow1129462 +Ref: Basic High Level-Footnote-11132691 +Node: Basic Data Typing1132876 +Node: Glossary1136231 +Node: Copying1161462 +Node: GNU Free Documentation License1199018 +Node: Index1224154  End Tag Table -- cgit v1.2.3 From f4cc4f9178ac30cdee6b2fca38b42985af42e097 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 2 May 2014 08:43:44 +0300 Subject: Edits through Chapter 8, new figure. --- doc/gawk.info | 1183 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 597 insertions(+), 586 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 8c13d181..dfe1589e 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -9555,9 +9555,9 @@ of these automatically, so that they enable you to tell `awk' how to do certain things. Others are set automatically by `awk', so that they carry information from the internal workings of `awk' to your program. - This minor node documents all the built-in variables of `gawk', most -of which are also documented in the chapters describing their areas of -activity. + This minor node documents all of `gawk''s built-in variables, most +of which are also documented in the major nodes describing their areas +of activity. * Menu: @@ -9574,8 +9574,13 @@ File: gawk.info, Node: User-modified, Next: Auto-set, Up: Built-in Variables ------------------------------------------- The following is an alphabetical list of variables that you can change -to control how `awk' does certain things. The variables that are -specific to `gawk' are marked with a pound sign (`#'). +to control how `awk' does certain things. + + The variables that are specific to `gawk' are marked with a pound +sign (`#'). These variables are `gawk' extensions. In other `awk' +implementations or if `gawk' is in compatibility mode (*note +Options::), they are not special. (Any exceptions are noted in the +description of each variable.) `BINMODE #' On non-POSIX systems, this variable specifies use of binary mode @@ -9588,14 +9593,11 @@ specific to `gawk' are marked with a pound sign (`#'). string value of `"rw"' or `"wr"' indicates that all files should use binary I/O. Any other string value is treated the same as `"rw"', but causes `gawk' to generate a warning message. - `BINMODE' is described in more detail in *note PC Using::. - - This variable is a `gawk' extension. In other `awk' - implementations (except `mawk', *note Other Versions::), or if - `gawk' is in compatibility mode (*note Options::), it is not - special. + `BINMODE' is described in more detail in *note PC Using::. `mawk' + *note Other Versions::), also supports this variable, but only + using numeric values. -`CONVFMT' +``CONVFMT'' This string controls conversion of numbers to strings (*note Conversion::). It works by being passed, in effect, as the first argument to the `sprintf()' function (*note String Functions::). @@ -9603,29 +9605,21 @@ specific to `gawk' are marked with a pound sign (`#'). POSIX standard. `FIELDWIDTHS #' - This is a space-separated list of columns that tells `gawk' how to - split input with fixed columnar boundaries. Assigning a value to + A space-separated list of columns that tells `gawk' how to split + input with fixed columnar boundaries. Assigning a value to `FIELDWIDTHS' overrides the use of `FS' and `FPAT' for field splitting. *Note Constant Size::, for more information. - If `gawk' is in compatibility mode (*note Options::), then - `FIELDWIDTHS' has no special meaning, and field-splitting - operations occur based exclusively on the value of `FS'. - `FPAT #' - This is a regular expression (as a string) that tells `gawk' to - create the fields based on text that matches the regular - expression. Assigning a value to `FPAT' overrides the use of `FS' - and `FIELDWIDTHS' for field splitting. *Note Splitting By - Content::, for more information. - - If `gawk' is in compatibility mode (*note Options::), then `FPAT' - has no special meaning, and field-splitting operations occur based - exclusively on the value of `FS'. + A regular expression (as a string) that tells `gawk' to create the + fields based on text that matches the regular expression. + Assigning a value to `FPAT' overrides the use of `FS' and + `FIELDWIDTHS' for field splitting. *Note Splitting By Content::, + for more information. `FS' - This is the input field separator (*note Field Separators::). The - value is a single-character string or a multicharacter regular + The input field separator (*note Field Separators::). The value + is a single-character string or a multicharacter regular expression that matches the separations between fields in an input record. If the value is the null string (`""'), then each character in the record becomes a separate field. (This behavior @@ -9661,13 +9655,9 @@ specific to `gawk' are marked with a pound sign (`#'). splitting when using a single-character field separator. *Note Case-sensitivity::. - If `gawk' is in compatibility mode (*note Options::), then - `IGNORECASE' has no special meaning. Thus, string and regexp - operations are always case-sensitive. - `LINT #' When this variable is true (nonzero or non-null), `gawk' behaves - as if the `--lint' command-line option is in effect. (*note + as if the `--lint' command-line option is in effect (*note Options::). With a value of `"fatal"', lint warnings become fatal errors. With a value of `"invalid"', only warnings about things that are actually invalid are issued. (This is not fully @@ -9683,13 +9673,13 @@ specific to `gawk' are marked with a pound sign (`#'). execution is independent of the flavor of `awk' being executed. `OFMT' - This string controls conversion of numbers to strings (*note - Conversion::) for printing with the `print' statement. It works - by being passed as the first argument to the `sprintf()' function - (*note String Functions::). Its default value is `"%.6g"'. - Earlier versions of `awk' also used `OFMT' to specify the format - for converting numbers to strings in general expressions; this is - now done by `CONVFMT'. + Controls conversion of numbers to strings (*note Conversion::) for + printing with the `print' statement. It works by being passed as + the first argument to the `sprintf()' function (*note String + Functions::). Its default value is `"%.6g"'. Earlier versions of + `awk' also used `OFMT' to specify the format for converting + numbers to strings in general expressions; this is now done by + `CONVFMT'. `OFS' This is the output field separator (*note Output Separators::). @@ -9697,8 +9687,8 @@ specific to `gawk' are marked with a pound sign (`#'). Its default value is `" "', a string consisting of a single space. `ORS' - This is the output record separator. It is output at the end of - every `print' statement. Its default value is `"\n"', the newline + The output record separator. It is output at the end of every + `print' statement. Its default value is `"\n"', the newline character. (*Note Output Separators::.) `PREC #' @@ -9708,38 +9698,34 @@ specific to `gawk' are marked with a pound sign (`#'). `ROUNDMODE #' The rounding mode to use for arbitrary precision arithmetic on numbers, by default `"N"' (`roundTiesToEven' in the IEEE-754 - standard) (*note Setting Rounding Mode::). + standard; *note Setting Rounding Mode::). -`RS' - This is `awk''s input record separator. Its default value is a - string containing a single newline character, which means that an - input record consists of a single line of text. It can also be - the null string, in which case records are separated by runs of - blank lines. If it is a regexp, records are separated by matches - of the regexp in the input text. (*Note Records::.) +``RS'' + The input record separator. Its default value is a string + containing a single newline character, which means that an input + record consists of a single line of text. It can also be the null + string, in which case records are separated by runs of blank lines. + If it is a regexp, records are separated by matches of the regexp + in the input text. (*Note Records::.) The ability for `RS' to be a regular expression is a `gawk' extension. In most other `awk' implementations, or if `gawk' is in compatibility mode (*note Options::), just the first character of `RS''s value is used. -`SUBSEP' - This is the subscript separator. It has the default value of - `"\034"' and is used to separate the parts of the indices of a - multidimensional array. Thus, the expression `foo["A", "B"]' - really accesses `foo["A\034B"]' (*note Multidimensional::). +``SUBSEP'' + The subscript separator. It has the default value of `"\034"' and + is used to separate the parts of the indices of a multidimensional + array. Thus, the expression `foo["A", "B"]' really accesses + `foo["A\034B"]' (*note Multidimensional::). `TEXTDOMAIN #' - This variable is used for internationalization of programs at the - `awk' level. It sets the default text domain for specially marked - string constants in the source text, as well as for the - `dcgettext()', `dcngettext()' and `bindtextdomain()' functions - (*note Internationalization::). The default value of `TEXTDOMAIN' - is `"messages"'. - - This variable is a `gawk' extension. In other `awk' - implementations, or if `gawk' is in compatibility mode (*note - Options::), it is not special. + Used for internationalization of programs at the `awk' level. It + sets the default text domain for specially marked string constants + in the source text, as well as for the `dcgettext()', + `dcngettext()' and `bindtextdomain()' functions (*note + Internationalization::). The default value of `TEXTDOMAIN' is + `"messages"'. ---------- Footnotes ---------- @@ -9753,8 +9739,12 @@ File: gawk.info, Node: Auto-set, Next: ARGC and ARGV, Prev: User-modified, U The following is an alphabetical list of variables that `awk' sets automatically on certain occasions in order to provide information to -your program. The variables that are specific to `gawk' are marked -with a pound sign (`#'). +your program. + + The variables that are specific to `gawk' are marked with a pound +sign (`#'). These variables are `gawk' extensions. In other `awk' +implementations or if `gawk' is in compatibility mode (*note +Options::), they are not special. `ARGC', `ARGV' The command-line arguments available to `awk' programs are stored @@ -9785,7 +9775,7 @@ with a pound sign (`#'). are any of `awk''s command-line options. *Note ARGC and ARGV::, for information about how `awk' uses these variables. (d.c.) -`ARGIND' # +`ARGIND #' The index in `ARGV' of the current file being processed. Every time `gawk' opens a new data file for processing, it sets `ARGIND' to the index in `ARGV' of the file name. When `gawk' is @@ -9801,26 +9791,23 @@ with a pound sign (`#'). program, `gawk' automatically sets it to a new value when the next file is opened. - This variable is a `gawk' extension. In other `awk' - implementations, or if `gawk' is in compatibility mode (*note - Options::), it is not special. - `ENVIRON' An associative array containing the values of the environment. The array indices are the environment variable names; the elements are the values of the particular environment variables. For - example, `ENVIRON["HOME"]' might be `/home/arnold'. Changing this - array does not affect the environment passed on to any programs - that `awk' may spawn via redirection or the `system()' function. + example, `ENVIRON["HOME"]' might be `"/home/arnold"'. Changing + this array does not affect the environment passed on to any + programs that `awk' may spawn via redirection or the `system()' + function. (In a future version of `gawk', it may do so.) Some operating systems may not have environment variables. On such systems, the `ENVIRON' array is empty (except for - `ENVIRON["AWKPATH"]', *note AWKPATH Variable:: and - `ENVIRON["AWKLIBPATH"]', *note AWKLIBPATH Variable::). + `ENVIRON["AWKPATH"]' and `ENVIRON["AWKLIBPATH"]'; *note AWKPATH + Variable::, and *note AWKLIBPATH Variable::). -`ERRNO' # - If a system error occurs during a redirection for `getline', - during a read for `getline', or during a `close()' operation, then +`ERRNO #' + If a system error occurs during a redirection for `getline', during + a read for `getline', or during a `close()' operation, then `ERRNO' contains a string describing the error. In addition, `gawk' clears `ERRNO' before opening each @@ -9834,19 +9821,14 @@ with a pound sign (`#'). `getline' returning -1. You are, of course, free to clear it yourself before doing an I/O operation. - This variable is a `gawk' extension. In other `awk' - implementations, or if `gawk' is in compatibility mode (*note - Options::), it is not special. - `FILENAME' - The name of the file that `awk' is currently reading. When no - data files are listed on the command line, `awk' reads from the - standard input and `FILENAME' is set to `"-"'. `FILENAME' is - changed each time a new file is read (*note Reading Files::). - Inside a `BEGIN' rule, the value of `FILENAME' is `""', since - there are no input files being processed yet.(1) (d.c.) Note, - though, that using `getline' (*note Getline::) inside a `BEGIN' - rule can give `FILENAME' a value. + The name of the current input file. When no data files are listed + on the command line, `awk' reads from the standard input and + `FILENAME' is set to `"-"'. `FILENAME' changes each time a new + file is read (*note Reading Files::). Inside a `BEGIN' rule, the + value of `FILENAME' is `""', since there are no input files being + processed yet.(1) (d.c.) Note, though, that using `getline' (*note + Getline::) inside a `BEGIN' rule can give `FILENAME' a value. `FNR' The current record number in the current file. `FNR' is @@ -9864,21 +9846,20 @@ with a pound sign (`#'). create or remove fields from the current record. *Note Changing Fields::. -`FUNCTAB' # +`FUNCTAB #' An array whose indices and corresponding values are the names of all the user-defined or extension functions in the program. NOTE: Attempting to use the `delete' statement with the - `FUNCTAB' array will cause a fatal error. Any attempt to - assign to an element of the `FUNCTAB' array will also cause a - fatal error. + `FUNCTAB' array causes a fatal error. Any attempt to assign + to an element of `FUNCTAB' also causes a fatal error. `NR' The number of input records `awk' has processed since the beginning of the program's execution (*note Records::). `NR' is incremented each time a new record is read. -`PROCINFO' # +`PROCINFO #' The elements of this array provide access to information about the running `awk' program. The following elements (listed alphabetically) are guaranteed to be available: @@ -9935,8 +9916,8 @@ with a pound sign (`#'). `PROCINFO["sorted_in"]' If this element exists in `PROCINFO', its value controls the - order in which array indices will be processed by `for (index - in array) ...' loops. Since this is an advanced feature, we + order in which array indices will be processed by `for (INDEX + in ARRAY)' loops. Since this is an advanced feature, we defer the full description until later; see *note Scanning an Array::. @@ -9994,10 +9975,6 @@ with a pound sign (`#'). open input file, pipe, or coprocess. *Note Read Timeout::, for more information. - This array is a `gawk' extension. In other `awk' implementations, - or if `gawk' is in compatibility mode (*note Options::), it is not - special. - `RLENGTH' The length of the substring matched by the `match()' function (*note String Functions::). `RLENGTH' is set by invoking the @@ -10011,15 +9988,11 @@ with a pound sign (`#'). of the string where the matched substring starts, or zero if no match was found. -`RT' # - This is set each time a record is read. It contains the input text - that matched the text denoted by `RS', the record separator. - - This variable is a `gawk' extension. In other `awk' - implementations, or if `gawk' is in compatibility mode (*note - Options::), it is not special. +`RT #' + The input text that matched the text denoted by `RS', the record + separator. It is set every time a record is read. -`SYMTAB' # +`SYMTAB #' An array whose indices are the names of all currently defined global variables and arrays in the program. The array may be used for indirect access to read or write the value of a variable: @@ -10053,7 +10026,7 @@ with a pound sign (`#'). return SYMTAB[variable] *= amount } - NOTE: In order to avoid severe time-travel paradoxes(2), + NOTE: In order to avoid severe time-travel paradoxes,(2) neither `FUNCTAB' nor `SYMTAB' are available as elements within the `SYMTAB' array. @@ -10203,7 +10176,7 @@ remove array elements. It also describes how `awk' simulates multidimensional arrays, as well as some of the less obvious points about array usage. The major node moves on to discuss `gawk''s facility for sorting arrays, and ends with a brief description of `gawk''s -ability to support true multidimensional arrays. +ability to support true arrays of arrays. `awk' maintains a single set of names that may be used for naming variables, arrays, and functions (*note User-defined::). Thus, you @@ -10281,12 +10254,13 @@ declared.) A contiguous array of four elements might look like the following example, conceptually, if the element values are 8, `"foo"', `""', and -30: +30 as shown in *note figure-array-elements::: - +---------+---------+--------+---------+ - | 8 | "foo" | "" | 30 | Value - +---------+---------+--------+---------+ - 0 1 2 3 Index ++---------+---------+--------+---------+ +| 8 | "foo" | "" | 30 | @r{Value} ++---------+---------+--------+---------+ + 0 1 2 3 @r{Index} +Figure 8.1: A Contiguous Array Only the values are stored; the indices are implicit from the order of the values. Here, 8 is the value at index zero, because 8 appears in the @@ -10329,9 +10303,9 @@ from English to French: Here we decided to translate the number one in both spelled-out and numeric form--thus illustrating that a single array can have both -numbers and strings as indices. In fact, array subscripts are always +numbers and strings as indices. (In fact, array subscripts are always strings; this is discussed in more detail in *note Numeric Array -Subscripts::. Here, the number `1' isn't double-quoted, since `awk' +Subscripts::.) Here, the number `1' isn't double-quoted, since `awk' automatically converts it to a string. The value of `IGNORECASE' has no effect upon array subscripting. @@ -10383,11 +10357,11 @@ been assigned any value as well as elements that have been deleted To determine whether an element exists in an array at a certain index, use the following expression: - IND in ARRAY + INDX in ARRAY -This expression tests whether the particular index IND exists, without +This expression tests whether the particular index INDX exists, without the side effect of creating that element if it is not present. The -expression has the value one (true) if `ARRAY[IND]' exists and zero +expression has the value one (true) if `ARRAY[INDX]' exists and zero (false) if it does not exist. For example, this statement tests whether the array `frequencies' contains the index `2': @@ -10522,19 +10496,54 @@ built-in function `length()'. The order in which elements of the array are accessed by this statement is determined by the internal arrangement of the array -elements within `awk' and normally cannot be controlled or changed. -This can lead to problems if new elements are added to ARRAY by -statements in the loop body; it is not predictable whether the `for' +elements within `awk' and in standard `awk' cannot be controlled or +changed. This can lead to problems if new elements are added to ARRAY +by statements in the loop body; it is not predictable whether the `for' loop will reach them. Similarly, changing VAR inside the loop may produce strange results. It is best to avoid such things. + As a point of information, `gawk' sets up the list of elements to be +iterated over before the loop starts, and does not change it. But not +all `awk' versions do so. Consider this program, named `loopcheck.awk': + + BEGIN { + a["here"] = "here" + a["is"] = "is" + a["a"] = "a" + a["loop"] = "loop" + for (i in a) { + j++ + a[j] = j + print i + } + } + + Here is what happens when run with `gawk': + + $ gawk -f loopcheck.awk + -| here + -| loop + -| a + -| is + + Contrast this to Brian Kernighan's `awk': + + $ nawk -f loopcheck.awk + -| loop + -| here + -| is + -| a + -| 1 +  File: gawk.info, Node: Controlling Scanning, Prev: Scanning an Array, Up: Array Basics -8.1.6 Using Predefined Array Scanning Orders --------------------------------------------- +8.1.6 Using Predefined Array Scanning Orders With `gawk' +-------------------------------------------------------- + +This node describes a feature that is specific to `gawk'. -By default, when a `for' loop traverses an array, the order is + By default, when a `for' loop traverses an array, the order is undefined, meaning that the `awk' implementation determines the order in which the array is traversed. This order is usually based on the internal implementation of arrays and will vary from one version of @@ -10820,7 +10829,7 @@ might look like this: -| line 3 -| line 2 - Unfortunately, the very first line of input data did not come out in + Unfortunately, the very first line of input data did not appear in the output! Upon first glance, we would think that this program should have @@ -30424,15 +30433,15 @@ Index (line 6) * archeologists: Bugs. (line 6) * arctangent: Numeric Functions. (line 11) -* ARGC/ARGV variables: Auto-set. (line 11) +* ARGC/ARGV variables: Auto-set. (line 15) * ARGC/ARGV variables, command-line arguments: Other Arguments. (line 12) * ARGC/ARGV variables, how to use: ARGC and ARGV. (line 6) * ARGC/ARGV variables, portability and: Executable Scripts. (line 42) -* ARGIND variable: Auto-set. (line 40) +* ARGIND variable: Auto-set. (line 44) * ARGIND variable, command-line arguments: Other Arguments. (line 12) * arguments, command-line <1>: ARGC and ARGV. (line 6) -* arguments, command-line <2>: Auto-set. (line 11) +* arguments, command-line <2>: Auto-set. (line 15) * arguments, command-line: Other Arguments. (line 6) * arguments, command-line, invoking awk: Command Line. (line 6) * arguments, in function calls: Function Calls. (line 18) @@ -30443,15 +30452,15 @@ Index * array members: Reference to Elements. (line 6) * array scanning order, controlling: Controlling Scanning. - (line 12) + (line 14) * array, number of elements: String Functions. (line 194) * arrays: Arrays. (line 6) * arrays of arrays: Arrays of Arrays. (line 6) * arrays, an example of using: Array Example. (line 6) -* arrays, and IGNORECASE variable: Array Intro. (line 91) +* arrays, and IGNORECASE variable: Array Intro. (line 92) * arrays, as parameters to functions: Pass By Value/Reference. (line 47) -* arrays, associative: Array Intro. (line 49) +* arrays, associative: Array Intro. (line 50) * arrays, associative, library functions and: Library Names. (line 57) * arrays, deleting entire contents: Delete. (line 39) * arrays, elements that don't exist: Reference to Elements. @@ -30462,7 +30471,7 @@ Index (line 48) * arrays, elements, retrieving number of: String Functions. (line 32) * arrays, for statement and: Scanning an Array. (line 20) -* arrays, indexing: Array Intro. (line 49) +* arrays, indexing: Array Intro. (line 50) * arrays, merging into strings: Join Function. (line 6) * arrays, multidimensional: Multidimensional. (line 10) * arrays, multidimensional, scanning: Multiscanning. (line 11) @@ -30476,7 +30485,7 @@ Index (line 6) * arrays, sorting, and IGNORECASE variable: Array Sorting Functions. (line 83) -* arrays, sparse: Array Intro. (line 70) +* arrays, sparse: Array Intro. (line 71) * arrays, subscripts, uninitialized variables as: Uninitialized Subscripts. (line 6) * arrays, unassigned elements: Reference to Elements. @@ -30504,7 +30513,7 @@ Index * assignment operators, evaluation order: Assignment Ops. (line 111) * assignment operators, lvalues/rvalues: Assignment Ops. (line 32) * assignments as filenames: Ignoring Assigns. (line 6) -* associative arrays: Array Intro. (line 49) +* associative arrays: Array Intro. (line 50) * asterisk (*), * operator, as multiplication operator: Precedence. (line 55) * asterisk (*), * operator, as regexp operator: Regexp Operators. @@ -30662,14 +30671,14 @@ Index * Benzinger, Michael: Contributors. (line 97) * Berry, Karl <1>: Ranges and Locales. (line 74) * Berry, Karl: Acknowledgments. (line 33) -* binary input/output: User-modified. (line 10) +* binary input/output: User-modified. (line 15) * bindtextdomain <1>: Programmer i18n. (line 47) * bindtextdomain: I18N Functions. (line 12) * bindtextdomain() function (C library): Explaining gettext. (line 49) * bindtextdomain() function (gawk), portability and: I18N Portability. (line 33) * BINMODE variable <1>: PC Using. (line 33) -* BINMODE variable: User-modified. (line 10) +* BINMODE variable: User-modified. (line 15) * bit-manipulation functions: Bitwise Functions. (line 6) * bits2str() user-defined function: Bitwise Functions. (line 70) * bitwise AND: Bitwise Functions. (line 39) @@ -30773,9 +30782,9 @@ Index (line 59) * caret (^), regexp operator: Regexp Operators. (line 22) * case keyword: Switch Statement. (line 6) -* case sensitivity, and regexps: User-modified. (line 82) -* case sensitivity, and string comparisons: User-modified. (line 82) -* case sensitivity, array indices and: Array Intro. (line 91) +* case sensitivity, and regexps: User-modified. (line 76) +* case sensitivity, and string comparisons: User-modified. (line 76) +* case sensitivity, array indices and: Array Intro. (line 92) * case sensitivity, converting case: String Functions. (line 520) * case sensitivity, example programs: Library Functions. (line 53) * case sensitivity, gawk: Case-sensitivity. (line 26) @@ -30827,7 +30836,7 @@ Index * comma (,), in range patterns: Ranges. (line 6) * command completion, in debugger: Readline Support. (line 6) * command line, arguments <1>: ARGC and ARGV. (line 6) -* command line, arguments <2>: Auto-set. (line 11) +* command line, arguments <2>: Auto-set. (line 15) * command line, arguments: Other Arguments. (line 6) * command line, directories on: Command line directories. (line 6) @@ -30909,7 +30918,7 @@ Index * continue statement: Continue Statement. (line 6) * control statements: Statements. (line 6) * controlling array scanning order: Controlling Scanning. - (line 12) + (line 14) * convert string to lower case: String Functions. (line 521) * convert string to number: String Functions. (line 385) * convert string to upper case: String Functions. (line 527) @@ -30920,7 +30929,7 @@ Index * converting, numbers to strings: Conversion. (line 6) * converting, strings to numbers <1>: Bitwise Functions. (line 109) * converting, strings to numbers: Conversion. (line 6) -* CONVFMT variable <1>: User-modified. (line 28) +* CONVFMT variable <1>: User-modified. (line 30) * CONVFMT variable: Conversion. (line 29) * CONVFMT variable, and array subscripts: Numeric Array Subscripts. (line 6) @@ -30969,9 +30978,9 @@ Index * dark corner, exit statement: Exit Statement. (line 30) * dark corner, field separators: Field Splitting Summary. (line 46) -* dark corner, FILENAME variable <1>: Auto-set. (line 93) +* dark corner, FILENAME variable <1>: Auto-set. (line 90) * dark corner, FILENAME variable: Getline Notes. (line 19) -* dark corner, FNR/NR variables: Auto-set. (line 314) +* dark corner, FNR/NR variables: Auto-set. (line 301) * dark corner, format-control characters: Control Letters. (line 18) * dark corner, FS as null string: Single Character Fields. (line 20) @@ -30990,7 +30999,7 @@ Index (line 43) * dark corner, split() function: String Functions. (line 359) * dark corner, strings, storing: gawk split records. (line 83) -* dark corner, value of ARGV[0]: Auto-set. (line 35) +* dark corner, value of ARGV[0]: Auto-set. (line 39) * data, fixed-width: Constant Size. (line 10) * data-driven languages: Basic High Level. (line 85) * database, group, reading: Group Functions. (line 6) @@ -31136,7 +31145,7 @@ Index * differences between gawk and awk: String Functions. (line 194) * differences in awk and gawk, ARGC/ARGV variables: ARGC and ARGV. (line 88) -* differences in awk and gawk, ARGIND variable: Auto-set. (line 40) +* differences in awk and gawk, ARGIND variable: Auto-set. (line 44) * differences in awk and gawk, array elements, deleting: Delete. (line 39) * differences in awk and gawk, AWKLIBPATH environment variable: AWKLIBPATH Variable. @@ -31150,22 +31159,22 @@ Index * differences in awk and gawk, BINMODE variable <1>: PC Using. (line 33) * differences in awk and gawk, BINMODE variable: User-modified. - (line 23) + (line 15) * differences in awk and gawk, close() function: Close Files And Pipes. (line 81) * differences in awk and gawk, command line directories: Command line directories. (line 6) -* differences in awk and gawk, ERRNO variable: Auto-set. (line 73) +* differences in awk and gawk, ERRNO variable: Auto-set. (line 74) * differences in awk and gawk, error messages: Special FD. (line 16) * differences in awk and gawk, FIELDWIDTHS variable: User-modified. - (line 35) -* differences in awk and gawk, FPAT variable: User-modified. (line 45) -* differences in awk and gawk, FUNCTAB variable: Auto-set. (line 119) + (line 37) +* differences in awk and gawk, FPAT variable: User-modified. (line 43) +* differences in awk and gawk, FUNCTAB variable: Auto-set. (line 115) * differences in awk and gawk, function arguments (gawk): Calling Built-in. (line 16) * differences in awk and gawk, getline command: Getline. (line 19) * differences in awk and gawk, IGNORECASE variable: User-modified. - (line 82) + (line 76) * differences in awk and gawk, implementation limitations <1>: Redirection. (line 135) * differences in awk and gawk, implementation limitations: Getline Notes. @@ -31178,12 +31187,12 @@ Index (line 6) * differences in awk and gawk, line continuations: Conditional Exp. (line 34) -* differences in awk and gawk, LINT variable: User-modified. (line 98) +* differences in awk and gawk, LINT variable: User-modified. (line 88) * differences in awk and gawk, match() function: String Functions. (line 257) * differences in awk and gawk, print/printf statements: Format Modifiers. (line 13) -* differences in awk and gawk, PROCINFO array: Auto-set. (line 133) +* differences in awk and gawk, PROCINFO array: Auto-set. (line 128) * differences in awk and gawk, read timeouts: Read Timeout. (line 6) * differences in awk and gawk, record separators: awk split records. (line 124) @@ -31193,7 +31202,7 @@ Index (line 26) * differences in awk and gawk, RS/RT variables: gawk split records. (line 58) -* differences in awk and gawk, RT variable: Auto-set. (line 266) +* differences in awk and gawk, RT variable: Auto-set. (line 257) * differences in awk and gawk, single-character fields: Single Character Fields. (line 6) * differences in awk and gawk, split() function: String Functions. @@ -31201,9 +31210,9 @@ Index * differences in awk and gawk, strings: Scalar Constants. (line 20) * differences in awk and gawk, strings, storing: gawk split records. (line 77) -* differences in awk and gawk, SYMTAB variable: Auto-set. (line 274) +* differences in awk and gawk, SYMTAB variable: Auto-set. (line 261) * differences in awk and gawk, TEXTDOMAIN variable: User-modified. - (line 162) + (line 152) * differences in awk and gawk, trunc-mod operation: Arithmetic Ops. (line 66) * directories, command line: Command line directories. @@ -31242,8 +31251,8 @@ Index * dynamically loaded extensions: Dynamic Extensions. (line 6) * e debugger command (alias for enable): Breakpoint Control. (line 73) * EBCDIC: Ordinal Functions. (line 45) -* effective group ID of gawk user: Auto-set. (line 138) -* effective user ID of gawk user: Auto-set. (line 142) +* effective group ID of gawk user: Auto-set. (line 133) +* effective user ID of gawk user: Auto-set. (line 137) * egrep utility <1>: Egrep Program. (line 6) * egrep utility: Bracket Expressions. (line 24) * egrep.awk program: Egrep Program. (line 54) @@ -31298,13 +31307,13 @@ Index (line 11) * EREs (Extended Regular Expressions): Bracket Expressions. (line 24) * ERRNO variable <1>: TCP/IP Networking. (line 54) -* ERRNO variable: Auto-set. (line 73) +* ERRNO variable: Auto-set. (line 74) * ERRNO variable, with BEGINFILE pattern: BEGINFILE/ENDFILE. (line 26) * ERRNO variable, with close() function: Close Files And Pipes. (line 139) * ERRNO variable, with getline command: Getline. (line 19) * error handling: Special FD. (line 16) -* error handling, ERRNO variable and: Auto-set. (line 73) +* error handling, ERRNO variable and: Auto-set. (line 74) * error output: Special FD. (line 6) * escape processing, gsub()/gensub()/sub() functions: Gory Details. (line 6) @@ -31358,7 +31367,7 @@ Index (line 6) * extension API version: Extension Versioning. (line 6) -* extension API, version number: Auto-set. (line 229) +* extension API, version number: Auto-set. (line 224) * extension example: Extension Example. (line 6) * extension registration: Registration Functions. (line 6) @@ -31407,11 +31416,11 @@ Index (line 6) * field separator, POSIX and: Field Splitting Summary. (line 40) -* field separators <1>: User-modified. (line 56) +* field separators <1>: User-modified. (line 50) * field separators: Field Separators. (line 15) * field separators, choice of: Field Separators. (line 51) -* field separators, FIELDWIDTHS variable and: User-modified. (line 35) -* field separators, FPAT variable and: User-modified. (line 45) +* field separators, FIELDWIDTHS variable and: User-modified. (line 37) +* field separators, FPAT variable and: User-modified. (line 43) * field separators, POSIX and: Fields. (line 6) * field separators, regular expressions as <1>: Regexp Field Splitting. (line 6) @@ -31431,13 +31440,13 @@ Index * fields, separating: Field Separators. (line 15) * fields, single-character: Single Character Fields. (line 6) -* FIELDWIDTHS variable <1>: User-modified. (line 35) +* FIELDWIDTHS variable <1>: User-modified. (line 37) * FIELDWIDTHS variable: Constant Size. (line 23) * file descriptors: Special FD. (line 6) -* file names, distinguishing: Auto-set. (line 52) +* file names, distinguishing: Auto-set. (line 56) * file names, in compatibility mode: Special Caveats. (line 9) * file names, standard streams in gawk: Special FD. (line 46) -* FILENAME variable <1>: Auto-set. (line 93) +* FILENAME variable <1>: Auto-set. (line 90) * FILENAME variable: Reading Files. (line 6) * FILENAME variable, getline, setting with: Getline Notes. (line 19) * filenames, assignments as: Ignoring Assigns. (line 6) @@ -31483,7 +31492,7 @@ Index * files, portable object, converting to message object files: I18N Example. (line 62) * files, portable object, generating: Options. (line 147) -* files, processing, ARGIND variable and: Auto-set. (line 47) +* files, processing, ARGIND variable and: Auto-set. (line 51) * files, reading: Rewind Function. (line 6) * files, reading, multiline records: Multiple Line. (line 6) * files, searching for regular expressions: Egrep Program. (line 6) @@ -31507,9 +31516,9 @@ Index * flush buffered output: I/O Functions. (line 25) * fnmatch() extension function: Extension Sample Fnmatch. (line 12) -* FNR variable <1>: Auto-set. (line 103) +* FNR variable <1>: Auto-set. (line 99) * FNR variable: Records. (line 6) -* FNR variable, changing: Auto-set. (line 314) +* FNR variable, changing: Auto-set. (line 301) * for statement: For Statement. (line 6) * for statement, looping over arrays: Scanning an Array. (line 20) * fork() extension function: Extension Sample Fork. @@ -31531,7 +31540,7 @@ Index * forward slash (/), /= operator, vs. /=.../ regexp constant: Assignment Ops. (line 148) * forward slash (/), patterns and: Expression Patterns. (line 24) -* FPAT variable <1>: User-modified. (line 45) +* FPAT variable <1>: User-modified. (line 43) * FPAT variable: Splitting By Content. (line 27) * frame debugger command: Execution Stack. (line 25) @@ -31541,7 +31550,7 @@ Index * Free Software Foundation (FSF) <2>: Getting. (line 10) * Free Software Foundation (FSF): Manual History. (line 6) * FreeBSD: Glossary. (line 616) -* FS variable <1>: User-modified. (line 56) +* FS variable <1>: User-modified. (line 50) * FS variable: Field Separators. (line 15) * FS variable, --field-separator option and: Options. (line 21) * FS variable, as null string: Single Character Fields. @@ -31559,7 +31568,7 @@ Index * FSF (Free Software Foundation): Manual History. (line 6) * fts() extension function: Extension Sample File Functions. (line 77) -* FUNCTAB array: Auto-set. (line 119) +* FUNCTAB array: Auto-set. (line 115) * function calls: Function Calls. (line 6) * function calls, indirect: Indirect Calls. (line 6) * function definition example: Function Example. (line 6) @@ -31609,7 +31618,7 @@ Index * G-d: Acknowledgments. (line 78) * Garfinkle, Scott: Contributors. (line 34) * gawk program, dynamic profiling: Profiling. (line 179) -* gawk version: Auto-set. (line 204) +* gawk version: Auto-set. (line 199) * gawk, ARGIND variable in: Other Arguments. (line 12) * gawk, awk and <1>: This Manual. (line 14) * gawk, awk and: Preface. (line 23) @@ -31630,7 +31639,7 @@ Index * gawk, distribution: Distribution contents. (line 6) * gawk, ERRNO variable in <1>: TCP/IP Networking. (line 54) -* gawk, ERRNO variable in <2>: Auto-set. (line 73) +* gawk, ERRNO variable in <2>: Auto-set. (line 74) * gawk, ERRNO variable in <3>: BEGINFILE/ENDFILE. (line 26) * gawk, ERRNO variable in <4>: Close Files And Pipes. (line 139) @@ -31639,22 +31648,22 @@ Index * gawk, extensions, disabling: Options. (line 254) * gawk, features, adding: Adding Code. (line 6) * gawk, features, advanced: Advanced Features. (line 6) -* gawk, field separators and: User-modified. (line 77) -* gawk, FIELDWIDTHS variable in <1>: User-modified. (line 35) +* gawk, field separators and: User-modified. (line 71) +* gawk, FIELDWIDTHS variable in <1>: User-modified. (line 37) * gawk, FIELDWIDTHS variable in: Constant Size. (line 23) * gawk, file names in: Special Files. (line 6) * gawk, format-control characters: Control Letters. (line 18) -* gawk, FPAT variable in <1>: User-modified. (line 45) +* gawk, FPAT variable in <1>: User-modified. (line 43) * gawk, FPAT variable in: Splitting By Content. (line 27) -* gawk, FUNCTAB array in: Auto-set. (line 119) +* gawk, FUNCTAB array in: Auto-set. (line 115) * gawk, function arguments and: Calling Built-in. (line 16) * gawk, hexadecimal numbers and: Nondecimal-numbers. (line 42) * gawk, IGNORECASE variable in <1>: Array Sorting Functions. (line 83) * gawk, IGNORECASE variable in <2>: String Functions. (line 48) -* gawk, IGNORECASE variable in <3>: Array Intro. (line 91) -* gawk, IGNORECASE variable in <4>: User-modified. (line 82) +* gawk, IGNORECASE variable in <3>: Array Intro. (line 92) +* gawk, IGNORECASE variable in <4>: User-modified. (line 76) * gawk, IGNORECASE variable in: Case-sensitivity. (line 26) * gawk, implementation issues: Notes. (line 6) * gawk, implementation issues, debugging: Compatibility Mode. (line 6) @@ -31669,7 +31678,7 @@ Index (line 6) * gawk, interval expressions and: Regexp Operators. (line 140) * gawk, line continuation in: Conditional Exp. (line 34) -* gawk, LINT variable in: User-modified. (line 98) +* gawk, LINT variable in: User-modified. (line 88) * gawk, list of contributors to: Contributors. (line 6) * gawk, MS-DOS version of: PC Using. (line 10) * gawk, MS-Windows version of: PC Using. (line 10) @@ -31678,7 +31687,7 @@ Index * gawk, OS/2 version of: PC Using. (line 10) * gawk, PROCINFO array in <1>: Two-way I/O. (line 116) * gawk, PROCINFO array in <2>: Time Functions. (line 47) -* gawk, PROCINFO array in: Auto-set. (line 133) +* gawk, PROCINFO array in: Auto-set. (line 128) * gawk, regexp constants and: Using Constant Regexps. (line 28) * gawk, regular expressions, case sensitivity: Case-sensitivity. @@ -31686,15 +31695,15 @@ Index * gawk, regular expressions, operators: GNU Regexp Operators. (line 6) * gawk, regular expressions, precedence: Regexp Operators. (line 162) -* gawk, RT variable in <1>: Auto-set. (line 266) +* gawk, RT variable in <1>: Auto-set. (line 257) * gawk, RT variable in <2>: Multiple Line. (line 129) * gawk, RT variable in: awk split records. (line 124) * gawk, See Also awk: Preface. (line 36) * gawk, source code, obtaining: Getting. (line 6) * gawk, splitting fields and: Constant Size. (line 88) * gawk, string-translation functions: I18N Functions. (line 6) -* gawk, SYMTAB array in: Auto-set. (line 274) -* gawk, TEXTDOMAIN variable in: User-modified. (line 162) +* gawk, SYMTAB array in: Auto-set. (line 261) +* gawk, TEXTDOMAIN variable in: User-modified. (line 152) * gawk, timestamps: Time Functions. (line 6) * gawk, uses for: Preface. (line 36) * gawk, versions of, information about, printing: Options. (line 300) @@ -31780,7 +31789,7 @@ Index * Grigera, Juan: Contributors. (line 57) * group database, reading: Group Functions. (line 6) * group file: Group Functions. (line 6) -* group ID of gawk user: Auto-set. (line 177) +* group ID of gawk user: Auto-set. (line 172) * groups, information about: Group Functions. (line 6) * gsub <1>: String Functions. (line 135) * gsub: Using Constant Regexps. @@ -31821,8 +31830,8 @@ Index * igawk.sh program: Igawk Program. (line 124) * ignore breakpoint: Breakpoint Control. (line 87) * ignore debugger command: Breakpoint Control. (line 87) -* IGNORECASE variable: User-modified. (line 82) -* IGNORECASE variable, and array indices: Array Intro. (line 91) +* IGNORECASE variable: User-modified. (line 76) +* IGNORECASE variable, and array indices: Array Intro. (line 92) * IGNORECASE variable, and array sorting functions: Array Sorting Functions. (line 83) * IGNORECASE variable, in example programs: Library Functions. @@ -31847,7 +31856,7 @@ Index * in operator, use in loops: Scanning an Array. (line 17) * increment operators: Increment Ops. (line 6) * index: String Functions. (line 151) -* indexing arrays: Array Intro. (line 49) +* indexing arrays: Array Intro. (line 50) * indirect function calls: Indirect Calls. (line 6) * infinite precision: Arbitrary Precision Arithmetic. (line 6) @@ -31874,7 +31883,7 @@ Index * input, standard <1>: Special FD. (line 6) * input, standard: Read Terminal. (line 6) * input/output functions: I/O Functions. (line 6) -* input/output, binary: User-modified. (line 10) +* input/output, binary: User-modified. (line 15) * input/output, from BEGIN and END: I/O And BEGIN/END. (line 6) * input/output, two-way: Two-way I/O. (line 44) * insomnia, cure for: Alarm Program. (line 6) @@ -31894,7 +31903,7 @@ Index * internationalization: I18N Functions. (line 6) * internationalization, localization <1>: Internationalization. (line 13) -* internationalization, localization: User-modified. (line 162) +* internationalization, localization: User-modified. (line 152) * internationalization, localization, character classes: Bracket Expressions. (line 90) * internationalization, localization, gawk and: Internationalization. @@ -32006,7 +32015,7 @@ Index * lines, duplicate, removing: History Sorting. (line 6) * lines, matching ranges of: Ranges. (line 6) * lines, skipping between markers: Ranges. (line 43) -* lint checking: User-modified. (line 98) +* lint checking: User-modified. (line 88) * lint checking, array elements: Delete. (line 34) * lint checking, array subscripts: Uninitialized Subscripts. (line 43) @@ -32016,7 +32025,7 @@ Index (line 340) * lint checking, undefined functions: Pass By Value/Reference. (line 88) -* LINT variable: User-modified. (line 98) +* LINT variable: User-modified. (line 88) * Linux <1>: Glossary. (line 616) * Linux <2>: I18N Example. (line 55) * Linux: Manual History. (line 28) @@ -32075,7 +32084,7 @@ Index * mawk utility <3>: Concatenation. (line 36) * mawk utility <4>: Getline/Pipe. (line 62) * mawk utility: Escape Sequences. (line 124) -* maximum precision supported by MPFR library: Auto-set. (line 218) +* maximum precision supported by MPFR library: Auto-set. (line 213) * McPhee, Patrick: Contributors. (line 100) * message object files: Explaining gettext. (line 41) * message object files, converting from portable object files: I18N Example. @@ -32087,7 +32096,7 @@ Index * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) * metacharacters, escape sequences for: Escape Sequences. (line 130) -* minimum precision supported by MPFR library: Auto-set. (line 221) +* minimum precision supported by MPFR library: Auto-set. (line 216) * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) * monetary information, localization: Explaining gettext. (line 103) @@ -32141,7 +32150,7 @@ Index (line 47) * nexti debugger command: Debugger Execution Control. (line 49) -* NF variable <1>: Auto-set. (line 108) +* NF variable <1>: Auto-set. (line 104) * NF variable: Fields. (line 33) * NF variable, decrementing: Changing Fields. (line 107) * ni debugger command (alias for nexti): Debugger Execution Control. @@ -32150,9 +32159,9 @@ Index * non-existent array elements: Reference to Elements. (line 23) * not Boolean-logic operator: Boolean Ops. (line 6) -* NR variable <1>: Auto-set. (line 128) +* NR variable <1>: Auto-set. (line 123) * NR variable: Records. (line 6) -* NR variable, changing: Auto-set. (line 314) +* NR variable, changing: Auto-set. (line 301) * null strings <1>: Basic Data Typing. (line 26) * null strings <2>: Truth Values. (line 6) * null strings <3>: Regexp Field Splitting. @@ -32176,7 +32185,7 @@ Index (line 6) * numbers, converting <1>: Bitwise Functions. (line 109) * numbers, converting: Conversion. (line 6) -* numbers, converting, to strings: User-modified. (line 28) +* numbers, converting, to strings: User-modified. (line 30) * numbers, floating-point: General Arithmetic. (line 6) * numbers, hexadecimal: Nondecimal-numbers. (line 6) * numbers, octal: Nondecimal-numbers. (line 6) @@ -32190,11 +32199,11 @@ Index * obsolete features: Obsolete. (line 6) * octal numbers: Nondecimal-numbers. (line 6) * octal values, enabling interpretation of: Options. (line 211) -* OFMT variable <1>: User-modified. (line 115) +* OFMT variable <1>: User-modified. (line 105) * OFMT variable <2>: Conversion. (line 55) * OFMT variable: OFMT. (line 15) * OFMT variable, POSIX awk and: OFMT. (line 27) -* OFS variable <1>: User-modified. (line 124) +* OFS variable <1>: User-modified. (line 114) * OFS variable <2>: Output Separators. (line 6) * OFS variable: Changing Fields. (line 64) * OpenBSD: Glossary. (line 616) @@ -32247,7 +32256,7 @@ Index (line 12) * ord() user-defined function: Ordinal Functions. (line 16) * order of evaluation, concatenation: Concatenation. (line 41) -* ORS variable <1>: User-modified. (line 129) +* ORS variable <1>: User-modified. (line 119) * ORS variable: Output Separators. (line 20) * output field separator, See OFS variable: Changing Fields. (line 64) * output record separator, See ORS variable: Output Separators. @@ -32267,7 +32276,7 @@ Index * p debugger command (alias for print): Viewing And Changing Data. (line 36) * P1003.1 POSIX standard: Glossary. (line 454) -* parent process ID of gawk process: Auto-set. (line 186) +* parent process ID of gawk process: Auto-set. (line 181) * parentheses (), in a profile: Profiling. (line 146) * parentheses (), regexp operator: Regexp Operators. (line 80) * password file: Passwd Functions. (line 16) @@ -32364,12 +32373,12 @@ Index * POSIX awk, break statement and: Break Statement. (line 51) * POSIX awk, changes in awk versions: POSIX. (line 6) * POSIX awk, continue statement and: Continue Statement. (line 43) -* POSIX awk, CONVFMT variable and: User-modified. (line 28) +* POSIX awk, CONVFMT variable and: User-modified. (line 30) * POSIX awk, date utility and: Time Functions. (line 263) * POSIX awk, field separators and <1>: Field Splitting Summary. (line 40) * POSIX awk, field separators and: Fields. (line 6) -* POSIX awk, FS variable and: User-modified. (line 66) +* POSIX awk, FS variable and: User-modified. (line 60) * POSIX awk, function keyword in: Definition Syntax. (line 83) * POSIX awk, functions and, gsub()/sub(): Gory Details. (line 54) * POSIX awk, functions and, length(): String Functions. (line 173) @@ -32390,7 +32399,7 @@ Index * POSIX, programs, implementing in awk: Clones. (line 6) * POSIXLY_CORRECT environment variable: Options. (line 340) * PREC variable <1>: Setting Precision. (line 6) -* PREC variable: User-modified. (line 134) +* PREC variable: User-modified. (line 124) * precedence <1>: Precedence. (line 6) * precedence: Increment Ops. (line 60) * precedence, regexp operators: Regexp Operators. (line 157) @@ -32401,7 +32410,7 @@ Index * print statement, commas, omitting: Print Examples. (line 31) * print statement, I/O operators in: Precedence. (line 71) * print statement, line continuations and: Print Examples. (line 76) -* print statement, OFMT variable and: User-modified. (line 124) +* print statement, OFMT variable and: User-modified. (line 114) * print statement, See Also redirection, of output: Redirection. (line 17) * print statement, sprintf() function and: Round Function. (line 6) @@ -32432,29 +32441,29 @@ Index * printing, unduplicated lines of text: Uniq Program. (line 6) * printing, user information: Id Program. (line 6) * private variables: Library Names. (line 11) -* process group idIDof gawk process: Auto-set. (line 180) -* process ID of gawk process: Auto-set. (line 183) +* process group idIDof gawk process: Auto-set. (line 175) +* process ID of gawk process: Auto-set. (line 178) * processes, two-way communications with: Two-way I/O. (line 23) * processing data: Basic High Level. (line 6) * PROCINFO array <1>: Passwd Functions. (line 6) * PROCINFO array <2>: Time Functions. (line 47) -* PROCINFO array: Auto-set. (line 133) +* PROCINFO array: Auto-set. (line 128) * PROCINFO array, and communications via ptys: Two-way I/O. (line 116) * PROCINFO array, and group membership: Group Functions. (line 6) * PROCINFO array, and user and group ID numbers: Id Program. (line 15) * PROCINFO array, testing the field splitting: Passwd Functions. (line 161) -* PROCINFO array, uses: Auto-set. (line 239) +* PROCINFO array, uses: Auto-set. (line 234) * PROCINFO, values of sorted_in: Controlling Scanning. - (line 24) + (line 26) * profiling awk programs: Profiling. (line 6) * profiling awk programs, dynamically: Profiling. (line 179) -* program identifiers: Auto-set. (line 151) +* program identifiers: Auto-set. (line 146) * program, definition of: Getting Started. (line 21) * programmers, attractiveness of: Two-way I/O. (line 6) * programming conventions, --non-decimal-data option: Nondecimal Data. (line 36) -* programming conventions, ARGC/ARGV variables: Auto-set. (line 31) +* programming conventions, ARGC/ARGV variables: Auto-set. (line 35) * programming conventions, exit statement: Exit Statement. (line 38) * programming conventions, function parameters: Return Statement. (line 45) @@ -32518,7 +32527,7 @@ Index * readfile() user-defined function: Readfile Function. (line 30) * reading input files: Reading Files. (line 6) * recipe for a programming language: History. (line 6) -* record separators <1>: User-modified. (line 143) +* record separators <1>: User-modified. (line 133) * record separators: awk split records. (line 6) * record separators, changing: awk split records. (line 85) * record separators, regular expressions as: awk split records. @@ -32559,7 +32568,7 @@ Index * regular expressions, as patterns: Regexp Usage. (line 6) * regular expressions, as record separators: awk split records. (line 124) -* regular expressions, case sensitivity <1>: User-modified. (line 82) +* regular expressions, case sensitivity <1>: User-modified. (line 76) * regular expressions, case sensitivity: Case-sensitivity. (line 6) * regular expressions, computed: Computed Regexps. (line 6) * regular expressions, constants, See regexp constants: Regexp Usage. @@ -32609,7 +32618,7 @@ Index * right shift: Bitwise Functions. (line 52) * right shift, bitwise: Bitwise Functions. (line 32) * Ritchie, Dennis: Basic Data Typing. (line 55) -* RLENGTH variable: Auto-set. (line 253) +* RLENGTH variable: Auto-set. (line 244) * RLENGTH variable, match() function and: String Functions. (line 221) * Robbins, Arnold <1>: Future Extensions. (line 6) * Robbins, Arnold <2>: Bugs. (line 32) @@ -32633,14 +32642,14 @@ Index * rounding numbers: Round Function. (line 6) * ROUNDMODE variable <1>: Setting Rounding Mode. (line 6) -* ROUNDMODE variable: User-modified. (line 138) -* RS variable <1>: User-modified. (line 143) +* ROUNDMODE variable: User-modified. (line 128) +* RS variable <1>: User-modified. (line 133) * RS variable: awk split records. (line 12) * RS variable, multiline records and: Multiple Line. (line 17) * rshift: Bitwise Functions. (line 52) -* RSTART variable: Auto-set. (line 259) +* RSTART variable: Auto-set. (line 250) * RSTART variable, match() function and: String Functions. (line 221) -* RT variable <1>: Auto-set. (line 266) +* RT variable <1>: Auto-set. (line 257) * RT variable <2>: Multiple Line. (line 129) * RT variable: awk split records. (line 124) * Rubin, Paul <1>: Contributors. (line 15) @@ -32660,6 +32669,7 @@ Index * scanning arrays: Scanning an Array. (line 6) * scanning multidimensional arrays: Multiscanning. (line 11) * Schorr, Andrew <1>: Contributors. (line 131) +* Schorr, Andrew <2>: Auto-set. (line 284) * Schorr, Andrew: Acknowledgments. (line 60) * Schreiber, Bert: Acknowledgments. (line 38) * Schreiber, Rita: Acknowledgments. (line 38) @@ -32687,16 +32697,16 @@ Index (line 19) * semicolon (;), separating statements in actions: Statements/Lines. (line 91) -* separators, field: User-modified. (line 56) -* separators, field, FIELDWIDTHS variable and: User-modified. (line 35) -* separators, field, FPAT variable and: User-modified. (line 45) +* separators, field: User-modified. (line 50) +* separators, field, FIELDWIDTHS variable and: User-modified. (line 37) +* separators, field, FPAT variable and: User-modified. (line 43) * separators, field, POSIX and: Fields. (line 6) -* separators, for records <1>: User-modified. (line 143) +* separators, for records <1>: User-modified. (line 133) * separators, for records: awk split records. (line 6) * separators, for records, regular expressions as: awk split records. (line 124) * separators, for statements in actions: Action Overview. (line 19) -* separators, subscript: User-modified. (line 156) +* separators, subscript: User-modified. (line 146) * set breakpoint: Breakpoint Control. (line 11) * set debugger command: Viewing And Changing Data. (line 59) @@ -32747,7 +32757,7 @@ Index (line 110) * sidebar, Changing FS Does Not Affect the Fields: Field Splitting Summary. (line 38) -* sidebar, Changing NR and FNR: Auto-set. (line 312) +* sidebar, Changing NR and FNR: Auto-set. (line 299) * sidebar, Controlling Output Buffering with system(): I/O Functions. (line 135) * sidebar, Escape Sequences for Metacharacters: Escape Sequences. @@ -32822,7 +32832,7 @@ Index * source code, QuikTrim Awk: Other Versions. (line 134) * source code, Solaris awk: Other Versions. (line 96) * source files, search path for: Igawk Program. (line 368) -* sparse arrays: Array Intro. (line 70) +* sparse arrays: Array Intro. (line 71) * Spencer, Henry: Glossary. (line 12) * split: String Functions. (line 313) * split string into array: String Functions. (line 291) @@ -32831,7 +32841,7 @@ Index * split.awk program: Split Program. (line 30) * sprintf <1>: String Functions. (line 378) * sprintf: OFMT. (line 15) -* sprintf() function, OFMT variable and: User-modified. (line 124) +* sprintf() function, OFMT variable and: User-modified. (line 114) * sprintf() function, print/printf statements and: Round Function. (line 6) * sqrt: Numeric Functions. (line 78) @@ -32877,7 +32887,7 @@ Index * strings, converting <1>: Bitwise Functions. (line 109) * strings, converting: Conversion. (line 6) * strings, converting letter case: String Functions. (line 520) -* strings, converting, numbers to: User-modified. (line 28) +* strings, converting, numbers to: User-modified. (line 30) * strings, empty, See null strings: awk split records. (line 114) * strings, extracting: String Extraction. (line 6) * strings, for localization: Programmer i18n. (line 14) @@ -32894,7 +32904,7 @@ Index (line 43) * sub() function, arguments of: String Functions. (line 460) * sub() function, escape processing: Gory Details. (line 6) -* subscript separators: User-modified. (line 156) +* subscript separators: User-modified. (line 146) * subscripts in arrays, multidimensional: Multidimensional. (line 10) * subscripts in arrays, multidimensional, scanning: Multiscanning. (line 11) @@ -32902,16 +32912,16 @@ Index (line 6) * subscripts in arrays, uninitialized variables as: Uninitialized Subscripts. (line 6) -* SUBSEP variable: User-modified. (line 156) +* SUBSEP variable: User-modified. (line 146) * SUBSEP variable, and multidimensional arrays: Multidimensional. (line 16) * substitute in string: String Functions. (line 82) * substr: String Functions. (line 479) * substring: String Functions. (line 479) * Sumner, Andrew: Other Versions. (line 64) -* supplementary groups of gawk process: Auto-set. (line 234) +* supplementary groups of gawk process: Auto-set. (line 229) * switch statement: Switch Statement. (line 6) -* SYMTAB array: Auto-set. (line 274) +* SYMTAB array: Auto-set. (line 261) * syntactic ambiguity: /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) * system: I/O Functions. (line 72) @@ -32941,7 +32951,7 @@ Index * text, printing: Print. (line 22) * text, printing, unduplicated lines of: Uniq Program. (line 6) * TEXTDOMAIN variable <1>: Programmer i18n. (line 9) -* TEXTDOMAIN variable: User-modified. (line 162) +* TEXTDOMAIN variable: User-modified. (line 152) * TEXTDOMAIN variable, BEGIN pattern and: Programmer i18n. (line 60) * TEXTDOMAIN variable, portability and: I18N Portability. (line 20) * textdomain() function (C library): Explaining gettext. (line 27) @@ -33090,10 +33100,10 @@ Index * variables, uninitialized, as array subscripts: Uninitialized Subscripts. (line 6) * variables, user-defined: Variables. (line 6) -* version of gawk: Auto-set. (line 204) -* version of gawk extension API: Auto-set. (line 229) -* version of GNU MP library: Auto-set. (line 215) -* version of GNU MPFR library: Auto-set. (line 211) +* version of gawk: Auto-set. (line 199) +* version of gawk extension API: Auto-set. (line 224) +* version of GNU MP library: Auto-set. (line 210) +* version of GNU MPFR library: Auto-set. (line 206) * vertical bar (|): Regexp Operators. (line 70) * vertical bar (|), | operator (I/O) <1>: Precedence. (line 65) * vertical bar (|), | operator (I/O): Getline/Pipe. (line 9) @@ -33369,344 +33379,345 @@ Node: Next Statement400827 Node: Nextfile Statement403217 Node: Exit Statement405872 Node: Built-in Variables408274 -Node: User-modified409369 -Ref: User-modified-Footnote-1417727 -Node: Auto-set417789 -Ref: Auto-set-Footnote-1430856 -Ref: Auto-set-Footnote-2431061 -Node: ARGC and ARGV431117 -Node: Arrays434971 -Node: Array Basics436476 -Node: Array Intro437302 -Node: Reference to Elements441619 -Node: Assigning Elements443889 -Node: Array Example444380 -Node: Scanning an Array446112 -Node: Controlling Scanning448426 -Ref: Controlling Scanning-Footnote-1453513 -Node: Delete453829 -Ref: Delete-Footnote-1456594 -Node: Numeric Array Subscripts456651 -Node: Uninitialized Subscripts458834 -Node: Multidimensional460461 -Node: Multiscanning463554 -Node: Arrays of Arrays465143 -Node: Functions469783 -Node: Built-in470602 -Node: Calling Built-in471680 -Node: Numeric Functions473668 -Ref: Numeric Functions-Footnote-1477502 -Ref: Numeric Functions-Footnote-2477859 -Ref: Numeric Functions-Footnote-3477907 -Node: String Functions478176 -Ref: String Functions-Footnote-1501179 -Ref: String Functions-Footnote-2501308 -Ref: String Functions-Footnote-3501556 -Node: Gory Details501643 -Ref: table-sub-escapes503322 -Ref: table-sub-posix-92504676 -Ref: table-sub-proposed506027 -Ref: table-posix-sub507381 -Ref: table-gensub-escapes508926 -Ref: Gory Details-Footnote-1510102 -Ref: Gory Details-Footnote-2510153 -Node: I/O Functions510304 -Ref: I/O Functions-Footnote-1517300 -Node: Time Functions517447 -Ref: Time Functions-Footnote-1528440 -Ref: Time Functions-Footnote-2528508 -Ref: Time Functions-Footnote-3528666 -Ref: Time Functions-Footnote-4528777 -Ref: Time Functions-Footnote-5528889 -Ref: Time Functions-Footnote-6529116 -Node: Bitwise Functions529382 -Ref: table-bitwise-ops529944 -Ref: Bitwise Functions-Footnote-1534189 -Node: Type Functions534373 -Node: I18N Functions535524 -Node: User-defined537176 -Node: Definition Syntax537980 -Ref: Definition Syntax-Footnote-1542894 -Node: Function Example542963 -Ref: Function Example-Footnote-1545612 -Node: Function Caveats545634 -Node: Calling A Function546152 -Node: Variable Scope547107 -Node: Pass By Value/Reference550070 -Node: Return Statement553578 -Node: Dynamic Typing556559 -Node: Indirect Calls557490 -Node: Library Functions567177 -Ref: Library Functions-Footnote-1570690 -Ref: Library Functions-Footnote-2570833 -Node: Library Names571004 -Ref: Library Names-Footnote-1574477 -Ref: Library Names-Footnote-2574697 -Node: General Functions574783 -Node: Strtonum Function575811 -Node: Assert Function578741 -Node: Round Function582067 -Node: Cliff Random Function583608 -Node: Ordinal Functions584624 -Ref: Ordinal Functions-Footnote-1587701 -Ref: Ordinal Functions-Footnote-2587953 -Node: Join Function588164 -Ref: Join Function-Footnote-1589935 -Node: Getlocaltime Function590135 -Node: Readfile Function593876 -Node: Data File Management595715 -Node: Filetrans Function596347 -Node: Rewind Function600416 -Node: File Checking601803 -Node: Empty Files602897 -Node: Ignoring Assigns605127 -Node: Getopt Function606681 -Ref: Getopt Function-Footnote-1617984 -Node: Passwd Functions618187 -Ref: Passwd Functions-Footnote-1627165 -Node: Group Functions627253 -Node: Walking Arrays635337 -Node: Sample Programs637473 -Node: Running Examples638147 -Node: Clones638875 -Node: Cut Program640099 -Node: Egrep Program649950 -Ref: Egrep Program-Footnote-1657723 -Node: Id Program657833 -Node: Split Program661482 -Ref: Split Program-Footnote-1665001 -Node: Tee Program665129 -Node: Uniq Program667932 -Node: Wc Program675361 -Ref: Wc Program-Footnote-1679627 -Ref: Wc Program-Footnote-2679827 -Node: Miscellaneous Programs679919 -Node: Dupword Program681107 -Node: Alarm Program683138 -Node: Translate Program687945 -Ref: Translate Program-Footnote-1692332 -Ref: Translate Program-Footnote-2692580 -Node: Labels Program692714 -Ref: Labels Program-Footnote-1696085 -Node: Word Sorting696169 -Node: History Sorting700053 -Node: Extract Program701892 -Ref: Extract Program-Footnote-1709395 -Node: Simple Sed709523 -Node: Igawk Program712585 -Ref: Igawk Program-Footnote-1727756 -Ref: Igawk Program-Footnote-2727957 -Node: Anagram Program728095 -Node: Signature Program731163 -Node: Advanced Features732263 -Node: Nondecimal Data734149 -Node: Array Sorting735732 -Node: Controlling Array Traversal736429 -Node: Array Sorting Functions744713 -Ref: Array Sorting Functions-Footnote-1748582 -Node: Two-way I/O748776 -Ref: Two-way I/O-Footnote-1754208 -Node: TCP/IP Networking754290 -Node: Profiling757134 -Node: Internationalization764637 -Node: I18N and L10N766062 -Node: Explaining gettext766748 -Ref: Explaining gettext-Footnote-1771816 -Ref: Explaining gettext-Footnote-2772000 -Node: Programmer i18n772165 -Node: Translator i18n776392 -Node: String Extraction777186 -Ref: String Extraction-Footnote-1778147 -Node: Printf Ordering778233 -Ref: Printf Ordering-Footnote-1781015 -Node: I18N Portability781079 -Ref: I18N Portability-Footnote-1783528 -Node: I18N Example783591 -Ref: I18N Example-Footnote-1786229 -Node: Gawk I18N786301 -Node: Debugger786922 -Node: Debugging787893 -Node: Debugging Concepts788326 -Node: Debugging Terms790182 -Node: Awk Debugging792779 -Node: Sample Debugging Session793671 -Node: Debugger Invocation794191 -Node: Finding The Bug795524 -Node: List of Debugger Commands802011 -Node: Breakpoint Control803345 -Node: Debugger Execution Control807009 -Node: Viewing And Changing Data810369 -Node: Execution Stack813725 -Node: Debugger Info815192 -Node: Miscellaneous Debugger Commands819186 -Node: Readline Support824364 -Node: Limitations825195 -Node: Arbitrary Precision Arithmetic827447 -Ref: Arbitrary Precision Arithmetic-Footnote-1829096 -Node: General Arithmetic829244 -Node: Floating Point Issues830964 -Node: String Conversion Precision831845 -Ref: String Conversion Precision-Footnote-1833550 -Node: Unexpected Results833659 -Node: POSIX Floating Point Problems835812 -Ref: POSIX Floating Point Problems-Footnote-1839637 -Node: Integer Programming839675 -Node: Floating-point Programming841414 -Ref: Floating-point Programming-Footnote-1847745 -Ref: Floating-point Programming-Footnote-2848015 -Node: Floating-point Representation848279 -Node: Floating-point Context849444 -Ref: table-ieee-formats850283 -Node: Rounding Mode851667 -Ref: table-rounding-modes852146 -Ref: Rounding Mode-Footnote-1855161 -Node: Gawk and MPFR855340 -Node: Arbitrary Precision Floats856749 -Ref: Arbitrary Precision Floats-Footnote-1859192 -Node: Setting Precision859508 -Ref: table-predefined-precision-strings860194 -Node: Setting Rounding Mode862339 -Ref: table-gawk-rounding-modes862743 -Node: Floating-point Constants863930 -Node: Changing Precision865359 -Ref: Changing Precision-Footnote-1866756 -Node: Exact Arithmetic866930 -Node: Arbitrary Precision Integers870068 -Ref: Arbitrary Precision Integers-Footnote-1873083 -Node: Dynamic Extensions873230 -Node: Extension Intro874688 -Node: Plugin License875953 -Node: Extension Mechanism Outline876638 -Ref: load-extension877055 -Ref: load-new-function878533 -Ref: call-new-function879528 -Node: Extension API Description881543 -Node: Extension API Functions Introduction882830 -Node: General Data Types887757 -Ref: General Data Types-Footnote-1893452 -Node: Requesting Values893751 -Ref: table-value-types-returned894488 -Node: Memory Allocation Functions895442 -Ref: Memory Allocation Functions-Footnote-1898188 -Node: Constructor Functions898284 -Node: Registration Functions900042 -Node: Extension Functions900727 -Node: Exit Callback Functions903029 -Node: Extension Version String904278 -Node: Input Parsers904928 -Node: Output Wrappers914685 -Node: Two-way processors919195 -Node: Printing Messages921403 -Ref: Printing Messages-Footnote-1922480 -Node: Updating `ERRNO'922632 -Node: Accessing Parameters923371 -Node: Symbol Table Access924601 -Node: Symbol table by name925115 -Node: Symbol table by cookie927091 -Ref: Symbol table by cookie-Footnote-1931223 -Node: Cached values931286 -Ref: Cached values-Footnote-1934776 -Node: Array Manipulation934867 -Ref: Array Manipulation-Footnote-1935965 -Node: Array Data Types936004 -Ref: Array Data Types-Footnote-1938707 -Node: Array Functions938799 -Node: Flattening Arrays942635 -Node: Creating Arrays949487 -Node: Extension API Variables954212 -Node: Extension Versioning954848 -Node: Extension API Informational Variables956749 -Node: Extension API Boilerplate957835 -Node: Finding Extensions961639 -Node: Extension Example962199 -Node: Internal File Description962929 -Node: Internal File Ops967020 -Ref: Internal File Ops-Footnote-1978529 -Node: Using Internal File Ops978669 -Ref: Using Internal File Ops-Footnote-1981016 -Node: Extension Samples981282 -Node: Extension Sample File Functions982806 -Node: Extension Sample Fnmatch991293 -Node: Extension Sample Fork993062 -Node: Extension Sample Inplace994275 -Node: Extension Sample Ord996053 -Node: Extension Sample Readdir996889 -Node: Extension Sample Revout998421 -Node: Extension Sample Rev2way999014 -Node: Extension Sample Read write array999704 -Node: Extension Sample Readfile1001587 -Node: Extension Sample API Tests1002687 -Node: Extension Sample Time1003212 -Node: gawkextlib1004576 -Node: Language History1007357 -Node: V7/SVR3.11008950 -Node: SVR41011270 -Node: POSIX1012712 -Node: BTL1014098 -Node: POSIX/GNU1014832 -Node: Feature History1020431 -Node: Common Extensions1033407 -Node: Ranges and Locales1034719 -Ref: Ranges and Locales-Footnote-11039336 -Ref: Ranges and Locales-Footnote-21039363 -Ref: Ranges and Locales-Footnote-31039597 -Node: Contributors1039818 -Node: Installation1045199 -Node: Gawk Distribution1046093 -Node: Getting1046577 -Node: Extracting1047403 -Node: Distribution contents1049095 -Node: Unix Installation1054816 -Node: Quick Installation1055433 -Node: Additional Configuration Options1057879 -Node: Configuration Philosophy1059615 -Node: Non-Unix Installation1061969 -Node: PC Installation1062427 -Node: PC Binary Installation1063726 -Node: PC Compiling1065574 -Node: PC Testing1068518 -Node: PC Using1069694 -Node: Cygwin1073862 -Node: MSYS1074671 -Node: VMS Installation1075185 -Node: VMS Compilation1075981 -Ref: VMS Compilation-Footnote-11077233 -Node: VMS Dynamic Extensions1077291 -Node: VMS Installation Details1078664 -Node: VMS Running1080915 -Node: VMS GNV1083749 -Node: VMS Old Gawk1084472 -Node: Bugs1084942 -Node: Other Versions1088860 -Node: Notes1094944 -Node: Compatibility Mode1095744 -Node: Additions1096527 -Node: Accessing The Source1097454 -Node: Adding Code1098894 -Node: New Ports1104939 -Node: Derived Files1109074 -Ref: Derived Files-Footnote-11114395 -Ref: Derived Files-Footnote-21114429 -Ref: Derived Files-Footnote-31115029 -Node: Future Extensions1115127 -Node: Implementation Limitations1115710 -Node: Extension Design1116958 -Node: Old Extension Problems1118112 -Ref: Old Extension Problems-Footnote-11119620 -Node: Extension New Mechanism Goals1119677 -Ref: Extension New Mechanism Goals-Footnote-11123042 -Node: Extension Other Design Decisions1123228 -Node: Extension Future Growth1125334 -Node: Old Extension Mechanism1126170 -Node: Basic Concepts1127910 -Node: Basic High Level1128591 -Ref: figure-general-flow1128863 -Ref: figure-process-flow1129462 -Ref: Basic High Level-Footnote-11132691 -Node: Basic Data Typing1132876 -Node: Glossary1136231 -Node: Copying1161462 -Node: GNU Free Documentation License1199018 -Node: Index1224154 +Node: User-modified409370 +Ref: User-modified-Footnote-1417055 +Node: Auto-set417117 +Ref: Auto-set-Footnote-1429682 +Ref: Auto-set-Footnote-2429887 +Node: ARGC and ARGV429943 +Node: Arrays433797 +Node: Array Basics435295 +Node: Array Intro436121 +Ref: figure-array-elements438094 +Node: Reference to Elements440501 +Node: Assigning Elements442774 +Node: Array Example443265 +Node: Scanning an Array444997 +Node: Controlling Scanning448012 +Ref: Controlling Scanning-Footnote-1453185 +Node: Delete453501 +Ref: Delete-Footnote-1456266 +Node: Numeric Array Subscripts456323 +Node: Uninitialized Subscripts458506 +Node: Multidimensional460131 +Node: Multiscanning463224 +Node: Arrays of Arrays464813 +Node: Functions469453 +Node: Built-in470272 +Node: Calling Built-in471350 +Node: Numeric Functions473338 +Ref: Numeric Functions-Footnote-1477172 +Ref: Numeric Functions-Footnote-2477529 +Ref: Numeric Functions-Footnote-3477577 +Node: String Functions477846 +Ref: String Functions-Footnote-1500849 +Ref: String Functions-Footnote-2500978 +Ref: String Functions-Footnote-3501226 +Node: Gory Details501313 +Ref: table-sub-escapes502992 +Ref: table-sub-posix-92504346 +Ref: table-sub-proposed505697 +Ref: table-posix-sub507051 +Ref: table-gensub-escapes508596 +Ref: Gory Details-Footnote-1509772 +Ref: Gory Details-Footnote-2509823 +Node: I/O Functions509974 +Ref: I/O Functions-Footnote-1516970 +Node: Time Functions517117 +Ref: Time Functions-Footnote-1528110 +Ref: Time Functions-Footnote-2528178 +Ref: Time Functions-Footnote-3528336 +Ref: Time Functions-Footnote-4528447 +Ref: Time Functions-Footnote-5528559 +Ref: Time Functions-Footnote-6528786 +Node: Bitwise Functions529052 +Ref: table-bitwise-ops529614 +Ref: Bitwise Functions-Footnote-1533859 +Node: Type Functions534043 +Node: I18N Functions535194 +Node: User-defined536846 +Node: Definition Syntax537650 +Ref: Definition Syntax-Footnote-1542564 +Node: Function Example542633 +Ref: Function Example-Footnote-1545282 +Node: Function Caveats545304 +Node: Calling A Function545822 +Node: Variable Scope546777 +Node: Pass By Value/Reference549740 +Node: Return Statement553248 +Node: Dynamic Typing556229 +Node: Indirect Calls557160 +Node: Library Functions566847 +Ref: Library Functions-Footnote-1570360 +Ref: Library Functions-Footnote-2570503 +Node: Library Names570674 +Ref: Library Names-Footnote-1574147 +Ref: Library Names-Footnote-2574367 +Node: General Functions574453 +Node: Strtonum Function575481 +Node: Assert Function578411 +Node: Round Function581737 +Node: Cliff Random Function583278 +Node: Ordinal Functions584294 +Ref: Ordinal Functions-Footnote-1587371 +Ref: Ordinal Functions-Footnote-2587623 +Node: Join Function587834 +Ref: Join Function-Footnote-1589605 +Node: Getlocaltime Function589805 +Node: Readfile Function593546 +Node: Data File Management595385 +Node: Filetrans Function596017 +Node: Rewind Function600086 +Node: File Checking601473 +Node: Empty Files602567 +Node: Ignoring Assigns604797 +Node: Getopt Function606351 +Ref: Getopt Function-Footnote-1617654 +Node: Passwd Functions617857 +Ref: Passwd Functions-Footnote-1626835 +Node: Group Functions626923 +Node: Walking Arrays635007 +Node: Sample Programs637143 +Node: Running Examples637817 +Node: Clones638545 +Node: Cut Program639769 +Node: Egrep Program649620 +Ref: Egrep Program-Footnote-1657393 +Node: Id Program657503 +Node: Split Program661152 +Ref: Split Program-Footnote-1664671 +Node: Tee Program664799 +Node: Uniq Program667602 +Node: Wc Program675031 +Ref: Wc Program-Footnote-1679297 +Ref: Wc Program-Footnote-2679497 +Node: Miscellaneous Programs679589 +Node: Dupword Program680777 +Node: Alarm Program682808 +Node: Translate Program687615 +Ref: Translate Program-Footnote-1692002 +Ref: Translate Program-Footnote-2692250 +Node: Labels Program692384 +Ref: Labels Program-Footnote-1695755 +Node: Word Sorting695839 +Node: History Sorting699723 +Node: Extract Program701562 +Ref: Extract Program-Footnote-1709065 +Node: Simple Sed709193 +Node: Igawk Program712255 +Ref: Igawk Program-Footnote-1727426 +Ref: Igawk Program-Footnote-2727627 +Node: Anagram Program727765 +Node: Signature Program730833 +Node: Advanced Features731933 +Node: Nondecimal Data733819 +Node: Array Sorting735402 +Node: Controlling Array Traversal736099 +Node: Array Sorting Functions744383 +Ref: Array Sorting Functions-Footnote-1748252 +Node: Two-way I/O748446 +Ref: Two-way I/O-Footnote-1753878 +Node: TCP/IP Networking753960 +Node: Profiling756804 +Node: Internationalization764307 +Node: I18N and L10N765732 +Node: Explaining gettext766418 +Ref: Explaining gettext-Footnote-1771486 +Ref: Explaining gettext-Footnote-2771670 +Node: Programmer i18n771835 +Node: Translator i18n776062 +Node: String Extraction776856 +Ref: String Extraction-Footnote-1777817 +Node: Printf Ordering777903 +Ref: Printf Ordering-Footnote-1780685 +Node: I18N Portability780749 +Ref: I18N Portability-Footnote-1783198 +Node: I18N Example783261 +Ref: I18N Example-Footnote-1785899 +Node: Gawk I18N785971 +Node: Debugger786592 +Node: Debugging787563 +Node: Debugging Concepts787996 +Node: Debugging Terms789852 +Node: Awk Debugging792449 +Node: Sample Debugging Session793341 +Node: Debugger Invocation793861 +Node: Finding The Bug795194 +Node: List of Debugger Commands801681 +Node: Breakpoint Control803015 +Node: Debugger Execution Control806679 +Node: Viewing And Changing Data810039 +Node: Execution Stack813395 +Node: Debugger Info814862 +Node: Miscellaneous Debugger Commands818856 +Node: Readline Support824034 +Node: Limitations824865 +Node: Arbitrary Precision Arithmetic827117 +Ref: Arbitrary Precision Arithmetic-Footnote-1828766 +Node: General Arithmetic828914 +Node: Floating Point Issues830634 +Node: String Conversion Precision831515 +Ref: String Conversion Precision-Footnote-1833220 +Node: Unexpected Results833329 +Node: POSIX Floating Point Problems835482 +Ref: POSIX Floating Point Problems-Footnote-1839307 +Node: Integer Programming839345 +Node: Floating-point Programming841084 +Ref: Floating-point Programming-Footnote-1847415 +Ref: Floating-point Programming-Footnote-2847685 +Node: Floating-point Representation847949 +Node: Floating-point Context849114 +Ref: table-ieee-formats849953 +Node: Rounding Mode851337 +Ref: table-rounding-modes851816 +Ref: Rounding Mode-Footnote-1854831 +Node: Gawk and MPFR855010 +Node: Arbitrary Precision Floats856419 +Ref: Arbitrary Precision Floats-Footnote-1858862 +Node: Setting Precision859178 +Ref: table-predefined-precision-strings859864 +Node: Setting Rounding Mode862009 +Ref: table-gawk-rounding-modes862413 +Node: Floating-point Constants863600 +Node: Changing Precision865029 +Ref: Changing Precision-Footnote-1866426 +Node: Exact Arithmetic866600 +Node: Arbitrary Precision Integers869738 +Ref: Arbitrary Precision Integers-Footnote-1872753 +Node: Dynamic Extensions872900 +Node: Extension Intro874358 +Node: Plugin License875623 +Node: Extension Mechanism Outline876308 +Ref: load-extension876725 +Ref: load-new-function878203 +Ref: call-new-function879198 +Node: Extension API Description881213 +Node: Extension API Functions Introduction882500 +Node: General Data Types887427 +Ref: General Data Types-Footnote-1893122 +Node: Requesting Values893421 +Ref: table-value-types-returned894158 +Node: Memory Allocation Functions895112 +Ref: Memory Allocation Functions-Footnote-1897858 +Node: Constructor Functions897954 +Node: Registration Functions899712 +Node: Extension Functions900397 +Node: Exit Callback Functions902699 +Node: Extension Version String903948 +Node: Input Parsers904598 +Node: Output Wrappers914355 +Node: Two-way processors918865 +Node: Printing Messages921073 +Ref: Printing Messages-Footnote-1922150 +Node: Updating `ERRNO'922302 +Node: Accessing Parameters923041 +Node: Symbol Table Access924271 +Node: Symbol table by name924785 +Node: Symbol table by cookie926761 +Ref: Symbol table by cookie-Footnote-1930893 +Node: Cached values930956 +Ref: Cached values-Footnote-1934446 +Node: Array Manipulation934537 +Ref: Array Manipulation-Footnote-1935635 +Node: Array Data Types935674 +Ref: Array Data Types-Footnote-1938377 +Node: Array Functions938469 +Node: Flattening Arrays942305 +Node: Creating Arrays949157 +Node: Extension API Variables953882 +Node: Extension Versioning954518 +Node: Extension API Informational Variables956419 +Node: Extension API Boilerplate957505 +Node: Finding Extensions961309 +Node: Extension Example961869 +Node: Internal File Description962599 +Node: Internal File Ops966690 +Ref: Internal File Ops-Footnote-1978199 +Node: Using Internal File Ops978339 +Ref: Using Internal File Ops-Footnote-1980686 +Node: Extension Samples980952 +Node: Extension Sample File Functions982476 +Node: Extension Sample Fnmatch990963 +Node: Extension Sample Fork992732 +Node: Extension Sample Inplace993945 +Node: Extension Sample Ord995723 +Node: Extension Sample Readdir996559 +Node: Extension Sample Revout998091 +Node: Extension Sample Rev2way998684 +Node: Extension Sample Read write array999374 +Node: Extension Sample Readfile1001257 +Node: Extension Sample API Tests1002357 +Node: Extension Sample Time1002882 +Node: gawkextlib1004246 +Node: Language History1007027 +Node: V7/SVR3.11008620 +Node: SVR41010940 +Node: POSIX1012382 +Node: BTL1013768 +Node: POSIX/GNU1014502 +Node: Feature History1020101 +Node: Common Extensions1033077 +Node: Ranges and Locales1034389 +Ref: Ranges and Locales-Footnote-11039006 +Ref: Ranges and Locales-Footnote-21039033 +Ref: Ranges and Locales-Footnote-31039267 +Node: Contributors1039488 +Node: Installation1044869 +Node: Gawk Distribution1045763 +Node: Getting1046247 +Node: Extracting1047073 +Node: Distribution contents1048765 +Node: Unix Installation1054486 +Node: Quick Installation1055103 +Node: Additional Configuration Options1057549 +Node: Configuration Philosophy1059285 +Node: Non-Unix Installation1061639 +Node: PC Installation1062097 +Node: PC Binary Installation1063396 +Node: PC Compiling1065244 +Node: PC Testing1068188 +Node: PC Using1069364 +Node: Cygwin1073532 +Node: MSYS1074341 +Node: VMS Installation1074855 +Node: VMS Compilation1075651 +Ref: VMS Compilation-Footnote-11076903 +Node: VMS Dynamic Extensions1076961 +Node: VMS Installation Details1078334 +Node: VMS Running1080585 +Node: VMS GNV1083419 +Node: VMS Old Gawk1084142 +Node: Bugs1084612 +Node: Other Versions1088530 +Node: Notes1094614 +Node: Compatibility Mode1095414 +Node: Additions1096197 +Node: Accessing The Source1097124 +Node: Adding Code1098564 +Node: New Ports1104609 +Node: Derived Files1108744 +Ref: Derived Files-Footnote-11114065 +Ref: Derived Files-Footnote-21114099 +Ref: Derived Files-Footnote-31114699 +Node: Future Extensions1114797 +Node: Implementation Limitations1115380 +Node: Extension Design1116628 +Node: Old Extension Problems1117782 +Ref: Old Extension Problems-Footnote-11119290 +Node: Extension New Mechanism Goals1119347 +Ref: Extension New Mechanism Goals-Footnote-11122712 +Node: Extension Other Design Decisions1122898 +Node: Extension Future Growth1125004 +Node: Old Extension Mechanism1125840 +Node: Basic Concepts1127580 +Node: Basic High Level1128261 +Ref: figure-general-flow1128533 +Ref: figure-process-flow1129132 +Ref: Basic High Level-Footnote-11132361 +Node: Basic Data Typing1132546 +Node: Glossary1135901 +Node: Copying1161132 +Node: GNU Free Documentation License1198688 +Node: Index1223824  End Tag Table -- cgit v1.2.3 From 628837bf58f885225532b6c2de41b60ffa7c14e9 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Mon, 5 May 2014 17:46:19 +0300 Subject: Doc edits, through Chapter 9. --- doc/gawk.info | 985 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 494 insertions(+), 491 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index dfe1589e..706dace1 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -8406,7 +8406,9 @@ File: gawk.info, Node: Locales, Prev: Precedence, Up: Expressions ==================================== Modern systems support the notion of "locales": a way to tell the -system about the local character set and language. +system about the local character set and language. The ISO C standard +defines a default `"C"' locale, which is an environment that is typical +of what many C programmers are used to. Once upon a time, the locale setting used to affect regexp matching (*note Ranges and Locales::), but this is no longer true. @@ -8418,6 +8420,13 @@ much better performance when reading records. Otherwise, `gawk' has to make several function calls, _per input character_, to find the record terminator. + Locales can affect how dates and times are formatted (*note Time +Functions::). For example, a common way to abbreviate the date +September 4, 2015 in the United States is "9/4/15." In many countries +in Europe, however, it is abbreviated "4.9.15." Thus, the `%x' +specification in a `"US"' locale might produce `9/4/15', while in a +`"EUROPE"' locale, it might produce `4.9.15'. + According to POSIX, string comparison is also affected by locales (similar to regular expressions). The details are presented in *note POSIX String Comparison::. @@ -11330,12 +11339,22 @@ returns the number of characters in a string, and not the number of bytes used to represent those characters. Similarly, `index()' works with character indices, and not byte indices. + CAUTION: A number of functions deal with indices into strings. + For these functions, the first character of a string is at + position (index) one. This is different from C and the languages + descended from it, where the first character is at position zero. + You need to remember this when doing index calculations, + particularly if you are used to C. + In the following list, optional parameters are enclosed in square brackets ([ ]). Several functions perform string substitution; the full discussion is provided in the description of the `sub()' function, which comes towards the end since the list is presented in alphabetic -order. Those functions that are specific to `gawk' are marked with a -pound sign (`#'): +order. + + Those functions that are specific to `gawk' are marked with a pound +sign (`#'). They are not available in compatibility mode (*note +Options::): * Menu: @@ -11343,8 +11362,8 @@ pound sign (`#'): `&' with `sub()', `gsub()', and `gensub()'. -`asort('SOURCE [`,' DEST [`,' HOW ] ]`)' # -`asorti('SOURCE [`,' DEST [`,' HOW ] ]`)' # +`asort('SOURCE [`,' DEST [`,' HOW ] ]`) #' +`asorti('SOURCE [`,' DEST [`,' HOW ] ]`) #' These two functions are similar in behavior, so they are described together. @@ -11391,10 +11410,7 @@ pound sign (`#'): a[2] = "last" a[3] = "middle" - `asort()' and `asorti()' are `gawk' extensions; they are not - available in compatibility mode (*note Options::). - -`gensub(REGEXP, REPLACEMENT, HOW' [`, TARGET']`)' # +`gensub(REGEXP, REPLACEMENT, HOW' [`, TARGET']`) #' Search the target string TARGET for matches of the regular expression REGEXP. If HOW is a string beginning with `g' or `G' (short for "global"), then replace all matches of REGEXP with @@ -11444,9 +11460,6 @@ pound sign (`#'): If REGEXP does not match TARGET, `gensub()''s return value is the original unchanged value of TARGET. - `gensub()' is a `gawk' extension; it is not available in - compatibility mode (*note Options::). - `gsub(REGEXP, REPLACEMENT' [`, TARGET']`)' Search TARGET for _all_ of the longest, leftmost, _nonoverlapping_ matching substrings it can find and replace them with REPLACEMENT. @@ -11471,8 +11484,7 @@ pound sign (`#'): $ awk 'BEGIN { print index("peanut", "an") }' -| 3 - If FIND is not found, `index()' returns zero. (Remember that - string indices in `awk' start at one.) + If FIND is not found, `index()' returns zero. It is a fatal error to use a regexp constant for FIND. @@ -11518,12 +11530,12 @@ pound sign (`#'): `match(STRING, REGEXP' [`, ARRAY']`)' Search STRING for the longest, leftmost substring matched by the - regular expression, REGEXP and return the character position, or - "index", at which that substring begins (one, if it starts at the + regular expression, REGEXP and return the character position + (index) at which that substring begins (one, if it starts at the beginning of STRING). If no match is found, return zero. - The REGEXP argument may be either a regexp constant (`/.../') or a - string constant (`"..."'). In the latter case, the string is + The REGEXP argument may be either a regexp constant (`/'...`/') or + a string constant (`"'...`"'). In the latter case, the string is treated as a regexp to be matched. *Note Computed Regexps::, for a discussion of the difference between the two forms, and the implications for writing your program correctly. @@ -11603,7 +11615,7 @@ pound sign (`#'): compatibility mode (*note Options::), using a third argument is a fatal error. -`patsplit(STRING, ARRAY' [`, FIELDPAT' [`, SEPS' ] ]`)' # +`patsplit(STRING, ARRAY' [`, FIELDPAT' [`, SEPS' ] ]`) #' Divide STRING into pieces defined by FIELDPAT and store the pieces in ARRAY and the separator strings in the SEPS array. The first piece is stored in `ARRAY[1]', the second piece in `ARRAY[2]', and @@ -11622,9 +11634,6 @@ pound sign (`#'): Before splitting the string, `patsplit()' deletes any previously existing elements in the arrays ARRAY and SEPS. - The `patsplit()' function is a `gawk' extension. In compatibility - mode (*note Options::), it is not available. - `split(STRING, ARRAY' [`, FIELDSEP' [`, SEPS' ] ]`)' Divide STRING into pieces separated by FIELDSEP and store the pieces in ARRAY and the separator strings in the SEPS array. The @@ -11690,6 +11699,9 @@ pound sign (`#'): has one element only. The value of that element is the original STRING. + In POSIX mode (*note Options::), the fourth argument is not + allowed. + `sprintf(FORMAT, EXPRESSION1, ...)' Return (without printing) the string that `printf' would have printed out with the same arguments (*note Printf::). For example: @@ -11698,7 +11710,7 @@ pound sign (`#'): assigns the string `pi = 3.14 (approx.)' to the variable `pival'. -`strtonum(STR)' # +`strtonum(STR) #' Examine STR and return its numeric value. If STR begins with a leading `0', `strtonum()' assumes that STR is an octal number. If STR begins with a leading `0x' or `0X', `strtonum()' assumes that @@ -11715,9 +11727,6 @@ pound sign (`#'): Note also that `strtonum()' uses the current locale's decimal point for recognizing numbers (*note Locales::). - `strtonum()' is a `gawk' extension; it is not available in - compatibility mode (*note Options::). - `sub(REGEXP, REPLACEMENT' [`, TARGET']`)' Search TARGET, which is treated as a string, for the leftmost, longest substring matched by the regular expression REGEXP. @@ -11725,8 +11734,8 @@ pound sign (`#'): REPLACEMENT. The modified string becomes the new value of TARGET. Return the number of substitutions made (zero or one). - The REGEXP argument may be either a regexp constant (`/.../') or a - string constant (`"..."'). In the latter case, the string is + The REGEXP argument may be either a regexp constant (`/'...`/') or + a string constant (`"'...`"'). In the latter case, the string is treated as a regexp to be matched. *Note Computed Regexps::, for a discussion of the difference between the two forms, and the implications for writing your program correctly. @@ -11869,9 +11878,9 @@ backslashes and ampersands into the replacement text, you need to remember that there are several levels of "escape processing" going on. First, there is the "lexical" level, which is when `awk' reads your -program and builds an internal copy of it that can be executed. Then -there is the runtime level, which is when `awk' actually scans the -replacement string to determine what to generate. +program and builds an internal copy of it to execute. Then there is +the runtime level, which is when `awk' actually scans the replacement +string to determine what to generate. At both levels, `awk' looks for a defined set of characters that can come after a backslash. At the lexical level, it looks for the escape @@ -12063,6 +12072,9 @@ parameters are enclosed in square brackets ([ ]): not matter. *Note Two-way I/O::, which discusses this feature in more detail and gives an example. + Note that the second argument to `close()' is a `gawk' extension; + it is not available in compatibility mode (*note Options::). + `fflush('[FILENAME]`)' Flush any buffered output associated with FILENAME, which is either a file opened for writing or a shell command for @@ -12079,10 +12091,10 @@ parameters are enclosed in square brackets ([ ]): function--`gawk' also buffers its output and the `fflush()' function forces `gawk' to flush its buffers. - `fflush()' was added to Brian Kernighan's version of `awk' in - April of 1992. For two decades, it was not part of the POSIX - standard. As of December, 2012, it was accepted for inclusion - into the POSIX standard. See the Austin Group website + `fflush()' was added to Brian Kernighan's `awk' in April of 1992. + For two decades, it was not part of the POSIX standard. As of + December, 2012, it was accepted for inclusion into the POSIX + standard. See the Austin Group website (http://austingroupbugs.net/view.php?id=634). POSIX standardizes `fflush()' as follows: If there is no argument, @@ -12100,7 +12112,7 @@ parameters are enclosed in square brackets ([ ]): to flush only the standard output. `fflush()' returns zero if the buffer is successfully flushed; - otherwise, it returns non-zero (`gawk' returns -1). In the case + otherwise, it returns non-zero. (`gawk' returns -1.) In the case where all buffers are flushed, the return value is zero only if all buffers were flushed successfully. Otherwise, it is -1, and `gawk' warns about the problem FILENAME. @@ -12270,7 +12282,7 @@ enclosed in square brackets ([ ]): If DATESPEC does not contain enough elements or if the resulting time is out of range, `mktime()' returns -1. -``strftime(' [FORMAT [`,' TIMESTAMP [`,' UTC-FLAG ]]]`)'' +`strftime(' [FORMAT [`,' TIMESTAMP [`,' UTC-FLAG] ] ]`)' Format the time specified by TIMESTAMP based on the contents of the FORMAT string and return the result. It is similar to the function of the same name in ISO C. If UTC-FLAG is present and is @@ -12350,11 +12362,11 @@ the following date format specifications: `%g' The year modulo 100 of the ISO 8601 week number, as a decimal - number (00-99). For example, January 1, 1993 is in week 53 of - 1992. Thus, the year of its ISO 8601 week number is 1992, even - though its year is 1993. Similarly, December 31, 1973 is in week - 1 of 1974. Thus, the year of its ISO week number is 1974, even - though its year is 1973. + number (00-99). For example, January 1, 2012 is in week 53 of + 2011. Thus, the year of its ISO 8601 week number is 2011, even + though its year is 2012. Similarly, December 31, 2012 is in week + 1 of 2013. Thus, the year of its ISO week number is 2013, even + though its year is 2012. `%G' The full year of the ISO week number, as a decimal number. @@ -12434,7 +12446,7 @@ the following date format specifications: The year modulo 100 as a decimal number (00-99). `%Y' - The full year as a decimal number (e.g., 2011). + The full year as a decimal number (e.g., 2015). `%z' The timezone offset in a +HHMM format (e.g., the format necessary @@ -12456,15 +12468,6 @@ the following date format specifications: If a conversion specifier is not one of the above, the behavior is undefined.(6) - Informally, a "locale" is the geographic place in which a program is -meant to run. For example, a common way to abbreviate the date -September 4, 2012 in the United States is "9/4/12." In many countries -in Europe, however, it is abbreviated "4.9.12." Thus, the `%x' -specification in a `"US"' locale might produce `9/4/12', while in a -`"EUROPE"' locale, it might produce `4.9.12'. The ISO C standard -defines a default `"C"' locale, which is an environment that is typical -of what many C programmers are used to. - For systems that are not yet fully standards-compliant, `gawk' supplies a copy of `strftime()' from the GNU C Library. It supports all of the just-listed format specifications. If that version is used @@ -12494,7 +12497,7 @@ to the standard output and interprets the current time according to the format specifiers in the string. For example: $ date '+Today is %A, %B %d, %Y.' - -| Today is Wednesday, March 30, 2011. + -| Today is Monday, May 05, 2014. Here is the `gawk' version of the `date' utility. It has a shell "wrapper" to handle the `-u' option, which requires that `date' run as @@ -12511,7 +12514,7 @@ if the time zone is set to UTC: esac gawk 'BEGIN { - format = "%a %b %e %H:%M:%S %Z %Y" + format = PROCINFO["strftime"] exitval = 0 if (ARGC > 2) @@ -12689,8 +12692,8 @@ File: gawk.info, Node: Type Functions, Next: I18N Functions, Prev: Bitwise Fu `gawk' provides a single function that lets you distinguish an array from a scalar variable. This is necessary for writing code that -traverses every element of a true multidimensional array (*note Arrays -of Arrays::). +traverses every element of an array of arrays. (*note Arrays of +Arrays::). `isarray(X)' Return a true value if X is an array. Otherwise return false. @@ -12720,7 +12723,7 @@ descriptions here are purposely brief. *Note Internationalization::, for the full story. Optional parameters are enclosed in square brackets ([ ]): -``bindtextdomain(DIRECTORY' [`,' DOMAIN ]`)'' +`bindtextdomain(DIRECTORY' [`,' DOMAIN]`)' Set the directory in which `gawk' will look for message translation files, in case they will not or cannot be placed in the "standard" locations (e.g., during testing). It returns the @@ -12730,13 +12733,13 @@ brackets ([ ]): the null string (`""'), then `bindtextdomain()' returns the current binding for the given DOMAIN. -``dcgettext(STRING' [`,' DOMAIN [`,' CATEGORY ]]`)'' +`dcgettext(STRING' [`,' DOMAIN [`,' CATEGORY] ]`)' Return the translation of STRING in text domain DOMAIN for locale category CATEGORY. The default value for DOMAIN is the current value of `TEXTDOMAIN'. The default value for CATEGORY is `"LC_MESSAGES"'. -``dcngettext(STRING1, STRING2, NUMBER' [`,' DOMAIN [`,' CATEGORY ]]`)'' +`dcngettext(STRING1, STRING2, NUMBER' [`,' DOMAIN [`,' CATEGORY] ]`)' Return the plural form used for NUMBER of the translation of STRING1 and STRING2 in text domain DOMAIN for locale category CATEGORY. STRING1 is the English singular variant of a message, @@ -12799,7 +12802,7 @@ a parameter with the same name as the function itself. In addition, according to the POSIX standard, function parameters cannot have the same name as one of the special built-in variables -(*note Built-in Variables::. Not all versions of `awk' enforce this +(*note Built-in Variables::). Not all versions of `awk' enforce this restriction.) The BODY-OF-FUNCTION consists of `awk' statements. It is the most @@ -12949,7 +12952,7 @@ an `awk' version of `ctime()': function ctime(ts, format) { - format = "%a %b %e %H:%M:%S %Z %Y" + format = PROCINFO["strftime"] if (ts == 0) ts = systime() # use current time as default return strftime(format, ts) @@ -13003,9 +13006,10 @@ File: gawk.info, Node: Variable Scope, Next: Pass By Value/Reference, Prev: C 9.2.3.2 Controlling Variable Scope .................................. -There is no way to make a variable local to a `{ ... }' block in `awk', -but you can make a variable local to a function. It is good practice to -do so whenever a variable is needed only in that function. +Unlike many languages, there is no way to make a variable local to a +`{' ... `}' block in `awk', but you can make a variable local to a +function. It is good practice to do so whenever a variable is needed +only in that function. To make a variable local to a function, simply declare the variable as an argument after the actual function arguments (*note Definition @@ -13228,7 +13232,7 @@ like this: The EXPRESSION part is optional. Due most likely to an oversight, POSIX does not define what the return value is if you omit the -EXPRESSION. Technically speaking, this make the returned value +EXPRESSION. Technically speaking, this makes the returned value undefined, and therefore, unpredictable. In practice, though, all versions of `awk' simply return the null string, which acts like zero if used in a numeric context. @@ -13322,8 +13326,8 @@ Here is an annotated sample program: } In this example, the first call to `foo()' generates a fatal error, -so `gawk' will not report the second error. If you comment out that -call, though, then `gawk' will report the second error. +so `awk' will not report the second error. If you comment out that +call, though, then `awk' does report the second error. Usually, such things aren't a big issue, but it's worth being aware of them. @@ -30218,7 +30222,7 @@ Index * --re-interval option: Options. (line 279) * --sandbox option: Options. (line 286) * --sandbox option, disabling system() function: I/O Functions. - (line 94) + (line 97) * --sandbox option, input redirection with getline: Getline. (line 19) * --sandbox option, output redirection with print, printf: Redirection. (line 6) @@ -30453,7 +30457,7 @@ Index (line 6) * array scanning order, controlling: Controlling Scanning. (line 14) -* array, number of elements: String Functions. (line 194) +* array, number of elements: String Functions. (line 197) * arrays: Arrays. (line 6) * arrays of arrays: Arrays of Arrays. (line 6) * arrays, an example of using: Array Example. (line 6) @@ -30469,7 +30473,7 @@ Index * arrays, elements, deleting: Delete. (line 6) * arrays, elements, order of access by in operator: Scanning an Array. (line 48) -* arrays, elements, retrieving number of: String Functions. (line 32) +* arrays, elements, retrieving number of: String Functions. (line 42) * arrays, for statement and: Scanning an Array. (line 20) * arrays, indexing: Array Intro. (line 50) * arrays, merging into strings: Join Function. (line 6) @@ -30496,12 +30500,12 @@ Index * ASCII: Ordinal Functions. (line 45) * asort <1>: Array Sorting Functions. (line 6) -* asort: String Functions. (line 32) +* asort: String Functions. (line 42) * asort() function (gawk), arrays, sorting: Array Sorting Functions. (line 6) * asorti <1>: Array Sorting Functions. (line 6) -* asorti: String Functions. (line 32) +* asorti: String Functions. (line 42) * asorti() function (gawk), arrays, sorting: Array Sorting Functions. (line 6) * assert() function (C library): Assert Function. (line 6) @@ -30726,7 +30730,7 @@ Index * Brennan, Michael <3>: Simple Sed. (line 25) * Brennan, Michael <4>: Delete. (line 56) * Brennan, Michael: Foreword. (line 83) -* Brian Kernighan's awk <1>: I/O Functions. (line 40) +* Brian Kernighan's awk <1>: I/O Functions. (line 43) * Brian Kernighan's awk <2>: Gory Details. (line 15) * Brian Kernighan's awk <3>: String Functions. (line 490) * Brian Kernighan's awk <4>: Delete. (line 48) @@ -30755,9 +30759,9 @@ Index * Buening, Andreas <2>: Contributors. (line 92) * Buening, Andreas: Acknowledgments. (line 60) * buffering, input/output <1>: Two-way I/O. (line 70) -* buffering, input/output: I/O Functions. (line 137) -* buffering, interactive vs. noninteractive: I/O Functions. (line 106) -* buffers, flushing: I/O Functions. (line 29) +* buffering, input/output: I/O Functions. (line 140) +* buffering, interactive vs. noninteractive: I/O Functions. (line 109) +* buffers, flushing: I/O Functions. (line 32) * buffers, operators for: GNU Regexp Operators. (line 48) * bug reports, email address, bug-gawk@gnu.org: Bugs. (line 30) @@ -30866,7 +30870,7 @@ Index * common extensions, delete to delete entire arrays: Delete. (line 39) * common extensions, func keyword: Definition Syntax. (line 83) * common extensions, length() applied to an array: String Functions. - (line 194) + (line 197) * common extensions, RS as a regexp: gawk split records. (line 6) * common extensions, single character fields: Single Character Fields. (line 6) @@ -30920,7 +30924,7 @@ Index * controlling array scanning order: Controlling Scanning. (line 14) * convert string to lower case: String Functions. (line 521) -* convert string to number: String Functions. (line 385) +* convert string to number: String Functions. (line 388) * convert string to upper case: String Functions. (line 527) * converting integer array subscripts: Numeric Array Subscripts. (line 31) @@ -30986,7 +30990,7 @@ Index (line 20) * dark corner, input files: awk split records. (line 110) * dark corner, invoking awk: Command Line. (line 16) -* dark corner, length() function: String Functions. (line 180) +* dark corner, length() function: String Functions. (line 183) * dark corner, locale's decimal point character: Conversion. (line 75) * dark corner, multiline records: Multiple Line. (line 35) * dark corner, NF variable, decrementing: Changing Fields. (line 107) @@ -31005,7 +31009,7 @@ Index * database, group, reading: Group Functions. (line 6) * database, users, reading: Passwd Functions. (line 6) * date utility, GNU: Time Functions. (line 17) -* date utility, POSIX: Time Functions. (line 263) +* date utility, POSIX: Time Functions. (line 254) * dates, converting to timestamps: Time Functions. (line 76) * dates, information related to, localization: Explaining gettext. (line 115) @@ -31142,7 +31146,7 @@ Index * deleting entire arrays: Delete. (line 39) * Demaille, Akim: Acknowledgments. (line 60) * describe call stack frame, in debugger: Debugger Info. (line 27) -* differences between gawk and awk: String Functions. (line 194) +* differences between gawk and awk: String Functions. (line 197) * differences in awk and gawk, ARGC/ARGV variables: ARGC and ARGV. (line 88) * differences in awk and gawk, ARGIND variable: Auto-set. (line 44) @@ -31189,7 +31193,7 @@ Index (line 34) * differences in awk and gawk, LINT variable: User-modified. (line 88) * differences in awk and gawk, match() function: String Functions. - (line 257) + (line 260) * differences in awk and gawk, print/printf statements: Format Modifiers. (line 13) * differences in awk and gawk, PROCINFO array: Auto-set. (line 128) @@ -31385,10 +31389,10 @@ Index * extensions, common, \x escape sequence: Escape Sequences. (line 61) * extensions, common, BINMODE variable: PC Using. (line 33) * extensions, common, delete to delete entire arrays: Delete. (line 39) -* extensions, common, fflush() function: I/O Functions. (line 40) +* extensions, common, fflush() function: I/O Functions. (line 43) * extensions, common, func keyword: Definition Syntax. (line 83) * extensions, common, length() applied to an array: String Functions. - (line 194) + (line 197) * extensions, common, RS as a regexp: gawk split records. (line 6) * extensions, common, single character fields: Single Character Fields. (line 6) @@ -31407,7 +31411,7 @@ Index * features, undocumented: Undocumented. (line 6) * Fenlason, Jay <1>: Contributors. (line 18) * Fenlason, Jay: History. (line 30) -* fflush: I/O Functions. (line 25) +* fflush: I/O Functions. (line 28) * field numbers: Nonconstant Fields. (line 6) * field operator $: Fields. (line 19) * field operators, dollar sign as: Fields. (line 19) @@ -31500,7 +31504,7 @@ Index * files, source, search path for: Igawk Program. (line 368) * files, splitting: Split Program. (line 6) * files, Texinfo, extracting programs from: Extract Program. (line 6) -* find substring in string: String Functions. (line 151) +* find substring in string: String Functions. (line 155) * finding extensions: Finding Extensions. (line 6) * finish debugger command: Debugger Execution Control. (line 39) @@ -31513,7 +31517,7 @@ Index * floating-point, numbers, arbitrary precision: Arbitrary Precision Arithmetic. (line 6) * floating-point, VAX/VMS: VMS Running. (line 51) -* flush buffered output: I/O Functions. (line 25) +* flush buffered output: I/O Functions. (line 28) * fnmatch() extension function: Extension Sample Fnmatch. (line 12) * FNR variable <1>: Auto-set. (line 99) @@ -31532,7 +31536,7 @@ Index * format time string: Time Functions. (line 48) * formats, numeric output: OFMT. (line 6) * formatting output: Printf. (line 6) -* formatting strings: String Functions. (line 378) +* formatting strings: String Functions. (line 381) * forward slash (/) to enclose regular expressions: Regexp. (line 10) * forward slash (/), / operator: Precedence. (line 55) * forward slash (/), /= operator <1>: Precedence. (line 95) @@ -31661,7 +31665,7 @@ Index * gawk, hexadecimal numbers and: Nondecimal-numbers. (line 42) * gawk, IGNORECASE variable in <1>: Array Sorting Functions. (line 83) -* gawk, IGNORECASE variable in <2>: String Functions. (line 48) +* gawk, IGNORECASE variable in <2>: String Functions. (line 58) * gawk, IGNORECASE variable in <3>: Array Intro. (line 92) * gawk, IGNORECASE variable in <4>: User-modified. (line 76) * gawk, IGNORECASE variable in: Case-sensitivity. (line 26) @@ -31715,7 +31719,7 @@ Index * General Public License (GPL): Glossary. (line 306) * General Public License, See GPL: Manual History. (line 11) * generate time values: Time Functions. (line 25) -* gensub <1>: String Functions. (line 82) +* gensub <1>: String Functions. (line 89) * gensub: Using Constant Regexps. (line 43) * gensub() function (gawk), escape processing: Gory Details. (line 6) @@ -31791,7 +31795,7 @@ Index * group file: Group Functions. (line 6) * group ID of gawk user: Auto-set. (line 172) * groups, information about: Group Functions. (line 6) -* gsub <1>: String Functions. (line 135) +* gsub <1>: String Functions. (line 139) * gsub: Using Constant Regexps. (line 43) * gsub() function, arguments of: String Functions. (line 460) @@ -31855,7 +31859,7 @@ Index (line 37) * in operator, use in loops: Scanning an Array. (line 17) * increment operators: Increment Ops. (line 6) -* index: String Functions. (line 151) +* index: String Functions. (line 155) * indexing arrays: Array Intro. (line 50) * indirect function calls: Indirect Calls. (line 6) * infinite precision: Arbitrary Precision Arithmetic. @@ -31873,7 +31877,7 @@ Index * input files, running awk without: Read Terminal. (line 6) * input files, variable assignments and: Other Arguments. (line 19) * input pipeline: Getline/Pipe. (line 9) -* input record, length of: String Functions. (line 171) +* input record, length of: String Functions. (line 174) * input redirection: Getline/File. (line 6) * input, data, nondecimal: Nondecimal Data. (line 6) * input, explicit: Getline. (line 6) @@ -31898,7 +31902,7 @@ Index * integers, arbitrary precision: Arbitrary Precision Integers. (line 6) * integers, unsigned: General Arithmetic. (line 15) -* interacting with other programs: I/O Functions. (line 72) +* interacting with other programs: I/O Functions. (line 75) * internationalization <1>: I18N and L10N. (line 6) * internationalization: I18N Functions. (line 6) * internationalization, localization <1>: Internationalization. @@ -31919,7 +31923,7 @@ Index * interpreted programs: Basic High Level. (line 15) * interval expressions, regexp operator: Regexp Operators. (line 117) * inventory-shipped file: Sample Data Files. (line 32) -* invoke shell command: I/O Functions. (line 72) +* invoke shell command: I/O Functions. (line 75) * isarray: Type Functions. (line 11) * ISO: Glossary. (line 368) * ISO 8859-1: Glossary. (line 133) @@ -31977,9 +31981,9 @@ Index * left shift: Bitwise Functions. (line 46) * left shift, bitwise: Bitwise Functions. (line 32) * leftmost longest match: Multiple Line. (line 26) -* length: String Functions. (line 164) -* length of input record: String Functions. (line 171) -* length of string: String Functions. (line 164) +* length: String Functions. (line 167) +* length of input record: String Functions. (line 174) +* length of string: String Functions. (line 167) * Lesser General Public License (LGPL): Glossary. (line 397) * LGPL (Lesser General Public License): Glossary. (line 397) * libmawk: Other Versions. (line 120) @@ -32071,10 +32075,10 @@ Index (line 6) * marked strings, extracting: String Extraction. (line 6) * Marx, Groucho: Increment Ops. (line 60) -* match: String Functions. (line 204) -* match regexp in string: String Functions. (line 204) +* match: String Functions. (line 207) +* match regexp in string: String Functions. (line 207) * match() function, RSTART/RLENGTH variables: String Functions. - (line 221) + (line 224) * matching, expressions, See comparison expressions: Typing and Comparison. (line 9) * matching, leftmost longest: Multiple Line. (line 26) @@ -32174,7 +32178,7 @@ Index * null strings, converting numbers to strings: Conversion. (line 21) * null strings, matching: Gory Details. (line 164) * number as string of bits: Bitwise Functions. (line 109) -* number of array elements: String Functions. (line 194) +* number of array elements: String Functions. (line 197) * number sign (#), #! (executable scripts): Executable Scripts. (line 6) * number sign (#), commenting: Comments. (line 6) @@ -32263,7 +32267,7 @@ Index (line 20) * output redirection: Redirection. (line 6) * output wrapper: Output Wrappers. (line 6) -* output, buffering: I/O Functions. (line 29) +* output, buffering: I/O Functions. (line 32) * output, duplicating into files: Tee Program. (line 6) * output, files, closing: Close Files And Pipes. (line 6) @@ -32280,7 +32284,7 @@ Index * parentheses (), in a profile: Profiling. (line 146) * parentheses (), regexp operator: Regexp Operators. (line 80) * password file: Passwd Functions. (line 16) -* patsplit: String Functions. (line 291) +* patsplit: String Functions. (line 294) * patterns: Patterns and Actions. (line 6) * patterns, comparison expressions as: Expression Patterns. (line 14) @@ -32336,7 +32340,7 @@ Index * portability, gawk: New Ports. (line 6) * portability, gettext library and: Explaining gettext. (line 10) * portability, internationalization and: I18N Portability. (line 6) -* portability, length() function: String Functions. (line 173) +* portability, length() function: String Functions. (line 176) * portability, new awk vs. old awk: Conversion. (line 55) * portability, next statement in user-defined functions: Pass By Value/Reference. (line 91) @@ -32374,14 +32378,14 @@ Index * POSIX awk, changes in awk versions: POSIX. (line 6) * POSIX awk, continue statement and: Continue Statement. (line 43) * POSIX awk, CONVFMT variable and: User-modified. (line 30) -* POSIX awk, date utility and: Time Functions. (line 263) +* POSIX awk, date utility and: Time Functions. (line 254) * POSIX awk, field separators and <1>: Field Splitting Summary. (line 40) * POSIX awk, field separators and: Fields. (line 6) * POSIX awk, FS variable and: User-modified. (line 60) * POSIX awk, function keyword in: Definition Syntax. (line 83) * POSIX awk, functions and, gsub()/sub(): Gory Details. (line 54) -* POSIX awk, functions and, length(): String Functions. (line 173) +* POSIX awk, functions and, length(): String Functions. (line 176) * POSIX awk, GNU long options and: Options. (line 15) * POSIX awk, interval expressions in: Regexp Operators. (line 136) * POSIX awk, next/nextfile statements and: Next Statement. (line 45) @@ -32619,7 +32623,7 @@ Index * right shift, bitwise: Bitwise Functions. (line 32) * Ritchie, Dennis: Basic Data Typing. (line 55) * RLENGTH variable: Auto-set. (line 244) -* RLENGTH variable, match() function and: String Functions. (line 221) +* RLENGTH variable, match() function and: String Functions. (line 224) * Robbins, Arnold <1>: Future Extensions. (line 6) * Robbins, Arnold <2>: Bugs. (line 32) * Robbins, Arnold <3>: Contributors. (line 139) @@ -32648,7 +32652,7 @@ Index * RS variable, multiline records and: Multiple Line. (line 17) * rshift: Bitwise Functions. (line 52) * RSTART variable: Auto-set. (line 250) -* RSTART variable, match() function and: String Functions. (line 221) +* RSTART variable, match() function and: String Functions. (line 224) * RT variable <1>: Auto-set. (line 257) * RT variable <2>: Multiple Line. (line 129) * RT variable: awk split records. (line 124) @@ -32673,8 +32677,8 @@ Index * Schorr, Andrew: Acknowledgments. (line 60) * Schreiber, Bert: Acknowledgments. (line 38) * Schreiber, Rita: Acknowledgments. (line 38) -* search and replace in strings: String Functions. (line 82) -* search in string: String Functions. (line 151) +* search and replace in strings: String Functions. (line 89) +* search in string: String Functions. (line 155) * search paths <1>: VMS Running. (line 58) * search paths <2>: PC Using. (line 10) * search paths: Igawk Program. (line 368) @@ -32759,13 +32763,13 @@ Index (line 38) * sidebar, Changing NR and FNR: Auto-set. (line 299) * sidebar, Controlling Output Buffering with system(): I/O Functions. - (line 135) + (line 138) * sidebar, Escape Sequences for Metacharacters: Escape Sequences. (line 128) * sidebar, FS and IGNORECASE: Field Splitting Summary. (line 64) * sidebar, Interactive Versus Noninteractive Buffering: I/O Functions. - (line 104) + (line 107) * sidebar, Matching the Null String: Gory Details. (line 162) * sidebar, Operator Evaluation Order: Increment Ops. (line 58) * sidebar, Piping into sh: Redirection. (line 140) @@ -32809,8 +32813,8 @@ Index * sleep() extension function: Extension Sample Time. (line 23) * Solaris, POSIX-compliant awk: Other Versions. (line 96) -* sort array: String Functions. (line 32) -* sort array indices: String Functions. (line 32) +* sort array: String Functions. (line 42) +* sort array indices: String Functions. (line 42) * sort function, arrays, sorting: Array Sorting Functions. (line 6) * sort utility: Word Sorting. (line 50) @@ -32835,11 +32839,11 @@ Index * sparse arrays: Array Intro. (line 71) * Spencer, Henry: Glossary. (line 12) * split: String Functions. (line 313) -* split string into array: String Functions. (line 291) +* split string into array: String Functions. (line 294) * split utility: Split Program. (line 6) * split() function, array elements, deleting: Delete. (line 61) * split.awk program: Split Program. (line 30) -* sprintf <1>: String Functions. (line 378) +* sprintf <1>: String Functions. (line 381) * sprintf: OFMT. (line 15) * sprintf() function, OFMT variable and: User-modified. (line 114) * sprintf() function, print/printf statements and: Round Function. @@ -32877,9 +32881,9 @@ Index * string constants, vs. regexp constants: Computed Regexps. (line 39) * string extraction (internationalization): String Extraction. (line 6) -* string length: String Functions. (line 164) +* string length: String Functions. (line 167) * string operators: Concatenation. (line 8) -* string, regular expression match: String Functions. (line 204) +* string, regular expression match: String Functions. (line 207) * string-manipulation functions: String Functions. (line 6) * string-matching operators: Regexp Usage. (line 19) * string-translation functions: I18N Functions. (line 6) @@ -32896,7 +32900,7 @@ Index * strings, null: Regexp Field Splitting. (line 43) * strings, numeric: Variable Typing. (line 6) -* strtonum: String Functions. (line 385) +* strtonum: String Functions. (line 388) * strtonum() function (gawk), --non-decimal-data option and: Nondecimal Data. (line 36) * sub <1>: String Functions. (line 406) @@ -32915,7 +32919,7 @@ Index * SUBSEP variable: User-modified. (line 146) * SUBSEP variable, and multidimensional arrays: Multidimensional. (line 16) -* substitute in string: String Functions. (line 82) +* substitute in string: String Functions. (line 89) * substr: String Functions. (line 479) * substring: String Functions. (line 479) * Sumner, Andrew: Other Versions. (line 64) @@ -32924,7 +32928,7 @@ Index * SYMTAB array: Auto-set. (line 261) * syntactic ambiguity: /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) -* system: I/O Functions. (line 72) +* system: I/O Functions. (line 75) * systime: Time Functions. (line 66) * t debugger command (alias for tbreak): Breakpoint Control. (line 90) * tbreak debugger command: Breakpoint Control. (line 90) @@ -32994,7 +32998,7 @@ Index (line 23) * troubleshooting, fatal errors, printf format strings: Format Modifiers. (line 159) -* troubleshooting, fflush() function: I/O Functions. (line 60) +* troubleshooting, fflush() function: I/O Functions. (line 63) * troubleshooting, function call syntax: Function Calls. (line 30) * troubleshooting, gawk: Compatibility Mode. (line 6) * troubleshooting, gawk, bug reports: Bugs. (line 9) @@ -33002,8 +33006,7 @@ Index (line 16) * troubleshooting, getline function: File Checking. (line 25) * troubleshooting, gsub()/sub() functions: String Functions. (line 470) -* troubleshooting, match() function: String Functions. (line 286) -* troubleshooting, patsplit() function: String Functions. (line 309) +* troubleshooting, match() function: String Functions. (line 289) * troubleshooting, print statement, omitting commas: Print Examples. (line 31) * troubleshooting, printing: Redirection. (line 118) @@ -33013,7 +33016,7 @@ Index (line 39) * troubleshooting, string concatenation: Concatenation. (line 26) * troubleshooting, substr() function: String Functions. (line 497) -* troubleshooting, system() function: I/O Functions. (line 94) +* troubleshooting, system() function: I/O Functions. (line 97) * troubleshooting, typographical errors, global variables: Options. (line 98) * true, logical: Truth Values. (line 6) @@ -33354,370 +33357,370 @@ Node: Conditional Exp350997 Node: Function Calls352724 Node: Precedence356482 Node: Locales360151 -Node: Patterns and Actions361240 -Node: Pattern Overview362294 -Node: Regexp Patterns363971 -Node: Expression Patterns364514 -Node: Ranges368295 -Node: BEGIN/END371401 -Node: Using BEGIN/END372163 -Ref: Using BEGIN/END-Footnote-1374899 -Node: I/O And BEGIN/END375005 -Node: BEGINFILE/ENDFILE377290 -Node: Empty380226 -Node: Using Shell Variables380543 -Node: Action Overview382826 -Node: Statements385171 -Node: If Statement387025 -Node: While Statement388524 -Node: Do Statement390568 -Node: For Statement391724 -Node: Switch Statement394876 -Node: Break Statement396979 -Node: Continue Statement399034 -Node: Next Statement400827 -Node: Nextfile Statement403217 -Node: Exit Statement405872 -Node: Built-in Variables408274 -Node: User-modified409370 -Ref: User-modified-Footnote-1417055 -Node: Auto-set417117 -Ref: Auto-set-Footnote-1429682 -Ref: Auto-set-Footnote-2429887 -Node: ARGC and ARGV429943 -Node: Arrays433797 -Node: Array Basics435295 -Node: Array Intro436121 -Ref: figure-array-elements438094 -Node: Reference to Elements440501 -Node: Assigning Elements442774 -Node: Array Example443265 -Node: Scanning an Array444997 -Node: Controlling Scanning448012 -Ref: Controlling Scanning-Footnote-1453185 -Node: Delete453501 -Ref: Delete-Footnote-1456266 -Node: Numeric Array Subscripts456323 -Node: Uninitialized Subscripts458506 -Node: Multidimensional460131 -Node: Multiscanning463224 -Node: Arrays of Arrays464813 -Node: Functions469453 -Node: Built-in470272 -Node: Calling Built-in471350 -Node: Numeric Functions473338 -Ref: Numeric Functions-Footnote-1477172 -Ref: Numeric Functions-Footnote-2477529 -Ref: Numeric Functions-Footnote-3477577 -Node: String Functions477846 -Ref: String Functions-Footnote-1500849 -Ref: String Functions-Footnote-2500978 -Ref: String Functions-Footnote-3501226 -Node: Gory Details501313 -Ref: table-sub-escapes502992 -Ref: table-sub-posix-92504346 -Ref: table-sub-proposed505697 -Ref: table-posix-sub507051 -Ref: table-gensub-escapes508596 -Ref: Gory Details-Footnote-1509772 -Ref: Gory Details-Footnote-2509823 -Node: I/O Functions509974 -Ref: I/O Functions-Footnote-1516970 -Node: Time Functions517117 -Ref: Time Functions-Footnote-1528110 -Ref: Time Functions-Footnote-2528178 -Ref: Time Functions-Footnote-3528336 -Ref: Time Functions-Footnote-4528447 -Ref: Time Functions-Footnote-5528559 -Ref: Time Functions-Footnote-6528786 -Node: Bitwise Functions529052 -Ref: table-bitwise-ops529614 -Ref: Bitwise Functions-Footnote-1533859 -Node: Type Functions534043 -Node: I18N Functions535194 -Node: User-defined536846 -Node: Definition Syntax537650 -Ref: Definition Syntax-Footnote-1542564 -Node: Function Example542633 -Ref: Function Example-Footnote-1545282 -Node: Function Caveats545304 -Node: Calling A Function545822 -Node: Variable Scope546777 -Node: Pass By Value/Reference549740 -Node: Return Statement553248 -Node: Dynamic Typing556229 -Node: Indirect Calls557160 -Node: Library Functions566847 -Ref: Library Functions-Footnote-1570360 -Ref: Library Functions-Footnote-2570503 -Node: Library Names570674 -Ref: Library Names-Footnote-1574147 -Ref: Library Names-Footnote-2574367 -Node: General Functions574453 -Node: Strtonum Function575481 -Node: Assert Function578411 -Node: Round Function581737 -Node: Cliff Random Function583278 -Node: Ordinal Functions584294 -Ref: Ordinal Functions-Footnote-1587371 -Ref: Ordinal Functions-Footnote-2587623 -Node: Join Function587834 -Ref: Join Function-Footnote-1589605 -Node: Getlocaltime Function589805 -Node: Readfile Function593546 -Node: Data File Management595385 -Node: Filetrans Function596017 -Node: Rewind Function600086 -Node: File Checking601473 -Node: Empty Files602567 -Node: Ignoring Assigns604797 -Node: Getopt Function606351 -Ref: Getopt Function-Footnote-1617654 -Node: Passwd Functions617857 -Ref: Passwd Functions-Footnote-1626835 -Node: Group Functions626923 -Node: Walking Arrays635007 -Node: Sample Programs637143 -Node: Running Examples637817 -Node: Clones638545 -Node: Cut Program639769 -Node: Egrep Program649620 -Ref: Egrep Program-Footnote-1657393 -Node: Id Program657503 -Node: Split Program661152 -Ref: Split Program-Footnote-1664671 -Node: Tee Program664799 -Node: Uniq Program667602 -Node: Wc Program675031 -Ref: Wc Program-Footnote-1679297 -Ref: Wc Program-Footnote-2679497 -Node: Miscellaneous Programs679589 -Node: Dupword Program680777 -Node: Alarm Program682808 -Node: Translate Program687615 -Ref: Translate Program-Footnote-1692002 -Ref: Translate Program-Footnote-2692250 -Node: Labels Program692384 -Ref: Labels Program-Footnote-1695755 -Node: Word Sorting695839 -Node: History Sorting699723 -Node: Extract Program701562 -Ref: Extract Program-Footnote-1709065 -Node: Simple Sed709193 -Node: Igawk Program712255 -Ref: Igawk Program-Footnote-1727426 -Ref: Igawk Program-Footnote-2727627 -Node: Anagram Program727765 -Node: Signature Program730833 -Node: Advanced Features731933 -Node: Nondecimal Data733819 -Node: Array Sorting735402 -Node: Controlling Array Traversal736099 -Node: Array Sorting Functions744383 -Ref: Array Sorting Functions-Footnote-1748252 -Node: Two-way I/O748446 -Ref: Two-way I/O-Footnote-1753878 -Node: TCP/IP Networking753960 -Node: Profiling756804 -Node: Internationalization764307 -Node: I18N and L10N765732 -Node: Explaining gettext766418 -Ref: Explaining gettext-Footnote-1771486 -Ref: Explaining gettext-Footnote-2771670 -Node: Programmer i18n771835 -Node: Translator i18n776062 -Node: String Extraction776856 -Ref: String Extraction-Footnote-1777817 -Node: Printf Ordering777903 -Ref: Printf Ordering-Footnote-1780685 -Node: I18N Portability780749 -Ref: I18N Portability-Footnote-1783198 -Node: I18N Example783261 -Ref: I18N Example-Footnote-1785899 -Node: Gawk I18N785971 -Node: Debugger786592 -Node: Debugging787563 -Node: Debugging Concepts787996 -Node: Debugging Terms789852 -Node: Awk Debugging792449 -Node: Sample Debugging Session793341 -Node: Debugger Invocation793861 -Node: Finding The Bug795194 -Node: List of Debugger Commands801681 -Node: Breakpoint Control803015 -Node: Debugger Execution Control806679 -Node: Viewing And Changing Data810039 -Node: Execution Stack813395 -Node: Debugger Info814862 -Node: Miscellaneous Debugger Commands818856 -Node: Readline Support824034 -Node: Limitations824865 -Node: Arbitrary Precision Arithmetic827117 -Ref: Arbitrary Precision Arithmetic-Footnote-1828766 -Node: General Arithmetic828914 -Node: Floating Point Issues830634 -Node: String Conversion Precision831515 -Ref: String Conversion Precision-Footnote-1833220 -Node: Unexpected Results833329 -Node: POSIX Floating Point Problems835482 -Ref: POSIX Floating Point Problems-Footnote-1839307 -Node: Integer Programming839345 -Node: Floating-point Programming841084 -Ref: Floating-point Programming-Footnote-1847415 -Ref: Floating-point Programming-Footnote-2847685 -Node: Floating-point Representation847949 -Node: Floating-point Context849114 -Ref: table-ieee-formats849953 -Node: Rounding Mode851337 -Ref: table-rounding-modes851816 -Ref: Rounding Mode-Footnote-1854831 -Node: Gawk and MPFR855010 -Node: Arbitrary Precision Floats856419 -Ref: Arbitrary Precision Floats-Footnote-1858862 -Node: Setting Precision859178 -Ref: table-predefined-precision-strings859864 -Node: Setting Rounding Mode862009 -Ref: table-gawk-rounding-modes862413 -Node: Floating-point Constants863600 -Node: Changing Precision865029 -Ref: Changing Precision-Footnote-1866426 -Node: Exact Arithmetic866600 -Node: Arbitrary Precision Integers869738 -Ref: Arbitrary Precision Integers-Footnote-1872753 -Node: Dynamic Extensions872900 -Node: Extension Intro874358 -Node: Plugin License875623 -Node: Extension Mechanism Outline876308 -Ref: load-extension876725 -Ref: load-new-function878203 -Ref: call-new-function879198 -Node: Extension API Description881213 -Node: Extension API Functions Introduction882500 -Node: General Data Types887427 -Ref: General Data Types-Footnote-1893122 -Node: Requesting Values893421 -Ref: table-value-types-returned894158 -Node: Memory Allocation Functions895112 -Ref: Memory Allocation Functions-Footnote-1897858 -Node: Constructor Functions897954 -Node: Registration Functions899712 -Node: Extension Functions900397 -Node: Exit Callback Functions902699 -Node: Extension Version String903948 -Node: Input Parsers904598 -Node: Output Wrappers914355 -Node: Two-way processors918865 -Node: Printing Messages921073 -Ref: Printing Messages-Footnote-1922150 -Node: Updating `ERRNO'922302 -Node: Accessing Parameters923041 -Node: Symbol Table Access924271 -Node: Symbol table by name924785 -Node: Symbol table by cookie926761 -Ref: Symbol table by cookie-Footnote-1930893 -Node: Cached values930956 -Ref: Cached values-Footnote-1934446 -Node: Array Manipulation934537 -Ref: Array Manipulation-Footnote-1935635 -Node: Array Data Types935674 -Ref: Array Data Types-Footnote-1938377 -Node: Array Functions938469 -Node: Flattening Arrays942305 -Node: Creating Arrays949157 -Node: Extension API Variables953882 -Node: Extension Versioning954518 -Node: Extension API Informational Variables956419 -Node: Extension API Boilerplate957505 -Node: Finding Extensions961309 -Node: Extension Example961869 -Node: Internal File Description962599 -Node: Internal File Ops966690 -Ref: Internal File Ops-Footnote-1978199 -Node: Using Internal File Ops978339 -Ref: Using Internal File Ops-Footnote-1980686 -Node: Extension Samples980952 -Node: Extension Sample File Functions982476 -Node: Extension Sample Fnmatch990963 -Node: Extension Sample Fork992732 -Node: Extension Sample Inplace993945 -Node: Extension Sample Ord995723 -Node: Extension Sample Readdir996559 -Node: Extension Sample Revout998091 -Node: Extension Sample Rev2way998684 -Node: Extension Sample Read write array999374 -Node: Extension Sample Readfile1001257 -Node: Extension Sample API Tests1002357 -Node: Extension Sample Time1002882 -Node: gawkextlib1004246 -Node: Language History1007027 -Node: V7/SVR3.11008620 -Node: SVR41010940 -Node: POSIX1012382 -Node: BTL1013768 -Node: POSIX/GNU1014502 -Node: Feature History1020101 -Node: Common Extensions1033077 -Node: Ranges and Locales1034389 -Ref: Ranges and Locales-Footnote-11039006 -Ref: Ranges and Locales-Footnote-21039033 -Ref: Ranges and Locales-Footnote-31039267 -Node: Contributors1039488 -Node: Installation1044869 -Node: Gawk Distribution1045763 -Node: Getting1046247 -Node: Extracting1047073 -Node: Distribution contents1048765 -Node: Unix Installation1054486 -Node: Quick Installation1055103 -Node: Additional Configuration Options1057549 -Node: Configuration Philosophy1059285 -Node: Non-Unix Installation1061639 -Node: PC Installation1062097 -Node: PC Binary Installation1063396 -Node: PC Compiling1065244 -Node: PC Testing1068188 -Node: PC Using1069364 -Node: Cygwin1073532 -Node: MSYS1074341 -Node: VMS Installation1074855 -Node: VMS Compilation1075651 -Ref: VMS Compilation-Footnote-11076903 -Node: VMS Dynamic Extensions1076961 -Node: VMS Installation Details1078334 -Node: VMS Running1080585 -Node: VMS GNV1083419 -Node: VMS Old Gawk1084142 -Node: Bugs1084612 -Node: Other Versions1088530 -Node: Notes1094614 -Node: Compatibility Mode1095414 -Node: Additions1096197 -Node: Accessing The Source1097124 -Node: Adding Code1098564 -Node: New Ports1104609 -Node: Derived Files1108744 -Ref: Derived Files-Footnote-11114065 -Ref: Derived Files-Footnote-21114099 -Ref: Derived Files-Footnote-31114699 -Node: Future Extensions1114797 -Node: Implementation Limitations1115380 -Node: Extension Design1116628 -Node: Old Extension Problems1117782 -Ref: Old Extension Problems-Footnote-11119290 -Node: Extension New Mechanism Goals1119347 -Ref: Extension New Mechanism Goals-Footnote-11122712 -Node: Extension Other Design Decisions1122898 -Node: Extension Future Growth1125004 -Node: Old Extension Mechanism1125840 -Node: Basic Concepts1127580 -Node: Basic High Level1128261 -Ref: figure-general-flow1128533 -Ref: figure-process-flow1129132 -Ref: Basic High Level-Footnote-11132361 -Node: Basic Data Typing1132546 -Node: Glossary1135901 -Node: Copying1161132 -Node: GNU Free Documentation License1198688 -Node: Index1223824 +Node: Patterns and Actions361754 +Node: Pattern Overview362808 +Node: Regexp Patterns364485 +Node: Expression Patterns365028 +Node: Ranges368809 +Node: BEGIN/END371915 +Node: Using BEGIN/END372677 +Ref: Using BEGIN/END-Footnote-1375413 +Node: I/O And BEGIN/END375519 +Node: BEGINFILE/ENDFILE377804 +Node: Empty380740 +Node: Using Shell Variables381057 +Node: Action Overview383340 +Node: Statements385685 +Node: If Statement387539 +Node: While Statement389038 +Node: Do Statement391082 +Node: For Statement392238 +Node: Switch Statement395390 +Node: Break Statement397493 +Node: Continue Statement399548 +Node: Next Statement401341 +Node: Nextfile Statement403731 +Node: Exit Statement406386 +Node: Built-in Variables408788 +Node: User-modified409884 +Ref: User-modified-Footnote-1417569 +Node: Auto-set417631 +Ref: Auto-set-Footnote-1430196 +Ref: Auto-set-Footnote-2430401 +Node: ARGC and ARGV430457 +Node: Arrays434311 +Node: Array Basics435809 +Node: Array Intro436635 +Ref: figure-array-elements438608 +Node: Reference to Elements441015 +Node: Assigning Elements443288 +Node: Array Example443779 +Node: Scanning an Array445511 +Node: Controlling Scanning448526 +Ref: Controlling Scanning-Footnote-1453699 +Node: Delete454015 +Ref: Delete-Footnote-1456780 +Node: Numeric Array Subscripts456837 +Node: Uninitialized Subscripts459020 +Node: Multidimensional460645 +Node: Multiscanning463738 +Node: Arrays of Arrays465327 +Node: Functions469967 +Node: Built-in470786 +Node: Calling Built-in471864 +Node: Numeric Functions473852 +Ref: Numeric Functions-Footnote-1477686 +Ref: Numeric Functions-Footnote-2478043 +Ref: Numeric Functions-Footnote-3478091 +Node: String Functions478360 +Ref: String Functions-Footnote-1501371 +Ref: String Functions-Footnote-2501500 +Ref: String Functions-Footnote-3501748 +Node: Gory Details501835 +Ref: table-sub-escapes503504 +Ref: table-sub-posix-92504858 +Ref: table-sub-proposed506209 +Ref: table-posix-sub507563 +Ref: table-gensub-escapes509108 +Ref: Gory Details-Footnote-1510284 +Ref: Gory Details-Footnote-2510335 +Node: I/O Functions510486 +Ref: I/O Functions-Footnote-1517609 +Node: Time Functions517756 +Ref: Time Functions-Footnote-1528220 +Ref: Time Functions-Footnote-2528288 +Ref: Time Functions-Footnote-3528446 +Ref: Time Functions-Footnote-4528557 +Ref: Time Functions-Footnote-5528669 +Ref: Time Functions-Footnote-6528896 +Node: Bitwise Functions529162 +Ref: table-bitwise-ops529724 +Ref: Bitwise Functions-Footnote-1533969 +Node: Type Functions534153 +Node: I18N Functions535295 +Node: User-defined536940 +Node: Definition Syntax537744 +Ref: Definition Syntax-Footnote-1542659 +Node: Function Example542728 +Ref: Function Example-Footnote-1545372 +Node: Function Caveats545394 +Node: Calling A Function545912 +Node: Variable Scope546867 +Node: Pass By Value/Reference549855 +Node: Return Statement553363 +Node: Dynamic Typing556345 +Node: Indirect Calls557274 +Node: Library Functions566961 +Ref: Library Functions-Footnote-1570474 +Ref: Library Functions-Footnote-2570617 +Node: Library Names570788 +Ref: Library Names-Footnote-1574261 +Ref: Library Names-Footnote-2574481 +Node: General Functions574567 +Node: Strtonum Function575595 +Node: Assert Function578525 +Node: Round Function581851 +Node: Cliff Random Function583392 +Node: Ordinal Functions584408 +Ref: Ordinal Functions-Footnote-1587485 +Ref: Ordinal Functions-Footnote-2587737 +Node: Join Function587948 +Ref: Join Function-Footnote-1589719 +Node: Getlocaltime Function589919 +Node: Readfile Function593660 +Node: Data File Management595499 +Node: Filetrans Function596131 +Node: Rewind Function600200 +Node: File Checking601587 +Node: Empty Files602681 +Node: Ignoring Assigns604911 +Node: Getopt Function606465 +Ref: Getopt Function-Footnote-1617768 +Node: Passwd Functions617971 +Ref: Passwd Functions-Footnote-1626949 +Node: Group Functions627037 +Node: Walking Arrays635121 +Node: Sample Programs637257 +Node: Running Examples637931 +Node: Clones638659 +Node: Cut Program639883 +Node: Egrep Program649734 +Ref: Egrep Program-Footnote-1657507 +Node: Id Program657617 +Node: Split Program661266 +Ref: Split Program-Footnote-1664785 +Node: Tee Program664913 +Node: Uniq Program667716 +Node: Wc Program675145 +Ref: Wc Program-Footnote-1679411 +Ref: Wc Program-Footnote-2679611 +Node: Miscellaneous Programs679703 +Node: Dupword Program680891 +Node: Alarm Program682922 +Node: Translate Program687729 +Ref: Translate Program-Footnote-1692116 +Ref: Translate Program-Footnote-2692364 +Node: Labels Program692498 +Ref: Labels Program-Footnote-1695869 +Node: Word Sorting695953 +Node: History Sorting699837 +Node: Extract Program701676 +Ref: Extract Program-Footnote-1709179 +Node: Simple Sed709307 +Node: Igawk Program712369 +Ref: Igawk Program-Footnote-1727540 +Ref: Igawk Program-Footnote-2727741 +Node: Anagram Program727879 +Node: Signature Program730947 +Node: Advanced Features732047 +Node: Nondecimal Data733933 +Node: Array Sorting735516 +Node: Controlling Array Traversal736213 +Node: Array Sorting Functions744497 +Ref: Array Sorting Functions-Footnote-1748366 +Node: Two-way I/O748560 +Ref: Two-way I/O-Footnote-1753992 +Node: TCP/IP Networking754074 +Node: Profiling756918 +Node: Internationalization764421 +Node: I18N and L10N765846 +Node: Explaining gettext766532 +Ref: Explaining gettext-Footnote-1771600 +Ref: Explaining gettext-Footnote-2771784 +Node: Programmer i18n771949 +Node: Translator i18n776176 +Node: String Extraction776970 +Ref: String Extraction-Footnote-1777931 +Node: Printf Ordering778017 +Ref: Printf Ordering-Footnote-1780799 +Node: I18N Portability780863 +Ref: I18N Portability-Footnote-1783312 +Node: I18N Example783375 +Ref: I18N Example-Footnote-1786013 +Node: Gawk I18N786085 +Node: Debugger786706 +Node: Debugging787677 +Node: Debugging Concepts788110 +Node: Debugging Terms789966 +Node: Awk Debugging792563 +Node: Sample Debugging Session793455 +Node: Debugger Invocation793975 +Node: Finding The Bug795308 +Node: List of Debugger Commands801795 +Node: Breakpoint Control803129 +Node: Debugger Execution Control806793 +Node: Viewing And Changing Data810153 +Node: Execution Stack813509 +Node: Debugger Info814976 +Node: Miscellaneous Debugger Commands818970 +Node: Readline Support824148 +Node: Limitations824979 +Node: Arbitrary Precision Arithmetic827231 +Ref: Arbitrary Precision Arithmetic-Footnote-1828880 +Node: General Arithmetic829028 +Node: Floating Point Issues830748 +Node: String Conversion Precision831629 +Ref: String Conversion Precision-Footnote-1833334 +Node: Unexpected Results833443 +Node: POSIX Floating Point Problems835596 +Ref: POSIX Floating Point Problems-Footnote-1839421 +Node: Integer Programming839459 +Node: Floating-point Programming841198 +Ref: Floating-point Programming-Footnote-1847529 +Ref: Floating-point Programming-Footnote-2847799 +Node: Floating-point Representation848063 +Node: Floating-point Context849228 +Ref: table-ieee-formats850067 +Node: Rounding Mode851451 +Ref: table-rounding-modes851930 +Ref: Rounding Mode-Footnote-1854945 +Node: Gawk and MPFR855124 +Node: Arbitrary Precision Floats856533 +Ref: Arbitrary Precision Floats-Footnote-1858976 +Node: Setting Precision859292 +Ref: table-predefined-precision-strings859978 +Node: Setting Rounding Mode862123 +Ref: table-gawk-rounding-modes862527 +Node: Floating-point Constants863714 +Node: Changing Precision865143 +Ref: Changing Precision-Footnote-1866540 +Node: Exact Arithmetic866714 +Node: Arbitrary Precision Integers869852 +Ref: Arbitrary Precision Integers-Footnote-1872867 +Node: Dynamic Extensions873014 +Node: Extension Intro874472 +Node: Plugin License875737 +Node: Extension Mechanism Outline876422 +Ref: load-extension876839 +Ref: load-new-function878317 +Ref: call-new-function879312 +Node: Extension API Description881327 +Node: Extension API Functions Introduction882614 +Node: General Data Types887541 +Ref: General Data Types-Footnote-1893236 +Node: Requesting Values893535 +Ref: table-value-types-returned894272 +Node: Memory Allocation Functions895226 +Ref: Memory Allocation Functions-Footnote-1897972 +Node: Constructor Functions898068 +Node: Registration Functions899826 +Node: Extension Functions900511 +Node: Exit Callback Functions902813 +Node: Extension Version String904062 +Node: Input Parsers904712 +Node: Output Wrappers914469 +Node: Two-way processors918979 +Node: Printing Messages921187 +Ref: Printing Messages-Footnote-1922264 +Node: Updating `ERRNO'922416 +Node: Accessing Parameters923155 +Node: Symbol Table Access924385 +Node: Symbol table by name924899 +Node: Symbol table by cookie926875 +Ref: Symbol table by cookie-Footnote-1931007 +Node: Cached values931070 +Ref: Cached values-Footnote-1934560 +Node: Array Manipulation934651 +Ref: Array Manipulation-Footnote-1935749 +Node: Array Data Types935788 +Ref: Array Data Types-Footnote-1938491 +Node: Array Functions938583 +Node: Flattening Arrays942419 +Node: Creating Arrays949271 +Node: Extension API Variables953996 +Node: Extension Versioning954632 +Node: Extension API Informational Variables956533 +Node: Extension API Boilerplate957619 +Node: Finding Extensions961423 +Node: Extension Example961983 +Node: Internal File Description962713 +Node: Internal File Ops966804 +Ref: Internal File Ops-Footnote-1978313 +Node: Using Internal File Ops978453 +Ref: Using Internal File Ops-Footnote-1980800 +Node: Extension Samples981066 +Node: Extension Sample File Functions982590 +Node: Extension Sample Fnmatch991077 +Node: Extension Sample Fork992846 +Node: Extension Sample Inplace994059 +Node: Extension Sample Ord995837 +Node: Extension Sample Readdir996673 +Node: Extension Sample Revout998205 +Node: Extension Sample Rev2way998798 +Node: Extension Sample Read write array999488 +Node: Extension Sample Readfile1001371 +Node: Extension Sample API Tests1002471 +Node: Extension Sample Time1002996 +Node: gawkextlib1004360 +Node: Language History1007141 +Node: V7/SVR3.11008734 +Node: SVR41011054 +Node: POSIX1012496 +Node: BTL1013882 +Node: POSIX/GNU1014616 +Node: Feature History1020215 +Node: Common Extensions1033191 +Node: Ranges and Locales1034503 +Ref: Ranges and Locales-Footnote-11039120 +Ref: Ranges and Locales-Footnote-21039147 +Ref: Ranges and Locales-Footnote-31039381 +Node: Contributors1039602 +Node: Installation1044983 +Node: Gawk Distribution1045877 +Node: Getting1046361 +Node: Extracting1047187 +Node: Distribution contents1048879 +Node: Unix Installation1054600 +Node: Quick Installation1055217 +Node: Additional Configuration Options1057663 +Node: Configuration Philosophy1059399 +Node: Non-Unix Installation1061753 +Node: PC Installation1062211 +Node: PC Binary Installation1063510 +Node: PC Compiling1065358 +Node: PC Testing1068302 +Node: PC Using1069478 +Node: Cygwin1073646 +Node: MSYS1074455 +Node: VMS Installation1074969 +Node: VMS Compilation1075765 +Ref: VMS Compilation-Footnote-11077017 +Node: VMS Dynamic Extensions1077075 +Node: VMS Installation Details1078448 +Node: VMS Running1080699 +Node: VMS GNV1083533 +Node: VMS Old Gawk1084256 +Node: Bugs1084726 +Node: Other Versions1088644 +Node: Notes1094728 +Node: Compatibility Mode1095528 +Node: Additions1096311 +Node: Accessing The Source1097238 +Node: Adding Code1098678 +Node: New Ports1104723 +Node: Derived Files1108858 +Ref: Derived Files-Footnote-11114179 +Ref: Derived Files-Footnote-21114213 +Ref: Derived Files-Footnote-31114813 +Node: Future Extensions1114911 +Node: Implementation Limitations1115494 +Node: Extension Design1116742 +Node: Old Extension Problems1117896 +Ref: Old Extension Problems-Footnote-11119404 +Node: Extension New Mechanism Goals1119461 +Ref: Extension New Mechanism Goals-Footnote-11122826 +Node: Extension Other Design Decisions1123012 +Node: Extension Future Growth1125118 +Node: Old Extension Mechanism1125954 +Node: Basic Concepts1127694 +Node: Basic High Level1128375 +Ref: figure-general-flow1128647 +Ref: figure-process-flow1129246 +Ref: Basic High Level-Footnote-11132475 +Node: Basic Data Typing1132660 +Node: Glossary1136015 +Node: Copying1161246 +Node: GNU Free Documentation License1198802 +Node: Index1223938  End Tag Table -- cgit v1.2.3 From 03edc59397a4924b29852107198c4f345c986e80 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 7 May 2014 22:29:20 +0300 Subject: Docbook edits. Document AWKBUFSIZE. --- doc/gawk.info | 971 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 490 insertions(+), 481 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 706dace1..9bcd7e0c 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -2875,9 +2875,18 @@ used by regular users. the `gawk' developers for testing and tuning. They are subject to change. The variables are: +`AWKBUFSIZE' + This variable only affects `gawk' on POSIX-compliant systems. + With a value of `exact', `gawk' uses the size of each input file + as the size of the memory buffer to allocate for I/O. Otherwise, + the value should be a number, and `gawk' uses that number as the + size of the buffer to allocate. (When this variable is not set, + `gawk' uses the smaller of the file's size and the "default" + blocksize, which is usually the file systems I/O blocksize.) + `AWK_HASH' - If this variable exists with a value of `gst', `gawk' will switch - to using the hash function from GNU Smalltalk for managing arrays. + If this variable exists with a value of `gst', `gawk' switches to + using the hash function from GNU Smalltalk for managing arrays. This function may be marginally faster than the standard function. `AWKREADFUNC' @@ -33243,484 +33252,484 @@ Ref: AWKPATH Variable-Footnote-1133823 Ref: AWKPATH Variable-Footnote-2133868 Node: AWKLIBPATH Variable134128 Node: Other Environment Variables134887 -Node: Exit Status138052 -Node: Include Files138727 -Node: Loading Shared Libraries142305 -Node: Obsolete143688 -Node: Undocumented144385 -Node: Regexp144627 -Node: Regexp Usage146016 -Node: Escape Sequences148049 -Node: Regexp Operators153716 -Ref: Regexp Operators-Footnote-1161196 -Ref: Regexp Operators-Footnote-2161343 -Node: Bracket Expressions161441 -Ref: table-char-classes163331 -Node: GNU Regexp Operators165854 -Node: Case-sensitivity169577 -Ref: Case-sensitivity-Footnote-1172469 -Ref: Case-sensitivity-Footnote-2172704 -Node: Leftmost Longest172812 -Node: Computed Regexps174013 -Node: Reading Files177362 -Node: Records179364 -Node: awk split records180099 -Node: gawk split records184957 -Ref: gawk split records-Footnote-1189478 -Node: Fields189515 -Ref: Fields-Footnote-1192479 -Node: Nonconstant Fields192565 -Ref: Nonconstant Fields-Footnote-1194795 -Node: Changing Fields194997 -Node: Field Separators200951 -Node: Default Field Splitting203653 -Node: Regexp Field Splitting204770 -Node: Single Character Fields208111 -Node: Command Line Field Separator209170 -Node: Full Line Fields212512 -Ref: Full Line Fields-Footnote-1213020 -Node: Field Splitting Summary213066 -Ref: Field Splitting Summary-Footnote-1216165 -Node: Constant Size216266 -Node: Splitting By Content220873 -Ref: Splitting By Content-Footnote-1224623 -Node: Multiple Line224663 -Ref: Multiple Line-Footnote-1230519 -Node: Getline230698 -Node: Plain Getline232914 -Node: Getline/Variable235009 -Node: Getline/File236156 -Node: Getline/Variable/File237540 -Ref: Getline/Variable/File-Footnote-1239139 -Node: Getline/Pipe239226 -Node: Getline/Variable/Pipe241925 -Node: Getline/Coprocess243032 -Node: Getline/Variable/Coprocess244284 -Node: Getline Notes245021 -Node: Getline Summary247825 -Ref: table-getline-variants248233 -Node: Read Timeout249145 -Ref: Read Timeout-Footnote-1252972 -Node: Command line directories253030 -Node: Printing253912 -Node: Print255543 -Node: Print Examples256884 -Node: Output Separators259663 -Node: OFMT261679 -Node: Printf263037 -Node: Basic Printf263943 -Node: Control Letters265482 -Node: Format Modifiers269336 -Node: Printf Examples275363 -Node: Redirection278070 -Node: Special Files285042 -Node: Special FD285575 -Ref: Special FD-Footnote-1289199 -Node: Special Network289273 -Node: Special Caveats290123 -Node: Close Files And Pipes290919 -Ref: Close Files And Pipes-Footnote-1298057 -Ref: Close Files And Pipes-Footnote-2298205 -Node: Expressions298355 -Node: Values299487 -Node: Constants300163 -Node: Scalar Constants300843 -Ref: Scalar Constants-Footnote-1301702 -Node: Nondecimal-numbers301952 -Node: Regexp Constants304952 -Node: Using Constant Regexps305427 -Node: Variables308497 -Node: Using Variables309152 -Node: Assignment Options310876 -Node: Conversion312751 -Ref: table-locale-affects318187 -Ref: Conversion-Footnote-1318811 -Node: All Operators318920 -Node: Arithmetic Ops319550 -Node: Concatenation322055 -Ref: Concatenation-Footnote-1324851 -Node: Assignment Ops324971 -Ref: table-assign-ops329954 -Node: Increment Ops331271 -Node: Truth Values and Conditions334709 -Node: Truth Values335792 -Node: Typing and Comparison336841 -Node: Variable Typing337634 -Ref: Variable Typing-Footnote-1341534 -Node: Comparison Operators341656 -Ref: table-relational-ops342066 -Node: POSIX String Comparison345614 -Ref: POSIX String Comparison-Footnote-1346698 -Node: Boolean Ops346836 -Ref: Boolean Ops-Footnote-1350906 -Node: Conditional Exp350997 -Node: Function Calls352724 -Node: Precedence356482 -Node: Locales360151 -Node: Patterns and Actions361754 -Node: Pattern Overview362808 -Node: Regexp Patterns364485 -Node: Expression Patterns365028 -Node: Ranges368809 -Node: BEGIN/END371915 -Node: Using BEGIN/END372677 -Ref: Using BEGIN/END-Footnote-1375413 -Node: I/O And BEGIN/END375519 -Node: BEGINFILE/ENDFILE377804 -Node: Empty380740 -Node: Using Shell Variables381057 -Node: Action Overview383340 -Node: Statements385685 -Node: If Statement387539 -Node: While Statement389038 -Node: Do Statement391082 -Node: For Statement392238 -Node: Switch Statement395390 -Node: Break Statement397493 -Node: Continue Statement399548 -Node: Next Statement401341 -Node: Nextfile Statement403731 -Node: Exit Statement406386 -Node: Built-in Variables408788 -Node: User-modified409884 -Ref: User-modified-Footnote-1417569 -Node: Auto-set417631 -Ref: Auto-set-Footnote-1430196 -Ref: Auto-set-Footnote-2430401 -Node: ARGC and ARGV430457 -Node: Arrays434311 -Node: Array Basics435809 -Node: Array Intro436635 -Ref: figure-array-elements438608 -Node: Reference to Elements441015 -Node: Assigning Elements443288 -Node: Array Example443779 -Node: Scanning an Array445511 -Node: Controlling Scanning448526 -Ref: Controlling Scanning-Footnote-1453699 -Node: Delete454015 -Ref: Delete-Footnote-1456780 -Node: Numeric Array Subscripts456837 -Node: Uninitialized Subscripts459020 -Node: Multidimensional460645 -Node: Multiscanning463738 -Node: Arrays of Arrays465327 -Node: Functions469967 -Node: Built-in470786 -Node: Calling Built-in471864 -Node: Numeric Functions473852 -Ref: Numeric Functions-Footnote-1477686 -Ref: Numeric Functions-Footnote-2478043 -Ref: Numeric Functions-Footnote-3478091 -Node: String Functions478360 -Ref: String Functions-Footnote-1501371 -Ref: String Functions-Footnote-2501500 -Ref: String Functions-Footnote-3501748 -Node: Gory Details501835 -Ref: table-sub-escapes503504 -Ref: table-sub-posix-92504858 -Ref: table-sub-proposed506209 -Ref: table-posix-sub507563 -Ref: table-gensub-escapes509108 -Ref: Gory Details-Footnote-1510284 -Ref: Gory Details-Footnote-2510335 -Node: I/O Functions510486 -Ref: I/O Functions-Footnote-1517609 -Node: Time Functions517756 -Ref: Time Functions-Footnote-1528220 -Ref: Time Functions-Footnote-2528288 -Ref: Time Functions-Footnote-3528446 -Ref: Time Functions-Footnote-4528557 -Ref: Time Functions-Footnote-5528669 -Ref: Time Functions-Footnote-6528896 -Node: Bitwise Functions529162 -Ref: table-bitwise-ops529724 -Ref: Bitwise Functions-Footnote-1533969 -Node: Type Functions534153 -Node: I18N Functions535295 -Node: User-defined536940 -Node: Definition Syntax537744 -Ref: Definition Syntax-Footnote-1542659 -Node: Function Example542728 -Ref: Function Example-Footnote-1545372 -Node: Function Caveats545394 -Node: Calling A Function545912 -Node: Variable Scope546867 -Node: Pass By Value/Reference549855 -Node: Return Statement553363 -Node: Dynamic Typing556345 -Node: Indirect Calls557274 -Node: Library Functions566961 -Ref: Library Functions-Footnote-1570474 -Ref: Library Functions-Footnote-2570617 -Node: Library Names570788 -Ref: Library Names-Footnote-1574261 -Ref: Library Names-Footnote-2574481 -Node: General Functions574567 -Node: Strtonum Function575595 -Node: Assert Function578525 -Node: Round Function581851 -Node: Cliff Random Function583392 -Node: Ordinal Functions584408 -Ref: Ordinal Functions-Footnote-1587485 -Ref: Ordinal Functions-Footnote-2587737 -Node: Join Function587948 -Ref: Join Function-Footnote-1589719 -Node: Getlocaltime Function589919 -Node: Readfile Function593660 -Node: Data File Management595499 -Node: Filetrans Function596131 -Node: Rewind Function600200 -Node: File Checking601587 -Node: Empty Files602681 -Node: Ignoring Assigns604911 -Node: Getopt Function606465 -Ref: Getopt Function-Footnote-1617768 -Node: Passwd Functions617971 -Ref: Passwd Functions-Footnote-1626949 -Node: Group Functions627037 -Node: Walking Arrays635121 -Node: Sample Programs637257 -Node: Running Examples637931 -Node: Clones638659 -Node: Cut Program639883 -Node: Egrep Program649734 -Ref: Egrep Program-Footnote-1657507 -Node: Id Program657617 -Node: Split Program661266 -Ref: Split Program-Footnote-1664785 -Node: Tee Program664913 -Node: Uniq Program667716 -Node: Wc Program675145 -Ref: Wc Program-Footnote-1679411 -Ref: Wc Program-Footnote-2679611 -Node: Miscellaneous Programs679703 -Node: Dupword Program680891 -Node: Alarm Program682922 -Node: Translate Program687729 -Ref: Translate Program-Footnote-1692116 -Ref: Translate Program-Footnote-2692364 -Node: Labels Program692498 -Ref: Labels Program-Footnote-1695869 -Node: Word Sorting695953 -Node: History Sorting699837 -Node: Extract Program701676 -Ref: Extract Program-Footnote-1709179 -Node: Simple Sed709307 -Node: Igawk Program712369 -Ref: Igawk Program-Footnote-1727540 -Ref: Igawk Program-Footnote-2727741 -Node: Anagram Program727879 -Node: Signature Program730947 -Node: Advanced Features732047 -Node: Nondecimal Data733933 -Node: Array Sorting735516 -Node: Controlling Array Traversal736213 -Node: Array Sorting Functions744497 -Ref: Array Sorting Functions-Footnote-1748366 -Node: Two-way I/O748560 -Ref: Two-way I/O-Footnote-1753992 -Node: TCP/IP Networking754074 -Node: Profiling756918 -Node: Internationalization764421 -Node: I18N and L10N765846 -Node: Explaining gettext766532 -Ref: Explaining gettext-Footnote-1771600 -Ref: Explaining gettext-Footnote-2771784 -Node: Programmer i18n771949 -Node: Translator i18n776176 -Node: String Extraction776970 -Ref: String Extraction-Footnote-1777931 -Node: Printf Ordering778017 -Ref: Printf Ordering-Footnote-1780799 -Node: I18N Portability780863 -Ref: I18N Portability-Footnote-1783312 -Node: I18N Example783375 -Ref: I18N Example-Footnote-1786013 -Node: Gawk I18N786085 -Node: Debugger786706 -Node: Debugging787677 -Node: Debugging Concepts788110 -Node: Debugging Terms789966 -Node: Awk Debugging792563 -Node: Sample Debugging Session793455 -Node: Debugger Invocation793975 -Node: Finding The Bug795308 -Node: List of Debugger Commands801795 -Node: Breakpoint Control803129 -Node: Debugger Execution Control806793 -Node: Viewing And Changing Data810153 -Node: Execution Stack813509 -Node: Debugger Info814976 -Node: Miscellaneous Debugger Commands818970 -Node: Readline Support824148 -Node: Limitations824979 -Node: Arbitrary Precision Arithmetic827231 -Ref: Arbitrary Precision Arithmetic-Footnote-1828880 -Node: General Arithmetic829028 -Node: Floating Point Issues830748 -Node: String Conversion Precision831629 -Ref: String Conversion Precision-Footnote-1833334 -Node: Unexpected Results833443 -Node: POSIX Floating Point Problems835596 -Ref: POSIX Floating Point Problems-Footnote-1839421 -Node: Integer Programming839459 -Node: Floating-point Programming841198 -Ref: Floating-point Programming-Footnote-1847529 -Ref: Floating-point Programming-Footnote-2847799 -Node: Floating-point Representation848063 -Node: Floating-point Context849228 -Ref: table-ieee-formats850067 -Node: Rounding Mode851451 -Ref: table-rounding-modes851930 -Ref: Rounding Mode-Footnote-1854945 -Node: Gawk and MPFR855124 -Node: Arbitrary Precision Floats856533 -Ref: Arbitrary Precision Floats-Footnote-1858976 -Node: Setting Precision859292 -Ref: table-predefined-precision-strings859978 -Node: Setting Rounding Mode862123 -Ref: table-gawk-rounding-modes862527 -Node: Floating-point Constants863714 -Node: Changing Precision865143 -Ref: Changing Precision-Footnote-1866540 -Node: Exact Arithmetic866714 -Node: Arbitrary Precision Integers869852 -Ref: Arbitrary Precision Integers-Footnote-1872867 -Node: Dynamic Extensions873014 -Node: Extension Intro874472 -Node: Plugin License875737 -Node: Extension Mechanism Outline876422 -Ref: load-extension876839 -Ref: load-new-function878317 -Ref: call-new-function879312 -Node: Extension API Description881327 -Node: Extension API Functions Introduction882614 -Node: General Data Types887541 -Ref: General Data Types-Footnote-1893236 -Node: Requesting Values893535 -Ref: table-value-types-returned894272 -Node: Memory Allocation Functions895226 -Ref: Memory Allocation Functions-Footnote-1897972 -Node: Constructor Functions898068 -Node: Registration Functions899826 -Node: Extension Functions900511 -Node: Exit Callback Functions902813 -Node: Extension Version String904062 -Node: Input Parsers904712 -Node: Output Wrappers914469 -Node: Two-way processors918979 -Node: Printing Messages921187 -Ref: Printing Messages-Footnote-1922264 -Node: Updating `ERRNO'922416 -Node: Accessing Parameters923155 -Node: Symbol Table Access924385 -Node: Symbol table by name924899 -Node: Symbol table by cookie926875 -Ref: Symbol table by cookie-Footnote-1931007 -Node: Cached values931070 -Ref: Cached values-Footnote-1934560 -Node: Array Manipulation934651 -Ref: Array Manipulation-Footnote-1935749 -Node: Array Data Types935788 -Ref: Array Data Types-Footnote-1938491 -Node: Array Functions938583 -Node: Flattening Arrays942419 -Node: Creating Arrays949271 -Node: Extension API Variables953996 -Node: Extension Versioning954632 -Node: Extension API Informational Variables956533 -Node: Extension API Boilerplate957619 -Node: Finding Extensions961423 -Node: Extension Example961983 -Node: Internal File Description962713 -Node: Internal File Ops966804 -Ref: Internal File Ops-Footnote-1978313 -Node: Using Internal File Ops978453 -Ref: Using Internal File Ops-Footnote-1980800 -Node: Extension Samples981066 -Node: Extension Sample File Functions982590 -Node: Extension Sample Fnmatch991077 -Node: Extension Sample Fork992846 -Node: Extension Sample Inplace994059 -Node: Extension Sample Ord995837 -Node: Extension Sample Readdir996673 -Node: Extension Sample Revout998205 -Node: Extension Sample Rev2way998798 -Node: Extension Sample Read write array999488 -Node: Extension Sample Readfile1001371 -Node: Extension Sample API Tests1002471 -Node: Extension Sample Time1002996 -Node: gawkextlib1004360 -Node: Language History1007141 -Node: V7/SVR3.11008734 -Node: SVR41011054 -Node: POSIX1012496 -Node: BTL1013882 -Node: POSIX/GNU1014616 -Node: Feature History1020215 -Node: Common Extensions1033191 -Node: Ranges and Locales1034503 -Ref: Ranges and Locales-Footnote-11039120 -Ref: Ranges and Locales-Footnote-21039147 -Ref: Ranges and Locales-Footnote-31039381 -Node: Contributors1039602 -Node: Installation1044983 -Node: Gawk Distribution1045877 -Node: Getting1046361 -Node: Extracting1047187 -Node: Distribution contents1048879 -Node: Unix Installation1054600 -Node: Quick Installation1055217 -Node: Additional Configuration Options1057663 -Node: Configuration Philosophy1059399 -Node: Non-Unix Installation1061753 -Node: PC Installation1062211 -Node: PC Binary Installation1063510 -Node: PC Compiling1065358 -Node: PC Testing1068302 -Node: PC Using1069478 -Node: Cygwin1073646 -Node: MSYS1074455 -Node: VMS Installation1074969 -Node: VMS Compilation1075765 -Ref: VMS Compilation-Footnote-11077017 -Node: VMS Dynamic Extensions1077075 -Node: VMS Installation Details1078448 -Node: VMS Running1080699 -Node: VMS GNV1083533 -Node: VMS Old Gawk1084256 -Node: Bugs1084726 -Node: Other Versions1088644 -Node: Notes1094728 -Node: Compatibility Mode1095528 -Node: Additions1096311 -Node: Accessing The Source1097238 -Node: Adding Code1098678 -Node: New Ports1104723 -Node: Derived Files1108858 -Ref: Derived Files-Footnote-11114179 -Ref: Derived Files-Footnote-21114213 -Ref: Derived Files-Footnote-31114813 -Node: Future Extensions1114911 -Node: Implementation Limitations1115494 -Node: Extension Design1116742 -Node: Old Extension Problems1117896 -Ref: Old Extension Problems-Footnote-11119404 -Node: Extension New Mechanism Goals1119461 -Ref: Extension New Mechanism Goals-Footnote-11122826 -Node: Extension Other Design Decisions1123012 -Node: Extension Future Growth1125118 -Node: Old Extension Mechanism1125954 -Node: Basic Concepts1127694 -Node: Basic High Level1128375 -Ref: figure-general-flow1128647 -Ref: figure-process-flow1129246 -Ref: Basic High Level-Footnote-11132475 -Node: Basic Data Typing1132660 -Node: Glossary1136015 -Node: Copying1161246 -Node: GNU Free Documentation License1198802 -Node: Index1223938 +Node: Exit Status138542 +Node: Include Files139217 +Node: Loading Shared Libraries142795 +Node: Obsolete144178 +Node: Undocumented144875 +Node: Regexp145117 +Node: Regexp Usage146506 +Node: Escape Sequences148539 +Node: Regexp Operators154206 +Ref: Regexp Operators-Footnote-1161686 +Ref: Regexp Operators-Footnote-2161833 +Node: Bracket Expressions161931 +Ref: table-char-classes163821 +Node: GNU Regexp Operators166344 +Node: Case-sensitivity170067 +Ref: Case-sensitivity-Footnote-1172959 +Ref: Case-sensitivity-Footnote-2173194 +Node: Leftmost Longest173302 +Node: Computed Regexps174503 +Node: Reading Files177852 +Node: Records179854 +Node: awk split records180589 +Node: gawk split records185447 +Ref: gawk split records-Footnote-1189968 +Node: Fields190005 +Ref: Fields-Footnote-1192969 +Node: Nonconstant Fields193055 +Ref: Nonconstant Fields-Footnote-1195285 +Node: Changing Fields195487 +Node: Field Separators201441 +Node: Default Field Splitting204143 +Node: Regexp Field Splitting205260 +Node: Single Character Fields208601 +Node: Command Line Field Separator209660 +Node: Full Line Fields213002 +Ref: Full Line Fields-Footnote-1213510 +Node: Field Splitting Summary213556 +Ref: Field Splitting Summary-Footnote-1216655 +Node: Constant Size216756 +Node: Splitting By Content221363 +Ref: Splitting By Content-Footnote-1225113 +Node: Multiple Line225153 +Ref: Multiple Line-Footnote-1231009 +Node: Getline231188 +Node: Plain Getline233404 +Node: Getline/Variable235499 +Node: Getline/File236646 +Node: Getline/Variable/File238030 +Ref: Getline/Variable/File-Footnote-1239629 +Node: Getline/Pipe239716 +Node: Getline/Variable/Pipe242415 +Node: Getline/Coprocess243522 +Node: Getline/Variable/Coprocess244774 +Node: Getline Notes245511 +Node: Getline Summary248315 +Ref: table-getline-variants248723 +Node: Read Timeout249635 +Ref: Read Timeout-Footnote-1253462 +Node: Command line directories253520 +Node: Printing254402 +Node: Print256033 +Node: Print Examples257374 +Node: Output Separators260153 +Node: OFMT262169 +Node: Printf263527 +Node: Basic Printf264433 +Node: Control Letters265972 +Node: Format Modifiers269826 +Node: Printf Examples275853 +Node: Redirection278560 +Node: Special Files285532 +Node: Special FD286065 +Ref: Special FD-Footnote-1289689 +Node: Special Network289763 +Node: Special Caveats290613 +Node: Close Files And Pipes291409 +Ref: Close Files And Pipes-Footnote-1298547 +Ref: Close Files And Pipes-Footnote-2298695 +Node: Expressions298845 +Node: Values299977 +Node: Constants300653 +Node: Scalar Constants301333 +Ref: Scalar Constants-Footnote-1302192 +Node: Nondecimal-numbers302442 +Node: Regexp Constants305442 +Node: Using Constant Regexps305917 +Node: Variables308987 +Node: Using Variables309642 +Node: Assignment Options311366 +Node: Conversion313241 +Ref: table-locale-affects318677 +Ref: Conversion-Footnote-1319301 +Node: All Operators319410 +Node: Arithmetic Ops320040 +Node: Concatenation322545 +Ref: Concatenation-Footnote-1325341 +Node: Assignment Ops325461 +Ref: table-assign-ops330444 +Node: Increment Ops331761 +Node: Truth Values and Conditions335199 +Node: Truth Values336282 +Node: Typing and Comparison337331 +Node: Variable Typing338124 +Ref: Variable Typing-Footnote-1342024 +Node: Comparison Operators342146 +Ref: table-relational-ops342556 +Node: POSIX String Comparison346104 +Ref: POSIX String Comparison-Footnote-1347188 +Node: Boolean Ops347326 +Ref: Boolean Ops-Footnote-1351396 +Node: Conditional Exp351487 +Node: Function Calls353214 +Node: Precedence356972 +Node: Locales360641 +Node: Patterns and Actions362244 +Node: Pattern Overview363298 +Node: Regexp Patterns364975 +Node: Expression Patterns365518 +Node: Ranges369299 +Node: BEGIN/END372405 +Node: Using BEGIN/END373167 +Ref: Using BEGIN/END-Footnote-1375903 +Node: I/O And BEGIN/END376009 +Node: BEGINFILE/ENDFILE378294 +Node: Empty381230 +Node: Using Shell Variables381547 +Node: Action Overview383830 +Node: Statements386175 +Node: If Statement388029 +Node: While Statement389528 +Node: Do Statement391572 +Node: For Statement392728 +Node: Switch Statement395880 +Node: Break Statement397983 +Node: Continue Statement400038 +Node: Next Statement401831 +Node: Nextfile Statement404221 +Node: Exit Statement406876 +Node: Built-in Variables409278 +Node: User-modified410374 +Ref: User-modified-Footnote-1418059 +Node: Auto-set418121 +Ref: Auto-set-Footnote-1430686 +Ref: Auto-set-Footnote-2430891 +Node: ARGC and ARGV430947 +Node: Arrays434801 +Node: Array Basics436299 +Node: Array Intro437125 +Ref: figure-array-elements439098 +Node: Reference to Elements441505 +Node: Assigning Elements443778 +Node: Array Example444269 +Node: Scanning an Array446001 +Node: Controlling Scanning449016 +Ref: Controlling Scanning-Footnote-1454189 +Node: Delete454505 +Ref: Delete-Footnote-1457270 +Node: Numeric Array Subscripts457327 +Node: Uninitialized Subscripts459510 +Node: Multidimensional461135 +Node: Multiscanning464228 +Node: Arrays of Arrays465817 +Node: Functions470457 +Node: Built-in471276 +Node: Calling Built-in472354 +Node: Numeric Functions474342 +Ref: Numeric Functions-Footnote-1478176 +Ref: Numeric Functions-Footnote-2478533 +Ref: Numeric Functions-Footnote-3478581 +Node: String Functions478850 +Ref: String Functions-Footnote-1501861 +Ref: String Functions-Footnote-2501990 +Ref: String Functions-Footnote-3502238 +Node: Gory Details502325 +Ref: table-sub-escapes503994 +Ref: table-sub-posix-92505348 +Ref: table-sub-proposed506699 +Ref: table-posix-sub508053 +Ref: table-gensub-escapes509598 +Ref: Gory Details-Footnote-1510774 +Ref: Gory Details-Footnote-2510825 +Node: I/O Functions510976 +Ref: I/O Functions-Footnote-1518099 +Node: Time Functions518246 +Ref: Time Functions-Footnote-1528710 +Ref: Time Functions-Footnote-2528778 +Ref: Time Functions-Footnote-3528936 +Ref: Time Functions-Footnote-4529047 +Ref: Time Functions-Footnote-5529159 +Ref: Time Functions-Footnote-6529386 +Node: Bitwise Functions529652 +Ref: table-bitwise-ops530214 +Ref: Bitwise Functions-Footnote-1534459 +Node: Type Functions534643 +Node: I18N Functions535785 +Node: User-defined537430 +Node: Definition Syntax538234 +Ref: Definition Syntax-Footnote-1543149 +Node: Function Example543218 +Ref: Function Example-Footnote-1545862 +Node: Function Caveats545884 +Node: Calling A Function546402 +Node: Variable Scope547357 +Node: Pass By Value/Reference550345 +Node: Return Statement553853 +Node: Dynamic Typing556835 +Node: Indirect Calls557764 +Node: Library Functions567451 +Ref: Library Functions-Footnote-1570964 +Ref: Library Functions-Footnote-2571107 +Node: Library Names571278 +Ref: Library Names-Footnote-1574751 +Ref: Library Names-Footnote-2574971 +Node: General Functions575057 +Node: Strtonum Function576085 +Node: Assert Function579015 +Node: Round Function582341 +Node: Cliff Random Function583882 +Node: Ordinal Functions584898 +Ref: Ordinal Functions-Footnote-1587975 +Ref: Ordinal Functions-Footnote-2588227 +Node: Join Function588438 +Ref: Join Function-Footnote-1590209 +Node: Getlocaltime Function590409 +Node: Readfile Function594150 +Node: Data File Management595989 +Node: Filetrans Function596621 +Node: Rewind Function600690 +Node: File Checking602077 +Node: Empty Files603171 +Node: Ignoring Assigns605401 +Node: Getopt Function606955 +Ref: Getopt Function-Footnote-1618258 +Node: Passwd Functions618461 +Ref: Passwd Functions-Footnote-1627439 +Node: Group Functions627527 +Node: Walking Arrays635611 +Node: Sample Programs637747 +Node: Running Examples638421 +Node: Clones639149 +Node: Cut Program640373 +Node: Egrep Program650224 +Ref: Egrep Program-Footnote-1657997 +Node: Id Program658107 +Node: Split Program661756 +Ref: Split Program-Footnote-1665275 +Node: Tee Program665403 +Node: Uniq Program668206 +Node: Wc Program675635 +Ref: Wc Program-Footnote-1679901 +Ref: Wc Program-Footnote-2680101 +Node: Miscellaneous Programs680193 +Node: Dupword Program681381 +Node: Alarm Program683412 +Node: Translate Program688219 +Ref: Translate Program-Footnote-1692606 +Ref: Translate Program-Footnote-2692854 +Node: Labels Program692988 +Ref: Labels Program-Footnote-1696359 +Node: Word Sorting696443 +Node: History Sorting700327 +Node: Extract Program702166 +Ref: Extract Program-Footnote-1709669 +Node: Simple Sed709797 +Node: Igawk Program712859 +Ref: Igawk Program-Footnote-1728030 +Ref: Igawk Program-Footnote-2728231 +Node: Anagram Program728369 +Node: Signature Program731437 +Node: Advanced Features732537 +Node: Nondecimal Data734423 +Node: Array Sorting736006 +Node: Controlling Array Traversal736703 +Node: Array Sorting Functions744987 +Ref: Array Sorting Functions-Footnote-1748856 +Node: Two-way I/O749050 +Ref: Two-way I/O-Footnote-1754482 +Node: TCP/IP Networking754564 +Node: Profiling757408 +Node: Internationalization764911 +Node: I18N and L10N766336 +Node: Explaining gettext767022 +Ref: Explaining gettext-Footnote-1772090 +Ref: Explaining gettext-Footnote-2772274 +Node: Programmer i18n772439 +Node: Translator i18n776666 +Node: String Extraction777460 +Ref: String Extraction-Footnote-1778421 +Node: Printf Ordering778507 +Ref: Printf Ordering-Footnote-1781289 +Node: I18N Portability781353 +Ref: I18N Portability-Footnote-1783802 +Node: I18N Example783865 +Ref: I18N Example-Footnote-1786503 +Node: Gawk I18N786575 +Node: Debugger787196 +Node: Debugging788167 +Node: Debugging Concepts788600 +Node: Debugging Terms790456 +Node: Awk Debugging793053 +Node: Sample Debugging Session793945 +Node: Debugger Invocation794465 +Node: Finding The Bug795798 +Node: List of Debugger Commands802285 +Node: Breakpoint Control803619 +Node: Debugger Execution Control807283 +Node: Viewing And Changing Data810643 +Node: Execution Stack813999 +Node: Debugger Info815466 +Node: Miscellaneous Debugger Commands819460 +Node: Readline Support824638 +Node: Limitations825469 +Node: Arbitrary Precision Arithmetic827721 +Ref: Arbitrary Precision Arithmetic-Footnote-1829370 +Node: General Arithmetic829518 +Node: Floating Point Issues831238 +Node: String Conversion Precision832119 +Ref: String Conversion Precision-Footnote-1833824 +Node: Unexpected Results833933 +Node: POSIX Floating Point Problems836086 +Ref: POSIX Floating Point Problems-Footnote-1839911 +Node: Integer Programming839949 +Node: Floating-point Programming841688 +Ref: Floating-point Programming-Footnote-1848019 +Ref: Floating-point Programming-Footnote-2848289 +Node: Floating-point Representation848553 +Node: Floating-point Context849718 +Ref: table-ieee-formats850557 +Node: Rounding Mode851941 +Ref: table-rounding-modes852420 +Ref: Rounding Mode-Footnote-1855435 +Node: Gawk and MPFR855614 +Node: Arbitrary Precision Floats857023 +Ref: Arbitrary Precision Floats-Footnote-1859466 +Node: Setting Precision859782 +Ref: table-predefined-precision-strings860468 +Node: Setting Rounding Mode862613 +Ref: table-gawk-rounding-modes863017 +Node: Floating-point Constants864204 +Node: Changing Precision865633 +Ref: Changing Precision-Footnote-1867030 +Node: Exact Arithmetic867204 +Node: Arbitrary Precision Integers870342 +Ref: Arbitrary Precision Integers-Footnote-1873357 +Node: Dynamic Extensions873504 +Node: Extension Intro874962 +Node: Plugin License876227 +Node: Extension Mechanism Outline876912 +Ref: load-extension877329 +Ref: load-new-function878807 +Ref: call-new-function879802 +Node: Extension API Description881817 +Node: Extension API Functions Introduction883104 +Node: General Data Types888031 +Ref: General Data Types-Footnote-1893726 +Node: Requesting Values894025 +Ref: table-value-types-returned894762 +Node: Memory Allocation Functions895716 +Ref: Memory Allocation Functions-Footnote-1898462 +Node: Constructor Functions898558 +Node: Registration Functions900316 +Node: Extension Functions901001 +Node: Exit Callback Functions903303 +Node: Extension Version String904552 +Node: Input Parsers905202 +Node: Output Wrappers914959 +Node: Two-way processors919469 +Node: Printing Messages921677 +Ref: Printing Messages-Footnote-1922754 +Node: Updating `ERRNO'922906 +Node: Accessing Parameters923645 +Node: Symbol Table Access924875 +Node: Symbol table by name925389 +Node: Symbol table by cookie927365 +Ref: Symbol table by cookie-Footnote-1931497 +Node: Cached values931560 +Ref: Cached values-Footnote-1935050 +Node: Array Manipulation935141 +Ref: Array Manipulation-Footnote-1936239 +Node: Array Data Types936278 +Ref: Array Data Types-Footnote-1938981 +Node: Array Functions939073 +Node: Flattening Arrays942909 +Node: Creating Arrays949761 +Node: Extension API Variables954486 +Node: Extension Versioning955122 +Node: Extension API Informational Variables957023 +Node: Extension API Boilerplate958109 +Node: Finding Extensions961913 +Node: Extension Example962473 +Node: Internal File Description963203 +Node: Internal File Ops967294 +Ref: Internal File Ops-Footnote-1978803 +Node: Using Internal File Ops978943 +Ref: Using Internal File Ops-Footnote-1981290 +Node: Extension Samples981556 +Node: Extension Sample File Functions983080 +Node: Extension Sample Fnmatch991567 +Node: Extension Sample Fork993336 +Node: Extension Sample Inplace994549 +Node: Extension Sample Ord996327 +Node: Extension Sample Readdir997163 +Node: Extension Sample Revout998695 +Node: Extension Sample Rev2way999288 +Node: Extension Sample Read write array999978 +Node: Extension Sample Readfile1001861 +Node: Extension Sample API Tests1002961 +Node: Extension Sample Time1003486 +Node: gawkextlib1004850 +Node: Language History1007631 +Node: V7/SVR3.11009224 +Node: SVR41011544 +Node: POSIX1012986 +Node: BTL1014372 +Node: POSIX/GNU1015106 +Node: Feature History1020705 +Node: Common Extensions1033681 +Node: Ranges and Locales1034993 +Ref: Ranges and Locales-Footnote-11039610 +Ref: Ranges and Locales-Footnote-21039637 +Ref: Ranges and Locales-Footnote-31039871 +Node: Contributors1040092 +Node: Installation1045473 +Node: Gawk Distribution1046367 +Node: Getting1046851 +Node: Extracting1047677 +Node: Distribution contents1049369 +Node: Unix Installation1055090 +Node: Quick Installation1055707 +Node: Additional Configuration Options1058153 +Node: Configuration Philosophy1059889 +Node: Non-Unix Installation1062243 +Node: PC Installation1062701 +Node: PC Binary Installation1064000 +Node: PC Compiling1065848 +Node: PC Testing1068792 +Node: PC Using1069968 +Node: Cygwin1074136 +Node: MSYS1074945 +Node: VMS Installation1075459 +Node: VMS Compilation1076255 +Ref: VMS Compilation-Footnote-11077507 +Node: VMS Dynamic Extensions1077565 +Node: VMS Installation Details1078938 +Node: VMS Running1081189 +Node: VMS GNV1084023 +Node: VMS Old Gawk1084746 +Node: Bugs1085216 +Node: Other Versions1089134 +Node: Notes1095218 +Node: Compatibility Mode1096018 +Node: Additions1096801 +Node: Accessing The Source1097728 +Node: Adding Code1099168 +Node: New Ports1105213 +Node: Derived Files1109348 +Ref: Derived Files-Footnote-11114669 +Ref: Derived Files-Footnote-21114703 +Ref: Derived Files-Footnote-31115303 +Node: Future Extensions1115401 +Node: Implementation Limitations1115984 +Node: Extension Design1117232 +Node: Old Extension Problems1118386 +Ref: Old Extension Problems-Footnote-11119894 +Node: Extension New Mechanism Goals1119951 +Ref: Extension New Mechanism Goals-Footnote-11123316 +Node: Extension Other Design Decisions1123502 +Node: Extension Future Growth1125608 +Node: Old Extension Mechanism1126444 +Node: Basic Concepts1128184 +Node: Basic High Level1128865 +Ref: figure-general-flow1129137 +Ref: figure-process-flow1129736 +Ref: Basic High Level-Footnote-11132965 +Node: Basic Data Typing1133150 +Node: Glossary1136505 +Node: Copying1161736 +Node: GNU Free Documentation License1199292 +Node: Index1224428  End Tag Table -- cgit v1.2.3 From cd78eac2bc3b182ddca47b97f7f460c3358c7b09 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 13 May 2014 22:17:05 +0300 Subject: Get print version set up to pass makeinfo. --- doc/gawk.info | 1091 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 546 insertions(+), 545 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 9bcd7e0c..5587b9e8 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -806,9 +806,10 @@ different computing environments. This Info file, while describing the of `awk' called `gawk' (which stands for "GNU `awk'"). `gawk' runs on a broad range of Unix systems, ranging from Intel(R)-architecture PC-based computers up through large-scale systems. `gawk' has also -been ported to Mac OS X, Microsoft Windows (all versions), and OpenVMS. -(Some other, obsolete systems to which `gawk' was once ported are no -longer supported and the code for those systems has been removed.) +been ported to Mac OS X, Microsoft Windows (all versions) and OS/2 PCs, +and OpenVMS. (Some other, obsolete systems to which `gawk' was once +ported are no longer supported and the code for those systems has been +removed.) * Menu: @@ -1047,7 +1048,7 @@ material for those who are completely unfamiliar with computer programming. The *note Glossary::, defines most, if not all, the significant -terms used throughout the book. If you find terms that you aren't +terms used throughout the Info file. If you find terms that you aren't familiar with, try looking them up here. *note Copying::, and *note GNU Free Documentation License::, present @@ -1125,7 +1126,7 @@ editor. GNU Emacs is the most widely used version of Emacs today. Software Foundation to create a complete, freely distributable, POSIX-compliant computing environment. The FSF uses the "GNU General Public License" (GPL) to ensure that their software's source code is -always available to the end user. A copy of the GPL is included for +always available to the end user. A copy of the GPL is included for your reference (*note Copying::). The GPL applies to the C language source code for `gawk'. To find out more about the FSF and the GNU Project online, see the GNU Project's home page (http://www.gnu.org). @@ -26557,14 +26558,14 @@ B.3.1 Installation on PC Operating Systems This minor node covers installation and usage of `gawk' on x86 machines running MS-DOS, any version of MS-Windows, or OS/2. In this minor node, the term "Windows32" refers to any of Microsoft -Windows-95/98/ME/NT/2000/XP/Vista/7. +Windows-95/98/ME/NT/2000/XP/Vista/7/8. - The limitations of MS-DOS (and MS-DOS shells under Windows32 or -OS/2) has meant that various "DOS extenders" are often used with -programs such as `gawk'. The varying capabilities of Microsoft Windows -3.1 and Windows32 can add to the confusion. For an overview of the -considerations, please refer to `README_d/README.pc' in the -distribution. + The limitations of MS-DOS (and MS-DOS shells under the other +operating systems) has meant that various "DOS extenders" are often +used with programs such as `gawk'. The varying capabilities of +Microsoft Windows 3.1 and Windows32 can add to the confusion. For an +overview of the considerations, please refer to `README_d/README.pc' in +the distribution. * Menu: @@ -26623,13 +26624,13 @@ B.3.1.2 Compiling `gawk' for PC Operating Systems ................................................. `gawk' can be compiled for MS-DOS, Windows32, and OS/2 using the GNU -development tools from DJ Delorie (DJGPP: MS-DOS only) or Eberhard -Mattes (EMX: MS-DOS, Windows32 and OS/2). The file -`README_d/README.pc' in the `gawk' distribution contains additional -notes, and `pc/Makefile' contains important information on compilation -options. +development tools from DJ Delorie (DJGPP: MS-DOS only), MinGW +(Windows32) or Eberhard Mattes (EMX: MS-DOS, Windows32 and OS/2). The +file `README_d/README.pc' in the `gawk' distribution contains +additional notes, and `pc/Makefile' contains important information on +compilation options. - To build `gawk' for MS-DOS and Windows32, copy the files in the `pc' +To build `gawk' for MS-DOS and Windows32, copy the files in the `pc' directory (_except_ for `ChangeLog') to the directory with the rest of the `gawk' sources, then invoke `make' with the appropriate target name as an argument to build `gawk'. The `Makefile' copied from the `pc' @@ -31697,7 +31698,7 @@ Index * gawk, MS-Windows version of: PC Using. (line 10) * gawk, newlines in: Statements/Lines. (line 12) * gawk, octal numbers and: Nondecimal-numbers. (line 42) -* gawk, OS/2 version of: PC Using. (line 10) +* gawk, OS/2 version of: PC Using. (line 16) * gawk, PROCINFO array in <1>: Two-way I/O. (line 116) * gawk, PROCINFO array in <2>: Time Functions. (line 47) * gawk, PROCINFO array in: Auto-set. (line 128) @@ -33205,531 +33206,531 @@ Tag Table: Node: Top1292 Node: Foreword40832 Node: Preface45177 -Ref: Preface-Footnote-148310 -Ref: Preface-Footnote-248417 -Node: History48649 -Node: Names51023 -Ref: Names-Footnote-152487 -Node: This Manual52560 -Ref: This Manual-Footnote-158334 -Node: Conventions58434 -Node: Manual History60590 -Ref: Manual History-Footnote-164020 -Ref: Manual History-Footnote-264061 -Node: How To Contribute64135 -Node: Acknowledgments65374 -Node: Getting Started69568 -Node: Running gawk71947 -Node: One-shot73137 -Node: Read Terminal74362 -Ref: Read Terminal-Footnote-176012 -Ref: Read Terminal-Footnote-276288 -Node: Long76459 -Node: Executable Scripts77835 -Ref: Executable Scripts-Footnote-179668 -Ref: Executable Scripts-Footnote-279770 -Node: Comments80317 -Node: Quoting82784 -Node: DOS Quoting88100 -Node: Sample Data Files88775 -Node: Very Simple91290 -Node: Two Rules95940 -Node: More Complex97835 -Ref: More Complex-Footnote-1100767 -Node: Statements/Lines100852 -Ref: Statements/Lines-Footnote-1105307 -Node: Other Features105572 -Node: When106500 -Node: Invoking Gawk108648 -Node: Command Line110111 -Node: Options110894 -Ref: Options-Footnote-1126706 -Node: Other Arguments126731 -Node: Naming Standard Input129393 -Node: Environment Variables130487 -Node: AWKPATH Variable131045 -Ref: AWKPATH Variable-Footnote-1133823 -Ref: AWKPATH Variable-Footnote-2133868 -Node: AWKLIBPATH Variable134128 -Node: Other Environment Variables134887 -Node: Exit Status138542 -Node: Include Files139217 -Node: Loading Shared Libraries142795 -Node: Obsolete144178 -Node: Undocumented144875 -Node: Regexp145117 -Node: Regexp Usage146506 -Node: Escape Sequences148539 -Node: Regexp Operators154206 -Ref: Regexp Operators-Footnote-1161686 -Ref: Regexp Operators-Footnote-2161833 -Node: Bracket Expressions161931 -Ref: table-char-classes163821 -Node: GNU Regexp Operators166344 -Node: Case-sensitivity170067 -Ref: Case-sensitivity-Footnote-1172959 -Ref: Case-sensitivity-Footnote-2173194 -Node: Leftmost Longest173302 -Node: Computed Regexps174503 -Node: Reading Files177852 -Node: Records179854 -Node: awk split records180589 -Node: gawk split records185447 -Ref: gawk split records-Footnote-1189968 -Node: Fields190005 -Ref: Fields-Footnote-1192969 -Node: Nonconstant Fields193055 -Ref: Nonconstant Fields-Footnote-1195285 -Node: Changing Fields195487 -Node: Field Separators201441 -Node: Default Field Splitting204143 -Node: Regexp Field Splitting205260 -Node: Single Character Fields208601 -Node: Command Line Field Separator209660 -Node: Full Line Fields213002 -Ref: Full Line Fields-Footnote-1213510 -Node: Field Splitting Summary213556 -Ref: Field Splitting Summary-Footnote-1216655 -Node: Constant Size216756 -Node: Splitting By Content221363 -Ref: Splitting By Content-Footnote-1225113 -Node: Multiple Line225153 -Ref: Multiple Line-Footnote-1231009 -Node: Getline231188 -Node: Plain Getline233404 -Node: Getline/Variable235499 -Node: Getline/File236646 -Node: Getline/Variable/File238030 -Ref: Getline/Variable/File-Footnote-1239629 -Node: Getline/Pipe239716 -Node: Getline/Variable/Pipe242415 -Node: Getline/Coprocess243522 -Node: Getline/Variable/Coprocess244774 -Node: Getline Notes245511 -Node: Getline Summary248315 -Ref: table-getline-variants248723 -Node: Read Timeout249635 -Ref: Read Timeout-Footnote-1253462 -Node: Command line directories253520 -Node: Printing254402 -Node: Print256033 -Node: Print Examples257374 -Node: Output Separators260153 -Node: OFMT262169 -Node: Printf263527 -Node: Basic Printf264433 -Node: Control Letters265972 -Node: Format Modifiers269826 -Node: Printf Examples275853 -Node: Redirection278560 -Node: Special Files285532 -Node: Special FD286065 -Ref: Special FD-Footnote-1289689 -Node: Special Network289763 -Node: Special Caveats290613 -Node: Close Files And Pipes291409 -Ref: Close Files And Pipes-Footnote-1298547 -Ref: Close Files And Pipes-Footnote-2298695 -Node: Expressions298845 -Node: Values299977 -Node: Constants300653 -Node: Scalar Constants301333 -Ref: Scalar Constants-Footnote-1302192 -Node: Nondecimal-numbers302442 -Node: Regexp Constants305442 -Node: Using Constant Regexps305917 -Node: Variables308987 -Node: Using Variables309642 -Node: Assignment Options311366 -Node: Conversion313241 -Ref: table-locale-affects318677 -Ref: Conversion-Footnote-1319301 -Node: All Operators319410 -Node: Arithmetic Ops320040 -Node: Concatenation322545 -Ref: Concatenation-Footnote-1325341 -Node: Assignment Ops325461 -Ref: table-assign-ops330444 -Node: Increment Ops331761 -Node: Truth Values and Conditions335199 -Node: Truth Values336282 -Node: Typing and Comparison337331 -Node: Variable Typing338124 -Ref: Variable Typing-Footnote-1342024 -Node: Comparison Operators342146 -Ref: table-relational-ops342556 -Node: POSIX String Comparison346104 -Ref: POSIX String Comparison-Footnote-1347188 -Node: Boolean Ops347326 -Ref: Boolean Ops-Footnote-1351396 -Node: Conditional Exp351487 -Node: Function Calls353214 -Node: Precedence356972 -Node: Locales360641 -Node: Patterns and Actions362244 -Node: Pattern Overview363298 -Node: Regexp Patterns364975 -Node: Expression Patterns365518 -Node: Ranges369299 -Node: BEGIN/END372405 -Node: Using BEGIN/END373167 -Ref: Using BEGIN/END-Footnote-1375903 -Node: I/O And BEGIN/END376009 -Node: BEGINFILE/ENDFILE378294 -Node: Empty381230 -Node: Using Shell Variables381547 -Node: Action Overview383830 -Node: Statements386175 -Node: If Statement388029 -Node: While Statement389528 -Node: Do Statement391572 -Node: For Statement392728 -Node: Switch Statement395880 -Node: Break Statement397983 -Node: Continue Statement400038 -Node: Next Statement401831 -Node: Nextfile Statement404221 -Node: Exit Statement406876 -Node: Built-in Variables409278 -Node: User-modified410374 -Ref: User-modified-Footnote-1418059 -Node: Auto-set418121 -Ref: Auto-set-Footnote-1430686 -Ref: Auto-set-Footnote-2430891 -Node: ARGC and ARGV430947 -Node: Arrays434801 -Node: Array Basics436299 -Node: Array Intro437125 -Ref: figure-array-elements439098 -Node: Reference to Elements441505 -Node: Assigning Elements443778 -Node: Array Example444269 -Node: Scanning an Array446001 -Node: Controlling Scanning449016 -Ref: Controlling Scanning-Footnote-1454189 -Node: Delete454505 -Ref: Delete-Footnote-1457270 -Node: Numeric Array Subscripts457327 -Node: Uninitialized Subscripts459510 -Node: Multidimensional461135 -Node: Multiscanning464228 -Node: Arrays of Arrays465817 -Node: Functions470457 -Node: Built-in471276 -Node: Calling Built-in472354 -Node: Numeric Functions474342 -Ref: Numeric Functions-Footnote-1478176 -Ref: Numeric Functions-Footnote-2478533 -Ref: Numeric Functions-Footnote-3478581 -Node: String Functions478850 -Ref: String Functions-Footnote-1501861 -Ref: String Functions-Footnote-2501990 -Ref: String Functions-Footnote-3502238 -Node: Gory Details502325 -Ref: table-sub-escapes503994 -Ref: table-sub-posix-92505348 -Ref: table-sub-proposed506699 -Ref: table-posix-sub508053 -Ref: table-gensub-escapes509598 -Ref: Gory Details-Footnote-1510774 -Ref: Gory Details-Footnote-2510825 -Node: I/O Functions510976 -Ref: I/O Functions-Footnote-1518099 -Node: Time Functions518246 -Ref: Time Functions-Footnote-1528710 -Ref: Time Functions-Footnote-2528778 -Ref: Time Functions-Footnote-3528936 -Ref: Time Functions-Footnote-4529047 -Ref: Time Functions-Footnote-5529159 -Ref: Time Functions-Footnote-6529386 -Node: Bitwise Functions529652 -Ref: table-bitwise-ops530214 -Ref: Bitwise Functions-Footnote-1534459 -Node: Type Functions534643 -Node: I18N Functions535785 -Node: User-defined537430 -Node: Definition Syntax538234 -Ref: Definition Syntax-Footnote-1543149 -Node: Function Example543218 -Ref: Function Example-Footnote-1545862 -Node: Function Caveats545884 -Node: Calling A Function546402 -Node: Variable Scope547357 -Node: Pass By Value/Reference550345 -Node: Return Statement553853 -Node: Dynamic Typing556835 -Node: Indirect Calls557764 -Node: Library Functions567451 -Ref: Library Functions-Footnote-1570964 -Ref: Library Functions-Footnote-2571107 -Node: Library Names571278 -Ref: Library Names-Footnote-1574751 -Ref: Library Names-Footnote-2574971 -Node: General Functions575057 -Node: Strtonum Function576085 -Node: Assert Function579015 -Node: Round Function582341 -Node: Cliff Random Function583882 -Node: Ordinal Functions584898 -Ref: Ordinal Functions-Footnote-1587975 -Ref: Ordinal Functions-Footnote-2588227 -Node: Join Function588438 -Ref: Join Function-Footnote-1590209 -Node: Getlocaltime Function590409 -Node: Readfile Function594150 -Node: Data File Management595989 -Node: Filetrans Function596621 -Node: Rewind Function600690 -Node: File Checking602077 -Node: Empty Files603171 -Node: Ignoring Assigns605401 -Node: Getopt Function606955 -Ref: Getopt Function-Footnote-1618258 -Node: Passwd Functions618461 -Ref: Passwd Functions-Footnote-1627439 -Node: Group Functions627527 -Node: Walking Arrays635611 -Node: Sample Programs637747 -Node: Running Examples638421 -Node: Clones639149 -Node: Cut Program640373 -Node: Egrep Program650224 -Ref: Egrep Program-Footnote-1657997 -Node: Id Program658107 -Node: Split Program661756 -Ref: Split Program-Footnote-1665275 -Node: Tee Program665403 -Node: Uniq Program668206 -Node: Wc Program675635 -Ref: Wc Program-Footnote-1679901 -Ref: Wc Program-Footnote-2680101 -Node: Miscellaneous Programs680193 -Node: Dupword Program681381 -Node: Alarm Program683412 -Node: Translate Program688219 -Ref: Translate Program-Footnote-1692606 -Ref: Translate Program-Footnote-2692854 -Node: Labels Program692988 -Ref: Labels Program-Footnote-1696359 -Node: Word Sorting696443 -Node: History Sorting700327 -Node: Extract Program702166 -Ref: Extract Program-Footnote-1709669 -Node: Simple Sed709797 -Node: Igawk Program712859 -Ref: Igawk Program-Footnote-1728030 -Ref: Igawk Program-Footnote-2728231 -Node: Anagram Program728369 -Node: Signature Program731437 -Node: Advanced Features732537 -Node: Nondecimal Data734423 -Node: Array Sorting736006 -Node: Controlling Array Traversal736703 -Node: Array Sorting Functions744987 -Ref: Array Sorting Functions-Footnote-1748856 -Node: Two-way I/O749050 -Ref: Two-way I/O-Footnote-1754482 -Node: TCP/IP Networking754564 -Node: Profiling757408 -Node: Internationalization764911 -Node: I18N and L10N766336 -Node: Explaining gettext767022 -Ref: Explaining gettext-Footnote-1772090 -Ref: Explaining gettext-Footnote-2772274 -Node: Programmer i18n772439 -Node: Translator i18n776666 -Node: String Extraction777460 -Ref: String Extraction-Footnote-1778421 -Node: Printf Ordering778507 -Ref: Printf Ordering-Footnote-1781289 -Node: I18N Portability781353 -Ref: I18N Portability-Footnote-1783802 -Node: I18N Example783865 -Ref: I18N Example-Footnote-1786503 -Node: Gawk I18N786575 -Node: Debugger787196 -Node: Debugging788167 -Node: Debugging Concepts788600 -Node: Debugging Terms790456 -Node: Awk Debugging793053 -Node: Sample Debugging Session793945 -Node: Debugger Invocation794465 -Node: Finding The Bug795798 -Node: List of Debugger Commands802285 -Node: Breakpoint Control803619 -Node: Debugger Execution Control807283 -Node: Viewing And Changing Data810643 -Node: Execution Stack813999 -Node: Debugger Info815466 -Node: Miscellaneous Debugger Commands819460 -Node: Readline Support824638 -Node: Limitations825469 -Node: Arbitrary Precision Arithmetic827721 -Ref: Arbitrary Precision Arithmetic-Footnote-1829370 -Node: General Arithmetic829518 -Node: Floating Point Issues831238 -Node: String Conversion Precision832119 -Ref: String Conversion Precision-Footnote-1833824 -Node: Unexpected Results833933 -Node: POSIX Floating Point Problems836086 -Ref: POSIX Floating Point Problems-Footnote-1839911 -Node: Integer Programming839949 -Node: Floating-point Programming841688 -Ref: Floating-point Programming-Footnote-1848019 -Ref: Floating-point Programming-Footnote-2848289 -Node: Floating-point Representation848553 -Node: Floating-point Context849718 -Ref: table-ieee-formats850557 -Node: Rounding Mode851941 -Ref: table-rounding-modes852420 -Ref: Rounding Mode-Footnote-1855435 -Node: Gawk and MPFR855614 -Node: Arbitrary Precision Floats857023 -Ref: Arbitrary Precision Floats-Footnote-1859466 -Node: Setting Precision859782 -Ref: table-predefined-precision-strings860468 -Node: Setting Rounding Mode862613 -Ref: table-gawk-rounding-modes863017 -Node: Floating-point Constants864204 -Node: Changing Precision865633 -Ref: Changing Precision-Footnote-1867030 -Node: Exact Arithmetic867204 -Node: Arbitrary Precision Integers870342 -Ref: Arbitrary Precision Integers-Footnote-1873357 -Node: Dynamic Extensions873504 -Node: Extension Intro874962 -Node: Plugin License876227 -Node: Extension Mechanism Outline876912 -Ref: load-extension877329 -Ref: load-new-function878807 -Ref: call-new-function879802 -Node: Extension API Description881817 -Node: Extension API Functions Introduction883104 -Node: General Data Types888031 -Ref: General Data Types-Footnote-1893726 -Node: Requesting Values894025 -Ref: table-value-types-returned894762 -Node: Memory Allocation Functions895716 -Ref: Memory Allocation Functions-Footnote-1898462 -Node: Constructor Functions898558 -Node: Registration Functions900316 -Node: Extension Functions901001 -Node: Exit Callback Functions903303 -Node: Extension Version String904552 -Node: Input Parsers905202 -Node: Output Wrappers914959 -Node: Two-way processors919469 -Node: Printing Messages921677 -Ref: Printing Messages-Footnote-1922754 -Node: Updating `ERRNO'922906 -Node: Accessing Parameters923645 -Node: Symbol Table Access924875 -Node: Symbol table by name925389 -Node: Symbol table by cookie927365 -Ref: Symbol table by cookie-Footnote-1931497 -Node: Cached values931560 -Ref: Cached values-Footnote-1935050 -Node: Array Manipulation935141 -Ref: Array Manipulation-Footnote-1936239 -Node: Array Data Types936278 -Ref: Array Data Types-Footnote-1938981 -Node: Array Functions939073 -Node: Flattening Arrays942909 -Node: Creating Arrays949761 -Node: Extension API Variables954486 -Node: Extension Versioning955122 -Node: Extension API Informational Variables957023 -Node: Extension API Boilerplate958109 -Node: Finding Extensions961913 -Node: Extension Example962473 -Node: Internal File Description963203 -Node: Internal File Ops967294 -Ref: Internal File Ops-Footnote-1978803 -Node: Using Internal File Ops978943 -Ref: Using Internal File Ops-Footnote-1981290 -Node: Extension Samples981556 -Node: Extension Sample File Functions983080 -Node: Extension Sample Fnmatch991567 -Node: Extension Sample Fork993336 -Node: Extension Sample Inplace994549 -Node: Extension Sample Ord996327 -Node: Extension Sample Readdir997163 -Node: Extension Sample Revout998695 -Node: Extension Sample Rev2way999288 -Node: Extension Sample Read write array999978 -Node: Extension Sample Readfile1001861 -Node: Extension Sample API Tests1002961 -Node: Extension Sample Time1003486 -Node: gawkextlib1004850 -Node: Language History1007631 -Node: V7/SVR3.11009224 -Node: SVR41011544 -Node: POSIX1012986 -Node: BTL1014372 -Node: POSIX/GNU1015106 -Node: Feature History1020705 -Node: Common Extensions1033681 -Node: Ranges and Locales1034993 -Ref: Ranges and Locales-Footnote-11039610 -Ref: Ranges and Locales-Footnote-21039637 -Ref: Ranges and Locales-Footnote-31039871 -Node: Contributors1040092 -Node: Installation1045473 -Node: Gawk Distribution1046367 -Node: Getting1046851 -Node: Extracting1047677 -Node: Distribution contents1049369 -Node: Unix Installation1055090 -Node: Quick Installation1055707 -Node: Additional Configuration Options1058153 -Node: Configuration Philosophy1059889 -Node: Non-Unix Installation1062243 -Node: PC Installation1062701 -Node: PC Binary Installation1064000 -Node: PC Compiling1065848 -Node: PC Testing1068792 -Node: PC Using1069968 -Node: Cygwin1074136 -Node: MSYS1074945 -Node: VMS Installation1075459 -Node: VMS Compilation1076255 -Ref: VMS Compilation-Footnote-11077507 -Node: VMS Dynamic Extensions1077565 -Node: VMS Installation Details1078938 -Node: VMS Running1081189 -Node: VMS GNV1084023 -Node: VMS Old Gawk1084746 -Node: Bugs1085216 -Node: Other Versions1089134 -Node: Notes1095218 -Node: Compatibility Mode1096018 -Node: Additions1096801 -Node: Accessing The Source1097728 -Node: Adding Code1099168 -Node: New Ports1105213 -Node: Derived Files1109348 -Ref: Derived Files-Footnote-11114669 -Ref: Derived Files-Footnote-21114703 -Ref: Derived Files-Footnote-31115303 -Node: Future Extensions1115401 -Node: Implementation Limitations1115984 -Node: Extension Design1117232 -Node: Old Extension Problems1118386 -Ref: Old Extension Problems-Footnote-11119894 -Node: Extension New Mechanism Goals1119951 -Ref: Extension New Mechanism Goals-Footnote-11123316 -Node: Extension Other Design Decisions1123502 -Node: Extension Future Growth1125608 -Node: Old Extension Mechanism1126444 -Node: Basic Concepts1128184 -Node: Basic High Level1128865 -Ref: figure-general-flow1129137 -Ref: figure-process-flow1129736 -Ref: Basic High Level-Footnote-11132965 -Node: Basic Data Typing1133150 -Node: Glossary1136505 -Node: Copying1161736 -Node: GNU Free Documentation License1199292 -Node: Index1224428 +Ref: Preface-Footnote-148324 +Ref: Preface-Footnote-248431 +Node: History48663 +Node: Names51037 +Ref: Names-Footnote-152501 +Node: This Manual52574 +Ref: This Manual-Footnote-158353 +Node: Conventions58453 +Node: Manual History60609 +Ref: Manual History-Footnote-164040 +Ref: Manual History-Footnote-264081 +Node: How To Contribute64155 +Node: Acknowledgments65394 +Node: Getting Started69588 +Node: Running gawk71967 +Node: One-shot73157 +Node: Read Terminal74382 +Ref: Read Terminal-Footnote-176032 +Ref: Read Terminal-Footnote-276308 +Node: Long76479 +Node: Executable Scripts77855 +Ref: Executable Scripts-Footnote-179688 +Ref: Executable Scripts-Footnote-279790 +Node: Comments80337 +Node: Quoting82804 +Node: DOS Quoting88120 +Node: Sample Data Files88795 +Node: Very Simple91310 +Node: Two Rules95960 +Node: More Complex97855 +Ref: More Complex-Footnote-1100787 +Node: Statements/Lines100872 +Ref: Statements/Lines-Footnote-1105327 +Node: Other Features105592 +Node: When106520 +Node: Invoking Gawk108668 +Node: Command Line110131 +Node: Options110914 +Ref: Options-Footnote-1126726 +Node: Other Arguments126751 +Node: Naming Standard Input129413 +Node: Environment Variables130507 +Node: AWKPATH Variable131065 +Ref: AWKPATH Variable-Footnote-1133843 +Ref: AWKPATH Variable-Footnote-2133888 +Node: AWKLIBPATH Variable134148 +Node: Other Environment Variables134907 +Node: Exit Status138562 +Node: Include Files139237 +Node: Loading Shared Libraries142815 +Node: Obsolete144198 +Node: Undocumented144895 +Node: Regexp145137 +Node: Regexp Usage146526 +Node: Escape Sequences148559 +Node: Regexp Operators154226 +Ref: Regexp Operators-Footnote-1161706 +Ref: Regexp Operators-Footnote-2161853 +Node: Bracket Expressions161951 +Ref: table-char-classes163841 +Node: GNU Regexp Operators166364 +Node: Case-sensitivity170087 +Ref: Case-sensitivity-Footnote-1172979 +Ref: Case-sensitivity-Footnote-2173214 +Node: Leftmost Longest173322 +Node: Computed Regexps174523 +Node: Reading Files177872 +Node: Records179874 +Node: awk split records180609 +Node: gawk split records185467 +Ref: gawk split records-Footnote-1189988 +Node: Fields190025 +Ref: Fields-Footnote-1192989 +Node: Nonconstant Fields193075 +Ref: Nonconstant Fields-Footnote-1195305 +Node: Changing Fields195507 +Node: Field Separators201461 +Node: Default Field Splitting204163 +Node: Regexp Field Splitting205280 +Node: Single Character Fields208621 +Node: Command Line Field Separator209680 +Node: Full Line Fields213022 +Ref: Full Line Fields-Footnote-1213530 +Node: Field Splitting Summary213576 +Ref: Field Splitting Summary-Footnote-1216675 +Node: Constant Size216776 +Node: Splitting By Content221383 +Ref: Splitting By Content-Footnote-1225133 +Node: Multiple Line225173 +Ref: Multiple Line-Footnote-1231029 +Node: Getline231208 +Node: Plain Getline233424 +Node: Getline/Variable235519 +Node: Getline/File236666 +Node: Getline/Variable/File238050 +Ref: Getline/Variable/File-Footnote-1239649 +Node: Getline/Pipe239736 +Node: Getline/Variable/Pipe242435 +Node: Getline/Coprocess243542 +Node: Getline/Variable/Coprocess244794 +Node: Getline Notes245531 +Node: Getline Summary248335 +Ref: table-getline-variants248743 +Node: Read Timeout249655 +Ref: Read Timeout-Footnote-1253482 +Node: Command line directories253540 +Node: Printing254422 +Node: Print256053 +Node: Print Examples257394 +Node: Output Separators260173 +Node: OFMT262189 +Node: Printf263547 +Node: Basic Printf264453 +Node: Control Letters265992 +Node: Format Modifiers269846 +Node: Printf Examples275873 +Node: Redirection278580 +Node: Special Files285552 +Node: Special FD286085 +Ref: Special FD-Footnote-1289709 +Node: Special Network289783 +Node: Special Caveats290633 +Node: Close Files And Pipes291429 +Ref: Close Files And Pipes-Footnote-1298567 +Ref: Close Files And Pipes-Footnote-2298715 +Node: Expressions298865 +Node: Values299997 +Node: Constants300673 +Node: Scalar Constants301353 +Ref: Scalar Constants-Footnote-1302212 +Node: Nondecimal-numbers302462 +Node: Regexp Constants305462 +Node: Using Constant Regexps305937 +Node: Variables309007 +Node: Using Variables309662 +Node: Assignment Options311386 +Node: Conversion313261 +Ref: table-locale-affects318697 +Ref: Conversion-Footnote-1319321 +Node: All Operators319430 +Node: Arithmetic Ops320060 +Node: Concatenation322565 +Ref: Concatenation-Footnote-1325361 +Node: Assignment Ops325481 +Ref: table-assign-ops330464 +Node: Increment Ops331781 +Node: Truth Values and Conditions335219 +Node: Truth Values336302 +Node: Typing and Comparison337351 +Node: Variable Typing338144 +Ref: Variable Typing-Footnote-1342044 +Node: Comparison Operators342166 +Ref: table-relational-ops342576 +Node: POSIX String Comparison346124 +Ref: POSIX String Comparison-Footnote-1347208 +Node: Boolean Ops347346 +Ref: Boolean Ops-Footnote-1351416 +Node: Conditional Exp351507 +Node: Function Calls353234 +Node: Precedence356992 +Node: Locales360661 +Node: Patterns and Actions362264 +Node: Pattern Overview363318 +Node: Regexp Patterns364995 +Node: Expression Patterns365538 +Node: Ranges369319 +Node: BEGIN/END372425 +Node: Using BEGIN/END373187 +Ref: Using BEGIN/END-Footnote-1375923 +Node: I/O And BEGIN/END376029 +Node: BEGINFILE/ENDFILE378314 +Node: Empty381250 +Node: Using Shell Variables381567 +Node: Action Overview383850 +Node: Statements386195 +Node: If Statement388049 +Node: While Statement389548 +Node: Do Statement391592 +Node: For Statement392748 +Node: Switch Statement395900 +Node: Break Statement398003 +Node: Continue Statement400058 +Node: Next Statement401851 +Node: Nextfile Statement404241 +Node: Exit Statement406896 +Node: Built-in Variables409298 +Node: User-modified410394 +Ref: User-modified-Footnote-1418079 +Node: Auto-set418141 +Ref: Auto-set-Footnote-1430706 +Ref: Auto-set-Footnote-2430911 +Node: ARGC and ARGV430967 +Node: Arrays434821 +Node: Array Basics436319 +Node: Array Intro437145 +Ref: figure-array-elements439118 +Node: Reference to Elements441525 +Node: Assigning Elements443798 +Node: Array Example444289 +Node: Scanning an Array446021 +Node: Controlling Scanning449036 +Ref: Controlling Scanning-Footnote-1454209 +Node: Delete454525 +Ref: Delete-Footnote-1457290 +Node: Numeric Array Subscripts457347 +Node: Uninitialized Subscripts459530 +Node: Multidimensional461155 +Node: Multiscanning464248 +Node: Arrays of Arrays465837 +Node: Functions470477 +Node: Built-in471296 +Node: Calling Built-in472374 +Node: Numeric Functions474362 +Ref: Numeric Functions-Footnote-1478196 +Ref: Numeric Functions-Footnote-2478553 +Ref: Numeric Functions-Footnote-3478601 +Node: String Functions478870 +Ref: String Functions-Footnote-1501881 +Ref: String Functions-Footnote-2502010 +Ref: String Functions-Footnote-3502258 +Node: Gory Details502345 +Ref: table-sub-escapes504014 +Ref: table-sub-posix-92505368 +Ref: table-sub-proposed506719 +Ref: table-posix-sub508073 +Ref: table-gensub-escapes509618 +Ref: Gory Details-Footnote-1510794 +Ref: Gory Details-Footnote-2510845 +Node: I/O Functions510996 +Ref: I/O Functions-Footnote-1518119 +Node: Time Functions518266 +Ref: Time Functions-Footnote-1528730 +Ref: Time Functions-Footnote-2528798 +Ref: Time Functions-Footnote-3528956 +Ref: Time Functions-Footnote-4529067 +Ref: Time Functions-Footnote-5529179 +Ref: Time Functions-Footnote-6529406 +Node: Bitwise Functions529672 +Ref: table-bitwise-ops530234 +Ref: Bitwise Functions-Footnote-1534479 +Node: Type Functions534663 +Node: I18N Functions535805 +Node: User-defined537450 +Node: Definition Syntax538254 +Ref: Definition Syntax-Footnote-1543169 +Node: Function Example543238 +Ref: Function Example-Footnote-1545882 +Node: Function Caveats545904 +Node: Calling A Function546422 +Node: Variable Scope547377 +Node: Pass By Value/Reference550365 +Node: Return Statement553873 +Node: Dynamic Typing556855 +Node: Indirect Calls557784 +Node: Library Functions567471 +Ref: Library Functions-Footnote-1570984 +Ref: Library Functions-Footnote-2571127 +Node: Library Names571298 +Ref: Library Names-Footnote-1574771 +Ref: Library Names-Footnote-2574991 +Node: General Functions575077 +Node: Strtonum Function576105 +Node: Assert Function579035 +Node: Round Function582361 +Node: Cliff Random Function583902 +Node: Ordinal Functions584918 +Ref: Ordinal Functions-Footnote-1587995 +Ref: Ordinal Functions-Footnote-2588247 +Node: Join Function588458 +Ref: Join Function-Footnote-1590229 +Node: Getlocaltime Function590429 +Node: Readfile Function594170 +Node: Data File Management596009 +Node: Filetrans Function596641 +Node: Rewind Function600710 +Node: File Checking602097 +Node: Empty Files603191 +Node: Ignoring Assigns605421 +Node: Getopt Function606975 +Ref: Getopt Function-Footnote-1618278 +Node: Passwd Functions618481 +Ref: Passwd Functions-Footnote-1627459 +Node: Group Functions627547 +Node: Walking Arrays635631 +Node: Sample Programs637767 +Node: Running Examples638441 +Node: Clones639169 +Node: Cut Program640393 +Node: Egrep Program650244 +Ref: Egrep Program-Footnote-1658017 +Node: Id Program658127 +Node: Split Program661776 +Ref: Split Program-Footnote-1665295 +Node: Tee Program665423 +Node: Uniq Program668226 +Node: Wc Program675655 +Ref: Wc Program-Footnote-1679921 +Ref: Wc Program-Footnote-2680121 +Node: Miscellaneous Programs680213 +Node: Dupword Program681401 +Node: Alarm Program683432 +Node: Translate Program688239 +Ref: Translate Program-Footnote-1692626 +Ref: Translate Program-Footnote-2692874 +Node: Labels Program693008 +Ref: Labels Program-Footnote-1696379 +Node: Word Sorting696463 +Node: History Sorting700347 +Node: Extract Program702186 +Ref: Extract Program-Footnote-1709689 +Node: Simple Sed709817 +Node: Igawk Program712879 +Ref: Igawk Program-Footnote-1728050 +Ref: Igawk Program-Footnote-2728251 +Node: Anagram Program728389 +Node: Signature Program731457 +Node: Advanced Features732557 +Node: Nondecimal Data734443 +Node: Array Sorting736026 +Node: Controlling Array Traversal736723 +Node: Array Sorting Functions745007 +Ref: Array Sorting Functions-Footnote-1748876 +Node: Two-way I/O749070 +Ref: Two-way I/O-Footnote-1754502 +Node: TCP/IP Networking754584 +Node: Profiling757428 +Node: Internationalization764931 +Node: I18N and L10N766356 +Node: Explaining gettext767042 +Ref: Explaining gettext-Footnote-1772110 +Ref: Explaining gettext-Footnote-2772294 +Node: Programmer i18n772459 +Node: Translator i18n776686 +Node: String Extraction777480 +Ref: String Extraction-Footnote-1778441 +Node: Printf Ordering778527 +Ref: Printf Ordering-Footnote-1781309 +Node: I18N Portability781373 +Ref: I18N Portability-Footnote-1783822 +Node: I18N Example783885 +Ref: I18N Example-Footnote-1786523 +Node: Gawk I18N786595 +Node: Debugger787216 +Node: Debugging788187 +Node: Debugging Concepts788620 +Node: Debugging Terms790476 +Node: Awk Debugging793073 +Node: Sample Debugging Session793965 +Node: Debugger Invocation794485 +Node: Finding The Bug795818 +Node: List of Debugger Commands802305 +Node: Breakpoint Control803639 +Node: Debugger Execution Control807303 +Node: Viewing And Changing Data810663 +Node: Execution Stack814019 +Node: Debugger Info815486 +Node: Miscellaneous Debugger Commands819480 +Node: Readline Support824658 +Node: Limitations825489 +Node: Arbitrary Precision Arithmetic827741 +Ref: Arbitrary Precision Arithmetic-Footnote-1829390 +Node: General Arithmetic829538 +Node: Floating Point Issues831258 +Node: String Conversion Precision832139 +Ref: String Conversion Precision-Footnote-1833844 +Node: Unexpected Results833953 +Node: POSIX Floating Point Problems836106 +Ref: POSIX Floating Point Problems-Footnote-1839931 +Node: Integer Programming839969 +Node: Floating-point Programming841708 +Ref: Floating-point Programming-Footnote-1848039 +Ref: Floating-point Programming-Footnote-2848309 +Node: Floating-point Representation848573 +Node: Floating-point Context849738 +Ref: table-ieee-formats850577 +Node: Rounding Mode851961 +Ref: table-rounding-modes852440 +Ref: Rounding Mode-Footnote-1855455 +Node: Gawk and MPFR855634 +Node: Arbitrary Precision Floats857043 +Ref: Arbitrary Precision Floats-Footnote-1859486 +Node: Setting Precision859802 +Ref: table-predefined-precision-strings860488 +Node: Setting Rounding Mode862633 +Ref: table-gawk-rounding-modes863037 +Node: Floating-point Constants864224 +Node: Changing Precision865653 +Ref: Changing Precision-Footnote-1867050 +Node: Exact Arithmetic867224 +Node: Arbitrary Precision Integers870362 +Ref: Arbitrary Precision Integers-Footnote-1873377 +Node: Dynamic Extensions873524 +Node: Extension Intro874982 +Node: Plugin License876247 +Node: Extension Mechanism Outline876932 +Ref: load-extension877349 +Ref: load-new-function878827 +Ref: call-new-function879822 +Node: Extension API Description881837 +Node: Extension API Functions Introduction883124 +Node: General Data Types888051 +Ref: General Data Types-Footnote-1893746 +Node: Requesting Values894045 +Ref: table-value-types-returned894782 +Node: Memory Allocation Functions895736 +Ref: Memory Allocation Functions-Footnote-1898482 +Node: Constructor Functions898578 +Node: Registration Functions900336 +Node: Extension Functions901021 +Node: Exit Callback Functions903323 +Node: Extension Version String904572 +Node: Input Parsers905222 +Node: Output Wrappers914979 +Node: Two-way processors919489 +Node: Printing Messages921697 +Ref: Printing Messages-Footnote-1922774 +Node: Updating `ERRNO'922926 +Node: Accessing Parameters923665 +Node: Symbol Table Access924895 +Node: Symbol table by name925409 +Node: Symbol table by cookie927385 +Ref: Symbol table by cookie-Footnote-1931517 +Node: Cached values931580 +Ref: Cached values-Footnote-1935070 +Node: Array Manipulation935161 +Ref: Array Manipulation-Footnote-1936259 +Node: Array Data Types936298 +Ref: Array Data Types-Footnote-1939001 +Node: Array Functions939093 +Node: Flattening Arrays942929 +Node: Creating Arrays949781 +Node: Extension API Variables954506 +Node: Extension Versioning955142 +Node: Extension API Informational Variables957043 +Node: Extension API Boilerplate958129 +Node: Finding Extensions961933 +Node: Extension Example962493 +Node: Internal File Description963223 +Node: Internal File Ops967314 +Ref: Internal File Ops-Footnote-1978823 +Node: Using Internal File Ops978963 +Ref: Using Internal File Ops-Footnote-1981310 +Node: Extension Samples981576 +Node: Extension Sample File Functions983100 +Node: Extension Sample Fnmatch991587 +Node: Extension Sample Fork993356 +Node: Extension Sample Inplace994569 +Node: Extension Sample Ord996347 +Node: Extension Sample Readdir997183 +Node: Extension Sample Revout998715 +Node: Extension Sample Rev2way999308 +Node: Extension Sample Read write array999998 +Node: Extension Sample Readfile1001881 +Node: Extension Sample API Tests1002981 +Node: Extension Sample Time1003506 +Node: gawkextlib1004870 +Node: Language History1007651 +Node: V7/SVR3.11009244 +Node: SVR41011564 +Node: POSIX1013006 +Node: BTL1014392 +Node: POSIX/GNU1015126 +Node: Feature History1020725 +Node: Common Extensions1033701 +Node: Ranges and Locales1035013 +Ref: Ranges and Locales-Footnote-11039630 +Ref: Ranges and Locales-Footnote-21039657 +Ref: Ranges and Locales-Footnote-31039891 +Node: Contributors1040112 +Node: Installation1045493 +Node: Gawk Distribution1046387 +Node: Getting1046871 +Node: Extracting1047697 +Node: Distribution contents1049389 +Node: Unix Installation1055110 +Node: Quick Installation1055727 +Node: Additional Configuration Options1058173 +Node: Configuration Philosophy1059909 +Node: Non-Unix Installation1062263 +Node: PC Installation1062721 +Node: PC Binary Installation1064032 +Node: PC Compiling1065880 +Node: PC Testing1068840 +Node: PC Using1070016 +Node: Cygwin1074184 +Node: MSYS1074993 +Node: VMS Installation1075507 +Node: VMS Compilation1076303 +Ref: VMS Compilation-Footnote-11077555 +Node: VMS Dynamic Extensions1077613 +Node: VMS Installation Details1078986 +Node: VMS Running1081237 +Node: VMS GNV1084071 +Node: VMS Old Gawk1084794 +Node: Bugs1085264 +Node: Other Versions1089182 +Node: Notes1095266 +Node: Compatibility Mode1096066 +Node: Additions1096849 +Node: Accessing The Source1097776 +Node: Adding Code1099216 +Node: New Ports1105261 +Node: Derived Files1109396 +Ref: Derived Files-Footnote-11114717 +Ref: Derived Files-Footnote-21114751 +Ref: Derived Files-Footnote-31115351 +Node: Future Extensions1115449 +Node: Implementation Limitations1116032 +Node: Extension Design1117280 +Node: Old Extension Problems1118434 +Ref: Old Extension Problems-Footnote-11119942 +Node: Extension New Mechanism Goals1119999 +Ref: Extension New Mechanism Goals-Footnote-11123364 +Node: Extension Other Design Decisions1123550 +Node: Extension Future Growth1125656 +Node: Old Extension Mechanism1126492 +Node: Basic Concepts1128232 +Node: Basic High Level1128913 +Ref: figure-general-flow1129185 +Ref: figure-process-flow1129784 +Ref: Basic High Level-Footnote-11133013 +Node: Basic Data Typing1133198 +Node: Glossary1136553 +Node: Copying1161784 +Node: GNU Free Documentation License1199340 +Node: Index1224476  End Tag Table -- cgit v1.2.3 From b34ea22faeecc99f81f4d897d5c4cc815eab2ddb Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 14 May 2014 22:15:02 +0300 Subject: Fix real preface for docbook. --- doc/gawk.info | 1032 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 513 insertions(+), 519 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 5587b9e8..d725b73e 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1300,12 +1300,6 @@ also must acknowledge my gratitude to G-d, for the many opportunities He has sent my way, as well as for the gifts He has given me with which to take advantage of those opportunities. - -Arnold Robbins -Nof Ayalon -ISRAEL -May, 2014 -  File: gawk.info, Node: Getting Started, Next: Invoking Gawk, Prev: Preface, Up: Top @@ -33219,518 +33213,518 @@ Ref: Manual History-Footnote-164040 Ref: Manual History-Footnote-264081 Node: How To Contribute64155 Node: Acknowledgments65394 -Node: Getting Started69588 -Node: Running gawk71967 -Node: One-shot73157 -Node: Read Terminal74382 -Ref: Read Terminal-Footnote-176032 -Ref: Read Terminal-Footnote-276308 -Node: Long76479 -Node: Executable Scripts77855 -Ref: Executable Scripts-Footnote-179688 -Ref: Executable Scripts-Footnote-279790 -Node: Comments80337 -Node: Quoting82804 -Node: DOS Quoting88120 -Node: Sample Data Files88795 -Node: Very Simple91310 -Node: Two Rules95960 -Node: More Complex97855 -Ref: More Complex-Footnote-1100787 -Node: Statements/Lines100872 -Ref: Statements/Lines-Footnote-1105327 -Node: Other Features105592 -Node: When106520 -Node: Invoking Gawk108668 -Node: Command Line110131 -Node: Options110914 -Ref: Options-Footnote-1126726 -Node: Other Arguments126751 -Node: Naming Standard Input129413 -Node: Environment Variables130507 -Node: AWKPATH Variable131065 -Ref: AWKPATH Variable-Footnote-1133843 -Ref: AWKPATH Variable-Footnote-2133888 -Node: AWKLIBPATH Variable134148 -Node: Other Environment Variables134907 -Node: Exit Status138562 -Node: Include Files139237 -Node: Loading Shared Libraries142815 -Node: Obsolete144198 -Node: Undocumented144895 -Node: Regexp145137 -Node: Regexp Usage146526 -Node: Escape Sequences148559 -Node: Regexp Operators154226 -Ref: Regexp Operators-Footnote-1161706 -Ref: Regexp Operators-Footnote-2161853 -Node: Bracket Expressions161951 -Ref: table-char-classes163841 -Node: GNU Regexp Operators166364 -Node: Case-sensitivity170087 -Ref: Case-sensitivity-Footnote-1172979 -Ref: Case-sensitivity-Footnote-2173214 -Node: Leftmost Longest173322 -Node: Computed Regexps174523 -Node: Reading Files177872 -Node: Records179874 -Node: awk split records180609 -Node: gawk split records185467 -Ref: gawk split records-Footnote-1189988 -Node: Fields190025 -Ref: Fields-Footnote-1192989 -Node: Nonconstant Fields193075 -Ref: Nonconstant Fields-Footnote-1195305 -Node: Changing Fields195507 -Node: Field Separators201461 -Node: Default Field Splitting204163 -Node: Regexp Field Splitting205280 -Node: Single Character Fields208621 -Node: Command Line Field Separator209680 -Node: Full Line Fields213022 -Ref: Full Line Fields-Footnote-1213530 -Node: Field Splitting Summary213576 -Ref: Field Splitting Summary-Footnote-1216675 -Node: Constant Size216776 -Node: Splitting By Content221383 -Ref: Splitting By Content-Footnote-1225133 -Node: Multiple Line225173 -Ref: Multiple Line-Footnote-1231029 -Node: Getline231208 -Node: Plain Getline233424 -Node: Getline/Variable235519 -Node: Getline/File236666 -Node: Getline/Variable/File238050 -Ref: Getline/Variable/File-Footnote-1239649 -Node: Getline/Pipe239736 -Node: Getline/Variable/Pipe242435 -Node: Getline/Coprocess243542 -Node: Getline/Variable/Coprocess244794 -Node: Getline Notes245531 -Node: Getline Summary248335 -Ref: table-getline-variants248743 -Node: Read Timeout249655 -Ref: Read Timeout-Footnote-1253482 -Node: Command line directories253540 -Node: Printing254422 -Node: Print256053 -Node: Print Examples257394 -Node: Output Separators260173 -Node: OFMT262189 -Node: Printf263547 -Node: Basic Printf264453 -Node: Control Letters265992 -Node: Format Modifiers269846 -Node: Printf Examples275873 -Node: Redirection278580 -Node: Special Files285552 -Node: Special FD286085 -Ref: Special FD-Footnote-1289709 -Node: Special Network289783 -Node: Special Caveats290633 -Node: Close Files And Pipes291429 -Ref: Close Files And Pipes-Footnote-1298567 -Ref: Close Files And Pipes-Footnote-2298715 -Node: Expressions298865 -Node: Values299997 -Node: Constants300673 -Node: Scalar Constants301353 -Ref: Scalar Constants-Footnote-1302212 -Node: Nondecimal-numbers302462 -Node: Regexp Constants305462 -Node: Using Constant Regexps305937 -Node: Variables309007 -Node: Using Variables309662 -Node: Assignment Options311386 -Node: Conversion313261 -Ref: table-locale-affects318697 -Ref: Conversion-Footnote-1319321 -Node: All Operators319430 -Node: Arithmetic Ops320060 -Node: Concatenation322565 -Ref: Concatenation-Footnote-1325361 -Node: Assignment Ops325481 -Ref: table-assign-ops330464 -Node: Increment Ops331781 -Node: Truth Values and Conditions335219 -Node: Truth Values336302 -Node: Typing and Comparison337351 -Node: Variable Typing338144 -Ref: Variable Typing-Footnote-1342044 -Node: Comparison Operators342166 -Ref: table-relational-ops342576 -Node: POSIX String Comparison346124 -Ref: POSIX String Comparison-Footnote-1347208 -Node: Boolean Ops347346 -Ref: Boolean Ops-Footnote-1351416 -Node: Conditional Exp351507 -Node: Function Calls353234 -Node: Precedence356992 -Node: Locales360661 -Node: Patterns and Actions362264 -Node: Pattern Overview363318 -Node: Regexp Patterns364995 -Node: Expression Patterns365538 -Node: Ranges369319 -Node: BEGIN/END372425 -Node: Using BEGIN/END373187 -Ref: Using BEGIN/END-Footnote-1375923 -Node: I/O And BEGIN/END376029 -Node: BEGINFILE/ENDFILE378314 -Node: Empty381250 -Node: Using Shell Variables381567 -Node: Action Overview383850 -Node: Statements386195 -Node: If Statement388049 -Node: While Statement389548 -Node: Do Statement391592 -Node: For Statement392748 -Node: Switch Statement395900 -Node: Break Statement398003 -Node: Continue Statement400058 -Node: Next Statement401851 -Node: Nextfile Statement404241 -Node: Exit Statement406896 -Node: Built-in Variables409298 -Node: User-modified410394 -Ref: User-modified-Footnote-1418079 -Node: Auto-set418141 -Ref: Auto-set-Footnote-1430706 -Ref: Auto-set-Footnote-2430911 -Node: ARGC and ARGV430967 -Node: Arrays434821 -Node: Array Basics436319 -Node: Array Intro437145 -Ref: figure-array-elements439118 -Node: Reference to Elements441525 -Node: Assigning Elements443798 -Node: Array Example444289 -Node: Scanning an Array446021 -Node: Controlling Scanning449036 -Ref: Controlling Scanning-Footnote-1454209 -Node: Delete454525 -Ref: Delete-Footnote-1457290 -Node: Numeric Array Subscripts457347 -Node: Uninitialized Subscripts459530 -Node: Multidimensional461155 -Node: Multiscanning464248 -Node: Arrays of Arrays465837 -Node: Functions470477 -Node: Built-in471296 -Node: Calling Built-in472374 -Node: Numeric Functions474362 -Ref: Numeric Functions-Footnote-1478196 -Ref: Numeric Functions-Footnote-2478553 -Ref: Numeric Functions-Footnote-3478601 -Node: String Functions478870 -Ref: String Functions-Footnote-1501881 -Ref: String Functions-Footnote-2502010 -Ref: String Functions-Footnote-3502258 -Node: Gory Details502345 -Ref: table-sub-escapes504014 -Ref: table-sub-posix-92505368 -Ref: table-sub-proposed506719 -Ref: table-posix-sub508073 -Ref: table-gensub-escapes509618 -Ref: Gory Details-Footnote-1510794 -Ref: Gory Details-Footnote-2510845 -Node: I/O Functions510996 -Ref: I/O Functions-Footnote-1518119 -Node: Time Functions518266 -Ref: Time Functions-Footnote-1528730 -Ref: Time Functions-Footnote-2528798 -Ref: Time Functions-Footnote-3528956 -Ref: Time Functions-Footnote-4529067 -Ref: Time Functions-Footnote-5529179 -Ref: Time Functions-Footnote-6529406 -Node: Bitwise Functions529672 -Ref: table-bitwise-ops530234 -Ref: Bitwise Functions-Footnote-1534479 -Node: Type Functions534663 -Node: I18N Functions535805 -Node: User-defined537450 -Node: Definition Syntax538254 -Ref: Definition Syntax-Footnote-1543169 -Node: Function Example543238 -Ref: Function Example-Footnote-1545882 -Node: Function Caveats545904 -Node: Calling A Function546422 -Node: Variable Scope547377 -Node: Pass By Value/Reference550365 -Node: Return Statement553873 -Node: Dynamic Typing556855 -Node: Indirect Calls557784 -Node: Library Functions567471 -Ref: Library Functions-Footnote-1570984 -Ref: Library Functions-Footnote-2571127 -Node: Library Names571298 -Ref: Library Names-Footnote-1574771 -Ref: Library Names-Footnote-2574991 -Node: General Functions575077 -Node: Strtonum Function576105 -Node: Assert Function579035 -Node: Round Function582361 -Node: Cliff Random Function583902 -Node: Ordinal Functions584918 -Ref: Ordinal Functions-Footnote-1587995 -Ref: Ordinal Functions-Footnote-2588247 -Node: Join Function588458 -Ref: Join Function-Footnote-1590229 -Node: Getlocaltime Function590429 -Node: Readfile Function594170 -Node: Data File Management596009 -Node: Filetrans Function596641 -Node: Rewind Function600710 -Node: File Checking602097 -Node: Empty Files603191 -Node: Ignoring Assigns605421 -Node: Getopt Function606975 -Ref: Getopt Function-Footnote-1618278 -Node: Passwd Functions618481 -Ref: Passwd Functions-Footnote-1627459 -Node: Group Functions627547 -Node: Walking Arrays635631 -Node: Sample Programs637767 -Node: Running Examples638441 -Node: Clones639169 -Node: Cut Program640393 -Node: Egrep Program650244 -Ref: Egrep Program-Footnote-1658017 -Node: Id Program658127 -Node: Split Program661776 -Ref: Split Program-Footnote-1665295 -Node: Tee Program665423 -Node: Uniq Program668226 -Node: Wc Program675655 -Ref: Wc Program-Footnote-1679921 -Ref: Wc Program-Footnote-2680121 -Node: Miscellaneous Programs680213 -Node: Dupword Program681401 -Node: Alarm Program683432 -Node: Translate Program688239 -Ref: Translate Program-Footnote-1692626 -Ref: Translate Program-Footnote-2692874 -Node: Labels Program693008 -Ref: Labels Program-Footnote-1696379 -Node: Word Sorting696463 -Node: History Sorting700347 -Node: Extract Program702186 -Ref: Extract Program-Footnote-1709689 -Node: Simple Sed709817 -Node: Igawk Program712879 -Ref: Igawk Program-Footnote-1728050 -Ref: Igawk Program-Footnote-2728251 -Node: Anagram Program728389 -Node: Signature Program731457 -Node: Advanced Features732557 -Node: Nondecimal Data734443 -Node: Array Sorting736026 -Node: Controlling Array Traversal736723 -Node: Array Sorting Functions745007 -Ref: Array Sorting Functions-Footnote-1748876 -Node: Two-way I/O749070 -Ref: Two-way I/O-Footnote-1754502 -Node: TCP/IP Networking754584 -Node: Profiling757428 -Node: Internationalization764931 -Node: I18N and L10N766356 -Node: Explaining gettext767042 -Ref: Explaining gettext-Footnote-1772110 -Ref: Explaining gettext-Footnote-2772294 -Node: Programmer i18n772459 -Node: Translator i18n776686 -Node: String Extraction777480 -Ref: String Extraction-Footnote-1778441 -Node: Printf Ordering778527 -Ref: Printf Ordering-Footnote-1781309 -Node: I18N Portability781373 -Ref: I18N Portability-Footnote-1783822 -Node: I18N Example783885 -Ref: I18N Example-Footnote-1786523 -Node: Gawk I18N786595 -Node: Debugger787216 -Node: Debugging788187 -Node: Debugging Concepts788620 -Node: Debugging Terms790476 -Node: Awk Debugging793073 -Node: Sample Debugging Session793965 -Node: Debugger Invocation794485 -Node: Finding The Bug795818 -Node: List of Debugger Commands802305 -Node: Breakpoint Control803639 -Node: Debugger Execution Control807303 -Node: Viewing And Changing Data810663 -Node: Execution Stack814019 -Node: Debugger Info815486 -Node: Miscellaneous Debugger Commands819480 -Node: Readline Support824658 -Node: Limitations825489 -Node: Arbitrary Precision Arithmetic827741 -Ref: Arbitrary Precision Arithmetic-Footnote-1829390 -Node: General Arithmetic829538 -Node: Floating Point Issues831258 -Node: String Conversion Precision832139 -Ref: String Conversion Precision-Footnote-1833844 -Node: Unexpected Results833953 -Node: POSIX Floating Point Problems836106 -Ref: POSIX Floating Point Problems-Footnote-1839931 -Node: Integer Programming839969 -Node: Floating-point Programming841708 -Ref: Floating-point Programming-Footnote-1848039 -Ref: Floating-point Programming-Footnote-2848309 -Node: Floating-point Representation848573 -Node: Floating-point Context849738 -Ref: table-ieee-formats850577 -Node: Rounding Mode851961 -Ref: table-rounding-modes852440 -Ref: Rounding Mode-Footnote-1855455 -Node: Gawk and MPFR855634 -Node: Arbitrary Precision Floats857043 -Ref: Arbitrary Precision Floats-Footnote-1859486 -Node: Setting Precision859802 -Ref: table-predefined-precision-strings860488 -Node: Setting Rounding Mode862633 -Ref: table-gawk-rounding-modes863037 -Node: Floating-point Constants864224 -Node: Changing Precision865653 -Ref: Changing Precision-Footnote-1867050 -Node: Exact Arithmetic867224 -Node: Arbitrary Precision Integers870362 -Ref: Arbitrary Precision Integers-Footnote-1873377 -Node: Dynamic Extensions873524 -Node: Extension Intro874982 -Node: Plugin License876247 -Node: Extension Mechanism Outline876932 -Ref: load-extension877349 -Ref: load-new-function878827 -Ref: call-new-function879822 -Node: Extension API Description881837 -Node: Extension API Functions Introduction883124 -Node: General Data Types888051 -Ref: General Data Types-Footnote-1893746 -Node: Requesting Values894045 -Ref: table-value-types-returned894782 -Node: Memory Allocation Functions895736 -Ref: Memory Allocation Functions-Footnote-1898482 -Node: Constructor Functions898578 -Node: Registration Functions900336 -Node: Extension Functions901021 -Node: Exit Callback Functions903323 -Node: Extension Version String904572 -Node: Input Parsers905222 -Node: Output Wrappers914979 -Node: Two-way processors919489 -Node: Printing Messages921697 -Ref: Printing Messages-Footnote-1922774 -Node: Updating `ERRNO'922926 -Node: Accessing Parameters923665 -Node: Symbol Table Access924895 -Node: Symbol table by name925409 -Node: Symbol table by cookie927385 -Ref: Symbol table by cookie-Footnote-1931517 -Node: Cached values931580 -Ref: Cached values-Footnote-1935070 -Node: Array Manipulation935161 -Ref: Array Manipulation-Footnote-1936259 -Node: Array Data Types936298 -Ref: Array Data Types-Footnote-1939001 -Node: Array Functions939093 -Node: Flattening Arrays942929 -Node: Creating Arrays949781 -Node: Extension API Variables954506 -Node: Extension Versioning955142 -Node: Extension API Informational Variables957043 -Node: Extension API Boilerplate958129 -Node: Finding Extensions961933 -Node: Extension Example962493 -Node: Internal File Description963223 -Node: Internal File Ops967314 -Ref: Internal File Ops-Footnote-1978823 -Node: Using Internal File Ops978963 -Ref: Using Internal File Ops-Footnote-1981310 -Node: Extension Samples981576 -Node: Extension Sample File Functions983100 -Node: Extension Sample Fnmatch991587 -Node: Extension Sample Fork993356 -Node: Extension Sample Inplace994569 -Node: Extension Sample Ord996347 -Node: Extension Sample Readdir997183 -Node: Extension Sample Revout998715 -Node: Extension Sample Rev2way999308 -Node: Extension Sample Read write array999998 -Node: Extension Sample Readfile1001881 -Node: Extension Sample API Tests1002981 -Node: Extension Sample Time1003506 -Node: gawkextlib1004870 -Node: Language History1007651 -Node: V7/SVR3.11009244 -Node: SVR41011564 -Node: POSIX1013006 -Node: BTL1014392 -Node: POSIX/GNU1015126 -Node: Feature History1020725 -Node: Common Extensions1033701 -Node: Ranges and Locales1035013 -Ref: Ranges and Locales-Footnote-11039630 -Ref: Ranges and Locales-Footnote-21039657 -Ref: Ranges and Locales-Footnote-31039891 -Node: Contributors1040112 -Node: Installation1045493 -Node: Gawk Distribution1046387 -Node: Getting1046871 -Node: Extracting1047697 -Node: Distribution contents1049389 -Node: Unix Installation1055110 -Node: Quick Installation1055727 -Node: Additional Configuration Options1058173 -Node: Configuration Philosophy1059909 -Node: Non-Unix Installation1062263 -Node: PC Installation1062721 -Node: PC Binary Installation1064032 -Node: PC Compiling1065880 -Node: PC Testing1068840 -Node: PC Using1070016 -Node: Cygwin1074184 -Node: MSYS1074993 -Node: VMS Installation1075507 -Node: VMS Compilation1076303 -Ref: VMS Compilation-Footnote-11077555 -Node: VMS Dynamic Extensions1077613 -Node: VMS Installation Details1078986 -Node: VMS Running1081237 -Node: VMS GNV1084071 -Node: VMS Old Gawk1084794 -Node: Bugs1085264 -Node: Other Versions1089182 -Node: Notes1095266 -Node: Compatibility Mode1096066 -Node: Additions1096849 -Node: Accessing The Source1097776 -Node: Adding Code1099216 -Node: New Ports1105261 -Node: Derived Files1109396 -Ref: Derived Files-Footnote-11114717 -Ref: Derived Files-Footnote-21114751 -Ref: Derived Files-Footnote-31115351 -Node: Future Extensions1115449 -Node: Implementation Limitations1116032 -Node: Extension Design1117280 -Node: Old Extension Problems1118434 -Ref: Old Extension Problems-Footnote-11119942 -Node: Extension New Mechanism Goals1119999 -Ref: Extension New Mechanism Goals-Footnote-11123364 -Node: Extension Other Design Decisions1123550 -Node: Extension Future Growth1125656 -Node: Old Extension Mechanism1126492 -Node: Basic Concepts1128232 -Node: Basic High Level1128913 -Ref: figure-general-flow1129185 -Ref: figure-process-flow1129784 -Ref: Basic High Level-Footnote-11133013 -Node: Basic Data Typing1133198 -Node: Glossary1136553 -Node: Copying1161784 -Node: GNU Free Documentation License1199340 -Node: Index1224476 +Node: Getting Started69543 +Node: Running gawk71922 +Node: One-shot73112 +Node: Read Terminal74337 +Ref: Read Terminal-Footnote-175987 +Ref: Read Terminal-Footnote-276263 +Node: Long76434 +Node: Executable Scripts77810 +Ref: Executable Scripts-Footnote-179643 +Ref: Executable Scripts-Footnote-279745 +Node: Comments80292 +Node: Quoting82759 +Node: DOS Quoting88075 +Node: Sample Data Files88750 +Node: Very Simple91265 +Node: Two Rules95915 +Node: More Complex97810 +Ref: More Complex-Footnote-1100742 +Node: Statements/Lines100827 +Ref: Statements/Lines-Footnote-1105282 +Node: Other Features105547 +Node: When106475 +Node: Invoking Gawk108623 +Node: Command Line110086 +Node: Options110869 +Ref: Options-Footnote-1126681 +Node: Other Arguments126706 +Node: Naming Standard Input129368 +Node: Environment Variables130462 +Node: AWKPATH Variable131020 +Ref: AWKPATH Variable-Footnote-1133798 +Ref: AWKPATH Variable-Footnote-2133843 +Node: AWKLIBPATH Variable134103 +Node: Other Environment Variables134862 +Node: Exit Status138517 +Node: Include Files139192 +Node: Loading Shared Libraries142770 +Node: Obsolete144153 +Node: Undocumented144850 +Node: Regexp145092 +Node: Regexp Usage146481 +Node: Escape Sequences148514 +Node: Regexp Operators154181 +Ref: Regexp Operators-Footnote-1161661 +Ref: Regexp Operators-Footnote-2161808 +Node: Bracket Expressions161906 +Ref: table-char-classes163796 +Node: GNU Regexp Operators166319 +Node: Case-sensitivity170042 +Ref: Case-sensitivity-Footnote-1172934 +Ref: Case-sensitivity-Footnote-2173169 +Node: Leftmost Longest173277 +Node: Computed Regexps174478 +Node: Reading Files177827 +Node: Records179829 +Node: awk split records180564 +Node: gawk split records185422 +Ref: gawk split records-Footnote-1189943 +Node: Fields189980 +Ref: Fields-Footnote-1192944 +Node: Nonconstant Fields193030 +Ref: Nonconstant Fields-Footnote-1195260 +Node: Changing Fields195462 +Node: Field Separators201416 +Node: Default Field Splitting204118 +Node: Regexp Field Splitting205235 +Node: Single Character Fields208576 +Node: Command Line Field Separator209635 +Node: Full Line Fields212977 +Ref: Full Line Fields-Footnote-1213485 +Node: Field Splitting Summary213531 +Ref: Field Splitting Summary-Footnote-1216630 +Node: Constant Size216731 +Node: Splitting By Content221338 +Ref: Splitting By Content-Footnote-1225088 +Node: Multiple Line225128 +Ref: Multiple Line-Footnote-1230984 +Node: Getline231163 +Node: Plain Getline233379 +Node: Getline/Variable235474 +Node: Getline/File236621 +Node: Getline/Variable/File238005 +Ref: Getline/Variable/File-Footnote-1239604 +Node: Getline/Pipe239691 +Node: Getline/Variable/Pipe242390 +Node: Getline/Coprocess243497 +Node: Getline/Variable/Coprocess244749 +Node: Getline Notes245486 +Node: Getline Summary248290 +Ref: table-getline-variants248698 +Node: Read Timeout249610 +Ref: Read Timeout-Footnote-1253437 +Node: Command line directories253495 +Node: Printing254377 +Node: Print256008 +Node: Print Examples257349 +Node: Output Separators260128 +Node: OFMT262144 +Node: Printf263502 +Node: Basic Printf264408 +Node: Control Letters265947 +Node: Format Modifiers269801 +Node: Printf Examples275828 +Node: Redirection278535 +Node: Special Files285507 +Node: Special FD286040 +Ref: Special FD-Footnote-1289664 +Node: Special Network289738 +Node: Special Caveats290588 +Node: Close Files And Pipes291384 +Ref: Close Files And Pipes-Footnote-1298522 +Ref: Close Files And Pipes-Footnote-2298670 +Node: Expressions298820 +Node: Values299952 +Node: Constants300628 +Node: Scalar Constants301308 +Ref: Scalar Constants-Footnote-1302167 +Node: Nondecimal-numbers302417 +Node: Regexp Constants305417 +Node: Using Constant Regexps305892 +Node: Variables308962 +Node: Using Variables309617 +Node: Assignment Options311341 +Node: Conversion313216 +Ref: table-locale-affects318652 +Ref: Conversion-Footnote-1319276 +Node: All Operators319385 +Node: Arithmetic Ops320015 +Node: Concatenation322520 +Ref: Concatenation-Footnote-1325316 +Node: Assignment Ops325436 +Ref: table-assign-ops330419 +Node: Increment Ops331736 +Node: Truth Values and Conditions335174 +Node: Truth Values336257 +Node: Typing and Comparison337306 +Node: Variable Typing338099 +Ref: Variable Typing-Footnote-1341999 +Node: Comparison Operators342121 +Ref: table-relational-ops342531 +Node: POSIX String Comparison346079 +Ref: POSIX String Comparison-Footnote-1347163 +Node: Boolean Ops347301 +Ref: Boolean Ops-Footnote-1351371 +Node: Conditional Exp351462 +Node: Function Calls353189 +Node: Precedence356947 +Node: Locales360616 +Node: Patterns and Actions362219 +Node: Pattern Overview363273 +Node: Regexp Patterns364950 +Node: Expression Patterns365493 +Node: Ranges369274 +Node: BEGIN/END372380 +Node: Using BEGIN/END373142 +Ref: Using BEGIN/END-Footnote-1375878 +Node: I/O And BEGIN/END375984 +Node: BEGINFILE/ENDFILE378269 +Node: Empty381205 +Node: Using Shell Variables381522 +Node: Action Overview383805 +Node: Statements386150 +Node: If Statement388004 +Node: While Statement389503 +Node: Do Statement391547 +Node: For Statement392703 +Node: Switch Statement395855 +Node: Break Statement397958 +Node: Continue Statement400013 +Node: Next Statement401806 +Node: Nextfile Statement404196 +Node: Exit Statement406851 +Node: Built-in Variables409253 +Node: User-modified410349 +Ref: User-modified-Footnote-1418034 +Node: Auto-set418096 +Ref: Auto-set-Footnote-1430661 +Ref: Auto-set-Footnote-2430866 +Node: ARGC and ARGV430922 +Node: Arrays434776 +Node: Array Basics436274 +Node: Array Intro437100 +Ref: figure-array-elements439073 +Node: Reference to Elements441480 +Node: Assigning Elements443753 +Node: Array Example444244 +Node: Scanning an Array445976 +Node: Controlling Scanning448991 +Ref: Controlling Scanning-Footnote-1454164 +Node: Delete454480 +Ref: Delete-Footnote-1457245 +Node: Numeric Array Subscripts457302 +Node: Uninitialized Subscripts459485 +Node: Multidimensional461110 +Node: Multiscanning464203 +Node: Arrays of Arrays465792 +Node: Functions470432 +Node: Built-in471251 +Node: Calling Built-in472329 +Node: Numeric Functions474317 +Ref: Numeric Functions-Footnote-1478151 +Ref: Numeric Functions-Footnote-2478508 +Ref: Numeric Functions-Footnote-3478556 +Node: String Functions478825 +Ref: String Functions-Footnote-1501836 +Ref: String Functions-Footnote-2501965 +Ref: String Functions-Footnote-3502213 +Node: Gory Details502300 +Ref: table-sub-escapes503969 +Ref: table-sub-posix-92505323 +Ref: table-sub-proposed506674 +Ref: table-posix-sub508028 +Ref: table-gensub-escapes509573 +Ref: Gory Details-Footnote-1510749 +Ref: Gory Details-Footnote-2510800 +Node: I/O Functions510951 +Ref: I/O Functions-Footnote-1518074 +Node: Time Functions518221 +Ref: Time Functions-Footnote-1528685 +Ref: Time Functions-Footnote-2528753 +Ref: Time Functions-Footnote-3528911 +Ref: Time Functions-Footnote-4529022 +Ref: Time Functions-Footnote-5529134 +Ref: Time Functions-Footnote-6529361 +Node: Bitwise Functions529627 +Ref: table-bitwise-ops530189 +Ref: Bitwise Functions-Footnote-1534434 +Node: Type Functions534618 +Node: I18N Functions535760 +Node: User-defined537405 +Node: Definition Syntax538209 +Ref: Definition Syntax-Footnote-1543124 +Node: Function Example543193 +Ref: Function Example-Footnote-1545837 +Node: Function Caveats545859 +Node: Calling A Function546377 +Node: Variable Scope547332 +Node: Pass By Value/Reference550320 +Node: Return Statement553828 +Node: Dynamic Typing556810 +Node: Indirect Calls557739 +Node: Library Functions567426 +Ref: Library Functions-Footnote-1570939 +Ref: Library Functions-Footnote-2571082 +Node: Library Names571253 +Ref: Library Names-Footnote-1574726 +Ref: Library Names-Footnote-2574946 +Node: General Functions575032 +Node: Strtonum Function576060 +Node: Assert Function578990 +Node: Round Function582316 +Node: Cliff Random Function583857 +Node: Ordinal Functions584873 +Ref: Ordinal Functions-Footnote-1587950 +Ref: Ordinal Functions-Footnote-2588202 +Node: Join Function588413 +Ref: Join Function-Footnote-1590184 +Node: Getlocaltime Function590384 +Node: Readfile Function594125 +Node: Data File Management595964 +Node: Filetrans Function596596 +Node: Rewind Function600665 +Node: File Checking602052 +Node: Empty Files603146 +Node: Ignoring Assigns605376 +Node: Getopt Function606930 +Ref: Getopt Function-Footnote-1618233 +Node: Passwd Functions618436 +Ref: Passwd Functions-Footnote-1627414 +Node: Group Functions627502 +Node: Walking Arrays635586 +Node: Sample Programs637722 +Node: Running Examples638396 +Node: Clones639124 +Node: Cut Program640348 +Node: Egrep Program650199 +Ref: Egrep Program-Footnote-1657972 +Node: Id Program658082 +Node: Split Program661731 +Ref: Split Program-Footnote-1665250 +Node: Tee Program665378 +Node: Uniq Program668181 +Node: Wc Program675610 +Ref: Wc Program-Footnote-1679876 +Ref: Wc Program-Footnote-2680076 +Node: Miscellaneous Programs680168 +Node: Dupword Program681356 +Node: Alarm Program683387 +Node: Translate Program688194 +Ref: Translate Program-Footnote-1692581 +Ref: Translate Program-Footnote-2692829 +Node: Labels Program692963 +Ref: Labels Program-Footnote-1696334 +Node: Word Sorting696418 +Node: History Sorting700302 +Node: Extract Program702141 +Ref: Extract Program-Footnote-1709644 +Node: Simple Sed709772 +Node: Igawk Program712834 +Ref: Igawk Program-Footnote-1728005 +Ref: Igawk Program-Footnote-2728206 +Node: Anagram Program728344 +Node: Signature Program731412 +Node: Advanced Features732512 +Node: Nondecimal Data734398 +Node: Array Sorting735981 +Node: Controlling Array Traversal736678 +Node: Array Sorting Functions744962 +Ref: Array Sorting Functions-Footnote-1748831 +Node: Two-way I/O749025 +Ref: Two-way I/O-Footnote-1754457 +Node: TCP/IP Networking754539 +Node: Profiling757383 +Node: Internationalization764886 +Node: I18N and L10N766311 +Node: Explaining gettext766997 +Ref: Explaining gettext-Footnote-1772065 +Ref: Explaining gettext-Footnote-2772249 +Node: Programmer i18n772414 +Node: Translator i18n776641 +Node: String Extraction777435 +Ref: String Extraction-Footnote-1778396 +Node: Printf Ordering778482 +Ref: Printf Ordering-Footnote-1781264 +Node: I18N Portability781328 +Ref: I18N Portability-Footnote-1783777 +Node: I18N Example783840 +Ref: I18N Example-Footnote-1786478 +Node: Gawk I18N786550 +Node: Debugger787171 +Node: Debugging788142 +Node: Debugging Concepts788575 +Node: Debugging Terms790431 +Node: Awk Debugging793028 +Node: Sample Debugging Session793920 +Node: Debugger Invocation794440 +Node: Finding The Bug795773 +Node: List of Debugger Commands802260 +Node: Breakpoint Control803594 +Node: Debugger Execution Control807258 +Node: Viewing And Changing Data810618 +Node: Execution Stack813974 +Node: Debugger Info815441 +Node: Miscellaneous Debugger Commands819435 +Node: Readline Support824613 +Node: Limitations825444 +Node: Arbitrary Precision Arithmetic827696 +Ref: Arbitrary Precision Arithmetic-Footnote-1829345 +Node: General Arithmetic829493 +Node: Floating Point Issues831213 +Node: String Conversion Precision832094 +Ref: String Conversion Precision-Footnote-1833799 +Node: Unexpected Results833908 +Node: POSIX Floating Point Problems836061 +Ref: POSIX Floating Point Problems-Footnote-1839886 +Node: Integer Programming839924 +Node: Floating-point Programming841663 +Ref: Floating-point Programming-Footnote-1847994 +Ref: Floating-point Programming-Footnote-2848264 +Node: Floating-point Representation848528 +Node: Floating-point Context849693 +Ref: table-ieee-formats850532 +Node: Rounding Mode851916 +Ref: table-rounding-modes852395 +Ref: Rounding Mode-Footnote-1855410 +Node: Gawk and MPFR855589 +Node: Arbitrary Precision Floats856998 +Ref: Arbitrary Precision Floats-Footnote-1859441 +Node: Setting Precision859757 +Ref: table-predefined-precision-strings860443 +Node: Setting Rounding Mode862588 +Ref: table-gawk-rounding-modes862992 +Node: Floating-point Constants864179 +Node: Changing Precision865608 +Ref: Changing Precision-Footnote-1867005 +Node: Exact Arithmetic867179 +Node: Arbitrary Precision Integers870317 +Ref: Arbitrary Precision Integers-Footnote-1873332 +Node: Dynamic Extensions873479 +Node: Extension Intro874937 +Node: Plugin License876202 +Node: Extension Mechanism Outline876887 +Ref: load-extension877304 +Ref: load-new-function878782 +Ref: call-new-function879777 +Node: Extension API Description881792 +Node: Extension API Functions Introduction883079 +Node: General Data Types888006 +Ref: General Data Types-Footnote-1893701 +Node: Requesting Values894000 +Ref: table-value-types-returned894737 +Node: Memory Allocation Functions895691 +Ref: Memory Allocation Functions-Footnote-1898437 +Node: Constructor Functions898533 +Node: Registration Functions900291 +Node: Extension Functions900976 +Node: Exit Callback Functions903278 +Node: Extension Version String904527 +Node: Input Parsers905177 +Node: Output Wrappers914934 +Node: Two-way processors919444 +Node: Printing Messages921652 +Ref: Printing Messages-Footnote-1922729 +Node: Updating `ERRNO'922881 +Node: Accessing Parameters923620 +Node: Symbol Table Access924850 +Node: Symbol table by name925364 +Node: Symbol table by cookie927340 +Ref: Symbol table by cookie-Footnote-1931472 +Node: Cached values931535 +Ref: Cached values-Footnote-1935025 +Node: Array Manipulation935116 +Ref: Array Manipulation-Footnote-1936214 +Node: Array Data Types936253 +Ref: Array Data Types-Footnote-1938956 +Node: Array Functions939048 +Node: Flattening Arrays942884 +Node: Creating Arrays949736 +Node: Extension API Variables954461 +Node: Extension Versioning955097 +Node: Extension API Informational Variables956998 +Node: Extension API Boilerplate958084 +Node: Finding Extensions961888 +Node: Extension Example962448 +Node: Internal File Description963178 +Node: Internal File Ops967269 +Ref: Internal File Ops-Footnote-1978778 +Node: Using Internal File Ops978918 +Ref: Using Internal File Ops-Footnote-1981265 +Node: Extension Samples981531 +Node: Extension Sample File Functions983055 +Node: Extension Sample Fnmatch991542 +Node: Extension Sample Fork993311 +Node: Extension Sample Inplace994524 +Node: Extension Sample Ord996302 +Node: Extension Sample Readdir997138 +Node: Extension Sample Revout998670 +Node: Extension Sample Rev2way999263 +Node: Extension Sample Read write array999953 +Node: Extension Sample Readfile1001836 +Node: Extension Sample API Tests1002936 +Node: Extension Sample Time1003461 +Node: gawkextlib1004825 +Node: Language History1007606 +Node: V7/SVR3.11009199 +Node: SVR41011519 +Node: POSIX1012961 +Node: BTL1014347 +Node: POSIX/GNU1015081 +Node: Feature History1020680 +Node: Common Extensions1033656 +Node: Ranges and Locales1034968 +Ref: Ranges and Locales-Footnote-11039585 +Ref: Ranges and Locales-Footnote-21039612 +Ref: Ranges and Locales-Footnote-31039846 +Node: Contributors1040067 +Node: Installation1045448 +Node: Gawk Distribution1046342 +Node: Getting1046826 +Node: Extracting1047652 +Node: Distribution contents1049344 +Node: Unix Installation1055065 +Node: Quick Installation1055682 +Node: Additional Configuration Options1058128 +Node: Configuration Philosophy1059864 +Node: Non-Unix Installation1062218 +Node: PC Installation1062676 +Node: PC Binary Installation1063987 +Node: PC Compiling1065835 +Node: PC Testing1068795 +Node: PC Using1069971 +Node: Cygwin1074139 +Node: MSYS1074948 +Node: VMS Installation1075462 +Node: VMS Compilation1076258 +Ref: VMS Compilation-Footnote-11077510 +Node: VMS Dynamic Extensions1077568 +Node: VMS Installation Details1078941 +Node: VMS Running1081192 +Node: VMS GNV1084026 +Node: VMS Old Gawk1084749 +Node: Bugs1085219 +Node: Other Versions1089137 +Node: Notes1095221 +Node: Compatibility Mode1096021 +Node: Additions1096804 +Node: Accessing The Source1097731 +Node: Adding Code1099171 +Node: New Ports1105216 +Node: Derived Files1109351 +Ref: Derived Files-Footnote-11114672 +Ref: Derived Files-Footnote-21114706 +Ref: Derived Files-Footnote-31115306 +Node: Future Extensions1115404 +Node: Implementation Limitations1115987 +Node: Extension Design1117235 +Node: Old Extension Problems1118389 +Ref: Old Extension Problems-Footnote-11119897 +Node: Extension New Mechanism Goals1119954 +Ref: Extension New Mechanism Goals-Footnote-11123319 +Node: Extension Other Design Decisions1123505 +Node: Extension Future Growth1125611 +Node: Old Extension Mechanism1126447 +Node: Basic Concepts1128187 +Node: Basic High Level1128868 +Ref: figure-general-flow1129140 +Ref: figure-process-flow1129739 +Ref: Basic High Level-Footnote-11132968 +Node: Basic Data Typing1133153 +Node: Glossary1136508 +Node: Copying1161739 +Node: GNU Free Documentation License1199295 +Node: Index1224431  End Tag Table -- cgit v1.2.3 From 8b086817a7907d54dbe813f0dd05626b86e56cd1 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 15 May 2014 22:28:21 +0300 Subject: Edits through Chapter 11, fix displays for docbook. --- doc/gawk.info | 1210 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 616 insertions(+), 594 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index d725b73e..a9fcc117 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -2276,8 +2276,8 @@ There are two ways to run `awk'--with an explicit program or with one or more program files. Here are templates for both of them; items enclosed in [...] in these templates are optional: - awk [OPTIONS] -f progfile [`--'] FILE ... - awk [OPTIONS] [`--'] 'PROGRAM' FILE ... + `awk' [OPTIONS] `-f' PROGFILE [`--'] FILE ... + `awk' [OPTIONS] [`--'] `'PROGRAM'' FILE ... Besides traditional one-letter POSIX-style options, `gawk' also supports GNU long options. @@ -8933,10 +8933,10 @@ which (but not both) may be omitted. The purpose of the "action" is to tell `awk' what to do once a match for the pattern is found. Thus, in outline, an `awk' program generally looks like this: - [PATTERN] { ACTION } - PATTERN [{ ACTION }] + [PATTERN] `{ ACTION }' + PATTERN [`{ ACTION }'] ... - function NAME(ARGS) { ... } + `function NAME(ARGS) { ... }' ... An action consists of one or more `awk' "statements", enclosed in @@ -9024,7 +9024,7 @@ File: gawk.info, Node: If Statement, Next: While Statement, Up: Statements The `if'-`else' statement is `awk''s decision-making statement. It looks like this: - if (CONDITION) THEN-BODY [else ELSE-BODY] + `if (CONDITION) THEN-BODY' [`else ELSE-BODY'] The CONDITION is an expression that controls what the rest of the statement does. If the CONDITION is true, THEN-BODY is executed; @@ -9507,7 +9507,7 @@ The `exit' statement causes `awk' to immediately stop executing the current rule and to stop processing input; any remaining input is ignored. The `exit' statement is written as follows: - exit [RETURN CODE] + `exit' [RETURN CODE] When an `exit' statement is executed from a `BEGIN' rule, the program stops processing everything immediately. No input records are @@ -12786,10 +12786,10 @@ starting to execute any of it. The definition of a function named NAME looks like this: - function NAME([PARAMETER-LIST]) - { + `function' NAME`('[PARAMETER-LIST]`)' + `{' BODY-OF-FUNCTION - } + `}' Here, NAME is the name of the function to define. A valid function name is like a valid variable name: a sequence of letters, digits, and @@ -13232,7 +13232,7 @@ control to the calling part of the `awk' program. It can also be used to return a value for use in the rest of the `awk' program. It looks like this: - return [EXPRESSION] + `return' [EXPRESSION] The EXPRESSION part is optional. Due most likely to an oversight, POSIX does not define what the return value is if you omit the @@ -14250,7 +14250,7 @@ current time formatted in the same way as the `date' utility: now = systime() # return date(1)-style output - ret = strftime("%a %b %e %H:%M:%S %Z %Y", now) + ret = strftime(PROCINFO["strftime"], now) # clear out target array delete time @@ -14510,8 +14510,8 @@ File: gawk.info, Node: File Checking, Next: Empty Files, Prev: Rewind Functio Normally, if you give `awk' a data file that isn't readable, it stops with a fatal error. There are times when you might want to just ignore -such files and keep going. You can do this by prepending the following -program to your `awk' program: +such files and keep going.(1) You can do this by prepending the +following program to your `awk' program: # readable.awk --- library file to skip over unreadable files @@ -14531,10 +14531,16 @@ program to your `awk' program: element from `ARGV' with `delete' skips the file (since it's no longer in the list). See also *note ARGC and ARGV::. + ---------- Footnotes ---------- + + (1) The `BEGINFILE' special pattern (*note BEGINFILE/ENDFILE::) +provides an alternative mechanism for dealing with files that can't be +opened. However, the code here provides a portable solution. +  File: gawk.info, Node: Empty Files, Next: Ignoring Assigns, Prev: File Checking, Up: Data File Management -10.3.4 Checking For Zero-length Files +10.3.4 Checking for Zero-length Files ------------------------------------- All known `awk' implementations silently skip over zero-length files. @@ -14879,7 +14885,7 @@ is in `ARGV[0]': # test program if (_getopt_test) { while ((_go_c = getopt(ARGC, ARGV, "ab:cd")) != -1) - printf("c = <%c>, optarg = <%s>\n", + printf("c = <%c>, Optarg = <%s>\n", _go_c, Optarg) printf("non-option arguments:\n") for (; Optind < ARGC; Optind++) @@ -14892,17 +14898,17 @@ is in `ARGV[0]': result of two sample runs of the test program: $ awk -f getopt.awk -v _getopt_test=1 -- -a -cbARG bax -x - -| c = , optarg = <> - -| c = , optarg = <> - -| c = , optarg = + -| c = , Optarg = <> + -| c = , Optarg = <> + -| c = , Optarg = -| non-option arguments: -| ARGV[3] = -| ARGV[4] = <-x> $ awk -f getopt.awk -v _getopt_test=1 -- -a -x -- xyz abc - -| c = , optarg = <> + -| c = , Optarg = <> error--> x -- invalid option - -| c = , optarg = <> + -| c = , Optarg = <> -| non-option arguments: -| ARGV[4] = -| ARGV[5] = @@ -14961,7 +14967,7 @@ that "cats" the password database: /* * pwcat.c * - * Generate a printable version of the password database + * Generate a printable version of the password database. */ #include #include @@ -15186,7 +15192,7 @@ group database, is as follows: /* * grcat.c * - * Generate a printable version of the group database + * Generate a printable version of the group database. */ #include #include @@ -15222,9 +15228,10 @@ Group Password used; it is usually empty or set to `*'. Group ID Number - The group's numeric group ID number; this number must be unique - within the file. (On some systems it's a C `long', and not an - `int'. Thus we cast it to `long' for all cases.) + The group's numeric group ID number; the association of name to + number must be unique within the file. (On some systems it's a C + `long', and not an `int'. Thus we cast it to `long' for all + cases.) Group Member List A comma-separated list of user names. These users are members of @@ -15333,10 +15340,7 @@ following: For this reason, `_gr_init()' looks to see if a group name or group ID number is already seen. If it is, then the user names are simply -concatenated onto the previous list of users. (There is actually a -subtle problem with the code just presented. Suppose that the first -time there were no names. This code adds the names with a leading -comma. It also doesn't check that there is a `$4'.) +concatenated onto the previous list of users.(1) Finally, `_gr_init()' closes the pipeline to `grcat', restores `FS' (and `FIELDWIDTHS' or `FPAT' if necessary), `RS', and `$0', initializes @@ -15401,6 +15405,12 @@ very simple, relying on `awk''s associative arrays to do work. The `id' program in *note Id Program::, uses these functions. + ---------- Footnotes ---------- + + (1) There is actually a subtle problem with the code just presented. +Suppose that the first time there were no names. This code adds the +names with a leading comma. It also doesn't check that there is a `$4'. +  File: gawk.info, Node: Walking Arrays, Prev: Group Functions, Up: Library Functions @@ -15637,7 +15647,7 @@ by characters, the output field separator is set to the null string: if (FS == " ") # defeat awk semantics FS = "[ ]" } else if (c == "s") - suppress++ + suppress = 1 else usage() } @@ -15806,7 +15816,7 @@ The `egrep' utility searches files for patterns. It uses regular expressions that are almost identical to those available in `awk' (*note Regexp::). You invoke it as follows: - egrep [ OPTIONS ] 'PATTERN' FILES ... + `egrep' [OPTIONS] `'PATTERN'' FILES ... The PATTERN is a regular expression. In typical usage, the regular expression is quoted to prevent the shell from expanding any of the @@ -15950,6 +15960,11 @@ know the total number of lines that matched the pattern: total += fcount } + The `BEGINFILE' and `ENDFILE' special patterns (*note +BEGINFILE/ENDFILE::) could be used, but then the program would be +`gawk'-specific. Additionally, this example was written before `gawk' +acquired `BEGINFILE' and `ENDFILE'. + The following rule does most of the work of matching lines. The variable `matches' is true if the line matched the pattern. If the user wants lines that did not match, the sense of `matches' is inverted @@ -15997,9 +16012,7 @@ there are no matches, the exit status is one; otherwise it is zero: END \ { - if (total == 0) - exit 1 - exit 0 + exit (total == 0) } The `usage()' function prints a usage message in case of invalid @@ -16041,7 +16054,7 @@ different from the real ones. If possible, `id' also supplies the corresponding user and group names. The output might look like this: $ id - -| uid=500(arnold) gid=500(arnold) groups=6(disk),7(lp),19(floppy) + -| uid=1000(arnold) gid=1000(arnold) groups=1000(arnold),4(adm),7(lp),27(sudo) This information is part of what is provided by `gawk''s `PROCINFO' array (*note Built-in Variables::). However, the `id' utility provides @@ -16074,34 +16087,26 @@ and the group numbers: printf("uid=%d", uid) pw = getpwuid(uid) - if (pw != "") { - split(pw, a, ":") - printf("(%s)", a[1]) - } + if (pw != "") + pr_first_field(pw) if (euid != uid) { printf(" euid=%d", euid) pw = getpwuid(euid) - if (pw != "") { - split(pw, a, ":") - printf("(%s)", a[1]) - } + if (pw != "") + pr_first_field(pw) } printf(" gid=%d", gid) pw = getgrgid(gid) - if (pw != "") { - split(pw, a, ":") - printf("(%s)", a[1]) - } + if (pw != "") + pr_first_field(pw) if (egid != gid) { printf(" egid=%d", egid) pw = getgrgid(egid) - if (pw != "") { - split(pw, a, ":") - printf("(%s)", a[1]) - } + if (pw != "") + pr_first_field(pw) } for (i = 1; ("group" i) in PROCINFO; i++) { @@ -16110,10 +16115,8 @@ and the group numbers: group = PROCINFO["group" i] printf("%d", group) pw = getgrgid(group) - if (pw != "") { - split(pw, a, ":") - printf("(%s)", a[1]) - } + if (pw != "") + pr_first_field(pw) if (("group" (i+1)) in PROCINFO) printf(",") } @@ -16121,6 +16124,12 @@ and the group numbers: print "" } + function pr_first_field(str, a) + { + split(str, a, ":") + printf("(%s)", a[1]) + } + The test in the `for' loop is worth noting. Any supplementary groups in the `PROCINFO' array have the indices `"group1"' through `"groupN"' for some N, i.e., the total number of supplementary groups. @@ -16135,6 +16144,10 @@ the last group in the array and the loop exits. then the condition is false the first time it's tested, and the loop body never executes. + The `pr_first_field()' function simply isolates out some code that +is used repeatedly, making the whole program slightly shorter and +cleaner. +  File: gawk.info, Node: Split Program, Next: Tee Program, Prev: Id Program, Up: Clones @@ -16144,7 +16157,7 @@ File: gawk.info, Node: Split Program, Next: Tee Program, Prev: Id Program, U The `split' program splits large text files into smaller pieces. Usage is as follows:(1) - split [-COUNT] file [ PREFIX ] + `split' [`-COUNT'] [FILE] [PREFIX] By default, the output files are named `xaa', `xab', and so on. Each file has 1000 lines in it, with the likely exception of the last file. @@ -16168,7 +16181,7 @@ output file names: # split.awk --- do split in awk # # Requires ord() and chr() library functions - # usage: split [-num] [file] [outname] + # usage: split [-count] [file] [outname] BEGIN { outfile = "x" # default @@ -16177,7 +16190,7 @@ output file names: usage() i = 1 - if (ARGV[i] ~ /^-[[:digit:]]+$/) { + if (i in ARGV && ARGV[i] ~ /^-[[:digit:]]+$/) { count = -ARGV[i] ARGV[i] = "" i++ @@ -16253,7 +16266,7 @@ The `tee' program is known as a "pipe fitting." `tee' copies its standard input to its standard output and also duplicates it to the files named on the command line. Its usage is as follows: - tee [-a] file ... + `tee' [`-a'] FILE ... The `-a' option tells `tee' to append to the named files, instead of truncating them and starting over. @@ -16342,7 +16355,7 @@ and by default removes duplicate lines. In other words, it only prints unique lines--hence the name. `uniq' has a number of options. The usage is as follows: - uniq [-udc [-N]] [+N] [ INPUT FILE [ OUTPUT FILE ]] + `uniq' [`-udc' [`-N']] [`+N'] [INPUTFILE [OUTPUTFILE]] The options for `uniq' are: @@ -16365,11 +16378,11 @@ usage is as follows: Skip N characters before comparing lines. Any fields specified with `-N' are skipped first. -`INPUT FILE' +`INPUTFILE' Data is read from the input file named on the command line, instead of from the standard input. -`OUTPUT FILE' +`OUTPUTFILE' The generated output is sent to the named output file, instead of to the standard output. @@ -16559,7 +16572,7 @@ File: gawk.info, Node: Wc Program, Prev: Uniq Program, Up: Clones The `wc' (word count) utility counts lines, words, and characters in one or more input files. Its usage is as follows: - wc [-lwc] [ FILES ... ] + `wc' [`-lwc'] [FILES ...] If no files are specified on the command line, `wc' reads its standard input. If there are multiple files, it also prints total @@ -16925,11 +16938,11 @@ there are more characters in the "from" list than in the "to" list, the last character of the "to" list is used for the remaining characters in the "from" list. - Some time ago, a user proposed that a transliteration function should -be added to `gawk'. The following program was written to prove that -character transliteration could be done with a user-level function. -This program is not as complete as the system `tr' utility but it does -most of the job. + Once upon a time, a user proposed that a transliteration function +should be added to `gawk'. The following program was written to prove +that character transliteration could be done with a user-level +function. This program is not as complete as the system `tr' utility +but it does most of the job. The `translate' program demonstrates one of the few weaknesses of standard `awk': dealing with individual characters is very painful, @@ -17010,8 +17023,8 @@ record: While it is possible to do character transliteration in a user-level function, it is not necessarily efficient, and we (the `gawk' authors) started to consider adding a built-in function. However, shortly after -writing this program, we learned that the System V Release 4 `awk' had -added the `toupper()' and `tolower()' functions (*note String +writing this program, we learned that Brian Kernighan had added the +`toupper()' and `tolower()' functions to his `awk' (*note String Functions::). These functions handle the vast majority of the cases where character transliteration is necessary, and so we chose to simply add those functions to `gawk' as well and then leave well enough alone. @@ -17023,10 +17036,10 @@ program. ---------- Footnotes ---------- - (1) On some older systems, including Solaris, `tr' may require that -the lists be written as range expressions enclosed in square brackets -(`[a-z]') and quoted, to prevent the shell from attempting a file name -expansion. This is not a feature. + (1) On some older systems, including Solaris, the system version of +`tr' may require that the lists be written as range expressions +enclosed in square brackets (`[a-z]') and quoted, to prevent the shell +from attempting a file name expansion. This is not a feature. (2) This program was written before `gawk' acquired the ability to split each character in a string into separate array elements. @@ -17146,7 +17159,7 @@ File: gawk.info, Node: Word Sorting, Next: History Sorting, Prev: Labels Prog When working with large amounts of text, it can be interesting to know how often different words appear. For example, an author may overuse -certain words, in which case she might wish to find synonyms to +certain words, in which case he or she might wish to find synonyms to substitute for words that appear too often. This node develops a program for counting words and presenting the frequency information in a useful format. @@ -17209,6 +17222,10 @@ script. Here is the new version of the program: printf "%s\t%d\n", word, freq[word] } + The regexp `/[^[:alnum:]_[:blank:]]/' might have been written +`/[[:punct:]]/', but then underscores would also be removed, and we +want to keep them. + Assuming we have saved this program in a file named `wordfreq.awk', and that the data is in `file1', the following pipeline: @@ -17286,8 +17303,7 @@ information. For example, using the following `print' statement in the print data[lines[i]], lines[i] - This works because `data[$0]' is incremented each time a line is -seen. +This works because `data[$0]' is incremented each time a line is seen.  File: gawk.info, Node: Extract Program, Next: Simple Sed, Prev: History Sorting, Up: Miscellaneous Programs @@ -17418,8 +17434,9 @@ elements (`@@' in the original file), we have to add a single `@' symbol back in.(1) When the processing of the array is finished, `join()' is called -with the value of `SUBSEP', to rejoin the pieces back into a single -line. That line is then printed to the output file: +with the value of `SUBSEP' (*note Multidimensional::), to rejoin the +pieces back into a single line. That line is then printed to the +output file: /^@c(omment)?[ \t]+file/ \ { @@ -17488,7 +17505,7 @@ closing the open file: ---------- Footnotes ---------- (1) This program was written before `gawk' had the `gensub()' -function. Consider how you might use it to simplify the code. +function. Consider how you might use it to simplify the code.  File: gawk.info, Node: Simple Sed, Next: Igawk Program, Prev: Extract Program, Up: Miscellaneous Programs @@ -17827,12 +17844,12 @@ which represents the current directory: pathlist[i] = "." } - The stack is initialized with `ARGV[1]', which will be `/dev/stdin'. -The main loop comes next. Input lines are read in succession. Lines -that do not start with `@include' are printed verbatim. If the line -does start with `@include', the file name is in `$2'. `pathto()' is -called to generate the full path. If it cannot, then the program -prints an error message and continues. + The stack is initialized with `ARGV[1]', which will be +`"/dev/stdin"'. The main loop comes next. Input lines are read in +succession. Lines that do not start with `@include' are printed +verbatim. If the line does start with `@include', the file name is in +`$2'. `pathto()' is called to generate the full path. If it cannot, +then the program prints an error message and continues. The next thing to check is if the file is included already. The `processed' array is indexed by the full file name of each included @@ -17909,7 +17926,7 @@ supplied. The `eval' command is a shell construct that reruns the shell's parsing process. This keeps things properly quoted. - This version of `igawk' represents my fifth version of this program. + This version of `igawk' represents the fifth version of this program. There are four key simplifications that make the program work better: * Using `@include' even for the files named with `-f' makes building @@ -18083,7 +18100,9 @@ supplies the following copyright terms: X*(X-x)-o*o,(x+X)*o*o+o,x*(X-x)-O-O,x-O+(O+o+X+x)*(o+O),X*X-X*(x-O)-x+O, O+X*(o*(o+O)+O),+x+O+X*o,x*(x-o),(o+X+x)*o*o-(x-O-O),O+(X-x)*(X+O),x-O}' - We leave it to you to determine what the program does. + We leave it to you to determine what the program does. (If you are +truly desperate to understand it, see Chris Johansen's explanation, +which is embedded in the Texinfo source file for this Info file.)  File: gawk.info, Node: Advanced Features, Next: Internationalization, Prev: Sample Programs, Up: Top @@ -20413,7 +20432,7 @@ categories, as follows: Program::) demonstrates: gawk> dump - -| # BEGIN + -| # BEGIN -| -| [ 1:0xfcd340] Op_rule : [in_rule = BEGIN] [source_file = brini.awk] -| [ 1:0xfcc240] Op_push_i : "~" [MALLOC|STRING|STRCUR] @@ -30122,7 +30141,7 @@ Index * Menu: * ! (exclamation point), ! operator: Boolean Ops. (line 67) -* ! (exclamation point), ! operator <1>: Egrep Program. (line 170) +* ! (exclamation point), ! operator <1>: Egrep Program. (line 175) * ! (exclamation point), ! operator <2>: Ranges. (line 48) * ! (exclamation point), ! operator: Precedence. (line 52) * ! (exclamation point), != operator <1>: Precedence. (line 65) @@ -30358,7 +30377,7 @@ Index (line 38) * \ (backslash), as field separator: Command Line Field Separator. (line 27) -* \ (backslash), continuing lines and <1>: Egrep Program. (line 220) +* \ (backslash), continuing lines and <1>: Egrep Program. (line 223) * \ (backslash), continuing lines and: Statements/Lines. (line 19) * \ (backslash), continuing lines and, comments and: Statements/Lines. (line 76) @@ -30386,7 +30405,7 @@ Index * _ (underscore), in names of private variables: Library Names. (line 29) * _ (underscore), translatable string: Programmer i18n. (line 69) -* _gr_init() user-defined function: Group Functions. (line 82) +* _gr_init() user-defined function: Group Functions. (line 83) * _ord_init() user-defined function: Ordinal Functions. (line 16) * _pw_init() user-defined function: Passwd Functions. (line 105) * accessing fields: Fields. (line 6) @@ -30632,7 +30651,7 @@ Index (line 38) * backslash (\), as field separator: Command Line Field Separator. (line 27) -* backslash (\), continuing lines and <1>: Egrep Program. (line 220) +* backslash (\), continuing lines and <1>: Egrep Program. (line 223) * backslash (\), continuing lines and: Statements/Lines. (line 19) * backslash (\), continuing lines and, comments and: Statements/Lines. (line 76) @@ -31288,7 +31307,7 @@ Index * END pattern, and profiling: Profiling. (line 62) * END pattern, assert() user-defined function and: Assert Function. (line 75) -* END pattern, backslash continuation and: Egrep Program. (line 220) +* END pattern, backslash continuation and: Egrep Program. (line 223) * END pattern, Boolean patterns and: Expression Patterns. (line 70) * END pattern, exit statement and: Exit Statement. (line 12) * END pattern, next/nextfile statements and <1>: Next Statement. @@ -31300,8 +31319,8 @@ Index * ENDFILE pattern: BEGINFILE/ENDFILE. (line 6) * ENDFILE pattern, Boolean patterns and: Expression Patterns. (line 70) * endfile() user-defined function: Filetrans Function. (line 62) -* endgrent() function (C library): Group Functions. (line 215) -* endgrent() user-defined function: Group Functions. (line 218) +* endgrent() function (C library): Group Functions. (line 213) +* endgrent() user-defined function: Group Functions. (line 216) * endpwent() function (C library): Passwd Functions. (line 210) * endpwent() user-defined function: Passwd Functions. (line 213) * ENVIRON array: Auto-set. (line 60) @@ -31334,7 +31353,7 @@ Index * evaluation order, concatenation: Concatenation. (line 41) * evaluation order, functions: Calling Built-in. (line 30) * examining fields: Fields. (line 6) -* exclamation point (!), ! operator <1>: Egrep Program. (line 170) +* exclamation point (!), ! operator <1>: Egrep Program. (line 175) * exclamation point (!), ! operator <2>: Precedence. (line 52) * exclamation point (!), ! operator: Boolean Ops. (line 67) * exclamation point (!), != operator <1>: Precedence. (line 65) @@ -31730,15 +31749,15 @@ Index * getaddrinfo() function (C library): TCP/IP Networking. (line 38) * getgrent() function (C library): Group Functions. (line 6) * getgrent() user-defined function: Group Functions. (line 6) -* getgrgid() function (C library): Group Functions. (line 186) -* getgrgid() user-defined function: Group Functions. (line 189) -* getgrnam() function (C library): Group Functions. (line 175) -* getgrnam() user-defined function: Group Functions. (line 180) -* getgruser() function (C library): Group Functions. (line 195) -* getgruser() function, user-defined: Group Functions. (line 198) +* getgrgid() function (C library): Group Functions. (line 184) +* getgrgid() user-defined function: Group Functions. (line 187) +* getgrnam() function (C library): Group Functions. (line 173) +* getgrnam() user-defined function: Group Functions. (line 178) +* getgruser() function (C library): Group Functions. (line 193) +* getgruser() function, user-defined: Group Functions. (line 196) * getline command: Reading Files. (line 20) * getline command, _gr_init() user-defined function: Group Functions. - (line 82) + (line 83) * getline command, _pw_init() function: Passwd Functions. (line 154) * getline command, coprocesses, using from <1>: Close Files And Pipes. (line 6) @@ -31939,6 +31958,7 @@ Index * Java programming language: Glossary. (line 380) * jawk: Other Versions. (line 112) * Jedi knights: Undocumented. (line 6) +* Johansen, Chris: Signature Program. (line 25) * join() user-defined function: Join Function. (line 18) * Kahrs, Ju"rgen <1>: Contributors. (line 70) * Kahrs, Ju"rgen: Acknowledgments. (line 60) @@ -33237,494 +33257,496 @@ Node: Other Features105547 Node: When106475 Node: Invoking Gawk108623 Node: Command Line110086 -Node: Options110869 -Ref: Options-Footnote-1126681 -Node: Other Arguments126706 -Node: Naming Standard Input129368 -Node: Environment Variables130462 -Node: AWKPATH Variable131020 -Ref: AWKPATH Variable-Footnote-1133798 -Ref: AWKPATH Variable-Footnote-2133843 -Node: AWKLIBPATH Variable134103 -Node: Other Environment Variables134862 -Node: Exit Status138517 -Node: Include Files139192 -Node: Loading Shared Libraries142770 -Node: Obsolete144153 -Node: Undocumented144850 -Node: Regexp145092 -Node: Regexp Usage146481 -Node: Escape Sequences148514 -Node: Regexp Operators154181 -Ref: Regexp Operators-Footnote-1161661 -Ref: Regexp Operators-Footnote-2161808 -Node: Bracket Expressions161906 -Ref: table-char-classes163796 -Node: GNU Regexp Operators166319 -Node: Case-sensitivity170042 -Ref: Case-sensitivity-Footnote-1172934 -Ref: Case-sensitivity-Footnote-2173169 -Node: Leftmost Longest173277 -Node: Computed Regexps174478 -Node: Reading Files177827 -Node: Records179829 -Node: awk split records180564 -Node: gawk split records185422 -Ref: gawk split records-Footnote-1189943 -Node: Fields189980 -Ref: Fields-Footnote-1192944 -Node: Nonconstant Fields193030 -Ref: Nonconstant Fields-Footnote-1195260 -Node: Changing Fields195462 -Node: Field Separators201416 -Node: Default Field Splitting204118 -Node: Regexp Field Splitting205235 -Node: Single Character Fields208576 -Node: Command Line Field Separator209635 -Node: Full Line Fields212977 -Ref: Full Line Fields-Footnote-1213485 -Node: Field Splitting Summary213531 -Ref: Field Splitting Summary-Footnote-1216630 -Node: Constant Size216731 -Node: Splitting By Content221338 -Ref: Splitting By Content-Footnote-1225088 -Node: Multiple Line225128 -Ref: Multiple Line-Footnote-1230984 -Node: Getline231163 -Node: Plain Getline233379 -Node: Getline/Variable235474 -Node: Getline/File236621 -Node: Getline/Variable/File238005 -Ref: Getline/Variable/File-Footnote-1239604 -Node: Getline/Pipe239691 -Node: Getline/Variable/Pipe242390 -Node: Getline/Coprocess243497 -Node: Getline/Variable/Coprocess244749 -Node: Getline Notes245486 -Node: Getline Summary248290 -Ref: table-getline-variants248698 -Node: Read Timeout249610 -Ref: Read Timeout-Footnote-1253437 -Node: Command line directories253495 -Node: Printing254377 -Node: Print256008 -Node: Print Examples257349 -Node: Output Separators260128 -Node: OFMT262144 -Node: Printf263502 -Node: Basic Printf264408 -Node: Control Letters265947 -Node: Format Modifiers269801 -Node: Printf Examples275828 -Node: Redirection278535 -Node: Special Files285507 -Node: Special FD286040 -Ref: Special FD-Footnote-1289664 -Node: Special Network289738 -Node: Special Caveats290588 -Node: Close Files And Pipes291384 -Ref: Close Files And Pipes-Footnote-1298522 -Ref: Close Files And Pipes-Footnote-2298670 -Node: Expressions298820 -Node: Values299952 -Node: Constants300628 -Node: Scalar Constants301308 -Ref: Scalar Constants-Footnote-1302167 -Node: Nondecimal-numbers302417 -Node: Regexp Constants305417 -Node: Using Constant Regexps305892 -Node: Variables308962 -Node: Using Variables309617 -Node: Assignment Options311341 -Node: Conversion313216 -Ref: table-locale-affects318652 -Ref: Conversion-Footnote-1319276 -Node: All Operators319385 -Node: Arithmetic Ops320015 -Node: Concatenation322520 -Ref: Concatenation-Footnote-1325316 -Node: Assignment Ops325436 -Ref: table-assign-ops330419 -Node: Increment Ops331736 -Node: Truth Values and Conditions335174 -Node: Truth Values336257 -Node: Typing and Comparison337306 -Node: Variable Typing338099 -Ref: Variable Typing-Footnote-1341999 -Node: Comparison Operators342121 -Ref: table-relational-ops342531 -Node: POSIX String Comparison346079 -Ref: POSIX String Comparison-Footnote-1347163 -Node: Boolean Ops347301 -Ref: Boolean Ops-Footnote-1351371 -Node: Conditional Exp351462 -Node: Function Calls353189 -Node: Precedence356947 -Node: Locales360616 -Node: Patterns and Actions362219 -Node: Pattern Overview363273 -Node: Regexp Patterns364950 -Node: Expression Patterns365493 -Node: Ranges369274 -Node: BEGIN/END372380 -Node: Using BEGIN/END373142 -Ref: Using BEGIN/END-Footnote-1375878 -Node: I/O And BEGIN/END375984 -Node: BEGINFILE/ENDFILE378269 -Node: Empty381205 -Node: Using Shell Variables381522 -Node: Action Overview383805 -Node: Statements386150 -Node: If Statement388004 -Node: While Statement389503 -Node: Do Statement391547 -Node: For Statement392703 -Node: Switch Statement395855 -Node: Break Statement397958 -Node: Continue Statement400013 -Node: Next Statement401806 -Node: Nextfile Statement404196 -Node: Exit Statement406851 -Node: Built-in Variables409253 -Node: User-modified410349 -Ref: User-modified-Footnote-1418034 -Node: Auto-set418096 -Ref: Auto-set-Footnote-1430661 -Ref: Auto-set-Footnote-2430866 -Node: ARGC and ARGV430922 -Node: Arrays434776 -Node: Array Basics436274 -Node: Array Intro437100 -Ref: figure-array-elements439073 -Node: Reference to Elements441480 -Node: Assigning Elements443753 -Node: Array Example444244 -Node: Scanning an Array445976 -Node: Controlling Scanning448991 -Ref: Controlling Scanning-Footnote-1454164 -Node: Delete454480 -Ref: Delete-Footnote-1457245 -Node: Numeric Array Subscripts457302 -Node: Uninitialized Subscripts459485 -Node: Multidimensional461110 -Node: Multiscanning464203 -Node: Arrays of Arrays465792 -Node: Functions470432 -Node: Built-in471251 -Node: Calling Built-in472329 -Node: Numeric Functions474317 -Ref: Numeric Functions-Footnote-1478151 -Ref: Numeric Functions-Footnote-2478508 -Ref: Numeric Functions-Footnote-3478556 -Node: String Functions478825 -Ref: String Functions-Footnote-1501836 -Ref: String Functions-Footnote-2501965 -Ref: String Functions-Footnote-3502213 -Node: Gory Details502300 -Ref: table-sub-escapes503969 -Ref: table-sub-posix-92505323 -Ref: table-sub-proposed506674 -Ref: table-posix-sub508028 -Ref: table-gensub-escapes509573 -Ref: Gory Details-Footnote-1510749 -Ref: Gory Details-Footnote-2510800 -Node: I/O Functions510951 -Ref: I/O Functions-Footnote-1518074 -Node: Time Functions518221 -Ref: Time Functions-Footnote-1528685 -Ref: Time Functions-Footnote-2528753 -Ref: Time Functions-Footnote-3528911 -Ref: Time Functions-Footnote-4529022 -Ref: Time Functions-Footnote-5529134 -Ref: Time Functions-Footnote-6529361 -Node: Bitwise Functions529627 -Ref: table-bitwise-ops530189 -Ref: Bitwise Functions-Footnote-1534434 -Node: Type Functions534618 -Node: I18N Functions535760 -Node: User-defined537405 -Node: Definition Syntax538209 -Ref: Definition Syntax-Footnote-1543124 -Node: Function Example543193 -Ref: Function Example-Footnote-1545837 -Node: Function Caveats545859 -Node: Calling A Function546377 -Node: Variable Scope547332 -Node: Pass By Value/Reference550320 -Node: Return Statement553828 -Node: Dynamic Typing556810 -Node: Indirect Calls557739 -Node: Library Functions567426 -Ref: Library Functions-Footnote-1570939 -Ref: Library Functions-Footnote-2571082 -Node: Library Names571253 -Ref: Library Names-Footnote-1574726 -Ref: Library Names-Footnote-2574946 -Node: General Functions575032 -Node: Strtonum Function576060 -Node: Assert Function578990 -Node: Round Function582316 -Node: Cliff Random Function583857 -Node: Ordinal Functions584873 -Ref: Ordinal Functions-Footnote-1587950 -Ref: Ordinal Functions-Footnote-2588202 -Node: Join Function588413 -Ref: Join Function-Footnote-1590184 -Node: Getlocaltime Function590384 -Node: Readfile Function594125 -Node: Data File Management595964 -Node: Filetrans Function596596 -Node: Rewind Function600665 -Node: File Checking602052 -Node: Empty Files603146 -Node: Ignoring Assigns605376 -Node: Getopt Function606930 -Ref: Getopt Function-Footnote-1618233 -Node: Passwd Functions618436 -Ref: Passwd Functions-Footnote-1627414 -Node: Group Functions627502 -Node: Walking Arrays635586 -Node: Sample Programs637722 -Node: Running Examples638396 -Node: Clones639124 -Node: Cut Program640348 -Node: Egrep Program650199 -Ref: Egrep Program-Footnote-1657972 -Node: Id Program658082 -Node: Split Program661731 -Ref: Split Program-Footnote-1665250 -Node: Tee Program665378 -Node: Uniq Program668181 -Node: Wc Program675610 -Ref: Wc Program-Footnote-1679876 -Ref: Wc Program-Footnote-2680076 -Node: Miscellaneous Programs680168 -Node: Dupword Program681356 -Node: Alarm Program683387 -Node: Translate Program688194 -Ref: Translate Program-Footnote-1692581 -Ref: Translate Program-Footnote-2692829 -Node: Labels Program692963 -Ref: Labels Program-Footnote-1696334 -Node: Word Sorting696418 -Node: History Sorting700302 -Node: Extract Program702141 -Ref: Extract Program-Footnote-1709644 -Node: Simple Sed709772 -Node: Igawk Program712834 -Ref: Igawk Program-Footnote-1728005 -Ref: Igawk Program-Footnote-2728206 -Node: Anagram Program728344 -Node: Signature Program731412 -Node: Advanced Features732512 -Node: Nondecimal Data734398 -Node: Array Sorting735981 -Node: Controlling Array Traversal736678 -Node: Array Sorting Functions744962 -Ref: Array Sorting Functions-Footnote-1748831 -Node: Two-way I/O749025 -Ref: Two-way I/O-Footnote-1754457 -Node: TCP/IP Networking754539 -Node: Profiling757383 -Node: Internationalization764886 -Node: I18N and L10N766311 -Node: Explaining gettext766997 -Ref: Explaining gettext-Footnote-1772065 -Ref: Explaining gettext-Footnote-2772249 -Node: Programmer i18n772414 -Node: Translator i18n776641 -Node: String Extraction777435 -Ref: String Extraction-Footnote-1778396 -Node: Printf Ordering778482 -Ref: Printf Ordering-Footnote-1781264 -Node: I18N Portability781328 -Ref: I18N Portability-Footnote-1783777 -Node: I18N Example783840 -Ref: I18N Example-Footnote-1786478 -Node: Gawk I18N786550 -Node: Debugger787171 -Node: Debugging788142 -Node: Debugging Concepts788575 -Node: Debugging Terms790431 -Node: Awk Debugging793028 -Node: Sample Debugging Session793920 -Node: Debugger Invocation794440 -Node: Finding The Bug795773 -Node: List of Debugger Commands802260 -Node: Breakpoint Control803594 -Node: Debugger Execution Control807258 -Node: Viewing And Changing Data810618 -Node: Execution Stack813974 -Node: Debugger Info815441 -Node: Miscellaneous Debugger Commands819435 -Node: Readline Support824613 -Node: Limitations825444 -Node: Arbitrary Precision Arithmetic827696 -Ref: Arbitrary Precision Arithmetic-Footnote-1829345 -Node: General Arithmetic829493 -Node: Floating Point Issues831213 -Node: String Conversion Precision832094 -Ref: String Conversion Precision-Footnote-1833799 -Node: Unexpected Results833908 -Node: POSIX Floating Point Problems836061 -Ref: POSIX Floating Point Problems-Footnote-1839886 -Node: Integer Programming839924 -Node: Floating-point Programming841663 -Ref: Floating-point Programming-Footnote-1847994 -Ref: Floating-point Programming-Footnote-2848264 -Node: Floating-point Representation848528 -Node: Floating-point Context849693 -Ref: table-ieee-formats850532 -Node: Rounding Mode851916 -Ref: table-rounding-modes852395 -Ref: Rounding Mode-Footnote-1855410 -Node: Gawk and MPFR855589 -Node: Arbitrary Precision Floats856998 -Ref: Arbitrary Precision Floats-Footnote-1859441 -Node: Setting Precision859757 -Ref: table-predefined-precision-strings860443 -Node: Setting Rounding Mode862588 -Ref: table-gawk-rounding-modes862992 -Node: Floating-point Constants864179 -Node: Changing Precision865608 -Ref: Changing Precision-Footnote-1867005 -Node: Exact Arithmetic867179 -Node: Arbitrary Precision Integers870317 -Ref: Arbitrary Precision Integers-Footnote-1873332 -Node: Dynamic Extensions873479 -Node: Extension Intro874937 -Node: Plugin License876202 -Node: Extension Mechanism Outline876887 -Ref: load-extension877304 -Ref: load-new-function878782 -Ref: call-new-function879777 -Node: Extension API Description881792 -Node: Extension API Functions Introduction883079 -Node: General Data Types888006 -Ref: General Data Types-Footnote-1893701 -Node: Requesting Values894000 -Ref: table-value-types-returned894737 -Node: Memory Allocation Functions895691 -Ref: Memory Allocation Functions-Footnote-1898437 -Node: Constructor Functions898533 -Node: Registration Functions900291 -Node: Extension Functions900976 -Node: Exit Callback Functions903278 -Node: Extension Version String904527 -Node: Input Parsers905177 -Node: Output Wrappers914934 -Node: Two-way processors919444 -Node: Printing Messages921652 -Ref: Printing Messages-Footnote-1922729 -Node: Updating `ERRNO'922881 -Node: Accessing Parameters923620 -Node: Symbol Table Access924850 -Node: Symbol table by name925364 -Node: Symbol table by cookie927340 -Ref: Symbol table by cookie-Footnote-1931472 -Node: Cached values931535 -Ref: Cached values-Footnote-1935025 -Node: Array Manipulation935116 -Ref: Array Manipulation-Footnote-1936214 -Node: Array Data Types936253 -Ref: Array Data Types-Footnote-1938956 -Node: Array Functions939048 -Node: Flattening Arrays942884 -Node: Creating Arrays949736 -Node: Extension API Variables954461 -Node: Extension Versioning955097 -Node: Extension API Informational Variables956998 -Node: Extension API Boilerplate958084 -Node: Finding Extensions961888 -Node: Extension Example962448 -Node: Internal File Description963178 -Node: Internal File Ops967269 -Ref: Internal File Ops-Footnote-1978778 -Node: Using Internal File Ops978918 -Ref: Using Internal File Ops-Footnote-1981265 -Node: Extension Samples981531 -Node: Extension Sample File Functions983055 -Node: Extension Sample Fnmatch991542 -Node: Extension Sample Fork993311 -Node: Extension Sample Inplace994524 -Node: Extension Sample Ord996302 -Node: Extension Sample Readdir997138 -Node: Extension Sample Revout998670 -Node: Extension Sample Rev2way999263 -Node: Extension Sample Read write array999953 -Node: Extension Sample Readfile1001836 -Node: Extension Sample API Tests1002936 -Node: Extension Sample Time1003461 -Node: gawkextlib1004825 -Node: Language History1007606 -Node: V7/SVR3.11009199 -Node: SVR41011519 -Node: POSIX1012961 -Node: BTL1014347 -Node: POSIX/GNU1015081 -Node: Feature History1020680 -Node: Common Extensions1033656 -Node: Ranges and Locales1034968 -Ref: Ranges and Locales-Footnote-11039585 -Ref: Ranges and Locales-Footnote-21039612 -Ref: Ranges and Locales-Footnote-31039846 -Node: Contributors1040067 -Node: Installation1045448 -Node: Gawk Distribution1046342 -Node: Getting1046826 -Node: Extracting1047652 -Node: Distribution contents1049344 -Node: Unix Installation1055065 -Node: Quick Installation1055682 -Node: Additional Configuration Options1058128 -Node: Configuration Philosophy1059864 -Node: Non-Unix Installation1062218 -Node: PC Installation1062676 -Node: PC Binary Installation1063987 -Node: PC Compiling1065835 -Node: PC Testing1068795 -Node: PC Using1069971 -Node: Cygwin1074139 -Node: MSYS1074948 -Node: VMS Installation1075462 -Node: VMS Compilation1076258 -Ref: VMS Compilation-Footnote-11077510 -Node: VMS Dynamic Extensions1077568 -Node: VMS Installation Details1078941 -Node: VMS Running1081192 -Node: VMS GNV1084026 -Node: VMS Old Gawk1084749 -Node: Bugs1085219 -Node: Other Versions1089137 -Node: Notes1095221 -Node: Compatibility Mode1096021 -Node: Additions1096804 -Node: Accessing The Source1097731 -Node: Adding Code1099171 -Node: New Ports1105216 -Node: Derived Files1109351 -Ref: Derived Files-Footnote-11114672 -Ref: Derived Files-Footnote-21114706 -Ref: Derived Files-Footnote-31115306 -Node: Future Extensions1115404 -Node: Implementation Limitations1115987 -Node: Extension Design1117235 -Node: Old Extension Problems1118389 -Ref: Old Extension Problems-Footnote-11119897 -Node: Extension New Mechanism Goals1119954 -Ref: Extension New Mechanism Goals-Footnote-11123319 -Node: Extension Other Design Decisions1123505 -Node: Extension Future Growth1125611 -Node: Old Extension Mechanism1126447 -Node: Basic Concepts1128187 -Node: Basic High Level1128868 -Ref: figure-general-flow1129140 -Ref: figure-process-flow1129739 -Ref: Basic High Level-Footnote-11132968 -Node: Basic Data Typing1133153 -Node: Glossary1136508 -Node: Copying1161739 -Node: GNU Free Documentation License1199295 -Node: Index1224431 +Node: Options110877 +Ref: Options-Footnote-1126689 +Node: Other Arguments126714 +Node: Naming Standard Input129376 +Node: Environment Variables130470 +Node: AWKPATH Variable131028 +Ref: AWKPATH Variable-Footnote-1133806 +Ref: AWKPATH Variable-Footnote-2133851 +Node: AWKLIBPATH Variable134111 +Node: Other Environment Variables134870 +Node: Exit Status138525 +Node: Include Files139200 +Node: Loading Shared Libraries142778 +Node: Obsolete144161 +Node: Undocumented144858 +Node: Regexp145100 +Node: Regexp Usage146489 +Node: Escape Sequences148522 +Node: Regexp Operators154189 +Ref: Regexp Operators-Footnote-1161669 +Ref: Regexp Operators-Footnote-2161816 +Node: Bracket Expressions161914 +Ref: table-char-classes163804 +Node: GNU Regexp Operators166327 +Node: Case-sensitivity170050 +Ref: Case-sensitivity-Footnote-1172942 +Ref: Case-sensitivity-Footnote-2173177 +Node: Leftmost Longest173285 +Node: Computed Regexps174486 +Node: Reading Files177835 +Node: Records179837 +Node: awk split records180572 +Node: gawk split records185430 +Ref: gawk split records-Footnote-1189951 +Node: Fields189988 +Ref: Fields-Footnote-1192952 +Node: Nonconstant Fields193038 +Ref: Nonconstant Fields-Footnote-1195268 +Node: Changing Fields195470 +Node: Field Separators201424 +Node: Default Field Splitting204126 +Node: Regexp Field Splitting205243 +Node: Single Character Fields208584 +Node: Command Line Field Separator209643 +Node: Full Line Fields212985 +Ref: Full Line Fields-Footnote-1213493 +Node: Field Splitting Summary213539 +Ref: Field Splitting Summary-Footnote-1216638 +Node: Constant Size216739 +Node: Splitting By Content221346 +Ref: Splitting By Content-Footnote-1225096 +Node: Multiple Line225136 +Ref: Multiple Line-Footnote-1230992 +Node: Getline231171 +Node: Plain Getline233387 +Node: Getline/Variable235482 +Node: Getline/File236629 +Node: Getline/Variable/File238013 +Ref: Getline/Variable/File-Footnote-1239612 +Node: Getline/Pipe239699 +Node: Getline/Variable/Pipe242398 +Node: Getline/Coprocess243505 +Node: Getline/Variable/Coprocess244757 +Node: Getline Notes245494 +Node: Getline Summary248298 +Ref: table-getline-variants248706 +Node: Read Timeout249618 +Ref: Read Timeout-Footnote-1253445 +Node: Command line directories253503 +Node: Printing254385 +Node: Print256016 +Node: Print Examples257357 +Node: Output Separators260136 +Node: OFMT262152 +Node: Printf263510 +Node: Basic Printf264416 +Node: Control Letters265955 +Node: Format Modifiers269809 +Node: Printf Examples275836 +Node: Redirection278543 +Node: Special Files285515 +Node: Special FD286048 +Ref: Special FD-Footnote-1289672 +Node: Special Network289746 +Node: Special Caveats290596 +Node: Close Files And Pipes291392 +Ref: Close Files And Pipes-Footnote-1298530 +Ref: Close Files And Pipes-Footnote-2298678 +Node: Expressions298828 +Node: Values299960 +Node: Constants300636 +Node: Scalar Constants301316 +Ref: Scalar Constants-Footnote-1302175 +Node: Nondecimal-numbers302425 +Node: Regexp Constants305425 +Node: Using Constant Regexps305900 +Node: Variables308970 +Node: Using Variables309625 +Node: Assignment Options311349 +Node: Conversion313224 +Ref: table-locale-affects318660 +Ref: Conversion-Footnote-1319284 +Node: All Operators319393 +Node: Arithmetic Ops320023 +Node: Concatenation322528 +Ref: Concatenation-Footnote-1325324 +Node: Assignment Ops325444 +Ref: table-assign-ops330427 +Node: Increment Ops331744 +Node: Truth Values and Conditions335182 +Node: Truth Values336265 +Node: Typing and Comparison337314 +Node: Variable Typing338107 +Ref: Variable Typing-Footnote-1342007 +Node: Comparison Operators342129 +Ref: table-relational-ops342539 +Node: POSIX String Comparison346087 +Ref: POSIX String Comparison-Footnote-1347171 +Node: Boolean Ops347309 +Ref: Boolean Ops-Footnote-1351379 +Node: Conditional Exp351470 +Node: Function Calls353197 +Node: Precedence356955 +Node: Locales360624 +Node: Patterns and Actions362227 +Node: Pattern Overview363281 +Node: Regexp Patterns364958 +Node: Expression Patterns365501 +Node: Ranges369282 +Node: BEGIN/END372388 +Node: Using BEGIN/END373150 +Ref: Using BEGIN/END-Footnote-1375886 +Node: I/O And BEGIN/END375992 +Node: BEGINFILE/ENDFILE378277 +Node: Empty381213 +Node: Using Shell Variables381530 +Node: Action Overview383813 +Node: Statements386164 +Node: If Statement388018 +Node: While Statement389521 +Node: Do Statement391565 +Node: For Statement392721 +Node: Switch Statement395873 +Node: Break Statement397976 +Node: Continue Statement400031 +Node: Next Statement401824 +Node: Nextfile Statement404214 +Node: Exit Statement406869 +Node: Built-in Variables409273 +Node: User-modified410369 +Ref: User-modified-Footnote-1418054 +Node: Auto-set418116 +Ref: Auto-set-Footnote-1430681 +Ref: Auto-set-Footnote-2430886 +Node: ARGC and ARGV430942 +Node: Arrays434796 +Node: Array Basics436294 +Node: Array Intro437120 +Ref: figure-array-elements439093 +Node: Reference to Elements441500 +Node: Assigning Elements443773 +Node: Array Example444264 +Node: Scanning an Array445996 +Node: Controlling Scanning449011 +Ref: Controlling Scanning-Footnote-1454184 +Node: Delete454500 +Ref: Delete-Footnote-1457265 +Node: Numeric Array Subscripts457322 +Node: Uninitialized Subscripts459505 +Node: Multidimensional461130 +Node: Multiscanning464223 +Node: Arrays of Arrays465812 +Node: Functions470452 +Node: Built-in471271 +Node: Calling Built-in472349 +Node: Numeric Functions474337 +Ref: Numeric Functions-Footnote-1478171 +Ref: Numeric Functions-Footnote-2478528 +Ref: Numeric Functions-Footnote-3478576 +Node: String Functions478845 +Ref: String Functions-Footnote-1501856 +Ref: String Functions-Footnote-2501985 +Ref: String Functions-Footnote-3502233 +Node: Gory Details502320 +Ref: table-sub-escapes503989 +Ref: table-sub-posix-92505343 +Ref: table-sub-proposed506694 +Ref: table-posix-sub508048 +Ref: table-gensub-escapes509593 +Ref: Gory Details-Footnote-1510769 +Ref: Gory Details-Footnote-2510820 +Node: I/O Functions510971 +Ref: I/O Functions-Footnote-1518094 +Node: Time Functions518241 +Ref: Time Functions-Footnote-1528705 +Ref: Time Functions-Footnote-2528773 +Ref: Time Functions-Footnote-3528931 +Ref: Time Functions-Footnote-4529042 +Ref: Time Functions-Footnote-5529154 +Ref: Time Functions-Footnote-6529381 +Node: Bitwise Functions529647 +Ref: table-bitwise-ops530209 +Ref: Bitwise Functions-Footnote-1534454 +Node: Type Functions534638 +Node: I18N Functions535780 +Node: User-defined537425 +Node: Definition Syntax538229 +Ref: Definition Syntax-Footnote-1543154 +Node: Function Example543223 +Ref: Function Example-Footnote-1545867 +Node: Function Caveats545889 +Node: Calling A Function546407 +Node: Variable Scope547362 +Node: Pass By Value/Reference550350 +Node: Return Statement553858 +Node: Dynamic Typing556842 +Node: Indirect Calls557771 +Node: Library Functions567458 +Ref: Library Functions-Footnote-1570971 +Ref: Library Functions-Footnote-2571114 +Node: Library Names571285 +Ref: Library Names-Footnote-1574758 +Ref: Library Names-Footnote-2574978 +Node: General Functions575064 +Node: Strtonum Function576092 +Node: Assert Function579022 +Node: Round Function582348 +Node: Cliff Random Function583889 +Node: Ordinal Functions584905 +Ref: Ordinal Functions-Footnote-1587982 +Ref: Ordinal Functions-Footnote-2588234 +Node: Join Function588445 +Ref: Join Function-Footnote-1590216 +Node: Getlocaltime Function590416 +Node: Readfile Function594152 +Node: Data File Management595991 +Node: Filetrans Function596623 +Node: Rewind Function600692 +Node: File Checking602079 +Ref: File Checking-Footnote-1603211 +Node: Empty Files603412 +Node: Ignoring Assigns605642 +Node: Getopt Function607196 +Ref: Getopt Function-Footnote-1618499 +Node: Passwd Functions618702 +Ref: Passwd Functions-Footnote-1627681 +Node: Group Functions627769 +Ref: Group Functions-Footnote-1635711 +Node: Walking Arrays635924 +Node: Sample Programs638060 +Node: Running Examples638734 +Node: Clones639462 +Node: Cut Program640686 +Node: Egrep Program650539 +Ref: Egrep Program-Footnote-1658510 +Node: Id Program658620 +Node: Split Program662284 +Ref: Split Program-Footnote-1665822 +Node: Tee Program665950 +Node: Uniq Program668757 +Node: Wc Program676187 +Ref: Wc Program-Footnote-1680455 +Ref: Wc Program-Footnote-2680655 +Node: Miscellaneous Programs680747 +Node: Dupword Program681935 +Node: Alarm Program683966 +Node: Translate Program688773 +Ref: Translate Program-Footnote-1693164 +Ref: Translate Program-Footnote-2693434 +Node: Labels Program693568 +Ref: Labels Program-Footnote-1696939 +Node: Word Sorting697023 +Node: History Sorting701066 +Node: Extract Program702902 +Ref: Extract Program-Footnote-1710432 +Node: Simple Sed710561 +Node: Igawk Program713623 +Ref: Igawk Program-Footnote-1728798 +Ref: Igawk Program-Footnote-2728999 +Node: Anagram Program729137 +Node: Signature Program732205 +Node: Advanced Features733452 +Node: Nondecimal Data735338 +Node: Array Sorting736921 +Node: Controlling Array Traversal737618 +Node: Array Sorting Functions745902 +Ref: Array Sorting Functions-Footnote-1749771 +Node: Two-way I/O749965 +Ref: Two-way I/O-Footnote-1755397 +Node: TCP/IP Networking755479 +Node: Profiling758323 +Node: Internationalization765826 +Node: I18N and L10N767251 +Node: Explaining gettext767937 +Ref: Explaining gettext-Footnote-1773005 +Ref: Explaining gettext-Footnote-2773189 +Node: Programmer i18n773354 +Node: Translator i18n777581 +Node: String Extraction778375 +Ref: String Extraction-Footnote-1779336 +Node: Printf Ordering779422 +Ref: Printf Ordering-Footnote-1782204 +Node: I18N Portability782268 +Ref: I18N Portability-Footnote-1784717 +Node: I18N Example784780 +Ref: I18N Example-Footnote-1787418 +Node: Gawk I18N787490 +Node: Debugger788111 +Node: Debugging789082 +Node: Debugging Concepts789515 +Node: Debugging Terms791371 +Node: Awk Debugging793968 +Node: Sample Debugging Session794860 +Node: Debugger Invocation795380 +Node: Finding The Bug796713 +Node: List of Debugger Commands803200 +Node: Breakpoint Control804534 +Node: Debugger Execution Control808198 +Node: Viewing And Changing Data811558 +Node: Execution Stack814914 +Node: Debugger Info816381 +Node: Miscellaneous Debugger Commands820375 +Node: Readline Support825559 +Node: Limitations826390 +Node: Arbitrary Precision Arithmetic828642 +Ref: Arbitrary Precision Arithmetic-Footnote-1830291 +Node: General Arithmetic830439 +Node: Floating Point Issues832159 +Node: String Conversion Precision833040 +Ref: String Conversion Precision-Footnote-1834745 +Node: Unexpected Results834854 +Node: POSIX Floating Point Problems837007 +Ref: POSIX Floating Point Problems-Footnote-1840832 +Node: Integer Programming840870 +Node: Floating-point Programming842609 +Ref: Floating-point Programming-Footnote-1848940 +Ref: Floating-point Programming-Footnote-2849210 +Node: Floating-point Representation849474 +Node: Floating-point Context850639 +Ref: table-ieee-formats851478 +Node: Rounding Mode852862 +Ref: table-rounding-modes853341 +Ref: Rounding Mode-Footnote-1856356 +Node: Gawk and MPFR856535 +Node: Arbitrary Precision Floats857944 +Ref: Arbitrary Precision Floats-Footnote-1860387 +Node: Setting Precision860703 +Ref: table-predefined-precision-strings861389 +Node: Setting Rounding Mode863534 +Ref: table-gawk-rounding-modes863938 +Node: Floating-point Constants865125 +Node: Changing Precision866554 +Ref: Changing Precision-Footnote-1867951 +Node: Exact Arithmetic868125 +Node: Arbitrary Precision Integers871263 +Ref: Arbitrary Precision Integers-Footnote-1874278 +Node: Dynamic Extensions874425 +Node: Extension Intro875883 +Node: Plugin License877148 +Node: Extension Mechanism Outline877833 +Ref: load-extension878250 +Ref: load-new-function879728 +Ref: call-new-function880723 +Node: Extension API Description882738 +Node: Extension API Functions Introduction884025 +Node: General Data Types888952 +Ref: General Data Types-Footnote-1894647 +Node: Requesting Values894946 +Ref: table-value-types-returned895683 +Node: Memory Allocation Functions896637 +Ref: Memory Allocation Functions-Footnote-1899383 +Node: Constructor Functions899479 +Node: Registration Functions901237 +Node: Extension Functions901922 +Node: Exit Callback Functions904224 +Node: Extension Version String905473 +Node: Input Parsers906123 +Node: Output Wrappers915880 +Node: Two-way processors920390 +Node: Printing Messages922598 +Ref: Printing Messages-Footnote-1923675 +Node: Updating `ERRNO'923827 +Node: Accessing Parameters924566 +Node: Symbol Table Access925796 +Node: Symbol table by name926310 +Node: Symbol table by cookie928286 +Ref: Symbol table by cookie-Footnote-1932418 +Node: Cached values932481 +Ref: Cached values-Footnote-1935971 +Node: Array Manipulation936062 +Ref: Array Manipulation-Footnote-1937160 +Node: Array Data Types937199 +Ref: Array Data Types-Footnote-1939902 +Node: Array Functions939994 +Node: Flattening Arrays943830 +Node: Creating Arrays950682 +Node: Extension API Variables955407 +Node: Extension Versioning956043 +Node: Extension API Informational Variables957944 +Node: Extension API Boilerplate959030 +Node: Finding Extensions962834 +Node: Extension Example963394 +Node: Internal File Description964124 +Node: Internal File Ops968215 +Ref: Internal File Ops-Footnote-1979724 +Node: Using Internal File Ops979864 +Ref: Using Internal File Ops-Footnote-1982211 +Node: Extension Samples982477 +Node: Extension Sample File Functions984001 +Node: Extension Sample Fnmatch992488 +Node: Extension Sample Fork994257 +Node: Extension Sample Inplace995470 +Node: Extension Sample Ord997248 +Node: Extension Sample Readdir998084 +Node: Extension Sample Revout999616 +Node: Extension Sample Rev2way1000209 +Node: Extension Sample Read write array1000899 +Node: Extension Sample Readfile1002782 +Node: Extension Sample API Tests1003882 +Node: Extension Sample Time1004407 +Node: gawkextlib1005771 +Node: Language History1008552 +Node: V7/SVR3.11010145 +Node: SVR41012465 +Node: POSIX1013907 +Node: BTL1015293 +Node: POSIX/GNU1016027 +Node: Feature History1021626 +Node: Common Extensions1034602 +Node: Ranges and Locales1035914 +Ref: Ranges and Locales-Footnote-11040531 +Ref: Ranges and Locales-Footnote-21040558 +Ref: Ranges and Locales-Footnote-31040792 +Node: Contributors1041013 +Node: Installation1046394 +Node: Gawk Distribution1047288 +Node: Getting1047772 +Node: Extracting1048598 +Node: Distribution contents1050290 +Node: Unix Installation1056011 +Node: Quick Installation1056628 +Node: Additional Configuration Options1059074 +Node: Configuration Philosophy1060810 +Node: Non-Unix Installation1063164 +Node: PC Installation1063622 +Node: PC Binary Installation1064933 +Node: PC Compiling1066781 +Node: PC Testing1069741 +Node: PC Using1070917 +Node: Cygwin1075085 +Node: MSYS1075894 +Node: VMS Installation1076408 +Node: VMS Compilation1077204 +Ref: VMS Compilation-Footnote-11078456 +Node: VMS Dynamic Extensions1078514 +Node: VMS Installation Details1079887 +Node: VMS Running1082138 +Node: VMS GNV1084972 +Node: VMS Old Gawk1085695 +Node: Bugs1086165 +Node: Other Versions1090083 +Node: Notes1096167 +Node: Compatibility Mode1096967 +Node: Additions1097750 +Node: Accessing The Source1098677 +Node: Adding Code1100117 +Node: New Ports1106162 +Node: Derived Files1110297 +Ref: Derived Files-Footnote-11115618 +Ref: Derived Files-Footnote-21115652 +Ref: Derived Files-Footnote-31116252 +Node: Future Extensions1116350 +Node: Implementation Limitations1116933 +Node: Extension Design1118181 +Node: Old Extension Problems1119335 +Ref: Old Extension Problems-Footnote-11120843 +Node: Extension New Mechanism Goals1120900 +Ref: Extension New Mechanism Goals-Footnote-11124265 +Node: Extension Other Design Decisions1124451 +Node: Extension Future Growth1126557 +Node: Old Extension Mechanism1127393 +Node: Basic Concepts1129133 +Node: Basic High Level1129814 +Ref: figure-general-flow1130086 +Ref: figure-process-flow1130685 +Ref: Basic High Level-Footnote-11133914 +Node: Basic Data Typing1134099 +Node: Glossary1137454 +Node: Copying1162685 +Node: GNU Free Documentation License1200241 +Node: Index1225377  End Tag Table -- cgit v1.2.3 From 353b9af72c79e25ba2d45c62d543536aa82c02cf Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 16 May 2014 12:07:33 +0300 Subject: Edits through chapter 14. --- doc/gawk.info | 606 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 303 insertions(+), 303 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index a9fcc117..5cf6129d 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -18171,8 +18171,8 @@ your data as numeric: The `print' statement treats its expressions as strings. Although the fields can act as numbers when necessary, they are still strings, so -`print' does not try to treat them numerically. You may need to add -zero to a field to force it to be treated as a number. For example: +`print' does not try to treat them numerically. You need to add zero +to a field to force it to be treated as a number. For example: $ echo 0123 123 0x123 | gawk --non-decimal-data ' > { print $1, $2, $3 @@ -18187,7 +18187,7 @@ request it. CAUTION: _Use of this option is not recommended._ It can break old programs very badly. Instead, use the `strtonum()' function to - convert your data (*note Nondecimal-numbers::). This makes your + convert your data (*note String Functions::). This makes your programs easier to write and easier to read, and leads to less surprising results. @@ -18226,7 +18226,7 @@ you do this. *note Controlling Scanning::, describes how you can assign special, pre-defined values to `PROCINFO["sorted_in"]' in order to control the -order in which `gawk' will traverse an array during a `for' loop. +order in which `gawk' traverses an array during a `for' loop. In addition, the value of `PROCINFO["sorted_in"]' can be a function name. This lets you traverse an array based on any custom criterion. @@ -18499,9 +18499,9 @@ become the values of the result array: So far, so good. Now it starts to get interesting. Both `asort()' and `asorti()' accept a third string argument to control comparison of -array elements. In *note String Functions::, we ignored this third -argument; however, the time has now come to describe how this argument -affects these two functions. +array elements. When we introduced `asort()' and `asorti()' in *note +String Functions::, we ignored this third argument; however, now is the +time to describe how this argument affects these two functions. Basically, the third argument specifies how the array is to be sorted. There are two possibilities. As with `PROCINFO["sorted_in"]', @@ -18649,7 +18649,8 @@ the `gawk' program. Once all of the data has been read, `gawk' terminates the coprocess and exits. As a side note, the assignment `LC_ALL=C' in the `sort' command -ensures traditional Unix (ASCII) sorting from `sort'. +ensures traditional Unix (ASCII) sorting from `sort'. This is not +strictly necessary here, but it's good to know how to do this. You may also use pseudo-ttys (ptys) for two-way communication instead of pipes, if your system supports them. This is done on a @@ -18661,10 +18662,10 @@ per-command basis, by setting a special element in the `PROCINFO' array print ... |& command # start two-way pipe ... -Using ptys avoids the buffer deadlock issues described earlier, at some -loss in performance. If your system does not have ptys, or if all the -system's ptys are in use, `gawk' automatically falls back to using -regular pipes. +Using ptys usually avoids the buffer deadlock issues described earlier, +at some loss in performance. If your system does not have ptys, or if +all the system's ptys are in use, `gawk' automatically falls back to +using regular pipes. ---------- Footnotes ---------- @@ -18945,7 +18946,7 @@ As usual, the profiled version of the program is written to `awkprof.out', or to a different file if one specified with the `--profile' option. - Along with the regular profile, as shown earlier, the profile + Along with the regular profile, as shown earlier, the profile file includes a trace of any active functions: # Function Call Stack: @@ -19029,6 +19030,7 @@ File: gawk.info, Node: Explaining gettext, Next: Programmer i18n, Prev: I18N 13.2 GNU `gettext' ================== +`gawk' uses GNU `gettext' to provide its internationalization features. The facilities in GNU `gettext' focus on messages; strings printed by a program, either directly or via formatting with `printf' or `sprintf()'.(1) @@ -19175,7 +19177,7 @@ internationalization: for translation at runtime. String constants without a leading underscore are not translated. -``dcgettext(STRING' [`,' DOMAIN [`,' CATEGORY ]]`)'' +``dcgettext(STRING' [`,' DOMAIN [`,' CATEGORY]]`)'' Return the translation of STRING in text domain DOMAIN for locale category CATEGORY. The default value for DOMAIN is the current value of `TEXTDOMAIN'. The default value for CATEGORY is @@ -19192,7 +19194,7 @@ internationalization: be simple and to allow for reasonable `awk'-style default arguments. -``dcngettext(STRING1, STRING2, NUMBER' [`,' DOMAIN [`,' CATEGORY ]]`)'' +``dcngettext(STRING1, STRING2, NUMBER' [`,' DOMAIN [`,' CATEGORY]]`)'' Return the plural form used for NUMBER of the translation of STRING1 and STRING2 in text domain DOMAIN for locale category CATEGORY. STRING1 is the English singular variant of a message, @@ -19508,19 +19510,20 @@ Following are the translations: msgstr "Like, the scoop is" The next step is to make the directory to hold the binary message -object file and then to create the `guide.gmo' file. The directory +object file and then to create the `guide.mo' file. We pretend that +our file is to be used in the `en_US.UTF-8' locale. The directory layout shown here is standard for GNU `gettext' on GNU/Linux systems. Other versions of `gettext' may use a different layout: - $ mkdir en_US en_US/LC_MESSAGES + $ mkdir en_US.UTF-8 en_US.UTF-8/LC_MESSAGES The `msgfmt' utility does the conversion from human-readable `.po' -file to machine-readable `.gmo' file. By default, `msgfmt' creates a +file to machine-readable `.mo' file. By default, `msgfmt' creates a file named `messages'. This file must be renamed and placed in the proper directory so that `gawk' can find it: $ msgfmt guide-mellow.po - $ mv messages en_US/LC_MESSAGES/guide.gmo + $ mv messages en_US.UTF-8/LC_MESSAGES/guide.mo Finally, we run the program to test it: @@ -19584,8 +19587,8 @@ program is easy.  File: gawk.info, Node: Debugging, Next: Sample Debugging Session, Up: Debugger -14.1 Introduction to `gawk' Debugger -==================================== +14.1 Introduction to The `gawk' Debugger +======================================== This minor node introduces debugging in general and begins the discussion of debugging in `gawk'. @@ -19871,11 +19874,7 @@ typing `n' (for "next"): decides whether to give the lines the special "field skipping" treatment indicated by the `-f' command-line option. (Notice that we skipped from where we were before at line 64 to here, since the condition in -line 64 - - if (fcount == 0 && charcount == 0) - -was false.) +line 64 `if (fcount == 0 && charcount == 0)' was false.) Continuing to step, we now get to the splitting of the current and last records: @@ -19981,7 +19980,7 @@ following descriptions, commands which may be abbreviated show the abbreviation on a second description line. A debugger command name may also be truncated if that partial name is unambiguous. The debugger has the built-in capability to automatically repeat the previous command -when just hitting . This works for the commands `list', `next', +just by hitting . This works for the commands `list', `next', `nexti', `step', `stepi' and `continue' executed without any argument. * Menu: @@ -20241,7 +20240,7 @@ AWK STATEMENTS `set' VAR`='VALUE Assign a constant (number or string) value to an `awk' variable or field. String values must be enclosed between double quotes - (`"..."'). + (`"'...`"'). You can also set special `awk' variables, such as `FS', `NF', `NR', etc. @@ -20295,11 +20294,12 @@ are: `frame' [N] `f' [N] - Select and print (frame number, function and argument names, - source file, and the source line) stack frame N. Frame 0 is the - currently executing, or "innermost", frame (function call), frame - 1 is the frame that called the innermost one. The highest numbered - frame is the one for the main program. + Select and print stack frame N. Frame 0 is the currently + executing, or "innermost", frame (function call), frame 1 is the + frame that called the innermost one. The highest numbered frame is + the one for the main program. The printed information consists of + the frame number, function and argument names, source file, and + the source line. `up' [COUNT] Move COUNT (default 1) frames up the stack toward the outermost @@ -20538,9 +20538,10 @@ File: gawk.info, Node: Readline Support, Next: Limitations, Prev: List of Deb 14.4 Readline Support ===================== -If `gawk' is compiled with the `readline' library, you can take -advantage of that library's command completion and history expansion -features. The following types of completion are available: +If `gawk' is compiled with the `readline' library +(http://cnswww.cns.cwru.edu/php/chet/readline/readline.html), you can +take advantage of that library's command completion and history +expansion features. The following types of completion are available: Command completion Command names. @@ -20579,15 +20580,14 @@ some limitations. A few which are worth being aware of are: you will realize that much of the internal manipulation of data in `gawk', as in many interpreters, is done on a stack. `Op_push', `Op_pop', etc., are the "bread and butter" of most `gawk' code. - Unfortunately, as of now, the `gawk' debugger does not allow you - to examine the stack's contents. - That is, the intermediate results of expression evaluation are on - the stack, but cannot be printed. Rather, only variables which - are defined in the program can be printed. Of course, a - workaround for this is to use more explicit variables at the - debugging stage and then change back to obscure, perhaps more - optimal code later. + Unfortunately, as of now, the `gawk' debugger does not allow you + to examine the stack's contents. That is, the intermediate + results of expression evaluation are on the stack, but cannot be + printed. Rather, only variables which are defined in the program + can be printed. Of course, a workaround for this is to use more + explicit variables at the debugging stage and then change back to + obscure, perhaps more optimal code later. * There is no way to look "inside" the process of compiling regular expressions to see if you got it right. As an `awk' programmer, @@ -30289,14 +30289,14 @@ Index * -v option: Options. (line 32) * -W option: Options. (line 46) * . (period), regexp operator: Regexp Operators. (line 44) -* .gmo files: Explaining gettext. (line 41) -* .gmo files, converting from .po: I18N Example. (line 62) +* .gmo files: Explaining gettext. (line 42) * .gmo files, specifying directory of <1>: Programmer i18n. (line 47) -* .gmo files, specifying directory of: Explaining gettext. (line 53) +* .gmo files, specifying directory of: Explaining gettext. (line 54) +* .mo files, converting from .po: I18N Example. (line 63) * .po files <1>: Translator i18n. (line 6) -* .po files: Explaining gettext. (line 36) -* .po files, converting to .gmo: I18N Example. (line 62) -* .pot files: Explaining gettext. (line 30) +* .po files: Explaining gettext. (line 37) +* .po files, converting to .mo: I18N Example. (line 63) +* .pot files: Explaining gettext. (line 31) * / (forward slash) to enclose regular expressions: Regexp. (line 10) * / (forward slash), / operator: Precedence. (line 55) * / (forward slash), /= operator <1>: Precedence. (line 95) @@ -30401,7 +30401,7 @@ Index * ^ (caret), regexp operator <1>: GNU Regexp Operators. (line 59) * ^ (caret), regexp operator: Regexp Operators. (line 22) -* _ (underscore), C macro: Explaining gettext. (line 70) +* _ (underscore), C macro: Explaining gettext. (line 71) * _ (underscore), in names of private variables: Library Names. (line 29) * _ (underscore), translatable string: Programmer i18n. (line 69) @@ -30701,7 +30701,7 @@ Index * binary input/output: User-modified. (line 15) * bindtextdomain <1>: Programmer i18n. (line 47) * bindtextdomain: I18N Functions. (line 12) -* bindtextdomain() function (C library): Explaining gettext. (line 49) +* bindtextdomain() function (C library): Explaining gettext. (line 50) * bindtextdomain() function (gawk), portability and: I18N Portability. (line 33) * BINMODE variable <1>: PC Using. (line 33) @@ -30973,7 +30973,7 @@ Index * csh utility, POSIXLY_CORRECT environment variable: Options. (line 355) * csh utility, |& operator, comparison with: Two-way I/O. (line 44) * ctime() user-defined function: Function Example. (line 73) -* currency symbols, localization: Explaining gettext. (line 103) +* currency symbols, localization: Explaining gettext. (line 104) * current system time: Time Functions. (line 66) * custom.h file: Configuration Philosophy. (line 30) @@ -31035,7 +31035,7 @@ Index * date utility, POSIX: Time Functions. (line 254) * dates, converting to timestamps: Time Functions. (line 76) * dates, information related to, localization: Explaining gettext. - (line 115) + (line 116) * Davies, Stephen <1>: Contributors. (line 74) * Davies, Stephen: Acknowledgments. (line 60) * dcgettext <1>: Programmer i18n. (line 19) @@ -31138,7 +31138,7 @@ Index (line 83) * debugger commands, unwatch: Viewing And Changing Data. (line 84) -* debugger commands, up: Execution Stack. (line 33) +* debugger commands, up: Execution Stack. (line 34) * debugger commands, w (watch): Viewing And Changing Data. (line 67) * debugger commands, watch: Viewing And Changing Data. @@ -31477,14 +31477,14 @@ Index * FILENAME variable: Reading Files. (line 6) * FILENAME variable, getline, setting with: Getline Notes. (line 19) * filenames, assignments as: Ignoring Assigns. (line 6) -* files, .gmo: Explaining gettext. (line 41) -* files, .gmo, converting from .po: I18N Example. (line 62) +* files, .gmo: Explaining gettext. (line 42) * files, .gmo, specifying directory of <1>: Programmer i18n. (line 47) -* files, .gmo, specifying directory of: Explaining gettext. (line 53) +* files, .gmo, specifying directory of: Explaining gettext. (line 54) +* files, .mo, converting from .po: I18N Example. (line 63) * files, .po <1>: Translator i18n. (line 6) -* files, .po: Explaining gettext. (line 36) -* files, .po, converting to .gmo: I18N Example. (line 62) -* files, .pot: Explaining gettext. (line 30) +* files, .po: Explaining gettext. (line 37) +* files, .po, converting to .mo: I18N Example. (line 63) +* files, .pot: Explaining gettext. (line 31) * files, /dev/... special files: Special FD. (line 46) * files, /inet/... (gawk): TCP/IP Networking. (line 6) * files, /inet4/... (gawk): TCP/IP Networking. (line 6) @@ -31501,23 +31501,23 @@ Index * files, managing: Data File Management. (line 6) * files, managing, data file boundaries: Filetrans Function. (line 6) -* files, message object: Explaining gettext. (line 41) +* files, message object: Explaining gettext. (line 42) * files, message object, converting from portable object files: I18N Example. - (line 62) + (line 63) * files, message object, specifying directory of <1>: Programmer i18n. (line 47) * files, message object, specifying directory of: Explaining gettext. - (line 53) + (line 54) * files, multiple passes over: Other Arguments. (line 49) * files, multiple, duplicating output into: Tee Program. (line 6) * files, output, See output files: Close Files And Pipes. (line 6) * files, password: Passwd Functions. (line 16) * files, portable object <1>: Translator i18n. (line 6) -* files, portable object: Explaining gettext. (line 36) -* files, portable object template: Explaining gettext. (line 30) +* files, portable object: Explaining gettext. (line 37) +* files, portable object template: Explaining gettext. (line 31) * files, portable object, converting to message object files: I18N Example. - (line 62) + (line 63) * files, portable object, generating: Options. (line 147) * files, processing, ARGIND variable and: Auto-set. (line 51) * files, reading: Rewind Function. (line 6) @@ -31712,7 +31712,7 @@ Index * gawk, newlines in: Statements/Lines. (line 12) * gawk, octal numbers and: Nondecimal-numbers. (line 42) * gawk, OS/2 version of: PC Using. (line 16) -* gawk, PROCINFO array in <1>: Two-way I/O. (line 116) +* gawk, PROCINFO array in <1>: Two-way I/O. (line 117) * gawk, PROCINFO array in <2>: Time Functions. (line 47) * gawk, PROCINFO array in: Auto-set. (line 128) * gawk, regexp constants and: Using Constant Regexps. @@ -31783,8 +31783,8 @@ Index * getpwuid() function (C library): Passwd Functions. (line 188) * getpwuid() user-defined function: Passwd Functions. (line 192) * gettext library: Explaining gettext. (line 6) -* gettext library, locale categories: Explaining gettext. (line 80) -* gettext() function (C library): Explaining gettext. (line 62) +* gettext library, locale categories: Explaining gettext. (line 81) +* gettext() function (C library): Explaining gettext. (line 63) * gettimeofday() extension function: Extension Sample Time. (line 13) * git utility <1>: Adding Code. (line 111) @@ -31936,7 +31936,7 @@ Index * internationalization, localization, gawk and: Internationalization. (line 13) * internationalization, localization, locale categories: Explaining gettext. - (line 80) + (line 81) * internationalization, localization, marked strings: Programmer i18n. (line 14) * internationalization, localization, portability and: I18N Portability. @@ -31985,16 +31985,16 @@ Index * labels.awk program: Labels Program. (line 51) * languages, data-driven: Basic High Level. (line 85) * Laurie, Dirk: Changing Precision. (line 6) -* LC_ALL locale category: Explaining gettext. (line 120) -* LC_COLLATE locale category: Explaining gettext. (line 93) -* LC_CTYPE locale category: Explaining gettext. (line 97) -* LC_MESSAGES locale category: Explaining gettext. (line 87) +* LC_ALL locale category: Explaining gettext. (line 121) +* LC_COLLATE locale category: Explaining gettext. (line 94) +* LC_CTYPE locale category: Explaining gettext. (line 98) +* LC_MESSAGES locale category: Explaining gettext. (line 88) * LC_MESSAGES locale category, bindtextdomain() function (gawk): Programmer i18n. (line 88) -* LC_MONETARY locale category: Explaining gettext. (line 103) -* LC_NUMERIC locale category: Explaining gettext. (line 107) -* LC_RESPONSE locale category: Explaining gettext. (line 111) -* LC_TIME locale category: Explaining gettext. (line 115) +* LC_MONETARY locale category: Explaining gettext. (line 104) +* LC_NUMERIC locale category: Explaining gettext. (line 108) +* LC_RESPONSE locale category: Explaining gettext. (line 112) +* LC_TIME locale category: Explaining gettext. (line 116) * left angle bracket (<), < operator <1>: Precedence. (line 65) * left angle bracket (<), < operator: Comparison Operators. (line 11) @@ -32063,7 +32063,7 @@ Index * list function definitions, in debugger: Debugger Info. (line 30) * loading, extensions: Options. (line 173) * local variables, in a function: Variable Scope. (line 6) -* locale categories: Explaining gettext. (line 80) +* locale categories: Explaining gettext. (line 81) * locale decimal point character: Options. (line 270) * locale, definition of: Locales. (line 6) * localization: I18N and L10N. (line 6) @@ -32114,23 +32114,23 @@ Index * mawk utility: Escape Sequences. (line 124) * maximum precision supported by MPFR library: Auto-set. (line 213) * McPhee, Patrick: Contributors. (line 100) -* message object files: Explaining gettext. (line 41) +* message object files: Explaining gettext. (line 42) * message object files, converting from portable object files: I18N Example. - (line 62) + (line 63) * message object files, specifying directory of <1>: Programmer i18n. (line 47) * message object files, specifying directory of: Explaining gettext. - (line 53) + (line 54) * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) * metacharacters, escape sequences for: Escape Sequences. (line 130) * minimum precision supported by MPFR library: Auto-set. (line 216) * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) -* monetary information, localization: Explaining gettext. (line 103) +* monetary information, localization: Explaining gettext. (line 104) * Moore, Duncan: Getline Notes. (line 40) * MPFR: Gawk and MPFR. (line 6) -* msgfmt utility: I18N Example. (line 62) +* msgfmt utility: I18N Example. (line 63) * multiple precision: Arbitrary Precision Arithmetic. (line 6) * multiple-line records: Multiple Line. (line 6) @@ -32362,7 +32362,7 @@ Index * portability, example programs: Library Functions. (line 42) * portability, functions, defining: Definition Syntax. (line 99) * portability, gawk: New Ports. (line 6) -* portability, gettext library and: Explaining gettext. (line 10) +* portability, gettext library and: Explaining gettext. (line 11) * portability, internationalization and: I18N Portability. (line 6) * portability, length() function: String Functions. (line 176) * portability, new awk vs. old awk: Conversion. (line 55) @@ -32374,11 +32374,11 @@ Index * portability, POSIXLY_CORRECT environment variable: Options. (line 360) * portability, substr() function: String Functions. (line 510) * portable object files <1>: Translator i18n. (line 6) -* portable object files: Explaining gettext. (line 36) +* portable object files: Explaining gettext. (line 37) * portable object files, converting to message object files: I18N Example. - (line 62) + (line 63) * portable object files, generating: Options. (line 147) -* portable object template files: Explaining gettext. (line 30) +* portable object template files: Explaining gettext. (line 31) * porting gawk: New Ports. (line 6) * positional specifiers, printf statement <1>: Printf Ordering. (line 6) @@ -32476,7 +32476,7 @@ Index * PROCINFO array <1>: Passwd Functions. (line 6) * PROCINFO array <2>: Time Functions. (line 47) * PROCINFO array: Auto-set. (line 128) -* PROCINFO array, and communications via ptys: Two-way I/O. (line 116) +* PROCINFO array, and communications via ptys: Two-way I/O. (line 117) * PROCINFO array, and group membership: Group Functions. (line 6) * PROCINFO array, and user and group ID numbers: Id Program. (line 15) * PROCINFO array, testing the field splitting: Passwd Functions. @@ -32844,7 +32844,7 @@ Index * sort utility: Word Sorting. (line 50) * sort utility, coprocesses and: Two-way I/O. (line 83) * sorting characters in different languages: Explaining gettext. - (line 93) + (line 94) * source code, awka: Other Versions. (line 64) * source code, Brian Kernighan's awk: Other Versions. (line 13) * source code, Busybox Awk: Other Versions. (line 88) @@ -32982,7 +32982,7 @@ Index * TEXTDOMAIN variable: User-modified. (line 152) * TEXTDOMAIN variable, BEGIN pattern and: Programmer i18n. (line 60) * TEXTDOMAIN variable, portability and: I18N Portability. (line 20) -* textdomain() function (C library): Explaining gettext. (line 27) +* textdomain() function (C library): Explaining gettext. (line 28) * tilde (~), ~ operator <1>: Expression Patterns. (line 24) * tilde (~), ~ operator <2>: Precedence. (line 80) * tilde (~), ~ operator <3>: Comparison Operators. @@ -32993,7 +32993,7 @@ Index * tilde (~), ~ operator: Regexp Usage. (line 19) * time functions: Time Functions. (line 6) * time, alarm clock example program: Alarm Program. (line 11) -* time, localization and: Explaining gettext. (line 115) +* time, localization and: Explaining gettext. (line 116) * time, managing: Getlocaltime Function. (line 6) * time, retrieving: Time Functions. (line 17) @@ -33056,7 +33056,7 @@ Index (line 18) * undefined functions: Pass By Value/Reference. (line 71) -* underscore (_), C macro: Explaining gettext. (line 70) +* underscore (_), C macro: Explaining gettext. (line 71) * underscore (_), in names of private variables: Library Names. (line 29) * underscore (_), translatable string: Programmer i18n. (line 69) @@ -33084,7 +33084,7 @@ Index (line 83) * unwatch debugger command: Viewing And Changing Data. (line 84) -* up debugger command: Execution Stack. (line 33) +* up debugger command: Execution Stack. (line 34) * user database, reading: Passwd Functions. (line 6) * user-defined functions: User-defined. (line 6) * user-defined, functions, counts, in a profile: Profiling. (line 137) @@ -33540,213 +33540,213 @@ Node: Anagram Program729137 Node: Signature Program732205 Node: Advanced Features733452 Node: Nondecimal Data735338 -Node: Array Sorting736921 -Node: Controlling Array Traversal737618 -Node: Array Sorting Functions745902 -Ref: Array Sorting Functions-Footnote-1749771 -Node: Two-way I/O749965 -Ref: Two-way I/O-Footnote-1755397 -Node: TCP/IP Networking755479 -Node: Profiling758323 -Node: Internationalization765826 -Node: I18N and L10N767251 -Node: Explaining gettext767937 -Ref: Explaining gettext-Footnote-1773005 -Ref: Explaining gettext-Footnote-2773189 -Node: Programmer i18n773354 -Node: Translator i18n777581 -Node: String Extraction778375 -Ref: String Extraction-Footnote-1779336 -Node: Printf Ordering779422 -Ref: Printf Ordering-Footnote-1782204 -Node: I18N Portability782268 -Ref: I18N Portability-Footnote-1784717 -Node: I18N Example784780 -Ref: I18N Example-Footnote-1787418 -Node: Gawk I18N787490 -Node: Debugger788111 -Node: Debugging789082 -Node: Debugging Concepts789515 -Node: Debugging Terms791371 -Node: Awk Debugging793968 -Node: Sample Debugging Session794860 -Node: Debugger Invocation795380 -Node: Finding The Bug796713 -Node: List of Debugger Commands803200 -Node: Breakpoint Control804534 -Node: Debugger Execution Control808198 -Node: Viewing And Changing Data811558 -Node: Execution Stack814914 -Node: Debugger Info816381 -Node: Miscellaneous Debugger Commands820375 -Node: Readline Support825559 -Node: Limitations826390 -Node: Arbitrary Precision Arithmetic828642 -Ref: Arbitrary Precision Arithmetic-Footnote-1830291 -Node: General Arithmetic830439 -Node: Floating Point Issues832159 -Node: String Conversion Precision833040 -Ref: String Conversion Precision-Footnote-1834745 -Node: Unexpected Results834854 -Node: POSIX Floating Point Problems837007 -Ref: POSIX Floating Point Problems-Footnote-1840832 -Node: Integer Programming840870 -Node: Floating-point Programming842609 -Ref: Floating-point Programming-Footnote-1848940 -Ref: Floating-point Programming-Footnote-2849210 -Node: Floating-point Representation849474 -Node: Floating-point Context850639 -Ref: table-ieee-formats851478 -Node: Rounding Mode852862 -Ref: table-rounding-modes853341 -Ref: Rounding Mode-Footnote-1856356 -Node: Gawk and MPFR856535 -Node: Arbitrary Precision Floats857944 -Ref: Arbitrary Precision Floats-Footnote-1860387 -Node: Setting Precision860703 -Ref: table-predefined-precision-strings861389 -Node: Setting Rounding Mode863534 -Ref: table-gawk-rounding-modes863938 -Node: Floating-point Constants865125 -Node: Changing Precision866554 -Ref: Changing Precision-Footnote-1867951 -Node: Exact Arithmetic868125 -Node: Arbitrary Precision Integers871263 -Ref: Arbitrary Precision Integers-Footnote-1874278 -Node: Dynamic Extensions874425 -Node: Extension Intro875883 -Node: Plugin License877148 -Node: Extension Mechanism Outline877833 -Ref: load-extension878250 -Ref: load-new-function879728 -Ref: call-new-function880723 -Node: Extension API Description882738 -Node: Extension API Functions Introduction884025 -Node: General Data Types888952 -Ref: General Data Types-Footnote-1894647 -Node: Requesting Values894946 -Ref: table-value-types-returned895683 -Node: Memory Allocation Functions896637 -Ref: Memory Allocation Functions-Footnote-1899383 -Node: Constructor Functions899479 -Node: Registration Functions901237 -Node: Extension Functions901922 -Node: Exit Callback Functions904224 -Node: Extension Version String905473 -Node: Input Parsers906123 -Node: Output Wrappers915880 -Node: Two-way processors920390 -Node: Printing Messages922598 -Ref: Printing Messages-Footnote-1923675 -Node: Updating `ERRNO'923827 -Node: Accessing Parameters924566 -Node: Symbol Table Access925796 -Node: Symbol table by name926310 -Node: Symbol table by cookie928286 -Ref: Symbol table by cookie-Footnote-1932418 -Node: Cached values932481 -Ref: Cached values-Footnote-1935971 -Node: Array Manipulation936062 -Ref: Array Manipulation-Footnote-1937160 -Node: Array Data Types937199 -Ref: Array Data Types-Footnote-1939902 -Node: Array Functions939994 -Node: Flattening Arrays943830 -Node: Creating Arrays950682 -Node: Extension API Variables955407 -Node: Extension Versioning956043 -Node: Extension API Informational Variables957944 -Node: Extension API Boilerplate959030 -Node: Finding Extensions962834 -Node: Extension Example963394 -Node: Internal File Description964124 -Node: Internal File Ops968215 -Ref: Internal File Ops-Footnote-1979724 -Node: Using Internal File Ops979864 -Ref: Using Internal File Ops-Footnote-1982211 -Node: Extension Samples982477 -Node: Extension Sample File Functions984001 -Node: Extension Sample Fnmatch992488 -Node: Extension Sample Fork994257 -Node: Extension Sample Inplace995470 -Node: Extension Sample Ord997248 -Node: Extension Sample Readdir998084 -Node: Extension Sample Revout999616 -Node: Extension Sample Rev2way1000209 -Node: Extension Sample Read write array1000899 -Node: Extension Sample Readfile1002782 -Node: Extension Sample API Tests1003882 -Node: Extension Sample Time1004407 -Node: gawkextlib1005771 -Node: Language History1008552 -Node: V7/SVR3.11010145 -Node: SVR41012465 -Node: POSIX1013907 -Node: BTL1015293 -Node: POSIX/GNU1016027 -Node: Feature History1021626 -Node: Common Extensions1034602 -Node: Ranges and Locales1035914 -Ref: Ranges and Locales-Footnote-11040531 -Ref: Ranges and Locales-Footnote-21040558 -Ref: Ranges and Locales-Footnote-31040792 -Node: Contributors1041013 -Node: Installation1046394 -Node: Gawk Distribution1047288 -Node: Getting1047772 -Node: Extracting1048598 -Node: Distribution contents1050290 -Node: Unix Installation1056011 -Node: Quick Installation1056628 -Node: Additional Configuration Options1059074 -Node: Configuration Philosophy1060810 -Node: Non-Unix Installation1063164 -Node: PC Installation1063622 -Node: PC Binary Installation1064933 -Node: PC Compiling1066781 -Node: PC Testing1069741 -Node: PC Using1070917 -Node: Cygwin1075085 -Node: MSYS1075894 -Node: VMS Installation1076408 -Node: VMS Compilation1077204 -Ref: VMS Compilation-Footnote-11078456 -Node: VMS Dynamic Extensions1078514 -Node: VMS Installation Details1079887 -Node: VMS Running1082138 -Node: VMS GNV1084972 -Node: VMS Old Gawk1085695 -Node: Bugs1086165 -Node: Other Versions1090083 -Node: Notes1096167 -Node: Compatibility Mode1096967 -Node: Additions1097750 -Node: Accessing The Source1098677 -Node: Adding Code1100117 -Node: New Ports1106162 -Node: Derived Files1110297 -Ref: Derived Files-Footnote-11115618 -Ref: Derived Files-Footnote-21115652 -Ref: Derived Files-Footnote-31116252 -Node: Future Extensions1116350 -Node: Implementation Limitations1116933 -Node: Extension Design1118181 -Node: Old Extension Problems1119335 -Ref: Old Extension Problems-Footnote-11120843 -Node: Extension New Mechanism Goals1120900 -Ref: Extension New Mechanism Goals-Footnote-11124265 -Node: Extension Other Design Decisions1124451 -Node: Extension Future Growth1126557 -Node: Old Extension Mechanism1127393 -Node: Basic Concepts1129133 -Node: Basic High Level1129814 -Ref: figure-general-flow1130086 -Ref: figure-process-flow1130685 -Ref: Basic High Level-Footnote-11133914 -Node: Basic Data Typing1134099 -Node: Glossary1137454 -Node: Copying1162685 -Node: GNU Free Documentation License1200241 -Node: Index1225377 +Node: Array Sorting736915 +Node: Controlling Array Traversal737612 +Node: Array Sorting Functions745892 +Ref: Array Sorting Functions-Footnote-1749799 +Node: Two-way I/O749993 +Ref: Two-way I/O-Footnote-1755509 +Node: TCP/IP Networking755591 +Node: Profiling758435 +Node: Internationalization765943 +Node: I18N and L10N767368 +Node: Explaining gettext768054 +Ref: Explaining gettext-Footnote-1773194 +Ref: Explaining gettext-Footnote-2773378 +Node: Programmer i18n773543 +Node: Translator i18n777768 +Node: String Extraction778562 +Ref: String Extraction-Footnote-1779523 +Node: Printf Ordering779609 +Ref: Printf Ordering-Footnote-1782391 +Node: I18N Portability782455 +Ref: I18N Portability-Footnote-1784904 +Node: I18N Example784967 +Ref: I18N Example-Footnote-1787689 +Node: Gawk I18N787761 +Node: Debugger788382 +Node: Debugging789353 +Node: Debugging Concepts789794 +Node: Debugging Terms791650 +Node: Awk Debugging794247 +Node: Sample Debugging Session795139 +Node: Debugger Invocation795659 +Node: Finding The Bug796992 +Node: List of Debugger Commands803474 +Node: Breakpoint Control804806 +Node: Debugger Execution Control808470 +Node: Viewing And Changing Data811830 +Node: Execution Stack815188 +Node: Debugger Info816701 +Node: Miscellaneous Debugger Commands820695 +Node: Readline Support825879 +Node: Limitations826771 +Node: Arbitrary Precision Arithmetic829019 +Ref: Arbitrary Precision Arithmetic-Footnote-1830668 +Node: General Arithmetic830816 +Node: Floating Point Issues832536 +Node: String Conversion Precision833417 +Ref: String Conversion Precision-Footnote-1835122 +Node: Unexpected Results835231 +Node: POSIX Floating Point Problems837384 +Ref: POSIX Floating Point Problems-Footnote-1841209 +Node: Integer Programming841247 +Node: Floating-point Programming842986 +Ref: Floating-point Programming-Footnote-1849317 +Ref: Floating-point Programming-Footnote-2849587 +Node: Floating-point Representation849851 +Node: Floating-point Context851016 +Ref: table-ieee-formats851855 +Node: Rounding Mode853239 +Ref: table-rounding-modes853718 +Ref: Rounding Mode-Footnote-1856733 +Node: Gawk and MPFR856912 +Node: Arbitrary Precision Floats858321 +Ref: Arbitrary Precision Floats-Footnote-1860764 +Node: Setting Precision861080 +Ref: table-predefined-precision-strings861766 +Node: Setting Rounding Mode863911 +Ref: table-gawk-rounding-modes864315 +Node: Floating-point Constants865502 +Node: Changing Precision866931 +Ref: Changing Precision-Footnote-1868328 +Node: Exact Arithmetic868502 +Node: Arbitrary Precision Integers871640 +Ref: Arbitrary Precision Integers-Footnote-1874655 +Node: Dynamic Extensions874802 +Node: Extension Intro876260 +Node: Plugin License877525 +Node: Extension Mechanism Outline878210 +Ref: load-extension878627 +Ref: load-new-function880105 +Ref: call-new-function881100 +Node: Extension API Description883115 +Node: Extension API Functions Introduction884402 +Node: General Data Types889329 +Ref: General Data Types-Footnote-1895024 +Node: Requesting Values895323 +Ref: table-value-types-returned896060 +Node: Memory Allocation Functions897014 +Ref: Memory Allocation Functions-Footnote-1899760 +Node: Constructor Functions899856 +Node: Registration Functions901614 +Node: Extension Functions902299 +Node: Exit Callback Functions904601 +Node: Extension Version String905850 +Node: Input Parsers906500 +Node: Output Wrappers916257 +Node: Two-way processors920767 +Node: Printing Messages922975 +Ref: Printing Messages-Footnote-1924052 +Node: Updating `ERRNO'924204 +Node: Accessing Parameters924943 +Node: Symbol Table Access926173 +Node: Symbol table by name926687 +Node: Symbol table by cookie928663 +Ref: Symbol table by cookie-Footnote-1932795 +Node: Cached values932858 +Ref: Cached values-Footnote-1936348 +Node: Array Manipulation936439 +Ref: Array Manipulation-Footnote-1937537 +Node: Array Data Types937576 +Ref: Array Data Types-Footnote-1940279 +Node: Array Functions940371 +Node: Flattening Arrays944207 +Node: Creating Arrays951059 +Node: Extension API Variables955784 +Node: Extension Versioning956420 +Node: Extension API Informational Variables958321 +Node: Extension API Boilerplate959407 +Node: Finding Extensions963211 +Node: Extension Example963771 +Node: Internal File Description964501 +Node: Internal File Ops968592 +Ref: Internal File Ops-Footnote-1980101 +Node: Using Internal File Ops980241 +Ref: Using Internal File Ops-Footnote-1982588 +Node: Extension Samples982854 +Node: Extension Sample File Functions984378 +Node: Extension Sample Fnmatch992865 +Node: Extension Sample Fork994634 +Node: Extension Sample Inplace995847 +Node: Extension Sample Ord997625 +Node: Extension Sample Readdir998461 +Node: Extension Sample Revout999993 +Node: Extension Sample Rev2way1000586 +Node: Extension Sample Read write array1001276 +Node: Extension Sample Readfile1003159 +Node: Extension Sample API Tests1004259 +Node: Extension Sample Time1004784 +Node: gawkextlib1006148 +Node: Language History1008929 +Node: V7/SVR3.11010522 +Node: SVR41012842 +Node: POSIX1014284 +Node: BTL1015670 +Node: POSIX/GNU1016404 +Node: Feature History1022003 +Node: Common Extensions1034979 +Node: Ranges and Locales1036291 +Ref: Ranges and Locales-Footnote-11040908 +Ref: Ranges and Locales-Footnote-21040935 +Ref: Ranges and Locales-Footnote-31041169 +Node: Contributors1041390 +Node: Installation1046771 +Node: Gawk Distribution1047665 +Node: Getting1048149 +Node: Extracting1048975 +Node: Distribution contents1050667 +Node: Unix Installation1056388 +Node: Quick Installation1057005 +Node: Additional Configuration Options1059451 +Node: Configuration Philosophy1061187 +Node: Non-Unix Installation1063541 +Node: PC Installation1063999 +Node: PC Binary Installation1065310 +Node: PC Compiling1067158 +Node: PC Testing1070118 +Node: PC Using1071294 +Node: Cygwin1075462 +Node: MSYS1076271 +Node: VMS Installation1076785 +Node: VMS Compilation1077581 +Ref: VMS Compilation-Footnote-11078833 +Node: VMS Dynamic Extensions1078891 +Node: VMS Installation Details1080264 +Node: VMS Running1082515 +Node: VMS GNV1085349 +Node: VMS Old Gawk1086072 +Node: Bugs1086542 +Node: Other Versions1090460 +Node: Notes1096544 +Node: Compatibility Mode1097344 +Node: Additions1098127 +Node: Accessing The Source1099054 +Node: Adding Code1100494 +Node: New Ports1106539 +Node: Derived Files1110674 +Ref: Derived Files-Footnote-11115995 +Ref: Derived Files-Footnote-21116029 +Ref: Derived Files-Footnote-31116629 +Node: Future Extensions1116727 +Node: Implementation Limitations1117310 +Node: Extension Design1118558 +Node: Old Extension Problems1119712 +Ref: Old Extension Problems-Footnote-11121220 +Node: Extension New Mechanism Goals1121277 +Ref: Extension New Mechanism Goals-Footnote-11124642 +Node: Extension Other Design Decisions1124828 +Node: Extension Future Growth1126934 +Node: Old Extension Mechanism1127770 +Node: Basic Concepts1129510 +Node: Basic High Level1130191 +Ref: figure-general-flow1130463 +Ref: figure-process-flow1131062 +Ref: Basic High Level-Footnote-11134291 +Node: Basic Data Typing1134476 +Node: Glossary1137831 +Node: Copying1163062 +Node: GNU Free Documentation License1200618 +Node: Index1225754  End Tag Table -- cgit v1.2.3 From a29f25b08f9dce05bea6892e3d5396cf201417c8 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sat, 17 May 2014 23:01:43 +0300 Subject: Edits through Chapter 16. --- doc/gawk.info | 627 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 309 insertions(+), 318 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 5cf6129d..e860045e 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -9710,7 +9710,7 @@ description of each variable.) `ROUNDMODE #' The rounding mode to use for arbitrary precision arithmetic on - numbers, by default `"N"' (`roundTiesToEven' in the IEEE-754 + numbers, by default `"N"' (`roundTiesToEven' in the IEEE 754 standard; *note Setting Rounding Mode::). ``RS'' @@ -20893,8 +20893,8 @@ as follows: $ echo 0xDeadBeef | gawk '{ print $1 + 0 }' -| 0 - `gawk' does ignore case in the four special values. Thus `+nan' - and `+NaN' are the same. + `gawk' ignores case in the four special values. Thus `+nan' and + `+NaN' are the same. ---------- Footnotes ---------- @@ -20908,13 +20908,14 @@ File: gawk.info, Node: Integer Programming, Prev: Floating Point Issues, Up: As has been mentioned already, `awk' uses hardware double precision with 64-bit IEEE binary floating-point representation for numbers on -most systems. A large integer like 9,007,199,254,740,997 has a binary +most systems. A large integer like 9,007,199,254,740,997 has a binary representation that, although finite, is more than 53 bits long; it -must also be rounded to 53 bits. The biggest integer that can be +must also be rounded to 53 bits. (The details are discussed in *note +Floating-point Representation::.) The biggest integer that can be stored in a C `double' is usually the same as the largest possible value of a `double'. If your system `double' is an IEEE 64-bit `double', this largest possible value is an integer and can be -represented precisely. What more should one know about integers? +represented precisely. What more should you know about integers? If you want to know what is the largest integer, such that it and all smaller integers can be stored in 64-bit doubles without losing @@ -20972,9 +20973,9 @@ matters worse, with arbitrary precision floating-point, you can set the precision before starting a computation, but then you cannot be sure of the number of significant decimal places in the final result. - Sometimes, before you start to write any code, you should think more -about what you really want and what's really happening. Consider the -two numbers in the following example: + So, before you start to write any code, you should think more about +what you really want and what's really happening. Consider the two +numbers in the following example: x = 0.875 # 1/2 + 1/4 + 1/8 y = 0.425 @@ -20999,8 +21000,8 @@ previous example, produces an output identical to the input. Because the underlying representation can be a little bit off from the exact value, comparing floating-point values to see if they are -equal is generally not a good idea. Here is an example where it does -not work like you expect: +exactly equal is generally a bad idea. Here is an example where it +does not work like you expect: $ gawk 'BEGIN { print (0.1 + 12.2 == 12.3) }' -| 0 @@ -21056,7 +21057,7 @@ operations in your calculation. The stability and the accuracy of the computation of the constant pi in the earlier example can be enhanced by using the following simple algebraic transformation: - (sqrt(x * x + 1) - 1) / x = x / (sqrt(x * x + 1) + 1) + (sqrt(x * x + 1) - 1) / x == x / (sqrt(x * x + 1) + 1) After making this, change the program does converge to pi in under 30 iterations: @@ -21110,7 +21111,7 @@ File: gawk.info, Node: Floating-point Representation, Next: Floating-point Con Although floating-point representations vary from machine to machine, the most commonly encountered representation is that defined by the -IEEE 754 Standard. An IEEE-754 format value has three components: +IEEE 754 Standard. An IEEE 754 format value has three components: * A sign bit telling whether the number is positive or negative. @@ -21120,11 +21121,11 @@ IEEE 754 Standard. An IEEE-754 format value has three components: The value of the number is then S * 2^E. The first bit of a non-zero binary significand is always one, so the significand in an -IEEE-754 format only includes the fractional part, leaving the leading +IEEE 754 format only includes the fractional part, leaving the leading one implicit. The significand is stored in "normalized" format, which means that the first bit is always a one. - Three of the standard IEEE-754 types are 32-bit single precision, + Three of the standard IEEE 754 types are 32-bit single precision, 64-bit double precision and 128-bit quadruple precision. The standard also specifies extended precision formats to allow greater precisions and larger exponent ranges. @@ -21156,7 +21157,7 @@ components: The rounding mode of the context. *note table-ieee-formats:: lists the precision and exponent field -values for the basic IEEE-754 binary formats: +values for the basic IEEE 754 binary formats: Name Total bits Precision emin emax --------------------------------------------------------------------------- @@ -21171,10 +21172,10 @@ Table 15.1: Basic IEEE Format Context Values A floating-point context can also determine which signals are treated as exceptions, and can set rules for arithmetic with special values. -Please consult the IEEE-754 standard or other resources for details. +Please consult the IEEE 754 standard or other resources for details. `gawk' ordinarily uses the hardware double precision representation -for numbers. On most systems, this is IEEE-754 floating-point format, +for numbers. On most systems, this is IEEE 754 floating-point format, corresponding to 64-bit binary with 53 bits of precision. NOTE: In case an underflow occurs, the standard allows, but does @@ -21182,8 +21183,8 @@ corresponding to 64-bit binary with 53 bits of precision. number smaller than the smallest nonzero normalized number. Such numbers do not have as many significant digits as normal numbers, and are called "denormals" or "subnormals". The alternative, - simply returning a zero, is called "flush to zero". The basic - IEEE-754 binary formats support subnormal numbers. + simply returning a zero, is called "flush to zero". The basic IEEE + 754 binary formats support subnormal numbers.  File: gawk.info, Node: Rounding Mode, Prev: Floating-point Context, Up: Floating-point Programming @@ -21194,7 +21195,7 @@ File: gawk.info, Node: Rounding Mode, Prev: Floating-point Context, Up: Float The "rounding mode" specifies the behavior for the results of numerical operations when discarding extra precision. Each rounding mode indicates how the least significant returned digit of a rounded result is to be -calculated. *note table-rounding-modes:: lists the IEEE-754 defined +calculated. *note table-rounding-modes:: lists the IEEE 754 defined rounding modes: Rounding Mode IEEE Name @@ -21244,7 +21245,7 @@ produces the following output when run on the author's system:(1) The theory behind the rounding mode `roundTiesToEven' is that it more or less evenly distributes upward and downward rounds of exact halves, which might cause any round-off error to cancel itself out. -This is the default rounding mode used in IEEE-754 computing functions +This is the default rounding mode used in IEEE 754 computing functions and operators. The other rounding modes are rarely used. Round toward positive @@ -21269,7 +21270,7 @@ significant difference in output when you change the rounding mode. ---------- Footnotes ---------- (1) It is possible for the output to be completely different if the -C library in your system does not use the IEEE-754 even-rounding rule +C library in your system does not use the IEEE 754 even-rounding rule to round halfway cases for `printf'.  @@ -21325,14 +21326,14 @@ rounding mode are set globally for every operation to follow. The default working precision for arbitrary precision floating-point values is 53 bits, and the default value for `ROUNDMODE' is `"N"', -which selects the IEEE-754 `roundTiesToEven' rounding mode (*note +which selects the IEEE 754 `roundTiesToEven' rounding mode (*note Rounding Mode::).(1) `gawk' uses the default exponent range in MPFR (EMAX = 2^30 - 1, EMIN = -EMAX) for all floating-point contexts. There is no explicit mechanism to adjust the exponent range. MPFR does not implement subnormal numbers by default, and this behavior cannot be changed in `gawk'. - NOTE: When emulating an IEEE-754 format (*note Setting + NOTE: When emulating an IEEE 754 format (*note Setting Precision::), `gawk' internally adjusts the exponent range to the value defined for the format and also performs computations needed for gradual underflow (subnormal numbers). @@ -21355,7 +21356,7 @@ changed in `gawk'. (1) The default precision is 53 bits, since according to the MPFR documentation, the library should be able to exactly reproduce all -computations with double-precision machine floating-point numbers +computations done with double-precision machine floating-point numbers (`double' type in C), except the default exponent range is much wider and subnormal numbers are not implemented. @@ -21369,12 +21370,12 @@ File: gawk.info, Node: Setting Precision, Next: Setting Rounding Mode, Up: Ar precision or accuracy of individual numbers. Performing an arithmetic operation or calling a built-in function rounds the result to the current working precision. The default working precision is 53 bits, -which can be modified using the built-in variable `PREC'. You can also -set the value to one of the pre-defined case-insensitive strings shown -in *note table-predefined-precision-strings::, to emulate an IEEE-754 +which you can modify using the built-in variable `PREC'. You can also +set the value to one of the predefined case-insensitive strings shown +in *note table-predefined-precision-strings::, to emulate an IEEE 754 binary format. -`PREC' IEEE-754 Binary Format +`PREC' IEEE 754 Binary Format --------------------------------------------------- `"half"' 16-bit half-precision. `"single"' Basic 32-bit single precision. @@ -21447,9 +21448,9 @@ from zero Table 15.4: `gawk' Rounding Modes - `ROUNDMODE' has the default value `"N"', which selects the IEEE-754 + `ROUNDMODE' has the default value `"N"', which selects the IEEE 754 rounding mode `roundTiesToEven'. In *note Table 15.4: -table-gawk-rounding-modes, `"A"' is listed to select the IEEE-754 mode +table-gawk-rounding-modes, `"A"' is listed to select the IEEE 754 mode `roundTiesToAway'. This is only available if your version of the MPFR library supports it; otherwise setting `ROUNDMODE' to this value has no effect. *Note Rounding Mode::, for the meanings of the various rounding @@ -21468,16 +21469,16 @@ File: gawk.info, Node: Floating-point Constants, Next: Changing Precision, Pr -------------------------------------------- Be wary of floating-point constants! When reading a floating-point -constant from program source code, `gawk' uses the default precision, -unless overridden by an assignment to the special variable `PREC' on -the command line, to store it internally as a MPFR number. Changing -the precision using `PREC' in the program text does _not_ change the -precision of a constant. If you need to represent a floating-point -constant at a higher precision than the default and cannot use a -command line assignment to `PREC', you should either specify the -constant as a string, or as a rational number, whenever possible. The -following example illustrates the differences among various ways to -print a floating-point constant: +constant from program source code, `gawk' uses the default precision +(that of a C `double'), unless overridden by an assignment to the +special variable `PREC' on the command line, to store it internally as +a MPFR number. Changing the precision using `PREC' in the program text +does _not_ change the precision of a constant. If you need to represent +a floating-point constant at a higher precision than the default and +cannot use a command line assignment to `PREC', you should either +specify the constant as a string, or as a rational number, whenever +possible. The following example illustrates the differences among +various ways to print a floating-point constant: $ gawk -M 'BEGIN { PREC = 113; printf("%0.25f\n", 0.1) }' -| 0.1000000000000000055511151 @@ -21509,8 +21510,8 @@ File: gawk.info, Node: Changing Precision, Next: Exact Arithmetic, Prev: Floa `gawk' does not implicitly modify the precision of any previously computed results when the working precision is changed with an assignment to `PREC'. The precision of a number is always the one that -was used at the time of its creation, and there is no way for the user -to explicitly change it afterwards. However, since the result of a +was used at the time of its creation, and there is no way for you to +explicitly change it afterwards. However, since the result of a floating-point arithmetic operation is always an arbitrary precision floating-point value--with a precision set by the value of `PREC'--one of the following workarounds effectively accomplishes the desired @@ -21570,10 +21571,10 @@ straight test for equality may not work. So, don't assume that floating-point values can be compared for equality. You should also exercise caution when using other forms of -comparisons. The standard way to compare between floating-point -numbers is to determine how much error (or "tolerance") you will allow -in a comparison and check to see if one value is within this error -range of the other. +comparisons. The standard way to compare two floating-point numbers is +to determine how much error (or "tolerance") you will allow in a +comparison and check to see if one value is within this error range of +the other. In applications where 15 or fewer decimal places suffice, hardware double precision arithmetic can be adequate, and is usually much faster. @@ -21833,9 +21834,9 @@ Figure 16.3: Calling The New Function the API `struct' to do its work, such as updating variables or arrays, printing messages, setting `ERRNO', and so on. - Convenience macros in the `gawkapi.h' header file make calling -through the function pointers look like regular function calls so that -extension code is quite readable and understandable. + Convenience macros make calling through the function pointers look +like regular function calls so that extension code is quite readable +and understandable. Although all of this sounds somewhat complicated, the result is that extension code is quite straightforward to write and to read. You can @@ -21862,7 +21863,10 @@ File: gawk.info, Node: Extension API Description, Next: Finding Extensions, P 16.4 API Description ==================== -This (rather large) minor node describes the API in detail. +C or C++ code for an extension must include the header file +`gawkapi.h', which declares the functions and defines the data types +used to communicate with `gawk'. This (rather large) minor node +describes the API in detail. * Menu: @@ -21946,6 +21950,7 @@ operations: C Entity Header File ------------------------------------------- `EOF' `' + Values for `errno' `' `FILE' `' `NULL' `' `memcpy()' `' @@ -21960,9 +21965,6 @@ operations: a portability hodge-podge as can be seen in some parts of the `gawk' source code. - To pass reasonable integer values for `ERRNO', you will also need - to include `'. - * The `gawkapi.h' file may be included more than once without ill effect. Doing so, however, is poor coding practice. @@ -21982,7 +21984,7 @@ operations: * The API defines several simple `struct's that map values as seen from `awk'. A value can be a `double', a string, or an array (as in multidimensional arrays, or when creating a new array). String - values maintain both pointer and length since embedded `NUL' + values maintain both pointer and length since embedded NUL characters are allowed. NOTE: By intent, strings are maintained using the current @@ -22106,7 +22108,7 @@ that use them. indicates what is in the `union'. Representing numbers is easy--the API uses a C `double'. Strings -require more work. Since `gawk' allows embedded `NUL' bytes in string +require more work. Since `gawk' allows embedded NUL bytes in string values, a string must be represented as a pair containing a data-pointer and length. This is the `awk_string_t' type. @@ -22476,7 +22478,8 @@ used for `RT', if any. A pointer to your `XXX_take_control_of()' function. `awk_const struct input_parser *awk_const next;' - This pointer is used by `gawk'. The extension cannot modify it. + This is for use by `gawk'; therefore it is marked `awk_const' so + that the extension cannot modify it. The steps are as follows: @@ -22515,8 +22518,8 @@ as follows: Otherwise, it will. `struct stat sbuf;' - If file descriptor is valid, then `gawk' will have filled in this - structure via a call to the `fstat()' system call. + If the file descriptor is valid, then `gawk' will have filled in + this structure via a call to the `fstat()' system call. The `XXX_can_take_file()' function should examine these fields and decide if the input parser should be used for the file. The decision @@ -22679,8 +22682,8 @@ an extension to take over the output to a file opened with the `>' or false otherwise. `awk_const struct output_wrapper *awk_const next;' - This is for use by `gawk'; therefore they are marked `awk_const' - so that the extension cannot modify them. + This is for use by `gawk'; therefore it is marked `awk_const' so + that the extension cannot modify it. The `awk_output_buf_t' structure looks like this: @@ -22737,9 +22740,9 @@ in the `awk_output_buf_t'. The data members are as follows: the `name' and `mode' fields, and any additional state (such as `awk' variable values) that is appropriate. - When `gawk' calls `XXX_take_control_of()', it should fill in the -other fields, as appropriate, except for `fp', which it should just use -normally. + When `gawk' calls `XXX_take_control_of()', that function should fill +in the other fields, as appropriate, except for `fp', which it should +just use normally. You register your output wrapper with the following function: @@ -22787,8 +22790,8 @@ structures as described earlier. respectively. These structures were described earlier. `awk_const struct two_way_processor *awk_const next;' - This is for use by `gawk'; therefore they are marked `awk_const' - so that the extension cannot modify them. + This is for use by `gawk'; therefore it is marked `awk_const' so + that the extension cannot modify it. As with the input parser and output processor, you provide "yes I can take this" and "take over for this" functions, @@ -22957,7 +22960,7 @@ was discussed earlier, in *note General Data Types::. `awk_bool_t sym_update_scalar(awk_scalar_t cookie, awk_value_t *value);' Update the value associated with a scalar cookie. Return false if - the new value is not one of `AWK_STRING' or `AWK_NUMBER'. Here + the new value is not of type `AWK_STRING' or `AWK_NUMBER'. Here too, the built-in variables may not be updated. It is not obvious at first glance how to work with scalar cookies or @@ -23072,9 +23075,10 @@ follows: `awk_bool_t create_value(awk_value_t *value, awk_value_cookie_t *result);' Create a cached string or numeric value from `value' for efficient - later assignment. Only `AWK_NUMBER' and `AWK_STRING' values are - allowed. Any other type is rejected. While `AWK_UNDEFINED' could - be allowed, doing so would result in inferior performance. + later assignment. Only values of type `AWK_NUMBER' and + `AWK_STRING' are allowed. Any other type is rejected. While + `AWK_UNDEFINED' could be allowed, doing so would result in + inferior performance. `awk_bool_t release_value(awk_value_cookie_t vc);' Release the memory associated with a value cookie obtained from @@ -23128,11 +23132,11 @@ if `awk' code assigns a new value to `VAR1', are all the others be changed too?" That's a great question. The answer is that no, it's not a problem. -Internally, `gawk' uses reference-counted strings. This means that many -variables can share the same string value, and `gawk' keeps track of -the usage. When a variable's value changes, `gawk' simply decrements -the reference count on the old value and updates the variable to use -the new value. +Internally, `gawk' uses "reference-counted strings". This means that +many variables can share the same string value, and `gawk' keeps track +of the usage. When a variable's value changes, `gawk' simply +decrements the reference count on the old value and updates the +variable to use the new value. Finally, as part of your clean up action (*note Exit Callback Functions::) you should release any cached values that you created, @@ -23275,7 +23279,7 @@ The following functions relate to individual array elements. ` const awk_value_t *const value);' In the array represented by `a_cookie', create or modify the element whose index is given by `index'. The `ARGV' and `ENVIRON' - arrays may not be changed. + arrays may not be changed, although the `PROCINFO' array can be. `awk_bool_t set_array_element_by_elem(awk_array_t a_cookie,' ` awk_element_t element);' @@ -23513,8 +23517,8 @@ code: Thus, the correct way to build an array is to work "top down." Create the array, and immediately install it in `gawk''s symbol table using `sym_update()', or install it as an element in a - previously existing array using `set_element()'. We show example - code shortly. + previously existing array using `set_array_element()'. We show + example code shortly. 2. Due to gawk internals, after using `sym_update()' to install an array into `gawk', you have to retrieve the array cookie from the @@ -23704,13 +23708,15 @@ The API provides access to several variables that describe whether the corresponding command-line options were enabled when `gawk' was invoked. The variables are: +`do_debug' + This variable is true if `gawk' was invoked with `--debug' option. + `do_lint' This variable is true if `gawk' was invoked with `--lint' option (*note Options::). -`do_traditional' - This variable is true if `gawk' was invoked with `--traditional' - option. +`do_mpfr' + This variable is true if `gawk' was invoked with `--bignum' option. `do_profile' This variable is true if `gawk' was invoked with `--profile' @@ -23720,11 +23726,9 @@ invoked. The variables are: This variable is true if `gawk' was invoked with `--sandbox' option. -`do_debug' - This variable is true if `gawk' was invoked with `--debug' option. - -`do_mpfr' - This variable is true if `gawk' was invoked with `--bignum' option. +`do_traditional' + This variable is true if `gawk' was invoked with `--traditional' + option. The value of `do_lint' can change if `awk' code modifies the `LINT' built-in variable (*note Built-in Variables::). The others should not @@ -24324,7 +24328,9 @@ for loading each function into `gawk': static awk_ext_func_t func_table[] = { { "chdir", do_chdir, 1 }, { "stat", do_stat, 2 }, + #ifndef __MINGW32__ { "fts", do_fts, 3 }, + #endif }; Each extension must have a routine named `dl_load()' to load @@ -24484,52 +24490,36 @@ follows: The usage is: successful, `stat()' fills the `statdata' array with information retrieved from the filesystem, as follows: - `statdata["name"]' The name of the file. - `statdata["dev"]' Corresponds to the `st_dev' field in - the `struct stat'. - `statdata["ino"]' Corresponds to the `st_ino' field in - the `struct stat'. - `statdata["mode"]' Corresponds to the `st_mode' field in - the `struct stat'. - `statdata["nlink"]' Corresponds to the `st_nlink' field in - the `struct stat'. - `statdata["uid"]' Corresponds to the `st_uid' field in - the `struct stat'. - `statdata["gid"]' Corresponds to the `st_gid' field in - the `struct stat'. - `statdata["size"]' Corresponds to the `st_size' field in - the `struct stat'. - `statdata["atime"]' Corresponds to the `st_atime' field in - the `struct stat'. - `statdata["mtime"]' Corresponds to the `st_mtime' field in - the `struct stat'. - `statdata["ctime"]' Corresponds to the `st_ctime' field in - the `struct stat'. - `statdata["rdev"]' Corresponds to the `st_rdev' field in - the `struct stat'. This element is - only present for device files. - `statdata["major"]' Corresponds to the `st_major' field in - the `struct stat'. This element is - only present for device files. - `statdata["minor"]' Corresponds to the `st_minor' field in - the `struct stat'. This element is - only present for device files. - `statdata["blksize"]' Corresponds to the `st_blksize' field - in the `struct stat', if this field is - present on your system. (It is present - on all modern systems that we know of.) - `statdata["pmode"]' A human-readable version of the mode - value, such as printed by `ls'. For - example, `"-rwxr-xr-x"'. - `statdata["linkval"]' If the named file is a symbolic link, - this element will exist and its value - is the value of the symbolic link - (where the symbolic link points to). - `statdata["type"]' The type of the file as a string. One - of `"file"', `"blockdev"', `"chardev"', - `"directory"', `"socket"', `"fifo"', - `"symlink"', `"door"', or `"unknown"'. - Not all systems support all file types. + Subscript Field in `struct stat' File type + ------------------------------------------------------------ + `"name"' The file name All + `"dev"' `st_dev' All + `"ino"' `st_ino' All + `"mode"' `st_mode' All + `"nlink"' `st_nlink' All + `"uid"' `st_uid' All + `"gid"' `st_gid' All + `"size"' `st_size' All + `"atime"' `st_atime' All + `"mtime"' `st_mtime' All + `"ctime"' `st_ctime' All + `"rdev"' `st_rdev' Device files + `"major"' `st_major' Device files + `"minor"' `st_minor' Device files + `"blksize"'`st_blksize' All + `"pmode"' A human-readable version of the All + mode value, such as printed by + `ls'. For example, + `"-rwxr-xr-x"' + `"linkval"'The value of the symbolic link Symbolic + links + `"type"' The type of the file as a string. All + One of `"file"', `"blockdev"', + `"chardev"', `"directory"', + `"socket"', `"fifo"', `"symlink"', + `"door"', or `"unknown"'. Not + all systems support all file + types. `flags = or(FTS_PHYSICAL, ...)' `result = fts(pathlist, flags, filedata)' @@ -24674,18 +24664,14 @@ constant (`FNM_NOMATCH'), and an array of flag values named `FNM'. The flags are follows: -`FNM["CASEFOLD"]' Corresponds to the `FNM_CASEFOLD' flag as defined in - `fnmatch()'. -`FNM["FILE_NAME"]' Corresponds to the `FNM_FILE_NAME' flag as defined - in `fnmatch()'. -`FNM["LEADING_DIR"]' Corresponds to the `FNM_LEADING_DIR' flag as defined - in `fnmatch()'. -`FNM["NOESCAPE"]' Corresponds to the `FNM_NOESCAPE' flag as defined in - `fnmatch()'. -`FNM["PATHNAME"]' Corresponds to the `FNM_PATHNAME' flag as defined in - `fnmatch()'. -`FNM["PERIOD"]' Corresponds to the `FNM_PERIOD' flag as defined in - `fnmatch()'. +Array element Corresponding lag defined by `fnmatch()' +-------------------------------------------------------------------------- +`FNM["CASEFOLD"]' `FNM_CASEFOLD' +`FNM["FILE_NAME"]' `FNM_FILE_NAME' +`FNM["LEADING_DIR"]'`FNM_LEADING_DIR' +`FNM["NOESCAPE"]' `FNM_NOESCAPE' +`FNM["PATHNAME"]' `FNM_PATHNAME' +`FNM["PERIOD"]' `FNM_PERIOD' Here is an example: @@ -24826,7 +24812,8 @@ returned as a record. number and the filename, separated by a forward slash character. On systems where the directory entry contains the file type, the record has a third field (also separated by a slash) which is a single letter -indicating the type of the file: +indicating the type of the file. The letters are file types are shown +in *note table-readdir-file-types::. Letter File Type -------------------------------------------------------------------------- @@ -24839,6 +24826,8 @@ Letter File Type `s' Socket `u' Anything else (unknown) +Table 16.2: File types returned by `readdir()' + On systems without the file type information, the third field is always `u'. @@ -24870,10 +24859,10 @@ unwary. Here is an example: BEGIN { REVOUT = 1 - print "hello, world" > "/dev/stdout" + print "don't panic" > "/dev/stdout" } - The output from this program is: `dlrow ,olleh'. + The output from this program is: `cinap t'nod'.  File: gawk.info, Node: Extension Sample Rev2way, Next: Extension Sample Read write array, Prev: Extension Sample Revout, Up: Extension Samples @@ -24891,12 +24880,14 @@ example shows how to use it: BEGIN { cmd = "/magic/mirror" - print "hello, world" |& cmd + print "don't panic" |& cmd cmd |& getline result print result close(cmd) } + The output from this program is: `cinap t'nod'. +  File: gawk.info, Node: Extension Sample Read write array, Next: Extension Sample Readfile, Prev: Extension Sample Rev2way, Up: Extension Samples @@ -24908,8 +24899,8 @@ The `rwarray' extension adds two functions, named `writea()' and `ret = writea(file, array)' This function takes a string argument, which is the name of the - file to which dump the array, and the array itself as the second - argument. `writea()' understands multidimensional arrays. It + file to which to dump the array, and the array itself as the + second argument. `writea()' understands arrays of arrays. It returns one on success, or zero upon failure. `ret = reada(file, array)' @@ -24992,9 +24983,8 @@ File: gawk.info, Node: Extension Sample Time, Prev: Extension Sample API Tests 16.7.12 Extension Time Functions -------------------------------- -These functions can be used either by invoking `gawk' with a -command-line argument of `-l time' or by inserting `@load "time"' in -your script. +The `time' extension adds two functions, named `gettimeofday()' and +`sleep()', as follows: `@load "time"' This is how you load the extension. @@ -25006,7 +24996,7 @@ your script. have sub-second precision, but the actual precision may vary based on the platform. If the standard C `gettimeofday()' system call is available on this platform, then it simply returns the value. - Otherwise, if on Windows, it tries to use + Otherwise, if on MS-Windows, it tries to use `GetSystemTimeAsFileTime()'. `result = sleep(SECONDS)' @@ -31594,7 +31584,7 @@ Index * FSF (Free Software Foundation) <2>: Getting. (line 10) * FSF (Free Software Foundation): Manual History. (line 6) * fts() extension function: Extension Sample File Functions. - (line 77) + (line 61) * FUNCTAB array: Auto-set. (line 115) * function calls: Function Calls. (line 6) * function calls, indirect: Indirect Calls. (line 6) @@ -31786,7 +31776,7 @@ Index * gettext library, locale categories: Explaining gettext. (line 81) * gettext() function (C library): Explaining gettext. (line 63) * gettimeofday() extension function: Extension Sample Time. - (line 13) + (line 12) * git utility <1>: Adding Code. (line 111) * git utility <2>: Accessing The Source. (line 10) @@ -31849,7 +31839,7 @@ Index * i debugger command (alias for info): Debugger Info. (line 13) * id utility: Id Program. (line 6) * id.awk program: Id Program. (line 30) -* IEEE-754 format: Floating-point Representation. +* IEEE 754 format: Floating-point Representation. (line 6) * if statement: If Statement. (line 6) * if statement, actions, changing: Ranges. (line 25) @@ -32835,7 +32825,7 @@ Index * Skywalker, Luke: Undocumented. (line 6) * sleep utility: Alarm Program. (line 111) * sleep() extension function: Extension Sample Time. - (line 23) + (line 22) * Solaris, POSIX-compliant awk: Other Versions. (line 96) * sort array: String Functions. (line 42) * sort array indices: String Functions. (line 42) @@ -33589,164 +33579,165 @@ Node: String Conversion Precision833417 Ref: String Conversion Precision-Footnote-1835122 Node: Unexpected Results835231 Node: POSIX Floating Point Problems837384 -Ref: POSIX Floating Point Problems-Footnote-1841209 -Node: Integer Programming841247 -Node: Floating-point Programming842986 -Ref: Floating-point Programming-Footnote-1849317 -Ref: Floating-point Programming-Footnote-2849587 -Node: Floating-point Representation849851 -Node: Floating-point Context851016 -Ref: table-ieee-formats851855 -Node: Rounding Mode853239 -Ref: table-rounding-modes853718 -Ref: Rounding Mode-Footnote-1856733 -Node: Gawk and MPFR856912 -Node: Arbitrary Precision Floats858321 -Ref: Arbitrary Precision Floats-Footnote-1860764 -Node: Setting Precision861080 -Ref: table-predefined-precision-strings861766 -Node: Setting Rounding Mode863911 -Ref: table-gawk-rounding-modes864315 -Node: Floating-point Constants865502 -Node: Changing Precision866931 -Ref: Changing Precision-Footnote-1868328 -Node: Exact Arithmetic868502 -Node: Arbitrary Precision Integers871640 -Ref: Arbitrary Precision Integers-Footnote-1874655 -Node: Dynamic Extensions874802 -Node: Extension Intro876260 -Node: Plugin License877525 -Node: Extension Mechanism Outline878210 -Ref: load-extension878627 -Ref: load-new-function880105 -Ref: call-new-function881100 -Node: Extension API Description883115 -Node: Extension API Functions Introduction884402 -Node: General Data Types889329 -Ref: General Data Types-Footnote-1895024 -Node: Requesting Values895323 -Ref: table-value-types-returned896060 -Node: Memory Allocation Functions897014 -Ref: Memory Allocation Functions-Footnote-1899760 -Node: Constructor Functions899856 -Node: Registration Functions901614 -Node: Extension Functions902299 -Node: Exit Callback Functions904601 -Node: Extension Version String905850 -Node: Input Parsers906500 -Node: Output Wrappers916257 -Node: Two-way processors920767 -Node: Printing Messages922975 -Ref: Printing Messages-Footnote-1924052 -Node: Updating `ERRNO'924204 -Node: Accessing Parameters924943 -Node: Symbol Table Access926173 -Node: Symbol table by name926687 -Node: Symbol table by cookie928663 -Ref: Symbol table by cookie-Footnote-1932795 -Node: Cached values932858 -Ref: Cached values-Footnote-1936348 -Node: Array Manipulation936439 -Ref: Array Manipulation-Footnote-1937537 -Node: Array Data Types937576 -Ref: Array Data Types-Footnote-1940279 -Node: Array Functions940371 -Node: Flattening Arrays944207 -Node: Creating Arrays951059 -Node: Extension API Variables955784 -Node: Extension Versioning956420 -Node: Extension API Informational Variables958321 -Node: Extension API Boilerplate959407 -Node: Finding Extensions963211 -Node: Extension Example963771 -Node: Internal File Description964501 -Node: Internal File Ops968592 -Ref: Internal File Ops-Footnote-1980101 -Node: Using Internal File Ops980241 -Ref: Using Internal File Ops-Footnote-1982588 -Node: Extension Samples982854 -Node: Extension Sample File Functions984378 -Node: Extension Sample Fnmatch992865 -Node: Extension Sample Fork994634 -Node: Extension Sample Inplace995847 -Node: Extension Sample Ord997625 -Node: Extension Sample Readdir998461 -Node: Extension Sample Revout999993 -Node: Extension Sample Rev2way1000586 -Node: Extension Sample Read write array1001276 -Node: Extension Sample Readfile1003159 -Node: Extension Sample API Tests1004259 -Node: Extension Sample Time1004784 -Node: gawkextlib1006148 -Node: Language History1008929 -Node: V7/SVR3.11010522 -Node: SVR41012842 -Node: POSIX1014284 -Node: BTL1015670 -Node: POSIX/GNU1016404 -Node: Feature History1022003 -Node: Common Extensions1034979 -Node: Ranges and Locales1036291 -Ref: Ranges and Locales-Footnote-11040908 -Ref: Ranges and Locales-Footnote-21040935 -Ref: Ranges and Locales-Footnote-31041169 -Node: Contributors1041390 -Node: Installation1046771 -Node: Gawk Distribution1047665 -Node: Getting1048149 -Node: Extracting1048975 -Node: Distribution contents1050667 -Node: Unix Installation1056388 -Node: Quick Installation1057005 -Node: Additional Configuration Options1059451 -Node: Configuration Philosophy1061187 -Node: Non-Unix Installation1063541 -Node: PC Installation1063999 -Node: PC Binary Installation1065310 -Node: PC Compiling1067158 -Node: PC Testing1070118 -Node: PC Using1071294 -Node: Cygwin1075462 -Node: MSYS1076271 -Node: VMS Installation1076785 -Node: VMS Compilation1077581 -Ref: VMS Compilation-Footnote-11078833 -Node: VMS Dynamic Extensions1078891 -Node: VMS Installation Details1080264 -Node: VMS Running1082515 -Node: VMS GNV1085349 -Node: VMS Old Gawk1086072 -Node: Bugs1086542 -Node: Other Versions1090460 -Node: Notes1096544 -Node: Compatibility Mode1097344 -Node: Additions1098127 -Node: Accessing The Source1099054 -Node: Adding Code1100494 -Node: New Ports1106539 -Node: Derived Files1110674 -Ref: Derived Files-Footnote-11115995 -Ref: Derived Files-Footnote-21116029 -Ref: Derived Files-Footnote-31116629 -Node: Future Extensions1116727 -Node: Implementation Limitations1117310 -Node: Extension Design1118558 -Node: Old Extension Problems1119712 -Ref: Old Extension Problems-Footnote-11121220 -Node: Extension New Mechanism Goals1121277 -Ref: Extension New Mechanism Goals-Footnote-11124642 -Node: Extension Other Design Decisions1124828 -Node: Extension Future Growth1126934 -Node: Old Extension Mechanism1127770 -Node: Basic Concepts1129510 -Node: Basic High Level1130191 -Ref: figure-general-flow1130463 -Ref: figure-process-flow1131062 -Ref: Basic High Level-Footnote-11134291 -Node: Basic Data Typing1134476 -Node: Glossary1137831 -Node: Copying1163062 -Node: GNU Free Documentation License1200618 -Node: Index1225754 +Ref: POSIX Floating Point Problems-Footnote-1841205 +Node: Integer Programming841243 +Node: Floating-point Programming843054 +Ref: Floating-point Programming-Footnote-1849382 +Ref: Floating-point Programming-Footnote-2849652 +Node: Floating-point Representation849916 +Node: Floating-point Context851081 +Ref: table-ieee-formats851920 +Node: Rounding Mode853304 +Ref: table-rounding-modes853783 +Ref: Rounding Mode-Footnote-1856798 +Node: Gawk and MPFR856977 +Node: Arbitrary Precision Floats858386 +Ref: Arbitrary Precision Floats-Footnote-1860829 +Node: Setting Precision861150 +Ref: table-predefined-precision-strings861834 +Node: Setting Rounding Mode863979 +Ref: table-gawk-rounding-modes864383 +Node: Floating-point Constants865570 +Node: Changing Precision867022 +Ref: Changing Precision-Footnote-1868414 +Node: Exact Arithmetic868588 +Node: Arbitrary Precision Integers871722 +Ref: Arbitrary Precision Integers-Footnote-1874737 +Node: Dynamic Extensions874884 +Node: Extension Intro876342 +Node: Plugin License877607 +Node: Extension Mechanism Outline878292 +Ref: load-extension878709 +Ref: load-new-function880187 +Ref: call-new-function881182 +Node: Extension API Description883166 +Node: Extension API Functions Introduction884616 +Node: General Data Types889482 +Ref: General Data Types-Footnote-1895175 +Node: Requesting Values895474 +Ref: table-value-types-returned896211 +Node: Memory Allocation Functions897165 +Ref: Memory Allocation Functions-Footnote-1899911 +Node: Constructor Functions900007 +Node: Registration Functions901765 +Node: Extension Functions902450 +Node: Exit Callback Functions904752 +Node: Extension Version String906001 +Node: Input Parsers906651 +Node: Output Wrappers916454 +Node: Two-way processors920970 +Node: Printing Messages923173 +Ref: Printing Messages-Footnote-1924250 +Node: Updating `ERRNO'924402 +Node: Accessing Parameters925141 +Node: Symbol Table Access926371 +Node: Symbol table by name926885 +Node: Symbol table by cookie928861 +Ref: Symbol table by cookie-Footnote-1932994 +Node: Cached values933057 +Ref: Cached values-Footnote-1936562 +Node: Array Manipulation936653 +Ref: Array Manipulation-Footnote-1937751 +Node: Array Data Types937790 +Ref: Array Data Types-Footnote-1940493 +Node: Array Functions940585 +Node: Flattening Arrays944459 +Node: Creating Arrays951311 +Node: Extension API Variables956042 +Node: Extension Versioning956678 +Node: Extension API Informational Variables958579 +Node: Extension API Boilerplate959665 +Node: Finding Extensions963469 +Node: Extension Example964029 +Node: Internal File Description964759 +Node: Internal File Ops968850 +Ref: Internal File Ops-Footnote-1980396 +Node: Using Internal File Ops980536 +Ref: Using Internal File Ops-Footnote-1982883 +Node: Extension Samples983149 +Node: Extension Sample File Functions984673 +Node: Extension Sample Fnmatch992240 +Node: Extension Sample Fork993719 +Node: Extension Sample Inplace994932 +Node: Extension Sample Ord996710 +Node: Extension Sample Readdir997546 +Ref: table-readdir-file-types998401 +Node: Extension Sample Revout999200 +Node: Extension Sample Rev2way999791 +Node: Extension Sample Read write array1000532 +Node: Extension Sample Readfile1002411 +Node: Extension Sample API Tests1003511 +Node: Extension Sample Time1004036 +Node: gawkextlib1005351 +Node: Language History1008132 +Node: V7/SVR3.11009725 +Node: SVR41012045 +Node: POSIX1013487 +Node: BTL1014873 +Node: POSIX/GNU1015607 +Node: Feature History1021206 +Node: Common Extensions1034182 +Node: Ranges and Locales1035494 +Ref: Ranges and Locales-Footnote-11040111 +Ref: Ranges and Locales-Footnote-21040138 +Ref: Ranges and Locales-Footnote-31040372 +Node: Contributors1040593 +Node: Installation1045974 +Node: Gawk Distribution1046868 +Node: Getting1047352 +Node: Extracting1048178 +Node: Distribution contents1049870 +Node: Unix Installation1055591 +Node: Quick Installation1056208 +Node: Additional Configuration Options1058654 +Node: Configuration Philosophy1060390 +Node: Non-Unix Installation1062744 +Node: PC Installation1063202 +Node: PC Binary Installation1064513 +Node: PC Compiling1066361 +Node: PC Testing1069321 +Node: PC Using1070497 +Node: Cygwin1074665 +Node: MSYS1075474 +Node: VMS Installation1075988 +Node: VMS Compilation1076784 +Ref: VMS Compilation-Footnote-11078036 +Node: VMS Dynamic Extensions1078094 +Node: VMS Installation Details1079467 +Node: VMS Running1081718 +Node: VMS GNV1084552 +Node: VMS Old Gawk1085275 +Node: Bugs1085745 +Node: Other Versions1089663 +Node: Notes1095747 +Node: Compatibility Mode1096547 +Node: Additions1097330 +Node: Accessing The Source1098257 +Node: Adding Code1099697 +Node: New Ports1105742 +Node: Derived Files1109877 +Ref: Derived Files-Footnote-11115198 +Ref: Derived Files-Footnote-21115232 +Ref: Derived Files-Footnote-31115832 +Node: Future Extensions1115930 +Node: Implementation Limitations1116513 +Node: Extension Design1117761 +Node: Old Extension Problems1118915 +Ref: Old Extension Problems-Footnote-11120423 +Node: Extension New Mechanism Goals1120480 +Ref: Extension New Mechanism Goals-Footnote-11123845 +Node: Extension Other Design Decisions1124031 +Node: Extension Future Growth1126137 +Node: Old Extension Mechanism1126973 +Node: Basic Concepts1128713 +Node: Basic High Level1129394 +Ref: figure-general-flow1129666 +Ref: figure-process-flow1130265 +Ref: Basic High Level-Footnote-11133494 +Node: Basic Data Typing1133679 +Node: Glossary1137034 +Node: Copying1162265 +Node: GNU Free Documentation License1199821 +Node: Index1224957  End Tag Table -- cgit v1.2.3 From 9e5b2c4106be2d9aaf98730a03e75d313cfa2e80 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 20 May 2014 21:46:59 +0300 Subject: More docbook fixes. --- doc/gawk.info | 277 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 139 insertions(+), 138 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index e860045e..55cc9829 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -21383,7 +21383,7 @@ binary format. `"quad"' Basic 128-bit quadruple precision. `"oct"' 256-bit octuple precision. -Table 15.3: Predefined precision strings for `PREC' +Table 15.3: Predefined Precision Strings For `PREC' The following example illustrates the effects of changing precision on arithmetic operations: @@ -21761,7 +21761,8 @@ File: gawk.info, Node: Extension Mechanism Outline, Next: Extension API Descri Communication between `gawk' and an extension is two-way. First, when an extension is loaded, it is passed a pointer to a `struct' whose -fields are function pointers. This is shown in *note load-extension::. +fields are function pointers. This is shown in *note +figure-load-extension::. API Struct @@ -21793,7 +21794,7 @@ Figure 16.1: Loading The Extension function pointers, at runtime, without needing (link-time) access to `gawk''s symbols. One of these function pointers is to a function for "registering" new built-in functions. This is shown in *note -load-new-function::. +figure-load-new-function::. register_ext_func({ "chdir", do_chdir, 1 }); @@ -21813,7 +21814,7 @@ Figure 16.2: Loading The New Function with `gawk' by passing function pointers to the functions that provide the new feature (`do_chdir()', for example). `gawk' associates the function pointer with a name and can then call it, using a defined -calling convention. This is shown in *note call-new-function::. +calling convention. This is shown in *note figure-call-new-function::. BEGIN { chdir("/path") (*fnptr)(1); @@ -22188,7 +22189,7 @@ Requested: Scalar Scalar Scalar false false Value false false false false Cookie -Table 16.1: Value Types Returned +Table 16.1: API Value Types Returned  File: gawk.info, Node: Memory Allocation Functions, Next: Constructor Functions, Prev: Requesting Values, Up: Extension API Description @@ -24826,7 +24827,7 @@ Letter File Type `s' Socket `u' Anything else (unknown) -Table 16.2: File types returned by `readdir()' +Table 16.2: File Types Returned By `readdir()' On systems without the file type information, the third field is always `u'. @@ -33607,137 +33608,137 @@ Node: Dynamic Extensions874884 Node: Extension Intro876342 Node: Plugin License877607 Node: Extension Mechanism Outline878292 -Ref: load-extension878709 -Ref: load-new-function880187 -Ref: call-new-function881182 -Node: Extension API Description883166 -Node: Extension API Functions Introduction884616 -Node: General Data Types889482 -Ref: General Data Types-Footnote-1895175 -Node: Requesting Values895474 -Ref: table-value-types-returned896211 -Node: Memory Allocation Functions897165 -Ref: Memory Allocation Functions-Footnote-1899911 -Node: Constructor Functions900007 -Node: Registration Functions901765 -Node: Extension Functions902450 -Node: Exit Callback Functions904752 -Node: Extension Version String906001 -Node: Input Parsers906651 -Node: Output Wrappers916454 -Node: Two-way processors920970 -Node: Printing Messages923173 -Ref: Printing Messages-Footnote-1924250 -Node: Updating `ERRNO'924402 -Node: Accessing Parameters925141 -Node: Symbol Table Access926371 -Node: Symbol table by name926885 -Node: Symbol table by cookie928861 -Ref: Symbol table by cookie-Footnote-1932994 -Node: Cached values933057 -Ref: Cached values-Footnote-1936562 -Node: Array Manipulation936653 -Ref: Array Manipulation-Footnote-1937751 -Node: Array Data Types937790 -Ref: Array Data Types-Footnote-1940493 -Node: Array Functions940585 -Node: Flattening Arrays944459 -Node: Creating Arrays951311 -Node: Extension API Variables956042 -Node: Extension Versioning956678 -Node: Extension API Informational Variables958579 -Node: Extension API Boilerplate959665 -Node: Finding Extensions963469 -Node: Extension Example964029 -Node: Internal File Description964759 -Node: Internal File Ops968850 -Ref: Internal File Ops-Footnote-1980396 -Node: Using Internal File Ops980536 -Ref: Using Internal File Ops-Footnote-1982883 -Node: Extension Samples983149 -Node: Extension Sample File Functions984673 -Node: Extension Sample Fnmatch992240 -Node: Extension Sample Fork993719 -Node: Extension Sample Inplace994932 -Node: Extension Sample Ord996710 -Node: Extension Sample Readdir997546 -Ref: table-readdir-file-types998401 -Node: Extension Sample Revout999200 -Node: Extension Sample Rev2way999791 -Node: Extension Sample Read write array1000532 -Node: Extension Sample Readfile1002411 -Node: Extension Sample API Tests1003511 -Node: Extension Sample Time1004036 -Node: gawkextlib1005351 -Node: Language History1008132 -Node: V7/SVR3.11009725 -Node: SVR41012045 -Node: POSIX1013487 -Node: BTL1014873 -Node: POSIX/GNU1015607 -Node: Feature History1021206 -Node: Common Extensions1034182 -Node: Ranges and Locales1035494 -Ref: Ranges and Locales-Footnote-11040111 -Ref: Ranges and Locales-Footnote-21040138 -Ref: Ranges and Locales-Footnote-31040372 -Node: Contributors1040593 -Node: Installation1045974 -Node: Gawk Distribution1046868 -Node: Getting1047352 -Node: Extracting1048178 -Node: Distribution contents1049870 -Node: Unix Installation1055591 -Node: Quick Installation1056208 -Node: Additional Configuration Options1058654 -Node: Configuration Philosophy1060390 -Node: Non-Unix Installation1062744 -Node: PC Installation1063202 -Node: PC Binary Installation1064513 -Node: PC Compiling1066361 -Node: PC Testing1069321 -Node: PC Using1070497 -Node: Cygwin1074665 -Node: MSYS1075474 -Node: VMS Installation1075988 -Node: VMS Compilation1076784 -Ref: VMS Compilation-Footnote-11078036 -Node: VMS Dynamic Extensions1078094 -Node: VMS Installation Details1079467 -Node: VMS Running1081718 -Node: VMS GNV1084552 -Node: VMS Old Gawk1085275 -Node: Bugs1085745 -Node: Other Versions1089663 -Node: Notes1095747 -Node: Compatibility Mode1096547 -Node: Additions1097330 -Node: Accessing The Source1098257 -Node: Adding Code1099697 -Node: New Ports1105742 -Node: Derived Files1109877 -Ref: Derived Files-Footnote-11115198 -Ref: Derived Files-Footnote-21115232 -Ref: Derived Files-Footnote-31115832 -Node: Future Extensions1115930 -Node: Implementation Limitations1116513 -Node: Extension Design1117761 -Node: Old Extension Problems1118915 -Ref: Old Extension Problems-Footnote-11120423 -Node: Extension New Mechanism Goals1120480 -Ref: Extension New Mechanism Goals-Footnote-11123845 -Node: Extension Other Design Decisions1124031 -Node: Extension Future Growth1126137 -Node: Old Extension Mechanism1126973 -Node: Basic Concepts1128713 -Node: Basic High Level1129394 -Ref: figure-general-flow1129666 -Ref: figure-process-flow1130265 -Ref: Basic High Level-Footnote-11133494 -Node: Basic Data Typing1133679 -Node: Glossary1137034 -Node: Copying1162265 -Node: GNU Free Documentation License1199821 -Node: Index1224957 +Ref: figure-load-extension878716 +Ref: figure-load-new-function880201 +Ref: figure-call-new-function881203 +Node: Extension API Description883187 +Node: Extension API Functions Introduction884637 +Node: General Data Types889503 +Ref: General Data Types-Footnote-1895196 +Node: Requesting Values895495 +Ref: table-value-types-returned896232 +Node: Memory Allocation Functions897190 +Ref: Memory Allocation Functions-Footnote-1899936 +Node: Constructor Functions900032 +Node: Registration Functions901790 +Node: Extension Functions902475 +Node: Exit Callback Functions904777 +Node: Extension Version String906026 +Node: Input Parsers906676 +Node: Output Wrappers916479 +Node: Two-way processors920995 +Node: Printing Messages923198 +Ref: Printing Messages-Footnote-1924275 +Node: Updating `ERRNO'924427 +Node: Accessing Parameters925166 +Node: Symbol Table Access926396 +Node: Symbol table by name926910 +Node: Symbol table by cookie928886 +Ref: Symbol table by cookie-Footnote-1933019 +Node: Cached values933082 +Ref: Cached values-Footnote-1936587 +Node: Array Manipulation936678 +Ref: Array Manipulation-Footnote-1937776 +Node: Array Data Types937815 +Ref: Array Data Types-Footnote-1940518 +Node: Array Functions940610 +Node: Flattening Arrays944484 +Node: Creating Arrays951336 +Node: Extension API Variables956067 +Node: Extension Versioning956703 +Node: Extension API Informational Variables958604 +Node: Extension API Boilerplate959690 +Node: Finding Extensions963494 +Node: Extension Example964054 +Node: Internal File Description964784 +Node: Internal File Ops968875 +Ref: Internal File Ops-Footnote-1980421 +Node: Using Internal File Ops980561 +Ref: Using Internal File Ops-Footnote-1982908 +Node: Extension Samples983174 +Node: Extension Sample File Functions984698 +Node: Extension Sample Fnmatch992265 +Node: Extension Sample Fork993744 +Node: Extension Sample Inplace994957 +Node: Extension Sample Ord996735 +Node: Extension Sample Readdir997571 +Ref: table-readdir-file-types998426 +Node: Extension Sample Revout999225 +Node: Extension Sample Rev2way999816 +Node: Extension Sample Read write array1000557 +Node: Extension Sample Readfile1002436 +Node: Extension Sample API Tests1003536 +Node: Extension Sample Time1004061 +Node: gawkextlib1005376 +Node: Language History1008157 +Node: V7/SVR3.11009750 +Node: SVR41012070 +Node: POSIX1013512 +Node: BTL1014898 +Node: POSIX/GNU1015632 +Node: Feature History1021231 +Node: Common Extensions1034207 +Node: Ranges and Locales1035519 +Ref: Ranges and Locales-Footnote-11040136 +Ref: Ranges and Locales-Footnote-21040163 +Ref: Ranges and Locales-Footnote-31040397 +Node: Contributors1040618 +Node: Installation1045999 +Node: Gawk Distribution1046893 +Node: Getting1047377 +Node: Extracting1048203 +Node: Distribution contents1049895 +Node: Unix Installation1055616 +Node: Quick Installation1056233 +Node: Additional Configuration Options1058679 +Node: Configuration Philosophy1060415 +Node: Non-Unix Installation1062769 +Node: PC Installation1063227 +Node: PC Binary Installation1064538 +Node: PC Compiling1066386 +Node: PC Testing1069346 +Node: PC Using1070522 +Node: Cygwin1074690 +Node: MSYS1075499 +Node: VMS Installation1076013 +Node: VMS Compilation1076809 +Ref: VMS Compilation-Footnote-11078061 +Node: VMS Dynamic Extensions1078119 +Node: VMS Installation Details1079492 +Node: VMS Running1081743 +Node: VMS GNV1084577 +Node: VMS Old Gawk1085300 +Node: Bugs1085770 +Node: Other Versions1089688 +Node: Notes1095772 +Node: Compatibility Mode1096572 +Node: Additions1097355 +Node: Accessing The Source1098282 +Node: Adding Code1099722 +Node: New Ports1105767 +Node: Derived Files1109902 +Ref: Derived Files-Footnote-11115223 +Ref: Derived Files-Footnote-21115257 +Ref: Derived Files-Footnote-31115857 +Node: Future Extensions1115955 +Node: Implementation Limitations1116538 +Node: Extension Design1117786 +Node: Old Extension Problems1118940 +Ref: Old Extension Problems-Footnote-11120448 +Node: Extension New Mechanism Goals1120505 +Ref: Extension New Mechanism Goals-Footnote-11123870 +Node: Extension Other Design Decisions1124056 +Node: Extension Future Growth1126162 +Node: Old Extension Mechanism1126998 +Node: Basic Concepts1128738 +Node: Basic High Level1129419 +Ref: figure-general-flow1129691 +Ref: figure-process-flow1130290 +Ref: Basic High Level-Footnote-11133519 +Node: Basic Data Typing1133704 +Node: Glossary1137059 +Node: Copying1162290 +Node: GNU Free Documentation License1199846 +Node: Index1224982  End Tag Table -- cgit v1.2.3 From cb3db09270b4caaddb0d606ec892841c149698eb Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 22 May 2014 06:11:32 +0300 Subject: Allow any redirected getline inside BEGINFILE/ENDFILE. --- doc/gawk.info | 718 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 359 insertions(+), 359 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 55cc9829..4852a58f 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -8849,7 +8849,7 @@ either a `BEGINFILE' or and `ENDFILE' rule. The `nextfile' statement but not inside an `ENDFILE' rule. The `getline' statement (*note Getline::) is restricted inside both -`BEGINFILE' and `ENDFILE'. Only the `getline VARIABLE < FILE' form is +`BEGINFILE' and `ENDFILE': only redirected forms of `getline' are allowed. `BEGINFILE' and `ENDFILE' are `gawk' extensions. In most other @@ -33382,363 +33382,363 @@ Node: Using BEGIN/END373150 Ref: Using BEGIN/END-Footnote-1375886 Node: I/O And BEGIN/END375992 Node: BEGINFILE/ENDFILE378277 -Node: Empty381213 -Node: Using Shell Variables381530 -Node: Action Overview383813 -Node: Statements386164 -Node: If Statement388018 -Node: While Statement389521 -Node: Do Statement391565 -Node: For Statement392721 -Node: Switch Statement395873 -Node: Break Statement397976 -Node: Continue Statement400031 -Node: Next Statement401824 -Node: Nextfile Statement404214 -Node: Exit Statement406869 -Node: Built-in Variables409273 -Node: User-modified410369 -Ref: User-modified-Footnote-1418054 -Node: Auto-set418116 -Ref: Auto-set-Footnote-1430681 -Ref: Auto-set-Footnote-2430886 -Node: ARGC and ARGV430942 -Node: Arrays434796 -Node: Array Basics436294 -Node: Array Intro437120 -Ref: figure-array-elements439093 -Node: Reference to Elements441500 -Node: Assigning Elements443773 -Node: Array Example444264 -Node: Scanning an Array445996 -Node: Controlling Scanning449011 -Ref: Controlling Scanning-Footnote-1454184 -Node: Delete454500 -Ref: Delete-Footnote-1457265 -Node: Numeric Array Subscripts457322 -Node: Uninitialized Subscripts459505 -Node: Multidimensional461130 -Node: Multiscanning464223 -Node: Arrays of Arrays465812 -Node: Functions470452 -Node: Built-in471271 -Node: Calling Built-in472349 -Node: Numeric Functions474337 -Ref: Numeric Functions-Footnote-1478171 -Ref: Numeric Functions-Footnote-2478528 -Ref: Numeric Functions-Footnote-3478576 -Node: String Functions478845 -Ref: String Functions-Footnote-1501856 -Ref: String Functions-Footnote-2501985 -Ref: String Functions-Footnote-3502233 -Node: Gory Details502320 -Ref: table-sub-escapes503989 -Ref: table-sub-posix-92505343 -Ref: table-sub-proposed506694 -Ref: table-posix-sub508048 -Ref: table-gensub-escapes509593 -Ref: Gory Details-Footnote-1510769 -Ref: Gory Details-Footnote-2510820 -Node: I/O Functions510971 -Ref: I/O Functions-Footnote-1518094 -Node: Time Functions518241 -Ref: Time Functions-Footnote-1528705 -Ref: Time Functions-Footnote-2528773 -Ref: Time Functions-Footnote-3528931 -Ref: Time Functions-Footnote-4529042 -Ref: Time Functions-Footnote-5529154 -Ref: Time Functions-Footnote-6529381 -Node: Bitwise Functions529647 -Ref: table-bitwise-ops530209 -Ref: Bitwise Functions-Footnote-1534454 -Node: Type Functions534638 -Node: I18N Functions535780 -Node: User-defined537425 -Node: Definition Syntax538229 -Ref: Definition Syntax-Footnote-1543154 -Node: Function Example543223 -Ref: Function Example-Footnote-1545867 -Node: Function Caveats545889 -Node: Calling A Function546407 -Node: Variable Scope547362 -Node: Pass By Value/Reference550350 -Node: Return Statement553858 -Node: Dynamic Typing556842 -Node: Indirect Calls557771 -Node: Library Functions567458 -Ref: Library Functions-Footnote-1570971 -Ref: Library Functions-Footnote-2571114 -Node: Library Names571285 -Ref: Library Names-Footnote-1574758 -Ref: Library Names-Footnote-2574978 -Node: General Functions575064 -Node: Strtonum Function576092 -Node: Assert Function579022 -Node: Round Function582348 -Node: Cliff Random Function583889 -Node: Ordinal Functions584905 -Ref: Ordinal Functions-Footnote-1587982 -Ref: Ordinal Functions-Footnote-2588234 -Node: Join Function588445 -Ref: Join Function-Footnote-1590216 -Node: Getlocaltime Function590416 -Node: Readfile Function594152 -Node: Data File Management595991 -Node: Filetrans Function596623 -Node: Rewind Function600692 -Node: File Checking602079 -Ref: File Checking-Footnote-1603211 -Node: Empty Files603412 -Node: Ignoring Assigns605642 -Node: Getopt Function607196 -Ref: Getopt Function-Footnote-1618499 -Node: Passwd Functions618702 -Ref: Passwd Functions-Footnote-1627681 -Node: Group Functions627769 -Ref: Group Functions-Footnote-1635711 -Node: Walking Arrays635924 -Node: Sample Programs638060 -Node: Running Examples638734 -Node: Clones639462 -Node: Cut Program640686 -Node: Egrep Program650539 -Ref: Egrep Program-Footnote-1658510 -Node: Id Program658620 -Node: Split Program662284 -Ref: Split Program-Footnote-1665822 -Node: Tee Program665950 -Node: Uniq Program668757 -Node: Wc Program676187 -Ref: Wc Program-Footnote-1680455 -Ref: Wc Program-Footnote-2680655 -Node: Miscellaneous Programs680747 -Node: Dupword Program681935 -Node: Alarm Program683966 -Node: Translate Program688773 -Ref: Translate Program-Footnote-1693164 -Ref: Translate Program-Footnote-2693434 -Node: Labels Program693568 -Ref: Labels Program-Footnote-1696939 -Node: Word Sorting697023 -Node: History Sorting701066 -Node: Extract Program702902 -Ref: Extract Program-Footnote-1710432 -Node: Simple Sed710561 -Node: Igawk Program713623 -Ref: Igawk Program-Footnote-1728798 -Ref: Igawk Program-Footnote-2728999 -Node: Anagram Program729137 -Node: Signature Program732205 -Node: Advanced Features733452 -Node: Nondecimal Data735338 -Node: Array Sorting736915 -Node: Controlling Array Traversal737612 -Node: Array Sorting Functions745892 -Ref: Array Sorting Functions-Footnote-1749799 -Node: Two-way I/O749993 -Ref: Two-way I/O-Footnote-1755509 -Node: TCP/IP Networking755591 -Node: Profiling758435 -Node: Internationalization765943 -Node: I18N and L10N767368 -Node: Explaining gettext768054 -Ref: Explaining gettext-Footnote-1773194 -Ref: Explaining gettext-Footnote-2773378 -Node: Programmer i18n773543 -Node: Translator i18n777768 -Node: String Extraction778562 -Ref: String Extraction-Footnote-1779523 -Node: Printf Ordering779609 -Ref: Printf Ordering-Footnote-1782391 -Node: I18N Portability782455 -Ref: I18N Portability-Footnote-1784904 -Node: I18N Example784967 -Ref: I18N Example-Footnote-1787689 -Node: Gawk I18N787761 -Node: Debugger788382 -Node: Debugging789353 -Node: Debugging Concepts789794 -Node: Debugging Terms791650 -Node: Awk Debugging794247 -Node: Sample Debugging Session795139 -Node: Debugger Invocation795659 -Node: Finding The Bug796992 -Node: List of Debugger Commands803474 -Node: Breakpoint Control804806 -Node: Debugger Execution Control808470 -Node: Viewing And Changing Data811830 -Node: Execution Stack815188 -Node: Debugger Info816701 -Node: Miscellaneous Debugger Commands820695 -Node: Readline Support825879 -Node: Limitations826771 -Node: Arbitrary Precision Arithmetic829019 -Ref: Arbitrary Precision Arithmetic-Footnote-1830668 -Node: General Arithmetic830816 -Node: Floating Point Issues832536 -Node: String Conversion Precision833417 -Ref: String Conversion Precision-Footnote-1835122 -Node: Unexpected Results835231 -Node: POSIX Floating Point Problems837384 -Ref: POSIX Floating Point Problems-Footnote-1841205 -Node: Integer Programming841243 -Node: Floating-point Programming843054 -Ref: Floating-point Programming-Footnote-1849382 -Ref: Floating-point Programming-Footnote-2849652 -Node: Floating-point Representation849916 -Node: Floating-point Context851081 -Ref: table-ieee-formats851920 -Node: Rounding Mode853304 -Ref: table-rounding-modes853783 -Ref: Rounding Mode-Footnote-1856798 -Node: Gawk and MPFR856977 -Node: Arbitrary Precision Floats858386 -Ref: Arbitrary Precision Floats-Footnote-1860829 -Node: Setting Precision861150 -Ref: table-predefined-precision-strings861834 -Node: Setting Rounding Mode863979 -Ref: table-gawk-rounding-modes864383 -Node: Floating-point Constants865570 -Node: Changing Precision867022 -Ref: Changing Precision-Footnote-1868414 -Node: Exact Arithmetic868588 -Node: Arbitrary Precision Integers871722 -Ref: Arbitrary Precision Integers-Footnote-1874737 -Node: Dynamic Extensions874884 -Node: Extension Intro876342 -Node: Plugin License877607 -Node: Extension Mechanism Outline878292 -Ref: figure-load-extension878716 -Ref: figure-load-new-function880201 -Ref: figure-call-new-function881203 -Node: Extension API Description883187 -Node: Extension API Functions Introduction884637 -Node: General Data Types889503 -Ref: General Data Types-Footnote-1895196 -Node: Requesting Values895495 -Ref: table-value-types-returned896232 -Node: Memory Allocation Functions897190 -Ref: Memory Allocation Functions-Footnote-1899936 -Node: Constructor Functions900032 -Node: Registration Functions901790 -Node: Extension Functions902475 -Node: Exit Callback Functions904777 -Node: Extension Version String906026 -Node: Input Parsers906676 -Node: Output Wrappers916479 -Node: Two-way processors920995 -Node: Printing Messages923198 -Ref: Printing Messages-Footnote-1924275 -Node: Updating `ERRNO'924427 -Node: Accessing Parameters925166 -Node: Symbol Table Access926396 -Node: Symbol table by name926910 -Node: Symbol table by cookie928886 -Ref: Symbol table by cookie-Footnote-1933019 -Node: Cached values933082 -Ref: Cached values-Footnote-1936587 -Node: Array Manipulation936678 -Ref: Array Manipulation-Footnote-1937776 -Node: Array Data Types937815 -Ref: Array Data Types-Footnote-1940518 -Node: Array Functions940610 -Node: Flattening Arrays944484 -Node: Creating Arrays951336 -Node: Extension API Variables956067 -Node: Extension Versioning956703 -Node: Extension API Informational Variables958604 -Node: Extension API Boilerplate959690 -Node: Finding Extensions963494 -Node: Extension Example964054 -Node: Internal File Description964784 -Node: Internal File Ops968875 -Ref: Internal File Ops-Footnote-1980421 -Node: Using Internal File Ops980561 -Ref: Using Internal File Ops-Footnote-1982908 -Node: Extension Samples983174 -Node: Extension Sample File Functions984698 -Node: Extension Sample Fnmatch992265 -Node: Extension Sample Fork993744 -Node: Extension Sample Inplace994957 -Node: Extension Sample Ord996735 -Node: Extension Sample Readdir997571 -Ref: table-readdir-file-types998426 -Node: Extension Sample Revout999225 -Node: Extension Sample Rev2way999816 -Node: Extension Sample Read write array1000557 -Node: Extension Sample Readfile1002436 -Node: Extension Sample API Tests1003536 -Node: Extension Sample Time1004061 -Node: gawkextlib1005376 -Node: Language History1008157 -Node: V7/SVR3.11009750 -Node: SVR41012070 -Node: POSIX1013512 -Node: BTL1014898 -Node: POSIX/GNU1015632 -Node: Feature History1021231 -Node: Common Extensions1034207 -Node: Ranges and Locales1035519 -Ref: Ranges and Locales-Footnote-11040136 -Ref: Ranges and Locales-Footnote-21040163 -Ref: Ranges and Locales-Footnote-31040397 -Node: Contributors1040618 -Node: Installation1045999 -Node: Gawk Distribution1046893 -Node: Getting1047377 -Node: Extracting1048203 -Node: Distribution contents1049895 -Node: Unix Installation1055616 -Node: Quick Installation1056233 -Node: Additional Configuration Options1058679 -Node: Configuration Philosophy1060415 -Node: Non-Unix Installation1062769 -Node: PC Installation1063227 -Node: PC Binary Installation1064538 -Node: PC Compiling1066386 -Node: PC Testing1069346 -Node: PC Using1070522 -Node: Cygwin1074690 -Node: MSYS1075499 -Node: VMS Installation1076013 -Node: VMS Compilation1076809 -Ref: VMS Compilation-Footnote-11078061 -Node: VMS Dynamic Extensions1078119 -Node: VMS Installation Details1079492 -Node: VMS Running1081743 -Node: VMS GNV1084577 -Node: VMS Old Gawk1085300 -Node: Bugs1085770 -Node: Other Versions1089688 -Node: Notes1095772 -Node: Compatibility Mode1096572 -Node: Additions1097355 -Node: Accessing The Source1098282 -Node: Adding Code1099722 -Node: New Ports1105767 -Node: Derived Files1109902 -Ref: Derived Files-Footnote-11115223 -Ref: Derived Files-Footnote-21115257 -Ref: Derived Files-Footnote-31115857 -Node: Future Extensions1115955 -Node: Implementation Limitations1116538 -Node: Extension Design1117786 -Node: Old Extension Problems1118940 -Ref: Old Extension Problems-Footnote-11120448 -Node: Extension New Mechanism Goals1120505 -Ref: Extension New Mechanism Goals-Footnote-11123870 -Node: Extension Other Design Decisions1124056 -Node: Extension Future Growth1126162 -Node: Old Extension Mechanism1126998 -Node: Basic Concepts1128738 -Node: Basic High Level1129419 -Ref: figure-general-flow1129691 -Ref: figure-process-flow1130290 -Ref: Basic High Level-Footnote-11133519 -Node: Basic Data Typing1133704 -Node: Glossary1137059 -Node: Copying1162290 -Node: GNU Free Documentation License1199846 -Node: Index1224982 +Node: Empty381208 +Node: Using Shell Variables381525 +Node: Action Overview383808 +Node: Statements386159 +Node: If Statement388013 +Node: While Statement389516 +Node: Do Statement391560 +Node: For Statement392716 +Node: Switch Statement395868 +Node: Break Statement397971 +Node: Continue Statement400026 +Node: Next Statement401819 +Node: Nextfile Statement404209 +Node: Exit Statement406864 +Node: Built-in Variables409268 +Node: User-modified410364 +Ref: User-modified-Footnote-1418049 +Node: Auto-set418111 +Ref: Auto-set-Footnote-1430676 +Ref: Auto-set-Footnote-2430881 +Node: ARGC and ARGV430937 +Node: Arrays434791 +Node: Array Basics436289 +Node: Array Intro437115 +Ref: figure-array-elements439088 +Node: Reference to Elements441495 +Node: Assigning Elements443768 +Node: Array Example444259 +Node: Scanning an Array445991 +Node: Controlling Scanning449006 +Ref: Controlling Scanning-Footnote-1454179 +Node: Delete454495 +Ref: Delete-Footnote-1457260 +Node: Numeric Array Subscripts457317 +Node: Uninitialized Subscripts459500 +Node: Multidimensional461125 +Node: Multiscanning464218 +Node: Arrays of Arrays465807 +Node: Functions470447 +Node: Built-in471266 +Node: Calling Built-in472344 +Node: Numeric Functions474332 +Ref: Numeric Functions-Footnote-1478166 +Ref: Numeric Functions-Footnote-2478523 +Ref: Numeric Functions-Footnote-3478571 +Node: String Functions478840 +Ref: String Functions-Footnote-1501851 +Ref: String Functions-Footnote-2501980 +Ref: String Functions-Footnote-3502228 +Node: Gory Details502315 +Ref: table-sub-escapes503984 +Ref: table-sub-posix-92505338 +Ref: table-sub-proposed506689 +Ref: table-posix-sub508043 +Ref: table-gensub-escapes509588 +Ref: Gory Details-Footnote-1510764 +Ref: Gory Details-Footnote-2510815 +Node: I/O Functions510966 +Ref: I/O Functions-Footnote-1518089 +Node: Time Functions518236 +Ref: Time Functions-Footnote-1528700 +Ref: Time Functions-Footnote-2528768 +Ref: Time Functions-Footnote-3528926 +Ref: Time Functions-Footnote-4529037 +Ref: Time Functions-Footnote-5529149 +Ref: Time Functions-Footnote-6529376 +Node: Bitwise Functions529642 +Ref: table-bitwise-ops530204 +Ref: Bitwise Functions-Footnote-1534449 +Node: Type Functions534633 +Node: I18N Functions535775 +Node: User-defined537420 +Node: Definition Syntax538224 +Ref: Definition Syntax-Footnote-1543149 +Node: Function Example543218 +Ref: Function Example-Footnote-1545862 +Node: Function Caveats545884 +Node: Calling A Function546402 +Node: Variable Scope547357 +Node: Pass By Value/Reference550345 +Node: Return Statement553853 +Node: Dynamic Typing556837 +Node: Indirect Calls557766 +Node: Library Functions567453 +Ref: Library Functions-Footnote-1570966 +Ref: Library Functions-Footnote-2571109 +Node: Library Names571280 +Ref: Library Names-Footnote-1574753 +Ref: Library Names-Footnote-2574973 +Node: General Functions575059 +Node: Strtonum Function576087 +Node: Assert Function579017 +Node: Round Function582343 +Node: Cliff Random Function583884 +Node: Ordinal Functions584900 +Ref: Ordinal Functions-Footnote-1587977 +Ref: Ordinal Functions-Footnote-2588229 +Node: Join Function588440 +Ref: Join Function-Footnote-1590211 +Node: Getlocaltime Function590411 +Node: Readfile Function594147 +Node: Data File Management595986 +Node: Filetrans Function596618 +Node: Rewind Function600687 +Node: File Checking602074 +Ref: File Checking-Footnote-1603206 +Node: Empty Files603407 +Node: Ignoring Assigns605637 +Node: Getopt Function607191 +Ref: Getopt Function-Footnote-1618494 +Node: Passwd Functions618697 +Ref: Passwd Functions-Footnote-1627676 +Node: Group Functions627764 +Ref: Group Functions-Footnote-1635706 +Node: Walking Arrays635919 +Node: Sample Programs638055 +Node: Running Examples638729 +Node: Clones639457 +Node: Cut Program640681 +Node: Egrep Program650534 +Ref: Egrep Program-Footnote-1658505 +Node: Id Program658615 +Node: Split Program662279 +Ref: Split Program-Footnote-1665817 +Node: Tee Program665945 +Node: Uniq Program668752 +Node: Wc Program676182 +Ref: Wc Program-Footnote-1680450 +Ref: Wc Program-Footnote-2680650 +Node: Miscellaneous Programs680742 +Node: Dupword Program681930 +Node: Alarm Program683961 +Node: Translate Program688768 +Ref: Translate Program-Footnote-1693159 +Ref: Translate Program-Footnote-2693429 +Node: Labels Program693563 +Ref: Labels Program-Footnote-1696934 +Node: Word Sorting697018 +Node: History Sorting701061 +Node: Extract Program702897 +Ref: Extract Program-Footnote-1710427 +Node: Simple Sed710556 +Node: Igawk Program713618 +Ref: Igawk Program-Footnote-1728793 +Ref: Igawk Program-Footnote-2728994 +Node: Anagram Program729132 +Node: Signature Program732200 +Node: Advanced Features733447 +Node: Nondecimal Data735333 +Node: Array Sorting736910 +Node: Controlling Array Traversal737607 +Node: Array Sorting Functions745887 +Ref: Array Sorting Functions-Footnote-1749794 +Node: Two-way I/O749988 +Ref: Two-way I/O-Footnote-1755504 +Node: TCP/IP Networking755586 +Node: Profiling758430 +Node: Internationalization765938 +Node: I18N and L10N767363 +Node: Explaining gettext768049 +Ref: Explaining gettext-Footnote-1773189 +Ref: Explaining gettext-Footnote-2773373 +Node: Programmer i18n773538 +Node: Translator i18n777763 +Node: String Extraction778557 +Ref: String Extraction-Footnote-1779518 +Node: Printf Ordering779604 +Ref: Printf Ordering-Footnote-1782386 +Node: I18N Portability782450 +Ref: I18N Portability-Footnote-1784899 +Node: I18N Example784962 +Ref: I18N Example-Footnote-1787684 +Node: Gawk I18N787756 +Node: Debugger788377 +Node: Debugging789348 +Node: Debugging Concepts789789 +Node: Debugging Terms791645 +Node: Awk Debugging794242 +Node: Sample Debugging Session795134 +Node: Debugger Invocation795654 +Node: Finding The Bug796987 +Node: List of Debugger Commands803469 +Node: Breakpoint Control804801 +Node: Debugger Execution Control808465 +Node: Viewing And Changing Data811825 +Node: Execution Stack815183 +Node: Debugger Info816696 +Node: Miscellaneous Debugger Commands820690 +Node: Readline Support825874 +Node: Limitations826766 +Node: Arbitrary Precision Arithmetic829014 +Ref: Arbitrary Precision Arithmetic-Footnote-1830663 +Node: General Arithmetic830811 +Node: Floating Point Issues832531 +Node: String Conversion Precision833412 +Ref: String Conversion Precision-Footnote-1835117 +Node: Unexpected Results835226 +Node: POSIX Floating Point Problems837379 +Ref: POSIX Floating Point Problems-Footnote-1841200 +Node: Integer Programming841238 +Node: Floating-point Programming843049 +Ref: Floating-point Programming-Footnote-1849377 +Ref: Floating-point Programming-Footnote-2849647 +Node: Floating-point Representation849911 +Node: Floating-point Context851076 +Ref: table-ieee-formats851915 +Node: Rounding Mode853299 +Ref: table-rounding-modes853778 +Ref: Rounding Mode-Footnote-1856793 +Node: Gawk and MPFR856972 +Node: Arbitrary Precision Floats858381 +Ref: Arbitrary Precision Floats-Footnote-1860824 +Node: Setting Precision861145 +Ref: table-predefined-precision-strings861829 +Node: Setting Rounding Mode863974 +Ref: table-gawk-rounding-modes864378 +Node: Floating-point Constants865565 +Node: Changing Precision867017 +Ref: Changing Precision-Footnote-1868409 +Node: Exact Arithmetic868583 +Node: Arbitrary Precision Integers871717 +Ref: Arbitrary Precision Integers-Footnote-1874732 +Node: Dynamic Extensions874879 +Node: Extension Intro876337 +Node: Plugin License877602 +Node: Extension Mechanism Outline878287 +Ref: figure-load-extension878711 +Ref: figure-load-new-function880196 +Ref: figure-call-new-function881198 +Node: Extension API Description883182 +Node: Extension API Functions Introduction884632 +Node: General Data Types889498 +Ref: General Data Types-Footnote-1895191 +Node: Requesting Values895490 +Ref: table-value-types-returned896227 +Node: Memory Allocation Functions897185 +Ref: Memory Allocation Functions-Footnote-1899931 +Node: Constructor Functions900027 +Node: Registration Functions901785 +Node: Extension Functions902470 +Node: Exit Callback Functions904772 +Node: Extension Version String906021 +Node: Input Parsers906671 +Node: Output Wrappers916474 +Node: Two-way processors920990 +Node: Printing Messages923193 +Ref: Printing Messages-Footnote-1924270 +Node: Updating `ERRNO'924422 +Node: Accessing Parameters925161 +Node: Symbol Table Access926391 +Node: Symbol table by name926905 +Node: Symbol table by cookie928881 +Ref: Symbol table by cookie-Footnote-1933014 +Node: Cached values933077 +Ref: Cached values-Footnote-1936582 +Node: Array Manipulation936673 +Ref: Array Manipulation-Footnote-1937771 +Node: Array Data Types937810 +Ref: Array Data Types-Footnote-1940513 +Node: Array Functions940605 +Node: Flattening Arrays944479 +Node: Creating Arrays951331 +Node: Extension API Variables956062 +Node: Extension Versioning956698 +Node: Extension API Informational Variables958599 +Node: Extension API Boilerplate959685 +Node: Finding Extensions963489 +Node: Extension Example964049 +Node: Internal File Description964779 +Node: Internal File Ops968870 +Ref: Internal File Ops-Footnote-1980416 +Node: Using Internal File Ops980556 +Ref: Using Internal File Ops-Footnote-1982903 +Node: Extension Samples983169 +Node: Extension Sample File Functions984693 +Node: Extension Sample Fnmatch992260 +Node: Extension Sample Fork993739 +Node: Extension Sample Inplace994952 +Node: Extension Sample Ord996730 +Node: Extension Sample Readdir997566 +Ref: table-readdir-file-types998421 +Node: Extension Sample Revout999220 +Node: Extension Sample Rev2way999811 +Node: Extension Sample Read write array1000552 +Node: Extension Sample Readfile1002431 +Node: Extension Sample API Tests1003531 +Node: Extension Sample Time1004056 +Node: gawkextlib1005371 +Node: Language History1008152 +Node: V7/SVR3.11009745 +Node: SVR41012065 +Node: POSIX1013507 +Node: BTL1014893 +Node: POSIX/GNU1015627 +Node: Feature History1021226 +Node: Common Extensions1034202 +Node: Ranges and Locales1035514 +Ref: Ranges and Locales-Footnote-11040131 +Ref: Ranges and Locales-Footnote-21040158 +Ref: Ranges and Locales-Footnote-31040392 +Node: Contributors1040613 +Node: Installation1045994 +Node: Gawk Distribution1046888 +Node: Getting1047372 +Node: Extracting1048198 +Node: Distribution contents1049890 +Node: Unix Installation1055611 +Node: Quick Installation1056228 +Node: Additional Configuration Options1058674 +Node: Configuration Philosophy1060410 +Node: Non-Unix Installation1062764 +Node: PC Installation1063222 +Node: PC Binary Installation1064533 +Node: PC Compiling1066381 +Node: PC Testing1069341 +Node: PC Using1070517 +Node: Cygwin1074685 +Node: MSYS1075494 +Node: VMS Installation1076008 +Node: VMS Compilation1076804 +Ref: VMS Compilation-Footnote-11078056 +Node: VMS Dynamic Extensions1078114 +Node: VMS Installation Details1079487 +Node: VMS Running1081738 +Node: VMS GNV1084572 +Node: VMS Old Gawk1085295 +Node: Bugs1085765 +Node: Other Versions1089683 +Node: Notes1095767 +Node: Compatibility Mode1096567 +Node: Additions1097350 +Node: Accessing The Source1098277 +Node: Adding Code1099717 +Node: New Ports1105762 +Node: Derived Files1109897 +Ref: Derived Files-Footnote-11115218 +Ref: Derived Files-Footnote-21115252 +Ref: Derived Files-Footnote-31115852 +Node: Future Extensions1115950 +Node: Implementation Limitations1116533 +Node: Extension Design1117781 +Node: Old Extension Problems1118935 +Ref: Old Extension Problems-Footnote-11120443 +Node: Extension New Mechanism Goals1120500 +Ref: Extension New Mechanism Goals-Footnote-11123865 +Node: Extension Other Design Decisions1124051 +Node: Extension Future Growth1126157 +Node: Old Extension Mechanism1126993 +Node: Basic Concepts1128733 +Node: Basic High Level1129414 +Ref: figure-general-flow1129686 +Ref: figure-process-flow1130285 +Ref: Basic High Level-Footnote-11133514 +Node: Basic Data Typing1133699 +Node: Glossary1137054 +Node: Copying1162285 +Node: GNU Free Documentation License1199841 +Node: Index1224977  End Tag Table -- cgit v1.2.3 From 4e18efb370c2e688c35b64270e1bcb625ea3abb0 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sun, 25 May 2014 06:21:55 +0300 Subject: Edits through Appendix A. --- doc/gawk.info | 168 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 85 insertions(+), 83 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 4852a58f..48a8e9a4 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -25090,7 +25090,7 @@ the POSIX specification. Many long-time `awk' users learned `awk' programming with the original `awk' implementation in Version 7 Unix. (This implementation was the basis for `awk' in Berkeley Unix, through 4.3-Reno. Subsequent versions of Berkeley Unix, and some systems -derived from 4.4BSD-Lite, use various versions of `gawk' for their +derived from 4.4BSD-Lite, used various versions of `gawk' for their `awk'.) This major node briefly describes the evolution of the `awk' language, with cross-references to other parts of the Info file where you can find more information. @@ -25532,8 +25532,8 @@ in POSIX `awk', in the order they were added to `gawk'. * The `next file' statement became `nextfile' (*note Nextfile Statement::). - * The `fflush()' function from the Bell Laboratories research - version of `awk' (*note I/O Functions::). + * The `fflush()' function from Brian Kernighan's `awk' (then at Bell + Laboratories; *note I/O Functions::). * New command line options: @@ -25541,8 +25541,9 @@ in POSIX `awk', in the order they were added to `gawk'. available in the original Version 7 Unix version of `awk' (*note V7/SVR3.1::). - - The `-m' option from the Bell Laboratories research version - of `awk' This was later removed. + - The `-m' option from Brian Kernighan's `awk'. (He was still + at Bell Laboratories at the time.) This was later removed + from both his `awk' and from `gawk'. - The `--re-interval' option to provide interval expressions in regexps (*note Regexp Operators::). @@ -25553,7 +25554,7 @@ in POSIX `awk', in the order they were added to `gawk'. * The use of GNU Autoconf to control the configuration process (*note Quick Installation::). - * Amiga support. + * Amiga support. This has since been removed. Version 3.1 of `gawk' introduced the following features: @@ -25644,7 +25645,8 @@ in POSIX `awk', in the order they were added to `gawk'. * Tandem support. This was later removed. - * The Atari port became officially unsupported. + * The Atari port became officially unsupported and was later removed + entirely. * The source code changed to use ISO C standard-style function definitions. @@ -25706,8 +25708,8 @@ in POSIX `awk', in the order they were added to `gawk'. output redirections (*note I/O Functions::). * The `isarray()' function which distinguishes if an item is an array - or not, to make it possible to traverse multidimensional arrays - (*note Type Functions::). + or not, to make it possible to traverse arrays of arrays (*note + Type Functions::). * The `patsplit()' function which gives the same capability as `FPAT', for splitting (*note String Functions::). @@ -26008,8 +26010,8 @@ Info file, in approximate chronological order: * Michal Jaegermann provided the port to Atari systems and its documentation. (This port is no longer supported.) He continues - to provide portability checking with DEC Alpha systems, and has - done a lot of work to make sure `gawk' works on non-32-bit systems. + to provide portability checking, and has done a lot of work to + make sure `gawk' works on non-32-bit systems. * Fred Fish provided the port to Amiga systems and its documentation. (With Fred's sad passing, this is no longer supported.) @@ -26074,8 +26076,8 @@ Info file, in approximate chronological order: - The modifications to convert `gawk' into a byte-code interpreter, including the debugger. - - The addition of true multidimensional arrays. *note Arrays - of Arrays::. + - The addition of true arrays of arrays. *note Arrays of + Arrays::. - The additional modifications for support of arbitrary precision arithmetic. @@ -32153,7 +32155,7 @@ Index (line 19) * next debugger command: Debugger Execution Control. (line 43) -* next file statement: Feature History. (line 168) +* next file statement: Feature History. (line 169) * next statement <1>: Next Statement. (line 6) * next statement: Boolean Ops. (line 85) * next statement, BEGIN/END patterns and: I/O And BEGIN/END. (line 37) @@ -33671,74 +33673,74 @@ Node: Extension Sample API Tests1003531 Node: Extension Sample Time1004056 Node: gawkextlib1005371 Node: Language History1008152 -Node: V7/SVR3.11009745 -Node: SVR41012065 -Node: POSIX1013507 -Node: BTL1014893 -Node: POSIX/GNU1015627 -Node: Feature History1021226 -Node: Common Extensions1034202 -Node: Ranges and Locales1035514 -Ref: Ranges and Locales-Footnote-11040131 -Ref: Ranges and Locales-Footnote-21040158 -Ref: Ranges and Locales-Footnote-31040392 -Node: Contributors1040613 -Node: Installation1045994 -Node: Gawk Distribution1046888 -Node: Getting1047372 -Node: Extracting1048198 -Node: Distribution contents1049890 -Node: Unix Installation1055611 -Node: Quick Installation1056228 -Node: Additional Configuration Options1058674 -Node: Configuration Philosophy1060410 -Node: Non-Unix Installation1062764 -Node: PC Installation1063222 -Node: PC Binary Installation1064533 -Node: PC Compiling1066381 -Node: PC Testing1069341 -Node: PC Using1070517 -Node: Cygwin1074685 -Node: MSYS1075494 -Node: VMS Installation1076008 -Node: VMS Compilation1076804 -Ref: VMS Compilation-Footnote-11078056 -Node: VMS Dynamic Extensions1078114 -Node: VMS Installation Details1079487 -Node: VMS Running1081738 -Node: VMS GNV1084572 -Node: VMS Old Gawk1085295 -Node: Bugs1085765 -Node: Other Versions1089683 -Node: Notes1095767 -Node: Compatibility Mode1096567 -Node: Additions1097350 -Node: Accessing The Source1098277 -Node: Adding Code1099717 -Node: New Ports1105762 -Node: Derived Files1109897 -Ref: Derived Files-Footnote-11115218 -Ref: Derived Files-Footnote-21115252 -Ref: Derived Files-Footnote-31115852 -Node: Future Extensions1115950 -Node: Implementation Limitations1116533 -Node: Extension Design1117781 -Node: Old Extension Problems1118935 -Ref: Old Extension Problems-Footnote-11120443 -Node: Extension New Mechanism Goals1120500 -Ref: Extension New Mechanism Goals-Footnote-11123865 -Node: Extension Other Design Decisions1124051 -Node: Extension Future Growth1126157 -Node: Old Extension Mechanism1126993 -Node: Basic Concepts1128733 -Node: Basic High Level1129414 -Ref: figure-general-flow1129686 -Ref: figure-process-flow1130285 -Ref: Basic High Level-Footnote-11133514 -Node: Basic Data Typing1133699 -Node: Glossary1137054 -Node: Copying1162285 -Node: GNU Free Documentation License1199841 -Node: Index1224977 +Node: V7/SVR3.11009746 +Node: SVR41012066 +Node: POSIX1013508 +Node: BTL1014894 +Node: POSIX/GNU1015628 +Node: Feature History1021227 +Node: Common Extensions1034339 +Node: Ranges and Locales1035651 +Ref: Ranges and Locales-Footnote-11040268 +Ref: Ranges and Locales-Footnote-21040295 +Ref: Ranges and Locales-Footnote-31040529 +Node: Contributors1040750 +Node: Installation1046101 +Node: Gawk Distribution1046995 +Node: Getting1047479 +Node: Extracting1048305 +Node: Distribution contents1049997 +Node: Unix Installation1055718 +Node: Quick Installation1056335 +Node: Additional Configuration Options1058781 +Node: Configuration Philosophy1060517 +Node: Non-Unix Installation1062871 +Node: PC Installation1063329 +Node: PC Binary Installation1064640 +Node: PC Compiling1066488 +Node: PC Testing1069448 +Node: PC Using1070624 +Node: Cygwin1074792 +Node: MSYS1075601 +Node: VMS Installation1076115 +Node: VMS Compilation1076911 +Ref: VMS Compilation-Footnote-11078163 +Node: VMS Dynamic Extensions1078221 +Node: VMS Installation Details1079594 +Node: VMS Running1081845 +Node: VMS GNV1084679 +Node: VMS Old Gawk1085402 +Node: Bugs1085872 +Node: Other Versions1089790 +Node: Notes1095874 +Node: Compatibility Mode1096674 +Node: Additions1097457 +Node: Accessing The Source1098384 +Node: Adding Code1099824 +Node: New Ports1105869 +Node: Derived Files1110004 +Ref: Derived Files-Footnote-11115325 +Ref: Derived Files-Footnote-21115359 +Ref: Derived Files-Footnote-31115959 +Node: Future Extensions1116057 +Node: Implementation Limitations1116640 +Node: Extension Design1117888 +Node: Old Extension Problems1119042 +Ref: Old Extension Problems-Footnote-11120550 +Node: Extension New Mechanism Goals1120607 +Ref: Extension New Mechanism Goals-Footnote-11123972 +Node: Extension Other Design Decisions1124158 +Node: Extension Future Growth1126264 +Node: Old Extension Mechanism1127100 +Node: Basic Concepts1128840 +Node: Basic High Level1129521 +Ref: figure-general-flow1129793 +Ref: figure-process-flow1130392 +Ref: Basic High Level-Footnote-11133621 +Node: Basic Data Typing1133806 +Node: Glossary1137161 +Node: Copying1162392 +Node: GNU Free Documentation License1199948 +Node: Index1225084  End Tag Table -- cgit v1.2.3 From a7eae6112b56320655433e4e3c8a67f6f7321bdd Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 27 May 2014 07:13:01 +0300 Subject: Finish edits! --- doc/gawk.info | 1505 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 755 insertions(+), 750 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 48a8e9a4..ceeeb6f7 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -637,7 +637,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * New Ports:: Porting `gawk' to a new operating system. * Derived Files:: Why derived files are kept in the - `git' repository. + Git repository. * Future Extensions:: New features that may be implemented one day. * Implementation Limitations:: Some limitations of the @@ -1328,7 +1328,7 @@ for now. *Note User-defined::.) Each rule specifies one pattern to search for and one action to perform upon finding the pattern. Syntactically, a rule consists of a pattern followed by an action. -The action is enclosed in curly braces to separate it from the pattern. +The action is enclosed in braces to separate it from the pattern. Newlines usually separate rules. Therefore, an `awk' program looks like this: @@ -1877,10 +1877,10 @@ for _every_ input line. If the action is omitted, the default action is to print all lines that match the pattern. Thus, we could leave out the action (the `print' statement and the -curly braces) in the previous example and the result would be the same: -`awk' prints all lines matching the pattern `li'. By comparison, -omitting the `print' statement but retaining the curly braces makes an -empty action that does nothing (i.e., no lines are printed). +braces) in the previous example and the result would be the same: `awk' +prints all lines matching the pattern `li'. By comparison, omitting +the `print' statement but retaining the braces makes an empty action +that does nothing (i.e., no lines are printed). Many practical `awk' programs are just a line or two. Following is a collection of useful, short programs to get you started. Some of these @@ -8940,12 +8940,12 @@ outline, an `awk' program generally looks like this: ... An action consists of one or more `awk' "statements", enclosed in -curly braces (`{...}'). Each statement specifies one thing to do. The -statements are separated by newlines or semicolons. The curly braces -around an action must be used even if the action contains only one -statement, or if it contains no statements at all. However, if you -omit the action entirely, omit the curly braces as well. An omitted -action is equivalent to `{ print $0 }': +braces (`{...}'). Each statement specifies one thing to do. The +statements are separated by newlines or semicolons. The braces around +an action must be used even if the action contains only one statement, +or if it contains no statements at all. However, if you omit the +action entirely, omit the braces as well. An omitted action is +equivalent to `{ print $0 }': /foo/ { } match `foo', do nothing -- empty action /foo/ match `foo', print the record -- omitted action @@ -8964,9 +8964,9 @@ Control statements well as a few special ones (*note Statements::). Compound statements - Enclose one or more statements in curly braces. A compound - statement is used in order to put several statements together in - the body of an `if', `while', `do', or `for' statement. + Enclose one or more statements in braces. A compound statement is + used in order to put several statements together in the body of an + `if', `while', `do', or `for' statement. Input statements Use the `getline' command (*note Getline::). Also supplied in @@ -8995,7 +8995,7 @@ statements contain other statements. For example, the `if' statement contains another statement that may or may not be executed. The contained statement is called the "body". To include more than one statement in the body, group them into a single "compound statement" -with curly braces, separating them with newlines or semicolons. +with braces, separating them with newlines or semicolons. * Menu: @@ -9043,8 +9043,8 @@ the value of `x' is evenly divisible by two), then the first `print' statement is executed; otherwise, the second `print' statement is executed. If the `else' keyword appears on the same line as THEN-BODY and THEN-BODY is not a compound statement (i.e., not surrounded by -curly braces), then a semicolon must separate THEN-BODY from the `else'. -To illustrate this, the previous example can be rewritten as: +braces), then a semicolon must separate THEN-BODY from the `else'. To +illustrate this, the previous example can be rewritten as: if (x % 2 == 0) print "x is even"; else print "x is odd" @@ -24427,7 +24427,7 @@ directory and run the program: ---------- Footnotes ---------- (1) In practice, you would probably want to use the GNU -Autotools--Automake, Autoconf, Libtool, and Gettext--to configure and +Autotools--Automake, Autoconf, Libtool, and `gettext'--to configure and build your libraries. Instructions for doing so are beyond the scope of this Info file. *Note gawkextlib::, for WWW links to the tools. @@ -25050,7 +25050,7 @@ parser library installed in order to build and use the XML extension. In addition, you must have the GNU Autotools installed (Autoconf (http://www.gnu.org/software/autoconf), Automake (http://www.gnu.org/software/automake), Libtool -(http://www.gnu.org/software/libtool), and Gettext +(http://www.gnu.org/software/libtool), and GNU `gettext' (http://www.gnu.org/software/gettext)). The simple recipe for building and testing `gawkextlib' is as @@ -26181,7 +26181,6 @@ the GNU Zip program, `gzip'. use `gzip' to expand the file and then use `tar' to extract it. You can use the following pipeline to produce the `gawk' distribution: - # Under System V, add 'o' to the tar options gzip -d -c gawk-4.1.1.tar.gz | tar -xvpf - On a system with GNU `tar', you can let `tar' do the decompression @@ -26317,8 +26316,8 @@ Various `.c', `.y', and `.h' files `Makefile.am' `*/Makefile.am' - Files used by the GNU `automake' software for generating the - `Makefile.in' files used by `autoconf' and `configure'. + Files used by the GNU Automake software for generating the + `Makefile.in' files used by Autoconf and `configure'. `Makefile.in' `aclocal.m4' @@ -26409,8 +26408,8 @@ environment for MS-Windows. `gawk-4.1.1'. Like most GNU software, `gawk' is configured automatically for your system by running the `configure' program. This program is a Bourne shell script that is generated automatically using -GNU `autoconf'. (The `autoconf' software is described fully starting -with *note (Autoconf)Top:: autoconf,Autoconf--Generating Automatic +GNU Autoconf. (The Autoconf software is described fully starting with +*note (Autoconf)Top:: autoconf,Autoconf--Generating Automatic Configuration Scripts.) To configure `gawk', simply run `configure': @@ -26488,8 +26487,8 @@ command line when compiling `gawk' from scratch, including: improvement. `--with-whiny-user-strftime' - Force use of the included version of the `strftime()' function for - deficient systems. + Force use of the included version of the C `strftime()' function + for deficient systems. Use the command `./configure --help' to see the full list of options that `configure' supplies. @@ -26533,9 +26532,9 @@ any constants that `configure' defined and should not have. `custom.h' is automatically included by `config.h'. It is also possible that the `configure' program generated by -`autoconf' will not work on your system in some other fashion. If you -do have a problem, the file `configure.ac' is the input for `autoconf'. -You may be able to change this file and generate a new version of +Autoconf will not work on your system in some other fashion. If you do +have a problem, the file `configure.ac' is the input for Autoconf. You +may be able to change this file and generate a new version of `configure' that works on your system (*note Bugs::, for information on how to report problems in configuring `gawk'). The same mechanism may be used to send in updates to `configure.ac' and/or `custom.h'. @@ -26696,7 +26695,12 @@ other set of (self-consistent) environment variables and compiler flags. NOTE: Ancient OS/2 ports of GNU `make' are not able to handle the Makefiles of this package. If you encounter any problems with `make', try GNU Make 3.79.1 or later versions. You should find - the latest version on `ftp://hobbes.nmsu.edu/pub/os2/'. + the latest version on `ftp://hobbes.nmsu.edu/pub/os2/'.(1) + + ---------- Footnotes ---------- + + (1) As of May, 2014, this site is still there, but the author could +not find a package for GNU Make.  File: gawk.info, Node: PC Testing, Next: PC Using, Prev: PC Compiling, Up: PC Installation @@ -26737,11 +26741,11 @@ Networking::). EMX (OS/2 only) supports at least the `|&' operator. files as described in *note AWKPATH Variable::. However, semicolons (rather than colons) separate elements in the `AWKPATH' variable. If `AWKPATH' is not set or is empty, then the default search path for -MS-Windows and MS-DOS versions is `".;c:/lib/awk;c:/gnu/lib/awk"'. +MS-Windows and MS-DOS versions is `.;c:/lib/awk;c:/gnu/lib/awk'. The search path for OS/2 (32 bit, EMX) is determined by the prefix directory (most likely `/usr' or `c:/usr') that has been specified as -an option of the `configure' script like it is the case for the Unix +an option of the `configure' script as is the case for the Unix versions. If `c:/usr' is the prefix directory then the default search path contains `.' and `c:/usr/share/awk'. Additionally, to support binary distributions of `gawk' for OS/2 systems whose drive `c:' might @@ -26749,7 +26753,7 @@ not support long file names or might not exist at all, there is a special environment variable. If `UNIXROOT' specifies a drive then this specific drive is also searched for program files. E.g., if `UNIXROOT' is set to `e:' the complete default search path is -`".;c:/usr/share/awk;e:/usr/share/awk"'. +`.;c:/usr/share/awk;e:/usr/share/awk'. An `sh'-like shell (as opposed to `command.com' under MS-DOS or `cmd.exe' under MS-Windows or OS/2) may be useful for `awk' programming. @@ -26757,10 +26761,9 @@ The DJGPP collection of tools includes an MS-DOS port of Bash, and several shells are available for OS/2, including `ksh'. Under MS-Windows, OS/2 and MS-DOS, `gawk' (and many other text -programs) silently translate end-of-line `"\r\n"' to `"\n"' on input -and `"\n"' to `"\r\n"' on output. A special `BINMODE' variable -(c.e.) allows control over these translations and is interpreted as -follows: +programs) silently translate end-of-line `\r\n' to `\n' on input and +`\n' to `\r\n' on output. A special `BINMODE' variable (c.e.) allows +control over these translations and is interpreted as follows: * If `BINMODE' is `"r"', or one, then binary mode is set on read (i.e., no translations on reads). @@ -26786,11 +26789,11 @@ and cannot be changed mid-stream. Versions::). `mawk' and `gawk' handle `BINMODE' similarly; however, `mawk' adds a `-W BINMODE=N' option and an environment variable that can set `BINMODE', `RS', and `ORS'. The files `binmode[1-3].awk' -(under `gnu/lib/awk' in some of the prepared distributions) have been -chosen to match `mawk''s `-W BINMODE=N' option. These can be changed -or discarded; in particular, the setting of `RS' giving the fewest -"surprises" is open to debate. `mawk' uses `RS = "\r\n"' if binary -mode is set on read, which is appropriate for files with the +(under `gnu/lib/awk' in some of the prepared binary distributions) have +been chosen to match `mawk''s `-W BINMODE=N' option. These can be +changed or discarded; in particular, the setting of `RS' giving the +fewest "surprises" is open to debate. `mawk' uses `RS = "\r\n"' if +binary mode is set on read, which is appropriate for files with the MS-DOS-style end-of-line. To illustrate, the following examples set binary mode on writes for @@ -26893,10 +26896,10 @@ or: $ MMK/DESCRIPTION=[.vms]descrip.mms gawk `MMK' is an open source, free, near-clone of `MMS' and can better -handle `ODS-5' volumes with upper- and lowercase filenames. `MMK' is +handle ODS-5 volumes with upper- and lowercase filenames. `MMK' is available from `https://github.com/endlesssoftware/mmk'. - With `ODS-5' volumes and extended parsing enabled, the case of the + With ODS-5 volumes and extended parsing enabled, the case of the target parameter may need to be exact. `gawk' has been tested under VAX/VMS 7.3 and Alpha/VMS 7.3-1 using @@ -26904,8 +26907,8 @@ Compaq C V6.4, and Alpha/VMS 7.3, Alpha/VMS 7.3-2, and IA64/VMS 8.3. The most recent builds used HP C V7.3 on Alpha VMS 8.3 and both Alpha and IA64 VMS 8.4 used HP C 7.3.(1) - The `[.vms]gawk_build_steps.txt' provides information on how to build -`gawk' into a PCSI kit that is compatible with the GNV product. + *Note VMS GNV::, for information on building `gawk' as a PCSI kit +that is compatible with the GNV product. ---------- Footnotes ---------- @@ -27147,11 +27150,12 @@ get this information with the command `gawk --version'. Once you have a precise problem, send email to . - Using this address automatically sends a copy of your mail to me. -If necessary, I can be reached directly at . The -bug reporting address is preferred since the email list is archived at -the GNU Project. _All email should be in English, since that is my -native language._ + The `gawk' maintainers subscribe to this address and thus they will +receive your bug report. If necessary, the primary maintainer can be +reached directly at . The bug reporting address is +preferred since the email list is archived at the GNU Project. _All +email should be in English. This is the only language understood in +common by all the maintainers._ CAUTION: Do _not_ try to report bugs in `gawk' by posting to the Usenet/Internet newsgroup `comp.lang.awk'. While the `gawk' @@ -27186,7 +27190,7 @@ considered authoritative if it conflicts with this Info file. The people maintaining the non-Unix ports of `gawk' are as follows: MS-DOS with DJGPP Scott Deifik, . -MS-Windows with MINGW Eli Zaretskii, . +MS-Windows with MinGW Eli Zaretskii, . OS/2 Andreas Buening, . VMS Pat Rankin, , and John Malmberg, . @@ -27292,12 +27296,13 @@ Busybox Awk (http://busybox.net). The OpenSolaris POSIX `awk' - The version of `awk' in `/usr/xpg4/bin' on Solaris is more-or-less - POSIX-compliant. It is based on the `awk' from Mortice Kern - Systems for PCs. This author was able to make it compile and work - under GNU/Linux with 1-2 hours of work. Making it more generally - portable (using GNU Autoconf and/or Automake) would take more - work, and this has not been done, at least to our knowledge. + The versions of `awk' in `/usr/xpg4/bin' and `/usr/xpg6/bin' on + Solaris are more-or-less POSIX-compliant. They are based on the + `awk' from Mortice Kern Systems for PCs. This author was able to + make this code compile and work under GNU/Linux with 1-2 hours of + work. Making it more generally portable (using GNU Autoconf + and/or Automake) would take more work, and this has not been done, + at least to our knowledge. The source code used to be available from the OpenSolaris web site. However, that project was ended and the web site shut down. @@ -27335,6 +27340,9 @@ QSE Awk `http://www.quiktrim.org/QTawk.html' for more information, including the manual and a download link. + The project may als be frozen; no new code changes have been made + since approximately 2008. + Other Versions See also the Wikipedia article (http://en.wikipedia.org/wiki/Awk_language#Versions_and_implementations), @@ -27377,7 +27385,7 @@ one more option available on the command line: `-Y' `--parsedebug' - Prints out the parse stack information as the program is being + Print out the parse stack information as the program is being parsed. This option is intended only for serious `gawk' developers and not @@ -27406,7 +27414,7 @@ as well as any considerations you should bear in mind. * New Ports:: Porting `gawk' to a new operating system. * Derived Files:: Why derived files are kept in the - `git' repository. + Git repository.  File: gawk.info, Node: Accessing The Source, Next: Adding Code, Up: Additions @@ -27427,9 +27435,9 @@ doesn't have it. Once you have done so, use the command: git clone git://git.savannah.gnu.org/gawk.git -This will clone the `gawk' repository. If you are behind a firewall -that will not allow you to use the Git native protocol, you can still -access the repository using: +This clones the `gawk' repository. If you are behind a firewall that +does not allow you to use the Git native protocol, you can still access +the repository using: git clone http://git.savannah.gnu.org/r/gawk.git @@ -27451,7 +27459,7 @@ C.2.2 Adding New Features You are free to add any new features you like to `gawk'. However, if you want your changes to be incorporated into the `gawk' distribution, there are several steps that you need to take in order to make it -possible to include your changes: +possible to include them: 1. Before building the new feature into `gawk' itself, consider writing it as an extension module (*note Dynamic Extensions::). @@ -27468,9 +27476,10 @@ possible to include your changes: 3. Get the latest version. It is much easier for me to integrate changes if they are relative to the most recent distributed - version of `gawk'. If your version of `gawk' is very old, I may - not be able to integrate them at all. (*Note Getting::, for - information on getting the latest version of `gawk'.) + version of `gawk', or better yet, relative to the latest code in + the Git repository. If your version of `gawk' is very old, I may + not be able to integrate your changes at all. (*Note Getting::, + for information on getting the latest version of `gawk'.) 4. See *note (Version)Top:: standards, GNU Coding Standards. This document describes how GNU software should be written. If you @@ -27567,7 +27576,8 @@ possible to include your changes: 8. Include an entry for the `ChangeLog' file with your submission. This helps further minimize the amount of work I have to do, - making it easier for me to accept patches. + making it easier for me to accept patches. It is simplest if you + just make this part of your diff. Although this sounds like a lot of work, please remember that while you may write the new code, I have to maintain it and support it. If it @@ -27608,18 +27618,24 @@ steps: people. Thus, you should not change them unless it is for a very good reason; i.e., changes are not out of the question, but changes to these files are scrutinized extra carefully. The files - are `dfa.c', `dfa.h', `getopt1.c', `getopt.c', `getopt.h', - `install-sh', `mkinstalldirs', `regcomp.c', `regex.c', - `regexec.c', `regexex.c', `regex.h', `regex_internal.c', and - `regex_internal.h'. - - 5. Be willing to continue to maintain the port. Non-Unix operating + are `dfa.c', `dfa.h', `getopt.c', `getopt.h', `getopt1.c', + `getopt_int.h', `gettext.h', `regcomp.c', `regex.c', `regex.h', + `regex_internal.c', `regex_internal.h', and `regexec.c'. + + 5. A number of other files are provided by the GNU Autotools + (Autoconf, Automake, and GNU `gettext'). You should not change + them either, unless it is for a very good reason. The files are + `ABOUT-NLS', `config.guess', `config.rpath', `config.sub', + `depcomp', `INSTALL', `install-sh', `missing', `mkinstalldirs', + `xalloc.h', and `ylwrap'. + + 6. Be willing to continue to maintain the port. Non-Unix operating systems are supported by volunteers who maintain the code needed to compile and run `gawk' on their systems. If noone volunteers to maintain a port, it becomes unsupported and it may be necessary to remove it from the distribution. - 6. Supply an appropriate `gawkmisc.???' file. Each port has its own + 7. Supply an appropriate `gawkmisc.???' file. Each port has its own `gawkmisc.???' that implements certain operating system specific functions. This is cleaner than a plethora of `#ifdef's scattered throughout the code. The `gawkmisc.c' in the main source @@ -27635,7 +27651,7 @@ steps: (Currently, this is only an issue for the PC operating system ports.) - 7. Supply a `Makefile' as well as any other C source and header files + 8. Supply a `Makefile' as well as any other C source and header files that are necessary for your operating system. All your code should be in a separate subdirectory, with a name that is the same as, or reminiscent of, either your operating system or the @@ -27645,7 +27661,7 @@ steps: avoid using names for your files that duplicate the names of files in the main source directory. - 8. Update the documentation. Please write a section (or sections) + 9. Update the documentation. Please write a section (or sections) for this Info file describing the installation and compilation steps needed to compile and/or install `gawk' for your system. @@ -27659,13 +27675,13 @@ style and brace layout that suits your taste.  File: gawk.info, Node: Derived Files, Prev: New Ports, Up: Additions -C.2.4 Why Generated Files Are Kept In `git' -------------------------------------------- +C.2.4 Why Generated Files Are Kept In Git +----------------------------------------- -If you look at the `gawk' source in the `git' repository, you will -notice that it includes files that are automatically generated by GNU -infrastructure tools, such as `Makefile.in' from `automake' and even -`configure' from `autoconf'. +If you look at the `gawk' source in the Git repository, you will notice +that it includes files that are automatically generated by GNU +infrastructure tools, such as `Makefile.in' from Automake and even +`configure' from Autoconf. This is different from many Free Software projects that do not store the derived files, because that keeps the repository less cluttered, @@ -27692,10 +27708,10 @@ build?) If the repository has all the generated files, then it's easy to just check them out and build. (Or _easier_, depending upon how far -back we go. `:-)') +back we go.) And that brings us to the second (and stronger) reason why all the -files really need to be in `git'. It boils down to who do you cater +files really need to be in Git. It boils down to who do you cater to--the `gawk' developer(s), or the user who just wants to check out a version and try it out? @@ -27721,7 +27737,7 @@ idea how to create it, and that was not the only problem.) He felt _extremely_ frustrated. With respect to that branch, the maintainer is no different than Jane User who wants to try to build -`gawk-4.0-stable' or `master' from the repository. +`gawk-4.1-stable' or `master' from the repository. Thus, the maintainer thinks that it's not just important, but critical, that for any given branch, the above incantation _just works_. @@ -27736,32 +27752,26 @@ critical, that for any given branch, the above incantation _just works_. B. He is really good at `git diff x y > /tmp/diff1 ; gvim /tmp/diff1' to remove the diffs that aren't of interest in - order to review code. `:-)' + order to review code. 2. It would certainly help if everyone used the same versions of the GNU tools as he does, which in general are the latest released - versions of `automake', `autoconf', `bison', and `gettext'. + versions of Automake, Autoconf, `bison', and `gettext'. - A. Installing from source is quite easy. It's how the maintainer - worked for years under Fedora. He had `/usr/local/bin' at - the front of his `PATH' and just did: - - wget http://ftp.gnu.org/gnu/PACKAGE/PACKAGE-X.Y.Z.tar.gz - tar -xpzvf PACKAGE-X.Y.Z.tar.gz - cd PACKAGE-X.Y.Z - ./configure && make && make check - make install # as root - - B. These days the maintainer uses Ubuntu 12.04 which is medium - current, but he is already doing the above for `autoconf', - `automake' and `bison'. + Installing from source is quite easy. It's how the maintainer + worked for years, and still works. He had `/usr/local/bin' at the + front of his `PATH' and just did: + wget http://ftp.gnu.org/gnu/PACKAGE/PACKAGE-X.Y.Z.tar.gz + tar -xpzvf PACKAGE-X.Y.Z.tar.gz + cd PACKAGE-X.Y.Z + ./configure && make && make check + make install # as root Most of the above was originally written by the maintainer to other `gawk' developers. It raised the objection from one of the developers -"... that anybody pulling down the source from `git' is not an end -user." +"... that anybody pulling down the source from Git is not an end user." However, this is not true. There are "power `awk' users" who can build `gawk' (using the magic incantation shown previously) but who @@ -27770,12 +27780,12 @@ all the time. It was then suggested that there be a `cron' job to create nightly tarballs of "the source." Here, the problem is that there are source -trees, corresponding to the various branches! So, nightly tar balls +trees, corresponding to the various branches! So, nightly tarballs aren't the answer, especially as the repository can go for weeks without significant change being introduced. - Fortunately, the `git' server can meet this need. For any given -branch named BRANCHNAME, use: + Fortunately, the Git server can meet this need. For any given branch +named BRANCHNAME, use: wget http://git.savannah.gnu.org/cgit/gawk.git/snapshot/gawk-BRANCHNAME.tar.gz @@ -27786,9 +27796,9 @@ to retrieve a snapshot of the given branch. (1) We tried. It was painful. (2) There is one GNU program that is (in our opinion) severely -difficult to bootstrap from the `git' repository. For example, on the -author's old (but still working) PowerPC macintosh with Mac OS X 10.5, -it was necessary to bootstrap a ton of software, starting with `git' +difficult to bootstrap from the Git repository. For example, on the +author's old (but still working) PowerPC Macintosh with Mac OS X 10.5, +it was necessary to bootstrap a ton of software, starting with Git itself, in order to try to work with the latest code. It's not pleasant, and especially on older systems, it's a big waste of time. @@ -27796,8 +27806,8 @@ pleasant, and especially on older systems, it's a big waste of time. maintainers had dropped `.gz' and `.bz2' files and only distribute `.tar.xz' files. It was necessary to bootstrap `xz' first! - (3) A branch created by one of the other developers that did not -include the generated files. + (3) A branch (since removed) created by one of the other developers +that did not include the generated files.  File: gawk.info, Node: Future Extensions, Next: Implementation Limitations, Prev: Additions, Up: Notes @@ -27810,11 +27820,11 @@ C.3 Probable Future Extensions Hey! -- Larry Wall - The `TODO' file in the `gawk' Git repository lists possible future -enhancements. Some of these relate to the source code, and others to -possible new features. Please see that file for the list. *Note -Additions::, if you are interested in tackling any of the projects -listed there. + The `TODO' file in the `master' branch of the `gawk' Git repository +lists possible future enhancements. Some of these relate to the source +code, and others to possible new features. Please see that file for +the list. *Note Additions::, if you are interested in tackling any of +the projects listed there.  File: gawk.info, Node: Implementation Limitations, Next: Extension Design, Prev: Future Extensions, Up: Notes @@ -27891,9 +27901,9 @@ The old extension mechanism had several problems: * Being able to call into `gawk' from an extension required linker facilities that are common on Unix-derived systems but that did - not work on Windows systems; users wanting extensions on Windows - had to statically link them into `gawk', even though Windows - supports dynamic loading of shared objects. + not work on MS-Windows systems; users wanting extensions on + MS-Windows had to statically link them into `gawk', even though + MS-Windows supports dynamic loading of shared objects. * The API would change occasionally as `gawk' changed; no compatibility between versions was ever offered or planned for. @@ -27941,8 +27951,8 @@ Some goals for the new API were: flattening") in order to loop over all the element in an easy fashion for C code. - - The ability to create arrays (including `gawk''s true - multidimensional arrays). + - The ability to create arrays (including `gawk''s true arrays + of arrays). Some additional important goals were: @@ -27956,7 +27966,7 @@ Some goals for the new API were: * The API mechanism should not require access to `gawk''s symbols(1) by the compile-time or dynamic linker, in order to enable creation - of extensions that also work on Windows. + of extensions that also work on MS-Windows. During development, it became clear that there were other features that should be available to extensions, which were also subsequently @@ -27994,7 +28004,7 @@ Mechanism Outline::, for the details. (1) The "symbols" are the variables and functions defined inside `gawk'. Access to these symbols by code external to `gawk' loaded -dynamically at runtime is problematic on Windows. +dynamically at runtime is problematic on MS-Windows.  File: gawk.info, Node: Extension Other Design Decisions, Next: Extension Future Growth, Prev: Extension New Mechanism Goals, Up: Extension Design @@ -28250,15 +28260,14 @@ like this: `""'. Humans are used to working in decimal; i.e., base 10. In base 10, numbers go from 0 to 9, and then "roll over" into the next column. -(Remember grade school? 42 is 4 times 10 plus 2.) +(Remember grade school? 42 = 4 x 10 + 2.) There are other number bases though. Computers commonly use base 2 or "binary", base 8 or "octal", and base 16 or "hexadecimal". In binary, each column represents two times the value in the column to its right. Each column may contain either a 0 or a 1. Thus, binary 1010 -represents 1 times 8, plus 0 times 4, plus 1 times 2, plus 0 times 1, -or decimal 10. Octal and hexadecimal are discussed more in *note -Nondecimal-numbers::. +represents (1 x 8) + (0 x 4) + (1 x 2) + (0 x 1), or decimal 10. Octal +and hexadecimal are discussed more in *note Nondecimal-numbers::. At the very lowest level, computers store values as groups of binary digits, or "bits". Modern computers group bits into groups of eight, @@ -28290,8 +28299,7 @@ Glossary Action A series of `awk' statements attached to a rule. If the rule's pattern matches an input record, `awk' executes the rule's action. - Actions are always enclosed in curly braces. (*Note Action - Overview::.) + Actions are always enclosed in braces. (*Note Action Overview::.) Amazing `awk' Assembler Henry Spencer at the University of Toronto wrote a retargetable @@ -28377,9 +28385,9 @@ Boolean Expression Bourne Shell The standard shell (`/bin/sh') on Unix and Unix-like systems, - originally written by Steven R. Bourne. Many shells (Bash, `ksh', - `pdksh', `zsh') are generally upwardly compatible with the Bourne - shell. + originally written by Steven R. Bourne at Bell Laboratories. Many + shells (Bash, `ksh', `pdksh', `zsh') are generally upwardly + compatible with the Bourne shell. Built-in Function The `awk' language provides built-in functions that perform various @@ -28400,7 +28408,8 @@ Built-in Variable Variables::.) Braces - See "Curly Braces." + The characters `{' and `}'. Braces are used in `awk' for + delimiting actions, compound statements, and function bodies. C The system programming language that most GNU software is written @@ -28421,8 +28430,8 @@ Character Set ASCII (American Standard Code for Information Interchange). Many European countries use an extension of ASCII known as ISO-8859-1 (ISO Latin-1). The Unicode character set (http://www.unicode.org) - is becoming increasingly popular and standard, and is particularly - widely used on GNU/Linux systems. + is increasingly popular and standard, and is particularly widely + used on GNU/Linux systems. CHEM A preprocessor for `pic' that reads descriptions of molecules and @@ -28432,7 +28441,7 @@ CHEM Cookie A peculiar goodie, token, saying or remembrance produced by or - presented to a program. (With thanks to Doug McIlroy.) + presented to a program. (With thanks to Professor Doug McIlroy.) Coprocess A subordinate program with which two-way communications is @@ -28467,8 +28476,7 @@ Comparison Expression process. (*Note Typing and Comparison::.) Curly Braces - The characters `{' and `}'. Curly braces are used in `awk' for - delimiting actions, compound statements, and function bodies. + See "Braces." Dark Corner An area in the language where specifications often were (or still @@ -28508,8 +28516,8 @@ Dynamic Regular Expression (*Note Computed Regexps::.) Environment - A collection of strings, of the form NAME`='`val', that each - program has available to it. Users generally place values into the + A collection of strings, of the form `NAME=VAL', that each program + has available to it. Users generally place values into the environment in order to provide information to various programs. Typical examples are the environment variables `HOME' and `PATH'. @@ -28559,11 +28567,11 @@ Floating-Point Number See also "Double Precision" and "Single Precision." Format - Format strings are used to control the appearance of output in the - `strftime()' and `sprintf()' functions, and are used in the - `printf' statement as well. Also, data conversions from numbers - to strings are controlled by the format strings contained in the - built-in variables `CONVFMT' and `OFMT'. (*Note Control Letters::.) + Format strings control the appearance of output in the + `strftime()' and `sprintf()' functions, and in the `printf' + statement as well. Also, data conversions from numbers to strings + are controlled by the format strings contained in the built-in + variables `CONVFMT' and `OFMT'. (*Note Control Letters::.) Free Documentation License This document describes the terms under which this Info file is @@ -28618,8 +28626,8 @@ Hexadecimal Base 16 notation, where the digits are `0'-`9' and `A'-`F', with `A' representing 10, `B' representing 11, and so on, up to `F' for 15. Hexadecimal numbers are written in C using a leading `0x', to - indicate their base. Thus, `0x12' is 18 (1 times 16 plus 2). - *Note Nondecimal-numbers::. + indicate their base. Thus, `0x12' is 18 ((1 x 16) + 2). *Note + Nondecimal-numbers::. I/O Abbreviation for "Input/Output," the act of moving data into and/or @@ -28676,7 +28684,7 @@ Keyword `gawk''s keywords are: `BEGIN', `BEGINFILE', `END', `ENDFILE', `break', `case', `continue', `default' `delete', `do...while', `else', `exit', `for...in', `for', `function', `func', `if', - `nextfile', `next', `switch', and `while'. + `next', `nextfile', `switch', and `while'. Lesser General Public License This document describes the terms under which binary library @@ -28732,11 +28740,7 @@ Number Octal Base-eight notation, where the digits are `0'-`7'. Octal numbers are written in C using a leading `0', to indicate their base. - Thus, `013' is 11 (one times 8 plus 3). *Note - Nondecimal-numbers::. - -P1003.1 - See "POSIX." + Thus, `013' is 11 ((1 x 8) + 3). *Note Nondecimal-numbers::. Pattern Patterns tell `awk' which input records are interesting to which @@ -28777,9 +28781,9 @@ Range (of input lines) specify single lines. (*Note Pattern Overview::.) Recursion - When a function calls itself, either directly or indirectly. As - long as this is not clear, refer to the entry for "recursion." If - this is clear, stop, and proceed to the next entry. + When a function calls itself, either directly or indirectly. If + this is clear, stop, and proceed to the next entry. Otherwise, + refer to the entry for "recursion." Redirection Redirection means performing input from something other than the @@ -28860,8 +28864,8 @@ Single Precision parts. Single precision numbers keep track of fewer digits than do double precision numbers, but operations on them are sometimes less expensive in terms of CPU time. This is the type used by - some very old versions of `awk' to store numeric values. It is - the C type `float'. + some ancient versions of `awk' to store numeric values. It is the + C type `float'. Space The character generated by hitting the space bar on the keyboard. @@ -28895,7 +28899,7 @@ Text Domain Timestamp A value in the "seconds since the epoch" format used by Unix and POSIX systems. Used for the `gawk' functions `mktime()', - `strftime()', and `systime()'. See also "Epoch" and "UTC." + `strftime()', and `systime()'. See also "Epoch," "GMT," and "UTC." Unix A computer operating system originally developed in the early @@ -30410,7 +30414,7 @@ Index * actions, control statements in: Statements. (line 6) * actions, default: Very Simple. (line 34) * actions, empty: Very Simple. (line 39) -* Ada programming language: Glossary. (line 20) +* Ada programming language: Glossary. (line 19) * adding, features to gawk: Adding Code. (line 6) * adding, fields: Changing Fields. (line 53) * advanced features, fixed-width data: Constant Size. (line 10) @@ -30429,8 +30433,8 @@ Index * allocating memory for extensions: Memory Allocation Functions. (line 6) * Alpha (DEC): Manual History. (line 28) -* amazing awk assembler (aaa): Glossary. (line 12) -* amazingly workable formatter (awf): Glossary. (line 25) +* amazing awk assembler (aaa): Glossary. (line 11) +* amazingly workable formatter (awf): Glossary. (line 24) * ambiguity, syntactic: /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) * ampersand (&), && operator <1>: Precedence. (line 86) @@ -30442,7 +30446,7 @@ Index * and: Bitwise Functions. (line 39) * AND bitwise operation: Bitwise Functions. (line 6) * and Boolean-logic operator: Boolean Ops. (line 6) -* ANSI: Glossary. (line 35) +* ANSI: Glossary. (line 34) * API informational variables: Extension API Informational Variables. (line 6) * API version: Extension Versioning. @@ -30548,7 +30552,7 @@ Index * asterisk (*), *= operator: Assignment Ops. (line 130) * atan2: Numeric Functions. (line 11) * automatic displays, in debugger: Debugger Info. (line 24) -* awf (amazingly workable formatter) program: Glossary. (line 25) +* awf (amazingly workable formatter) program: Glossary. (line 24) * awk debugging, enabling: Options. (line 108) * awk language, POSIX version: Assignment Ops. (line 137) * awk profiling, enabling: Options. (line 242) @@ -30769,9 +30773,9 @@ Index * Brink, Jeroen: DOS Quoting. (line 10) * Broder, Alan J.: Contributors. (line 88) * Brown, Martin: Contributors. (line 82) -* BSD-based operating systems: Glossary. (line 616) +* BSD-based operating systems: Glossary. (line 611) * bt debugger command (alias for backtrace): Execution Stack. (line 13) -* Buening, Andreas <1>: Bugs. (line 70) +* Buening, Andreas <1>: Bugs. (line 71) * Buening, Andreas <2>: Contributors. (line 92) * Buening, Andreas: Acknowledgments. (line 60) * buffering, input/output <1>: Two-way I/O. (line 70) @@ -30890,7 +30894,7 @@ Index * common extensions, RS as a regexp: gawk split records. (line 6) * common extensions, single character fields: Single Character Fields. (line 6) -* comp.lang.awk newsgroup: Bugs. (line 38) +* comp.lang.awk newsgroup: Bugs. (line 39) * comparison expressions: Typing and Comparison. (line 9) * comparison expressions, as patterns: Expression Patterns. (line 14) @@ -30977,7 +30981,7 @@ Index * cut.awk program: Cut Program. (line 45) * d debugger command (alias for delete): Breakpoint Control. (line 64) * d.c., See dark corner: Conventions. (line 38) -* dark corner <1>: Glossary. (line 189) +* dark corner <1>: Glossary. (line 188) * dark corner: Conventions. (line 38) * dark corner, "0" is actually true: Truth Values. (line 24) * dark corner, /= operator vs. /=.../ regexp constant: Assignment Ops. @@ -31148,7 +31152,7 @@ Index * decimal point character, locale specific: Options. (line 270) * decrement operators: Increment Ops. (line 35) * default keyword: Switch Statement. (line 6) -* Deifik, Scott <1>: Bugs. (line 70) +* Deifik, Scott <1>: Bugs. (line 71) * Deifik, Scott <2>: Contributors. (line 53) * Deifik, Scott: Acknowledgments. (line 60) * delete ARRAY: Delete. (line 39) @@ -31320,7 +31324,7 @@ Index * environment variables used by gawk: Environment Variables. (line 6) * environment variables, in ENVIRON array: Auto-set. (line 60) -* epoch, definition of: Glossary. (line 235) +* epoch, definition of: Glossary. (line 234) * equals sign (=), = operator: Assignment Ops. (line 6) * equals sign (=), == operator <1>: Precedence. (line 65) * equals sign (=), == operator: Comparison Operators. @@ -31566,10 +31570,10 @@ Index * frame debugger command: Execution Stack. (line 25) * Free Documentation License (FDL): GNU Free Documentation License. (line 7) -* Free Software Foundation (FSF) <1>: Glossary. (line 297) +* Free Software Foundation (FSF) <1>: Glossary. (line 296) * Free Software Foundation (FSF) <2>: Getting. (line 10) * Free Software Foundation (FSF): Manual History. (line 6) -* FreeBSD: Glossary. (line 616) +* FreeBSD: Glossary. (line 611) * FS variable <1>: User-modified. (line 50) * FS variable: Field Separators. (line 15) * FS variable, --field-separator option and: Options. (line 21) @@ -31583,7 +31587,7 @@ Index * FS, containing ^: Regexp Field Splitting. (line 59) * FS, in multiline records: Multiple Line. (line 41) -* FSF (Free Software Foundation) <1>: Glossary. (line 297) +* FSF (Free Software Foundation) <1>: Glossary. (line 296) * FSF (Free Software Foundation) <2>: Getting. (line 10) * FSF (Free Software Foundation): Manual History. (line 6) * fts() extension function: Extension Sample File Functions. @@ -31646,7 +31650,7 @@ Index * gawk, break statement in: Break Statement. (line 51) * gawk, built-in variables and: Built-in Variables. (line 14) * gawk, character classes and: Bracket Expressions. (line 90) -* gawk, coding style in: Adding Code. (line 38) +* gawk, coding style in: Adding Code. (line 39) * gawk, command-line options, and regular expressions: GNU Regexp Operators. (line 70) * gawk, comparison operators and: Comparison Operators. @@ -31732,7 +31736,7 @@ Index (line 63) * gawkextlib: gawkextlib. (line 6) * gawkextlib project: gawkextlib. (line 6) -* General Public License (GPL): Glossary. (line 306) +* General Public License (GPL): Glossary. (line 305) * General Public License, See GPL: Manual History. (line 11) * generate time values: Time Functions. (line 25) * gensub <1>: String Functions. (line 89) @@ -31780,29 +31784,29 @@ Index * gettext() function (C library): Explaining gettext. (line 63) * gettimeofday() extension function: Extension Sample Time. (line 12) -* git utility <1>: Adding Code. (line 111) +* git utility <1>: Adding Code. (line 112) * git utility <2>: Accessing The Source. (line 10) * git utility <3>: Other Versions. (line 29) * git utility: gawkextlib. (line 29) -* git, use of for gawk source code: Derived Files. (line 6) +* Git, use of for gawk source code: Derived Files. (line 6) * GMP: Gawk and MPFR. (line 6) * GNITS mailing list: Acknowledgments. (line 52) * GNU awk, See gawk: Preface. (line 53) * GNU Free Documentation License: GNU Free Documentation License. (line 7) -* GNU General Public License: Glossary. (line 306) -* GNU Lesser General Public License: Glossary. (line 397) +* GNU General Public License: Glossary. (line 305) +* GNU Lesser General Public License: Glossary. (line 396) * GNU long options <1>: Options. (line 6) * GNU long options: Command Line. (line 13) * GNU long options, printing list of: Options. (line 154) -* GNU Project <1>: Glossary. (line 315) +* GNU Project <1>: Glossary. (line 314) * GNU Project: Manual History. (line 11) -* GNU/Linux <1>: Glossary. (line 616) +* GNU/Linux <1>: Glossary. (line 611) * GNU/Linux <2>: I18N Example. (line 55) * GNU/Linux: Manual History. (line 28) * Gordon, Assaf: Contributors. (line 105) -* GPL (General Public License) <1>: Glossary. (line 306) +* GPL (General Public License) <1>: Glossary. (line 305) * GPL (General Public License): Manual History. (line 11) * GPL (General Public License), printing: Options. (line 88) * grcat program: Group Functions. (line 16) @@ -31858,8 +31862,8 @@ Index (line 53) * IGNORECASE variable, with ~ and !~ operators: Case-sensitivity. (line 26) -* Illumos: Other Versions. (line 104) -* Illumos, POSIX-compliant awk: Other Versions. (line 104) +* Illumos: Other Versions. (line 105) +* Illumos, POSIX-compliant awk: Other Versions. (line 105) * implementation issues, gawk: Notes. (line 6) * implementation issues, gawk, debugging: Compatibility Mode. (line 6) * implementation issues, gawk, limits <1>: Redirection. (line 135) @@ -31935,21 +31939,21 @@ Index * internationalization, localization, portability and: I18N Portability. (line 6) * internationalizing a program: Explaining gettext. (line 6) -* interpreted programs <1>: Glossary. (line 357) +* interpreted programs <1>: Glossary. (line 356) * interpreted programs: Basic High Level. (line 15) * interval expressions, regexp operator: Regexp Operators. (line 117) * inventory-shipped file: Sample Data Files. (line 32) * invoke shell command: I/O Functions. (line 75) * isarray: Type Functions. (line 11) -* ISO: Glossary. (line 368) +* ISO: Glossary. (line 367) * ISO 8859-1: Glossary. (line 133) * ISO Latin-1: Glossary. (line 133) * Jacobs, Andrew: Passwd Functions. (line 90) * Jaegermann, Michal <1>: Contributors. (line 45) * Jaegermann, Michal: Acknowledgments. (line 60) -* Java implementation of awk: Other Versions. (line 112) -* Java programming language: Glossary. (line 380) -* jawk: Other Versions. (line 112) +* Java implementation of awk: Other Versions. (line 113) +* Java programming language: Glossary. (line 379) +* jawk: Other Versions. (line 113) * Jedi knights: Undocumented. (line 6) * Johansen, Chris: Signature Program. (line 25) * join() user-defined function: Join Function. (line 18) @@ -31958,7 +31962,7 @@ Index * Kasal, Stepan: Acknowledgments. (line 60) * Kenobi, Obi-Wan: Undocumented. (line 6) * Kernighan, Brian <1>: Glossary. (line 143) -* Kernighan, Brian <2>: Basic Data Typing. (line 55) +* Kernighan, Brian <2>: Basic Data Typing. (line 54) * Kernighan, Brian <3>: Other Versions. (line 13) * Kernighan, Brian <4>: Contributors. (line 11) * Kernighan, Brian <5>: BTL. (line 6) @@ -32001,9 +32005,9 @@ Index * length: String Functions. (line 167) * length of input record: String Functions. (line 174) * length of string: String Functions. (line 167) -* Lesser General Public License (LGPL): Glossary. (line 397) -* LGPL (Lesser General Public License): Glossary. (line 397) -* libmawk: Other Versions. (line 120) +* Lesser General Public License (LGPL): Glossary. (line 396) +* LGPL (Lesser General Public License): Glossary. (line 396) +* libmawk: Other Versions. (line 121) * libraries of awk functions: Library Functions. (line 6) * libraries of awk functions, assertions: Assert Function. (line 6) * libraries of awk functions, associative arrays and: Library Names. @@ -32047,7 +32051,7 @@ Index * lint checking, undefined functions: Pass By Value/Reference. (line 88) * LINT variable: User-modified. (line 88) -* Linux <1>: Glossary. (line 616) +* Linux <1>: Glossary. (line 611) * Linux <2>: I18N Example. (line 55) * Linux: Manual History. (line 28) * list all global variables, in debugger: Debugger Info. (line 48) @@ -32085,7 +32089,7 @@ Index * mail-list file: Sample Data Files. (line 6) * mailing labels, printing: Labels Program. (line 6) * mailing list, GNITS: Acknowledgments. (line 52) -* Malmberg, John <1>: Bugs. (line 70) +* Malmberg, John <1>: Bugs. (line 71) * Malmberg, John: Acknowledgments. (line 60) * mark parity: Ordinal Functions. (line 45) * marked string extraction (internationalization): String Extraction. @@ -32106,6 +32110,7 @@ Index * mawk utility <4>: Getline/Pipe. (line 62) * mawk utility: Escape Sequences. (line 124) * maximum precision supported by MPFR library: Auto-set. (line 213) +* McIlroy, Doug: Glossary. (line 149) * McPhee, Patrick: Contributors. (line 100) * message object files: Explaining gettext. (line 42) * message object files, converting from portable object files: I18N Example. @@ -32138,7 +32143,7 @@ Index * namespace issues, functions: Definition Syntax. (line 20) * nawk utility: Names. (line 10) * negative zero: Unexpected Results. (line 34) -* NetBSD: Glossary. (line 616) +* NetBSD: Glossary. (line 611) * networks, programming: TCP/IP Networking. (line 6) * networks, support for: Special Network. (line 6) * newlines <1>: Boolean Ops. (line 67) @@ -32227,7 +32232,7 @@ Index * OFS variable <1>: User-modified. (line 114) * OFS variable <2>: Output Separators. (line 6) * OFS variable: Changing Fields. (line 64) -* OpenBSD: Glossary. (line 616) +* OpenBSD: Glossary. (line 611) * OpenSolaris: Other Versions. (line 96) * operating systems, BSD-based: Manual History. (line 28) * operating systems, PC, gawk on: PC Using. (line 6) @@ -32296,7 +32301,6 @@ Index * output, standard: Special FD. (line 6) * p debugger command (alias for print): Viewing And Changing Data. (line 36) -* P1003.1 POSIX standard: Glossary. (line 454) * parent process ID of gawk process: Auto-set. (line 181) * parentheses (), in a profile: Profiling. (line 146) * parentheses (), regexp operator: Regexp Operators. (line 80) @@ -32314,7 +32318,7 @@ Index * patterns, types of: Pattern Overview. (line 15) * pawk (profiling version of Brian Kernighan's awk): Other Versions. (line 78) -* pawk, awk-like facilities for Python: Other Versions. (line 124) +* pawk, awk-like facilities for Python: Other Versions. (line 125) * PC operating systems, gawk on: PC Using. (line 6) * PC operating systems, gawk on, installing: PC Installation. (line 6) * percent sign (%), % operator: Precedence. (line 55) @@ -32328,7 +32332,7 @@ Index (line 6) * pipe, input: Getline/Pipe. (line 9) * pipe, output: Redirection. (line 57) -* Pitts, Dave <1>: Bugs. (line 70) +* Pitts, Dave <1>: Bugs. (line 71) * Pitts, Dave: Acknowledgments. (line 60) * Plauger, P.J.: Library Functions. (line 12) * plug-in: Extension Intro. (line 6) @@ -32497,22 +32501,22 @@ Index * programming conventions, private variable names: Library Names. (line 23) * programming language, recipe for: History. (line 6) -* programming languages, Ada: Glossary. (line 20) +* programming languages, Ada: Glossary. (line 19) * programming languages, data-driven vs. procedural: Getting Started. (line 12) -* programming languages, Java: Glossary. (line 380) +* programming languages, Java: Glossary. (line 379) * programming, basic steps: Basic High Level. (line 20) * programming, concepts: Basic Concepts. (line 6) * pwcat program: Passwd Functions. (line 23) * q debugger command (alias for quit): Miscellaneous Debugger Commands. (line 99) -* QSE Awk: Other Versions. (line 130) +* QSE Awk: Other Versions. (line 131) * Quanstrom, Erik: Alarm Program. (line 8) * question mark (?), ?: operator: Precedence. (line 92) * question mark (?), regexp operator <1>: GNU Regexp Operators. (line 59) * question mark (?), regexp operator: Regexp Operators. (line 112) -* QuikTrim Awk: Other Versions. (line 134) +* QuikTrim Awk: Other Versions. (line 135) * quit debugger command: Miscellaneous Debugger Commands. (line 99) * QUIT signal (MS-Windows): Profiling. (line 214) @@ -32533,7 +32537,7 @@ Index * range expressions (regexps): Bracket Expressions. (line 6) * range patterns: Ranges. (line 6) * range patterns, line continuation and: Ranges. (line 65) -* Rankin, Pat <1>: Bugs. (line 70) +* Rankin, Pat <1>: Bugs. (line 71) * Rankin, Pat <2>: Contributors. (line 37) * Rankin, Pat <3>: Assignment Ops. (line 100) * Rankin, Pat: Acknowledgments. (line 60) @@ -32638,7 +32642,7 @@ Index * right angle bracket (>), >> operator (I/O): Redirection. (line 50) * right shift: Bitwise Functions. (line 52) * right shift, bitwise: Bitwise Functions. (line 32) -* Ritchie, Dennis: Basic Data Typing. (line 55) +* Ritchie, Dennis: Basic Data Typing. (line 54) * RLENGTH variable: Auto-set. (line 244) * RLENGTH variable, match() function and: String Functions. (line 224) * Robbins, Arnold <1>: Future Extensions. (line 6) @@ -32706,7 +32710,7 @@ Index * search paths, for source files: AWKPATH Variable. (line 6) * searching, files for regular expressions: Egrep Program. (line 6) * searching, for words: Dupword Program. (line 6) -* sed utility <1>: Glossary. (line 12) +* sed utility <1>: Glossary. (line 11) * sed utility <2>: Simple Sed. (line 6) * sed utility: Field Splitting Summary. (line 46) @@ -32842,19 +32846,19 @@ Index * source code, Brian Kernighan's awk: Other Versions. (line 13) * source code, Busybox Awk: Other Versions. (line 88) * source code, gawk: Gawk Distribution. (line 6) -* source code, Illumos awk: Other Versions. (line 104) -* source code, jawk: Other Versions. (line 112) -* source code, libmawk: Other Versions. (line 120) +* source code, Illumos awk: Other Versions. (line 105) +* source code, jawk: Other Versions. (line 113) +* source code, libmawk: Other Versions. (line 121) * source code, mawk: Other Versions. (line 44) * source code, mixing: Options. (line 117) * source code, pawk: Other Versions. (line 78) -* source code, pawk (Python version): Other Versions. (line 124) -* source code, QSE Awk: Other Versions. (line 130) -* source code, QuikTrim Awk: Other Versions. (line 134) +* source code, pawk (Python version): Other Versions. (line 125) +* source code, QSE Awk: Other Versions. (line 131) +* source code, QuikTrim Awk: Other Versions. (line 135) * source code, Solaris awk: Other Versions. (line 96) * source files, search path for: Igawk Program. (line 368) * sparse arrays: Array Intro. (line 71) -* Spencer, Henry: Glossary. (line 12) +* Spencer, Henry: Glossary. (line 11) * split: String Functions. (line 313) * split string into array: String Functions. (line 294) * split utility: Split Program. (line 6) @@ -32870,7 +32874,7 @@ Index * square root: Numeric Functions. (line 78) * srand: Numeric Functions. (line 82) * stack frame: Debugging Terms. (line 10) -* Stallman, Richard <1>: Glossary. (line 297) +* Stallman, Richard <1>: Glossary. (line 296) * Stallman, Richard <2>: Contributors. (line 23) * Stallman, Richard <3>: Acknowledgments. (line 18) * Stallman, Richard: Manual History. (line 6) @@ -32959,7 +32963,7 @@ Index * testbits.awk program: Bitwise Functions. (line 70) * testext extension: Extension Sample API Tests. (line 6) -* Texinfo <1>: Adding Code. (line 99) +* Texinfo <1>: Adding Code. (line 100) * Texinfo <2>: Distribution contents. (line 77) * Texinfo <3>: Extract Program. (line 12) @@ -33063,7 +33067,7 @@ Index (line 6) * uniq utility: Uniq Program. (line 6) * uniq.awk program: Uniq Program. (line 65) -* Unix: Glossary. (line 616) +* Unix: Glossary. (line 611) * Unix awk, backslashes in escape sequences: Escape Sequences. (line 124) * Unix awk, close() function and: Close Files And Pipes. @@ -33177,7 +33181,7 @@ Index * xor: Bitwise Functions. (line 55) * XOR bitwise operation: Bitwise Functions. (line 6) * Yawitz, Efraim: Contributors. (line 129) -* Zaretskii, Eli <1>: Bugs. (line 70) +* Zaretskii, Eli <1>: Bugs. (line 71) * Zaretskii, Eli <2>: Contributors. (line 55) * Zaretskii, Eli: Acknowledgments. (line 60) * zero, negative vs. positive: Unexpected Results. (line 34) @@ -33211,536 +33215,537 @@ Index  Tag Table: Node: Top1292 -Node: Foreword40832 -Node: Preface45177 -Ref: Preface-Footnote-148324 -Ref: Preface-Footnote-248431 -Node: History48663 -Node: Names51037 -Ref: Names-Footnote-152501 -Node: This Manual52574 -Ref: This Manual-Footnote-158353 -Node: Conventions58453 -Node: Manual History60609 -Ref: Manual History-Footnote-164040 -Ref: Manual History-Footnote-264081 -Node: How To Contribute64155 -Node: Acknowledgments65394 -Node: Getting Started69543 -Node: Running gawk71922 -Node: One-shot73112 -Node: Read Terminal74337 -Ref: Read Terminal-Footnote-175987 -Ref: Read Terminal-Footnote-276263 -Node: Long76434 -Node: Executable Scripts77810 -Ref: Executable Scripts-Footnote-179643 -Ref: Executable Scripts-Footnote-279745 -Node: Comments80292 -Node: Quoting82759 -Node: DOS Quoting88075 -Node: Sample Data Files88750 -Node: Very Simple91265 -Node: Two Rules95915 -Node: More Complex97810 -Ref: More Complex-Footnote-1100742 -Node: Statements/Lines100827 -Ref: Statements/Lines-Footnote-1105282 -Node: Other Features105547 -Node: When106475 -Node: Invoking Gawk108623 -Node: Command Line110086 -Node: Options110877 -Ref: Options-Footnote-1126689 -Node: Other Arguments126714 -Node: Naming Standard Input129376 -Node: Environment Variables130470 -Node: AWKPATH Variable131028 -Ref: AWKPATH Variable-Footnote-1133806 -Ref: AWKPATH Variable-Footnote-2133851 -Node: AWKLIBPATH Variable134111 -Node: Other Environment Variables134870 -Node: Exit Status138525 -Node: Include Files139200 -Node: Loading Shared Libraries142778 -Node: Obsolete144161 -Node: Undocumented144858 -Node: Regexp145100 -Node: Regexp Usage146489 -Node: Escape Sequences148522 -Node: Regexp Operators154189 -Ref: Regexp Operators-Footnote-1161669 -Ref: Regexp Operators-Footnote-2161816 -Node: Bracket Expressions161914 -Ref: table-char-classes163804 -Node: GNU Regexp Operators166327 -Node: Case-sensitivity170050 -Ref: Case-sensitivity-Footnote-1172942 -Ref: Case-sensitivity-Footnote-2173177 -Node: Leftmost Longest173285 -Node: Computed Regexps174486 -Node: Reading Files177835 -Node: Records179837 -Node: awk split records180572 -Node: gawk split records185430 -Ref: gawk split records-Footnote-1189951 -Node: Fields189988 -Ref: Fields-Footnote-1192952 -Node: Nonconstant Fields193038 -Ref: Nonconstant Fields-Footnote-1195268 -Node: Changing Fields195470 -Node: Field Separators201424 -Node: Default Field Splitting204126 -Node: Regexp Field Splitting205243 -Node: Single Character Fields208584 -Node: Command Line Field Separator209643 -Node: Full Line Fields212985 -Ref: Full Line Fields-Footnote-1213493 -Node: Field Splitting Summary213539 -Ref: Field Splitting Summary-Footnote-1216638 -Node: Constant Size216739 -Node: Splitting By Content221346 -Ref: Splitting By Content-Footnote-1225096 -Node: Multiple Line225136 -Ref: Multiple Line-Footnote-1230992 -Node: Getline231171 -Node: Plain Getline233387 -Node: Getline/Variable235482 -Node: Getline/File236629 -Node: Getline/Variable/File238013 -Ref: Getline/Variable/File-Footnote-1239612 -Node: Getline/Pipe239699 -Node: Getline/Variable/Pipe242398 -Node: Getline/Coprocess243505 -Node: Getline/Variable/Coprocess244757 -Node: Getline Notes245494 -Node: Getline Summary248298 -Ref: table-getline-variants248706 -Node: Read Timeout249618 -Ref: Read Timeout-Footnote-1253445 -Node: Command line directories253503 -Node: Printing254385 -Node: Print256016 -Node: Print Examples257357 -Node: Output Separators260136 -Node: OFMT262152 -Node: Printf263510 -Node: Basic Printf264416 -Node: Control Letters265955 -Node: Format Modifiers269809 -Node: Printf Examples275836 -Node: Redirection278543 -Node: Special Files285515 -Node: Special FD286048 -Ref: Special FD-Footnote-1289672 -Node: Special Network289746 -Node: Special Caveats290596 -Node: Close Files And Pipes291392 -Ref: Close Files And Pipes-Footnote-1298530 -Ref: Close Files And Pipes-Footnote-2298678 -Node: Expressions298828 -Node: Values299960 -Node: Constants300636 -Node: Scalar Constants301316 -Ref: Scalar Constants-Footnote-1302175 -Node: Nondecimal-numbers302425 -Node: Regexp Constants305425 -Node: Using Constant Regexps305900 -Node: Variables308970 -Node: Using Variables309625 -Node: Assignment Options311349 -Node: Conversion313224 -Ref: table-locale-affects318660 -Ref: Conversion-Footnote-1319284 -Node: All Operators319393 -Node: Arithmetic Ops320023 -Node: Concatenation322528 -Ref: Concatenation-Footnote-1325324 -Node: Assignment Ops325444 -Ref: table-assign-ops330427 -Node: Increment Ops331744 -Node: Truth Values and Conditions335182 -Node: Truth Values336265 -Node: Typing and Comparison337314 -Node: Variable Typing338107 -Ref: Variable Typing-Footnote-1342007 -Node: Comparison Operators342129 -Ref: table-relational-ops342539 -Node: POSIX String Comparison346087 -Ref: POSIX String Comparison-Footnote-1347171 -Node: Boolean Ops347309 -Ref: Boolean Ops-Footnote-1351379 -Node: Conditional Exp351470 -Node: Function Calls353197 -Node: Precedence356955 -Node: Locales360624 -Node: Patterns and Actions362227 -Node: Pattern Overview363281 -Node: Regexp Patterns364958 -Node: Expression Patterns365501 -Node: Ranges369282 -Node: BEGIN/END372388 -Node: Using BEGIN/END373150 -Ref: Using BEGIN/END-Footnote-1375886 -Node: I/O And BEGIN/END375992 -Node: BEGINFILE/ENDFILE378277 -Node: Empty381208 -Node: Using Shell Variables381525 -Node: Action Overview383808 -Node: Statements386159 -Node: If Statement388013 -Node: While Statement389516 -Node: Do Statement391560 -Node: For Statement392716 -Node: Switch Statement395868 -Node: Break Statement397971 -Node: Continue Statement400026 -Node: Next Statement401819 -Node: Nextfile Statement404209 -Node: Exit Statement406864 -Node: Built-in Variables409268 -Node: User-modified410364 -Ref: User-modified-Footnote-1418049 -Node: Auto-set418111 -Ref: Auto-set-Footnote-1430676 -Ref: Auto-set-Footnote-2430881 -Node: ARGC and ARGV430937 -Node: Arrays434791 -Node: Array Basics436289 -Node: Array Intro437115 -Ref: figure-array-elements439088 -Node: Reference to Elements441495 -Node: Assigning Elements443768 -Node: Array Example444259 -Node: Scanning an Array445991 -Node: Controlling Scanning449006 -Ref: Controlling Scanning-Footnote-1454179 -Node: Delete454495 -Ref: Delete-Footnote-1457260 -Node: Numeric Array Subscripts457317 -Node: Uninitialized Subscripts459500 -Node: Multidimensional461125 -Node: Multiscanning464218 -Node: Arrays of Arrays465807 -Node: Functions470447 -Node: Built-in471266 -Node: Calling Built-in472344 -Node: Numeric Functions474332 -Ref: Numeric Functions-Footnote-1478166 -Ref: Numeric Functions-Footnote-2478523 -Ref: Numeric Functions-Footnote-3478571 -Node: String Functions478840 -Ref: String Functions-Footnote-1501851 -Ref: String Functions-Footnote-2501980 -Ref: String Functions-Footnote-3502228 -Node: Gory Details502315 -Ref: table-sub-escapes503984 -Ref: table-sub-posix-92505338 -Ref: table-sub-proposed506689 -Ref: table-posix-sub508043 -Ref: table-gensub-escapes509588 -Ref: Gory Details-Footnote-1510764 -Ref: Gory Details-Footnote-2510815 -Node: I/O Functions510966 -Ref: I/O Functions-Footnote-1518089 -Node: Time Functions518236 -Ref: Time Functions-Footnote-1528700 -Ref: Time Functions-Footnote-2528768 -Ref: Time Functions-Footnote-3528926 -Ref: Time Functions-Footnote-4529037 -Ref: Time Functions-Footnote-5529149 -Ref: Time Functions-Footnote-6529376 -Node: Bitwise Functions529642 -Ref: table-bitwise-ops530204 -Ref: Bitwise Functions-Footnote-1534449 -Node: Type Functions534633 -Node: I18N Functions535775 -Node: User-defined537420 -Node: Definition Syntax538224 -Ref: Definition Syntax-Footnote-1543149 -Node: Function Example543218 -Ref: Function Example-Footnote-1545862 -Node: Function Caveats545884 -Node: Calling A Function546402 -Node: Variable Scope547357 -Node: Pass By Value/Reference550345 -Node: Return Statement553853 -Node: Dynamic Typing556837 -Node: Indirect Calls557766 -Node: Library Functions567453 -Ref: Library Functions-Footnote-1570966 -Ref: Library Functions-Footnote-2571109 -Node: Library Names571280 -Ref: Library Names-Footnote-1574753 -Ref: Library Names-Footnote-2574973 -Node: General Functions575059 -Node: Strtonum Function576087 -Node: Assert Function579017 -Node: Round Function582343 -Node: Cliff Random Function583884 -Node: Ordinal Functions584900 -Ref: Ordinal Functions-Footnote-1587977 -Ref: Ordinal Functions-Footnote-2588229 -Node: Join Function588440 -Ref: Join Function-Footnote-1590211 -Node: Getlocaltime Function590411 -Node: Readfile Function594147 -Node: Data File Management595986 -Node: Filetrans Function596618 -Node: Rewind Function600687 -Node: File Checking602074 -Ref: File Checking-Footnote-1603206 -Node: Empty Files603407 -Node: Ignoring Assigns605637 -Node: Getopt Function607191 -Ref: Getopt Function-Footnote-1618494 -Node: Passwd Functions618697 -Ref: Passwd Functions-Footnote-1627676 -Node: Group Functions627764 -Ref: Group Functions-Footnote-1635706 -Node: Walking Arrays635919 -Node: Sample Programs638055 -Node: Running Examples638729 -Node: Clones639457 -Node: Cut Program640681 -Node: Egrep Program650534 -Ref: Egrep Program-Footnote-1658505 -Node: Id Program658615 -Node: Split Program662279 -Ref: Split Program-Footnote-1665817 -Node: Tee Program665945 -Node: Uniq Program668752 -Node: Wc Program676182 -Ref: Wc Program-Footnote-1680450 -Ref: Wc Program-Footnote-2680650 -Node: Miscellaneous Programs680742 -Node: Dupword Program681930 -Node: Alarm Program683961 -Node: Translate Program688768 -Ref: Translate Program-Footnote-1693159 -Ref: Translate Program-Footnote-2693429 -Node: Labels Program693563 -Ref: Labels Program-Footnote-1696934 -Node: Word Sorting697018 -Node: History Sorting701061 -Node: Extract Program702897 -Ref: Extract Program-Footnote-1710427 -Node: Simple Sed710556 -Node: Igawk Program713618 -Ref: Igawk Program-Footnote-1728793 -Ref: Igawk Program-Footnote-2728994 -Node: Anagram Program729132 -Node: Signature Program732200 -Node: Advanced Features733447 -Node: Nondecimal Data735333 -Node: Array Sorting736910 -Node: Controlling Array Traversal737607 -Node: Array Sorting Functions745887 -Ref: Array Sorting Functions-Footnote-1749794 -Node: Two-way I/O749988 -Ref: Two-way I/O-Footnote-1755504 -Node: TCP/IP Networking755586 -Node: Profiling758430 -Node: Internationalization765938 -Node: I18N and L10N767363 -Node: Explaining gettext768049 -Ref: Explaining gettext-Footnote-1773189 -Ref: Explaining gettext-Footnote-2773373 -Node: Programmer i18n773538 -Node: Translator i18n777763 -Node: String Extraction778557 -Ref: String Extraction-Footnote-1779518 -Node: Printf Ordering779604 -Ref: Printf Ordering-Footnote-1782386 -Node: I18N Portability782450 -Ref: I18N Portability-Footnote-1784899 -Node: I18N Example784962 -Ref: I18N Example-Footnote-1787684 -Node: Gawk I18N787756 -Node: Debugger788377 -Node: Debugging789348 -Node: Debugging Concepts789789 -Node: Debugging Terms791645 -Node: Awk Debugging794242 -Node: Sample Debugging Session795134 -Node: Debugger Invocation795654 -Node: Finding The Bug796987 -Node: List of Debugger Commands803469 -Node: Breakpoint Control804801 -Node: Debugger Execution Control808465 -Node: Viewing And Changing Data811825 -Node: Execution Stack815183 -Node: Debugger Info816696 -Node: Miscellaneous Debugger Commands820690 -Node: Readline Support825874 -Node: Limitations826766 -Node: Arbitrary Precision Arithmetic829014 -Ref: Arbitrary Precision Arithmetic-Footnote-1830663 -Node: General Arithmetic830811 -Node: Floating Point Issues832531 -Node: String Conversion Precision833412 -Ref: String Conversion Precision-Footnote-1835117 -Node: Unexpected Results835226 -Node: POSIX Floating Point Problems837379 -Ref: POSIX Floating Point Problems-Footnote-1841200 -Node: Integer Programming841238 -Node: Floating-point Programming843049 -Ref: Floating-point Programming-Footnote-1849377 -Ref: Floating-point Programming-Footnote-2849647 -Node: Floating-point Representation849911 -Node: Floating-point Context851076 -Ref: table-ieee-formats851915 -Node: Rounding Mode853299 -Ref: table-rounding-modes853778 -Ref: Rounding Mode-Footnote-1856793 -Node: Gawk and MPFR856972 -Node: Arbitrary Precision Floats858381 -Ref: Arbitrary Precision Floats-Footnote-1860824 -Node: Setting Precision861145 -Ref: table-predefined-precision-strings861829 -Node: Setting Rounding Mode863974 -Ref: table-gawk-rounding-modes864378 -Node: Floating-point Constants865565 -Node: Changing Precision867017 -Ref: Changing Precision-Footnote-1868409 -Node: Exact Arithmetic868583 -Node: Arbitrary Precision Integers871717 -Ref: Arbitrary Precision Integers-Footnote-1874732 -Node: Dynamic Extensions874879 -Node: Extension Intro876337 -Node: Plugin License877602 -Node: Extension Mechanism Outline878287 -Ref: figure-load-extension878711 -Ref: figure-load-new-function880196 -Ref: figure-call-new-function881198 -Node: Extension API Description883182 -Node: Extension API Functions Introduction884632 -Node: General Data Types889498 -Ref: General Data Types-Footnote-1895191 -Node: Requesting Values895490 -Ref: table-value-types-returned896227 -Node: Memory Allocation Functions897185 -Ref: Memory Allocation Functions-Footnote-1899931 -Node: Constructor Functions900027 -Node: Registration Functions901785 -Node: Extension Functions902470 -Node: Exit Callback Functions904772 -Node: Extension Version String906021 -Node: Input Parsers906671 -Node: Output Wrappers916474 -Node: Two-way processors920990 -Node: Printing Messages923193 -Ref: Printing Messages-Footnote-1924270 -Node: Updating `ERRNO'924422 -Node: Accessing Parameters925161 -Node: Symbol Table Access926391 -Node: Symbol table by name926905 -Node: Symbol table by cookie928881 -Ref: Symbol table by cookie-Footnote-1933014 -Node: Cached values933077 -Ref: Cached values-Footnote-1936582 -Node: Array Manipulation936673 -Ref: Array Manipulation-Footnote-1937771 -Node: Array Data Types937810 -Ref: Array Data Types-Footnote-1940513 -Node: Array Functions940605 -Node: Flattening Arrays944479 -Node: Creating Arrays951331 -Node: Extension API Variables956062 -Node: Extension Versioning956698 -Node: Extension API Informational Variables958599 -Node: Extension API Boilerplate959685 -Node: Finding Extensions963489 -Node: Extension Example964049 -Node: Internal File Description964779 -Node: Internal File Ops968870 -Ref: Internal File Ops-Footnote-1980416 -Node: Using Internal File Ops980556 -Ref: Using Internal File Ops-Footnote-1982903 -Node: Extension Samples983169 -Node: Extension Sample File Functions984693 -Node: Extension Sample Fnmatch992260 -Node: Extension Sample Fork993739 -Node: Extension Sample Inplace994952 -Node: Extension Sample Ord996730 -Node: Extension Sample Readdir997566 -Ref: table-readdir-file-types998421 -Node: Extension Sample Revout999220 -Node: Extension Sample Rev2way999811 -Node: Extension Sample Read write array1000552 -Node: Extension Sample Readfile1002431 -Node: Extension Sample API Tests1003531 -Node: Extension Sample Time1004056 -Node: gawkextlib1005371 -Node: Language History1008152 -Node: V7/SVR3.11009746 -Node: SVR41012066 -Node: POSIX1013508 -Node: BTL1014894 -Node: POSIX/GNU1015628 -Node: Feature History1021227 -Node: Common Extensions1034339 -Node: Ranges and Locales1035651 -Ref: Ranges and Locales-Footnote-11040268 -Ref: Ranges and Locales-Footnote-21040295 -Ref: Ranges and Locales-Footnote-31040529 -Node: Contributors1040750 -Node: Installation1046101 -Node: Gawk Distribution1046995 -Node: Getting1047479 -Node: Extracting1048305 -Node: Distribution contents1049997 -Node: Unix Installation1055718 -Node: Quick Installation1056335 -Node: Additional Configuration Options1058781 -Node: Configuration Philosophy1060517 -Node: Non-Unix Installation1062871 -Node: PC Installation1063329 -Node: PC Binary Installation1064640 -Node: PC Compiling1066488 -Node: PC Testing1069448 -Node: PC Using1070624 -Node: Cygwin1074792 -Node: MSYS1075601 -Node: VMS Installation1076115 -Node: VMS Compilation1076911 -Ref: VMS Compilation-Footnote-11078163 -Node: VMS Dynamic Extensions1078221 -Node: VMS Installation Details1079594 -Node: VMS Running1081845 -Node: VMS GNV1084679 -Node: VMS Old Gawk1085402 -Node: Bugs1085872 -Node: Other Versions1089790 -Node: Notes1095874 -Node: Compatibility Mode1096674 -Node: Additions1097457 -Node: Accessing The Source1098384 -Node: Adding Code1099824 -Node: New Ports1105869 -Node: Derived Files1110004 -Ref: Derived Files-Footnote-11115325 -Ref: Derived Files-Footnote-21115359 -Ref: Derived Files-Footnote-31115959 -Node: Future Extensions1116057 -Node: Implementation Limitations1116640 -Node: Extension Design1117888 -Node: Old Extension Problems1119042 -Ref: Old Extension Problems-Footnote-11120550 -Node: Extension New Mechanism Goals1120607 -Ref: Extension New Mechanism Goals-Footnote-11123972 -Node: Extension Other Design Decisions1124158 -Node: Extension Future Growth1126264 -Node: Old Extension Mechanism1127100 -Node: Basic Concepts1128840 -Node: Basic High Level1129521 -Ref: figure-general-flow1129793 -Ref: figure-process-flow1130392 -Ref: Basic High Level-Footnote-11133621 -Node: Basic Data Typing1133806 -Node: Glossary1137161 -Node: Copying1162392 -Node: GNU Free Documentation License1199948 -Node: Index1225084 +Node: Foreword40830 +Node: Preface45175 +Ref: Preface-Footnote-148322 +Ref: Preface-Footnote-248429 +Node: History48661 +Node: Names51035 +Ref: Names-Footnote-152499 +Node: This Manual52572 +Ref: This Manual-Footnote-158351 +Node: Conventions58451 +Node: Manual History60607 +Ref: Manual History-Footnote-164038 +Ref: Manual History-Footnote-264079 +Node: How To Contribute64153 +Node: Acknowledgments65392 +Node: Getting Started69541 +Node: Running gawk71914 +Node: One-shot73104 +Node: Read Terminal74329 +Ref: Read Terminal-Footnote-175979 +Ref: Read Terminal-Footnote-276255 +Node: Long76426 +Node: Executable Scripts77802 +Ref: Executable Scripts-Footnote-179635 +Ref: Executable Scripts-Footnote-279737 +Node: Comments80284 +Node: Quoting82751 +Node: DOS Quoting88067 +Node: Sample Data Files88742 +Node: Very Simple91257 +Node: Two Rules95895 +Node: More Complex97790 +Ref: More Complex-Footnote-1100722 +Node: Statements/Lines100807 +Ref: Statements/Lines-Footnote-1105262 +Node: Other Features105527 +Node: When106455 +Node: Invoking Gawk108603 +Node: Command Line110066 +Node: Options110857 +Ref: Options-Footnote-1126669 +Node: Other Arguments126694 +Node: Naming Standard Input129356 +Node: Environment Variables130450 +Node: AWKPATH Variable131008 +Ref: AWKPATH Variable-Footnote-1133786 +Ref: AWKPATH Variable-Footnote-2133831 +Node: AWKLIBPATH Variable134091 +Node: Other Environment Variables134850 +Node: Exit Status138505 +Node: Include Files139180 +Node: Loading Shared Libraries142758 +Node: Obsolete144141 +Node: Undocumented144838 +Node: Regexp145080 +Node: Regexp Usage146469 +Node: Escape Sequences148502 +Node: Regexp Operators154169 +Ref: Regexp Operators-Footnote-1161649 +Ref: Regexp Operators-Footnote-2161796 +Node: Bracket Expressions161894 +Ref: table-char-classes163784 +Node: GNU Regexp Operators166307 +Node: Case-sensitivity170030 +Ref: Case-sensitivity-Footnote-1172922 +Ref: Case-sensitivity-Footnote-2173157 +Node: Leftmost Longest173265 +Node: Computed Regexps174466 +Node: Reading Files177815 +Node: Records179817 +Node: awk split records180552 +Node: gawk split records185410 +Ref: gawk split records-Footnote-1189931 +Node: Fields189968 +Ref: Fields-Footnote-1192932 +Node: Nonconstant Fields193018 +Ref: Nonconstant Fields-Footnote-1195248 +Node: Changing Fields195450 +Node: Field Separators201404 +Node: Default Field Splitting204106 +Node: Regexp Field Splitting205223 +Node: Single Character Fields208564 +Node: Command Line Field Separator209623 +Node: Full Line Fields212965 +Ref: Full Line Fields-Footnote-1213473 +Node: Field Splitting Summary213519 +Ref: Field Splitting Summary-Footnote-1216618 +Node: Constant Size216719 +Node: Splitting By Content221326 +Ref: Splitting By Content-Footnote-1225076 +Node: Multiple Line225116 +Ref: Multiple Line-Footnote-1230972 +Node: Getline231151 +Node: Plain Getline233367 +Node: Getline/Variable235462 +Node: Getline/File236609 +Node: Getline/Variable/File237993 +Ref: Getline/Variable/File-Footnote-1239592 +Node: Getline/Pipe239679 +Node: Getline/Variable/Pipe242378 +Node: Getline/Coprocess243485 +Node: Getline/Variable/Coprocess244737 +Node: Getline Notes245474 +Node: Getline Summary248278 +Ref: table-getline-variants248686 +Node: Read Timeout249598 +Ref: Read Timeout-Footnote-1253425 +Node: Command line directories253483 +Node: Printing254365 +Node: Print255996 +Node: Print Examples257337 +Node: Output Separators260116 +Node: OFMT262132 +Node: Printf263490 +Node: Basic Printf264396 +Node: Control Letters265935 +Node: Format Modifiers269789 +Node: Printf Examples275816 +Node: Redirection278523 +Node: Special Files285495 +Node: Special FD286028 +Ref: Special FD-Footnote-1289652 +Node: Special Network289726 +Node: Special Caveats290576 +Node: Close Files And Pipes291372 +Ref: Close Files And Pipes-Footnote-1298510 +Ref: Close Files And Pipes-Footnote-2298658 +Node: Expressions298808 +Node: Values299940 +Node: Constants300616 +Node: Scalar Constants301296 +Ref: Scalar Constants-Footnote-1302155 +Node: Nondecimal-numbers302405 +Node: Regexp Constants305405 +Node: Using Constant Regexps305880 +Node: Variables308950 +Node: Using Variables309605 +Node: Assignment Options311329 +Node: Conversion313204 +Ref: table-locale-affects318640 +Ref: Conversion-Footnote-1319264 +Node: All Operators319373 +Node: Arithmetic Ops320003 +Node: Concatenation322508 +Ref: Concatenation-Footnote-1325304 +Node: Assignment Ops325424 +Ref: table-assign-ops330407 +Node: Increment Ops331724 +Node: Truth Values and Conditions335162 +Node: Truth Values336245 +Node: Typing and Comparison337294 +Node: Variable Typing338087 +Ref: Variable Typing-Footnote-1341987 +Node: Comparison Operators342109 +Ref: table-relational-ops342519 +Node: POSIX String Comparison346067 +Ref: POSIX String Comparison-Footnote-1347151 +Node: Boolean Ops347289 +Ref: Boolean Ops-Footnote-1351359 +Node: Conditional Exp351450 +Node: Function Calls353177 +Node: Precedence356935 +Node: Locales360604 +Node: Patterns and Actions362207 +Node: Pattern Overview363261 +Node: Regexp Patterns364938 +Node: Expression Patterns365481 +Node: Ranges369262 +Node: BEGIN/END372368 +Node: Using BEGIN/END373130 +Ref: Using BEGIN/END-Footnote-1375866 +Node: I/O And BEGIN/END375972 +Node: BEGINFILE/ENDFILE378257 +Node: Empty381188 +Node: Using Shell Variables381505 +Node: Action Overview383788 +Node: Statements386115 +Node: If Statement387963 +Node: While Statement389461 +Node: Do Statement391505 +Node: For Statement392661 +Node: Switch Statement395813 +Node: Break Statement397916 +Node: Continue Statement399971 +Node: Next Statement401764 +Node: Nextfile Statement404154 +Node: Exit Statement406809 +Node: Built-in Variables409213 +Node: User-modified410309 +Ref: User-modified-Footnote-1417994 +Node: Auto-set418056 +Ref: Auto-set-Footnote-1430621 +Ref: Auto-set-Footnote-2430826 +Node: ARGC and ARGV430882 +Node: Arrays434736 +Node: Array Basics436234 +Node: Array Intro437060 +Ref: figure-array-elements439033 +Node: Reference to Elements441440 +Node: Assigning Elements443713 +Node: Array Example444204 +Node: Scanning an Array445936 +Node: Controlling Scanning448951 +Ref: Controlling Scanning-Footnote-1454124 +Node: Delete454440 +Ref: Delete-Footnote-1457205 +Node: Numeric Array Subscripts457262 +Node: Uninitialized Subscripts459445 +Node: Multidimensional461070 +Node: Multiscanning464163 +Node: Arrays of Arrays465752 +Node: Functions470392 +Node: Built-in471211 +Node: Calling Built-in472289 +Node: Numeric Functions474277 +Ref: Numeric Functions-Footnote-1478111 +Ref: Numeric Functions-Footnote-2478468 +Ref: Numeric Functions-Footnote-3478516 +Node: String Functions478785 +Ref: String Functions-Footnote-1501796 +Ref: String Functions-Footnote-2501925 +Ref: String Functions-Footnote-3502173 +Node: Gory Details502260 +Ref: table-sub-escapes503929 +Ref: table-sub-posix-92505283 +Ref: table-sub-proposed506634 +Ref: table-posix-sub507988 +Ref: table-gensub-escapes509533 +Ref: Gory Details-Footnote-1510709 +Ref: Gory Details-Footnote-2510760 +Node: I/O Functions510911 +Ref: I/O Functions-Footnote-1518034 +Node: Time Functions518181 +Ref: Time Functions-Footnote-1528645 +Ref: Time Functions-Footnote-2528713 +Ref: Time Functions-Footnote-3528871 +Ref: Time Functions-Footnote-4528982 +Ref: Time Functions-Footnote-5529094 +Ref: Time Functions-Footnote-6529321 +Node: Bitwise Functions529587 +Ref: table-bitwise-ops530149 +Ref: Bitwise Functions-Footnote-1534394 +Node: Type Functions534578 +Node: I18N Functions535720 +Node: User-defined537365 +Node: Definition Syntax538169 +Ref: Definition Syntax-Footnote-1543094 +Node: Function Example543163 +Ref: Function Example-Footnote-1545807 +Node: Function Caveats545829 +Node: Calling A Function546347 +Node: Variable Scope547302 +Node: Pass By Value/Reference550290 +Node: Return Statement553798 +Node: Dynamic Typing556782 +Node: Indirect Calls557711 +Node: Library Functions567398 +Ref: Library Functions-Footnote-1570911 +Ref: Library Functions-Footnote-2571054 +Node: Library Names571225 +Ref: Library Names-Footnote-1574698 +Ref: Library Names-Footnote-2574918 +Node: General Functions575004 +Node: Strtonum Function576032 +Node: Assert Function578962 +Node: Round Function582288 +Node: Cliff Random Function583829 +Node: Ordinal Functions584845 +Ref: Ordinal Functions-Footnote-1587922 +Ref: Ordinal Functions-Footnote-2588174 +Node: Join Function588385 +Ref: Join Function-Footnote-1590156 +Node: Getlocaltime Function590356 +Node: Readfile Function594092 +Node: Data File Management595931 +Node: Filetrans Function596563 +Node: Rewind Function600632 +Node: File Checking602019 +Ref: File Checking-Footnote-1603151 +Node: Empty Files603352 +Node: Ignoring Assigns605582 +Node: Getopt Function607136 +Ref: Getopt Function-Footnote-1618439 +Node: Passwd Functions618642 +Ref: Passwd Functions-Footnote-1627621 +Node: Group Functions627709 +Ref: Group Functions-Footnote-1635651 +Node: Walking Arrays635864 +Node: Sample Programs638000 +Node: Running Examples638674 +Node: Clones639402 +Node: Cut Program640626 +Node: Egrep Program650479 +Ref: Egrep Program-Footnote-1658450 +Node: Id Program658560 +Node: Split Program662224 +Ref: Split Program-Footnote-1665762 +Node: Tee Program665890 +Node: Uniq Program668697 +Node: Wc Program676127 +Ref: Wc Program-Footnote-1680395 +Ref: Wc Program-Footnote-2680595 +Node: Miscellaneous Programs680687 +Node: Dupword Program681875 +Node: Alarm Program683906 +Node: Translate Program688713 +Ref: Translate Program-Footnote-1693104 +Ref: Translate Program-Footnote-2693374 +Node: Labels Program693508 +Ref: Labels Program-Footnote-1696879 +Node: Word Sorting696963 +Node: History Sorting701006 +Node: Extract Program702842 +Ref: Extract Program-Footnote-1710372 +Node: Simple Sed710501 +Node: Igawk Program713563 +Ref: Igawk Program-Footnote-1728738 +Ref: Igawk Program-Footnote-2728939 +Node: Anagram Program729077 +Node: Signature Program732145 +Node: Advanced Features733392 +Node: Nondecimal Data735278 +Node: Array Sorting736855 +Node: Controlling Array Traversal737552 +Node: Array Sorting Functions745832 +Ref: Array Sorting Functions-Footnote-1749739 +Node: Two-way I/O749933 +Ref: Two-way I/O-Footnote-1755449 +Node: TCP/IP Networking755531 +Node: Profiling758375 +Node: Internationalization765883 +Node: I18N and L10N767308 +Node: Explaining gettext767994 +Ref: Explaining gettext-Footnote-1773134 +Ref: Explaining gettext-Footnote-2773318 +Node: Programmer i18n773483 +Node: Translator i18n777708 +Node: String Extraction778502 +Ref: String Extraction-Footnote-1779463 +Node: Printf Ordering779549 +Ref: Printf Ordering-Footnote-1782331 +Node: I18N Portability782395 +Ref: I18N Portability-Footnote-1784844 +Node: I18N Example784907 +Ref: I18N Example-Footnote-1787629 +Node: Gawk I18N787701 +Node: Debugger788322 +Node: Debugging789293 +Node: Debugging Concepts789734 +Node: Debugging Terms791590 +Node: Awk Debugging794187 +Node: Sample Debugging Session795079 +Node: Debugger Invocation795599 +Node: Finding The Bug796932 +Node: List of Debugger Commands803414 +Node: Breakpoint Control804746 +Node: Debugger Execution Control808410 +Node: Viewing And Changing Data811770 +Node: Execution Stack815128 +Node: Debugger Info816641 +Node: Miscellaneous Debugger Commands820635 +Node: Readline Support825819 +Node: Limitations826711 +Node: Arbitrary Precision Arithmetic828959 +Ref: Arbitrary Precision Arithmetic-Footnote-1830608 +Node: General Arithmetic830756 +Node: Floating Point Issues832476 +Node: String Conversion Precision833357 +Ref: String Conversion Precision-Footnote-1835062 +Node: Unexpected Results835171 +Node: POSIX Floating Point Problems837324 +Ref: POSIX Floating Point Problems-Footnote-1841145 +Node: Integer Programming841183 +Node: Floating-point Programming842994 +Ref: Floating-point Programming-Footnote-1849322 +Ref: Floating-point Programming-Footnote-2849592 +Node: Floating-point Representation849856 +Node: Floating-point Context851021 +Ref: table-ieee-formats851860 +Node: Rounding Mode853244 +Ref: table-rounding-modes853723 +Ref: Rounding Mode-Footnote-1856738 +Node: Gawk and MPFR856917 +Node: Arbitrary Precision Floats858326 +Ref: Arbitrary Precision Floats-Footnote-1860769 +Node: Setting Precision861090 +Ref: table-predefined-precision-strings861774 +Node: Setting Rounding Mode863919 +Ref: table-gawk-rounding-modes864323 +Node: Floating-point Constants865510 +Node: Changing Precision866962 +Ref: Changing Precision-Footnote-1868354 +Node: Exact Arithmetic868528 +Node: Arbitrary Precision Integers871662 +Ref: Arbitrary Precision Integers-Footnote-1874677 +Node: Dynamic Extensions874824 +Node: Extension Intro876282 +Node: Plugin License877547 +Node: Extension Mechanism Outline878232 +Ref: figure-load-extension878656 +Ref: figure-load-new-function880141 +Ref: figure-call-new-function881143 +Node: Extension API Description883127 +Node: Extension API Functions Introduction884577 +Node: General Data Types889443 +Ref: General Data Types-Footnote-1895136 +Node: Requesting Values895435 +Ref: table-value-types-returned896172 +Node: Memory Allocation Functions897130 +Ref: Memory Allocation Functions-Footnote-1899876 +Node: Constructor Functions899972 +Node: Registration Functions901730 +Node: Extension Functions902415 +Node: Exit Callback Functions904717 +Node: Extension Version String905966 +Node: Input Parsers906616 +Node: Output Wrappers916419 +Node: Two-way processors920935 +Node: Printing Messages923138 +Ref: Printing Messages-Footnote-1924215 +Node: Updating `ERRNO'924367 +Node: Accessing Parameters925106 +Node: Symbol Table Access926336 +Node: Symbol table by name926850 +Node: Symbol table by cookie928826 +Ref: Symbol table by cookie-Footnote-1932959 +Node: Cached values933022 +Ref: Cached values-Footnote-1936527 +Node: Array Manipulation936618 +Ref: Array Manipulation-Footnote-1937716 +Node: Array Data Types937755 +Ref: Array Data Types-Footnote-1940458 +Node: Array Functions940550 +Node: Flattening Arrays944424 +Node: Creating Arrays951276 +Node: Extension API Variables956007 +Node: Extension Versioning956643 +Node: Extension API Informational Variables958544 +Node: Extension API Boilerplate959630 +Node: Finding Extensions963434 +Node: Extension Example963994 +Node: Internal File Description964724 +Node: Internal File Ops968815 +Ref: Internal File Ops-Footnote-1980361 +Node: Using Internal File Ops980501 +Ref: Using Internal File Ops-Footnote-1982848 +Node: Extension Samples983116 +Node: Extension Sample File Functions984640 +Node: Extension Sample Fnmatch992207 +Node: Extension Sample Fork993686 +Node: Extension Sample Inplace994899 +Node: Extension Sample Ord996677 +Node: Extension Sample Readdir997513 +Ref: table-readdir-file-types998368 +Node: Extension Sample Revout999167 +Node: Extension Sample Rev2way999758 +Node: Extension Sample Read write array1000499 +Node: Extension Sample Readfile1002378 +Node: Extension Sample API Tests1003478 +Node: Extension Sample Time1004003 +Node: gawkextlib1005318 +Node: Language History1008105 +Node: V7/SVR3.11009699 +Node: SVR41012019 +Node: POSIX1013461 +Node: BTL1014847 +Node: POSIX/GNU1015581 +Node: Feature History1021180 +Node: Common Extensions1034292 +Node: Ranges and Locales1035604 +Ref: Ranges and Locales-Footnote-11040221 +Ref: Ranges and Locales-Footnote-21040248 +Ref: Ranges and Locales-Footnote-31040482 +Node: Contributors1040703 +Node: Installation1046054 +Node: Gawk Distribution1046948 +Node: Getting1047432 +Node: Extracting1048258 +Node: Distribution contents1049900 +Node: Unix Installation1055617 +Node: Quick Installation1056234 +Node: Additional Configuration Options1058676 +Node: Configuration Philosophy1060414 +Node: Non-Unix Installation1062765 +Node: PC Installation1063223 +Node: PC Binary Installation1064534 +Node: PC Compiling1066382 +Ref: PC Compiling-Footnote-11069381 +Node: PC Testing1069486 +Node: PC Using1070662 +Node: Cygwin1074820 +Node: MSYS1075629 +Node: VMS Installation1076143 +Node: VMS Compilation1076939 +Ref: VMS Compilation-Footnote-11078160 +Node: VMS Dynamic Extensions1078218 +Node: VMS Installation Details1079591 +Node: VMS Running1081842 +Node: VMS GNV1084676 +Node: VMS Old Gawk1085399 +Node: Bugs1085869 +Node: Other Versions1089873 +Node: Notes1096098 +Node: Compatibility Mode1096898 +Node: Additions1097680 +Node: Accessing The Source1098605 +Node: Adding Code1100041 +Node: New Ports1106219 +Node: Derived Files1110700 +Ref: Derived Files-Footnote-11115776 +Ref: Derived Files-Footnote-21115810 +Ref: Derived Files-Footnote-31116406 +Node: Future Extensions1116520 +Node: Implementation Limitations1117126 +Node: Extension Design1118374 +Node: Old Extension Problems1119528 +Ref: Old Extension Problems-Footnote-11121045 +Node: Extension New Mechanism Goals1121102 +Ref: Extension New Mechanism Goals-Footnote-11124463 +Node: Extension Other Design Decisions1124652 +Node: Extension Future Growth1126758 +Node: Old Extension Mechanism1127594 +Node: Basic Concepts1129334 +Node: Basic High Level1130015 +Ref: figure-general-flow1130287 +Ref: figure-process-flow1130886 +Ref: Basic High Level-Footnote-11134115 +Node: Basic Data Typing1134300 +Node: Glossary1137627 +Node: Copying1162779 +Node: GNU Free Documentation License1200335 +Node: Index1225471  End Tag Table -- cgit v1.2.3 From d029488bda4b1cdddc5a7c397375da080d476efa Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 29 May 2014 21:29:29 +0300 Subject: More cleanup edits in gawk doc. --- doc/gawk.info | 1078 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 543 insertions(+), 535 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index ceeeb6f7..cb22b934 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1165,13 +1165,13 @@ published the first two editions under the title `The GNU Awk User's Guide'. This edition maintains the basic structure of the previous editions. -For Edition 4.0, the content has been thoroughly reviewed and updated. -All references to `gawk' versions prior to 4.0 have been removed. Of -significant note for this edition was *note Debugger::. +For FSF edition 4.0, the content has been thoroughly reviewed and +updated. All references to `gawk' versions prior to 4.0 have been +removed. Of significant note for this edition was *note Debugger::. - For edition 4.1, the content has been reorganized into parts, and -the major new additions are *note Arbitrary Precision Arithmetic::, and -*note Dynamic Extensions::. + For FSF edition 4.1, the content has been reorganized into parts, +and the major new additions are *note Arbitrary Precision Arithmetic::, +and *note Dynamic Extensions::. This Info file will undoubtedly continue to evolve. An electronic version comes with the `gawk' distribution from the FSF. If you find @@ -2797,7 +2797,9 @@ filename. `.' explicitly in the path or write a null entry in the path. (A null entry is indicated by starting or ending the path with a colon or by placing two colons next to each other [`::'].) This - path search mechanism is similar to the shell's. + path search mechanism is similar to the shell's. (See `The + Bourne-Again SHell manual'. + (http://www.gnu.org/software/bash/manual/)) However, `gawk' always looks in the current directory _before_ searching `AWKPATH', so there is no real reason to include the @@ -22232,6 +22234,7 @@ not return a value. `#define emalloc(pointer, type, size, message) ...' The arguments to this macro are as follows: + `pointer' The pointer variable to point at the allocated storage. @@ -22391,6 +22394,7 @@ function with `gawk' using the following function. `void awk_atexit(void (*funcp)(void *data, int exit_status),' ` void *arg0);' The parameters are: + `funcp' A pointer to the function to be called before `gawk' exits. The `data' parameter will be the original value of `arg0'. @@ -26092,6 +26096,9 @@ Info file, in approximate chronological order: - The improved array sorting features were driven by John together with Pat Rankin. + Panos Papadopoulos contributed the original text for *note Include + Files::. + * Efraim Yawitz contributed the original text for *note Debugger::. * The development of the extension API first released with `gawk' @@ -27756,11 +27763,11 @@ critical, that for any given branch, the above incantation _just works_. 2. It would certainly help if everyone used the same versions of the GNU tools as he does, which in general are the latest released - versions of Automake, Autoconf, `bison', and `gettext'. + versions of Automake, Autoconf, `bison', and GNU `gettext'. Installing from source is quite easy. It's how the maintainer - worked for years, and still works. He had `/usr/local/bin' at the - front of his `PATH' and just did: + worked for years (and still works). He had `/usr/local/bin' at + the front of his `PATH' and just did: wget http://ftp.gnu.org/gnu/PACKAGE/PACKAGE-X.Y.Z.tar.gz tar -xpzvf PACKAGE-X.Y.Z.tar.gz @@ -30853,7 +30860,7 @@ Index * Collado, Manuel: Acknowledgments. (line 60) * collating elements: Bracket Expressions. (line 69) * collating symbols: Bracket Expressions. (line 76) -* Colombo, Antonio <1>: Contributors. (line 135) +* Colombo, Antonio <1>: Contributors. (line 138) * Colombo, Antonio: Acknowledgments. (line 60) * columns, aligning: Print Examples. (line 70) * columns, cutting: Cut Program. (line 6) @@ -32301,6 +32308,7 @@ Index * output, standard: Special FD. (line 6) * p debugger command (alias for print): Viewing And Changing Data. (line 36) +* Papadopoulos, Panos: Contributors. (line 129) * parent process ID of gawk process: Auto-set. (line 181) * parentheses (), in a profile: Profiling. (line 146) * parentheses (), regexp operator: Regexp Operators. (line 80) @@ -32647,7 +32655,7 @@ Index * RLENGTH variable, match() function and: String Functions. (line 224) * Robbins, Arnold <1>: Future Extensions. (line 6) * Robbins, Arnold <2>: Bugs. (line 32) -* Robbins, Arnold <3>: Contributors. (line 139) +* Robbins, Arnold <3>: Contributors. (line 142) * Robbins, Arnold <4>: General Data Types. (line 6) * Robbins, Arnold <5>: Alarm Program. (line 6) * Robbins, Arnold <6>: Passwd Functions. (line 90) @@ -32693,7 +32701,7 @@ Index * scalar values: Basic Data Typing. (line 13) * scanning arrays: Scanning an Array. (line 6) * scanning multidimensional arrays: Multiscanning. (line 11) -* Schorr, Andrew <1>: Contributors. (line 131) +* Schorr, Andrew <1>: Contributors. (line 134) * Schorr, Andrew <2>: Auto-set. (line 284) * Schorr, Andrew: Acknowledgments. (line 60) * Schreiber, Bert: Acknowledgments. (line 38) @@ -33180,7 +33188,7 @@ Index * xgettext utility: String Extraction. (line 13) * xor: Bitwise Functions. (line 55) * XOR bitwise operation: Bitwise Functions. (line 6) -* Yawitz, Efraim: Contributors. (line 129) +* Yawitz, Efraim: Contributors. (line 132) * Zaretskii, Eli <1>: Bugs. (line 71) * Zaretskii, Eli <2>: Contributors. (line 55) * Zaretskii, Eli: Acknowledgments. (line 60) @@ -33226,526 +33234,526 @@ Node: This Manual52572 Ref: This Manual-Footnote-158351 Node: Conventions58451 Node: Manual History60607 -Ref: Manual History-Footnote-164038 -Ref: Manual History-Footnote-264079 -Node: How To Contribute64153 -Node: Acknowledgments65392 -Node: Getting Started69541 -Node: Running gawk71914 -Node: One-shot73104 -Node: Read Terminal74329 -Ref: Read Terminal-Footnote-175979 -Ref: Read Terminal-Footnote-276255 -Node: Long76426 -Node: Executable Scripts77802 -Ref: Executable Scripts-Footnote-179635 -Ref: Executable Scripts-Footnote-279737 -Node: Comments80284 -Node: Quoting82751 -Node: DOS Quoting88067 -Node: Sample Data Files88742 -Node: Very Simple91257 -Node: Two Rules95895 -Node: More Complex97790 -Ref: More Complex-Footnote-1100722 -Node: Statements/Lines100807 -Ref: Statements/Lines-Footnote-1105262 -Node: Other Features105527 -Node: When106455 -Node: Invoking Gawk108603 -Node: Command Line110066 -Node: Options110857 -Ref: Options-Footnote-1126669 -Node: Other Arguments126694 -Node: Naming Standard Input129356 -Node: Environment Variables130450 -Node: AWKPATH Variable131008 -Ref: AWKPATH Variable-Footnote-1133786 -Ref: AWKPATH Variable-Footnote-2133831 -Node: AWKLIBPATH Variable134091 -Node: Other Environment Variables134850 -Node: Exit Status138505 -Node: Include Files139180 -Node: Loading Shared Libraries142758 -Node: Obsolete144141 -Node: Undocumented144838 -Node: Regexp145080 -Node: Regexp Usage146469 -Node: Escape Sequences148502 -Node: Regexp Operators154169 -Ref: Regexp Operators-Footnote-1161649 -Ref: Regexp Operators-Footnote-2161796 -Node: Bracket Expressions161894 -Ref: table-char-classes163784 -Node: GNU Regexp Operators166307 -Node: Case-sensitivity170030 -Ref: Case-sensitivity-Footnote-1172922 -Ref: Case-sensitivity-Footnote-2173157 -Node: Leftmost Longest173265 -Node: Computed Regexps174466 -Node: Reading Files177815 -Node: Records179817 -Node: awk split records180552 -Node: gawk split records185410 -Ref: gawk split records-Footnote-1189931 -Node: Fields189968 -Ref: Fields-Footnote-1192932 -Node: Nonconstant Fields193018 -Ref: Nonconstant Fields-Footnote-1195248 -Node: Changing Fields195450 -Node: Field Separators201404 -Node: Default Field Splitting204106 -Node: Regexp Field Splitting205223 -Node: Single Character Fields208564 -Node: Command Line Field Separator209623 -Node: Full Line Fields212965 -Ref: Full Line Fields-Footnote-1213473 -Node: Field Splitting Summary213519 -Ref: Field Splitting Summary-Footnote-1216618 -Node: Constant Size216719 -Node: Splitting By Content221326 -Ref: Splitting By Content-Footnote-1225076 -Node: Multiple Line225116 -Ref: Multiple Line-Footnote-1230972 -Node: Getline231151 -Node: Plain Getline233367 -Node: Getline/Variable235462 -Node: Getline/File236609 -Node: Getline/Variable/File237993 -Ref: Getline/Variable/File-Footnote-1239592 -Node: Getline/Pipe239679 -Node: Getline/Variable/Pipe242378 -Node: Getline/Coprocess243485 -Node: Getline/Variable/Coprocess244737 -Node: Getline Notes245474 -Node: Getline Summary248278 -Ref: table-getline-variants248686 -Node: Read Timeout249598 -Ref: Read Timeout-Footnote-1253425 -Node: Command line directories253483 -Node: Printing254365 -Node: Print255996 -Node: Print Examples257337 -Node: Output Separators260116 -Node: OFMT262132 -Node: Printf263490 -Node: Basic Printf264396 -Node: Control Letters265935 -Node: Format Modifiers269789 -Node: Printf Examples275816 -Node: Redirection278523 -Node: Special Files285495 -Node: Special FD286028 -Ref: Special FD-Footnote-1289652 -Node: Special Network289726 -Node: Special Caveats290576 -Node: Close Files And Pipes291372 -Ref: Close Files And Pipes-Footnote-1298510 -Ref: Close Files And Pipes-Footnote-2298658 -Node: Expressions298808 -Node: Values299940 -Node: Constants300616 -Node: Scalar Constants301296 -Ref: Scalar Constants-Footnote-1302155 -Node: Nondecimal-numbers302405 -Node: Regexp Constants305405 -Node: Using Constant Regexps305880 -Node: Variables308950 -Node: Using Variables309605 -Node: Assignment Options311329 -Node: Conversion313204 -Ref: table-locale-affects318640 -Ref: Conversion-Footnote-1319264 -Node: All Operators319373 -Node: Arithmetic Ops320003 -Node: Concatenation322508 -Ref: Concatenation-Footnote-1325304 -Node: Assignment Ops325424 -Ref: table-assign-ops330407 -Node: Increment Ops331724 -Node: Truth Values and Conditions335162 -Node: Truth Values336245 -Node: Typing and Comparison337294 -Node: Variable Typing338087 -Ref: Variable Typing-Footnote-1341987 -Node: Comparison Operators342109 -Ref: table-relational-ops342519 -Node: POSIX String Comparison346067 -Ref: POSIX String Comparison-Footnote-1347151 -Node: Boolean Ops347289 -Ref: Boolean Ops-Footnote-1351359 -Node: Conditional Exp351450 -Node: Function Calls353177 -Node: Precedence356935 -Node: Locales360604 -Node: Patterns and Actions362207 -Node: Pattern Overview363261 -Node: Regexp Patterns364938 -Node: Expression Patterns365481 -Node: Ranges369262 -Node: BEGIN/END372368 -Node: Using BEGIN/END373130 -Ref: Using BEGIN/END-Footnote-1375866 -Node: I/O And BEGIN/END375972 -Node: BEGINFILE/ENDFILE378257 -Node: Empty381188 -Node: Using Shell Variables381505 -Node: Action Overview383788 -Node: Statements386115 -Node: If Statement387963 -Node: While Statement389461 -Node: Do Statement391505 -Node: For Statement392661 -Node: Switch Statement395813 -Node: Break Statement397916 -Node: Continue Statement399971 -Node: Next Statement401764 -Node: Nextfile Statement404154 -Node: Exit Statement406809 -Node: Built-in Variables409213 -Node: User-modified410309 -Ref: User-modified-Footnote-1417994 -Node: Auto-set418056 -Ref: Auto-set-Footnote-1430621 -Ref: Auto-set-Footnote-2430826 -Node: ARGC and ARGV430882 -Node: Arrays434736 -Node: Array Basics436234 -Node: Array Intro437060 -Ref: figure-array-elements439033 -Node: Reference to Elements441440 -Node: Assigning Elements443713 -Node: Array Example444204 -Node: Scanning an Array445936 -Node: Controlling Scanning448951 -Ref: Controlling Scanning-Footnote-1454124 -Node: Delete454440 -Ref: Delete-Footnote-1457205 -Node: Numeric Array Subscripts457262 -Node: Uninitialized Subscripts459445 -Node: Multidimensional461070 -Node: Multiscanning464163 -Node: Arrays of Arrays465752 -Node: Functions470392 -Node: Built-in471211 -Node: Calling Built-in472289 -Node: Numeric Functions474277 -Ref: Numeric Functions-Footnote-1478111 -Ref: Numeric Functions-Footnote-2478468 -Ref: Numeric Functions-Footnote-3478516 -Node: String Functions478785 -Ref: String Functions-Footnote-1501796 -Ref: String Functions-Footnote-2501925 -Ref: String Functions-Footnote-3502173 -Node: Gory Details502260 -Ref: table-sub-escapes503929 -Ref: table-sub-posix-92505283 -Ref: table-sub-proposed506634 -Ref: table-posix-sub507988 -Ref: table-gensub-escapes509533 -Ref: Gory Details-Footnote-1510709 -Ref: Gory Details-Footnote-2510760 -Node: I/O Functions510911 -Ref: I/O Functions-Footnote-1518034 -Node: Time Functions518181 -Ref: Time Functions-Footnote-1528645 -Ref: Time Functions-Footnote-2528713 -Ref: Time Functions-Footnote-3528871 -Ref: Time Functions-Footnote-4528982 -Ref: Time Functions-Footnote-5529094 -Ref: Time Functions-Footnote-6529321 -Node: Bitwise Functions529587 -Ref: table-bitwise-ops530149 -Ref: Bitwise Functions-Footnote-1534394 -Node: Type Functions534578 -Node: I18N Functions535720 -Node: User-defined537365 -Node: Definition Syntax538169 -Ref: Definition Syntax-Footnote-1543094 -Node: Function Example543163 -Ref: Function Example-Footnote-1545807 -Node: Function Caveats545829 -Node: Calling A Function546347 -Node: Variable Scope547302 -Node: Pass By Value/Reference550290 -Node: Return Statement553798 -Node: Dynamic Typing556782 -Node: Indirect Calls557711 -Node: Library Functions567398 -Ref: Library Functions-Footnote-1570911 -Ref: Library Functions-Footnote-2571054 -Node: Library Names571225 -Ref: Library Names-Footnote-1574698 -Ref: Library Names-Footnote-2574918 -Node: General Functions575004 -Node: Strtonum Function576032 -Node: Assert Function578962 -Node: Round Function582288 -Node: Cliff Random Function583829 -Node: Ordinal Functions584845 -Ref: Ordinal Functions-Footnote-1587922 -Ref: Ordinal Functions-Footnote-2588174 -Node: Join Function588385 -Ref: Join Function-Footnote-1590156 -Node: Getlocaltime Function590356 -Node: Readfile Function594092 -Node: Data File Management595931 -Node: Filetrans Function596563 -Node: Rewind Function600632 -Node: File Checking602019 -Ref: File Checking-Footnote-1603151 -Node: Empty Files603352 -Node: Ignoring Assigns605582 -Node: Getopt Function607136 -Ref: Getopt Function-Footnote-1618439 -Node: Passwd Functions618642 -Ref: Passwd Functions-Footnote-1627621 -Node: Group Functions627709 -Ref: Group Functions-Footnote-1635651 -Node: Walking Arrays635864 -Node: Sample Programs638000 -Node: Running Examples638674 -Node: Clones639402 -Node: Cut Program640626 -Node: Egrep Program650479 -Ref: Egrep Program-Footnote-1658450 -Node: Id Program658560 -Node: Split Program662224 -Ref: Split Program-Footnote-1665762 -Node: Tee Program665890 -Node: Uniq Program668697 -Node: Wc Program676127 -Ref: Wc Program-Footnote-1680395 -Ref: Wc Program-Footnote-2680595 -Node: Miscellaneous Programs680687 -Node: Dupword Program681875 -Node: Alarm Program683906 -Node: Translate Program688713 -Ref: Translate Program-Footnote-1693104 -Ref: Translate Program-Footnote-2693374 -Node: Labels Program693508 -Ref: Labels Program-Footnote-1696879 -Node: Word Sorting696963 -Node: History Sorting701006 -Node: Extract Program702842 -Ref: Extract Program-Footnote-1710372 -Node: Simple Sed710501 -Node: Igawk Program713563 -Ref: Igawk Program-Footnote-1728738 -Ref: Igawk Program-Footnote-2728939 -Node: Anagram Program729077 -Node: Signature Program732145 -Node: Advanced Features733392 -Node: Nondecimal Data735278 -Node: Array Sorting736855 -Node: Controlling Array Traversal737552 -Node: Array Sorting Functions745832 -Ref: Array Sorting Functions-Footnote-1749739 -Node: Two-way I/O749933 -Ref: Two-way I/O-Footnote-1755449 -Node: TCP/IP Networking755531 -Node: Profiling758375 -Node: Internationalization765883 -Node: I18N and L10N767308 -Node: Explaining gettext767994 -Ref: Explaining gettext-Footnote-1773134 -Ref: Explaining gettext-Footnote-2773318 -Node: Programmer i18n773483 -Node: Translator i18n777708 -Node: String Extraction778502 -Ref: String Extraction-Footnote-1779463 -Node: Printf Ordering779549 -Ref: Printf Ordering-Footnote-1782331 -Node: I18N Portability782395 -Ref: I18N Portability-Footnote-1784844 -Node: I18N Example784907 -Ref: I18N Example-Footnote-1787629 -Node: Gawk I18N787701 -Node: Debugger788322 -Node: Debugging789293 -Node: Debugging Concepts789734 -Node: Debugging Terms791590 -Node: Awk Debugging794187 -Node: Sample Debugging Session795079 -Node: Debugger Invocation795599 -Node: Finding The Bug796932 -Node: List of Debugger Commands803414 -Node: Breakpoint Control804746 -Node: Debugger Execution Control808410 -Node: Viewing And Changing Data811770 -Node: Execution Stack815128 -Node: Debugger Info816641 -Node: Miscellaneous Debugger Commands820635 -Node: Readline Support825819 -Node: Limitations826711 -Node: Arbitrary Precision Arithmetic828959 -Ref: Arbitrary Precision Arithmetic-Footnote-1830608 -Node: General Arithmetic830756 -Node: Floating Point Issues832476 -Node: String Conversion Precision833357 -Ref: String Conversion Precision-Footnote-1835062 -Node: Unexpected Results835171 -Node: POSIX Floating Point Problems837324 -Ref: POSIX Floating Point Problems-Footnote-1841145 -Node: Integer Programming841183 -Node: Floating-point Programming842994 -Ref: Floating-point Programming-Footnote-1849322 -Ref: Floating-point Programming-Footnote-2849592 -Node: Floating-point Representation849856 -Node: Floating-point Context851021 -Ref: table-ieee-formats851860 -Node: Rounding Mode853244 -Ref: table-rounding-modes853723 -Ref: Rounding Mode-Footnote-1856738 -Node: Gawk and MPFR856917 -Node: Arbitrary Precision Floats858326 -Ref: Arbitrary Precision Floats-Footnote-1860769 -Node: Setting Precision861090 -Ref: table-predefined-precision-strings861774 -Node: Setting Rounding Mode863919 -Ref: table-gawk-rounding-modes864323 -Node: Floating-point Constants865510 -Node: Changing Precision866962 -Ref: Changing Precision-Footnote-1868354 -Node: Exact Arithmetic868528 -Node: Arbitrary Precision Integers871662 -Ref: Arbitrary Precision Integers-Footnote-1874677 -Node: Dynamic Extensions874824 -Node: Extension Intro876282 -Node: Plugin License877547 -Node: Extension Mechanism Outline878232 -Ref: figure-load-extension878656 -Ref: figure-load-new-function880141 -Ref: figure-call-new-function881143 -Node: Extension API Description883127 -Node: Extension API Functions Introduction884577 -Node: General Data Types889443 -Ref: General Data Types-Footnote-1895136 -Node: Requesting Values895435 -Ref: table-value-types-returned896172 -Node: Memory Allocation Functions897130 -Ref: Memory Allocation Functions-Footnote-1899876 -Node: Constructor Functions899972 -Node: Registration Functions901730 -Node: Extension Functions902415 -Node: Exit Callback Functions904717 -Node: Extension Version String905966 -Node: Input Parsers906616 -Node: Output Wrappers916419 -Node: Two-way processors920935 -Node: Printing Messages923138 -Ref: Printing Messages-Footnote-1924215 -Node: Updating `ERRNO'924367 -Node: Accessing Parameters925106 -Node: Symbol Table Access926336 -Node: Symbol table by name926850 -Node: Symbol table by cookie928826 -Ref: Symbol table by cookie-Footnote-1932959 -Node: Cached values933022 -Ref: Cached values-Footnote-1936527 -Node: Array Manipulation936618 -Ref: Array Manipulation-Footnote-1937716 -Node: Array Data Types937755 -Ref: Array Data Types-Footnote-1940458 -Node: Array Functions940550 -Node: Flattening Arrays944424 -Node: Creating Arrays951276 -Node: Extension API Variables956007 -Node: Extension Versioning956643 -Node: Extension API Informational Variables958544 -Node: Extension API Boilerplate959630 -Node: Finding Extensions963434 -Node: Extension Example963994 -Node: Internal File Description964724 -Node: Internal File Ops968815 -Ref: Internal File Ops-Footnote-1980361 -Node: Using Internal File Ops980501 -Ref: Using Internal File Ops-Footnote-1982848 -Node: Extension Samples983116 -Node: Extension Sample File Functions984640 -Node: Extension Sample Fnmatch992207 -Node: Extension Sample Fork993686 -Node: Extension Sample Inplace994899 -Node: Extension Sample Ord996677 -Node: Extension Sample Readdir997513 -Ref: table-readdir-file-types998368 -Node: Extension Sample Revout999167 -Node: Extension Sample Rev2way999758 -Node: Extension Sample Read write array1000499 -Node: Extension Sample Readfile1002378 -Node: Extension Sample API Tests1003478 -Node: Extension Sample Time1004003 -Node: gawkextlib1005318 -Node: Language History1008105 -Node: V7/SVR3.11009699 -Node: SVR41012019 -Node: POSIX1013461 -Node: BTL1014847 -Node: POSIX/GNU1015581 -Node: Feature History1021180 -Node: Common Extensions1034292 -Node: Ranges and Locales1035604 -Ref: Ranges and Locales-Footnote-11040221 -Ref: Ranges and Locales-Footnote-21040248 -Ref: Ranges and Locales-Footnote-31040482 -Node: Contributors1040703 -Node: Installation1046054 -Node: Gawk Distribution1046948 -Node: Getting1047432 -Node: Extracting1048258 -Node: Distribution contents1049900 -Node: Unix Installation1055617 -Node: Quick Installation1056234 -Node: Additional Configuration Options1058676 -Node: Configuration Philosophy1060414 -Node: Non-Unix Installation1062765 -Node: PC Installation1063223 -Node: PC Binary Installation1064534 -Node: PC Compiling1066382 -Ref: PC Compiling-Footnote-11069381 -Node: PC Testing1069486 -Node: PC Using1070662 -Node: Cygwin1074820 -Node: MSYS1075629 -Node: VMS Installation1076143 -Node: VMS Compilation1076939 -Ref: VMS Compilation-Footnote-11078160 -Node: VMS Dynamic Extensions1078218 -Node: VMS Installation Details1079591 -Node: VMS Running1081842 -Node: VMS GNV1084676 -Node: VMS Old Gawk1085399 -Node: Bugs1085869 -Node: Other Versions1089873 -Node: Notes1096098 -Node: Compatibility Mode1096898 -Node: Additions1097680 -Node: Accessing The Source1098605 -Node: Adding Code1100041 -Node: New Ports1106219 -Node: Derived Files1110700 -Ref: Derived Files-Footnote-11115776 -Ref: Derived Files-Footnote-21115810 -Ref: Derived Files-Footnote-31116406 -Node: Future Extensions1116520 -Node: Implementation Limitations1117126 -Node: Extension Design1118374 -Node: Old Extension Problems1119528 -Ref: Old Extension Problems-Footnote-11121045 -Node: Extension New Mechanism Goals1121102 -Ref: Extension New Mechanism Goals-Footnote-11124463 -Node: Extension Other Design Decisions1124652 -Node: Extension Future Growth1126758 -Node: Old Extension Mechanism1127594 -Node: Basic Concepts1129334 -Node: Basic High Level1130015 -Ref: figure-general-flow1130287 -Ref: figure-process-flow1130886 -Ref: Basic High Level-Footnote-11134115 -Node: Basic Data Typing1134300 -Node: Glossary1137627 -Node: Copying1162779 -Node: GNU Free Documentation License1200335 -Node: Index1225471 +Ref: Manual History-Footnote-164046 +Ref: Manual History-Footnote-264087 +Node: How To Contribute64161 +Node: Acknowledgments65400 +Node: Getting Started69549 +Node: Running gawk71922 +Node: One-shot73112 +Node: Read Terminal74337 +Ref: Read Terminal-Footnote-175987 +Ref: Read Terminal-Footnote-276263 +Node: Long76434 +Node: Executable Scripts77810 +Ref: Executable Scripts-Footnote-179643 +Ref: Executable Scripts-Footnote-279745 +Node: Comments80292 +Node: Quoting82759 +Node: DOS Quoting88075 +Node: Sample Data Files88750 +Node: Very Simple91265 +Node: Two Rules95903 +Node: More Complex97798 +Ref: More Complex-Footnote-1100730 +Node: Statements/Lines100815 +Ref: Statements/Lines-Footnote-1105270 +Node: Other Features105535 +Node: When106463 +Node: Invoking Gawk108611 +Node: Command Line110074 +Node: Options110865 +Ref: Options-Footnote-1126677 +Node: Other Arguments126702 +Node: Naming Standard Input129364 +Node: Environment Variables130458 +Node: AWKPATH Variable131016 +Ref: AWKPATH Variable-Footnote-1133887 +Ref: AWKPATH Variable-Footnote-2133932 +Node: AWKLIBPATH Variable134192 +Node: Other Environment Variables134951 +Node: Exit Status138606 +Node: Include Files139281 +Node: Loading Shared Libraries142859 +Node: Obsolete144242 +Node: Undocumented144939 +Node: Regexp145181 +Node: Regexp Usage146570 +Node: Escape Sequences148603 +Node: Regexp Operators154270 +Ref: Regexp Operators-Footnote-1161750 +Ref: Regexp Operators-Footnote-2161897 +Node: Bracket Expressions161995 +Ref: table-char-classes163885 +Node: GNU Regexp Operators166408 +Node: Case-sensitivity170131 +Ref: Case-sensitivity-Footnote-1173023 +Ref: Case-sensitivity-Footnote-2173258 +Node: Leftmost Longest173366 +Node: Computed Regexps174567 +Node: Reading Files177916 +Node: Records179918 +Node: awk split records180653 +Node: gawk split records185511 +Ref: gawk split records-Footnote-1190032 +Node: Fields190069 +Ref: Fields-Footnote-1193033 +Node: Nonconstant Fields193119 +Ref: Nonconstant Fields-Footnote-1195349 +Node: Changing Fields195551 +Node: Field Separators201505 +Node: Default Field Splitting204207 +Node: Regexp Field Splitting205324 +Node: Single Character Fields208665 +Node: Command Line Field Separator209724 +Node: Full Line Fields213066 +Ref: Full Line Fields-Footnote-1213574 +Node: Field Splitting Summary213620 +Ref: Field Splitting Summary-Footnote-1216719 +Node: Constant Size216820 +Node: Splitting By Content221427 +Ref: Splitting By Content-Footnote-1225177 +Node: Multiple Line225217 +Ref: Multiple Line-Footnote-1231073 +Node: Getline231252 +Node: Plain Getline233468 +Node: Getline/Variable235563 +Node: Getline/File236710 +Node: Getline/Variable/File238094 +Ref: Getline/Variable/File-Footnote-1239693 +Node: Getline/Pipe239780 +Node: Getline/Variable/Pipe242479 +Node: Getline/Coprocess243586 +Node: Getline/Variable/Coprocess244838 +Node: Getline Notes245575 +Node: Getline Summary248379 +Ref: table-getline-variants248787 +Node: Read Timeout249699 +Ref: Read Timeout-Footnote-1253526 +Node: Command line directories253584 +Node: Printing254466 +Node: Print256097 +Node: Print Examples257438 +Node: Output Separators260217 +Node: OFMT262233 +Node: Printf263591 +Node: Basic Printf264497 +Node: Control Letters266036 +Node: Format Modifiers269890 +Node: Printf Examples275917 +Node: Redirection278624 +Node: Special Files285596 +Node: Special FD286129 +Ref: Special FD-Footnote-1289753 +Node: Special Network289827 +Node: Special Caveats290677 +Node: Close Files And Pipes291473 +Ref: Close Files And Pipes-Footnote-1298611 +Ref: Close Files And Pipes-Footnote-2298759 +Node: Expressions298909 +Node: Values300041 +Node: Constants300717 +Node: Scalar Constants301397 +Ref: Scalar Constants-Footnote-1302256 +Node: Nondecimal-numbers302506 +Node: Regexp Constants305506 +Node: Using Constant Regexps305981 +Node: Variables309051 +Node: Using Variables309706 +Node: Assignment Options311430 +Node: Conversion313305 +Ref: table-locale-affects318741 +Ref: Conversion-Footnote-1319365 +Node: All Operators319474 +Node: Arithmetic Ops320104 +Node: Concatenation322609 +Ref: Concatenation-Footnote-1325405 +Node: Assignment Ops325525 +Ref: table-assign-ops330508 +Node: Increment Ops331825 +Node: Truth Values and Conditions335263 +Node: Truth Values336346 +Node: Typing and Comparison337395 +Node: Variable Typing338188 +Ref: Variable Typing-Footnote-1342088 +Node: Comparison Operators342210 +Ref: table-relational-ops342620 +Node: POSIX String Comparison346168 +Ref: POSIX String Comparison-Footnote-1347252 +Node: Boolean Ops347390 +Ref: Boolean Ops-Footnote-1351460 +Node: Conditional Exp351551 +Node: Function Calls353278 +Node: Precedence357036 +Node: Locales360705 +Node: Patterns and Actions362308 +Node: Pattern Overview363362 +Node: Regexp Patterns365039 +Node: Expression Patterns365582 +Node: Ranges369363 +Node: BEGIN/END372469 +Node: Using BEGIN/END373231 +Ref: Using BEGIN/END-Footnote-1375967 +Node: I/O And BEGIN/END376073 +Node: BEGINFILE/ENDFILE378358 +Node: Empty381289 +Node: Using Shell Variables381606 +Node: Action Overview383889 +Node: Statements386216 +Node: If Statement388064 +Node: While Statement389562 +Node: Do Statement391606 +Node: For Statement392762 +Node: Switch Statement395914 +Node: Break Statement398017 +Node: Continue Statement400072 +Node: Next Statement401865 +Node: Nextfile Statement404255 +Node: Exit Statement406910 +Node: Built-in Variables409314 +Node: User-modified410410 +Ref: User-modified-Footnote-1418095 +Node: Auto-set418157 +Ref: Auto-set-Footnote-1430722 +Ref: Auto-set-Footnote-2430927 +Node: ARGC and ARGV430983 +Node: Arrays434837 +Node: Array Basics436335 +Node: Array Intro437161 +Ref: figure-array-elements439134 +Node: Reference to Elements441541 +Node: Assigning Elements443814 +Node: Array Example444305 +Node: Scanning an Array446037 +Node: Controlling Scanning449052 +Ref: Controlling Scanning-Footnote-1454225 +Node: Delete454541 +Ref: Delete-Footnote-1457306 +Node: Numeric Array Subscripts457363 +Node: Uninitialized Subscripts459546 +Node: Multidimensional461171 +Node: Multiscanning464264 +Node: Arrays of Arrays465853 +Node: Functions470493 +Node: Built-in471312 +Node: Calling Built-in472390 +Node: Numeric Functions474378 +Ref: Numeric Functions-Footnote-1478212 +Ref: Numeric Functions-Footnote-2478569 +Ref: Numeric Functions-Footnote-3478617 +Node: String Functions478886 +Ref: String Functions-Footnote-1501897 +Ref: String Functions-Footnote-2502026 +Ref: String Functions-Footnote-3502274 +Node: Gory Details502361 +Ref: table-sub-escapes504030 +Ref: table-sub-posix-92505384 +Ref: table-sub-proposed506735 +Ref: table-posix-sub508089 +Ref: table-gensub-escapes509634 +Ref: Gory Details-Footnote-1510810 +Ref: Gory Details-Footnote-2510861 +Node: I/O Functions511012 +Ref: I/O Functions-Footnote-1518135 +Node: Time Functions518282 +Ref: Time Functions-Footnote-1528746 +Ref: Time Functions-Footnote-2528814 +Ref: Time Functions-Footnote-3528972 +Ref: Time Functions-Footnote-4529083 +Ref: Time Functions-Footnote-5529195 +Ref: Time Functions-Footnote-6529422 +Node: Bitwise Functions529688 +Ref: table-bitwise-ops530250 +Ref: Bitwise Functions-Footnote-1534495 +Node: Type Functions534679 +Node: I18N Functions535821 +Node: User-defined537466 +Node: Definition Syntax538270 +Ref: Definition Syntax-Footnote-1543195 +Node: Function Example543264 +Ref: Function Example-Footnote-1545908 +Node: Function Caveats545930 +Node: Calling A Function546448 +Node: Variable Scope547403 +Node: Pass By Value/Reference550391 +Node: Return Statement553899 +Node: Dynamic Typing556883 +Node: Indirect Calls557812 +Node: Library Functions567499 +Ref: Library Functions-Footnote-1571012 +Ref: Library Functions-Footnote-2571155 +Node: Library Names571326 +Ref: Library Names-Footnote-1574799 +Ref: Library Names-Footnote-2575019 +Node: General Functions575105 +Node: Strtonum Function576133 +Node: Assert Function579063 +Node: Round Function582389 +Node: Cliff Random Function583930 +Node: Ordinal Functions584946 +Ref: Ordinal Functions-Footnote-1588023 +Ref: Ordinal Functions-Footnote-2588275 +Node: Join Function588486 +Ref: Join Function-Footnote-1590257 +Node: Getlocaltime Function590457 +Node: Readfile Function594193 +Node: Data File Management596032 +Node: Filetrans Function596664 +Node: Rewind Function600733 +Node: File Checking602120 +Ref: File Checking-Footnote-1603252 +Node: Empty Files603453 +Node: Ignoring Assigns605683 +Node: Getopt Function607237 +Ref: Getopt Function-Footnote-1618540 +Node: Passwd Functions618743 +Ref: Passwd Functions-Footnote-1627722 +Node: Group Functions627810 +Ref: Group Functions-Footnote-1635752 +Node: Walking Arrays635965 +Node: Sample Programs638101 +Node: Running Examples638775 +Node: Clones639503 +Node: Cut Program640727 +Node: Egrep Program650580 +Ref: Egrep Program-Footnote-1658551 +Node: Id Program658661 +Node: Split Program662325 +Ref: Split Program-Footnote-1665863 +Node: Tee Program665991 +Node: Uniq Program668798 +Node: Wc Program676228 +Ref: Wc Program-Footnote-1680496 +Ref: Wc Program-Footnote-2680696 +Node: Miscellaneous Programs680788 +Node: Dupword Program681976 +Node: Alarm Program684007 +Node: Translate Program688814 +Ref: Translate Program-Footnote-1693205 +Ref: Translate Program-Footnote-2693475 +Node: Labels Program693609 +Ref: Labels Program-Footnote-1696980 +Node: Word Sorting697064 +Node: History Sorting701107 +Node: Extract Program702943 +Ref: Extract Program-Footnote-1710473 +Node: Simple Sed710602 +Node: Igawk Program713664 +Ref: Igawk Program-Footnote-1728839 +Ref: Igawk Program-Footnote-2729040 +Node: Anagram Program729178 +Node: Signature Program732246 +Node: Advanced Features733493 +Node: Nondecimal Data735379 +Node: Array Sorting736956 +Node: Controlling Array Traversal737653 +Node: Array Sorting Functions745933 +Ref: Array Sorting Functions-Footnote-1749840 +Node: Two-way I/O750034 +Ref: Two-way I/O-Footnote-1755550 +Node: TCP/IP Networking755632 +Node: Profiling758476 +Node: Internationalization765984 +Node: I18N and L10N767409 +Node: Explaining gettext768095 +Ref: Explaining gettext-Footnote-1773235 +Ref: Explaining gettext-Footnote-2773419 +Node: Programmer i18n773584 +Node: Translator i18n777809 +Node: String Extraction778603 +Ref: String Extraction-Footnote-1779564 +Node: Printf Ordering779650 +Ref: Printf Ordering-Footnote-1782432 +Node: I18N Portability782496 +Ref: I18N Portability-Footnote-1784945 +Node: I18N Example785008 +Ref: I18N Example-Footnote-1787730 +Node: Gawk I18N787802 +Node: Debugger788423 +Node: Debugging789394 +Node: Debugging Concepts789835 +Node: Debugging Terms791691 +Node: Awk Debugging794288 +Node: Sample Debugging Session795180 +Node: Debugger Invocation795700 +Node: Finding The Bug797033 +Node: List of Debugger Commands803515 +Node: Breakpoint Control804847 +Node: Debugger Execution Control808511 +Node: Viewing And Changing Data811871 +Node: Execution Stack815229 +Node: Debugger Info816742 +Node: Miscellaneous Debugger Commands820736 +Node: Readline Support825920 +Node: Limitations826812 +Node: Arbitrary Precision Arithmetic829060 +Ref: Arbitrary Precision Arithmetic-Footnote-1830709 +Node: General Arithmetic830857 +Node: Floating Point Issues832577 +Node: String Conversion Precision833458 +Ref: String Conversion Precision-Footnote-1835163 +Node: Unexpected Results835272 +Node: POSIX Floating Point Problems837425 +Ref: POSIX Floating Point Problems-Footnote-1841246 +Node: Integer Programming841284 +Node: Floating-point Programming843095 +Ref: Floating-point Programming-Footnote-1849423 +Ref: Floating-point Programming-Footnote-2849693 +Node: Floating-point Representation849957 +Node: Floating-point Context851122 +Ref: table-ieee-formats851961 +Node: Rounding Mode853345 +Ref: table-rounding-modes853824 +Ref: Rounding Mode-Footnote-1856839 +Node: Gawk and MPFR857018 +Node: Arbitrary Precision Floats858427 +Ref: Arbitrary Precision Floats-Footnote-1860870 +Node: Setting Precision861191 +Ref: table-predefined-precision-strings861875 +Node: Setting Rounding Mode864020 +Ref: table-gawk-rounding-modes864424 +Node: Floating-point Constants865611 +Node: Changing Precision867063 +Ref: Changing Precision-Footnote-1868455 +Node: Exact Arithmetic868629 +Node: Arbitrary Precision Integers871763 +Ref: Arbitrary Precision Integers-Footnote-1874778 +Node: Dynamic Extensions874925 +Node: Extension Intro876383 +Node: Plugin License877648 +Node: Extension Mechanism Outline878333 +Ref: figure-load-extension878757 +Ref: figure-load-new-function880242 +Ref: figure-call-new-function881244 +Node: Extension API Description883228 +Node: Extension API Functions Introduction884678 +Node: General Data Types889544 +Ref: General Data Types-Footnote-1895237 +Node: Requesting Values895536 +Ref: table-value-types-returned896273 +Node: Memory Allocation Functions897231 +Ref: Memory Allocation Functions-Footnote-1899978 +Node: Constructor Functions900074 +Node: Registration Functions901832 +Node: Extension Functions902517 +Node: Exit Callback Functions904819 +Node: Extension Version String906069 +Node: Input Parsers906719 +Node: Output Wrappers916522 +Node: Two-way processors921038 +Node: Printing Messages923241 +Ref: Printing Messages-Footnote-1924318 +Node: Updating `ERRNO'924470 +Node: Accessing Parameters925209 +Node: Symbol Table Access926439 +Node: Symbol table by name926953 +Node: Symbol table by cookie928929 +Ref: Symbol table by cookie-Footnote-1933062 +Node: Cached values933125 +Ref: Cached values-Footnote-1936630 +Node: Array Manipulation936721 +Ref: Array Manipulation-Footnote-1937819 +Node: Array Data Types937858 +Ref: Array Data Types-Footnote-1940561 +Node: Array Functions940653 +Node: Flattening Arrays944527 +Node: Creating Arrays951379 +Node: Extension API Variables956110 +Node: Extension Versioning956746 +Node: Extension API Informational Variables958647 +Node: Extension API Boilerplate959733 +Node: Finding Extensions963537 +Node: Extension Example964097 +Node: Internal File Description964827 +Node: Internal File Ops968918 +Ref: Internal File Ops-Footnote-1980464 +Node: Using Internal File Ops980604 +Ref: Using Internal File Ops-Footnote-1982951 +Node: Extension Samples983219 +Node: Extension Sample File Functions984743 +Node: Extension Sample Fnmatch992310 +Node: Extension Sample Fork993789 +Node: Extension Sample Inplace995002 +Node: Extension Sample Ord996780 +Node: Extension Sample Readdir997616 +Ref: table-readdir-file-types998471 +Node: Extension Sample Revout999270 +Node: Extension Sample Rev2way999861 +Node: Extension Sample Read write array1000602 +Node: Extension Sample Readfile1002481 +Node: Extension Sample API Tests1003581 +Node: Extension Sample Time1004106 +Node: gawkextlib1005421 +Node: Language History1008208 +Node: V7/SVR3.11009802 +Node: SVR41012122 +Node: POSIX1013564 +Node: BTL1014950 +Node: POSIX/GNU1015684 +Node: Feature History1021283 +Node: Common Extensions1034395 +Node: Ranges and Locales1035707 +Ref: Ranges and Locales-Footnote-11040324 +Ref: Ranges and Locales-Footnote-21040351 +Ref: Ranges and Locales-Footnote-31040585 +Node: Contributors1040806 +Node: Installation1046244 +Node: Gawk Distribution1047138 +Node: Getting1047622 +Node: Extracting1048448 +Node: Distribution contents1050090 +Node: Unix Installation1055807 +Node: Quick Installation1056424 +Node: Additional Configuration Options1058866 +Node: Configuration Philosophy1060604 +Node: Non-Unix Installation1062955 +Node: PC Installation1063413 +Node: PC Binary Installation1064724 +Node: PC Compiling1066572 +Ref: PC Compiling-Footnote-11069571 +Node: PC Testing1069676 +Node: PC Using1070852 +Node: Cygwin1075010 +Node: MSYS1075819 +Node: VMS Installation1076333 +Node: VMS Compilation1077129 +Ref: VMS Compilation-Footnote-11078350 +Node: VMS Dynamic Extensions1078408 +Node: VMS Installation Details1079781 +Node: VMS Running1082032 +Node: VMS GNV1084866 +Node: VMS Old Gawk1085589 +Node: Bugs1086059 +Node: Other Versions1090063 +Node: Notes1096288 +Node: Compatibility Mode1097088 +Node: Additions1097870 +Node: Accessing The Source1098795 +Node: Adding Code1100231 +Node: New Ports1106409 +Node: Derived Files1110890 +Ref: Derived Files-Footnote-11115971 +Ref: Derived Files-Footnote-21116005 +Ref: Derived Files-Footnote-31116601 +Node: Future Extensions1116715 +Node: Implementation Limitations1117321 +Node: Extension Design1118569 +Node: Old Extension Problems1119723 +Ref: Old Extension Problems-Footnote-11121240 +Node: Extension New Mechanism Goals1121297 +Ref: Extension New Mechanism Goals-Footnote-11124658 +Node: Extension Other Design Decisions1124847 +Node: Extension Future Growth1126953 +Node: Old Extension Mechanism1127789 +Node: Basic Concepts1129529 +Node: Basic High Level1130210 +Ref: figure-general-flow1130482 +Ref: figure-process-flow1131081 +Ref: Basic High Level-Footnote-11134310 +Node: Basic Data Typing1134495 +Node: Glossary1137822 +Node: Copying1162974 +Node: GNU Free Documentation License1200530 +Node: Index1225666  End Tag Table -- cgit v1.2.3 From daf5b0c87115b6793c5ac6568009916d4be3152b Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 3 Jun 2014 16:41:42 +0300 Subject: More doc improvements. --- doc/gawk.info | 1509 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 752 insertions(+), 757 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index cb22b934..c5038115 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1483,7 +1483,7 @@ tell `awk' to use that file for its program, you type: awk -f SOURCE-FILE INPUT-FILE1 INPUT-FILE2 ... The `-f' instructs the `awk' utility to get the `awk' program from -the file SOURCE-FILE. Any file name can be used for SOURCE-FILE. For +the file SOURCE-FILE. Any FN can be used for SOURCE-FILE. For example, you could put the program: BEGIN { print "Don't Panic!" } @@ -1497,16 +1497,15 @@ does the same thing as this one: awk "BEGIN { print \"Don't Panic!\" }" This was explained earlier (*note Read Terminal::). Note that you -don't usually need single quotes around the file name that you specify -with `-f', because most file names don't contain any of the shell's -special characters. Notice that in `advice', the `awk' program did not -have single quotes around it. The quotes are only needed for programs -that are provided on the `awk' command line. +don't usually need single quotes around the FN that you specify with +`-f', because most FNs don't contain any of the shell's special +characters. Notice that in `advice', the `awk' program did not have +single quotes around it. The quotes are only needed for programs that +are provided on the `awk' command line. If you want to clearly identify your `awk' program files as such, -you can add the extension `.awk' to the file name. This doesn't affect -the execution of the `awk' program but it does make "housekeeping" -easier. +you can add the extension `.awk' to the FN. This doesn't affect the +execution of the `awk' program but it does make "housekeeping" easier.  File: gawk.info, Node: Executable Scripts, Next: Comments, Prev: Long, Up: Running gawk @@ -1561,14 +1560,14 @@ the name of your script (`advice'). (d.c.) Don't rely on the value of (1) The `#!' mechanism works on GNU/Linux systems, BSD-based systems and commercial Unix systems. - (2) The line beginning with `#!' lists the full file name of an -interpreter to run and an optional initial command-line argument to -pass to that interpreter. The operating system then runs the -interpreter with the given argument and the full argument list of the -executed program. The first argument in the list is the full file name -of the `awk' program. The rest of the argument list contains either -options to `awk', or data files, or both. Note that on many systems -`awk' may be found in `/usr/bin' instead of in `/bin'. Caveat Emptor. + (2) The line beginning with `#!' lists the full FN of an interpreter +to run and an optional initial command-line argument to pass to that +interpreter. The operating system then runs the interpreter with the +given argument and the full argument list of the executed program. The +first argument in the list is the full FN of the `awk' program. The +rest of the argument list contains either options to `awk', or data +files, or both. Note that on many systems `awk' may be found in +`/usr/bin' instead of in `/bin'. Caveat Emptor.  File: gawk.info, Node: Comments, Next: Quoting, Prev: Executable Scripts, Up: Running gawk @@ -1708,9 +1707,9 @@ the quoting rules. awk -F"" 'PROGRAM' FILES # wrong! In the second case, `awk' will attempt to use the text of the - program as the value of `FS', and the first file name as the text - of the program! This results in syntax errors at best, and - confusing behavior at worst. + program as the value of `FS', and the first FN as the text of the + program! This results in syntax errors at best, and confusing + behavior at worst. Mixing single and double quotes is difficult. You have to resort to shell quoting tricks, like this: @@ -1889,9 +1888,9 @@ description of the program will give you a good idea of what is going on, but please read the rest of the Info file to become an `awk' expert!) Most of the examples use a data file named `data'. This is just a placeholder; if you use these programs yourself, substitute your -own file names for `data'. For future reference, note that there is -often more than one way to do things in `awk'. At some point, you may -want to look back at these examples and see if you can come up with +own FNs for `data'. For future reference, note that there is often +more than one way to do things in `awk'. At some point, you may want +to look back at these examples and see if you can come up with different ways to do the same things shown here: * Print the length of the longest input line: @@ -2035,7 +2034,7 @@ identifies the owner of the file. The fourth field identifies the group of the file. The fifth field contains the size of the file in bytes. The sixth, seventh, and eighth fields contain the month, day, and time, respectively, that the file was last modified. Finally, the ninth field -contains the file name.(1) +contains the FN.(1) The `$6 == "Nov"' in our `awk' program is an expression that tests whether the sixth field of the output from `ls -l' matches the string @@ -2349,10 +2348,10 @@ The following list describes options mandated by the POSIX standard: This interpretation of `--' follows the POSIX argument parsing conventions. - This is useful if you have file names that start with `-', or in - shell scripts, if you have file names that will be specified by - the user that could start with `-'. It is also useful for passing - options on to the `awk' program; see *note Getopt Function::. + This is useful if you have FNs that start with `-', or in shell + scripts, if you have FNs that will be specified by the user that + could start with `-'. It is also useful for passing options on to + the `awk' program; see *note Getopt Function::. The following list describes `gawk'-specific options: @@ -2517,8 +2516,8 @@ The following list describes options mandated by the POSIX standard: Enable pretty-printing of `awk' programs. By default, output program is created in a file named `awkprof.out' (*note Profiling::). The optional FILE argument allows you to specify a - different file name for the output. No space is allowed between - the `-o' and FILE, if FILE is supplied. + different FN for the output. No space is allowed between the `-o' + and FILE, if FILE is supplied. NOTE: Due to the way `gawk' has evolved, with this option your program is still executed. This will change in the next @@ -2534,9 +2533,9 @@ The following list describes options mandated by the POSIX standard: `--profile'[`='FILE] Enable profiling of `awk' programs (*note Profiling::). By default, profiles are created in a file named `awkprof.out'. The - optional FILE argument allows you to specify a different file name - for the profile file. No space is allowed between the `-p' and - FILE, if FILE is supplied. + optional FILE argument allows you to specify a different FN for + the profile file. No space is allowed between the `-p' and FILE, + if FILE is supplied. The profile contains execution counts for each statement in the program in the left margin, and function call counts for each @@ -2677,11 +2676,11 @@ arguments, including variable assignments, are included. As each element of `ARGV' is processed, `gawk' sets the variable `ARGIND' to the index in `ARGV' of the current element. - The distinction between file name arguments and variable-assignment + The distinction between FN arguments and variable-assignment arguments is made when `awk' is about to open the next input file. At -that point in execution, it checks the file name to see whether it is -really a variable assignment; if so, `awk' sets the variable instead of -reading a file. +that point in execution, it checks the FN to see whether it is really a +variable assignment; if so, `awk' sets the variable instead of reading +a file. Therefore, the variables actually receive the given values after all previously specified files have been read. In particular, the values of @@ -2693,13 +2692,13 @@ begins scanning the argument list. escape sequences (*note Escape Sequences::). (d.c.) In some very early implementations of `awk', when a variable -assignment occurred before any file names, the assignment would happen -_before_ the `BEGIN' rule was executed. `awk''s behavior was thus -inconsistent; some command-line assignments were available inside the -`BEGIN' rule, while others were not. Unfortunately, some applications -came to depend upon this "feature." When `awk' was changed to be more -consistent, the `-v' option was added to accommodate applications that -depended upon the old behavior. +assignment occurred before any FNs, the assignment would happen _before_ +the `BEGIN' rule was executed. `awk''s behavior was thus inconsistent; +some command-line assignments were available inside the `BEGIN' rule, +while others were not. Unfortunately, some applications came to depend +upon this "feature." When `awk' was changed to be more consistent, the +`-v' option was added to accommodate applications that depended upon +the old behavior. The variable assignment feature is most useful for assigning to variables such as `RS', `OFS', and `ORS', which control input and @@ -2735,11 +2734,11 @@ SOME_COMMAND, and finally it reads `file2'. You may also use `"-"' to name standard input when reading files with `getline' (*note Getline/File::). - In addition, `gawk' allows you to specify the special file name + In addition, `gawk' allows you to specify the special FN `/dev/stdin', both on the command line and with `getline'. Some other versions of `awk' also support this, but it is not standard. (Some operating systems provide a `/dev/stdin' file in the file system; -however, `gawk' always processes this file name itself.) +however, `gawk' always processes this FN itself.)  File: gawk.info, Node: Environment Variables, Next: Exit Status, Prev: Naming Standard Input, Up: Invoking Gawk @@ -2767,7 +2766,7 @@ The previous minor node described how `awk' program files can be named on the command-line with the `-f' option. In most `awk' implementations, you must supply a precise path name for each program file, unless the file is in the current directory. But in `gawk', if -the file name supplied to the `-f' or `-i' options does not contain a +the FN supplied to the `-f' or `-i' options does not contain a directory separator `/', then `gawk' searches a list of directories (called the "search path"), one by one, looking for a file with the specified name. @@ -2780,8 +2779,8 @@ variable. If that variable does not exist, `gawk' uses a default path, The search path feature is particularly helpful for building libraries of useful `awk' functions. The library files can be placed in a standard directory in the default path and then specified on the -command line with a short file name. Otherwise, the full file name -would have to be typed for each file. +command line with a short FN. Otherwise, the full FN would have to be +typed for each file. By using the `-i' option, or the `--source' and `-f' options, your command-line `awk' programs can use facilities in `awk' library files @@ -2790,8 +2789,8 @@ in compatibility mode. This is true for both `--traditional' and `--posix'. *Note Options::. If the source code is not found after the initial search, the path -is searched again after adding the default `.awk' suffix to the -filename. +is searched again after adding the default `.awk' suffix to the file +name. NOTE: To include the current directory in the path, either place `.' explicitly in the path or write a null entry in the path. (A @@ -2989,8 +2988,8 @@ and here is `test2': use `@include' followed by the name of the file to be included, enclosed in double quotes. - NOTE: Keep in mind that this is a language construct and the file - name cannot be a string variable, but rather just a literal string + NOTE: Keep in mind that this is a language construct and the FN + cannot be a string variable, but rather just a literal string constant in double quotes. The files to be included may be nested; e.g., given a third script, @@ -3008,7 +3007,7 @@ Running `gawk' with the `test3' script produces the following results: -| This is file test2. -| This is file test3. - The file name can, of course, be a pathname. For example: + The FN can, of course, be a pathname. For example: @include "../io_funcs" @@ -3060,8 +3059,8 @@ The `AWKLIBPATH' variable is used to search for the extension. Using If the extension is not initially found in `AWKLIBPATH', another search is conducted after appending the platform's default shared -library suffix to the filename. For example, on GNU/Linux systems, the -suffix `.so' is used. +library suffix to the file name. For example, on GNU/Linux systems, +the suffix `.so' is used. $ gawk '@load "ordchr"; BEGIN {print chr(65)}' -| A @@ -5319,11 +5318,11 @@ File: gawk.info, Node: Getline/File, Next: Getline/Variable/File, Prev: Getli --------------------------------- Use `getline < FILE' to read the next record from FILE. Here FILE is a -string-valued expression that specifies the file name. `< FILE' is -called a "redirection" because it directs input to come from a -different place. For example, the following program reads its input -record from the file `secondary.input' when it encounters a first field -with a value equal to 10 in the current input file: +string-valued expression that specifies the FN. `< FILE' is called a +"redirection" because it directs input to come from a different place. +For example, the following program reads its input record from the file +`secondary.input' when it encounters a first field with a value equal +to 10 in the current input file: { if ($1 == 10) { @@ -5756,8 +5755,8 @@ OFMT::.) For printing with specifications, you need the `printf' statement (*note Printf::). Besides basic and formatted printing, this major node also covers -I/O redirections to files and pipes, introduces the special file names -that `gawk' processes internally, and discusses the `close()' built-in +I/O redirections to files and pipes, introduces the special FNs that +`gawk' processes internally, and discusses the `close()' built-in function. * Menu: @@ -6393,9 +6392,8 @@ work identically for `printf': `print ITEMS > OUTPUT-FILE' This redirection prints the items into the output file named - OUTPUT-FILE. The file name OUTPUT-FILE can be any expression. - Its value is changed to a string and then used as a file name - (*note Expressions::). + OUTPUT-FILE. The FN OUTPUT-FILE can be any expression. Its value + is changed to a string and then used as a FN (*note Expressions::). When this type of redirection is used, the OUTPUT-FILE is erased before the first output is written to it. Subsequent writes to @@ -6513,9 +6511,9 @@ underlying operating system permits. A particularly powerful way to use redirection is to build command lines and pipe them into the shell, `sh'. For example, suppose you -have a list of files brought over from a system where all the file names -are stored in uppercase, and you wish to rename them to have names in -all lowercase. The following program is both simple and efficient: +have a list of files brought over from a system where all the FNs are +stored in uppercase, and you wish to rename them to have names in all +lowercase. The following program is both simple and efficient: { printf("mv %s %s\n", $0, tolower($0)) | "sh" } @@ -6529,12 +6527,12 @@ to rename the files. It then sends the list to the shell for execution.  File: gawk.info, Node: Special Files, Next: Close Files And Pipes, Prev: Redirection, Up: Printing -5.7 Special File Names in `gawk' -================================ +5.7 Special File Name in `gawk' +=============================== -`gawk' provides a number of special file names that it interprets -internally. These file names provide access to standard file -descriptors and TCP/IP networking. +`gawk' provides a number of special FNs that it interprets internally. +These FNs provide access to standard file descriptors and TCP/IP +networking. * Menu: @@ -6580,13 +6578,13 @@ happens, writing to the screen is not correct. In fact, if `awk' is run from a background job, it may not have a terminal at all. Then opening `/dev/tty' fails. - `gawk' provides special file names for accessing the three standard + `gawk' provides special FNs for accessing the three standard streams. (c.e.) It also provides syntax for accessing any other -inherited open files. If the file name matches one of these special -names when `gawk' redirects input or output, then it directly uses the -stream that the file name stands for. These special file names work -for all operating systems that `gawk' has been ported to, not just -those that are POSIX-compliant: +inherited open files. If the FN matches one of these special names +when `gawk' redirects input or output, then it directly uses the stream +that the FN stands for. These special FNs work for all operating +systems that `gawk' has been ported to, not just those that are +POSIX-compliant: `/dev/stdin' The standard input (file descriptor 0). @@ -6603,18 +6601,18 @@ those that are POSIX-compliant: the shell). Unless special pains are taken in the shell from which `gawk' is invoked, only descriptors 0, 1, and 2 are available. - The file names `/dev/stdin', `/dev/stdout', and `/dev/stderr' are -aliases for `/dev/fd/0', `/dev/fd/1', and `/dev/fd/2', respectively. -However, they are more self-explanatory. The proper way to write an -error message in a `gawk' program is to use `/dev/stderr', like this: + The FNs `/dev/stdin', `/dev/stdout', and `/dev/stderr' are aliases +for `/dev/fd/0', `/dev/fd/1', and `/dev/fd/2', respectively. However, +they are more self-explanatory. The proper way to write an error +message in a `gawk' program is to use `/dev/stderr', like this: print "Serious error detected!" > "/dev/stderr" - Note the use of quotes around the file name. Like any other -redirection, the value must be a string. It is a common error to omit -the quotes, which leads to confusing results. + Note the use of quotes around the FN. Like any other redirection, +the value must be a string. It is a common error to omit the quotes, +which leads to confusing results. - Finally, using the `close()' function on a file name of the form + Finally, using the `close()' function on a FN of the form `"/dev/fd/N"', for file descriptor numbers above two, does actually close the given file descriptor. @@ -6632,16 +6630,15 @@ File: gawk.info, Node: Special Network, Next: Special Caveats, Prev: Special ---------------------------------------------- `gawk' programs can open a two-way TCP/IP connection, acting as either -a client or a server. This is done using a special file name of the -form: +a client or a server. This is done using a special FN of the form: `/NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT' The NET-TYPE is one of `inet', `inet4' or `inet6'. The PROTOCOL is one of `tcp' or `udp', and the other fields represent the other essential pieces of information for making a networking connection. -These file names are used with the `|&' operator for communicating with -a coprocess (*note Two-way I/O::). This is an advanced feature, +These FNs are used with the `|&' operator for communicating with a +coprocess (*note Two-way I/O::). This is an advanced feature, mentioned here only for completeness. Full discussion is delayed until *note TCP/IP Networking::. @@ -6651,15 +6648,15 @@ File: gawk.info, Node: Special Caveats, Prev: Special Network, Up: Special Fi 5.7.3 Special File Name Caveats ------------------------------- -Here is a list of things to bear in mind when using the special file -names that `gawk' provides: +Here is a list of things to bear in mind when using the special FNs +that `gawk' provides: - * Recognition of these special file names is disabled if `gawk' is in + * Recognition of these special FNs is disabled if `gawk' is in compatibility mode (*note Options::). - * `gawk' _always_ interprets these special file names. For example, - using `/dev/fd/4' for output actually writes on file descriptor 4, - and not on a new file descriptor that is `dup()''ed from file + * `gawk' _always_ interprets these special FNs. For example, using + `/dev/fd/4' for output actually writes on file descriptor 4, and + not on a new file descriptor that is `dup()''ed from file descriptor 4. Most of the time this does not matter; however, it is important to _not_ close any of the files related to file descriptors 0, 1, and 2. Doing so results in unpredictable @@ -6671,17 +6668,17 @@ File: gawk.info, Node: Close Files And Pipes, Prev: Special Files, Up: Printi 5.8 Closing Input and Output Redirections ========================================= -If the same file name or the same shell command is used with `getline' -more than once during the execution of an `awk' program (*note -Getline::), the file is opened (or the command is executed) the first -time only. At that time, the first record of input is read from that -file or command. The next time the same file or command is used with -`getline', another record is read from it, and so on. +If the same FN or the same shell command is used with `getline' more +than once during the execution of an `awk' program (*note Getline::), +the file is opened (or the command is executed) the first time only. +At that time, the first record of input is read from that file or +command. The next time the same file or command is used with `getline', +another record is read from it, and so on. Similarly, when a file or pipe is opened for output, `awk' remembers -the file name or command associated with it, and subsequent writes to -the same file or command are appended to the previous writes. The file -or pipe stays open until `awk' exits. +the FN or command associated with it, and subsequent writes to the same +file or command are appended to the previous writes. The file or pipe +stays open until `awk' exits. This implies that special steps are necessary in order to read the same file again from the beginning, or to rerun a shell command (rather @@ -6710,8 +6707,8 @@ file or command, or the next `print' or `printf' to that file or command, reopens the file or reruns the command. Because the expression that you use to close a file or pipeline must exactly match the expression used to open the file or run the command, it is good -practice to use a variable to store the file name or command. The -previous example becomes the following: +practice to use a variable to store the FN or command. The previous +example becomes the following: sortcom = "sort -r names" sortcom | getline foo @@ -7166,11 +7163,11 @@ option, as in the following: the variable is set at the very beginning, even before the `BEGIN' rules execute. The `-v' option and its assignment must precede all the -file name arguments, as well as the program text. (*Note Options::, -for more information about the `-v' option.) Otherwise, the variable -assignment is performed at a time determined by its position among the -input file arguments--after the processing of the preceding input file -argument. For example: +FN arguments, as well as the program text. (*Note Options::, for more +information about the `-v' option.) Otherwise, the variable assignment +is performed at a time determined by its position among the input file +arguments--after the processing of the preceding input file argument. +For example: awk '{ print $n }' n=4 inventory-shipped n=2 mail-list @@ -9793,14 +9790,13 @@ Options::), they are not special. `ARGIND #' The index in `ARGV' of the current file being processed. Every time `gawk' opens a new data file for processing, it sets `ARGIND' - to the index in `ARGV' of the file name. When `gawk' is - processing the input files, `FILENAME == ARGV[ARGIND]' is always - true. + to the index in `ARGV' of the FN. When `gawk' is processing the + input files, `FILENAME == ARGV[ARGIND]' is always true. This variable is useful in file processing; it allows you to tell how far along you are in the list of data files as well as to - distinguish between successive instances of the same file name on - the command line. + distinguish between successive instances of the same FN on the + command line. While you can change the value of `ARGIND' within your `awk' program, `gawk' automatically sets it to a new value when the next @@ -10127,13 +10123,13 @@ incrementing `ARGC' causes additional files to be read. If the value of `ARGC' is decreased, that eliminates input files from the end of the list. By recording the old value of `ARGC' elsewhere, a program can treat the eliminated arguments as something -other than file names. +other than FNs. To eliminate a file from the middle of the list, store the null string (`""') into `ARGV' in place of the file's name. As a special -feature, `awk' ignores file names that have been replaced with the null -string. Another option is to use the `delete' statement to remove -elements from `ARGV' (*note Delete::). +feature, `awk' ignores FNs that have been replaced with the null string. +Another option is to use the `delete' statement to remove elements from +`ARGV' (*note Delete::). All of these actions are typically done in the `BEGIN' rule, before actual processing of the input begins. *Note Split Program::, and see @@ -14411,16 +14407,16 @@ does so _portably_; this works with any implementation of `awk': the rule it supplies is executed first. This rule relies on `awk''s `FILENAME' variable that automatically -changes for each new data file. The current file name is saved in a -private variable, `_oldfilename'. If `FILENAME' does not equal -`_oldfilename', then a new data file is being processed and it is -necessary to call `endfile()' for the old file. Because `endfile()' -should only be called if a file has been processed, the program first -checks to make sure that `_oldfilename' is not the null string. The -program then assigns the current file name to `_oldfilename' and calls -`beginfile()' for the file. Because, like all `awk' variables, -`_oldfilename' is initialized to the null string, this rule executes -correctly even for the first data file. +changes for each new data file. The current FN is saved in a private +variable, `_oldfilename'. If `FILENAME' does not equal `_oldfilename', +then a new data file is being processed and it is necessary to call +`endfile()' for the old file. Because `endfile()' should only be +called if a file has been processed, the program first checks to make +sure that `_oldfilename' is not the null string. The program then +assigns the current FN to `_oldfilename' and calls `beginfile()' for +the file. Because, like all `awk' variables, `_oldfilename' is +initialized to the null string, this rule executes correctly even for +the first data file. The program also supplies an `END' rule to do the final processing for the last file. Because this `END' rule comes before any `END' rules @@ -14557,8 +14553,8 @@ program code. possible to detect when an empty data file has been skipped. Similar to the library file presented in *note Filetrans Function::, the following library file calls a function named `zerofile()' that the -user must provide. The arguments passed are the file name and the -position in `ARGV' where it was found: +user must provide. The arguments passed are the FN and the position in +`ARGV' where it was found: # zerofile.awk --- library file to process empty input files @@ -14599,13 +14595,13 @@ intervening value in `ARGV' is a variable assignment.  File: gawk.info, Node: Ignoring Assigns, Prev: Empty Files, Up: Data File Management -10.3.5 Treating Assignments as File Names ------------------------------------------ +10.3.5 Treating Assignments as File Name +---------------------------------------- Occasionally, you might not want `awk' to process command-line variable assignments (*note Assignment Options::). In particular, if you have a -file name that contains an `=' character, `awk' treats the file name as -an assignment, and does not process it. +FN that contains an `=' character, `awk' treats the FN as an +assignment, and does not process it. Some users have suggested an additional command-line option for `gawk' to disable command-line assignments. However, some simple @@ -14632,7 +14628,7 @@ programming with a library file does the trick: The function works by looping through the arguments. It prepends `./' to any argument that matches the form of a variable assignment, -turning that argument into a file name. +turning that argument into a FN. The use of `No_command_assign' allows you to disable command-line assignments at invocation time, by giving the variable a true value. @@ -14921,7 +14917,7 @@ that it does not try to interpret the `-a', etc., as its own options. NOTE: After `getopt()' is through, it is the responsibility of the user level code to clear out all the elements of `ARGV' from 1 to `Optind', so that `awk' does not try to process the command-line - options as file names. + options as FNs. Several of the sample programs presented in *note Sample Programs::, use `getopt()' to process their arguments. @@ -15640,7 +15636,7 @@ by characters, the output field separator is set to the null string: OFS = "" } else if (c == "d") { if (length(Optarg) > 1) { - printf("Using first character of %s" \ + printf("cut: using first character of %s" \ " for delimiter\n", Optarg) > "/dev/stderr" Optarg = substr(Optarg, 1, 1) } @@ -15665,7 +15661,7 @@ we want them to be separated with individual spaces. Also remember that after `getopt()' is through (as described in *note Getopt Function::), we have to clear out all the elements of `ARGV' from 1 to `Optind', so that `awk' does not try to process the command-line options -as file names. +as FNs. After dealing with the command-line options, the program verifies that the options make sense. Only one or the other of `-c' and `-f' @@ -15707,7 +15703,7 @@ splitting: if (index(f[i], "-") != 0) { # a range m = split(f[i], g, "-") if (m != 2 || g[1] >= g[2]) { - printf("bad field list: %s\n", + printf("cut: bad field list: %s\n", f[i]) > "/dev/stderr" exit 1 } @@ -15745,7 +15741,7 @@ filler fields: if (index(f[i], "-") != 0) { # range m = split(f[i], g, "-") if (m != 2 || g[1] >= g[2]) { - printf("bad character list: %s\n", + printf("cut: bad character list: %s\n", f[i]) > "/dev/stderr" exit 1 } @@ -15822,10 +15818,9 @@ expressions that are almost identical to those available in `awk' The PATTERN is a regular expression. In typical usage, the regular expression is quoted to prevent the shell from expanding any of the -special characters as file name wildcards. Normally, `egrep' prints -the lines that matched. If multiple file names are provided on the -command line, each output line is preceded by the name of the file and -a colon. +special characters as FN wildcards. Normally, `egrep' prints the lines +that matched. If multiple FNs are provided on the command line, each +output line is preceded by the name of the file and a colon. The options to `egrep' are as follows: @@ -15897,8 +15892,8 @@ pattern is supplied with `-e', the first nonoption on the command line is used. The `awk' command-line arguments up to `ARGV[Optind]' are cleared, so that `awk' won't try to process them as files. If no files are specified, the standard input is used, and if multiple files are -specified, we make sure to note this so that the file names can precede -the matched lines in the output: +specified, we make sure to note this so that the FNs can precede the +matched lines in the output: if (pattern == "") pattern = ARGV[Optind++] @@ -15979,9 +15974,9 @@ just moves on to the next record. are not counting lines. First, if the user only wants exit status (`no_print' is true), then it is enough to know that _one_ line in this file matched, and we can skip on to the next file with `nextfile'. -Similarly, if we are only printing file names, we can print the file -name, and then skip to the next file with `nextfile'. Finally, each -line is printed, with a leading file name and colon if necessary: +Similarly, if we are only printing FNs, we can print the FN, and then +skip to the next file with `nextfile'. Finally, each line is printed, +with a leading FN and colon if necessary: { matches = ($0 ~ pattern) @@ -16167,7 +16162,7 @@ To change the number of lines in each file, supply a number on the command line preceded with a minus; e.g., `-500' for files with 500 lines in them instead of 1000. To change the name of the output files to something like `myfileaa', `myfileab', and so on, supply an -additional argument that specifies the file name prefix. +additional argument that specifies the FN prefix. Here is a version of `split' in `awk'. It uses the `ord()' and `chr()' functions presented in *note Ordinal Functions::. @@ -16892,7 +16887,7 @@ alarm: # how long to sleep for naptime = target - current if (naptime <= 0) { - print "time is in the past!" > "/dev/stderr" + print "alarm: time is in the past!" > "/dev/stderr" exit 1 } @@ -17394,7 +17389,7 @@ with a zero exit status, signifying OK: /^@c(omment)?[ \t]+system/ \ { if (NF < 3) { - e = (FILENAME ":" FNR) + e = ("extract: " FILENAME ":" FNR) e = (e ": badly formed `system' line") print e > "/dev/stderr" next @@ -17403,7 +17398,7 @@ with a zero exit status, signifying OK: $2 = "" stat = system($0) if (stat != 0) { - e = (FILENAME ":" FNR) + e = ("extract: " FILENAME ":" FNR) e = (e ": warning: system returned " stat) print e > "/dev/stderr" } @@ -17443,7 +17438,7 @@ output file: /^@c(omment)?[ \t]+file/ \ { if (NF != 3) { - e = (FILENAME ":" FNR ": badly formed `file' line") + e = ("extract: " FILENAME ":" FNR ": badly formed `file' line") print e > "/dev/stderr" next } @@ -17494,7 +17489,7 @@ closing the open file: function unexpected_eof() { - printf("%s:%d: unexpected EOF or error\n", + printf("extract: %s:%d: unexpected EOF or error\n", FILENAME, FNR) > "/dev/stderr" exit 1 } @@ -17874,7 +17869,7 @@ zero, the program is done: } fpath = pathto($2) if (fpath == "") { - printf("igawk:%s:%d: cannot find %s\n", + printf("igawk: %s:%d: cannot find %s\n", input[stackptr], FNR, $2) > "/dev/stderr" continue } @@ -19556,8 +19551,8 @@ File: gawk.info, Node: Gawk I18N, Prev: I18N Example, Up: Internationalizatio `gawk' itself has been internationalized using the GNU `gettext' package. (GNU `gettext' is described in complete detail in *note (GNU `gettext' utilities)Top:: gettext, GNU gettext tools.) As of this -writing, the latest version of GNU `gettext' is version 0.18.2.1 -(ftp://ftp.gnu.org/gnu/gettext/gettext-0.18.2.1.tar.gz). +writing, the latest version of GNU `gettext' is version 0.19 +(ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.tar.gz). If a translation of `gawk''s messages exists, then `gawk' produces usage messages, warnings, and fatal errors in the local language. @@ -22784,7 +22779,7 @@ structures as described earlier. `awk_bool_t (*can_take_two_way)(const char *name);' This function returns true if it wants to take over two-way I/O - for this filename. It should not change any state (variable + for this file name. It should not change any state (variable values, etc.) within `gawk'. `awk_bool_t (*take_control_of)(const char *name,' @@ -24542,7 +24537,7 @@ requested hierarchies. The arguments are as follows: `pathlist' - An array of filenames. The element values are used; the index + An array of file names. The element values are used; the index values are ignored. `flags' @@ -24658,10 +24653,10 @@ constant (`FNM_NOMATCH'), and an array of flag values named `FNM'. The arguments to `fnmatch()' are: `pattern' - The filename wildcard to match. + The FN wildcard to match. `string' - The filename string. + The FN string. `flag' Either zero, or the bitwise OR of one or more of the flags in the @@ -24753,8 +24748,8 @@ standard output to a temporary file configured to have the same owner and permissions as the original. After the file has been processed, the extension restores standard output to its original destination. If `INPLACE_SUFFIX' is not an empty string, the original file is linked to -a backup filename created by appending that suffix. Finally, the -temporary file is renamed to the original filename. +a backup FN created by appending that suffix. Finally, the temporary +file is renamed to the original FN. If any error occurs, the extension issues a fatal error to terminate processing immediately without damaging the original file. @@ -24814,9 +24809,9 @@ on the command line (or with `getline'), they are read, with each entry returned as a record. The record consists of three fields. The first two are the inode -number and the filename, separated by a forward slash character. On -systems where the directory entry contains the file type, the record -has a third field (also separated by a slash) which is a single letter +number and the FN, separated by a forward slash character. On systems +where the directory entry contains the file type, the record has a +third field (also separated by a slash) which is a single letter indicating the type of the file. The letters are file types are shown in *note table-readdir-file-types::. @@ -26903,8 +26898,8 @@ or: $ MMK/DESCRIPTION=[.vms]descrip.mms gawk `MMK' is an open source, free, near-clone of `MMS' and can better -handle ODS-5 volumes with upper- and lowercase filenames. `MMK' is -available from `https://github.com/endlesssoftware/mmk'. +handle ODS-5 volumes with upper- and lowercase FNs. `MMK' is available +from `https://github.com/endlesssoftware/mmk'. With ODS-5 volumes and extended parsing enabled, the case of the target parameter may need to be exact. @@ -27024,9 +27019,9 @@ has no device or directory path information in it, `gawk' looks in the current directory first, then in the directory specified by the translation of `AWK_LIBRARY' if the file is not found. If, after searching in both directories, the file still is not found, `gawk' -appends the suffix `.awk' to the filename and retries the file search. -If `AWK_LIBRARY' has no definition, a default value of `SYS$LIBRARY:' -is used for it. +appends the suffix `.awk' to the FN and retries the file search. If +`AWK_LIBRARY' has no definition, a default value of `SYS$LIBRARY:' is +used for it.  File: gawk.info, Node: VMS Running, Next: VMS GNV, Prev: VMS Installation Details, Up: VMS Installation @@ -30145,7 +30140,7 @@ Index * Menu: * ! (exclamation point), ! operator: Boolean Ops. (line 67) -* ! (exclamation point), ! operator <1>: Egrep Program. (line 175) +* ! (exclamation point), ! operator <1>: Egrep Program. (line 174) * ! (exclamation point), ! operator <2>: Ranges. (line 48) * ! (exclamation point), ! operator: Precedence. (line 52) * ! (exclamation point), != operator <1>: Precedence. (line 65) @@ -30340,7 +30335,7 @@ Index * > (right angle bracket), >= operator: Comparison Operators. (line 11) * > (right angle bracket), >> operator (I/O) <1>: Precedence. (line 65) -* > (right angle bracket), >> operator (I/O): Redirection. (line 50) +* > (right angle bracket), >> operator (I/O): Redirection. (line 49) * ? (question mark), ?: operator: Precedence. (line 92) * ? (question mark), regexp operator <1>: GNU Regexp Operators. (line 59) @@ -30381,7 +30376,7 @@ Index (line 38) * \ (backslash), as field separator: Command Line Field Separator. (line 27) -* \ (backslash), continuing lines and <1>: Egrep Program. (line 223) +* \ (backslash), continuing lines and <1>: Egrep Program. (line 222) * \ (backslash), continuing lines and: Statements/Lines. (line 19) * \ (backslash), continuing lines and, comments and: Statements/Lines. (line 76) @@ -30588,7 +30583,7 @@ Index * awk, gawk and <1>: This Manual. (line 14) * awk, gawk and: Preface. (line 23) * awk, history of: History. (line 17) -* awk, implementation issues, pipes: Redirection. (line 135) +* awk, implementation issues, pipes: Redirection. (line 134) * awk, implementations: Other Versions. (line 6) * awk, implementations, limits: Getline Notes. (line 14) * awk, invoking: Command Line. (line 6) @@ -30655,7 +30650,7 @@ Index (line 38) * backslash (\), as field separator: Command Line Field Separator. (line 27) -* backslash (\), continuing lines and <1>: Egrep Program. (line 223) +* backslash (\), continuing lines and <1>: Egrep Program. (line 222) * backslash (\), continuing lines and: Statements/Lines. (line 19) * backslash (\), continuing lines and, comments and: Statements/Lines. (line 76) @@ -30966,7 +30961,7 @@ Index (line 6) * cookie: Glossary. (line 149) * coprocesses <1>: Two-way I/O. (line 44) -* coprocesses: Redirection. (line 102) +* coprocesses: Redirection. (line 101) * coprocesses, closing: Close Files And Pipes. (line 6) * coprocesses, getline from: Getline/Coprocess. (line 6) @@ -31009,9 +31004,9 @@ Index * dark corner, exit statement: Exit Statement. (line 30) * dark corner, field separators: Field Splitting Summary. (line 46) -* dark corner, FILENAME variable <1>: Auto-set. (line 90) +* dark corner, FILENAME variable <1>: Auto-set. (line 89) * dark corner, FILENAME variable: Getline Notes. (line 19) -* dark corner, FNR/NR variables: Auto-set. (line 301) +* dark corner, FNR/NR variables: Auto-set. (line 300) * dark corner, format-control characters: Control Letters. (line 18) * dark corner, FS as null string: Single Character Fields. (line 20) @@ -31195,25 +31190,25 @@ Index (line 81) * differences in awk and gawk, command line directories: Command line directories. (line 6) -* differences in awk and gawk, ERRNO variable: Auto-set. (line 74) +* differences in awk and gawk, ERRNO variable: Auto-set. (line 73) * differences in awk and gawk, error messages: Special FD. (line 16) * differences in awk and gawk, FIELDWIDTHS variable: User-modified. (line 37) * differences in awk and gawk, FPAT variable: User-modified. (line 43) -* differences in awk and gawk, FUNCTAB variable: Auto-set. (line 115) +* differences in awk and gawk, FUNCTAB variable: Auto-set. (line 114) * differences in awk and gawk, function arguments (gawk): Calling Built-in. (line 16) * differences in awk and gawk, getline command: Getline. (line 19) * differences in awk and gawk, IGNORECASE variable: User-modified. (line 76) * differences in awk and gawk, implementation limitations <1>: Redirection. - (line 135) + (line 134) * differences in awk and gawk, implementation limitations: Getline Notes. (line 14) * differences in awk and gawk, indirect function calls: Indirect Calls. (line 6) * differences in awk and gawk, input/output operators <1>: Redirection. - (line 102) + (line 101) * differences in awk and gawk, input/output operators: Getline/Coprocess. (line 6) * differences in awk and gawk, line continuations: Conditional Exp. @@ -31223,7 +31218,7 @@ Index (line 260) * differences in awk and gawk, print/printf statements: Format Modifiers. (line 13) -* differences in awk and gawk, PROCINFO array: Auto-set. (line 128) +* differences in awk and gawk, PROCINFO array: Auto-set. (line 127) * differences in awk and gawk, read timeouts: Read Timeout. (line 6) * differences in awk and gawk, record separators: awk split records. (line 124) @@ -31233,7 +31228,7 @@ Index (line 26) * differences in awk and gawk, RS/RT variables: gawk split records. (line 58) -* differences in awk and gawk, RT variable: Auto-set. (line 257) +* differences in awk and gawk, RT variable: Auto-set. (line 256) * differences in awk and gawk, single-character fields: Single Character Fields. (line 6) * differences in awk and gawk, split() function: String Functions. @@ -31241,7 +31236,7 @@ Index * differences in awk and gawk, strings: Scalar Constants. (line 20) * differences in awk and gawk, strings, storing: gawk split records. (line 77) -* differences in awk and gawk, SYMTAB variable: Auto-set. (line 261) +* differences in awk and gawk, SYMTAB variable: Auto-set. (line 260) * differences in awk and gawk, TEXTDOMAIN variable: User-modified. (line 152) * differences in awk and gawk, trunc-mod operation: Arithmetic Ops. @@ -31282,11 +31277,11 @@ Index * dynamically loaded extensions: Dynamic Extensions. (line 6) * e debugger command (alias for enable): Breakpoint Control. (line 73) * EBCDIC: Ordinal Functions. (line 45) -* effective group ID of gawk user: Auto-set. (line 133) -* effective user ID of gawk user: Auto-set. (line 137) +* effective group ID of gawk user: Auto-set. (line 132) +* effective user ID of gawk user: Auto-set. (line 136) * egrep utility <1>: Egrep Program. (line 6) * egrep utility: Bracket Expressions. (line 24) -* egrep.awk program: Egrep Program. (line 54) +* egrep.awk program: Egrep Program. (line 53) * elements in arrays, assigning values: Assigning Elements. (line 6) * elements in arrays, deleting: Delete. (line 6) * elements in arrays, order of access by in operator: Scanning an Array. @@ -31311,7 +31306,7 @@ Index * END pattern, and profiling: Profiling. (line 62) * END pattern, assert() user-defined function and: Assert Function. (line 75) -* END pattern, backslash continuation and: Egrep Program. (line 223) +* END pattern, backslash continuation and: Egrep Program. (line 222) * END pattern, Boolean patterns and: Expression Patterns. (line 70) * END pattern, exit statement and: Exit Statement. (line 12) * END pattern, next/nextfile statements and <1>: Next Statement. @@ -31327,10 +31322,10 @@ Index * endgrent() user-defined function: Group Functions. (line 216) * endpwent() function (C library): Passwd Functions. (line 210) * endpwent() user-defined function: Passwd Functions. (line 213) -* ENVIRON array: Auto-set. (line 60) +* ENVIRON array: Auto-set. (line 59) * environment variables used by gawk: Environment Variables. (line 6) -* environment variables, in ENVIRON array: Auto-set. (line 60) +* environment variables, in ENVIRON array: Auto-set. (line 59) * epoch, definition of: Glossary. (line 234) * equals sign (=), = operator: Assignment Ops. (line 6) * equals sign (=), == operator <1>: Precedence. (line 65) @@ -31338,13 +31333,13 @@ Index (line 11) * EREs (Extended Regular Expressions): Bracket Expressions. (line 24) * ERRNO variable <1>: TCP/IP Networking. (line 54) -* ERRNO variable: Auto-set. (line 74) +* ERRNO variable: Auto-set. (line 73) * ERRNO variable, with BEGINFILE pattern: BEGINFILE/ENDFILE. (line 26) * ERRNO variable, with close() function: Close Files And Pipes. (line 139) * ERRNO variable, with getline command: Getline. (line 19) * error handling: Special FD. (line 16) -* error handling, ERRNO variable and: Auto-set. (line 74) +* error handling, ERRNO variable and: Auto-set. (line 73) * error output: Special FD. (line 6) * escape processing, gsub()/gensub()/sub() functions: Gory Details. (line 6) @@ -31357,7 +31352,7 @@ Index * evaluation order, concatenation: Concatenation. (line 41) * evaluation order, functions: Calling Built-in. (line 30) * examining fields: Fields. (line 6) -* exclamation point (!), ! operator <1>: Egrep Program. (line 175) +* exclamation point (!), ! operator <1>: Egrep Program. (line 174) * exclamation point (!), ! operator <2>: Precedence. (line 52) * exclamation point (!), ! operator: Boolean Ops. (line 67) * exclamation point (!), != operator <1>: Precedence. (line 65) @@ -31398,7 +31393,7 @@ Index (line 6) * extension API version: Extension Versioning. (line 6) -* extension API, version number: Auto-set. (line 224) +* extension API, version number: Auto-set. (line 223) * extension example: Extension Example. (line 6) * extension registration: Registration Functions. (line 6) @@ -31474,10 +31469,10 @@ Index * FIELDWIDTHS variable <1>: User-modified. (line 37) * FIELDWIDTHS variable: Constant Size. (line 23) * file descriptors: Special FD. (line 6) -* file names, distinguishing: Auto-set. (line 56) +* file names, distinguishing: Auto-set. (line 55) * file names, in compatibility mode: Special Caveats. (line 9) * file names, standard streams in gawk: Special FD. (line 46) -* FILENAME variable <1>: Auto-set. (line 90) +* FILENAME variable <1>: Auto-set. (line 89) * FILENAME variable: Reading Files. (line 6) * FILENAME variable, getline, setting with: Getline Notes. (line 19) * filenames, assignments as: Ignoring Assigns. (line 6) @@ -31523,7 +31518,7 @@ Index * files, portable object, converting to message object files: I18N Example. (line 63) * files, portable object, generating: Options. (line 147) -* files, processing, ARGIND variable and: Auto-set. (line 51) +* files, processing, ARGIND variable and: Auto-set. (line 50) * files, reading: Rewind Function. (line 6) * files, reading, multiline records: Multiple Line. (line 6) * files, searching for regular expressions: Egrep Program. (line 6) @@ -31547,9 +31542,9 @@ Index * flush buffered output: I/O Functions. (line 28) * fnmatch() extension function: Extension Sample Fnmatch. (line 12) -* FNR variable <1>: Auto-set. (line 99) +* FNR variable <1>: Auto-set. (line 98) * FNR variable: Records. (line 6) -* FNR variable, changing: Auto-set. (line 301) +* FNR variable, changing: Auto-set. (line 300) * for statement: For Statement. (line 6) * for statement, looping over arrays: Scanning an Array. (line 20) * fork() extension function: Extension Sample Fork. @@ -31599,7 +31594,7 @@ Index * FSF (Free Software Foundation): Manual History. (line 6) * fts() extension function: Extension Sample File Functions. (line 61) -* FUNCTAB array: Auto-set. (line 115) +* FUNCTAB array: Auto-set. (line 114) * function calls: Function Calls. (line 6) * function calls, indirect: Indirect Calls. (line 6) * function definition example: Function Example. (line 6) @@ -31649,7 +31644,7 @@ Index * G-d: Acknowledgments. (line 78) * Garfinkle, Scott: Contributors. (line 34) * gawk program, dynamic profiling: Profiling. (line 179) -* gawk version: Auto-set. (line 199) +* gawk version: Auto-set. (line 198) * gawk, ARGIND variable in: Other Arguments. (line 12) * gawk, awk and <1>: This Manual. (line 14) * gawk, awk and: Preface. (line 23) @@ -31670,7 +31665,7 @@ Index * gawk, distribution: Distribution contents. (line 6) * gawk, ERRNO variable in <1>: TCP/IP Networking. (line 54) -* gawk, ERRNO variable in <2>: Auto-set. (line 74) +* gawk, ERRNO variable in <2>: Auto-set. (line 73) * gawk, ERRNO variable in <3>: BEGINFILE/ENDFILE. (line 26) * gawk, ERRNO variable in <4>: Close Files And Pipes. (line 139) @@ -31687,7 +31682,7 @@ Index * gawk, FPAT variable in <1>: User-modified. (line 43) * gawk, FPAT variable in: Splitting By Content. (line 27) -* gawk, FUNCTAB array in: Auto-set. (line 115) +* gawk, FUNCTAB array in: Auto-set. (line 114) * gawk, function arguments and: Calling Built-in. (line 16) * gawk, hexadecimal numbers and: Nondecimal-numbers. (line 42) * gawk, IGNORECASE variable in <1>: Array Sorting Functions. @@ -31701,7 +31696,7 @@ Index * gawk, implementation issues, downward compatibility: Compatibility Mode. (line 6) * gawk, implementation issues, limits: Getline Notes. (line 14) -* gawk, implementation issues, pipes: Redirection. (line 135) +* gawk, implementation issues, pipes: Redirection. (line 134) * gawk, installing: Installation. (line 6) * gawk, internationalization and, See internationalization: Internationalization. (line 13) @@ -31718,7 +31713,7 @@ Index * gawk, OS/2 version of: PC Using. (line 16) * gawk, PROCINFO array in <1>: Two-way I/O. (line 117) * gawk, PROCINFO array in <2>: Time Functions. (line 47) -* gawk, PROCINFO array in: Auto-set. (line 128) +* gawk, PROCINFO array in: Auto-set. (line 127) * gawk, regexp constants and: Using Constant Regexps. (line 28) * gawk, regular expressions, case sensitivity: Case-sensitivity. @@ -31726,14 +31721,14 @@ Index * gawk, regular expressions, operators: GNU Regexp Operators. (line 6) * gawk, regular expressions, precedence: Regexp Operators. (line 162) -* gawk, RT variable in <1>: Auto-set. (line 257) +* gawk, RT variable in <1>: Auto-set. (line 256) * gawk, RT variable in <2>: Multiple Line. (line 129) * gawk, RT variable in: awk split records. (line 124) * gawk, See Also awk: Preface. (line 36) * gawk, source code, obtaining: Getting. (line 6) * gawk, splitting fields and: Constant Size. (line 88) * gawk, string-translation functions: I18N Functions. (line 6) -* gawk, SYMTAB array in: Auto-set. (line 261) +* gawk, SYMTAB array in: Auto-set. (line 260) * gawk, TEXTDOMAIN variable in: User-modified. (line 152) * gawk, timestamps: Time Functions. (line 6) * gawk, uses for: Preface. (line 36) @@ -31820,7 +31815,7 @@ Index * Grigera, Juan: Contributors. (line 57) * group database, reading: Group Functions. (line 6) * group file: Group Functions. (line 6) -* group ID of gawk user: Auto-set. (line 172) +* group ID of gawk user: Auto-set. (line 171) * groups, information about: Group Functions. (line 6) * gsub <1>: String Functions. (line 139) * gsub: Using Constant Regexps. @@ -31873,7 +31868,7 @@ Index * Illumos, POSIX-compliant awk: Other Versions. (line 105) * implementation issues, gawk: Notes. (line 6) * implementation issues, gawk, debugging: Compatibility Mode. (line 6) -* implementation issues, gawk, limits <1>: Redirection. (line 135) +* implementation issues, gawk, limits <1>: Redirection. (line 134) * implementation issues, gawk, limits: Getline Notes. (line 14) * in operator <1>: For Statement. (line 75) * in operator <2>: Precedence. (line 83) @@ -32116,7 +32111,7 @@ Index * mawk utility <3>: Concatenation. (line 36) * mawk utility <4>: Getline/Pipe. (line 62) * mawk utility: Escape Sequences. (line 124) -* maximum precision supported by MPFR library: Auto-set. (line 213) +* maximum precision supported by MPFR library: Auto-set. (line 212) * McIlroy, Doug: Glossary. (line 149) * McPhee, Patrick: Contributors. (line 100) * message object files: Explaining gettext. (line 42) @@ -32129,7 +32124,7 @@ Index * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) * metacharacters, escape sequences for: Escape Sequences. (line 130) -* minimum precision supported by MPFR library: Auto-set. (line 216) +* minimum precision supported by MPFR library: Auto-set. (line 215) * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) * monetary information, localization: Explaining gettext. (line 104) @@ -32183,7 +32178,7 @@ Index (line 47) * nexti debugger command: Debugger Execution Control. (line 49) -* NF variable <1>: Auto-set. (line 104) +* NF variable <1>: Auto-set. (line 103) * NF variable: Fields. (line 33) * NF variable, decrementing: Changing Fields. (line 107) * ni debugger command (alias for nexti): Debugger Execution Control. @@ -32192,9 +32187,9 @@ Index * non-existent array elements: Reference to Elements. (line 23) * not Boolean-logic operator: Boolean Ops. (line 6) -* NR variable <1>: Auto-set. (line 123) +* NR variable <1>: Auto-set. (line 122) * NR variable: Records. (line 6) -* NR variable, changing: Auto-set. (line 301) +* NR variable, changing: Auto-set. (line 300) * null strings <1>: Basic Data Typing. (line 26) * null strings <2>: Truth Values. (line 6) * null strings <3>: Regexp Field Splitting. @@ -32302,14 +32297,14 @@ Index (line 6) * output, format specifier, OFMT: OFMT. (line 15) * output, formatted: Printf. (line 6) -* output, pipes: Redirection. (line 57) +* output, pipes: Redirection. (line 56) * output, printing, See printing: Printing. (line 6) * output, records: Output Separators. (line 20) * output, standard: Special FD. (line 6) * p debugger command (alias for print): Viewing And Changing Data. (line 36) * Papadopoulos, Panos: Contributors. (line 129) -* parent process ID of gawk process: Auto-set. (line 181) +* parent process ID of gawk process: Auto-set. (line 180) * parentheses (), in a profile: Profiling. (line 146) * parentheses (), regexp operator: Regexp Operators. (line 80) * password file: Passwd Functions. (line 16) @@ -32339,7 +32334,7 @@ Index * pipe, closing: Close Files And Pipes. (line 6) * pipe, input: Getline/Pipe. (line 9) -* pipe, output: Redirection. (line 57) +* pipe, output: Redirection. (line 56) * Pitts, Dave <1>: Bugs. (line 71) * Pitts, Dave: Acknowledgments. (line 60) * Plauger, P.J.: Library Functions. (line 12) @@ -32474,24 +32469,24 @@ Index * printing, unduplicated lines of text: Uniq Program. (line 6) * printing, user information: Id Program. (line 6) * private variables: Library Names. (line 11) -* process group idIDof gawk process: Auto-set. (line 175) -* process ID of gawk process: Auto-set. (line 178) +* process group idIDof gawk process: Auto-set. (line 174) +* process ID of gawk process: Auto-set. (line 177) * processes, two-way communications with: Two-way I/O. (line 23) * processing data: Basic High Level. (line 6) * PROCINFO array <1>: Passwd Functions. (line 6) * PROCINFO array <2>: Time Functions. (line 47) -* PROCINFO array: Auto-set. (line 128) +* PROCINFO array: Auto-set. (line 127) * PROCINFO array, and communications via ptys: Two-way I/O. (line 117) * PROCINFO array, and group membership: Group Functions. (line 6) * PROCINFO array, and user and group ID numbers: Id Program. (line 15) * PROCINFO array, testing the field splitting: Passwd Functions. (line 161) -* PROCINFO array, uses: Auto-set. (line 234) +* PROCINFO array, uses: Auto-set. (line 233) * PROCINFO, values of sorted_in: Controlling Scanning. (line 26) * profiling awk programs: Profiling. (line 6) * profiling awk programs, dynamically: Profiling. (line 179) -* program identifiers: Auto-set. (line 146) +* program identifiers: Auto-set. (line 145) * program, definition of: Getting Started. (line 21) * programmers, attractiveness of: Two-way I/O. (line 6) * programming conventions, --non-decimal-data option: Nondecimal Data. @@ -32647,11 +32642,11 @@ Index * right angle bracket (>), >= operator: Comparison Operators. (line 11) * right angle bracket (>), >> operator (I/O) <1>: Precedence. (line 65) -* right angle bracket (>), >> operator (I/O): Redirection. (line 50) +* right angle bracket (>), >> operator (I/O): Redirection. (line 49) * right shift: Bitwise Functions. (line 52) * right shift, bitwise: Bitwise Functions. (line 32) * Ritchie, Dennis: Basic Data Typing. (line 54) -* RLENGTH variable: Auto-set. (line 244) +* RLENGTH variable: Auto-set. (line 243) * RLENGTH variable, match() function and: String Functions. (line 224) * Robbins, Arnold <1>: Future Extensions. (line 6) * Robbins, Arnold <2>: Bugs. (line 32) @@ -32680,9 +32675,9 @@ Index * RS variable: awk split records. (line 12) * RS variable, multiline records and: Multiple Line. (line 17) * rshift: Bitwise Functions. (line 52) -* RSTART variable: Auto-set. (line 250) +* RSTART variable: Auto-set. (line 249) * RSTART variable, match() function and: String Functions. (line 224) -* RT variable <1>: Auto-set. (line 257) +* RT variable <1>: Auto-set. (line 256) * RT variable <2>: Multiple Line. (line 129) * RT variable: awk split records. (line 124) * Rubin, Paul <1>: Contributors. (line 15) @@ -32702,7 +32697,7 @@ Index * scanning arrays: Scanning an Array. (line 6) * scanning multidimensional arrays: Multiscanning. (line 11) * Schorr, Andrew <1>: Contributors. (line 134) -* Schorr, Andrew <2>: Auto-set. (line 284) +* Schorr, Andrew <2>: Auto-set. (line 283) * Schorr, Andrew: Acknowledgments. (line 60) * Schreiber, Bert: Acknowledgments. (line 38) * Schreiber, Rita: Acknowledgments. (line 38) @@ -32752,7 +32747,7 @@ Index * shadowing of variable values: Definition Syntax. (line 61) * shell quoting, double quote: Read Terminal. (line 25) * shell quoting, rules for: Quoting. (line 6) -* shells, piping commands into: Redirection. (line 142) +* shells, piping commands into: Redirection. (line 141) * shells, quoting: Using Shell Variables. (line 12) * shells, quoting, rules for: Quoting. (line 18) @@ -32790,7 +32785,7 @@ Index (line 110) * sidebar, Changing FS Does Not Affect the Fields: Field Splitting Summary. (line 38) -* sidebar, Changing NR and FNR: Auto-set. (line 299) +* sidebar, Changing NR and FNR: Auto-set. (line 298) * sidebar, Controlling Output Buffering with system(): I/O Functions. (line 138) * sidebar, Escape Sequences for Metacharacters: Escape Sequences. @@ -32801,7 +32796,7 @@ Index (line 107) * sidebar, Matching the Null String: Gory Details. (line 162) * sidebar, Operator Evaluation Order: Increment Ops. (line 58) -* sidebar, Piping into sh: Redirection. (line 140) +* sidebar, Piping into sh: Redirection. (line 139) * sidebar, Portability Issues with #!: Executable Scripts. (line 31) * sidebar, Recipe For A Programming Language: History. (line 6) * sidebar, RS = "\0" Is Not Portable: gawk split records. (line 63) @@ -32952,9 +32947,9 @@ Index * substr: String Functions. (line 479) * substring: String Functions. (line 479) * Sumner, Andrew: Other Versions. (line 64) -* supplementary groups of gawk process: Auto-set. (line 229) +* supplementary groups of gawk process: Auto-set. (line 228) * switch statement: Switch Statement. (line 6) -* SYMTAB array: Auto-set. (line 261) +* SYMTAB array: Auto-set. (line 260) * syntactic ambiguity: /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) * system: I/O Functions. (line 75) @@ -33038,7 +33033,7 @@ Index * troubleshooting, match() function: String Functions. (line 289) * troubleshooting, print statement, omitting commas: Print Examples. (line 31) -* troubleshooting, printing: Redirection. (line 118) +* troubleshooting, printing: Redirection. (line 117) * troubleshooting, quotes with file names: Special FD. (line 68) * troubleshooting, readable data files: File Checking. (line 6) * troubleshooting, regexp constants vs. string constants: Computed Regexps. @@ -33132,10 +33127,10 @@ Index * variables, uninitialized, as array subscripts: Uninitialized Subscripts. (line 6) * variables, user-defined: Variables. (line 6) -* version of gawk: Auto-set. (line 199) -* version of gawk extension API: Auto-set. (line 224) -* version of GNU MP library: Auto-set. (line 210) -* version of GNU MPFR library: Auto-set. (line 206) +* version of gawk: Auto-set. (line 198) +* version of gawk extension API: Auto-set. (line 223) +* version of GNU MP library: Auto-set. (line 209) +* version of GNU MPFR library: Auto-set. (line 205) * vertical bar (|): Regexp Operators. (line 70) * vertical bar (|), | operator (I/O) <1>: Precedence. (line 65) * vertical bar (|), | operator (I/O): Getline/Pipe. (line 9) @@ -33200,11 +33195,11 @@ Index * {} (braces), statements, grouping: Statements. (line 10) * | (vertical bar): Regexp Operators. (line 70) * | (vertical bar), | operator (I/O) <1>: Precedence. (line 65) -* | (vertical bar), | operator (I/O) <2>: Redirection. (line 57) +* | (vertical bar), | operator (I/O) <2>: Redirection. (line 56) * | (vertical bar), | operator (I/O): Getline/Pipe. (line 9) * | (vertical bar), |& operator (I/O) <1>: Two-way I/O. (line 44) * | (vertical bar), |& operator (I/O) <2>: Precedence. (line 65) -* | (vertical bar), |& operator (I/O) <3>: Redirection. (line 102) +* | (vertical bar), |& operator (I/O) <3>: Redirection. (line 101) * | (vertical bar), |& operator (I/O): Getline/Coprocess. (line 6) * | (vertical bar), |& operator (I/O), pipes, closing: Close Files And Pipes. (line 119) @@ -33245,515 +33240,515 @@ Node: Read Terminal74337 Ref: Read Terminal-Footnote-175987 Ref: Read Terminal-Footnote-276263 Node: Long76434 -Node: Executable Scripts77810 -Ref: Executable Scripts-Footnote-179643 -Ref: Executable Scripts-Footnote-279745 -Node: Comments80292 -Node: Quoting82759 -Node: DOS Quoting88075 -Node: Sample Data Files88750 -Node: Very Simple91265 -Node: Two Rules95903 -Node: More Complex97798 -Ref: More Complex-Footnote-1100730 -Node: Statements/Lines100815 -Ref: Statements/Lines-Footnote-1105270 -Node: Other Features105535 -Node: When106463 -Node: Invoking Gawk108611 -Node: Command Line110074 -Node: Options110865 -Ref: Options-Footnote-1126677 -Node: Other Arguments126702 -Node: Naming Standard Input129364 -Node: Environment Variables130458 -Node: AWKPATH Variable131016 -Ref: AWKPATH Variable-Footnote-1133887 -Ref: AWKPATH Variable-Footnote-2133932 -Node: AWKLIBPATH Variable134192 -Node: Other Environment Variables134951 -Node: Exit Status138606 -Node: Include Files139281 -Node: Loading Shared Libraries142859 -Node: Obsolete144242 -Node: Undocumented144939 -Node: Regexp145181 -Node: Regexp Usage146570 -Node: Escape Sequences148603 -Node: Regexp Operators154270 -Ref: Regexp Operators-Footnote-1161750 -Ref: Regexp Operators-Footnote-2161897 -Node: Bracket Expressions161995 -Ref: table-char-classes163885 -Node: GNU Regexp Operators166408 -Node: Case-sensitivity170131 -Ref: Case-sensitivity-Footnote-1173023 -Ref: Case-sensitivity-Footnote-2173258 -Node: Leftmost Longest173366 -Node: Computed Regexps174567 -Node: Reading Files177916 -Node: Records179918 -Node: awk split records180653 -Node: gawk split records185511 -Ref: gawk split records-Footnote-1190032 -Node: Fields190069 -Ref: Fields-Footnote-1193033 -Node: Nonconstant Fields193119 -Ref: Nonconstant Fields-Footnote-1195349 -Node: Changing Fields195551 -Node: Field Separators201505 -Node: Default Field Splitting204207 -Node: Regexp Field Splitting205324 -Node: Single Character Fields208665 -Node: Command Line Field Separator209724 -Node: Full Line Fields213066 -Ref: Full Line Fields-Footnote-1213574 -Node: Field Splitting Summary213620 -Ref: Field Splitting Summary-Footnote-1216719 -Node: Constant Size216820 -Node: Splitting By Content221427 -Ref: Splitting By Content-Footnote-1225177 -Node: Multiple Line225217 -Ref: Multiple Line-Footnote-1231073 -Node: Getline231252 -Node: Plain Getline233468 -Node: Getline/Variable235563 -Node: Getline/File236710 -Node: Getline/Variable/File238094 -Ref: Getline/Variable/File-Footnote-1239693 -Node: Getline/Pipe239780 -Node: Getline/Variable/Pipe242479 -Node: Getline/Coprocess243586 -Node: Getline/Variable/Coprocess244838 -Node: Getline Notes245575 -Node: Getline Summary248379 -Ref: table-getline-variants248787 -Node: Read Timeout249699 -Ref: Read Timeout-Footnote-1253526 -Node: Command line directories253584 -Node: Printing254466 -Node: Print256097 -Node: Print Examples257438 -Node: Output Separators260217 -Node: OFMT262233 -Node: Printf263591 -Node: Basic Printf264497 -Node: Control Letters266036 -Node: Format Modifiers269890 -Node: Printf Examples275917 -Node: Redirection278624 -Node: Special Files285596 -Node: Special FD286129 -Ref: Special FD-Footnote-1289753 -Node: Special Network289827 -Node: Special Caveats290677 -Node: Close Files And Pipes291473 -Ref: Close Files And Pipes-Footnote-1298611 -Ref: Close Files And Pipes-Footnote-2298759 -Node: Expressions298909 -Node: Values300041 -Node: Constants300717 -Node: Scalar Constants301397 -Ref: Scalar Constants-Footnote-1302256 -Node: Nondecimal-numbers302506 -Node: Regexp Constants305506 -Node: Using Constant Regexps305981 -Node: Variables309051 -Node: Using Variables309706 -Node: Assignment Options311430 -Node: Conversion313305 -Ref: table-locale-affects318741 -Ref: Conversion-Footnote-1319365 -Node: All Operators319474 -Node: Arithmetic Ops320104 -Node: Concatenation322609 -Ref: Concatenation-Footnote-1325405 -Node: Assignment Ops325525 -Ref: table-assign-ops330508 -Node: Increment Ops331825 -Node: Truth Values and Conditions335263 -Node: Truth Values336346 -Node: Typing and Comparison337395 -Node: Variable Typing338188 -Ref: Variable Typing-Footnote-1342088 -Node: Comparison Operators342210 -Ref: table-relational-ops342620 -Node: POSIX String Comparison346168 -Ref: POSIX String Comparison-Footnote-1347252 -Node: Boolean Ops347390 -Ref: Boolean Ops-Footnote-1351460 -Node: Conditional Exp351551 -Node: Function Calls353278 -Node: Precedence357036 -Node: Locales360705 -Node: Patterns and Actions362308 -Node: Pattern Overview363362 -Node: Regexp Patterns365039 -Node: Expression Patterns365582 -Node: Ranges369363 -Node: BEGIN/END372469 -Node: Using BEGIN/END373231 -Ref: Using BEGIN/END-Footnote-1375967 -Node: I/O And BEGIN/END376073 -Node: BEGINFILE/ENDFILE378358 -Node: Empty381289 -Node: Using Shell Variables381606 -Node: Action Overview383889 -Node: Statements386216 -Node: If Statement388064 -Node: While Statement389562 -Node: Do Statement391606 -Node: For Statement392762 -Node: Switch Statement395914 -Node: Break Statement398017 -Node: Continue Statement400072 -Node: Next Statement401865 -Node: Nextfile Statement404255 -Node: Exit Statement406910 -Node: Built-in Variables409314 -Node: User-modified410410 -Ref: User-modified-Footnote-1418095 -Node: Auto-set418157 -Ref: Auto-set-Footnote-1430722 -Ref: Auto-set-Footnote-2430927 -Node: ARGC and ARGV430983 -Node: Arrays434837 -Node: Array Basics436335 -Node: Array Intro437161 -Ref: figure-array-elements439134 -Node: Reference to Elements441541 -Node: Assigning Elements443814 -Node: Array Example444305 -Node: Scanning an Array446037 -Node: Controlling Scanning449052 -Ref: Controlling Scanning-Footnote-1454225 -Node: Delete454541 -Ref: Delete-Footnote-1457306 -Node: Numeric Array Subscripts457363 -Node: Uninitialized Subscripts459546 -Node: Multidimensional461171 -Node: Multiscanning464264 -Node: Arrays of Arrays465853 -Node: Functions470493 -Node: Built-in471312 -Node: Calling Built-in472390 -Node: Numeric Functions474378 -Ref: Numeric Functions-Footnote-1478212 -Ref: Numeric Functions-Footnote-2478569 -Ref: Numeric Functions-Footnote-3478617 -Node: String Functions478886 -Ref: String Functions-Footnote-1501897 -Ref: String Functions-Footnote-2502026 -Ref: String Functions-Footnote-3502274 -Node: Gory Details502361 -Ref: table-sub-escapes504030 -Ref: table-sub-posix-92505384 -Ref: table-sub-proposed506735 -Ref: table-posix-sub508089 -Ref: table-gensub-escapes509634 -Ref: Gory Details-Footnote-1510810 -Ref: Gory Details-Footnote-2510861 -Node: I/O Functions511012 -Ref: I/O Functions-Footnote-1518135 -Node: Time Functions518282 -Ref: Time Functions-Footnote-1528746 -Ref: Time Functions-Footnote-2528814 -Ref: Time Functions-Footnote-3528972 -Ref: Time Functions-Footnote-4529083 -Ref: Time Functions-Footnote-5529195 -Ref: Time Functions-Footnote-6529422 -Node: Bitwise Functions529688 -Ref: table-bitwise-ops530250 -Ref: Bitwise Functions-Footnote-1534495 -Node: Type Functions534679 -Node: I18N Functions535821 -Node: User-defined537466 -Node: Definition Syntax538270 -Ref: Definition Syntax-Footnote-1543195 -Node: Function Example543264 -Ref: Function Example-Footnote-1545908 -Node: Function Caveats545930 -Node: Calling A Function546448 -Node: Variable Scope547403 -Node: Pass By Value/Reference550391 -Node: Return Statement553899 -Node: Dynamic Typing556883 -Node: Indirect Calls557812 -Node: Library Functions567499 -Ref: Library Functions-Footnote-1571012 -Ref: Library Functions-Footnote-2571155 -Node: Library Names571326 -Ref: Library Names-Footnote-1574799 -Ref: Library Names-Footnote-2575019 -Node: General Functions575105 -Node: Strtonum Function576133 -Node: Assert Function579063 -Node: Round Function582389 -Node: Cliff Random Function583930 -Node: Ordinal Functions584946 -Ref: Ordinal Functions-Footnote-1588023 -Ref: Ordinal Functions-Footnote-2588275 -Node: Join Function588486 -Ref: Join Function-Footnote-1590257 -Node: Getlocaltime Function590457 -Node: Readfile Function594193 -Node: Data File Management596032 -Node: Filetrans Function596664 -Node: Rewind Function600733 -Node: File Checking602120 -Ref: File Checking-Footnote-1603252 -Node: Empty Files603453 -Node: Ignoring Assigns605683 -Node: Getopt Function607237 -Ref: Getopt Function-Footnote-1618540 -Node: Passwd Functions618743 -Ref: Passwd Functions-Footnote-1627722 -Node: Group Functions627810 -Ref: Group Functions-Footnote-1635752 -Node: Walking Arrays635965 -Node: Sample Programs638101 -Node: Running Examples638775 -Node: Clones639503 -Node: Cut Program640727 -Node: Egrep Program650580 -Ref: Egrep Program-Footnote-1658551 -Node: Id Program658661 -Node: Split Program662325 -Ref: Split Program-Footnote-1665863 -Node: Tee Program665991 -Node: Uniq Program668798 -Node: Wc Program676228 -Ref: Wc Program-Footnote-1680496 -Ref: Wc Program-Footnote-2680696 -Node: Miscellaneous Programs680788 -Node: Dupword Program681976 -Node: Alarm Program684007 -Node: Translate Program688814 -Ref: Translate Program-Footnote-1693205 -Ref: Translate Program-Footnote-2693475 -Node: Labels Program693609 -Ref: Labels Program-Footnote-1696980 -Node: Word Sorting697064 -Node: History Sorting701107 -Node: Extract Program702943 -Ref: Extract Program-Footnote-1710473 -Node: Simple Sed710602 -Node: Igawk Program713664 -Ref: Igawk Program-Footnote-1728839 -Ref: Igawk Program-Footnote-2729040 -Node: Anagram Program729178 -Node: Signature Program732246 -Node: Advanced Features733493 -Node: Nondecimal Data735379 -Node: Array Sorting736956 -Node: Controlling Array Traversal737653 -Node: Array Sorting Functions745933 -Ref: Array Sorting Functions-Footnote-1749840 -Node: Two-way I/O750034 -Ref: Two-way I/O-Footnote-1755550 -Node: TCP/IP Networking755632 -Node: Profiling758476 -Node: Internationalization765984 -Node: I18N and L10N767409 -Node: Explaining gettext768095 -Ref: Explaining gettext-Footnote-1773235 -Ref: Explaining gettext-Footnote-2773419 -Node: Programmer i18n773584 -Node: Translator i18n777809 -Node: String Extraction778603 -Ref: String Extraction-Footnote-1779564 -Node: Printf Ordering779650 -Ref: Printf Ordering-Footnote-1782432 -Node: I18N Portability782496 -Ref: I18N Portability-Footnote-1784945 -Node: I18N Example785008 -Ref: I18N Example-Footnote-1787730 -Node: Gawk I18N787802 -Node: Debugger788423 -Node: Debugging789394 -Node: Debugging Concepts789835 -Node: Debugging Terms791691 -Node: Awk Debugging794288 -Node: Sample Debugging Session795180 -Node: Debugger Invocation795700 -Node: Finding The Bug797033 -Node: List of Debugger Commands803515 -Node: Breakpoint Control804847 -Node: Debugger Execution Control808511 -Node: Viewing And Changing Data811871 -Node: Execution Stack815229 -Node: Debugger Info816742 -Node: Miscellaneous Debugger Commands820736 -Node: Readline Support825920 -Node: Limitations826812 -Node: Arbitrary Precision Arithmetic829060 -Ref: Arbitrary Precision Arithmetic-Footnote-1830709 -Node: General Arithmetic830857 -Node: Floating Point Issues832577 -Node: String Conversion Precision833458 -Ref: String Conversion Precision-Footnote-1835163 -Node: Unexpected Results835272 -Node: POSIX Floating Point Problems837425 -Ref: POSIX Floating Point Problems-Footnote-1841246 -Node: Integer Programming841284 -Node: Floating-point Programming843095 -Ref: Floating-point Programming-Footnote-1849423 -Ref: Floating-point Programming-Footnote-2849693 -Node: Floating-point Representation849957 -Node: Floating-point Context851122 -Ref: table-ieee-formats851961 -Node: Rounding Mode853345 -Ref: table-rounding-modes853824 -Ref: Rounding Mode-Footnote-1856839 -Node: Gawk and MPFR857018 -Node: Arbitrary Precision Floats858427 -Ref: Arbitrary Precision Floats-Footnote-1860870 -Node: Setting Precision861191 -Ref: table-predefined-precision-strings861875 -Node: Setting Rounding Mode864020 -Ref: table-gawk-rounding-modes864424 -Node: Floating-point Constants865611 -Node: Changing Precision867063 -Ref: Changing Precision-Footnote-1868455 -Node: Exact Arithmetic868629 -Node: Arbitrary Precision Integers871763 -Ref: Arbitrary Precision Integers-Footnote-1874778 -Node: Dynamic Extensions874925 -Node: Extension Intro876383 -Node: Plugin License877648 -Node: Extension Mechanism Outline878333 -Ref: figure-load-extension878757 -Ref: figure-load-new-function880242 -Ref: figure-call-new-function881244 -Node: Extension API Description883228 -Node: Extension API Functions Introduction884678 -Node: General Data Types889544 -Ref: General Data Types-Footnote-1895237 -Node: Requesting Values895536 -Ref: table-value-types-returned896273 -Node: Memory Allocation Functions897231 -Ref: Memory Allocation Functions-Footnote-1899978 -Node: Constructor Functions900074 -Node: Registration Functions901832 -Node: Extension Functions902517 -Node: Exit Callback Functions904819 -Node: Extension Version String906069 -Node: Input Parsers906719 -Node: Output Wrappers916522 -Node: Two-way processors921038 -Node: Printing Messages923241 -Ref: Printing Messages-Footnote-1924318 -Node: Updating `ERRNO'924470 -Node: Accessing Parameters925209 -Node: Symbol Table Access926439 -Node: Symbol table by name926953 -Node: Symbol table by cookie928929 -Ref: Symbol table by cookie-Footnote-1933062 -Node: Cached values933125 -Ref: Cached values-Footnote-1936630 -Node: Array Manipulation936721 -Ref: Array Manipulation-Footnote-1937819 -Node: Array Data Types937858 -Ref: Array Data Types-Footnote-1940561 -Node: Array Functions940653 -Node: Flattening Arrays944527 -Node: Creating Arrays951379 -Node: Extension API Variables956110 -Node: Extension Versioning956746 -Node: Extension API Informational Variables958647 -Node: Extension API Boilerplate959733 -Node: Finding Extensions963537 -Node: Extension Example964097 -Node: Internal File Description964827 -Node: Internal File Ops968918 -Ref: Internal File Ops-Footnote-1980464 -Node: Using Internal File Ops980604 -Ref: Using Internal File Ops-Footnote-1982951 -Node: Extension Samples983219 -Node: Extension Sample File Functions984743 -Node: Extension Sample Fnmatch992310 -Node: Extension Sample Fork993789 -Node: Extension Sample Inplace995002 -Node: Extension Sample Ord996780 -Node: Extension Sample Readdir997616 -Ref: table-readdir-file-types998471 -Node: Extension Sample Revout999270 -Node: Extension Sample Rev2way999861 -Node: Extension Sample Read write array1000602 -Node: Extension Sample Readfile1002481 -Node: Extension Sample API Tests1003581 -Node: Extension Sample Time1004106 -Node: gawkextlib1005421 -Node: Language History1008208 -Node: V7/SVR3.11009802 -Node: SVR41012122 -Node: POSIX1013564 -Node: BTL1014950 -Node: POSIX/GNU1015684 -Node: Feature History1021283 -Node: Common Extensions1034395 -Node: Ranges and Locales1035707 -Ref: Ranges and Locales-Footnote-11040324 -Ref: Ranges and Locales-Footnote-21040351 -Ref: Ranges and Locales-Footnote-31040585 -Node: Contributors1040806 -Node: Installation1046244 -Node: Gawk Distribution1047138 -Node: Getting1047622 -Node: Extracting1048448 -Node: Distribution contents1050090 -Node: Unix Installation1055807 -Node: Quick Installation1056424 -Node: Additional Configuration Options1058866 -Node: Configuration Philosophy1060604 -Node: Non-Unix Installation1062955 -Node: PC Installation1063413 -Node: PC Binary Installation1064724 -Node: PC Compiling1066572 -Ref: PC Compiling-Footnote-11069571 -Node: PC Testing1069676 -Node: PC Using1070852 -Node: Cygwin1075010 -Node: MSYS1075819 -Node: VMS Installation1076333 -Node: VMS Compilation1077129 -Ref: VMS Compilation-Footnote-11078350 -Node: VMS Dynamic Extensions1078408 -Node: VMS Installation Details1079781 -Node: VMS Running1082032 -Node: VMS GNV1084866 -Node: VMS Old Gawk1085589 -Node: Bugs1086059 -Node: Other Versions1090063 -Node: Notes1096288 -Node: Compatibility Mode1097088 -Node: Additions1097870 -Node: Accessing The Source1098795 -Node: Adding Code1100231 -Node: New Ports1106409 -Node: Derived Files1110890 -Ref: Derived Files-Footnote-11115971 -Ref: Derived Files-Footnote-21116005 -Ref: Derived Files-Footnote-31116601 -Node: Future Extensions1116715 -Node: Implementation Limitations1117321 -Node: Extension Design1118569 -Node: Old Extension Problems1119723 -Ref: Old Extension Problems-Footnote-11121240 -Node: Extension New Mechanism Goals1121297 -Ref: Extension New Mechanism Goals-Footnote-11124658 -Node: Extension Other Design Decisions1124847 -Node: Extension Future Growth1126953 -Node: Old Extension Mechanism1127789 -Node: Basic Concepts1129529 -Node: Basic High Level1130210 -Ref: figure-general-flow1130482 -Ref: figure-process-flow1131081 -Ref: Basic High Level-Footnote-11134310 -Node: Basic Data Typing1134495 -Node: Glossary1137822 -Node: Copying1162974 -Node: GNU Free Documentation License1200530 -Node: Index1225666 +Node: Executable Scripts77782 +Ref: Executable Scripts-Footnote-179615 +Ref: Executable Scripts-Footnote-279717 +Node: Comments80250 +Node: Quoting82717 +Node: DOS Quoting88026 +Node: Sample Data Files88701 +Node: Very Simple91216 +Node: Two Rules95847 +Node: More Complex97742 +Ref: More Complex-Footnote-1100667 +Node: Statements/Lines100752 +Ref: Statements/Lines-Footnote-1105207 +Node: Other Features105472 +Node: When106400 +Node: Invoking Gawk108548 +Node: Command Line110011 +Node: Options110802 +Ref: Options-Footnote-1126586 +Node: Other Arguments126611 +Node: Naming Standard Input129252 +Node: Environment Variables130332 +Node: AWKPATH Variable130890 +Ref: AWKPATH Variable-Footnote-1133741 +Ref: AWKPATH Variable-Footnote-2133786 +Node: AWKLIBPATH Variable134046 +Node: Other Environment Variables134805 +Node: Exit Status138460 +Node: Include Files139135 +Node: Loading Shared Libraries142699 +Node: Obsolete144083 +Node: Undocumented144780 +Node: Regexp145022 +Node: Regexp Usage146411 +Node: Escape Sequences148444 +Node: Regexp Operators154111 +Ref: Regexp Operators-Footnote-1161591 +Ref: Regexp Operators-Footnote-2161738 +Node: Bracket Expressions161836 +Ref: table-char-classes163726 +Node: GNU Regexp Operators166249 +Node: Case-sensitivity169972 +Ref: Case-sensitivity-Footnote-1172864 +Ref: Case-sensitivity-Footnote-2173099 +Node: Leftmost Longest173207 +Node: Computed Regexps174408 +Node: Reading Files177757 +Node: Records179759 +Node: awk split records180494 +Node: gawk split records185352 +Ref: gawk split records-Footnote-1189873 +Node: Fields189910 +Ref: Fields-Footnote-1192874 +Node: Nonconstant Fields192960 +Ref: Nonconstant Fields-Footnote-1195190 +Node: Changing Fields195392 +Node: Field Separators201346 +Node: Default Field Splitting204048 +Node: Regexp Field Splitting205165 +Node: Single Character Fields208506 +Node: Command Line Field Separator209565 +Node: Full Line Fields212907 +Ref: Full Line Fields-Footnote-1213415 +Node: Field Splitting Summary213461 +Ref: Field Splitting Summary-Footnote-1216560 +Node: Constant Size216661 +Node: Splitting By Content221268 +Ref: Splitting By Content-Footnote-1225018 +Node: Multiple Line225058 +Ref: Multiple Line-Footnote-1230914 +Node: Getline231093 +Node: Plain Getline233309 +Node: Getline/Variable235404 +Node: Getline/File236551 +Node: Getline/Variable/File237927 +Ref: Getline/Variable/File-Footnote-1239526 +Node: Getline/Pipe239613 +Node: Getline/Variable/Pipe242312 +Node: Getline/Coprocess243419 +Node: Getline/Variable/Coprocess244671 +Node: Getline Notes245408 +Node: Getline Summary248212 +Ref: table-getline-variants248620 +Node: Read Timeout249532 +Ref: Read Timeout-Footnote-1253359 +Node: Command line directories253417 +Node: Printing254299 +Node: Print255923 +Node: Print Examples257264 +Node: Output Separators260043 +Node: OFMT262059 +Node: Printf263417 +Node: Basic Printf264323 +Node: Control Letters265862 +Node: Format Modifiers269716 +Node: Printf Examples275743 +Node: Redirection278450 +Node: Special Files285397 +Node: Special FD285913 +Ref: Special FD-Footnote-1289488 +Node: Special Network289562 +Node: Special Caveats290398 +Node: Close Files And Pipes291173 +Ref: Close Files And Pipes-Footnote-1298289 +Ref: Close Files And Pipes-Footnote-2298437 +Node: Expressions298587 +Node: Values299719 +Node: Constants300395 +Node: Scalar Constants301075 +Ref: Scalar Constants-Footnote-1301934 +Node: Nondecimal-numbers302184 +Node: Regexp Constants305184 +Node: Using Constant Regexps305659 +Node: Variables308729 +Node: Using Variables309384 +Node: Assignment Options311108 +Node: Conversion312975 +Ref: table-locale-affects318411 +Ref: Conversion-Footnote-1319035 +Node: All Operators319144 +Node: Arithmetic Ops319774 +Node: Concatenation322279 +Ref: Concatenation-Footnote-1325075 +Node: Assignment Ops325195 +Ref: table-assign-ops330178 +Node: Increment Ops331495 +Node: Truth Values and Conditions334933 +Node: Truth Values336016 +Node: Typing and Comparison337065 +Node: Variable Typing337858 +Ref: Variable Typing-Footnote-1341758 +Node: Comparison Operators341880 +Ref: table-relational-ops342290 +Node: POSIX String Comparison345838 +Ref: POSIX String Comparison-Footnote-1346922 +Node: Boolean Ops347060 +Ref: Boolean Ops-Footnote-1351130 +Node: Conditional Exp351221 +Node: Function Calls352948 +Node: Precedence356706 +Node: Locales360375 +Node: Patterns and Actions361978 +Node: Pattern Overview363032 +Node: Regexp Patterns364709 +Node: Expression Patterns365252 +Node: Ranges369033 +Node: BEGIN/END372139 +Node: Using BEGIN/END372901 +Ref: Using BEGIN/END-Footnote-1375637 +Node: I/O And BEGIN/END375743 +Node: BEGINFILE/ENDFILE378028 +Node: Empty380959 +Node: Using Shell Variables381276 +Node: Action Overview383559 +Node: Statements385886 +Node: If Statement387734 +Node: While Statement389232 +Node: Do Statement391276 +Node: For Statement392432 +Node: Switch Statement395584 +Node: Break Statement397687 +Node: Continue Statement399742 +Node: Next Statement401535 +Node: Nextfile Statement403925 +Node: Exit Statement406580 +Node: Built-in Variables408984 +Node: User-modified410080 +Ref: User-modified-Footnote-1417765 +Node: Auto-set417827 +Ref: Auto-set-Footnote-1430373 +Ref: Auto-set-Footnote-2430578 +Node: ARGC and ARGV430634 +Node: Arrays434473 +Node: Array Basics435971 +Node: Array Intro436797 +Ref: figure-array-elements438770 +Node: Reference to Elements441177 +Node: Assigning Elements443450 +Node: Array Example443941 +Node: Scanning an Array445673 +Node: Controlling Scanning448688 +Ref: Controlling Scanning-Footnote-1453861 +Node: Delete454177 +Ref: Delete-Footnote-1456942 +Node: Numeric Array Subscripts456999 +Node: Uninitialized Subscripts459182 +Node: Multidimensional460807 +Node: Multiscanning463900 +Node: Arrays of Arrays465489 +Node: Functions470129 +Node: Built-in470948 +Node: Calling Built-in472026 +Node: Numeric Functions474014 +Ref: Numeric Functions-Footnote-1477848 +Ref: Numeric Functions-Footnote-2478205 +Ref: Numeric Functions-Footnote-3478253 +Node: String Functions478522 +Ref: String Functions-Footnote-1501533 +Ref: String Functions-Footnote-2501662 +Ref: String Functions-Footnote-3501910 +Node: Gory Details501997 +Ref: table-sub-escapes503666 +Ref: table-sub-posix-92505020 +Ref: table-sub-proposed506371 +Ref: table-posix-sub507725 +Ref: table-gensub-escapes509270 +Ref: Gory Details-Footnote-1510446 +Ref: Gory Details-Footnote-2510497 +Node: I/O Functions510648 +Ref: I/O Functions-Footnote-1517771 +Node: Time Functions517918 +Ref: Time Functions-Footnote-1528382 +Ref: Time Functions-Footnote-2528450 +Ref: Time Functions-Footnote-3528608 +Ref: Time Functions-Footnote-4528719 +Ref: Time Functions-Footnote-5528831 +Ref: Time Functions-Footnote-6529058 +Node: Bitwise Functions529324 +Ref: table-bitwise-ops529886 +Ref: Bitwise Functions-Footnote-1534131 +Node: Type Functions534315 +Node: I18N Functions535457 +Node: User-defined537102 +Node: Definition Syntax537906 +Ref: Definition Syntax-Footnote-1542831 +Node: Function Example542900 +Ref: Function Example-Footnote-1545544 +Node: Function Caveats545566 +Node: Calling A Function546084 +Node: Variable Scope547039 +Node: Pass By Value/Reference550027 +Node: Return Statement553535 +Node: Dynamic Typing556519 +Node: Indirect Calls557448 +Node: Library Functions567135 +Ref: Library Functions-Footnote-1570648 +Ref: Library Functions-Footnote-2570791 +Node: Library Names570962 +Ref: Library Names-Footnote-1574435 +Ref: Library Names-Footnote-2574655 +Node: General Functions574741 +Node: Strtonum Function575769 +Node: Assert Function578699 +Node: Round Function582025 +Node: Cliff Random Function583566 +Node: Ordinal Functions584582 +Ref: Ordinal Functions-Footnote-1587659 +Ref: Ordinal Functions-Footnote-2587911 +Node: Join Function588122 +Ref: Join Function-Footnote-1589893 +Node: Getlocaltime Function590093 +Node: Readfile Function593829 +Node: Data File Management595668 +Node: Filetrans Function596300 +Node: Rewind Function600355 +Node: File Checking601742 +Ref: File Checking-Footnote-1602874 +Node: Empty Files603075 +Node: Ignoring Assigns605298 +Node: Getopt Function606829 +Ref: Getopt Function-Footnote-1618125 +Node: Passwd Functions618328 +Ref: Passwd Functions-Footnote-1627307 +Node: Group Functions627395 +Ref: Group Functions-Footnote-1635337 +Node: Walking Arrays635550 +Node: Sample Programs637686 +Node: Running Examples638360 +Node: Clones639088 +Node: Cut Program640312 +Node: Egrep Program650173 +Ref: Egrep Program-Footnote-1658102 +Node: Id Program658212 +Node: Split Program661876 +Ref: Split Program-Footnote-1665407 +Node: Tee Program665535 +Node: Uniq Program668342 +Node: Wc Program675772 +Ref: Wc Program-Footnote-1680040 +Ref: Wc Program-Footnote-2680240 +Node: Miscellaneous Programs680332 +Node: Dupword Program681520 +Node: Alarm Program683551 +Node: Translate Program688365 +Ref: Translate Program-Footnote-1692756 +Ref: Translate Program-Footnote-2693026 +Node: Labels Program693160 +Ref: Labels Program-Footnote-1696531 +Node: Word Sorting696615 +Node: History Sorting700658 +Node: Extract Program702494 +Ref: Extract Program-Footnote-1710069 +Node: Simple Sed710198 +Node: Igawk Program713260 +Ref: Igawk Program-Footnote-1728436 +Ref: Igawk Program-Footnote-2728637 +Node: Anagram Program728775 +Node: Signature Program731843 +Node: Advanced Features733090 +Node: Nondecimal Data734976 +Node: Array Sorting736553 +Node: Controlling Array Traversal737250 +Node: Array Sorting Functions745530 +Ref: Array Sorting Functions-Footnote-1749437 +Node: Two-way I/O749631 +Ref: Two-way I/O-Footnote-1755147 +Node: TCP/IP Networking755229 +Node: Profiling758073 +Node: Internationalization765581 +Node: I18N and L10N767006 +Node: Explaining gettext767692 +Ref: Explaining gettext-Footnote-1772832 +Ref: Explaining gettext-Footnote-2773016 +Node: Programmer i18n773181 +Node: Translator i18n777406 +Node: String Extraction778200 +Ref: String Extraction-Footnote-1779161 +Node: Printf Ordering779247 +Ref: Printf Ordering-Footnote-1782029 +Node: I18N Portability782093 +Ref: I18N Portability-Footnote-1784542 +Node: I18N Example784605 +Ref: I18N Example-Footnote-1787327 +Node: Gawk I18N787399 +Node: Debugger788012 +Node: Debugging788983 +Node: Debugging Concepts789424 +Node: Debugging Terms791280 +Node: Awk Debugging793877 +Node: Sample Debugging Session794769 +Node: Debugger Invocation795289 +Node: Finding The Bug796622 +Node: List of Debugger Commands803104 +Node: Breakpoint Control804436 +Node: Debugger Execution Control808100 +Node: Viewing And Changing Data811460 +Node: Execution Stack814818 +Node: Debugger Info816331 +Node: Miscellaneous Debugger Commands820325 +Node: Readline Support825509 +Node: Limitations826401 +Node: Arbitrary Precision Arithmetic828649 +Ref: Arbitrary Precision Arithmetic-Footnote-1830298 +Node: General Arithmetic830446 +Node: Floating Point Issues832166 +Node: String Conversion Precision833047 +Ref: String Conversion Precision-Footnote-1834752 +Node: Unexpected Results834861 +Node: POSIX Floating Point Problems837014 +Ref: POSIX Floating Point Problems-Footnote-1840835 +Node: Integer Programming840873 +Node: Floating-point Programming842684 +Ref: Floating-point Programming-Footnote-1849012 +Ref: Floating-point Programming-Footnote-2849282 +Node: Floating-point Representation849546 +Node: Floating-point Context850711 +Ref: table-ieee-formats851550 +Node: Rounding Mode852934 +Ref: table-rounding-modes853413 +Ref: Rounding Mode-Footnote-1856428 +Node: Gawk and MPFR856607 +Node: Arbitrary Precision Floats858016 +Ref: Arbitrary Precision Floats-Footnote-1860459 +Node: Setting Precision860780 +Ref: table-predefined-precision-strings861464 +Node: Setting Rounding Mode863609 +Ref: table-gawk-rounding-modes864013 +Node: Floating-point Constants865200 +Node: Changing Precision866652 +Ref: Changing Precision-Footnote-1868044 +Node: Exact Arithmetic868218 +Node: Arbitrary Precision Integers871352 +Ref: Arbitrary Precision Integers-Footnote-1874367 +Node: Dynamic Extensions874514 +Node: Extension Intro875972 +Node: Plugin License877237 +Node: Extension Mechanism Outline877922 +Ref: figure-load-extension878346 +Ref: figure-load-new-function879831 +Ref: figure-call-new-function880833 +Node: Extension API Description882817 +Node: Extension API Functions Introduction884267 +Node: General Data Types889133 +Ref: General Data Types-Footnote-1894826 +Node: Requesting Values895125 +Ref: table-value-types-returned895862 +Node: Memory Allocation Functions896820 +Ref: Memory Allocation Functions-Footnote-1899567 +Node: Constructor Functions899663 +Node: Registration Functions901421 +Node: Extension Functions902106 +Node: Exit Callback Functions904408 +Node: Extension Version String905658 +Node: Input Parsers906308 +Node: Output Wrappers916111 +Node: Two-way processors920627 +Node: Printing Messages922831 +Ref: Printing Messages-Footnote-1923908 +Node: Updating `ERRNO'924060 +Node: Accessing Parameters924799 +Node: Symbol Table Access926029 +Node: Symbol table by name926543 +Node: Symbol table by cookie928519 +Ref: Symbol table by cookie-Footnote-1932652 +Node: Cached values932715 +Ref: Cached values-Footnote-1936220 +Node: Array Manipulation936311 +Ref: Array Manipulation-Footnote-1937409 +Node: Array Data Types937448 +Ref: Array Data Types-Footnote-1940151 +Node: Array Functions940243 +Node: Flattening Arrays944117 +Node: Creating Arrays950969 +Node: Extension API Variables955700 +Node: Extension Versioning956336 +Node: Extension API Informational Variables958237 +Node: Extension API Boilerplate959323 +Node: Finding Extensions963127 +Node: Extension Example963687 +Node: Internal File Description964417 +Node: Internal File Ops968508 +Ref: Internal File Ops-Footnote-1980054 +Node: Using Internal File Ops980194 +Ref: Using Internal File Ops-Footnote-1982541 +Node: Extension Samples982809 +Node: Extension Sample File Functions984333 +Node: Extension Sample Fnmatch991901 +Node: Extension Sample Fork993368 +Node: Extension Sample Inplace994581 +Node: Extension Sample Ord996347 +Node: Extension Sample Readdir997183 +Ref: table-readdir-file-types998032 +Node: Extension Sample Revout998831 +Node: Extension Sample Rev2way999422 +Node: Extension Sample Read write array1000163 +Node: Extension Sample Readfile1002042 +Node: Extension Sample API Tests1003142 +Node: Extension Sample Time1003667 +Node: gawkextlib1004982 +Node: Language History1007769 +Node: V7/SVR3.11009363 +Node: SVR41011683 +Node: POSIX1013125 +Node: BTL1014511 +Node: POSIX/GNU1015245 +Node: Feature History1020844 +Node: Common Extensions1033956 +Node: Ranges and Locales1035268 +Ref: Ranges and Locales-Footnote-11039885 +Ref: Ranges and Locales-Footnote-21039912 +Ref: Ranges and Locales-Footnote-31040146 +Node: Contributors1040367 +Node: Installation1045805 +Node: Gawk Distribution1046699 +Node: Getting1047183 +Node: Extracting1048009 +Node: Distribution contents1049651 +Node: Unix Installation1055368 +Node: Quick Installation1055985 +Node: Additional Configuration Options1058427 +Node: Configuration Philosophy1060165 +Node: Non-Unix Installation1062516 +Node: PC Installation1062974 +Node: PC Binary Installation1064285 +Node: PC Compiling1066133 +Ref: PC Compiling-Footnote-11069132 +Node: PC Testing1069237 +Node: PC Using1070413 +Node: Cygwin1074571 +Node: MSYS1075380 +Node: VMS Installation1075894 +Node: VMS Compilation1076690 +Ref: VMS Compilation-Footnote-11077905 +Node: VMS Dynamic Extensions1077963 +Node: VMS Installation Details1079336 +Node: VMS Running1081582 +Node: VMS GNV1084416 +Node: VMS Old Gawk1085139 +Node: Bugs1085609 +Node: Other Versions1089613 +Node: Notes1095838 +Node: Compatibility Mode1096638 +Node: Additions1097420 +Node: Accessing The Source1098345 +Node: Adding Code1099781 +Node: New Ports1105959 +Node: Derived Files1110440 +Ref: Derived Files-Footnote-11115521 +Ref: Derived Files-Footnote-21115555 +Ref: Derived Files-Footnote-31116151 +Node: Future Extensions1116265 +Node: Implementation Limitations1116871 +Node: Extension Design1118119 +Node: Old Extension Problems1119273 +Ref: Old Extension Problems-Footnote-11120790 +Node: Extension New Mechanism Goals1120847 +Ref: Extension New Mechanism Goals-Footnote-11124208 +Node: Extension Other Design Decisions1124397 +Node: Extension Future Growth1126503 +Node: Old Extension Mechanism1127339 +Node: Basic Concepts1129079 +Node: Basic High Level1129760 +Ref: figure-general-flow1130032 +Ref: figure-process-flow1130631 +Ref: Basic High Level-Footnote-11133860 +Node: Basic Data Typing1134045 +Node: Glossary1137372 +Node: Copying1162524 +Node: GNU Free Documentation License1200080 +Node: Index1225216  End Tag Table -- cgit v1.2.3 From 4bf0a8ccb72ea56ae4e7f576dd1902603b521e8d Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sun, 8 Jun 2014 22:57:54 +0300 Subject: Start adding summary sections. --- doc/gawk.info | 1204 +++++++++++++++++++++++++++++++-------------------------- 1 file changed, 660 insertions(+), 544 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index c5038115..50ccda25 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -126,8 +126,8 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) includes command-line syntax. * One-shot:: Running a short throwaway `awk' program. -* Read Terminal:: Using no input files (input from - the keyboard instead). +* Read Terminal:: Using no input files (input from the + keyboard instead). * Long:: Putting permanent `awk' programs in files. * Executable Scripts:: Making self-contained `awk' @@ -149,6 +149,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Other Features:: Other Features of `awk'. * When:: When to use `gawk' and when to use other things. +* Intro Summary:: Summary of the introduction. * Command Line:: How to run `awk'. * Options:: Command-line options and their meanings. @@ -170,6 +171,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) program. * Obsolete:: Obsolete Options and/or features. * Undocumented:: Undocumented Options and Features. +* Invoking Summary:: Invocation summary. * Regexp Usage:: How to Use Regular Expressions. * Escape Sequences:: How to write nonprinting characters. * Regexp Operators:: Regular Expression Operators. @@ -178,8 +180,12 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Case-sensitivity:: How to do case-insensitive matching. * Leftmost Longest:: How much text matches. * Computed Regexps:: Using Dynamic Regexps. +* Regexp Summary:: Regular expressions summary. * Records:: Controlling how data is split into records. +* awk split records:: How standard `awk' splits + records. +* gawk split records:: How `gawk' splits records. * Fields:: An introduction to fields. * Nonconstant Fields:: Nonconstant Field Numbers. * Changing Fields:: Changing the Contents of a Field. @@ -636,8 +642,8 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) `gawk'. * New Ports:: Porting `gawk' to a new operating system. -* Derived Files:: Why derived files are kept in the - Git repository. +* Derived Files:: Why derived files are kept in the Git + repository. * Future Extensions:: New features that may be implemented one day. * Implementation Limitations:: Some limitations of the @@ -1351,6 +1357,7 @@ like this: * Other Features:: Other Features of `awk'. * When:: When to use `gawk' and when to use other things. +* Intro Summary:: Summary of the introduction.  File: gawk.info, Node: Running gawk, Next: Sample Data Files, Up: Getting Started @@ -2194,7 +2201,7 @@ most of the variables and many of the functions. They are described systematically in *note Built-in Variables::, and *note Built-in::.  -File: gawk.info, Node: When, Prev: Other Features, Up: Getting Started +File: gawk.info, Node: When, Next: Intro Summary, Prev: Other Features, Up: Getting Started 1.8 When to Use `awk' ===================== @@ -2234,6 +2241,30 @@ languages may require more lines of source code than the equivalent `awk' programs, but they are easier to maintain and usually run more efficiently. + +File: gawk.info, Node: Intro Summary, Prev: When, Up: Getting Started + +1.9 Summary +=========== + + * Programs in `awk' consist of PATTERN-ACTION pairs. + + * Use either `awk 'PROGRAM' FILES' or `awk -f PROGRAM-FILE FILES' to + run `awk'. + + * You may use the special `#!' header line to create `awk' programs + that are directly executable. + + * Comments in `awk' programs start with `#' and continue to the end + of the same line. + + * Be aware of quoting issues when writing `awk' programs as part of + a larger shell script (or MS-Windows batch file). + + * You may use backslash continuation to continue a source line. + Lines are automatically continued after a comma, open brace, + question mark, colon, `||', `&&', `do' and `else'. +  File: gawk.info, Node: Invoking Gawk, Next: Regexp, Prev: Getting Started, Up: Top @@ -2264,6 +2295,7 @@ this major node that don't interest you right now. * Loading Shared Libraries:: Loading shared libraries into your program. * Obsolete:: Obsolete Options and/or features. * Undocumented:: Undocumented Options and Features. +* Invoking Summary:: Invocation summary.  File: gawk.info, Node: Command Line, Next: Options, Up: Invoking Gawk @@ -3094,7 +3126,7 @@ worked. As of version 4.0, they are no longer interpreted specially by `gawk'. (Use `PROCINFO' instead; see *note Auto-set::.)  -File: gawk.info, Node: Undocumented, Prev: Obsolete, Up: Invoking Gawk +File: gawk.info, Node: Undocumented, Next: Invoking Summary, Prev: Obsolete, Up: Invoking Gawk 2.10 Undocumented Options and Features ====================================== @@ -3103,6 +3135,48 @@ File: gawk.info, Node: Undocumented, Prev: Obsolete, Up: Invoking Gawk This minor node intentionally left blank. + +File: gawk.info, Node: Invoking Summary, Prev: Undocumented, Up: Invoking Gawk + +2.11 Summary +============ + + * Use either `awk 'PROGRAM' FILES' or `awk -f PROGRAM-FILE FILES' to + run `awk'. + + * The three standard `awk' options are `-f', `-F' and `-v'. `gawk' + supplies these and many others, as well as corresponding GNU-style + long options. + + * Non-option command-line arguments are usually treated as file + names, unless they have the form `VAR=VALUE', in which case they + are taken as variable assignments to be performed at that point in + processing the input. + + * All non-option command-line arguments, excluding the program text, + are placed in the `ARGV' array. Adjusting `ARGC' and `ARGV' + affects how `awk' processes input. + + * You can use a single minus sign (`-') to refer to standard input + on the command line. + + * `gawk' pays attention to a number of environment variables. + `AWKPATH', `AWKLIBPATH', and `POSIXLY_CORRECT' are the most + important ones. + + * `gawk''s exit status conveys information to the program that + invoked it. Use the `exit' statement from within an `awk' program + to set the exit status. + + * `gawk' allows you to include other `awk' source files into your + program using the `@include' statement and/or the `-i' and `-f' + command-line options. + + * `gawk' allows you to load additional functions written in C or C++ + using the `@load' statement and/or the `-l' option. (This + advanced feature is described later on in *note Dynamic + Extensions::.) +  File: gawk.info, Node: Regexp, Next: Reading Files, Prev: Invoking Gawk, Up: Top @@ -3132,6 +3206,7 @@ you specify more complicated classes of strings. * Case-sensitivity:: How to do case-insensitive matching. * Leftmost Longest:: How much text matches. * Computed Regexps:: Using Dynamic Regexps. +* Regexp Summary:: Regular expressions summary.  File: gawk.info, Node: Regexp Usage, Next: Escape Sequences, Up: Regexp @@ -3811,7 +3886,7 @@ this principle is also important for regexp-based record and field splitting (*note Records::, and also *note Field Separators::).  -File: gawk.info, Node: Computed Regexps, Prev: Leftmost Longest, Up: Regexp +File: gawk.info, Node: Computed Regexps, Next: Regexp Summary, Prev: Leftmost Longest, Up: Regexp 3.8 Using Dynamic Regexps ========================= @@ -3889,6 +3964,44 @@ inside a bracket expression for a dynamic regexp: `gawk' does not have this problem, and it isn't likely to occur often in practice, but it's worth noting for future reference. + +File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp + +3.9 Summary +=========== + + * Regular expressions describe sets of strings to be matched. In + `awk', regular expression constants are written enclosed between + slashes: `/'...`/'. + + * Regexp constants may be used by standalone in patterns and in + conditional expressions, or as part of matching expressions using + the `~' and `!~' operators. + + * Escape sequences let you represent non-printable characters and + also let you represent regexp metacharacters as literal characters + to be matched. + + * Regexp operators provide grouping, alternation and repetition. + + * Bracket expressions give you a shorthand for specifyings sets of + characters that can match at a particular point in a regexp. + Within bracket expressions, POSIX character classes let you specify + certain groups of characters in a locale-independent fashion. + + * `gawk''s `IGNORECASE' variable lets you control the case + sensitivity of regexp matching. In other `awk' versions, use + `tolower()' or `toupper()'. + + * Regular expressions match the leftmost longest text in the string + being matched. This matters for cases where you need to know the + extent of the match, such as for text substitution and when the + record separator is a regexp. + + * Matching expressions may use dynamic regexps; that is string values + treated as regular expressions. + +  File: gawk.info, Node: Reading Files, Next: Printing, Prev: Regexp, Up: Top @@ -3946,8 +4059,8 @@ is never automatically reset to zero. * Menu: -* awk split records:: How standard `awk' splits records. -* gawk split records:: How `gawk' splits records. +* awk split records:: How standard `awk' splits records. +* gawk split records:: How `gawk' splits records.  File: gawk.info, Node: awk split records, Next: gawk split records, Up: Records @@ -8029,7 +8142,7 @@ has the value one if `x' contains `foo', such as `"Oh, what a fool am I!"'. The righthand operand of the `~' and `!~' operators may be either a -regexp constant (`/.../') or an ordinary expression. In the latter +regexp constant (`/'...`/') or an ordinary expression. In the latter case, the value of the expression as a string is used as a dynamic regexp (*note Regexp Usage::; also *note Computed Regexps::). @@ -27415,8 +27528,8 @@ as well as any considerations you should bear in mind. `gawk'. * New Ports:: Porting `gawk' to a new operating system. -* Derived Files:: Why derived files are kept in the - Git repository. +* Derived Files:: Why derived files are kept in the Git + repository.  File: gawk.info, Node: Accessing The Source, Next: Adding Code, Up: Additions @@ -33218,537 +33331,540 @@ Index  Tag Table: Node: Top1292 -Node: Foreword40830 -Node: Preface45175 -Ref: Preface-Footnote-148322 -Ref: Preface-Footnote-248429 -Node: History48661 -Node: Names51035 -Ref: Names-Footnote-152499 -Node: This Manual52572 -Ref: This Manual-Footnote-158351 -Node: Conventions58451 -Node: Manual History60607 -Ref: Manual History-Footnote-164046 -Ref: Manual History-Footnote-264087 -Node: How To Contribute64161 -Node: Acknowledgments65400 -Node: Getting Started69549 -Node: Running gawk71922 -Node: One-shot73112 -Node: Read Terminal74337 -Ref: Read Terminal-Footnote-175987 -Ref: Read Terminal-Footnote-276263 -Node: Long76434 -Node: Executable Scripts77782 -Ref: Executable Scripts-Footnote-179615 -Ref: Executable Scripts-Footnote-279717 -Node: Comments80250 -Node: Quoting82717 -Node: DOS Quoting88026 -Node: Sample Data Files88701 -Node: Very Simple91216 -Node: Two Rules95847 -Node: More Complex97742 -Ref: More Complex-Footnote-1100667 -Node: Statements/Lines100752 -Ref: Statements/Lines-Footnote-1105207 -Node: Other Features105472 -Node: When106400 -Node: Invoking Gawk108548 -Node: Command Line110011 -Node: Options110802 -Ref: Options-Footnote-1126586 -Node: Other Arguments126611 -Node: Naming Standard Input129252 -Node: Environment Variables130332 -Node: AWKPATH Variable130890 -Ref: AWKPATH Variable-Footnote-1133741 -Ref: AWKPATH Variable-Footnote-2133786 -Node: AWKLIBPATH Variable134046 -Node: Other Environment Variables134805 -Node: Exit Status138460 -Node: Include Files139135 -Node: Loading Shared Libraries142699 -Node: Obsolete144083 -Node: Undocumented144780 -Node: Regexp145022 -Node: Regexp Usage146411 -Node: Escape Sequences148444 -Node: Regexp Operators154111 -Ref: Regexp Operators-Footnote-1161591 -Ref: Regexp Operators-Footnote-2161738 -Node: Bracket Expressions161836 -Ref: table-char-classes163726 -Node: GNU Regexp Operators166249 -Node: Case-sensitivity169972 -Ref: Case-sensitivity-Footnote-1172864 -Ref: Case-sensitivity-Footnote-2173099 -Node: Leftmost Longest173207 -Node: Computed Regexps174408 -Node: Reading Files177757 -Node: Records179759 -Node: awk split records180494 -Node: gawk split records185352 -Ref: gawk split records-Footnote-1189873 -Node: Fields189910 -Ref: Fields-Footnote-1192874 -Node: Nonconstant Fields192960 -Ref: Nonconstant Fields-Footnote-1195190 -Node: Changing Fields195392 -Node: Field Separators201346 -Node: Default Field Splitting204048 -Node: Regexp Field Splitting205165 -Node: Single Character Fields208506 -Node: Command Line Field Separator209565 -Node: Full Line Fields212907 -Ref: Full Line Fields-Footnote-1213415 -Node: Field Splitting Summary213461 -Ref: Field Splitting Summary-Footnote-1216560 -Node: Constant Size216661 -Node: Splitting By Content221268 -Ref: Splitting By Content-Footnote-1225018 -Node: Multiple Line225058 -Ref: Multiple Line-Footnote-1230914 -Node: Getline231093 -Node: Plain Getline233309 -Node: Getline/Variable235404 -Node: Getline/File236551 -Node: Getline/Variable/File237927 -Ref: Getline/Variable/File-Footnote-1239526 -Node: Getline/Pipe239613 -Node: Getline/Variable/Pipe242312 -Node: Getline/Coprocess243419 -Node: Getline/Variable/Coprocess244671 -Node: Getline Notes245408 -Node: Getline Summary248212 -Ref: table-getline-variants248620 -Node: Read Timeout249532 -Ref: Read Timeout-Footnote-1253359 -Node: Command line directories253417 -Node: Printing254299 -Node: Print255923 -Node: Print Examples257264 -Node: Output Separators260043 -Node: OFMT262059 -Node: Printf263417 -Node: Basic Printf264323 -Node: Control Letters265862 -Node: Format Modifiers269716 -Node: Printf Examples275743 -Node: Redirection278450 -Node: Special Files285397 -Node: Special FD285913 -Ref: Special FD-Footnote-1289488 -Node: Special Network289562 -Node: Special Caveats290398 -Node: Close Files And Pipes291173 -Ref: Close Files And Pipes-Footnote-1298289 -Ref: Close Files And Pipes-Footnote-2298437 -Node: Expressions298587 -Node: Values299719 -Node: Constants300395 -Node: Scalar Constants301075 -Ref: Scalar Constants-Footnote-1301934 -Node: Nondecimal-numbers302184 -Node: Regexp Constants305184 -Node: Using Constant Regexps305659 -Node: Variables308729 -Node: Using Variables309384 -Node: Assignment Options311108 -Node: Conversion312975 -Ref: table-locale-affects318411 -Ref: Conversion-Footnote-1319035 -Node: All Operators319144 -Node: Arithmetic Ops319774 -Node: Concatenation322279 -Ref: Concatenation-Footnote-1325075 -Node: Assignment Ops325195 -Ref: table-assign-ops330178 -Node: Increment Ops331495 -Node: Truth Values and Conditions334933 -Node: Truth Values336016 -Node: Typing and Comparison337065 -Node: Variable Typing337858 -Ref: Variable Typing-Footnote-1341758 -Node: Comparison Operators341880 -Ref: table-relational-ops342290 -Node: POSIX String Comparison345838 -Ref: POSIX String Comparison-Footnote-1346922 -Node: Boolean Ops347060 -Ref: Boolean Ops-Footnote-1351130 -Node: Conditional Exp351221 -Node: Function Calls352948 -Node: Precedence356706 -Node: Locales360375 -Node: Patterns and Actions361978 -Node: Pattern Overview363032 -Node: Regexp Patterns364709 -Node: Expression Patterns365252 -Node: Ranges369033 -Node: BEGIN/END372139 -Node: Using BEGIN/END372901 -Ref: Using BEGIN/END-Footnote-1375637 -Node: I/O And BEGIN/END375743 -Node: BEGINFILE/ENDFILE378028 -Node: Empty380959 -Node: Using Shell Variables381276 -Node: Action Overview383559 -Node: Statements385886 -Node: If Statement387734 -Node: While Statement389232 -Node: Do Statement391276 -Node: For Statement392432 -Node: Switch Statement395584 -Node: Break Statement397687 -Node: Continue Statement399742 -Node: Next Statement401535 -Node: Nextfile Statement403925 -Node: Exit Statement406580 -Node: Built-in Variables408984 -Node: User-modified410080 -Ref: User-modified-Footnote-1417765 -Node: Auto-set417827 -Ref: Auto-set-Footnote-1430373 -Ref: Auto-set-Footnote-2430578 -Node: ARGC and ARGV430634 -Node: Arrays434473 -Node: Array Basics435971 -Node: Array Intro436797 -Ref: figure-array-elements438770 -Node: Reference to Elements441177 -Node: Assigning Elements443450 -Node: Array Example443941 -Node: Scanning an Array445673 -Node: Controlling Scanning448688 -Ref: Controlling Scanning-Footnote-1453861 -Node: Delete454177 -Ref: Delete-Footnote-1456942 -Node: Numeric Array Subscripts456999 -Node: Uninitialized Subscripts459182 -Node: Multidimensional460807 -Node: Multiscanning463900 -Node: Arrays of Arrays465489 -Node: Functions470129 -Node: Built-in470948 -Node: Calling Built-in472026 -Node: Numeric Functions474014 -Ref: Numeric Functions-Footnote-1477848 -Ref: Numeric Functions-Footnote-2478205 -Ref: Numeric Functions-Footnote-3478253 -Node: String Functions478522 -Ref: String Functions-Footnote-1501533 -Ref: String Functions-Footnote-2501662 -Ref: String Functions-Footnote-3501910 -Node: Gory Details501997 -Ref: table-sub-escapes503666 -Ref: table-sub-posix-92505020 -Ref: table-sub-proposed506371 -Ref: table-posix-sub507725 -Ref: table-gensub-escapes509270 -Ref: Gory Details-Footnote-1510446 -Ref: Gory Details-Footnote-2510497 -Node: I/O Functions510648 -Ref: I/O Functions-Footnote-1517771 -Node: Time Functions517918 -Ref: Time Functions-Footnote-1528382 -Ref: Time Functions-Footnote-2528450 -Ref: Time Functions-Footnote-3528608 -Ref: Time Functions-Footnote-4528719 -Ref: Time Functions-Footnote-5528831 -Ref: Time Functions-Footnote-6529058 -Node: Bitwise Functions529324 -Ref: table-bitwise-ops529886 -Ref: Bitwise Functions-Footnote-1534131 -Node: Type Functions534315 -Node: I18N Functions535457 -Node: User-defined537102 -Node: Definition Syntax537906 -Ref: Definition Syntax-Footnote-1542831 -Node: Function Example542900 -Ref: Function Example-Footnote-1545544 -Node: Function Caveats545566 -Node: Calling A Function546084 -Node: Variable Scope547039 -Node: Pass By Value/Reference550027 -Node: Return Statement553535 -Node: Dynamic Typing556519 -Node: Indirect Calls557448 -Node: Library Functions567135 -Ref: Library Functions-Footnote-1570648 -Ref: Library Functions-Footnote-2570791 -Node: Library Names570962 -Ref: Library Names-Footnote-1574435 -Ref: Library Names-Footnote-2574655 -Node: General Functions574741 -Node: Strtonum Function575769 -Node: Assert Function578699 -Node: Round Function582025 -Node: Cliff Random Function583566 -Node: Ordinal Functions584582 -Ref: Ordinal Functions-Footnote-1587659 -Ref: Ordinal Functions-Footnote-2587911 -Node: Join Function588122 -Ref: Join Function-Footnote-1589893 -Node: Getlocaltime Function590093 -Node: Readfile Function593829 -Node: Data File Management595668 -Node: Filetrans Function596300 -Node: Rewind Function600355 -Node: File Checking601742 -Ref: File Checking-Footnote-1602874 -Node: Empty Files603075 -Node: Ignoring Assigns605298 -Node: Getopt Function606829 -Ref: Getopt Function-Footnote-1618125 -Node: Passwd Functions618328 -Ref: Passwd Functions-Footnote-1627307 -Node: Group Functions627395 -Ref: Group Functions-Footnote-1635337 -Node: Walking Arrays635550 -Node: Sample Programs637686 -Node: Running Examples638360 -Node: Clones639088 -Node: Cut Program640312 -Node: Egrep Program650173 -Ref: Egrep Program-Footnote-1658102 -Node: Id Program658212 -Node: Split Program661876 -Ref: Split Program-Footnote-1665407 -Node: Tee Program665535 -Node: Uniq Program668342 -Node: Wc Program675772 -Ref: Wc Program-Footnote-1680040 -Ref: Wc Program-Footnote-2680240 -Node: Miscellaneous Programs680332 -Node: Dupword Program681520 -Node: Alarm Program683551 -Node: Translate Program688365 -Ref: Translate Program-Footnote-1692756 -Ref: Translate Program-Footnote-2693026 -Node: Labels Program693160 -Ref: Labels Program-Footnote-1696531 -Node: Word Sorting696615 -Node: History Sorting700658 -Node: Extract Program702494 -Ref: Extract Program-Footnote-1710069 -Node: Simple Sed710198 -Node: Igawk Program713260 -Ref: Igawk Program-Footnote-1728436 -Ref: Igawk Program-Footnote-2728637 -Node: Anagram Program728775 -Node: Signature Program731843 -Node: Advanced Features733090 -Node: Nondecimal Data734976 -Node: Array Sorting736553 -Node: Controlling Array Traversal737250 -Node: Array Sorting Functions745530 -Ref: Array Sorting Functions-Footnote-1749437 -Node: Two-way I/O749631 -Ref: Two-way I/O-Footnote-1755147 -Node: TCP/IP Networking755229 -Node: Profiling758073 -Node: Internationalization765581 -Node: I18N and L10N767006 -Node: Explaining gettext767692 -Ref: Explaining gettext-Footnote-1772832 -Ref: Explaining gettext-Footnote-2773016 -Node: Programmer i18n773181 -Node: Translator i18n777406 -Node: String Extraction778200 -Ref: String Extraction-Footnote-1779161 -Node: Printf Ordering779247 -Ref: Printf Ordering-Footnote-1782029 -Node: I18N Portability782093 -Ref: I18N Portability-Footnote-1784542 -Node: I18N Example784605 -Ref: I18N Example-Footnote-1787327 -Node: Gawk I18N787399 -Node: Debugger788012 -Node: Debugging788983 -Node: Debugging Concepts789424 -Node: Debugging Terms791280 -Node: Awk Debugging793877 -Node: Sample Debugging Session794769 -Node: Debugger Invocation795289 -Node: Finding The Bug796622 -Node: List of Debugger Commands803104 -Node: Breakpoint Control804436 -Node: Debugger Execution Control808100 -Node: Viewing And Changing Data811460 -Node: Execution Stack814818 -Node: Debugger Info816331 -Node: Miscellaneous Debugger Commands820325 -Node: Readline Support825509 -Node: Limitations826401 -Node: Arbitrary Precision Arithmetic828649 -Ref: Arbitrary Precision Arithmetic-Footnote-1830298 -Node: General Arithmetic830446 -Node: Floating Point Issues832166 -Node: String Conversion Precision833047 -Ref: String Conversion Precision-Footnote-1834752 -Node: Unexpected Results834861 -Node: POSIX Floating Point Problems837014 -Ref: POSIX Floating Point Problems-Footnote-1840835 -Node: Integer Programming840873 -Node: Floating-point Programming842684 -Ref: Floating-point Programming-Footnote-1849012 -Ref: Floating-point Programming-Footnote-2849282 -Node: Floating-point Representation849546 -Node: Floating-point Context850711 -Ref: table-ieee-formats851550 -Node: Rounding Mode852934 -Ref: table-rounding-modes853413 -Ref: Rounding Mode-Footnote-1856428 -Node: Gawk and MPFR856607 -Node: Arbitrary Precision Floats858016 -Ref: Arbitrary Precision Floats-Footnote-1860459 -Node: Setting Precision860780 -Ref: table-predefined-precision-strings861464 -Node: Setting Rounding Mode863609 -Ref: table-gawk-rounding-modes864013 -Node: Floating-point Constants865200 -Node: Changing Precision866652 -Ref: Changing Precision-Footnote-1868044 -Node: Exact Arithmetic868218 -Node: Arbitrary Precision Integers871352 -Ref: Arbitrary Precision Integers-Footnote-1874367 -Node: Dynamic Extensions874514 -Node: Extension Intro875972 -Node: Plugin License877237 -Node: Extension Mechanism Outline877922 -Ref: figure-load-extension878346 -Ref: figure-load-new-function879831 -Ref: figure-call-new-function880833 -Node: Extension API Description882817 -Node: Extension API Functions Introduction884267 -Node: General Data Types889133 -Ref: General Data Types-Footnote-1894826 -Node: Requesting Values895125 -Ref: table-value-types-returned895862 -Node: Memory Allocation Functions896820 -Ref: Memory Allocation Functions-Footnote-1899567 -Node: Constructor Functions899663 -Node: Registration Functions901421 -Node: Extension Functions902106 -Node: Exit Callback Functions904408 -Node: Extension Version String905658 -Node: Input Parsers906308 -Node: Output Wrappers916111 -Node: Two-way processors920627 -Node: Printing Messages922831 -Ref: Printing Messages-Footnote-1923908 -Node: Updating `ERRNO'924060 -Node: Accessing Parameters924799 -Node: Symbol Table Access926029 -Node: Symbol table by name926543 -Node: Symbol table by cookie928519 -Ref: Symbol table by cookie-Footnote-1932652 -Node: Cached values932715 -Ref: Cached values-Footnote-1936220 -Node: Array Manipulation936311 -Ref: Array Manipulation-Footnote-1937409 -Node: Array Data Types937448 -Ref: Array Data Types-Footnote-1940151 -Node: Array Functions940243 -Node: Flattening Arrays944117 -Node: Creating Arrays950969 -Node: Extension API Variables955700 -Node: Extension Versioning956336 -Node: Extension API Informational Variables958237 -Node: Extension API Boilerplate959323 -Node: Finding Extensions963127 -Node: Extension Example963687 -Node: Internal File Description964417 -Node: Internal File Ops968508 -Ref: Internal File Ops-Footnote-1980054 -Node: Using Internal File Ops980194 -Ref: Using Internal File Ops-Footnote-1982541 -Node: Extension Samples982809 -Node: Extension Sample File Functions984333 -Node: Extension Sample Fnmatch991901 -Node: Extension Sample Fork993368 -Node: Extension Sample Inplace994581 -Node: Extension Sample Ord996347 -Node: Extension Sample Readdir997183 -Ref: table-readdir-file-types998032 -Node: Extension Sample Revout998831 -Node: Extension Sample Rev2way999422 -Node: Extension Sample Read write array1000163 -Node: Extension Sample Readfile1002042 -Node: Extension Sample API Tests1003142 -Node: Extension Sample Time1003667 -Node: gawkextlib1004982 -Node: Language History1007769 -Node: V7/SVR3.11009363 -Node: SVR41011683 -Node: POSIX1013125 -Node: BTL1014511 -Node: POSIX/GNU1015245 -Node: Feature History1020844 -Node: Common Extensions1033956 -Node: Ranges and Locales1035268 -Ref: Ranges and Locales-Footnote-11039885 -Ref: Ranges and Locales-Footnote-21039912 -Ref: Ranges and Locales-Footnote-31040146 -Node: Contributors1040367 -Node: Installation1045805 -Node: Gawk Distribution1046699 -Node: Getting1047183 -Node: Extracting1048009 -Node: Distribution contents1049651 -Node: Unix Installation1055368 -Node: Quick Installation1055985 -Node: Additional Configuration Options1058427 -Node: Configuration Philosophy1060165 -Node: Non-Unix Installation1062516 -Node: PC Installation1062974 -Node: PC Binary Installation1064285 -Node: PC Compiling1066133 -Ref: PC Compiling-Footnote-11069132 -Node: PC Testing1069237 -Node: PC Using1070413 -Node: Cygwin1074571 -Node: MSYS1075380 -Node: VMS Installation1075894 -Node: VMS Compilation1076690 -Ref: VMS Compilation-Footnote-11077905 -Node: VMS Dynamic Extensions1077963 -Node: VMS Installation Details1079336 -Node: VMS Running1081582 -Node: VMS GNV1084416 -Node: VMS Old Gawk1085139 -Node: Bugs1085609 -Node: Other Versions1089613 -Node: Notes1095838 -Node: Compatibility Mode1096638 -Node: Additions1097420 -Node: Accessing The Source1098345 -Node: Adding Code1099781 -Node: New Ports1105959 -Node: Derived Files1110440 -Ref: Derived Files-Footnote-11115521 -Ref: Derived Files-Footnote-21115555 -Ref: Derived Files-Footnote-31116151 -Node: Future Extensions1116265 -Node: Implementation Limitations1116871 -Node: Extension Design1118119 -Node: Old Extension Problems1119273 -Ref: Old Extension Problems-Footnote-11120790 -Node: Extension New Mechanism Goals1120847 -Ref: Extension New Mechanism Goals-Footnote-11124208 -Node: Extension Other Design Decisions1124397 -Node: Extension Future Growth1126503 -Node: Old Extension Mechanism1127339 -Node: Basic Concepts1129079 -Node: Basic High Level1129760 -Ref: figure-general-flow1130032 -Ref: figure-process-flow1130631 -Ref: Basic High Level-Footnote-11133860 -Node: Basic Data Typing1134045 -Node: Glossary1137372 -Node: Copying1162524 -Node: GNU Free Documentation License1200080 -Node: Index1225216 +Node: Foreword41210 +Node: Preface45555 +Ref: Preface-Footnote-148702 +Ref: Preface-Footnote-248809 +Node: History49041 +Node: Names51415 +Ref: Names-Footnote-152879 +Node: This Manual52952 +Ref: This Manual-Footnote-158731 +Node: Conventions58831 +Node: Manual History60987 +Ref: Manual History-Footnote-164426 +Ref: Manual History-Footnote-264467 +Node: How To Contribute64541 +Node: Acknowledgments65780 +Node: Getting Started69929 +Node: Running gawk72363 +Node: One-shot73553 +Node: Read Terminal74778 +Ref: Read Terminal-Footnote-176428 +Ref: Read Terminal-Footnote-276704 +Node: Long76875 +Node: Executable Scripts78223 +Ref: Executable Scripts-Footnote-180056 +Ref: Executable Scripts-Footnote-280158 +Node: Comments80691 +Node: Quoting83158 +Node: DOS Quoting88467 +Node: Sample Data Files89142 +Node: Very Simple91657 +Node: Two Rules96288 +Node: More Complex98183 +Ref: More Complex-Footnote-1101108 +Node: Statements/Lines101193 +Ref: Statements/Lines-Footnote-1105648 +Node: Other Features105913 +Node: When106841 +Node: Intro Summary109011 +Node: Invoking Gawk109777 +Node: Command Line111292 +Node: Options112083 +Ref: Options-Footnote-1127867 +Node: Other Arguments127892 +Node: Naming Standard Input130533 +Node: Environment Variables131613 +Node: AWKPATH Variable132171 +Ref: AWKPATH Variable-Footnote-1135022 +Ref: AWKPATH Variable-Footnote-2135067 +Node: AWKLIBPATH Variable135327 +Node: Other Environment Variables136086 +Node: Exit Status139741 +Node: Include Files140416 +Node: Loading Shared Libraries143980 +Node: Obsolete145364 +Node: Undocumented146061 +Node: Invoking Summary146328 +Node: Regexp147908 +Node: Regexp Usage149358 +Node: Escape Sequences151391 +Node: Regexp Operators157058 +Ref: Regexp Operators-Footnote-1164538 +Ref: Regexp Operators-Footnote-2164685 +Node: Bracket Expressions164783 +Ref: table-char-classes166673 +Node: GNU Regexp Operators169196 +Node: Case-sensitivity172919 +Ref: Case-sensitivity-Footnote-1175811 +Ref: Case-sensitivity-Footnote-2176046 +Node: Leftmost Longest176154 +Node: Computed Regexps177355 +Node: Regexp Summary180727 +Node: Reading Files182199 +Node: Records184201 +Node: awk split records184944 +Node: gawk split records189802 +Ref: gawk split records-Footnote-1194323 +Node: Fields194360 +Ref: Fields-Footnote-1197324 +Node: Nonconstant Fields197410 +Ref: Nonconstant Fields-Footnote-1199640 +Node: Changing Fields199842 +Node: Field Separators205796 +Node: Default Field Splitting208498 +Node: Regexp Field Splitting209615 +Node: Single Character Fields212956 +Node: Command Line Field Separator214015 +Node: Full Line Fields217357 +Ref: Full Line Fields-Footnote-1217865 +Node: Field Splitting Summary217911 +Ref: Field Splitting Summary-Footnote-1221010 +Node: Constant Size221111 +Node: Splitting By Content225718 +Ref: Splitting By Content-Footnote-1229468 +Node: Multiple Line229508 +Ref: Multiple Line-Footnote-1235364 +Node: Getline235543 +Node: Plain Getline237759 +Node: Getline/Variable239854 +Node: Getline/File241001 +Node: Getline/Variable/File242377 +Ref: Getline/Variable/File-Footnote-1243976 +Node: Getline/Pipe244063 +Node: Getline/Variable/Pipe246762 +Node: Getline/Coprocess247869 +Node: Getline/Variable/Coprocess249121 +Node: Getline Notes249858 +Node: Getline Summary252662 +Ref: table-getline-variants253070 +Node: Read Timeout253982 +Ref: Read Timeout-Footnote-1257809 +Node: Command line directories257867 +Node: Printing258749 +Node: Print260373 +Node: Print Examples261714 +Node: Output Separators264493 +Node: OFMT266509 +Node: Printf267867 +Node: Basic Printf268773 +Node: Control Letters270312 +Node: Format Modifiers274166 +Node: Printf Examples280193 +Node: Redirection282900 +Node: Special Files289847 +Node: Special FD290363 +Ref: Special FD-Footnote-1293938 +Node: Special Network294012 +Node: Special Caveats294848 +Node: Close Files And Pipes295623 +Ref: Close Files And Pipes-Footnote-1302739 +Ref: Close Files And Pipes-Footnote-2302887 +Node: Expressions303037 +Node: Values304169 +Node: Constants304845 +Node: Scalar Constants305525 +Ref: Scalar Constants-Footnote-1306384 +Node: Nondecimal-numbers306634 +Node: Regexp Constants309634 +Node: Using Constant Regexps310109 +Node: Variables313179 +Node: Using Variables313834 +Node: Assignment Options315558 +Node: Conversion317425 +Ref: table-locale-affects322861 +Ref: Conversion-Footnote-1323485 +Node: All Operators323594 +Node: Arithmetic Ops324224 +Node: Concatenation326729 +Ref: Concatenation-Footnote-1329525 +Node: Assignment Ops329645 +Ref: table-assign-ops334628 +Node: Increment Ops335945 +Node: Truth Values and Conditions339383 +Node: Truth Values340466 +Node: Typing and Comparison341515 +Node: Variable Typing342308 +Ref: Variable Typing-Footnote-1346208 +Node: Comparison Operators346330 +Ref: table-relational-ops346740 +Node: POSIX String Comparison350290 +Ref: POSIX String Comparison-Footnote-1351374 +Node: Boolean Ops351512 +Ref: Boolean Ops-Footnote-1355582 +Node: Conditional Exp355673 +Node: Function Calls357400 +Node: Precedence361158 +Node: Locales364827 +Node: Patterns and Actions366430 +Node: Pattern Overview367484 +Node: Regexp Patterns369161 +Node: Expression Patterns369704 +Node: Ranges373485 +Node: BEGIN/END376591 +Node: Using BEGIN/END377353 +Ref: Using BEGIN/END-Footnote-1380089 +Node: I/O And BEGIN/END380195 +Node: BEGINFILE/ENDFILE382480 +Node: Empty385411 +Node: Using Shell Variables385728 +Node: Action Overview388011 +Node: Statements390338 +Node: If Statement392186 +Node: While Statement393684 +Node: Do Statement395728 +Node: For Statement396884 +Node: Switch Statement400036 +Node: Break Statement402139 +Node: Continue Statement404194 +Node: Next Statement405987 +Node: Nextfile Statement408377 +Node: Exit Statement411032 +Node: Built-in Variables413436 +Node: User-modified414532 +Ref: User-modified-Footnote-1422217 +Node: Auto-set422279 +Ref: Auto-set-Footnote-1434825 +Ref: Auto-set-Footnote-2435030 +Node: ARGC and ARGV435086 +Node: Arrays438925 +Node: Array Basics440423 +Node: Array Intro441249 +Ref: figure-array-elements443222 +Node: Reference to Elements445629 +Node: Assigning Elements447902 +Node: Array Example448393 +Node: Scanning an Array450125 +Node: Controlling Scanning453140 +Ref: Controlling Scanning-Footnote-1458313 +Node: Delete458629 +Ref: Delete-Footnote-1461394 +Node: Numeric Array Subscripts461451 +Node: Uninitialized Subscripts463634 +Node: Multidimensional465259 +Node: Multiscanning468352 +Node: Arrays of Arrays469941 +Node: Functions474581 +Node: Built-in475400 +Node: Calling Built-in476478 +Node: Numeric Functions478466 +Ref: Numeric Functions-Footnote-1482300 +Ref: Numeric Functions-Footnote-2482657 +Ref: Numeric Functions-Footnote-3482705 +Node: String Functions482974 +Ref: String Functions-Footnote-1505985 +Ref: String Functions-Footnote-2506114 +Ref: String Functions-Footnote-3506362 +Node: Gory Details506449 +Ref: table-sub-escapes508118 +Ref: table-sub-posix-92509472 +Ref: table-sub-proposed510823 +Ref: table-posix-sub512177 +Ref: table-gensub-escapes513722 +Ref: Gory Details-Footnote-1514898 +Ref: Gory Details-Footnote-2514949 +Node: I/O Functions515100 +Ref: I/O Functions-Footnote-1522223 +Node: Time Functions522370 +Ref: Time Functions-Footnote-1532834 +Ref: Time Functions-Footnote-2532902 +Ref: Time Functions-Footnote-3533060 +Ref: Time Functions-Footnote-4533171 +Ref: Time Functions-Footnote-5533283 +Ref: Time Functions-Footnote-6533510 +Node: Bitwise Functions533776 +Ref: table-bitwise-ops534338 +Ref: Bitwise Functions-Footnote-1538583 +Node: Type Functions538767 +Node: I18N Functions539909 +Node: User-defined541554 +Node: Definition Syntax542358 +Ref: Definition Syntax-Footnote-1547283 +Node: Function Example547352 +Ref: Function Example-Footnote-1549996 +Node: Function Caveats550018 +Node: Calling A Function550536 +Node: Variable Scope551491 +Node: Pass By Value/Reference554479 +Node: Return Statement557987 +Node: Dynamic Typing560971 +Node: Indirect Calls561900 +Node: Library Functions571587 +Ref: Library Functions-Footnote-1575100 +Ref: Library Functions-Footnote-2575243 +Node: Library Names575414 +Ref: Library Names-Footnote-1578887 +Ref: Library Names-Footnote-2579107 +Node: General Functions579193 +Node: Strtonum Function580221 +Node: Assert Function583151 +Node: Round Function586477 +Node: Cliff Random Function588018 +Node: Ordinal Functions589034 +Ref: Ordinal Functions-Footnote-1592111 +Ref: Ordinal Functions-Footnote-2592363 +Node: Join Function592574 +Ref: Join Function-Footnote-1594345 +Node: Getlocaltime Function594545 +Node: Readfile Function598281 +Node: Data File Management600120 +Node: Filetrans Function600752 +Node: Rewind Function604807 +Node: File Checking606194 +Ref: File Checking-Footnote-1607326 +Node: Empty Files607527 +Node: Ignoring Assigns609750 +Node: Getopt Function611281 +Ref: Getopt Function-Footnote-1622577 +Node: Passwd Functions622780 +Ref: Passwd Functions-Footnote-1631759 +Node: Group Functions631847 +Ref: Group Functions-Footnote-1639789 +Node: Walking Arrays640002 +Node: Sample Programs642138 +Node: Running Examples642812 +Node: Clones643540 +Node: Cut Program644764 +Node: Egrep Program654625 +Ref: Egrep Program-Footnote-1662554 +Node: Id Program662664 +Node: Split Program666328 +Ref: Split Program-Footnote-1669859 +Node: Tee Program669987 +Node: Uniq Program672794 +Node: Wc Program680224 +Ref: Wc Program-Footnote-1684492 +Ref: Wc Program-Footnote-2684692 +Node: Miscellaneous Programs684784 +Node: Dupword Program685972 +Node: Alarm Program688003 +Node: Translate Program692817 +Ref: Translate Program-Footnote-1697208 +Ref: Translate Program-Footnote-2697478 +Node: Labels Program697612 +Ref: Labels Program-Footnote-1700983 +Node: Word Sorting701067 +Node: History Sorting705110 +Node: Extract Program706946 +Ref: Extract Program-Footnote-1714521 +Node: Simple Sed714650 +Node: Igawk Program717712 +Ref: Igawk Program-Footnote-1732888 +Ref: Igawk Program-Footnote-2733089 +Node: Anagram Program733227 +Node: Signature Program736295 +Node: Advanced Features737542 +Node: Nondecimal Data739428 +Node: Array Sorting741005 +Node: Controlling Array Traversal741702 +Node: Array Sorting Functions749982 +Ref: Array Sorting Functions-Footnote-1753889 +Node: Two-way I/O754083 +Ref: Two-way I/O-Footnote-1759599 +Node: TCP/IP Networking759681 +Node: Profiling762525 +Node: Internationalization770033 +Node: I18N and L10N771458 +Node: Explaining gettext772144 +Ref: Explaining gettext-Footnote-1777284 +Ref: Explaining gettext-Footnote-2777468 +Node: Programmer i18n777633 +Node: Translator i18n781858 +Node: String Extraction782652 +Ref: String Extraction-Footnote-1783613 +Node: Printf Ordering783699 +Ref: Printf Ordering-Footnote-1786481 +Node: I18N Portability786545 +Ref: I18N Portability-Footnote-1788994 +Node: I18N Example789057 +Ref: I18N Example-Footnote-1791779 +Node: Gawk I18N791851 +Node: Debugger792464 +Node: Debugging793435 +Node: Debugging Concepts793876 +Node: Debugging Terms795732 +Node: Awk Debugging798329 +Node: Sample Debugging Session799221 +Node: Debugger Invocation799741 +Node: Finding The Bug801074 +Node: List of Debugger Commands807556 +Node: Breakpoint Control808888 +Node: Debugger Execution Control812552 +Node: Viewing And Changing Data815912 +Node: Execution Stack819270 +Node: Debugger Info820783 +Node: Miscellaneous Debugger Commands824777 +Node: Readline Support829961 +Node: Limitations830853 +Node: Arbitrary Precision Arithmetic833101 +Ref: Arbitrary Precision Arithmetic-Footnote-1834750 +Node: General Arithmetic834898 +Node: Floating Point Issues836618 +Node: String Conversion Precision837499 +Ref: String Conversion Precision-Footnote-1839204 +Node: Unexpected Results839313 +Node: POSIX Floating Point Problems841466 +Ref: POSIX Floating Point Problems-Footnote-1845287 +Node: Integer Programming845325 +Node: Floating-point Programming847136 +Ref: Floating-point Programming-Footnote-1853464 +Ref: Floating-point Programming-Footnote-2853734 +Node: Floating-point Representation853998 +Node: Floating-point Context855163 +Ref: table-ieee-formats856002 +Node: Rounding Mode857386 +Ref: table-rounding-modes857865 +Ref: Rounding Mode-Footnote-1860880 +Node: Gawk and MPFR861059 +Node: Arbitrary Precision Floats862468 +Ref: Arbitrary Precision Floats-Footnote-1864911 +Node: Setting Precision865232 +Ref: table-predefined-precision-strings865916 +Node: Setting Rounding Mode868061 +Ref: table-gawk-rounding-modes868465 +Node: Floating-point Constants869652 +Node: Changing Precision871104 +Ref: Changing Precision-Footnote-1872496 +Node: Exact Arithmetic872670 +Node: Arbitrary Precision Integers875804 +Ref: Arbitrary Precision Integers-Footnote-1878819 +Node: Dynamic Extensions878966 +Node: Extension Intro880424 +Node: Plugin License881689 +Node: Extension Mechanism Outline882374 +Ref: figure-load-extension882798 +Ref: figure-load-new-function884283 +Ref: figure-call-new-function885285 +Node: Extension API Description887269 +Node: Extension API Functions Introduction888719 +Node: General Data Types893585 +Ref: General Data Types-Footnote-1899278 +Node: Requesting Values899577 +Ref: table-value-types-returned900314 +Node: Memory Allocation Functions901272 +Ref: Memory Allocation Functions-Footnote-1904019 +Node: Constructor Functions904115 +Node: Registration Functions905873 +Node: Extension Functions906558 +Node: Exit Callback Functions908860 +Node: Extension Version String910110 +Node: Input Parsers910760 +Node: Output Wrappers920563 +Node: Two-way processors925079 +Node: Printing Messages927283 +Ref: Printing Messages-Footnote-1928360 +Node: Updating `ERRNO'928512 +Node: Accessing Parameters929251 +Node: Symbol Table Access930481 +Node: Symbol table by name930995 +Node: Symbol table by cookie932971 +Ref: Symbol table by cookie-Footnote-1937104 +Node: Cached values937167 +Ref: Cached values-Footnote-1940672 +Node: Array Manipulation940763 +Ref: Array Manipulation-Footnote-1941861 +Node: Array Data Types941900 +Ref: Array Data Types-Footnote-1944603 +Node: Array Functions944695 +Node: Flattening Arrays948569 +Node: Creating Arrays955421 +Node: Extension API Variables960152 +Node: Extension Versioning960788 +Node: Extension API Informational Variables962689 +Node: Extension API Boilerplate963775 +Node: Finding Extensions967579 +Node: Extension Example968139 +Node: Internal File Description968869 +Node: Internal File Ops972960 +Ref: Internal File Ops-Footnote-1984506 +Node: Using Internal File Ops984646 +Ref: Using Internal File Ops-Footnote-1986993 +Node: Extension Samples987261 +Node: Extension Sample File Functions988785 +Node: Extension Sample Fnmatch996353 +Node: Extension Sample Fork997820 +Node: Extension Sample Inplace999033 +Node: Extension Sample Ord1000799 +Node: Extension Sample Readdir1001635 +Ref: table-readdir-file-types1002484 +Node: Extension Sample Revout1003283 +Node: Extension Sample Rev2way1003874 +Node: Extension Sample Read write array1004615 +Node: Extension Sample Readfile1006494 +Node: Extension Sample API Tests1007594 +Node: Extension Sample Time1008119 +Node: gawkextlib1009434 +Node: Language History1012221 +Node: V7/SVR3.11013815 +Node: SVR41016135 +Node: POSIX1017577 +Node: BTL1018963 +Node: POSIX/GNU1019697 +Node: Feature History1025296 +Node: Common Extensions1038408 +Node: Ranges and Locales1039720 +Ref: Ranges and Locales-Footnote-11044337 +Ref: Ranges and Locales-Footnote-21044364 +Ref: Ranges and Locales-Footnote-31044598 +Node: Contributors1044819 +Node: Installation1050257 +Node: Gawk Distribution1051151 +Node: Getting1051635 +Node: Extracting1052461 +Node: Distribution contents1054103 +Node: Unix Installation1059820 +Node: Quick Installation1060437 +Node: Additional Configuration Options1062879 +Node: Configuration Philosophy1064617 +Node: Non-Unix Installation1066968 +Node: PC Installation1067426 +Node: PC Binary Installation1068737 +Node: PC Compiling1070585 +Ref: PC Compiling-Footnote-11073584 +Node: PC Testing1073689 +Node: PC Using1074865 +Node: Cygwin1079023 +Node: MSYS1079832 +Node: VMS Installation1080346 +Node: VMS Compilation1081142 +Ref: VMS Compilation-Footnote-11082357 +Node: VMS Dynamic Extensions1082415 +Node: VMS Installation Details1083788 +Node: VMS Running1086034 +Node: VMS GNV1088868 +Node: VMS Old Gawk1089591 +Node: Bugs1090061 +Node: Other Versions1094065 +Node: Notes1100290 +Node: Compatibility Mode1101090 +Node: Additions1101872 +Node: Accessing The Source1102797 +Node: Adding Code1104233 +Node: New Ports1110411 +Node: Derived Files1114892 +Ref: Derived Files-Footnote-11119973 +Ref: Derived Files-Footnote-21120007 +Ref: Derived Files-Footnote-31120603 +Node: Future Extensions1120717 +Node: Implementation Limitations1121323 +Node: Extension Design1122571 +Node: Old Extension Problems1123725 +Ref: Old Extension Problems-Footnote-11125242 +Node: Extension New Mechanism Goals1125299 +Ref: Extension New Mechanism Goals-Footnote-11128660 +Node: Extension Other Design Decisions1128849 +Node: Extension Future Growth1130955 +Node: Old Extension Mechanism1131791 +Node: Basic Concepts1133531 +Node: Basic High Level1134212 +Ref: figure-general-flow1134484 +Ref: figure-process-flow1135083 +Ref: Basic High Level-Footnote-11138312 +Node: Basic Data Typing1138497 +Node: Glossary1141824 +Node: Copying1166976 +Node: GNU Free Documentation License1204532 +Node: Index1229668  End Tag Table -- cgit v1.2.3 From e0cb2b1f1b87cfc493db276c85bbec8246cd4b3b Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Mon, 9 Jun 2014 20:13:44 +0300 Subject: More summary sections. --- doc/gawk.info | 1142 ++++++++++++++++++++++++++++++++++----------------------- 1 file changed, 675 insertions(+), 467 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 50ccda25..9d472b67 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -4042,6 +4042,7 @@ have to be named on the `awk' command line (*note Getline::). * Read Timeout:: Reading input with a timeout. * Command line directories:: What happens if you put a directory on the command line. +* Input Summary:: Input summary.  File: gawk.info, Node: Records, Next: Fields, Up: Reading Files @@ -5829,7 +5830,7 @@ writing. (1) This assumes that standard input is the keyboard.  -File: gawk.info, Node: Command line directories, Prev: Read Timeout, Up: Reading Files +File: gawk.info, Node: Command line directories, Next: Input Summary, Prev: Read Timeout, Up: Reading Files 4.11 Directories On The Command Line ==================================== @@ -5851,6 +5852,75 @@ error. *Note Extension Sample Readdir::, for a way to treat directories as usable data from an `awk' program. + +File: gawk.info, Node: Input Summary, Prev: Command line directories, Up: Reading Files + +4.12 Summary +============ + + * Input is split into records based on the value of `RS'. The + possibilities are as follows: + + Value of `RS' Records are split on `awk' / `gawk' + ---------------------------------------------------------------------- + Any single That character `awk' + character + The empty string Runs of two or more `awk' + (`""') newlines + A regexp Text that matches the `gawk' + regexp + + * `gawk' sets `RT' to the text matched by `RS'. + + * After splitting the input into records, `awk' further splits the + record into individual fields, named `$1', `$2' and so on. `$0' is + the whole record, and `NF' indicates how many fields there are. + The default way to split fields is between whitespace characters. + + * Fields may be referenced using a variable, as in `$NF'. Fields + may also be assigned values, which causes the value of `$0' to be + recomputed when it is later referenced. Assigning to a field with + a number greater than `NF' creates the field and rebuilds the + record, using `OFS' to separate the fields. Incrementing `NF' + does the same thing. Decrementing `NF' throws away fields and + rebuilds the record. + + * Field splitting is more complicated than record splitting. + + Field separator value Fields are split ... `awk' / + `gawk' + ---------------------------------------------------------------------- + `FS == " "' On runs of whitespace `awk' + `FS == ANY SINGLE On that character `awk' + CHARACTER' + `FS == REGEXP' On text matching the `awk' + regexp + `FS == ""' Each individual character `gawk' + is a separate field + `FIELDWIDTHS == LIST OF Based on character `gawk' + COLUMNS' position + `FPAT == REGEXP' On text around text `gawk' + matching the regexp + + Using `FS = "\n"' causes the entire record to be a single field + (assuming that newlines separate records). + + * `FS' may be set from the command line using the `-F' option. This + can also be done using command-line variable assignment. + + * `PROCINFO["FS"]' can be used to see how fields are being split. + + * Use `getline' in its varioius forms to read additional records, + from the default input stream, from a file, or from a pipe or + co-process. + + * Use `PROCINFO[FILE, "READ_TIMEOUT"]' to cause reads to timeout for + FILE. + + * Directories on the command line are fatal for standard `awk'; + `gawk' ignores them if not in POSIX mode. + +  File: gawk.info, Node: Printing, Next: Expressions, Prev: Reading Files, Up: Top @@ -5885,6 +5955,7 @@ function. `gawk' allows access to inherited file descriptors. * Close Files And Pipes:: Closing Input and Output Files and Pipes. +* Output Summary:: Output summary.  File: gawk.info, Node: Print, Next: Print Examples, Up: Printing @@ -6776,7 +6847,7 @@ that `gawk' provides: behavior.  -File: gawk.info, Node: Close Files And Pipes, Prev: Special Files, Up: Printing +File: gawk.info, Node: Close Files And Pipes, Next: Output Summary, Prev: Special Files, Up: Printing 5.8 Closing Input and Output Redirections ========================================= @@ -6942,6 +7013,32 @@ is called a "zombie," and cleaning up after it is referred to as call. See the system manual pages for information on how to decode this value. + +File: gawk.info, Node: Output Summary, Prev: Close Files And Pipes, Up: Printing + +5.9 Summary +=========== + + * The `print' statement prints comma-separated expressions. Each + expression is separated by the value of `OFS' and terminated by + the value of `ORS'. `OFMT' provides the conversion format for + numeric values for the `print' statement. + + * The `printf' statement provides finer-grained control over output, + with format control letters for different data types and various + flags that modify the behavior of the format control letters. + + * Output from both `print' and `printf' may be redirected to files, + pipes, and co-processes. + + * `gawk' provides special file names for access to standard input, + output and error, and for network communications. + + * Use `close()' to close open file, pipe and co-process redirections. + For co-processes, it is possible to close only one direction of the + communications. + +  File: gawk.info, Node: Expressions, Next: Patterns and Actions, Prev: Printing, Up: Top @@ -6968,6 +7065,7 @@ operators. * Function Calls:: A function call is an expression. * Precedence:: How various operators nest. * Locales:: How the locale affects things. +* Expressions Summary:: Expressions summary.  File: gawk.info, Node: Values, Next: All Operators, Up: Expressions @@ -8516,7 +8614,7 @@ String Concatenation POSIX. For maximum portability, do not use them.  -File: gawk.info, Node: Locales, Prev: Precedence, Up: Expressions +File: gawk.info, Node: Locales, Next: Expressions Summary, Prev: Precedence, Up: Expressions 6.6 Where You Are Makes A Difference ==================================== @@ -8551,6 +8649,62 @@ POSIX String Comparison::. used when `gawk' parses input data. This is discussed in detail in *note Conversion::. + +File: gawk.info, Node: Expressions Summary, Prev: Locales, Up: Expressions + +6.7 Summary +=========== + + * Expressions are the basic elements of computation in programs. + They are built from constants, variables, function calls and + combinations of the various kinds of values with operators. + + * `awk' supplies three kinds of constants: numeric, string, and + regexp. `gawk' lets you specify numeric constants in octal and + hexadecimal (bases 8 and 16) in addition to decimal (base 10). In + certain contexts, a standalone regexp constant such as `/foo/' has + the same meaning as `$0 ~ /foo/'. + + * Variables hold values between uses in computations. A number of + built-in variables provide information to your `awk' program, and + a number of others let you control how `awk' behaves. + + * Numbers are automatically converted to strings, and strings to + numbers, as needed by `awk'. Numeric values are converted as if + they were formatted with `sprintf()' using the format in `CONVFMT'. + + * `awk' provides the usual arithmetic operators (addition, + subtraction, multiplication, division, modulus), and unary plus + and minus. It also provides comparison operators, boolean + operators, and regexp matching operators. String concatenation is + accomplished by placing two expressions next to each other; there + is no explicit operator. The three-operand `?:' operator provides + an "if-else" test within expressions. + + * Assignment operators provide convenient shorthands for common + arithmetic operations. + + * In `awk', a value is considered to be true if it is non-zero _or_ + non-null. Otherwise, the value is false. + + * A value's type is set upon each assignment and may change over its + lifetime. The type determines how it behaves in comparisons + (string or numeric). + + * Function calls return a value which may be used as part of a larger + expression. Expressions used to pass parameter values are fully + evaluated before the function is called. `awk' provides built-in + and user-defined functions; this is described later on in this + Info file. + + * Operator precedence specifies the order in which operations are + performed, unless explicitly overridden by parentheses. `awk''s + operator precedence is compatible with that of C. + + * Locales can affect the format of data as output by an `awk' + program, and occasionally the format for data read as input. + +  File: gawk.info, Node: Patterns and Actions, Next: Arrays, Prev: Expressions, Up: Top @@ -8575,6 +8729,7 @@ top of. Now it's time to start building something useful. * Statements:: Describes the various control statements in detail. * Built-in Variables:: Summarizes the built-in variables. +* Pattern Action Summary:: Patterns and Actions summary.  File: gawk.info, Node: Pattern Overview, Next: Using Shell Variables, Up: Patterns and Actions @@ -9667,7 +9822,7 @@ statement with a nonzero argument, as shown in the following example: systems.  -File: gawk.info, Node: Built-in Variables, Prev: Statements, Up: Patterns and Actions +File: gawk.info, Node: Built-in Variables, Next: Pattern Action Summary, Prev: Statements, Up: Patterns and Actions 7.5 Built-in Variables ====================== @@ -10284,6 +10439,55 @@ Because `-q' is not a valid `gawk' option, it and the following `-v' are passed on to the `awk' program. (*Note Getopt Function::, for an `awk' library function that parses command-line options.) + +File: gawk.info, Node: Pattern Action Summary, Prev: Built-in Variables, Up: Patterns and Actions + +7.6 Summary +=========== + + * Pattern-action pairs make up the basic elements of an `awk' + program. Patterns are either normal expressions, range + expressions, regexp constants, one of the special keywords + `BEGIN', `END', `BEGINFILE', `ENDFILE', or empty. The action + executes if the current record matches the pattern. Empty + (missing) patterns match all records. + + * I/O from `BEGIN' and `END' rules have certain constraints. This + is also true, only more so, for `BEGINFILE' and `ENDFILE' rules. + The latter two give you "hooks" into `gawk''s file processing, + allowing you to recover from a file that otherwise would cause a + fatal error (such as a file that cannot be opened). + + * Shell variables can be used in `awk' programs by careful use of + shell quoting. It is easier to pass a shell variable into `awk' + by using the `-v' option and an `awk' variable. + + * Actions consist of statements enclosed in curly braces. Statements + are built up from expressions, control statements, compound + statements, input and output statements, and deletion statements. + + * The control statements in `awk' are `if'-`else', `while', `for', + and `do'-`while'. `gawk' adds the `switch' statement. There are + two flavors of `for' statement: one for for performing general + looping, and the other iterating through an array. + + * `break' and `continue' let you exit early or start the next + iteration of a loop (or get out of a `switch'). + + * `next' and `nextfile' let you read the next record and start over + at the top of your program, or skip to the next input file and + start over, respectively. + + * The `exit' statement terminates your program. When executed from + an action (or function body) it transfers control to the `END' + statements. From an `END' statement body, it exits immediately. + You may pass an optional numeric value to be used at `awk''s exit + status. + + * Some built-in variables provide control over `awk', mainly for I/O. + Other variables convey information from `awk' to your program. + +  File: gawk.info, Node: Arrays, Next: Functions, Prev: Patterns and Actions, Up: Top @@ -33403,468 +33607,472 @@ Node: Leftmost Longest176154 Node: Computed Regexps177355 Node: Regexp Summary180727 Node: Reading Files182199 -Node: Records184201 -Node: awk split records184944 -Node: gawk split records189802 -Ref: gawk split records-Footnote-1194323 -Node: Fields194360 -Ref: Fields-Footnote-1197324 -Node: Nonconstant Fields197410 -Ref: Nonconstant Fields-Footnote-1199640 -Node: Changing Fields199842 -Node: Field Separators205796 -Node: Default Field Splitting208498 -Node: Regexp Field Splitting209615 -Node: Single Character Fields212956 -Node: Command Line Field Separator214015 -Node: Full Line Fields217357 -Ref: Full Line Fields-Footnote-1217865 -Node: Field Splitting Summary217911 -Ref: Field Splitting Summary-Footnote-1221010 -Node: Constant Size221111 -Node: Splitting By Content225718 -Ref: Splitting By Content-Footnote-1229468 -Node: Multiple Line229508 -Ref: Multiple Line-Footnote-1235364 -Node: Getline235543 -Node: Plain Getline237759 -Node: Getline/Variable239854 -Node: Getline/File241001 -Node: Getline/Variable/File242377 -Ref: Getline/Variable/File-Footnote-1243976 -Node: Getline/Pipe244063 -Node: Getline/Variable/Pipe246762 -Node: Getline/Coprocess247869 -Node: Getline/Variable/Coprocess249121 -Node: Getline Notes249858 -Node: Getline Summary252662 -Ref: table-getline-variants253070 -Node: Read Timeout253982 -Ref: Read Timeout-Footnote-1257809 -Node: Command line directories257867 -Node: Printing258749 -Node: Print260373 -Node: Print Examples261714 -Node: Output Separators264493 -Node: OFMT266509 -Node: Printf267867 -Node: Basic Printf268773 -Node: Control Letters270312 -Node: Format Modifiers274166 -Node: Printf Examples280193 -Node: Redirection282900 -Node: Special Files289847 -Node: Special FD290363 -Ref: Special FD-Footnote-1293938 -Node: Special Network294012 -Node: Special Caveats294848 -Node: Close Files And Pipes295623 -Ref: Close Files And Pipes-Footnote-1302739 -Ref: Close Files And Pipes-Footnote-2302887 -Node: Expressions303037 -Node: Values304169 -Node: Constants304845 -Node: Scalar Constants305525 -Ref: Scalar Constants-Footnote-1306384 -Node: Nondecimal-numbers306634 -Node: Regexp Constants309634 -Node: Using Constant Regexps310109 -Node: Variables313179 -Node: Using Variables313834 -Node: Assignment Options315558 -Node: Conversion317425 -Ref: table-locale-affects322861 -Ref: Conversion-Footnote-1323485 -Node: All Operators323594 -Node: Arithmetic Ops324224 -Node: Concatenation326729 -Ref: Concatenation-Footnote-1329525 -Node: Assignment Ops329645 -Ref: table-assign-ops334628 -Node: Increment Ops335945 -Node: Truth Values and Conditions339383 -Node: Truth Values340466 -Node: Typing and Comparison341515 -Node: Variable Typing342308 -Ref: Variable Typing-Footnote-1346208 -Node: Comparison Operators346330 -Ref: table-relational-ops346740 -Node: POSIX String Comparison350290 -Ref: POSIX String Comparison-Footnote-1351374 -Node: Boolean Ops351512 -Ref: Boolean Ops-Footnote-1355582 -Node: Conditional Exp355673 -Node: Function Calls357400 -Node: Precedence361158 -Node: Locales364827 -Node: Patterns and Actions366430 -Node: Pattern Overview367484 -Node: Regexp Patterns369161 -Node: Expression Patterns369704 -Node: Ranges373485 -Node: BEGIN/END376591 -Node: Using BEGIN/END377353 -Ref: Using BEGIN/END-Footnote-1380089 -Node: I/O And BEGIN/END380195 -Node: BEGINFILE/ENDFILE382480 -Node: Empty385411 -Node: Using Shell Variables385728 -Node: Action Overview388011 -Node: Statements390338 -Node: If Statement392186 -Node: While Statement393684 -Node: Do Statement395728 -Node: For Statement396884 -Node: Switch Statement400036 -Node: Break Statement402139 -Node: Continue Statement404194 -Node: Next Statement405987 -Node: Nextfile Statement408377 -Node: Exit Statement411032 -Node: Built-in Variables413436 -Node: User-modified414532 -Ref: User-modified-Footnote-1422217 -Node: Auto-set422279 -Ref: Auto-set-Footnote-1434825 -Ref: Auto-set-Footnote-2435030 -Node: ARGC and ARGV435086 -Node: Arrays438925 -Node: Array Basics440423 -Node: Array Intro441249 -Ref: figure-array-elements443222 -Node: Reference to Elements445629 -Node: Assigning Elements447902 -Node: Array Example448393 -Node: Scanning an Array450125 -Node: Controlling Scanning453140 -Ref: Controlling Scanning-Footnote-1458313 -Node: Delete458629 -Ref: Delete-Footnote-1461394 -Node: Numeric Array Subscripts461451 -Node: Uninitialized Subscripts463634 -Node: Multidimensional465259 -Node: Multiscanning468352 -Node: Arrays of Arrays469941 -Node: Functions474581 -Node: Built-in475400 -Node: Calling Built-in476478 -Node: Numeric Functions478466 -Ref: Numeric Functions-Footnote-1482300 -Ref: Numeric Functions-Footnote-2482657 -Ref: Numeric Functions-Footnote-3482705 -Node: String Functions482974 -Ref: String Functions-Footnote-1505985 -Ref: String Functions-Footnote-2506114 -Ref: String Functions-Footnote-3506362 -Node: Gory Details506449 -Ref: table-sub-escapes508118 -Ref: table-sub-posix-92509472 -Ref: table-sub-proposed510823 -Ref: table-posix-sub512177 -Ref: table-gensub-escapes513722 -Ref: Gory Details-Footnote-1514898 -Ref: Gory Details-Footnote-2514949 -Node: I/O Functions515100 -Ref: I/O Functions-Footnote-1522223 -Node: Time Functions522370 -Ref: Time Functions-Footnote-1532834 -Ref: Time Functions-Footnote-2532902 -Ref: Time Functions-Footnote-3533060 -Ref: Time Functions-Footnote-4533171 -Ref: Time Functions-Footnote-5533283 -Ref: Time Functions-Footnote-6533510 -Node: Bitwise Functions533776 -Ref: table-bitwise-ops534338 -Ref: Bitwise Functions-Footnote-1538583 -Node: Type Functions538767 -Node: I18N Functions539909 -Node: User-defined541554 -Node: Definition Syntax542358 -Ref: Definition Syntax-Footnote-1547283 -Node: Function Example547352 -Ref: Function Example-Footnote-1549996 -Node: Function Caveats550018 -Node: Calling A Function550536 -Node: Variable Scope551491 -Node: Pass By Value/Reference554479 -Node: Return Statement557987 -Node: Dynamic Typing560971 -Node: Indirect Calls561900 -Node: Library Functions571587 -Ref: Library Functions-Footnote-1575100 -Ref: Library Functions-Footnote-2575243 -Node: Library Names575414 -Ref: Library Names-Footnote-1578887 -Ref: Library Names-Footnote-2579107 -Node: General Functions579193 -Node: Strtonum Function580221 -Node: Assert Function583151 -Node: Round Function586477 -Node: Cliff Random Function588018 -Node: Ordinal Functions589034 -Ref: Ordinal Functions-Footnote-1592111 -Ref: Ordinal Functions-Footnote-2592363 -Node: Join Function592574 -Ref: Join Function-Footnote-1594345 -Node: Getlocaltime Function594545 -Node: Readfile Function598281 -Node: Data File Management600120 -Node: Filetrans Function600752 -Node: Rewind Function604807 -Node: File Checking606194 -Ref: File Checking-Footnote-1607326 -Node: Empty Files607527 -Node: Ignoring Assigns609750 -Node: Getopt Function611281 -Ref: Getopt Function-Footnote-1622577 -Node: Passwd Functions622780 -Ref: Passwd Functions-Footnote-1631759 -Node: Group Functions631847 -Ref: Group Functions-Footnote-1639789 -Node: Walking Arrays640002 -Node: Sample Programs642138 -Node: Running Examples642812 -Node: Clones643540 -Node: Cut Program644764 -Node: Egrep Program654625 -Ref: Egrep Program-Footnote-1662554 -Node: Id Program662664 -Node: Split Program666328 -Ref: Split Program-Footnote-1669859 -Node: Tee Program669987 -Node: Uniq Program672794 -Node: Wc Program680224 -Ref: Wc Program-Footnote-1684492 -Ref: Wc Program-Footnote-2684692 -Node: Miscellaneous Programs684784 -Node: Dupword Program685972 -Node: Alarm Program688003 -Node: Translate Program692817 -Ref: Translate Program-Footnote-1697208 -Ref: Translate Program-Footnote-2697478 -Node: Labels Program697612 -Ref: Labels Program-Footnote-1700983 -Node: Word Sorting701067 -Node: History Sorting705110 -Node: Extract Program706946 -Ref: Extract Program-Footnote-1714521 -Node: Simple Sed714650 -Node: Igawk Program717712 -Ref: Igawk Program-Footnote-1732888 -Ref: Igawk Program-Footnote-2733089 -Node: Anagram Program733227 -Node: Signature Program736295 -Node: Advanced Features737542 -Node: Nondecimal Data739428 -Node: Array Sorting741005 -Node: Controlling Array Traversal741702 -Node: Array Sorting Functions749982 -Ref: Array Sorting Functions-Footnote-1753889 -Node: Two-way I/O754083 -Ref: Two-way I/O-Footnote-1759599 -Node: TCP/IP Networking759681 -Node: Profiling762525 -Node: Internationalization770033 -Node: I18N and L10N771458 -Node: Explaining gettext772144 -Ref: Explaining gettext-Footnote-1777284 -Ref: Explaining gettext-Footnote-2777468 -Node: Programmer i18n777633 -Node: Translator i18n781858 -Node: String Extraction782652 -Ref: String Extraction-Footnote-1783613 -Node: Printf Ordering783699 -Ref: Printf Ordering-Footnote-1786481 -Node: I18N Portability786545 -Ref: I18N Portability-Footnote-1788994 -Node: I18N Example789057 -Ref: I18N Example-Footnote-1791779 -Node: Gawk I18N791851 -Node: Debugger792464 -Node: Debugging793435 -Node: Debugging Concepts793876 -Node: Debugging Terms795732 -Node: Awk Debugging798329 -Node: Sample Debugging Session799221 -Node: Debugger Invocation799741 -Node: Finding The Bug801074 -Node: List of Debugger Commands807556 -Node: Breakpoint Control808888 -Node: Debugger Execution Control812552 -Node: Viewing And Changing Data815912 -Node: Execution Stack819270 -Node: Debugger Info820783 -Node: Miscellaneous Debugger Commands824777 -Node: Readline Support829961 -Node: Limitations830853 -Node: Arbitrary Precision Arithmetic833101 -Ref: Arbitrary Precision Arithmetic-Footnote-1834750 -Node: General Arithmetic834898 -Node: Floating Point Issues836618 -Node: String Conversion Precision837499 -Ref: String Conversion Precision-Footnote-1839204 -Node: Unexpected Results839313 -Node: POSIX Floating Point Problems841466 -Ref: POSIX Floating Point Problems-Footnote-1845287 -Node: Integer Programming845325 -Node: Floating-point Programming847136 -Ref: Floating-point Programming-Footnote-1853464 -Ref: Floating-point Programming-Footnote-2853734 -Node: Floating-point Representation853998 -Node: Floating-point Context855163 -Ref: table-ieee-formats856002 -Node: Rounding Mode857386 -Ref: table-rounding-modes857865 -Ref: Rounding Mode-Footnote-1860880 -Node: Gawk and MPFR861059 -Node: Arbitrary Precision Floats862468 -Ref: Arbitrary Precision Floats-Footnote-1864911 -Node: Setting Precision865232 -Ref: table-predefined-precision-strings865916 -Node: Setting Rounding Mode868061 -Ref: table-gawk-rounding-modes868465 -Node: Floating-point Constants869652 -Node: Changing Precision871104 -Ref: Changing Precision-Footnote-1872496 -Node: Exact Arithmetic872670 -Node: Arbitrary Precision Integers875804 -Ref: Arbitrary Precision Integers-Footnote-1878819 -Node: Dynamic Extensions878966 -Node: Extension Intro880424 -Node: Plugin License881689 -Node: Extension Mechanism Outline882374 -Ref: figure-load-extension882798 -Ref: figure-load-new-function884283 -Ref: figure-call-new-function885285 -Node: Extension API Description887269 -Node: Extension API Functions Introduction888719 -Node: General Data Types893585 -Ref: General Data Types-Footnote-1899278 -Node: Requesting Values899577 -Ref: table-value-types-returned900314 -Node: Memory Allocation Functions901272 -Ref: Memory Allocation Functions-Footnote-1904019 -Node: Constructor Functions904115 -Node: Registration Functions905873 -Node: Extension Functions906558 -Node: Exit Callback Functions908860 -Node: Extension Version String910110 -Node: Input Parsers910760 -Node: Output Wrappers920563 -Node: Two-way processors925079 -Node: Printing Messages927283 -Ref: Printing Messages-Footnote-1928360 -Node: Updating `ERRNO'928512 -Node: Accessing Parameters929251 -Node: Symbol Table Access930481 -Node: Symbol table by name930995 -Node: Symbol table by cookie932971 -Ref: Symbol table by cookie-Footnote-1937104 -Node: Cached values937167 -Ref: Cached values-Footnote-1940672 -Node: Array Manipulation940763 -Ref: Array Manipulation-Footnote-1941861 -Node: Array Data Types941900 -Ref: Array Data Types-Footnote-1944603 -Node: Array Functions944695 -Node: Flattening Arrays948569 -Node: Creating Arrays955421 -Node: Extension API Variables960152 -Node: Extension Versioning960788 -Node: Extension API Informational Variables962689 -Node: Extension API Boilerplate963775 -Node: Finding Extensions967579 -Node: Extension Example968139 -Node: Internal File Description968869 -Node: Internal File Ops972960 -Ref: Internal File Ops-Footnote-1984506 -Node: Using Internal File Ops984646 -Ref: Using Internal File Ops-Footnote-1986993 -Node: Extension Samples987261 -Node: Extension Sample File Functions988785 -Node: Extension Sample Fnmatch996353 -Node: Extension Sample Fork997820 -Node: Extension Sample Inplace999033 -Node: Extension Sample Ord1000799 -Node: Extension Sample Readdir1001635 -Ref: table-readdir-file-types1002484 -Node: Extension Sample Revout1003283 -Node: Extension Sample Rev2way1003874 -Node: Extension Sample Read write array1004615 -Node: Extension Sample Readfile1006494 -Node: Extension Sample API Tests1007594 -Node: Extension Sample Time1008119 -Node: gawkextlib1009434 -Node: Language History1012221 -Node: V7/SVR3.11013815 -Node: SVR41016135 -Node: POSIX1017577 -Node: BTL1018963 -Node: POSIX/GNU1019697 -Node: Feature History1025296 -Node: Common Extensions1038408 -Node: Ranges and Locales1039720 -Ref: Ranges and Locales-Footnote-11044337 -Ref: Ranges and Locales-Footnote-21044364 -Ref: Ranges and Locales-Footnote-31044598 -Node: Contributors1044819 -Node: Installation1050257 -Node: Gawk Distribution1051151 -Node: Getting1051635 -Node: Extracting1052461 -Node: Distribution contents1054103 -Node: Unix Installation1059820 -Node: Quick Installation1060437 -Node: Additional Configuration Options1062879 -Node: Configuration Philosophy1064617 -Node: Non-Unix Installation1066968 -Node: PC Installation1067426 -Node: PC Binary Installation1068737 -Node: PC Compiling1070585 -Ref: PC Compiling-Footnote-11073584 -Node: PC Testing1073689 -Node: PC Using1074865 -Node: Cygwin1079023 -Node: MSYS1079832 -Node: VMS Installation1080346 -Node: VMS Compilation1081142 -Ref: VMS Compilation-Footnote-11082357 -Node: VMS Dynamic Extensions1082415 -Node: VMS Installation Details1083788 -Node: VMS Running1086034 -Node: VMS GNV1088868 -Node: VMS Old Gawk1089591 -Node: Bugs1090061 -Node: Other Versions1094065 -Node: Notes1100290 -Node: Compatibility Mode1101090 -Node: Additions1101872 -Node: Accessing The Source1102797 -Node: Adding Code1104233 -Node: New Ports1110411 -Node: Derived Files1114892 -Ref: Derived Files-Footnote-11119973 -Ref: Derived Files-Footnote-21120007 -Ref: Derived Files-Footnote-31120603 -Node: Future Extensions1120717 -Node: Implementation Limitations1121323 -Node: Extension Design1122571 -Node: Old Extension Problems1123725 -Ref: Old Extension Problems-Footnote-11125242 -Node: Extension New Mechanism Goals1125299 -Ref: Extension New Mechanism Goals-Footnote-11128660 -Node: Extension Other Design Decisions1128849 -Node: Extension Future Growth1130955 -Node: Old Extension Mechanism1131791 -Node: Basic Concepts1133531 -Node: Basic High Level1134212 -Ref: figure-general-flow1134484 -Ref: figure-process-flow1135083 -Ref: Basic High Level-Footnote-11138312 -Node: Basic Data Typing1138497 -Node: Glossary1141824 -Node: Copying1166976 -Node: GNU Free Documentation License1204532 -Node: Index1229668 +Node: Records184248 +Node: awk split records184991 +Node: gawk split records189849 +Ref: gawk split records-Footnote-1194370 +Node: Fields194407 +Ref: Fields-Footnote-1197371 +Node: Nonconstant Fields197457 +Ref: Nonconstant Fields-Footnote-1199687 +Node: Changing Fields199889 +Node: Field Separators205843 +Node: Default Field Splitting208545 +Node: Regexp Field Splitting209662 +Node: Single Character Fields213003 +Node: Command Line Field Separator214062 +Node: Full Line Fields217404 +Ref: Full Line Fields-Footnote-1217912 +Node: Field Splitting Summary217958 +Ref: Field Splitting Summary-Footnote-1221057 +Node: Constant Size221158 +Node: Splitting By Content225765 +Ref: Splitting By Content-Footnote-1229515 +Node: Multiple Line229555 +Ref: Multiple Line-Footnote-1235411 +Node: Getline235590 +Node: Plain Getline237806 +Node: Getline/Variable239901 +Node: Getline/File241048 +Node: Getline/Variable/File242424 +Ref: Getline/Variable/File-Footnote-1244023 +Node: Getline/Pipe244110 +Node: Getline/Variable/Pipe246809 +Node: Getline/Coprocess247916 +Node: Getline/Variable/Coprocess249168 +Node: Getline Notes249905 +Node: Getline Summary252709 +Ref: table-getline-variants253117 +Node: Read Timeout254029 +Ref: Read Timeout-Footnote-1257856 +Node: Command line directories257914 +Node: Input Summary258818 +Node: Printing261932 +Node: Print263604 +Node: Print Examples264945 +Node: Output Separators267724 +Node: OFMT269740 +Node: Printf271098 +Node: Basic Printf272004 +Node: Control Letters273543 +Node: Format Modifiers277397 +Node: Printf Examples283424 +Node: Redirection286131 +Node: Special Files293078 +Node: Special FD293594 +Ref: Special FD-Footnote-1297169 +Node: Special Network297243 +Node: Special Caveats298079 +Node: Close Files And Pipes298854 +Ref: Close Files And Pipes-Footnote-1305993 +Ref: Close Files And Pipes-Footnote-2306141 +Node: Output Summary306291 +Node: Expressions307263 +Node: Values308448 +Node: Constants309124 +Node: Scalar Constants309804 +Ref: Scalar Constants-Footnote-1310663 +Node: Nondecimal-numbers310913 +Node: Regexp Constants313913 +Node: Using Constant Regexps314388 +Node: Variables317458 +Node: Using Variables318113 +Node: Assignment Options319837 +Node: Conversion321704 +Ref: table-locale-affects327140 +Ref: Conversion-Footnote-1327764 +Node: All Operators327873 +Node: Arithmetic Ops328503 +Node: Concatenation331008 +Ref: Concatenation-Footnote-1333804 +Node: Assignment Ops333924 +Ref: table-assign-ops338907 +Node: Increment Ops340224 +Node: Truth Values and Conditions343662 +Node: Truth Values344745 +Node: Typing and Comparison345794 +Node: Variable Typing346587 +Ref: Variable Typing-Footnote-1350487 +Node: Comparison Operators350609 +Ref: table-relational-ops351019 +Node: POSIX String Comparison354569 +Ref: POSIX String Comparison-Footnote-1355653 +Node: Boolean Ops355791 +Ref: Boolean Ops-Footnote-1359861 +Node: Conditional Exp359952 +Node: Function Calls361679 +Node: Precedence365437 +Node: Locales369106 +Node: Expressions Summary370737 +Node: Patterns and Actions373234 +Node: Pattern Overview374350 +Node: Regexp Patterns376027 +Node: Expression Patterns376570 +Node: Ranges380351 +Node: BEGIN/END383457 +Node: Using BEGIN/END384219 +Ref: Using BEGIN/END-Footnote-1386955 +Node: I/O And BEGIN/END387061 +Node: BEGINFILE/ENDFILE389346 +Node: Empty392277 +Node: Using Shell Variables392594 +Node: Action Overview394877 +Node: Statements397204 +Node: If Statement399052 +Node: While Statement400550 +Node: Do Statement402594 +Node: For Statement403750 +Node: Switch Statement406902 +Node: Break Statement409005 +Node: Continue Statement411060 +Node: Next Statement412853 +Node: Nextfile Statement415243 +Node: Exit Statement417898 +Node: Built-in Variables420302 +Node: User-modified421429 +Ref: User-modified-Footnote-1429114 +Node: Auto-set429176 +Ref: Auto-set-Footnote-1441722 +Ref: Auto-set-Footnote-2441927 +Node: ARGC and ARGV441983 +Node: Pattern Action Summary445822 +Node: Arrays448045 +Node: Array Basics449543 +Node: Array Intro450369 +Ref: figure-array-elements452342 +Node: Reference to Elements454749 +Node: Assigning Elements457022 +Node: Array Example457513 +Node: Scanning an Array459245 +Node: Controlling Scanning462260 +Ref: Controlling Scanning-Footnote-1467433 +Node: Delete467749 +Ref: Delete-Footnote-1470514 +Node: Numeric Array Subscripts470571 +Node: Uninitialized Subscripts472754 +Node: Multidimensional474379 +Node: Multiscanning477472 +Node: Arrays of Arrays479061 +Node: Functions483701 +Node: Built-in484520 +Node: Calling Built-in485598 +Node: Numeric Functions487586 +Ref: Numeric Functions-Footnote-1491420 +Ref: Numeric Functions-Footnote-2491777 +Ref: Numeric Functions-Footnote-3491825 +Node: String Functions492094 +Ref: String Functions-Footnote-1515105 +Ref: String Functions-Footnote-2515234 +Ref: String Functions-Footnote-3515482 +Node: Gory Details515569 +Ref: table-sub-escapes517238 +Ref: table-sub-posix-92518592 +Ref: table-sub-proposed519943 +Ref: table-posix-sub521297 +Ref: table-gensub-escapes522842 +Ref: Gory Details-Footnote-1524018 +Ref: Gory Details-Footnote-2524069 +Node: I/O Functions524220 +Ref: I/O Functions-Footnote-1531343 +Node: Time Functions531490 +Ref: Time Functions-Footnote-1541954 +Ref: Time Functions-Footnote-2542022 +Ref: Time Functions-Footnote-3542180 +Ref: Time Functions-Footnote-4542291 +Ref: Time Functions-Footnote-5542403 +Ref: Time Functions-Footnote-6542630 +Node: Bitwise Functions542896 +Ref: table-bitwise-ops543458 +Ref: Bitwise Functions-Footnote-1547703 +Node: Type Functions547887 +Node: I18N Functions549029 +Node: User-defined550674 +Node: Definition Syntax551478 +Ref: Definition Syntax-Footnote-1556403 +Node: Function Example556472 +Ref: Function Example-Footnote-1559116 +Node: Function Caveats559138 +Node: Calling A Function559656 +Node: Variable Scope560611 +Node: Pass By Value/Reference563599 +Node: Return Statement567107 +Node: Dynamic Typing570091 +Node: Indirect Calls571020 +Node: Library Functions580707 +Ref: Library Functions-Footnote-1584220 +Ref: Library Functions-Footnote-2584363 +Node: Library Names584534 +Ref: Library Names-Footnote-1588007 +Ref: Library Names-Footnote-2588227 +Node: General Functions588313 +Node: Strtonum Function589341 +Node: Assert Function592271 +Node: Round Function595597 +Node: Cliff Random Function597138 +Node: Ordinal Functions598154 +Ref: Ordinal Functions-Footnote-1601231 +Ref: Ordinal Functions-Footnote-2601483 +Node: Join Function601694 +Ref: Join Function-Footnote-1603465 +Node: Getlocaltime Function603665 +Node: Readfile Function607401 +Node: Data File Management609240 +Node: Filetrans Function609872 +Node: Rewind Function613927 +Node: File Checking615314 +Ref: File Checking-Footnote-1616446 +Node: Empty Files616647 +Node: Ignoring Assigns618870 +Node: Getopt Function620401 +Ref: Getopt Function-Footnote-1631697 +Node: Passwd Functions631900 +Ref: Passwd Functions-Footnote-1640879 +Node: Group Functions640967 +Ref: Group Functions-Footnote-1648909 +Node: Walking Arrays649122 +Node: Sample Programs651258 +Node: Running Examples651932 +Node: Clones652660 +Node: Cut Program653884 +Node: Egrep Program663745 +Ref: Egrep Program-Footnote-1671674 +Node: Id Program671784 +Node: Split Program675448 +Ref: Split Program-Footnote-1678979 +Node: Tee Program679107 +Node: Uniq Program681914 +Node: Wc Program689344 +Ref: Wc Program-Footnote-1693612 +Ref: Wc Program-Footnote-2693812 +Node: Miscellaneous Programs693904 +Node: Dupword Program695092 +Node: Alarm Program697123 +Node: Translate Program701937 +Ref: Translate Program-Footnote-1706328 +Ref: Translate Program-Footnote-2706598 +Node: Labels Program706732 +Ref: Labels Program-Footnote-1710103 +Node: Word Sorting710187 +Node: History Sorting714230 +Node: Extract Program716066 +Ref: Extract Program-Footnote-1723641 +Node: Simple Sed723770 +Node: Igawk Program726832 +Ref: Igawk Program-Footnote-1742008 +Ref: Igawk Program-Footnote-2742209 +Node: Anagram Program742347 +Node: Signature Program745415 +Node: Advanced Features746662 +Node: Nondecimal Data748548 +Node: Array Sorting750125 +Node: Controlling Array Traversal750822 +Node: Array Sorting Functions759102 +Ref: Array Sorting Functions-Footnote-1763009 +Node: Two-way I/O763203 +Ref: Two-way I/O-Footnote-1768719 +Node: TCP/IP Networking768801 +Node: Profiling771645 +Node: Internationalization779153 +Node: I18N and L10N780578 +Node: Explaining gettext781264 +Ref: Explaining gettext-Footnote-1786404 +Ref: Explaining gettext-Footnote-2786588 +Node: Programmer i18n786753 +Node: Translator i18n790978 +Node: String Extraction791772 +Ref: String Extraction-Footnote-1792733 +Node: Printf Ordering792819 +Ref: Printf Ordering-Footnote-1795601 +Node: I18N Portability795665 +Ref: I18N Portability-Footnote-1798114 +Node: I18N Example798177 +Ref: I18N Example-Footnote-1800899 +Node: Gawk I18N800971 +Node: Debugger801584 +Node: Debugging802555 +Node: Debugging Concepts802996 +Node: Debugging Terms804852 +Node: Awk Debugging807449 +Node: Sample Debugging Session808341 +Node: Debugger Invocation808861 +Node: Finding The Bug810194 +Node: List of Debugger Commands816676 +Node: Breakpoint Control818008 +Node: Debugger Execution Control821672 +Node: Viewing And Changing Data825032 +Node: Execution Stack828390 +Node: Debugger Info829903 +Node: Miscellaneous Debugger Commands833897 +Node: Readline Support839081 +Node: Limitations839973 +Node: Arbitrary Precision Arithmetic842221 +Ref: Arbitrary Precision Arithmetic-Footnote-1843870 +Node: General Arithmetic844018 +Node: Floating Point Issues845738 +Node: String Conversion Precision846619 +Ref: String Conversion Precision-Footnote-1848324 +Node: Unexpected Results848433 +Node: POSIX Floating Point Problems850586 +Ref: POSIX Floating Point Problems-Footnote-1854407 +Node: Integer Programming854445 +Node: Floating-point Programming856256 +Ref: Floating-point Programming-Footnote-1862584 +Ref: Floating-point Programming-Footnote-2862854 +Node: Floating-point Representation863118 +Node: Floating-point Context864283 +Ref: table-ieee-formats865122 +Node: Rounding Mode866506 +Ref: table-rounding-modes866985 +Ref: Rounding Mode-Footnote-1870000 +Node: Gawk and MPFR870179 +Node: Arbitrary Precision Floats871588 +Ref: Arbitrary Precision Floats-Footnote-1874031 +Node: Setting Precision874352 +Ref: table-predefined-precision-strings875036 +Node: Setting Rounding Mode877181 +Ref: table-gawk-rounding-modes877585 +Node: Floating-point Constants878772 +Node: Changing Precision880224 +Ref: Changing Precision-Footnote-1881616 +Node: Exact Arithmetic881790 +Node: Arbitrary Precision Integers884924 +Ref: Arbitrary Precision Integers-Footnote-1887939 +Node: Dynamic Extensions888086 +Node: Extension Intro889544 +Node: Plugin License890809 +Node: Extension Mechanism Outline891494 +Ref: figure-load-extension891918 +Ref: figure-load-new-function893403 +Ref: figure-call-new-function894405 +Node: Extension API Description896389 +Node: Extension API Functions Introduction897839 +Node: General Data Types902705 +Ref: General Data Types-Footnote-1908398 +Node: Requesting Values908697 +Ref: table-value-types-returned909434 +Node: Memory Allocation Functions910392 +Ref: Memory Allocation Functions-Footnote-1913139 +Node: Constructor Functions913235 +Node: Registration Functions914993 +Node: Extension Functions915678 +Node: Exit Callback Functions917980 +Node: Extension Version String919230 +Node: Input Parsers919880 +Node: Output Wrappers929683 +Node: Two-way processors934199 +Node: Printing Messages936403 +Ref: Printing Messages-Footnote-1937480 +Node: Updating `ERRNO'937632 +Node: Accessing Parameters938371 +Node: Symbol Table Access939601 +Node: Symbol table by name940115 +Node: Symbol table by cookie942091 +Ref: Symbol table by cookie-Footnote-1946224 +Node: Cached values946287 +Ref: Cached values-Footnote-1949792 +Node: Array Manipulation949883 +Ref: Array Manipulation-Footnote-1950981 +Node: Array Data Types951020 +Ref: Array Data Types-Footnote-1953723 +Node: Array Functions953815 +Node: Flattening Arrays957689 +Node: Creating Arrays964541 +Node: Extension API Variables969272 +Node: Extension Versioning969908 +Node: Extension API Informational Variables971809 +Node: Extension API Boilerplate972895 +Node: Finding Extensions976699 +Node: Extension Example977259 +Node: Internal File Description977989 +Node: Internal File Ops982080 +Ref: Internal File Ops-Footnote-1993626 +Node: Using Internal File Ops993766 +Ref: Using Internal File Ops-Footnote-1996113 +Node: Extension Samples996381 +Node: Extension Sample File Functions997905 +Node: Extension Sample Fnmatch1005473 +Node: Extension Sample Fork1006940 +Node: Extension Sample Inplace1008153 +Node: Extension Sample Ord1009919 +Node: Extension Sample Readdir1010755 +Ref: table-readdir-file-types1011604 +Node: Extension Sample Revout1012403 +Node: Extension Sample Rev2way1012994 +Node: Extension Sample Read write array1013735 +Node: Extension Sample Readfile1015614 +Node: Extension Sample API Tests1016714 +Node: Extension Sample Time1017239 +Node: gawkextlib1018554 +Node: Language History1021341 +Node: V7/SVR3.11022935 +Node: SVR41025255 +Node: POSIX1026697 +Node: BTL1028083 +Node: POSIX/GNU1028817 +Node: Feature History1034416 +Node: Common Extensions1047528 +Node: Ranges and Locales1048840 +Ref: Ranges and Locales-Footnote-11053457 +Ref: Ranges and Locales-Footnote-21053484 +Ref: Ranges and Locales-Footnote-31053718 +Node: Contributors1053939 +Node: Installation1059377 +Node: Gawk Distribution1060271 +Node: Getting1060755 +Node: Extracting1061581 +Node: Distribution contents1063223 +Node: Unix Installation1068940 +Node: Quick Installation1069557 +Node: Additional Configuration Options1071999 +Node: Configuration Philosophy1073737 +Node: Non-Unix Installation1076088 +Node: PC Installation1076546 +Node: PC Binary Installation1077857 +Node: PC Compiling1079705 +Ref: PC Compiling-Footnote-11082704 +Node: PC Testing1082809 +Node: PC Using1083985 +Node: Cygwin1088143 +Node: MSYS1088952 +Node: VMS Installation1089466 +Node: VMS Compilation1090262 +Ref: VMS Compilation-Footnote-11091477 +Node: VMS Dynamic Extensions1091535 +Node: VMS Installation Details1092908 +Node: VMS Running1095154 +Node: VMS GNV1097988 +Node: VMS Old Gawk1098711 +Node: Bugs1099181 +Node: Other Versions1103185 +Node: Notes1109410 +Node: Compatibility Mode1110210 +Node: Additions1110992 +Node: Accessing The Source1111917 +Node: Adding Code1113353 +Node: New Ports1119531 +Node: Derived Files1124012 +Ref: Derived Files-Footnote-11129093 +Ref: Derived Files-Footnote-21129127 +Ref: Derived Files-Footnote-31129723 +Node: Future Extensions1129837 +Node: Implementation Limitations1130443 +Node: Extension Design1131691 +Node: Old Extension Problems1132845 +Ref: Old Extension Problems-Footnote-11134362 +Node: Extension New Mechanism Goals1134419 +Ref: Extension New Mechanism Goals-Footnote-11137780 +Node: Extension Other Design Decisions1137969 +Node: Extension Future Growth1140075 +Node: Old Extension Mechanism1140911 +Node: Basic Concepts1142651 +Node: Basic High Level1143332 +Ref: figure-general-flow1143604 +Ref: figure-process-flow1144203 +Ref: Basic High Level-Footnote-11147432 +Node: Basic Data Typing1147617 +Node: Glossary1150944 +Node: Copying1176096 +Node: GNU Free Documentation License1213652 +Node: Index1238788  End Tag Table -- cgit v1.2.3 From b6c937359a778e40a5d532c2a3aed8b21b89b3be Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 11 Jun 2014 20:28:49 +0300 Subject: More summaries. Through chapter 10. --- doc/gawk.info | 836 ++++++++++++++++++++++++++++++++++------------------------ 1 file changed, 492 insertions(+), 344 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 9d472b67..ff50955b 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -10522,6 +10522,7 @@ cannot have a variable and an array with the same name in the same * Multidimensional:: Emulating multidimensional arrays in `awk'. * Arrays of Arrays:: True multidimensional arrays. +* Arrays Summary:: Summary of arrays.  File: gawk.info, Node: Array Basics, Next: Delete, Up: Arrays @@ -11312,7 +11313,7 @@ The result is to set `separate[1]' to `"1"' and `separate[2]' to recovered.  -File: gawk.info, Node: Arrays of Arrays, Prev: Multidimensional, Up: Arrays +File: gawk.info, Node: Arrays of Arrays, Next: Arrays Summary, Prev: Multidimensional, Up: Arrays 8.6 Arrays of Arrays ==================== @@ -11433,6 +11434,54 @@ by creating an arbitrary index: $ gawk 'BEGIN { b[1][1] = ""; split("a b c d", b[1]); print b[1][1] }' -| a + +File: gawk.info, Node: Arrays Summary, Prev: Arrays of Arrays, Up: Arrays + +8.7 Summary +=========== + + * Standard `awk' provides one-dimensional associative arrays (arrays + indexed by string values). All arrays are associative; numeric + indices are converted automatically to strings. + + * Array elements are referenced as `ARRAY[INDX]'. Referencing an + element creates it if it did not exist previously. + + * The proper way to see if an array has an element with a given index + is to use the `in' operator: `INDX in ARRAY'. + + * Use `for (INDX in ARRAY) ...' to scan through all the individual + elements of an array. In the body of the loop, INDX takes on the + value of each element's index in turn. + + * The order in which a `for (INDX in ARRAY)' loop traverses an array + is undefined in POSIX `awk' and varies among implementations. + `gawk' lets you control the order by assigning special predefined + values to `PROCINFO["sorted_in"]'. + + * Use `delete ARRAY[INDX]' to delete an individual element. You may + also use `delete ARRAY' to delete all of the elements in the + array. This latter feature has been a common extension for many + years and is now standard, but may not be supported by all + commercial versions of `awk'. + + * Standard `awk' simulates multidimensional arrays by separating + subscript values with a comma. The values are concatenated into a + single string, separated by the value of `SUBSEP'. The fact that + such a subscript was created in this way is not retained; thus + changing `SUBSEP' may have unexpected consequences. You can use + `(SUB1, SUB2, ...) in ARRAY' to see if such a multidimensional + subscript exists in ARRAY. + + * `gawk' provides true arrays of arrays. You use a separate set of + square brackets for each dimension in such an array: + `data[row][col]', for example. Array elements may thus be either + scalar values (number or string) or another array. + + * Use the `isarray()' built-in function to determine if an array + element is itself a subarray. + +  File: gawk.info, Node: Functions, Next: Library Functions, Prev: Arrays, Up: Top @@ -11453,6 +11502,7 @@ major node describes these "user-defined" functions. * Built-in:: Summarizes the built-in functions. * User-defined:: Describes User-defined functions in detail. * Indirect Calls:: Choosing the function to call at runtime. +* Functions Summary:: Summary of functions.  File: gawk.info, Node: Built-in, Next: User-defined, Up: Functions @@ -13652,7 +13702,7 @@ call, though, then `awk' does report the second error. of them.  -File: gawk.info, Node: Indirect Calls, Prev: User-defined, Up: Functions +File: gawk.info, Node: Indirect Calls, Next: Functions Summary, Prev: User-defined, Up: Functions 9.3 Indirect Function Calls =========================== @@ -13939,6 +13989,63 @@ example, in the following case: `gawk' will look up the actual function to call only once. + +File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions + +9.4 Summary +=========== + + * `awk' provides built-in functions and lets you define your own + functions. + + * POSIX `awk' provides three kinds of built-in functions: numeric, + string, and I/O. `gawk' provides functions that work with values + representing time, do bit manipulation, sort arrays, and + internationalize and localize programs. `gawk' also provides + several extensions to some of standard functions, typically in the + form of additional arguments. + + * Functions accept zero or more arguments and return a value. The + expressions that provide the argument values are comnpletely + evaluated before the function is called. Order of evaluation is + not defined. The return value can be ignored. + + * The handling of backslash in `sub()' and `gsub()' is not simple. + It is more straightforward in `gawk''s `gensub()' function, but + that function still requires care in its use. + + * User-defined functions provide important capabilities but come + with some syntactic inelegancies. In a function call, there cannot + be any space between the function name and the opening left + parethesis of the argument list. Also, there is no provision for + local variables, so the convention is to add extra parameters, and + to separate them visually from the real parameters by extra + whitespace. + + * User-defined functions may call other user-defined (and built-in) + functions and may call themselves recursively. Function parameters + "hide" any global variables of the same names. + + * Scalar values are passed to user-defined functions by value. Array + parameters are passed by reference; any changes made by the + function to array parameters are thus visible after the function + has returned. + + * Use the `return' statement to return from a user-defined function. + An optional expression becomes the function's return value. Only + scalar values may be returned by a function. + + * If a variable that has never been used is passed to a user-defined + function, how that function treats the variable can set its + nature: either scalar or array. + + * `gawk' provides indirect function calls using a special syntax. + By setting a variable to the name of a user-defined function, you + can determine at runtime what function will be called at that + point in the program. This is equivalent to function pointers in C + and C++. + +  File: gawk.info, Node: Library Functions, Next: Sample Programs, Prev: Functions, Up: Top @@ -14015,6 +14122,7 @@ for different implementations of `awk' is pretty straightforward. * Passwd Functions:: Functions for getting user information. * Group Functions:: Functions for getting group information. * Walking Arrays:: A function to walk arrays of arrays. +* Library Functions Summary:: Summary of library functions. ---------- Footnotes ---------- @@ -14912,8 +15020,8 @@ intervening value in `ARGV' is a variable assignment.  File: gawk.info, Node: Ignoring Assigns, Prev: Empty Files, Up: Data File Management -10.3.5 Treating Assignments as File Name ----------------------------------------- +10.3.5 Treating Assignments as File Names +----------------------------------------- Occasionally, you might not want `awk' to process command-line variable assignments (*note Assignment Options::). In particular, if you have a @@ -15727,7 +15835,7 @@ Suppose that the first time there were no names. This code adds the names with a leading comma. It also doesn't check that there is a `$4'.  -File: gawk.info, Node: Walking Arrays, Prev: Group Functions, Up: Library Functions +File: gawk.info, Node: Walking Arrays, Next: Library Functions Summary, Prev: Group Functions, Up: Library Functions 10.7 Traversing Arrays of Arrays ================================ @@ -15789,6 +15897,43 @@ Calls::) on `process', passing it the index and the value. user-defined function that expects to receive an index and a value, and then processes the element. + +File: gawk.info, Node: Library Functions Summary, Prev: Walking Arrays, Up: Library Functions + +10.8 Summary +============ + + * Reading programs is an excellent way to learn Good Programming. + The functions provided in this major node and the next are intended + to serve that purpose. + + * When writing general-purpose library functions, put some thought + into how to name any global variables so that they won't conflict + with variables from a user's program. + + * The functions presented here fit into the following categories: + + General problems + Number to string conversion, assertions, rounding, random + number generation, converting characters to numbers, joining + strings, getting easily usable time-of-day information, and + reading a whole file in one shot. + + Managing data files + Noting data file boundaries, rereading the current file, + checking for readable files, checking for zero-length files, + and treating assignments as file names. + + Processing command-line options + An `awk' version of the standard C `getopt()' function. + + Reading the user and group databases + Two sets of routines that parallel the C library versions. + + Traversing arrays of arrays + A simple function to traverse an array of arrays to any depth. + +  File: gawk.info, Node: Sample Programs, Next: Advanced Features, Prev: Library Functions, Up: Top @@ -19868,8 +20013,8 @@ File: gawk.info, Node: Gawk I18N, Prev: I18N Example, Up: Internationalizatio `gawk' itself has been internationalized using the GNU `gettext' package. (GNU `gettext' is described in complete detail in *note (GNU `gettext' utilities)Top:: gettext, GNU gettext tools.) As of this -writing, the latest version of GNU `gettext' is version 0.19 -(ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.tar.gz). +writing, the latest version of GNU `gettext' is version 0.19.1 +(ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.1.tar.gz). If a translation of `gawk''s messages exists, then `gawk' produces usage messages, warnings, and fatal errors in the local language. @@ -33737,342 +33882,345 @@ Ref: Auto-set-Footnote-2441927 Node: ARGC and ARGV441983 Node: Pattern Action Summary445822 Node: Arrays448045 -Node: Array Basics449543 -Node: Array Intro450369 -Ref: figure-array-elements452342 -Node: Reference to Elements454749 -Node: Assigning Elements457022 -Node: Array Example457513 -Node: Scanning an Array459245 -Node: Controlling Scanning462260 -Ref: Controlling Scanning-Footnote-1467433 -Node: Delete467749 -Ref: Delete-Footnote-1470514 -Node: Numeric Array Subscripts470571 -Node: Uninitialized Subscripts472754 -Node: Multidimensional474379 -Node: Multiscanning477472 -Node: Arrays of Arrays479061 -Node: Functions483701 -Node: Built-in484520 -Node: Calling Built-in485598 -Node: Numeric Functions487586 -Ref: Numeric Functions-Footnote-1491420 -Ref: Numeric Functions-Footnote-2491777 -Ref: Numeric Functions-Footnote-3491825 -Node: String Functions492094 -Ref: String Functions-Footnote-1515105 -Ref: String Functions-Footnote-2515234 -Ref: String Functions-Footnote-3515482 -Node: Gory Details515569 -Ref: table-sub-escapes517238 -Ref: table-sub-posix-92518592 -Ref: table-sub-proposed519943 -Ref: table-posix-sub521297 -Ref: table-gensub-escapes522842 -Ref: Gory Details-Footnote-1524018 -Ref: Gory Details-Footnote-2524069 -Node: I/O Functions524220 -Ref: I/O Functions-Footnote-1531343 -Node: Time Functions531490 -Ref: Time Functions-Footnote-1541954 -Ref: Time Functions-Footnote-2542022 -Ref: Time Functions-Footnote-3542180 -Ref: Time Functions-Footnote-4542291 -Ref: Time Functions-Footnote-5542403 -Ref: Time Functions-Footnote-6542630 -Node: Bitwise Functions542896 -Ref: table-bitwise-ops543458 -Ref: Bitwise Functions-Footnote-1547703 -Node: Type Functions547887 -Node: I18N Functions549029 -Node: User-defined550674 -Node: Definition Syntax551478 -Ref: Definition Syntax-Footnote-1556403 -Node: Function Example556472 -Ref: Function Example-Footnote-1559116 -Node: Function Caveats559138 -Node: Calling A Function559656 -Node: Variable Scope560611 -Node: Pass By Value/Reference563599 -Node: Return Statement567107 -Node: Dynamic Typing570091 -Node: Indirect Calls571020 -Node: Library Functions580707 -Ref: Library Functions-Footnote-1584220 -Ref: Library Functions-Footnote-2584363 -Node: Library Names584534 -Ref: Library Names-Footnote-1588007 -Ref: Library Names-Footnote-2588227 -Node: General Functions588313 -Node: Strtonum Function589341 -Node: Assert Function592271 -Node: Round Function595597 -Node: Cliff Random Function597138 -Node: Ordinal Functions598154 -Ref: Ordinal Functions-Footnote-1601231 -Ref: Ordinal Functions-Footnote-2601483 -Node: Join Function601694 -Ref: Join Function-Footnote-1603465 -Node: Getlocaltime Function603665 -Node: Readfile Function607401 -Node: Data File Management609240 -Node: Filetrans Function609872 -Node: Rewind Function613927 -Node: File Checking615314 -Ref: File Checking-Footnote-1616446 -Node: Empty Files616647 -Node: Ignoring Assigns618870 -Node: Getopt Function620401 -Ref: Getopt Function-Footnote-1631697 -Node: Passwd Functions631900 -Ref: Passwd Functions-Footnote-1640879 -Node: Group Functions640967 -Ref: Group Functions-Footnote-1648909 -Node: Walking Arrays649122 -Node: Sample Programs651258 -Node: Running Examples651932 -Node: Clones652660 -Node: Cut Program653884 -Node: Egrep Program663745 -Ref: Egrep Program-Footnote-1671674 -Node: Id Program671784 -Node: Split Program675448 -Ref: Split Program-Footnote-1678979 -Node: Tee Program679107 -Node: Uniq Program681914 -Node: Wc Program689344 -Ref: Wc Program-Footnote-1693612 -Ref: Wc Program-Footnote-2693812 -Node: Miscellaneous Programs693904 -Node: Dupword Program695092 -Node: Alarm Program697123 -Node: Translate Program701937 -Ref: Translate Program-Footnote-1706328 -Ref: Translate Program-Footnote-2706598 -Node: Labels Program706732 -Ref: Labels Program-Footnote-1710103 -Node: Word Sorting710187 -Node: History Sorting714230 -Node: Extract Program716066 -Ref: Extract Program-Footnote-1723641 -Node: Simple Sed723770 -Node: Igawk Program726832 -Ref: Igawk Program-Footnote-1742008 -Ref: Igawk Program-Footnote-2742209 -Node: Anagram Program742347 -Node: Signature Program745415 -Node: Advanced Features746662 -Node: Nondecimal Data748548 -Node: Array Sorting750125 -Node: Controlling Array Traversal750822 -Node: Array Sorting Functions759102 -Ref: Array Sorting Functions-Footnote-1763009 -Node: Two-way I/O763203 -Ref: Two-way I/O-Footnote-1768719 -Node: TCP/IP Networking768801 -Node: Profiling771645 -Node: Internationalization779153 -Node: I18N and L10N780578 -Node: Explaining gettext781264 -Ref: Explaining gettext-Footnote-1786404 -Ref: Explaining gettext-Footnote-2786588 -Node: Programmer i18n786753 -Node: Translator i18n790978 -Node: String Extraction791772 -Ref: String Extraction-Footnote-1792733 -Node: Printf Ordering792819 -Ref: Printf Ordering-Footnote-1795601 -Node: I18N Portability795665 -Ref: I18N Portability-Footnote-1798114 -Node: I18N Example798177 -Ref: I18N Example-Footnote-1800899 -Node: Gawk I18N800971 -Node: Debugger801584 -Node: Debugging802555 -Node: Debugging Concepts802996 -Node: Debugging Terms804852 -Node: Awk Debugging807449 -Node: Sample Debugging Session808341 -Node: Debugger Invocation808861 -Node: Finding The Bug810194 -Node: List of Debugger Commands816676 -Node: Breakpoint Control818008 -Node: Debugger Execution Control821672 -Node: Viewing And Changing Data825032 -Node: Execution Stack828390 -Node: Debugger Info829903 -Node: Miscellaneous Debugger Commands833897 -Node: Readline Support839081 -Node: Limitations839973 -Node: Arbitrary Precision Arithmetic842221 -Ref: Arbitrary Precision Arithmetic-Footnote-1843870 -Node: General Arithmetic844018 -Node: Floating Point Issues845738 -Node: String Conversion Precision846619 -Ref: String Conversion Precision-Footnote-1848324 -Node: Unexpected Results848433 -Node: POSIX Floating Point Problems850586 -Ref: POSIX Floating Point Problems-Footnote-1854407 -Node: Integer Programming854445 -Node: Floating-point Programming856256 -Ref: Floating-point Programming-Footnote-1862584 -Ref: Floating-point Programming-Footnote-2862854 -Node: Floating-point Representation863118 -Node: Floating-point Context864283 -Ref: table-ieee-formats865122 -Node: Rounding Mode866506 -Ref: table-rounding-modes866985 -Ref: Rounding Mode-Footnote-1870000 -Node: Gawk and MPFR870179 -Node: Arbitrary Precision Floats871588 -Ref: Arbitrary Precision Floats-Footnote-1874031 -Node: Setting Precision874352 -Ref: table-predefined-precision-strings875036 -Node: Setting Rounding Mode877181 -Ref: table-gawk-rounding-modes877585 -Node: Floating-point Constants878772 -Node: Changing Precision880224 -Ref: Changing Precision-Footnote-1881616 -Node: Exact Arithmetic881790 -Node: Arbitrary Precision Integers884924 -Ref: Arbitrary Precision Integers-Footnote-1887939 -Node: Dynamic Extensions888086 -Node: Extension Intro889544 -Node: Plugin License890809 -Node: Extension Mechanism Outline891494 -Ref: figure-load-extension891918 -Ref: figure-load-new-function893403 -Ref: figure-call-new-function894405 -Node: Extension API Description896389 -Node: Extension API Functions Introduction897839 -Node: General Data Types902705 -Ref: General Data Types-Footnote-1908398 -Node: Requesting Values908697 -Ref: table-value-types-returned909434 -Node: Memory Allocation Functions910392 -Ref: Memory Allocation Functions-Footnote-1913139 -Node: Constructor Functions913235 -Node: Registration Functions914993 -Node: Extension Functions915678 -Node: Exit Callback Functions917980 -Node: Extension Version String919230 -Node: Input Parsers919880 -Node: Output Wrappers929683 -Node: Two-way processors934199 -Node: Printing Messages936403 -Ref: Printing Messages-Footnote-1937480 -Node: Updating `ERRNO'937632 -Node: Accessing Parameters938371 -Node: Symbol Table Access939601 -Node: Symbol table by name940115 -Node: Symbol table by cookie942091 -Ref: Symbol table by cookie-Footnote-1946224 -Node: Cached values946287 -Ref: Cached values-Footnote-1949792 -Node: Array Manipulation949883 -Ref: Array Manipulation-Footnote-1950981 -Node: Array Data Types951020 -Ref: Array Data Types-Footnote-1953723 -Node: Array Functions953815 -Node: Flattening Arrays957689 -Node: Creating Arrays964541 -Node: Extension API Variables969272 -Node: Extension Versioning969908 -Node: Extension API Informational Variables971809 -Node: Extension API Boilerplate972895 -Node: Finding Extensions976699 -Node: Extension Example977259 -Node: Internal File Description977989 -Node: Internal File Ops982080 -Ref: Internal File Ops-Footnote-1993626 -Node: Using Internal File Ops993766 -Ref: Using Internal File Ops-Footnote-1996113 -Node: Extension Samples996381 -Node: Extension Sample File Functions997905 -Node: Extension Sample Fnmatch1005473 -Node: Extension Sample Fork1006940 -Node: Extension Sample Inplace1008153 -Node: Extension Sample Ord1009919 -Node: Extension Sample Readdir1010755 -Ref: table-readdir-file-types1011604 -Node: Extension Sample Revout1012403 -Node: Extension Sample Rev2way1012994 -Node: Extension Sample Read write array1013735 -Node: Extension Sample Readfile1015614 -Node: Extension Sample API Tests1016714 -Node: Extension Sample Time1017239 -Node: gawkextlib1018554 -Node: Language History1021341 -Node: V7/SVR3.11022935 -Node: SVR41025255 -Node: POSIX1026697 -Node: BTL1028083 -Node: POSIX/GNU1028817 -Node: Feature History1034416 -Node: Common Extensions1047528 -Node: Ranges and Locales1048840 -Ref: Ranges and Locales-Footnote-11053457 -Ref: Ranges and Locales-Footnote-21053484 -Ref: Ranges and Locales-Footnote-31053718 -Node: Contributors1053939 -Node: Installation1059377 -Node: Gawk Distribution1060271 -Node: Getting1060755 -Node: Extracting1061581 -Node: Distribution contents1063223 -Node: Unix Installation1068940 -Node: Quick Installation1069557 -Node: Additional Configuration Options1071999 -Node: Configuration Philosophy1073737 -Node: Non-Unix Installation1076088 -Node: PC Installation1076546 -Node: PC Binary Installation1077857 -Node: PC Compiling1079705 -Ref: PC Compiling-Footnote-11082704 -Node: PC Testing1082809 -Node: PC Using1083985 -Node: Cygwin1088143 -Node: MSYS1088952 -Node: VMS Installation1089466 -Node: VMS Compilation1090262 -Ref: VMS Compilation-Footnote-11091477 -Node: VMS Dynamic Extensions1091535 -Node: VMS Installation Details1092908 -Node: VMS Running1095154 -Node: VMS GNV1097988 -Node: VMS Old Gawk1098711 -Node: Bugs1099181 -Node: Other Versions1103185 -Node: Notes1109410 -Node: Compatibility Mode1110210 -Node: Additions1110992 -Node: Accessing The Source1111917 -Node: Adding Code1113353 -Node: New Ports1119531 -Node: Derived Files1124012 -Ref: Derived Files-Footnote-11129093 -Ref: Derived Files-Footnote-21129127 -Ref: Derived Files-Footnote-31129723 -Node: Future Extensions1129837 -Node: Implementation Limitations1130443 -Node: Extension Design1131691 -Node: Old Extension Problems1132845 -Ref: Old Extension Problems-Footnote-11134362 -Node: Extension New Mechanism Goals1134419 -Ref: Extension New Mechanism Goals-Footnote-11137780 -Node: Extension Other Design Decisions1137969 -Node: Extension Future Growth1140075 -Node: Old Extension Mechanism1140911 -Node: Basic Concepts1142651 -Node: Basic High Level1143332 -Ref: figure-general-flow1143604 -Ref: figure-process-flow1144203 -Ref: Basic High Level-Footnote-11147432 -Node: Basic Data Typing1147617 -Node: Glossary1150944 -Node: Copying1176096 -Node: GNU Free Documentation License1213652 -Node: Index1238788 +Node: Array Basics449594 +Node: Array Intro450420 +Ref: figure-array-elements452393 +Node: Reference to Elements454800 +Node: Assigning Elements457073 +Node: Array Example457564 +Node: Scanning an Array459296 +Node: Controlling Scanning462311 +Ref: Controlling Scanning-Footnote-1467484 +Node: Delete467800 +Ref: Delete-Footnote-1470565 +Node: Numeric Array Subscripts470622 +Node: Uninitialized Subscripts472805 +Node: Multidimensional474430 +Node: Multiscanning477523 +Node: Arrays of Arrays479112 +Node: Arrays Summary483775 +Node: Functions485880 +Node: Built-in486753 +Node: Calling Built-in487831 +Node: Numeric Functions489819 +Ref: Numeric Functions-Footnote-1493653 +Ref: Numeric Functions-Footnote-2494010 +Ref: Numeric Functions-Footnote-3494058 +Node: String Functions494327 +Ref: String Functions-Footnote-1517338 +Ref: String Functions-Footnote-2517467 +Ref: String Functions-Footnote-3517715 +Node: Gory Details517802 +Ref: table-sub-escapes519471 +Ref: table-sub-posix-92520825 +Ref: table-sub-proposed522176 +Ref: table-posix-sub523530 +Ref: table-gensub-escapes525075 +Ref: Gory Details-Footnote-1526251 +Ref: Gory Details-Footnote-2526302 +Node: I/O Functions526453 +Ref: I/O Functions-Footnote-1533576 +Node: Time Functions533723 +Ref: Time Functions-Footnote-1544187 +Ref: Time Functions-Footnote-2544255 +Ref: Time Functions-Footnote-3544413 +Ref: Time Functions-Footnote-4544524 +Ref: Time Functions-Footnote-5544636 +Ref: Time Functions-Footnote-6544863 +Node: Bitwise Functions545129 +Ref: table-bitwise-ops545691 +Ref: Bitwise Functions-Footnote-1549936 +Node: Type Functions550120 +Node: I18N Functions551262 +Node: User-defined552907 +Node: Definition Syntax553711 +Ref: Definition Syntax-Footnote-1558636 +Node: Function Example558705 +Ref: Function Example-Footnote-1561349 +Node: Function Caveats561371 +Node: Calling A Function561889 +Node: Variable Scope562844 +Node: Pass By Value/Reference565832 +Node: Return Statement569340 +Node: Dynamic Typing572324 +Node: Indirect Calls573253 +Node: Functions Summary582966 +Node: Library Functions585505 +Ref: Library Functions-Footnote-1589080 +Ref: Library Functions-Footnote-2589223 +Node: Library Names589394 +Ref: Library Names-Footnote-1592867 +Ref: Library Names-Footnote-2593087 +Node: General Functions593173 +Node: Strtonum Function594201 +Node: Assert Function597131 +Node: Round Function600457 +Node: Cliff Random Function601998 +Node: Ordinal Functions603014 +Ref: Ordinal Functions-Footnote-1606091 +Ref: Ordinal Functions-Footnote-2606343 +Node: Join Function606554 +Ref: Join Function-Footnote-1608325 +Node: Getlocaltime Function608525 +Node: Readfile Function612261 +Node: Data File Management614100 +Node: Filetrans Function614732 +Node: Rewind Function618787 +Node: File Checking620174 +Ref: File Checking-Footnote-1621306 +Node: Empty Files621507 +Node: Ignoring Assigns623730 +Node: Getopt Function625263 +Ref: Getopt Function-Footnote-1636559 +Node: Passwd Functions636762 +Ref: Passwd Functions-Footnote-1645741 +Node: Group Functions645829 +Ref: Group Functions-Footnote-1653771 +Node: Walking Arrays653984 +Node: Library Functions Summary656154 +Node: Sample Programs657516 +Node: Running Examples658190 +Node: Clones658918 +Node: Cut Program660142 +Node: Egrep Program670003 +Ref: Egrep Program-Footnote-1677932 +Node: Id Program678042 +Node: Split Program681706 +Ref: Split Program-Footnote-1685237 +Node: Tee Program685365 +Node: Uniq Program688172 +Node: Wc Program695602 +Ref: Wc Program-Footnote-1699870 +Ref: Wc Program-Footnote-2700070 +Node: Miscellaneous Programs700162 +Node: Dupword Program701350 +Node: Alarm Program703381 +Node: Translate Program708195 +Ref: Translate Program-Footnote-1712586 +Ref: Translate Program-Footnote-2712856 +Node: Labels Program712990 +Ref: Labels Program-Footnote-1716361 +Node: Word Sorting716445 +Node: History Sorting720488 +Node: Extract Program722324 +Ref: Extract Program-Footnote-1729899 +Node: Simple Sed730028 +Node: Igawk Program733090 +Ref: Igawk Program-Footnote-1748266 +Ref: Igawk Program-Footnote-2748467 +Node: Anagram Program748605 +Node: Signature Program751673 +Node: Advanced Features752920 +Node: Nondecimal Data754806 +Node: Array Sorting756383 +Node: Controlling Array Traversal757080 +Node: Array Sorting Functions765360 +Ref: Array Sorting Functions-Footnote-1769267 +Node: Two-way I/O769461 +Ref: Two-way I/O-Footnote-1774977 +Node: TCP/IP Networking775059 +Node: Profiling777903 +Node: Internationalization785411 +Node: I18N and L10N786836 +Node: Explaining gettext787522 +Ref: Explaining gettext-Footnote-1792662 +Ref: Explaining gettext-Footnote-2792846 +Node: Programmer i18n793011 +Node: Translator i18n797236 +Node: String Extraction798030 +Ref: String Extraction-Footnote-1798991 +Node: Printf Ordering799077 +Ref: Printf Ordering-Footnote-1801859 +Node: I18N Portability801923 +Ref: I18N Portability-Footnote-1804372 +Node: I18N Example804435 +Ref: I18N Example-Footnote-1807157 +Node: Gawk I18N807229 +Node: Debugger807846 +Node: Debugging808817 +Node: Debugging Concepts809258 +Node: Debugging Terms811114 +Node: Awk Debugging813711 +Node: Sample Debugging Session814603 +Node: Debugger Invocation815123 +Node: Finding The Bug816456 +Node: List of Debugger Commands822938 +Node: Breakpoint Control824270 +Node: Debugger Execution Control827934 +Node: Viewing And Changing Data831294 +Node: Execution Stack834652 +Node: Debugger Info836165 +Node: Miscellaneous Debugger Commands840159 +Node: Readline Support845343 +Node: Limitations846235 +Node: Arbitrary Precision Arithmetic848483 +Ref: Arbitrary Precision Arithmetic-Footnote-1850132 +Node: General Arithmetic850280 +Node: Floating Point Issues852000 +Node: String Conversion Precision852881 +Ref: String Conversion Precision-Footnote-1854586 +Node: Unexpected Results854695 +Node: POSIX Floating Point Problems856848 +Ref: POSIX Floating Point Problems-Footnote-1860669 +Node: Integer Programming860707 +Node: Floating-point Programming862518 +Ref: Floating-point Programming-Footnote-1868846 +Ref: Floating-point Programming-Footnote-2869116 +Node: Floating-point Representation869380 +Node: Floating-point Context870545 +Ref: table-ieee-formats871384 +Node: Rounding Mode872768 +Ref: table-rounding-modes873247 +Ref: Rounding Mode-Footnote-1876262 +Node: Gawk and MPFR876441 +Node: Arbitrary Precision Floats877850 +Ref: Arbitrary Precision Floats-Footnote-1880293 +Node: Setting Precision880614 +Ref: table-predefined-precision-strings881298 +Node: Setting Rounding Mode883443 +Ref: table-gawk-rounding-modes883847 +Node: Floating-point Constants885034 +Node: Changing Precision886486 +Ref: Changing Precision-Footnote-1887878 +Node: Exact Arithmetic888052 +Node: Arbitrary Precision Integers891186 +Ref: Arbitrary Precision Integers-Footnote-1894201 +Node: Dynamic Extensions894348 +Node: Extension Intro895806 +Node: Plugin License897071 +Node: Extension Mechanism Outline897756 +Ref: figure-load-extension898180 +Ref: figure-load-new-function899665 +Ref: figure-call-new-function900667 +Node: Extension API Description902651 +Node: Extension API Functions Introduction904101 +Node: General Data Types908967 +Ref: General Data Types-Footnote-1914660 +Node: Requesting Values914959 +Ref: table-value-types-returned915696 +Node: Memory Allocation Functions916654 +Ref: Memory Allocation Functions-Footnote-1919401 +Node: Constructor Functions919497 +Node: Registration Functions921255 +Node: Extension Functions921940 +Node: Exit Callback Functions924242 +Node: Extension Version String925492 +Node: Input Parsers926142 +Node: Output Wrappers935945 +Node: Two-way processors940461 +Node: Printing Messages942665 +Ref: Printing Messages-Footnote-1943742 +Node: Updating `ERRNO'943894 +Node: Accessing Parameters944633 +Node: Symbol Table Access945863 +Node: Symbol table by name946377 +Node: Symbol table by cookie948353 +Ref: Symbol table by cookie-Footnote-1952486 +Node: Cached values952549 +Ref: Cached values-Footnote-1956054 +Node: Array Manipulation956145 +Ref: Array Manipulation-Footnote-1957243 +Node: Array Data Types957282 +Ref: Array Data Types-Footnote-1959985 +Node: Array Functions960077 +Node: Flattening Arrays963951 +Node: Creating Arrays970803 +Node: Extension API Variables975534 +Node: Extension Versioning976170 +Node: Extension API Informational Variables978071 +Node: Extension API Boilerplate979157 +Node: Finding Extensions982961 +Node: Extension Example983521 +Node: Internal File Description984251 +Node: Internal File Ops988342 +Ref: Internal File Ops-Footnote-1999888 +Node: Using Internal File Ops1000028 +Ref: Using Internal File Ops-Footnote-11002375 +Node: Extension Samples1002643 +Node: Extension Sample File Functions1004167 +Node: Extension Sample Fnmatch1011735 +Node: Extension Sample Fork1013202 +Node: Extension Sample Inplace1014415 +Node: Extension Sample Ord1016181 +Node: Extension Sample Readdir1017017 +Ref: table-readdir-file-types1017866 +Node: Extension Sample Revout1018665 +Node: Extension Sample Rev2way1019256 +Node: Extension Sample Read write array1019997 +Node: Extension Sample Readfile1021876 +Node: Extension Sample API Tests1022976 +Node: Extension Sample Time1023501 +Node: gawkextlib1024816 +Node: Language History1027603 +Node: V7/SVR3.11029197 +Node: SVR41031517 +Node: POSIX1032959 +Node: BTL1034345 +Node: POSIX/GNU1035079 +Node: Feature History1040678 +Node: Common Extensions1053790 +Node: Ranges and Locales1055102 +Ref: Ranges and Locales-Footnote-11059719 +Ref: Ranges and Locales-Footnote-21059746 +Ref: Ranges and Locales-Footnote-31059980 +Node: Contributors1060201 +Node: Installation1065639 +Node: Gawk Distribution1066533 +Node: Getting1067017 +Node: Extracting1067843 +Node: Distribution contents1069485 +Node: Unix Installation1075202 +Node: Quick Installation1075819 +Node: Additional Configuration Options1078261 +Node: Configuration Philosophy1079999 +Node: Non-Unix Installation1082350 +Node: PC Installation1082808 +Node: PC Binary Installation1084119 +Node: PC Compiling1085967 +Ref: PC Compiling-Footnote-11088966 +Node: PC Testing1089071 +Node: PC Using1090247 +Node: Cygwin1094405 +Node: MSYS1095214 +Node: VMS Installation1095728 +Node: VMS Compilation1096524 +Ref: VMS Compilation-Footnote-11097739 +Node: VMS Dynamic Extensions1097797 +Node: VMS Installation Details1099170 +Node: VMS Running1101416 +Node: VMS GNV1104250 +Node: VMS Old Gawk1104973 +Node: Bugs1105443 +Node: Other Versions1109447 +Node: Notes1115672 +Node: Compatibility Mode1116472 +Node: Additions1117254 +Node: Accessing The Source1118179 +Node: Adding Code1119615 +Node: New Ports1125793 +Node: Derived Files1130274 +Ref: Derived Files-Footnote-11135355 +Ref: Derived Files-Footnote-21135389 +Ref: Derived Files-Footnote-31135985 +Node: Future Extensions1136099 +Node: Implementation Limitations1136705 +Node: Extension Design1137953 +Node: Old Extension Problems1139107 +Ref: Old Extension Problems-Footnote-11140624 +Node: Extension New Mechanism Goals1140681 +Ref: Extension New Mechanism Goals-Footnote-11144042 +Node: Extension Other Design Decisions1144231 +Node: Extension Future Growth1146337 +Node: Old Extension Mechanism1147173 +Node: Basic Concepts1148913 +Node: Basic High Level1149594 +Ref: figure-general-flow1149866 +Ref: figure-process-flow1150465 +Ref: Basic High Level-Footnote-11153694 +Node: Basic Data Typing1153879 +Node: Glossary1157206 +Node: Copying1182358 +Node: GNU Free Documentation License1219914 +Node: Index1245050  End Tag Table -- cgit v1.2.3 From 4a42ca2e31b40f0d46634f9ab77d82e4fe727c22 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 12 Jun 2014 22:01:31 +0300 Subject: And more summaries in the doc. --- doc/gawk.info | 648 +++++++++++++++++++++++++++++++++++----------------------- 1 file changed, 396 insertions(+), 252 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index ff50955b..9033128e 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -14014,9 +14014,9 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions It is more straightforward in `gawk''s `gensub()' function, but that function still requires care in its use. - * User-defined functions provide important capabilities but come - with some syntactic inelegancies. In a function call, there cannot - be any space between the function name and the opening left + * User-defined functions provide important capabilities but come with + some syntactic inelegancies. In a function call, there cannot be + any space between the function name and the opening left parethesis of the argument list. Also, there is no provision for local variables, so the convention is to add extra parameters, and to separate them visually from the real parameters by extra @@ -14036,8 +14036,8 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions scalar values may be returned by a function. * If a variable that has never been used is passed to a user-defined - function, how that function treats the variable can set its - nature: either scalar or array. + function, how that function treats the variable can set its nature: + either scalar or array. * `gawk' provides indirect function calls using a special syntax. By setting a variable to the name of a user-defined function, you @@ -15953,6 +15953,7 @@ Library Functions::. * Running Examples:: How to run these examples. * Clones:: Clones of common utilities. * Miscellaneous Programs:: Some interesting `awk' programs. +* Programs Summary:: Summary of programs.  File: gawk.info, Node: Running Examples, Next: Clones, Up: Sample Programs @@ -17168,7 +17169,7 @@ has already been reset by the time `endfile()' is called. characters, not bytes.  -File: gawk.info, Node: Miscellaneous Programs, Prev: Clones, Up: Sample Programs +File: gawk.info, Node: Miscellaneous Programs, Next: Programs Summary, Prev: Clones, Up: Sample Programs 11.3 A Grab Bag of `awk' Programs ================================= @@ -18563,6 +18564,36 @@ supplies the following copyright terms: truly desperate to understand it, see Chris Johansen's explanation, which is embedded in the Texinfo source file for this Info file.) + +File: gawk.info, Node: Programs Summary, Prev: Miscellaneous Programs, Up: Sample Programs + +11.4 Summary +============ + + * The functions provided in this major node and the previous one + continue on the theme that reading programs is an excellent way to + learn Good Programming. + + * Using `#!' to make `awk' programs directly runnable makes them + easier to use. Otherwise, invoke the program using `awk -f ...'. + + * Reimplementing standard POSIX programs in `awk' is a pleasant + exercise; `awk''s expressive power lets you write such programs in + relatively few lines of code, yet they are functionally complete + and usable. + + * One of standard `awk''s weaknesses is working with individual + characters. The ability to use `split()' with the empty string as + the separator can considerably simplify such tasks. + + * The library functions from *note Library Functions::, proved their + usefulness for a number of real (if small) programs. + + * Besides reinventing POSIX wheels, other programs solved a + selection of interesting problems, such as finding duplicates + words in text, printing mailing labels, and finding anagrams. + +  File: gawk.info, Node: Advanced Features, Next: Internationalization, Prev: Sample Programs, Up: Top @@ -18607,6 +18638,7 @@ own: * Two-way I/O:: Two-way communications with another process. * TCP/IP Networking:: Using `gawk' for network programming. * Profiling:: Profiling your `awk' programs. +* Advanced Features Summary:: Summary of advanced features.  File: gawk.info, Node: Nondecimal Data, Next: Array Sorting, Up: Advanced Features @@ -19209,7 +19241,7 @@ much more complete introduction and discussion, as well as extensive examples.  -File: gawk.info, Node: Profiling, Prev: TCP/IP Networking, Up: Advanced Features +File: gawk.info, Node: Profiling, Next: Advanced Features Summary, Prev: TCP/IP Networking, Up: Advanced Features 12.5 Profiling Your `awk' Programs ================================== @@ -19437,6 +19469,48 @@ without any execution counts. NOTE: The `--pretty-print' option still runs your program. This will change in the next major release. + +File: gawk.info, Node: Advanced Features Summary, Prev: Profiling, Up: Advanced Features + +12.6 Summary +============ + + * The `--non-decimal-data' option causes `gawk' to treat octal- and + hexadecimal-looking input data as octal and hexadecimal. This + option should be used with caution or not at all; use of + `strtonum()' is preferable. + + * You can take over complete control of sorting in `for (INDX in + ARRAY)' array traversal by setting `PROCINFO["sorted_in"]' to the + name of a user-defined function that does the comparison of array + elements based on index and value. + + * Similarly, you can supply the name of a user-defined comparison + function as the third argument to either `asort()' or `asorti()' + to control how those functions sort arrays. Or you may provide one + of the predefined control strings that work for + `PROCINFO["sorted_in"]'. + + * You can use the `|&' operator to create a two-way pipe to a + co-process. You read from the co-process with `getline' and write + to it with `print' or `printf'. Use `close()' to close off the + co-process completely, or optionally, close off one side of the + two-way communications. + + * By using special "file names" with the `|&' operator, you can open + a TCP/IP (or UDP/IP) connection to remote hosts in the Internet. + `gawk' supports both IPv4 an IPv6. + + * You can generate statement count profiles of your program. This + can help you determine which parts of your program may be taking + the most time and let you tune them more easily. Sending the + `USR1' signal while profiling causes `gawk' to dump the profile + and keep going, including a function call stack. + + * You can also just "pretty print" the program. This currently also + runs the program, but that will change in the next major release. + +  File: gawk.info, Node: Internationalization, Next: Debugger, Prev: Advanced Features, Up: Top @@ -19467,6 +19541,7 @@ requirement. * Translator i18n:: Features for the translator. * I18N Example:: A simple i18n example. * Gawk I18N:: `gawk' is also internationalized. +* I18N Summary:: Summary of I18N stuff.  File: gawk.info, Node: I18N and L10N, Next: Explaining gettext, Up: Internationalization @@ -20005,7 +20080,7 @@ and `bindtextdomain()' (*note I18N Portability::) are in a file named (1) Perhaps it would be better if it were called "Hippy." Ah, well.  -File: gawk.info, Node: Gawk I18N, Prev: I18N Example, Up: Internationalization +File: gawk.info, Node: Gawk I18N, Next: I18N Summary, Prev: I18N Example, Up: Internationalization 13.6 `gawk' Can Speak Your Language =================================== @@ -20019,6 +20094,39 @@ writing, the latest version of GNU `gettext' is version 0.19.1 If a translation of `gawk''s messages exists, then `gawk' produces usage messages, warnings, and fatal errors in the local language. + +File: gawk.info, Node: I18N Summary, Prev: Gawk I18N, Up: Internationalization + +13.7 Summary +============ + + * Internationalization means writing a program such that it can use + multiple languages without requiring source-code changes. + Localization means providing the data necessary for an + internationalized program to work in a particular language. + + * `gawk' uses GNU `gettext' to let you internationalize and localize + `awk' programs. A program's text domain identifies the program + for grouping all messages and other data together. + + * You mark a program's strings for translation by preceding them with + an underscore. Once that is done, the strings are extracted into a + `.pot' file. This file is copied for each langauge into a `.po' + file, and the `.po' files are compiled into `.gmo' files for use + at runtime. + + * You can use position specifications with `sprintf()' and `printf' + to rearrange the placement of argument values in formatted strings + and output. This is useful for the translations of format control + strings. + + * The internationalization features have been designed so that they + can be easily worked around in a standard `awk'. + + * `gawk' itself has been internationalized and ships with a number + of translations for its messages. + +  File: gawk.info, Node: Debugger, Next: Arbitrary Precision Arithmetic, Prev: Internationalization, Up: Top @@ -20042,6 +20150,7 @@ program is easy. * List of Debugger Commands:: Main debugger commands. * Readline Support:: Readline support. * Limitations:: Limitations and future plans. +* Debugging Summary:: Debugging summary.  File: gawk.info, Node: Debugging, Next: Sample Debugging Session, Up: Debugger @@ -21020,7 +21129,7 @@ Variable name completion  -File: gawk.info, Node: Limitations, Prev: Readline Support, Up: Debugger +File: gawk.info, Node: Limitations, Next: Debugging Summary, Prev: Readline Support, Up: Debugger 14.5 Limitations and Future Plans ================================= @@ -21066,6 +21175,35 @@ some limitations. A few which are worth being aware of are: features may be added, and of course feel free to try to add them yourself! + +File: gawk.info, Node: Debugging Summary, Prev: Limitations, Up: Debugger + +14.6 Summary +============ + + * Programs rarely work correctly the first time. Finding bugs is + "debugging" and a program that helps you find bugs is a + "debugger". `gawk' has a built-in debugger that works very + similarly to the GNU Debugger, GDB. + + * Debuggers let you step through your program one statement at a + time, examine and change variable and array values, and do a + number of other things that let understand what your program is + actually doing (as opposed to what it is supposed to do). + + * Like most debuggers, the `gawk' debugger works in terms of stack + frames, and lets you set both breakpoints (stop at a point in the + code) and watchpoints (stop when a data value changes). + + * The debugger command set is fairly complete, providing control over + breakpoints, execution, viewing and changing data, working with + the stack, getting information, and other tasks. + + * If the `readline' library is available when `gawk' is compiled, it + is used by the debugger to provide command-line history and + editing. + +  File: gawk.info, Node: Arbitrary Precision Arithmetic, Next: Dynamic Extensions, Prev: Debugger, Up: Top @@ -31784,6 +31922,7 @@ Index * endgrent() user-defined function: Group Functions. (line 216) * endpwent() function (C library): Passwd Functions. (line 210) * endpwent() user-defined function: Passwd Functions. (line 213) +* English, Steve: Advanced Features. (line 6) * ENVIRON array: Auto-set. (line 59) * environment variables used by gawk: Environment Variables. (line 6) @@ -32444,6 +32583,7 @@ Index * l debugger command (alias for list): Miscellaneous Debugger Commands. (line 72) * labels.awk program: Labels Program. (line 51) +* Langston, Peter: Advanced Features. (line 6) * languages, data-driven: Basic High Level. (line 85) * Laurie, Dirk: Changing Precision. (line 6) * LC_ALL locale category: Explaining gettext. (line 121) @@ -33979,248 +34119,252 @@ Ref: Group Functions-Footnote-1653771 Node: Walking Arrays653984 Node: Library Functions Summary656154 Node: Sample Programs657516 -Node: Running Examples658190 -Node: Clones658918 -Node: Cut Program660142 -Node: Egrep Program670003 -Ref: Egrep Program-Footnote-1677932 -Node: Id Program678042 -Node: Split Program681706 -Ref: Split Program-Footnote-1685237 -Node: Tee Program685365 -Node: Uniq Program688172 -Node: Wc Program695602 -Ref: Wc Program-Footnote-1699870 -Ref: Wc Program-Footnote-2700070 -Node: Miscellaneous Programs700162 -Node: Dupword Program701350 -Node: Alarm Program703381 -Node: Translate Program708195 -Ref: Translate Program-Footnote-1712586 -Ref: Translate Program-Footnote-2712856 -Node: Labels Program712990 -Ref: Labels Program-Footnote-1716361 -Node: Word Sorting716445 -Node: History Sorting720488 -Node: Extract Program722324 -Ref: Extract Program-Footnote-1729899 -Node: Simple Sed730028 -Node: Igawk Program733090 -Ref: Igawk Program-Footnote-1748266 -Ref: Igawk Program-Footnote-2748467 -Node: Anagram Program748605 -Node: Signature Program751673 -Node: Advanced Features752920 -Node: Nondecimal Data754806 -Node: Array Sorting756383 -Node: Controlling Array Traversal757080 -Node: Array Sorting Functions765360 -Ref: Array Sorting Functions-Footnote-1769267 -Node: Two-way I/O769461 -Ref: Two-way I/O-Footnote-1774977 -Node: TCP/IP Networking775059 -Node: Profiling777903 -Node: Internationalization785411 -Node: I18N and L10N786836 -Node: Explaining gettext787522 -Ref: Explaining gettext-Footnote-1792662 -Ref: Explaining gettext-Footnote-2792846 -Node: Programmer i18n793011 -Node: Translator i18n797236 -Node: String Extraction798030 -Ref: String Extraction-Footnote-1798991 -Node: Printf Ordering799077 -Ref: Printf Ordering-Footnote-1801859 -Node: I18N Portability801923 -Ref: I18N Portability-Footnote-1804372 -Node: I18N Example804435 -Ref: I18N Example-Footnote-1807157 -Node: Gawk I18N807229 -Node: Debugger807846 -Node: Debugging808817 -Node: Debugging Concepts809258 -Node: Debugging Terms811114 -Node: Awk Debugging813711 -Node: Sample Debugging Session814603 -Node: Debugger Invocation815123 -Node: Finding The Bug816456 -Node: List of Debugger Commands822938 -Node: Breakpoint Control824270 -Node: Debugger Execution Control827934 -Node: Viewing And Changing Data831294 -Node: Execution Stack834652 -Node: Debugger Info836165 -Node: Miscellaneous Debugger Commands840159 -Node: Readline Support845343 -Node: Limitations846235 -Node: Arbitrary Precision Arithmetic848483 -Ref: Arbitrary Precision Arithmetic-Footnote-1850132 -Node: General Arithmetic850280 -Node: Floating Point Issues852000 -Node: String Conversion Precision852881 -Ref: String Conversion Precision-Footnote-1854586 -Node: Unexpected Results854695 -Node: POSIX Floating Point Problems856848 -Ref: POSIX Floating Point Problems-Footnote-1860669 -Node: Integer Programming860707 -Node: Floating-point Programming862518 -Ref: Floating-point Programming-Footnote-1868846 -Ref: Floating-point Programming-Footnote-2869116 -Node: Floating-point Representation869380 -Node: Floating-point Context870545 -Ref: table-ieee-formats871384 -Node: Rounding Mode872768 -Ref: table-rounding-modes873247 -Ref: Rounding Mode-Footnote-1876262 -Node: Gawk and MPFR876441 -Node: Arbitrary Precision Floats877850 -Ref: Arbitrary Precision Floats-Footnote-1880293 -Node: Setting Precision880614 -Ref: table-predefined-precision-strings881298 -Node: Setting Rounding Mode883443 -Ref: table-gawk-rounding-modes883847 -Node: Floating-point Constants885034 -Node: Changing Precision886486 -Ref: Changing Precision-Footnote-1887878 -Node: Exact Arithmetic888052 -Node: Arbitrary Precision Integers891186 -Ref: Arbitrary Precision Integers-Footnote-1894201 -Node: Dynamic Extensions894348 -Node: Extension Intro895806 -Node: Plugin License897071 -Node: Extension Mechanism Outline897756 -Ref: figure-load-extension898180 -Ref: figure-load-new-function899665 -Ref: figure-call-new-function900667 -Node: Extension API Description902651 -Node: Extension API Functions Introduction904101 -Node: General Data Types908967 -Ref: General Data Types-Footnote-1914660 -Node: Requesting Values914959 -Ref: table-value-types-returned915696 -Node: Memory Allocation Functions916654 -Ref: Memory Allocation Functions-Footnote-1919401 -Node: Constructor Functions919497 -Node: Registration Functions921255 -Node: Extension Functions921940 -Node: Exit Callback Functions924242 -Node: Extension Version String925492 -Node: Input Parsers926142 -Node: Output Wrappers935945 -Node: Two-way processors940461 -Node: Printing Messages942665 -Ref: Printing Messages-Footnote-1943742 -Node: Updating `ERRNO'943894 -Node: Accessing Parameters944633 -Node: Symbol Table Access945863 -Node: Symbol table by name946377 -Node: Symbol table by cookie948353 -Ref: Symbol table by cookie-Footnote-1952486 -Node: Cached values952549 -Ref: Cached values-Footnote-1956054 -Node: Array Manipulation956145 -Ref: Array Manipulation-Footnote-1957243 -Node: Array Data Types957282 -Ref: Array Data Types-Footnote-1959985 -Node: Array Functions960077 -Node: Flattening Arrays963951 -Node: Creating Arrays970803 -Node: Extension API Variables975534 -Node: Extension Versioning976170 -Node: Extension API Informational Variables978071 -Node: Extension API Boilerplate979157 -Node: Finding Extensions982961 -Node: Extension Example983521 -Node: Internal File Description984251 -Node: Internal File Ops988342 -Ref: Internal File Ops-Footnote-1999888 -Node: Using Internal File Ops1000028 -Ref: Using Internal File Ops-Footnote-11002375 -Node: Extension Samples1002643 -Node: Extension Sample File Functions1004167 -Node: Extension Sample Fnmatch1011735 -Node: Extension Sample Fork1013202 -Node: Extension Sample Inplace1014415 -Node: Extension Sample Ord1016181 -Node: Extension Sample Readdir1017017 -Ref: table-readdir-file-types1017866 -Node: Extension Sample Revout1018665 -Node: Extension Sample Rev2way1019256 -Node: Extension Sample Read write array1019997 -Node: Extension Sample Readfile1021876 -Node: Extension Sample API Tests1022976 -Node: Extension Sample Time1023501 -Node: gawkextlib1024816 -Node: Language History1027603 -Node: V7/SVR3.11029197 -Node: SVR41031517 -Node: POSIX1032959 -Node: BTL1034345 -Node: POSIX/GNU1035079 -Node: Feature History1040678 -Node: Common Extensions1053790 -Node: Ranges and Locales1055102 -Ref: Ranges and Locales-Footnote-11059719 -Ref: Ranges and Locales-Footnote-21059746 -Ref: Ranges and Locales-Footnote-31059980 -Node: Contributors1060201 -Node: Installation1065639 -Node: Gawk Distribution1066533 -Node: Getting1067017 -Node: Extracting1067843 -Node: Distribution contents1069485 -Node: Unix Installation1075202 -Node: Quick Installation1075819 -Node: Additional Configuration Options1078261 -Node: Configuration Philosophy1079999 -Node: Non-Unix Installation1082350 -Node: PC Installation1082808 -Node: PC Binary Installation1084119 -Node: PC Compiling1085967 -Ref: PC Compiling-Footnote-11088966 -Node: PC Testing1089071 -Node: PC Using1090247 -Node: Cygwin1094405 -Node: MSYS1095214 -Node: VMS Installation1095728 -Node: VMS Compilation1096524 -Ref: VMS Compilation-Footnote-11097739 -Node: VMS Dynamic Extensions1097797 -Node: VMS Installation Details1099170 -Node: VMS Running1101416 -Node: VMS GNV1104250 -Node: VMS Old Gawk1104973 -Node: Bugs1105443 -Node: Other Versions1109447 -Node: Notes1115672 -Node: Compatibility Mode1116472 -Node: Additions1117254 -Node: Accessing The Source1118179 -Node: Adding Code1119615 -Node: New Ports1125793 -Node: Derived Files1130274 -Ref: Derived Files-Footnote-11135355 -Ref: Derived Files-Footnote-21135389 -Ref: Derived Files-Footnote-31135985 -Node: Future Extensions1136099 -Node: Implementation Limitations1136705 -Node: Extension Design1137953 -Node: Old Extension Problems1139107 -Ref: Old Extension Problems-Footnote-11140624 -Node: Extension New Mechanism Goals1140681 -Ref: Extension New Mechanism Goals-Footnote-11144042 -Node: Extension Other Design Decisions1144231 -Node: Extension Future Growth1146337 -Node: Old Extension Mechanism1147173 -Node: Basic Concepts1148913 -Node: Basic High Level1149594 -Ref: figure-general-flow1149866 -Ref: figure-process-flow1150465 -Ref: Basic High Level-Footnote-11153694 -Node: Basic Data Typing1153879 -Node: Glossary1157206 -Node: Copying1182358 -Node: GNU Free Documentation License1219914 -Node: Index1245050 +Node: Running Examples658243 +Node: Clones658971 +Node: Cut Program660195 +Node: Egrep Program670056 +Ref: Egrep Program-Footnote-1677985 +Node: Id Program678095 +Node: Split Program681759 +Ref: Split Program-Footnote-1685290 +Node: Tee Program685418 +Node: Uniq Program688225 +Node: Wc Program695655 +Ref: Wc Program-Footnote-1699923 +Ref: Wc Program-Footnote-2700123 +Node: Miscellaneous Programs700215 +Node: Dupword Program701428 +Node: Alarm Program703459 +Node: Translate Program708273 +Ref: Translate Program-Footnote-1712664 +Ref: Translate Program-Footnote-2712934 +Node: Labels Program713068 +Ref: Labels Program-Footnote-1716439 +Node: Word Sorting716523 +Node: History Sorting720566 +Node: Extract Program722402 +Ref: Extract Program-Footnote-1729977 +Node: Simple Sed730106 +Node: Igawk Program733168 +Ref: Igawk Program-Footnote-1748344 +Ref: Igawk Program-Footnote-2748545 +Node: Anagram Program748683 +Node: Signature Program751751 +Node: Programs Summary752998 +Node: Advanced Features754186 +Node: Nondecimal Data756134 +Node: Array Sorting757711 +Node: Controlling Array Traversal758408 +Node: Array Sorting Functions766688 +Ref: Array Sorting Functions-Footnote-1770595 +Node: Two-way I/O770789 +Ref: Two-way I/O-Footnote-1776305 +Node: TCP/IP Networking776387 +Node: Profiling779231 +Node: Advanced Features Summary786773 +Node: Internationalization788637 +Node: I18N and L10N790117 +Node: Explaining gettext790803 +Ref: Explaining gettext-Footnote-1795943 +Ref: Explaining gettext-Footnote-2796127 +Node: Programmer i18n796292 +Node: Translator i18n800517 +Node: String Extraction801311 +Ref: String Extraction-Footnote-1802272 +Node: Printf Ordering802358 +Ref: Printf Ordering-Footnote-1805140 +Node: I18N Portability805204 +Ref: I18N Portability-Footnote-1807653 +Node: I18N Example807716 +Ref: I18N Example-Footnote-1810438 +Node: Gawk I18N810510 +Node: I18N Summary811148 +Node: Debugger812487 +Node: Debugging813509 +Node: Debugging Concepts813950 +Node: Debugging Terms815806 +Node: Awk Debugging818403 +Node: Sample Debugging Session819295 +Node: Debugger Invocation819815 +Node: Finding The Bug821148 +Node: List of Debugger Commands827630 +Node: Breakpoint Control828962 +Node: Debugger Execution Control832626 +Node: Viewing And Changing Data835986 +Node: Execution Stack839344 +Node: Debugger Info840857 +Node: Miscellaneous Debugger Commands844851 +Node: Readline Support850035 +Node: Limitations850927 +Node: Debugging Summary853201 +Node: Arbitrary Precision Arithmetic854365 +Ref: Arbitrary Precision Arithmetic-Footnote-1856014 +Node: General Arithmetic856162 +Node: Floating Point Issues857882 +Node: String Conversion Precision858763 +Ref: String Conversion Precision-Footnote-1860468 +Node: Unexpected Results860577 +Node: POSIX Floating Point Problems862730 +Ref: POSIX Floating Point Problems-Footnote-1866551 +Node: Integer Programming866589 +Node: Floating-point Programming868400 +Ref: Floating-point Programming-Footnote-1874728 +Ref: Floating-point Programming-Footnote-2874998 +Node: Floating-point Representation875262 +Node: Floating-point Context876427 +Ref: table-ieee-formats877266 +Node: Rounding Mode878650 +Ref: table-rounding-modes879129 +Ref: Rounding Mode-Footnote-1882144 +Node: Gawk and MPFR882323 +Node: Arbitrary Precision Floats883732 +Ref: Arbitrary Precision Floats-Footnote-1886175 +Node: Setting Precision886496 +Ref: table-predefined-precision-strings887180 +Node: Setting Rounding Mode889325 +Ref: table-gawk-rounding-modes889729 +Node: Floating-point Constants890916 +Node: Changing Precision892368 +Ref: Changing Precision-Footnote-1893760 +Node: Exact Arithmetic893934 +Node: Arbitrary Precision Integers897068 +Ref: Arbitrary Precision Integers-Footnote-1900083 +Node: Dynamic Extensions900230 +Node: Extension Intro901688 +Node: Plugin License902953 +Node: Extension Mechanism Outline903638 +Ref: figure-load-extension904062 +Ref: figure-load-new-function905547 +Ref: figure-call-new-function906549 +Node: Extension API Description908533 +Node: Extension API Functions Introduction909983 +Node: General Data Types914849 +Ref: General Data Types-Footnote-1920542 +Node: Requesting Values920841 +Ref: table-value-types-returned921578 +Node: Memory Allocation Functions922536 +Ref: Memory Allocation Functions-Footnote-1925283 +Node: Constructor Functions925379 +Node: Registration Functions927137 +Node: Extension Functions927822 +Node: Exit Callback Functions930124 +Node: Extension Version String931374 +Node: Input Parsers932024 +Node: Output Wrappers941827 +Node: Two-way processors946343 +Node: Printing Messages948547 +Ref: Printing Messages-Footnote-1949624 +Node: Updating `ERRNO'949776 +Node: Accessing Parameters950515 +Node: Symbol Table Access951745 +Node: Symbol table by name952259 +Node: Symbol table by cookie954235 +Ref: Symbol table by cookie-Footnote-1958368 +Node: Cached values958431 +Ref: Cached values-Footnote-1961936 +Node: Array Manipulation962027 +Ref: Array Manipulation-Footnote-1963125 +Node: Array Data Types963164 +Ref: Array Data Types-Footnote-1965867 +Node: Array Functions965959 +Node: Flattening Arrays969833 +Node: Creating Arrays976685 +Node: Extension API Variables981416 +Node: Extension Versioning982052 +Node: Extension API Informational Variables983953 +Node: Extension API Boilerplate985039 +Node: Finding Extensions988843 +Node: Extension Example989403 +Node: Internal File Description990133 +Node: Internal File Ops994224 +Ref: Internal File Ops-Footnote-11005770 +Node: Using Internal File Ops1005910 +Ref: Using Internal File Ops-Footnote-11008257 +Node: Extension Samples1008525 +Node: Extension Sample File Functions1010049 +Node: Extension Sample Fnmatch1017617 +Node: Extension Sample Fork1019084 +Node: Extension Sample Inplace1020297 +Node: Extension Sample Ord1022063 +Node: Extension Sample Readdir1022899 +Ref: table-readdir-file-types1023748 +Node: Extension Sample Revout1024547 +Node: Extension Sample Rev2way1025138 +Node: Extension Sample Read write array1025879 +Node: Extension Sample Readfile1027758 +Node: Extension Sample API Tests1028858 +Node: Extension Sample Time1029383 +Node: gawkextlib1030698 +Node: Language History1033485 +Node: V7/SVR3.11035079 +Node: SVR41037399 +Node: POSIX1038841 +Node: BTL1040227 +Node: POSIX/GNU1040961 +Node: Feature History1046560 +Node: Common Extensions1059672 +Node: Ranges and Locales1060984 +Ref: Ranges and Locales-Footnote-11065601 +Ref: Ranges and Locales-Footnote-21065628 +Ref: Ranges and Locales-Footnote-31065862 +Node: Contributors1066083 +Node: Installation1071521 +Node: Gawk Distribution1072415 +Node: Getting1072899 +Node: Extracting1073725 +Node: Distribution contents1075367 +Node: Unix Installation1081084 +Node: Quick Installation1081701 +Node: Additional Configuration Options1084143 +Node: Configuration Philosophy1085881 +Node: Non-Unix Installation1088232 +Node: PC Installation1088690 +Node: PC Binary Installation1090001 +Node: PC Compiling1091849 +Ref: PC Compiling-Footnote-11094848 +Node: PC Testing1094953 +Node: PC Using1096129 +Node: Cygwin1100287 +Node: MSYS1101096 +Node: VMS Installation1101610 +Node: VMS Compilation1102406 +Ref: VMS Compilation-Footnote-11103621 +Node: VMS Dynamic Extensions1103679 +Node: VMS Installation Details1105052 +Node: VMS Running1107298 +Node: VMS GNV1110132 +Node: VMS Old Gawk1110855 +Node: Bugs1111325 +Node: Other Versions1115329 +Node: Notes1121554 +Node: Compatibility Mode1122354 +Node: Additions1123136 +Node: Accessing The Source1124061 +Node: Adding Code1125497 +Node: New Ports1131675 +Node: Derived Files1136156 +Ref: Derived Files-Footnote-11141237 +Ref: Derived Files-Footnote-21141271 +Ref: Derived Files-Footnote-31141867 +Node: Future Extensions1141981 +Node: Implementation Limitations1142587 +Node: Extension Design1143835 +Node: Old Extension Problems1144989 +Ref: Old Extension Problems-Footnote-11146506 +Node: Extension New Mechanism Goals1146563 +Ref: Extension New Mechanism Goals-Footnote-11149924 +Node: Extension Other Design Decisions1150113 +Node: Extension Future Growth1152219 +Node: Old Extension Mechanism1153055 +Node: Basic Concepts1154795 +Node: Basic High Level1155476 +Ref: figure-general-flow1155748 +Ref: figure-process-flow1156347 +Ref: Basic High Level-Footnote-11159576 +Node: Basic Data Typing1159761 +Node: Glossary1163088 +Node: Copying1188240 +Node: GNU Free Documentation License1225796 +Node: Index1250932  End Tag Table -- cgit v1.2.3 From f20d398e580607d3d986e94dcbd0ae189f528478 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 13 Jun 2014 08:03:58 +0300 Subject: Fix typos for filename macro in doc. --- doc/gawk.info | 1501 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 753 insertions(+), 748 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 9033128e..39aa56b1 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1490,7 +1490,7 @@ tell `awk' to use that file for its program, you type: awk -f SOURCE-FILE INPUT-FILE1 INPUT-FILE2 ... The `-f' instructs the `awk' utility to get the `awk' program from -the file SOURCE-FILE. Any FN can be used for SOURCE-FILE. For +the file SOURCE-FILE. Any file name can be used for SOURCE-FILE. For example, you could put the program: BEGIN { print "Don't Panic!" } @@ -1504,15 +1504,16 @@ does the same thing as this one: awk "BEGIN { print \"Don't Panic!\" }" This was explained earlier (*note Read Terminal::). Note that you -don't usually need single quotes around the FN that you specify with -`-f', because most FNs don't contain any of the shell's special -characters. Notice that in `advice', the `awk' program did not have -single quotes around it. The quotes are only needed for programs that -are provided on the `awk' command line. +don't usually need single quotes around the file name that you specify +with `-f', because most file names don't contain any of the shell's +special characters. Notice that in `advice', the `awk' program did not +have single quotes around it. The quotes are only needed for programs +that are provided on the `awk' command line. If you want to clearly identify your `awk' program files as such, -you can add the extension `.awk' to the FN. This doesn't affect the -execution of the `awk' program but it does make "housekeeping" easier. +you can add the extension `.awk' to the file name. This doesn't affect +the execution of the `awk' program but it does make "housekeeping" +easier.  File: gawk.info, Node: Executable Scripts, Next: Comments, Prev: Long, Up: Running gawk @@ -1567,14 +1568,14 @@ the name of your script (`advice'). (d.c.) Don't rely on the value of (1) The `#!' mechanism works on GNU/Linux systems, BSD-based systems and commercial Unix systems. - (2) The line beginning with `#!' lists the full FN of an interpreter -to run and an optional initial command-line argument to pass to that -interpreter. The operating system then runs the interpreter with the -given argument and the full argument list of the executed program. The -first argument in the list is the full FN of the `awk' program. The -rest of the argument list contains either options to `awk', or data -files, or both. Note that on many systems `awk' may be found in -`/usr/bin' instead of in `/bin'. Caveat Emptor. + (2) The line beginning with `#!' lists the full file name of an +interpreter to run and an optional initial command-line argument to +pass to that interpreter. The operating system then runs the +interpreter with the given argument and the full argument list of the +executed program. The first argument in the list is the full file name +of the `awk' program. The rest of the argument list contains either +options to `awk', or data files, or both. Note that on many systems +`awk' may be found in `/usr/bin' instead of in `/bin'. Caveat Emptor.  File: gawk.info, Node: Comments, Next: Quoting, Prev: Executable Scripts, Up: Running gawk @@ -1714,9 +1715,9 @@ the quoting rules. awk -F"" 'PROGRAM' FILES # wrong! In the second case, `awk' will attempt to use the text of the - program as the value of `FS', and the first FN as the text of the - program! This results in syntax errors at best, and confusing - behavior at worst. + program as the value of `FS', and the first file name as the text + of the program! This results in syntax errors at best, and + confusing behavior at worst. Mixing single and double quotes is difficult. You have to resort to shell quoting tricks, like this: @@ -1895,9 +1896,9 @@ description of the program will give you a good idea of what is going on, but please read the rest of the Info file to become an `awk' expert!) Most of the examples use a data file named `data'. This is just a placeholder; if you use these programs yourself, substitute your -own FNs for `data'. For future reference, note that there is often -more than one way to do things in `awk'. At some point, you may want -to look back at these examples and see if you can come up with +own file names for `data'. For future reference, note that there is +often more than one way to do things in `awk'. At some point, you may +want to look back at these examples and see if you can come up with different ways to do the same things shown here: * Print the length of the longest input line: @@ -2041,7 +2042,7 @@ identifies the owner of the file. The fourth field identifies the group of the file. The fifth field contains the size of the file in bytes. The sixth, seventh, and eighth fields contain the month, day, and time, respectively, that the file was last modified. Finally, the ninth field -contains the FN.(1) +contains the file name.(1) The `$6 == "Nov"' in our `awk' program is an expression that tests whether the sixth field of the output from `ls -l' matches the string @@ -2380,10 +2381,10 @@ The following list describes options mandated by the POSIX standard: This interpretation of `--' follows the POSIX argument parsing conventions. - This is useful if you have FNs that start with `-', or in shell - scripts, if you have FNs that will be specified by the user that - could start with `-'. It is also useful for passing options on to - the `awk' program; see *note Getopt Function::. + This is useful if you have file names that start with `-', or in + shell scripts, if you have file names that will be specified by + the user that could start with `-'. It is also useful for passing + options on to the `awk' program; see *note Getopt Function::. The following list describes `gawk'-specific options: @@ -2548,8 +2549,8 @@ The following list describes options mandated by the POSIX standard: Enable pretty-printing of `awk' programs. By default, output program is created in a file named `awkprof.out' (*note Profiling::). The optional FILE argument allows you to specify a - different FN for the output. No space is allowed between the `-o' - and FILE, if FILE is supplied. + different file name for the output. No space is allowed between + the `-o' and FILE, if FILE is supplied. NOTE: Due to the way `gawk' has evolved, with this option your program is still executed. This will change in the next @@ -2565,9 +2566,9 @@ The following list describes options mandated by the POSIX standard: `--profile'[`='FILE] Enable profiling of `awk' programs (*note Profiling::). By default, profiles are created in a file named `awkprof.out'. The - optional FILE argument allows you to specify a different FN for - the profile file. No space is allowed between the `-p' and FILE, - if FILE is supplied. + optional FILE argument allows you to specify a different file name + for the profile file. No space is allowed between the `-p' and + FILE, if FILE is supplied. The profile contains execution counts for each statement in the program in the left margin, and function call counts for each @@ -2708,11 +2709,11 @@ arguments, including variable assignments, are included. As each element of `ARGV' is processed, `gawk' sets the variable `ARGIND' to the index in `ARGV' of the current element. - The distinction between FN arguments and variable-assignment + The distinction between file name arguments and variable-assignment arguments is made when `awk' is about to open the next input file. At -that point in execution, it checks the FN to see whether it is really a -variable assignment; if so, `awk' sets the variable instead of reading -a file. +that point in execution, it checks the file name to see whether it is +really a variable assignment; if so, `awk' sets the variable instead of +reading a file. Therefore, the variables actually receive the given values after all previously specified files have been read. In particular, the values of @@ -2724,13 +2725,13 @@ begins scanning the argument list. escape sequences (*note Escape Sequences::). (d.c.) In some very early implementations of `awk', when a variable -assignment occurred before any FNs, the assignment would happen _before_ -the `BEGIN' rule was executed. `awk''s behavior was thus inconsistent; -some command-line assignments were available inside the `BEGIN' rule, -while others were not. Unfortunately, some applications came to depend -upon this "feature." When `awk' was changed to be more consistent, the -`-v' option was added to accommodate applications that depended upon -the old behavior. +assignment occurred before any file names, the assignment would happen +_before_ the `BEGIN' rule was executed. `awk''s behavior was thus +inconsistent; some command-line assignments were available inside the +`BEGIN' rule, while others were not. Unfortunately, some applications +came to depend upon this "feature." When `awk' was changed to be more +consistent, the `-v' option was added to accommodate applications that +depended upon the old behavior. The variable assignment feature is most useful for assigning to variables such as `RS', `OFS', and `ORS', which control input and @@ -2766,11 +2767,11 @@ SOME_COMMAND, and finally it reads `file2'. You may also use `"-"' to name standard input when reading files with `getline' (*note Getline/File::). - In addition, `gawk' allows you to specify the special FN + In addition, `gawk' allows you to specify the special file name `/dev/stdin', both on the command line and with `getline'. Some other versions of `awk' also support this, but it is not standard. (Some operating systems provide a `/dev/stdin' file in the file system; -however, `gawk' always processes this FN itself.) +however, `gawk' always processes this file name itself.)  File: gawk.info, Node: Environment Variables, Next: Exit Status, Prev: Naming Standard Input, Up: Invoking Gawk @@ -2798,7 +2799,7 @@ The previous minor node described how `awk' program files can be named on the command-line with the `-f' option. In most `awk' implementations, you must supply a precise path name for each program file, unless the file is in the current directory. But in `gawk', if -the FN supplied to the `-f' or `-i' options does not contain a +the file name supplied to the `-f' or `-i' options does not contain a directory separator `/', then `gawk' searches a list of directories (called the "search path"), one by one, looking for a file with the specified name. @@ -2811,8 +2812,8 @@ variable. If that variable does not exist, `gawk' uses a default path, The search path feature is particularly helpful for building libraries of useful `awk' functions. The library files can be placed in a standard directory in the default path and then specified on the -command line with a short FN. Otherwise, the full FN would have to be -typed for each file. +command line with a short file name. Otherwise, the full file name +would have to be typed for each file. By using the `-i' option, or the `--source' and `-f' options, your command-line `awk' programs can use facilities in `awk' library files @@ -3020,8 +3021,8 @@ and here is `test2': use `@include' followed by the name of the file to be included, enclosed in double quotes. - NOTE: Keep in mind that this is a language construct and the FN - cannot be a string variable, but rather just a literal string + NOTE: Keep in mind that this is a language construct and the file + name cannot be a string variable, but rather just a literal string constant in double quotes. The files to be included may be nested; e.g., given a third script, @@ -3039,7 +3040,7 @@ Running `gawk' with the `test3' script produces the following results: -| This is file test2. -| This is file test3. - The FN can, of course, be a pathname. For example: + The file name can, of course, be a pathname. For example: @include "../io_funcs" @@ -5432,11 +5433,11 @@ File: gawk.info, Node: Getline/File, Next: Getline/Variable/File, Prev: Getli --------------------------------- Use `getline < FILE' to read the next record from FILE. Here FILE is a -string-valued expression that specifies the FN. `< FILE' is called a -"redirection" because it directs input to come from a different place. -For example, the following program reads its input record from the file -`secondary.input' when it encounters a first field with a value equal -to 10 in the current input file: +string-valued expression that specifies the file name. `< FILE' is +called a "redirection" because it directs input to come from a +different place. For example, the following program reads its input +record from the file `secondary.input' when it encounters a first field +with a value equal to 10 in the current input file: { if ($1 == 10) { @@ -5938,8 +5939,8 @@ OFMT::.) For printing with specifications, you need the `printf' statement (*note Printf::). Besides basic and formatted printing, this major node also covers -I/O redirections to files and pipes, introduces the special FNs that -`gawk' processes internally, and discusses the `close()' built-in +I/O redirections to files and pipes, introduces the special file names +that `gawk' processes internally, and discusses the `close()' built-in function. * Menu: @@ -6576,8 +6577,9 @@ work identically for `printf': `print ITEMS > OUTPUT-FILE' This redirection prints the items into the output file named - OUTPUT-FILE. The FN OUTPUT-FILE can be any expression. Its value - is changed to a string and then used as a FN (*note Expressions::). + {No value for `output-file'}. The file name OUTPUT-FILE can be any + expression. Its value is changed to a string and then used as a + file name (*note Expressions::). When this type of redirection is used, the OUTPUT-FILE is erased before the first output is written to it. Subsequent writes to @@ -6695,9 +6697,9 @@ underlying operating system permits. A particularly powerful way to use redirection is to build command lines and pipe them into the shell, `sh'. For example, suppose you -have a list of files brought over from a system where all the FNs are -stored in uppercase, and you wish to rename them to have names in all -lowercase. The following program is both simple and efficient: +have a list of files brought over from a system where all the file names +are stored in uppercase, and you wish to rename them to have names in +all lowercase. The following program is both simple and efficient: { printf("mv %s %s\n", $0, tolower($0)) | "sh" } @@ -6714,9 +6716,9 @@ File: gawk.info, Node: Special Files, Next: Close Files And Pipes, Prev: Redi 5.7 Special File Name in `gawk' =============================== -`gawk' provides a number of special FNs that it interprets internally. -These FNs provide access to standard file descriptors and TCP/IP -networking. +`gawk' provides a number of special file names that it interprets +internally. These file names provide access to standard file +descriptors and TCP/IP networking. * Menu: @@ -6762,13 +6764,13 @@ happens, writing to the screen is not correct. In fact, if `awk' is run from a background job, it may not have a terminal at all. Then opening `/dev/tty' fails. - `gawk' provides special FNs for accessing the three standard + `gawk' provides special file names for accessing the three standard streams. (c.e.) It also provides syntax for accessing any other -inherited open files. If the FN matches one of these special names -when `gawk' redirects input or output, then it directly uses the stream -that the FN stands for. These special FNs work for all operating -systems that `gawk' has been ported to, not just those that are -POSIX-compliant: +inherited open files. If the file name matches one of these special +names when `gawk' redirects input or output, then it directly uses the +stream that the file name stands for. These special file names work +for all operating systems that `gawk' has been ported to, not just +those that are POSIX-compliant: `/dev/stdin' The standard input (file descriptor 0). @@ -6785,18 +6787,18 @@ POSIX-compliant: the shell). Unless special pains are taken in the shell from which `gawk' is invoked, only descriptors 0, 1, and 2 are available. - The FNs `/dev/stdin', `/dev/stdout', and `/dev/stderr' are aliases -for `/dev/fd/0', `/dev/fd/1', and `/dev/fd/2', respectively. However, -they are more self-explanatory. The proper way to write an error -message in a `gawk' program is to use `/dev/stderr', like this: + The file names `/dev/stdin', `/dev/stdout', and `/dev/stderr' are +aliases for `/dev/fd/0', `/dev/fd/1', and `/dev/fd/2', respectively. +However, they are more self-explanatory. The proper way to write an +error message in a `gawk' program is to use `/dev/stderr', like this: print "Serious error detected!" > "/dev/stderr" - Note the use of quotes around the FN. Like any other redirection, -the value must be a string. It is a common error to omit the quotes, -which leads to confusing results. + Note the use of quotes around the file name. Like any other +redirection, the value must be a string. It is a common error to omit +the quotes, which leads to confusing results. - Finally, using the `close()' function on a FN of the form + Finally, using the `close()' function on a file name of the form `"/dev/fd/N"', for file descriptor numbers above two, does actually close the given file descriptor. @@ -6814,15 +6816,16 @@ File: gawk.info, Node: Special Network, Next: Special Caveats, Prev: Special ---------------------------------------------- `gawk' programs can open a two-way TCP/IP connection, acting as either -a client or a server. This is done using a special FN of the form: +a client or a server. This is done using a special file name of the +form: `/NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT' The NET-TYPE is one of `inet', `inet4' or `inet6'. The PROTOCOL is one of `tcp' or `udp', and the other fields represent the other essential pieces of information for making a networking connection. -These FNs are used with the `|&' operator for communicating with a -coprocess (*note Two-way I/O::). This is an advanced feature, +These file names are used with the `|&' operator for communicating with +a coprocess (*note Two-way I/O::). This is an advanced feature, mentioned here only for completeness. Full discussion is delayed until *note TCP/IP Networking::. @@ -6832,15 +6835,15 @@ File: gawk.info, Node: Special Caveats, Prev: Special Network, Up: Special Fi 5.7.3 Special File Name Caveats ------------------------------- -Here is a list of things to bear in mind when using the special FNs -that `gawk' provides: +Here is a list of things to bear in mind when using the special file +names that `gawk' provides: - * Recognition of these special FNs is disabled if `gawk' is in + * Recognition of these special file names is disabled if `gawk' is in compatibility mode (*note Options::). - * `gawk' _always_ interprets these special FNs. For example, using - `/dev/fd/4' for output actually writes on file descriptor 4, and - not on a new file descriptor that is `dup()''ed from file + * `gawk' _always_ interprets these special file names. For example, + using `/dev/fd/4' for output actually writes on file descriptor 4, + and not on a new file descriptor that is `dup()''ed from file descriptor 4. Most of the time this does not matter; however, it is important to _not_ close any of the files related to file descriptors 0, 1, and 2. Doing so results in unpredictable @@ -6852,17 +6855,17 @@ File: gawk.info, Node: Close Files And Pipes, Next: Output Summary, Prev: Spe 5.8 Closing Input and Output Redirections ========================================= -If the same FN or the same shell command is used with `getline' more -than once during the execution of an `awk' program (*note Getline::), -the file is opened (or the command is executed) the first time only. -At that time, the first record of input is read from that file or -command. The next time the same file or command is used with `getline', -another record is read from it, and so on. +If the same file name or the same shell command is used with `getline' +more than once during the execution of an `awk' program (*note +Getline::), the file is opened (or the command is executed) the first +time only. At that time, the first record of input is read from that +file or command. The next time the same file or command is used with +`getline', another record is read from it, and so on. Similarly, when a file or pipe is opened for output, `awk' remembers -the FN or command associated with it, and subsequent writes to the same -file or command are appended to the previous writes. The file or pipe -stays open until `awk' exits. +the file name or command associated with it, and subsequent writes to +the same file or command are appended to the previous writes. The file +or pipe stays open until `awk' exits. This implies that special steps are necessary in order to read the same file again from the beginning, or to rerun a shell command (rather @@ -6891,8 +6894,8 @@ file or command, or the next `print' or `printf' to that file or command, reopens the file or reruns the command. Because the expression that you use to close a file or pipeline must exactly match the expression used to open the file or run the command, it is good -practice to use a variable to store the FN or command. The previous -example becomes the following: +practice to use a valueiable to store the file name or command. The +previous example becomes the following: sortcom = "sort -r names" sortcom | getline foo @@ -7374,11 +7377,11 @@ option, as in the following: the variable is set at the very beginning, even before the `BEGIN' rules execute. The `-v' option and its assignment must precede all the -FN arguments, as well as the program text. (*Note Options::, for more -information about the `-v' option.) Otherwise, the variable assignment -is performed at a time determined by its position among the input file -arguments--after the processing of the preceding input file argument. -For example: +file name arguments, as well as the program text. (*Note Options::, +for more information about the `-v' option.) Otherwise, the variable +assignment is performed at a time determined by its position among the +input file arguments--after the processing of the preceding input file +argument. For example: awk '{ print $n }' n=4 inventory-shipped n=2 mail-list @@ -10058,13 +10061,14 @@ Options::), they are not special. `ARGIND #' The index in `ARGV' of the current file being processed. Every time `gawk' opens a new data file for processing, it sets `ARGIND' - to the index in `ARGV' of the FN. When `gawk' is processing the - input files, `FILENAME == ARGV[ARGIND]' is always true. + to the index in `ARGV' of the file name. When `gawk' is + processing the input files, `FILENAME == ARGV[ARGIND]' is always + true. This variable is useful in file processing; it allows you to tell how far along you are in the list of data files as well as to - distinguish between successive instances of the same FN on the - command line. + distinguish between successive instances of the same file name on + the command line. While you can change the value of `ARGIND' within your `awk' program, `gawk' automatically sets it to a new value when the next @@ -10391,13 +10395,13 @@ incrementing `ARGC' causes additional files to be read. If the value of `ARGC' is decreased, that eliminates input files from the end of the list. By recording the old value of `ARGC' elsewhere, a program can treat the eliminated arguments as something -other than FNs. +other than file names. To eliminate a file from the middle of the list, store the null string (`""') into `ARGV' in place of the file's name. As a special -feature, `awk' ignores FNs that have been replaced with the null string. -Another option is to use the `delete' statement to remove elements from -`ARGV' (*note Delete::). +feature, `awk' ignores file names that have been replaced with the null +string. Another option is to use the `delete' statement to remove +elements from `ARGV' (*note Delete::). All of these actions are typically done in the `BEGIN' rule, before actual processing of the input begins. *Note Split Program::, and see @@ -14832,16 +14836,16 @@ does so _portably_; this works with any implementation of `awk': the rule it supplies is executed first. This rule relies on `awk''s `FILENAME' variable that automatically -changes for each new data file. The current FN is saved in a private -variable, `_oldfilename'. If `FILENAME' does not equal `_oldfilename', -then a new data file is being processed and it is necessary to call -`endfile()' for the old file. Because `endfile()' should only be -called if a file has been processed, the program first checks to make -sure that `_oldfilename' is not the null string. The program then -assigns the current FN to `_oldfilename' and calls `beginfile()' for -the file. Because, like all `awk' variables, `_oldfilename' is -initialized to the null string, this rule executes correctly even for -the first data file. +changes for each new data file. The current file name is saved in a +private variable, `_oldfilename'. If `FILENAME' does not equal +`_oldfilename', then a new data file is being processed and it is +necessary to call `endfile()' for the old file. Because `endfile()' +should only be called if a file has been processed, the program first +checks to make sure that `_oldfilename' is not the null string. The +program then assigns the current file name to `_oldfilename' and calls +`beginfile()' for the file. Because, like all `awk' variables, +`_oldfilename' is initialized to the null string, this rule executes +correctly even for the first data file. The program also supplies an `END' rule to do the final processing for the last file. Because this `END' rule comes before any `END' rules @@ -14978,8 +14982,8 @@ program code. possible to detect when an empty data file has been skipped. Similar to the library file presented in *note Filetrans Function::, the following library file calls a function named `zerofile()' that the -user must provide. The arguments passed are the FN and the position in -`ARGV' where it was found: +user must provide. The arguments passed are the file name and the +position in `ARGV' where it was found: # zerofile.awk --- library file to process empty input files @@ -15025,8 +15029,8 @@ File: gawk.info, Node: Ignoring Assigns, Prev: Empty Files, Up: Data File Man Occasionally, you might not want `awk' to process command-line variable assignments (*note Assignment Options::). In particular, if you have a -FN that contains an `=' character, `awk' treats the FN as an -assignment, and does not process it. +file name that contains an `=' character, `awk' treats the file name as +an assignment, and does not process it. Some users have suggested an additional command-line option for `gawk' to disable command-line assignments. However, some simple @@ -15053,7 +15057,7 @@ programming with a library file does the trick: The function works by looping through the arguments. It prepends `./' to any argument that matches the form of a variable assignment, -turning that argument into a FN. +turning that argument into a file name. The use of `No_command_assign' allows you to disable command-line assignments at invocation time, by giving the variable a true value. @@ -15342,7 +15346,7 @@ that it does not try to interpret the `-a', etc., as its own options. NOTE: After `getopt()' is through, it is the responsibility of the user level code to clear out all the elements of `ARGV' from 1 to `Optind', so that `awk' does not try to process the command-line - options as FNs. + options as file names. Several of the sample programs presented in *note Sample Programs::, use `getopt()' to process their arguments. @@ -16124,7 +16128,7 @@ we want them to be separated with individual spaces. Also remember that after `getopt()' is through (as described in *note Getopt Function::), we have to clear out all the elements of `ARGV' from 1 to `Optind', so that `awk' does not try to process the command-line options -as FNs. +as file names. After dealing with the command-line options, the program verifies that the options make sense. Only one or the other of `-c' and `-f' @@ -16281,9 +16285,10 @@ expressions that are almost identical to those available in `awk' The PATTERN is a regular expression. In typical usage, the regular expression is quoted to prevent the shell from expanding any of the -special characters as FN wildcards. Normally, `egrep' prints the lines -that matched. If multiple FNs are provided on the command line, each -output line is preceded by the name of the file and a colon. +special characters as file name wildcards. Normally, `egrep' prints +the lines that matched. If multiple file names are provided on the +command line, each output line is preceded by the name of the file and +a colon. The options to `egrep' are as follows: @@ -16355,8 +16360,8 @@ pattern is supplied with `-e', the first nonoption on the command line is used. The `awk' command-line arguments up to `ARGV[Optind]' are cleared, so that `awk' won't try to process them as files. If no files are specified, the standard input is used, and if multiple files are -specified, we make sure to note this so that the FNs can precede the -matched lines in the output: +specified, we make sure to note this so that the file names can precede +the matched lines in the output: if (pattern == "") pattern = ARGV[Optind++] @@ -16437,9 +16442,9 @@ just moves on to the next record. are not counting lines. First, if the user only wants exit status (`no_print' is true), then it is enough to know that _one_ line in this file matched, and we can skip on to the next file with `nextfile'. -Similarly, if we are only printing FNs, we can print the FN, and then -skip to the next file with `nextfile'. Finally, each line is printed, -with a leading FN and colon if necessary: +Similarly, if we are only printing file names, we can print the file +name, and then skip to the next file with `nextfile'. Finally, each +line is printed, with a leading file name and colon if necessary: { matches = ($0 ~ pattern) @@ -16625,7 +16630,7 @@ To change the number of lines in each file, supply a number on the command line preceded with a minus; e.g., `-500' for files with 500 lines in them instead of 1000. To change the name of the output files to something like `myfileaa', `myfileab', and so on, supply an -additional argument that specifies the FN prefix. +additional argument that specifies the file name prefix. Here is a version of `split' in `awk'. It uses the `ord()' and `chr()' functions presented in *note Ordinal Functions::. @@ -22981,7 +22986,7 @@ File: gawk.info, Node: Exit Callback Functions, Next: Extension Version String .............................................. An "exit callback" function is a function that `gawk' calls before it -exits. Such functions are useful if you have general "clean up" tasks +exits. Such functions are useful if you have general "cleanup" tasks that should be performed in your extension (such as closing data base connections or other resource deallocations). You can register such a function with `gawk' using the following function. @@ -23738,7 +23743,7 @@ of the usage. When a variable's value changes, `gawk' simply decrements the reference count on the old value and updates the variable to use the new value. - Finally, as part of your clean up action (*note Exit Callback + Finally, as part of your cleanup action (*note Exit Callback Functions::) you should release any cached values that you created, using `release_value()'. @@ -25253,10 +25258,10 @@ constant (`FNM_NOMATCH'), and an array of flag values named `FNM'. The arguments to `fnmatch()' are: `pattern' - The FN wildcard to match. + The file name wildcard to match. `string' - The FN string. + The file name string. `flag' Either zero, or the bitwise OR of one or more of the flags in the @@ -25348,8 +25353,8 @@ standard output to a temporary file configured to have the same owner and permissions as the original. After the file has been processed, the extension restores standard output to its original destination. If `INPLACE_SUFFIX' is not an empty string, the original file is linked to -a backup FN created by appending that suffix. Finally, the temporary -file is renamed to the original FN. +a backup file name created by appending that suffix. Finally, the +temporary file is renamed to the original file name. If any error occurs, the extension issues a fatal error to terminate processing immediately without damaging the original file. @@ -25409,9 +25414,9 @@ on the command line (or with `getline'), they are read, with each entry returned as a record. The record consists of three fields. The first two are the inode -number and the FN, separated by a forward slash character. On systems -where the directory entry contains the file type, the record has a -third field (also separated by a slash) which is a single letter +number and the file name, separated by a forward slash character. On +systems where the directory entry contains the file type, the record +has a third field (also separated by a slash) which is a single letter indicating the type of the file. The letters are file types are shown in *note table-readdir-file-types::. @@ -27498,8 +27503,8 @@ or: $ MMK/DESCRIPTION=[.vms]descrip.mms gawk `MMK' is an open source, free, near-clone of `MMS' and can better -handle ODS-5 volumes with upper- and lowercase FNs. `MMK' is available -from `https://github.com/endlesssoftware/mmk'. +handle ODS-5 volumes with upper- and lowercase file names. `MMK' is +available from `https://github.com/endlesssoftware/mmk'. With ODS-5 volumes and extended parsing enabled, the case of the target parameter may need to be exact. @@ -27619,9 +27624,9 @@ has no device or directory path information in it, `gawk' looks in the current directory first, then in the directory specified by the translation of `AWK_LIBRARY' if the file is not found. If, after searching in both directories, the file still is not found, `gawk' -appends the suffix `.awk' to the FN and retries the file search. If -`AWK_LIBRARY' has no definition, a default value of `SYS$LIBRARY:' is -used for it. +appends the suffix `.awk' to the file name and retries the file search. +If `AWK_LIBRARY' has no definition, a default value of `SYS$LIBRARY:' +is used for it.  File: gawk.info, Node: VMS Running, Next: VMS GNV, Prev: VMS Installation Details, Up: VMS Installation @@ -28581,7 +28586,7 @@ provided: hook into input processing, output processing, and two-way I/O. * An extension should be able to provide a "call back" function to - perform clean up actions when `gawk' exits. + perform cleanup actions when `gawk' exits. * An extension should be able to provide a version string so that `gawk''s `--version' option can provide information about @@ -30740,7 +30745,7 @@ Index * Menu: * ! (exclamation point), ! operator: Boolean Ops. (line 67) -* ! (exclamation point), ! operator <1>: Egrep Program. (line 174) +* ! (exclamation point), ! operator <1>: Egrep Program. (line 175) * ! (exclamation point), ! operator <2>: Ranges. (line 48) * ! (exclamation point), ! operator: Precedence. (line 52) * ! (exclamation point), != operator <1>: Precedence. (line 65) @@ -30935,7 +30940,7 @@ Index * > (right angle bracket), >= operator: Comparison Operators. (line 11) * > (right angle bracket), >> operator (I/O) <1>: Precedence. (line 65) -* > (right angle bracket), >> operator (I/O): Redirection. (line 49) +* > (right angle bracket), >> operator (I/O): Redirection. (line 50) * ? (question mark), ?: operator: Precedence. (line 92) * ? (question mark), regexp operator <1>: GNU Regexp Operators. (line 59) @@ -30976,7 +30981,7 @@ Index (line 38) * \ (backslash), as field separator: Command Line Field Separator. (line 27) -* \ (backslash), continuing lines and <1>: Egrep Program. (line 222) +* \ (backslash), continuing lines and <1>: Egrep Program. (line 223) * \ (backslash), continuing lines and: Statements/Lines. (line 19) * \ (backslash), continuing lines and, comments and: Statements/Lines. (line 76) @@ -31183,7 +31188,7 @@ Index * awk, gawk and <1>: This Manual. (line 14) * awk, gawk and: Preface. (line 23) * awk, history of: History. (line 17) -* awk, implementation issues, pipes: Redirection. (line 134) +* awk, implementation issues, pipes: Redirection. (line 135) * awk, implementations: Other Versions. (line 6) * awk, implementations, limits: Getline Notes. (line 14) * awk, invoking: Command Line. (line 6) @@ -31250,7 +31255,7 @@ Index (line 38) * backslash (\), as field separator: Command Line Field Separator. (line 27) -* backslash (\), continuing lines and <1>: Egrep Program. (line 222) +* backslash (\), continuing lines and <1>: Egrep Program. (line 223) * backslash (\), continuing lines and: Statements/Lines. (line 19) * backslash (\), continuing lines and, comments and: Statements/Lines. (line 76) @@ -31561,7 +31566,7 @@ Index (line 6) * cookie: Glossary. (line 149) * coprocesses <1>: Two-way I/O. (line 44) -* coprocesses: Redirection. (line 101) +* coprocesses: Redirection. (line 102) * coprocesses, closing: Close Files And Pipes. (line 6) * coprocesses, getline from: Getline/Coprocess. (line 6) @@ -31604,9 +31609,9 @@ Index * dark corner, exit statement: Exit Statement. (line 30) * dark corner, field separators: Field Splitting Summary. (line 46) -* dark corner, FILENAME variable <1>: Auto-set. (line 89) +* dark corner, FILENAME variable <1>: Auto-set. (line 90) * dark corner, FILENAME variable: Getline Notes. (line 19) -* dark corner, FNR/NR variables: Auto-set. (line 300) +* dark corner, FNR/NR variables: Auto-set. (line 301) * dark corner, format-control characters: Control Letters. (line 18) * dark corner, FS as null string: Single Character Fields. (line 20) @@ -31790,25 +31795,25 @@ Index (line 81) * differences in awk and gawk, command line directories: Command line directories. (line 6) -* differences in awk and gawk, ERRNO variable: Auto-set. (line 73) +* differences in awk and gawk, ERRNO variable: Auto-set. (line 74) * differences in awk and gawk, error messages: Special FD. (line 16) * differences in awk and gawk, FIELDWIDTHS variable: User-modified. (line 37) * differences in awk and gawk, FPAT variable: User-modified. (line 43) -* differences in awk and gawk, FUNCTAB variable: Auto-set. (line 114) +* differences in awk and gawk, FUNCTAB variable: Auto-set. (line 115) * differences in awk and gawk, function arguments (gawk): Calling Built-in. (line 16) * differences in awk and gawk, getline command: Getline. (line 19) * differences in awk and gawk, IGNORECASE variable: User-modified. (line 76) * differences in awk and gawk, implementation limitations <1>: Redirection. - (line 134) + (line 135) * differences in awk and gawk, implementation limitations: Getline Notes. (line 14) * differences in awk and gawk, indirect function calls: Indirect Calls. (line 6) * differences in awk and gawk, input/output operators <1>: Redirection. - (line 101) + (line 102) * differences in awk and gawk, input/output operators: Getline/Coprocess. (line 6) * differences in awk and gawk, line continuations: Conditional Exp. @@ -31818,7 +31823,7 @@ Index (line 260) * differences in awk and gawk, print/printf statements: Format Modifiers. (line 13) -* differences in awk and gawk, PROCINFO array: Auto-set. (line 127) +* differences in awk and gawk, PROCINFO array: Auto-set. (line 128) * differences in awk and gawk, read timeouts: Read Timeout. (line 6) * differences in awk and gawk, record separators: awk split records. (line 124) @@ -31828,7 +31833,7 @@ Index (line 26) * differences in awk and gawk, RS/RT variables: gawk split records. (line 58) -* differences in awk and gawk, RT variable: Auto-set. (line 256) +* differences in awk and gawk, RT variable: Auto-set. (line 257) * differences in awk and gawk, single-character fields: Single Character Fields. (line 6) * differences in awk and gawk, split() function: String Functions. @@ -31836,7 +31841,7 @@ Index * differences in awk and gawk, strings: Scalar Constants. (line 20) * differences in awk and gawk, strings, storing: gawk split records. (line 77) -* differences in awk and gawk, SYMTAB variable: Auto-set. (line 260) +* differences in awk and gawk, SYMTAB variable: Auto-set. (line 261) * differences in awk and gawk, TEXTDOMAIN variable: User-modified. (line 152) * differences in awk and gawk, trunc-mod operation: Arithmetic Ops. @@ -31877,11 +31882,11 @@ Index * dynamically loaded extensions: Dynamic Extensions. (line 6) * e debugger command (alias for enable): Breakpoint Control. (line 73) * EBCDIC: Ordinal Functions. (line 45) -* effective group ID of gawk user: Auto-set. (line 132) -* effective user ID of gawk user: Auto-set. (line 136) +* effective group ID of gawk user: Auto-set. (line 133) +* effective user ID of gawk user: Auto-set. (line 137) * egrep utility <1>: Egrep Program. (line 6) * egrep utility: Bracket Expressions. (line 24) -* egrep.awk program: Egrep Program. (line 53) +* egrep.awk program: Egrep Program. (line 54) * elements in arrays, assigning values: Assigning Elements. (line 6) * elements in arrays, deleting: Delete. (line 6) * elements in arrays, order of access by in operator: Scanning an Array. @@ -31906,7 +31911,7 @@ Index * END pattern, and profiling: Profiling. (line 62) * END pattern, assert() user-defined function and: Assert Function. (line 75) -* END pattern, backslash continuation and: Egrep Program. (line 222) +* END pattern, backslash continuation and: Egrep Program. (line 223) * END pattern, Boolean patterns and: Expression Patterns. (line 70) * END pattern, exit statement and: Exit Statement. (line 12) * END pattern, next/nextfile statements and <1>: Next Statement. @@ -31923,10 +31928,10 @@ Index * endpwent() function (C library): Passwd Functions. (line 210) * endpwent() user-defined function: Passwd Functions. (line 213) * English, Steve: Advanced Features. (line 6) -* ENVIRON array: Auto-set. (line 59) +* ENVIRON array: Auto-set. (line 60) * environment variables used by gawk: Environment Variables. (line 6) -* environment variables, in ENVIRON array: Auto-set. (line 59) +* environment variables, in ENVIRON array: Auto-set. (line 60) * epoch, definition of: Glossary. (line 234) * equals sign (=), = operator: Assignment Ops. (line 6) * equals sign (=), == operator <1>: Precedence. (line 65) @@ -31934,13 +31939,13 @@ Index (line 11) * EREs (Extended Regular Expressions): Bracket Expressions. (line 24) * ERRNO variable <1>: TCP/IP Networking. (line 54) -* ERRNO variable: Auto-set. (line 73) +* ERRNO variable: Auto-set. (line 74) * ERRNO variable, with BEGINFILE pattern: BEGINFILE/ENDFILE. (line 26) * ERRNO variable, with close() function: Close Files And Pipes. (line 139) * ERRNO variable, with getline command: Getline. (line 19) * error handling: Special FD. (line 16) -* error handling, ERRNO variable and: Auto-set. (line 73) +* error handling, ERRNO variable and: Auto-set. (line 74) * error output: Special FD. (line 6) * escape processing, gsub()/gensub()/sub() functions: Gory Details. (line 6) @@ -31953,7 +31958,7 @@ Index * evaluation order, concatenation: Concatenation. (line 41) * evaluation order, functions: Calling Built-in. (line 30) * examining fields: Fields. (line 6) -* exclamation point (!), ! operator <1>: Egrep Program. (line 174) +* exclamation point (!), ! operator <1>: Egrep Program. (line 175) * exclamation point (!), ! operator <2>: Precedence. (line 52) * exclamation point (!), ! operator: Boolean Ops. (line 67) * exclamation point (!), != operator <1>: Precedence. (line 65) @@ -31994,7 +31999,7 @@ Index (line 6) * extension API version: Extension Versioning. (line 6) -* extension API, version number: Auto-set. (line 223) +* extension API, version number: Auto-set. (line 224) * extension example: Extension Example. (line 6) * extension registration: Registration Functions. (line 6) @@ -32070,10 +32075,10 @@ Index * FIELDWIDTHS variable <1>: User-modified. (line 37) * FIELDWIDTHS variable: Constant Size. (line 23) * file descriptors: Special FD. (line 6) -* file names, distinguishing: Auto-set. (line 55) +* file names, distinguishing: Auto-set. (line 56) * file names, in compatibility mode: Special Caveats. (line 9) * file names, standard streams in gawk: Special FD. (line 46) -* FILENAME variable <1>: Auto-set. (line 89) +* FILENAME variable <1>: Auto-set. (line 90) * FILENAME variable: Reading Files. (line 6) * FILENAME variable, getline, setting with: Getline Notes. (line 19) * filenames, assignments as: Ignoring Assigns. (line 6) @@ -32119,7 +32124,7 @@ Index * files, portable object, converting to message object files: I18N Example. (line 63) * files, portable object, generating: Options. (line 147) -* files, processing, ARGIND variable and: Auto-set. (line 50) +* files, processing, ARGIND variable and: Auto-set. (line 51) * files, reading: Rewind Function. (line 6) * files, reading, multiline records: Multiple Line. (line 6) * files, searching for regular expressions: Egrep Program. (line 6) @@ -32143,9 +32148,9 @@ Index * flush buffered output: I/O Functions. (line 28) * fnmatch() extension function: Extension Sample Fnmatch. (line 12) -* FNR variable <1>: Auto-set. (line 98) +* FNR variable <1>: Auto-set. (line 99) * FNR variable: Records. (line 6) -* FNR variable, changing: Auto-set. (line 300) +* FNR variable, changing: Auto-set. (line 301) * for statement: For Statement. (line 6) * for statement, looping over arrays: Scanning an Array. (line 20) * fork() extension function: Extension Sample Fork. @@ -32195,7 +32200,7 @@ Index * FSF (Free Software Foundation): Manual History. (line 6) * fts() extension function: Extension Sample File Functions. (line 61) -* FUNCTAB array: Auto-set. (line 114) +* FUNCTAB array: Auto-set. (line 115) * function calls: Function Calls. (line 6) * function calls, indirect: Indirect Calls. (line 6) * function definition example: Function Example. (line 6) @@ -32245,7 +32250,7 @@ Index * G-d: Acknowledgments. (line 78) * Garfinkle, Scott: Contributors. (line 34) * gawk program, dynamic profiling: Profiling. (line 179) -* gawk version: Auto-set. (line 198) +* gawk version: Auto-set. (line 199) * gawk, ARGIND variable in: Other Arguments. (line 12) * gawk, awk and <1>: This Manual. (line 14) * gawk, awk and: Preface. (line 23) @@ -32266,7 +32271,7 @@ Index * gawk, distribution: Distribution contents. (line 6) * gawk, ERRNO variable in <1>: TCP/IP Networking. (line 54) -* gawk, ERRNO variable in <2>: Auto-set. (line 73) +* gawk, ERRNO variable in <2>: Auto-set. (line 74) * gawk, ERRNO variable in <3>: BEGINFILE/ENDFILE. (line 26) * gawk, ERRNO variable in <4>: Close Files And Pipes. (line 139) @@ -32283,7 +32288,7 @@ Index * gawk, FPAT variable in <1>: User-modified. (line 43) * gawk, FPAT variable in: Splitting By Content. (line 27) -* gawk, FUNCTAB array in: Auto-set. (line 114) +* gawk, FUNCTAB array in: Auto-set. (line 115) * gawk, function arguments and: Calling Built-in. (line 16) * gawk, hexadecimal numbers and: Nondecimal-numbers. (line 42) * gawk, IGNORECASE variable in <1>: Array Sorting Functions. @@ -32297,7 +32302,7 @@ Index * gawk, implementation issues, downward compatibility: Compatibility Mode. (line 6) * gawk, implementation issues, limits: Getline Notes. (line 14) -* gawk, implementation issues, pipes: Redirection. (line 134) +* gawk, implementation issues, pipes: Redirection. (line 135) * gawk, installing: Installation. (line 6) * gawk, internationalization and, See internationalization: Internationalization. (line 13) @@ -32314,7 +32319,7 @@ Index * gawk, OS/2 version of: PC Using. (line 16) * gawk, PROCINFO array in <1>: Two-way I/O. (line 117) * gawk, PROCINFO array in <2>: Time Functions. (line 47) -* gawk, PROCINFO array in: Auto-set. (line 127) +* gawk, PROCINFO array in: Auto-set. (line 128) * gawk, regexp constants and: Using Constant Regexps. (line 28) * gawk, regular expressions, case sensitivity: Case-sensitivity. @@ -32322,14 +32327,14 @@ Index * gawk, regular expressions, operators: GNU Regexp Operators. (line 6) * gawk, regular expressions, precedence: Regexp Operators. (line 162) -* gawk, RT variable in <1>: Auto-set. (line 256) +* gawk, RT variable in <1>: Auto-set. (line 257) * gawk, RT variable in <2>: Multiple Line. (line 129) * gawk, RT variable in: awk split records. (line 124) * gawk, See Also awk: Preface. (line 36) * gawk, source code, obtaining: Getting. (line 6) * gawk, splitting fields and: Constant Size. (line 88) * gawk, string-translation functions: I18N Functions. (line 6) -* gawk, SYMTAB array in: Auto-set. (line 260) +* gawk, SYMTAB array in: Auto-set. (line 261) * gawk, TEXTDOMAIN variable in: User-modified. (line 152) * gawk, timestamps: Time Functions. (line 6) * gawk, uses for: Preface. (line 36) @@ -32416,7 +32421,7 @@ Index * Grigera, Juan: Contributors. (line 57) * group database, reading: Group Functions. (line 6) * group file: Group Functions. (line 6) -* group ID of gawk user: Auto-set. (line 171) +* group ID of gawk user: Auto-set. (line 172) * groups, information about: Group Functions. (line 6) * gsub <1>: String Functions. (line 139) * gsub: Using Constant Regexps. @@ -32469,7 +32474,7 @@ Index * Illumos, POSIX-compliant awk: Other Versions. (line 105) * implementation issues, gawk: Notes. (line 6) * implementation issues, gawk, debugging: Compatibility Mode. (line 6) -* implementation issues, gawk, limits <1>: Redirection. (line 134) +* implementation issues, gawk, limits <1>: Redirection. (line 135) * implementation issues, gawk, limits: Getline Notes. (line 14) * in operator <1>: For Statement. (line 75) * in operator <2>: Precedence. (line 83) @@ -32713,7 +32718,7 @@ Index * mawk utility <3>: Concatenation. (line 36) * mawk utility <4>: Getline/Pipe. (line 62) * mawk utility: Escape Sequences. (line 124) -* maximum precision supported by MPFR library: Auto-set. (line 212) +* maximum precision supported by MPFR library: Auto-set. (line 213) * McIlroy, Doug: Glossary. (line 149) * McPhee, Patrick: Contributors. (line 100) * message object files: Explaining gettext. (line 42) @@ -32726,7 +32731,7 @@ Index * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) * metacharacters, escape sequences for: Escape Sequences. (line 130) -* minimum precision supported by MPFR library: Auto-set. (line 215) +* minimum precision supported by MPFR library: Auto-set. (line 216) * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) * monetary information, localization: Explaining gettext. (line 104) @@ -32780,7 +32785,7 @@ Index (line 47) * nexti debugger command: Debugger Execution Control. (line 49) -* NF variable <1>: Auto-set. (line 103) +* NF variable <1>: Auto-set. (line 104) * NF variable: Fields. (line 33) * NF variable, decrementing: Changing Fields. (line 107) * ni debugger command (alias for nexti): Debugger Execution Control. @@ -32789,9 +32794,9 @@ Index * non-existent array elements: Reference to Elements. (line 23) * not Boolean-logic operator: Boolean Ops. (line 6) -* NR variable <1>: Auto-set. (line 122) +* NR variable <1>: Auto-set. (line 123) * NR variable: Records. (line 6) -* NR variable, changing: Auto-set. (line 300) +* NR variable, changing: Auto-set. (line 301) * null strings <1>: Basic Data Typing. (line 26) * null strings <2>: Truth Values. (line 6) * null strings <3>: Regexp Field Splitting. @@ -32899,14 +32904,14 @@ Index (line 6) * output, format specifier, OFMT: OFMT. (line 15) * output, formatted: Printf. (line 6) -* output, pipes: Redirection. (line 56) +* output, pipes: Redirection. (line 57) * output, printing, See printing: Printing. (line 6) * output, records: Output Separators. (line 20) * output, standard: Special FD. (line 6) * p debugger command (alias for print): Viewing And Changing Data. (line 36) * Papadopoulos, Panos: Contributors. (line 129) -* parent process ID of gawk process: Auto-set. (line 180) +* parent process ID of gawk process: Auto-set. (line 181) * parentheses (), in a profile: Profiling. (line 146) * parentheses (), regexp operator: Regexp Operators. (line 80) * password file: Passwd Functions. (line 16) @@ -32936,7 +32941,7 @@ Index * pipe, closing: Close Files And Pipes. (line 6) * pipe, input: Getline/Pipe. (line 9) -* pipe, output: Redirection. (line 56) +* pipe, output: Redirection. (line 57) * Pitts, Dave <1>: Bugs. (line 71) * Pitts, Dave: Acknowledgments. (line 60) * Plauger, P.J.: Library Functions. (line 12) @@ -33071,24 +33076,24 @@ Index * printing, unduplicated lines of text: Uniq Program. (line 6) * printing, user information: Id Program. (line 6) * private variables: Library Names. (line 11) -* process group idIDof gawk process: Auto-set. (line 174) -* process ID of gawk process: Auto-set. (line 177) +* process group idIDof gawk process: Auto-set. (line 175) +* process ID of gawk process: Auto-set. (line 178) * processes, two-way communications with: Two-way I/O. (line 23) * processing data: Basic High Level. (line 6) * PROCINFO array <1>: Passwd Functions. (line 6) * PROCINFO array <2>: Time Functions. (line 47) -* PROCINFO array: Auto-set. (line 127) +* PROCINFO array: Auto-set. (line 128) * PROCINFO array, and communications via ptys: Two-way I/O. (line 117) * PROCINFO array, and group membership: Group Functions. (line 6) * PROCINFO array, and user and group ID numbers: Id Program. (line 15) * PROCINFO array, testing the field splitting: Passwd Functions. (line 161) -* PROCINFO array, uses: Auto-set. (line 233) +* PROCINFO array, uses: Auto-set. (line 234) * PROCINFO, values of sorted_in: Controlling Scanning. (line 26) * profiling awk programs: Profiling. (line 6) * profiling awk programs, dynamically: Profiling. (line 179) -* program identifiers: Auto-set. (line 145) +* program identifiers: Auto-set. (line 146) * program, definition of: Getting Started. (line 21) * programmers, attractiveness of: Two-way I/O. (line 6) * programming conventions, --non-decimal-data option: Nondecimal Data. @@ -33244,11 +33249,11 @@ Index * right angle bracket (>), >= operator: Comparison Operators. (line 11) * right angle bracket (>), >> operator (I/O) <1>: Precedence. (line 65) -* right angle bracket (>), >> operator (I/O): Redirection. (line 49) +* right angle bracket (>), >> operator (I/O): Redirection. (line 50) * right shift: Bitwise Functions. (line 52) * right shift, bitwise: Bitwise Functions. (line 32) * Ritchie, Dennis: Basic Data Typing. (line 54) -* RLENGTH variable: Auto-set. (line 243) +* RLENGTH variable: Auto-set. (line 244) * RLENGTH variable, match() function and: String Functions. (line 224) * Robbins, Arnold <1>: Future Extensions. (line 6) * Robbins, Arnold <2>: Bugs. (line 32) @@ -33277,9 +33282,9 @@ Index * RS variable: awk split records. (line 12) * RS variable, multiline records and: Multiple Line. (line 17) * rshift: Bitwise Functions. (line 52) -* RSTART variable: Auto-set. (line 249) +* RSTART variable: Auto-set. (line 250) * RSTART variable, match() function and: String Functions. (line 224) -* RT variable <1>: Auto-set. (line 256) +* RT variable <1>: Auto-set. (line 257) * RT variable <2>: Multiple Line. (line 129) * RT variable: awk split records. (line 124) * Rubin, Paul <1>: Contributors. (line 15) @@ -33299,7 +33304,7 @@ Index * scanning arrays: Scanning an Array. (line 6) * scanning multidimensional arrays: Multiscanning. (line 11) * Schorr, Andrew <1>: Contributors. (line 134) -* Schorr, Andrew <2>: Auto-set. (line 283) +* Schorr, Andrew <2>: Auto-set. (line 284) * Schorr, Andrew: Acknowledgments. (line 60) * Schreiber, Bert: Acknowledgments. (line 38) * Schreiber, Rita: Acknowledgments. (line 38) @@ -33349,7 +33354,7 @@ Index * shadowing of variable values: Definition Syntax. (line 61) * shell quoting, double quote: Read Terminal. (line 25) * shell quoting, rules for: Quoting. (line 6) -* shells, piping commands into: Redirection. (line 141) +* shells, piping commands into: Redirection. (line 142) * shells, quoting: Using Shell Variables. (line 12) * shells, quoting, rules for: Quoting. (line 18) @@ -33387,7 +33392,7 @@ Index (line 110) * sidebar, Changing FS Does Not Affect the Fields: Field Splitting Summary. (line 38) -* sidebar, Changing NR and FNR: Auto-set. (line 298) +* sidebar, Changing NR and FNR: Auto-set. (line 299) * sidebar, Controlling Output Buffering with system(): I/O Functions. (line 138) * sidebar, Escape Sequences for Metacharacters: Escape Sequences. @@ -33398,7 +33403,7 @@ Index (line 107) * sidebar, Matching the Null String: Gory Details. (line 162) * sidebar, Operator Evaluation Order: Increment Ops. (line 58) -* sidebar, Piping into sh: Redirection. (line 139) +* sidebar, Piping into sh: Redirection. (line 140) * sidebar, Portability Issues with #!: Executable Scripts. (line 31) * sidebar, Recipe For A Programming Language: History. (line 6) * sidebar, RS = "\0" Is Not Portable: gawk split records. (line 63) @@ -33549,9 +33554,9 @@ Index * substr: String Functions. (line 479) * substring: String Functions. (line 479) * Sumner, Andrew: Other Versions. (line 64) -* supplementary groups of gawk process: Auto-set. (line 228) +* supplementary groups of gawk process: Auto-set. (line 229) * switch statement: Switch Statement. (line 6) -* SYMTAB array: Auto-set. (line 260) +* SYMTAB array: Auto-set. (line 261) * syntactic ambiguity: /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) * system: I/O Functions. (line 75) @@ -33635,7 +33640,7 @@ Index * troubleshooting, match() function: String Functions. (line 289) * troubleshooting, print statement, omitting commas: Print Examples. (line 31) -* troubleshooting, printing: Redirection. (line 117) +* troubleshooting, printing: Redirection. (line 118) * troubleshooting, quotes with file names: Special FD. (line 68) * troubleshooting, readable data files: File Checking. (line 6) * troubleshooting, regexp constants vs. string constants: Computed Regexps. @@ -33729,10 +33734,10 @@ Index * variables, uninitialized, as array subscripts: Uninitialized Subscripts. (line 6) * variables, user-defined: Variables. (line 6) -* version of gawk: Auto-set. (line 198) -* version of gawk extension API: Auto-set. (line 223) -* version of GNU MP library: Auto-set. (line 209) -* version of GNU MPFR library: Auto-set. (line 205) +* version of gawk: Auto-set. (line 199) +* version of gawk extension API: Auto-set. (line 224) +* version of GNU MP library: Auto-set. (line 210) +* version of GNU MPFR library: Auto-set. (line 206) * vertical bar (|): Regexp Operators. (line 70) * vertical bar (|), | operator (I/O) <1>: Precedence. (line 65) * vertical bar (|), | operator (I/O): Getline/Pipe. (line 9) @@ -33797,11 +33802,11 @@ Index * {} (braces), statements, grouping: Statements. (line 10) * | (vertical bar): Regexp Operators. (line 70) * | (vertical bar), | operator (I/O) <1>: Precedence. (line 65) -* | (vertical bar), | operator (I/O) <2>: Redirection. (line 56) +* | (vertical bar), | operator (I/O) <2>: Redirection. (line 57) * | (vertical bar), | operator (I/O): Getline/Pipe. (line 9) * | (vertical bar), |& operator (I/O) <1>: Two-way I/O. (line 44) * | (vertical bar), |& operator (I/O) <2>: Precedence. (line 65) -* | (vertical bar), |& operator (I/O) <3>: Redirection. (line 101) +* | (vertical bar), |& operator (I/O) <3>: Redirection. (line 102) * | (vertical bar), |& operator (I/O): Getline/Coprocess. (line 6) * | (vertical bar), |& operator (I/O), pipes, closing: Close Files And Pipes. (line 119) @@ -33842,529 +33847,529 @@ Node: Read Terminal74778 Ref: Read Terminal-Footnote-176428 Ref: Read Terminal-Footnote-276704 Node: Long76875 -Node: Executable Scripts78223 -Ref: Executable Scripts-Footnote-180056 -Ref: Executable Scripts-Footnote-280158 -Node: Comments80691 -Node: Quoting83158 -Node: DOS Quoting88467 -Node: Sample Data Files89142 -Node: Very Simple91657 -Node: Two Rules96288 -Node: More Complex98183 -Ref: More Complex-Footnote-1101108 -Node: Statements/Lines101193 -Ref: Statements/Lines-Footnote-1105648 -Node: Other Features105913 -Node: When106841 -Node: Intro Summary109011 -Node: Invoking Gawk109777 -Node: Command Line111292 -Node: Options112083 -Ref: Options-Footnote-1127867 -Node: Other Arguments127892 -Node: Naming Standard Input130533 -Node: Environment Variables131613 -Node: AWKPATH Variable132171 -Ref: AWKPATH Variable-Footnote-1135022 -Ref: AWKPATH Variable-Footnote-2135067 -Node: AWKLIBPATH Variable135327 -Node: Other Environment Variables136086 -Node: Exit Status139741 -Node: Include Files140416 -Node: Loading Shared Libraries143980 -Node: Obsolete145364 -Node: Undocumented146061 -Node: Invoking Summary146328 -Node: Regexp147908 -Node: Regexp Usage149358 -Node: Escape Sequences151391 -Node: Regexp Operators157058 -Ref: Regexp Operators-Footnote-1164538 -Ref: Regexp Operators-Footnote-2164685 -Node: Bracket Expressions164783 -Ref: table-char-classes166673 -Node: GNU Regexp Operators169196 -Node: Case-sensitivity172919 -Ref: Case-sensitivity-Footnote-1175811 -Ref: Case-sensitivity-Footnote-2176046 -Node: Leftmost Longest176154 -Node: Computed Regexps177355 -Node: Regexp Summary180727 -Node: Reading Files182199 -Node: Records184248 -Node: awk split records184991 -Node: gawk split records189849 -Ref: gawk split records-Footnote-1194370 -Node: Fields194407 -Ref: Fields-Footnote-1197371 -Node: Nonconstant Fields197457 -Ref: Nonconstant Fields-Footnote-1199687 -Node: Changing Fields199889 -Node: Field Separators205843 -Node: Default Field Splitting208545 -Node: Regexp Field Splitting209662 -Node: Single Character Fields213003 -Node: Command Line Field Separator214062 -Node: Full Line Fields217404 -Ref: Full Line Fields-Footnote-1217912 -Node: Field Splitting Summary217958 -Ref: Field Splitting Summary-Footnote-1221057 -Node: Constant Size221158 -Node: Splitting By Content225765 -Ref: Splitting By Content-Footnote-1229515 -Node: Multiple Line229555 -Ref: Multiple Line-Footnote-1235411 -Node: Getline235590 -Node: Plain Getline237806 -Node: Getline/Variable239901 -Node: Getline/File241048 -Node: Getline/Variable/File242424 -Ref: Getline/Variable/File-Footnote-1244023 -Node: Getline/Pipe244110 -Node: Getline/Variable/Pipe246809 -Node: Getline/Coprocess247916 -Node: Getline/Variable/Coprocess249168 -Node: Getline Notes249905 -Node: Getline Summary252709 -Ref: table-getline-variants253117 -Node: Read Timeout254029 -Ref: Read Timeout-Footnote-1257856 -Node: Command line directories257914 -Node: Input Summary258818 -Node: Printing261932 -Node: Print263604 -Node: Print Examples264945 -Node: Output Separators267724 -Node: OFMT269740 -Node: Printf271098 -Node: Basic Printf272004 -Node: Control Letters273543 -Node: Format Modifiers277397 -Node: Printf Examples283424 -Node: Redirection286131 -Node: Special Files293078 -Node: Special FD293594 -Ref: Special FD-Footnote-1297169 -Node: Special Network297243 -Node: Special Caveats298079 -Node: Close Files And Pipes298854 -Ref: Close Files And Pipes-Footnote-1305993 -Ref: Close Files And Pipes-Footnote-2306141 -Node: Output Summary306291 -Node: Expressions307263 -Node: Values308448 -Node: Constants309124 -Node: Scalar Constants309804 -Ref: Scalar Constants-Footnote-1310663 -Node: Nondecimal-numbers310913 -Node: Regexp Constants313913 -Node: Using Constant Regexps314388 -Node: Variables317458 -Node: Using Variables318113 -Node: Assignment Options319837 -Node: Conversion321704 -Ref: table-locale-affects327140 -Ref: Conversion-Footnote-1327764 -Node: All Operators327873 -Node: Arithmetic Ops328503 -Node: Concatenation331008 -Ref: Concatenation-Footnote-1333804 -Node: Assignment Ops333924 -Ref: table-assign-ops338907 -Node: Increment Ops340224 -Node: Truth Values and Conditions343662 -Node: Truth Values344745 -Node: Typing and Comparison345794 -Node: Variable Typing346587 -Ref: Variable Typing-Footnote-1350487 -Node: Comparison Operators350609 -Ref: table-relational-ops351019 -Node: POSIX String Comparison354569 -Ref: POSIX String Comparison-Footnote-1355653 -Node: Boolean Ops355791 -Ref: Boolean Ops-Footnote-1359861 -Node: Conditional Exp359952 -Node: Function Calls361679 -Node: Precedence365437 -Node: Locales369106 -Node: Expressions Summary370737 -Node: Patterns and Actions373234 -Node: Pattern Overview374350 -Node: Regexp Patterns376027 -Node: Expression Patterns376570 -Node: Ranges380351 -Node: BEGIN/END383457 -Node: Using BEGIN/END384219 -Ref: Using BEGIN/END-Footnote-1386955 -Node: I/O And BEGIN/END387061 -Node: BEGINFILE/ENDFILE389346 -Node: Empty392277 -Node: Using Shell Variables392594 -Node: Action Overview394877 -Node: Statements397204 -Node: If Statement399052 -Node: While Statement400550 -Node: Do Statement402594 -Node: For Statement403750 -Node: Switch Statement406902 -Node: Break Statement409005 -Node: Continue Statement411060 -Node: Next Statement412853 -Node: Nextfile Statement415243 -Node: Exit Statement417898 -Node: Built-in Variables420302 -Node: User-modified421429 -Ref: User-modified-Footnote-1429114 -Node: Auto-set429176 -Ref: Auto-set-Footnote-1441722 -Ref: Auto-set-Footnote-2441927 -Node: ARGC and ARGV441983 -Node: Pattern Action Summary445822 -Node: Arrays448045 -Node: Array Basics449594 -Node: Array Intro450420 -Ref: figure-array-elements452393 -Node: Reference to Elements454800 -Node: Assigning Elements457073 -Node: Array Example457564 -Node: Scanning an Array459296 -Node: Controlling Scanning462311 -Ref: Controlling Scanning-Footnote-1467484 -Node: Delete467800 -Ref: Delete-Footnote-1470565 -Node: Numeric Array Subscripts470622 -Node: Uninitialized Subscripts472805 -Node: Multidimensional474430 -Node: Multiscanning477523 -Node: Arrays of Arrays479112 -Node: Arrays Summary483775 -Node: Functions485880 -Node: Built-in486753 -Node: Calling Built-in487831 -Node: Numeric Functions489819 -Ref: Numeric Functions-Footnote-1493653 -Ref: Numeric Functions-Footnote-2494010 -Ref: Numeric Functions-Footnote-3494058 -Node: String Functions494327 -Ref: String Functions-Footnote-1517338 -Ref: String Functions-Footnote-2517467 -Ref: String Functions-Footnote-3517715 -Node: Gory Details517802 -Ref: table-sub-escapes519471 -Ref: table-sub-posix-92520825 -Ref: table-sub-proposed522176 -Ref: table-posix-sub523530 -Ref: table-gensub-escapes525075 -Ref: Gory Details-Footnote-1526251 -Ref: Gory Details-Footnote-2526302 -Node: I/O Functions526453 -Ref: I/O Functions-Footnote-1533576 -Node: Time Functions533723 -Ref: Time Functions-Footnote-1544187 -Ref: Time Functions-Footnote-2544255 -Ref: Time Functions-Footnote-3544413 -Ref: Time Functions-Footnote-4544524 -Ref: Time Functions-Footnote-5544636 -Ref: Time Functions-Footnote-6544863 -Node: Bitwise Functions545129 -Ref: table-bitwise-ops545691 -Ref: Bitwise Functions-Footnote-1549936 -Node: Type Functions550120 -Node: I18N Functions551262 -Node: User-defined552907 -Node: Definition Syntax553711 -Ref: Definition Syntax-Footnote-1558636 -Node: Function Example558705 -Ref: Function Example-Footnote-1561349 -Node: Function Caveats561371 -Node: Calling A Function561889 -Node: Variable Scope562844 -Node: Pass By Value/Reference565832 -Node: Return Statement569340 -Node: Dynamic Typing572324 -Node: Indirect Calls573253 -Node: Functions Summary582966 -Node: Library Functions585505 -Ref: Library Functions-Footnote-1589080 -Ref: Library Functions-Footnote-2589223 -Node: Library Names589394 -Ref: Library Names-Footnote-1592867 -Ref: Library Names-Footnote-2593087 -Node: General Functions593173 -Node: Strtonum Function594201 -Node: Assert Function597131 -Node: Round Function600457 -Node: Cliff Random Function601998 -Node: Ordinal Functions603014 -Ref: Ordinal Functions-Footnote-1606091 -Ref: Ordinal Functions-Footnote-2606343 -Node: Join Function606554 -Ref: Join Function-Footnote-1608325 -Node: Getlocaltime Function608525 -Node: Readfile Function612261 -Node: Data File Management614100 -Node: Filetrans Function614732 -Node: Rewind Function618787 -Node: File Checking620174 -Ref: File Checking-Footnote-1621306 -Node: Empty Files621507 -Node: Ignoring Assigns623730 -Node: Getopt Function625263 -Ref: Getopt Function-Footnote-1636559 -Node: Passwd Functions636762 -Ref: Passwd Functions-Footnote-1645741 -Node: Group Functions645829 -Ref: Group Functions-Footnote-1653771 -Node: Walking Arrays653984 -Node: Library Functions Summary656154 -Node: Sample Programs657516 -Node: Running Examples658243 -Node: Clones658971 -Node: Cut Program660195 -Node: Egrep Program670056 -Ref: Egrep Program-Footnote-1677985 -Node: Id Program678095 -Node: Split Program681759 -Ref: Split Program-Footnote-1685290 -Node: Tee Program685418 -Node: Uniq Program688225 -Node: Wc Program695655 -Ref: Wc Program-Footnote-1699923 -Ref: Wc Program-Footnote-2700123 -Node: Miscellaneous Programs700215 -Node: Dupword Program701428 -Node: Alarm Program703459 -Node: Translate Program708273 -Ref: Translate Program-Footnote-1712664 -Ref: Translate Program-Footnote-2712934 -Node: Labels Program713068 -Ref: Labels Program-Footnote-1716439 -Node: Word Sorting716523 -Node: History Sorting720566 -Node: Extract Program722402 -Ref: Extract Program-Footnote-1729977 -Node: Simple Sed730106 -Node: Igawk Program733168 -Ref: Igawk Program-Footnote-1748344 -Ref: Igawk Program-Footnote-2748545 -Node: Anagram Program748683 -Node: Signature Program751751 -Node: Programs Summary752998 -Node: Advanced Features754186 -Node: Nondecimal Data756134 -Node: Array Sorting757711 -Node: Controlling Array Traversal758408 -Node: Array Sorting Functions766688 -Ref: Array Sorting Functions-Footnote-1770595 -Node: Two-way I/O770789 -Ref: Two-way I/O-Footnote-1776305 -Node: TCP/IP Networking776387 -Node: Profiling779231 -Node: Advanced Features Summary786773 -Node: Internationalization788637 -Node: I18N and L10N790117 -Node: Explaining gettext790803 -Ref: Explaining gettext-Footnote-1795943 -Ref: Explaining gettext-Footnote-2796127 -Node: Programmer i18n796292 -Node: Translator i18n800517 -Node: String Extraction801311 -Ref: String Extraction-Footnote-1802272 -Node: Printf Ordering802358 -Ref: Printf Ordering-Footnote-1805140 -Node: I18N Portability805204 -Ref: I18N Portability-Footnote-1807653 -Node: I18N Example807716 -Ref: I18N Example-Footnote-1810438 -Node: Gawk I18N810510 -Node: I18N Summary811148 -Node: Debugger812487 -Node: Debugging813509 -Node: Debugging Concepts813950 -Node: Debugging Terms815806 -Node: Awk Debugging818403 -Node: Sample Debugging Session819295 -Node: Debugger Invocation819815 -Node: Finding The Bug821148 -Node: List of Debugger Commands827630 -Node: Breakpoint Control828962 -Node: Debugger Execution Control832626 -Node: Viewing And Changing Data835986 -Node: Execution Stack839344 -Node: Debugger Info840857 -Node: Miscellaneous Debugger Commands844851 -Node: Readline Support850035 -Node: Limitations850927 -Node: Debugging Summary853201 -Node: Arbitrary Precision Arithmetic854365 -Ref: Arbitrary Precision Arithmetic-Footnote-1856014 -Node: General Arithmetic856162 -Node: Floating Point Issues857882 -Node: String Conversion Precision858763 -Ref: String Conversion Precision-Footnote-1860468 -Node: Unexpected Results860577 -Node: POSIX Floating Point Problems862730 -Ref: POSIX Floating Point Problems-Footnote-1866551 -Node: Integer Programming866589 -Node: Floating-point Programming868400 -Ref: Floating-point Programming-Footnote-1874728 -Ref: Floating-point Programming-Footnote-2874998 -Node: Floating-point Representation875262 -Node: Floating-point Context876427 -Ref: table-ieee-formats877266 -Node: Rounding Mode878650 -Ref: table-rounding-modes879129 -Ref: Rounding Mode-Footnote-1882144 -Node: Gawk and MPFR882323 -Node: Arbitrary Precision Floats883732 -Ref: Arbitrary Precision Floats-Footnote-1886175 -Node: Setting Precision886496 -Ref: table-predefined-precision-strings887180 -Node: Setting Rounding Mode889325 -Ref: table-gawk-rounding-modes889729 -Node: Floating-point Constants890916 -Node: Changing Precision892368 -Ref: Changing Precision-Footnote-1893760 -Node: Exact Arithmetic893934 -Node: Arbitrary Precision Integers897068 -Ref: Arbitrary Precision Integers-Footnote-1900083 -Node: Dynamic Extensions900230 -Node: Extension Intro901688 -Node: Plugin License902953 -Node: Extension Mechanism Outline903638 -Ref: figure-load-extension904062 -Ref: figure-load-new-function905547 -Ref: figure-call-new-function906549 -Node: Extension API Description908533 -Node: Extension API Functions Introduction909983 -Node: General Data Types914849 -Ref: General Data Types-Footnote-1920542 -Node: Requesting Values920841 -Ref: table-value-types-returned921578 -Node: Memory Allocation Functions922536 -Ref: Memory Allocation Functions-Footnote-1925283 -Node: Constructor Functions925379 -Node: Registration Functions927137 -Node: Extension Functions927822 -Node: Exit Callback Functions930124 -Node: Extension Version String931374 -Node: Input Parsers932024 -Node: Output Wrappers941827 -Node: Two-way processors946343 -Node: Printing Messages948547 -Ref: Printing Messages-Footnote-1949624 -Node: Updating `ERRNO'949776 -Node: Accessing Parameters950515 -Node: Symbol Table Access951745 -Node: Symbol table by name952259 -Node: Symbol table by cookie954235 -Ref: Symbol table by cookie-Footnote-1958368 -Node: Cached values958431 -Ref: Cached values-Footnote-1961936 -Node: Array Manipulation962027 -Ref: Array Manipulation-Footnote-1963125 -Node: Array Data Types963164 -Ref: Array Data Types-Footnote-1965867 -Node: Array Functions965959 -Node: Flattening Arrays969833 -Node: Creating Arrays976685 -Node: Extension API Variables981416 -Node: Extension Versioning982052 -Node: Extension API Informational Variables983953 -Node: Extension API Boilerplate985039 -Node: Finding Extensions988843 -Node: Extension Example989403 -Node: Internal File Description990133 -Node: Internal File Ops994224 -Ref: Internal File Ops-Footnote-11005770 -Node: Using Internal File Ops1005910 -Ref: Using Internal File Ops-Footnote-11008257 -Node: Extension Samples1008525 -Node: Extension Sample File Functions1010049 -Node: Extension Sample Fnmatch1017617 -Node: Extension Sample Fork1019084 -Node: Extension Sample Inplace1020297 -Node: Extension Sample Ord1022063 -Node: Extension Sample Readdir1022899 -Ref: table-readdir-file-types1023748 -Node: Extension Sample Revout1024547 -Node: Extension Sample Rev2way1025138 -Node: Extension Sample Read write array1025879 -Node: Extension Sample Readfile1027758 -Node: Extension Sample API Tests1028858 -Node: Extension Sample Time1029383 -Node: gawkextlib1030698 -Node: Language History1033485 -Node: V7/SVR3.11035079 -Node: SVR41037399 -Node: POSIX1038841 -Node: BTL1040227 -Node: POSIX/GNU1040961 -Node: Feature History1046560 -Node: Common Extensions1059672 -Node: Ranges and Locales1060984 -Ref: Ranges and Locales-Footnote-11065601 -Ref: Ranges and Locales-Footnote-21065628 -Ref: Ranges and Locales-Footnote-31065862 -Node: Contributors1066083 -Node: Installation1071521 -Node: Gawk Distribution1072415 -Node: Getting1072899 -Node: Extracting1073725 -Node: Distribution contents1075367 -Node: Unix Installation1081084 -Node: Quick Installation1081701 -Node: Additional Configuration Options1084143 -Node: Configuration Philosophy1085881 -Node: Non-Unix Installation1088232 -Node: PC Installation1088690 -Node: PC Binary Installation1090001 -Node: PC Compiling1091849 -Ref: PC Compiling-Footnote-11094848 -Node: PC Testing1094953 -Node: PC Using1096129 -Node: Cygwin1100287 -Node: MSYS1101096 -Node: VMS Installation1101610 -Node: VMS Compilation1102406 -Ref: VMS Compilation-Footnote-11103621 -Node: VMS Dynamic Extensions1103679 -Node: VMS Installation Details1105052 -Node: VMS Running1107298 -Node: VMS GNV1110132 -Node: VMS Old Gawk1110855 -Node: Bugs1111325 -Node: Other Versions1115329 -Node: Notes1121554 -Node: Compatibility Mode1122354 -Node: Additions1123136 -Node: Accessing The Source1124061 -Node: Adding Code1125497 -Node: New Ports1131675 -Node: Derived Files1136156 -Ref: Derived Files-Footnote-11141237 -Ref: Derived Files-Footnote-21141271 -Ref: Derived Files-Footnote-31141867 -Node: Future Extensions1141981 -Node: Implementation Limitations1142587 -Node: Extension Design1143835 -Node: Old Extension Problems1144989 -Ref: Old Extension Problems-Footnote-11146506 -Node: Extension New Mechanism Goals1146563 -Ref: Extension New Mechanism Goals-Footnote-11149924 -Node: Extension Other Design Decisions1150113 -Node: Extension Future Growth1152219 -Node: Old Extension Mechanism1153055 -Node: Basic Concepts1154795 -Node: Basic High Level1155476 -Ref: figure-general-flow1155748 -Ref: figure-process-flow1156347 -Ref: Basic High Level-Footnote-11159576 -Node: Basic Data Typing1159761 -Node: Glossary1163088 -Node: Copying1188240 -Node: GNU Free Documentation License1225796 -Node: Index1250932 +Node: Executable Scripts78251 +Ref: Executable Scripts-Footnote-180084 +Ref: Executable Scripts-Footnote-280186 +Node: Comments80733 +Node: Quoting83200 +Node: DOS Quoting88516 +Node: Sample Data Files89191 +Node: Very Simple91706 +Node: Two Rules96344 +Node: More Complex98239 +Ref: More Complex-Footnote-1101171 +Node: Statements/Lines101256 +Ref: Statements/Lines-Footnote-1105711 +Node: Other Features105976 +Node: When106904 +Node: Intro Summary109074 +Node: Invoking Gawk109840 +Node: Command Line111355 +Node: Options112146 +Ref: Options-Footnote-1127958 +Node: Other Arguments127983 +Node: Naming Standard Input130645 +Node: Environment Variables131739 +Node: AWKPATH Variable132297 +Ref: AWKPATH Variable-Footnote-1135169 +Ref: AWKPATH Variable-Footnote-2135214 +Node: AWKLIBPATH Variable135474 +Node: Other Environment Variables136233 +Node: Exit Status139888 +Node: Include Files140563 +Node: Loading Shared Libraries144141 +Node: Obsolete145525 +Node: Undocumented146222 +Node: Invoking Summary146489 +Node: Regexp148069 +Node: Regexp Usage149519 +Node: Escape Sequences151552 +Node: Regexp Operators157219 +Ref: Regexp Operators-Footnote-1164699 +Ref: Regexp Operators-Footnote-2164846 +Node: Bracket Expressions164944 +Ref: table-char-classes166834 +Node: GNU Regexp Operators169357 +Node: Case-sensitivity173080 +Ref: Case-sensitivity-Footnote-1175972 +Ref: Case-sensitivity-Footnote-2176207 +Node: Leftmost Longest176315 +Node: Computed Regexps177516 +Node: Regexp Summary180888 +Node: Reading Files182360 +Node: Records184409 +Node: awk split records185152 +Node: gawk split records190010 +Ref: gawk split records-Footnote-1194531 +Node: Fields194568 +Ref: Fields-Footnote-1197532 +Node: Nonconstant Fields197618 +Ref: Nonconstant Fields-Footnote-1199848 +Node: Changing Fields200050 +Node: Field Separators206004 +Node: Default Field Splitting208706 +Node: Regexp Field Splitting209823 +Node: Single Character Fields213164 +Node: Command Line Field Separator214223 +Node: Full Line Fields217565 +Ref: Full Line Fields-Footnote-1218073 +Node: Field Splitting Summary218119 +Ref: Field Splitting Summary-Footnote-1221218 +Node: Constant Size221319 +Node: Splitting By Content225926 +Ref: Splitting By Content-Footnote-1229676 +Node: Multiple Line229716 +Ref: Multiple Line-Footnote-1235572 +Node: Getline235751 +Node: Plain Getline237967 +Node: Getline/Variable240062 +Node: Getline/File241209 +Node: Getline/Variable/File242593 +Ref: Getline/Variable/File-Footnote-1244192 +Node: Getline/Pipe244279 +Node: Getline/Variable/Pipe246978 +Node: Getline/Coprocess248085 +Node: Getline/Variable/Coprocess249337 +Node: Getline Notes250074 +Node: Getline Summary252878 +Ref: table-getline-variants253286 +Node: Read Timeout254198 +Ref: Read Timeout-Footnote-1258025 +Node: Command line directories258083 +Node: Input Summary258987 +Node: Printing262101 +Node: Print263780 +Node: Print Examples265121 +Node: Output Separators267900 +Node: OFMT269916 +Node: Printf271274 +Node: Basic Printf272180 +Node: Control Letters273719 +Node: Format Modifiers277573 +Node: Printf Examples283600 +Node: Redirection286307 +Node: Special Files293297 +Node: Special FD293828 +Ref: Special FD-Footnote-1297452 +Node: Special Network297526 +Node: Special Caveats298376 +Node: Close Files And Pipes299172 +Ref: Close Files And Pipes-Footnote-1306335 +Ref: Close Files And Pipes-Footnote-2306483 +Node: Output Summary306633 +Node: Expressions307605 +Node: Values308790 +Node: Constants309466 +Node: Scalar Constants310146 +Ref: Scalar Constants-Footnote-1311005 +Node: Nondecimal-numbers311255 +Node: Regexp Constants314255 +Node: Using Constant Regexps314730 +Node: Variables317800 +Node: Using Variables318455 +Node: Assignment Options320179 +Node: Conversion322054 +Ref: table-locale-affects327490 +Ref: Conversion-Footnote-1328114 +Node: All Operators328223 +Node: Arithmetic Ops328853 +Node: Concatenation331358 +Ref: Concatenation-Footnote-1334154 +Node: Assignment Ops334274 +Ref: table-assign-ops339257 +Node: Increment Ops340574 +Node: Truth Values and Conditions344012 +Node: Truth Values345095 +Node: Typing and Comparison346144 +Node: Variable Typing346937 +Ref: Variable Typing-Footnote-1350837 +Node: Comparison Operators350959 +Ref: table-relational-ops351369 +Node: POSIX String Comparison354919 +Ref: POSIX String Comparison-Footnote-1356003 +Node: Boolean Ops356141 +Ref: Boolean Ops-Footnote-1360211 +Node: Conditional Exp360302 +Node: Function Calls362029 +Node: Precedence365787 +Node: Locales369456 +Node: Expressions Summary371087 +Node: Patterns and Actions373584 +Node: Pattern Overview374700 +Node: Regexp Patterns376377 +Node: Expression Patterns376920 +Node: Ranges380701 +Node: BEGIN/END383807 +Node: Using BEGIN/END384569 +Ref: Using BEGIN/END-Footnote-1387305 +Node: I/O And BEGIN/END387411 +Node: BEGINFILE/ENDFILE389696 +Node: Empty392627 +Node: Using Shell Variables392944 +Node: Action Overview395227 +Node: Statements397554 +Node: If Statement399402 +Node: While Statement400900 +Node: Do Statement402944 +Node: For Statement404100 +Node: Switch Statement407252 +Node: Break Statement409355 +Node: Continue Statement411410 +Node: Next Statement413203 +Node: Nextfile Statement415593 +Node: Exit Statement418248 +Node: Built-in Variables420652 +Node: User-modified421779 +Ref: User-modified-Footnote-1429464 +Node: Auto-set429526 +Ref: Auto-set-Footnote-1442091 +Ref: Auto-set-Footnote-2442296 +Node: ARGC and ARGV442352 +Node: Pattern Action Summary446206 +Node: Arrays448429 +Node: Array Basics449978 +Node: Array Intro450804 +Ref: figure-array-elements452777 +Node: Reference to Elements455184 +Node: Assigning Elements457457 +Node: Array Example457948 +Node: Scanning an Array459680 +Node: Controlling Scanning462695 +Ref: Controlling Scanning-Footnote-1467868 +Node: Delete468184 +Ref: Delete-Footnote-1470949 +Node: Numeric Array Subscripts471006 +Node: Uninitialized Subscripts473189 +Node: Multidimensional474814 +Node: Multiscanning477907 +Node: Arrays of Arrays479496 +Node: Arrays Summary484159 +Node: Functions486264 +Node: Built-in487137 +Node: Calling Built-in488215 +Node: Numeric Functions490203 +Ref: Numeric Functions-Footnote-1494037 +Ref: Numeric Functions-Footnote-2494394 +Ref: Numeric Functions-Footnote-3494442 +Node: String Functions494711 +Ref: String Functions-Footnote-1517722 +Ref: String Functions-Footnote-2517851 +Ref: String Functions-Footnote-3518099 +Node: Gory Details518186 +Ref: table-sub-escapes519855 +Ref: table-sub-posix-92521209 +Ref: table-sub-proposed522560 +Ref: table-posix-sub523914 +Ref: table-gensub-escapes525459 +Ref: Gory Details-Footnote-1526635 +Ref: Gory Details-Footnote-2526686 +Node: I/O Functions526837 +Ref: I/O Functions-Footnote-1533960 +Node: Time Functions534107 +Ref: Time Functions-Footnote-1544571 +Ref: Time Functions-Footnote-2544639 +Ref: Time Functions-Footnote-3544797 +Ref: Time Functions-Footnote-4544908 +Ref: Time Functions-Footnote-5545020 +Ref: Time Functions-Footnote-6545247 +Node: Bitwise Functions545513 +Ref: table-bitwise-ops546075 +Ref: Bitwise Functions-Footnote-1550320 +Node: Type Functions550504 +Node: I18N Functions551646 +Node: User-defined553291 +Node: Definition Syntax554095 +Ref: Definition Syntax-Footnote-1559020 +Node: Function Example559089 +Ref: Function Example-Footnote-1561733 +Node: Function Caveats561755 +Node: Calling A Function562273 +Node: Variable Scope563228 +Node: Pass By Value/Reference566216 +Node: Return Statement569724 +Node: Dynamic Typing572708 +Node: Indirect Calls573637 +Node: Functions Summary583350 +Node: Library Functions585889 +Ref: Library Functions-Footnote-1589464 +Ref: Library Functions-Footnote-2589607 +Node: Library Names589778 +Ref: Library Names-Footnote-1593251 +Ref: Library Names-Footnote-2593471 +Node: General Functions593557 +Node: Strtonum Function594585 +Node: Assert Function597515 +Node: Round Function600841 +Node: Cliff Random Function602382 +Node: Ordinal Functions603398 +Ref: Ordinal Functions-Footnote-1606475 +Ref: Ordinal Functions-Footnote-2606727 +Node: Join Function606938 +Ref: Join Function-Footnote-1608709 +Node: Getlocaltime Function608909 +Node: Readfile Function612645 +Node: Data File Management614484 +Node: Filetrans Function615116 +Node: Rewind Function619185 +Node: File Checking620572 +Ref: File Checking-Footnote-1621704 +Node: Empty Files621905 +Node: Ignoring Assigns624135 +Node: Getopt Function625689 +Ref: Getopt Function-Footnote-1636992 +Node: Passwd Functions637195 +Ref: Passwd Functions-Footnote-1646174 +Node: Group Functions646262 +Ref: Group Functions-Footnote-1654204 +Node: Walking Arrays654417 +Node: Library Functions Summary656587 +Node: Sample Programs657949 +Node: Running Examples658676 +Node: Clones659404 +Node: Cut Program660628 +Node: Egrep Program670496 +Ref: Egrep Program-Footnote-1678467 +Node: Id Program678577 +Node: Split Program682241 +Ref: Split Program-Footnote-1685779 +Node: Tee Program685907 +Node: Uniq Program688714 +Node: Wc Program696144 +Ref: Wc Program-Footnote-1700412 +Ref: Wc Program-Footnote-2700612 +Node: Miscellaneous Programs700704 +Node: Dupword Program701917 +Node: Alarm Program703948 +Node: Translate Program708762 +Ref: Translate Program-Footnote-1713153 +Ref: Translate Program-Footnote-2713423 +Node: Labels Program713557 +Ref: Labels Program-Footnote-1716928 +Node: Word Sorting717012 +Node: History Sorting721055 +Node: Extract Program722891 +Ref: Extract Program-Footnote-1730466 +Node: Simple Sed730595 +Node: Igawk Program733657 +Ref: Igawk Program-Footnote-1748833 +Ref: Igawk Program-Footnote-2749034 +Node: Anagram Program749172 +Node: Signature Program752240 +Node: Programs Summary753487 +Node: Advanced Features754675 +Node: Nondecimal Data756623 +Node: Array Sorting758200 +Node: Controlling Array Traversal758897 +Node: Array Sorting Functions767177 +Ref: Array Sorting Functions-Footnote-1771084 +Node: Two-way I/O771278 +Ref: Two-way I/O-Footnote-1776794 +Node: TCP/IP Networking776876 +Node: Profiling779720 +Node: Advanced Features Summary787262 +Node: Internationalization789126 +Node: I18N and L10N790606 +Node: Explaining gettext791292 +Ref: Explaining gettext-Footnote-1796432 +Ref: Explaining gettext-Footnote-2796616 +Node: Programmer i18n796781 +Node: Translator i18n801006 +Node: String Extraction801800 +Ref: String Extraction-Footnote-1802761 +Node: Printf Ordering802847 +Ref: Printf Ordering-Footnote-1805629 +Node: I18N Portability805693 +Ref: I18N Portability-Footnote-1808142 +Node: I18N Example808205 +Ref: I18N Example-Footnote-1810927 +Node: Gawk I18N810999 +Node: I18N Summary811637 +Node: Debugger812976 +Node: Debugging813998 +Node: Debugging Concepts814439 +Node: Debugging Terms816295 +Node: Awk Debugging818892 +Node: Sample Debugging Session819784 +Node: Debugger Invocation820304 +Node: Finding The Bug821637 +Node: List of Debugger Commands828119 +Node: Breakpoint Control829451 +Node: Debugger Execution Control833115 +Node: Viewing And Changing Data836475 +Node: Execution Stack839833 +Node: Debugger Info841346 +Node: Miscellaneous Debugger Commands845340 +Node: Readline Support850524 +Node: Limitations851416 +Node: Debugging Summary853690 +Node: Arbitrary Precision Arithmetic854854 +Ref: Arbitrary Precision Arithmetic-Footnote-1856503 +Node: General Arithmetic856651 +Node: Floating Point Issues858371 +Node: String Conversion Precision859252 +Ref: String Conversion Precision-Footnote-1860957 +Node: Unexpected Results861066 +Node: POSIX Floating Point Problems863219 +Ref: POSIX Floating Point Problems-Footnote-1867040 +Node: Integer Programming867078 +Node: Floating-point Programming868889 +Ref: Floating-point Programming-Footnote-1875217 +Ref: Floating-point Programming-Footnote-2875487 +Node: Floating-point Representation875751 +Node: Floating-point Context876916 +Ref: table-ieee-formats877755 +Node: Rounding Mode879139 +Ref: table-rounding-modes879618 +Ref: Rounding Mode-Footnote-1882633 +Node: Gawk and MPFR882812 +Node: Arbitrary Precision Floats884221 +Ref: Arbitrary Precision Floats-Footnote-1886664 +Node: Setting Precision886985 +Ref: table-predefined-precision-strings887669 +Node: Setting Rounding Mode889814 +Ref: table-gawk-rounding-modes890218 +Node: Floating-point Constants891405 +Node: Changing Precision892857 +Ref: Changing Precision-Footnote-1894249 +Node: Exact Arithmetic894423 +Node: Arbitrary Precision Integers897557 +Ref: Arbitrary Precision Integers-Footnote-1900572 +Node: Dynamic Extensions900719 +Node: Extension Intro902177 +Node: Plugin License903442 +Node: Extension Mechanism Outline904127 +Ref: figure-load-extension904551 +Ref: figure-load-new-function906036 +Ref: figure-call-new-function907038 +Node: Extension API Description909022 +Node: Extension API Functions Introduction910472 +Node: General Data Types915338 +Ref: General Data Types-Footnote-1921031 +Node: Requesting Values921330 +Ref: table-value-types-returned922067 +Node: Memory Allocation Functions923025 +Ref: Memory Allocation Functions-Footnote-1925772 +Node: Constructor Functions925868 +Node: Registration Functions927626 +Node: Extension Functions928311 +Node: Exit Callback Functions930613 +Node: Extension Version String931862 +Node: Input Parsers932512 +Node: Output Wrappers942315 +Node: Two-way processors946831 +Node: Printing Messages949035 +Ref: Printing Messages-Footnote-1950112 +Node: Updating `ERRNO'950264 +Node: Accessing Parameters951003 +Node: Symbol Table Access952233 +Node: Symbol table by name952747 +Node: Symbol table by cookie954723 +Ref: Symbol table by cookie-Footnote-1958856 +Node: Cached values958919 +Ref: Cached values-Footnote-1962423 +Node: Array Manipulation962514 +Ref: Array Manipulation-Footnote-1963612 +Node: Array Data Types963651 +Ref: Array Data Types-Footnote-1966354 +Node: Array Functions966446 +Node: Flattening Arrays970320 +Node: Creating Arrays977172 +Node: Extension API Variables981903 +Node: Extension Versioning982539 +Node: Extension API Informational Variables984440 +Node: Extension API Boilerplate985526 +Node: Finding Extensions989330 +Node: Extension Example989890 +Node: Internal File Description990620 +Node: Internal File Ops994711 +Ref: Internal File Ops-Footnote-11006257 +Node: Using Internal File Ops1006397 +Ref: Using Internal File Ops-Footnote-11008744 +Node: Extension Samples1009012 +Node: Extension Sample File Functions1010536 +Node: Extension Sample Fnmatch1018104 +Node: Extension Sample Fork1019585 +Node: Extension Sample Inplace1020798 +Node: Extension Sample Ord1022578 +Node: Extension Sample Readdir1023414 +Ref: table-readdir-file-types1024270 +Node: Extension Sample Revout1025069 +Node: Extension Sample Rev2way1025660 +Node: Extension Sample Read write array1026401 +Node: Extension Sample Readfile1028280 +Node: Extension Sample API Tests1029380 +Node: Extension Sample Time1029905 +Node: gawkextlib1031220 +Node: Language History1034007 +Node: V7/SVR3.11035601 +Node: SVR41037921 +Node: POSIX1039363 +Node: BTL1040749 +Node: POSIX/GNU1041483 +Node: Feature History1047082 +Node: Common Extensions1060194 +Node: Ranges and Locales1061506 +Ref: Ranges and Locales-Footnote-11066123 +Ref: Ranges and Locales-Footnote-21066150 +Ref: Ranges and Locales-Footnote-31066384 +Node: Contributors1066605 +Node: Installation1072043 +Node: Gawk Distribution1072937 +Node: Getting1073421 +Node: Extracting1074247 +Node: Distribution contents1075889 +Node: Unix Installation1081606 +Node: Quick Installation1082223 +Node: Additional Configuration Options1084665 +Node: Configuration Philosophy1086403 +Node: Non-Unix Installation1088754 +Node: PC Installation1089212 +Node: PC Binary Installation1090523 +Node: PC Compiling1092371 +Ref: PC Compiling-Footnote-11095370 +Node: PC Testing1095475 +Node: PC Using1096651 +Node: Cygwin1100809 +Node: MSYS1101618 +Node: VMS Installation1102132 +Node: VMS Compilation1102928 +Ref: VMS Compilation-Footnote-11104150 +Node: VMS Dynamic Extensions1104208 +Node: VMS Installation Details1105581 +Node: VMS Running1107833 +Node: VMS GNV1110667 +Node: VMS Old Gawk1111390 +Node: Bugs1111860 +Node: Other Versions1115864 +Node: Notes1122089 +Node: Compatibility Mode1122889 +Node: Additions1123671 +Node: Accessing The Source1124596 +Node: Adding Code1126032 +Node: New Ports1132210 +Node: Derived Files1136691 +Ref: Derived Files-Footnote-11141772 +Ref: Derived Files-Footnote-21141806 +Ref: Derived Files-Footnote-31142402 +Node: Future Extensions1142516 +Node: Implementation Limitations1143122 +Node: Extension Design1144370 +Node: Old Extension Problems1145524 +Ref: Old Extension Problems-Footnote-11147041 +Node: Extension New Mechanism Goals1147098 +Ref: Extension New Mechanism Goals-Footnote-11150458 +Node: Extension Other Design Decisions1150647 +Node: Extension Future Growth1152753 +Node: Old Extension Mechanism1153589 +Node: Basic Concepts1155329 +Node: Basic High Level1156010 +Ref: figure-general-flow1156282 +Ref: figure-process-flow1156881 +Ref: Basic High Level-Footnote-11160110 +Node: Basic Data Typing1160295 +Node: Glossary1163622 +Node: Copying1188774 +Node: GNU Free Documentation License1226330 +Node: Index1251466  End Tag Table -- cgit v1.2.3 From 4f04830cdcef50ac2449b6dbc97c67acc4ec238d Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 13 Jun 2014 08:06:51 +0300 Subject: Another typo fix. --- doc/gawk.info | 852 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 426 insertions(+), 426 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 39aa56b1..2e30ad95 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -6577,9 +6577,9 @@ work identically for `printf': `print ITEMS > OUTPUT-FILE' This redirection prints the items into the output file named - {No value for `output-file'}. The file name OUTPUT-FILE can be any - expression. Its value is changed to a string and then used as a - file name (*note Expressions::). + OUTPUT-FILE. The file name OUTPUT-FILE can be any expression. + Its value is changed to a string and then used as a file name + (*note Expressions::). When this type of redirection is used, the OUTPUT-FILE is erased before the first output is written to it. Subsequent writes to @@ -33948,428 +33948,428 @@ Node: Control Letters273719 Node: Format Modifiers277573 Node: Printf Examples283600 Node: Redirection286307 -Node: Special Files293297 -Node: Special FD293828 -Ref: Special FD-Footnote-1297452 -Node: Special Network297526 -Node: Special Caveats298376 -Node: Close Files And Pipes299172 -Ref: Close Files And Pipes-Footnote-1306335 -Ref: Close Files And Pipes-Footnote-2306483 -Node: Output Summary306633 -Node: Expressions307605 -Node: Values308790 -Node: Constants309466 -Node: Scalar Constants310146 -Ref: Scalar Constants-Footnote-1311005 -Node: Nondecimal-numbers311255 -Node: Regexp Constants314255 -Node: Using Constant Regexps314730 -Node: Variables317800 -Node: Using Variables318455 -Node: Assignment Options320179 -Node: Conversion322054 -Ref: table-locale-affects327490 -Ref: Conversion-Footnote-1328114 -Node: All Operators328223 -Node: Arithmetic Ops328853 -Node: Concatenation331358 -Ref: Concatenation-Footnote-1334154 -Node: Assignment Ops334274 -Ref: table-assign-ops339257 -Node: Increment Ops340574 -Node: Truth Values and Conditions344012 -Node: Truth Values345095 -Node: Typing and Comparison346144 -Node: Variable Typing346937 -Ref: Variable Typing-Footnote-1350837 -Node: Comparison Operators350959 -Ref: table-relational-ops351369 -Node: POSIX String Comparison354919 -Ref: POSIX String Comparison-Footnote-1356003 -Node: Boolean Ops356141 -Ref: Boolean Ops-Footnote-1360211 -Node: Conditional Exp360302 -Node: Function Calls362029 -Node: Precedence365787 -Node: Locales369456 -Node: Expressions Summary371087 -Node: Patterns and Actions373584 -Node: Pattern Overview374700 -Node: Regexp Patterns376377 -Node: Expression Patterns376920 -Node: Ranges380701 -Node: BEGIN/END383807 -Node: Using BEGIN/END384569 -Ref: Using BEGIN/END-Footnote-1387305 -Node: I/O And BEGIN/END387411 -Node: BEGINFILE/ENDFILE389696 -Node: Empty392627 -Node: Using Shell Variables392944 -Node: Action Overview395227 -Node: Statements397554 -Node: If Statement399402 -Node: While Statement400900 -Node: Do Statement402944 -Node: For Statement404100 -Node: Switch Statement407252 -Node: Break Statement409355 -Node: Continue Statement411410 -Node: Next Statement413203 -Node: Nextfile Statement415593 -Node: Exit Statement418248 -Node: Built-in Variables420652 -Node: User-modified421779 -Ref: User-modified-Footnote-1429464 -Node: Auto-set429526 -Ref: Auto-set-Footnote-1442091 -Ref: Auto-set-Footnote-2442296 -Node: ARGC and ARGV442352 -Node: Pattern Action Summary446206 -Node: Arrays448429 -Node: Array Basics449978 -Node: Array Intro450804 -Ref: figure-array-elements452777 -Node: Reference to Elements455184 -Node: Assigning Elements457457 -Node: Array Example457948 -Node: Scanning an Array459680 -Node: Controlling Scanning462695 -Ref: Controlling Scanning-Footnote-1467868 -Node: Delete468184 -Ref: Delete-Footnote-1470949 -Node: Numeric Array Subscripts471006 -Node: Uninitialized Subscripts473189 -Node: Multidimensional474814 -Node: Multiscanning477907 -Node: Arrays of Arrays479496 -Node: Arrays Summary484159 -Node: Functions486264 -Node: Built-in487137 -Node: Calling Built-in488215 -Node: Numeric Functions490203 -Ref: Numeric Functions-Footnote-1494037 -Ref: Numeric Functions-Footnote-2494394 -Ref: Numeric Functions-Footnote-3494442 -Node: String Functions494711 -Ref: String Functions-Footnote-1517722 -Ref: String Functions-Footnote-2517851 -Ref: String Functions-Footnote-3518099 -Node: Gory Details518186 -Ref: table-sub-escapes519855 -Ref: table-sub-posix-92521209 -Ref: table-sub-proposed522560 -Ref: table-posix-sub523914 -Ref: table-gensub-escapes525459 -Ref: Gory Details-Footnote-1526635 -Ref: Gory Details-Footnote-2526686 -Node: I/O Functions526837 -Ref: I/O Functions-Footnote-1533960 -Node: Time Functions534107 -Ref: Time Functions-Footnote-1544571 -Ref: Time Functions-Footnote-2544639 -Ref: Time Functions-Footnote-3544797 -Ref: Time Functions-Footnote-4544908 -Ref: Time Functions-Footnote-5545020 -Ref: Time Functions-Footnote-6545247 -Node: Bitwise Functions545513 -Ref: table-bitwise-ops546075 -Ref: Bitwise Functions-Footnote-1550320 -Node: Type Functions550504 -Node: I18N Functions551646 -Node: User-defined553291 -Node: Definition Syntax554095 -Ref: Definition Syntax-Footnote-1559020 -Node: Function Example559089 -Ref: Function Example-Footnote-1561733 -Node: Function Caveats561755 -Node: Calling A Function562273 -Node: Variable Scope563228 -Node: Pass By Value/Reference566216 -Node: Return Statement569724 -Node: Dynamic Typing572708 -Node: Indirect Calls573637 -Node: Functions Summary583350 -Node: Library Functions585889 -Ref: Library Functions-Footnote-1589464 -Ref: Library Functions-Footnote-2589607 -Node: Library Names589778 -Ref: Library Names-Footnote-1593251 -Ref: Library Names-Footnote-2593471 -Node: General Functions593557 -Node: Strtonum Function594585 -Node: Assert Function597515 -Node: Round Function600841 -Node: Cliff Random Function602382 -Node: Ordinal Functions603398 -Ref: Ordinal Functions-Footnote-1606475 -Ref: Ordinal Functions-Footnote-2606727 -Node: Join Function606938 -Ref: Join Function-Footnote-1608709 -Node: Getlocaltime Function608909 -Node: Readfile Function612645 -Node: Data File Management614484 -Node: Filetrans Function615116 -Node: Rewind Function619185 -Node: File Checking620572 -Ref: File Checking-Footnote-1621704 -Node: Empty Files621905 -Node: Ignoring Assigns624135 -Node: Getopt Function625689 -Ref: Getopt Function-Footnote-1636992 -Node: Passwd Functions637195 -Ref: Passwd Functions-Footnote-1646174 -Node: Group Functions646262 -Ref: Group Functions-Footnote-1654204 -Node: Walking Arrays654417 -Node: Library Functions Summary656587 -Node: Sample Programs657949 -Node: Running Examples658676 -Node: Clones659404 -Node: Cut Program660628 -Node: Egrep Program670496 -Ref: Egrep Program-Footnote-1678467 -Node: Id Program678577 -Node: Split Program682241 -Ref: Split Program-Footnote-1685779 -Node: Tee Program685907 -Node: Uniq Program688714 -Node: Wc Program696144 -Ref: Wc Program-Footnote-1700412 -Ref: Wc Program-Footnote-2700612 -Node: Miscellaneous Programs700704 -Node: Dupword Program701917 -Node: Alarm Program703948 -Node: Translate Program708762 -Ref: Translate Program-Footnote-1713153 -Ref: Translate Program-Footnote-2713423 -Node: Labels Program713557 -Ref: Labels Program-Footnote-1716928 -Node: Word Sorting717012 -Node: History Sorting721055 -Node: Extract Program722891 -Ref: Extract Program-Footnote-1730466 -Node: Simple Sed730595 -Node: Igawk Program733657 -Ref: Igawk Program-Footnote-1748833 -Ref: Igawk Program-Footnote-2749034 -Node: Anagram Program749172 -Node: Signature Program752240 -Node: Programs Summary753487 -Node: Advanced Features754675 -Node: Nondecimal Data756623 -Node: Array Sorting758200 -Node: Controlling Array Traversal758897 -Node: Array Sorting Functions767177 -Ref: Array Sorting Functions-Footnote-1771084 -Node: Two-way I/O771278 -Ref: Two-way I/O-Footnote-1776794 -Node: TCP/IP Networking776876 -Node: Profiling779720 -Node: Advanced Features Summary787262 -Node: Internationalization789126 -Node: I18N and L10N790606 -Node: Explaining gettext791292 -Ref: Explaining gettext-Footnote-1796432 -Ref: Explaining gettext-Footnote-2796616 -Node: Programmer i18n796781 -Node: Translator i18n801006 -Node: String Extraction801800 -Ref: String Extraction-Footnote-1802761 -Node: Printf Ordering802847 -Ref: Printf Ordering-Footnote-1805629 -Node: I18N Portability805693 -Ref: I18N Portability-Footnote-1808142 -Node: I18N Example808205 -Ref: I18N Example-Footnote-1810927 -Node: Gawk I18N810999 -Node: I18N Summary811637 -Node: Debugger812976 -Node: Debugging813998 -Node: Debugging Concepts814439 -Node: Debugging Terms816295 -Node: Awk Debugging818892 -Node: Sample Debugging Session819784 -Node: Debugger Invocation820304 -Node: Finding The Bug821637 -Node: List of Debugger Commands828119 -Node: Breakpoint Control829451 -Node: Debugger Execution Control833115 -Node: Viewing And Changing Data836475 -Node: Execution Stack839833 -Node: Debugger Info841346 -Node: Miscellaneous Debugger Commands845340 -Node: Readline Support850524 -Node: Limitations851416 -Node: Debugging Summary853690 -Node: Arbitrary Precision Arithmetic854854 -Ref: Arbitrary Precision Arithmetic-Footnote-1856503 -Node: General Arithmetic856651 -Node: Floating Point Issues858371 -Node: String Conversion Precision859252 -Ref: String Conversion Precision-Footnote-1860957 -Node: Unexpected Results861066 -Node: POSIX Floating Point Problems863219 -Ref: POSIX Floating Point Problems-Footnote-1867040 -Node: Integer Programming867078 -Node: Floating-point Programming868889 -Ref: Floating-point Programming-Footnote-1875217 -Ref: Floating-point Programming-Footnote-2875487 -Node: Floating-point Representation875751 -Node: Floating-point Context876916 -Ref: table-ieee-formats877755 -Node: Rounding Mode879139 -Ref: table-rounding-modes879618 -Ref: Rounding Mode-Footnote-1882633 -Node: Gawk and MPFR882812 -Node: Arbitrary Precision Floats884221 -Ref: Arbitrary Precision Floats-Footnote-1886664 -Node: Setting Precision886985 -Ref: table-predefined-precision-strings887669 -Node: Setting Rounding Mode889814 -Ref: table-gawk-rounding-modes890218 -Node: Floating-point Constants891405 -Node: Changing Precision892857 -Ref: Changing Precision-Footnote-1894249 -Node: Exact Arithmetic894423 -Node: Arbitrary Precision Integers897557 -Ref: Arbitrary Precision Integers-Footnote-1900572 -Node: Dynamic Extensions900719 -Node: Extension Intro902177 -Node: Plugin License903442 -Node: Extension Mechanism Outline904127 -Ref: figure-load-extension904551 -Ref: figure-load-new-function906036 -Ref: figure-call-new-function907038 -Node: Extension API Description909022 -Node: Extension API Functions Introduction910472 -Node: General Data Types915338 -Ref: General Data Types-Footnote-1921031 -Node: Requesting Values921330 -Ref: table-value-types-returned922067 -Node: Memory Allocation Functions923025 -Ref: Memory Allocation Functions-Footnote-1925772 -Node: Constructor Functions925868 -Node: Registration Functions927626 -Node: Extension Functions928311 -Node: Exit Callback Functions930613 -Node: Extension Version String931862 -Node: Input Parsers932512 -Node: Output Wrappers942315 -Node: Two-way processors946831 -Node: Printing Messages949035 -Ref: Printing Messages-Footnote-1950112 -Node: Updating `ERRNO'950264 -Node: Accessing Parameters951003 -Node: Symbol Table Access952233 -Node: Symbol table by name952747 -Node: Symbol table by cookie954723 -Ref: Symbol table by cookie-Footnote-1958856 -Node: Cached values958919 -Ref: Cached values-Footnote-1962423 -Node: Array Manipulation962514 -Ref: Array Manipulation-Footnote-1963612 -Node: Array Data Types963651 -Ref: Array Data Types-Footnote-1966354 -Node: Array Functions966446 -Node: Flattening Arrays970320 -Node: Creating Arrays977172 -Node: Extension API Variables981903 -Node: Extension Versioning982539 -Node: Extension API Informational Variables984440 -Node: Extension API Boilerplate985526 -Node: Finding Extensions989330 -Node: Extension Example989890 -Node: Internal File Description990620 -Node: Internal File Ops994711 -Ref: Internal File Ops-Footnote-11006257 -Node: Using Internal File Ops1006397 -Ref: Using Internal File Ops-Footnote-11008744 -Node: Extension Samples1009012 -Node: Extension Sample File Functions1010536 -Node: Extension Sample Fnmatch1018104 -Node: Extension Sample Fork1019585 -Node: Extension Sample Inplace1020798 -Node: Extension Sample Ord1022578 -Node: Extension Sample Readdir1023414 -Ref: table-readdir-file-types1024270 -Node: Extension Sample Revout1025069 -Node: Extension Sample Rev2way1025660 -Node: Extension Sample Read write array1026401 -Node: Extension Sample Readfile1028280 -Node: Extension Sample API Tests1029380 -Node: Extension Sample Time1029905 -Node: gawkextlib1031220 -Node: Language History1034007 -Node: V7/SVR3.11035601 -Node: SVR41037921 -Node: POSIX1039363 -Node: BTL1040749 -Node: POSIX/GNU1041483 -Node: Feature History1047082 -Node: Common Extensions1060194 -Node: Ranges and Locales1061506 -Ref: Ranges and Locales-Footnote-11066123 -Ref: Ranges and Locales-Footnote-21066150 -Ref: Ranges and Locales-Footnote-31066384 -Node: Contributors1066605 -Node: Installation1072043 -Node: Gawk Distribution1072937 -Node: Getting1073421 -Node: Extracting1074247 -Node: Distribution contents1075889 -Node: Unix Installation1081606 -Node: Quick Installation1082223 -Node: Additional Configuration Options1084665 -Node: Configuration Philosophy1086403 -Node: Non-Unix Installation1088754 -Node: PC Installation1089212 -Node: PC Binary Installation1090523 -Node: PC Compiling1092371 -Ref: PC Compiling-Footnote-11095370 -Node: PC Testing1095475 -Node: PC Using1096651 -Node: Cygwin1100809 -Node: MSYS1101618 -Node: VMS Installation1102132 -Node: VMS Compilation1102928 -Ref: VMS Compilation-Footnote-11104150 -Node: VMS Dynamic Extensions1104208 -Node: VMS Installation Details1105581 -Node: VMS Running1107833 -Node: VMS GNV1110667 -Node: VMS Old Gawk1111390 -Node: Bugs1111860 -Node: Other Versions1115864 -Node: Notes1122089 -Node: Compatibility Mode1122889 -Node: Additions1123671 -Node: Accessing The Source1124596 -Node: Adding Code1126032 -Node: New Ports1132210 -Node: Derived Files1136691 -Ref: Derived Files-Footnote-11141772 -Ref: Derived Files-Footnote-21141806 -Ref: Derived Files-Footnote-31142402 -Node: Future Extensions1142516 -Node: Implementation Limitations1143122 -Node: Extension Design1144370 -Node: Old Extension Problems1145524 -Ref: Old Extension Problems-Footnote-11147041 -Node: Extension New Mechanism Goals1147098 -Ref: Extension New Mechanism Goals-Footnote-11150458 -Node: Extension Other Design Decisions1150647 -Node: Extension Future Growth1152753 -Node: Old Extension Mechanism1153589 -Node: Basic Concepts1155329 -Node: Basic High Level1156010 -Ref: figure-general-flow1156282 -Ref: figure-process-flow1156881 -Ref: Basic High Level-Footnote-11160110 -Node: Basic Data Typing1160295 -Node: Glossary1163622 -Node: Copying1188774 -Node: GNU Free Documentation License1226330 -Node: Index1251466 +Node: Special Files293279 +Node: Special FD293810 +Ref: Special FD-Footnote-1297434 +Node: Special Network297508 +Node: Special Caveats298358 +Node: Close Files And Pipes299154 +Ref: Close Files And Pipes-Footnote-1306317 +Ref: Close Files And Pipes-Footnote-2306465 +Node: Output Summary306615 +Node: Expressions307587 +Node: Values308772 +Node: Constants309448 +Node: Scalar Constants310128 +Ref: Scalar Constants-Footnote-1310987 +Node: Nondecimal-numbers311237 +Node: Regexp Constants314237 +Node: Using Constant Regexps314712 +Node: Variables317782 +Node: Using Variables318437 +Node: Assignment Options320161 +Node: Conversion322036 +Ref: table-locale-affects327472 +Ref: Conversion-Footnote-1328096 +Node: All Operators328205 +Node: Arithmetic Ops328835 +Node: Concatenation331340 +Ref: Concatenation-Footnote-1334136 +Node: Assignment Ops334256 +Ref: table-assign-ops339239 +Node: Increment Ops340556 +Node: Truth Values and Conditions343994 +Node: Truth Values345077 +Node: Typing and Comparison346126 +Node: Variable Typing346919 +Ref: Variable Typing-Footnote-1350819 +Node: Comparison Operators350941 +Ref: table-relational-ops351351 +Node: POSIX String Comparison354901 +Ref: POSIX String Comparison-Footnote-1355985 +Node: Boolean Ops356123 +Ref: Boolean Ops-Footnote-1360193 +Node: Conditional Exp360284 +Node: Function Calls362011 +Node: Precedence365769 +Node: Locales369438 +Node: Expressions Summary371069 +Node: Patterns and Actions373566 +Node: Pattern Overview374682 +Node: Regexp Patterns376359 +Node: Expression Patterns376902 +Node: Ranges380683 +Node: BEGIN/END383789 +Node: Using BEGIN/END384551 +Ref: Using BEGIN/END-Footnote-1387287 +Node: I/O And BEGIN/END387393 +Node: BEGINFILE/ENDFILE389678 +Node: Empty392609 +Node: Using Shell Variables392926 +Node: Action Overview395209 +Node: Statements397536 +Node: If Statement399384 +Node: While Statement400882 +Node: Do Statement402926 +Node: For Statement404082 +Node: Switch Statement407234 +Node: Break Statement409337 +Node: Continue Statement411392 +Node: Next Statement413185 +Node: Nextfile Statement415575 +Node: Exit Statement418230 +Node: Built-in Variables420634 +Node: User-modified421761 +Ref: User-modified-Footnote-1429446 +Node: Auto-set429508 +Ref: Auto-set-Footnote-1442073 +Ref: Auto-set-Footnote-2442278 +Node: ARGC and ARGV442334 +Node: Pattern Action Summary446188 +Node: Arrays448411 +Node: Array Basics449960 +Node: Array Intro450786 +Ref: figure-array-elements452759 +Node: Reference to Elements455166 +Node: Assigning Elements457439 +Node: Array Example457930 +Node: Scanning an Array459662 +Node: Controlling Scanning462677 +Ref: Controlling Scanning-Footnote-1467850 +Node: Delete468166 +Ref: Delete-Footnote-1470931 +Node: Numeric Array Subscripts470988 +Node: Uninitialized Subscripts473171 +Node: Multidimensional474796 +Node: Multiscanning477889 +Node: Arrays of Arrays479478 +Node: Arrays Summary484141 +Node: Functions486246 +Node: Built-in487119 +Node: Calling Built-in488197 +Node: Numeric Functions490185 +Ref: Numeric Functions-Footnote-1494019 +Ref: Numeric Functions-Footnote-2494376 +Ref: Numeric Functions-Footnote-3494424 +Node: String Functions494693 +Ref: String Functions-Footnote-1517704 +Ref: String Functions-Footnote-2517833 +Ref: String Functions-Footnote-3518081 +Node: Gory Details518168 +Ref: table-sub-escapes519837 +Ref: table-sub-posix-92521191 +Ref: table-sub-proposed522542 +Ref: table-posix-sub523896 +Ref: table-gensub-escapes525441 +Ref: Gory Details-Footnote-1526617 +Ref: Gory Details-Footnote-2526668 +Node: I/O Functions526819 +Ref: I/O Functions-Footnote-1533942 +Node: Time Functions534089 +Ref: Time Functions-Footnote-1544553 +Ref: Time Functions-Footnote-2544621 +Ref: Time Functions-Footnote-3544779 +Ref: Time Functions-Footnote-4544890 +Ref: Time Functions-Footnote-5545002 +Ref: Time Functions-Footnote-6545229 +Node: Bitwise Functions545495 +Ref: table-bitwise-ops546057 +Ref: Bitwise Functions-Footnote-1550302 +Node: Type Functions550486 +Node: I18N Functions551628 +Node: User-defined553273 +Node: Definition Syntax554077 +Ref: Definition Syntax-Footnote-1559002 +Node: Function Example559071 +Ref: Function Example-Footnote-1561715 +Node: Function Caveats561737 +Node: Calling A Function562255 +Node: Variable Scope563210 +Node: Pass By Value/Reference566198 +Node: Return Statement569706 +Node: Dynamic Typing572690 +Node: Indirect Calls573619 +Node: Functions Summary583332 +Node: Library Functions585871 +Ref: Library Functions-Footnote-1589446 +Ref: Library Functions-Footnote-2589589 +Node: Library Names589760 +Ref: Library Names-Footnote-1593233 +Ref: Library Names-Footnote-2593453 +Node: General Functions593539 +Node: Strtonum Function594567 +Node: Assert Function597497 +Node: Round Function600823 +Node: Cliff Random Function602364 +Node: Ordinal Functions603380 +Ref: Ordinal Functions-Footnote-1606457 +Ref: Ordinal Functions-Footnote-2606709 +Node: Join Function606920 +Ref: Join Function-Footnote-1608691 +Node: Getlocaltime Function608891 +Node: Readfile Function612627 +Node: Data File Management614466 +Node: Filetrans Function615098 +Node: Rewind Function619167 +Node: File Checking620554 +Ref: File Checking-Footnote-1621686 +Node: Empty Files621887 +Node: Ignoring Assigns624117 +Node: Getopt Function625671 +Ref: Getopt Function-Footnote-1636974 +Node: Passwd Functions637177 +Ref: Passwd Functions-Footnote-1646156 +Node: Group Functions646244 +Ref: Group Functions-Footnote-1654186 +Node: Walking Arrays654399 +Node: Library Functions Summary656569 +Node: Sample Programs657931 +Node: Running Examples658658 +Node: Clones659386 +Node: Cut Program660610 +Node: Egrep Program670478 +Ref: Egrep Program-Footnote-1678449 +Node: Id Program678559 +Node: Split Program682223 +Ref: Split Program-Footnote-1685761 +Node: Tee Program685889 +Node: Uniq Program688696 +Node: Wc Program696126 +Ref: Wc Program-Footnote-1700394 +Ref: Wc Program-Footnote-2700594 +Node: Miscellaneous Programs700686 +Node: Dupword Program701899 +Node: Alarm Program703930 +Node: Translate Program708744 +Ref: Translate Program-Footnote-1713135 +Ref: Translate Program-Footnote-2713405 +Node: Labels Program713539 +Ref: Labels Program-Footnote-1716910 +Node: Word Sorting716994 +Node: History Sorting721037 +Node: Extract Program722873 +Ref: Extract Program-Footnote-1730448 +Node: Simple Sed730577 +Node: Igawk Program733639 +Ref: Igawk Program-Footnote-1748815 +Ref: Igawk Program-Footnote-2749016 +Node: Anagram Program749154 +Node: Signature Program752222 +Node: Programs Summary753469 +Node: Advanced Features754657 +Node: Nondecimal Data756605 +Node: Array Sorting758182 +Node: Controlling Array Traversal758879 +Node: Array Sorting Functions767159 +Ref: Array Sorting Functions-Footnote-1771066 +Node: Two-way I/O771260 +Ref: Two-way I/O-Footnote-1776776 +Node: TCP/IP Networking776858 +Node: Profiling779702 +Node: Advanced Features Summary787244 +Node: Internationalization789108 +Node: I18N and L10N790588 +Node: Explaining gettext791274 +Ref: Explaining gettext-Footnote-1796414 +Ref: Explaining gettext-Footnote-2796598 +Node: Programmer i18n796763 +Node: Translator i18n800988 +Node: String Extraction801782 +Ref: String Extraction-Footnote-1802743 +Node: Printf Ordering802829 +Ref: Printf Ordering-Footnote-1805611 +Node: I18N Portability805675 +Ref: I18N Portability-Footnote-1808124 +Node: I18N Example808187 +Ref: I18N Example-Footnote-1810909 +Node: Gawk I18N810981 +Node: I18N Summary811619 +Node: Debugger812958 +Node: Debugging813980 +Node: Debugging Concepts814421 +Node: Debugging Terms816277 +Node: Awk Debugging818874 +Node: Sample Debugging Session819766 +Node: Debugger Invocation820286 +Node: Finding The Bug821619 +Node: List of Debugger Commands828101 +Node: Breakpoint Control829433 +Node: Debugger Execution Control833097 +Node: Viewing And Changing Data836457 +Node: Execution Stack839815 +Node: Debugger Info841328 +Node: Miscellaneous Debugger Commands845322 +Node: Readline Support850506 +Node: Limitations851398 +Node: Debugging Summary853672 +Node: Arbitrary Precision Arithmetic854836 +Ref: Arbitrary Precision Arithmetic-Footnote-1856485 +Node: General Arithmetic856633 +Node: Floating Point Issues858353 +Node: String Conversion Precision859234 +Ref: String Conversion Precision-Footnote-1860939 +Node: Unexpected Results861048 +Node: POSIX Floating Point Problems863201 +Ref: POSIX Floating Point Problems-Footnote-1867022 +Node: Integer Programming867060 +Node: Floating-point Programming868871 +Ref: Floating-point Programming-Footnote-1875199 +Ref: Floating-point Programming-Footnote-2875469 +Node: Floating-point Representation875733 +Node: Floating-point Context876898 +Ref: table-ieee-formats877737 +Node: Rounding Mode879121 +Ref: table-rounding-modes879600 +Ref: Rounding Mode-Footnote-1882615 +Node: Gawk and MPFR882794 +Node: Arbitrary Precision Floats884203 +Ref: Arbitrary Precision Floats-Footnote-1886646 +Node: Setting Precision886967 +Ref: table-predefined-precision-strings887651 +Node: Setting Rounding Mode889796 +Ref: table-gawk-rounding-modes890200 +Node: Floating-point Constants891387 +Node: Changing Precision892839 +Ref: Changing Precision-Footnote-1894231 +Node: Exact Arithmetic894405 +Node: Arbitrary Precision Integers897539 +Ref: Arbitrary Precision Integers-Footnote-1900554 +Node: Dynamic Extensions900701 +Node: Extension Intro902159 +Node: Plugin License903424 +Node: Extension Mechanism Outline904109 +Ref: figure-load-extension904533 +Ref: figure-load-new-function906018 +Ref: figure-call-new-function907020 +Node: Extension API Description909004 +Node: Extension API Functions Introduction910454 +Node: General Data Types915320 +Ref: General Data Types-Footnote-1921013 +Node: Requesting Values921312 +Ref: table-value-types-returned922049 +Node: Memory Allocation Functions923007 +Ref: Memory Allocation Functions-Footnote-1925754 +Node: Constructor Functions925850 +Node: Registration Functions927608 +Node: Extension Functions928293 +Node: Exit Callback Functions930595 +Node: Extension Version String931844 +Node: Input Parsers932494 +Node: Output Wrappers942297 +Node: Two-way processors946813 +Node: Printing Messages949017 +Ref: Printing Messages-Footnote-1950094 +Node: Updating `ERRNO'950246 +Node: Accessing Parameters950985 +Node: Symbol Table Access952215 +Node: Symbol table by name952729 +Node: Symbol table by cookie954705 +Ref: Symbol table by cookie-Footnote-1958838 +Node: Cached values958901 +Ref: Cached values-Footnote-1962405 +Node: Array Manipulation962496 +Ref: Array Manipulation-Footnote-1963594 +Node: Array Data Types963633 +Ref: Array Data Types-Footnote-1966336 +Node: Array Functions966428 +Node: Flattening Arrays970302 +Node: Creating Arrays977154 +Node: Extension API Variables981885 +Node: Extension Versioning982521 +Node: Extension API Informational Variables984422 +Node: Extension API Boilerplate985508 +Node: Finding Extensions989312 +Node: Extension Example989872 +Node: Internal File Description990602 +Node: Internal File Ops994693 +Ref: Internal File Ops-Footnote-11006239 +Node: Using Internal File Ops1006379 +Ref: Using Internal File Ops-Footnote-11008726 +Node: Extension Samples1008994 +Node: Extension Sample File Functions1010518 +Node: Extension Sample Fnmatch1018086 +Node: Extension Sample Fork1019567 +Node: Extension Sample Inplace1020780 +Node: Extension Sample Ord1022560 +Node: Extension Sample Readdir1023396 +Ref: table-readdir-file-types1024252 +Node: Extension Sample Revout1025051 +Node: Extension Sample Rev2way1025642 +Node: Extension Sample Read write array1026383 +Node: Extension Sample Readfile1028262 +Node: Extension Sample API Tests1029362 +Node: Extension Sample Time1029887 +Node: gawkextlib1031202 +Node: Language History1033989 +Node: V7/SVR3.11035583 +Node: SVR41037903 +Node: POSIX1039345 +Node: BTL1040731 +Node: POSIX/GNU1041465 +Node: Feature History1047064 +Node: Common Extensions1060176 +Node: Ranges and Locales1061488 +Ref: Ranges and Locales-Footnote-11066105 +Ref: Ranges and Locales-Footnote-21066132 +Ref: Ranges and Locales-Footnote-31066366 +Node: Contributors1066587 +Node: Installation1072025 +Node: Gawk Distribution1072919 +Node: Getting1073403 +Node: Extracting1074229 +Node: Distribution contents1075871 +Node: Unix Installation1081588 +Node: Quick Installation1082205 +Node: Additional Configuration Options1084647 +Node: Configuration Philosophy1086385 +Node: Non-Unix Installation1088736 +Node: PC Installation1089194 +Node: PC Binary Installation1090505 +Node: PC Compiling1092353 +Ref: PC Compiling-Footnote-11095352 +Node: PC Testing1095457 +Node: PC Using1096633 +Node: Cygwin1100791 +Node: MSYS1101600 +Node: VMS Installation1102114 +Node: VMS Compilation1102910 +Ref: VMS Compilation-Footnote-11104132 +Node: VMS Dynamic Extensions1104190 +Node: VMS Installation Details1105563 +Node: VMS Running1107815 +Node: VMS GNV1110649 +Node: VMS Old Gawk1111372 +Node: Bugs1111842 +Node: Other Versions1115846 +Node: Notes1122071 +Node: Compatibility Mode1122871 +Node: Additions1123653 +Node: Accessing The Source1124578 +Node: Adding Code1126014 +Node: New Ports1132192 +Node: Derived Files1136673 +Ref: Derived Files-Footnote-11141754 +Ref: Derived Files-Footnote-21141788 +Ref: Derived Files-Footnote-31142384 +Node: Future Extensions1142498 +Node: Implementation Limitations1143104 +Node: Extension Design1144352 +Node: Old Extension Problems1145506 +Ref: Old Extension Problems-Footnote-11147023 +Node: Extension New Mechanism Goals1147080 +Ref: Extension New Mechanism Goals-Footnote-11150440 +Node: Extension Other Design Decisions1150629 +Node: Extension Future Growth1152735 +Node: Old Extension Mechanism1153571 +Node: Basic Concepts1155311 +Node: Basic High Level1155992 +Ref: figure-general-flow1156264 +Ref: figure-process-flow1156863 +Ref: Basic High Level-Footnote-11160092 +Node: Basic Data Typing1160277 +Node: Glossary1163604 +Node: Copying1188756 +Node: GNU Free Documentation License1226312 +Node: Index1251448  End Tag Table -- cgit v1.2.3 From ec27289f558e73b40c3d90f599cf392a9d03e864 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sun, 15 Jun 2014 20:36:33 +0300 Subject: Finish up summaries. Improvements in mystrtonum(). --- doc/gawk.info | 1249 +++++++++++++++++++++++++++++++++------------------------ 1 file changed, 717 insertions(+), 532 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 2e30ad95..d7442017 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1614,7 +1614,7 @@ at a later time. will probably print strange messages about syntax errors. For example, look at the following: - $ awk '{ print "hello" } # let's be cute' + $ awk 'BEGIN { print "hello" } # let's be cute' > The shell sees that the first two quotes match, and that a new @@ -14253,7 +14253,7 @@ versions of `awk': # mystrtonum --- convert string to number - function mystrtonum(str, ret, chars, n, i, k, c) + function mystrtonum(str, ret, n, i, k, c) { if (str ~ /^0[0-7]*$/) { # octal @@ -14266,7 +14266,7 @@ versions of `awk': ret = ret * 8 + k } - } else if (str ~ /^0[xX][[:xdigit:]]+/) { + } else if (str ~ /^0[xX][[:xdigit:]]+$/) { # hexadecimal str = substr(str, 3) # lop off leading 0x n = length(str) @@ -14274,10 +14274,7 @@ versions of `awk': for (i = 1; i <= n; i++) { c = substr(str, i, 1) c = tolower(c) - if ((k = index("0123456789", c)) > 0) - k-- # adjust for 1-basing in awk - else if ((k = index("abcdef", c)) > 0) - k += 9 + k = index("123456789abcdef", c) ret = ret * 16 + k } @@ -22310,6 +22307,7 @@ sample extensions are automatically built and installed when `gawk' is. * Extension Samples:: The sample extensions that ship with `gawk'. * gawkextlib:: The `gawkextlib' project. +* Extension summary:: Extension summary.  File: gawk.info, Node: Extension Intro, Next: Plugin License, Up: Dynamic Extensions @@ -22501,7 +22499,7 @@ through function pointers passed into your extension. API function pointers are provided for the following kinds of operations: - * Registrations functions. You may register: + * Registration functions. You may register: - extension functions, - exit callbacks, @@ -25614,7 +25612,7 @@ The `time' extension adds two functions, named `gettimeofday()' and delay.  -File: gawk.info, Node: gawkextlib, Prev: Extension Samples, Up: Dynamic Extensions +File: gawk.info, Node: gawkextlib, Next: Extension summary, Prev: Extension Samples, Up: Dynamic Extensions 16.8 The `gawkextlib' Project ============================= @@ -25683,6 +25681,95 @@ You may also need to use the `sudo' utility to install both `gawk' and users, please consider doing so through the `gawkextlib' project. See the project's web site for more information. + +File: gawk.info, Node: Extension summary, Prev: gawkextlib, Up: Dynamic Extensions + +16.9 Summary +============ + + * You can write extensions (sometimes called plug-ins) for `gawk' in + C or C++ using the Application Programming Interface (API) defined + by the `gawk' developers. + + * Extensions must have a license compatible with the GNU General + Public License (GPL), and they must assert that fact by declaring + a variable named `plugin_is_GPL_compatible'. + + * Communication between `gawk' and an extension is two-way. `gawk' + passes a `struct' to the extension which contains various data + fields and function pointers. The extension can then call into + `gawk' via the supplied function pointers to accomplish certain + tasks. + + * One of these tasks is to "register" the name and implementation of + a new `awk'-level function with `gawk'. The implementation takes + the form of a C function pointer with a defined signature. By + convention, implementation functions are named `do_XXXX()' for + some `awk'-level function `XXXX()'. + + * The API is defined in a header file named `gawkpi.h'. You must + include a number of standard header files _before_ including it in + your source file. + + * API function pointers are provided for the following kinds of + operations: + + * Registration functions. You may register extension functions, + exit callbacks, a version string, input parsers, output + wrappers, and two-way processors. + + * Printing fatal, warning, and "lint" warning messages. + + * Updating `ERRNO', or unsetting it. + + * Accessing parameters, including converting an undefined + parameter into an array. + + * Symbol table access: retrieving a global variable, creating + one, or changing one. + + * Allocating, reallocating, and releasing memory. + + * Creating and releasing cached values; this provides an + efficient way to use values for multiple variables and can be + a big performance win. + + * Manipulating arrays: retrieving, adding, deleting, and + modifying elements; getting the count of elements in an array; + creating a new array; clearing an array; and flattening an + array for easy C style looping over all its indices and + elements + + * The API defines a number of standard data types for representing + `awk' values, array elements, and arrays. + + * The API provide convenience functions for constructing values. It + also provides memory management functions to ensure compatibility + between memory allocated by `gawk' and memory allocated by an + extension. + + * _All_ memory passed from `gawk' to an extension must be treated as + read-only by the extension. + + * _All_ memory passed from an extension to `gawk' must come from the + API's memory allocation functions. `gawk' takes responsibility for + the memory and will release it when appropriate. + + * The API provides information about the running version of `gawk' so + that an extension can make sure it is compatible with the `gawk' + that loaded it. + + * It is easiest to start a new extension by copying the boilerplate + code described in this major node. Macros in the `gawkapi.h' make + this easier to do. + + * The `gawk' distribution includes a number of small but useful + sample extensions. The `gawkextlib' project includes several more, + larger, extensions. If you wish to write an extension and + contribute it to the community of `gawk' users, the `gawkextlib' + project should be the place to do so. + +  File: gawk.info, Node: Language History, Next: Installation, Prev: Dynamic Extensions, Up: Top @@ -25714,6 +25801,7 @@ you can find more information. * Common Extensions:: Common Extensions Summary. * Ranges and Locales:: How locales used to affect regexp ranges. * Contributors:: The major contributors to `gawk'. +* History summary:: History summary.  File: gawk.info, Node: V7/SVR3.1, Next: SVR4, Up: Language History @@ -26568,7 +26656,7 @@ and its rationale (http://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xbd_chap09.html#tag_21_09_03_05).  -File: gawk.info, Node: Contributors, Prev: Ranges and Locales, Up: Language History +File: gawk.info, Node: Contributors, Next: History summary, Prev: Ranges and Locales, Up: Language History A.9 Major Contributors to `gawk' ================================ @@ -26713,6 +26801,38 @@ Info file, in approximate chronological order: helping David Trueman, and as the primary maintainer since around 1994. + +File: gawk.info, Node: History summary, Prev: Contributors, Up: Language History + +A.10 Summary +============ + + * The `awk' language has evolved over time. The first release was + with V7 Unix circa 1978. In 1987 for System V Release 3.1, major + additions, including user-defined functions, were made to the + language. Additional changes were made for System V Release 4, in + 1989. Since then, further minor changes happen under the auspices + of the POSIX standard. + + * Brian Kernighan's `awk' provides a small number of extensions that + are implemented in common with other versions of `awk'. + + * `gawk' provides a large number of extensions over POSIX `awk'. + They can be disabled with either the `--traditional' or `--posix' + options. + + * The interaction of POSIX locales and regexp matching in `gawk' has + been confusing over the years. Today, `gawk' implements Rational + Range Interpretation, where ranges of the form `[a-z]' match + _only_ the characters numerically between `a' through `z' in the + machine's native character set. Usually this is ASCII but it can + be EBCDIC on IBM S/390 systems. + + * Many people have contributed to `gawk' development over the years. + We hope that the list provided in this major node is complete and + gives the appropriate credit where credit is due. + +  File: gawk.info, Node: Installation, Next: Notes, Prev: Language History, Up: Top @@ -26734,6 +26854,7 @@ people who did the respective ports. * Bugs:: Reporting Problems and Bugs. * Other Versions:: Other freely available `awk' implementations. +* Installation summary:: Summary of installation.  File: gawk.info, Node: Gawk Distribution, Next: Unix Installation, Up: Installation @@ -27807,7 +27928,7 @@ z/OS (OS/390) Dave Pitts, . your report to the email list as well.  -File: gawk.info, Node: Other Versions, Prev: Bugs, Up: Installation +File: gawk.info, Node: Other Versions, Next: Installation summary, Prev: Bugs, Up: Installation B.5 Other Freely Available `awk' Implementations ================================================ @@ -27956,6 +28077,34 @@ Other Versions for information on additional versions. + +File: gawk.info, Node: Installation summary, Prev: Other Versions, Up: Installation + +B.6 Summary +=========== + + * The `gawk' distribution is availble from GNU project's main + distribution site, `ftp.gnu.org'. The canonical build recipe is: + + wget http://ftp.gnu.org/gnu/gawk/gawk-4.1.1.tar.gz + tar -xvpzf gawk-4.1.1.tar.gz + cd gawk-4.1.1 + ./configure && make && make check + + * `gawk' may be built on non-POSIX systems as well. The currently + supported systems are MS-Windows using DJGPP, MSYS, MinGW and + Cygwin, OS/2 using EMX, and both Vax/VMS and OpenVMS. + Instructions for each system are included in this major node. + + * Bug reports should be sent via email to . Bug + reports should be in English, and should include the version of + `gawk', how it was compiled, and a short program and data file + which demonstrate the problem. + + * There are a number of other freely available `awk' + implementations. Many are POSIX compliant; others are less so. + +  File: gawk.info, Node: Notes, Next: Basic Concepts, Prev: Installation, Up: Top @@ -27975,6 +28124,7 @@ and maintainers of `gawk'. Everything in it applies specifically to * Implementation Limitations:: Some limitations of the implementation. * Extension Design:: Design notes about the extension API. * Old Extension Mechanism:: Some compatibility for old extensions. +* Notes summary:: Summary of implementation notes.  File: gawk.info, Node: Compatibility Mode, Next: Additions, Up: Notes @@ -28679,7 +28829,7 @@ The API can later be expanded, in two ways: respect to any of the above.  -File: gawk.info, Node: Old Extension Mechanism, Prev: Extension Design, Up: Notes +File: gawk.info, Node: Old Extension Mechanism, Next: Notes summary, Prev: Extension Design, Up: Notes C.6 Compatibility For Old Extensions ==================================== @@ -28716,6 +28866,37 @@ without conflict. old extensions that you may have to use the new API described in *note Dynamic Extensions::. + +File: gawk.info, Node: Notes summary, Prev: Old Extension Mechanism, Up: Notes + +C.7 Summary +=========== + + * `gawk''s extensions can be disabled with either the + `--traditional' option or with the `--posix' option. The + `--parsedebug' option is availble if `gawk' is compiled with + `-DDEBUG'. + + * The source code for `gawk' is maintained in a publicly accessable + Git repository. Anyone may check it out and view the source. + + * Contributions to `gawk' are welcome. Following the steps outlined + in this major node will make it easier to integrate your + contributions into the code base. This applies both to new + feature contributions and to ports to additional operating systems. + + * `gawk' has some limits--generally those that are imposed by the + machine architecture. + + * The extension API design was intended to solve a number of problems + with the previous extension mechanism, enable features needed by + the `xgawk' project, and provide binary compatibility going + forward. + + * The previous extension mechanism is still supported in version 4.1 + of `gawk', but it _will_ be removed in the next major release. + +  File: gawk.info, Node: Basic Concepts, Next: Glossary, Prev: Notes, Up: Top @@ -33851,525 +34032,529 @@ Node: Executable Scripts78251 Ref: Executable Scripts-Footnote-180084 Ref: Executable Scripts-Footnote-280186 Node: Comments80733 -Node: Quoting83200 -Node: DOS Quoting88516 -Node: Sample Data Files89191 -Node: Very Simple91706 -Node: Two Rules96344 -Node: More Complex98239 -Ref: More Complex-Footnote-1101171 -Node: Statements/Lines101256 -Ref: Statements/Lines-Footnote-1105711 -Node: Other Features105976 -Node: When106904 -Node: Intro Summary109074 -Node: Invoking Gawk109840 -Node: Command Line111355 -Node: Options112146 -Ref: Options-Footnote-1127958 -Node: Other Arguments127983 -Node: Naming Standard Input130645 -Node: Environment Variables131739 -Node: AWKPATH Variable132297 -Ref: AWKPATH Variable-Footnote-1135169 -Ref: AWKPATH Variable-Footnote-2135214 -Node: AWKLIBPATH Variable135474 -Node: Other Environment Variables136233 -Node: Exit Status139888 -Node: Include Files140563 -Node: Loading Shared Libraries144141 -Node: Obsolete145525 -Node: Undocumented146222 -Node: Invoking Summary146489 -Node: Regexp148069 -Node: Regexp Usage149519 -Node: Escape Sequences151552 -Node: Regexp Operators157219 -Ref: Regexp Operators-Footnote-1164699 -Ref: Regexp Operators-Footnote-2164846 -Node: Bracket Expressions164944 -Ref: table-char-classes166834 -Node: GNU Regexp Operators169357 -Node: Case-sensitivity173080 -Ref: Case-sensitivity-Footnote-1175972 -Ref: Case-sensitivity-Footnote-2176207 -Node: Leftmost Longest176315 -Node: Computed Regexps177516 -Node: Regexp Summary180888 -Node: Reading Files182360 -Node: Records184409 -Node: awk split records185152 -Node: gawk split records190010 -Ref: gawk split records-Footnote-1194531 -Node: Fields194568 -Ref: Fields-Footnote-1197532 -Node: Nonconstant Fields197618 -Ref: Nonconstant Fields-Footnote-1199848 -Node: Changing Fields200050 -Node: Field Separators206004 -Node: Default Field Splitting208706 -Node: Regexp Field Splitting209823 -Node: Single Character Fields213164 -Node: Command Line Field Separator214223 -Node: Full Line Fields217565 -Ref: Full Line Fields-Footnote-1218073 -Node: Field Splitting Summary218119 -Ref: Field Splitting Summary-Footnote-1221218 -Node: Constant Size221319 -Node: Splitting By Content225926 -Ref: Splitting By Content-Footnote-1229676 -Node: Multiple Line229716 -Ref: Multiple Line-Footnote-1235572 -Node: Getline235751 -Node: Plain Getline237967 -Node: Getline/Variable240062 -Node: Getline/File241209 -Node: Getline/Variable/File242593 -Ref: Getline/Variable/File-Footnote-1244192 -Node: Getline/Pipe244279 -Node: Getline/Variable/Pipe246978 -Node: Getline/Coprocess248085 -Node: Getline/Variable/Coprocess249337 -Node: Getline Notes250074 -Node: Getline Summary252878 -Ref: table-getline-variants253286 -Node: Read Timeout254198 -Ref: Read Timeout-Footnote-1258025 -Node: Command line directories258083 -Node: Input Summary258987 -Node: Printing262101 -Node: Print263780 -Node: Print Examples265121 -Node: Output Separators267900 -Node: OFMT269916 -Node: Printf271274 -Node: Basic Printf272180 -Node: Control Letters273719 -Node: Format Modifiers277573 -Node: Printf Examples283600 -Node: Redirection286307 -Node: Special Files293279 -Node: Special FD293810 -Ref: Special FD-Footnote-1297434 -Node: Special Network297508 -Node: Special Caveats298358 -Node: Close Files And Pipes299154 -Ref: Close Files And Pipes-Footnote-1306317 -Ref: Close Files And Pipes-Footnote-2306465 -Node: Output Summary306615 -Node: Expressions307587 -Node: Values308772 -Node: Constants309448 -Node: Scalar Constants310128 -Ref: Scalar Constants-Footnote-1310987 -Node: Nondecimal-numbers311237 -Node: Regexp Constants314237 -Node: Using Constant Regexps314712 -Node: Variables317782 -Node: Using Variables318437 -Node: Assignment Options320161 -Node: Conversion322036 -Ref: table-locale-affects327472 -Ref: Conversion-Footnote-1328096 -Node: All Operators328205 -Node: Arithmetic Ops328835 -Node: Concatenation331340 -Ref: Concatenation-Footnote-1334136 -Node: Assignment Ops334256 -Ref: table-assign-ops339239 -Node: Increment Ops340556 -Node: Truth Values and Conditions343994 -Node: Truth Values345077 -Node: Typing and Comparison346126 -Node: Variable Typing346919 -Ref: Variable Typing-Footnote-1350819 -Node: Comparison Operators350941 -Ref: table-relational-ops351351 -Node: POSIX String Comparison354901 -Ref: POSIX String Comparison-Footnote-1355985 -Node: Boolean Ops356123 -Ref: Boolean Ops-Footnote-1360193 -Node: Conditional Exp360284 -Node: Function Calls362011 -Node: Precedence365769 -Node: Locales369438 -Node: Expressions Summary371069 -Node: Patterns and Actions373566 -Node: Pattern Overview374682 -Node: Regexp Patterns376359 -Node: Expression Patterns376902 -Node: Ranges380683 -Node: BEGIN/END383789 -Node: Using BEGIN/END384551 -Ref: Using BEGIN/END-Footnote-1387287 -Node: I/O And BEGIN/END387393 -Node: BEGINFILE/ENDFILE389678 -Node: Empty392609 -Node: Using Shell Variables392926 -Node: Action Overview395209 -Node: Statements397536 -Node: If Statement399384 -Node: While Statement400882 -Node: Do Statement402926 -Node: For Statement404082 -Node: Switch Statement407234 -Node: Break Statement409337 -Node: Continue Statement411392 -Node: Next Statement413185 -Node: Nextfile Statement415575 -Node: Exit Statement418230 -Node: Built-in Variables420634 -Node: User-modified421761 -Ref: User-modified-Footnote-1429446 -Node: Auto-set429508 -Ref: Auto-set-Footnote-1442073 -Ref: Auto-set-Footnote-2442278 -Node: ARGC and ARGV442334 -Node: Pattern Action Summary446188 -Node: Arrays448411 -Node: Array Basics449960 -Node: Array Intro450786 -Ref: figure-array-elements452759 -Node: Reference to Elements455166 -Node: Assigning Elements457439 -Node: Array Example457930 -Node: Scanning an Array459662 -Node: Controlling Scanning462677 -Ref: Controlling Scanning-Footnote-1467850 -Node: Delete468166 -Ref: Delete-Footnote-1470931 -Node: Numeric Array Subscripts470988 -Node: Uninitialized Subscripts473171 -Node: Multidimensional474796 -Node: Multiscanning477889 -Node: Arrays of Arrays479478 -Node: Arrays Summary484141 -Node: Functions486246 -Node: Built-in487119 -Node: Calling Built-in488197 -Node: Numeric Functions490185 -Ref: Numeric Functions-Footnote-1494019 -Ref: Numeric Functions-Footnote-2494376 -Ref: Numeric Functions-Footnote-3494424 -Node: String Functions494693 -Ref: String Functions-Footnote-1517704 -Ref: String Functions-Footnote-2517833 -Ref: String Functions-Footnote-3518081 -Node: Gory Details518168 -Ref: table-sub-escapes519837 -Ref: table-sub-posix-92521191 -Ref: table-sub-proposed522542 -Ref: table-posix-sub523896 -Ref: table-gensub-escapes525441 -Ref: Gory Details-Footnote-1526617 -Ref: Gory Details-Footnote-2526668 -Node: I/O Functions526819 -Ref: I/O Functions-Footnote-1533942 -Node: Time Functions534089 -Ref: Time Functions-Footnote-1544553 -Ref: Time Functions-Footnote-2544621 -Ref: Time Functions-Footnote-3544779 -Ref: Time Functions-Footnote-4544890 -Ref: Time Functions-Footnote-5545002 -Ref: Time Functions-Footnote-6545229 -Node: Bitwise Functions545495 -Ref: table-bitwise-ops546057 -Ref: Bitwise Functions-Footnote-1550302 -Node: Type Functions550486 -Node: I18N Functions551628 -Node: User-defined553273 -Node: Definition Syntax554077 -Ref: Definition Syntax-Footnote-1559002 -Node: Function Example559071 -Ref: Function Example-Footnote-1561715 -Node: Function Caveats561737 -Node: Calling A Function562255 -Node: Variable Scope563210 -Node: Pass By Value/Reference566198 -Node: Return Statement569706 -Node: Dynamic Typing572690 -Node: Indirect Calls573619 -Node: Functions Summary583332 -Node: Library Functions585871 -Ref: Library Functions-Footnote-1589446 -Ref: Library Functions-Footnote-2589589 -Node: Library Names589760 -Ref: Library Names-Footnote-1593233 -Ref: Library Names-Footnote-2593453 -Node: General Functions593539 -Node: Strtonum Function594567 -Node: Assert Function597497 -Node: Round Function600823 -Node: Cliff Random Function602364 -Node: Ordinal Functions603380 -Ref: Ordinal Functions-Footnote-1606457 -Ref: Ordinal Functions-Footnote-2606709 -Node: Join Function606920 -Ref: Join Function-Footnote-1608691 -Node: Getlocaltime Function608891 -Node: Readfile Function612627 -Node: Data File Management614466 -Node: Filetrans Function615098 -Node: Rewind Function619167 -Node: File Checking620554 -Ref: File Checking-Footnote-1621686 -Node: Empty Files621887 -Node: Ignoring Assigns624117 -Node: Getopt Function625671 -Ref: Getopt Function-Footnote-1636974 -Node: Passwd Functions637177 -Ref: Passwd Functions-Footnote-1646156 -Node: Group Functions646244 -Ref: Group Functions-Footnote-1654186 -Node: Walking Arrays654399 -Node: Library Functions Summary656569 -Node: Sample Programs657931 -Node: Running Examples658658 -Node: Clones659386 -Node: Cut Program660610 -Node: Egrep Program670478 -Ref: Egrep Program-Footnote-1678449 -Node: Id Program678559 -Node: Split Program682223 -Ref: Split Program-Footnote-1685761 -Node: Tee Program685889 -Node: Uniq Program688696 -Node: Wc Program696126 -Ref: Wc Program-Footnote-1700394 -Ref: Wc Program-Footnote-2700594 -Node: Miscellaneous Programs700686 -Node: Dupword Program701899 -Node: Alarm Program703930 -Node: Translate Program708744 -Ref: Translate Program-Footnote-1713135 -Ref: Translate Program-Footnote-2713405 -Node: Labels Program713539 -Ref: Labels Program-Footnote-1716910 -Node: Word Sorting716994 -Node: History Sorting721037 -Node: Extract Program722873 -Ref: Extract Program-Footnote-1730448 -Node: Simple Sed730577 -Node: Igawk Program733639 -Ref: Igawk Program-Footnote-1748815 -Ref: Igawk Program-Footnote-2749016 -Node: Anagram Program749154 -Node: Signature Program752222 -Node: Programs Summary753469 -Node: Advanced Features754657 -Node: Nondecimal Data756605 -Node: Array Sorting758182 -Node: Controlling Array Traversal758879 -Node: Array Sorting Functions767159 -Ref: Array Sorting Functions-Footnote-1771066 -Node: Two-way I/O771260 -Ref: Two-way I/O-Footnote-1776776 -Node: TCP/IP Networking776858 -Node: Profiling779702 -Node: Advanced Features Summary787244 -Node: Internationalization789108 -Node: I18N and L10N790588 -Node: Explaining gettext791274 -Ref: Explaining gettext-Footnote-1796414 -Ref: Explaining gettext-Footnote-2796598 -Node: Programmer i18n796763 -Node: Translator i18n800988 -Node: String Extraction801782 -Ref: String Extraction-Footnote-1802743 -Node: Printf Ordering802829 -Ref: Printf Ordering-Footnote-1805611 -Node: I18N Portability805675 -Ref: I18N Portability-Footnote-1808124 -Node: I18N Example808187 -Ref: I18N Example-Footnote-1810909 -Node: Gawk I18N810981 -Node: I18N Summary811619 -Node: Debugger812958 -Node: Debugging813980 -Node: Debugging Concepts814421 -Node: Debugging Terms816277 -Node: Awk Debugging818874 -Node: Sample Debugging Session819766 -Node: Debugger Invocation820286 -Node: Finding The Bug821619 -Node: List of Debugger Commands828101 -Node: Breakpoint Control829433 -Node: Debugger Execution Control833097 -Node: Viewing And Changing Data836457 -Node: Execution Stack839815 -Node: Debugger Info841328 -Node: Miscellaneous Debugger Commands845322 -Node: Readline Support850506 -Node: Limitations851398 -Node: Debugging Summary853672 -Node: Arbitrary Precision Arithmetic854836 -Ref: Arbitrary Precision Arithmetic-Footnote-1856485 -Node: General Arithmetic856633 -Node: Floating Point Issues858353 -Node: String Conversion Precision859234 -Ref: String Conversion Precision-Footnote-1860939 -Node: Unexpected Results861048 -Node: POSIX Floating Point Problems863201 -Ref: POSIX Floating Point Problems-Footnote-1867022 -Node: Integer Programming867060 -Node: Floating-point Programming868871 -Ref: Floating-point Programming-Footnote-1875199 -Ref: Floating-point Programming-Footnote-2875469 -Node: Floating-point Representation875733 -Node: Floating-point Context876898 -Ref: table-ieee-formats877737 -Node: Rounding Mode879121 -Ref: table-rounding-modes879600 -Ref: Rounding Mode-Footnote-1882615 -Node: Gawk and MPFR882794 -Node: Arbitrary Precision Floats884203 -Ref: Arbitrary Precision Floats-Footnote-1886646 -Node: Setting Precision886967 -Ref: table-predefined-precision-strings887651 -Node: Setting Rounding Mode889796 -Ref: table-gawk-rounding-modes890200 -Node: Floating-point Constants891387 -Node: Changing Precision892839 -Ref: Changing Precision-Footnote-1894231 -Node: Exact Arithmetic894405 -Node: Arbitrary Precision Integers897539 -Ref: Arbitrary Precision Integers-Footnote-1900554 -Node: Dynamic Extensions900701 -Node: Extension Intro902159 -Node: Plugin License903424 -Node: Extension Mechanism Outline904109 -Ref: figure-load-extension904533 -Ref: figure-load-new-function906018 -Ref: figure-call-new-function907020 -Node: Extension API Description909004 -Node: Extension API Functions Introduction910454 -Node: General Data Types915320 -Ref: General Data Types-Footnote-1921013 -Node: Requesting Values921312 -Ref: table-value-types-returned922049 -Node: Memory Allocation Functions923007 -Ref: Memory Allocation Functions-Footnote-1925754 -Node: Constructor Functions925850 -Node: Registration Functions927608 -Node: Extension Functions928293 -Node: Exit Callback Functions930595 -Node: Extension Version String931844 -Node: Input Parsers932494 -Node: Output Wrappers942297 -Node: Two-way processors946813 -Node: Printing Messages949017 -Ref: Printing Messages-Footnote-1950094 -Node: Updating `ERRNO'950246 -Node: Accessing Parameters950985 -Node: Symbol Table Access952215 -Node: Symbol table by name952729 -Node: Symbol table by cookie954705 -Ref: Symbol table by cookie-Footnote-1958838 -Node: Cached values958901 -Ref: Cached values-Footnote-1962405 -Node: Array Manipulation962496 -Ref: Array Manipulation-Footnote-1963594 -Node: Array Data Types963633 -Ref: Array Data Types-Footnote-1966336 -Node: Array Functions966428 -Node: Flattening Arrays970302 -Node: Creating Arrays977154 -Node: Extension API Variables981885 -Node: Extension Versioning982521 -Node: Extension API Informational Variables984422 -Node: Extension API Boilerplate985508 -Node: Finding Extensions989312 -Node: Extension Example989872 -Node: Internal File Description990602 -Node: Internal File Ops994693 -Ref: Internal File Ops-Footnote-11006239 -Node: Using Internal File Ops1006379 -Ref: Using Internal File Ops-Footnote-11008726 -Node: Extension Samples1008994 -Node: Extension Sample File Functions1010518 -Node: Extension Sample Fnmatch1018086 -Node: Extension Sample Fork1019567 -Node: Extension Sample Inplace1020780 -Node: Extension Sample Ord1022560 -Node: Extension Sample Readdir1023396 -Ref: table-readdir-file-types1024252 -Node: Extension Sample Revout1025051 -Node: Extension Sample Rev2way1025642 -Node: Extension Sample Read write array1026383 -Node: Extension Sample Readfile1028262 -Node: Extension Sample API Tests1029362 -Node: Extension Sample Time1029887 -Node: gawkextlib1031202 -Node: Language History1033989 -Node: V7/SVR3.11035583 -Node: SVR41037903 -Node: POSIX1039345 -Node: BTL1040731 -Node: POSIX/GNU1041465 -Node: Feature History1047064 -Node: Common Extensions1060176 -Node: Ranges and Locales1061488 -Ref: Ranges and Locales-Footnote-11066105 -Ref: Ranges and Locales-Footnote-21066132 -Ref: Ranges and Locales-Footnote-31066366 -Node: Contributors1066587 -Node: Installation1072025 -Node: Gawk Distribution1072919 -Node: Getting1073403 -Node: Extracting1074229 -Node: Distribution contents1075871 -Node: Unix Installation1081588 -Node: Quick Installation1082205 -Node: Additional Configuration Options1084647 -Node: Configuration Philosophy1086385 -Node: Non-Unix Installation1088736 -Node: PC Installation1089194 -Node: PC Binary Installation1090505 -Node: PC Compiling1092353 -Ref: PC Compiling-Footnote-11095352 -Node: PC Testing1095457 -Node: PC Using1096633 -Node: Cygwin1100791 -Node: MSYS1101600 -Node: VMS Installation1102114 -Node: VMS Compilation1102910 -Ref: VMS Compilation-Footnote-11104132 -Node: VMS Dynamic Extensions1104190 -Node: VMS Installation Details1105563 -Node: VMS Running1107815 -Node: VMS GNV1110649 -Node: VMS Old Gawk1111372 -Node: Bugs1111842 -Node: Other Versions1115846 -Node: Notes1122071 -Node: Compatibility Mode1122871 -Node: Additions1123653 -Node: Accessing The Source1124578 -Node: Adding Code1126014 -Node: New Ports1132192 -Node: Derived Files1136673 -Ref: Derived Files-Footnote-11141754 -Ref: Derived Files-Footnote-21141788 -Ref: Derived Files-Footnote-31142384 -Node: Future Extensions1142498 -Node: Implementation Limitations1143104 -Node: Extension Design1144352 -Node: Old Extension Problems1145506 -Ref: Old Extension Problems-Footnote-11147023 -Node: Extension New Mechanism Goals1147080 -Ref: Extension New Mechanism Goals-Footnote-11150440 -Node: Extension Other Design Decisions1150629 -Node: Extension Future Growth1152735 -Node: Old Extension Mechanism1153571 -Node: Basic Concepts1155311 -Node: Basic High Level1155992 -Ref: figure-general-flow1156264 -Ref: figure-process-flow1156863 -Ref: Basic High Level-Footnote-11160092 -Node: Basic Data Typing1160277 -Node: Glossary1163604 -Node: Copying1188756 -Node: GNU Free Documentation License1226312 -Node: Index1251448 +Node: Quoting83206 +Node: DOS Quoting88522 +Node: Sample Data Files89197 +Node: Very Simple91712 +Node: Two Rules96350 +Node: More Complex98245 +Ref: More Complex-Footnote-1101177 +Node: Statements/Lines101262 +Ref: Statements/Lines-Footnote-1105717 +Node: Other Features105982 +Node: When106910 +Node: Intro Summary109080 +Node: Invoking Gawk109846 +Node: Command Line111361 +Node: Options112152 +Ref: Options-Footnote-1127964 +Node: Other Arguments127989 +Node: Naming Standard Input130651 +Node: Environment Variables131745 +Node: AWKPATH Variable132303 +Ref: AWKPATH Variable-Footnote-1135175 +Ref: AWKPATH Variable-Footnote-2135220 +Node: AWKLIBPATH Variable135480 +Node: Other Environment Variables136239 +Node: Exit Status139894 +Node: Include Files140569 +Node: Loading Shared Libraries144147 +Node: Obsolete145531 +Node: Undocumented146228 +Node: Invoking Summary146495 +Node: Regexp148075 +Node: Regexp Usage149525 +Node: Escape Sequences151558 +Node: Regexp Operators157225 +Ref: Regexp Operators-Footnote-1164705 +Ref: Regexp Operators-Footnote-2164852 +Node: Bracket Expressions164950 +Ref: table-char-classes166840 +Node: GNU Regexp Operators169363 +Node: Case-sensitivity173086 +Ref: Case-sensitivity-Footnote-1175978 +Ref: Case-sensitivity-Footnote-2176213 +Node: Leftmost Longest176321 +Node: Computed Regexps177522 +Node: Regexp Summary180894 +Node: Reading Files182366 +Node: Records184415 +Node: awk split records185158 +Node: gawk split records190016 +Ref: gawk split records-Footnote-1194537 +Node: Fields194574 +Ref: Fields-Footnote-1197538 +Node: Nonconstant Fields197624 +Ref: Nonconstant Fields-Footnote-1199854 +Node: Changing Fields200056 +Node: Field Separators206010 +Node: Default Field Splitting208712 +Node: Regexp Field Splitting209829 +Node: Single Character Fields213170 +Node: Command Line Field Separator214229 +Node: Full Line Fields217571 +Ref: Full Line Fields-Footnote-1218079 +Node: Field Splitting Summary218125 +Ref: Field Splitting Summary-Footnote-1221224 +Node: Constant Size221325 +Node: Splitting By Content225932 +Ref: Splitting By Content-Footnote-1229682 +Node: Multiple Line229722 +Ref: Multiple Line-Footnote-1235578 +Node: Getline235757 +Node: Plain Getline237973 +Node: Getline/Variable240068 +Node: Getline/File241215 +Node: Getline/Variable/File242599 +Ref: Getline/Variable/File-Footnote-1244198 +Node: Getline/Pipe244285 +Node: Getline/Variable/Pipe246984 +Node: Getline/Coprocess248091 +Node: Getline/Variable/Coprocess249343 +Node: Getline Notes250080 +Node: Getline Summary252884 +Ref: table-getline-variants253292 +Node: Read Timeout254204 +Ref: Read Timeout-Footnote-1258031 +Node: Command line directories258089 +Node: Input Summary258993 +Node: Printing262107 +Node: Print263786 +Node: Print Examples265127 +Node: Output Separators267906 +Node: OFMT269922 +Node: Printf271280 +Node: Basic Printf272186 +Node: Control Letters273725 +Node: Format Modifiers277579 +Node: Printf Examples283606 +Node: Redirection286313 +Node: Special Files293285 +Node: Special FD293816 +Ref: Special FD-Footnote-1297440 +Node: Special Network297514 +Node: Special Caveats298364 +Node: Close Files And Pipes299160 +Ref: Close Files And Pipes-Footnote-1306323 +Ref: Close Files And Pipes-Footnote-2306471 +Node: Output Summary306621 +Node: Expressions307593 +Node: Values308778 +Node: Constants309454 +Node: Scalar Constants310134 +Ref: Scalar Constants-Footnote-1310993 +Node: Nondecimal-numbers311243 +Node: Regexp Constants314243 +Node: Using Constant Regexps314718 +Node: Variables317788 +Node: Using Variables318443 +Node: Assignment Options320167 +Node: Conversion322042 +Ref: table-locale-affects327478 +Ref: Conversion-Footnote-1328102 +Node: All Operators328211 +Node: Arithmetic Ops328841 +Node: Concatenation331346 +Ref: Concatenation-Footnote-1334142 +Node: Assignment Ops334262 +Ref: table-assign-ops339245 +Node: Increment Ops340562 +Node: Truth Values and Conditions344000 +Node: Truth Values345083 +Node: Typing and Comparison346132 +Node: Variable Typing346925 +Ref: Variable Typing-Footnote-1350825 +Node: Comparison Operators350947 +Ref: table-relational-ops351357 +Node: POSIX String Comparison354907 +Ref: POSIX String Comparison-Footnote-1355991 +Node: Boolean Ops356129 +Ref: Boolean Ops-Footnote-1360199 +Node: Conditional Exp360290 +Node: Function Calls362017 +Node: Precedence365775 +Node: Locales369444 +Node: Expressions Summary371075 +Node: Patterns and Actions373572 +Node: Pattern Overview374688 +Node: Regexp Patterns376365 +Node: Expression Patterns376908 +Node: Ranges380689 +Node: BEGIN/END383795 +Node: Using BEGIN/END384557 +Ref: Using BEGIN/END-Footnote-1387293 +Node: I/O And BEGIN/END387399 +Node: BEGINFILE/ENDFILE389684 +Node: Empty392615 +Node: Using Shell Variables392932 +Node: Action Overview395215 +Node: Statements397542 +Node: If Statement399390 +Node: While Statement400888 +Node: Do Statement402932 +Node: For Statement404088 +Node: Switch Statement407240 +Node: Break Statement409343 +Node: Continue Statement411398 +Node: Next Statement413191 +Node: Nextfile Statement415581 +Node: Exit Statement418236 +Node: Built-in Variables420640 +Node: User-modified421767 +Ref: User-modified-Footnote-1429452 +Node: Auto-set429514 +Ref: Auto-set-Footnote-1442079 +Ref: Auto-set-Footnote-2442284 +Node: ARGC and ARGV442340 +Node: Pattern Action Summary446194 +Node: Arrays448417 +Node: Array Basics449966 +Node: Array Intro450792 +Ref: figure-array-elements452765 +Node: Reference to Elements455172 +Node: Assigning Elements457445 +Node: Array Example457936 +Node: Scanning an Array459668 +Node: Controlling Scanning462683 +Ref: Controlling Scanning-Footnote-1467856 +Node: Delete468172 +Ref: Delete-Footnote-1470937 +Node: Numeric Array Subscripts470994 +Node: Uninitialized Subscripts473177 +Node: Multidimensional474802 +Node: Multiscanning477895 +Node: Arrays of Arrays479484 +Node: Arrays Summary484147 +Node: Functions486252 +Node: Built-in487125 +Node: Calling Built-in488203 +Node: Numeric Functions490191 +Ref: Numeric Functions-Footnote-1494025 +Ref: Numeric Functions-Footnote-2494382 +Ref: Numeric Functions-Footnote-3494430 +Node: String Functions494699 +Ref: String Functions-Footnote-1517710 +Ref: String Functions-Footnote-2517839 +Ref: String Functions-Footnote-3518087 +Node: Gory Details518174 +Ref: table-sub-escapes519843 +Ref: table-sub-posix-92521197 +Ref: table-sub-proposed522548 +Ref: table-posix-sub523902 +Ref: table-gensub-escapes525447 +Ref: Gory Details-Footnote-1526623 +Ref: Gory Details-Footnote-2526674 +Node: I/O Functions526825 +Ref: I/O Functions-Footnote-1533948 +Node: Time Functions534095 +Ref: Time Functions-Footnote-1544559 +Ref: Time Functions-Footnote-2544627 +Ref: Time Functions-Footnote-3544785 +Ref: Time Functions-Footnote-4544896 +Ref: Time Functions-Footnote-5545008 +Ref: Time Functions-Footnote-6545235 +Node: Bitwise Functions545501 +Ref: table-bitwise-ops546063 +Ref: Bitwise Functions-Footnote-1550308 +Node: Type Functions550492 +Node: I18N Functions551634 +Node: User-defined553279 +Node: Definition Syntax554083 +Ref: Definition Syntax-Footnote-1559008 +Node: Function Example559077 +Ref: Function Example-Footnote-1561721 +Node: Function Caveats561743 +Node: Calling A Function562261 +Node: Variable Scope563216 +Node: Pass By Value/Reference566204 +Node: Return Statement569712 +Node: Dynamic Typing572696 +Node: Indirect Calls573625 +Node: Functions Summary583338 +Node: Library Functions585877 +Ref: Library Functions-Footnote-1589452 +Ref: Library Functions-Footnote-2589595 +Node: Library Names589766 +Ref: Library Names-Footnote-1593239 +Ref: Library Names-Footnote-2593459 +Node: General Functions593545 +Node: Strtonum Function594573 +Node: Assert Function597353 +Node: Round Function600679 +Node: Cliff Random Function602220 +Node: Ordinal Functions603236 +Ref: Ordinal Functions-Footnote-1606313 +Ref: Ordinal Functions-Footnote-2606565 +Node: Join Function606776 +Ref: Join Function-Footnote-1608547 +Node: Getlocaltime Function608747 +Node: Readfile Function612483 +Node: Data File Management614322 +Node: Filetrans Function614954 +Node: Rewind Function619023 +Node: File Checking620410 +Ref: File Checking-Footnote-1621542 +Node: Empty Files621743 +Node: Ignoring Assigns623973 +Node: Getopt Function625527 +Ref: Getopt Function-Footnote-1636830 +Node: Passwd Functions637033 +Ref: Passwd Functions-Footnote-1646012 +Node: Group Functions646100 +Ref: Group Functions-Footnote-1654042 +Node: Walking Arrays654255 +Node: Library Functions Summary656425 +Node: Sample Programs657787 +Node: Running Examples658514 +Node: Clones659242 +Node: Cut Program660466 +Node: Egrep Program670334 +Ref: Egrep Program-Footnote-1678305 +Node: Id Program678415 +Node: Split Program682079 +Ref: Split Program-Footnote-1685617 +Node: Tee Program685745 +Node: Uniq Program688552 +Node: Wc Program695982 +Ref: Wc Program-Footnote-1700250 +Ref: Wc Program-Footnote-2700450 +Node: Miscellaneous Programs700542 +Node: Dupword Program701755 +Node: Alarm Program703786 +Node: Translate Program708600 +Ref: Translate Program-Footnote-1712991 +Ref: Translate Program-Footnote-2713261 +Node: Labels Program713395 +Ref: Labels Program-Footnote-1716766 +Node: Word Sorting716850 +Node: History Sorting720893 +Node: Extract Program722729 +Ref: Extract Program-Footnote-1730304 +Node: Simple Sed730433 +Node: Igawk Program733495 +Ref: Igawk Program-Footnote-1748671 +Ref: Igawk Program-Footnote-2748872 +Node: Anagram Program749010 +Node: Signature Program752078 +Node: Programs Summary753325 +Node: Advanced Features754513 +Node: Nondecimal Data756461 +Node: Array Sorting758038 +Node: Controlling Array Traversal758735 +Node: Array Sorting Functions767015 +Ref: Array Sorting Functions-Footnote-1770922 +Node: Two-way I/O771116 +Ref: Two-way I/O-Footnote-1776632 +Node: TCP/IP Networking776714 +Node: Profiling779558 +Node: Advanced Features Summary787100 +Node: Internationalization788964 +Node: I18N and L10N790444 +Node: Explaining gettext791130 +Ref: Explaining gettext-Footnote-1796270 +Ref: Explaining gettext-Footnote-2796454 +Node: Programmer i18n796619 +Node: Translator i18n800844 +Node: String Extraction801638 +Ref: String Extraction-Footnote-1802599 +Node: Printf Ordering802685 +Ref: Printf Ordering-Footnote-1805467 +Node: I18N Portability805531 +Ref: I18N Portability-Footnote-1807980 +Node: I18N Example808043 +Ref: I18N Example-Footnote-1810765 +Node: Gawk I18N810837 +Node: I18N Summary811475 +Node: Debugger812814 +Node: Debugging813836 +Node: Debugging Concepts814277 +Node: Debugging Terms816133 +Node: Awk Debugging818730 +Node: Sample Debugging Session819622 +Node: Debugger Invocation820142 +Node: Finding The Bug821475 +Node: List of Debugger Commands827957 +Node: Breakpoint Control829289 +Node: Debugger Execution Control832953 +Node: Viewing And Changing Data836313 +Node: Execution Stack839671 +Node: Debugger Info841184 +Node: Miscellaneous Debugger Commands845178 +Node: Readline Support850362 +Node: Limitations851254 +Node: Debugging Summary853528 +Node: Arbitrary Precision Arithmetic854692 +Ref: Arbitrary Precision Arithmetic-Footnote-1856341 +Node: General Arithmetic856489 +Node: Floating Point Issues858209 +Node: String Conversion Precision859090 +Ref: String Conversion Precision-Footnote-1860795 +Node: Unexpected Results860904 +Node: POSIX Floating Point Problems863057 +Ref: POSIX Floating Point Problems-Footnote-1866878 +Node: Integer Programming866916 +Node: Floating-point Programming868727 +Ref: Floating-point Programming-Footnote-1875055 +Ref: Floating-point Programming-Footnote-2875325 +Node: Floating-point Representation875589 +Node: Floating-point Context876754 +Ref: table-ieee-formats877593 +Node: Rounding Mode878977 +Ref: table-rounding-modes879456 +Ref: Rounding Mode-Footnote-1882471 +Node: Gawk and MPFR882650 +Node: Arbitrary Precision Floats884059 +Ref: Arbitrary Precision Floats-Footnote-1886502 +Node: Setting Precision886823 +Ref: table-predefined-precision-strings887507 +Node: Setting Rounding Mode889652 +Ref: table-gawk-rounding-modes890056 +Node: Floating-point Constants891243 +Node: Changing Precision892695 +Ref: Changing Precision-Footnote-1894087 +Node: Exact Arithmetic894261 +Node: Arbitrary Precision Integers897395 +Ref: Arbitrary Precision Integers-Footnote-1900410 +Node: Dynamic Extensions900557 +Node: Extension Intro902066 +Node: Plugin License903331 +Node: Extension Mechanism Outline904016 +Ref: figure-load-extension904440 +Ref: figure-load-new-function905925 +Ref: figure-call-new-function906927 +Node: Extension API Description908911 +Node: Extension API Functions Introduction910361 +Node: General Data Types915226 +Ref: General Data Types-Footnote-1920919 +Node: Requesting Values921218 +Ref: table-value-types-returned921955 +Node: Memory Allocation Functions922913 +Ref: Memory Allocation Functions-Footnote-1925660 +Node: Constructor Functions925756 +Node: Registration Functions927514 +Node: Extension Functions928199 +Node: Exit Callback Functions930501 +Node: Extension Version String931750 +Node: Input Parsers932400 +Node: Output Wrappers942203 +Node: Two-way processors946719 +Node: Printing Messages948923 +Ref: Printing Messages-Footnote-1950000 +Node: Updating `ERRNO'950152 +Node: Accessing Parameters950891 +Node: Symbol Table Access952121 +Node: Symbol table by name952635 +Node: Symbol table by cookie954611 +Ref: Symbol table by cookie-Footnote-1958744 +Node: Cached values958807 +Ref: Cached values-Footnote-1962311 +Node: Array Manipulation962402 +Ref: Array Manipulation-Footnote-1963500 +Node: Array Data Types963539 +Ref: Array Data Types-Footnote-1966242 +Node: Array Functions966334 +Node: Flattening Arrays970208 +Node: Creating Arrays977060 +Node: Extension API Variables981791 +Node: Extension Versioning982427 +Node: Extension API Informational Variables984328 +Node: Extension API Boilerplate985414 +Node: Finding Extensions989218 +Node: Extension Example989778 +Node: Internal File Description990508 +Node: Internal File Ops994599 +Ref: Internal File Ops-Footnote-11006145 +Node: Using Internal File Ops1006285 +Ref: Using Internal File Ops-Footnote-11008632 +Node: Extension Samples1008900 +Node: Extension Sample File Functions1010424 +Node: Extension Sample Fnmatch1017992 +Node: Extension Sample Fork1019473 +Node: Extension Sample Inplace1020686 +Node: Extension Sample Ord1022466 +Node: Extension Sample Readdir1023302 +Ref: table-readdir-file-types1024158 +Node: Extension Sample Revout1024957 +Node: Extension Sample Rev2way1025548 +Node: Extension Sample Read write array1026289 +Node: Extension Sample Readfile1028168 +Node: Extension Sample API Tests1029268 +Node: Extension Sample Time1029793 +Node: gawkextlib1031108 +Node: Extension summary1033921 +Node: Language History1037586 +Node: V7/SVR3.11039229 +Node: SVR41041549 +Node: POSIX1042991 +Node: BTL1044377 +Node: POSIX/GNU1045111 +Node: Feature History1050710 +Node: Common Extensions1063822 +Node: Ranges and Locales1065134 +Ref: Ranges and Locales-Footnote-11069751 +Ref: Ranges and Locales-Footnote-21069778 +Ref: Ranges and Locales-Footnote-31070012 +Node: Contributors1070233 +Node: History summary1075695 +Node: Installation1077064 +Node: Gawk Distribution1078015 +Node: Getting1078499 +Node: Extracting1079325 +Node: Distribution contents1080967 +Node: Unix Installation1086684 +Node: Quick Installation1087301 +Node: Additional Configuration Options1089743 +Node: Configuration Philosophy1091481 +Node: Non-Unix Installation1093832 +Node: PC Installation1094290 +Node: PC Binary Installation1095601 +Node: PC Compiling1097449 +Ref: PC Compiling-Footnote-11100448 +Node: PC Testing1100553 +Node: PC Using1101729 +Node: Cygwin1105887 +Node: MSYS1106696 +Node: VMS Installation1107210 +Node: VMS Compilation1108006 +Ref: VMS Compilation-Footnote-11109228 +Node: VMS Dynamic Extensions1109286 +Node: VMS Installation Details1110659 +Node: VMS Running1112911 +Node: VMS GNV1115745 +Node: VMS Old Gawk1116468 +Node: Bugs1116938 +Node: Other Versions1120942 +Node: Installation summary1127196 +Node: Notes1128251 +Node: Compatibility Mode1129116 +Node: Additions1129898 +Node: Accessing The Source1130823 +Node: Adding Code1132259 +Node: New Ports1138437 +Node: Derived Files1142918 +Ref: Derived Files-Footnote-11147999 +Ref: Derived Files-Footnote-21148033 +Ref: Derived Files-Footnote-31148629 +Node: Future Extensions1148743 +Node: Implementation Limitations1149349 +Node: Extension Design1150597 +Node: Old Extension Problems1151751 +Ref: Old Extension Problems-Footnote-11153268 +Node: Extension New Mechanism Goals1153325 +Ref: Extension New Mechanism Goals-Footnote-11156685 +Node: Extension Other Design Decisions1156874 +Node: Extension Future Growth1158980 +Node: Old Extension Mechanism1159816 +Node: Notes summary1161578 +Node: Basic Concepts1162763 +Node: Basic High Level1163444 +Ref: figure-general-flow1163716 +Ref: figure-process-flow1164315 +Ref: Basic High Level-Footnote-11167544 +Node: Basic Data Typing1167729 +Node: Glossary1171056 +Node: Copying1196208 +Node: GNU Free Documentation License1233764 +Node: Index1258900  End Tag Table -- cgit v1.2.3 From 3a73ec7f27db0fec9ca68e97800f30f9ad33e293 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Mon, 16 Jun 2014 22:51:53 +0300 Subject: Start adding exercises. --- doc/gawk.info | 1065 ++++++++++++++++++++++++++++++--------------------------- 1 file changed, 561 insertions(+), 504 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index d7442017..6f84e273 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -4044,6 +4044,7 @@ have to be named on the `awk' command line (*note Getline::). * Command line directories:: What happens if you put a directory on the command line. * Input Summary:: Input summary. +* Input Exercises:: Exercises.  File: gawk.info, Node: Records, Next: Fields, Up: Reading Files @@ -5854,7 +5855,7 @@ error. usable data from an `awk' program.  -File: gawk.info, Node: Input Summary, Prev: Command line directories, Up: Reading Files +File: gawk.info, Node: Input Summary, Next: Input Exercises, Prev: Command line directories, Up: Reading Files 4.12 Summary ============ @@ -5922,6 +5923,25 @@ File: gawk.info, Node: Input Summary, Prev: Command line directories, Up: Rea `gawk' ignores them if not in POSIX mode. + +File: gawk.info, Node: Input Exercises, Prev: Input Summary, Up: Reading Files + +4.13 Exercises +============== + + 1. Using the `FIELDWIDTHS' variable (*note Constant Size::), write a + program to read election data, where each record represents one + voter's votes. Come up with a way to define which columns are + associated with each ballot item, and print the total votes, + including abstentions, for each item. + + 2. *note Plain Getline::, presented a program to remove C-style + comments (`/* ... */') from the input. That program does not work + if one comment ends on one line and another one starts later on + the same line. Write a program that does handle multiple comments + on the line. + +  File: gawk.info, Node: Printing, Next: Expressions, Prev: Reading Files, Up: Top @@ -5957,6 +5977,7 @@ function. descriptors. * Close Files And Pipes:: Closing Input and Output Files and Pipes. * Output Summary:: Output summary. +* Output exercises:: Exercises.  File: gawk.info, Node: Print, Next: Print Examples, Up: Printing @@ -6548,11 +6569,6 @@ be emphasized by storing it in a variable, like this: printf format, "----", "------" } { printf format, $1, $2 }' mail-list - At this point, it would be a worthwhile exercise to use the `printf' -statement to line up the headings and table data for the -`inventory-shipped' example that was covered earlier in the minor node -on the `print' statement (*note Print::). -  File: gawk.info, Node: Redirection, Next: Special Files, Prev: Printf, Up: Printing @@ -7017,7 +7033,7 @@ call. See the system manual pages for information on how to decode this value.  -File: gawk.info, Node: Output Summary, Prev: Close Files And Pipes, Up: Printing +File: gawk.info, Node: Output Summary, Next: Output exercises, Prev: Close Files And Pipes, Up: Printing 5.9 Summary =========== @@ -7042,6 +7058,30 @@ File: gawk.info, Node: Output Summary, Prev: Close Files And Pipes, Up: Print communications. + +File: gawk.info, Node: Output exercises, Prev: Output Summary, Up: Printing + +5.10 Exercises +============== + + 1. Rewrite the program: + + awk 'BEGIN { print "Month Crates" + print "----- ------" } + { print $1, " ", $2 }' inventory-shipped + + from *note Output Separators::, by using a new value of `OFS'. + + 2. Use the `printf' statement to line up the headings and table data + for the `inventory-shipped' example that was covered in *note + Print::. + + 3. What happens if you forget the double quotes when redirecting + output, as follows: + + BEGIN { print "Serious error detected!" > /dev/stderr } + +  File: gawk.info, Node: Expressions, Next: Patterns and Actions, Prev: Printing, Up: Top @@ -14127,6 +14167,7 @@ for different implementations of `awk' is pretty straightforward. * Group Functions:: Functions for getting group information. * Walking Arrays:: A function to walk arrays of arrays. * Library Functions Summary:: Summary of library functions. +* Library exercises:: Exercises. ---------- Footnotes ---------- @@ -15012,12 +15053,6 @@ normal case. end of the command-line arguments. Note that the test in the condition of the `for' loop uses the `<=' operator, not `<'. - As an exercise, you might consider whether this same problem can be -solved without relying on `gawk''s `ARGIND' variable. - - As a second exercise, revise this code to handle the case where an -intervening value in `ARGV' is a variable assignment. -  File: gawk.info, Node: Ignoring Assigns, Prev: Empty Files, Up: Data File Management @@ -15886,20 +15921,8 @@ value. Here is a main program to demonstrate: -| a[2][2] = 22 -| a[3] = 3 - Walking an array and processing each element is a general-purpose -operation. You might want to consider generalizing the `walk_array()' -function by adding an additional parameter named `process'. - - Then, inside the loop, instead of simply printing the array element's -index and value, use the indirect function call syntax (*note Indirect -Calls::) on `process', passing it the index and the value. - - When calling `walk_array()', you would pass the name of a -user-defined function that expects to receive an index and a value, and -then processes the element. -  -File: gawk.info, Node: Library Functions Summary, Prev: Walking Arrays, Up: Library Functions +File: gawk.info, Node: Library Functions Summary, Next: Library exercises, Prev: Walking Arrays, Up: Library Functions 10.8 Summary ============ @@ -15935,6 +15958,37 @@ File: gawk.info, Node: Library Functions Summary, Prev: Walking Arrays, Up: L A simple function to traverse an array of arrays to any depth. + +File: gawk.info, Node: Library exercises, Prev: Library Functions Summary, Up: Library Functions + +10.9 Exercises +============== + + 1. In *note Empty Files::, we presented the `zerofile.awk' program, + which made use of `gawk''s `ARGIND' variable. Can this problem be + solved without relying on `ARGIND'? If so, how? + + 2. As a related challenge, revise that code to handle the case where + an intervening value in `ARGV' is a variable assignment. + + 3. *note Walking Arrays::, presented a function that walked a + multidimensional array to print it out. However, walking an array + and processing each element is a general-purpose operation. + Generalize the `walk_array()' function by adding an additional + parameter named `process'. + + Then, inside the loop, instead of printing the array element's + index and value, use the indirect function call syntax (*note + Indirect Calls::) on `process', passing it the index and the value. + + When calling `walk_array()', you would pass the name of a + user-defined function that expects to receive an index and a value, + and then processes the element. + + Test your new version by printing the array; you should end up with + output identical to that of the original version. + +  File: gawk.info, Node: Sample Programs, Next: Advanced Features, Prev: Library Functions, Up: Top @@ -34078,483 +34132,486 @@ Node: Leftmost Longest176321 Node: Computed Regexps177522 Node: Regexp Summary180894 Node: Reading Files182366 -Node: Records184415 -Node: awk split records185158 -Node: gawk split records190016 -Ref: gawk split records-Footnote-1194537 -Node: Fields194574 -Ref: Fields-Footnote-1197538 -Node: Nonconstant Fields197624 -Ref: Nonconstant Fields-Footnote-1199854 -Node: Changing Fields200056 -Node: Field Separators206010 -Node: Default Field Splitting208712 -Node: Regexp Field Splitting209829 -Node: Single Character Fields213170 -Node: Command Line Field Separator214229 -Node: Full Line Fields217571 -Ref: Full Line Fields-Footnote-1218079 -Node: Field Splitting Summary218125 -Ref: Field Splitting Summary-Footnote-1221224 -Node: Constant Size221325 -Node: Splitting By Content225932 -Ref: Splitting By Content-Footnote-1229682 -Node: Multiple Line229722 -Ref: Multiple Line-Footnote-1235578 -Node: Getline235757 -Node: Plain Getline237973 -Node: Getline/Variable240068 -Node: Getline/File241215 -Node: Getline/Variable/File242599 -Ref: Getline/Variable/File-Footnote-1244198 -Node: Getline/Pipe244285 -Node: Getline/Variable/Pipe246984 -Node: Getline/Coprocess248091 -Node: Getline/Variable/Coprocess249343 -Node: Getline Notes250080 -Node: Getline Summary252884 -Ref: table-getline-variants253292 -Node: Read Timeout254204 -Ref: Read Timeout-Footnote-1258031 -Node: Command line directories258089 -Node: Input Summary258993 -Node: Printing262107 -Node: Print263786 -Node: Print Examples265127 -Node: Output Separators267906 -Node: OFMT269922 -Node: Printf271280 -Node: Basic Printf272186 -Node: Control Letters273725 -Node: Format Modifiers277579 -Node: Printf Examples283606 -Node: Redirection286313 -Node: Special Files293285 -Node: Special FD293816 -Ref: Special FD-Footnote-1297440 -Node: Special Network297514 -Node: Special Caveats298364 -Node: Close Files And Pipes299160 -Ref: Close Files And Pipes-Footnote-1306323 -Ref: Close Files And Pipes-Footnote-2306471 -Node: Output Summary306621 -Node: Expressions307593 -Node: Values308778 -Node: Constants309454 -Node: Scalar Constants310134 -Ref: Scalar Constants-Footnote-1310993 -Node: Nondecimal-numbers311243 -Node: Regexp Constants314243 -Node: Using Constant Regexps314718 -Node: Variables317788 -Node: Using Variables318443 -Node: Assignment Options320167 -Node: Conversion322042 -Ref: table-locale-affects327478 -Ref: Conversion-Footnote-1328102 -Node: All Operators328211 -Node: Arithmetic Ops328841 -Node: Concatenation331346 -Ref: Concatenation-Footnote-1334142 -Node: Assignment Ops334262 -Ref: table-assign-ops339245 -Node: Increment Ops340562 -Node: Truth Values and Conditions344000 -Node: Truth Values345083 -Node: Typing and Comparison346132 -Node: Variable Typing346925 -Ref: Variable Typing-Footnote-1350825 -Node: Comparison Operators350947 -Ref: table-relational-ops351357 -Node: POSIX String Comparison354907 -Ref: POSIX String Comparison-Footnote-1355991 -Node: Boolean Ops356129 -Ref: Boolean Ops-Footnote-1360199 -Node: Conditional Exp360290 -Node: Function Calls362017 -Node: Precedence365775 -Node: Locales369444 -Node: Expressions Summary371075 -Node: Patterns and Actions373572 -Node: Pattern Overview374688 -Node: Regexp Patterns376365 -Node: Expression Patterns376908 -Node: Ranges380689 -Node: BEGIN/END383795 -Node: Using BEGIN/END384557 -Ref: Using BEGIN/END-Footnote-1387293 -Node: I/O And BEGIN/END387399 -Node: BEGINFILE/ENDFILE389684 -Node: Empty392615 -Node: Using Shell Variables392932 -Node: Action Overview395215 -Node: Statements397542 -Node: If Statement399390 -Node: While Statement400888 -Node: Do Statement402932 -Node: For Statement404088 -Node: Switch Statement407240 -Node: Break Statement409343 -Node: Continue Statement411398 -Node: Next Statement413191 -Node: Nextfile Statement415581 -Node: Exit Statement418236 -Node: Built-in Variables420640 -Node: User-modified421767 -Ref: User-modified-Footnote-1429452 -Node: Auto-set429514 -Ref: Auto-set-Footnote-1442079 -Ref: Auto-set-Footnote-2442284 -Node: ARGC and ARGV442340 -Node: Pattern Action Summary446194 -Node: Arrays448417 -Node: Array Basics449966 -Node: Array Intro450792 -Ref: figure-array-elements452765 -Node: Reference to Elements455172 -Node: Assigning Elements457445 -Node: Array Example457936 -Node: Scanning an Array459668 -Node: Controlling Scanning462683 -Ref: Controlling Scanning-Footnote-1467856 -Node: Delete468172 -Ref: Delete-Footnote-1470937 -Node: Numeric Array Subscripts470994 -Node: Uninitialized Subscripts473177 -Node: Multidimensional474802 -Node: Multiscanning477895 -Node: Arrays of Arrays479484 -Node: Arrays Summary484147 -Node: Functions486252 -Node: Built-in487125 -Node: Calling Built-in488203 -Node: Numeric Functions490191 -Ref: Numeric Functions-Footnote-1494025 -Ref: Numeric Functions-Footnote-2494382 -Ref: Numeric Functions-Footnote-3494430 -Node: String Functions494699 -Ref: String Functions-Footnote-1517710 -Ref: String Functions-Footnote-2517839 -Ref: String Functions-Footnote-3518087 -Node: Gory Details518174 -Ref: table-sub-escapes519843 -Ref: table-sub-posix-92521197 -Ref: table-sub-proposed522548 -Ref: table-posix-sub523902 -Ref: table-gensub-escapes525447 -Ref: Gory Details-Footnote-1526623 -Ref: Gory Details-Footnote-2526674 -Node: I/O Functions526825 -Ref: I/O Functions-Footnote-1533948 -Node: Time Functions534095 -Ref: Time Functions-Footnote-1544559 -Ref: Time Functions-Footnote-2544627 -Ref: Time Functions-Footnote-3544785 -Ref: Time Functions-Footnote-4544896 -Ref: Time Functions-Footnote-5545008 -Ref: Time Functions-Footnote-6545235 -Node: Bitwise Functions545501 -Ref: table-bitwise-ops546063 -Ref: Bitwise Functions-Footnote-1550308 -Node: Type Functions550492 -Node: I18N Functions551634 -Node: User-defined553279 -Node: Definition Syntax554083 -Ref: Definition Syntax-Footnote-1559008 -Node: Function Example559077 -Ref: Function Example-Footnote-1561721 -Node: Function Caveats561743 -Node: Calling A Function562261 -Node: Variable Scope563216 -Node: Pass By Value/Reference566204 -Node: Return Statement569712 -Node: Dynamic Typing572696 -Node: Indirect Calls573625 -Node: Functions Summary583338 -Node: Library Functions585877 -Ref: Library Functions-Footnote-1589452 -Ref: Library Functions-Footnote-2589595 -Node: Library Names589766 -Ref: Library Names-Footnote-1593239 -Ref: Library Names-Footnote-2593459 -Node: General Functions593545 -Node: Strtonum Function594573 -Node: Assert Function597353 -Node: Round Function600679 -Node: Cliff Random Function602220 -Node: Ordinal Functions603236 -Ref: Ordinal Functions-Footnote-1606313 -Ref: Ordinal Functions-Footnote-2606565 -Node: Join Function606776 -Ref: Join Function-Footnote-1608547 -Node: Getlocaltime Function608747 -Node: Readfile Function612483 -Node: Data File Management614322 -Node: Filetrans Function614954 -Node: Rewind Function619023 -Node: File Checking620410 -Ref: File Checking-Footnote-1621542 -Node: Empty Files621743 -Node: Ignoring Assigns623973 -Node: Getopt Function625527 -Ref: Getopt Function-Footnote-1636830 -Node: Passwd Functions637033 -Ref: Passwd Functions-Footnote-1646012 -Node: Group Functions646100 -Ref: Group Functions-Footnote-1654042 -Node: Walking Arrays654255 -Node: Library Functions Summary656425 -Node: Sample Programs657787 -Node: Running Examples658514 -Node: Clones659242 -Node: Cut Program660466 -Node: Egrep Program670334 -Ref: Egrep Program-Footnote-1678305 -Node: Id Program678415 -Node: Split Program682079 -Ref: Split Program-Footnote-1685617 -Node: Tee Program685745 -Node: Uniq Program688552 -Node: Wc Program695982 -Ref: Wc Program-Footnote-1700250 -Ref: Wc Program-Footnote-2700450 -Node: Miscellaneous Programs700542 -Node: Dupword Program701755 -Node: Alarm Program703786 -Node: Translate Program708600 -Ref: Translate Program-Footnote-1712991 -Ref: Translate Program-Footnote-2713261 -Node: Labels Program713395 -Ref: Labels Program-Footnote-1716766 -Node: Word Sorting716850 -Node: History Sorting720893 -Node: Extract Program722729 -Ref: Extract Program-Footnote-1730304 -Node: Simple Sed730433 -Node: Igawk Program733495 -Ref: Igawk Program-Footnote-1748671 -Ref: Igawk Program-Footnote-2748872 -Node: Anagram Program749010 -Node: Signature Program752078 -Node: Programs Summary753325 -Node: Advanced Features754513 -Node: Nondecimal Data756461 -Node: Array Sorting758038 -Node: Controlling Array Traversal758735 -Node: Array Sorting Functions767015 -Ref: Array Sorting Functions-Footnote-1770922 -Node: Two-way I/O771116 -Ref: Two-way I/O-Footnote-1776632 -Node: TCP/IP Networking776714 -Node: Profiling779558 -Node: Advanced Features Summary787100 -Node: Internationalization788964 -Node: I18N and L10N790444 -Node: Explaining gettext791130 -Ref: Explaining gettext-Footnote-1796270 -Ref: Explaining gettext-Footnote-2796454 -Node: Programmer i18n796619 -Node: Translator i18n800844 -Node: String Extraction801638 -Ref: String Extraction-Footnote-1802599 -Node: Printf Ordering802685 -Ref: Printf Ordering-Footnote-1805467 -Node: I18N Portability805531 -Ref: I18N Portability-Footnote-1807980 -Node: I18N Example808043 -Ref: I18N Example-Footnote-1810765 -Node: Gawk I18N810837 -Node: I18N Summary811475 -Node: Debugger812814 -Node: Debugging813836 -Node: Debugging Concepts814277 -Node: Debugging Terms816133 -Node: Awk Debugging818730 -Node: Sample Debugging Session819622 -Node: Debugger Invocation820142 -Node: Finding The Bug821475 -Node: List of Debugger Commands827957 -Node: Breakpoint Control829289 -Node: Debugger Execution Control832953 -Node: Viewing And Changing Data836313 -Node: Execution Stack839671 -Node: Debugger Info841184 -Node: Miscellaneous Debugger Commands845178 -Node: Readline Support850362 -Node: Limitations851254 -Node: Debugging Summary853528 -Node: Arbitrary Precision Arithmetic854692 -Ref: Arbitrary Precision Arithmetic-Footnote-1856341 -Node: General Arithmetic856489 -Node: Floating Point Issues858209 -Node: String Conversion Precision859090 -Ref: String Conversion Precision-Footnote-1860795 -Node: Unexpected Results860904 -Node: POSIX Floating Point Problems863057 -Ref: POSIX Floating Point Problems-Footnote-1866878 -Node: Integer Programming866916 -Node: Floating-point Programming868727 -Ref: Floating-point Programming-Footnote-1875055 -Ref: Floating-point Programming-Footnote-2875325 -Node: Floating-point Representation875589 -Node: Floating-point Context876754 -Ref: table-ieee-formats877593 -Node: Rounding Mode878977 -Ref: table-rounding-modes879456 -Ref: Rounding Mode-Footnote-1882471 -Node: Gawk and MPFR882650 -Node: Arbitrary Precision Floats884059 -Ref: Arbitrary Precision Floats-Footnote-1886502 -Node: Setting Precision886823 -Ref: table-predefined-precision-strings887507 -Node: Setting Rounding Mode889652 -Ref: table-gawk-rounding-modes890056 -Node: Floating-point Constants891243 -Node: Changing Precision892695 -Ref: Changing Precision-Footnote-1894087 -Node: Exact Arithmetic894261 -Node: Arbitrary Precision Integers897395 -Ref: Arbitrary Precision Integers-Footnote-1900410 -Node: Dynamic Extensions900557 -Node: Extension Intro902066 -Node: Plugin License903331 -Node: Extension Mechanism Outline904016 -Ref: figure-load-extension904440 -Ref: figure-load-new-function905925 -Ref: figure-call-new-function906927 -Node: Extension API Description908911 -Node: Extension API Functions Introduction910361 -Node: General Data Types915226 -Ref: General Data Types-Footnote-1920919 -Node: Requesting Values921218 -Ref: table-value-types-returned921955 -Node: Memory Allocation Functions922913 -Ref: Memory Allocation Functions-Footnote-1925660 -Node: Constructor Functions925756 -Node: Registration Functions927514 -Node: Extension Functions928199 -Node: Exit Callback Functions930501 -Node: Extension Version String931750 -Node: Input Parsers932400 -Node: Output Wrappers942203 -Node: Two-way processors946719 -Node: Printing Messages948923 -Ref: Printing Messages-Footnote-1950000 -Node: Updating `ERRNO'950152 -Node: Accessing Parameters950891 -Node: Symbol Table Access952121 -Node: Symbol table by name952635 -Node: Symbol table by cookie954611 -Ref: Symbol table by cookie-Footnote-1958744 -Node: Cached values958807 -Ref: Cached values-Footnote-1962311 -Node: Array Manipulation962402 -Ref: Array Manipulation-Footnote-1963500 -Node: Array Data Types963539 -Ref: Array Data Types-Footnote-1966242 -Node: Array Functions966334 -Node: Flattening Arrays970208 -Node: Creating Arrays977060 -Node: Extension API Variables981791 -Node: Extension Versioning982427 -Node: Extension API Informational Variables984328 -Node: Extension API Boilerplate985414 -Node: Finding Extensions989218 -Node: Extension Example989778 -Node: Internal File Description990508 -Node: Internal File Ops994599 -Ref: Internal File Ops-Footnote-11006145 -Node: Using Internal File Ops1006285 -Ref: Using Internal File Ops-Footnote-11008632 -Node: Extension Samples1008900 -Node: Extension Sample File Functions1010424 -Node: Extension Sample Fnmatch1017992 -Node: Extension Sample Fork1019473 -Node: Extension Sample Inplace1020686 -Node: Extension Sample Ord1022466 -Node: Extension Sample Readdir1023302 -Ref: table-readdir-file-types1024158 -Node: Extension Sample Revout1024957 -Node: Extension Sample Rev2way1025548 -Node: Extension Sample Read write array1026289 -Node: Extension Sample Readfile1028168 -Node: Extension Sample API Tests1029268 -Node: Extension Sample Time1029793 -Node: gawkextlib1031108 -Node: Extension summary1033921 -Node: Language History1037586 -Node: V7/SVR3.11039229 -Node: SVR41041549 -Node: POSIX1042991 -Node: BTL1044377 -Node: POSIX/GNU1045111 -Node: Feature History1050710 -Node: Common Extensions1063822 -Node: Ranges and Locales1065134 -Ref: Ranges and Locales-Footnote-11069751 -Ref: Ranges and Locales-Footnote-21069778 -Ref: Ranges and Locales-Footnote-31070012 -Node: Contributors1070233 -Node: History summary1075695 -Node: Installation1077064 -Node: Gawk Distribution1078015 -Node: Getting1078499 -Node: Extracting1079325 -Node: Distribution contents1080967 -Node: Unix Installation1086684 -Node: Quick Installation1087301 -Node: Additional Configuration Options1089743 -Node: Configuration Philosophy1091481 -Node: Non-Unix Installation1093832 -Node: PC Installation1094290 -Node: PC Binary Installation1095601 -Node: PC Compiling1097449 -Ref: PC Compiling-Footnote-11100448 -Node: PC Testing1100553 -Node: PC Using1101729 -Node: Cygwin1105887 -Node: MSYS1106696 -Node: VMS Installation1107210 -Node: VMS Compilation1108006 -Ref: VMS Compilation-Footnote-11109228 -Node: VMS Dynamic Extensions1109286 -Node: VMS Installation Details1110659 -Node: VMS Running1112911 -Node: VMS GNV1115745 -Node: VMS Old Gawk1116468 -Node: Bugs1116938 -Node: Other Versions1120942 -Node: Installation summary1127196 -Node: Notes1128251 -Node: Compatibility Mode1129116 -Node: Additions1129898 -Node: Accessing The Source1130823 -Node: Adding Code1132259 -Node: New Ports1138437 -Node: Derived Files1142918 -Ref: Derived Files-Footnote-11147999 -Ref: Derived Files-Footnote-21148033 -Ref: Derived Files-Footnote-31148629 -Node: Future Extensions1148743 -Node: Implementation Limitations1149349 -Node: Extension Design1150597 -Node: Old Extension Problems1151751 -Ref: Old Extension Problems-Footnote-11153268 -Node: Extension New Mechanism Goals1153325 -Ref: Extension New Mechanism Goals-Footnote-11156685 -Node: Extension Other Design Decisions1156874 -Node: Extension Future Growth1158980 -Node: Old Extension Mechanism1159816 -Node: Notes summary1161578 -Node: Basic Concepts1162763 -Node: Basic High Level1163444 -Ref: figure-general-flow1163716 -Ref: figure-process-flow1164315 -Ref: Basic High Level-Footnote-11167544 -Node: Basic Data Typing1167729 -Node: Glossary1171056 -Node: Copying1196208 -Node: GNU Free Documentation License1233764 -Node: Index1258900 +Node: Records184458 +Node: awk split records185201 +Node: gawk split records190059 +Ref: gawk split records-Footnote-1194580 +Node: Fields194617 +Ref: Fields-Footnote-1197581 +Node: Nonconstant Fields197667 +Ref: Nonconstant Fields-Footnote-1199897 +Node: Changing Fields200099 +Node: Field Separators206053 +Node: Default Field Splitting208755 +Node: Regexp Field Splitting209872 +Node: Single Character Fields213213 +Node: Command Line Field Separator214272 +Node: Full Line Fields217614 +Ref: Full Line Fields-Footnote-1218122 +Node: Field Splitting Summary218168 +Ref: Field Splitting Summary-Footnote-1221267 +Node: Constant Size221368 +Node: Splitting By Content225975 +Ref: Splitting By Content-Footnote-1229725 +Node: Multiple Line229765 +Ref: Multiple Line-Footnote-1235621 +Node: Getline235800 +Node: Plain Getline238016 +Node: Getline/Variable240111 +Node: Getline/File241258 +Node: Getline/Variable/File242642 +Ref: Getline/Variable/File-Footnote-1244241 +Node: Getline/Pipe244328 +Node: Getline/Variable/Pipe247027 +Node: Getline/Coprocess248134 +Node: Getline/Variable/Coprocess249386 +Node: Getline Notes250123 +Node: Getline Summary252927 +Ref: table-getline-variants253335 +Node: Read Timeout254247 +Ref: Read Timeout-Footnote-1258074 +Node: Command line directories258132 +Node: Input Summary259036 +Node: Input Exercises262174 +Node: Printing262907 +Node: Print264630 +Node: Print Examples265971 +Node: Output Separators268750 +Node: OFMT270766 +Node: Printf272124 +Node: Basic Printf273030 +Node: Control Letters274569 +Node: Format Modifiers278423 +Node: Printf Examples284450 +Node: Redirection286914 +Node: Special Files293886 +Node: Special FD294417 +Ref: Special FD-Footnote-1298041 +Node: Special Network298115 +Node: Special Caveats298965 +Node: Close Files And Pipes299761 +Ref: Close Files And Pipes-Footnote-1306924 +Ref: Close Files And Pipes-Footnote-2307072 +Node: Output Summary307222 +Node: Output exercises308219 +Node: Expressions308899 +Node: Values310084 +Node: Constants310760 +Node: Scalar Constants311440 +Ref: Scalar Constants-Footnote-1312299 +Node: Nondecimal-numbers312549 +Node: Regexp Constants315549 +Node: Using Constant Regexps316024 +Node: Variables319094 +Node: Using Variables319749 +Node: Assignment Options321473 +Node: Conversion323348 +Ref: table-locale-affects328784 +Ref: Conversion-Footnote-1329408 +Node: All Operators329517 +Node: Arithmetic Ops330147 +Node: Concatenation332652 +Ref: Concatenation-Footnote-1335448 +Node: Assignment Ops335568 +Ref: table-assign-ops340551 +Node: Increment Ops341868 +Node: Truth Values and Conditions345306 +Node: Truth Values346389 +Node: Typing and Comparison347438 +Node: Variable Typing348231 +Ref: Variable Typing-Footnote-1352131 +Node: Comparison Operators352253 +Ref: table-relational-ops352663 +Node: POSIX String Comparison356213 +Ref: POSIX String Comparison-Footnote-1357297 +Node: Boolean Ops357435 +Ref: Boolean Ops-Footnote-1361505 +Node: Conditional Exp361596 +Node: Function Calls363323 +Node: Precedence367081 +Node: Locales370750 +Node: Expressions Summary372381 +Node: Patterns and Actions374878 +Node: Pattern Overview375994 +Node: Regexp Patterns377671 +Node: Expression Patterns378214 +Node: Ranges381995 +Node: BEGIN/END385101 +Node: Using BEGIN/END385863 +Ref: Using BEGIN/END-Footnote-1388599 +Node: I/O And BEGIN/END388705 +Node: BEGINFILE/ENDFILE390990 +Node: Empty393921 +Node: Using Shell Variables394238 +Node: Action Overview396521 +Node: Statements398848 +Node: If Statement400696 +Node: While Statement402194 +Node: Do Statement404238 +Node: For Statement405394 +Node: Switch Statement408546 +Node: Break Statement410649 +Node: Continue Statement412704 +Node: Next Statement414497 +Node: Nextfile Statement416887 +Node: Exit Statement419542 +Node: Built-in Variables421946 +Node: User-modified423073 +Ref: User-modified-Footnote-1430758 +Node: Auto-set430820 +Ref: Auto-set-Footnote-1443385 +Ref: Auto-set-Footnote-2443590 +Node: ARGC and ARGV443646 +Node: Pattern Action Summary447500 +Node: Arrays449723 +Node: Array Basics451272 +Node: Array Intro452098 +Ref: figure-array-elements454071 +Node: Reference to Elements456478 +Node: Assigning Elements458751 +Node: Array Example459242 +Node: Scanning an Array460974 +Node: Controlling Scanning463989 +Ref: Controlling Scanning-Footnote-1469162 +Node: Delete469478 +Ref: Delete-Footnote-1472243 +Node: Numeric Array Subscripts472300 +Node: Uninitialized Subscripts474483 +Node: Multidimensional476108 +Node: Multiscanning479201 +Node: Arrays of Arrays480790 +Node: Arrays Summary485453 +Node: Functions487558 +Node: Built-in488431 +Node: Calling Built-in489509 +Node: Numeric Functions491497 +Ref: Numeric Functions-Footnote-1495331 +Ref: Numeric Functions-Footnote-2495688 +Ref: Numeric Functions-Footnote-3495736 +Node: String Functions496005 +Ref: String Functions-Footnote-1519016 +Ref: String Functions-Footnote-2519145 +Ref: String Functions-Footnote-3519393 +Node: Gory Details519480 +Ref: table-sub-escapes521149 +Ref: table-sub-posix-92522503 +Ref: table-sub-proposed523854 +Ref: table-posix-sub525208 +Ref: table-gensub-escapes526753 +Ref: Gory Details-Footnote-1527929 +Ref: Gory Details-Footnote-2527980 +Node: I/O Functions528131 +Ref: I/O Functions-Footnote-1535254 +Node: Time Functions535401 +Ref: Time Functions-Footnote-1545865 +Ref: Time Functions-Footnote-2545933 +Ref: Time Functions-Footnote-3546091 +Ref: Time Functions-Footnote-4546202 +Ref: Time Functions-Footnote-5546314 +Ref: Time Functions-Footnote-6546541 +Node: Bitwise Functions546807 +Ref: table-bitwise-ops547369 +Ref: Bitwise Functions-Footnote-1551614 +Node: Type Functions551798 +Node: I18N Functions552940 +Node: User-defined554585 +Node: Definition Syntax555389 +Ref: Definition Syntax-Footnote-1560314 +Node: Function Example560383 +Ref: Function Example-Footnote-1563027 +Node: Function Caveats563049 +Node: Calling A Function563567 +Node: Variable Scope564522 +Node: Pass By Value/Reference567510 +Node: Return Statement571018 +Node: Dynamic Typing574002 +Node: Indirect Calls574931 +Node: Functions Summary584644 +Node: Library Functions587183 +Ref: Library Functions-Footnote-1590801 +Ref: Library Functions-Footnote-2590944 +Node: Library Names591115 +Ref: Library Names-Footnote-1594588 +Ref: Library Names-Footnote-2594808 +Node: General Functions594894 +Node: Strtonum Function595922 +Node: Assert Function598702 +Node: Round Function602028 +Node: Cliff Random Function603569 +Node: Ordinal Functions604585 +Ref: Ordinal Functions-Footnote-1607662 +Ref: Ordinal Functions-Footnote-2607914 +Node: Join Function608125 +Ref: Join Function-Footnote-1609896 +Node: Getlocaltime Function610096 +Node: Readfile Function613832 +Node: Data File Management615671 +Node: Filetrans Function616303 +Node: Rewind Function620372 +Node: File Checking621759 +Ref: File Checking-Footnote-1622891 +Node: Empty Files623092 +Node: Ignoring Assigns625071 +Node: Getopt Function626625 +Ref: Getopt Function-Footnote-1637928 +Node: Passwd Functions638131 +Ref: Passwd Functions-Footnote-1647110 +Node: Group Functions647198 +Ref: Group Functions-Footnote-1655140 +Node: Walking Arrays655353 +Node: Library Functions Summary656956 +Node: Library exercises658344 +Node: Sample Programs659624 +Node: Running Examples660351 +Node: Clones661079 +Node: Cut Program662303 +Node: Egrep Program672171 +Ref: Egrep Program-Footnote-1680142 +Node: Id Program680252 +Node: Split Program683916 +Ref: Split Program-Footnote-1687454 +Node: Tee Program687582 +Node: Uniq Program690389 +Node: Wc Program697819 +Ref: Wc Program-Footnote-1702087 +Ref: Wc Program-Footnote-2702287 +Node: Miscellaneous Programs702379 +Node: Dupword Program703592 +Node: Alarm Program705623 +Node: Translate Program710437 +Ref: Translate Program-Footnote-1714828 +Ref: Translate Program-Footnote-2715098 +Node: Labels Program715232 +Ref: Labels Program-Footnote-1718603 +Node: Word Sorting718687 +Node: History Sorting722730 +Node: Extract Program724566 +Ref: Extract Program-Footnote-1732141 +Node: Simple Sed732270 +Node: Igawk Program735332 +Ref: Igawk Program-Footnote-1750508 +Ref: Igawk Program-Footnote-2750709 +Node: Anagram Program750847 +Node: Signature Program753915 +Node: Programs Summary755162 +Node: Advanced Features756350 +Node: Nondecimal Data758298 +Node: Array Sorting759875 +Node: Controlling Array Traversal760572 +Node: Array Sorting Functions768852 +Ref: Array Sorting Functions-Footnote-1772759 +Node: Two-way I/O772953 +Ref: Two-way I/O-Footnote-1778469 +Node: TCP/IP Networking778551 +Node: Profiling781395 +Node: Advanced Features Summary788937 +Node: Internationalization790801 +Node: I18N and L10N792281 +Node: Explaining gettext792967 +Ref: Explaining gettext-Footnote-1798107 +Ref: Explaining gettext-Footnote-2798291 +Node: Programmer i18n798456 +Node: Translator i18n802681 +Node: String Extraction803475 +Ref: String Extraction-Footnote-1804436 +Node: Printf Ordering804522 +Ref: Printf Ordering-Footnote-1807304 +Node: I18N Portability807368 +Ref: I18N Portability-Footnote-1809817 +Node: I18N Example809880 +Ref: I18N Example-Footnote-1812602 +Node: Gawk I18N812674 +Node: I18N Summary813312 +Node: Debugger814651 +Node: Debugging815673 +Node: Debugging Concepts816114 +Node: Debugging Terms817970 +Node: Awk Debugging820567 +Node: Sample Debugging Session821459 +Node: Debugger Invocation821979 +Node: Finding The Bug823312 +Node: List of Debugger Commands829794 +Node: Breakpoint Control831126 +Node: Debugger Execution Control834790 +Node: Viewing And Changing Data838150 +Node: Execution Stack841508 +Node: Debugger Info843021 +Node: Miscellaneous Debugger Commands847015 +Node: Readline Support852199 +Node: Limitations853091 +Node: Debugging Summary855365 +Node: Arbitrary Precision Arithmetic856529 +Ref: Arbitrary Precision Arithmetic-Footnote-1858178 +Node: General Arithmetic858326 +Node: Floating Point Issues860046 +Node: String Conversion Precision860927 +Ref: String Conversion Precision-Footnote-1862632 +Node: Unexpected Results862741 +Node: POSIX Floating Point Problems864894 +Ref: POSIX Floating Point Problems-Footnote-1868715 +Node: Integer Programming868753 +Node: Floating-point Programming870564 +Ref: Floating-point Programming-Footnote-1876892 +Ref: Floating-point Programming-Footnote-2877162 +Node: Floating-point Representation877426 +Node: Floating-point Context878591 +Ref: table-ieee-formats879430 +Node: Rounding Mode880814 +Ref: table-rounding-modes881293 +Ref: Rounding Mode-Footnote-1884308 +Node: Gawk and MPFR884487 +Node: Arbitrary Precision Floats885896 +Ref: Arbitrary Precision Floats-Footnote-1888339 +Node: Setting Precision888660 +Ref: table-predefined-precision-strings889344 +Node: Setting Rounding Mode891489 +Ref: table-gawk-rounding-modes891893 +Node: Floating-point Constants893080 +Node: Changing Precision894532 +Ref: Changing Precision-Footnote-1895924 +Node: Exact Arithmetic896098 +Node: Arbitrary Precision Integers899232 +Ref: Arbitrary Precision Integers-Footnote-1902247 +Node: Dynamic Extensions902394 +Node: Extension Intro903903 +Node: Plugin License905168 +Node: Extension Mechanism Outline905853 +Ref: figure-load-extension906277 +Ref: figure-load-new-function907762 +Ref: figure-call-new-function908764 +Node: Extension API Description910748 +Node: Extension API Functions Introduction912198 +Node: General Data Types917063 +Ref: General Data Types-Footnote-1922756 +Node: Requesting Values923055 +Ref: table-value-types-returned923792 +Node: Memory Allocation Functions924750 +Ref: Memory Allocation Functions-Footnote-1927497 +Node: Constructor Functions927593 +Node: Registration Functions929351 +Node: Extension Functions930036 +Node: Exit Callback Functions932338 +Node: Extension Version String933587 +Node: Input Parsers934237 +Node: Output Wrappers944040 +Node: Two-way processors948556 +Node: Printing Messages950760 +Ref: Printing Messages-Footnote-1951837 +Node: Updating `ERRNO'951989 +Node: Accessing Parameters952728 +Node: Symbol Table Access953958 +Node: Symbol table by name954472 +Node: Symbol table by cookie956448 +Ref: Symbol table by cookie-Footnote-1960581 +Node: Cached values960644 +Ref: Cached values-Footnote-1964148 +Node: Array Manipulation964239 +Ref: Array Manipulation-Footnote-1965337 +Node: Array Data Types965376 +Ref: Array Data Types-Footnote-1968079 +Node: Array Functions968171 +Node: Flattening Arrays972045 +Node: Creating Arrays978897 +Node: Extension API Variables983628 +Node: Extension Versioning984264 +Node: Extension API Informational Variables986165 +Node: Extension API Boilerplate987251 +Node: Finding Extensions991055 +Node: Extension Example991615 +Node: Internal File Description992345 +Node: Internal File Ops996436 +Ref: Internal File Ops-Footnote-11007982 +Node: Using Internal File Ops1008122 +Ref: Using Internal File Ops-Footnote-11010469 +Node: Extension Samples1010737 +Node: Extension Sample File Functions1012261 +Node: Extension Sample Fnmatch1019829 +Node: Extension Sample Fork1021310 +Node: Extension Sample Inplace1022523 +Node: Extension Sample Ord1024303 +Node: Extension Sample Readdir1025139 +Ref: table-readdir-file-types1025995 +Node: Extension Sample Revout1026794 +Node: Extension Sample Rev2way1027385 +Node: Extension Sample Read write array1028126 +Node: Extension Sample Readfile1030005 +Node: Extension Sample API Tests1031105 +Node: Extension Sample Time1031630 +Node: gawkextlib1032945 +Node: Extension summary1035758 +Node: Language History1039423 +Node: V7/SVR3.11041066 +Node: SVR41043386 +Node: POSIX1044828 +Node: BTL1046214 +Node: POSIX/GNU1046948 +Node: Feature History1052547 +Node: Common Extensions1065659 +Node: Ranges and Locales1066971 +Ref: Ranges and Locales-Footnote-11071588 +Ref: Ranges and Locales-Footnote-21071615 +Ref: Ranges and Locales-Footnote-31071849 +Node: Contributors1072070 +Node: History summary1077532 +Node: Installation1078901 +Node: Gawk Distribution1079852 +Node: Getting1080336 +Node: Extracting1081162 +Node: Distribution contents1082804 +Node: Unix Installation1088521 +Node: Quick Installation1089138 +Node: Additional Configuration Options1091580 +Node: Configuration Philosophy1093318 +Node: Non-Unix Installation1095669 +Node: PC Installation1096127 +Node: PC Binary Installation1097438 +Node: PC Compiling1099286 +Ref: PC Compiling-Footnote-11102285 +Node: PC Testing1102390 +Node: PC Using1103566 +Node: Cygwin1107724 +Node: MSYS1108533 +Node: VMS Installation1109047 +Node: VMS Compilation1109843 +Ref: VMS Compilation-Footnote-11111065 +Node: VMS Dynamic Extensions1111123 +Node: VMS Installation Details1112496 +Node: VMS Running1114748 +Node: VMS GNV1117582 +Node: VMS Old Gawk1118305 +Node: Bugs1118775 +Node: Other Versions1122779 +Node: Installation summary1129033 +Node: Notes1130088 +Node: Compatibility Mode1130953 +Node: Additions1131735 +Node: Accessing The Source1132660 +Node: Adding Code1134096 +Node: New Ports1140274 +Node: Derived Files1144755 +Ref: Derived Files-Footnote-11149836 +Ref: Derived Files-Footnote-21149870 +Ref: Derived Files-Footnote-31150466 +Node: Future Extensions1150580 +Node: Implementation Limitations1151186 +Node: Extension Design1152434 +Node: Old Extension Problems1153588 +Ref: Old Extension Problems-Footnote-11155105 +Node: Extension New Mechanism Goals1155162 +Ref: Extension New Mechanism Goals-Footnote-11158522 +Node: Extension Other Design Decisions1158711 +Node: Extension Future Growth1160817 +Node: Old Extension Mechanism1161653 +Node: Notes summary1163415 +Node: Basic Concepts1164600 +Node: Basic High Level1165281 +Ref: figure-general-flow1165553 +Ref: figure-process-flow1166152 +Ref: Basic High Level-Footnote-11169381 +Node: Basic Data Typing1169566 +Node: Glossary1172893 +Node: Copying1198045 +Node: GNU Free Documentation License1235601 +Node: Index1260737  End Tag Table -- cgit v1.2.3 From 7e29c49a236619b84c20ba8c9f5361feba063e21 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 17 Jun 2014 20:30:12 +0300 Subject: Finish exercises, update chapter 15, menus. Update NEWS. --- doc/gawk.info | 2780 +++++++++++++++++++++++++++------------------------------ 1 file changed, 1309 insertions(+), 1471 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 6f84e273..0fb3d400 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -224,6 +224,8 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Read Timeout:: Reading input with a timeout. * Command line directories:: What happens if you put a directory on the command line. +* Input Summary:: Input summary. +* Input Exercises:: Exercises. * Print:: The `print' statement. * Print Examples:: Simple examples of `print' statements. @@ -247,6 +249,8 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Special Caveats:: Things to watch out for. * Close Files And Pipes:: Closing Input and Output Files and Pipes. +* Output Summary:: Output summary. +* Output exercises:: Exercises. * Values:: Constants, Variables, and Regular Expressions. * Constants:: String, numeric and regexp constants. @@ -289,6 +293,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Function Calls:: A function call is an expression. * Precedence:: How various operators nest. * Locales:: How the locale affects things. +* Expressions Summary:: Expressions summary. * Pattern Overview:: What goes into a pattern. * Regexp Patterns:: Using regexps as patterns. * Expression Patterns:: Any expression can be used as a @@ -335,6 +340,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) gives you information. * ARGC and ARGV:: Ways to use `ARGC' and `ARGV'. +* Pattern Action Summary:: Patterns and Actions summary. * Array Basics:: The basics of arrays. * Array Intro:: Introduction to Arrays * Reference to Elements:: How to examine one element of an @@ -357,6 +363,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) `awk'. * Multiscanning:: Scanning multidimensional arrays. * Arrays of Arrays:: True multidimensional arrays. +* Arrays Summary:: Summary of arrays. * Built-in:: Summarizes the built-in functions. * Calling Built-in:: How to call built-in functions. * Numeric Functions:: Functions that work with numbers, @@ -391,6 +398,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) runtime. * Indirect Calls:: Choosing the function to call at runtime. +* Functions Summary:: Summary of functions. * Library Names:: How to best name private global variables in library functions. * General Functions:: Functions that are of general use. @@ -425,6 +433,8 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Group Functions:: Functions for getting group information. * Walking Arrays:: A function to walk arrays of arrays. +* Library Functions Summary:: Summary of library functions. +* Library exercises:: Exercises. * Running Examples:: How to run these examples. * Clones:: Clones of common utilities. * Cut Program:: The `cut' utility. @@ -454,6 +464,8 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Anagram Program:: Finding anagrams from a dictionary. * Signature Program:: People do amazing things with too much time on their hands. +* Programs Summary:: Summary of programs. +* Programs Exercises:: Exercises. * Nondecimal Data:: Allowing nondecimal input data. * Array Sorting:: Facilities for controlling array traversal and sorting arrays. @@ -465,6 +477,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * TCP/IP Networking:: Using `gawk' for network programming. * Profiling:: Profiling your `awk' programs. +* Advanced Features Summary:: Summary of advanced features. * I18N and L10N:: Internationalization and Localization. * Explaining gettext:: How GNU `gettext' works. * Programmer i18n:: Features for the programmer. @@ -476,6 +489,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * I18N Example:: A simple i18n example. * Gawk I18N:: `gawk' is also internationalized. +* I18N Summary:: Summary of I18N stuff. * Debugging:: Introduction to `gawk' debugger. * Debugging Concepts:: Debugging in General. @@ -494,31 +508,23 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Miscellaneous Debugger Commands:: Miscellaneous Commands. * Readline Support:: Readline support. * Limitations:: Limitations and future plans. -* General Arithmetic:: An introduction to computer - arithmetic. -* Floating Point Issues:: Stuff to know about floating-point - numbers. -* String Conversion Precision:: The String Value Can Lie. -* Unexpected Results:: Floating Point Numbers Are Not - Abstract Numbers. -* POSIX Floating Point Problems:: Standards Versus Existing Practice. -* Integer Programming:: Effective integer programming. -* Floating-point Programming:: Effective Floating-point Programming. -* Floating-point Representation:: Binary floating-point representation. -* Floating-point Context:: Floating-point context. -* Rounding Mode:: Floating-point rounding mode. -* Gawk and MPFR:: How `gawk' provides - arbitrary-precision arithmetic. -* Arbitrary Precision Floats:: Arbitrary Precision Floating-point - Arithmetic with `gawk'. -* Setting Precision:: Setting the working precision. -* Setting Rounding Mode:: Setting the rounding mode. -* Floating-point Constants:: Representing floating-point constants. -* Changing Precision:: Changing the precision of a number. -* Exact Arithmetic:: Exact arithmetic with floating-point - numbers. +* Debugging Summary:: Debugging summary. +* Computer Arithmetic:: A quick intro to computer math. +* Math Definitions:: Defining terms used. +* MPFR features:: The MPFR features in `gawk'. +* FP Math Caution:: Things to know. +* Inexactness of computations:: Floating point math is not exact. +* Inexact representation:: Numbers are not exactly represented. +* Comparing FP Values:: How to compare floating point values. +* Errors accumulate:: Errors get bigger as they go. +* Getting Accuracy:: Getting more accuracy takes some work. +* Try To Round:: Add digits and round. +* Setting precision:: How to set the precision. +* Setting the rounding mode:: How to set the rounding mode. * Arbitrary Precision Integers:: Arbitrary Precision Integer Arithmetic with `gawk'. +* POSIX Floating Point Problems:: Standards Versus Existing Practice. +* Floating point summary:: Summary of floating point discussion. * Extension Intro:: What is an extension. * Plugin License:: A note about licensing. * Extension Mechanism Outline:: An outline of how it works. @@ -580,6 +586,8 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Extension Sample Time:: An interface to `gettimeofday()' and `sleep()'. * gawkextlib:: The `gawkextlib' project. +* Extension summary:: Extension summary. +* Extension Exercises:: Exercises. * V7/SVR3.1:: The major changes between V7 and System V Release 3.1. * SVR4:: Minor changes between System V @@ -596,6 +604,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) ranges. * Contributors:: The major contributors to `gawk'. +* History summary:: History summary. * Gawk Distribution:: What is in the `gawk' distribution. * Getting:: How to get the distribution. @@ -634,6 +643,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Bugs:: Reporting Problems and Bugs. * Other Versions:: Other freely available `awk' implementations. +* Installation summary:: Summary of installation. * Compatibility Mode:: How to disable certain `gawk' extensions. * Additions:: Making Additions To `gawk'. @@ -654,6 +664,7 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) * Extension Other Design Decisions:: Some other design decisions. * Extension Future Growth:: Some room for future growth. * Old Extension Mechanism:: Some compatibility for old extensions. +* Notes summary:: Summary of implementation notes. * Basic High Level:: The high level view. * Basic Data Typing:: A very quick intro to data types. @@ -1968,9 +1979,8 @@ File: gawk.info, Node: Two Rules, Next: More Complex, Prev: Very Simple, Up: The `awk' utility reads the input files one line at a time. For each line, `awk' tries the patterns of each of the rules. If several -patterns match, then several actions execture in the order in which -they appear in the `awk' program. If no patterns match, then no -actions run. +patterns match, then several actions execute in the order in which they +appear in the `awk' program. If no patterns match, then no actions run. After processing all the rules that match the line (and perhaps there are none), `awk' reads the next line. (However, *note Next @@ -2529,7 +2539,7 @@ The following list describes options mandated by the POSIX standard: `--bignum' Force arbitrary precision arithmetic on numbers. This option has no effect if `gawk' is not compiled to use the GNU MPFR and MP - libraries (*note Gawk and MPFR::). + libraries (*note Arbitrary Precision Arithmetic::). `-n' `--non-decimal-data' @@ -3985,7 +3995,7 @@ File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp * Regexp operators provide grouping, alternation and repetition. - * Bracket expressions give you a shorthand for specifyings sets of + * Bracket expressions give you a shorthand for specifying sets of characters that can match at a particular point in a regexp. Within bracket expressions, POSIX character classes let you specify certain groups of characters in a locale-independent fashion. @@ -5912,7 +5922,7 @@ File: gawk.info, Node: Input Summary, Next: Input Exercises, Prev: Command li * `PROCINFO["FS"]' can be used to see how fields are being split. - * Use `getline' in its varioius forms to read additional records, + * Use `getline' in its various forms to read additional records, from the default input stream, from a file, or from a pipe or co-process. @@ -5977,7 +5987,7 @@ function. descriptors. * Close Files And Pipes:: Closing Input and Output Files and Pipes. * Output Summary:: Output summary. -* Output exercises:: Exercises. +* Output exercises:: Exercises.  File: gawk.info, Node: Print, Next: Print Examples, Up: Printing @@ -6296,7 +6306,7 @@ width. Here is a list of the format-control letters: representing negative infinity are formatted as `-inf' or `-infinity', and positive infinity as `inf' and `infinity'. The special "not a number" value formats as `-nan' or `nan' (*note - General Arithmetic::). + Math Definitions::). `%F' Like `%f' but the infinity and "not a number" values are spelled @@ -6910,7 +6920,7 @@ file or command, or the next `print' or `printf' to that file or command, reopens the file or reruns the command. Because the expression that you use to close a file or pipeline must exactly match the expression used to open the file or run the command, it is good -practice to use a valueiable to store the file name or command. The +practice to use a variable to store the file name or command. The previous example becomes the following: sortcom = "sort -r names" @@ -10016,12 +10026,12 @@ description of each variable.) `PREC #' The working precision of arbitrary precision floating-point - numbers, 53 bits by default (*note Setting Precision::). + numbers, 53 bits by default (*note Setting precision::). `ROUNDMODE #' The rounding mode to use for arbitrary precision arithmetic on numbers, by default `"N"' (`roundTiesToEven' in the IEEE 754 - standard; *note Setting Rounding Mode::). + standard; *note Setting the rounding mode::). ``RS'' The input record separator. Its default value is a string @@ -10257,8 +10267,8 @@ Options::), they are not special. The following additional elements in the array are available to provide information about the MPFR and GMP libraries if your - version of `gawk' supports arbitrary precision numbers (*note Gawk - and MPFR::): + version of `gawk' supports arbitrary precision numbers (*note + Arbitrary Precision Arithmetic::): `PROCINFO["mpfr_version"]' The version of the GNU MPFR library. @@ -14050,7 +14060,7 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions form of additional arguments. * Functions accept zero or more arguments and return a value. The - expressions that provide the argument values are comnpletely + expressions that provide the argument values are completely evaluated before the function is called. Order of evaluation is not defined. The return value can be ignored. @@ -14061,7 +14071,7 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions * User-defined functions provide important capabilities but come with some syntactic inelegancies. In a function call, there cannot be any space between the function name and the opening left - parethesis of the argument list. Also, there is no provision for + parenthesis of the argument list. Also, there is no provision for local variables, so the convention is to add extra parameters, and to separate them visually from the real parameters by extra whitespace. @@ -15794,7 +15804,7 @@ the database for the same group. This is common when a group has a large number of members. A pair of such entries might look like the following: - tvpeople:*:101:johnny,jay,arsenio + tvpeople:*:101:johny,jay,arsenio tvpeople:*:101:david,conan,tom,joan For this reason, `_gr_init()' looks to see if a group name or group @@ -16009,6 +16019,7 @@ Library Functions::. * Clones:: Clones of common utilities. * Miscellaneous Programs:: Some interesting `awk' programs. * Programs Summary:: Summary of programs. +* Programs Exercises:: Exercises.  File: gawk.info, Node: Running Examples, Next: Clones, Up: Sample Programs @@ -17168,7 +17179,7 @@ lines, words, and characters to zero, and saves the current file name in } The `endfile()' function adds the current file's numbers to the -running totals of lines, words, and characters.(1) It then prints out +running totals of lines, words, and characters. It then prints out those numbers for the file that was just read. It relies on `beginfile()' to reset the numbers for the following data file: @@ -17187,7 +17198,7 @@ those numbers for the file that was just read. It relies on } There is one rule that is executed for each line. It adds the length -of the record, plus one, to `chars'.(2) Adding one plus the record +of the record, plus one, to `chars'.(1) Adding one plus the record length is needed because the newline character separating records (the value of `RS') is not part of the record itself, and thus not included in its length. Next, `lines' is incremented for each line read, and @@ -17217,11 +17228,7 @@ in its length. Next, `lines' is incremented for each line read, and ---------- Footnotes ---------- - (1) `wc' can't just use the value of `FNR' in `endfile()'. If you -examine the code in *note Filetrans Function::, you will see that `FNR' -has already been reset by the time `endfile()' is called. - - (2) Since `gawk' understands multibyte locales, this code counts + (1) Since `gawk' understands multibyte locales, this code counts characters, not bytes.  @@ -17947,7 +17954,7 @@ function (*note String Functions::). The `@' symbol is used as the separator character. Each element of `a' that is empty indicates two successive `@' symbols in the original line. For each two empty elements (`@@' in the original file), we have to add a single `@' -symbol back in.(1) +symbol back in. When the processing of the array is finished, `join()' is called with the value of `SUBSEP' (*note Multidimensional::), to rejoin the @@ -18018,11 +18025,6 @@ closing the open file: close(curfile) } - ---------- Footnotes ---------- - - (1) This program was written before `gawk' had the `gensub()' -function. Consider how you might use it to simplify the code. -  File: gawk.info, Node: Simple Sed, Next: Igawk Program, Prev: Extract Program, Up: Miscellaneous Programs @@ -18472,26 +18474,6 @@ manipulation using the shell than it is in `awk'. Finally, `igawk' shows that it is not always necessary to add new features to a program; they can often be layered on top. - As an additional example of this, consider the idea of having two -files in a directory in the search path: - -`default.awk' - This file contains a set of default library functions, such as - `getopt()' and `assert()'. - -`site.awk' - This file contains library functions that are specific to a site or - installation; i.e., locally developed functions. Having a - separate file allows `default.awk' to change with new `gawk' - releases, without requiring the system administrator to update it - each time by adding the local functions. - - One user suggested that `gawk' be modified to automatically read -these files upon startup. Instead, it would be very simple to modify -`igawk' to do this. Since `igawk' can process nested `@include' -directives, `default.awk' could simply contain `@include' statements -for the desired library functions. - ---------- Footnotes ---------- (1) Fully explaining the `sh' language is beyond the scope of this @@ -18621,7 +18603,7 @@ truly desperate to understand it, see Chris Johansen's explanation, which is embedded in the Texinfo source file for this Info file.)  -File: gawk.info, Node: Programs Summary, Prev: Miscellaneous Programs, Up: Sample Programs +File: gawk.info, Node: Programs Summary, Next: Programs Exercises, Prev: Miscellaneous Programs, Up: Sample Programs 11.4 Summary ============ @@ -18650,6 +18632,96 @@ File: gawk.info, Node: Programs Summary, Prev: Miscellaneous Programs, Up: Sa words in text, printing mailing labels, and finding anagrams. + +File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample Programs + +11.5 Exercises +============== + + 1. Rewrite `cut.awk' (*note Cut Program::) using `split()' with `""' + as the seperator. + + 2. In *note Egrep Program::, we mentioned that `egrep -i' could be + simulated in versions of `awk' without `IGNORECASE' by using + `tolower()' on the line and the pattern. In a footnote there, we + also mentioned that this solution has a bug: the translated line is + output, and not the original one. Fix this problem. + + 3. The POSIX version of `id' takes options that control which + information is printed. Modify the `awk' version (*note Id + Program::) to accept the same arguments and perform in the same + way. + + 4. The `split.awk' program (*note Split Program::) uses the `chr()' + and `ord()' functions to move through the letters of the alphabet. + Modify the program to instead use only the `awk' built-in + functions, such as `index()' and `substr()'. + + 5. The `split.awk' program (*note Split Program::) assumes that + letters are contiguous in the character set, which isn't true for + EBCDIC systems. Fix this problem. + + 6. Why can't the `wc.awk' program (*note Wc Program::) just use the + value of `FNR' in `endfile()'? Hint: examine the code in *note + Filetrans Function::. + + 7. Manipulation of individual characters in the `translate' program + (*note Translate Program::) is painful using standard `awk' + functions. Given that `gawk' can split strings into individual + characters using `""' as the separator, how might you use this + feature to simplify the program? + + 8. The `extract.awk' program (*note Extract Program::) was written + before `gawk' had the `gensub()' function. Use it to simplify the + code. + + 9. Compare the performance of the `awksed.awk' program (*note Simple + Sed::) with the more straightforward: + + BEGIN { + pat = ARGV[1] + repl = ARGV[2] + ARGV[1] = ARGV[2] = "" + } + + { gsub(pat, repl); print } + + 10. What are the advantages and disadvantages of `awksed.awk' versus + the real `sed' utility? + + 11. In *note Igawk Program::, we mentioned that not trying to save the + line read with `getline' in the `pathto()' function when testing + for the file's accessibility for use with the main program + simplifies things considerably. What problem does this engender + though? + + 12. As an additional example of the idea that it is not always + necessary to add new features to a program, consider the idea of + having two files in a directory in the search path: + + `default.awk' + This file contains a set of default library functions, such + as `getopt()' and `assert()'. + + `site.awk' + This file contains library functions that are specific to a + site or installation; i.e., locally developed functions. + Having a separate file allows `default.awk' to change with + new `gawk' releases, without requiring the system + administrator to update it each time by adding the local + functions. + + One user suggested that `gawk' be modified to automatically read + these files upon startup. Instead, it would be very simple to + modify `igawk' to do this. Since `igawk' can process nested + `@include' directives, `default.awk' could simply contain + `@include' statements for the desired library functions. Make + this change. + + 13. Modify `anagram.awk' (*note Anagram Program::), to avoid the use + of the external `sort' utility. + +  File: gawk.info, Node: Advanced Features, Next: Internationalization, Prev: Sample Programs, Up: Top @@ -20167,7 +20239,7 @@ File: gawk.info, Node: I18N Summary, Prev: Gawk I18N, Up: Internationalizatio * You mark a program's strings for translation by preceding them with an underscore. Once that is done, the strings are extracted into a - `.pot' file. This file is copied for each langauge into a `.po' + `.pot' file. This file is copied for each language into a `.po' file, and the `.po' files are compiled into `.gmo' files for use at runtime. @@ -21266,358 +21338,285 @@ File: gawk.info, Node: Arbitrary Precision Arithmetic, Next: Dynamic Extension 15 Arithmetic and Arbitrary Precision Arithmetic with `gawk' ************************************************************ - There's a credibility gap: We don't know how much of the - computer's answers to believe. Novice computer users solve this - problem by implicitly trusting in the computer as an infallible - authority; they tend to believe that all digits of a printed - answer are significant. Disillusioned computer users have just the - opposite approach; they are constantly afraid that their answers - are almost meaningless.(1) -- Donald Knuth - - This major node discusses issues that you may encounter when -performing arithmetic. It begins by discussing some of the general -attributes of computer arithmetic, along with how this can influence -what you see when running `awk' programs. This discussion applies to -all versions of `awk'. - - The major node then moves on to describe "arbitrary precision -arithmetic", a feature which is specific to `gawk'. +This major node introduces some basic concepts relating to how +computers do arithmetic and briefly lists the features in `gawk' for +performing arbitrary precision floating point computations. It then +proceeds to describe floating-point arithmetic, which is what `awk' +uses for all its computations, including a discussion of arbitrary +precision floating point arithmetic, which is a feature available only +in `gawk'. It continues on to present arbitrary precision integers, and +concludes with a description of some points where `gawk' and the POSIX +standard are not quite in agreement. * Menu: -* General Arithmetic:: An introduction to computer arithmetic. -* Floating-point Programming:: Effective Floating-point Programming. -* Gawk and MPFR:: How `gawk' provides - arbitrary-precision arithmetic. -* Arbitrary Precision Floats:: Arbitrary Precision Floating-point Arithmetic - with `gawk'. -* Arbitrary Precision Integers:: Arbitrary Precision Integer Arithmetic with - `gawk'. - - ---------- Footnotes ---------- - - (1) Donald E. Knuth. `The Art of Computer Programming'. Volume 2, -`Seminumerical Algorithms', third edition, 1998, ISBN 0-201-89683-4, p. -229. +* Computer Arithmetic:: A quick intro to computer math. +* Math Definitions:: Defining terms used. +* MPFR features:: The MPFR features in `gawk'. +* FP Math Caution:: Things to know. +* Arbitrary Precision Integers:: Arbitrary Precision Integer Arithmetic with + `gawk'. +* POSIX Floating Point Problems:: Standards Versus Existing Practice. +* Floating point summary:: Summary of floating point discussion.  -File: gawk.info, Node: General Arithmetic, Next: Floating-point Programming, Up: Arbitrary Precision Arithmetic +File: gawk.info, Node: Computer Arithmetic, Next: Math Definitions, Up: Arbitrary Precision Arithmetic 15.1 A General Description of Computer Arithmetic ================================================= -Within computers, there are two kinds of numeric values: "integers" and -"floating-point". In school, integer values were referred to as -"whole" numbers--that is, numbers without any fractional part, such as -1, 42, or -17. The advantage to integer numbers is that they represent -values exactly. The disadvantage is that their range is limited. On -most systems, this range is -2,147,483,648 to 2,147,483,647. However, -many systems now support a range from -9,223,372,036,854,775,808 to -9,223,372,036,854,775,807. - - Integer values come in two flavors: "signed" and "unsigned". Signed -values may be negative or positive, with the range of values just -described. Unsigned values are always positive. On most systems, the -range is from 0 to 4,294,967,295. However, many systems now support a -range from 0 to 18,446,744,073,709,551,615. - - Floating-point numbers represent what are called "real" numbers; -i.e., those that do have a fractional part, such as 3.1415927. The -advantage to floating-point numbers is that they can represent a much -larger range of values. The disadvantage is that there are numbers -that they cannot represent exactly. `awk' uses "double precision" -floating-point numbers, which can hold more digits than "single -precision" floating-point numbers. - - There a several important issues to be aware of, described next. - -* Menu: - -* Floating Point Issues:: Stuff to know about floating-point numbers. -* Integer Programming:: Effective integer programming. - - -File: gawk.info, Node: Floating Point Issues, Next: Integer Programming, Up: General Arithmetic - -15.1.1 Floating-Point Number Caveats ------------------------------------- - -This minor node describes some of the issues involved in using -floating-point numbers. - - There is a very nice paper on floating-point arithmetic -(http://www.validlab.com/goldberg/paper.pdf) by David Goldberg, "What -Every Computer Scientist Should Know About Floating-point Arithmetic," -`ACM Computing Surveys' *23*, 1 (1991-03), 5-48. This is worth reading -if you are interested in the details, but it does require a background -in computer science. +Until now, we have worked with data as either numbers or strings. +Ultimately, however, computers represent everything in terms of "binary +digits", or "bits". A decimal digit can take on any of 10 values: zero +through nine. A binary digit can take on any of two values, zero or +one. Using binary, computers (and computer software) can represent and +manipulate numerical and character data. In general, the more bits you +can use to represent a particular thing, the greater the range of +possible values it can take on. + + Modern computers support at least two, and often more, ways to do +arithmetic. Each kind of arithmetic uses a different representation +(organization of the bits) for the numbers. The kinds of arithmetic +that interest us are: + +Decimal arithmetic + This is the kind of arithmetic you learned in elementary school, + using paper and pencil (and/or a calculator). In theory, numbers + can have an arbitrary number of digits on either side (or both + sides) of the decimal point, and the results of a computation are + always exact. + + Some modern system can do decimal arithmetic in hardware, but + usually you need a special software library to provide access to + these instructions. There are also libraries that do decimal + arithmetic entirely in software. + + Despite the fact that some users expect `gawk' to be performing + decimal arithmetic,(1) it does not do so. + +Integer arithmetic + In school, integer values were referred to as "whole" numbers--that + is, numbers without any fractional part, such as 1, 42, or -17. + The advantage to integer numbers is that they represent values + exactly. The disadvantage is that their range is limited. + + In computers, integer values come in two flavors: "signed" and + "unsigned". Signed values may be negative or positive, whereas + unsigned values are always positive (that is, greater than or equal + to zero). + + In computer systems, integer arithmetic is exact, but the possible + range of values is limited. Integer arithmetic is generally + faster than floating point arithmetic. + +Floating point arithmetic + Floating-point numbers represent what were called in school "real" + numbers; i.e., those that have a fractional part, such as + 3.1415927. The advantage to floating-point numbers is that they + can represent a much larger range of values than can integers. + The disadvantage is that there are numbers that they cannot + represent exactly. + + Modern systems support floating point arithmetic in hardware, with + a limited range of values. There are software libraries that allow + the use of arbitrary precision floating point calculations. + + POSIX `awk' uses "double precision" floating-point numbers, which + can hold more digits than "single precision" floating-point + numbers. `gawk' has facilities for performing arbitrary precision + floating point arithmetic, which we describe in more detail + shortly. + + Computers work with integer and floating point values of different +ranges. Integer values are usually either 32 or 64 bits in size. Single +precision floating point values occupy 32 bits, whereas double precision +floating point values occupy 64 bits. Floating point values are always +signed. The possible ranges of values are shown in the following table. + +Numeric representation Miniumum value Maximum value +--------------------------------------------------------------------------- +32-bit signed integer -2,147,483,648 2,147,483,647 +32-bit unsigned integer 0 4,294,967,295 +64-bit signed integer -9,223,372,036,854,775,8089,223,372,036,854,775,807 +64-bit unsigned integer 0 18,446,744,073,709,551,615 +Single precision `1.175494e-38' `3.402823e+38' +floating point +(approximate) +Double precision `2.225074e-308' `1.797693e+308' +floating point +(approximate) -* Menu: + ---------- Footnotes ---------- -* String Conversion Precision:: The String Value Can Lie. -* Unexpected Results:: Floating Point Numbers Are Not Abstract - Numbers. -* POSIX Floating Point Problems:: Standards Versus Existing Practice. + (1) We don't know why they expect this, but they do.  -File: gawk.info, Node: String Conversion Precision, Next: Unexpected Results, Up: Floating Point Issues +File: gawk.info, Node: Math Definitions, Next: MPFR features, Prev: Computer Arithmetic, Up: Arbitrary Precision Arithmetic -15.1.1.1 The String Value Can Lie -................................. - -Internally, `awk' keeps both the numeric value (double precision -floating-point) and the string value for a variable. Separately, `awk' -keeps track of what type the variable has (*note Typing and -Comparison::), which plays a role in how variables are used in -comparisons. +15.2 Other Stuff To Know +======================== - It is important to note that the string value for a number may not -reflect the full value (all the digits) that the numeric value actually -contains. The following program, `values.awk', illustrates this: +The rest of this major node uses a number of terms. Here are some +informal definitions that should help you work your way through the +material here. - { - sum = $1 + $2 - # see it for what it is - printf("sum = %.12g\n", sum) - # use CONVFMT - a = "<" sum ">" - print "a =", a - # use OFMT - print "sum =", sum - } +"Accuracy" + A floating-point calculation's accuracy is how close it comes to + the real (paper and pencil) value. -This program shows the full value of the sum of `$1' and `$2' using -`printf', and then prints the string values obtained from both -automatic conversion (via `CONVFMT') and from printing (via `OFMT'). +"Error" + The difference between what the result of a computation "should be" + and what it actually is. It is best to minimize error as much as + possible. - Here is what happens when the program is run: +"Exponent" + The order of magnitude of a value; some number of bits in a + floating-point value store the exponent. - $ echo 3.654321 1.2345678 | awk -f values.awk - -| sum = 4.8888888 - -| a = <4.88889> - -| sum = 4.88889 +"Inf" + A special value representing infinity. Operations involving another + number and infinity produce infinity. - This makes it clear that the full numeric value is different from -what the default string representations show. +"NaN" + "Not A Number." A special value indicating a result that can't + happen in real math, but that can happen in floating-point + computations. - `CONVFMT''s default value is `"%.6g"', which yields a value with at -most six significant digits. For some applications, you might want to -change it to specify more precision. On most modern machines, most of -the time, 17 digits is enough to capture a floating-point number's -value exactly.(1) +"Normalized" + How the significand (see later in this list) is usually stored. The + value is adjusted so that the first bit is one, and then that + leading one is assumed instead of physically stored. This + provides one extra bit of precision. - ---------- Footnotes ---------- +"Precision" + The number of bits used to represent a floating-point number. The + more bits, the more digits you can represent. Binary and decimal + precisions are related approximately, according to the formula: - (1) Pathological cases can require up to 752 digits (!), but we -doubt that you need to worry about this. + PREC = 3.322 * DPS - -File: gawk.info, Node: Unexpected Results, Next: POSIX Floating Point Problems, Prev: String Conversion Precision, Up: Floating Point Issues + Here, PREC denotes the binary precision (measured in bits) and DPS + (short for decimal places) is the decimal digits. -15.1.1.2 Floating Point Numbers Are Not Abstract Numbers -........................................................ +"Rounding mode" + How numbers are rounded up or down when necessary. More details + are provided later. -Unlike numbers in the abstract sense (such as what you studied in high -school or college arithmetic), numbers stored in computers are limited -in certain ways. They cannot represent an infinite number of digits, -nor can they always represent things exactly. In particular, -floating-point numbers cannot always represent values exactly. Here is -an example: +"Significand" + A floating point value consists the significand multiplied by 10 + to the power of the exponent. For example, in `1.2345e67', the + significand is `1.2345'. - $ awk '{ printf("%010d\n", $1 * 100) }' - 515.79 - -| 0000051579 - 515.80 - -| 0000051579 - 515.81 - -| 0000051580 - 515.82 - -| 0000051582 - Ctrl-d +"Stability" + From the Wikipedia article on numerical stability + (http://en.wikipedia.org/wiki/Numerical_stability): "Calculations + that can be proven not to magnify approximation errors are called + "numerically stable"." -This shows that some values can be represented exactly, whereas others -are only approximated. This is not a "bug" in `awk', but simply an -artifact of how computers represent numbers. + See the Wikipedia article on accuracy and precision +(http://en.wikipedia.org/wiki/Accuracy_and_precision) for more +information on some of those terms. - NOTE: It cannot be emphasized enough that the behavior just - described is fundamental to modern computers. You will see this - kind of thing happen in _any_ programming language using hardware - floating-point numbers. It is _not_ a bug in `gawk', nor is it - something that can be "just fixed." + On modern systems, floating-point hardware uses the representation +and operations defined by the IEEE 754 standard. Three of the standard +IEEE 754 types are 32-bit single precision, 64-bit double precision and +128-bit quadruple precision. The standard also specifies extended +precision formats to allow greater precisions and larger exponent +ranges. (`awk' uses only the 64-bit double precision format.) - Another peculiarity of floating-point numbers on modern systems is -that they often have more than one representation for the number zero! -In particular, it is possible to represent "minus zero" as well as -regular, or "positive" zero. + *note table-ieee-formats:: lists the precision and exponent field +values for the basic IEEE 754 binary formats: - This example shows that negative and positive zero are distinct -values when stored internally, but that they are in fact equal to each -other, as well as to "regular" zero: +Name Total bits Precision emin emax +--------------------------------------------------------------------------- +Single 32 24 -126 +127 +Double 64 53 -1022 +1023 +Quadruple 128 113 -16382 +16383 - $ gawk 'BEGIN { mz = -0 ; pz = 0 - > printf "-0 = %g, +0 = %g, (-0 == +0) -> %d\n", mz, pz, mz == pz - > printf "mz == 0 -> %d, pz == 0 -> %d\n", mz == 0, pz == 0 - > }' - -| -0 = -0, +0 = 0, (-0 == +0) -> 1 - -| mz == 0 -> 1, pz == 0 -> 1 +Table 15.1: Basic IEEE Format Context Values - It helps to keep this in mind should you process numeric data that -contains negative zero values; the fact that the zero is negative is -noted and can affect comparisons. + NOTE: The precision numbers include the implied leading one that + gives them one extra bit of significand.  -File: gawk.info, Node: POSIX Floating Point Problems, Prev: Unexpected Results, Up: Floating Point Issues - -15.1.1.3 Standards Versus Existing Practice -........................................... - -Historically, `awk' has converted any non-numeric looking string to the -numeric value zero, when required. Furthermore, the original -definition of the language and the original POSIX standards specified -that `awk' only understands decimal numbers (base 10), and not octal -(base 8) or hexadecimal numbers (base 16). +File: gawk.info, Node: MPFR features, Next: FP Math Caution, Prev: Math Definitions, Up: Arbitrary Precision Arithmetic - Changes in the language of the 2001 and 2004 POSIX standards can be -interpreted to imply that `awk' should support additional features. -These features are: +15.3 Arbitrary Precison Arithmetic Features In `gawk' +===================================================== - * Interpretation of floating point data values specified in - hexadecimal notation (`0xDEADBEEF'). (Note: data values, _not_ - source code constants.) +By default, `gawk' uses the double precision floating point values +supplied by the hardware of the system it runs on. However, if it was +compiled to do, `gawk' uses the GNU MPFR (http://www.mpfr.org) and GNU +MP (http://gmplib.org) (GMP) libraries for arbitrary precision +arithmetic on numbers. You can see if MPFR support is available like +so: - * Support for the special IEEE 754 floating point values "Not A - Number" (NaN), positive Infinity ("inf") and negative Infinity - ("-inf"). In particular, the format for these values is as - specified by the ISO 1999 C standard, which ignores case and can - allow machine-dependent additional characters after the `nan' and - allow either `inf' or `infinity'. + $ gawk --version + -| GNU Awk 4.1.1, API: 1.1 (GNU MPFR 3.1.0-p3, GNU MP 5.0.2) + -| Copyright (C) 1989, 1991-2014 Free Software Foundation. + ... - The first problem is that both of these are clear changes to -historical practice: +(You may see different version numbers than what's shown here. That's +OK; what's important is to see that GNU MPFR and GNU MP are listed in +the output.) - * The `gawk' maintainer feels that supporting hexadecimal floating - point values, in particular, is ugly, and was never intended by the - original designers to be part of the language. + Additionally, there are a few elements available in the `PROCINFO' +array to provide information about the MPFR and GMP libraries (*note +Auto-set::). - * Allowing completely alphabetic strings to have valid numeric - values is also a very severe departure from historical practice. + The MPFR library provides precise control over precisions and +rounding modes, and gives correctly rounded, reproducible, +platform-independent results. With either of the command-line options +`--bignum' or `-M', all floating-point arithmetic operators and numeric +functions can yield results to any desired precision level supported by +MPFR. - The second problem is that the `gawk' maintainer feels that this -interpretation of the standard, which requires a certain amount of -"language lawyering" to arrive at in the first place, was not even -intended by the standard developers. In other words, "we see how you -got where you are, but we don't think that that's where you want to be." + Two built-in variables, `PREC' and `ROUNDMODE', provide control over +the working precision and the rounding mode. The precision and the +rounding mode are set globally for every operation to follow. *Note +Auto-set::, for more information. - Recognizing the above issues, but attempting to provide compatibility -with the earlier versions of the standard, the 2008 POSIX standard -added explicit wording to allow, but not require, that `awk' support -hexadecimal floating point values and special values for "Not A Number" -and infinity. + +File: gawk.info, Node: FP Math Caution, Next: Arbitrary Precision Integers, Prev: MPFR features, Up: Arbitrary Precision Arithmetic - Although the `gawk' maintainer continues to feel that providing -those features is inadvisable, nevertheless, on systems that support -IEEE floating point, it seems reasonable to provide _some_ way to -support NaN and Infinity values. The solution implemented in `gawk' is -as follows: +15.4 Floating Point Arithmetic: Caveat Emptor! +============================================== - * With the `--posix' command-line option, `gawk' becomes "hands - off." String values are passed directly to the system library's - `strtod()' function, and if it successfully returns a numeric - value, that is what's used.(1) By definition, the results are not - portable across different systems. They are also a little - surprising: + Math class is tough! -- Late 1980's Barbie - $ echo nanny | gawk --posix '{ print $1 + 0 }' - -| nan - $ echo 0xDeadBeef | gawk --posix '{ print $1 + 0 }' - -| 3735928559 + This minor node provides a high level overview of the issues +involved when doing lots of floating-point arithmetic.(1) The +discussion applies to both hardware and arbitrary-precision +floating-point arithmetic. - * Without `--posix', `gawk' interprets the four strings `+inf', - `-inf', `+nan', and `-nan' specially, producing the corresponding - special numeric values. The leading sign acts a signal to `gawk' - (and the user) that the value is really numeric. Hexadecimal - floating point is not supported (unless you also use - `--non-decimal-data', which is _not_ recommended). For example: + CAUTION: The material here is purposely general. If you need to do + serious computer arithmetic, you should do some research first, + and not rely just on what we tell you. - $ echo nanny | gawk '{ print $1 + 0 }' - -| 0 - $ echo +nan | gawk '{ print $1 + 0 }' - -| nan - $ echo 0xDeadBeef | gawk '{ print $1 + 0 }' - -| 0 +* Menu: - `gawk' ignores case in the four special values. Thus `+nan' and - `+NaN' are the same. +* Inexactness of computations:: Floating point math is not exact. +* Getting Accuracy:: Getting more accuracy takes some work. +* Try To Round:: Add digits and round. +* Setting precision:: How to set the precision. +* Setting the rounding mode:: How to set the rounding mode. ---------- Footnotes ---------- - (1) You asked for it, you got it. + (1) There is a very nice paper on floating-point arithmetic +(http://www.validlab.com/goldberg/paper.pdf) by David Goldberg, "What +Every Computer Scientist Should Know About Floating-point Arithmetic," +`ACM Computing Surveys' *23*, 1 (1991-03), 5-48. This is worth reading +if you are interested in the details, but it does require a background +in computer science.  -File: gawk.info, Node: Integer Programming, Prev: Floating Point Issues, Up: General Arithmetic - -15.1.2 Mixing Integers And Floating-point ------------------------------------------ +File: gawk.info, Node: Inexactness of computations, Next: Getting Accuracy, Up: FP Math Caution -As has been mentioned already, `awk' uses hardware double precision -with 64-bit IEEE binary floating-point representation for numbers on -most systems. A large integer like 9,007,199,254,740,997 has a binary -representation that, although finite, is more than 53 bits long; it -must also be rounded to 53 bits. (The details are discussed in *note -Floating-point Representation::.) The biggest integer that can be -stored in a C `double' is usually the same as the largest possible -value of a `double'. If your system `double' is an IEEE 64-bit -`double', this largest possible value is an integer and can be -represented precisely. What more should you know about integers? - - If you want to know what is the largest integer, such that it and -all smaller integers can be stored in 64-bit doubles without losing -precision, then the answer is 2^53. The next representable number is -the even number 2^53 + 2, meaning it is unlikely that you will be able -to make `gawk' print 2^53 + 1 in integer format. The range of integers -exactly representable by a 64-bit double is [-2^53, 2^53]. If you ever -see an integer outside this range in `awk' using 64-bit doubles, you -have reason to be very suspicious about the accuracy of the output. -Here is a simple program with erroneous output: - - $ gawk 'BEGIN { i = 2^53 - 1; for (j = 0; j < 4; j++) print i + j }' - -| 9007199254740991 - -| 9007199254740992 - -| 9007199254740992 - -| 9007199254740994 - - The lesson is to not assume that any large integer printed by `awk' -represents an exact result from your computation, especially if it wraps -around on your screen. - - -File: gawk.info, Node: Floating-point Programming, Next: Gawk and MPFR, Prev: General Arithmetic, Up: Arbitrary Precision Arithmetic - -15.2 Understanding Floating-point Programming -============================================= +15.4.1 Floating Point Arithmetic Is Not Exact +--------------------------------------------- -Numerical programming is an extensive area; if you need to develop -sophisticated numerical algorithms then `gawk' may not be the ideal -tool, and this documentation may not be sufficient. It might require -digesting a book or two(1) to really internalize how to compute with -ideal accuracy and precision, and the result often depends on the -particular application. - - NOTE: A floating-point calculation's "accuracy" is how close it - comes to the real value. This is as opposed to the "precision", - which usually refers to the number of bits used to represent the - number (see the Wikipedia article - (http://en.wikipedia.org/wiki/Accuracy_and_precision) for more - information). - - There are two options for doing floating-point calculations: -hardware floating-point (as used by standard `awk' and the default for -`gawk'), and "arbitrary-precision" floating-point, which is software -based. From this point forward, this major node aims to provide enough -information to understand both, and then will focus on `gawk''s -facilities for the latter.(2) - - Binary floating-point representations and arithmetic are inexact. +Binary floating-point representations and arithmetic are inexact. Simple values like 0.1 cannot be precisely represented using binary floating-point numbers, and the limited precision of floating-point numbers means that slight changes in the order of operations or the @@ -21626,9 +21625,21 @@ matters worse, with arbitrary precision floating-point, you can set the precision before starting a computation, but then you cannot be sure of the number of significant decimal places in the final result. - So, before you start to write any code, you should think more about -what you really want and what's really happening. Consider the two -numbers in the following example: +* Menu: + +* Inexact representation:: Numbers are not exactly represented. +* Comparing FP Values:: How to compare floating point values. +* Errors accumulate:: Errors get bigger as they go. + + +File: gawk.info, Node: Inexact representation, Next: Comparing FP Values, Up: Inexactness of computations + +15.4.1.1 Many Numbers Cannot Be Represented Exactly +................................................... + +So, before you start to write any code, you should think about what you +really want and what's really happening. Consider the two numbers in +the following example: x = 0.875 # 1/2 + 1/4 + 1/8 y = 0.425 @@ -21651,20 +21662,44 @@ you can always specify how much precision you would like in your output. Usually this is a format string like `"%.15g"', which when used in the previous example, produces an output identical to the input. - Because the underlying representation can be a little bit off from -the exact value, comparing floating-point values to see if they are -exactly equal is generally a bad idea. Here is an example where it -does not work like you expect: + +File: gawk.info, Node: Comparing FP Values, Next: Errors accumulate, Prev: Inexact representation, Up: Inexactness of computations + +15.4.1.2 Be Careful Comparing Values +.................................... + +Because the underlying representation can be a little bit off from the +exact value, comparing floating-point values to see if they are exactly +equal is generally a bad idea. Here is an example where it does not +work like you would expect: $ gawk 'BEGIN { print (0.1 + 12.2 == 12.3) }' -| 0 - The loss of accuracy during a single computation with floating-point + The general wisdom when comparing floating-point values is to see if +they are within some small range of each other (called a "delta", or +"tolerance"). You have to decide how small a delta is important to +you. Code to do this looks something like this: + + delta = 0.00001 # for example + difference = abs(a) - abs(b) # subtract the two values + if (difference < delta) + # all ok + else + # not ok + + +File: gawk.info, Node: Errors accumulate, Prev: Comparing FP Values, Up: Inexactness of computations + +15.4.1.3 Errors Accumulate +.......................... + +The loss of accuracy during a single computation with floating-point numbers usually isn't enough to worry about. However, if you compute a value which is the result of a sequence of floating point operations, the error can accumulate and greatly affect the computation itself. -Here is an attempt to compute the value of the constant pi using one of -its many series representations: +Here is an attempt to compute the value of pi using one of its many +series representations: BEGIN { x = 1.0 / sqrt(3.0) @@ -21676,9 +21711,9 @@ its many series representations: } } - When run, the early errors propagating through later computations -cause the loop to terminate prematurely after an attempt to divide by -zero. + When run, the early errors propagate through later computations, +causing the loop to terminate prematurely after attempting to divide by +zero: $ gawk -f pi.awk -| 3.215390309173475 @@ -21701,166 +21736,176 @@ representations yield an unexpected result: > }' -| 4 - Can computation using arbitrary precision help with the previous -examples? If you are impatient to know, see *note Exact Arithmetic::. + +File: gawk.info, Node: Getting Accuracy, Next: Try To Round, Prev: Inexactness of computations, Up: FP Math Caution - Instead of arbitrary precision floating-point arithmetic, often all -you need is an adjustment of your logic or a different order for the -operations in your calculation. The stability and the accuracy of the -computation of the constant pi in the earlier example can be enhanced -by using the following simple algebraic transformation: +15.4.2 Getting The Accuracy You Need +------------------------------------ - (sqrt(x * x + 1) - 1) / x == x / (sqrt(x * x + 1) + 1) +Can arbitrary precision arithmetic give exact results? There are no +easy answers. The standard rules of algebra often do not apply when +using floating-point arithmetic. Among other things, the distributive +and associative laws do not hold completely, and order of operation may +be important for your computation. Rounding error, cumulative precision +loss and underflow are often troublesome. -After making this, change the program does converge to pi in under 30 -iterations: + When `gawk' tests the expressions `0.1 + 12.2' and `12.3' for +equality using the machine double precision arithmetic, it decides that +they are not equal! (*Note Comparing FP Values::.) You can get the +result you want by increasing the precision; 56 bits in this case does +the job: - $ gawk -f pi2.awk - -| 3.215390309173473 - -| 3.159659942097501 - -| 3.146086215131436 - -| 3.142714599645370 - -| 3.141873049979825 - ... - -| 3.141592653589797 - -| 3.141592653589797 + $ gawk -M -v PREC=56 'BEGIN { print (0.1 + 12.2 == 12.3) }' + -| 1 - There is no need to be unduly suspicious about the results from -floating-point arithmetic. The lesson to remember is that -floating-point arithmetic is always more complex than arithmetic using -pencil and paper. In order to take advantage of the power of computer -floating-point, you need to know its limitations and work within them. -For most casual use of floating-point arithmetic, you will often get -the expected result in the end if you simply round the display of your -final results to the correct number of significant decimal digits. + If adding more bits is good, perhaps adding even more bits of +precision is better? Here is what happens if we use an even larger +value of `PREC': - As general advice, avoid presenting numerical data in a manner that -implies better precision than is actually the case. + $ gawk -M -v PREC=201 'BEGIN { print (0.1 + 12.2 == 12.3) }' + -| 0 -* Menu: + This is not a bug in `gawk' or in the MPFR library. It is easy to +forget that the finite number of bits used to store the value is often +just an approximation after proper rounding. The test for equality +succeeds if and only if _all_ bits in the two operands are exactly the +same. Since this is not necessarily true after floating-point +computations with a particular precision and effective rounding rule, a +straight test for equality may not work. Instead, compare the two +numbers to see if they are within the desirable delta of each other. -* Floating-point Representation:: Binary floating-point representation. -* Floating-point Context:: Floating-point context. -* Rounding Mode:: Floating-point rounding mode. + In applications where 15 or fewer decimal places suffice, hardware +double precision arithmetic can be adequate, and is usually much faster. +But you need to keep in mind that every floating-point operation can +suffer a new rounding error with catastrophic consequences as +illustrated by our earlier attempt to compute the value of pi. Extra +precision can greatly enhance the stability and the accuracy of your +computation in such cases. - ---------- Footnotes ---------- + Repeated addition is not necessarily equivalent to multiplication in +floating-point arithmetic. In the example in *note Errors accumulate::: - (1) One recommended title is `Numerical Computing with IEEE Floating -Point Arithmetic', Michael L. Overton, Society for Industrial and -Applied Mathematics, 2004. ISBN: 0-89871-482-6, ISBN-13: -978-0-89871-482-1. See `http://www.cs.nyu.edu/cs/faculty/overton/book'. + $ gawk 'BEGIN { + > for (d = 1.1; d <= 1.5; d += 0.1) # loop five times (?) + > i++ + > print i + > }' + -| 4 - (2) If you are interested in other tools that perform arbitrary -precision arithmetic, you may want to investigate the POSIX `bc' tool. -See the POSIX specification for it -(http://pubs.opengroup.org/onlinepubs/009695399/utilities/bc.html), for -more information. +you may or may not succeed in getting the correct result by choosing an +arbitrarily large value for `PREC'. Reformulation of the problem at +hand is often the correct approach in such situations.  -File: gawk.info, Node: Floating-point Representation, Next: Floating-point Context, Up: Floating-point Programming - -15.2.1 Binary Floating-point Representation -------------------------------------------- +File: gawk.info, Node: Try To Round, Next: Setting precision, Prev: Getting Accuracy, Up: FP Math Caution -Although floating-point representations vary from machine to machine, -the most commonly encountered representation is that defined by the -IEEE 754 Standard. An IEEE 754 format value has three components: +15.4.3 Try A Few Extra Bits of Precision and Rounding +----------------------------------------------------- - * A sign bit telling whether the number is positive or negative. - - * An "exponent", E, giving its order of magnitude. +Instead of arbitrary precision floating-point arithmetic, often all you +need is an adjustment of your logic or a different order for the +operations in your calculation. The stability and the accuracy of the +computation of pi in the earlier example can be enhanced by using the +following simple algebraic transformation: - * A "significand", S, specifying the actual digits of the number. + (sqrt(x * x + 1) - 1) / x == x / (sqrt(x * x + 1) + 1) - The value of the number is then S * 2^E. The first bit of a -non-zero binary significand is always one, so the significand in an -IEEE 754 format only includes the fractional part, leaving the leading -one implicit. The significand is stored in "normalized" format, which -means that the first bit is always a one. +After making this, change the program converges to pi in under 30 +iterations: - Three of the standard IEEE 754 types are 32-bit single precision, -64-bit double precision and 128-bit quadruple precision. The standard -also specifies extended precision formats to allow greater precisions -and larger exponent ranges. + $ gawk -f pi2.awk + -| 3.215390309173473 + -| 3.159659942097501 + -| 3.146086215131436 + -| 3.142714599645370 + -| 3.141873049979825 + ... + -| 3.141592653589797 + -| 3.141592653589797  -File: gawk.info, Node: Floating-point Context, Next: Rounding Mode, Prev: Floating-point Representation, Up: Floating-point Programming - -15.2.2 Floating-point Context ------------------------------ - -A floating-point "context" defines the environment for arithmetic -operations. It governs precision, sets rules for rounding, and limits -the range for exponents. The context has the following primary -components: - -"Precision" - Precision of the floating-point format in bits. - -"emax" - Maximum exponent allowed for the format. - -"emin" - Minimum exponent allowed for the format. +File: gawk.info, Node: Setting precision, Next: Setting the rounding mode, Prev: Try To Round, Up: FP Math Caution -"Underflow behavior" - The format may or may not support gradual underflow. - -"Rounding" - The rounding mode of the context. +15.4.4 Setting The Precision +---------------------------- - *note table-ieee-formats:: lists the precision and exponent field -values for the basic IEEE 754 binary formats: +`gawk' uses a global working precision; it does not keep track of the +precision or accuracy of individual numbers. Performing an arithmetic +operation or calling a built-in function rounds the result to the +current working precision. The default working precision is 53 bits, +which you can modify using the built-in variable `PREC'. You can also +set the value to one of the predefined case-insensitive strings shown +in *note table-predefined-precision-strings::, to emulate an IEEE 754 +binary format. -Name Total bits Precision emin emax ---------------------------------------------------------------------------- -Single 32 24 -126 +127 -Double 64 53 -1022 +1023 -Quadruple 128 113 -16382 +16383 +`PREC' IEEE 754 Binary Format +--------------------------------------------------- +`"half"' 16-bit half-precision. +`"single"' Basic 32-bit single precision. +`"double"' Basic 64-bit double precision. +`"quad"' Basic 128-bit quadruple precision. +`"oct"' 256-bit octuple precision. -Table 15.1: Basic IEEE Format Context Values +Table 15.2: Predefined Precision Strings For `PREC' - NOTE: The precision numbers include the implied leading one that - gives them one extra bit of significand. + The following example illustrates the effects of changing precision +on arithmetic operations: - A floating-point context can also determine which signals are treated -as exceptions, and can set rules for arithmetic with special values. -Please consult the IEEE 754 standard or other resources for details. + $ gawk -M -v PREC=100 'BEGIN { x = 1.0e-400; print x + 0 + > PREC = "double"; print x + 0 }' + -| 1e-400 + -| 0 - `gawk' ordinarily uses the hardware double precision representation -for numbers. On most systems, this is IEEE 754 floating-point format, -corresponding to 64-bit binary with 53 bits of precision. + CAUTION: Be wary of floating-point constants! When reading a + floating-point constant from program source code, `gawk' uses the + default precision (that of a C `double'), unless overridden by an + assignment to the special variable `PREC' on the command line, to + store it internally as a MPFR number. Changing the precision + using `PREC' in the program text does _not_ change the precision + of a constant. + + If you need to represent a floating-point constant at a higher + precision than the default and cannot use a command line + assignment to `PREC', you should either specify the constant as a + string, or as a rational number, whenever possible. The following + example illustrates the differences among various ways to print a + floating-point constant: - NOTE: In case an underflow occurs, the standard allows, but does - not require, the result from an arithmetic operation to be a - number smaller than the smallest nonzero normalized number. Such - numbers do not have as many significant digits as normal numbers, - and are called "denormals" or "subnormals". The alternative, - simply returning a zero, is called "flush to zero". The basic IEEE - 754 binary formats support subnormal numbers. + $ gawk -M 'BEGIN { PREC = 113; printf("%0.25f\n", 0.1) }' + -| 0.1000000000000000055511151 + $ gawk -M -v PREC=113 'BEGIN { printf("%0.25f\n", 0.1) }' + -| 0.1000000000000000000000000 + $ gawk -M 'BEGIN { PREC = 113; printf("%0.25f\n", "0.1") }' + -| 0.1000000000000000000000000 + $ gawk -M 'BEGIN { PREC = 113; printf("%0.25f\n", 1/10) }' + -| 0.1000000000000000000000000  -File: gawk.info, Node: Rounding Mode, Prev: Floating-point Context, Up: Floating-point Programming +File: gawk.info, Node: Setting the rounding mode, Prev: Setting precision, Up: FP Math Caution -15.2.3 Floating-point Rounding Mode ------------------------------------ +15.4.5 Setting The Rounding Mode +-------------------------------- -The "rounding mode" specifies the behavior for the results of numerical -operations when discarding extra precision. Each rounding mode indicates -how the least significant returned digit of a rounded result is to be -calculated. *note table-rounding-modes:: lists the IEEE 754 defined -rounding modes: +The `ROUNDMODE' variable provides program level control over the +rounding mode. The correspondence between `ROUNDMODE' and the IEEE +rounding modes is shown in *note table-gawk-rounding-modes::. -Rounding Mode IEEE Name --------------------------------------------------------------------------- -Round to nearest, ties to even `roundTiesToEven' -Round toward plus Infinity `roundTowardPositive' -Round toward negative Infinity `roundTowardNegative' -Round toward zero `roundTowardZero' -Round to nearest, ties away `roundTiesToAway' -from zero +Rounding Mode IEEE Name `ROUNDMODE' +--------------------------------------------------------------------------- +Round to nearest, ties to even `roundTiesToEven' `"N"' or `"n"' +Round toward plus Infinity `roundTowardPositive' `"U"' or `"u"' +Round toward negative Infinity `roundTowardNegative' `"D"' or `"d"' +Round toward zero `roundTowardZero' `"Z"' or `"z"' +Round to nearest, ties away `roundTiesToAway' `"A"' or `"a"' +from zero -Table 15.2: IEEE 754 Rounding Modes +Table 15.3: `gawk' Rounding Modes + + `ROUNDMODE' has the default value `"N"', which selects the IEEE 754 +rounding mode `roundTiesToEven'. In *note Table 15.3: +table-gawk-rounding-modes, the value `"A"' selects `roundTiesToAway'. +This is only available if your version of the MPFR library supports it; +otherwise setting `ROUNDMODE' to `"A"' has no effect. The default mode `roundTiesToEven' is the most preferred, but the least intuitive. This method does the obvious thing for most values, by @@ -21895,20 +21940,19 @@ produces the following output when run on the author's system:(1) 3.5 => 4 4.5 => 4 - The theory behind the rounding mode `roundTiesToEven' is that it -more or less evenly distributes upward and downward rounds of exact -halves, which might cause any round-off error to cancel itself out. -This is the default rounding mode used in IEEE 754 computing functions -and operators. + The theory behind `roundTiesToEven' is that it more or less evenly +distributes upward and downward rounds of exact halves, which might +cause any accumulating round-off error to cancel itself out. This is the +default rounding mode for IEEE 754 computing functions and operators. The other rounding modes are rarely used. Round toward positive infinity (`roundTowardPositive') and round toward negative infinity -(`roundTowardNegative') are often used to implement interval arithmetic, -where you adjust the rounding mode to calculate upper and lower bounds -for the range of output. The `roundTowardZero' mode can be used for -converting floating-point numbers to integers. The rounding mode -`roundTiesToAway' rounds the result to the nearest number and selects -the number with the larger magnitude if a tie occurs. +(`roundTowardNegative') are often used to implement interval +arithmetic, where you adjust the rounding mode to calculate upper and +lower bounds for the range of output. The `roundTowardZero' mode can be +used for converting floating-point numbers to integers. The rounding +mode `roundTiesToAway' rounds the result to the nearest number and +selects the number with the larger magnitude if a tie occurs. Some numerical analysts will tell you that your choice of rounding style has tremendous impact on the final outcome, and advise you to @@ -21917,8 +21961,8 @@ round-off error problems by setting the precision initially to some value sufficiently larger than the final desired precision, so that the accumulation of round-off error does not influence the outcome. If you suspect that results from your computation are sensitive to -accumulation of round-off error, one way to be sure is to look for a -significant difference in output when you change the rounding mode. +accumulation of round-off error, look for a significant difference in +output when you change the rounding mode to be sure. ---------- Footnotes ---------- @@ -21927,408 +21971,221 @@ C library in your system does not use the IEEE 754 even-rounding rule to round halfway cases for `printf'.  -File: gawk.info, Node: Gawk and MPFR, Next: Arbitrary Precision Floats, Prev: Floating-point Programming, Up: Arbitrary Precision Arithmetic +File: gawk.info, Node: Arbitrary Precision Integers, Next: POSIX Floating Point Problems, Prev: FP Math Caution, Up: Arbitrary Precision Arithmetic -15.3 `gawk' + MPFR = Powerful Arithmetic -======================================== - -The rest of this major node describes how to use the arbitrary precision -(also known as "multiple precision" or "infinite precision") numeric -capabilities in `gawk' to produce maximally accurate results when you -need it. - - But first you should check if your version of `gawk' supports -arbitrary precision arithmetic. The easiest way to find out is to look -at the output of the following command: - - $ gawk --version - -| GNU Awk 4.1.1, API: 1.1 (GNU MPFR 3.1.0-p3, GNU MP 5.0.2) - -| Copyright (C) 1989, 1991-2014 Free Software Foundation. - ... - -(You may see different version numbers than what's shown here. That's -OK; what's important is to see that GNU MPFR and GNU MP are listed in -the output.) - - `gawk' uses the GNU MPFR (http://www.mpfr.org) and GNU MP -(http://gmplib.org) (GMP) libraries for arbitrary precision arithmetic -on numbers. So if you do not see the names of these libraries in the -output, then your version of `gawk' does not support arbitrary -precision arithmetic. - - Additionally, there are a few elements available in the `PROCINFO' -array to provide information about the MPFR and GMP libraries. *Note -Auto-set::, for more information. - - -File: gawk.info, Node: Arbitrary Precision Floats, Next: Arbitrary Precision Integers, Prev: Gawk and MPFR, Up: Arbitrary Precision Arithmetic - -15.4 Arbitrary Precision Floating-point Arithmetic with `gawk' -============================================================== - -`gawk' uses the GNU MPFR library for arbitrary precision floating-point -arithmetic. The MPFR library provides precise control over precisions -and rounding modes, and gives correctly rounded, reproducible, -platform-independent results. With one of the command-line options -`--bignum' or `-M', all floating-point arithmetic operators and numeric -functions can yield results to any desired precision level supported by -MPFR. Two built-in variables, `PREC' and `ROUNDMODE', provide control -over the working precision and the rounding mode (*note Setting -Precision::, and *note Setting Rounding Mode::). The precision and the -rounding mode are set globally for every operation to follow. - - The default working precision for arbitrary precision floating-point -values is 53 bits, and the default value for `ROUNDMODE' is `"N"', -which selects the IEEE 754 `roundTiesToEven' rounding mode (*note -Rounding Mode::).(1) `gawk' uses the default exponent range in MPFR -(EMAX = 2^30 - 1, EMIN = -EMAX) for all floating-point contexts. There -is no explicit mechanism to adjust the exponent range. MPFR does not -implement subnormal numbers by default, and this behavior cannot be -changed in `gawk'. - - NOTE: When emulating an IEEE 754 format (*note Setting - Precision::), `gawk' internally adjusts the exponent range to the - value defined for the format and also performs computations needed - for gradual underflow (subnormal numbers). - - NOTE: MPFR numbers are variable-size entities, consuming only as - much space as needed to store the significant digits. Since the - performance using MPFR numbers pales in comparison to doing - arithmetic using the underlying machine types, you should consider - using only as much precision as needed by your program. +15.5 Arbitrary Precision Integer Arithmetic with `gawk' +======================================================= -* Menu: +When given one of the options `--bignum' or `-M', `gawk' performs all +integer arithmetic using GMP arbitrary precision integers. Any number +that looks like an integer in a source or data file is stored as an +arbitrary precision integer. The size of the integer is limited only +by the available memory. For example, the following computes 5^4^3^2, +the result of which is beyond the limits of ordinary `gawk' numbers: -* Setting Precision:: Setting the working precision. -* Setting Rounding Mode:: Setting the rounding mode. -* Floating-point Constants:: Representing floating-point constants. -* Changing Precision:: Changing the precision of a number. -* Exact Arithmetic:: Exact arithmetic with floating-point numbers. + $ gawk -M 'BEGIN { + > x = 5^4^3^2 + > print "# of digits =", length(x) + > print substr(x, 1, 20), "...", substr(x, length(x) - 19, 20) + > }' + -| # of digits = 183231 + -| 62060698786608744707 ... 92256259918212890625 - ---------- Footnotes ---------- + If instead you were to compute the same value using arbitrary +precision floating-point values, the precision needed for correct +output (using the formula `prec = 3.322 * dps'), would be 3.322 x +183231, or 608693. - (1) The default precision is 53 bits, since according to the MPFR -documentation, the library should be able to exactly reproduce all -computations done with double-precision machine floating-point numbers -(`double' type in C), except the default exponent range is much wider -and subnormal numbers are not implemented. + The result from an arithmetic operation with an integer and a +floating-point value is a floating-point value with a precision equal +to the working precision. The following program calculates the eighth +term in Sylvester's sequence(1) using a recurrence: - -File: gawk.info, Node: Setting Precision, Next: Setting Rounding Mode, Up: Arbitrary Precision Floats + $ gawk -M 'BEGIN { + > s = 2.0 + > for (i = 1; i <= 7; i++) + > s = s * (s - 1) + 1 + > print s + > }' + -| 113423713055421845118910464 -15.4.1 Setting the Working Precision ------------------------------------- + The output differs from the actual number, +113,423,713,055,421,844,361,000,443, because the default precision of +53 bits is not enough to represent the floating-point results exactly. +You can either increase the precision (100 bits is enough in this +case), or replace the floating-point constant `2.0' with an integer, to +perform all computations using integer arithmetic to get the correct +output. -`gawk' uses a global working precision; it does not keep track of the -precision or accuracy of individual numbers. Performing an arithmetic -operation or calling a built-in function rounds the result to the -current working precision. The default working precision is 53 bits, -which you can modify using the built-in variable `PREC'. You can also -set the value to one of the predefined case-insensitive strings shown -in *note table-predefined-precision-strings::, to emulate an IEEE 754 -binary format. + Sometimes `gawk' must implicitly convert an arbitrary precision +integer into an arbitrary precision floating-point value. This is +primarily because the MPFR library does not always provide the relevant +interface to process arbitrary precision integers or mixed-mode numbers +as needed by an operation or function. In such a case, the precision is +set to the minimum value necessary for exact conversion, and the working +precision is not used for this purpose. If this is not what you need or +want, you can employ a subterfuge, and convert the integer to floating +point first, like this: -`PREC' IEEE 754 Binary Format ---------------------------------------------------- -`"half"' 16-bit half-precision. -`"single"' Basic 32-bit single precision. -`"double"' Basic 64-bit double precision. -`"quad"' Basic 128-bit quadruple precision. -`"oct"' 256-bit octuple precision. + gawk -M 'BEGIN { n = 13; print (n + 0.0) % 2.0 }' -Table 15.3: Predefined Precision Strings For `PREC' + You can avoid this issue altogether by specifying the number as a +floating-point value to begin with: - The following example illustrates the effects of changing precision -on arithmetic operations: + gawk -M 'BEGIN { n = 13.0; print n % 2.0 }' - $ gawk -M -v PREC=100 'BEGIN { x = 1.0e-400; print x + 0 - > PREC = "double"; print x + 0 }' - -| 1e-400 - -| 0 + Note that for the particular example above, it is likely best to +just use the following: - Binary and decimal precisions are related approximately, according -to the formula: - - PREC = 3.322 * DPS - -Here, PREC denotes the binary precision (measured in bits) and DPS -(short for decimal places) is the decimal digits. We can easily -calculate how many decimal digits the 53-bit significand of an IEEE -double is equivalent to: 53 / 3.322 which is equal to about 15.95. But -what does 15.95 digits actually mean? It depends whether you are -concerned about how many digits you can rely on, or how many digits you -need. - - It is important to know how many bits it takes to uniquely identify -a double-precision value (the C type `double'). If you want to convert -from `double' to decimal and back to `double' (e.g., saving a `double' -representing an intermediate result to a file, and later reading it -back to restart the computation), then a few more decimal digits are -required. 17 digits is generally enough for a `double'. - - It can also be important to know what decimal numbers can be uniquely -represented with a `double'. If you want to convert from decimal to -`double' and back again, 15 digits is the most that you can get. Stated -differently, you should not present the numbers from your -floating-point computations with more than 15 significant digits in -them. + gawk -M 'BEGIN { n = 13; print n % 2 }' - Conversely, it takes a precision of 332 bits to hold an approximation -of the constant pi that is accurate to 100 decimal places. + ---------- Footnotes ---------- - You should always add some extra bits in order to avoid the -confusing round-off issues that occur because numbers are stored -internally in binary. + (1) Weisstein, Eric W. `Sylvester's Sequence'. From MathWorld--A +Wolfram Web Resource +(`http://mathworld.wolfram.com/SylvestersSequence.html').  -File: gawk.info, Node: Setting Rounding Mode, Next: Floating-point Constants, Prev: Setting Precision, Up: Arbitrary Precision Floats +File: gawk.info, Node: POSIX Floating Point Problems, Next: Floating point summary, Prev: Arbitrary Precision Integers, Up: Arbitrary Precision Arithmetic -15.4.2 Setting the Rounding Mode --------------------------------- - -The `ROUNDMODE' variable provides program level control over the -rounding mode. The correspondence between `ROUNDMODE' and the IEEE -rounding modes is shown in *note table-gawk-rounding-modes::. +15.6 Standards Versus Existing Practice +======================================= -Rounding Mode IEEE Name `ROUNDMODE' ---------------------------------------------------------------------------- -Round to nearest, ties to even `roundTiesToEven' `"N"' or `"n"' -Round toward plus Infinity `roundTowardPositive' `"U"' or `"u"' -Round toward negative Infinity `roundTowardNegative' `"D"' or `"d"' -Round toward zero `roundTowardZero' `"Z"' or `"z"' -Round to nearest, ties away `roundTiesToAway' `"A"' or `"a"' -from zero +Historically, `awk' has converted any non-numeric looking string to the +numeric value zero, when required. Furthermore, the original +definition of the language and the original POSIX standards specified +that `awk' only understands decimal numbers (base 10), and not octal +(base 8) or hexadecimal numbers (base 16). -Table 15.4: `gawk' Rounding Modes + Changes in the language of the 2001 and 2004 POSIX standards can be +interpreted to imply that `awk' should support additional features. +These features are: - `ROUNDMODE' has the default value `"N"', which selects the IEEE 754 -rounding mode `roundTiesToEven'. In *note Table 15.4: -table-gawk-rounding-modes, `"A"' is listed to select the IEEE 754 mode -`roundTiesToAway'. This is only available if your version of the MPFR -library supports it; otherwise setting `ROUNDMODE' to this value has no -effect. *Note Rounding Mode::, for the meanings of the various rounding -modes. + * Interpretation of floating point data values specified in + hexadecimal notation (e.g., `0xDEADBEEF'). (Note: data values, + _not_ source code constants.) - Here is an example of how to change the default rounding behavior of -`printf''s output: + * Support for the special IEEE 754 floating point values "Not A + Number" (NaN), positive Infinity ("inf") and negative Infinity + ("-inf"). In particular, the format for these values is as + specified by the ISO 1999 C standard, which ignores case and can + allow machine-dependent additional characters after the `nan' and + allow either `inf' or `infinity'. - $ gawk -M -v ROUNDMODE="Z" 'BEGIN { printf("%.2f\n", 1.378) }' - -| 1.37 + The first problem is that both of these are clear changes to +historical practice: - -File: gawk.info, Node: Floating-point Constants, Next: Changing Precision, Prev: Setting Rounding Mode, Up: Arbitrary Precision Floats + * The `gawk' maintainer feels that supporting hexadecimal floating + point values, in particular, is ugly, and was never intended by the + original designers to be part of the language. -15.4.3 Representing Floating-point Constants --------------------------------------------- + * Allowing completely alphabetic strings to have valid numeric + values is also a very severe departure from historical practice. -Be wary of floating-point constants! When reading a floating-point -constant from program source code, `gawk' uses the default precision -(that of a C `double'), unless overridden by an assignment to the -special variable `PREC' on the command line, to store it internally as -a MPFR number. Changing the precision using `PREC' in the program text -does _not_ change the precision of a constant. If you need to represent -a floating-point constant at a higher precision than the default and -cannot use a command line assignment to `PREC', you should either -specify the constant as a string, or as a rational number, whenever -possible. The following example illustrates the differences among -various ways to print a floating-point constant: + The second problem is that the `gawk' maintainer feels that this +interpretation of the standard, which requires a certain amount of +"language lawyering" to arrive at in the first place, was not even +intended by the standard developers. In other words, "we see how you +got where you are, but we don't think that that's where you want to be." - $ gawk -M 'BEGIN { PREC = 113; printf("%0.25f\n", 0.1) }' - -| 0.1000000000000000055511151 - $ gawk -M -v PREC=113 'BEGIN { printf("%0.25f\n", 0.1) }' - -| 0.1000000000000000000000000 - $ gawk -M 'BEGIN { PREC = 113; printf("%0.25f\n", "0.1") }' - -| 0.1000000000000000000000000 - $ gawk -M 'BEGIN { PREC = 113; printf("%0.25f\n", 1/10) }' - -| 0.1000000000000000000000000 + Recognizing the above issues, but attempting to provide compatibility +with the earlier versions of the standard, the 2008 POSIX standard +added explicit wording to allow, but not require, that `awk' support +hexadecimal floating point values and special values for "Not A Number" +and infinity. - In the first case, the number is stored with the default precision -of 53 bits. + Although the `gawk' maintainer continues to feel that providing +those features is inadvisable, nevertheless, on systems that support +IEEE floating point, it seems reasonable to provide _some_ way to +support NaN and Infinity values. The solution implemented in `gawk' is +as follows: - -File: gawk.info, Node: Changing Precision, Next: Exact Arithmetic, Prev: Floating-point Constants, Up: Arbitrary Precision Floats + * With the `--posix' command-line option, `gawk' becomes "hands + off." String values are passed directly to the system library's + `strtod()' function, and if it successfully returns a numeric + value, that is what's used.(1) By definition, the results are not + portable across different systems. They are also a little + surprising: -15.4.4 Changing the Precision of a Number ------------------------------------------ + $ echo nanny | gawk --posix '{ print $1 + 0 }' + -| nan + $ echo 0xDeadBeef | gawk --posix '{ print $1 + 0 }' + -| 3735928559 - The point is that in any variable-precision package, a decision is - made on how to treat numbers given as data, or arising in - intermediate results, which are represented in floating-point - format to a precision lower than working precision. Do we promote - them to full membership of the high-precision club, or do we treat - them and all their associates as second-class citizens? Sometimes - the first course is proper, sometimes the second, and it takes - careful analysis to tell which.(1) -- Dirk Laurie - - `gawk' does not implicitly modify the precision of any previously -computed results when the working precision is changed with an -assignment to `PREC'. The precision of a number is always the one that -was used at the time of its creation, and there is no way for you to -explicitly change it afterwards. However, since the result of a -floating-point arithmetic operation is always an arbitrary precision -floating-point value--with a precision set by the value of `PREC'--one -of the following workarounds effectively accomplishes the desired -behavior: - - x = x + 0.0 + * Without `--posix', `gawk' interprets the four strings `+inf', + `-inf', `+nan', and `-nan' specially, producing the corresponding + special numeric values. The leading sign acts a signal to `gawk' + (and the user) that the value is really numeric. Hexadecimal + floating point is not supported (unless you also use + `--non-decimal-data', which is _not_ recommended). For example: -or: + $ echo nanny | gawk '{ print $1 + 0 }' + -| 0 + $ echo +nan | gawk '{ print $1 + 0 }' + -| nan + $ echo 0xDeadBeef | gawk '{ print $1 + 0 }' + -| 0 - x += 0.0 + `gawk' ignores case in the four special values. Thus `+nan' and + `+NaN' are the same. ---------- Footnotes ---------- - (1) Dirk Laurie. `Variable-precision Arithmetic Considered Perilous --- A Detective Story'. Electronic Transactions on Numerical Analysis. -Volume 28, pp. 168-173, 2008. - - -File: gawk.info, Node: Exact Arithmetic, Prev: Changing Precision, Up: Arbitrary Precision Floats - -15.4.5 Exact Arithmetic with Floating-point Numbers ---------------------------------------------------- - - CAUTION: Never depend on the exactness of floating-point - arithmetic, even for apparently simple expressions! - - Can arbitrary precision arithmetic give exact results? There are no -easy answers. The standard rules of algebra often do not apply when -using floating-point arithmetic. Among other things, the distributive -and associative laws do not hold completely, and order of operation may -be important for your computation. Rounding error, cumulative precision -loss and underflow are often troublesome. - - When `gawk' tests the expressions `0.1 + 12.2' and `12.3' for -equality using the machine double precision arithmetic, it decides that -they are not equal! (*Note Floating-point Programming::.) You can get -the result you want by increasing the precision; 56 bits in this case -will get the job done: - - $ gawk -M -v PREC=56 'BEGIN { print (0.1 + 12.2 == 12.3) }' - -| 1 - - If adding more bits is good, perhaps adding even more bits of -precision is better? Here is what happens if we use an even larger -value of `PREC': - - $ gawk -M -v PREC=201 'BEGIN { print (0.1 + 12.2 == 12.3) }' - -| 0 - - This is not a bug in `gawk' or in the MPFR library. It is easy to -forget that the finite number of bits used to store the value is often -just an approximation after proper rounding. The test for equality -succeeds if and only if _all_ bits in the two operands are exactly the -same. Since this is not necessarily true after floating-point -computations with a particular precision and effective rounding rule, a -straight test for equality may not work. - - So, don't assume that floating-point values can be compared for -equality. You should also exercise caution when using other forms of -comparisons. The standard way to compare two floating-point numbers is -to determine how much error (or "tolerance") you will allow in a -comparison and check to see if one value is within this error range of -the other. - - In applications where 15 or fewer decimal places suffice, hardware -double precision arithmetic can be adequate, and is usually much faster. -But you do need to keep in mind that every floating-point operation can -suffer a new rounding error with catastrophic consequences as -illustrated by our earlier attempt to compute the value of the constant -pi (*note Floating-point Programming::). Extra precision can greatly -enhance the stability and the accuracy of your computation in such -cases. - - Repeated addition is not necessarily equivalent to multiplication in -floating-point arithmetic. In the example in *note Floating-point -Programming::: - - $ gawk 'BEGIN { - > for (d = 1.1; d <= 1.5; d += 0.1) # loop five times (?) - > i++ - > print i - > }' - -| 4 - -you may or may not succeed in getting the correct result by choosing an -arbitrarily large value for `PREC'. Reformulation of the problem at -hand is often the correct approach in such situations. + (1) You asked for it, you got it.  -File: gawk.info, Node: Arbitrary Precision Integers, Prev: Arbitrary Precision Floats, Up: Arbitrary Precision Arithmetic +File: gawk.info, Node: Floating point summary, Prev: POSIX Floating Point Problems, Up: Arbitrary Precision Arithmetic -15.5 Arbitrary Precision Integer Arithmetic with `gawk' -======================================================= +15.7 Summary +============ -If one of the options `--bignum' or `-M' is specified, `gawk' performs -all integer arithmetic using GMP arbitrary precision integers. Any -number that looks like an integer in a program source or data file is -stored as an arbitrary precision integer. The size of the integer is -limited only by your computer's memory. The current floating-point -context has no effect on operations involving integers. For example, -the following computes 5^4^3^2, the result of which is beyond the -limits of ordinary `gawk' numbers: + * Most computer arithmetic is done using either integers or + floating-point values. The default for `awk' is to use + double-precision floating-point values. - $ gawk -M 'BEGIN { - > x = 5^4^3^2 - > print "# of digits =", length(x) - > print substr(x, 1, 20), "...", substr(x, length(x) - 19, 20) - > }' - -| # of digits = 183231 - -| 62060698786608744707 ... 92256259918212890625 + * In the 1980's, Barbie mistakenly said "Math class is tough!" + While math isn't tough, floating-point arithmetic isn't the same + as pencil and paper math, and care must be taken: - If you were to compute the same value using arbitrary precision -floating-point values instead, the precision needed for correct output -(using the formula `prec = 3.322 * dps'), would be 3.322 x 183231, or -608693. + - Not all numbers can be represented exactly. - The result from an arithmetic operation with an integer and a -floating-point value is a floating-point value with a precision equal -to the working precision. The following program calculates the eighth -term in Sylvester's sequence(1) using a recurrence: + - Comparing values should use a delta, instead of being done + directly with `==' and `!='. - $ gawk -M 'BEGIN { - > s = 2.0 - > for (i = 1; i <= 7; i++) - > s = s * (s - 1) + 1 - > print s - > }' - -| 113423713055421845118910464 + - Errors accumulate. - The output differs from the actual number, -113,423,713,055,421,844,361,000,443, because the default precision of -53 bits is not enough to represent the floating-point results exactly. -You can either increase the precision (100 bits is enough in this -case), or replace the floating-point constant `2.0' with an integer, to -perform all computations using integer arithmetic to get the correct -output. + - Operations are not always truly associative or distributive. - It will sometimes be necessary for `gawk' to implicitly convert an -arbitrary precision integer into an arbitrary precision floating-point -value. This is primarily because the MPFR library does not always -provide the relevant interface to process arbitrary precision integers -or mixed-mode numbers as needed by an operation or function. In such a -case, the precision is set to the minimum value necessary for exact -conversion, and the working precision is not used for this purpose. If -this is not what you need or want, you can employ a subterfuge like -this: + * Increasing the accuracy can help, but it is not a panacea. - gawk -M 'BEGIN { n = 13; print (n + 0.0) % 2.0 }' + * Often, increasing the accuracy and then rounding to the desired + number of digits produces reasonable results. - You can avoid this issue altogether by specifying the number as a -floating-point value to begin with: + * Use either `-M' or `--bignum' to enable MPFR arithmetic. Use + `PREC' to set the precision in bits, and `ROUNDMODE' to set the + IEEE 754 rounding mode. - gawk -M 'BEGIN { n = 13.0; print n % 2.0 }' + * With `-M' or `--bignum', `gawk' performs arbitrary precision + integer arithmetic using the GMP library. This is faster and more + space efficient than using MPFR for the same calculations. - Note that for the particular example above, it is likely best to -just use the following: + * There are several "dark corners" with respect to floating-point + numbers where `gawk' disagrees with the POSIX standard. It pays + to be aware of them. - gawk -M 'BEGIN { n = 13; print n % 2 }' + * Overall, there is no need to be unduly suspicious about the + results from floating-point arithmetic. The lesson to remember is + that floating-point arithmetic is always more complex than + arithmetic using pencil and paper. In order to take advantage of + the power of computer floating-point, you need to know its + limitations and work within them. For most casual use of + floating-point arithmetic, you will often get the expected result + if you simply round the display of your final results to the + correct number of significant decimal digits. - ---------- Footnotes ---------- + * As general advice, avoid presenting numerical data in a manner that + implies better precision than is actually the case. - (1) Weisstein, Eric W. `Sylvester's Sequence'. From MathWorld--A -Wolfram Web Resource. -`http://mathworld.wolfram.com/SylvestersSequence.html'  File: gawk.info, Node: Dynamic Extensions, Next: Language History, Prev: Arbitrary Precision Arithmetic, Up: Top @@ -22362,6 +22219,7 @@ sample extensions are automatically built and installed when `gawk' is. `gawk'. * gawkextlib:: The `gawkextlib' project. * Extension summary:: Extension summary. +* Extension Exercises:: Exercises.  File: gawk.info, Node: Extension Intro, Next: Plugin License, Up: Dynamic Extensions @@ -24998,8 +24856,7 @@ everything that needs to be loaded. It is simplest to use the dl_load_func(func_table, filefuncs, "") - And that's it! As an exercise, consider adding functions to -implement system calls such as `chown()', `chmod()', and `umask()'. + And that's it! ---------- Footnotes ---------- @@ -25420,9 +25277,6 @@ processing immediately without damaging the original file. $ gawk -i inplace -v INPLACE_SUFFIX=.bak '{ gsub(/foo/, "bar") } > { print }' file1 file2 file3 - We leave it as an exercise to write a wrapper script that presents an -interface similar to `sed -i'. -  File: gawk.info, Node: Extension Sample Ord, Next: Extension Sample Readdir, Prev: Extension Sample Inplace, Up: Extension Samples @@ -25736,7 +25590,7 @@ users, please consider doing so through the `gawkextlib' project. See the project's web site for more information.  -File: gawk.info, Node: Extension summary, Prev: gawkextlib, Up: Dynamic Extensions +File: gawk.info, Node: Extension summary, Next: Extension Exercises, Prev: gawkextlib, Up: Dynamic Extensions 16.9 Summary ============ @@ -25824,6 +25678,26 @@ File: gawk.info, Node: Extension summary, Prev: gawkextlib, Up: Dynamic Exten project should be the place to do so. + +File: gawk.info, Node: Extension Exercises, Prev: Extension summary, Up: Dynamic Extensions + +16.10 Exercises +=============== + + 1. Add functions to implement system calls such as `chown()', + `chmod()', and `umask()' to the file operations extension + presented in *note Internal File Ops::. + + 2. (Hard.) How would you provide namespaces in `gawk', so that the + names of functions in different extensions don't conflict with + each other? If you come up with a really good scheme, contact the + `gawk' maintainer to tell him about it. + + 3. Write a wrapper script that provides an interface similar to `sed + -i' for the "inplace" extension presented in *note Extension + Sample Inplace::. + +  File: gawk.info, Node: Language History, Next: Installation, Prev: Dynamic Extensions, Up: Top @@ -26359,7 +26233,7 @@ in POSIX `awk', in the order they were added to `gawk'. * The support for `next file' as two words was removed completely (*note Nextfile Statement::). - * Additional commnd line options (*note Options::): + * Additional command-line options (*note Options::): - The `--dump-variables' option to print a list of all global variables. @@ -26561,8 +26435,8 @@ in POSIX `awk', in the order they were added to `gawk'. - The `-R' option was removed. - * Support for high precision arithmetic with MPFR. (*note Gawk and - MPFR::). + * Support for high precision arithmetic with MPFR. (*note Arbitrary + Precision Arithmetic::). * The `and()', `or()' and `xor()' functions changed to allow any number of arguments, with a minimum of two (*note Bitwise @@ -28137,7 +28011,7 @@ File: gawk.info, Node: Installation summary, Prev: Other Versions, Up: Instal B.6 Summary =========== - * The `gawk' distribution is availble from GNU project's main + * The `gawk' distribution is available from GNU project's main distribution site, `ftp.gnu.org'. The canonical build recipe is: wget http://ftp.gnu.org/gnu/gawk/gawk-4.1.1.tar.gz @@ -28928,7 +28802,7 @@ C.7 Summary * `gawk''s extensions can be disabled with either the `--traditional' option or with the `--posix' option. The - `--parsedebug' option is availble if `gawk' is compiled with + `--parsedebug' option is available if `gawk' is compiled with `-DDEBUG'. * The source code for `gawk' is maintained in a publicly accessable @@ -29088,7 +28962,7 @@ characters that comprise them. Individual variables, as well as numeric and string variables, are referred to as "scalar" values. Groups of values, such as arrays, are not scalars. - *note General Arithmetic::, provided a basic introduction to numeric + *note Computer Arithmetic::, provided a basic introduction to numeric types (integer and floating-point) and how they are used in a computer. Please review that information, including a number of caveats that were presented. @@ -31656,7 +31530,6 @@ Index * case sensitivity, gawk: Case-sensitivity. (line 26) * case sensitivity, regexps and: Case-sensitivity. (line 6) * CGI, awk scripts for: Options. (line 125) -* changing precision of a number: Changing Precision. (line 6) * character classes, See bracket expressions: Regexp Operators. (line 56) * character lists in regular expression: Bracket Expressions. (line 6) @@ -31772,13 +31645,9 @@ Index * configuration options, gawk: Additional Configuration Options. (line 6) * constant regexps: Regexp Usage. (line 57) -* constants, floating-point: Floating-point Constants. - (line 6) * constants, nondecimal: Nondecimal Data. (line 6) * constants, numeric: Scalar Constants. (line 6) * constants, types of: Constants. (line 6) -* context, floating-point: Floating-point Context. - (line 6) * continue program, in debugger: Debugger Execution Control. (line 33) * continue statement: Continue Statement. (line 6) @@ -32083,7 +31952,7 @@ Index (line 66) * directories, command line: Command line directories. (line 6) -* directories, searching: Igawk Program. (line 368) +* directories, searching: Programs Exercises. (line 63) * directories, searching for loadable extensions: AWKLIBPATH Variable. (line 6) * directories, searching for source files: AWKPATH Variable. (line 6) @@ -32103,7 +31972,6 @@ Index * dollar sign ($), incrementing fields and arrays: Increment Ops. (line 30) * dollar sign ($), regexp operator: Regexp Operators. (line 35) -* double precision floating-point: General Arithmetic. (line 21) * double quote (") in shell commands: Read Terminal. (line 25) * double quote ("), in regexp constants: Computed Regexps. (line 29) * double quote ("), in shell commands: Quoting. (line 54) @@ -32364,7 +32232,7 @@ Index * files, reading, multiline records: Multiple Line. (line 6) * files, searching for regular expressions: Egrep Program. (line 6) * files, skipping: File Checking. (line 6) -* files, source, search path for: Igawk Program. (line 368) +* files, source, search path for: Programs Exercises. (line 63) * files, splitting: Split Program. (line 6) * files, Texinfo, extracting programs from: Extract Program. (line 6) * find substring in string: String Functions. (line 155) @@ -32375,8 +32243,6 @@ Index * fixed-width data: Constant Size. (line 10) * flag variables <1>: Tee Program. (line 20) * flag variables: Boolean Ops. (line 67) -* floating-point, numbers <1>: Unexpected Results. (line 6) -* floating-point, numbers: General Arithmetic. (line 6) * floating-point, numbers, arbitrary precision: Arbitrary Precision Arithmetic. (line 6) * floating-point, VAX/VMS: VMS Running. (line 51) @@ -32633,7 +32499,6 @@ Index * git utility <3>: Other Versions. (line 29) * git utility: gawkextlib. (line 29) * Git, use of for gawk source code: Derived Files. (line 6) -* GMP: Gawk and MPFR. (line 6) * GNITS mailing list: Acknowledgments. (line 52) * GNU awk, See gawk: Preface. (line 53) * GNU Free Documentation License: GNU Free Documentation License. @@ -32689,8 +32554,6 @@ Index * i debugger command (alias for info): Debugger Info. (line 13) * id utility: Id Program. (line 6) * id.awk program: Id Program. (line 30) -* IEEE 754 format: Floating-point Representation. - (line 6) * if statement: If Statement. (line 6) * if statement, actions, changing: Ranges. (line 25) * if statement, use of regexps in: Regexp Usage. (line 19) @@ -32761,10 +32624,9 @@ Index * INT signal (MS-Windows): Profiling. (line 214) * integer array indices: Numeric Array Subscripts. (line 31) -* integers: General Arithmetic. (line 6) * integers, arbitrary precision: Arbitrary Precision Integers. (line 6) -* integers, unsigned: General Arithmetic. (line 15) +* integers, unsigned: Computer Arithmetic. (line 41) * interacting with other programs: I/O Functions. (line 75) * internationalization <1>: I18N and L10N. (line 6) * internationalization: I18N Functions. (line 6) @@ -32817,15 +32679,12 @@ Index * Kernighan, Brian: History. (line 17) * kill command, dynamic profiling: Profiling. (line 188) * Knights, jedi: Undocumented. (line 6) -* Knuth, Donald: Arbitrary Precision Arithmetic. - (line 6) * Kwok, Conrad: Contributors. (line 34) * l debugger command (alias for list): Miscellaneous Debugger Commands. (line 72) * labels.awk program: Labels Program. (line 51) * Langston, Peter: Advanced Features. (line 6) * languages, data-driven: Basic High Level. (line 85) -* Laurie, Dirk: Changing Precision. (line 6) * LC_ALL locale category: Explaining gettext. (line 121) * LC_COLLATE locale category: Explaining gettext. (line 94) * LC_CTYPE locale category: Explaining gettext. (line 98) @@ -32971,7 +32830,6 @@ Index * modifiers, in format specifiers: Format Modifiers. (line 6) * monetary information, localization: Explaining gettext. (line 104) * Moore, Duncan: Getline Notes. (line 40) -* MPFR: Gawk and MPFR. (line 6) * msgfmt utility: I18N Example. (line 63) * multiple precision: Arbitrary Precision Arithmetic. (line 6) @@ -32986,7 +32844,6 @@ Index * namespace issues: Arrays. (line 18) * namespace issues, functions: Definition Syntax. (line 20) * nawk utility: Names. (line 10) -* negative zero: Unexpected Results. (line 34) * NetBSD: Glossary. (line 611) * networks, programming: TCP/IP Networking. (line 6) * networks, support for: Special Network. (line 6) @@ -33056,7 +32913,6 @@ Index * numbers, converting <1>: Bitwise Functions. (line 109) * numbers, converting: Conversion. (line 6) * numbers, converting, to strings: User-modified. (line 30) -* numbers, floating-point: General Arithmetic. (line 6) * numbers, hexadecimal: Nondecimal-numbers. (line 6) * numbers, octal: Nondecimal-numbers. (line 6) * numbers, rounding: Round Function. (line 6) @@ -33227,7 +33083,6 @@ Index * positional specifiers, printf statement: Format Modifiers. (line 13) * positional specifiers, printf statement, mixing with regular formats: Printf Ordering. (line 57) -* positive zero: Unexpected Results. (line 34) * POSIX awk <1>: Assignment Ops. (line 137) * POSIX awk: This Manual. (line 14) * POSIX awk, ** operator and: Precedence. (line 98) @@ -33268,7 +33123,6 @@ Index * POSIX, gawk extensions not included in: POSIX/GNU. (line 6) * POSIX, programs, implementing in awk: Clones. (line 6) * POSIXLY_CORRECT environment variable: Options. (line 340) -* PREC variable <1>: Setting Precision. (line 6) * PREC variable: User-modified. (line 124) * precedence <1>: Precedence. (line 6) * precedence: Increment Ops. (line 60) @@ -33508,10 +33362,7 @@ Index * Rommel, Kai Uwe: Contributors. (line 42) * round to nearest integer: Numeric Functions. (line 23) * round() user-defined function: Round Function. (line 16) -* rounding mode, floating-point: Rounding Mode. (line 6) * rounding numbers: Round Function. (line 6) -* ROUNDMODE variable <1>: Setting Rounding Mode. - (line 6) * ROUNDMODE variable: User-modified. (line 128) * RS variable <1>: User-modified. (line 133) * RS variable: awk split records. (line 12) @@ -33547,11 +33398,11 @@ Index * search in string: String Functions. (line 155) * search paths <1>: VMS Running. (line 58) * search paths <2>: PC Using. (line 10) -* search paths: Igawk Program. (line 368) +* search paths: Programs Exercises. (line 63) * search paths, for loadable extensions: AWKLIBPATH Variable. (line 6) * search paths, for source files <1>: VMS Running. (line 58) * search paths, for source files <2>: PC Using. (line 10) -* search paths, for source files <3>: Igawk Program. (line 368) +* search paths, for source files <3>: Programs Exercises. (line 63) * search paths, for source files: AWKPATH Variable. (line 6) * searching, files for regular expressions: Egrep Program. (line 6) * searching, for words: Dupword Program. (line 6) @@ -33583,9 +33434,6 @@ Index * set directory of message catalogs: I18N Functions. (line 12) * set watchpoint: Viewing And Changing Data. (line 67) -* setting rounding mode: Setting Rounding Mode. - (line 6) -* setting working precision: Setting Precision. (line 6) * shadowing of variable values: Definition Syntax. (line 61) * shell quoting, double quote: Read Terminal. (line 25) * shell quoting, rules for: Quoting. (line 6) @@ -33664,7 +33512,6 @@ Index (line 10) * sin: Numeric Functions. (line 75) * sine: Numeric Functions. (line 75) -* single precision floating-point: General Arithmetic. (line 21) * single quote ('): One-shot. (line 15) * single quote (') in gawk command lines: Long. (line 33) * single quote ('), in shell commands: Quoting. (line 48) @@ -33701,7 +33548,7 @@ Index * source code, QSE Awk: Other Versions. (line 131) * source code, QuikTrim Awk: Other Versions. (line 135) * source code, Solaris awk: Other Versions. (line 96) -* source files, search path for: Igawk Program. (line 368) +* source files, search path for: Programs Exercises. (line 63) * sparse arrays: Array Intro. (line 71) * Spencer, Henry: Glossary. (line 11) * split: String Functions. (line 313) @@ -33921,7 +33768,7 @@ Index (line 64) * Unix, awk scripts and: Executable Scripts. (line 6) * UNIXROOT variable, on OS/2 systems: PC Using. (line 16) -* unsigned integers: General Arithmetic. (line 15) +* unsigned integers: Computer Arithmetic. (line 41) * until debugger command: Debugger Execution Control. (line 83) * unwatch debugger command: Viewing And Changing Data. @@ -34029,7 +33876,6 @@ Index * Zaretskii, Eli <1>: Bugs. (line 71) * Zaretskii, Eli <2>: Contributors. (line 55) * Zaretskii, Eli: Acknowledgments. (line 60) -* zero, negative vs. positive: Unexpected Results. (line 34) * zerofile.awk program: Empty Files. (line 21) * Zoulas, Christos: Contributors. (line 66) * {} (braces): Profiling. (line 142) @@ -34060,558 +33906,550 @@ Index  Tag Table: Node: Top1292 -Node: Foreword41210 -Node: Preface45555 -Ref: Preface-Footnote-148702 -Ref: Preface-Footnote-248809 -Node: History49041 -Node: Names51415 -Ref: Names-Footnote-152879 -Node: This Manual52952 -Ref: This Manual-Footnote-158731 -Node: Conventions58831 -Node: Manual History60987 -Ref: Manual History-Footnote-164426 -Ref: Manual History-Footnote-264467 -Node: How To Contribute64541 -Node: Acknowledgments65780 -Node: Getting Started69929 -Node: Running gawk72363 -Node: One-shot73553 -Node: Read Terminal74778 -Ref: Read Terminal-Footnote-176428 -Ref: Read Terminal-Footnote-276704 -Node: Long76875 -Node: Executable Scripts78251 -Ref: Executable Scripts-Footnote-180084 -Ref: Executable Scripts-Footnote-280186 -Node: Comments80733 -Node: Quoting83206 -Node: DOS Quoting88522 -Node: Sample Data Files89197 -Node: Very Simple91712 -Node: Two Rules96350 -Node: More Complex98245 -Ref: More Complex-Footnote-1101177 -Node: Statements/Lines101262 -Ref: Statements/Lines-Footnote-1105717 -Node: Other Features105982 -Node: When106910 -Node: Intro Summary109080 -Node: Invoking Gawk109846 -Node: Command Line111361 -Node: Options112152 -Ref: Options-Footnote-1127964 -Node: Other Arguments127989 -Node: Naming Standard Input130651 -Node: Environment Variables131745 -Node: AWKPATH Variable132303 -Ref: AWKPATH Variable-Footnote-1135175 -Ref: AWKPATH Variable-Footnote-2135220 -Node: AWKLIBPATH Variable135480 -Node: Other Environment Variables136239 -Node: Exit Status139894 -Node: Include Files140569 -Node: Loading Shared Libraries144147 -Node: Obsolete145531 -Node: Undocumented146228 -Node: Invoking Summary146495 -Node: Regexp148075 -Node: Regexp Usage149525 -Node: Escape Sequences151558 -Node: Regexp Operators157225 -Ref: Regexp Operators-Footnote-1164705 -Ref: Regexp Operators-Footnote-2164852 -Node: Bracket Expressions164950 -Ref: table-char-classes166840 -Node: GNU Regexp Operators169363 -Node: Case-sensitivity173086 -Ref: Case-sensitivity-Footnote-1175978 -Ref: Case-sensitivity-Footnote-2176213 -Node: Leftmost Longest176321 -Node: Computed Regexps177522 -Node: Regexp Summary180894 -Node: Reading Files182366 -Node: Records184458 -Node: awk split records185201 -Node: gawk split records190059 -Ref: gawk split records-Footnote-1194580 -Node: Fields194617 -Ref: Fields-Footnote-1197581 -Node: Nonconstant Fields197667 -Ref: Nonconstant Fields-Footnote-1199897 -Node: Changing Fields200099 -Node: Field Separators206053 -Node: Default Field Splitting208755 -Node: Regexp Field Splitting209872 -Node: Single Character Fields213213 -Node: Command Line Field Separator214272 -Node: Full Line Fields217614 -Ref: Full Line Fields-Footnote-1218122 -Node: Field Splitting Summary218168 -Ref: Field Splitting Summary-Footnote-1221267 -Node: Constant Size221368 -Node: Splitting By Content225975 -Ref: Splitting By Content-Footnote-1229725 -Node: Multiple Line229765 -Ref: Multiple Line-Footnote-1235621 -Node: Getline235800 -Node: Plain Getline238016 -Node: Getline/Variable240111 -Node: Getline/File241258 -Node: Getline/Variable/File242642 -Ref: Getline/Variable/File-Footnote-1244241 -Node: Getline/Pipe244328 -Node: Getline/Variable/Pipe247027 -Node: Getline/Coprocess248134 -Node: Getline/Variable/Coprocess249386 -Node: Getline Notes250123 -Node: Getline Summary252927 -Ref: table-getline-variants253335 -Node: Read Timeout254247 -Ref: Read Timeout-Footnote-1258074 -Node: Command line directories258132 -Node: Input Summary259036 -Node: Input Exercises262174 -Node: Printing262907 -Node: Print264630 -Node: Print Examples265971 -Node: Output Separators268750 -Node: OFMT270766 -Node: Printf272124 -Node: Basic Printf273030 -Node: Control Letters274569 -Node: Format Modifiers278423 -Node: Printf Examples284450 -Node: Redirection286914 -Node: Special Files293886 -Node: Special FD294417 -Ref: Special FD-Footnote-1298041 -Node: Special Network298115 -Node: Special Caveats298965 -Node: Close Files And Pipes299761 -Ref: Close Files And Pipes-Footnote-1306924 -Ref: Close Files And Pipes-Footnote-2307072 -Node: Output Summary307222 -Node: Output exercises308219 -Node: Expressions308899 -Node: Values310084 -Node: Constants310760 -Node: Scalar Constants311440 -Ref: Scalar Constants-Footnote-1312299 -Node: Nondecimal-numbers312549 -Node: Regexp Constants315549 -Node: Using Constant Regexps316024 -Node: Variables319094 -Node: Using Variables319749 -Node: Assignment Options321473 -Node: Conversion323348 -Ref: table-locale-affects328784 -Ref: Conversion-Footnote-1329408 -Node: All Operators329517 -Node: Arithmetic Ops330147 -Node: Concatenation332652 -Ref: Concatenation-Footnote-1335448 -Node: Assignment Ops335568 -Ref: table-assign-ops340551 -Node: Increment Ops341868 -Node: Truth Values and Conditions345306 -Node: Truth Values346389 -Node: Typing and Comparison347438 -Node: Variable Typing348231 -Ref: Variable Typing-Footnote-1352131 -Node: Comparison Operators352253 -Ref: table-relational-ops352663 -Node: POSIX String Comparison356213 -Ref: POSIX String Comparison-Footnote-1357297 -Node: Boolean Ops357435 -Ref: Boolean Ops-Footnote-1361505 -Node: Conditional Exp361596 -Node: Function Calls363323 -Node: Precedence367081 -Node: Locales370750 -Node: Expressions Summary372381 -Node: Patterns and Actions374878 -Node: Pattern Overview375994 -Node: Regexp Patterns377671 -Node: Expression Patterns378214 -Node: Ranges381995 -Node: BEGIN/END385101 -Node: Using BEGIN/END385863 -Ref: Using BEGIN/END-Footnote-1388599 -Node: I/O And BEGIN/END388705 -Node: BEGINFILE/ENDFILE390990 -Node: Empty393921 -Node: Using Shell Variables394238 -Node: Action Overview396521 -Node: Statements398848 -Node: If Statement400696 -Node: While Statement402194 -Node: Do Statement404238 -Node: For Statement405394 -Node: Switch Statement408546 -Node: Break Statement410649 -Node: Continue Statement412704 -Node: Next Statement414497 -Node: Nextfile Statement416887 -Node: Exit Statement419542 -Node: Built-in Variables421946 -Node: User-modified423073 -Ref: User-modified-Footnote-1430758 -Node: Auto-set430820 -Ref: Auto-set-Footnote-1443385 -Ref: Auto-set-Footnote-2443590 -Node: ARGC and ARGV443646 -Node: Pattern Action Summary447500 -Node: Arrays449723 -Node: Array Basics451272 -Node: Array Intro452098 -Ref: figure-array-elements454071 -Node: Reference to Elements456478 -Node: Assigning Elements458751 -Node: Array Example459242 -Node: Scanning an Array460974 -Node: Controlling Scanning463989 -Ref: Controlling Scanning-Footnote-1469162 -Node: Delete469478 -Ref: Delete-Footnote-1472243 -Node: Numeric Array Subscripts472300 -Node: Uninitialized Subscripts474483 -Node: Multidimensional476108 -Node: Multiscanning479201 -Node: Arrays of Arrays480790 -Node: Arrays Summary485453 -Node: Functions487558 -Node: Built-in488431 -Node: Calling Built-in489509 -Node: Numeric Functions491497 -Ref: Numeric Functions-Footnote-1495331 -Ref: Numeric Functions-Footnote-2495688 -Ref: Numeric Functions-Footnote-3495736 -Node: String Functions496005 -Ref: String Functions-Footnote-1519016 -Ref: String Functions-Footnote-2519145 -Ref: String Functions-Footnote-3519393 -Node: Gory Details519480 -Ref: table-sub-escapes521149 -Ref: table-sub-posix-92522503 -Ref: table-sub-proposed523854 -Ref: table-posix-sub525208 -Ref: table-gensub-escapes526753 -Ref: Gory Details-Footnote-1527929 -Ref: Gory Details-Footnote-2527980 -Node: I/O Functions528131 -Ref: I/O Functions-Footnote-1535254 -Node: Time Functions535401 -Ref: Time Functions-Footnote-1545865 -Ref: Time Functions-Footnote-2545933 -Ref: Time Functions-Footnote-3546091 -Ref: Time Functions-Footnote-4546202 -Ref: Time Functions-Footnote-5546314 -Ref: Time Functions-Footnote-6546541 -Node: Bitwise Functions546807 -Ref: table-bitwise-ops547369 -Ref: Bitwise Functions-Footnote-1551614 -Node: Type Functions551798 -Node: I18N Functions552940 -Node: User-defined554585 -Node: Definition Syntax555389 -Ref: Definition Syntax-Footnote-1560314 -Node: Function Example560383 -Ref: Function Example-Footnote-1563027 -Node: Function Caveats563049 -Node: Calling A Function563567 -Node: Variable Scope564522 -Node: Pass By Value/Reference567510 -Node: Return Statement571018 -Node: Dynamic Typing574002 -Node: Indirect Calls574931 -Node: Functions Summary584644 -Node: Library Functions587183 -Ref: Library Functions-Footnote-1590801 -Ref: Library Functions-Footnote-2590944 -Node: Library Names591115 -Ref: Library Names-Footnote-1594588 -Ref: Library Names-Footnote-2594808 -Node: General Functions594894 -Node: Strtonum Function595922 -Node: Assert Function598702 -Node: Round Function602028 -Node: Cliff Random Function603569 -Node: Ordinal Functions604585 -Ref: Ordinal Functions-Footnote-1607662 -Ref: Ordinal Functions-Footnote-2607914 -Node: Join Function608125 -Ref: Join Function-Footnote-1609896 -Node: Getlocaltime Function610096 -Node: Readfile Function613832 -Node: Data File Management615671 -Node: Filetrans Function616303 -Node: Rewind Function620372 -Node: File Checking621759 -Ref: File Checking-Footnote-1622891 -Node: Empty Files623092 -Node: Ignoring Assigns625071 -Node: Getopt Function626625 -Ref: Getopt Function-Footnote-1637928 -Node: Passwd Functions638131 -Ref: Passwd Functions-Footnote-1647110 -Node: Group Functions647198 -Ref: Group Functions-Footnote-1655140 -Node: Walking Arrays655353 -Node: Library Functions Summary656956 -Node: Library exercises658344 -Node: Sample Programs659624 -Node: Running Examples660351 -Node: Clones661079 -Node: Cut Program662303 -Node: Egrep Program672171 -Ref: Egrep Program-Footnote-1680142 -Node: Id Program680252 -Node: Split Program683916 -Ref: Split Program-Footnote-1687454 -Node: Tee Program687582 -Node: Uniq Program690389 -Node: Wc Program697819 -Ref: Wc Program-Footnote-1702087 -Ref: Wc Program-Footnote-2702287 -Node: Miscellaneous Programs702379 -Node: Dupword Program703592 -Node: Alarm Program705623 -Node: Translate Program710437 -Ref: Translate Program-Footnote-1714828 -Ref: Translate Program-Footnote-2715098 -Node: Labels Program715232 -Ref: Labels Program-Footnote-1718603 -Node: Word Sorting718687 -Node: History Sorting722730 -Node: Extract Program724566 -Ref: Extract Program-Footnote-1732141 -Node: Simple Sed732270 -Node: Igawk Program735332 -Ref: Igawk Program-Footnote-1750508 -Ref: Igawk Program-Footnote-2750709 -Node: Anagram Program750847 -Node: Signature Program753915 -Node: Programs Summary755162 -Node: Advanced Features756350 -Node: Nondecimal Data758298 -Node: Array Sorting759875 -Node: Controlling Array Traversal760572 -Node: Array Sorting Functions768852 -Ref: Array Sorting Functions-Footnote-1772759 -Node: Two-way I/O772953 -Ref: Two-way I/O-Footnote-1778469 -Node: TCP/IP Networking778551 -Node: Profiling781395 -Node: Advanced Features Summary788937 -Node: Internationalization790801 -Node: I18N and L10N792281 -Node: Explaining gettext792967 -Ref: Explaining gettext-Footnote-1798107 -Ref: Explaining gettext-Footnote-2798291 -Node: Programmer i18n798456 -Node: Translator i18n802681 -Node: String Extraction803475 -Ref: String Extraction-Footnote-1804436 -Node: Printf Ordering804522 -Ref: Printf Ordering-Footnote-1807304 -Node: I18N Portability807368 -Ref: I18N Portability-Footnote-1809817 -Node: I18N Example809880 -Ref: I18N Example-Footnote-1812602 -Node: Gawk I18N812674 -Node: I18N Summary813312 -Node: Debugger814651 -Node: Debugging815673 -Node: Debugging Concepts816114 -Node: Debugging Terms817970 -Node: Awk Debugging820567 -Node: Sample Debugging Session821459 -Node: Debugger Invocation821979 -Node: Finding The Bug823312 -Node: List of Debugger Commands829794 -Node: Breakpoint Control831126 -Node: Debugger Execution Control834790 -Node: Viewing And Changing Data838150 -Node: Execution Stack841508 -Node: Debugger Info843021 -Node: Miscellaneous Debugger Commands847015 -Node: Readline Support852199 -Node: Limitations853091 -Node: Debugging Summary855365 -Node: Arbitrary Precision Arithmetic856529 -Ref: Arbitrary Precision Arithmetic-Footnote-1858178 -Node: General Arithmetic858326 -Node: Floating Point Issues860046 -Node: String Conversion Precision860927 -Ref: String Conversion Precision-Footnote-1862632 -Node: Unexpected Results862741 -Node: POSIX Floating Point Problems864894 -Ref: POSIX Floating Point Problems-Footnote-1868715 -Node: Integer Programming868753 -Node: Floating-point Programming870564 -Ref: Floating-point Programming-Footnote-1876892 -Ref: Floating-point Programming-Footnote-2877162 -Node: Floating-point Representation877426 -Node: Floating-point Context878591 -Ref: table-ieee-formats879430 -Node: Rounding Mode880814 -Ref: table-rounding-modes881293 -Ref: Rounding Mode-Footnote-1884308 -Node: Gawk and MPFR884487 -Node: Arbitrary Precision Floats885896 -Ref: Arbitrary Precision Floats-Footnote-1888339 -Node: Setting Precision888660 -Ref: table-predefined-precision-strings889344 -Node: Setting Rounding Mode891489 -Ref: table-gawk-rounding-modes891893 -Node: Floating-point Constants893080 -Node: Changing Precision894532 -Ref: Changing Precision-Footnote-1895924 -Node: Exact Arithmetic896098 -Node: Arbitrary Precision Integers899232 -Ref: Arbitrary Precision Integers-Footnote-1902247 -Node: Dynamic Extensions902394 -Node: Extension Intro903903 -Node: Plugin License905168 -Node: Extension Mechanism Outline905853 -Ref: figure-load-extension906277 -Ref: figure-load-new-function907762 -Ref: figure-call-new-function908764 -Node: Extension API Description910748 -Node: Extension API Functions Introduction912198 -Node: General Data Types917063 -Ref: General Data Types-Footnote-1922756 -Node: Requesting Values923055 -Ref: table-value-types-returned923792 -Node: Memory Allocation Functions924750 -Ref: Memory Allocation Functions-Footnote-1927497 -Node: Constructor Functions927593 -Node: Registration Functions929351 -Node: Extension Functions930036 -Node: Exit Callback Functions932338 -Node: Extension Version String933587 -Node: Input Parsers934237 -Node: Output Wrappers944040 -Node: Two-way processors948556 -Node: Printing Messages950760 -Ref: Printing Messages-Footnote-1951837 -Node: Updating `ERRNO'951989 -Node: Accessing Parameters952728 -Node: Symbol Table Access953958 -Node: Symbol table by name954472 -Node: Symbol table by cookie956448 -Ref: Symbol table by cookie-Footnote-1960581 -Node: Cached values960644 -Ref: Cached values-Footnote-1964148 -Node: Array Manipulation964239 -Ref: Array Manipulation-Footnote-1965337 -Node: Array Data Types965376 -Ref: Array Data Types-Footnote-1968079 -Node: Array Functions968171 -Node: Flattening Arrays972045 -Node: Creating Arrays978897 -Node: Extension API Variables983628 -Node: Extension Versioning984264 -Node: Extension API Informational Variables986165 -Node: Extension API Boilerplate987251 -Node: Finding Extensions991055 -Node: Extension Example991615 -Node: Internal File Description992345 -Node: Internal File Ops996436 -Ref: Internal File Ops-Footnote-11007982 -Node: Using Internal File Ops1008122 -Ref: Using Internal File Ops-Footnote-11010469 -Node: Extension Samples1010737 -Node: Extension Sample File Functions1012261 -Node: Extension Sample Fnmatch1019829 -Node: Extension Sample Fork1021310 -Node: Extension Sample Inplace1022523 -Node: Extension Sample Ord1024303 -Node: Extension Sample Readdir1025139 -Ref: table-readdir-file-types1025995 -Node: Extension Sample Revout1026794 -Node: Extension Sample Rev2way1027385 -Node: Extension Sample Read write array1028126 -Node: Extension Sample Readfile1030005 -Node: Extension Sample API Tests1031105 -Node: Extension Sample Time1031630 -Node: gawkextlib1032945 -Node: Extension summary1035758 -Node: Language History1039423 -Node: V7/SVR3.11041066 -Node: SVR41043386 -Node: POSIX1044828 -Node: BTL1046214 -Node: POSIX/GNU1046948 -Node: Feature History1052547 -Node: Common Extensions1065659 -Node: Ranges and Locales1066971 -Ref: Ranges and Locales-Footnote-11071588 -Ref: Ranges and Locales-Footnote-21071615 -Ref: Ranges and Locales-Footnote-31071849 -Node: Contributors1072070 -Node: History summary1077532 -Node: Installation1078901 -Node: Gawk Distribution1079852 -Node: Getting1080336 -Node: Extracting1081162 -Node: Distribution contents1082804 -Node: Unix Installation1088521 -Node: Quick Installation1089138 -Node: Additional Configuration Options1091580 -Node: Configuration Philosophy1093318 -Node: Non-Unix Installation1095669 -Node: PC Installation1096127 -Node: PC Binary Installation1097438 -Node: PC Compiling1099286 -Ref: PC Compiling-Footnote-11102285 -Node: PC Testing1102390 -Node: PC Using1103566 -Node: Cygwin1107724 -Node: MSYS1108533 -Node: VMS Installation1109047 -Node: VMS Compilation1109843 -Ref: VMS Compilation-Footnote-11111065 -Node: VMS Dynamic Extensions1111123 -Node: VMS Installation Details1112496 -Node: VMS Running1114748 -Node: VMS GNV1117582 -Node: VMS Old Gawk1118305 -Node: Bugs1118775 -Node: Other Versions1122779 -Node: Installation summary1129033 -Node: Notes1130088 -Node: Compatibility Mode1130953 -Node: Additions1131735 -Node: Accessing The Source1132660 -Node: Adding Code1134096 -Node: New Ports1140274 -Node: Derived Files1144755 -Ref: Derived Files-Footnote-11149836 -Ref: Derived Files-Footnote-21149870 -Ref: Derived Files-Footnote-31150466 -Node: Future Extensions1150580 -Node: Implementation Limitations1151186 -Node: Extension Design1152434 -Node: Old Extension Problems1153588 -Ref: Old Extension Problems-Footnote-11155105 -Node: Extension New Mechanism Goals1155162 -Ref: Extension New Mechanism Goals-Footnote-11158522 -Node: Extension Other Design Decisions1158711 -Node: Extension Future Growth1160817 -Node: Old Extension Mechanism1161653 -Node: Notes summary1163415 -Node: Basic Concepts1164600 -Node: Basic High Level1165281 -Ref: figure-general-flow1165553 -Ref: figure-process-flow1166152 -Ref: Basic High Level-Footnote-11169381 -Node: Basic Data Typing1169566 -Node: Glossary1172893 -Node: Copying1198045 -Node: GNU Free Documentation License1235601 -Node: Index1260737 +Node: Foreword41827 +Node: Preface46172 +Ref: Preface-Footnote-149319 +Ref: Preface-Footnote-249426 +Node: History49658 +Node: Names52032 +Ref: Names-Footnote-153496 +Node: This Manual53569 +Ref: This Manual-Footnote-159348 +Node: Conventions59448 +Node: Manual History61604 +Ref: Manual History-Footnote-165043 +Ref: Manual History-Footnote-265084 +Node: How To Contribute65158 +Node: Acknowledgments66397 +Node: Getting Started70546 +Node: Running gawk72980 +Node: One-shot74170 +Node: Read Terminal75395 +Ref: Read Terminal-Footnote-177045 +Ref: Read Terminal-Footnote-277321 +Node: Long77492 +Node: Executable Scripts78868 +Ref: Executable Scripts-Footnote-180701 +Ref: Executable Scripts-Footnote-280803 +Node: Comments81350 +Node: Quoting83823 +Node: DOS Quoting89139 +Node: Sample Data Files89814 +Node: Very Simple92329 +Node: Two Rules96967 +Node: More Complex98861 +Ref: More Complex-Footnote-1101793 +Node: Statements/Lines101878 +Ref: Statements/Lines-Footnote-1106333 +Node: Other Features106598 +Node: When107526 +Node: Intro Summary109696 +Node: Invoking Gawk110462 +Node: Command Line111977 +Node: Options112768 +Ref: Options-Footnote-1128597 +Node: Other Arguments128622 +Node: Naming Standard Input131284 +Node: Environment Variables132378 +Node: AWKPATH Variable132936 +Ref: AWKPATH Variable-Footnote-1135808 +Ref: AWKPATH Variable-Footnote-2135853 +Node: AWKLIBPATH Variable136113 +Node: Other Environment Variables136872 +Node: Exit Status140527 +Node: Include Files141202 +Node: Loading Shared Libraries144780 +Node: Obsolete146164 +Node: Undocumented146861 +Node: Invoking Summary147128 +Node: Regexp148708 +Node: Regexp Usage150158 +Node: Escape Sequences152191 +Node: Regexp Operators157858 +Ref: Regexp Operators-Footnote-1165338 +Ref: Regexp Operators-Footnote-2165485 +Node: Bracket Expressions165583 +Ref: table-char-classes167473 +Node: GNU Regexp Operators169996 +Node: Case-sensitivity173719 +Ref: Case-sensitivity-Footnote-1176611 +Ref: Case-sensitivity-Footnote-2176846 +Node: Leftmost Longest176954 +Node: Computed Regexps178155 +Node: Regexp Summary181527 +Node: Reading Files182998 +Node: Records185090 +Node: awk split records185833 +Node: gawk split records190691 +Ref: gawk split records-Footnote-1195212 +Node: Fields195249 +Ref: Fields-Footnote-1198213 +Node: Nonconstant Fields198299 +Ref: Nonconstant Fields-Footnote-1200529 +Node: Changing Fields200731 +Node: Field Separators206685 +Node: Default Field Splitting209387 +Node: Regexp Field Splitting210504 +Node: Single Character Fields213845 +Node: Command Line Field Separator214904 +Node: Full Line Fields218246 +Ref: Full Line Fields-Footnote-1218754 +Node: Field Splitting Summary218800 +Ref: Field Splitting Summary-Footnote-1221899 +Node: Constant Size222000 +Node: Splitting By Content226607 +Ref: Splitting By Content-Footnote-1230357 +Node: Multiple Line230397 +Ref: Multiple Line-Footnote-1236253 +Node: Getline236432 +Node: Plain Getline238648 +Node: Getline/Variable240743 +Node: Getline/File241890 +Node: Getline/Variable/File243274 +Ref: Getline/Variable/File-Footnote-1244873 +Node: Getline/Pipe244960 +Node: Getline/Variable/Pipe247659 +Node: Getline/Coprocess248766 +Node: Getline/Variable/Coprocess250018 +Node: Getline Notes250755 +Node: Getline Summary253559 +Ref: table-getline-variants253967 +Node: Read Timeout254879 +Ref: Read Timeout-Footnote-1258706 +Node: Command line directories258764 +Node: Input Summary259668 +Node: Input Exercises262805 +Node: Printing263538 +Node: Print265260 +Node: Print Examples266601 +Node: Output Separators269380 +Node: OFMT271396 +Node: Printf272754 +Node: Basic Printf273660 +Node: Control Letters275199 +Node: Format Modifiers279051 +Node: Printf Examples285078 +Node: Redirection287542 +Node: Special Files294514 +Node: Special FD295045 +Ref: Special FD-Footnote-1298669 +Node: Special Network298743 +Node: Special Caveats299593 +Node: Close Files And Pipes300389 +Ref: Close Files And Pipes-Footnote-1307550 +Ref: Close Files And Pipes-Footnote-2307698 +Node: Output Summary307848 +Node: Output exercises308845 +Node: Expressions309525 +Node: Values310710 +Node: Constants311386 +Node: Scalar Constants312066 +Ref: Scalar Constants-Footnote-1312925 +Node: Nondecimal-numbers313175 +Node: Regexp Constants316175 +Node: Using Constant Regexps316650 +Node: Variables319720 +Node: Using Variables320375 +Node: Assignment Options322099 +Node: Conversion323974 +Ref: table-locale-affects329410 +Ref: Conversion-Footnote-1330034 +Node: All Operators330143 +Node: Arithmetic Ops330773 +Node: Concatenation333278 +Ref: Concatenation-Footnote-1336074 +Node: Assignment Ops336194 +Ref: table-assign-ops341177 +Node: Increment Ops342494 +Node: Truth Values and Conditions345932 +Node: Truth Values347015 +Node: Typing and Comparison348064 +Node: Variable Typing348857 +Ref: Variable Typing-Footnote-1352757 +Node: Comparison Operators352879 +Ref: table-relational-ops353289 +Node: POSIX String Comparison356839 +Ref: POSIX String Comparison-Footnote-1357923 +Node: Boolean Ops358061 +Ref: Boolean Ops-Footnote-1362131 +Node: Conditional Exp362222 +Node: Function Calls363949 +Node: Precedence367707 +Node: Locales371376 +Node: Expressions Summary373007 +Node: Patterns and Actions375504 +Node: Pattern Overview376620 +Node: Regexp Patterns378297 +Node: Expression Patterns378840 +Node: Ranges382621 +Node: BEGIN/END385727 +Node: Using BEGIN/END386489 +Ref: Using BEGIN/END-Footnote-1389225 +Node: I/O And BEGIN/END389331 +Node: BEGINFILE/ENDFILE391616 +Node: Empty394547 +Node: Using Shell Variables394864 +Node: Action Overview397147 +Node: Statements399474 +Node: If Statement401322 +Node: While Statement402820 +Node: Do Statement404864 +Node: For Statement406020 +Node: Switch Statement409172 +Node: Break Statement411275 +Node: Continue Statement413330 +Node: Next Statement415123 +Node: Nextfile Statement417513 +Node: Exit Statement420168 +Node: Built-in Variables422572 +Node: User-modified423699 +Ref: User-modified-Footnote-1431388 +Node: Auto-set431450 +Ref: Auto-set-Footnote-1444032 +Ref: Auto-set-Footnote-2444237 +Node: ARGC and ARGV444293 +Node: Pattern Action Summary448147 +Node: Arrays450370 +Node: Array Basics451919 +Node: Array Intro452745 +Ref: figure-array-elements454718 +Node: Reference to Elements457125 +Node: Assigning Elements459398 +Node: Array Example459889 +Node: Scanning an Array461621 +Node: Controlling Scanning464636 +Ref: Controlling Scanning-Footnote-1469809 +Node: Delete470125 +Ref: Delete-Footnote-1472890 +Node: Numeric Array Subscripts472947 +Node: Uninitialized Subscripts475130 +Node: Multidimensional476755 +Node: Multiscanning479848 +Node: Arrays of Arrays481437 +Node: Arrays Summary486100 +Node: Functions488205 +Node: Built-in489078 +Node: Calling Built-in490156 +Node: Numeric Functions492144 +Ref: Numeric Functions-Footnote-1495978 +Ref: Numeric Functions-Footnote-2496335 +Ref: Numeric Functions-Footnote-3496383 +Node: String Functions496652 +Ref: String Functions-Footnote-1519663 +Ref: String Functions-Footnote-2519792 +Ref: String Functions-Footnote-3520040 +Node: Gory Details520127 +Ref: table-sub-escapes521796 +Ref: table-sub-posix-92523150 +Ref: table-sub-proposed524501 +Ref: table-posix-sub525855 +Ref: table-gensub-escapes527400 +Ref: Gory Details-Footnote-1528576 +Ref: Gory Details-Footnote-2528627 +Node: I/O Functions528778 +Ref: I/O Functions-Footnote-1535901 +Node: Time Functions536048 +Ref: Time Functions-Footnote-1546512 +Ref: Time Functions-Footnote-2546580 +Ref: Time Functions-Footnote-3546738 +Ref: Time Functions-Footnote-4546849 +Ref: Time Functions-Footnote-5546961 +Ref: Time Functions-Footnote-6547188 +Node: Bitwise Functions547454 +Ref: table-bitwise-ops548016 +Ref: Bitwise Functions-Footnote-1552261 +Node: Type Functions552445 +Node: I18N Functions553587 +Node: User-defined555232 +Node: Definition Syntax556036 +Ref: Definition Syntax-Footnote-1560961 +Node: Function Example561030 +Ref: Function Example-Footnote-1563674 +Node: Function Caveats563696 +Node: Calling A Function564214 +Node: Variable Scope565169 +Node: Pass By Value/Reference568157 +Node: Return Statement571665 +Node: Dynamic Typing574649 +Node: Indirect Calls575578 +Node: Functions Summary585291 +Node: Library Functions587830 +Ref: Library Functions-Footnote-1591448 +Ref: Library Functions-Footnote-2591591 +Node: Library Names591762 +Ref: Library Names-Footnote-1595235 +Ref: Library Names-Footnote-2595455 +Node: General Functions595541 +Node: Strtonum Function596569 +Node: Assert Function599349 +Node: Round Function602675 +Node: Cliff Random Function604216 +Node: Ordinal Functions605232 +Ref: Ordinal Functions-Footnote-1608309 +Ref: Ordinal Functions-Footnote-2608561 +Node: Join Function608772 +Ref: Join Function-Footnote-1610543 +Node: Getlocaltime Function610743 +Node: Readfile Function614479 +Node: Data File Management616318 +Node: Filetrans Function616950 +Node: Rewind Function621019 +Node: File Checking622406 +Ref: File Checking-Footnote-1623538 +Node: Empty Files623739 +Node: Ignoring Assigns625718 +Node: Getopt Function627272 +Ref: Getopt Function-Footnote-1638575 +Node: Passwd Functions638778 +Ref: Passwd Functions-Footnote-1647757 +Node: Group Functions647845 +Ref: Group Functions-Footnote-1655786 +Node: Walking Arrays655999 +Node: Library Functions Summary657602 +Node: Library exercises658990 +Node: Sample Programs660270 +Node: Running Examples661040 +Node: Clones661768 +Node: Cut Program662992 +Node: Egrep Program672860 +Ref: Egrep Program-Footnote-1680831 +Node: Id Program680941 +Node: Split Program684605 +Ref: Split Program-Footnote-1688143 +Node: Tee Program688271 +Node: Uniq Program691078 +Node: Wc Program698508 +Ref: Wc Program-Footnote-1702773 +Node: Miscellaneous Programs702865 +Node: Dupword Program704078 +Node: Alarm Program706109 +Node: Translate Program710923 +Ref: Translate Program-Footnote-1715314 +Ref: Translate Program-Footnote-2715584 +Node: Labels Program715718 +Ref: Labels Program-Footnote-1719089 +Node: Word Sorting719173 +Node: History Sorting723216 +Node: Extract Program725052 +Node: Simple Sed732588 +Node: Igawk Program735650 +Ref: Igawk Program-Footnote-1749961 +Ref: Igawk Program-Footnote-2750162 +Node: Anagram Program750300 +Node: Signature Program753368 +Node: Programs Summary754615 +Node: Programs Exercises755830 +Node: Advanced Features759481 +Node: Nondecimal Data761429 +Node: Array Sorting763006 +Node: Controlling Array Traversal763703 +Node: Array Sorting Functions771983 +Ref: Array Sorting Functions-Footnote-1775890 +Node: Two-way I/O776084 +Ref: Two-way I/O-Footnote-1781600 +Node: TCP/IP Networking781682 +Node: Profiling784526 +Node: Advanced Features Summary792068 +Node: Internationalization793932 +Node: I18N and L10N795412 +Node: Explaining gettext796098 +Ref: Explaining gettext-Footnote-1801238 +Ref: Explaining gettext-Footnote-2801422 +Node: Programmer i18n801587 +Node: Translator i18n805812 +Node: String Extraction806606 +Ref: String Extraction-Footnote-1807567 +Node: Printf Ordering807653 +Ref: Printf Ordering-Footnote-1810435 +Node: I18N Portability810499 +Ref: I18N Portability-Footnote-1812948 +Node: I18N Example813011 +Ref: I18N Example-Footnote-1815733 +Node: Gawk I18N815805 +Node: I18N Summary816443 +Node: Debugger817782 +Node: Debugging818804 +Node: Debugging Concepts819245 +Node: Debugging Terms821101 +Node: Awk Debugging823698 +Node: Sample Debugging Session824590 +Node: Debugger Invocation825110 +Node: Finding The Bug826443 +Node: List of Debugger Commands832925 +Node: Breakpoint Control834257 +Node: Debugger Execution Control837921 +Node: Viewing And Changing Data841281 +Node: Execution Stack844639 +Node: Debugger Info846152 +Node: Miscellaneous Debugger Commands850146 +Node: Readline Support855330 +Node: Limitations856222 +Node: Debugging Summary858496 +Node: Arbitrary Precision Arithmetic859660 +Node: Computer Arithmetic860989 +Ref: Computer Arithmetic-Footnote-1865376 +Node: Math Definitions865433 +Ref: table-ieee-formats868317 +Node: MPFR features868821 +Node: FP Math Caution870463 +Ref: FP Math Caution-Footnote-1871504 +Node: Inexactness of computations871873 +Node: Inexact representation872821 +Node: Comparing FP Values874176 +Node: Errors accumulate875140 +Node: Getting Accuracy876573 +Node: Try To Round879232 +Node: Setting precision880131 +Ref: table-predefined-precision-strings880813 +Node: Setting the rounding mode882606 +Ref: table-gawk-rounding-modes882970 +Ref: Setting the rounding mode-Footnote-1886424 +Node: Arbitrary Precision Integers886603 +Ref: Arbitrary Precision Integers-Footnote-1889573 +Node: POSIX Floating Point Problems889722 +Ref: POSIX Floating Point Problems-Footnote-1893591 +Node: Floating point summary893629 +Node: Dynamic Extensions895846 +Node: Extension Intro897398 +Node: Plugin License898663 +Node: Extension Mechanism Outline899348 +Ref: figure-load-extension899772 +Ref: figure-load-new-function901257 +Ref: figure-call-new-function902259 +Node: Extension API Description904243 +Node: Extension API Functions Introduction905693 +Node: General Data Types910558 +Ref: General Data Types-Footnote-1916251 +Node: Requesting Values916550 +Ref: table-value-types-returned917287 +Node: Memory Allocation Functions918245 +Ref: Memory Allocation Functions-Footnote-1920992 +Node: Constructor Functions921088 +Node: Registration Functions922846 +Node: Extension Functions923531 +Node: Exit Callback Functions925833 +Node: Extension Version String927082 +Node: Input Parsers927732 +Node: Output Wrappers937535 +Node: Two-way processors942051 +Node: Printing Messages944255 +Ref: Printing Messages-Footnote-1945332 +Node: Updating `ERRNO'945484 +Node: Accessing Parameters946223 +Node: Symbol Table Access947453 +Node: Symbol table by name947967 +Node: Symbol table by cookie949943 +Ref: Symbol table by cookie-Footnote-1954076 +Node: Cached values954139 +Ref: Cached values-Footnote-1957643 +Node: Array Manipulation957734 +Ref: Array Manipulation-Footnote-1958832 +Node: Array Data Types958871 +Ref: Array Data Types-Footnote-1961574 +Node: Array Functions961666 +Node: Flattening Arrays965540 +Node: Creating Arrays972392 +Node: Extension API Variables977123 +Node: Extension Versioning977759 +Node: Extension API Informational Variables979660 +Node: Extension API Boilerplate980746 +Node: Finding Extensions984550 +Node: Extension Example985110 +Node: Internal File Description985840 +Node: Internal File Ops989931 +Ref: Internal File Ops-Footnote-11001363 +Node: Using Internal File Ops1001503 +Ref: Using Internal File Ops-Footnote-11003850 +Node: Extension Samples1004118 +Node: Extension Sample File Functions1005642 +Node: Extension Sample Fnmatch1013210 +Node: Extension Sample Fork1014691 +Node: Extension Sample Inplace1015904 +Node: Extension Sample Ord1017579 +Node: Extension Sample Readdir1018415 +Ref: table-readdir-file-types1019271 +Node: Extension Sample Revout1020070 +Node: Extension Sample Rev2way1020661 +Node: Extension Sample Read write array1021402 +Node: Extension Sample Readfile1023281 +Node: Extension Sample API Tests1024381 +Node: Extension Sample Time1024906 +Node: gawkextlib1026221 +Node: Extension summary1029034 +Node: Extension Exercises1032727 +Node: Language History1033449 +Node: V7/SVR3.11035092 +Node: SVR41037412 +Node: POSIX1038854 +Node: BTL1040240 +Node: POSIX/GNU1040974 +Node: Feature History1046573 +Node: Common Extensions1059703 +Node: Ranges and Locales1061015 +Ref: Ranges and Locales-Footnote-11065632 +Ref: Ranges and Locales-Footnote-21065659 +Ref: Ranges and Locales-Footnote-31065893 +Node: Contributors1066114 +Node: History summary1071576 +Node: Installation1072945 +Node: Gawk Distribution1073896 +Node: Getting1074380 +Node: Extracting1075206 +Node: Distribution contents1076848 +Node: Unix Installation1082565 +Node: Quick Installation1083182 +Node: Additional Configuration Options1085624 +Node: Configuration Philosophy1087362 +Node: Non-Unix Installation1089713 +Node: PC Installation1090171 +Node: PC Binary Installation1091482 +Node: PC Compiling1093330 +Ref: PC Compiling-Footnote-11096329 +Node: PC Testing1096434 +Node: PC Using1097610 +Node: Cygwin1101768 +Node: MSYS1102577 +Node: VMS Installation1103091 +Node: VMS Compilation1103887 +Ref: VMS Compilation-Footnote-11105109 +Node: VMS Dynamic Extensions1105167 +Node: VMS Installation Details1106540 +Node: VMS Running1108792 +Node: VMS GNV1111626 +Node: VMS Old Gawk1112349 +Node: Bugs1112819 +Node: Other Versions1116823 +Node: Installation summary1123077 +Node: Notes1124133 +Node: Compatibility Mode1124998 +Node: Additions1125780 +Node: Accessing The Source1126705 +Node: Adding Code1128141 +Node: New Ports1134319 +Node: Derived Files1138800 +Ref: Derived Files-Footnote-11143881 +Ref: Derived Files-Footnote-21143915 +Ref: Derived Files-Footnote-31144511 +Node: Future Extensions1144625 +Node: Implementation Limitations1145231 +Node: Extension Design1146479 +Node: Old Extension Problems1147633 +Ref: Old Extension Problems-Footnote-11149150 +Node: Extension New Mechanism Goals1149207 +Ref: Extension New Mechanism Goals-Footnote-11152567 +Node: Extension Other Design Decisions1152756 +Node: Extension Future Growth1154862 +Node: Old Extension Mechanism1155698 +Node: Notes summary1157460 +Node: Basic Concepts1158646 +Node: Basic High Level1159327 +Ref: figure-general-flow1159599 +Ref: figure-process-flow1160198 +Ref: Basic High Level-Footnote-11163427 +Node: Basic Data Typing1163612 +Node: Glossary1166940 +Node: Copying1192092 +Node: GNU Free Documentation License1229648 +Node: Index1254784  End Tag Table -- cgit v1.2.3 From e0027b635872545e584975cf89909b3d0d553163 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 17 Jun 2014 22:38:21 +0300 Subject: Minor fixes, esp for docbook. --- doc/gawk.info | 120 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 60 insertions(+), 60 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 0fb3d400..a7d489bd 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -18662,7 +18662,7 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample EBCDIC systems. Fix this problem. 6. Why can't the `wc.awk' program (*note Wc Program::) just use the - value of `FNR' in `endfile()'? Hint: examine the code in *note + value of `FNR' in `endfile()'? Hint: Examine the code in *note Filetrans Function::. 7. Manipulation of individual characters in the `translate' program @@ -26805,7 +26805,7 @@ File: gawk.info, Node: Getting, Next: Extracting, Up: Gawk Distribution B.1.1 Getting the `gawk' Distribution ------------------------------------- -There are three ways to get GNU software: +There are two ways to get GNU software: * Copy it from someone else who already has it. @@ -27996,7 +27996,7 @@ QSE Awk `http://www.quiktrim.org/QTawk.html' for more information, including the manual and a download link. - The project may als be frozen; no new code changes have been made + The project may also be frozen; no new code changes have been made since approximately 2008. Other Versions @@ -34394,62 +34394,62 @@ Node: History summary1071576 Node: Installation1072945 Node: Gawk Distribution1073896 Node: Getting1074380 -Node: Extracting1075206 -Node: Distribution contents1076848 -Node: Unix Installation1082565 -Node: Quick Installation1083182 -Node: Additional Configuration Options1085624 -Node: Configuration Philosophy1087362 -Node: Non-Unix Installation1089713 -Node: PC Installation1090171 -Node: PC Binary Installation1091482 -Node: PC Compiling1093330 -Ref: PC Compiling-Footnote-11096329 -Node: PC Testing1096434 -Node: PC Using1097610 -Node: Cygwin1101768 -Node: MSYS1102577 -Node: VMS Installation1103091 -Node: VMS Compilation1103887 -Ref: VMS Compilation-Footnote-11105109 -Node: VMS Dynamic Extensions1105167 -Node: VMS Installation Details1106540 -Node: VMS Running1108792 -Node: VMS GNV1111626 -Node: VMS Old Gawk1112349 -Node: Bugs1112819 -Node: Other Versions1116823 -Node: Installation summary1123077 -Node: Notes1124133 -Node: Compatibility Mode1124998 -Node: Additions1125780 -Node: Accessing The Source1126705 -Node: Adding Code1128141 -Node: New Ports1134319 -Node: Derived Files1138800 -Ref: Derived Files-Footnote-11143881 -Ref: Derived Files-Footnote-21143915 -Ref: Derived Files-Footnote-31144511 -Node: Future Extensions1144625 -Node: Implementation Limitations1145231 -Node: Extension Design1146479 -Node: Old Extension Problems1147633 -Ref: Old Extension Problems-Footnote-11149150 -Node: Extension New Mechanism Goals1149207 -Ref: Extension New Mechanism Goals-Footnote-11152567 -Node: Extension Other Design Decisions1152756 -Node: Extension Future Growth1154862 -Node: Old Extension Mechanism1155698 -Node: Notes summary1157460 -Node: Basic Concepts1158646 -Node: Basic High Level1159327 -Ref: figure-general-flow1159599 -Ref: figure-process-flow1160198 -Ref: Basic High Level-Footnote-11163427 -Node: Basic Data Typing1163612 -Node: Glossary1166940 -Node: Copying1192092 -Node: GNU Free Documentation License1229648 -Node: Index1254784 +Node: Extracting1075204 +Node: Distribution contents1076846 +Node: Unix Installation1082563 +Node: Quick Installation1083180 +Node: Additional Configuration Options1085622 +Node: Configuration Philosophy1087360 +Node: Non-Unix Installation1089711 +Node: PC Installation1090169 +Node: PC Binary Installation1091480 +Node: PC Compiling1093328 +Ref: PC Compiling-Footnote-11096327 +Node: PC Testing1096432 +Node: PC Using1097608 +Node: Cygwin1101766 +Node: MSYS1102575 +Node: VMS Installation1103089 +Node: VMS Compilation1103885 +Ref: VMS Compilation-Footnote-11105107 +Node: VMS Dynamic Extensions1105165 +Node: VMS Installation Details1106538 +Node: VMS Running1108790 +Node: VMS GNV1111624 +Node: VMS Old Gawk1112347 +Node: Bugs1112817 +Node: Other Versions1116821 +Node: Installation summary1123076 +Node: Notes1124132 +Node: Compatibility Mode1124997 +Node: Additions1125779 +Node: Accessing The Source1126704 +Node: Adding Code1128140 +Node: New Ports1134318 +Node: Derived Files1138799 +Ref: Derived Files-Footnote-11143880 +Ref: Derived Files-Footnote-21143914 +Ref: Derived Files-Footnote-31144510 +Node: Future Extensions1144624 +Node: Implementation Limitations1145230 +Node: Extension Design1146478 +Node: Old Extension Problems1147632 +Ref: Old Extension Problems-Footnote-11149149 +Node: Extension New Mechanism Goals1149206 +Ref: Extension New Mechanism Goals-Footnote-11152566 +Node: Extension Other Design Decisions1152755 +Node: Extension Future Growth1154861 +Node: Old Extension Mechanism1155697 +Node: Notes summary1157459 +Node: Basic Concepts1158645 +Node: Basic High Level1159326 +Ref: figure-general-flow1159598 +Ref: figure-process-flow1160197 +Ref: Basic High Level-Footnote-11163426 +Node: Basic Data Typing1163611 +Node: Glossary1166939 +Node: Copying1192091 +Node: GNU Free Documentation License1229647 +Node: Index1254783  End Tag Table -- cgit v1.2.3 From fe3173cd6266b73b5400bcf7dd6862979e64e4df Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 18 Jun 2014 17:26:56 +0300 Subject: Subsections in 6.1.4. --- doc/gawk.info | 1171 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 603 insertions(+), 568 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index a7d489bd..cf5c6036 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -266,6 +266,9 @@ texts being (a) (see below), and with the Back-Cover Texts being (b) This is an advanced method of input. * Conversion:: The conversion of strings to numbers and vice versa. +* Strings And Numbers:: How `awk' Converts Between + Strings And Numbers. +* Locale influences conversions:: How the locale may affect conversions. * All Operators:: `gawk''s operators. * Arithmetic Ops:: Arithmetic operations (`+', `-', etc.) @@ -7461,6 +7464,22 @@ File: gawk.info, Node: Conversion, Prev: Variables, Up: Values 6.1.4 Conversion of Strings and Numbers --------------------------------------- +Number to string and string to number conversion are generally +straightforward. There can be subtleties to be aware of; this minor +node discusses this important facet of `awk'. + +* Menu: + +* Strings And Numbers:: How `awk' Converts Between Strings And + Numbers. +* Locale influences conversions:: How the locale may affect conversions. + + +File: gawk.info, Node: Strings And Numbers, Next: Locale influences conversions, Up: Conversion + +6.1.4.1 How `awk' Converts Between Strings And Numbers +...................................................... + Strings are converted to numbers and numbers are converted to strings, if the context of the `awk' program demands it. For example, if the value of either `foo' or `bar' in the expression `foo + bar' happens to @@ -7510,6 +7529,8 @@ value of `CONVFMT' may be. Given the following code fragment: `b' has the value `"12"', not `"12.00"'. (d.c.) + Pre-POSIX `awk' Used `OFMT' For String Conversion + Prior to the POSIX standard, `awk' used the value of `OFMT' for converting numbers to strings. `OFMT' specifies the output format to use when printing numbers with `print'. `CONVFMT' was introduced in @@ -7519,8 +7540,19 @@ printing. Both `CONVFMT' and `OFMT' have the same default value: change their behavior. *Note Print::, for more information on the `print' statement. - Where you are can matter when it comes to converting between numbers -and strings. The local character set and language--the "locale"--can + ---------- Footnotes ---------- + + (1) Pathological cases can require up to 752 digits (!), but we +doubt that you need to worry about this. + + +File: gawk.info, Node: Locale influences conversions, Prev: Strings And Numbers, Up: Conversion + +6.1.4.2 Locales Can Influence Conversion +........................................ + +Where you are can matter when it comes to converting between numbers and +strings. The local character set and language--the "locale"--can affect numeric formats. In particular, for `awk' programs, it affects the decimal point character and the thousands-separator character. The `"C"' locale, and most English-language locales, use the period @@ -7582,11 +7614,6 @@ representation can have an unusual but important effect on the way `gawk' converts some special string values to numbers. The details are presented in *note POSIX Floating Point Problems::. - ---------- Footnotes ---------- - - (1) Pathological cases can require up to 752 digits (!), but we -doubt that you need to worry about this. -  File: gawk.info, Node: All Operators, Next: Truth Values and Conditions, Prev: Values, Up: Expressions @@ -8725,6 +8752,7 @@ File: gawk.info, Node: Expressions Summary, Prev: Locales, Up: Expressions * Numbers are automatically converted to strings, and strings to numbers, as needed by `awk'. Numeric values are converted as if they were formatted with `sprintf()' using the format in `CONVFMT'. + Locales can influence the conversions. * `awk' provides the usual arithmetic operators (addition, subtraction, multiplication, division, modulus), and unary plus @@ -21981,7 +22009,8 @@ integer arithmetic using GMP arbitrary precision integers. Any number that looks like an integer in a source or data file is stored as an arbitrary precision integer. The size of the integer is limited only by the available memory. For example, the following computes 5^4^3^2, -the result of which is beyond the limits of ordinary `gawk' numbers: +the result of which is beyond the limits of ordinary hardware +double-precision floating point values: $ gawk -M 'BEGIN { > x = 5^4^3^2 @@ -22069,8 +22098,8 @@ These features are: Number" (NaN), positive Infinity ("inf") and negative Infinity ("-inf"). In particular, the format for these values is as specified by the ISO 1999 C standard, which ignores case and can - allow machine-dependent additional characters after the `nan' and - allow either `inf' or `infinity'. + allow implementation-dependent additional characters after the + `nan' and allow either `inf' or `infinity'. The first problem is that both of these are clear changes to historical practice: @@ -31302,7 +31331,7 @@ Index * awk, implementations, limits: Getline Notes. (line 14) * awk, invoking: Command Line. (line 6) * awk, new vs. old: Names. (line 6) -* awk, new vs. old, OFMT variable: Conversion. (line 55) +* awk, new vs. old, OFMT variable: Strings And Numbers. (line 57) * awk, POSIX and: Preface. (line 23) * awk, POSIX and, See Also POSIX awk: Preface. (line 23) * awk, regexp constants and: Comparison Operators. @@ -31661,11 +31690,11 @@ Index (line 31) * converting, dates to timestamps: Time Functions. (line 76) * converting, numbers to strings <1>: Bitwise Functions. (line 109) -* converting, numbers to strings: Conversion. (line 6) +* converting, numbers to strings: Strings And Numbers. (line 6) * converting, strings to numbers <1>: Bitwise Functions. (line 109) -* converting, strings to numbers: Conversion. (line 6) +* converting, strings to numbers: Strings And Numbers. (line 6) * CONVFMT variable <1>: User-modified. (line 30) -* CONVFMT variable: Conversion. (line 29) +* CONVFMT variable: Strings And Numbers. (line 29) * CONVFMT variable, and array subscripts: Numeric Array Subscripts. (line 6) * cookie: Glossary. (line 149) @@ -31706,7 +31735,7 @@ Index (line 131) * dark corner, command-line arguments: Assignment Options. (line 43) * dark corner, continue statement: Continue Statement. (line 43) -* dark corner, CONVFMT variable: Conversion. (line 40) +* dark corner, CONVFMT variable: Strings And Numbers. (line 40) * dark corner, escape sequences: Other Arguments. (line 31) * dark corner, escape sequences, for metacharacters: Escape Sequences. (line 134) @@ -31722,7 +31751,8 @@ Index * dark corner, input files: awk split records. (line 110) * dark corner, invoking awk: Command Line. (line 16) * dark corner, length() function: String Functions. (line 183) -* dark corner, locale's decimal point character: Conversion. (line 75) +* dark corner, locale's decimal point character: Locale influences conversions. + (line 17) * dark corner, multiline records: Multiple Line. (line 35) * dark corner, NF variable, decrementing: Changing Fields. (line 107) * dark corner, OFMT variable: OFMT. (line 27) @@ -32898,7 +32928,8 @@ Index * null strings, and deleting array elements: Delete. (line 27) * null strings, as array subscripts: Uninitialized Subscripts. (line 43) -* null strings, converting numbers to strings: Conversion. (line 21) +* null strings, converting numbers to strings: Strings And Numbers. + (line 21) * null strings, matching: Gory Details. (line 164) * number as string of bits: Bitwise Functions. (line 109) * number of array elements: String Functions. (line 197) @@ -32911,7 +32942,7 @@ Index * numbers, Cliff random: Cliff Random Function. (line 6) * numbers, converting <1>: Bitwise Functions. (line 109) -* numbers, converting: Conversion. (line 6) +* numbers, converting: Strings And Numbers. (line 6) * numbers, converting, to strings: User-modified. (line 30) * numbers, hexadecimal: Nondecimal-numbers. (line 6) * numbers, octal: Nondecimal-numbers. (line 6) @@ -32926,7 +32957,7 @@ Index * octal numbers: Nondecimal-numbers. (line 6) * octal values, enabling interpretation of: Options. (line 211) * OFMT variable <1>: User-modified. (line 105) -* OFMT variable <2>: Conversion. (line 55) +* OFMT variable <2>: Strings And Numbers. (line 57) * OFMT variable: OFMT. (line 15) * OFMT variable, POSIX awk and: OFMT. (line 27) * OFS variable <1>: User-modified. (line 114) @@ -33063,7 +33094,7 @@ Index * portability, gettext library and: Explaining gettext. (line 11) * portability, internationalization and: I18N Portability. (line 6) * portability, length() function: String Functions. (line 176) -* portability, new awk vs. old awk: Conversion. (line 55) +* portability, new awk vs. old awk: Strings And Numbers. (line 57) * portability, next statement in user-defined functions: Pass By Value/Reference. (line 91) * portability, NF variable, decrementing: Changing Fields. (line 115) @@ -33111,7 +33142,7 @@ Index * POSIX awk, interval expressions in: Regexp Operators. (line 136) * POSIX awk, next/nextfile statements and: Next Statement. (line 45) * POSIX awk, numeric strings and: Variable Typing. (line 6) -* POSIX awk, OFMT variable and <1>: Conversion. (line 55) +* POSIX awk, OFMT variable and <1>: Strings And Numbers. (line 57) * POSIX awk, OFMT variable and: OFMT. (line 27) * POSIX awk, period (.), using: Regexp Operators. (line 51) * POSIX awk, printf format strings and: Format Modifiers. (line 159) @@ -33488,6 +33519,8 @@ Index * sidebar, Operator Evaluation Order: Increment Ops. (line 58) * sidebar, Piping into sh: Redirection. (line 140) * sidebar, Portability Issues with #!: Executable Scripts. (line 31) +* sidebar, Pre-POSIX awk Used OFMT For String Conversion: Strings And Numbers. + (line 55) * sidebar, Recipe For A Programming Language: History. (line 6) * sidebar, RS = "\0" Is Not Portable: gawk split records. (line 63) * sidebar, So Why Does gawk have BEGINFILE and ENDFILE?: Filetrans Function. @@ -33602,7 +33635,7 @@ Index * string-translation functions: I18N Functions. (line 6) * strings splitting, example: String Functions. (line 333) * strings, converting <1>: Bitwise Functions. (line 109) -* strings, converting: Conversion. (line 6) +* strings, converting: Strings And Numbers. (line 6) * strings, converting letter case: String Functions. (line 520) * strings, converting, numbers to: User-modified. (line 30) * strings, empty, See null strings: awk split records. (line 114) @@ -33738,7 +33771,7 @@ Index * Trueman, David: History. (line 30) * trunc-mod operation: Arithmetic Ops. (line 66) * truth values: Truth Values. (line 6) -* type conversion: Conversion. (line 21) +* type conversion: Strings And Numbers. (line 21) * u debugger command (alias for until): Debugger Execution Control. (line 83) * unassigned array elements: Reference to Elements. @@ -33906,550 +33939,552 @@ Index  Tag Table: Node: Top1292 -Node: Foreword41827 -Node: Preface46172 -Ref: Preface-Footnote-149319 -Ref: Preface-Footnote-249426 -Node: History49658 -Node: Names52032 -Ref: Names-Footnote-153496 -Node: This Manual53569 -Ref: This Manual-Footnote-159348 -Node: Conventions59448 -Node: Manual History61604 -Ref: Manual History-Footnote-165043 -Ref: Manual History-Footnote-265084 -Node: How To Contribute65158 -Node: Acknowledgments66397 -Node: Getting Started70546 -Node: Running gawk72980 -Node: One-shot74170 -Node: Read Terminal75395 -Ref: Read Terminal-Footnote-177045 -Ref: Read Terminal-Footnote-277321 -Node: Long77492 -Node: Executable Scripts78868 -Ref: Executable Scripts-Footnote-180701 -Ref: Executable Scripts-Footnote-280803 -Node: Comments81350 -Node: Quoting83823 -Node: DOS Quoting89139 -Node: Sample Data Files89814 -Node: Very Simple92329 -Node: Two Rules96967 -Node: More Complex98861 -Ref: More Complex-Footnote-1101793 -Node: Statements/Lines101878 -Ref: Statements/Lines-Footnote-1106333 -Node: Other Features106598 -Node: When107526 -Node: Intro Summary109696 -Node: Invoking Gawk110462 -Node: Command Line111977 -Node: Options112768 -Ref: Options-Footnote-1128597 -Node: Other Arguments128622 -Node: Naming Standard Input131284 -Node: Environment Variables132378 -Node: AWKPATH Variable132936 -Ref: AWKPATH Variable-Footnote-1135808 -Ref: AWKPATH Variable-Footnote-2135853 -Node: AWKLIBPATH Variable136113 -Node: Other Environment Variables136872 -Node: Exit Status140527 -Node: Include Files141202 -Node: Loading Shared Libraries144780 -Node: Obsolete146164 -Node: Undocumented146861 -Node: Invoking Summary147128 -Node: Regexp148708 -Node: Regexp Usage150158 -Node: Escape Sequences152191 -Node: Regexp Operators157858 -Ref: Regexp Operators-Footnote-1165338 -Ref: Regexp Operators-Footnote-2165485 -Node: Bracket Expressions165583 -Ref: table-char-classes167473 -Node: GNU Regexp Operators169996 -Node: Case-sensitivity173719 -Ref: Case-sensitivity-Footnote-1176611 -Ref: Case-sensitivity-Footnote-2176846 -Node: Leftmost Longest176954 -Node: Computed Regexps178155 -Node: Regexp Summary181527 -Node: Reading Files182998 -Node: Records185090 -Node: awk split records185833 -Node: gawk split records190691 -Ref: gawk split records-Footnote-1195212 -Node: Fields195249 -Ref: Fields-Footnote-1198213 -Node: Nonconstant Fields198299 -Ref: Nonconstant Fields-Footnote-1200529 -Node: Changing Fields200731 -Node: Field Separators206685 -Node: Default Field Splitting209387 -Node: Regexp Field Splitting210504 -Node: Single Character Fields213845 -Node: Command Line Field Separator214904 -Node: Full Line Fields218246 -Ref: Full Line Fields-Footnote-1218754 -Node: Field Splitting Summary218800 -Ref: Field Splitting Summary-Footnote-1221899 -Node: Constant Size222000 -Node: Splitting By Content226607 -Ref: Splitting By Content-Footnote-1230357 -Node: Multiple Line230397 -Ref: Multiple Line-Footnote-1236253 -Node: Getline236432 -Node: Plain Getline238648 -Node: Getline/Variable240743 -Node: Getline/File241890 -Node: Getline/Variable/File243274 -Ref: Getline/Variable/File-Footnote-1244873 -Node: Getline/Pipe244960 -Node: Getline/Variable/Pipe247659 -Node: Getline/Coprocess248766 -Node: Getline/Variable/Coprocess250018 -Node: Getline Notes250755 -Node: Getline Summary253559 -Ref: table-getline-variants253967 -Node: Read Timeout254879 -Ref: Read Timeout-Footnote-1258706 -Node: Command line directories258764 -Node: Input Summary259668 -Node: Input Exercises262805 -Node: Printing263538 -Node: Print265260 -Node: Print Examples266601 -Node: Output Separators269380 -Node: OFMT271396 -Node: Printf272754 -Node: Basic Printf273660 -Node: Control Letters275199 -Node: Format Modifiers279051 -Node: Printf Examples285078 -Node: Redirection287542 -Node: Special Files294514 -Node: Special FD295045 -Ref: Special FD-Footnote-1298669 -Node: Special Network298743 -Node: Special Caveats299593 -Node: Close Files And Pipes300389 -Ref: Close Files And Pipes-Footnote-1307550 -Ref: Close Files And Pipes-Footnote-2307698 -Node: Output Summary307848 -Node: Output exercises308845 -Node: Expressions309525 -Node: Values310710 -Node: Constants311386 -Node: Scalar Constants312066 -Ref: Scalar Constants-Footnote-1312925 -Node: Nondecimal-numbers313175 -Node: Regexp Constants316175 -Node: Using Constant Regexps316650 -Node: Variables319720 -Node: Using Variables320375 -Node: Assignment Options322099 -Node: Conversion323974 -Ref: table-locale-affects329410 -Ref: Conversion-Footnote-1330034 -Node: All Operators330143 -Node: Arithmetic Ops330773 -Node: Concatenation333278 -Ref: Concatenation-Footnote-1336074 -Node: Assignment Ops336194 -Ref: table-assign-ops341177 -Node: Increment Ops342494 -Node: Truth Values and Conditions345932 -Node: Truth Values347015 -Node: Typing and Comparison348064 -Node: Variable Typing348857 -Ref: Variable Typing-Footnote-1352757 -Node: Comparison Operators352879 -Ref: table-relational-ops353289 -Node: POSIX String Comparison356839 -Ref: POSIX String Comparison-Footnote-1357923 -Node: Boolean Ops358061 -Ref: Boolean Ops-Footnote-1362131 -Node: Conditional Exp362222 -Node: Function Calls363949 -Node: Precedence367707 -Node: Locales371376 -Node: Expressions Summary373007 -Node: Patterns and Actions375504 -Node: Pattern Overview376620 -Node: Regexp Patterns378297 -Node: Expression Patterns378840 -Node: Ranges382621 -Node: BEGIN/END385727 -Node: Using BEGIN/END386489 -Ref: Using BEGIN/END-Footnote-1389225 -Node: I/O And BEGIN/END389331 -Node: BEGINFILE/ENDFILE391616 -Node: Empty394547 -Node: Using Shell Variables394864 -Node: Action Overview397147 -Node: Statements399474 -Node: If Statement401322 -Node: While Statement402820 -Node: Do Statement404864 -Node: For Statement406020 -Node: Switch Statement409172 -Node: Break Statement411275 -Node: Continue Statement413330 -Node: Next Statement415123 -Node: Nextfile Statement417513 -Node: Exit Statement420168 -Node: Built-in Variables422572 -Node: User-modified423699 -Ref: User-modified-Footnote-1431388 -Node: Auto-set431450 -Ref: Auto-set-Footnote-1444032 -Ref: Auto-set-Footnote-2444237 -Node: ARGC and ARGV444293 -Node: Pattern Action Summary448147 -Node: Arrays450370 -Node: Array Basics451919 -Node: Array Intro452745 -Ref: figure-array-elements454718 -Node: Reference to Elements457125 -Node: Assigning Elements459398 -Node: Array Example459889 -Node: Scanning an Array461621 -Node: Controlling Scanning464636 -Ref: Controlling Scanning-Footnote-1469809 -Node: Delete470125 -Ref: Delete-Footnote-1472890 -Node: Numeric Array Subscripts472947 -Node: Uninitialized Subscripts475130 -Node: Multidimensional476755 -Node: Multiscanning479848 -Node: Arrays of Arrays481437 -Node: Arrays Summary486100 -Node: Functions488205 -Node: Built-in489078 -Node: Calling Built-in490156 -Node: Numeric Functions492144 -Ref: Numeric Functions-Footnote-1495978 -Ref: Numeric Functions-Footnote-2496335 -Ref: Numeric Functions-Footnote-3496383 -Node: String Functions496652 -Ref: String Functions-Footnote-1519663 -Ref: String Functions-Footnote-2519792 -Ref: String Functions-Footnote-3520040 -Node: Gory Details520127 -Ref: table-sub-escapes521796 -Ref: table-sub-posix-92523150 -Ref: table-sub-proposed524501 -Ref: table-posix-sub525855 -Ref: table-gensub-escapes527400 -Ref: Gory Details-Footnote-1528576 -Ref: Gory Details-Footnote-2528627 -Node: I/O Functions528778 -Ref: I/O Functions-Footnote-1535901 -Node: Time Functions536048 -Ref: Time Functions-Footnote-1546512 -Ref: Time Functions-Footnote-2546580 -Ref: Time Functions-Footnote-3546738 -Ref: Time Functions-Footnote-4546849 -Ref: Time Functions-Footnote-5546961 -Ref: Time Functions-Footnote-6547188 -Node: Bitwise Functions547454 -Ref: table-bitwise-ops548016 -Ref: Bitwise Functions-Footnote-1552261 -Node: Type Functions552445 -Node: I18N Functions553587 -Node: User-defined555232 -Node: Definition Syntax556036 -Ref: Definition Syntax-Footnote-1560961 -Node: Function Example561030 -Ref: Function Example-Footnote-1563674 -Node: Function Caveats563696 -Node: Calling A Function564214 -Node: Variable Scope565169 -Node: Pass By Value/Reference568157 -Node: Return Statement571665 -Node: Dynamic Typing574649 -Node: Indirect Calls575578 -Node: Functions Summary585291 -Node: Library Functions587830 -Ref: Library Functions-Footnote-1591448 -Ref: Library Functions-Footnote-2591591 -Node: Library Names591762 -Ref: Library Names-Footnote-1595235 -Ref: Library Names-Footnote-2595455 -Node: General Functions595541 -Node: Strtonum Function596569 -Node: Assert Function599349 -Node: Round Function602675 -Node: Cliff Random Function604216 -Node: Ordinal Functions605232 -Ref: Ordinal Functions-Footnote-1608309 -Ref: Ordinal Functions-Footnote-2608561 -Node: Join Function608772 -Ref: Join Function-Footnote-1610543 -Node: Getlocaltime Function610743 -Node: Readfile Function614479 -Node: Data File Management616318 -Node: Filetrans Function616950 -Node: Rewind Function621019 -Node: File Checking622406 -Ref: File Checking-Footnote-1623538 -Node: Empty Files623739 -Node: Ignoring Assigns625718 -Node: Getopt Function627272 -Ref: Getopt Function-Footnote-1638575 -Node: Passwd Functions638778 -Ref: Passwd Functions-Footnote-1647757 -Node: Group Functions647845 -Ref: Group Functions-Footnote-1655786 -Node: Walking Arrays655999 -Node: Library Functions Summary657602 -Node: Library exercises658990 -Node: Sample Programs660270 -Node: Running Examples661040 -Node: Clones661768 -Node: Cut Program662992 -Node: Egrep Program672860 -Ref: Egrep Program-Footnote-1680831 -Node: Id Program680941 -Node: Split Program684605 -Ref: Split Program-Footnote-1688143 -Node: Tee Program688271 -Node: Uniq Program691078 -Node: Wc Program698508 -Ref: Wc Program-Footnote-1702773 -Node: Miscellaneous Programs702865 -Node: Dupword Program704078 -Node: Alarm Program706109 -Node: Translate Program710923 -Ref: Translate Program-Footnote-1715314 -Ref: Translate Program-Footnote-2715584 -Node: Labels Program715718 -Ref: Labels Program-Footnote-1719089 -Node: Word Sorting719173 -Node: History Sorting723216 -Node: Extract Program725052 -Node: Simple Sed732588 -Node: Igawk Program735650 -Ref: Igawk Program-Footnote-1749961 -Ref: Igawk Program-Footnote-2750162 -Node: Anagram Program750300 -Node: Signature Program753368 -Node: Programs Summary754615 -Node: Programs Exercises755830 -Node: Advanced Features759481 -Node: Nondecimal Data761429 -Node: Array Sorting763006 -Node: Controlling Array Traversal763703 -Node: Array Sorting Functions771983 -Ref: Array Sorting Functions-Footnote-1775890 -Node: Two-way I/O776084 -Ref: Two-way I/O-Footnote-1781600 -Node: TCP/IP Networking781682 -Node: Profiling784526 -Node: Advanced Features Summary792068 -Node: Internationalization793932 -Node: I18N and L10N795412 -Node: Explaining gettext796098 -Ref: Explaining gettext-Footnote-1801238 -Ref: Explaining gettext-Footnote-2801422 -Node: Programmer i18n801587 -Node: Translator i18n805812 -Node: String Extraction806606 -Ref: String Extraction-Footnote-1807567 -Node: Printf Ordering807653 -Ref: Printf Ordering-Footnote-1810435 -Node: I18N Portability810499 -Ref: I18N Portability-Footnote-1812948 -Node: I18N Example813011 -Ref: I18N Example-Footnote-1815733 -Node: Gawk I18N815805 -Node: I18N Summary816443 -Node: Debugger817782 -Node: Debugging818804 -Node: Debugging Concepts819245 -Node: Debugging Terms821101 -Node: Awk Debugging823698 -Node: Sample Debugging Session824590 -Node: Debugger Invocation825110 -Node: Finding The Bug826443 -Node: List of Debugger Commands832925 -Node: Breakpoint Control834257 -Node: Debugger Execution Control837921 -Node: Viewing And Changing Data841281 -Node: Execution Stack844639 -Node: Debugger Info846152 -Node: Miscellaneous Debugger Commands850146 -Node: Readline Support855330 -Node: Limitations856222 -Node: Debugging Summary858496 -Node: Arbitrary Precision Arithmetic859660 -Node: Computer Arithmetic860989 -Ref: Computer Arithmetic-Footnote-1865376 -Node: Math Definitions865433 -Ref: table-ieee-formats868317 -Node: MPFR features868821 -Node: FP Math Caution870463 -Ref: FP Math Caution-Footnote-1871504 -Node: Inexactness of computations871873 -Node: Inexact representation872821 -Node: Comparing FP Values874176 -Node: Errors accumulate875140 -Node: Getting Accuracy876573 -Node: Try To Round879232 -Node: Setting precision880131 -Ref: table-predefined-precision-strings880813 -Node: Setting the rounding mode882606 -Ref: table-gawk-rounding-modes882970 -Ref: Setting the rounding mode-Footnote-1886424 -Node: Arbitrary Precision Integers886603 -Ref: Arbitrary Precision Integers-Footnote-1889573 -Node: POSIX Floating Point Problems889722 -Ref: POSIX Floating Point Problems-Footnote-1893591 -Node: Floating point summary893629 -Node: Dynamic Extensions895846 -Node: Extension Intro897398 -Node: Plugin License898663 -Node: Extension Mechanism Outline899348 -Ref: figure-load-extension899772 -Ref: figure-load-new-function901257 -Ref: figure-call-new-function902259 -Node: Extension API Description904243 -Node: Extension API Functions Introduction905693 -Node: General Data Types910558 -Ref: General Data Types-Footnote-1916251 -Node: Requesting Values916550 -Ref: table-value-types-returned917287 -Node: Memory Allocation Functions918245 -Ref: Memory Allocation Functions-Footnote-1920992 -Node: Constructor Functions921088 -Node: Registration Functions922846 -Node: Extension Functions923531 -Node: Exit Callback Functions925833 -Node: Extension Version String927082 -Node: Input Parsers927732 -Node: Output Wrappers937535 -Node: Two-way processors942051 -Node: Printing Messages944255 -Ref: Printing Messages-Footnote-1945332 -Node: Updating `ERRNO'945484 -Node: Accessing Parameters946223 -Node: Symbol Table Access947453 -Node: Symbol table by name947967 -Node: Symbol table by cookie949943 -Ref: Symbol table by cookie-Footnote-1954076 -Node: Cached values954139 -Ref: Cached values-Footnote-1957643 -Node: Array Manipulation957734 -Ref: Array Manipulation-Footnote-1958832 -Node: Array Data Types958871 -Ref: Array Data Types-Footnote-1961574 -Node: Array Functions961666 -Node: Flattening Arrays965540 -Node: Creating Arrays972392 -Node: Extension API Variables977123 -Node: Extension Versioning977759 -Node: Extension API Informational Variables979660 -Node: Extension API Boilerplate980746 -Node: Finding Extensions984550 -Node: Extension Example985110 -Node: Internal File Description985840 -Node: Internal File Ops989931 -Ref: Internal File Ops-Footnote-11001363 -Node: Using Internal File Ops1001503 -Ref: Using Internal File Ops-Footnote-11003850 -Node: Extension Samples1004118 -Node: Extension Sample File Functions1005642 -Node: Extension Sample Fnmatch1013210 -Node: Extension Sample Fork1014691 -Node: Extension Sample Inplace1015904 -Node: Extension Sample Ord1017579 -Node: Extension Sample Readdir1018415 -Ref: table-readdir-file-types1019271 -Node: Extension Sample Revout1020070 -Node: Extension Sample Rev2way1020661 -Node: Extension Sample Read write array1021402 -Node: Extension Sample Readfile1023281 -Node: Extension Sample API Tests1024381 -Node: Extension Sample Time1024906 -Node: gawkextlib1026221 -Node: Extension summary1029034 -Node: Extension Exercises1032727 -Node: Language History1033449 -Node: V7/SVR3.11035092 -Node: SVR41037412 -Node: POSIX1038854 -Node: BTL1040240 -Node: POSIX/GNU1040974 -Node: Feature History1046573 -Node: Common Extensions1059703 -Node: Ranges and Locales1061015 -Ref: Ranges and Locales-Footnote-11065632 -Ref: Ranges and Locales-Footnote-21065659 -Ref: Ranges and Locales-Footnote-31065893 -Node: Contributors1066114 -Node: History summary1071576 -Node: Installation1072945 -Node: Gawk Distribution1073896 -Node: Getting1074380 -Node: Extracting1075204 -Node: Distribution contents1076846 -Node: Unix Installation1082563 -Node: Quick Installation1083180 -Node: Additional Configuration Options1085622 -Node: Configuration Philosophy1087360 -Node: Non-Unix Installation1089711 -Node: PC Installation1090169 -Node: PC Binary Installation1091480 -Node: PC Compiling1093328 -Ref: PC Compiling-Footnote-11096327 -Node: PC Testing1096432 -Node: PC Using1097608 -Node: Cygwin1101766 -Node: MSYS1102575 -Node: VMS Installation1103089 -Node: VMS Compilation1103885 -Ref: VMS Compilation-Footnote-11105107 -Node: VMS Dynamic Extensions1105165 -Node: VMS Installation Details1106538 -Node: VMS Running1108790 -Node: VMS GNV1111624 -Node: VMS Old Gawk1112347 -Node: Bugs1112817 -Node: Other Versions1116821 -Node: Installation summary1123076 -Node: Notes1124132 -Node: Compatibility Mode1124997 -Node: Additions1125779 -Node: Accessing The Source1126704 -Node: Adding Code1128140 -Node: New Ports1134318 -Node: Derived Files1138799 -Ref: Derived Files-Footnote-11143880 -Ref: Derived Files-Footnote-21143914 -Ref: Derived Files-Footnote-31144510 -Node: Future Extensions1144624 -Node: Implementation Limitations1145230 -Node: Extension Design1146478 -Node: Old Extension Problems1147632 -Ref: Old Extension Problems-Footnote-11149149 -Node: Extension New Mechanism Goals1149206 -Ref: Extension New Mechanism Goals-Footnote-11152566 -Node: Extension Other Design Decisions1152755 -Node: Extension Future Growth1154861 -Node: Old Extension Mechanism1155697 -Node: Notes summary1157459 -Node: Basic Concepts1158645 -Node: Basic High Level1159326 -Ref: figure-general-flow1159598 -Ref: figure-process-flow1160197 -Ref: Basic High Level-Footnote-11163426 -Node: Basic Data Typing1163611 -Node: Glossary1166939 -Node: Copying1192091 -Node: GNU Free Documentation License1229647 -Node: Index1254783 +Node: Foreword42034 +Node: Preface46379 +Ref: Preface-Footnote-149526 +Ref: Preface-Footnote-249633 +Node: History49865 +Node: Names52239 +Ref: Names-Footnote-153703 +Node: This Manual53776 +Ref: This Manual-Footnote-159555 +Node: Conventions59655 +Node: Manual History61811 +Ref: Manual History-Footnote-165250 +Ref: Manual History-Footnote-265291 +Node: How To Contribute65365 +Node: Acknowledgments66604 +Node: Getting Started70753 +Node: Running gawk73187 +Node: One-shot74377 +Node: Read Terminal75602 +Ref: Read Terminal-Footnote-177252 +Ref: Read Terminal-Footnote-277528 +Node: Long77699 +Node: Executable Scripts79075 +Ref: Executable Scripts-Footnote-180908 +Ref: Executable Scripts-Footnote-281010 +Node: Comments81557 +Node: Quoting84030 +Node: DOS Quoting89346 +Node: Sample Data Files90021 +Node: Very Simple92536 +Node: Two Rules97174 +Node: More Complex99068 +Ref: More Complex-Footnote-1102000 +Node: Statements/Lines102085 +Ref: Statements/Lines-Footnote-1106540 +Node: Other Features106805 +Node: When107733 +Node: Intro Summary109903 +Node: Invoking Gawk110669 +Node: Command Line112184 +Node: Options112975 +Ref: Options-Footnote-1128804 +Node: Other Arguments128829 +Node: Naming Standard Input131491 +Node: Environment Variables132585 +Node: AWKPATH Variable133143 +Ref: AWKPATH Variable-Footnote-1136015 +Ref: AWKPATH Variable-Footnote-2136060 +Node: AWKLIBPATH Variable136320 +Node: Other Environment Variables137079 +Node: Exit Status140734 +Node: Include Files141409 +Node: Loading Shared Libraries144987 +Node: Obsolete146371 +Node: Undocumented147068 +Node: Invoking Summary147335 +Node: Regexp148915 +Node: Regexp Usage150365 +Node: Escape Sequences152398 +Node: Regexp Operators158065 +Ref: Regexp Operators-Footnote-1165545 +Ref: Regexp Operators-Footnote-2165692 +Node: Bracket Expressions165790 +Ref: table-char-classes167680 +Node: GNU Regexp Operators170203 +Node: Case-sensitivity173926 +Ref: Case-sensitivity-Footnote-1176818 +Ref: Case-sensitivity-Footnote-2177053 +Node: Leftmost Longest177161 +Node: Computed Regexps178362 +Node: Regexp Summary181734 +Node: Reading Files183205 +Node: Records185297 +Node: awk split records186040 +Node: gawk split records190898 +Ref: gawk split records-Footnote-1195419 +Node: Fields195456 +Ref: Fields-Footnote-1198420 +Node: Nonconstant Fields198506 +Ref: Nonconstant Fields-Footnote-1200736 +Node: Changing Fields200938 +Node: Field Separators206892 +Node: Default Field Splitting209594 +Node: Regexp Field Splitting210711 +Node: Single Character Fields214052 +Node: Command Line Field Separator215111 +Node: Full Line Fields218453 +Ref: Full Line Fields-Footnote-1218961 +Node: Field Splitting Summary219007 +Ref: Field Splitting Summary-Footnote-1222106 +Node: Constant Size222207 +Node: Splitting By Content226814 +Ref: Splitting By Content-Footnote-1230564 +Node: Multiple Line230604 +Ref: Multiple Line-Footnote-1236460 +Node: Getline236639 +Node: Plain Getline238855 +Node: Getline/Variable240950 +Node: Getline/File242097 +Node: Getline/Variable/File243481 +Ref: Getline/Variable/File-Footnote-1245080 +Node: Getline/Pipe245167 +Node: Getline/Variable/Pipe247866 +Node: Getline/Coprocess248973 +Node: Getline/Variable/Coprocess250225 +Node: Getline Notes250962 +Node: Getline Summary253766 +Ref: table-getline-variants254174 +Node: Read Timeout255086 +Ref: Read Timeout-Footnote-1258913 +Node: Command line directories258971 +Node: Input Summary259875 +Node: Input Exercises263012 +Node: Printing263745 +Node: Print265467 +Node: Print Examples266808 +Node: Output Separators269587 +Node: OFMT271603 +Node: Printf272961 +Node: Basic Printf273867 +Node: Control Letters275406 +Node: Format Modifiers279258 +Node: Printf Examples285285 +Node: Redirection287749 +Node: Special Files294721 +Node: Special FD295252 +Ref: Special FD-Footnote-1298876 +Node: Special Network298950 +Node: Special Caveats299800 +Node: Close Files And Pipes300596 +Ref: Close Files And Pipes-Footnote-1307757 +Ref: Close Files And Pipes-Footnote-2307905 +Node: Output Summary308055 +Node: Output exercises309052 +Node: Expressions309732 +Node: Values310917 +Node: Constants311593 +Node: Scalar Constants312273 +Ref: Scalar Constants-Footnote-1313132 +Node: Nondecimal-numbers313382 +Node: Regexp Constants316382 +Node: Using Constant Regexps316857 +Node: Variables319927 +Node: Using Variables320582 +Node: Assignment Options322306 +Node: Conversion324181 +Node: Strings And Numbers324705 +Ref: Strings And Numbers-Footnote-1327767 +Node: Locale influences conversions327876 +Ref: table-locale-affects330593 +Node: All Operators331181 +Node: Arithmetic Ops331811 +Node: Concatenation334316 +Ref: Concatenation-Footnote-1337112 +Node: Assignment Ops337232 +Ref: table-assign-ops342215 +Node: Increment Ops343532 +Node: Truth Values and Conditions346970 +Node: Truth Values348053 +Node: Typing and Comparison349102 +Node: Variable Typing349895 +Ref: Variable Typing-Footnote-1353795 +Node: Comparison Operators353917 +Ref: table-relational-ops354327 +Node: POSIX String Comparison357877 +Ref: POSIX String Comparison-Footnote-1358961 +Node: Boolean Ops359099 +Ref: Boolean Ops-Footnote-1363169 +Node: Conditional Exp363260 +Node: Function Calls364987 +Node: Precedence368745 +Node: Locales372414 +Node: Expressions Summary374045 +Node: Patterns and Actions376586 +Node: Pattern Overview377702 +Node: Regexp Patterns379379 +Node: Expression Patterns379922 +Node: Ranges383703 +Node: BEGIN/END386809 +Node: Using BEGIN/END387571 +Ref: Using BEGIN/END-Footnote-1390307 +Node: I/O And BEGIN/END390413 +Node: BEGINFILE/ENDFILE392698 +Node: Empty395629 +Node: Using Shell Variables395946 +Node: Action Overview398229 +Node: Statements400556 +Node: If Statement402404 +Node: While Statement403902 +Node: Do Statement405946 +Node: For Statement407102 +Node: Switch Statement410254 +Node: Break Statement412357 +Node: Continue Statement414412 +Node: Next Statement416205 +Node: Nextfile Statement418595 +Node: Exit Statement421250 +Node: Built-in Variables423654 +Node: User-modified424781 +Ref: User-modified-Footnote-1432470 +Node: Auto-set432532 +Ref: Auto-set-Footnote-1445114 +Ref: Auto-set-Footnote-2445319 +Node: ARGC and ARGV445375 +Node: Pattern Action Summary449229 +Node: Arrays451452 +Node: Array Basics453001 +Node: Array Intro453827 +Ref: figure-array-elements455800 +Node: Reference to Elements458207 +Node: Assigning Elements460480 +Node: Array Example460971 +Node: Scanning an Array462703 +Node: Controlling Scanning465718 +Ref: Controlling Scanning-Footnote-1470891 +Node: Delete471207 +Ref: Delete-Footnote-1473972 +Node: Numeric Array Subscripts474029 +Node: Uninitialized Subscripts476212 +Node: Multidimensional477837 +Node: Multiscanning480930 +Node: Arrays of Arrays482519 +Node: Arrays Summary487182 +Node: Functions489287 +Node: Built-in490160 +Node: Calling Built-in491238 +Node: Numeric Functions493226 +Ref: Numeric Functions-Footnote-1497060 +Ref: Numeric Functions-Footnote-2497417 +Ref: Numeric Functions-Footnote-3497465 +Node: String Functions497734 +Ref: String Functions-Footnote-1520745 +Ref: String Functions-Footnote-2520874 +Ref: String Functions-Footnote-3521122 +Node: Gory Details521209 +Ref: table-sub-escapes522878 +Ref: table-sub-posix-92524232 +Ref: table-sub-proposed525583 +Ref: table-posix-sub526937 +Ref: table-gensub-escapes528482 +Ref: Gory Details-Footnote-1529658 +Ref: Gory Details-Footnote-2529709 +Node: I/O Functions529860 +Ref: I/O Functions-Footnote-1536983 +Node: Time Functions537130 +Ref: Time Functions-Footnote-1547594 +Ref: Time Functions-Footnote-2547662 +Ref: Time Functions-Footnote-3547820 +Ref: Time Functions-Footnote-4547931 +Ref: Time Functions-Footnote-5548043 +Ref: Time Functions-Footnote-6548270 +Node: Bitwise Functions548536 +Ref: table-bitwise-ops549098 +Ref: Bitwise Functions-Footnote-1553343 +Node: Type Functions553527 +Node: I18N Functions554669 +Node: User-defined556314 +Node: Definition Syntax557118 +Ref: Definition Syntax-Footnote-1562043 +Node: Function Example562112 +Ref: Function Example-Footnote-1564756 +Node: Function Caveats564778 +Node: Calling A Function565296 +Node: Variable Scope566251 +Node: Pass By Value/Reference569239 +Node: Return Statement572747 +Node: Dynamic Typing575731 +Node: Indirect Calls576660 +Node: Functions Summary586373 +Node: Library Functions588912 +Ref: Library Functions-Footnote-1592530 +Ref: Library Functions-Footnote-2592673 +Node: Library Names592844 +Ref: Library Names-Footnote-1596317 +Ref: Library Names-Footnote-2596537 +Node: General Functions596623 +Node: Strtonum Function597651 +Node: Assert Function600431 +Node: Round Function603757 +Node: Cliff Random Function605298 +Node: Ordinal Functions606314 +Ref: Ordinal Functions-Footnote-1609391 +Ref: Ordinal Functions-Footnote-2609643 +Node: Join Function609854 +Ref: Join Function-Footnote-1611625 +Node: Getlocaltime Function611825 +Node: Readfile Function615561 +Node: Data File Management617400 +Node: Filetrans Function618032 +Node: Rewind Function622101 +Node: File Checking623488 +Ref: File Checking-Footnote-1624620 +Node: Empty Files624821 +Node: Ignoring Assigns626800 +Node: Getopt Function628354 +Ref: Getopt Function-Footnote-1639657 +Node: Passwd Functions639860 +Ref: Passwd Functions-Footnote-1648839 +Node: Group Functions648927 +Ref: Group Functions-Footnote-1656868 +Node: Walking Arrays657081 +Node: Library Functions Summary658684 +Node: Library exercises660072 +Node: Sample Programs661352 +Node: Running Examples662122 +Node: Clones662850 +Node: Cut Program664074 +Node: Egrep Program673942 +Ref: Egrep Program-Footnote-1681913 +Node: Id Program682023 +Node: Split Program685687 +Ref: Split Program-Footnote-1689225 +Node: Tee Program689353 +Node: Uniq Program692160 +Node: Wc Program699590 +Ref: Wc Program-Footnote-1703855 +Node: Miscellaneous Programs703947 +Node: Dupword Program705160 +Node: Alarm Program707191 +Node: Translate Program712005 +Ref: Translate Program-Footnote-1716396 +Ref: Translate Program-Footnote-2716666 +Node: Labels Program716800 +Ref: Labels Program-Footnote-1720171 +Node: Word Sorting720255 +Node: History Sorting724298 +Node: Extract Program726134 +Node: Simple Sed733670 +Node: Igawk Program736732 +Ref: Igawk Program-Footnote-1751043 +Ref: Igawk Program-Footnote-2751244 +Node: Anagram Program751382 +Node: Signature Program754450 +Node: Programs Summary755697 +Node: Programs Exercises756912 +Node: Advanced Features760563 +Node: Nondecimal Data762511 +Node: Array Sorting764088 +Node: Controlling Array Traversal764785 +Node: Array Sorting Functions773065 +Ref: Array Sorting Functions-Footnote-1776972 +Node: Two-way I/O777166 +Ref: Two-way I/O-Footnote-1782682 +Node: TCP/IP Networking782764 +Node: Profiling785608 +Node: Advanced Features Summary793150 +Node: Internationalization795014 +Node: I18N and L10N796494 +Node: Explaining gettext797180 +Ref: Explaining gettext-Footnote-1802320 +Ref: Explaining gettext-Footnote-2802504 +Node: Programmer i18n802669 +Node: Translator i18n806894 +Node: String Extraction807688 +Ref: String Extraction-Footnote-1808649 +Node: Printf Ordering808735 +Ref: Printf Ordering-Footnote-1811517 +Node: I18N Portability811581 +Ref: I18N Portability-Footnote-1814030 +Node: I18N Example814093 +Ref: I18N Example-Footnote-1816815 +Node: Gawk I18N816887 +Node: I18N Summary817525 +Node: Debugger818864 +Node: Debugging819886 +Node: Debugging Concepts820327 +Node: Debugging Terms822183 +Node: Awk Debugging824780 +Node: Sample Debugging Session825672 +Node: Debugger Invocation826192 +Node: Finding The Bug827525 +Node: List of Debugger Commands834007 +Node: Breakpoint Control835339 +Node: Debugger Execution Control839003 +Node: Viewing And Changing Data842363 +Node: Execution Stack845721 +Node: Debugger Info847234 +Node: Miscellaneous Debugger Commands851228 +Node: Readline Support856412 +Node: Limitations857304 +Node: Debugging Summary859578 +Node: Arbitrary Precision Arithmetic860742 +Node: Computer Arithmetic862071 +Ref: Computer Arithmetic-Footnote-1866458 +Node: Math Definitions866515 +Ref: table-ieee-formats869399 +Node: MPFR features869903 +Node: FP Math Caution871545 +Ref: FP Math Caution-Footnote-1872586 +Node: Inexactness of computations872955 +Node: Inexact representation873903 +Node: Comparing FP Values875258 +Node: Errors accumulate876222 +Node: Getting Accuracy877655 +Node: Try To Round880314 +Node: Setting precision881213 +Ref: table-predefined-precision-strings881895 +Node: Setting the rounding mode883688 +Ref: table-gawk-rounding-modes884052 +Ref: Setting the rounding mode-Footnote-1887506 +Node: Arbitrary Precision Integers887685 +Ref: Arbitrary Precision Integers-Footnote-1890688 +Node: POSIX Floating Point Problems890837 +Ref: POSIX Floating Point Problems-Footnote-1894713 +Node: Floating point summary894751 +Node: Dynamic Extensions896968 +Node: Extension Intro898520 +Node: Plugin License899785 +Node: Extension Mechanism Outline900470 +Ref: figure-load-extension900894 +Ref: figure-load-new-function902379 +Ref: figure-call-new-function903381 +Node: Extension API Description905365 +Node: Extension API Functions Introduction906815 +Node: General Data Types911680 +Ref: General Data Types-Footnote-1917373 +Node: Requesting Values917672 +Ref: table-value-types-returned918409 +Node: Memory Allocation Functions919367 +Ref: Memory Allocation Functions-Footnote-1922114 +Node: Constructor Functions922210 +Node: Registration Functions923968 +Node: Extension Functions924653 +Node: Exit Callback Functions926955 +Node: Extension Version String928204 +Node: Input Parsers928854 +Node: Output Wrappers938657 +Node: Two-way processors943173 +Node: Printing Messages945377 +Ref: Printing Messages-Footnote-1946454 +Node: Updating `ERRNO'946606 +Node: Accessing Parameters947345 +Node: Symbol Table Access948575 +Node: Symbol table by name949089 +Node: Symbol table by cookie951065 +Ref: Symbol table by cookie-Footnote-1955198 +Node: Cached values955261 +Ref: Cached values-Footnote-1958765 +Node: Array Manipulation958856 +Ref: Array Manipulation-Footnote-1959954 +Node: Array Data Types959993 +Ref: Array Data Types-Footnote-1962696 +Node: Array Functions962788 +Node: Flattening Arrays966662 +Node: Creating Arrays973514 +Node: Extension API Variables978245 +Node: Extension Versioning978881 +Node: Extension API Informational Variables980782 +Node: Extension API Boilerplate981868 +Node: Finding Extensions985672 +Node: Extension Example986232 +Node: Internal File Description986962 +Node: Internal File Ops991053 +Ref: Internal File Ops-Footnote-11002485 +Node: Using Internal File Ops1002625 +Ref: Using Internal File Ops-Footnote-11004972 +Node: Extension Samples1005240 +Node: Extension Sample File Functions1006764 +Node: Extension Sample Fnmatch1014332 +Node: Extension Sample Fork1015813 +Node: Extension Sample Inplace1017026 +Node: Extension Sample Ord1018701 +Node: Extension Sample Readdir1019537 +Ref: table-readdir-file-types1020393 +Node: Extension Sample Revout1021192 +Node: Extension Sample Rev2way1021783 +Node: Extension Sample Read write array1022524 +Node: Extension Sample Readfile1024403 +Node: Extension Sample API Tests1025503 +Node: Extension Sample Time1026028 +Node: gawkextlib1027343 +Node: Extension summary1030156 +Node: Extension Exercises1033849 +Node: Language History1034571 +Node: V7/SVR3.11036214 +Node: SVR41038534 +Node: POSIX1039976 +Node: BTL1041362 +Node: POSIX/GNU1042096 +Node: Feature History1047695 +Node: Common Extensions1060825 +Node: Ranges and Locales1062137 +Ref: Ranges and Locales-Footnote-11066754 +Ref: Ranges and Locales-Footnote-21066781 +Ref: Ranges and Locales-Footnote-31067015 +Node: Contributors1067236 +Node: History summary1072698 +Node: Installation1074067 +Node: Gawk Distribution1075018 +Node: Getting1075502 +Node: Extracting1076326 +Node: Distribution contents1077968 +Node: Unix Installation1083685 +Node: Quick Installation1084302 +Node: Additional Configuration Options1086744 +Node: Configuration Philosophy1088482 +Node: Non-Unix Installation1090833 +Node: PC Installation1091291 +Node: PC Binary Installation1092602 +Node: PC Compiling1094450 +Ref: PC Compiling-Footnote-11097449 +Node: PC Testing1097554 +Node: PC Using1098730 +Node: Cygwin1102888 +Node: MSYS1103697 +Node: VMS Installation1104211 +Node: VMS Compilation1105007 +Ref: VMS Compilation-Footnote-11106229 +Node: VMS Dynamic Extensions1106287 +Node: VMS Installation Details1107660 +Node: VMS Running1109912 +Node: VMS GNV1112746 +Node: VMS Old Gawk1113469 +Node: Bugs1113939 +Node: Other Versions1117943 +Node: Installation summary1124198 +Node: Notes1125254 +Node: Compatibility Mode1126119 +Node: Additions1126901 +Node: Accessing The Source1127826 +Node: Adding Code1129262 +Node: New Ports1135440 +Node: Derived Files1139921 +Ref: Derived Files-Footnote-11145002 +Ref: Derived Files-Footnote-21145036 +Ref: Derived Files-Footnote-31145632 +Node: Future Extensions1145746 +Node: Implementation Limitations1146352 +Node: Extension Design1147600 +Node: Old Extension Problems1148754 +Ref: Old Extension Problems-Footnote-11150271 +Node: Extension New Mechanism Goals1150328 +Ref: Extension New Mechanism Goals-Footnote-11153688 +Node: Extension Other Design Decisions1153877 +Node: Extension Future Growth1155983 +Node: Old Extension Mechanism1156819 +Node: Notes summary1158581 +Node: Basic Concepts1159767 +Node: Basic High Level1160448 +Ref: figure-general-flow1160720 +Ref: figure-process-flow1161319 +Ref: Basic High Level-Footnote-11164548 +Node: Basic Data Typing1164733 +Node: Glossary1168061 +Node: Copying1193213 +Node: GNU Free Documentation License1230769 +Node: Index1255905  End Tag Table -- cgit v1.2.3 From 46b2d10640dc4404680fc7ffc670dd06feb5ecf3 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 19 Jun 2014 20:24:58 +0300 Subject: Add more thanks, minor revision in doc. --- doc/gawk.info | 1121 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 566 insertions(+), 555 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index cf5c6036..95d81e89 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1306,6 +1306,10 @@ be a pleasure working with this team of fine people. Notable code and documentation contributions were made by a number of people. *Note Contributors::, for the full list. + Thanks to Patrice Dumas for the new `makeinfo' program. Thanks to +Karl Berry who continues to work to keep the Texinfo markup language +sane. + I would like to thank Brian Kernighan for invaluable assistance during the testing and debugging of `gawk', and for ongoing help and advice in clarifying numerous points about the language. We could not @@ -8546,8 +8550,9 @@ the number of which to take the square root: If those arguments are not supplied, the functions use a reasonable default value. *Note Built-in::, for full details. If arguments are omitted in calls to user-defined functions, then those arguments are -treated as local variables and initialized to the empty string (*note -User-defined::). +treated as local variables. Such local variables act like the empty +string if referenced where a string value is required, and like zero if +referenced where a numeric value is required (*note User-defined::). As an advanced feature, `gawk' provides indirect function calls, which is a way to choose the function to call at runtime, instead of @@ -13247,15 +13252,21 @@ function. PARAMETER-LIST is an optional list of the function's arguments and local variable names, separated by commas. When the function is called, the argument names are used to hold the argument values given in the -call. The local variables are initialized to the empty string. A -function cannot have two parameters with the same name, nor may it have -a parameter with the same name as the function itself. +call. - In addition, according to the POSIX standard, function parameters -cannot have the same name as one of the special built-in variables -(*note Built-in Variables::). Not all versions of `awk' enforce this + A function cannot have two parameters with the same name, nor may it +have a parameter with the same name as the function itself. In +addition, according to the POSIX standard, function parameters cannot +have the same name as one of the special built-in variables (*note +Built-in Variables::). Not all versions of `awk' enforce this restriction.) + Local variables act like the empty string if referenced where a +string value is required, and like zero if referenced where a numeric +value is required. This is the same as regular variables that have +never been assigned a value. (There is more to understand about local +variables; *note Dynamic Typing::.) + The BODY-OF-FUNCTION consists of `awk' statements. It is the most important part of the definition, because it says what the function should actually _do_. The argument names exist to give the body a way @@ -31632,7 +31643,7 @@ Index * common extensions, \x escape sequence: Escape Sequences. (line 61) * common extensions, BINMODE variable: PC Using. (line 33) * common extensions, delete to delete entire arrays: Delete. (line 39) -* common extensions, func keyword: Definition Syntax. (line 83) +* common extensions, func keyword: Definition Syntax. (line 89) * common extensions, length() applied to an array: String Functions. (line 197) * common extensions, RS as a regexp: gawk split records. (line 6) @@ -32151,7 +32162,7 @@ Index * extensions, common, BINMODE variable: PC Using. (line 33) * extensions, common, delete to delete entire arrays: Delete. (line 39) * extensions, common, fflush() function: I/O Functions. (line 43) -* extensions, common, func keyword: Definition Syntax. (line 83) +* extensions, common, func keyword: Definition Syntax. (line 89) * extensions, common, length() applied to an array: String Functions. (line 197) * extensions, common, RS as a regexp: gawk split records. (line 6) @@ -32366,7 +32377,7 @@ Index (line 6) * functions, names of <1>: Definition Syntax. (line 20) * functions, names of: Arrays. (line 18) -* functions, recursive: Definition Syntax. (line 73) +* functions, recursive: Definition Syntax. (line 79) * functions, string-translation: I18N Functions. (line 6) * functions, undefined: Pass By Value/Reference. (line 71) @@ -32378,7 +32389,7 @@ Index (line 47) * functions, user-defined, next/nextfile statements and: Next Statement. (line 45) -* G-d: Acknowledgments. (line 78) +* G-d: Acknowledgments. (line 82) * Garfinkle, Scott: Contributors. (line 34) * gawk program, dynamic profiling: Profiling. (line 179) * gawk version: Auto-set. (line 199) @@ -32704,7 +32715,7 @@ Index * Kernighan, Brian <6>: Library Functions. (line 12) * Kernighan, Brian <7>: Concatenation. (line 6) * Kernighan, Brian <8>: Getline/Pipe. (line 6) -* Kernighan, Brian <9>: Acknowledgments. (line 72) +* Kernighan, Brian <9>: Acknowledgments. (line 76) * Kernighan, Brian <10>: Conventions. (line 34) * Kernighan, Brian: History. (line 17) * kill command, dynamic profiling: Profiling. (line 188) @@ -33089,7 +33100,7 @@ Index (line 65) * portability, deleting array elements: Delete. (line 56) * portability, example programs: Library Functions. (line 42) -* portability, functions, defining: Definition Syntax. (line 99) +* portability, functions, defining: Definition Syntax. (line 105) * portability, gawk: New Ports. (line 6) * portability, gettext library and: Explaining gettext. (line 11) * portability, internationalization and: I18N Portability. (line 6) @@ -33135,7 +33146,7 @@ Index (line 40) * POSIX awk, field separators and: Fields. (line 6) * POSIX awk, FS variable and: User-modified. (line 60) -* POSIX awk, function keyword in: Definition Syntax. (line 83) +* POSIX awk, function keyword in: Definition Syntax. (line 89) * POSIX awk, functions and, gsub()/sub(): Gory Details. (line 54) * POSIX awk, functions and, length(): String Functions. (line 176) * POSIX awk, GNU long options and: Options. (line 15) @@ -33225,7 +33236,7 @@ Index * programming conventions, functions, calling: Calling Built-in. (line 10) * programming conventions, functions, writing: Definition Syntax. - (line 55) + (line 61) * programming conventions, gawk extensions: Internal File Ops. (line 45) * programming conventions, private variable names: Library Names. @@ -33295,7 +33306,7 @@ Index * records, splitting input into: Records. (line 6) * records, terminating: awk split records. (line 124) * records, treating files as: gawk split records. (line 92) -* recursive functions: Definition Syntax. (line 73) +* recursive functions: Definition Syntax. (line 79) * redirect gawk output, in debugger: Debugger Info. (line 72) * redirection of input: Getline/File. (line 6) * redirection of output: Redirection. (line 6) @@ -33385,11 +33396,11 @@ Index * Robbins, Arnold: Command Line Field Separator. (line 73) * Robbins, Bill: Getline/Pipe. (line 39) -* Robbins, Harry: Acknowledgments. (line 78) -* Robbins, Jean: Acknowledgments. (line 78) +* Robbins, Harry: Acknowledgments. (line 82) +* Robbins, Jean: Acknowledgments. (line 82) * Robbins, Miriam <1>: Passwd Functions. (line 90) * Robbins, Miriam <2>: Getline/Pipe. (line 39) -* Robbins, Miriam: Acknowledgments. (line 78) +* Robbins, Miriam: Acknowledgments. (line 82) * Rommel, Kai Uwe: Contributors. (line 42) * round to nearest integer: Numeric Functions. (line 23) * round() user-defined function: Round Function. (line 16) @@ -33465,7 +33476,7 @@ Index * set directory of message catalogs: I18N Functions. (line 12) * set watchpoint: Viewing And Changing Data. (line 67) -* shadowing of variable values: Definition Syntax. (line 61) +* shadowing of variable values: Definition Syntax. (line 67) * shell quoting, double quote: Read Terminal. (line 25) * shell quoting, rules for: Quoting. (line 6) * shells, piping commands into: Redirection. (line 142) @@ -33498,7 +33509,7 @@ Index * side effects, conditional expressions: Conditional Exp. (line 22) * side effects, decrement/increment operators: Increment Ops. (line 11) * side effects, FILENAME variable: Getline Notes. (line 19) -* side effects, function calls: Function Calls. (line 56) +* side effects, function calls: Function Calls. (line 57) * side effects, statements: Action Overview. (line 32) * sidebar, A Constant's Base Does Not Affect Its Value: Nondecimal-numbers. (line 64) @@ -33842,7 +33853,7 @@ Index * variables, names of: Arrays. (line 18) * variables, private: Library Names. (line 11) * variables, setting: Options. (line 32) -* variables, shadowing: Definition Syntax. (line 61) +* variables, shadowing: Definition Syntax. (line 67) * variables, types of: Assignment Ops. (line 40) * variables, types of, comparison expressions and: Typing and Comparison. (line 9) @@ -33954,537 +33965,537 @@ Ref: Manual History-Footnote-165250 Ref: Manual History-Footnote-265291 Node: How To Contribute65365 Node: Acknowledgments66604 -Node: Getting Started70753 -Node: Running gawk73187 -Node: One-shot74377 -Node: Read Terminal75602 -Ref: Read Terminal-Footnote-177252 -Ref: Read Terminal-Footnote-277528 -Node: Long77699 -Node: Executable Scripts79075 -Ref: Executable Scripts-Footnote-180908 -Ref: Executable Scripts-Footnote-281010 -Node: Comments81557 -Node: Quoting84030 -Node: DOS Quoting89346 -Node: Sample Data Files90021 -Node: Very Simple92536 -Node: Two Rules97174 -Node: More Complex99068 -Ref: More Complex-Footnote-1102000 -Node: Statements/Lines102085 -Ref: Statements/Lines-Footnote-1106540 -Node: Other Features106805 -Node: When107733 -Node: Intro Summary109903 -Node: Invoking Gawk110669 -Node: Command Line112184 -Node: Options112975 -Ref: Options-Footnote-1128804 -Node: Other Arguments128829 -Node: Naming Standard Input131491 -Node: Environment Variables132585 -Node: AWKPATH Variable133143 -Ref: AWKPATH Variable-Footnote-1136015 -Ref: AWKPATH Variable-Footnote-2136060 -Node: AWKLIBPATH Variable136320 -Node: Other Environment Variables137079 -Node: Exit Status140734 -Node: Include Files141409 -Node: Loading Shared Libraries144987 -Node: Obsolete146371 -Node: Undocumented147068 -Node: Invoking Summary147335 -Node: Regexp148915 -Node: Regexp Usage150365 -Node: Escape Sequences152398 -Node: Regexp Operators158065 -Ref: Regexp Operators-Footnote-1165545 -Ref: Regexp Operators-Footnote-2165692 -Node: Bracket Expressions165790 -Ref: table-char-classes167680 -Node: GNU Regexp Operators170203 -Node: Case-sensitivity173926 -Ref: Case-sensitivity-Footnote-1176818 -Ref: Case-sensitivity-Footnote-2177053 -Node: Leftmost Longest177161 -Node: Computed Regexps178362 -Node: Regexp Summary181734 -Node: Reading Files183205 -Node: Records185297 -Node: awk split records186040 -Node: gawk split records190898 -Ref: gawk split records-Footnote-1195419 -Node: Fields195456 -Ref: Fields-Footnote-1198420 -Node: Nonconstant Fields198506 -Ref: Nonconstant Fields-Footnote-1200736 -Node: Changing Fields200938 -Node: Field Separators206892 -Node: Default Field Splitting209594 -Node: Regexp Field Splitting210711 -Node: Single Character Fields214052 -Node: Command Line Field Separator215111 -Node: Full Line Fields218453 -Ref: Full Line Fields-Footnote-1218961 -Node: Field Splitting Summary219007 -Ref: Field Splitting Summary-Footnote-1222106 -Node: Constant Size222207 -Node: Splitting By Content226814 -Ref: Splitting By Content-Footnote-1230564 -Node: Multiple Line230604 -Ref: Multiple Line-Footnote-1236460 -Node: Getline236639 -Node: Plain Getline238855 -Node: Getline/Variable240950 -Node: Getline/File242097 -Node: Getline/Variable/File243481 -Ref: Getline/Variable/File-Footnote-1245080 -Node: Getline/Pipe245167 -Node: Getline/Variable/Pipe247866 -Node: Getline/Coprocess248973 -Node: Getline/Variable/Coprocess250225 -Node: Getline Notes250962 -Node: Getline Summary253766 -Ref: table-getline-variants254174 -Node: Read Timeout255086 -Ref: Read Timeout-Footnote-1258913 -Node: Command line directories258971 -Node: Input Summary259875 -Node: Input Exercises263012 -Node: Printing263745 -Node: Print265467 -Node: Print Examples266808 -Node: Output Separators269587 -Node: OFMT271603 -Node: Printf272961 -Node: Basic Printf273867 -Node: Control Letters275406 -Node: Format Modifiers279258 -Node: Printf Examples285285 -Node: Redirection287749 -Node: Special Files294721 -Node: Special FD295252 -Ref: Special FD-Footnote-1298876 -Node: Special Network298950 -Node: Special Caveats299800 -Node: Close Files And Pipes300596 -Ref: Close Files And Pipes-Footnote-1307757 -Ref: Close Files And Pipes-Footnote-2307905 -Node: Output Summary308055 -Node: Output exercises309052 -Node: Expressions309732 -Node: Values310917 -Node: Constants311593 -Node: Scalar Constants312273 -Ref: Scalar Constants-Footnote-1313132 -Node: Nondecimal-numbers313382 -Node: Regexp Constants316382 -Node: Using Constant Regexps316857 -Node: Variables319927 -Node: Using Variables320582 -Node: Assignment Options322306 -Node: Conversion324181 -Node: Strings And Numbers324705 -Ref: Strings And Numbers-Footnote-1327767 -Node: Locale influences conversions327876 -Ref: table-locale-affects330593 -Node: All Operators331181 -Node: Arithmetic Ops331811 -Node: Concatenation334316 -Ref: Concatenation-Footnote-1337112 -Node: Assignment Ops337232 -Ref: table-assign-ops342215 -Node: Increment Ops343532 -Node: Truth Values and Conditions346970 -Node: Truth Values348053 -Node: Typing and Comparison349102 -Node: Variable Typing349895 -Ref: Variable Typing-Footnote-1353795 -Node: Comparison Operators353917 -Ref: table-relational-ops354327 -Node: POSIX String Comparison357877 -Ref: POSIX String Comparison-Footnote-1358961 -Node: Boolean Ops359099 -Ref: Boolean Ops-Footnote-1363169 -Node: Conditional Exp363260 -Node: Function Calls364987 -Node: Precedence368745 -Node: Locales372414 -Node: Expressions Summary374045 -Node: Patterns and Actions376586 -Node: Pattern Overview377702 -Node: Regexp Patterns379379 -Node: Expression Patterns379922 -Node: Ranges383703 -Node: BEGIN/END386809 -Node: Using BEGIN/END387571 -Ref: Using BEGIN/END-Footnote-1390307 -Node: I/O And BEGIN/END390413 -Node: BEGINFILE/ENDFILE392698 -Node: Empty395629 -Node: Using Shell Variables395946 -Node: Action Overview398229 -Node: Statements400556 -Node: If Statement402404 -Node: While Statement403902 -Node: Do Statement405946 -Node: For Statement407102 -Node: Switch Statement410254 -Node: Break Statement412357 -Node: Continue Statement414412 -Node: Next Statement416205 -Node: Nextfile Statement418595 -Node: Exit Statement421250 -Node: Built-in Variables423654 -Node: User-modified424781 -Ref: User-modified-Footnote-1432470 -Node: Auto-set432532 -Ref: Auto-set-Footnote-1445114 -Ref: Auto-set-Footnote-2445319 -Node: ARGC and ARGV445375 -Node: Pattern Action Summary449229 -Node: Arrays451452 -Node: Array Basics453001 -Node: Array Intro453827 -Ref: figure-array-elements455800 -Node: Reference to Elements458207 -Node: Assigning Elements460480 -Node: Array Example460971 -Node: Scanning an Array462703 -Node: Controlling Scanning465718 -Ref: Controlling Scanning-Footnote-1470891 -Node: Delete471207 -Ref: Delete-Footnote-1473972 -Node: Numeric Array Subscripts474029 -Node: Uninitialized Subscripts476212 -Node: Multidimensional477837 -Node: Multiscanning480930 -Node: Arrays of Arrays482519 -Node: Arrays Summary487182 -Node: Functions489287 -Node: Built-in490160 -Node: Calling Built-in491238 -Node: Numeric Functions493226 -Ref: Numeric Functions-Footnote-1497060 -Ref: Numeric Functions-Footnote-2497417 -Ref: Numeric Functions-Footnote-3497465 -Node: String Functions497734 -Ref: String Functions-Footnote-1520745 -Ref: String Functions-Footnote-2520874 -Ref: String Functions-Footnote-3521122 -Node: Gory Details521209 -Ref: table-sub-escapes522878 -Ref: table-sub-posix-92524232 -Ref: table-sub-proposed525583 -Ref: table-posix-sub526937 -Ref: table-gensub-escapes528482 -Ref: Gory Details-Footnote-1529658 -Ref: Gory Details-Footnote-2529709 -Node: I/O Functions529860 -Ref: I/O Functions-Footnote-1536983 -Node: Time Functions537130 -Ref: Time Functions-Footnote-1547594 -Ref: Time Functions-Footnote-2547662 -Ref: Time Functions-Footnote-3547820 -Ref: Time Functions-Footnote-4547931 -Ref: Time Functions-Footnote-5548043 -Ref: Time Functions-Footnote-6548270 -Node: Bitwise Functions548536 -Ref: table-bitwise-ops549098 -Ref: Bitwise Functions-Footnote-1553343 -Node: Type Functions553527 -Node: I18N Functions554669 -Node: User-defined556314 -Node: Definition Syntax557118 -Ref: Definition Syntax-Footnote-1562043 -Node: Function Example562112 -Ref: Function Example-Footnote-1564756 -Node: Function Caveats564778 -Node: Calling A Function565296 -Node: Variable Scope566251 -Node: Pass By Value/Reference569239 -Node: Return Statement572747 -Node: Dynamic Typing575731 -Node: Indirect Calls576660 -Node: Functions Summary586373 -Node: Library Functions588912 -Ref: Library Functions-Footnote-1592530 -Ref: Library Functions-Footnote-2592673 -Node: Library Names592844 -Ref: Library Names-Footnote-1596317 -Ref: Library Names-Footnote-2596537 -Node: General Functions596623 -Node: Strtonum Function597651 -Node: Assert Function600431 -Node: Round Function603757 -Node: Cliff Random Function605298 -Node: Ordinal Functions606314 -Ref: Ordinal Functions-Footnote-1609391 -Ref: Ordinal Functions-Footnote-2609643 -Node: Join Function609854 -Ref: Join Function-Footnote-1611625 -Node: Getlocaltime Function611825 -Node: Readfile Function615561 -Node: Data File Management617400 -Node: Filetrans Function618032 -Node: Rewind Function622101 -Node: File Checking623488 -Ref: File Checking-Footnote-1624620 -Node: Empty Files624821 -Node: Ignoring Assigns626800 -Node: Getopt Function628354 -Ref: Getopt Function-Footnote-1639657 -Node: Passwd Functions639860 -Ref: Passwd Functions-Footnote-1648839 -Node: Group Functions648927 -Ref: Group Functions-Footnote-1656868 -Node: Walking Arrays657081 -Node: Library Functions Summary658684 -Node: Library exercises660072 -Node: Sample Programs661352 -Node: Running Examples662122 -Node: Clones662850 -Node: Cut Program664074 -Node: Egrep Program673942 -Ref: Egrep Program-Footnote-1681913 -Node: Id Program682023 -Node: Split Program685687 -Ref: Split Program-Footnote-1689225 -Node: Tee Program689353 -Node: Uniq Program692160 -Node: Wc Program699590 -Ref: Wc Program-Footnote-1703855 -Node: Miscellaneous Programs703947 -Node: Dupword Program705160 -Node: Alarm Program707191 -Node: Translate Program712005 -Ref: Translate Program-Footnote-1716396 -Ref: Translate Program-Footnote-2716666 -Node: Labels Program716800 -Ref: Labels Program-Footnote-1720171 -Node: Word Sorting720255 -Node: History Sorting724298 -Node: Extract Program726134 -Node: Simple Sed733670 -Node: Igawk Program736732 -Ref: Igawk Program-Footnote-1751043 -Ref: Igawk Program-Footnote-2751244 -Node: Anagram Program751382 -Node: Signature Program754450 -Node: Programs Summary755697 -Node: Programs Exercises756912 -Node: Advanced Features760563 -Node: Nondecimal Data762511 -Node: Array Sorting764088 -Node: Controlling Array Traversal764785 -Node: Array Sorting Functions773065 -Ref: Array Sorting Functions-Footnote-1776972 -Node: Two-way I/O777166 -Ref: Two-way I/O-Footnote-1782682 -Node: TCP/IP Networking782764 -Node: Profiling785608 -Node: Advanced Features Summary793150 -Node: Internationalization795014 -Node: I18N and L10N796494 -Node: Explaining gettext797180 -Ref: Explaining gettext-Footnote-1802320 -Ref: Explaining gettext-Footnote-2802504 -Node: Programmer i18n802669 -Node: Translator i18n806894 -Node: String Extraction807688 -Ref: String Extraction-Footnote-1808649 -Node: Printf Ordering808735 -Ref: Printf Ordering-Footnote-1811517 -Node: I18N Portability811581 -Ref: I18N Portability-Footnote-1814030 -Node: I18N Example814093 -Ref: I18N Example-Footnote-1816815 -Node: Gawk I18N816887 -Node: I18N Summary817525 -Node: Debugger818864 -Node: Debugging819886 -Node: Debugging Concepts820327 -Node: Debugging Terms822183 -Node: Awk Debugging824780 -Node: Sample Debugging Session825672 -Node: Debugger Invocation826192 -Node: Finding The Bug827525 -Node: List of Debugger Commands834007 -Node: Breakpoint Control835339 -Node: Debugger Execution Control839003 -Node: Viewing And Changing Data842363 -Node: Execution Stack845721 -Node: Debugger Info847234 -Node: Miscellaneous Debugger Commands851228 -Node: Readline Support856412 -Node: Limitations857304 -Node: Debugging Summary859578 -Node: Arbitrary Precision Arithmetic860742 -Node: Computer Arithmetic862071 -Ref: Computer Arithmetic-Footnote-1866458 -Node: Math Definitions866515 -Ref: table-ieee-formats869399 -Node: MPFR features869903 -Node: FP Math Caution871545 -Ref: FP Math Caution-Footnote-1872586 -Node: Inexactness of computations872955 -Node: Inexact representation873903 -Node: Comparing FP Values875258 -Node: Errors accumulate876222 -Node: Getting Accuracy877655 -Node: Try To Round880314 -Node: Setting precision881213 -Ref: table-predefined-precision-strings881895 -Node: Setting the rounding mode883688 -Ref: table-gawk-rounding-modes884052 -Ref: Setting the rounding mode-Footnote-1887506 -Node: Arbitrary Precision Integers887685 -Ref: Arbitrary Precision Integers-Footnote-1890688 -Node: POSIX Floating Point Problems890837 -Ref: POSIX Floating Point Problems-Footnote-1894713 -Node: Floating point summary894751 -Node: Dynamic Extensions896968 -Node: Extension Intro898520 -Node: Plugin License899785 -Node: Extension Mechanism Outline900470 -Ref: figure-load-extension900894 -Ref: figure-load-new-function902379 -Ref: figure-call-new-function903381 -Node: Extension API Description905365 -Node: Extension API Functions Introduction906815 -Node: General Data Types911680 -Ref: General Data Types-Footnote-1917373 -Node: Requesting Values917672 -Ref: table-value-types-returned918409 -Node: Memory Allocation Functions919367 -Ref: Memory Allocation Functions-Footnote-1922114 -Node: Constructor Functions922210 -Node: Registration Functions923968 -Node: Extension Functions924653 -Node: Exit Callback Functions926955 -Node: Extension Version String928204 -Node: Input Parsers928854 -Node: Output Wrappers938657 -Node: Two-way processors943173 -Node: Printing Messages945377 -Ref: Printing Messages-Footnote-1946454 -Node: Updating `ERRNO'946606 -Node: Accessing Parameters947345 -Node: Symbol Table Access948575 -Node: Symbol table by name949089 -Node: Symbol table by cookie951065 -Ref: Symbol table by cookie-Footnote-1955198 -Node: Cached values955261 -Ref: Cached values-Footnote-1958765 -Node: Array Manipulation958856 -Ref: Array Manipulation-Footnote-1959954 -Node: Array Data Types959993 -Ref: Array Data Types-Footnote-1962696 -Node: Array Functions962788 -Node: Flattening Arrays966662 -Node: Creating Arrays973514 -Node: Extension API Variables978245 -Node: Extension Versioning978881 -Node: Extension API Informational Variables980782 -Node: Extension API Boilerplate981868 -Node: Finding Extensions985672 -Node: Extension Example986232 -Node: Internal File Description986962 -Node: Internal File Ops991053 -Ref: Internal File Ops-Footnote-11002485 -Node: Using Internal File Ops1002625 -Ref: Using Internal File Ops-Footnote-11004972 -Node: Extension Samples1005240 -Node: Extension Sample File Functions1006764 -Node: Extension Sample Fnmatch1014332 -Node: Extension Sample Fork1015813 -Node: Extension Sample Inplace1017026 -Node: Extension Sample Ord1018701 -Node: Extension Sample Readdir1019537 -Ref: table-readdir-file-types1020393 -Node: Extension Sample Revout1021192 -Node: Extension Sample Rev2way1021783 -Node: Extension Sample Read write array1022524 -Node: Extension Sample Readfile1024403 -Node: Extension Sample API Tests1025503 -Node: Extension Sample Time1026028 -Node: gawkextlib1027343 -Node: Extension summary1030156 -Node: Extension Exercises1033849 -Node: Language History1034571 -Node: V7/SVR3.11036214 -Node: SVR41038534 -Node: POSIX1039976 -Node: BTL1041362 -Node: POSIX/GNU1042096 -Node: Feature History1047695 -Node: Common Extensions1060825 -Node: Ranges and Locales1062137 -Ref: Ranges and Locales-Footnote-11066754 -Ref: Ranges and Locales-Footnote-21066781 -Ref: Ranges and Locales-Footnote-31067015 -Node: Contributors1067236 -Node: History summary1072698 -Node: Installation1074067 -Node: Gawk Distribution1075018 -Node: Getting1075502 -Node: Extracting1076326 -Node: Distribution contents1077968 -Node: Unix Installation1083685 -Node: Quick Installation1084302 -Node: Additional Configuration Options1086744 -Node: Configuration Philosophy1088482 -Node: Non-Unix Installation1090833 -Node: PC Installation1091291 -Node: PC Binary Installation1092602 -Node: PC Compiling1094450 -Ref: PC Compiling-Footnote-11097449 -Node: PC Testing1097554 -Node: PC Using1098730 -Node: Cygwin1102888 -Node: MSYS1103697 -Node: VMS Installation1104211 -Node: VMS Compilation1105007 -Ref: VMS Compilation-Footnote-11106229 -Node: VMS Dynamic Extensions1106287 -Node: VMS Installation Details1107660 -Node: VMS Running1109912 -Node: VMS GNV1112746 -Node: VMS Old Gawk1113469 -Node: Bugs1113939 -Node: Other Versions1117943 -Node: Installation summary1124198 -Node: Notes1125254 -Node: Compatibility Mode1126119 -Node: Additions1126901 -Node: Accessing The Source1127826 -Node: Adding Code1129262 -Node: New Ports1135440 -Node: Derived Files1139921 -Ref: Derived Files-Footnote-11145002 -Ref: Derived Files-Footnote-21145036 -Ref: Derived Files-Footnote-31145632 -Node: Future Extensions1145746 -Node: Implementation Limitations1146352 -Node: Extension Design1147600 -Node: Old Extension Problems1148754 -Ref: Old Extension Problems-Footnote-11150271 -Node: Extension New Mechanism Goals1150328 -Ref: Extension New Mechanism Goals-Footnote-11153688 -Node: Extension Other Design Decisions1153877 -Node: Extension Future Growth1155983 -Node: Old Extension Mechanism1156819 -Node: Notes summary1158581 -Node: Basic Concepts1159767 -Node: Basic High Level1160448 -Ref: figure-general-flow1160720 -Ref: figure-process-flow1161319 -Ref: Basic High Level-Footnote-11164548 -Node: Basic Data Typing1164733 -Node: Glossary1168061 -Node: Copying1193213 -Node: GNU Free Documentation License1230769 -Node: Index1255905 +Node: Getting Started70900 +Node: Running gawk73334 +Node: One-shot74524 +Node: Read Terminal75749 +Ref: Read Terminal-Footnote-177399 +Ref: Read Terminal-Footnote-277675 +Node: Long77846 +Node: Executable Scripts79222 +Ref: Executable Scripts-Footnote-181055 +Ref: Executable Scripts-Footnote-281157 +Node: Comments81704 +Node: Quoting84177 +Node: DOS Quoting89493 +Node: Sample Data Files90168 +Node: Very Simple92683 +Node: Two Rules97321 +Node: More Complex99215 +Ref: More Complex-Footnote-1102147 +Node: Statements/Lines102232 +Ref: Statements/Lines-Footnote-1106687 +Node: Other Features106952 +Node: When107880 +Node: Intro Summary110050 +Node: Invoking Gawk110816 +Node: Command Line112331 +Node: Options113122 +Ref: Options-Footnote-1128951 +Node: Other Arguments128976 +Node: Naming Standard Input131638 +Node: Environment Variables132732 +Node: AWKPATH Variable133290 +Ref: AWKPATH Variable-Footnote-1136162 +Ref: AWKPATH Variable-Footnote-2136207 +Node: AWKLIBPATH Variable136467 +Node: Other Environment Variables137226 +Node: Exit Status140881 +Node: Include Files141556 +Node: Loading Shared Libraries145134 +Node: Obsolete146518 +Node: Undocumented147215 +Node: Invoking Summary147482 +Node: Regexp149062 +Node: Regexp Usage150512 +Node: Escape Sequences152545 +Node: Regexp Operators158212 +Ref: Regexp Operators-Footnote-1165692 +Ref: Regexp Operators-Footnote-2165839 +Node: Bracket Expressions165937 +Ref: table-char-classes167827 +Node: GNU Regexp Operators170350 +Node: Case-sensitivity174073 +Ref: Case-sensitivity-Footnote-1176965 +Ref: Case-sensitivity-Footnote-2177200 +Node: Leftmost Longest177308 +Node: Computed Regexps178509 +Node: Regexp Summary181881 +Node: Reading Files183352 +Node: Records185444 +Node: awk split records186187 +Node: gawk split records191045 +Ref: gawk split records-Footnote-1195566 +Node: Fields195603 +Ref: Fields-Footnote-1198567 +Node: Nonconstant Fields198653 +Ref: Nonconstant Fields-Footnote-1200883 +Node: Changing Fields201085 +Node: Field Separators207039 +Node: Default Field Splitting209741 +Node: Regexp Field Splitting210858 +Node: Single Character Fields214199 +Node: Command Line Field Separator215258 +Node: Full Line Fields218600 +Ref: Full Line Fields-Footnote-1219108 +Node: Field Splitting Summary219154 +Ref: Field Splitting Summary-Footnote-1222253 +Node: Constant Size222354 +Node: Splitting By Content226961 +Ref: Splitting By Content-Footnote-1230711 +Node: Multiple Line230751 +Ref: Multiple Line-Footnote-1236607 +Node: Getline236786 +Node: Plain Getline239002 +Node: Getline/Variable241097 +Node: Getline/File242244 +Node: Getline/Variable/File243628 +Ref: Getline/Variable/File-Footnote-1245227 +Node: Getline/Pipe245314 +Node: Getline/Variable/Pipe248013 +Node: Getline/Coprocess249120 +Node: Getline/Variable/Coprocess250372 +Node: Getline Notes251109 +Node: Getline Summary253913 +Ref: table-getline-variants254321 +Node: Read Timeout255233 +Ref: Read Timeout-Footnote-1259060 +Node: Command line directories259118 +Node: Input Summary260022 +Node: Input Exercises263159 +Node: Printing263892 +Node: Print265614 +Node: Print Examples266955 +Node: Output Separators269734 +Node: OFMT271750 +Node: Printf273108 +Node: Basic Printf274014 +Node: Control Letters275553 +Node: Format Modifiers279405 +Node: Printf Examples285432 +Node: Redirection287896 +Node: Special Files294868 +Node: Special FD295399 +Ref: Special FD-Footnote-1299023 +Node: Special Network299097 +Node: Special Caveats299947 +Node: Close Files And Pipes300743 +Ref: Close Files And Pipes-Footnote-1307904 +Ref: Close Files And Pipes-Footnote-2308052 +Node: Output Summary308202 +Node: Output exercises309199 +Node: Expressions309879 +Node: Values311064 +Node: Constants311740 +Node: Scalar Constants312420 +Ref: Scalar Constants-Footnote-1313279 +Node: Nondecimal-numbers313529 +Node: Regexp Constants316529 +Node: Using Constant Regexps317004 +Node: Variables320074 +Node: Using Variables320729 +Node: Assignment Options322453 +Node: Conversion324328 +Node: Strings And Numbers324852 +Ref: Strings And Numbers-Footnote-1327914 +Node: Locale influences conversions328023 +Ref: table-locale-affects330740 +Node: All Operators331328 +Node: Arithmetic Ops331958 +Node: Concatenation334463 +Ref: Concatenation-Footnote-1337259 +Node: Assignment Ops337379 +Ref: table-assign-ops342362 +Node: Increment Ops343679 +Node: Truth Values and Conditions347117 +Node: Truth Values348200 +Node: Typing and Comparison349249 +Node: Variable Typing350042 +Ref: Variable Typing-Footnote-1353942 +Node: Comparison Operators354064 +Ref: table-relational-ops354474 +Node: POSIX String Comparison358024 +Ref: POSIX String Comparison-Footnote-1359108 +Node: Boolean Ops359246 +Ref: Boolean Ops-Footnote-1363316 +Node: Conditional Exp363407 +Node: Function Calls365134 +Node: Precedence369014 +Node: Locales372683 +Node: Expressions Summary374314 +Node: Patterns and Actions376855 +Node: Pattern Overview377971 +Node: Regexp Patterns379648 +Node: Expression Patterns380191 +Node: Ranges383972 +Node: BEGIN/END387078 +Node: Using BEGIN/END387840 +Ref: Using BEGIN/END-Footnote-1390576 +Node: I/O And BEGIN/END390682 +Node: BEGINFILE/ENDFILE392967 +Node: Empty395898 +Node: Using Shell Variables396215 +Node: Action Overview398498 +Node: Statements400825 +Node: If Statement402673 +Node: While Statement404171 +Node: Do Statement406215 +Node: For Statement407371 +Node: Switch Statement410523 +Node: Break Statement412626 +Node: Continue Statement414681 +Node: Next Statement416474 +Node: Nextfile Statement418864 +Node: Exit Statement421519 +Node: Built-in Variables423923 +Node: User-modified425050 +Ref: User-modified-Footnote-1432739 +Node: Auto-set432801 +Ref: Auto-set-Footnote-1445383 +Ref: Auto-set-Footnote-2445588 +Node: ARGC and ARGV445644 +Node: Pattern Action Summary449498 +Node: Arrays451721 +Node: Array Basics453270 +Node: Array Intro454096 +Ref: figure-array-elements456069 +Node: Reference to Elements458476 +Node: Assigning Elements460749 +Node: Array Example461240 +Node: Scanning an Array462972 +Node: Controlling Scanning465987 +Ref: Controlling Scanning-Footnote-1471160 +Node: Delete471476 +Ref: Delete-Footnote-1474241 +Node: Numeric Array Subscripts474298 +Node: Uninitialized Subscripts476481 +Node: Multidimensional478106 +Node: Multiscanning481199 +Node: Arrays of Arrays482788 +Node: Arrays Summary487451 +Node: Functions489556 +Node: Built-in490429 +Node: Calling Built-in491507 +Node: Numeric Functions493495 +Ref: Numeric Functions-Footnote-1497329 +Ref: Numeric Functions-Footnote-2497686 +Ref: Numeric Functions-Footnote-3497734 +Node: String Functions498003 +Ref: String Functions-Footnote-1521014 +Ref: String Functions-Footnote-2521143 +Ref: String Functions-Footnote-3521391 +Node: Gory Details521478 +Ref: table-sub-escapes523147 +Ref: table-sub-posix-92524501 +Ref: table-sub-proposed525852 +Ref: table-posix-sub527206 +Ref: table-gensub-escapes528751 +Ref: Gory Details-Footnote-1529927 +Ref: Gory Details-Footnote-2529978 +Node: I/O Functions530129 +Ref: I/O Functions-Footnote-1537252 +Node: Time Functions537399 +Ref: Time Functions-Footnote-1547863 +Ref: Time Functions-Footnote-2547931 +Ref: Time Functions-Footnote-3548089 +Ref: Time Functions-Footnote-4548200 +Ref: Time Functions-Footnote-5548312 +Ref: Time Functions-Footnote-6548539 +Node: Bitwise Functions548805 +Ref: table-bitwise-ops549367 +Ref: Bitwise Functions-Footnote-1553612 +Node: Type Functions553796 +Node: I18N Functions554938 +Node: User-defined556583 +Node: Definition Syntax557387 +Ref: Definition Syntax-Footnote-1562566 +Node: Function Example562635 +Ref: Function Example-Footnote-1565279 +Node: Function Caveats565301 +Node: Calling A Function565819 +Node: Variable Scope566774 +Node: Pass By Value/Reference569762 +Node: Return Statement573270 +Node: Dynamic Typing576254 +Node: Indirect Calls577183 +Node: Functions Summary586896 +Node: Library Functions589435 +Ref: Library Functions-Footnote-1593053 +Ref: Library Functions-Footnote-2593196 +Node: Library Names593367 +Ref: Library Names-Footnote-1596840 +Ref: Library Names-Footnote-2597060 +Node: General Functions597146 +Node: Strtonum Function598174 +Node: Assert Function600954 +Node: Round Function604280 +Node: Cliff Random Function605821 +Node: Ordinal Functions606837 +Ref: Ordinal Functions-Footnote-1609914 +Ref: Ordinal Functions-Footnote-2610166 +Node: Join Function610377 +Ref: Join Function-Footnote-1612148 +Node: Getlocaltime Function612348 +Node: Readfile Function616084 +Node: Data File Management617923 +Node: Filetrans Function618555 +Node: Rewind Function622624 +Node: File Checking624011 +Ref: File Checking-Footnote-1625143 +Node: Empty Files625344 +Node: Ignoring Assigns627323 +Node: Getopt Function628877 +Ref: Getopt Function-Footnote-1640180 +Node: Passwd Functions640383 +Ref: Passwd Functions-Footnote-1649362 +Node: Group Functions649450 +Ref: Group Functions-Footnote-1657391 +Node: Walking Arrays657604 +Node: Library Functions Summary659207 +Node: Library exercises660595 +Node: Sample Programs661875 +Node: Running Examples662645 +Node: Clones663373 +Node: Cut Program664597 +Node: Egrep Program674465 +Ref: Egrep Program-Footnote-1682436 +Node: Id Program682546 +Node: Split Program686210 +Ref: Split Program-Footnote-1689748 +Node: Tee Program689876 +Node: Uniq Program692683 +Node: Wc Program700113 +Ref: Wc Program-Footnote-1704378 +Node: Miscellaneous Programs704470 +Node: Dupword Program705683 +Node: Alarm Program707714 +Node: Translate Program712528 +Ref: Translate Program-Footnote-1716919 +Ref: Translate Program-Footnote-2717189 +Node: Labels Program717323 +Ref: Labels Program-Footnote-1720694 +Node: Word Sorting720778 +Node: History Sorting724821 +Node: Extract Program726657 +Node: Simple Sed734193 +Node: Igawk Program737255 +Ref: Igawk Program-Footnote-1751566 +Ref: Igawk Program-Footnote-2751767 +Node: Anagram Program751905 +Node: Signature Program754973 +Node: Programs Summary756220 +Node: Programs Exercises757435 +Node: Advanced Features761086 +Node: Nondecimal Data763034 +Node: Array Sorting764611 +Node: Controlling Array Traversal765308 +Node: Array Sorting Functions773588 +Ref: Array Sorting Functions-Footnote-1777495 +Node: Two-way I/O777689 +Ref: Two-way I/O-Footnote-1783205 +Node: TCP/IP Networking783287 +Node: Profiling786131 +Node: Advanced Features Summary793673 +Node: Internationalization795537 +Node: I18N and L10N797017 +Node: Explaining gettext797703 +Ref: Explaining gettext-Footnote-1802843 +Ref: Explaining gettext-Footnote-2803027 +Node: Programmer i18n803192 +Node: Translator i18n807417 +Node: String Extraction808211 +Ref: String Extraction-Footnote-1809172 +Node: Printf Ordering809258 +Ref: Printf Ordering-Footnote-1812040 +Node: I18N Portability812104 +Ref: I18N Portability-Footnote-1814553 +Node: I18N Example814616 +Ref: I18N Example-Footnote-1817338 +Node: Gawk I18N817410 +Node: I18N Summary818048 +Node: Debugger819387 +Node: Debugging820409 +Node: Debugging Concepts820850 +Node: Debugging Terms822706 +Node: Awk Debugging825303 +Node: Sample Debugging Session826195 +Node: Debugger Invocation826715 +Node: Finding The Bug828048 +Node: List of Debugger Commands834530 +Node: Breakpoint Control835862 +Node: Debugger Execution Control839526 +Node: Viewing And Changing Data842886 +Node: Execution Stack846244 +Node: Debugger Info847757 +Node: Miscellaneous Debugger Commands851751 +Node: Readline Support856935 +Node: Limitations857827 +Node: Debugging Summary860101 +Node: Arbitrary Precision Arithmetic861265 +Node: Computer Arithmetic862594 +Ref: Computer Arithmetic-Footnote-1866981 +Node: Math Definitions867038 +Ref: table-ieee-formats869922 +Node: MPFR features870426 +Node: FP Math Caution872068 +Ref: FP Math Caution-Footnote-1873109 +Node: Inexactness of computations873478 +Node: Inexact representation874426 +Node: Comparing FP Values875781 +Node: Errors accumulate876745 +Node: Getting Accuracy878178 +Node: Try To Round880837 +Node: Setting precision881736 +Ref: table-predefined-precision-strings882418 +Node: Setting the rounding mode884211 +Ref: table-gawk-rounding-modes884575 +Ref: Setting the rounding mode-Footnote-1888029 +Node: Arbitrary Precision Integers888208 +Ref: Arbitrary Precision Integers-Footnote-1891211 +Node: POSIX Floating Point Problems891360 +Ref: POSIX Floating Point Problems-Footnote-1895236 +Node: Floating point summary895274 +Node: Dynamic Extensions897491 +Node: Extension Intro899043 +Node: Plugin License900308 +Node: Extension Mechanism Outline900993 +Ref: figure-load-extension901417 +Ref: figure-load-new-function902902 +Ref: figure-call-new-function903904 +Node: Extension API Description905888 +Node: Extension API Functions Introduction907338 +Node: General Data Types912203 +Ref: General Data Types-Footnote-1917896 +Node: Requesting Values918195 +Ref: table-value-types-returned918932 +Node: Memory Allocation Functions919890 +Ref: Memory Allocation Functions-Footnote-1922637 +Node: Constructor Functions922733 +Node: Registration Functions924491 +Node: Extension Functions925176 +Node: Exit Callback Functions927478 +Node: Extension Version String928727 +Node: Input Parsers929377 +Node: Output Wrappers939180 +Node: Two-way processors943696 +Node: Printing Messages945900 +Ref: Printing Messages-Footnote-1946977 +Node: Updating `ERRNO'947129 +Node: Accessing Parameters947868 +Node: Symbol Table Access949098 +Node: Symbol table by name949612 +Node: Symbol table by cookie951588 +Ref: Symbol table by cookie-Footnote-1955721 +Node: Cached values955784 +Ref: Cached values-Footnote-1959288 +Node: Array Manipulation959379 +Ref: Array Manipulation-Footnote-1960477 +Node: Array Data Types960516 +Ref: Array Data Types-Footnote-1963219 +Node: Array Functions963311 +Node: Flattening Arrays967185 +Node: Creating Arrays974037 +Node: Extension API Variables978768 +Node: Extension Versioning979404 +Node: Extension API Informational Variables981305 +Node: Extension API Boilerplate982391 +Node: Finding Extensions986195 +Node: Extension Example986755 +Node: Internal File Description987485 +Node: Internal File Ops991576 +Ref: Internal File Ops-Footnote-11003008 +Node: Using Internal File Ops1003148 +Ref: Using Internal File Ops-Footnote-11005495 +Node: Extension Samples1005763 +Node: Extension Sample File Functions1007287 +Node: Extension Sample Fnmatch1014855 +Node: Extension Sample Fork1016336 +Node: Extension Sample Inplace1017549 +Node: Extension Sample Ord1019224 +Node: Extension Sample Readdir1020060 +Ref: table-readdir-file-types1020916 +Node: Extension Sample Revout1021715 +Node: Extension Sample Rev2way1022306 +Node: Extension Sample Read write array1023047 +Node: Extension Sample Readfile1024926 +Node: Extension Sample API Tests1026026 +Node: Extension Sample Time1026551 +Node: gawkextlib1027866 +Node: Extension summary1030679 +Node: Extension Exercises1034372 +Node: Language History1035094 +Node: V7/SVR3.11036737 +Node: SVR41039057 +Node: POSIX1040499 +Node: BTL1041885 +Node: POSIX/GNU1042619 +Node: Feature History1048218 +Node: Common Extensions1061348 +Node: Ranges and Locales1062660 +Ref: Ranges and Locales-Footnote-11067277 +Ref: Ranges and Locales-Footnote-21067304 +Ref: Ranges and Locales-Footnote-31067538 +Node: Contributors1067759 +Node: History summary1073221 +Node: Installation1074590 +Node: Gawk Distribution1075541 +Node: Getting1076025 +Node: Extracting1076849 +Node: Distribution contents1078491 +Node: Unix Installation1084208 +Node: Quick Installation1084825 +Node: Additional Configuration Options1087267 +Node: Configuration Philosophy1089005 +Node: Non-Unix Installation1091356 +Node: PC Installation1091814 +Node: PC Binary Installation1093125 +Node: PC Compiling1094973 +Ref: PC Compiling-Footnote-11097972 +Node: PC Testing1098077 +Node: PC Using1099253 +Node: Cygwin1103411 +Node: MSYS1104220 +Node: VMS Installation1104734 +Node: VMS Compilation1105530 +Ref: VMS Compilation-Footnote-11106752 +Node: VMS Dynamic Extensions1106810 +Node: VMS Installation Details1108183 +Node: VMS Running1110435 +Node: VMS GNV1113269 +Node: VMS Old Gawk1113992 +Node: Bugs1114462 +Node: Other Versions1118466 +Node: Installation summary1124721 +Node: Notes1125777 +Node: Compatibility Mode1126642 +Node: Additions1127424 +Node: Accessing The Source1128349 +Node: Adding Code1129785 +Node: New Ports1135963 +Node: Derived Files1140444 +Ref: Derived Files-Footnote-11145525 +Ref: Derived Files-Footnote-21145559 +Ref: Derived Files-Footnote-31146155 +Node: Future Extensions1146269 +Node: Implementation Limitations1146875 +Node: Extension Design1148123 +Node: Old Extension Problems1149277 +Ref: Old Extension Problems-Footnote-11150794 +Node: Extension New Mechanism Goals1150851 +Ref: Extension New Mechanism Goals-Footnote-11154211 +Node: Extension Other Design Decisions1154400 +Node: Extension Future Growth1156506 +Node: Old Extension Mechanism1157342 +Node: Notes summary1159104 +Node: Basic Concepts1160290 +Node: Basic High Level1160971 +Ref: figure-general-flow1161243 +Ref: figure-process-flow1161842 +Ref: Basic High Level-Footnote-11165071 +Node: Basic Data Typing1165256 +Node: Glossary1168584 +Node: Copying1193736 +Node: GNU Free Documentation License1231292 +Node: Index1256428  End Tag Table -- cgit v1.2.3 From 57454ce9249bdfea6451c231858e6a8b5d26c775 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sun, 22 Jun 2014 22:06:32 +0300 Subject: Typos and other minor fixes. --- doc/gawk.info | 1047 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 523 insertions(+), 524 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 95d81e89..e1ee6b3a 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -2170,7 +2170,7 @@ comment, it ignores _everything_ on the rest of the line. For example: > BEGIN rule > }' error--> gawk: cmd. line:2: BEGIN rule - error--> gawk: cmd. line:2: ^ parse error + error--> gawk: cmd. line:2: ^ syntax error In this case, it looks like the backslash would continue the comment onto the next line. However, the backslash-newline combination is never @@ -25218,7 +25218,7 @@ constant (`FNM_NOMATCH'), and an array of flag values named `FNM'. The flags are follows: -Array element Corresponding lag defined by `fnmatch()' +Array element Corresponding flag defined by `fnmatch()' -------------------------------------------------------------------------- `FNM["CASEFOLD"]' `FNM_CASEFOLD' `FNM["FILE_NAME"]' `FNM_FILE_NAME' @@ -25589,7 +25589,7 @@ Time::) was originally from this project but has been moved in to the main `gawk' distribution. You can check out the code for the `gawkextlib' project using the -GIT (http://git-scm.com) distributed source code control system. The +Git (http://git-scm.com) distributed source code control system. The command is as follows: git clone git://git.code.sf.net/p/gawkextlib/code gawkextlib-code @@ -26736,8 +26736,7 @@ Info file, in approximate chronological order: - The modifications to convert `gawk' into a byte-code interpreter, including the debugger. - - The addition of true arrays of arrays. *note Arrays of - Arrays::. + - The addition of true arrays of arrays. - The additional modifications for support of arbitrary precision arithmetic. @@ -26752,7 +26751,7 @@ Info file, in approximate chronological order: - The improved array sorting features were driven by John together with Pat Rankin. - Panos Papadopoulos contributed the original text for *note Include + * Panos Papadopoulos contributed the original text for *note Include Files::. * Efraim Yawitz contributed the original text for *note Debugger::. @@ -31608,7 +31607,7 @@ Index * Collado, Manuel: Acknowledgments. (line 60) * collating elements: Bracket Expressions. (line 69) * collating symbols: Bracket Expressions. (line 76) -* Colombo, Antonio <1>: Contributors. (line 138) +* Colombo, Antonio <1>: Contributors. (line 137) * Colombo, Antonio: Acknowledgments. (line 60) * columns, aligning: Print Examples. (line 70) * columns, cutting: Cut Program. (line 6) @@ -33043,7 +33042,7 @@ Index * output, standard: Special FD. (line 6) * p debugger command (alias for print): Viewing And Changing Data. (line 36) -* Papadopoulos, Panos: Contributors. (line 129) +* Papadopoulos, Panos: Contributors. (line 128) * parent process ID of gawk process: Auto-set. (line 181) * parentheses (), in a profile: Profiling. (line 146) * parentheses (), regexp operator: Regexp Operators. (line 80) @@ -33388,7 +33387,7 @@ Index * RLENGTH variable, match() function and: String Functions. (line 224) * Robbins, Arnold <1>: Future Extensions. (line 6) * Robbins, Arnold <2>: Bugs. (line 32) -* Robbins, Arnold <3>: Contributors. (line 142) +* Robbins, Arnold <3>: Contributors. (line 141) * Robbins, Arnold <4>: General Data Types. (line 6) * Robbins, Arnold <5>: Alarm Program. (line 6) * Robbins, Arnold <6>: Passwd Functions. (line 90) @@ -33431,7 +33430,7 @@ Index * scalar values: Basic Data Typing. (line 13) * scanning arrays: Scanning an Array. (line 6) * scanning multidimensional arrays: Multiscanning. (line 11) -* Schorr, Andrew <1>: Contributors. (line 134) +* Schorr, Andrew <1>: Contributors. (line 133) * Schorr, Andrew <2>: Auto-set. (line 284) * Schorr, Andrew: Acknowledgments. (line 60) * Schreiber, Bert: Acknowledgments. (line 38) @@ -33916,7 +33915,7 @@ Index * xgettext utility: String Extraction. (line 13) * xor: Bitwise Functions. (line 55) * XOR bitwise operation: Bitwise Functions. (line 6) -* Yawitz, Efraim: Contributors. (line 132) +* Yawitz, Efraim: Contributors. (line 131) * Zaretskii, Eli <1>: Bugs. (line 71) * Zaretskii, Eli <2>: Contributors. (line 55) * Zaretskii, Eli: Acknowledgments. (line 60) @@ -33984,518 +33983,518 @@ Node: Two Rules97321 Node: More Complex99215 Ref: More Complex-Footnote-1102147 Node: Statements/Lines102232 -Ref: Statements/Lines-Footnote-1106687 -Node: Other Features106952 -Node: When107880 -Node: Intro Summary110050 -Node: Invoking Gawk110816 -Node: Command Line112331 -Node: Options113122 -Ref: Options-Footnote-1128951 -Node: Other Arguments128976 -Node: Naming Standard Input131638 -Node: Environment Variables132732 -Node: AWKPATH Variable133290 -Ref: AWKPATH Variable-Footnote-1136162 -Ref: AWKPATH Variable-Footnote-2136207 -Node: AWKLIBPATH Variable136467 -Node: Other Environment Variables137226 -Node: Exit Status140881 -Node: Include Files141556 -Node: Loading Shared Libraries145134 -Node: Obsolete146518 -Node: Undocumented147215 -Node: Invoking Summary147482 -Node: Regexp149062 -Node: Regexp Usage150512 -Node: Escape Sequences152545 -Node: Regexp Operators158212 -Ref: Regexp Operators-Footnote-1165692 -Ref: Regexp Operators-Footnote-2165839 -Node: Bracket Expressions165937 -Ref: table-char-classes167827 -Node: GNU Regexp Operators170350 -Node: Case-sensitivity174073 -Ref: Case-sensitivity-Footnote-1176965 -Ref: Case-sensitivity-Footnote-2177200 -Node: Leftmost Longest177308 -Node: Computed Regexps178509 -Node: Regexp Summary181881 -Node: Reading Files183352 -Node: Records185444 -Node: awk split records186187 -Node: gawk split records191045 -Ref: gawk split records-Footnote-1195566 -Node: Fields195603 -Ref: Fields-Footnote-1198567 -Node: Nonconstant Fields198653 -Ref: Nonconstant Fields-Footnote-1200883 -Node: Changing Fields201085 -Node: Field Separators207039 -Node: Default Field Splitting209741 -Node: Regexp Field Splitting210858 -Node: Single Character Fields214199 -Node: Command Line Field Separator215258 -Node: Full Line Fields218600 -Ref: Full Line Fields-Footnote-1219108 -Node: Field Splitting Summary219154 -Ref: Field Splitting Summary-Footnote-1222253 -Node: Constant Size222354 -Node: Splitting By Content226961 -Ref: Splitting By Content-Footnote-1230711 -Node: Multiple Line230751 -Ref: Multiple Line-Footnote-1236607 -Node: Getline236786 -Node: Plain Getline239002 -Node: Getline/Variable241097 -Node: Getline/File242244 -Node: Getline/Variable/File243628 -Ref: Getline/Variable/File-Footnote-1245227 -Node: Getline/Pipe245314 -Node: Getline/Variable/Pipe248013 -Node: Getline/Coprocess249120 -Node: Getline/Variable/Coprocess250372 -Node: Getline Notes251109 -Node: Getline Summary253913 -Ref: table-getline-variants254321 -Node: Read Timeout255233 -Ref: Read Timeout-Footnote-1259060 -Node: Command line directories259118 -Node: Input Summary260022 -Node: Input Exercises263159 -Node: Printing263892 -Node: Print265614 -Node: Print Examples266955 -Node: Output Separators269734 -Node: OFMT271750 -Node: Printf273108 -Node: Basic Printf274014 -Node: Control Letters275553 -Node: Format Modifiers279405 -Node: Printf Examples285432 -Node: Redirection287896 -Node: Special Files294868 -Node: Special FD295399 -Ref: Special FD-Footnote-1299023 -Node: Special Network299097 -Node: Special Caveats299947 -Node: Close Files And Pipes300743 -Ref: Close Files And Pipes-Footnote-1307904 -Ref: Close Files And Pipes-Footnote-2308052 -Node: Output Summary308202 -Node: Output exercises309199 -Node: Expressions309879 -Node: Values311064 -Node: Constants311740 -Node: Scalar Constants312420 -Ref: Scalar Constants-Footnote-1313279 -Node: Nondecimal-numbers313529 -Node: Regexp Constants316529 -Node: Using Constant Regexps317004 -Node: Variables320074 -Node: Using Variables320729 -Node: Assignment Options322453 -Node: Conversion324328 -Node: Strings And Numbers324852 -Ref: Strings And Numbers-Footnote-1327914 -Node: Locale influences conversions328023 -Ref: table-locale-affects330740 -Node: All Operators331328 -Node: Arithmetic Ops331958 -Node: Concatenation334463 -Ref: Concatenation-Footnote-1337259 -Node: Assignment Ops337379 -Ref: table-assign-ops342362 -Node: Increment Ops343679 -Node: Truth Values and Conditions347117 -Node: Truth Values348200 -Node: Typing and Comparison349249 -Node: Variable Typing350042 -Ref: Variable Typing-Footnote-1353942 -Node: Comparison Operators354064 -Ref: table-relational-ops354474 -Node: POSIX String Comparison358024 -Ref: POSIX String Comparison-Footnote-1359108 -Node: Boolean Ops359246 -Ref: Boolean Ops-Footnote-1363316 -Node: Conditional Exp363407 -Node: Function Calls365134 -Node: Precedence369014 -Node: Locales372683 -Node: Expressions Summary374314 -Node: Patterns and Actions376855 -Node: Pattern Overview377971 -Node: Regexp Patterns379648 -Node: Expression Patterns380191 -Node: Ranges383972 -Node: BEGIN/END387078 -Node: Using BEGIN/END387840 -Ref: Using BEGIN/END-Footnote-1390576 -Node: I/O And BEGIN/END390682 -Node: BEGINFILE/ENDFILE392967 -Node: Empty395898 -Node: Using Shell Variables396215 -Node: Action Overview398498 -Node: Statements400825 -Node: If Statement402673 -Node: While Statement404171 -Node: Do Statement406215 -Node: For Statement407371 -Node: Switch Statement410523 -Node: Break Statement412626 -Node: Continue Statement414681 -Node: Next Statement416474 -Node: Nextfile Statement418864 -Node: Exit Statement421519 -Node: Built-in Variables423923 -Node: User-modified425050 -Ref: User-modified-Footnote-1432739 -Node: Auto-set432801 -Ref: Auto-set-Footnote-1445383 -Ref: Auto-set-Footnote-2445588 -Node: ARGC and ARGV445644 -Node: Pattern Action Summary449498 -Node: Arrays451721 -Node: Array Basics453270 -Node: Array Intro454096 -Ref: figure-array-elements456069 -Node: Reference to Elements458476 -Node: Assigning Elements460749 -Node: Array Example461240 -Node: Scanning an Array462972 -Node: Controlling Scanning465987 -Ref: Controlling Scanning-Footnote-1471160 -Node: Delete471476 -Ref: Delete-Footnote-1474241 -Node: Numeric Array Subscripts474298 -Node: Uninitialized Subscripts476481 -Node: Multidimensional478106 -Node: Multiscanning481199 -Node: Arrays of Arrays482788 -Node: Arrays Summary487451 -Node: Functions489556 -Node: Built-in490429 -Node: Calling Built-in491507 -Node: Numeric Functions493495 -Ref: Numeric Functions-Footnote-1497329 -Ref: Numeric Functions-Footnote-2497686 -Ref: Numeric Functions-Footnote-3497734 -Node: String Functions498003 -Ref: String Functions-Footnote-1521014 -Ref: String Functions-Footnote-2521143 -Ref: String Functions-Footnote-3521391 -Node: Gory Details521478 -Ref: table-sub-escapes523147 -Ref: table-sub-posix-92524501 -Ref: table-sub-proposed525852 -Ref: table-posix-sub527206 -Ref: table-gensub-escapes528751 -Ref: Gory Details-Footnote-1529927 -Ref: Gory Details-Footnote-2529978 -Node: I/O Functions530129 -Ref: I/O Functions-Footnote-1537252 -Node: Time Functions537399 -Ref: Time Functions-Footnote-1547863 -Ref: Time Functions-Footnote-2547931 -Ref: Time Functions-Footnote-3548089 -Ref: Time Functions-Footnote-4548200 -Ref: Time Functions-Footnote-5548312 -Ref: Time Functions-Footnote-6548539 -Node: Bitwise Functions548805 -Ref: table-bitwise-ops549367 -Ref: Bitwise Functions-Footnote-1553612 -Node: Type Functions553796 -Node: I18N Functions554938 -Node: User-defined556583 -Node: Definition Syntax557387 -Ref: Definition Syntax-Footnote-1562566 -Node: Function Example562635 -Ref: Function Example-Footnote-1565279 -Node: Function Caveats565301 -Node: Calling A Function565819 -Node: Variable Scope566774 -Node: Pass By Value/Reference569762 -Node: Return Statement573270 -Node: Dynamic Typing576254 -Node: Indirect Calls577183 -Node: Functions Summary586896 -Node: Library Functions589435 -Ref: Library Functions-Footnote-1593053 -Ref: Library Functions-Footnote-2593196 -Node: Library Names593367 -Ref: Library Names-Footnote-1596840 -Ref: Library Names-Footnote-2597060 -Node: General Functions597146 -Node: Strtonum Function598174 -Node: Assert Function600954 -Node: Round Function604280 -Node: Cliff Random Function605821 -Node: Ordinal Functions606837 -Ref: Ordinal Functions-Footnote-1609914 -Ref: Ordinal Functions-Footnote-2610166 -Node: Join Function610377 -Ref: Join Function-Footnote-1612148 -Node: Getlocaltime Function612348 -Node: Readfile Function616084 -Node: Data File Management617923 -Node: Filetrans Function618555 -Node: Rewind Function622624 -Node: File Checking624011 -Ref: File Checking-Footnote-1625143 -Node: Empty Files625344 -Node: Ignoring Assigns627323 -Node: Getopt Function628877 -Ref: Getopt Function-Footnote-1640180 -Node: Passwd Functions640383 -Ref: Passwd Functions-Footnote-1649362 -Node: Group Functions649450 -Ref: Group Functions-Footnote-1657391 -Node: Walking Arrays657604 -Node: Library Functions Summary659207 -Node: Library exercises660595 -Node: Sample Programs661875 -Node: Running Examples662645 -Node: Clones663373 -Node: Cut Program664597 -Node: Egrep Program674465 -Ref: Egrep Program-Footnote-1682436 -Node: Id Program682546 -Node: Split Program686210 -Ref: Split Program-Footnote-1689748 -Node: Tee Program689876 -Node: Uniq Program692683 -Node: Wc Program700113 -Ref: Wc Program-Footnote-1704378 -Node: Miscellaneous Programs704470 -Node: Dupword Program705683 -Node: Alarm Program707714 -Node: Translate Program712528 -Ref: Translate Program-Footnote-1716919 -Ref: Translate Program-Footnote-2717189 -Node: Labels Program717323 -Ref: Labels Program-Footnote-1720694 -Node: Word Sorting720778 -Node: History Sorting724821 -Node: Extract Program726657 -Node: Simple Sed734193 -Node: Igawk Program737255 -Ref: Igawk Program-Footnote-1751566 -Ref: Igawk Program-Footnote-2751767 -Node: Anagram Program751905 -Node: Signature Program754973 -Node: Programs Summary756220 -Node: Programs Exercises757435 -Node: Advanced Features761086 -Node: Nondecimal Data763034 -Node: Array Sorting764611 -Node: Controlling Array Traversal765308 -Node: Array Sorting Functions773588 -Ref: Array Sorting Functions-Footnote-1777495 -Node: Two-way I/O777689 -Ref: Two-way I/O-Footnote-1783205 -Node: TCP/IP Networking783287 -Node: Profiling786131 -Node: Advanced Features Summary793673 -Node: Internationalization795537 -Node: I18N and L10N797017 -Node: Explaining gettext797703 -Ref: Explaining gettext-Footnote-1802843 -Ref: Explaining gettext-Footnote-2803027 -Node: Programmer i18n803192 -Node: Translator i18n807417 -Node: String Extraction808211 -Ref: String Extraction-Footnote-1809172 -Node: Printf Ordering809258 -Ref: Printf Ordering-Footnote-1812040 -Node: I18N Portability812104 -Ref: I18N Portability-Footnote-1814553 -Node: I18N Example814616 -Ref: I18N Example-Footnote-1817338 -Node: Gawk I18N817410 -Node: I18N Summary818048 -Node: Debugger819387 -Node: Debugging820409 -Node: Debugging Concepts820850 -Node: Debugging Terms822706 -Node: Awk Debugging825303 -Node: Sample Debugging Session826195 -Node: Debugger Invocation826715 -Node: Finding The Bug828048 -Node: List of Debugger Commands834530 -Node: Breakpoint Control835862 -Node: Debugger Execution Control839526 -Node: Viewing And Changing Data842886 -Node: Execution Stack846244 -Node: Debugger Info847757 -Node: Miscellaneous Debugger Commands851751 -Node: Readline Support856935 -Node: Limitations857827 -Node: Debugging Summary860101 -Node: Arbitrary Precision Arithmetic861265 -Node: Computer Arithmetic862594 -Ref: Computer Arithmetic-Footnote-1866981 -Node: Math Definitions867038 -Ref: table-ieee-formats869922 -Node: MPFR features870426 -Node: FP Math Caution872068 -Ref: FP Math Caution-Footnote-1873109 -Node: Inexactness of computations873478 -Node: Inexact representation874426 -Node: Comparing FP Values875781 -Node: Errors accumulate876745 -Node: Getting Accuracy878178 -Node: Try To Round880837 -Node: Setting precision881736 -Ref: table-predefined-precision-strings882418 -Node: Setting the rounding mode884211 -Ref: table-gawk-rounding-modes884575 -Ref: Setting the rounding mode-Footnote-1888029 -Node: Arbitrary Precision Integers888208 -Ref: Arbitrary Precision Integers-Footnote-1891211 -Node: POSIX Floating Point Problems891360 -Ref: POSIX Floating Point Problems-Footnote-1895236 -Node: Floating point summary895274 -Node: Dynamic Extensions897491 -Node: Extension Intro899043 -Node: Plugin License900308 -Node: Extension Mechanism Outline900993 -Ref: figure-load-extension901417 -Ref: figure-load-new-function902902 -Ref: figure-call-new-function903904 -Node: Extension API Description905888 -Node: Extension API Functions Introduction907338 -Node: General Data Types912203 -Ref: General Data Types-Footnote-1917896 -Node: Requesting Values918195 -Ref: table-value-types-returned918932 -Node: Memory Allocation Functions919890 -Ref: Memory Allocation Functions-Footnote-1922637 -Node: Constructor Functions922733 -Node: Registration Functions924491 -Node: Extension Functions925176 -Node: Exit Callback Functions927478 -Node: Extension Version String928727 -Node: Input Parsers929377 -Node: Output Wrappers939180 -Node: Two-way processors943696 -Node: Printing Messages945900 -Ref: Printing Messages-Footnote-1946977 -Node: Updating `ERRNO'947129 -Node: Accessing Parameters947868 -Node: Symbol Table Access949098 -Node: Symbol table by name949612 -Node: Symbol table by cookie951588 -Ref: Symbol table by cookie-Footnote-1955721 -Node: Cached values955784 -Ref: Cached values-Footnote-1959288 -Node: Array Manipulation959379 -Ref: Array Manipulation-Footnote-1960477 -Node: Array Data Types960516 -Ref: Array Data Types-Footnote-1963219 -Node: Array Functions963311 -Node: Flattening Arrays967185 -Node: Creating Arrays974037 -Node: Extension API Variables978768 -Node: Extension Versioning979404 -Node: Extension API Informational Variables981305 -Node: Extension API Boilerplate982391 -Node: Finding Extensions986195 -Node: Extension Example986755 -Node: Internal File Description987485 -Node: Internal File Ops991576 -Ref: Internal File Ops-Footnote-11003008 -Node: Using Internal File Ops1003148 -Ref: Using Internal File Ops-Footnote-11005495 -Node: Extension Samples1005763 -Node: Extension Sample File Functions1007287 -Node: Extension Sample Fnmatch1014855 -Node: Extension Sample Fork1016336 -Node: Extension Sample Inplace1017549 -Node: Extension Sample Ord1019224 -Node: Extension Sample Readdir1020060 -Ref: table-readdir-file-types1020916 -Node: Extension Sample Revout1021715 -Node: Extension Sample Rev2way1022306 -Node: Extension Sample Read write array1023047 -Node: Extension Sample Readfile1024926 -Node: Extension Sample API Tests1026026 -Node: Extension Sample Time1026551 -Node: gawkextlib1027866 -Node: Extension summary1030679 -Node: Extension Exercises1034372 -Node: Language History1035094 -Node: V7/SVR3.11036737 -Node: SVR41039057 -Node: POSIX1040499 -Node: BTL1041885 -Node: POSIX/GNU1042619 -Node: Feature History1048218 -Node: Common Extensions1061348 -Node: Ranges and Locales1062660 -Ref: Ranges and Locales-Footnote-11067277 -Ref: Ranges and Locales-Footnote-21067304 -Ref: Ranges and Locales-Footnote-31067538 -Node: Contributors1067759 -Node: History summary1073221 -Node: Installation1074590 -Node: Gawk Distribution1075541 -Node: Getting1076025 -Node: Extracting1076849 -Node: Distribution contents1078491 -Node: Unix Installation1084208 -Node: Quick Installation1084825 -Node: Additional Configuration Options1087267 -Node: Configuration Philosophy1089005 -Node: Non-Unix Installation1091356 -Node: PC Installation1091814 -Node: PC Binary Installation1093125 -Node: PC Compiling1094973 -Ref: PC Compiling-Footnote-11097972 -Node: PC Testing1098077 -Node: PC Using1099253 -Node: Cygwin1103411 -Node: MSYS1104220 -Node: VMS Installation1104734 -Node: VMS Compilation1105530 -Ref: VMS Compilation-Footnote-11106752 -Node: VMS Dynamic Extensions1106810 -Node: VMS Installation Details1108183 -Node: VMS Running1110435 -Node: VMS GNV1113269 -Node: VMS Old Gawk1113992 -Node: Bugs1114462 -Node: Other Versions1118466 -Node: Installation summary1124721 -Node: Notes1125777 -Node: Compatibility Mode1126642 -Node: Additions1127424 -Node: Accessing The Source1128349 -Node: Adding Code1129785 -Node: New Ports1135963 -Node: Derived Files1140444 -Ref: Derived Files-Footnote-11145525 -Ref: Derived Files-Footnote-21145559 -Ref: Derived Files-Footnote-31146155 -Node: Future Extensions1146269 -Node: Implementation Limitations1146875 -Node: Extension Design1148123 -Node: Old Extension Problems1149277 -Ref: Old Extension Problems-Footnote-11150794 -Node: Extension New Mechanism Goals1150851 -Ref: Extension New Mechanism Goals-Footnote-11154211 -Node: Extension Other Design Decisions1154400 -Node: Extension Future Growth1156506 -Node: Old Extension Mechanism1157342 -Node: Notes summary1159104 -Node: Basic Concepts1160290 -Node: Basic High Level1160971 -Ref: figure-general-flow1161243 -Ref: figure-process-flow1161842 -Ref: Basic High Level-Footnote-11165071 -Node: Basic Data Typing1165256 -Node: Glossary1168584 -Node: Copying1193736 -Node: GNU Free Documentation License1231292 -Node: Index1256428 +Ref: Statements/Lines-Footnote-1106688 +Node: Other Features106953 +Node: When107881 +Node: Intro Summary110051 +Node: Invoking Gawk110817 +Node: Command Line112332 +Node: Options113123 +Ref: Options-Footnote-1128952 +Node: Other Arguments128977 +Node: Naming Standard Input131639 +Node: Environment Variables132733 +Node: AWKPATH Variable133291 +Ref: AWKPATH Variable-Footnote-1136163 +Ref: AWKPATH Variable-Footnote-2136208 +Node: AWKLIBPATH Variable136468 +Node: Other Environment Variables137227 +Node: Exit Status140882 +Node: Include Files141557 +Node: Loading Shared Libraries145135 +Node: Obsolete146519 +Node: Undocumented147216 +Node: Invoking Summary147483 +Node: Regexp149063 +Node: Regexp Usage150513 +Node: Escape Sequences152546 +Node: Regexp Operators158213 +Ref: Regexp Operators-Footnote-1165693 +Ref: Regexp Operators-Footnote-2165840 +Node: Bracket Expressions165938 +Ref: table-char-classes167828 +Node: GNU Regexp Operators170351 +Node: Case-sensitivity174074 +Ref: Case-sensitivity-Footnote-1176966 +Ref: Case-sensitivity-Footnote-2177201 +Node: Leftmost Longest177309 +Node: Computed Regexps178510 +Node: Regexp Summary181882 +Node: Reading Files183353 +Node: Records185445 +Node: awk split records186188 +Node: gawk split records191046 +Ref: gawk split records-Footnote-1195567 +Node: Fields195604 +Ref: Fields-Footnote-1198568 +Node: Nonconstant Fields198654 +Ref: Nonconstant Fields-Footnote-1200884 +Node: Changing Fields201086 +Node: Field Separators207040 +Node: Default Field Splitting209742 +Node: Regexp Field Splitting210859 +Node: Single Character Fields214200 +Node: Command Line Field Separator215259 +Node: Full Line Fields218601 +Ref: Full Line Fields-Footnote-1219109 +Node: Field Splitting Summary219155 +Ref: Field Splitting Summary-Footnote-1222254 +Node: Constant Size222355 +Node: Splitting By Content226962 +Ref: Splitting By Content-Footnote-1230712 +Node: Multiple Line230752 +Ref: Multiple Line-Footnote-1236608 +Node: Getline236787 +Node: Plain Getline239003 +Node: Getline/Variable241098 +Node: Getline/File242245 +Node: Getline/Variable/File243629 +Ref: Getline/Variable/File-Footnote-1245228 +Node: Getline/Pipe245315 +Node: Getline/Variable/Pipe248014 +Node: Getline/Coprocess249121 +Node: Getline/Variable/Coprocess250373 +Node: Getline Notes251110 +Node: Getline Summary253914 +Ref: table-getline-variants254322 +Node: Read Timeout255234 +Ref: Read Timeout-Footnote-1259061 +Node: Command line directories259119 +Node: Input Summary260023 +Node: Input Exercises263160 +Node: Printing263893 +Node: Print265615 +Node: Print Examples266956 +Node: Output Separators269735 +Node: OFMT271751 +Node: Printf273109 +Node: Basic Printf274015 +Node: Control Letters275554 +Node: Format Modifiers279406 +Node: Printf Examples285433 +Node: Redirection287897 +Node: Special Files294869 +Node: Special FD295400 +Ref: Special FD-Footnote-1299024 +Node: Special Network299098 +Node: Special Caveats299948 +Node: Close Files And Pipes300744 +Ref: Close Files And Pipes-Footnote-1307905 +Ref: Close Files And Pipes-Footnote-2308053 +Node: Output Summary308203 +Node: Output exercises309200 +Node: Expressions309880 +Node: Values311065 +Node: Constants311741 +Node: Scalar Constants312421 +Ref: Scalar Constants-Footnote-1313280 +Node: Nondecimal-numbers313530 +Node: Regexp Constants316530 +Node: Using Constant Regexps317005 +Node: Variables320075 +Node: Using Variables320730 +Node: Assignment Options322454 +Node: Conversion324329 +Node: Strings And Numbers324853 +Ref: Strings And Numbers-Footnote-1327915 +Node: Locale influences conversions328024 +Ref: table-locale-affects330741 +Node: All Operators331329 +Node: Arithmetic Ops331959 +Node: Concatenation334464 +Ref: Concatenation-Footnote-1337260 +Node: Assignment Ops337380 +Ref: table-assign-ops342363 +Node: Increment Ops343680 +Node: Truth Values and Conditions347118 +Node: Truth Values348201 +Node: Typing and Comparison349250 +Node: Variable Typing350043 +Ref: Variable Typing-Footnote-1353943 +Node: Comparison Operators354065 +Ref: table-relational-ops354475 +Node: POSIX String Comparison358025 +Ref: POSIX String Comparison-Footnote-1359109 +Node: Boolean Ops359247 +Ref: Boolean Ops-Footnote-1363317 +Node: Conditional Exp363408 +Node: Function Calls365135 +Node: Precedence369015 +Node: Locales372684 +Node: Expressions Summary374315 +Node: Patterns and Actions376856 +Node: Pattern Overview377972 +Node: Regexp Patterns379649 +Node: Expression Patterns380192 +Node: Ranges383973 +Node: BEGIN/END387079 +Node: Using BEGIN/END387841 +Ref: Using BEGIN/END-Footnote-1390577 +Node: I/O And BEGIN/END390683 +Node: BEGINFILE/ENDFILE392968 +Node: Empty395899 +Node: Using Shell Variables396216 +Node: Action Overview398499 +Node: Statements400826 +Node: If Statement402674 +Node: While Statement404172 +Node: Do Statement406216 +Node: For Statement407372 +Node: Switch Statement410524 +Node: Break Statement412627 +Node: Continue Statement414682 +Node: Next Statement416475 +Node: Nextfile Statement418865 +Node: Exit Statement421520 +Node: Built-in Variables423924 +Node: User-modified425051 +Ref: User-modified-Footnote-1432740 +Node: Auto-set432802 +Ref: Auto-set-Footnote-1445384 +Ref: Auto-set-Footnote-2445589 +Node: ARGC and ARGV445645 +Node: Pattern Action Summary449499 +Node: Arrays451722 +Node: Array Basics453271 +Node: Array Intro454097 +Ref: figure-array-elements456070 +Node: Reference to Elements458477 +Node: Assigning Elements460750 +Node: Array Example461241 +Node: Scanning an Array462973 +Node: Controlling Scanning465988 +Ref: Controlling Scanning-Footnote-1471161 +Node: Delete471477 +Ref: Delete-Footnote-1474242 +Node: Numeric Array Subscripts474299 +Node: Uninitialized Subscripts476482 +Node: Multidimensional478107 +Node: Multiscanning481200 +Node: Arrays of Arrays482789 +Node: Arrays Summary487452 +Node: Functions489557 +Node: Built-in490430 +Node: Calling Built-in491508 +Node: Numeric Functions493496 +Ref: Numeric Functions-Footnote-1497330 +Ref: Numeric Functions-Footnote-2497687 +Ref: Numeric Functions-Footnote-3497735 +Node: String Functions498004 +Ref: String Functions-Footnote-1521015 +Ref: String Functions-Footnote-2521144 +Ref: String Functions-Footnote-3521392 +Node: Gory Details521479 +Ref: table-sub-escapes523148 +Ref: table-sub-posix-92524502 +Ref: table-sub-proposed525853 +Ref: table-posix-sub527207 +Ref: table-gensub-escapes528752 +Ref: Gory Details-Footnote-1529928 +Ref: Gory Details-Footnote-2529979 +Node: I/O Functions530130 +Ref: I/O Functions-Footnote-1537253 +Node: Time Functions537400 +Ref: Time Functions-Footnote-1547864 +Ref: Time Functions-Footnote-2547932 +Ref: Time Functions-Footnote-3548090 +Ref: Time Functions-Footnote-4548201 +Ref: Time Functions-Footnote-5548313 +Ref: Time Functions-Footnote-6548540 +Node: Bitwise Functions548806 +Ref: table-bitwise-ops549368 +Ref: Bitwise Functions-Footnote-1553613 +Node: Type Functions553797 +Node: I18N Functions554939 +Node: User-defined556584 +Node: Definition Syntax557388 +Ref: Definition Syntax-Footnote-1562567 +Node: Function Example562636 +Ref: Function Example-Footnote-1565280 +Node: Function Caveats565302 +Node: Calling A Function565820 +Node: Variable Scope566775 +Node: Pass By Value/Reference569763 +Node: Return Statement573271 +Node: Dynamic Typing576255 +Node: Indirect Calls577184 +Node: Functions Summary586897 +Node: Library Functions589436 +Ref: Library Functions-Footnote-1593054 +Ref: Library Functions-Footnote-2593197 +Node: Library Names593368 +Ref: Library Names-Footnote-1596841 +Ref: Library Names-Footnote-2597061 +Node: General Functions597147 +Node: Strtonum Function598175 +Node: Assert Function600955 +Node: Round Function604281 +Node: Cliff Random Function605822 +Node: Ordinal Functions606838 +Ref: Ordinal Functions-Footnote-1609915 +Ref: Ordinal Functions-Footnote-2610167 +Node: Join Function610378 +Ref: Join Function-Footnote-1612149 +Node: Getlocaltime Function612349 +Node: Readfile Function616085 +Node: Data File Management617924 +Node: Filetrans Function618556 +Node: Rewind Function622625 +Node: File Checking624012 +Ref: File Checking-Footnote-1625144 +Node: Empty Files625345 +Node: Ignoring Assigns627324 +Node: Getopt Function628878 +Ref: Getopt Function-Footnote-1640181 +Node: Passwd Functions640384 +Ref: Passwd Functions-Footnote-1649363 +Node: Group Functions649451 +Ref: Group Functions-Footnote-1657392 +Node: Walking Arrays657605 +Node: Library Functions Summary659208 +Node: Library exercises660596 +Node: Sample Programs661876 +Node: Running Examples662646 +Node: Clones663374 +Node: Cut Program664598 +Node: Egrep Program674466 +Ref: Egrep Program-Footnote-1682437 +Node: Id Program682547 +Node: Split Program686211 +Ref: Split Program-Footnote-1689749 +Node: Tee Program689877 +Node: Uniq Program692684 +Node: Wc Program700114 +Ref: Wc Program-Footnote-1704379 +Node: Miscellaneous Programs704471 +Node: Dupword Program705684 +Node: Alarm Program707715 +Node: Translate Program712529 +Ref: Translate Program-Footnote-1716920 +Ref: Translate Program-Footnote-2717190 +Node: Labels Program717324 +Ref: Labels Program-Footnote-1720695 +Node: Word Sorting720779 +Node: History Sorting724822 +Node: Extract Program726658 +Node: Simple Sed734194 +Node: Igawk Program737256 +Ref: Igawk Program-Footnote-1751567 +Ref: Igawk Program-Footnote-2751768 +Node: Anagram Program751906 +Node: Signature Program754974 +Node: Programs Summary756221 +Node: Programs Exercises757436 +Node: Advanced Features761087 +Node: Nondecimal Data763035 +Node: Array Sorting764612 +Node: Controlling Array Traversal765309 +Node: Array Sorting Functions773589 +Ref: Array Sorting Functions-Footnote-1777496 +Node: Two-way I/O777690 +Ref: Two-way I/O-Footnote-1783206 +Node: TCP/IP Networking783288 +Node: Profiling786132 +Node: Advanced Features Summary793674 +Node: Internationalization795538 +Node: I18N and L10N797018 +Node: Explaining gettext797704 +Ref: Explaining gettext-Footnote-1802844 +Ref: Explaining gettext-Footnote-2803028 +Node: Programmer i18n803193 +Node: Translator i18n807418 +Node: String Extraction808212 +Ref: String Extraction-Footnote-1809173 +Node: Printf Ordering809259 +Ref: Printf Ordering-Footnote-1812041 +Node: I18N Portability812105 +Ref: I18N Portability-Footnote-1814554 +Node: I18N Example814617 +Ref: I18N Example-Footnote-1817339 +Node: Gawk I18N817411 +Node: I18N Summary818049 +Node: Debugger819388 +Node: Debugging820410 +Node: Debugging Concepts820851 +Node: Debugging Terms822707 +Node: Awk Debugging825304 +Node: Sample Debugging Session826196 +Node: Debugger Invocation826716 +Node: Finding The Bug828049 +Node: List of Debugger Commands834531 +Node: Breakpoint Control835863 +Node: Debugger Execution Control839527 +Node: Viewing And Changing Data842887 +Node: Execution Stack846245 +Node: Debugger Info847758 +Node: Miscellaneous Debugger Commands851752 +Node: Readline Support856936 +Node: Limitations857828 +Node: Debugging Summary860102 +Node: Arbitrary Precision Arithmetic861266 +Node: Computer Arithmetic862595 +Ref: Computer Arithmetic-Footnote-1866982 +Node: Math Definitions867039 +Ref: table-ieee-formats869923 +Node: MPFR features870427 +Node: FP Math Caution872069 +Ref: FP Math Caution-Footnote-1873110 +Node: Inexactness of computations873479 +Node: Inexact representation874427 +Node: Comparing FP Values875782 +Node: Errors accumulate876746 +Node: Getting Accuracy878179 +Node: Try To Round880838 +Node: Setting precision881737 +Ref: table-predefined-precision-strings882419 +Node: Setting the rounding mode884212 +Ref: table-gawk-rounding-modes884576 +Ref: Setting the rounding mode-Footnote-1888030 +Node: Arbitrary Precision Integers888209 +Ref: Arbitrary Precision Integers-Footnote-1891212 +Node: POSIX Floating Point Problems891361 +Ref: POSIX Floating Point Problems-Footnote-1895237 +Node: Floating point summary895275 +Node: Dynamic Extensions897492 +Node: Extension Intro899044 +Node: Plugin License900309 +Node: Extension Mechanism Outline900994 +Ref: figure-load-extension901418 +Ref: figure-load-new-function902903 +Ref: figure-call-new-function903905 +Node: Extension API Description905889 +Node: Extension API Functions Introduction907339 +Node: General Data Types912204 +Ref: General Data Types-Footnote-1917897 +Node: Requesting Values918196 +Ref: table-value-types-returned918933 +Node: Memory Allocation Functions919891 +Ref: Memory Allocation Functions-Footnote-1922638 +Node: Constructor Functions922734 +Node: Registration Functions924492 +Node: Extension Functions925177 +Node: Exit Callback Functions927479 +Node: Extension Version String928728 +Node: Input Parsers929378 +Node: Output Wrappers939181 +Node: Two-way processors943697 +Node: Printing Messages945901 +Ref: Printing Messages-Footnote-1946978 +Node: Updating `ERRNO'947130 +Node: Accessing Parameters947869 +Node: Symbol Table Access949099 +Node: Symbol table by name949613 +Node: Symbol table by cookie951589 +Ref: Symbol table by cookie-Footnote-1955722 +Node: Cached values955785 +Ref: Cached values-Footnote-1959289 +Node: Array Manipulation959380 +Ref: Array Manipulation-Footnote-1960478 +Node: Array Data Types960517 +Ref: Array Data Types-Footnote-1963220 +Node: Array Functions963312 +Node: Flattening Arrays967186 +Node: Creating Arrays974038 +Node: Extension API Variables978769 +Node: Extension Versioning979405 +Node: Extension API Informational Variables981306 +Node: Extension API Boilerplate982392 +Node: Finding Extensions986196 +Node: Extension Example986756 +Node: Internal File Description987486 +Node: Internal File Ops991577 +Ref: Internal File Ops-Footnote-11003009 +Node: Using Internal File Ops1003149 +Ref: Using Internal File Ops-Footnote-11005496 +Node: Extension Samples1005764 +Node: Extension Sample File Functions1007288 +Node: Extension Sample Fnmatch1014856 +Node: Extension Sample Fork1016338 +Node: Extension Sample Inplace1017551 +Node: Extension Sample Ord1019226 +Node: Extension Sample Readdir1020062 +Ref: table-readdir-file-types1020918 +Node: Extension Sample Revout1021717 +Node: Extension Sample Rev2way1022308 +Node: Extension Sample Read write array1023049 +Node: Extension Sample Readfile1024928 +Node: Extension Sample API Tests1026028 +Node: Extension Sample Time1026553 +Node: gawkextlib1027868 +Node: Extension summary1030681 +Node: Extension Exercises1034374 +Node: Language History1035096 +Node: V7/SVR3.11036739 +Node: SVR41039059 +Node: POSIX1040501 +Node: BTL1041887 +Node: POSIX/GNU1042621 +Node: Feature History1048220 +Node: Common Extensions1061350 +Node: Ranges and Locales1062662 +Ref: Ranges and Locales-Footnote-11067279 +Ref: Ranges and Locales-Footnote-21067306 +Ref: Ranges and Locales-Footnote-31067540 +Node: Contributors1067761 +Node: History summary1073186 +Node: Installation1074555 +Node: Gawk Distribution1075506 +Node: Getting1075990 +Node: Extracting1076814 +Node: Distribution contents1078456 +Node: Unix Installation1084173 +Node: Quick Installation1084790 +Node: Additional Configuration Options1087232 +Node: Configuration Philosophy1088970 +Node: Non-Unix Installation1091321 +Node: PC Installation1091779 +Node: PC Binary Installation1093090 +Node: PC Compiling1094938 +Ref: PC Compiling-Footnote-11097937 +Node: PC Testing1098042 +Node: PC Using1099218 +Node: Cygwin1103376 +Node: MSYS1104185 +Node: VMS Installation1104699 +Node: VMS Compilation1105495 +Ref: VMS Compilation-Footnote-11106717 +Node: VMS Dynamic Extensions1106775 +Node: VMS Installation Details1108148 +Node: VMS Running1110400 +Node: VMS GNV1113234 +Node: VMS Old Gawk1113957 +Node: Bugs1114427 +Node: Other Versions1118431 +Node: Installation summary1124686 +Node: Notes1125742 +Node: Compatibility Mode1126607 +Node: Additions1127389 +Node: Accessing The Source1128314 +Node: Adding Code1129750 +Node: New Ports1135928 +Node: Derived Files1140409 +Ref: Derived Files-Footnote-11145490 +Ref: Derived Files-Footnote-21145524 +Ref: Derived Files-Footnote-31146120 +Node: Future Extensions1146234 +Node: Implementation Limitations1146840 +Node: Extension Design1148088 +Node: Old Extension Problems1149242 +Ref: Old Extension Problems-Footnote-11150759 +Node: Extension New Mechanism Goals1150816 +Ref: Extension New Mechanism Goals-Footnote-11154176 +Node: Extension Other Design Decisions1154365 +Node: Extension Future Growth1156471 +Node: Old Extension Mechanism1157307 +Node: Notes summary1159069 +Node: Basic Concepts1160255 +Node: Basic High Level1160936 +Ref: figure-general-flow1161208 +Ref: figure-process-flow1161807 +Ref: Basic High Level-Footnote-11165036 +Node: Basic Data Typing1165221 +Node: Glossary1168549 +Node: Copying1193701 +Node: GNU Free Documentation License1231257 +Node: Index1256393  End Tag Table -- cgit v1.2.3 From 3ceb23374fc269d883dc5d56e40518db77efea1a Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 24 Jun 2014 18:10:22 +0300 Subject: Make --pretty-print not run the program. --- doc/gawk.info | 1093 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 543 insertions(+), 550 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 44568736..bc82705d 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -2569,10 +2569,8 @@ The following list describes options mandated by the POSIX standard: different file name for the output. No space is allowed between the `-o' and FILE, if FILE is supplied. - NOTE: Due to the way `gawk' has evolved, with this option - your program is still executed. This will change in the next - major release such that `gawk' will only pretty-print the - program and not run it. + NOTE: In the past, this option would also execute your + program. This is no longer the case. `-O' `--optimize' @@ -2956,11 +2954,6 @@ change. The variables are: supposed to be differences, but occasionally theory and practice don't coordinate with each other.) -`GAWK_NO_PP_RUN' - If this variable exists, then when invoked with the - `--pretty-print' option, `gawk' skips running the program. This - variable will not survive into the next major release. - `GAWK_STACKSIZE' This specifies the amount by which `gawk' should grow its internal evaluation stack, when needed. @@ -19641,8 +19634,8 @@ by the `Ctrl-<\>' key. called this way, `gawk' "pretty prints" the program into `awkprof.out', without any execution counts. - NOTE: The `--pretty-print' option still runs your program. This - will change in the next major release. + NOTE: Once upon a time, the `--pretty-print' option would also run + your program. This is is no longer the case.  File: gawk.info, Node: Advanced Features Summary, Prev: Profiling, Up: Advanced Features @@ -30990,20 +30983,20 @@ Index * --include option: Options. (line 159) * --lint option <1>: Options. (line 185) * --lint option: Command Line. (line 20) -* --lint-old option: Options. (line 295) +* --lint-old option: Options. (line 293) * --load option: Options. (line 173) * --non-decimal-data option <1>: Nondecimal Data. (line 6) * --non-decimal-data option: Options. (line 211) * --non-decimal-data option, strtonum() function and: Nondecimal Data. (line 36) -* --optimize option: Options. (line 237) -* --posix option: Options. (line 254) -* --posix option, --traditional option and: Options. (line 273) +* --optimize option: Options. (line 235) +* --posix option: Options. (line 252) +* --posix option, --traditional option and: Options. (line 271) * --pretty-print option: Options. (line 224) * --profile option <1>: Profiling. (line 12) -* --profile option: Options. (line 242) -* --re-interval option: Options. (line 279) -* --sandbox option: Options. (line 286) +* --profile option: Options. (line 240) +* --re-interval option: Options. (line 277) +* --sandbox option: Options. (line 284) * --sandbox option, disabling system() function: I/O Functions. (line 97) * --sandbox option, input redirection with getline: Getline. (line 19) @@ -31011,9 +31004,9 @@ Index (line 6) * --source option: Options. (line 117) * --traditional option: Options. (line 81) -* --traditional option, --posix option and: Options. (line 273) +* --traditional option, --posix option and: Options. (line 271) * --use-lc-numeric option: Options. (line 219) -* --version option: Options. (line 300) +* --version option: Options. (line 298) * --with-whiny-user-strftime configuration option: Additional Configuration Options. (line 35) * -b option: Options. (line 68) @@ -31026,26 +31019,26 @@ Index * -f option: Options. (line 25) * -F option: Options. (line 21) * -f option: Long. (line 12) -* -F option, -Ft sets FS to TAB: Options. (line 308) +* -F option, -Ft sets FS to TAB: Options. (line 306) * -F option, command line: Command Line Field Separator. (line 6) -* -f option, multiple uses: Options. (line 313) +* -f option, multiple uses: Options. (line 311) * -g option: Options. (line 147) * -h option: Options. (line 154) * -i option: Options. (line 159) -* -L option: Options. (line 295) +* -L option: Options. (line 293) * -l option: Options. (line 173) * -M option: Options. (line 205) * -N option: Options. (line 219) * -n option: Options. (line 211) -* -O option: Options. (line 237) +* -O option: Options. (line 235) * -o option: Options. (line 224) -* -P option: Options. (line 254) -* -p option: Options. (line 242) -* -r option: Options. (line 279) -* -S option: Options. (line 286) +* -P option: Options. (line 252) +* -p option: Options. (line 240) +* -r option: Options. (line 277) +* -S option: Options. (line 284) * -v option: Assignment Options. (line 12) -* -V option: Options. (line 300) +* -V option: Options. (line 298) * -v option: Options. (line 32) * -W option: Options. (line 46) * . (period), regexp operator: Regexp Operators. (line 44) @@ -31318,7 +31311,7 @@ Index * awf (amazingly workable formatter) program: Glossary. (line 24) * awk debugging, enabling: Options. (line 108) * awk language, POSIX version: Assignment Ops. (line 137) -* awk profiling, enabling: Options. (line 242) +* awk profiling, enabling: Options. (line 240) * awk programs <1>: Two Rules. (line 6) * awk programs <2>: Executable Scripts. (line 6) * awk programs: Getting Started. (line 12) @@ -31725,7 +31718,7 @@ Index * cosine: Numeric Functions. (line 15) * counting: Wc Program. (line 6) * csh utility: Statements/Lines. (line 44) -* csh utility, POSIXLY_CORRECT environment variable: Options. (line 355) +* csh utility, POSIXLY_CORRECT environment variable: Options. (line 353) * csh utility, |& operator, comparison with: Two-way I/O. (line 44) * ctime() user-defined function: Function Example. (line 73) * currency symbols, localization: Explaining gettext. (line 104) @@ -31908,7 +31901,7 @@ Index * debugger, read commands from a file: Debugger Info. (line 96) * debugging awk programs: Debugger. (line 6) * debugging gawk, bug reports: Bugs. (line 9) -* decimal point character, locale specific: Options. (line 270) +* decimal point character, locale specific: Options. (line 268) * decrement operators: Increment Ops. (line 35) * default keyword: Switch Statement. (line 6) * Deifik, Scott <1>: Bugs. (line 71) @@ -32336,7 +32329,7 @@ Index * FS variable, --field-separator option and: Options. (line 21) * FS variable, as null string: Single Character Fields. (line 20) -* FS variable, as TAB character: Options. (line 266) +* FS variable, as TAB character: Options. (line 264) * FS variable, changing value of: Field Separators. (line 35) * FS variable, running awk programs and: Cut Program. (line 68) * FS variable, setting from command line: Command Line Field Separator. @@ -32426,7 +32419,7 @@ Index (line 139) * gawk, ERRNO variable in: Getline. (line 19) * gawk, escape sequences: Escape Sequences. (line 124) -* gawk, extensions, disabling: Options. (line 254) +* gawk, extensions, disabling: Options. (line 252) * gawk, features, adding: Adding Code. (line 6) * gawk, features, advanced: Advanced Features. (line 6) * gawk, field separators and: User-modified. (line 71) @@ -32487,7 +32480,7 @@ Index * gawk, TEXTDOMAIN variable in: User-modified. (line 152) * gawk, timestamps: Time Functions. (line 6) * gawk, uses for: Preface. (line 36) -* gawk, versions of, information about, printing: Options. (line 300) +* gawk, versions of, information about, printing: Options. (line 298) * gawk, VMS version of: VMS Installation. (line 6) * gawk, word-boundary operator: GNU Regexp Operators. (line 63) @@ -32798,7 +32791,7 @@ Index * lint checking, empty programs: Command Line. (line 16) * lint checking, issuing warnings: Options. (line 185) * lint checking, POSIXLY_CORRECT environment variable: Options. - (line 340) + (line 338) * lint checking, undefined functions: Pass By Value/Reference. (line 88) * LINT variable: User-modified. (line 88) @@ -32812,7 +32805,7 @@ Index * loading, extensions: Options. (line 173) * local variables, in a function: Variable Scope. (line 6) * locale categories: Explaining gettext. (line 81) -* locale decimal point character: Options. (line 270) +* locale decimal point character: Options. (line 268) * locale, definition of: Locales. (line 6) * localization: I18N and L10N. (line 6) * localization, See internationalization, localization: I18N and L10N. @@ -32896,7 +32889,7 @@ Index * networks, programming: TCP/IP Networking. (line 6) * networks, support for: Special Network. (line 6) * newlines <1>: Boolean Ops. (line 67) -* newlines <2>: Options. (line 260) +* newlines <2>: Options. (line 258) * newlines: Statements/Lines. (line 6) * newlines, as field separators: Default Field Splitting. (line 6) @@ -33118,7 +33111,7 @@ Index * portability, NF variable, decrementing: Changing Fields. (line 115) * portability, operators: Increment Ops. (line 60) * portability, operators, not in POSIX awk: Precedence. (line 98) -* portability, POSIXLY_CORRECT environment variable: Options. (line 360) +* portability, POSIXLY_CORRECT environment variable: Options. (line 358) * portability, substr() function: String Functions. (line 510) * portable object files <1>: Translator i18n. (line 6) * portable object files: Explaining gettext. (line 37) @@ -33167,11 +33160,11 @@ Index * POSIX awk, regular expressions and: Regexp Operators. (line 162) * POSIX awk, timestamps and: Time Functions. (line 6) * POSIX awk, | I/O operator and: Getline/Pipe. (line 55) -* POSIX mode: Options. (line 254) +* POSIX mode: Options. (line 252) * POSIX, awk and: Preface. (line 23) * POSIX, gawk extensions not included in: POSIX/GNU. (line 6) * POSIX, programs, implementing in awk: Clones. (line 6) -* POSIXLY_CORRECT environment variable: Options. (line 340) +* POSIXLY_CORRECT environment variable: Options. (line 338) * PREC variable: User-modified. (line 124) * precedence <1>: Precedence. (line 6) * precedence: Increment Ops. (line 60) @@ -33351,7 +33344,7 @@ Index (line 59) * regular expressions, gawk, command-line options: GNU Regexp Operators. (line 70) -* regular expressions, interval expressions and: Options. (line 279) +* regular expressions, interval expressions and: Options. (line 277) * regular expressions, leftmost longest match: Leftmost Longest. (line 6) * regular expressions, operators <1>: Regexp Operators. (line 6) @@ -33432,7 +33425,7 @@ Index (line 68) * sample debugging session: Sample Debugging Session. (line 6) -* sandbox mode: Options. (line 286) +* sandbox mode: Options. (line 284) * save debugger options: Debugger Info. (line 84) * scalar or array: Type Functions. (line 11) * scalar values: Basic Data Typing. (line 13) @@ -33904,7 +33897,7 @@ Index * whitespace, as field separators: Default Field Splitting. (line 6) * whitespace, functions, calling: Calling Built-in. (line 10) -* whitespace, newlines as: Options. (line 260) +* whitespace, newlines as: Options. (line 258) * Williams, Kent: Contributors. (line 34) * Woehlke, Matthew: Contributors. (line 79) * Woods, John: Contributors. (line 27) @@ -33998,511 +33991,511 @@ Node: Intro Summary110051 Node: Invoking Gawk110817 Node: Command Line112332 Node: Options113123 -Ref: Options-Footnote-1128952 -Node: Other Arguments128977 -Node: Naming Standard Input131639 -Node: Environment Variables132733 -Node: AWKPATH Variable133291 -Ref: AWKPATH Variable-Footnote-1136163 -Ref: AWKPATH Variable-Footnote-2136208 -Node: AWKLIBPATH Variable136468 -Node: Other Environment Variables137227 -Node: Exit Status140882 -Node: Include Files141557 -Node: Loading Shared Libraries145135 -Node: Obsolete146519 -Node: Undocumented147216 -Node: Invoking Summary147483 -Node: Regexp149063 -Node: Regexp Usage150513 -Node: Escape Sequences152546 -Node: Regexp Operators158213 -Ref: Regexp Operators-Footnote-1165693 -Ref: Regexp Operators-Footnote-2165840 -Node: Bracket Expressions165938 -Ref: table-char-classes167828 -Node: GNU Regexp Operators170351 -Node: Case-sensitivity174074 -Ref: Case-sensitivity-Footnote-1176966 -Ref: Case-sensitivity-Footnote-2177201 -Node: Leftmost Longest177309 -Node: Computed Regexps178510 -Node: Regexp Summary181882 -Node: Reading Files183353 -Node: Records185445 -Node: awk split records186188 -Node: gawk split records191046 -Ref: gawk split records-Footnote-1195567 -Node: Fields195604 -Ref: Fields-Footnote-1198568 -Node: Nonconstant Fields198654 -Ref: Nonconstant Fields-Footnote-1200884 -Node: Changing Fields201086 -Node: Field Separators207040 -Node: Default Field Splitting209742 -Node: Regexp Field Splitting210859 -Node: Single Character Fields214200 -Node: Command Line Field Separator215259 -Node: Full Line Fields218601 -Ref: Full Line Fields-Footnote-1219109 -Node: Field Splitting Summary219155 -Ref: Field Splitting Summary-Footnote-1222254 -Node: Constant Size222355 -Node: Splitting By Content226962 -Ref: Splitting By Content-Footnote-1230712 -Node: Multiple Line230752 -Ref: Multiple Line-Footnote-1236608 -Node: Getline236787 -Node: Plain Getline239003 -Node: Getline/Variable241098 -Node: Getline/File242245 -Node: Getline/Variable/File243629 -Ref: Getline/Variable/File-Footnote-1245228 -Node: Getline/Pipe245315 -Node: Getline/Variable/Pipe248014 -Node: Getline/Coprocess249121 -Node: Getline/Variable/Coprocess250373 -Node: Getline Notes251110 -Node: Getline Summary253914 -Ref: table-getline-variants254322 -Node: Read Timeout255234 -Ref: Read Timeout-Footnote-1259061 -Node: Command line directories259119 -Node: Input Summary260023 -Node: Input Exercises263160 -Node: Printing263893 -Node: Print265615 -Node: Print Examples266956 -Node: Output Separators269735 -Node: OFMT271751 -Node: Printf273109 -Node: Basic Printf274015 -Node: Control Letters275554 -Node: Format Modifiers279406 -Node: Printf Examples285433 -Node: Redirection287897 -Node: Special Files294869 -Node: Special FD295400 -Ref: Special FD-Footnote-1299024 -Node: Special Network299098 -Node: Special Caveats299948 -Node: Close Files And Pipes300744 -Ref: Close Files And Pipes-Footnote-1307905 -Ref: Close Files And Pipes-Footnote-2308053 -Node: Output Summary308203 -Node: Output exercises309200 -Node: Expressions309880 -Node: Values311065 -Node: Constants311741 -Node: Scalar Constants312421 -Ref: Scalar Constants-Footnote-1313280 -Node: Nondecimal-numbers313530 -Node: Regexp Constants316530 -Node: Using Constant Regexps317005 -Node: Variables320075 -Node: Using Variables320730 -Node: Assignment Options322454 -Node: Conversion324329 -Node: Strings And Numbers324853 -Ref: Strings And Numbers-Footnote-1327915 -Node: Locale influences conversions328024 -Ref: table-locale-affects330741 -Node: All Operators331329 -Node: Arithmetic Ops331959 -Node: Concatenation334464 -Ref: Concatenation-Footnote-1337260 -Node: Assignment Ops337380 -Ref: table-assign-ops342363 -Node: Increment Ops343680 -Node: Truth Values and Conditions347118 -Node: Truth Values348201 -Node: Typing and Comparison349250 -Node: Variable Typing350043 -Ref: Variable Typing-Footnote-1353943 -Node: Comparison Operators354065 -Ref: table-relational-ops354475 -Node: POSIX String Comparison358025 -Ref: POSIX String Comparison-Footnote-1359109 -Node: Boolean Ops359247 -Ref: Boolean Ops-Footnote-1363317 -Node: Conditional Exp363408 -Node: Function Calls365135 -Node: Precedence369015 -Node: Locales372684 -Node: Expressions Summary374315 -Node: Patterns and Actions376856 -Node: Pattern Overview377972 -Node: Regexp Patterns379649 -Node: Expression Patterns380192 -Node: Ranges383973 -Node: BEGIN/END387079 -Node: Using BEGIN/END387841 -Ref: Using BEGIN/END-Footnote-1390577 -Node: I/O And BEGIN/END390683 -Node: BEGINFILE/ENDFILE392968 -Node: Empty395899 -Node: Using Shell Variables396216 -Node: Action Overview398499 -Node: Statements400826 -Node: If Statement402674 -Node: While Statement404172 -Node: Do Statement406216 -Node: For Statement407372 -Node: Switch Statement410524 -Node: Break Statement412627 -Node: Continue Statement414682 -Node: Next Statement416475 -Node: Nextfile Statement418865 -Node: Exit Statement421520 -Node: Built-in Variables423924 -Node: User-modified425051 -Ref: User-modified-Footnote-1432740 -Node: Auto-set432802 -Ref: Auto-set-Footnote-1445721 -Ref: Auto-set-Footnote-2445926 -Node: ARGC and ARGV445982 -Node: Pattern Action Summary449836 -Node: Arrays452059 -Node: Array Basics453608 -Node: Array Intro454434 -Ref: figure-array-elements456407 -Node: Reference to Elements458814 -Node: Assigning Elements461087 -Node: Array Example461578 -Node: Scanning an Array463310 -Node: Controlling Scanning466325 -Ref: Controlling Scanning-Footnote-1471498 -Node: Delete471814 -Ref: Delete-Footnote-1474579 -Node: Numeric Array Subscripts474636 -Node: Uninitialized Subscripts476819 -Node: Multidimensional478444 -Node: Multiscanning481537 -Node: Arrays of Arrays483126 -Node: Arrays Summary487789 -Node: Functions489894 -Node: Built-in490767 -Node: Calling Built-in491845 -Node: Numeric Functions493833 -Ref: Numeric Functions-Footnote-1497667 -Ref: Numeric Functions-Footnote-2498024 -Ref: Numeric Functions-Footnote-3498072 -Node: String Functions498341 -Ref: String Functions-Footnote-1521352 -Ref: String Functions-Footnote-2521481 -Ref: String Functions-Footnote-3521729 -Node: Gory Details521816 -Ref: table-sub-escapes523485 -Ref: table-sub-posix-92524839 -Ref: table-sub-proposed526190 -Ref: table-posix-sub527544 -Ref: table-gensub-escapes529089 -Ref: Gory Details-Footnote-1530265 -Ref: Gory Details-Footnote-2530316 -Node: I/O Functions530467 -Ref: I/O Functions-Footnote-1537590 -Node: Time Functions537737 -Ref: Time Functions-Footnote-1548201 -Ref: Time Functions-Footnote-2548269 -Ref: Time Functions-Footnote-3548427 -Ref: Time Functions-Footnote-4548538 -Ref: Time Functions-Footnote-5548650 -Ref: Time Functions-Footnote-6548877 -Node: Bitwise Functions549143 -Ref: table-bitwise-ops549705 -Ref: Bitwise Functions-Footnote-1553950 -Node: Type Functions554134 -Node: I18N Functions555276 -Node: User-defined556921 -Node: Definition Syntax557725 -Ref: Definition Syntax-Footnote-1562904 -Node: Function Example562973 -Ref: Function Example-Footnote-1565617 -Node: Function Caveats565639 -Node: Calling A Function566157 -Node: Variable Scope567112 -Node: Pass By Value/Reference570100 -Node: Return Statement573608 -Node: Dynamic Typing576592 -Node: Indirect Calls577521 -Node: Functions Summary587234 -Node: Library Functions589773 -Ref: Library Functions-Footnote-1593391 -Ref: Library Functions-Footnote-2593534 -Node: Library Names593705 -Ref: Library Names-Footnote-1597178 -Ref: Library Names-Footnote-2597398 -Node: General Functions597484 -Node: Strtonum Function598512 -Node: Assert Function601292 -Node: Round Function604618 -Node: Cliff Random Function606159 -Node: Ordinal Functions607175 -Ref: Ordinal Functions-Footnote-1610252 -Ref: Ordinal Functions-Footnote-2610504 -Node: Join Function610715 -Ref: Join Function-Footnote-1612486 -Node: Getlocaltime Function612686 -Node: Readfile Function616422 -Node: Data File Management618261 -Node: Filetrans Function618893 -Node: Rewind Function622962 -Node: File Checking624349 -Ref: File Checking-Footnote-1625481 -Node: Empty Files625682 -Node: Ignoring Assigns627661 -Node: Getopt Function629215 -Ref: Getopt Function-Footnote-1640518 -Node: Passwd Functions640721 -Ref: Passwd Functions-Footnote-1649700 -Node: Group Functions649788 -Ref: Group Functions-Footnote-1657729 -Node: Walking Arrays657942 -Node: Library Functions Summary659545 -Node: Library exercises660933 -Node: Sample Programs662213 -Node: Running Examples662983 -Node: Clones663711 -Node: Cut Program664935 -Node: Egrep Program674803 -Ref: Egrep Program-Footnote-1682774 -Node: Id Program682884 -Node: Split Program686548 -Ref: Split Program-Footnote-1690086 -Node: Tee Program690214 -Node: Uniq Program693021 -Node: Wc Program700451 -Ref: Wc Program-Footnote-1704716 -Node: Miscellaneous Programs704808 -Node: Dupword Program706021 -Node: Alarm Program708052 -Node: Translate Program712866 -Ref: Translate Program-Footnote-1717257 -Ref: Translate Program-Footnote-2717527 -Node: Labels Program717661 -Ref: Labels Program-Footnote-1721032 -Node: Word Sorting721116 -Node: History Sorting725159 -Node: Extract Program726995 -Node: Simple Sed734531 -Node: Igawk Program737593 -Ref: Igawk Program-Footnote-1751904 -Ref: Igawk Program-Footnote-2752105 -Node: Anagram Program752243 -Node: Signature Program755311 -Node: Programs Summary756558 -Node: Programs Exercises757773 -Node: Advanced Features761424 -Node: Nondecimal Data763372 -Node: Array Sorting764949 -Node: Controlling Array Traversal765646 -Node: Array Sorting Functions773926 -Ref: Array Sorting Functions-Footnote-1777833 -Node: Two-way I/O778027 -Ref: Two-way I/O-Footnote-1783543 -Node: TCP/IP Networking783625 -Node: Profiling786469 -Node: Advanced Features Summary794011 -Node: Internationalization795875 -Node: I18N and L10N797355 -Node: Explaining gettext798041 -Ref: Explaining gettext-Footnote-1803181 -Ref: Explaining gettext-Footnote-2803365 -Node: Programmer i18n803530 -Node: Translator i18n807755 -Node: String Extraction808549 -Ref: String Extraction-Footnote-1809510 -Node: Printf Ordering809596 -Ref: Printf Ordering-Footnote-1812378 -Node: I18N Portability812442 -Ref: I18N Portability-Footnote-1814891 -Node: I18N Example814954 -Ref: I18N Example-Footnote-1817676 -Node: Gawk I18N817748 -Node: I18N Summary818386 -Node: Debugger819725 -Node: Debugging820747 -Node: Debugging Concepts821188 -Node: Debugging Terms823044 -Node: Awk Debugging825641 -Node: Sample Debugging Session826533 -Node: Debugger Invocation827053 -Node: Finding The Bug828386 -Node: List of Debugger Commands834868 -Node: Breakpoint Control836200 -Node: Debugger Execution Control839864 -Node: Viewing And Changing Data843224 -Node: Execution Stack846582 -Node: Debugger Info848095 -Node: Miscellaneous Debugger Commands852089 -Node: Readline Support857273 -Node: Limitations858165 -Node: Debugging Summary860439 -Node: Arbitrary Precision Arithmetic861603 -Node: Computer Arithmetic862932 -Ref: Computer Arithmetic-Footnote-1867319 -Node: Math Definitions867376 -Ref: table-ieee-formats870260 -Node: MPFR features870764 -Node: FP Math Caution872406 -Ref: FP Math Caution-Footnote-1873447 -Node: Inexactness of computations873816 -Node: Inexact representation874764 -Node: Comparing FP Values876119 -Node: Errors accumulate877083 -Node: Getting Accuracy878516 -Node: Try To Round881175 -Node: Setting precision882074 -Ref: table-predefined-precision-strings882756 -Node: Setting the rounding mode884549 -Ref: table-gawk-rounding-modes884913 -Ref: Setting the rounding mode-Footnote-1888367 -Node: Arbitrary Precision Integers888546 -Ref: Arbitrary Precision Integers-Footnote-1891549 -Node: POSIX Floating Point Problems891698 -Ref: POSIX Floating Point Problems-Footnote-1895574 -Node: Floating point summary895612 -Node: Dynamic Extensions897829 -Node: Extension Intro899381 -Node: Plugin License900646 -Node: Extension Mechanism Outline901331 -Ref: figure-load-extension901755 -Ref: figure-load-new-function903240 -Ref: figure-call-new-function904242 -Node: Extension API Description906226 -Node: Extension API Functions Introduction907676 -Node: General Data Types912541 -Ref: General Data Types-Footnote-1918234 -Node: Requesting Values918533 -Ref: table-value-types-returned919270 -Node: Memory Allocation Functions920228 -Ref: Memory Allocation Functions-Footnote-1922975 -Node: Constructor Functions923071 -Node: Registration Functions924829 -Node: Extension Functions925514 -Node: Exit Callback Functions927816 -Node: Extension Version String929065 -Node: Input Parsers929715 -Node: Output Wrappers939518 -Node: Two-way processors944034 -Node: Printing Messages946238 -Ref: Printing Messages-Footnote-1947315 -Node: Updating `ERRNO'947467 -Node: Accessing Parameters948206 -Node: Symbol Table Access949436 -Node: Symbol table by name949950 -Node: Symbol table by cookie951926 -Ref: Symbol table by cookie-Footnote-1956059 -Node: Cached values956122 -Ref: Cached values-Footnote-1959626 -Node: Array Manipulation959717 -Ref: Array Manipulation-Footnote-1960815 -Node: Array Data Types960854 -Ref: Array Data Types-Footnote-1963557 -Node: Array Functions963649 -Node: Flattening Arrays967523 -Node: Creating Arrays974375 -Node: Extension API Variables979106 -Node: Extension Versioning979742 -Node: Extension API Informational Variables981643 -Node: Extension API Boilerplate982729 -Node: Finding Extensions986533 -Node: Extension Example987093 -Node: Internal File Description987823 -Node: Internal File Ops991914 -Ref: Internal File Ops-Footnote-11003346 -Node: Using Internal File Ops1003486 -Ref: Using Internal File Ops-Footnote-11005833 -Node: Extension Samples1006101 -Node: Extension Sample File Functions1007625 -Node: Extension Sample Fnmatch1015193 -Node: Extension Sample Fork1016675 -Node: Extension Sample Inplace1017888 -Node: Extension Sample Ord1019563 -Node: Extension Sample Readdir1020399 -Ref: table-readdir-file-types1021255 -Node: Extension Sample Revout1022054 -Node: Extension Sample Rev2way1022645 -Node: Extension Sample Read write array1023386 -Node: Extension Sample Readfile1025265 -Node: Extension Sample API Tests1026365 -Node: Extension Sample Time1026890 -Node: gawkextlib1028205 -Node: Extension summary1031018 -Node: Extension Exercises1034711 -Node: Language History1035433 -Node: V7/SVR3.11037076 -Node: SVR41039396 -Node: POSIX1040838 -Node: BTL1042224 -Node: POSIX/GNU1042958 -Node: Feature History1048557 -Node: Common Extensions1061687 -Node: Ranges and Locales1062999 -Ref: Ranges and Locales-Footnote-11067616 -Ref: Ranges and Locales-Footnote-21067643 -Ref: Ranges and Locales-Footnote-31067877 -Node: Contributors1068098 -Node: History summary1073523 -Node: Installation1074892 -Node: Gawk Distribution1075843 -Node: Getting1076327 -Node: Extracting1077151 -Node: Distribution contents1078793 -Node: Unix Installation1084510 -Node: Quick Installation1085127 -Node: Additional Configuration Options1087569 -Node: Configuration Philosophy1089307 -Node: Non-Unix Installation1091658 -Node: PC Installation1092116 -Node: PC Binary Installation1093427 -Node: PC Compiling1095275 -Ref: PC Compiling-Footnote-11098274 -Node: PC Testing1098379 -Node: PC Using1099555 -Node: Cygwin1103713 -Node: MSYS1104522 -Node: VMS Installation1105036 -Node: VMS Compilation1105832 -Ref: VMS Compilation-Footnote-11107054 -Node: VMS Dynamic Extensions1107112 -Node: VMS Installation Details1108485 -Node: VMS Running1110737 -Node: VMS GNV1113571 -Node: VMS Old Gawk1114294 -Node: Bugs1114764 -Node: Other Versions1118768 -Node: Installation summary1125023 -Node: Notes1126079 -Node: Compatibility Mode1126944 -Node: Additions1127726 -Node: Accessing The Source1128651 -Node: Adding Code1130087 -Node: New Ports1136265 -Node: Derived Files1140746 -Ref: Derived Files-Footnote-11145827 -Ref: Derived Files-Footnote-21145861 -Ref: Derived Files-Footnote-31146457 -Node: Future Extensions1146571 -Node: Implementation Limitations1147177 -Node: Extension Design1148425 -Node: Old Extension Problems1149579 -Ref: Old Extension Problems-Footnote-11151096 -Node: Extension New Mechanism Goals1151153 -Ref: Extension New Mechanism Goals-Footnote-11154513 -Node: Extension Other Design Decisions1154702 -Node: Extension Future Growth1156808 -Node: Old Extension Mechanism1157644 -Node: Notes summary1159406 -Node: Basic Concepts1160592 -Node: Basic High Level1161273 -Ref: figure-general-flow1161545 -Ref: figure-process-flow1162144 -Ref: Basic High Level-Footnote-11165373 -Node: Basic Data Typing1165558 -Node: Glossary1168886 -Node: Copying1194038 -Node: GNU Free Documentation License1231594 -Node: Index1256730 +Ref: Options-Footnote-1128823 +Node: Other Arguments128848 +Node: Naming Standard Input131510 +Node: Environment Variables132604 +Node: AWKPATH Variable133162 +Ref: AWKPATH Variable-Footnote-1136034 +Ref: AWKPATH Variable-Footnote-2136079 +Node: AWKLIBPATH Variable136339 +Node: Other Environment Variables137098 +Node: Exit Status140548 +Node: Include Files141223 +Node: Loading Shared Libraries144801 +Node: Obsolete146185 +Node: Undocumented146882 +Node: Invoking Summary147149 +Node: Regexp148729 +Node: Regexp Usage150179 +Node: Escape Sequences152212 +Node: Regexp Operators157879 +Ref: Regexp Operators-Footnote-1165359 +Ref: Regexp Operators-Footnote-2165506 +Node: Bracket Expressions165604 +Ref: table-char-classes167494 +Node: GNU Regexp Operators170017 +Node: Case-sensitivity173740 +Ref: Case-sensitivity-Footnote-1176632 +Ref: Case-sensitivity-Footnote-2176867 +Node: Leftmost Longest176975 +Node: Computed Regexps178176 +Node: Regexp Summary181548 +Node: Reading Files183019 +Node: Records185111 +Node: awk split records185854 +Node: gawk split records190712 +Ref: gawk split records-Footnote-1195233 +Node: Fields195270 +Ref: Fields-Footnote-1198234 +Node: Nonconstant Fields198320 +Ref: Nonconstant Fields-Footnote-1200550 +Node: Changing Fields200752 +Node: Field Separators206706 +Node: Default Field Splitting209408 +Node: Regexp Field Splitting210525 +Node: Single Character Fields213866 +Node: Command Line Field Separator214925 +Node: Full Line Fields218267 +Ref: Full Line Fields-Footnote-1218775 +Node: Field Splitting Summary218821 +Ref: Field Splitting Summary-Footnote-1221920 +Node: Constant Size222021 +Node: Splitting By Content226628 +Ref: Splitting By Content-Footnote-1230378 +Node: Multiple Line230418 +Ref: Multiple Line-Footnote-1236274 +Node: Getline236453 +Node: Plain Getline238669 +Node: Getline/Variable240764 +Node: Getline/File241911 +Node: Getline/Variable/File243295 +Ref: Getline/Variable/File-Footnote-1244894 +Node: Getline/Pipe244981 +Node: Getline/Variable/Pipe247680 +Node: Getline/Coprocess248787 +Node: Getline/Variable/Coprocess250039 +Node: Getline Notes250776 +Node: Getline Summary253580 +Ref: table-getline-variants253988 +Node: Read Timeout254900 +Ref: Read Timeout-Footnote-1258727 +Node: Command line directories258785 +Node: Input Summary259689 +Node: Input Exercises262826 +Node: Printing263559 +Node: Print265281 +Node: Print Examples266622 +Node: Output Separators269401 +Node: OFMT271417 +Node: Printf272775 +Node: Basic Printf273681 +Node: Control Letters275220 +Node: Format Modifiers279072 +Node: Printf Examples285099 +Node: Redirection287563 +Node: Special Files294535 +Node: Special FD295066 +Ref: Special FD-Footnote-1298690 +Node: Special Network298764 +Node: Special Caveats299614 +Node: Close Files And Pipes300410 +Ref: Close Files And Pipes-Footnote-1307571 +Ref: Close Files And Pipes-Footnote-2307719 +Node: Output Summary307869 +Node: Output exercises308866 +Node: Expressions309546 +Node: Values310731 +Node: Constants311407 +Node: Scalar Constants312087 +Ref: Scalar Constants-Footnote-1312946 +Node: Nondecimal-numbers313196 +Node: Regexp Constants316196 +Node: Using Constant Regexps316671 +Node: Variables319741 +Node: Using Variables320396 +Node: Assignment Options322120 +Node: Conversion323995 +Node: Strings And Numbers324519 +Ref: Strings And Numbers-Footnote-1327581 +Node: Locale influences conversions327690 +Ref: table-locale-affects330407 +Node: All Operators330995 +Node: Arithmetic Ops331625 +Node: Concatenation334130 +Ref: Concatenation-Footnote-1336926 +Node: Assignment Ops337046 +Ref: table-assign-ops342029 +Node: Increment Ops343346 +Node: Truth Values and Conditions346784 +Node: Truth Values347867 +Node: Typing and Comparison348916 +Node: Variable Typing349709 +Ref: Variable Typing-Footnote-1353609 +Node: Comparison Operators353731 +Ref: table-relational-ops354141 +Node: POSIX String Comparison357691 +Ref: POSIX String Comparison-Footnote-1358775 +Node: Boolean Ops358913 +Ref: Boolean Ops-Footnote-1362983 +Node: Conditional Exp363074 +Node: Function Calls364801 +Node: Precedence368681 +Node: Locales372350 +Node: Expressions Summary373981 +Node: Patterns and Actions376522 +Node: Pattern Overview377638 +Node: Regexp Patterns379315 +Node: Expression Patterns379858 +Node: Ranges383639 +Node: BEGIN/END386745 +Node: Using BEGIN/END387507 +Ref: Using BEGIN/END-Footnote-1390243 +Node: I/O And BEGIN/END390349 +Node: BEGINFILE/ENDFILE392634 +Node: Empty395565 +Node: Using Shell Variables395882 +Node: Action Overview398165 +Node: Statements400492 +Node: If Statement402340 +Node: While Statement403838 +Node: Do Statement405882 +Node: For Statement407038 +Node: Switch Statement410190 +Node: Break Statement412293 +Node: Continue Statement414348 +Node: Next Statement416141 +Node: Nextfile Statement418531 +Node: Exit Statement421186 +Node: Built-in Variables423590 +Node: User-modified424717 +Ref: User-modified-Footnote-1432406 +Node: Auto-set432468 +Ref: Auto-set-Footnote-1445387 +Ref: Auto-set-Footnote-2445592 +Node: ARGC and ARGV445648 +Node: Pattern Action Summary449502 +Node: Arrays451725 +Node: Array Basics453274 +Node: Array Intro454100 +Ref: figure-array-elements456073 +Node: Reference to Elements458480 +Node: Assigning Elements460753 +Node: Array Example461244 +Node: Scanning an Array462976 +Node: Controlling Scanning465991 +Ref: Controlling Scanning-Footnote-1471164 +Node: Delete471480 +Ref: Delete-Footnote-1474245 +Node: Numeric Array Subscripts474302 +Node: Uninitialized Subscripts476485 +Node: Multidimensional478110 +Node: Multiscanning481203 +Node: Arrays of Arrays482792 +Node: Arrays Summary487455 +Node: Functions489560 +Node: Built-in490433 +Node: Calling Built-in491511 +Node: Numeric Functions493499 +Ref: Numeric Functions-Footnote-1497333 +Ref: Numeric Functions-Footnote-2497690 +Ref: Numeric Functions-Footnote-3497738 +Node: String Functions498007 +Ref: String Functions-Footnote-1521018 +Ref: String Functions-Footnote-2521147 +Ref: String Functions-Footnote-3521395 +Node: Gory Details521482 +Ref: table-sub-escapes523151 +Ref: table-sub-posix-92524505 +Ref: table-sub-proposed525856 +Ref: table-posix-sub527210 +Ref: table-gensub-escapes528755 +Ref: Gory Details-Footnote-1529931 +Ref: Gory Details-Footnote-2529982 +Node: I/O Functions530133 +Ref: I/O Functions-Footnote-1537256 +Node: Time Functions537403 +Ref: Time Functions-Footnote-1547867 +Ref: Time Functions-Footnote-2547935 +Ref: Time Functions-Footnote-3548093 +Ref: Time Functions-Footnote-4548204 +Ref: Time Functions-Footnote-5548316 +Ref: Time Functions-Footnote-6548543 +Node: Bitwise Functions548809 +Ref: table-bitwise-ops549371 +Ref: Bitwise Functions-Footnote-1553616 +Node: Type Functions553800 +Node: I18N Functions554942 +Node: User-defined556587 +Node: Definition Syntax557391 +Ref: Definition Syntax-Footnote-1562570 +Node: Function Example562639 +Ref: Function Example-Footnote-1565283 +Node: Function Caveats565305 +Node: Calling A Function565823 +Node: Variable Scope566778 +Node: Pass By Value/Reference569766 +Node: Return Statement573274 +Node: Dynamic Typing576258 +Node: Indirect Calls577187 +Node: Functions Summary586900 +Node: Library Functions589439 +Ref: Library Functions-Footnote-1593057 +Ref: Library Functions-Footnote-2593200 +Node: Library Names593371 +Ref: Library Names-Footnote-1596844 +Ref: Library Names-Footnote-2597064 +Node: General Functions597150 +Node: Strtonum Function598178 +Node: Assert Function600958 +Node: Round Function604284 +Node: Cliff Random Function605825 +Node: Ordinal Functions606841 +Ref: Ordinal Functions-Footnote-1609918 +Ref: Ordinal Functions-Footnote-2610170 +Node: Join Function610381 +Ref: Join Function-Footnote-1612152 +Node: Getlocaltime Function612352 +Node: Readfile Function616088 +Node: Data File Management617927 +Node: Filetrans Function618559 +Node: Rewind Function622628 +Node: File Checking624015 +Ref: File Checking-Footnote-1625147 +Node: Empty Files625348 +Node: Ignoring Assigns627327 +Node: Getopt Function628881 +Ref: Getopt Function-Footnote-1640184 +Node: Passwd Functions640387 +Ref: Passwd Functions-Footnote-1649366 +Node: Group Functions649454 +Ref: Group Functions-Footnote-1657395 +Node: Walking Arrays657608 +Node: Library Functions Summary659211 +Node: Library exercises660599 +Node: Sample Programs661879 +Node: Running Examples662649 +Node: Clones663377 +Node: Cut Program664601 +Node: Egrep Program674469 +Ref: Egrep Program-Footnote-1682440 +Node: Id Program682550 +Node: Split Program686214 +Ref: Split Program-Footnote-1689752 +Node: Tee Program689880 +Node: Uniq Program692687 +Node: Wc Program700117 +Ref: Wc Program-Footnote-1704382 +Node: Miscellaneous Programs704474 +Node: Dupword Program705687 +Node: Alarm Program707718 +Node: Translate Program712532 +Ref: Translate Program-Footnote-1716923 +Ref: Translate Program-Footnote-2717193 +Node: Labels Program717327 +Ref: Labels Program-Footnote-1720698 +Node: Word Sorting720782 +Node: History Sorting724825 +Node: Extract Program726661 +Node: Simple Sed734197 +Node: Igawk Program737259 +Ref: Igawk Program-Footnote-1751570 +Ref: Igawk Program-Footnote-2751771 +Node: Anagram Program751909 +Node: Signature Program754977 +Node: Programs Summary756224 +Node: Programs Exercises757439 +Node: Advanced Features761090 +Node: Nondecimal Data763038 +Node: Array Sorting764615 +Node: Controlling Array Traversal765312 +Node: Array Sorting Functions773592 +Ref: Array Sorting Functions-Footnote-1777499 +Node: Two-way I/O777693 +Ref: Two-way I/O-Footnote-1783209 +Node: TCP/IP Networking783291 +Node: Profiling786135 +Node: Advanced Features Summary793686 +Node: Internationalization795550 +Node: I18N and L10N797030 +Node: Explaining gettext797716 +Ref: Explaining gettext-Footnote-1802856 +Ref: Explaining gettext-Footnote-2803040 +Node: Programmer i18n803205 +Node: Translator i18n807430 +Node: String Extraction808224 +Ref: String Extraction-Footnote-1809185 +Node: Printf Ordering809271 +Ref: Printf Ordering-Footnote-1812053 +Node: I18N Portability812117 +Ref: I18N Portability-Footnote-1814566 +Node: I18N Example814629 +Ref: I18N Example-Footnote-1817351 +Node: Gawk I18N817423 +Node: I18N Summary818061 +Node: Debugger819400 +Node: Debugging820422 +Node: Debugging Concepts820863 +Node: Debugging Terms822719 +Node: Awk Debugging825316 +Node: Sample Debugging Session826208 +Node: Debugger Invocation826728 +Node: Finding The Bug828061 +Node: List of Debugger Commands834543 +Node: Breakpoint Control835875 +Node: Debugger Execution Control839539 +Node: Viewing And Changing Data842899 +Node: Execution Stack846257 +Node: Debugger Info847770 +Node: Miscellaneous Debugger Commands851764 +Node: Readline Support856948 +Node: Limitations857840 +Node: Debugging Summary860114 +Node: Arbitrary Precision Arithmetic861278 +Node: Computer Arithmetic862607 +Ref: Computer Arithmetic-Footnote-1866994 +Node: Math Definitions867051 +Ref: table-ieee-formats869935 +Node: MPFR features870439 +Node: FP Math Caution872081 +Ref: FP Math Caution-Footnote-1873122 +Node: Inexactness of computations873491 +Node: Inexact representation874439 +Node: Comparing FP Values875794 +Node: Errors accumulate876758 +Node: Getting Accuracy878191 +Node: Try To Round880850 +Node: Setting precision881749 +Ref: table-predefined-precision-strings882431 +Node: Setting the rounding mode884224 +Ref: table-gawk-rounding-modes884588 +Ref: Setting the rounding mode-Footnote-1888042 +Node: Arbitrary Precision Integers888221 +Ref: Arbitrary Precision Integers-Footnote-1891224 +Node: POSIX Floating Point Problems891373 +Ref: POSIX Floating Point Problems-Footnote-1895249 +Node: Floating point summary895287 +Node: Dynamic Extensions897504 +Node: Extension Intro899056 +Node: Plugin License900321 +Node: Extension Mechanism Outline901006 +Ref: figure-load-extension901430 +Ref: figure-load-new-function902915 +Ref: figure-call-new-function903917 +Node: Extension API Description905901 +Node: Extension API Functions Introduction907351 +Node: General Data Types912216 +Ref: General Data Types-Footnote-1917909 +Node: Requesting Values918208 +Ref: table-value-types-returned918945 +Node: Memory Allocation Functions919903 +Ref: Memory Allocation Functions-Footnote-1922650 +Node: Constructor Functions922746 +Node: Registration Functions924504 +Node: Extension Functions925189 +Node: Exit Callback Functions927491 +Node: Extension Version String928740 +Node: Input Parsers929390 +Node: Output Wrappers939193 +Node: Two-way processors943709 +Node: Printing Messages945913 +Ref: Printing Messages-Footnote-1946990 +Node: Updating `ERRNO'947142 +Node: Accessing Parameters947881 +Node: Symbol Table Access949111 +Node: Symbol table by name949625 +Node: Symbol table by cookie951601 +Ref: Symbol table by cookie-Footnote-1955734 +Node: Cached values955797 +Ref: Cached values-Footnote-1959301 +Node: Array Manipulation959392 +Ref: Array Manipulation-Footnote-1960490 +Node: Array Data Types960529 +Ref: Array Data Types-Footnote-1963232 +Node: Array Functions963324 +Node: Flattening Arrays967198 +Node: Creating Arrays974050 +Node: Extension API Variables978781 +Node: Extension Versioning979417 +Node: Extension API Informational Variables981318 +Node: Extension API Boilerplate982404 +Node: Finding Extensions986208 +Node: Extension Example986768 +Node: Internal File Description987498 +Node: Internal File Ops991589 +Ref: Internal File Ops-Footnote-11003021 +Node: Using Internal File Ops1003161 +Ref: Using Internal File Ops-Footnote-11005508 +Node: Extension Samples1005776 +Node: Extension Sample File Functions1007300 +Node: Extension Sample Fnmatch1014868 +Node: Extension Sample Fork1016350 +Node: Extension Sample Inplace1017563 +Node: Extension Sample Ord1019238 +Node: Extension Sample Readdir1020074 +Ref: table-readdir-file-types1020930 +Node: Extension Sample Revout1021729 +Node: Extension Sample Rev2way1022320 +Node: Extension Sample Read write array1023061 +Node: Extension Sample Readfile1024940 +Node: Extension Sample API Tests1026040 +Node: Extension Sample Time1026565 +Node: gawkextlib1027880 +Node: Extension summary1030693 +Node: Extension Exercises1034386 +Node: Language History1035108 +Node: V7/SVR3.11036751 +Node: SVR41039071 +Node: POSIX1040513 +Node: BTL1041899 +Node: POSIX/GNU1042633 +Node: Feature History1048232 +Node: Common Extensions1061362 +Node: Ranges and Locales1062674 +Ref: Ranges and Locales-Footnote-11067291 +Ref: Ranges and Locales-Footnote-21067318 +Ref: Ranges and Locales-Footnote-31067552 +Node: Contributors1067773 +Node: History summary1073198 +Node: Installation1074567 +Node: Gawk Distribution1075518 +Node: Getting1076002 +Node: Extracting1076826 +Node: Distribution contents1078468 +Node: Unix Installation1084185 +Node: Quick Installation1084802 +Node: Additional Configuration Options1087244 +Node: Configuration Philosophy1088982 +Node: Non-Unix Installation1091333 +Node: PC Installation1091791 +Node: PC Binary Installation1093102 +Node: PC Compiling1094950 +Ref: PC Compiling-Footnote-11097949 +Node: PC Testing1098054 +Node: PC Using1099230 +Node: Cygwin1103388 +Node: MSYS1104197 +Node: VMS Installation1104711 +Node: VMS Compilation1105507 +Ref: VMS Compilation-Footnote-11106729 +Node: VMS Dynamic Extensions1106787 +Node: VMS Installation Details1108160 +Node: VMS Running1110412 +Node: VMS GNV1113246 +Node: VMS Old Gawk1113969 +Node: Bugs1114439 +Node: Other Versions1118443 +Node: Installation summary1124698 +Node: Notes1125754 +Node: Compatibility Mode1126619 +Node: Additions1127401 +Node: Accessing The Source1128326 +Node: Adding Code1129762 +Node: New Ports1135940 +Node: Derived Files1140421 +Ref: Derived Files-Footnote-11145502 +Ref: Derived Files-Footnote-21145536 +Ref: Derived Files-Footnote-31146132 +Node: Future Extensions1146246 +Node: Implementation Limitations1146852 +Node: Extension Design1148100 +Node: Old Extension Problems1149254 +Ref: Old Extension Problems-Footnote-11150771 +Node: Extension New Mechanism Goals1150828 +Ref: Extension New Mechanism Goals-Footnote-11154188 +Node: Extension Other Design Decisions1154377 +Node: Extension Future Growth1156483 +Node: Old Extension Mechanism1157319 +Node: Notes summary1159081 +Node: Basic Concepts1160267 +Node: Basic High Level1160948 +Ref: figure-general-flow1161220 +Ref: figure-process-flow1161819 +Ref: Basic High Level-Footnote-11165048 +Node: Basic Data Typing1165233 +Node: Glossary1168561 +Node: Copying1193713 +Node: GNU Free Documentation License1231269 +Node: Index1256405  End Tag Table -- cgit v1.2.3 From 3a0515fa9a96d2847a539e8af616d85cedf6d788 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 25 Jun 2014 22:07:29 +0300 Subject: Update copying and back cover text. --- doc/gawk.info | 1126 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 560 insertions(+), 566 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index e1ee6b3a..65ac7ab8 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -20,16 +20,13 @@ implementation of AWK. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the -Invariant Sections being "GNU General Public License", the Front-Cover -texts being (a) (see below), and with the Back-Cover Texts being (b) -(see below). A copy of the license is included in the section entitled -"GNU Free Documentation License". +Invariant Sections being "GNU General Public License", with the +Front-Cover Texts being "A GNU Manual", and with the Back-Cover Texts +as in (a) below. A copy of the license is included in the section +entitled "GNU Free Documentation License". - a. "A GNU Manual" - - b. "You have the freedom to copy and modify this GNU manual. Buying - copies from the FSF supports it in developing GNU and promoting - software freedom." + a. The FSF's Back-Cover Text is: "You have the freedom to copy and + modify this GNU manual."  File: gawk.info, Node: Top, Next: Foreword, Up: (dir) @@ -51,16 +48,13 @@ implementation of AWK. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the -Invariant Sections being "GNU General Public License", the Front-Cover -texts being (a) (see below), and with the Back-Cover Texts being (b) -(see below). A copy of the license is included in the section entitled -"GNU Free Documentation License". - - a. "A GNU Manual" +Invariant Sections being "GNU General Public License", with the +Front-Cover Texts being "A GNU Manual", and with the Back-Cover Texts +as in (a) below. A copy of the license is included in the section +entitled "GNU Free Documentation License". - b. "You have the freedom to copy and modify this GNU manual. Buying - copies from the FSF supports it in developing GNU and promoting - software freedom." + a. The FSF's Back-Cover Text is: "You have the freedom to copy and + modify this GNU manual." * Menu: @@ -33948,553 +33942,553 @@ Index  Tag Table: -Node: Top1292 -Node: Foreword42034 -Node: Preface46379 -Ref: Preface-Footnote-149526 -Ref: Preface-Footnote-249633 -Node: History49865 -Node: Names52239 -Ref: Names-Footnote-153703 -Node: This Manual53776 -Ref: This Manual-Footnote-159555 -Node: Conventions59655 -Node: Manual History61811 -Ref: Manual History-Footnote-165250 -Ref: Manual History-Footnote-265291 -Node: How To Contribute65365 -Node: Acknowledgments66604 -Node: Getting Started70900 -Node: Running gawk73334 -Node: One-shot74524 -Node: Read Terminal75749 -Ref: Read Terminal-Footnote-177399 -Ref: Read Terminal-Footnote-277675 -Node: Long77846 -Node: Executable Scripts79222 -Ref: Executable Scripts-Footnote-181055 -Ref: Executable Scripts-Footnote-281157 -Node: Comments81704 -Node: Quoting84177 -Node: DOS Quoting89493 -Node: Sample Data Files90168 -Node: Very Simple92683 -Node: Two Rules97321 -Node: More Complex99215 -Ref: More Complex-Footnote-1102147 -Node: Statements/Lines102232 -Ref: Statements/Lines-Footnote-1106688 -Node: Other Features106953 -Node: When107881 -Node: Intro Summary110051 -Node: Invoking Gawk110817 -Node: Command Line112332 -Node: Options113123 -Ref: Options-Footnote-1128952 -Node: Other Arguments128977 -Node: Naming Standard Input131639 -Node: Environment Variables132733 -Node: AWKPATH Variable133291 -Ref: AWKPATH Variable-Footnote-1136163 -Ref: AWKPATH Variable-Footnote-2136208 -Node: AWKLIBPATH Variable136468 -Node: Other Environment Variables137227 -Node: Exit Status140882 -Node: Include Files141557 -Node: Loading Shared Libraries145135 -Node: Obsolete146519 -Node: Undocumented147216 -Node: Invoking Summary147483 -Node: Regexp149063 -Node: Regexp Usage150513 -Node: Escape Sequences152546 -Node: Regexp Operators158213 -Ref: Regexp Operators-Footnote-1165693 -Ref: Regexp Operators-Footnote-2165840 -Node: Bracket Expressions165938 -Ref: table-char-classes167828 -Node: GNU Regexp Operators170351 -Node: Case-sensitivity174074 -Ref: Case-sensitivity-Footnote-1176966 -Ref: Case-sensitivity-Footnote-2177201 -Node: Leftmost Longest177309 -Node: Computed Regexps178510 -Node: Regexp Summary181882 -Node: Reading Files183353 -Node: Records185445 -Node: awk split records186188 -Node: gawk split records191046 -Ref: gawk split records-Footnote-1195567 -Node: Fields195604 -Ref: Fields-Footnote-1198568 -Node: Nonconstant Fields198654 -Ref: Nonconstant Fields-Footnote-1200884 -Node: Changing Fields201086 -Node: Field Separators207040 -Node: Default Field Splitting209742 -Node: Regexp Field Splitting210859 -Node: Single Character Fields214200 -Node: Command Line Field Separator215259 -Node: Full Line Fields218601 -Ref: Full Line Fields-Footnote-1219109 -Node: Field Splitting Summary219155 -Ref: Field Splitting Summary-Footnote-1222254 -Node: Constant Size222355 -Node: Splitting By Content226962 -Ref: Splitting By Content-Footnote-1230712 -Node: Multiple Line230752 -Ref: Multiple Line-Footnote-1236608 -Node: Getline236787 -Node: Plain Getline239003 -Node: Getline/Variable241098 -Node: Getline/File242245 -Node: Getline/Variable/File243629 -Ref: Getline/Variable/File-Footnote-1245228 -Node: Getline/Pipe245315 -Node: Getline/Variable/Pipe248014 -Node: Getline/Coprocess249121 -Node: Getline/Variable/Coprocess250373 -Node: Getline Notes251110 -Node: Getline Summary253914 -Ref: table-getline-variants254322 -Node: Read Timeout255234 -Ref: Read Timeout-Footnote-1259061 -Node: Command line directories259119 -Node: Input Summary260023 -Node: Input Exercises263160 -Node: Printing263893 -Node: Print265615 -Node: Print Examples266956 -Node: Output Separators269735 -Node: OFMT271751 -Node: Printf273109 -Node: Basic Printf274015 -Node: Control Letters275554 -Node: Format Modifiers279406 -Node: Printf Examples285433 -Node: Redirection287897 -Node: Special Files294869 -Node: Special FD295400 -Ref: Special FD-Footnote-1299024 -Node: Special Network299098 -Node: Special Caveats299948 -Node: Close Files And Pipes300744 -Ref: Close Files And Pipes-Footnote-1307905 -Ref: Close Files And Pipes-Footnote-2308053 -Node: Output Summary308203 -Node: Output exercises309200 -Node: Expressions309880 -Node: Values311065 -Node: Constants311741 -Node: Scalar Constants312421 -Ref: Scalar Constants-Footnote-1313280 -Node: Nondecimal-numbers313530 -Node: Regexp Constants316530 -Node: Using Constant Regexps317005 -Node: Variables320075 -Node: Using Variables320730 -Node: Assignment Options322454 -Node: Conversion324329 -Node: Strings And Numbers324853 -Ref: Strings And Numbers-Footnote-1327915 -Node: Locale influences conversions328024 -Ref: table-locale-affects330741 -Node: All Operators331329 -Node: Arithmetic Ops331959 -Node: Concatenation334464 -Ref: Concatenation-Footnote-1337260 -Node: Assignment Ops337380 -Ref: table-assign-ops342363 -Node: Increment Ops343680 -Node: Truth Values and Conditions347118 -Node: Truth Values348201 -Node: Typing and Comparison349250 -Node: Variable Typing350043 -Ref: Variable Typing-Footnote-1353943 -Node: Comparison Operators354065 -Ref: table-relational-ops354475 -Node: POSIX String Comparison358025 -Ref: POSIX String Comparison-Footnote-1359109 -Node: Boolean Ops359247 -Ref: Boolean Ops-Footnote-1363317 -Node: Conditional Exp363408 -Node: Function Calls365135 -Node: Precedence369015 -Node: Locales372684 -Node: Expressions Summary374315 -Node: Patterns and Actions376856 -Node: Pattern Overview377972 -Node: Regexp Patterns379649 -Node: Expression Patterns380192 -Node: Ranges383973 -Node: BEGIN/END387079 -Node: Using BEGIN/END387841 -Ref: Using BEGIN/END-Footnote-1390577 -Node: I/O And BEGIN/END390683 -Node: BEGINFILE/ENDFILE392968 -Node: Empty395899 -Node: Using Shell Variables396216 -Node: Action Overview398499 -Node: Statements400826 -Node: If Statement402674 -Node: While Statement404172 -Node: Do Statement406216 -Node: For Statement407372 -Node: Switch Statement410524 -Node: Break Statement412627 -Node: Continue Statement414682 -Node: Next Statement416475 -Node: Nextfile Statement418865 -Node: Exit Statement421520 -Node: Built-in Variables423924 -Node: User-modified425051 -Ref: User-modified-Footnote-1432740 -Node: Auto-set432802 -Ref: Auto-set-Footnote-1445384 -Ref: Auto-set-Footnote-2445589 -Node: ARGC and ARGV445645 -Node: Pattern Action Summary449499 -Node: Arrays451722 -Node: Array Basics453271 -Node: Array Intro454097 -Ref: figure-array-elements456070 -Node: Reference to Elements458477 -Node: Assigning Elements460750 -Node: Array Example461241 -Node: Scanning an Array462973 -Node: Controlling Scanning465988 -Ref: Controlling Scanning-Footnote-1471161 -Node: Delete471477 -Ref: Delete-Footnote-1474242 -Node: Numeric Array Subscripts474299 -Node: Uninitialized Subscripts476482 -Node: Multidimensional478107 -Node: Multiscanning481200 -Node: Arrays of Arrays482789 -Node: Arrays Summary487452 -Node: Functions489557 -Node: Built-in490430 -Node: Calling Built-in491508 -Node: Numeric Functions493496 -Ref: Numeric Functions-Footnote-1497330 -Ref: Numeric Functions-Footnote-2497687 -Ref: Numeric Functions-Footnote-3497735 -Node: String Functions498004 -Ref: String Functions-Footnote-1521015 -Ref: String Functions-Footnote-2521144 -Ref: String Functions-Footnote-3521392 -Node: Gory Details521479 -Ref: table-sub-escapes523148 -Ref: table-sub-posix-92524502 -Ref: table-sub-proposed525853 -Ref: table-posix-sub527207 -Ref: table-gensub-escapes528752 -Ref: Gory Details-Footnote-1529928 -Ref: Gory Details-Footnote-2529979 -Node: I/O Functions530130 -Ref: I/O Functions-Footnote-1537253 -Node: Time Functions537400 -Ref: Time Functions-Footnote-1547864 -Ref: Time Functions-Footnote-2547932 -Ref: Time Functions-Footnote-3548090 -Ref: Time Functions-Footnote-4548201 -Ref: Time Functions-Footnote-5548313 -Ref: Time Functions-Footnote-6548540 -Node: Bitwise Functions548806 -Ref: table-bitwise-ops549368 -Ref: Bitwise Functions-Footnote-1553613 -Node: Type Functions553797 -Node: I18N Functions554939 -Node: User-defined556584 -Node: Definition Syntax557388 -Ref: Definition Syntax-Footnote-1562567 -Node: Function Example562636 -Ref: Function Example-Footnote-1565280 -Node: Function Caveats565302 -Node: Calling A Function565820 -Node: Variable Scope566775 -Node: Pass By Value/Reference569763 -Node: Return Statement573271 -Node: Dynamic Typing576255 -Node: Indirect Calls577184 -Node: Functions Summary586897 -Node: Library Functions589436 -Ref: Library Functions-Footnote-1593054 -Ref: Library Functions-Footnote-2593197 -Node: Library Names593368 -Ref: Library Names-Footnote-1596841 -Ref: Library Names-Footnote-2597061 -Node: General Functions597147 -Node: Strtonum Function598175 -Node: Assert Function600955 -Node: Round Function604281 -Node: Cliff Random Function605822 -Node: Ordinal Functions606838 -Ref: Ordinal Functions-Footnote-1609915 -Ref: Ordinal Functions-Footnote-2610167 -Node: Join Function610378 -Ref: Join Function-Footnote-1612149 -Node: Getlocaltime Function612349 -Node: Readfile Function616085 -Node: Data File Management617924 -Node: Filetrans Function618556 -Node: Rewind Function622625 -Node: File Checking624012 -Ref: File Checking-Footnote-1625144 -Node: Empty Files625345 -Node: Ignoring Assigns627324 -Node: Getopt Function628878 -Ref: Getopt Function-Footnote-1640181 -Node: Passwd Functions640384 -Ref: Passwd Functions-Footnote-1649363 -Node: Group Functions649451 -Ref: Group Functions-Footnote-1657392 -Node: Walking Arrays657605 -Node: Library Functions Summary659208 -Node: Library exercises660596 -Node: Sample Programs661876 -Node: Running Examples662646 -Node: Clones663374 -Node: Cut Program664598 -Node: Egrep Program674466 -Ref: Egrep Program-Footnote-1682437 -Node: Id Program682547 -Node: Split Program686211 -Ref: Split Program-Footnote-1689749 -Node: Tee Program689877 -Node: Uniq Program692684 -Node: Wc Program700114 -Ref: Wc Program-Footnote-1704379 -Node: Miscellaneous Programs704471 -Node: Dupword Program705684 -Node: Alarm Program707715 -Node: Translate Program712529 -Ref: Translate Program-Footnote-1716920 -Ref: Translate Program-Footnote-2717190 -Node: Labels Program717324 -Ref: Labels Program-Footnote-1720695 -Node: Word Sorting720779 -Node: History Sorting724822 -Node: Extract Program726658 -Node: Simple Sed734194 -Node: Igawk Program737256 -Ref: Igawk Program-Footnote-1751567 -Ref: Igawk Program-Footnote-2751768 -Node: Anagram Program751906 -Node: Signature Program754974 -Node: Programs Summary756221 -Node: Programs Exercises757436 -Node: Advanced Features761087 -Node: Nondecimal Data763035 -Node: Array Sorting764612 -Node: Controlling Array Traversal765309 -Node: Array Sorting Functions773589 -Ref: Array Sorting Functions-Footnote-1777496 -Node: Two-way I/O777690 -Ref: Two-way I/O-Footnote-1783206 -Node: TCP/IP Networking783288 -Node: Profiling786132 -Node: Advanced Features Summary793674 -Node: Internationalization795538 -Node: I18N and L10N797018 -Node: Explaining gettext797704 -Ref: Explaining gettext-Footnote-1802844 -Ref: Explaining gettext-Footnote-2803028 -Node: Programmer i18n803193 -Node: Translator i18n807418 -Node: String Extraction808212 -Ref: String Extraction-Footnote-1809173 -Node: Printf Ordering809259 -Ref: Printf Ordering-Footnote-1812041 -Node: I18N Portability812105 -Ref: I18N Portability-Footnote-1814554 -Node: I18N Example814617 -Ref: I18N Example-Footnote-1817339 -Node: Gawk I18N817411 -Node: I18N Summary818049 -Node: Debugger819388 -Node: Debugging820410 -Node: Debugging Concepts820851 -Node: Debugging Terms822707 -Node: Awk Debugging825304 -Node: Sample Debugging Session826196 -Node: Debugger Invocation826716 -Node: Finding The Bug828049 -Node: List of Debugger Commands834531 -Node: Breakpoint Control835863 -Node: Debugger Execution Control839527 -Node: Viewing And Changing Data842887 -Node: Execution Stack846245 -Node: Debugger Info847758 -Node: Miscellaneous Debugger Commands851752 -Node: Readline Support856936 -Node: Limitations857828 -Node: Debugging Summary860102 -Node: Arbitrary Precision Arithmetic861266 -Node: Computer Arithmetic862595 -Ref: Computer Arithmetic-Footnote-1866982 -Node: Math Definitions867039 -Ref: table-ieee-formats869923 -Node: MPFR features870427 -Node: FP Math Caution872069 -Ref: FP Math Caution-Footnote-1873110 -Node: Inexactness of computations873479 -Node: Inexact representation874427 -Node: Comparing FP Values875782 -Node: Errors accumulate876746 -Node: Getting Accuracy878179 -Node: Try To Round880838 -Node: Setting precision881737 -Ref: table-predefined-precision-strings882419 -Node: Setting the rounding mode884212 -Ref: table-gawk-rounding-modes884576 -Ref: Setting the rounding mode-Footnote-1888030 -Node: Arbitrary Precision Integers888209 -Ref: Arbitrary Precision Integers-Footnote-1891212 -Node: POSIX Floating Point Problems891361 -Ref: POSIX Floating Point Problems-Footnote-1895237 -Node: Floating point summary895275 -Node: Dynamic Extensions897492 -Node: Extension Intro899044 -Node: Plugin License900309 -Node: Extension Mechanism Outline900994 -Ref: figure-load-extension901418 -Ref: figure-load-new-function902903 -Ref: figure-call-new-function903905 -Node: Extension API Description905889 -Node: Extension API Functions Introduction907339 -Node: General Data Types912204 -Ref: General Data Types-Footnote-1917897 -Node: Requesting Values918196 -Ref: table-value-types-returned918933 -Node: Memory Allocation Functions919891 -Ref: Memory Allocation Functions-Footnote-1922638 -Node: Constructor Functions922734 -Node: Registration Functions924492 -Node: Extension Functions925177 -Node: Exit Callback Functions927479 -Node: Extension Version String928728 -Node: Input Parsers929378 -Node: Output Wrappers939181 -Node: Two-way processors943697 -Node: Printing Messages945901 -Ref: Printing Messages-Footnote-1946978 -Node: Updating `ERRNO'947130 -Node: Accessing Parameters947869 -Node: Symbol Table Access949099 -Node: Symbol table by name949613 -Node: Symbol table by cookie951589 -Ref: Symbol table by cookie-Footnote-1955722 -Node: Cached values955785 -Ref: Cached values-Footnote-1959289 -Node: Array Manipulation959380 -Ref: Array Manipulation-Footnote-1960478 -Node: Array Data Types960517 -Ref: Array Data Types-Footnote-1963220 -Node: Array Functions963312 -Node: Flattening Arrays967186 -Node: Creating Arrays974038 -Node: Extension API Variables978769 -Node: Extension Versioning979405 -Node: Extension API Informational Variables981306 -Node: Extension API Boilerplate982392 -Node: Finding Extensions986196 -Node: Extension Example986756 -Node: Internal File Description987486 -Node: Internal File Ops991577 -Ref: Internal File Ops-Footnote-11003009 -Node: Using Internal File Ops1003149 -Ref: Using Internal File Ops-Footnote-11005496 -Node: Extension Samples1005764 -Node: Extension Sample File Functions1007288 -Node: Extension Sample Fnmatch1014856 -Node: Extension Sample Fork1016338 -Node: Extension Sample Inplace1017551 -Node: Extension Sample Ord1019226 -Node: Extension Sample Readdir1020062 -Ref: table-readdir-file-types1020918 -Node: Extension Sample Revout1021717 -Node: Extension Sample Rev2way1022308 -Node: Extension Sample Read write array1023049 -Node: Extension Sample Readfile1024928 -Node: Extension Sample API Tests1026028 -Node: Extension Sample Time1026553 -Node: gawkextlib1027868 -Node: Extension summary1030681 -Node: Extension Exercises1034374 -Node: Language History1035096 -Node: V7/SVR3.11036739 -Node: SVR41039059 -Node: POSIX1040501 -Node: BTL1041887 -Node: POSIX/GNU1042621 -Node: Feature History1048220 -Node: Common Extensions1061350 -Node: Ranges and Locales1062662 -Ref: Ranges and Locales-Footnote-11067279 -Ref: Ranges and Locales-Footnote-21067306 -Ref: Ranges and Locales-Footnote-31067540 -Node: Contributors1067761 -Node: History summary1073186 -Node: Installation1074555 -Node: Gawk Distribution1075506 -Node: Getting1075990 -Node: Extracting1076814 -Node: Distribution contents1078456 -Node: Unix Installation1084173 -Node: Quick Installation1084790 -Node: Additional Configuration Options1087232 -Node: Configuration Philosophy1088970 -Node: Non-Unix Installation1091321 -Node: PC Installation1091779 -Node: PC Binary Installation1093090 -Node: PC Compiling1094938 -Ref: PC Compiling-Footnote-11097937 -Node: PC Testing1098042 -Node: PC Using1099218 -Node: Cygwin1103376 -Node: MSYS1104185 -Node: VMS Installation1104699 -Node: VMS Compilation1105495 -Ref: VMS Compilation-Footnote-11106717 -Node: VMS Dynamic Extensions1106775 -Node: VMS Installation Details1108148 -Node: VMS Running1110400 -Node: VMS GNV1113234 -Node: VMS Old Gawk1113957 -Node: Bugs1114427 -Node: Other Versions1118431 -Node: Installation summary1124686 -Node: Notes1125742 -Node: Compatibility Mode1126607 -Node: Additions1127389 -Node: Accessing The Source1128314 -Node: Adding Code1129750 -Node: New Ports1135928 -Node: Derived Files1140409 -Ref: Derived Files-Footnote-11145490 -Ref: Derived Files-Footnote-21145524 -Ref: Derived Files-Footnote-31146120 -Node: Future Extensions1146234 -Node: Implementation Limitations1146840 -Node: Extension Design1148088 -Node: Old Extension Problems1149242 -Ref: Old Extension Problems-Footnote-11150759 -Node: Extension New Mechanism Goals1150816 -Ref: Extension New Mechanism Goals-Footnote-11154176 -Node: Extension Other Design Decisions1154365 -Node: Extension Future Growth1156471 -Node: Old Extension Mechanism1157307 -Node: Notes summary1159069 -Node: Basic Concepts1160255 -Node: Basic High Level1160936 -Ref: figure-general-flow1161208 -Ref: figure-process-flow1161807 -Ref: Basic High Level-Footnote-11165036 -Node: Basic Data Typing1165221 -Node: Glossary1168549 -Node: Copying1193701 -Node: GNU Free Documentation License1231257 -Node: Index1256393 +Node: Top1204 +Node: Foreword41858 +Node: Preface46203 +Ref: Preface-Footnote-149350 +Ref: Preface-Footnote-249457 +Node: History49689 +Node: Names52063 +Ref: Names-Footnote-153527 +Node: This Manual53600 +Ref: This Manual-Footnote-159379 +Node: Conventions59479 +Node: Manual History61635 +Ref: Manual History-Footnote-165074 +Ref: Manual History-Footnote-265115 +Node: How To Contribute65189 +Node: Acknowledgments66428 +Node: Getting Started70724 +Node: Running gawk73158 +Node: One-shot74348 +Node: Read Terminal75573 +Ref: Read Terminal-Footnote-177223 +Ref: Read Terminal-Footnote-277499 +Node: Long77670 +Node: Executable Scripts79046 +Ref: Executable Scripts-Footnote-180879 +Ref: Executable Scripts-Footnote-280981 +Node: Comments81528 +Node: Quoting84001 +Node: DOS Quoting89317 +Node: Sample Data Files89992 +Node: Very Simple92507 +Node: Two Rules97145 +Node: More Complex99039 +Ref: More Complex-Footnote-1101971 +Node: Statements/Lines102056 +Ref: Statements/Lines-Footnote-1106512 +Node: Other Features106777 +Node: When107705 +Node: Intro Summary109875 +Node: Invoking Gawk110641 +Node: Command Line112156 +Node: Options112947 +Ref: Options-Footnote-1128776 +Node: Other Arguments128801 +Node: Naming Standard Input131463 +Node: Environment Variables132557 +Node: AWKPATH Variable133115 +Ref: AWKPATH Variable-Footnote-1135987 +Ref: AWKPATH Variable-Footnote-2136032 +Node: AWKLIBPATH Variable136292 +Node: Other Environment Variables137051 +Node: Exit Status140706 +Node: Include Files141381 +Node: Loading Shared Libraries144959 +Node: Obsolete146343 +Node: Undocumented147040 +Node: Invoking Summary147307 +Node: Regexp148887 +Node: Regexp Usage150337 +Node: Escape Sequences152370 +Node: Regexp Operators158037 +Ref: Regexp Operators-Footnote-1165517 +Ref: Regexp Operators-Footnote-2165664 +Node: Bracket Expressions165762 +Ref: table-char-classes167652 +Node: GNU Regexp Operators170175 +Node: Case-sensitivity173898 +Ref: Case-sensitivity-Footnote-1176790 +Ref: Case-sensitivity-Footnote-2177025 +Node: Leftmost Longest177133 +Node: Computed Regexps178334 +Node: Regexp Summary181706 +Node: Reading Files183177 +Node: Records185269 +Node: awk split records186012 +Node: gawk split records190870 +Ref: gawk split records-Footnote-1195391 +Node: Fields195428 +Ref: Fields-Footnote-1198392 +Node: Nonconstant Fields198478 +Ref: Nonconstant Fields-Footnote-1200708 +Node: Changing Fields200910 +Node: Field Separators206864 +Node: Default Field Splitting209566 +Node: Regexp Field Splitting210683 +Node: Single Character Fields214024 +Node: Command Line Field Separator215083 +Node: Full Line Fields218425 +Ref: Full Line Fields-Footnote-1218933 +Node: Field Splitting Summary218979 +Ref: Field Splitting Summary-Footnote-1222078 +Node: Constant Size222179 +Node: Splitting By Content226786 +Ref: Splitting By Content-Footnote-1230536 +Node: Multiple Line230576 +Ref: Multiple Line-Footnote-1236432 +Node: Getline236611 +Node: Plain Getline238827 +Node: Getline/Variable240922 +Node: Getline/File242069 +Node: Getline/Variable/File243453 +Ref: Getline/Variable/File-Footnote-1245052 +Node: Getline/Pipe245139 +Node: Getline/Variable/Pipe247838 +Node: Getline/Coprocess248945 +Node: Getline/Variable/Coprocess250197 +Node: Getline Notes250934 +Node: Getline Summary253738 +Ref: table-getline-variants254146 +Node: Read Timeout255058 +Ref: Read Timeout-Footnote-1258885 +Node: Command line directories258943 +Node: Input Summary259847 +Node: Input Exercises262984 +Node: Printing263717 +Node: Print265439 +Node: Print Examples266780 +Node: Output Separators269559 +Node: OFMT271575 +Node: Printf272933 +Node: Basic Printf273839 +Node: Control Letters275378 +Node: Format Modifiers279230 +Node: Printf Examples285257 +Node: Redirection287721 +Node: Special Files294693 +Node: Special FD295224 +Ref: Special FD-Footnote-1298848 +Node: Special Network298922 +Node: Special Caveats299772 +Node: Close Files And Pipes300568 +Ref: Close Files And Pipes-Footnote-1307729 +Ref: Close Files And Pipes-Footnote-2307877 +Node: Output Summary308027 +Node: Output exercises309024 +Node: Expressions309704 +Node: Values310889 +Node: Constants311565 +Node: Scalar Constants312245 +Ref: Scalar Constants-Footnote-1313104 +Node: Nondecimal-numbers313354 +Node: Regexp Constants316354 +Node: Using Constant Regexps316829 +Node: Variables319899 +Node: Using Variables320554 +Node: Assignment Options322278 +Node: Conversion324153 +Node: Strings And Numbers324677 +Ref: Strings And Numbers-Footnote-1327739 +Node: Locale influences conversions327848 +Ref: table-locale-affects330565 +Node: All Operators331153 +Node: Arithmetic Ops331783 +Node: Concatenation334288 +Ref: Concatenation-Footnote-1337084 +Node: Assignment Ops337204 +Ref: table-assign-ops342187 +Node: Increment Ops343504 +Node: Truth Values and Conditions346942 +Node: Truth Values348025 +Node: Typing and Comparison349074 +Node: Variable Typing349867 +Ref: Variable Typing-Footnote-1353767 +Node: Comparison Operators353889 +Ref: table-relational-ops354299 +Node: POSIX String Comparison357849 +Ref: POSIX String Comparison-Footnote-1358933 +Node: Boolean Ops359071 +Ref: Boolean Ops-Footnote-1363141 +Node: Conditional Exp363232 +Node: Function Calls364959 +Node: Precedence368839 +Node: Locales372508 +Node: Expressions Summary374139 +Node: Patterns and Actions376680 +Node: Pattern Overview377796 +Node: Regexp Patterns379473 +Node: Expression Patterns380016 +Node: Ranges383797 +Node: BEGIN/END386903 +Node: Using BEGIN/END387665 +Ref: Using BEGIN/END-Footnote-1390401 +Node: I/O And BEGIN/END390507 +Node: BEGINFILE/ENDFILE392792 +Node: Empty395723 +Node: Using Shell Variables396040 +Node: Action Overview398323 +Node: Statements400650 +Node: If Statement402498 +Node: While Statement403996 +Node: Do Statement406040 +Node: For Statement407196 +Node: Switch Statement410348 +Node: Break Statement412451 +Node: Continue Statement414506 +Node: Next Statement416299 +Node: Nextfile Statement418689 +Node: Exit Statement421344 +Node: Built-in Variables423748 +Node: User-modified424875 +Ref: User-modified-Footnote-1432564 +Node: Auto-set432626 +Ref: Auto-set-Footnote-1445208 +Ref: Auto-set-Footnote-2445413 +Node: ARGC and ARGV445469 +Node: Pattern Action Summary449323 +Node: Arrays451546 +Node: Array Basics453095 +Node: Array Intro453921 +Ref: figure-array-elements455894 +Node: Reference to Elements458301 +Node: Assigning Elements460574 +Node: Array Example461065 +Node: Scanning an Array462797 +Node: Controlling Scanning465812 +Ref: Controlling Scanning-Footnote-1470985 +Node: Delete471301 +Ref: Delete-Footnote-1474066 +Node: Numeric Array Subscripts474123 +Node: Uninitialized Subscripts476306 +Node: Multidimensional477931 +Node: Multiscanning481024 +Node: Arrays of Arrays482613 +Node: Arrays Summary487276 +Node: Functions489381 +Node: Built-in490254 +Node: Calling Built-in491332 +Node: Numeric Functions493320 +Ref: Numeric Functions-Footnote-1497154 +Ref: Numeric Functions-Footnote-2497511 +Ref: Numeric Functions-Footnote-3497559 +Node: String Functions497828 +Ref: String Functions-Footnote-1520839 +Ref: String Functions-Footnote-2520968 +Ref: String Functions-Footnote-3521216 +Node: Gory Details521303 +Ref: table-sub-escapes522972 +Ref: table-sub-posix-92524326 +Ref: table-sub-proposed525677 +Ref: table-posix-sub527031 +Ref: table-gensub-escapes528576 +Ref: Gory Details-Footnote-1529752 +Ref: Gory Details-Footnote-2529803 +Node: I/O Functions529954 +Ref: I/O Functions-Footnote-1537077 +Node: Time Functions537224 +Ref: Time Functions-Footnote-1547688 +Ref: Time Functions-Footnote-2547756 +Ref: Time Functions-Footnote-3547914 +Ref: Time Functions-Footnote-4548025 +Ref: Time Functions-Footnote-5548137 +Ref: Time Functions-Footnote-6548364 +Node: Bitwise Functions548630 +Ref: table-bitwise-ops549192 +Ref: Bitwise Functions-Footnote-1553437 +Node: Type Functions553621 +Node: I18N Functions554763 +Node: User-defined556408 +Node: Definition Syntax557212 +Ref: Definition Syntax-Footnote-1562391 +Node: Function Example562460 +Ref: Function Example-Footnote-1565104 +Node: Function Caveats565126 +Node: Calling A Function565644 +Node: Variable Scope566599 +Node: Pass By Value/Reference569587 +Node: Return Statement573095 +Node: Dynamic Typing576079 +Node: Indirect Calls577008 +Node: Functions Summary586721 +Node: Library Functions589260 +Ref: Library Functions-Footnote-1592878 +Ref: Library Functions-Footnote-2593021 +Node: Library Names593192 +Ref: Library Names-Footnote-1596665 +Ref: Library Names-Footnote-2596885 +Node: General Functions596971 +Node: Strtonum Function597999 +Node: Assert Function600779 +Node: Round Function604105 +Node: Cliff Random Function605646 +Node: Ordinal Functions606662 +Ref: Ordinal Functions-Footnote-1609739 +Ref: Ordinal Functions-Footnote-2609991 +Node: Join Function610202 +Ref: Join Function-Footnote-1611973 +Node: Getlocaltime Function612173 +Node: Readfile Function615909 +Node: Data File Management617748 +Node: Filetrans Function618380 +Node: Rewind Function622449 +Node: File Checking623836 +Ref: File Checking-Footnote-1624968 +Node: Empty Files625169 +Node: Ignoring Assigns627148 +Node: Getopt Function628702 +Ref: Getopt Function-Footnote-1640005 +Node: Passwd Functions640208 +Ref: Passwd Functions-Footnote-1649187 +Node: Group Functions649275 +Ref: Group Functions-Footnote-1657216 +Node: Walking Arrays657429 +Node: Library Functions Summary659032 +Node: Library exercises660420 +Node: Sample Programs661700 +Node: Running Examples662470 +Node: Clones663198 +Node: Cut Program664422 +Node: Egrep Program674290 +Ref: Egrep Program-Footnote-1682261 +Node: Id Program682371 +Node: Split Program686035 +Ref: Split Program-Footnote-1689573 +Node: Tee Program689701 +Node: Uniq Program692508 +Node: Wc Program699938 +Ref: Wc Program-Footnote-1704203 +Node: Miscellaneous Programs704295 +Node: Dupword Program705508 +Node: Alarm Program707539 +Node: Translate Program712353 +Ref: Translate Program-Footnote-1716744 +Ref: Translate Program-Footnote-2717014 +Node: Labels Program717148 +Ref: Labels Program-Footnote-1720519 +Node: Word Sorting720603 +Node: History Sorting724646 +Node: Extract Program726482 +Node: Simple Sed734018 +Node: Igawk Program737080 +Ref: Igawk Program-Footnote-1751391 +Ref: Igawk Program-Footnote-2751592 +Node: Anagram Program751730 +Node: Signature Program754798 +Node: Programs Summary756045 +Node: Programs Exercises757260 +Node: Advanced Features760911 +Node: Nondecimal Data762859 +Node: Array Sorting764436 +Node: Controlling Array Traversal765133 +Node: Array Sorting Functions773413 +Ref: Array Sorting Functions-Footnote-1777320 +Node: Two-way I/O777514 +Ref: Two-way I/O-Footnote-1783030 +Node: TCP/IP Networking783112 +Node: Profiling785956 +Node: Advanced Features Summary793498 +Node: Internationalization795362 +Node: I18N and L10N796842 +Node: Explaining gettext797528 +Ref: Explaining gettext-Footnote-1802668 +Ref: Explaining gettext-Footnote-2802852 +Node: Programmer i18n803017 +Node: Translator i18n807242 +Node: String Extraction808036 +Ref: String Extraction-Footnote-1808997 +Node: Printf Ordering809083 +Ref: Printf Ordering-Footnote-1811865 +Node: I18N Portability811929 +Ref: I18N Portability-Footnote-1814378 +Node: I18N Example814441 +Ref: I18N Example-Footnote-1817163 +Node: Gawk I18N817235 +Node: I18N Summary817873 +Node: Debugger819212 +Node: Debugging820234 +Node: Debugging Concepts820675 +Node: Debugging Terms822531 +Node: Awk Debugging825128 +Node: Sample Debugging Session826020 +Node: Debugger Invocation826540 +Node: Finding The Bug827873 +Node: List of Debugger Commands834355 +Node: Breakpoint Control835687 +Node: Debugger Execution Control839351 +Node: Viewing And Changing Data842711 +Node: Execution Stack846069 +Node: Debugger Info847582 +Node: Miscellaneous Debugger Commands851576 +Node: Readline Support856760 +Node: Limitations857652 +Node: Debugging Summary859926 +Node: Arbitrary Precision Arithmetic861090 +Node: Computer Arithmetic862419 +Ref: Computer Arithmetic-Footnote-1866806 +Node: Math Definitions866863 +Ref: table-ieee-formats869747 +Node: MPFR features870251 +Node: FP Math Caution871893 +Ref: FP Math Caution-Footnote-1872934 +Node: Inexactness of computations873303 +Node: Inexact representation874251 +Node: Comparing FP Values875606 +Node: Errors accumulate876570 +Node: Getting Accuracy878003 +Node: Try To Round880662 +Node: Setting precision881561 +Ref: table-predefined-precision-strings882243 +Node: Setting the rounding mode884036 +Ref: table-gawk-rounding-modes884400 +Ref: Setting the rounding mode-Footnote-1887854 +Node: Arbitrary Precision Integers888033 +Ref: Arbitrary Precision Integers-Footnote-1891036 +Node: POSIX Floating Point Problems891185 +Ref: POSIX Floating Point Problems-Footnote-1895061 +Node: Floating point summary895099 +Node: Dynamic Extensions897316 +Node: Extension Intro898868 +Node: Plugin License900133 +Node: Extension Mechanism Outline900818 +Ref: figure-load-extension901242 +Ref: figure-load-new-function902727 +Ref: figure-call-new-function903729 +Node: Extension API Description905713 +Node: Extension API Functions Introduction907163 +Node: General Data Types912028 +Ref: General Data Types-Footnote-1917721 +Node: Requesting Values918020 +Ref: table-value-types-returned918757 +Node: Memory Allocation Functions919715 +Ref: Memory Allocation Functions-Footnote-1922462 +Node: Constructor Functions922558 +Node: Registration Functions924316 +Node: Extension Functions925001 +Node: Exit Callback Functions927303 +Node: Extension Version String928552 +Node: Input Parsers929202 +Node: Output Wrappers939005 +Node: Two-way processors943521 +Node: Printing Messages945725 +Ref: Printing Messages-Footnote-1946802 +Node: Updating `ERRNO'946954 +Node: Accessing Parameters947693 +Node: Symbol Table Access948923 +Node: Symbol table by name949437 +Node: Symbol table by cookie951413 +Ref: Symbol table by cookie-Footnote-1955546 +Node: Cached values955609 +Ref: Cached values-Footnote-1959113 +Node: Array Manipulation959204 +Ref: Array Manipulation-Footnote-1960302 +Node: Array Data Types960341 +Ref: Array Data Types-Footnote-1963044 +Node: Array Functions963136 +Node: Flattening Arrays967010 +Node: Creating Arrays973862 +Node: Extension API Variables978593 +Node: Extension Versioning979229 +Node: Extension API Informational Variables981130 +Node: Extension API Boilerplate982216 +Node: Finding Extensions986020 +Node: Extension Example986580 +Node: Internal File Description987310 +Node: Internal File Ops991401 +Ref: Internal File Ops-Footnote-11002833 +Node: Using Internal File Ops1002973 +Ref: Using Internal File Ops-Footnote-11005320 +Node: Extension Samples1005588 +Node: Extension Sample File Functions1007112 +Node: Extension Sample Fnmatch1014680 +Node: Extension Sample Fork1016162 +Node: Extension Sample Inplace1017375 +Node: Extension Sample Ord1019050 +Node: Extension Sample Readdir1019886 +Ref: table-readdir-file-types1020742 +Node: Extension Sample Revout1021541 +Node: Extension Sample Rev2way1022132 +Node: Extension Sample Read write array1022873 +Node: Extension Sample Readfile1024752 +Node: Extension Sample API Tests1025852 +Node: Extension Sample Time1026377 +Node: gawkextlib1027692 +Node: Extension summary1030505 +Node: Extension Exercises1034198 +Node: Language History1034920 +Node: V7/SVR3.11036563 +Node: SVR41038883 +Node: POSIX1040325 +Node: BTL1041711 +Node: POSIX/GNU1042445 +Node: Feature History1048044 +Node: Common Extensions1061174 +Node: Ranges and Locales1062486 +Ref: Ranges and Locales-Footnote-11067103 +Ref: Ranges and Locales-Footnote-21067130 +Ref: Ranges and Locales-Footnote-31067364 +Node: Contributors1067585 +Node: History summary1073010 +Node: Installation1074379 +Node: Gawk Distribution1075330 +Node: Getting1075814 +Node: Extracting1076638 +Node: Distribution contents1078280 +Node: Unix Installation1083997 +Node: Quick Installation1084614 +Node: Additional Configuration Options1087056 +Node: Configuration Philosophy1088794 +Node: Non-Unix Installation1091145 +Node: PC Installation1091603 +Node: PC Binary Installation1092914 +Node: PC Compiling1094762 +Ref: PC Compiling-Footnote-11097761 +Node: PC Testing1097866 +Node: PC Using1099042 +Node: Cygwin1103200 +Node: MSYS1104009 +Node: VMS Installation1104523 +Node: VMS Compilation1105319 +Ref: VMS Compilation-Footnote-11106541 +Node: VMS Dynamic Extensions1106599 +Node: VMS Installation Details1107972 +Node: VMS Running1110224 +Node: VMS GNV1113058 +Node: VMS Old Gawk1113781 +Node: Bugs1114251 +Node: Other Versions1118255 +Node: Installation summary1124510 +Node: Notes1125566 +Node: Compatibility Mode1126431 +Node: Additions1127213 +Node: Accessing The Source1128138 +Node: Adding Code1129574 +Node: New Ports1135752 +Node: Derived Files1140233 +Ref: Derived Files-Footnote-11145314 +Ref: Derived Files-Footnote-21145348 +Ref: Derived Files-Footnote-31145944 +Node: Future Extensions1146058 +Node: Implementation Limitations1146664 +Node: Extension Design1147912 +Node: Old Extension Problems1149066 +Ref: Old Extension Problems-Footnote-11150583 +Node: Extension New Mechanism Goals1150640 +Ref: Extension New Mechanism Goals-Footnote-11154000 +Node: Extension Other Design Decisions1154189 +Node: Extension Future Growth1156295 +Node: Old Extension Mechanism1157131 +Node: Notes summary1158893 +Node: Basic Concepts1160079 +Node: Basic High Level1160760 +Ref: figure-general-flow1161032 +Ref: figure-process-flow1161631 +Ref: Basic High Level-Footnote-11164860 +Node: Basic Data Typing1165045 +Node: Glossary1168373 +Node: Copying1193525 +Node: GNU Free Documentation License1231081 +Node: Index1256217  End Tag Table -- cgit v1.2.3 From 577ece63770a6c4b5ad00d6998127fb7e85b86b9 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 25 Jun 2014 22:36:32 +0300 Subject: Don't install igawk and igawk.1 anymore. --- doc/gawk.info | 123 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 62 insertions(+), 61 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 88c30646..34a83bef 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -26998,7 +26998,9 @@ Various `.c', `.y', and `.h' files `doc/igawk.1' The `troff' source for a manual page describing the `igawk' - program presented in *note Igawk Program::. + program presented in *note Igawk Program::. (Since `gawk' can do + its own `@include' processing, neither `igawk' nor `igawk.1' are + installed.) `doc/Makefile.in' The input file used during the configuration process to generate @@ -27040,11 +27042,10 @@ Various `.c', `.y', and `.h' files contains a `Makefile.in' file, which `configure' uses to generate a `Makefile'. `Makefile.am' is used by GNU Automake to create `Makefile.in'. The library functions from *note Library - Functions::, and the `igawk' program from *note Igawk Program::, - are included as ready-to-use files in the `gawk' distribution. - They are installed as part of the installation process. The rest - of the programs in this Info file are available in appropriate - subdirectories of `awklib/eg'. + Functions::, are included as ready-to-use files in the `gawk' + distribution. They are installed as part of the installation + process. The rest of the programs in this Info file are available + in appropriate subdirectories of `awklib/eg'. `extension/*' The source code, manual pages, and infrastructure files for the @@ -34436,60 +34437,60 @@ Node: Gawk Distribution1075342 Node: Getting1075826 Node: Extracting1076650 Node: Distribution contents1078292 -Node: Unix Installation1084009 -Node: Quick Installation1084626 -Node: Additional Configuration Options1087068 -Node: Configuration Philosophy1088806 -Node: Non-Unix Installation1091157 -Node: PC Installation1091615 -Node: PC Binary Installation1092926 -Node: PC Compiling1094774 -Ref: PC Compiling-Footnote-11097773 -Node: PC Testing1097878 -Node: PC Using1099054 -Node: Cygwin1103212 -Node: MSYS1104021 -Node: VMS Installation1104535 -Node: VMS Compilation1105331 -Ref: VMS Compilation-Footnote-11106553 -Node: VMS Dynamic Extensions1106611 -Node: VMS Installation Details1107984 -Node: VMS Running1110236 -Node: VMS GNV1113070 -Node: VMS Old Gawk1113793 -Node: Bugs1114263 -Node: Other Versions1118267 -Node: Installation summary1124522 -Node: Notes1125578 -Node: Compatibility Mode1126443 -Node: Additions1127225 -Node: Accessing The Source1128150 -Node: Adding Code1129586 -Node: New Ports1135764 -Node: Derived Files1140245 -Ref: Derived Files-Footnote-11145326 -Ref: Derived Files-Footnote-21145360 -Ref: Derived Files-Footnote-31145956 -Node: Future Extensions1146070 -Node: Implementation Limitations1146676 -Node: Extension Design1147924 -Node: Old Extension Problems1149078 -Ref: Old Extension Problems-Footnote-11150595 -Node: Extension New Mechanism Goals1150652 -Ref: Extension New Mechanism Goals-Footnote-11154012 -Node: Extension Other Design Decisions1154201 -Node: Extension Future Growth1156307 -Node: Old Extension Mechanism1157143 -Node: Notes summary1158905 -Node: Basic Concepts1160091 -Node: Basic High Level1160772 -Ref: figure-general-flow1161044 -Ref: figure-process-flow1161643 -Ref: Basic High Level-Footnote-11164872 -Node: Basic Data Typing1165057 -Node: Glossary1168385 -Node: Copying1193537 -Node: GNU Free Documentation License1231093 -Node: Index1256229 +Node: Unix Installation1084062 +Node: Quick Installation1084679 +Node: Additional Configuration Options1087121 +Node: Configuration Philosophy1088859 +Node: Non-Unix Installation1091210 +Node: PC Installation1091668 +Node: PC Binary Installation1092979 +Node: PC Compiling1094827 +Ref: PC Compiling-Footnote-11097826 +Node: PC Testing1097931 +Node: PC Using1099107 +Node: Cygwin1103265 +Node: MSYS1104074 +Node: VMS Installation1104588 +Node: VMS Compilation1105384 +Ref: VMS Compilation-Footnote-11106606 +Node: VMS Dynamic Extensions1106664 +Node: VMS Installation Details1108037 +Node: VMS Running1110289 +Node: VMS GNV1113123 +Node: VMS Old Gawk1113846 +Node: Bugs1114316 +Node: Other Versions1118320 +Node: Installation summary1124575 +Node: Notes1125631 +Node: Compatibility Mode1126496 +Node: Additions1127278 +Node: Accessing The Source1128203 +Node: Adding Code1129639 +Node: New Ports1135817 +Node: Derived Files1140298 +Ref: Derived Files-Footnote-11145379 +Ref: Derived Files-Footnote-21145413 +Ref: Derived Files-Footnote-31146009 +Node: Future Extensions1146123 +Node: Implementation Limitations1146729 +Node: Extension Design1147977 +Node: Old Extension Problems1149131 +Ref: Old Extension Problems-Footnote-11150648 +Node: Extension New Mechanism Goals1150705 +Ref: Extension New Mechanism Goals-Footnote-11154065 +Node: Extension Other Design Decisions1154254 +Node: Extension Future Growth1156360 +Node: Old Extension Mechanism1157196 +Node: Notes summary1158958 +Node: Basic Concepts1160144 +Node: Basic High Level1160825 +Ref: figure-general-flow1161097 +Ref: figure-process-flow1161696 +Ref: Basic High Level-Footnote-11164925 +Node: Basic Data Typing1165110 +Node: Glossary1168438 +Node: Copying1193590 +Node: GNU Free Documentation License1231146 +Node: Index1256282  End Tag Table -- cgit v1.2.3 From f6e8ca91a0046536ed5ffef60bb818d674fadf54 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 4 Jul 2014 13:07:13 -0400 Subject: Document how to match ASCII characters. --- doc/gawk.info | 990 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 499 insertions(+), 491 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 65ac7ab8..8b5e572f 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -3670,6 +3670,14 @@ set had other alphabetic characters in it, this would not match them. With the POSIX character classes, you can write `/[[:alnum:]]/' to match the alphabetic and numeric characters in your character set. + Some utilities that match regular expressions provide a non-standard +`[:ascii:]' character class; `awk' does not. However, you can simulate +such a construct using `[\x00-\x7F]'. This matches all values +numerically between zero and 127, which is the defined range of the +ASCII character set. Use a complemented character list +(`[^\x00-\x7F]') to match any single-byte characters that are not in +the ASCII range. + Two additional special sequences can appear in bracket expressions. These apply to non-ASCII character sets, which can have single symbols (called "collating elements") that are represented with more than one @@ -31475,13 +31483,13 @@ Index * bracket expressions, character classes: Bracket Expressions. (line 30) * bracket expressions, collating elements: Bracket Expressions. - (line 69) + (line 77) * bracket expressions, collating symbols: Bracket Expressions. - (line 76) + (line 84) * bracket expressions, complemented: Regexp Operators. (line 64) * bracket expressions, equivalence classes: Bracket Expressions. - (line 82) -* bracket expressions, non-ASCII: Bracket Expressions. (line 69) + (line 90) +* bracket expressions, non-ASCII: Bracket Expressions. (line 77) * bracket expressions, range expressions: Bracket Expressions. (line 6) * break debugger command: Breakpoint Control. (line 11) @@ -31599,8 +31607,8 @@ Index * Close, Diane <1>: Contributors. (line 20) * Close, Diane: Manual History. (line 41) * Collado, Manuel: Acknowledgments. (line 60) -* collating elements: Bracket Expressions. (line 69) -* collating symbols: Bracket Expressions. (line 76) +* collating elements: Bracket Expressions. (line 77) +* collating symbols: Bracket Expressions. (line 84) * Colombo, Antonio <1>: Contributors. (line 137) * Colombo, Antonio: Acknowledgments. (line 60) * columns, aligning: Print Examples. (line 70) @@ -32392,7 +32400,7 @@ Index * gawk, bitwise operations in: Bitwise Functions. (line 39) * gawk, break statement in: Break Statement. (line 51) * gawk, built-in variables and: Built-in Variables. (line 14) -* gawk, character classes and: Bracket Expressions. (line 90) +* gawk, character classes and: Bracket Expressions. (line 98) * gawk, coding style in: Adding Code. (line 39) * gawk, command-line options, and regular expressions: GNU Regexp Operators. (line 70) @@ -32668,7 +32676,7 @@ Index (line 13) * internationalization, localization: User-modified. (line 152) * internationalization, localization, character classes: Bracket Expressions. - (line 90) + (line 98) * internationalization, localization, gawk and: Internationalization. (line 13) * internationalization, localization, locale categories: Explaining gettext. @@ -34007,488 +34015,488 @@ Ref: Regexp Operators-Footnote-1165517 Ref: Regexp Operators-Footnote-2165664 Node: Bracket Expressions165762 Ref: table-char-classes167652 -Node: GNU Regexp Operators170175 -Node: Case-sensitivity173898 -Ref: Case-sensitivity-Footnote-1176790 -Ref: Case-sensitivity-Footnote-2177025 -Node: Leftmost Longest177133 -Node: Computed Regexps178334 -Node: Regexp Summary181706 -Node: Reading Files183177 -Node: Records185269 -Node: awk split records186012 -Node: gawk split records190870 -Ref: gawk split records-Footnote-1195391 -Node: Fields195428 -Ref: Fields-Footnote-1198392 -Node: Nonconstant Fields198478 -Ref: Nonconstant Fields-Footnote-1200708 -Node: Changing Fields200910 -Node: Field Separators206864 -Node: Default Field Splitting209566 -Node: Regexp Field Splitting210683 -Node: Single Character Fields214024 -Node: Command Line Field Separator215083 -Node: Full Line Fields218425 -Ref: Full Line Fields-Footnote-1218933 -Node: Field Splitting Summary218979 -Ref: Field Splitting Summary-Footnote-1222078 -Node: Constant Size222179 -Node: Splitting By Content226786 -Ref: Splitting By Content-Footnote-1230536 -Node: Multiple Line230576 -Ref: Multiple Line-Footnote-1236432 -Node: Getline236611 -Node: Plain Getline238827 -Node: Getline/Variable240922 -Node: Getline/File242069 -Node: Getline/Variable/File243453 -Ref: Getline/Variable/File-Footnote-1245052 -Node: Getline/Pipe245139 -Node: Getline/Variable/Pipe247838 -Node: Getline/Coprocess248945 -Node: Getline/Variable/Coprocess250197 -Node: Getline Notes250934 -Node: Getline Summary253738 -Ref: table-getline-variants254146 -Node: Read Timeout255058 -Ref: Read Timeout-Footnote-1258885 -Node: Command line directories258943 -Node: Input Summary259847 -Node: Input Exercises262984 -Node: Printing263717 -Node: Print265439 -Node: Print Examples266780 -Node: Output Separators269559 -Node: OFMT271575 -Node: Printf272933 -Node: Basic Printf273839 -Node: Control Letters275378 -Node: Format Modifiers279230 -Node: Printf Examples285257 -Node: Redirection287721 -Node: Special Files294693 -Node: Special FD295224 -Ref: Special FD-Footnote-1298848 -Node: Special Network298922 -Node: Special Caveats299772 -Node: Close Files And Pipes300568 -Ref: Close Files And Pipes-Footnote-1307729 -Ref: Close Files And Pipes-Footnote-2307877 -Node: Output Summary308027 -Node: Output exercises309024 -Node: Expressions309704 -Node: Values310889 -Node: Constants311565 -Node: Scalar Constants312245 -Ref: Scalar Constants-Footnote-1313104 -Node: Nondecimal-numbers313354 -Node: Regexp Constants316354 -Node: Using Constant Regexps316829 -Node: Variables319899 -Node: Using Variables320554 -Node: Assignment Options322278 -Node: Conversion324153 -Node: Strings And Numbers324677 -Ref: Strings And Numbers-Footnote-1327739 -Node: Locale influences conversions327848 -Ref: table-locale-affects330565 -Node: All Operators331153 -Node: Arithmetic Ops331783 -Node: Concatenation334288 -Ref: Concatenation-Footnote-1337084 -Node: Assignment Ops337204 -Ref: table-assign-ops342187 -Node: Increment Ops343504 -Node: Truth Values and Conditions346942 -Node: Truth Values348025 -Node: Typing and Comparison349074 -Node: Variable Typing349867 -Ref: Variable Typing-Footnote-1353767 -Node: Comparison Operators353889 -Ref: table-relational-ops354299 -Node: POSIX String Comparison357849 -Ref: POSIX String Comparison-Footnote-1358933 -Node: Boolean Ops359071 -Ref: Boolean Ops-Footnote-1363141 -Node: Conditional Exp363232 -Node: Function Calls364959 -Node: Precedence368839 -Node: Locales372508 -Node: Expressions Summary374139 -Node: Patterns and Actions376680 -Node: Pattern Overview377796 -Node: Regexp Patterns379473 -Node: Expression Patterns380016 -Node: Ranges383797 -Node: BEGIN/END386903 -Node: Using BEGIN/END387665 -Ref: Using BEGIN/END-Footnote-1390401 -Node: I/O And BEGIN/END390507 -Node: BEGINFILE/ENDFILE392792 -Node: Empty395723 -Node: Using Shell Variables396040 -Node: Action Overview398323 -Node: Statements400650 -Node: If Statement402498 -Node: While Statement403996 -Node: Do Statement406040 -Node: For Statement407196 -Node: Switch Statement410348 -Node: Break Statement412451 -Node: Continue Statement414506 -Node: Next Statement416299 -Node: Nextfile Statement418689 -Node: Exit Statement421344 -Node: Built-in Variables423748 -Node: User-modified424875 -Ref: User-modified-Footnote-1432564 -Node: Auto-set432626 -Ref: Auto-set-Footnote-1445208 -Ref: Auto-set-Footnote-2445413 -Node: ARGC and ARGV445469 -Node: Pattern Action Summary449323 -Node: Arrays451546 -Node: Array Basics453095 -Node: Array Intro453921 -Ref: figure-array-elements455894 -Node: Reference to Elements458301 -Node: Assigning Elements460574 -Node: Array Example461065 -Node: Scanning an Array462797 -Node: Controlling Scanning465812 -Ref: Controlling Scanning-Footnote-1470985 -Node: Delete471301 -Ref: Delete-Footnote-1474066 -Node: Numeric Array Subscripts474123 -Node: Uninitialized Subscripts476306 -Node: Multidimensional477931 -Node: Multiscanning481024 -Node: Arrays of Arrays482613 -Node: Arrays Summary487276 -Node: Functions489381 -Node: Built-in490254 -Node: Calling Built-in491332 -Node: Numeric Functions493320 -Ref: Numeric Functions-Footnote-1497154 -Ref: Numeric Functions-Footnote-2497511 -Ref: Numeric Functions-Footnote-3497559 -Node: String Functions497828 -Ref: String Functions-Footnote-1520839 -Ref: String Functions-Footnote-2520968 -Ref: String Functions-Footnote-3521216 -Node: Gory Details521303 -Ref: table-sub-escapes522972 -Ref: table-sub-posix-92524326 -Ref: table-sub-proposed525677 -Ref: table-posix-sub527031 -Ref: table-gensub-escapes528576 -Ref: Gory Details-Footnote-1529752 -Ref: Gory Details-Footnote-2529803 -Node: I/O Functions529954 -Ref: I/O Functions-Footnote-1537077 -Node: Time Functions537224 -Ref: Time Functions-Footnote-1547688 -Ref: Time Functions-Footnote-2547756 -Ref: Time Functions-Footnote-3547914 -Ref: Time Functions-Footnote-4548025 -Ref: Time Functions-Footnote-5548137 -Ref: Time Functions-Footnote-6548364 -Node: Bitwise Functions548630 -Ref: table-bitwise-ops549192 -Ref: Bitwise Functions-Footnote-1553437 -Node: Type Functions553621 -Node: I18N Functions554763 -Node: User-defined556408 -Node: Definition Syntax557212 -Ref: Definition Syntax-Footnote-1562391 -Node: Function Example562460 -Ref: Function Example-Footnote-1565104 -Node: Function Caveats565126 -Node: Calling A Function565644 -Node: Variable Scope566599 -Node: Pass By Value/Reference569587 -Node: Return Statement573095 -Node: Dynamic Typing576079 -Node: Indirect Calls577008 -Node: Functions Summary586721 -Node: Library Functions589260 -Ref: Library Functions-Footnote-1592878 -Ref: Library Functions-Footnote-2593021 -Node: Library Names593192 -Ref: Library Names-Footnote-1596665 -Ref: Library Names-Footnote-2596885 -Node: General Functions596971 -Node: Strtonum Function597999 -Node: Assert Function600779 -Node: Round Function604105 -Node: Cliff Random Function605646 -Node: Ordinal Functions606662 -Ref: Ordinal Functions-Footnote-1609739 -Ref: Ordinal Functions-Footnote-2609991 -Node: Join Function610202 -Ref: Join Function-Footnote-1611973 -Node: Getlocaltime Function612173 -Node: Readfile Function615909 -Node: Data File Management617748 -Node: Filetrans Function618380 -Node: Rewind Function622449 -Node: File Checking623836 -Ref: File Checking-Footnote-1624968 -Node: Empty Files625169 -Node: Ignoring Assigns627148 -Node: Getopt Function628702 -Ref: Getopt Function-Footnote-1640005 -Node: Passwd Functions640208 -Ref: Passwd Functions-Footnote-1649187 -Node: Group Functions649275 -Ref: Group Functions-Footnote-1657216 -Node: Walking Arrays657429 -Node: Library Functions Summary659032 -Node: Library exercises660420 -Node: Sample Programs661700 -Node: Running Examples662470 -Node: Clones663198 -Node: Cut Program664422 -Node: Egrep Program674290 -Ref: Egrep Program-Footnote-1682261 -Node: Id Program682371 -Node: Split Program686035 -Ref: Split Program-Footnote-1689573 -Node: Tee Program689701 -Node: Uniq Program692508 -Node: Wc Program699938 -Ref: Wc Program-Footnote-1704203 -Node: Miscellaneous Programs704295 -Node: Dupword Program705508 -Node: Alarm Program707539 -Node: Translate Program712353 -Ref: Translate Program-Footnote-1716744 -Ref: Translate Program-Footnote-2717014 -Node: Labels Program717148 -Ref: Labels Program-Footnote-1720519 -Node: Word Sorting720603 -Node: History Sorting724646 -Node: Extract Program726482 -Node: Simple Sed734018 -Node: Igawk Program737080 -Ref: Igawk Program-Footnote-1751391 -Ref: Igawk Program-Footnote-2751592 -Node: Anagram Program751730 -Node: Signature Program754798 -Node: Programs Summary756045 -Node: Programs Exercises757260 -Node: Advanced Features760911 -Node: Nondecimal Data762859 -Node: Array Sorting764436 -Node: Controlling Array Traversal765133 -Node: Array Sorting Functions773413 -Ref: Array Sorting Functions-Footnote-1777320 -Node: Two-way I/O777514 -Ref: Two-way I/O-Footnote-1783030 -Node: TCP/IP Networking783112 -Node: Profiling785956 -Node: Advanced Features Summary793498 -Node: Internationalization795362 -Node: I18N and L10N796842 -Node: Explaining gettext797528 -Ref: Explaining gettext-Footnote-1802668 -Ref: Explaining gettext-Footnote-2802852 -Node: Programmer i18n803017 -Node: Translator i18n807242 -Node: String Extraction808036 -Ref: String Extraction-Footnote-1808997 -Node: Printf Ordering809083 -Ref: Printf Ordering-Footnote-1811865 -Node: I18N Portability811929 -Ref: I18N Portability-Footnote-1814378 -Node: I18N Example814441 -Ref: I18N Example-Footnote-1817163 -Node: Gawk I18N817235 -Node: I18N Summary817873 -Node: Debugger819212 -Node: Debugging820234 -Node: Debugging Concepts820675 -Node: Debugging Terms822531 -Node: Awk Debugging825128 -Node: Sample Debugging Session826020 -Node: Debugger Invocation826540 -Node: Finding The Bug827873 -Node: List of Debugger Commands834355 -Node: Breakpoint Control835687 -Node: Debugger Execution Control839351 -Node: Viewing And Changing Data842711 -Node: Execution Stack846069 -Node: Debugger Info847582 -Node: Miscellaneous Debugger Commands851576 -Node: Readline Support856760 -Node: Limitations857652 -Node: Debugging Summary859926 -Node: Arbitrary Precision Arithmetic861090 -Node: Computer Arithmetic862419 -Ref: Computer Arithmetic-Footnote-1866806 -Node: Math Definitions866863 -Ref: table-ieee-formats869747 -Node: MPFR features870251 -Node: FP Math Caution871893 -Ref: FP Math Caution-Footnote-1872934 -Node: Inexactness of computations873303 -Node: Inexact representation874251 -Node: Comparing FP Values875606 -Node: Errors accumulate876570 -Node: Getting Accuracy878003 -Node: Try To Round880662 -Node: Setting precision881561 -Ref: table-predefined-precision-strings882243 -Node: Setting the rounding mode884036 -Ref: table-gawk-rounding-modes884400 -Ref: Setting the rounding mode-Footnote-1887854 -Node: Arbitrary Precision Integers888033 -Ref: Arbitrary Precision Integers-Footnote-1891036 -Node: POSIX Floating Point Problems891185 -Ref: POSIX Floating Point Problems-Footnote-1895061 -Node: Floating point summary895099 -Node: Dynamic Extensions897316 -Node: Extension Intro898868 -Node: Plugin License900133 -Node: Extension Mechanism Outline900818 -Ref: figure-load-extension901242 -Ref: figure-load-new-function902727 -Ref: figure-call-new-function903729 -Node: Extension API Description905713 -Node: Extension API Functions Introduction907163 -Node: General Data Types912028 -Ref: General Data Types-Footnote-1917721 -Node: Requesting Values918020 -Ref: table-value-types-returned918757 -Node: Memory Allocation Functions919715 -Ref: Memory Allocation Functions-Footnote-1922462 -Node: Constructor Functions922558 -Node: Registration Functions924316 -Node: Extension Functions925001 -Node: Exit Callback Functions927303 -Node: Extension Version String928552 -Node: Input Parsers929202 -Node: Output Wrappers939005 -Node: Two-way processors943521 -Node: Printing Messages945725 -Ref: Printing Messages-Footnote-1946802 -Node: Updating `ERRNO'946954 -Node: Accessing Parameters947693 -Node: Symbol Table Access948923 -Node: Symbol table by name949437 -Node: Symbol table by cookie951413 -Ref: Symbol table by cookie-Footnote-1955546 -Node: Cached values955609 -Ref: Cached values-Footnote-1959113 -Node: Array Manipulation959204 -Ref: Array Manipulation-Footnote-1960302 -Node: Array Data Types960341 -Ref: Array Data Types-Footnote-1963044 -Node: Array Functions963136 -Node: Flattening Arrays967010 -Node: Creating Arrays973862 -Node: Extension API Variables978593 -Node: Extension Versioning979229 -Node: Extension API Informational Variables981130 -Node: Extension API Boilerplate982216 -Node: Finding Extensions986020 -Node: Extension Example986580 -Node: Internal File Description987310 -Node: Internal File Ops991401 -Ref: Internal File Ops-Footnote-11002833 -Node: Using Internal File Ops1002973 -Ref: Using Internal File Ops-Footnote-11005320 -Node: Extension Samples1005588 -Node: Extension Sample File Functions1007112 -Node: Extension Sample Fnmatch1014680 -Node: Extension Sample Fork1016162 -Node: Extension Sample Inplace1017375 -Node: Extension Sample Ord1019050 -Node: Extension Sample Readdir1019886 -Ref: table-readdir-file-types1020742 -Node: Extension Sample Revout1021541 -Node: Extension Sample Rev2way1022132 -Node: Extension Sample Read write array1022873 -Node: Extension Sample Readfile1024752 -Node: Extension Sample API Tests1025852 -Node: Extension Sample Time1026377 -Node: gawkextlib1027692 -Node: Extension summary1030505 -Node: Extension Exercises1034198 -Node: Language History1034920 -Node: V7/SVR3.11036563 -Node: SVR41038883 -Node: POSIX1040325 -Node: BTL1041711 -Node: POSIX/GNU1042445 -Node: Feature History1048044 -Node: Common Extensions1061174 -Node: Ranges and Locales1062486 -Ref: Ranges and Locales-Footnote-11067103 -Ref: Ranges and Locales-Footnote-21067130 -Ref: Ranges and Locales-Footnote-31067364 -Node: Contributors1067585 -Node: History summary1073010 -Node: Installation1074379 -Node: Gawk Distribution1075330 -Node: Getting1075814 -Node: Extracting1076638 -Node: Distribution contents1078280 -Node: Unix Installation1083997 -Node: Quick Installation1084614 -Node: Additional Configuration Options1087056 -Node: Configuration Philosophy1088794 -Node: Non-Unix Installation1091145 -Node: PC Installation1091603 -Node: PC Binary Installation1092914 -Node: PC Compiling1094762 -Ref: PC Compiling-Footnote-11097761 -Node: PC Testing1097866 -Node: PC Using1099042 -Node: Cygwin1103200 -Node: MSYS1104009 -Node: VMS Installation1104523 -Node: VMS Compilation1105319 -Ref: VMS Compilation-Footnote-11106541 -Node: VMS Dynamic Extensions1106599 -Node: VMS Installation Details1107972 -Node: VMS Running1110224 -Node: VMS GNV1113058 -Node: VMS Old Gawk1113781 -Node: Bugs1114251 -Node: Other Versions1118255 -Node: Installation summary1124510 -Node: Notes1125566 -Node: Compatibility Mode1126431 -Node: Additions1127213 -Node: Accessing The Source1128138 -Node: Adding Code1129574 -Node: New Ports1135752 -Node: Derived Files1140233 -Ref: Derived Files-Footnote-11145314 -Ref: Derived Files-Footnote-21145348 -Ref: Derived Files-Footnote-31145944 -Node: Future Extensions1146058 -Node: Implementation Limitations1146664 -Node: Extension Design1147912 -Node: Old Extension Problems1149066 -Ref: Old Extension Problems-Footnote-11150583 -Node: Extension New Mechanism Goals1150640 -Ref: Extension New Mechanism Goals-Footnote-11154000 -Node: Extension Other Design Decisions1154189 -Node: Extension Future Growth1156295 -Node: Old Extension Mechanism1157131 -Node: Notes summary1158893 -Node: Basic Concepts1160079 -Node: Basic High Level1160760 -Ref: figure-general-flow1161032 -Ref: figure-process-flow1161631 -Ref: Basic High Level-Footnote-11164860 -Node: Basic Data Typing1165045 -Node: Glossary1168373 -Node: Copying1193525 -Node: GNU Free Documentation License1231081 -Node: Index1256217 +Node: GNU Regexp Operators170592 +Node: Case-sensitivity174315 +Ref: Case-sensitivity-Footnote-1177207 +Ref: Case-sensitivity-Footnote-2177442 +Node: Leftmost Longest177550 +Node: Computed Regexps178751 +Node: Regexp Summary182123 +Node: Reading Files183594 +Node: Records185686 +Node: awk split records186429 +Node: gawk split records191287 +Ref: gawk split records-Footnote-1195808 +Node: Fields195845 +Ref: Fields-Footnote-1198809 +Node: Nonconstant Fields198895 +Ref: Nonconstant Fields-Footnote-1201125 +Node: Changing Fields201327 +Node: Field Separators207281 +Node: Default Field Splitting209983 +Node: Regexp Field Splitting211100 +Node: Single Character Fields214441 +Node: Command Line Field Separator215500 +Node: Full Line Fields218842 +Ref: Full Line Fields-Footnote-1219350 +Node: Field Splitting Summary219396 +Ref: Field Splitting Summary-Footnote-1222495 +Node: Constant Size222596 +Node: Splitting By Content227203 +Ref: Splitting By Content-Footnote-1230953 +Node: Multiple Line230993 +Ref: Multiple Line-Footnote-1236849 +Node: Getline237028 +Node: Plain Getline239244 +Node: Getline/Variable241339 +Node: Getline/File242486 +Node: Getline/Variable/File243870 +Ref: Getline/Variable/File-Footnote-1245469 +Node: Getline/Pipe245556 +Node: Getline/Variable/Pipe248255 +Node: Getline/Coprocess249362 +Node: Getline/Variable/Coprocess250614 +Node: Getline Notes251351 +Node: Getline Summary254155 +Ref: table-getline-variants254563 +Node: Read Timeout255475 +Ref: Read Timeout-Footnote-1259302 +Node: Command line directories259360 +Node: Input Summary260264 +Node: Input Exercises263401 +Node: Printing264134 +Node: Print265856 +Node: Print Examples267197 +Node: Output Separators269976 +Node: OFMT271992 +Node: Printf273350 +Node: Basic Printf274256 +Node: Control Letters275795 +Node: Format Modifiers279647 +Node: Printf Examples285674 +Node: Redirection288138 +Node: Special Files295110 +Node: Special FD295641 +Ref: Special FD-Footnote-1299265 +Node: Special Network299339 +Node: Special Caveats300189 +Node: Close Files And Pipes300985 +Ref: Close Files And Pipes-Footnote-1308146 +Ref: Close Files And Pipes-Footnote-2308294 +Node: Output Summary308444 +Node: Output exercises309441 +Node: Expressions310121 +Node: Values311306 +Node: Constants311982 +Node: Scalar Constants312662 +Ref: Scalar Constants-Footnote-1313521 +Node: Nondecimal-numbers313771 +Node: Regexp Constants316771 +Node: Using Constant Regexps317246 +Node: Variables320316 +Node: Using Variables320971 +Node: Assignment Options322695 +Node: Conversion324570 +Node: Strings And Numbers325094 +Ref: Strings And Numbers-Footnote-1328156 +Node: Locale influences conversions328265 +Ref: table-locale-affects330982 +Node: All Operators331570 +Node: Arithmetic Ops332200 +Node: Concatenation334705 +Ref: Concatenation-Footnote-1337501 +Node: Assignment Ops337621 +Ref: table-assign-ops342604 +Node: Increment Ops343921 +Node: Truth Values and Conditions347359 +Node: Truth Values348442 +Node: Typing and Comparison349491 +Node: Variable Typing350284 +Ref: Variable Typing-Footnote-1354184 +Node: Comparison Operators354306 +Ref: table-relational-ops354716 +Node: POSIX String Comparison358266 +Ref: POSIX String Comparison-Footnote-1359350 +Node: Boolean Ops359488 +Ref: Boolean Ops-Footnote-1363558 +Node: Conditional Exp363649 +Node: Function Calls365376 +Node: Precedence369256 +Node: Locales372925 +Node: Expressions Summary374556 +Node: Patterns and Actions377097 +Node: Pattern Overview378213 +Node: Regexp Patterns379890 +Node: Expression Patterns380433 +Node: Ranges384214 +Node: BEGIN/END387320 +Node: Using BEGIN/END388082 +Ref: Using BEGIN/END-Footnote-1390818 +Node: I/O And BEGIN/END390924 +Node: BEGINFILE/ENDFILE393209 +Node: Empty396140 +Node: Using Shell Variables396457 +Node: Action Overview398740 +Node: Statements401067 +Node: If Statement402915 +Node: While Statement404413 +Node: Do Statement406457 +Node: For Statement407613 +Node: Switch Statement410765 +Node: Break Statement412868 +Node: Continue Statement414923 +Node: Next Statement416716 +Node: Nextfile Statement419106 +Node: Exit Statement421761 +Node: Built-in Variables424165 +Node: User-modified425292 +Ref: User-modified-Footnote-1432981 +Node: Auto-set433043 +Ref: Auto-set-Footnote-1445625 +Ref: Auto-set-Footnote-2445830 +Node: ARGC and ARGV445886 +Node: Pattern Action Summary449740 +Node: Arrays451963 +Node: Array Basics453512 +Node: Array Intro454338 +Ref: figure-array-elements456311 +Node: Reference to Elements458718 +Node: Assigning Elements460991 +Node: Array Example461482 +Node: Scanning an Array463214 +Node: Controlling Scanning466229 +Ref: Controlling Scanning-Footnote-1471402 +Node: Delete471718 +Ref: Delete-Footnote-1474483 +Node: Numeric Array Subscripts474540 +Node: Uninitialized Subscripts476723 +Node: Multidimensional478348 +Node: Multiscanning481441 +Node: Arrays of Arrays483030 +Node: Arrays Summary487693 +Node: Functions489798 +Node: Built-in490671 +Node: Calling Built-in491749 +Node: Numeric Functions493737 +Ref: Numeric Functions-Footnote-1497571 +Ref: Numeric Functions-Footnote-2497928 +Ref: Numeric Functions-Footnote-3497976 +Node: String Functions498245 +Ref: String Functions-Footnote-1521256 +Ref: String Functions-Footnote-2521385 +Ref: String Functions-Footnote-3521633 +Node: Gory Details521720 +Ref: table-sub-escapes523389 +Ref: table-sub-posix-92524743 +Ref: table-sub-proposed526094 +Ref: table-posix-sub527448 +Ref: table-gensub-escapes528993 +Ref: Gory Details-Footnote-1530169 +Ref: Gory Details-Footnote-2530220 +Node: I/O Functions530371 +Ref: I/O Functions-Footnote-1537494 +Node: Time Functions537641 +Ref: Time Functions-Footnote-1548105 +Ref: Time Functions-Footnote-2548173 +Ref: Time Functions-Footnote-3548331 +Ref: Time Functions-Footnote-4548442 +Ref: Time Functions-Footnote-5548554 +Ref: Time Functions-Footnote-6548781 +Node: Bitwise Functions549047 +Ref: table-bitwise-ops549609 +Ref: Bitwise Functions-Footnote-1553854 +Node: Type Functions554038 +Node: I18N Functions555180 +Node: User-defined556825 +Node: Definition Syntax557629 +Ref: Definition Syntax-Footnote-1562808 +Node: Function Example562877 +Ref: Function Example-Footnote-1565521 +Node: Function Caveats565543 +Node: Calling A Function566061 +Node: Variable Scope567016 +Node: Pass By Value/Reference570004 +Node: Return Statement573512 +Node: Dynamic Typing576496 +Node: Indirect Calls577425 +Node: Functions Summary587138 +Node: Library Functions589677 +Ref: Library Functions-Footnote-1593295 +Ref: Library Functions-Footnote-2593438 +Node: Library Names593609 +Ref: Library Names-Footnote-1597082 +Ref: Library Names-Footnote-2597302 +Node: General Functions597388 +Node: Strtonum Function598416 +Node: Assert Function601196 +Node: Round Function604522 +Node: Cliff Random Function606063 +Node: Ordinal Functions607079 +Ref: Ordinal Functions-Footnote-1610156 +Ref: Ordinal Functions-Footnote-2610408 +Node: Join Function610619 +Ref: Join Function-Footnote-1612390 +Node: Getlocaltime Function612590 +Node: Readfile Function616326 +Node: Data File Management618165 +Node: Filetrans Function618797 +Node: Rewind Function622866 +Node: File Checking624253 +Ref: File Checking-Footnote-1625385 +Node: Empty Files625586 +Node: Ignoring Assigns627565 +Node: Getopt Function629119 +Ref: Getopt Function-Footnote-1640422 +Node: Passwd Functions640625 +Ref: Passwd Functions-Footnote-1649604 +Node: Group Functions649692 +Ref: Group Functions-Footnote-1657633 +Node: Walking Arrays657846 +Node: Library Functions Summary659449 +Node: Library exercises660837 +Node: Sample Programs662117 +Node: Running Examples662887 +Node: Clones663615 +Node: Cut Program664839 +Node: Egrep Program674707 +Ref: Egrep Program-Footnote-1682678 +Node: Id Program682788 +Node: Split Program686452 +Ref: Split Program-Footnote-1689990 +Node: Tee Program690118 +Node: Uniq Program692925 +Node: Wc Program700355 +Ref: Wc Program-Footnote-1704620 +Node: Miscellaneous Programs704712 +Node: Dupword Program705925 +Node: Alarm Program707956 +Node: Translate Program712770 +Ref: Translate Program-Footnote-1717161 +Ref: Translate Program-Footnote-2717431 +Node: Labels Program717565 +Ref: Labels Program-Footnote-1720936 +Node: Word Sorting721020 +Node: History Sorting725063 +Node: Extract Program726899 +Node: Simple Sed734435 +Node: Igawk Program737497 +Ref: Igawk Program-Footnote-1751808 +Ref: Igawk Program-Footnote-2752009 +Node: Anagram Program752147 +Node: Signature Program755215 +Node: Programs Summary756462 +Node: Programs Exercises757677 +Node: Advanced Features761328 +Node: Nondecimal Data763276 +Node: Array Sorting764853 +Node: Controlling Array Traversal765550 +Node: Array Sorting Functions773830 +Ref: Array Sorting Functions-Footnote-1777737 +Node: Two-way I/O777931 +Ref: Two-way I/O-Footnote-1783447 +Node: TCP/IP Networking783529 +Node: Profiling786373 +Node: Advanced Features Summary793915 +Node: Internationalization795779 +Node: I18N and L10N797259 +Node: Explaining gettext797945 +Ref: Explaining gettext-Footnote-1803085 +Ref: Explaining gettext-Footnote-2803269 +Node: Programmer i18n803434 +Node: Translator i18n807659 +Node: String Extraction808453 +Ref: String Extraction-Footnote-1809414 +Node: Printf Ordering809500 +Ref: Printf Ordering-Footnote-1812282 +Node: I18N Portability812346 +Ref: I18N Portability-Footnote-1814795 +Node: I18N Example814858 +Ref: I18N Example-Footnote-1817580 +Node: Gawk I18N817652 +Node: I18N Summary818290 +Node: Debugger819629 +Node: Debugging820651 +Node: Debugging Concepts821092 +Node: Debugging Terms822948 +Node: Awk Debugging825545 +Node: Sample Debugging Session826437 +Node: Debugger Invocation826957 +Node: Finding The Bug828290 +Node: List of Debugger Commands834772 +Node: Breakpoint Control836104 +Node: Debugger Execution Control839768 +Node: Viewing And Changing Data843128 +Node: Execution Stack846486 +Node: Debugger Info847999 +Node: Miscellaneous Debugger Commands851993 +Node: Readline Support857177 +Node: Limitations858069 +Node: Debugging Summary860343 +Node: Arbitrary Precision Arithmetic861507 +Node: Computer Arithmetic862836 +Ref: Computer Arithmetic-Footnote-1867223 +Node: Math Definitions867280 +Ref: table-ieee-formats870164 +Node: MPFR features870668 +Node: FP Math Caution872310 +Ref: FP Math Caution-Footnote-1873351 +Node: Inexactness of computations873720 +Node: Inexact representation874668 +Node: Comparing FP Values876023 +Node: Errors accumulate876987 +Node: Getting Accuracy878420 +Node: Try To Round881079 +Node: Setting precision881978 +Ref: table-predefined-precision-strings882660 +Node: Setting the rounding mode884453 +Ref: table-gawk-rounding-modes884817 +Ref: Setting the rounding mode-Footnote-1888271 +Node: Arbitrary Precision Integers888450 +Ref: Arbitrary Precision Integers-Footnote-1891453 +Node: POSIX Floating Point Problems891602 +Ref: POSIX Floating Point Problems-Footnote-1895478 +Node: Floating point summary895516 +Node: Dynamic Extensions897733 +Node: Extension Intro899285 +Node: Plugin License900550 +Node: Extension Mechanism Outline901235 +Ref: figure-load-extension901659 +Ref: figure-load-new-function903144 +Ref: figure-call-new-function904146 +Node: Extension API Description906130 +Node: Extension API Functions Introduction907580 +Node: General Data Types912445 +Ref: General Data Types-Footnote-1918138 +Node: Requesting Values918437 +Ref: table-value-types-returned919174 +Node: Memory Allocation Functions920132 +Ref: Memory Allocation Functions-Footnote-1922879 +Node: Constructor Functions922975 +Node: Registration Functions924733 +Node: Extension Functions925418 +Node: Exit Callback Functions927720 +Node: Extension Version String928969 +Node: Input Parsers929619 +Node: Output Wrappers939422 +Node: Two-way processors943938 +Node: Printing Messages946142 +Ref: Printing Messages-Footnote-1947219 +Node: Updating `ERRNO'947371 +Node: Accessing Parameters948110 +Node: Symbol Table Access949340 +Node: Symbol table by name949854 +Node: Symbol table by cookie951830 +Ref: Symbol table by cookie-Footnote-1955963 +Node: Cached values956026 +Ref: Cached values-Footnote-1959530 +Node: Array Manipulation959621 +Ref: Array Manipulation-Footnote-1960719 +Node: Array Data Types960758 +Ref: Array Data Types-Footnote-1963461 +Node: Array Functions963553 +Node: Flattening Arrays967427 +Node: Creating Arrays974279 +Node: Extension API Variables979010 +Node: Extension Versioning979646 +Node: Extension API Informational Variables981547 +Node: Extension API Boilerplate982633 +Node: Finding Extensions986437 +Node: Extension Example986997 +Node: Internal File Description987727 +Node: Internal File Ops991818 +Ref: Internal File Ops-Footnote-11003250 +Node: Using Internal File Ops1003390 +Ref: Using Internal File Ops-Footnote-11005737 +Node: Extension Samples1006005 +Node: Extension Sample File Functions1007529 +Node: Extension Sample Fnmatch1015097 +Node: Extension Sample Fork1016579 +Node: Extension Sample Inplace1017792 +Node: Extension Sample Ord1019467 +Node: Extension Sample Readdir1020303 +Ref: table-readdir-file-types1021159 +Node: Extension Sample Revout1021958 +Node: Extension Sample Rev2way1022549 +Node: Extension Sample Read write array1023290 +Node: Extension Sample Readfile1025169 +Node: Extension Sample API Tests1026269 +Node: Extension Sample Time1026794 +Node: gawkextlib1028109 +Node: Extension summary1030922 +Node: Extension Exercises1034615 +Node: Language History1035337 +Node: V7/SVR3.11036980 +Node: SVR41039300 +Node: POSIX1040742 +Node: BTL1042128 +Node: POSIX/GNU1042862 +Node: Feature History1048461 +Node: Common Extensions1061591 +Node: Ranges and Locales1062903 +Ref: Ranges and Locales-Footnote-11067520 +Ref: Ranges and Locales-Footnote-21067547 +Ref: Ranges and Locales-Footnote-31067781 +Node: Contributors1068002 +Node: History summary1073427 +Node: Installation1074796 +Node: Gawk Distribution1075747 +Node: Getting1076231 +Node: Extracting1077055 +Node: Distribution contents1078697 +Node: Unix Installation1084414 +Node: Quick Installation1085031 +Node: Additional Configuration Options1087473 +Node: Configuration Philosophy1089211 +Node: Non-Unix Installation1091562 +Node: PC Installation1092020 +Node: PC Binary Installation1093331 +Node: PC Compiling1095179 +Ref: PC Compiling-Footnote-11098178 +Node: PC Testing1098283 +Node: PC Using1099459 +Node: Cygwin1103617 +Node: MSYS1104426 +Node: VMS Installation1104940 +Node: VMS Compilation1105736 +Ref: VMS Compilation-Footnote-11106958 +Node: VMS Dynamic Extensions1107016 +Node: VMS Installation Details1108389 +Node: VMS Running1110641 +Node: VMS GNV1113475 +Node: VMS Old Gawk1114198 +Node: Bugs1114668 +Node: Other Versions1118672 +Node: Installation summary1124927 +Node: Notes1125983 +Node: Compatibility Mode1126848 +Node: Additions1127630 +Node: Accessing The Source1128555 +Node: Adding Code1129991 +Node: New Ports1136169 +Node: Derived Files1140650 +Ref: Derived Files-Footnote-11145731 +Ref: Derived Files-Footnote-21145765 +Ref: Derived Files-Footnote-31146361 +Node: Future Extensions1146475 +Node: Implementation Limitations1147081 +Node: Extension Design1148329 +Node: Old Extension Problems1149483 +Ref: Old Extension Problems-Footnote-11151000 +Node: Extension New Mechanism Goals1151057 +Ref: Extension New Mechanism Goals-Footnote-11154417 +Node: Extension Other Design Decisions1154606 +Node: Extension Future Growth1156712 +Node: Old Extension Mechanism1157548 +Node: Notes summary1159310 +Node: Basic Concepts1160496 +Node: Basic High Level1161177 +Ref: figure-general-flow1161449 +Ref: figure-process-flow1162048 +Ref: Basic High Level-Footnote-11165277 +Node: Basic Data Typing1165462 +Node: Glossary1168790 +Node: Copying1193942 +Node: GNU Free Documentation License1231498 +Node: Index1256634  End Tag Table -- cgit v1.2.3 From df2eaea6a92c7d89d604d0a4e885d064678ce3ed Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 10 Jul 2014 16:32:44 -0700 Subject: Add div() function for integer division & remainder. --- doc/gawk.info | 708 +++++++++++++++++++++++++++++++--------------------------- 1 file changed, 373 insertions(+), 335 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 8326cf82..e7854caf 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -11680,6 +11680,20 @@ brackets ([ ]): `cos(X)' Return the cosine of X, with X in radians. +`div(NUMERATOR, DENOMINATOR, RESULT)' + Perform integer division, similar to the standard C function of the + same name. First, truncate `numerator' and `denominator' to + integers. Clear the `result' array, and then set + `result["quotient"]' to the result of `numerator / denominator', + truncated to an integer, and set `result["remainder"]' to the + result of `numerator % denominator', truncated to an integer. + This function is primarily intended for use with arbitrary length + integers; it avoids creating MPFR arbitrary precision + floating-point values (*note Arbitrary Precision Integers::). + + This function is a `gawk' extension. It is not available in + compatibility mode (*note Options::). + `exp(X)' Return the exponential of X (`e ^ X') or report an error if X is out of range. The range of values X can have depends on your @@ -22082,6 +22096,29 @@ just use the following: gawk -M 'BEGIN { n = 13; print n % 2 }' + When dividing two arbitrary precision integers with either `/' or +`%', the result is typically an arbitrary precision floating point +value (unless the denominator evenly divides into the numerator). In +order to do integer division or remainder with arbitrary precision +integers, use the built-in `div()' function (*note Numeric Functions::). + + You can simulate the `div()' function in standard `awk' using this +user-defined function: + + # div --- do integer division + + function div(numerator, denominator, result, i) + { + split("", result) + + numerator = int(numerator) + denominator = int(denominator) + result["quotient"] = int(numerator / denominator) + result["remainder"] = int(numerator % denominator) + + return 0.0 + } + ---------- Footnotes ---------- (1) Weisstein, Eric W. `Sylvester's Sequence'. From MathWorld--A @@ -32005,6 +32042,7 @@ Index * display debugger command: Viewing And Changing Data. (line 8) * display debugger options: Debugger Info. (line 57) +* div: Numeric Functions. (line 18) * division: Arithmetic Ops. (line 44) * do-while statement: Do Statement. (line 6) * do-while statement, use of regexps in: Regexp Usage. (line 19) @@ -32125,10 +32163,10 @@ Index * exit status, of VMS: VMS Running. (line 29) * exit the debugger: Miscellaneous Debugger Commands. (line 99) -* exp: Numeric Functions. (line 18) +* exp: Numeric Functions. (line 32) * expand utility: Very Simple. (line 69) * Expat XML parser library: gawkextlib. (line 35) -* exponent: Numeric Functions. (line 18) +* exponent: Numeric Functions. (line 32) * expressions: Expressions. (line 6) * expressions, as patterns: Expression Patterns. (line 6) * expressions, assignment: Assignment Ops. (line 6) @@ -32664,7 +32702,7 @@ Index * installation, VMS: VMS Installation. (line 6) * installing gawk: Installation. (line 6) * instruction tracing, in debugger: Debugger Info. (line 89) -* int: Numeric Functions. (line 23) +* int: Numeric Functions. (line 37) * INT signal (MS-Windows): Profiling. (line 214) * integer array indices: Numeric Array Subscripts. (line 31) @@ -32813,9 +32851,9 @@ Index * localization: I18N and L10N. (line 6) * localization, See internationalization, localization: I18N and L10N. (line 6) -* log: Numeric Functions. (line 30) +* log: Numeric Functions. (line 44) * log files, timestamps in: Time Functions. (line 6) -* logarithm: Numeric Functions. (line 30) +* logarithm: Numeric Functions. (line 44) * logical false/true: Truth Values. (line 6) * logical operators, See Boolean expressions: Boolean Ops. (line 6) * login information: Passwd Functions. (line 16) @@ -33272,12 +33310,12 @@ Index * Rakitzis, Byron: History Sorting. (line 25) * Ramey, Chet <1>: General Data Types. (line 6) * Ramey, Chet: Acknowledgments. (line 60) -* rand: Numeric Functions. (line 34) +* rand: Numeric Functions. (line 48) * random numbers, Cliff: Cliff Random Function. (line 6) * random numbers, rand()/srand() functions: Numeric Functions. - (line 34) -* random numbers, seed of: Numeric Functions. (line 64) + (line 48) +* random numbers, seed of: Numeric Functions. (line 78) * range expressions (regexps): Bracket Expressions. (line 6) * range patterns: Ranges. (line 6) * range patterns, line continuation and: Ranges. (line 65) @@ -33405,7 +33443,7 @@ Index * Robbins, Miriam <2>: Getline/Pipe. (line 39) * Robbins, Miriam: Acknowledgments. (line 82) * Rommel, Kai Uwe: Contributors. (line 42) -* round to nearest integer: Numeric Functions. (line 23) +* round to nearest integer: Numeric Functions. (line 37) * round() user-defined function: Round Function. (line 16) * rounding numbers: Round Function. (line 6) * ROUNDMODE variable: User-modified. (line 128) @@ -33455,7 +33493,7 @@ Index * sed utility <2>: Simple Sed. (line 6) * sed utility: Field Splitting Summary. (line 46) -* seeding random number generator: Numeric Functions. (line 64) +* seeding random number generator: Numeric Functions. (line 78) * semicolon (;), AWKPATH variable and: PC Using. (line 10) * semicolon (;), separating statements in actions <1>: Statements. (line 10) @@ -33557,8 +33595,8 @@ Index * SIGUSR1 signal, for dynamic profiling: Profiling. (line 188) * silent debugger command: Debugger Execution Control. (line 10) -* sin: Numeric Functions. (line 75) -* sine: Numeric Functions. (line 75) +* sin: Numeric Functions. (line 89) +* sine: Numeric Functions. (line 89) * single quote ('): One-shot. (line 15) * single quote (') in gawk command lines: Long. (line 33) * single quote ('), in shell commands: Quoting. (line 48) @@ -33608,10 +33646,10 @@ Index * sprintf() function, OFMT variable and: User-modified. (line 114) * sprintf() function, print/printf statements and: Round Function. (line 6) -* sqrt: Numeric Functions. (line 78) +* sqrt: Numeric Functions. (line 92) * square brackets ([]), regexp operator: Regexp Operators. (line 56) -* square root: Numeric Functions. (line 78) -* srand: Numeric Functions. (line 82) +* square root: Numeric Functions. (line 92) +* srand: Numeric Functions. (line 96) * stack frame: Debugging Terms. (line 10) * Stallman, Richard <1>: Glossary. (line 296) * Stallman, Richard <2>: Contributors. (line 23) @@ -34180,325 +34218,325 @@ Node: Functions489801 Node: Built-in490674 Node: Calling Built-in491752 Node: Numeric Functions493740 -Ref: Numeric Functions-Footnote-1497574 -Ref: Numeric Functions-Footnote-2497931 -Ref: Numeric Functions-Footnote-3497979 -Node: String Functions498248 -Ref: String Functions-Footnote-1521259 -Ref: String Functions-Footnote-2521388 -Ref: String Functions-Footnote-3521636 -Node: Gory Details521723 -Ref: table-sub-escapes523392 -Ref: table-sub-posix-92524746 -Ref: table-sub-proposed526097 -Ref: table-posix-sub527451 -Ref: table-gensub-escapes528996 -Ref: Gory Details-Footnote-1530172 -Ref: Gory Details-Footnote-2530223 -Node: I/O Functions530374 -Ref: I/O Functions-Footnote-1537497 -Node: Time Functions537644 -Ref: Time Functions-Footnote-1548108 -Ref: Time Functions-Footnote-2548176 -Ref: Time Functions-Footnote-3548334 -Ref: Time Functions-Footnote-4548445 -Ref: Time Functions-Footnote-5548557 -Ref: Time Functions-Footnote-6548784 -Node: Bitwise Functions549050 -Ref: table-bitwise-ops549612 -Ref: Bitwise Functions-Footnote-1553857 -Node: Type Functions554041 -Node: I18N Functions555183 -Node: User-defined556828 -Node: Definition Syntax557632 -Ref: Definition Syntax-Footnote-1562811 -Node: Function Example562880 -Ref: Function Example-Footnote-1565524 -Node: Function Caveats565546 -Node: Calling A Function566064 -Node: Variable Scope567019 -Node: Pass By Value/Reference570007 -Node: Return Statement573515 -Node: Dynamic Typing576499 -Node: Indirect Calls577428 -Node: Functions Summary587141 -Node: Library Functions589680 -Ref: Library Functions-Footnote-1593298 -Ref: Library Functions-Footnote-2593441 -Node: Library Names593612 -Ref: Library Names-Footnote-1597085 -Ref: Library Names-Footnote-2597305 -Node: General Functions597391 -Node: Strtonum Function598419 -Node: Assert Function601199 -Node: Round Function604525 -Node: Cliff Random Function606066 -Node: Ordinal Functions607082 -Ref: Ordinal Functions-Footnote-1610159 -Ref: Ordinal Functions-Footnote-2610411 -Node: Join Function610622 -Ref: Join Function-Footnote-1612393 -Node: Getlocaltime Function612593 -Node: Readfile Function616329 -Node: Data File Management618168 -Node: Filetrans Function618800 -Node: Rewind Function622869 -Node: File Checking624256 -Ref: File Checking-Footnote-1625388 -Node: Empty Files625589 -Node: Ignoring Assigns627568 -Node: Getopt Function629122 -Ref: Getopt Function-Footnote-1640425 -Node: Passwd Functions640628 -Ref: Passwd Functions-Footnote-1649607 -Node: Group Functions649695 -Ref: Group Functions-Footnote-1657636 -Node: Walking Arrays657849 -Node: Library Functions Summary659452 -Node: Library exercises660840 -Node: Sample Programs662120 -Node: Running Examples662890 -Node: Clones663618 -Node: Cut Program664842 -Node: Egrep Program674710 -Ref: Egrep Program-Footnote-1682681 -Node: Id Program682791 -Node: Split Program686455 -Ref: Split Program-Footnote-1689993 -Node: Tee Program690121 -Node: Uniq Program692928 -Node: Wc Program700358 -Ref: Wc Program-Footnote-1704623 -Node: Miscellaneous Programs704715 -Node: Dupword Program705928 -Node: Alarm Program707959 -Node: Translate Program712773 -Ref: Translate Program-Footnote-1717164 -Ref: Translate Program-Footnote-2717434 -Node: Labels Program717568 -Ref: Labels Program-Footnote-1720939 -Node: Word Sorting721023 -Node: History Sorting725066 -Node: Extract Program726902 -Node: Simple Sed734438 -Node: Igawk Program737500 -Ref: Igawk Program-Footnote-1751811 -Ref: Igawk Program-Footnote-2752012 -Node: Anagram Program752150 -Node: Signature Program755218 -Node: Programs Summary756465 -Node: Programs Exercises757680 -Node: Advanced Features761331 -Node: Nondecimal Data763279 -Node: Array Sorting764856 -Node: Controlling Array Traversal765553 -Node: Array Sorting Functions773833 -Ref: Array Sorting Functions-Footnote-1777740 -Node: Two-way I/O777934 -Ref: Two-way I/O-Footnote-1783450 -Node: TCP/IP Networking783532 -Node: Profiling786376 -Node: Advanced Features Summary793927 -Node: Internationalization795791 -Node: I18N and L10N797271 -Node: Explaining gettext797957 -Ref: Explaining gettext-Footnote-1803097 -Ref: Explaining gettext-Footnote-2803281 -Node: Programmer i18n803446 -Node: Translator i18n807671 -Node: String Extraction808465 -Ref: String Extraction-Footnote-1809426 -Node: Printf Ordering809512 -Ref: Printf Ordering-Footnote-1812294 -Node: I18N Portability812358 -Ref: I18N Portability-Footnote-1814807 -Node: I18N Example814870 -Ref: I18N Example-Footnote-1817592 -Node: Gawk I18N817664 -Node: I18N Summary818302 -Node: Debugger819641 -Node: Debugging820663 -Node: Debugging Concepts821104 -Node: Debugging Terms822960 -Node: Awk Debugging825557 -Node: Sample Debugging Session826449 -Node: Debugger Invocation826969 -Node: Finding The Bug828302 -Node: List of Debugger Commands834784 -Node: Breakpoint Control836116 -Node: Debugger Execution Control839780 -Node: Viewing And Changing Data843140 -Node: Execution Stack846498 -Node: Debugger Info848011 -Node: Miscellaneous Debugger Commands852005 -Node: Readline Support857189 -Node: Limitations858081 -Node: Debugging Summary860355 -Node: Arbitrary Precision Arithmetic861519 -Node: Computer Arithmetic862848 -Ref: Computer Arithmetic-Footnote-1867235 -Node: Math Definitions867292 -Ref: table-ieee-formats870176 -Node: MPFR features870680 -Node: FP Math Caution872322 -Ref: FP Math Caution-Footnote-1873363 -Node: Inexactness of computations873732 -Node: Inexact representation874680 -Node: Comparing FP Values876035 -Node: Errors accumulate876999 -Node: Getting Accuracy878432 -Node: Try To Round881091 -Node: Setting precision881990 -Ref: table-predefined-precision-strings882672 -Node: Setting the rounding mode884465 -Ref: table-gawk-rounding-modes884829 -Ref: Setting the rounding mode-Footnote-1888283 -Node: Arbitrary Precision Integers888462 -Ref: Arbitrary Precision Integers-Footnote-1891465 -Node: POSIX Floating Point Problems891614 -Ref: POSIX Floating Point Problems-Footnote-1895490 -Node: Floating point summary895528 -Node: Dynamic Extensions897745 -Node: Extension Intro899297 -Node: Plugin License900562 -Node: Extension Mechanism Outline901247 -Ref: figure-load-extension901671 -Ref: figure-load-new-function903156 -Ref: figure-call-new-function904158 -Node: Extension API Description906142 -Node: Extension API Functions Introduction907592 -Node: General Data Types912457 -Ref: General Data Types-Footnote-1918150 -Node: Requesting Values918449 -Ref: table-value-types-returned919186 -Node: Memory Allocation Functions920144 -Ref: Memory Allocation Functions-Footnote-1922891 -Node: Constructor Functions922987 -Node: Registration Functions924745 -Node: Extension Functions925430 -Node: Exit Callback Functions927732 -Node: Extension Version String928981 -Node: Input Parsers929631 -Node: Output Wrappers939434 -Node: Two-way processors943950 -Node: Printing Messages946154 -Ref: Printing Messages-Footnote-1947231 -Node: Updating `ERRNO'947383 -Node: Accessing Parameters948122 -Node: Symbol Table Access949352 -Node: Symbol table by name949866 -Node: Symbol table by cookie951842 -Ref: Symbol table by cookie-Footnote-1955975 -Node: Cached values956038 -Ref: Cached values-Footnote-1959542 -Node: Array Manipulation959633 -Ref: Array Manipulation-Footnote-1960731 -Node: Array Data Types960770 -Ref: Array Data Types-Footnote-1963473 -Node: Array Functions963565 -Node: Flattening Arrays967439 -Node: Creating Arrays974291 -Node: Extension API Variables979022 -Node: Extension Versioning979658 -Node: Extension API Informational Variables981559 -Node: Extension API Boilerplate982645 -Node: Finding Extensions986449 -Node: Extension Example987009 -Node: Internal File Description987739 -Node: Internal File Ops991830 -Ref: Internal File Ops-Footnote-11003262 -Node: Using Internal File Ops1003402 -Ref: Using Internal File Ops-Footnote-11005749 -Node: Extension Samples1006017 -Node: Extension Sample File Functions1007541 -Node: Extension Sample Fnmatch1015109 -Node: Extension Sample Fork1016591 -Node: Extension Sample Inplace1017804 -Node: Extension Sample Ord1019479 -Node: Extension Sample Readdir1020315 -Ref: table-readdir-file-types1021171 -Node: Extension Sample Revout1021970 -Node: Extension Sample Rev2way1022561 -Node: Extension Sample Read write array1023302 -Node: Extension Sample Readfile1025181 -Node: Extension Sample API Tests1026281 -Node: Extension Sample Time1026806 -Node: gawkextlib1028121 -Node: Extension summary1030934 -Node: Extension Exercises1034627 -Node: Language History1035349 -Node: V7/SVR3.11036992 -Node: SVR41039312 -Node: POSIX1040754 -Node: BTL1042140 -Node: POSIX/GNU1042874 -Node: Feature History1048473 -Node: Common Extensions1061603 -Node: Ranges and Locales1062915 -Ref: Ranges and Locales-Footnote-11067532 -Ref: Ranges and Locales-Footnote-21067559 -Ref: Ranges and Locales-Footnote-31067793 -Node: Contributors1068014 -Node: History summary1073439 -Node: Installation1074808 -Node: Gawk Distribution1075759 -Node: Getting1076243 -Node: Extracting1077067 -Node: Distribution contents1078709 -Node: Unix Installation1084479 -Node: Quick Installation1085096 -Node: Additional Configuration Options1087538 -Node: Configuration Philosophy1089276 -Node: Non-Unix Installation1091627 -Node: PC Installation1092085 -Node: PC Binary Installation1093396 -Node: PC Compiling1095244 -Ref: PC Compiling-Footnote-11098243 -Node: PC Testing1098348 -Node: PC Using1099524 -Node: Cygwin1103682 -Node: MSYS1104491 -Node: VMS Installation1105005 -Node: VMS Compilation1105801 -Ref: VMS Compilation-Footnote-11107023 -Node: VMS Dynamic Extensions1107081 -Node: VMS Installation Details1108454 -Node: VMS Running1110706 -Node: VMS GNV1113540 -Node: VMS Old Gawk1114263 -Node: Bugs1114733 -Node: Other Versions1118737 -Node: Installation summary1124992 -Node: Notes1126048 -Node: Compatibility Mode1126913 -Node: Additions1127695 -Node: Accessing The Source1128620 -Node: Adding Code1130056 -Node: New Ports1136234 -Node: Derived Files1140715 -Ref: Derived Files-Footnote-11145796 -Ref: Derived Files-Footnote-21145830 -Ref: Derived Files-Footnote-31146426 -Node: Future Extensions1146540 -Node: Implementation Limitations1147146 -Node: Extension Design1148394 -Node: Old Extension Problems1149548 -Ref: Old Extension Problems-Footnote-11151065 -Node: Extension New Mechanism Goals1151122 -Ref: Extension New Mechanism Goals-Footnote-11154482 -Node: Extension Other Design Decisions1154671 -Node: Extension Future Growth1156777 -Node: Old Extension Mechanism1157613 -Node: Notes summary1159375 -Node: Basic Concepts1160561 -Node: Basic High Level1161242 -Ref: figure-general-flow1161514 -Ref: figure-process-flow1162113 -Ref: Basic High Level-Footnote-11165342 -Node: Basic Data Typing1165527 -Node: Glossary1168855 -Node: Copying1194007 -Node: GNU Free Documentation License1231563 -Node: Index1256699 +Ref: Numeric Functions-Footnote-1498318 +Ref: Numeric Functions-Footnote-2498675 +Ref: Numeric Functions-Footnote-3498723 +Node: String Functions498992 +Ref: String Functions-Footnote-1522003 +Ref: String Functions-Footnote-2522132 +Ref: String Functions-Footnote-3522380 +Node: Gory Details522467 +Ref: table-sub-escapes524136 +Ref: table-sub-posix-92525490 +Ref: table-sub-proposed526841 +Ref: table-posix-sub528195 +Ref: table-gensub-escapes529740 +Ref: Gory Details-Footnote-1530916 +Ref: Gory Details-Footnote-2530967 +Node: I/O Functions531118 +Ref: I/O Functions-Footnote-1538241 +Node: Time Functions538388 +Ref: Time Functions-Footnote-1548852 +Ref: Time Functions-Footnote-2548920 +Ref: Time Functions-Footnote-3549078 +Ref: Time Functions-Footnote-4549189 +Ref: Time Functions-Footnote-5549301 +Ref: Time Functions-Footnote-6549528 +Node: Bitwise Functions549794 +Ref: table-bitwise-ops550356 +Ref: Bitwise Functions-Footnote-1554601 +Node: Type Functions554785 +Node: I18N Functions555927 +Node: User-defined557572 +Node: Definition Syntax558376 +Ref: Definition Syntax-Footnote-1563555 +Node: Function Example563624 +Ref: Function Example-Footnote-1566268 +Node: Function Caveats566290 +Node: Calling A Function566808 +Node: Variable Scope567763 +Node: Pass By Value/Reference570751 +Node: Return Statement574259 +Node: Dynamic Typing577243 +Node: Indirect Calls578172 +Node: Functions Summary587885 +Node: Library Functions590424 +Ref: Library Functions-Footnote-1594042 +Ref: Library Functions-Footnote-2594185 +Node: Library Names594356 +Ref: Library Names-Footnote-1597829 +Ref: Library Names-Footnote-2598049 +Node: General Functions598135 +Node: Strtonum Function599163 +Node: Assert Function601943 +Node: Round Function605269 +Node: Cliff Random Function606810 +Node: Ordinal Functions607826 +Ref: Ordinal Functions-Footnote-1610903 +Ref: Ordinal Functions-Footnote-2611155 +Node: Join Function611366 +Ref: Join Function-Footnote-1613137 +Node: Getlocaltime Function613337 +Node: Readfile Function617073 +Node: Data File Management618912 +Node: Filetrans Function619544 +Node: Rewind Function623613 +Node: File Checking625000 +Ref: File Checking-Footnote-1626132 +Node: Empty Files626333 +Node: Ignoring Assigns628312 +Node: Getopt Function629866 +Ref: Getopt Function-Footnote-1641169 +Node: Passwd Functions641372 +Ref: Passwd Functions-Footnote-1650351 +Node: Group Functions650439 +Ref: Group Functions-Footnote-1658380 +Node: Walking Arrays658593 +Node: Library Functions Summary660196 +Node: Library exercises661584 +Node: Sample Programs662864 +Node: Running Examples663634 +Node: Clones664362 +Node: Cut Program665586 +Node: Egrep Program675454 +Ref: Egrep Program-Footnote-1683425 +Node: Id Program683535 +Node: Split Program687199 +Ref: Split Program-Footnote-1690737 +Node: Tee Program690865 +Node: Uniq Program693672 +Node: Wc Program701102 +Ref: Wc Program-Footnote-1705367 +Node: Miscellaneous Programs705459 +Node: Dupword Program706672 +Node: Alarm Program708703 +Node: Translate Program713517 +Ref: Translate Program-Footnote-1717908 +Ref: Translate Program-Footnote-2718178 +Node: Labels Program718312 +Ref: Labels Program-Footnote-1721683 +Node: Word Sorting721767 +Node: History Sorting725810 +Node: Extract Program727646 +Node: Simple Sed735182 +Node: Igawk Program738244 +Ref: Igawk Program-Footnote-1752555 +Ref: Igawk Program-Footnote-2752756 +Node: Anagram Program752894 +Node: Signature Program755962 +Node: Programs Summary757209 +Node: Programs Exercises758424 +Node: Advanced Features762075 +Node: Nondecimal Data764023 +Node: Array Sorting765600 +Node: Controlling Array Traversal766297 +Node: Array Sorting Functions774577 +Ref: Array Sorting Functions-Footnote-1778484 +Node: Two-way I/O778678 +Ref: Two-way I/O-Footnote-1784194 +Node: TCP/IP Networking784276 +Node: Profiling787120 +Node: Advanced Features Summary794671 +Node: Internationalization796535 +Node: I18N and L10N798015 +Node: Explaining gettext798701 +Ref: Explaining gettext-Footnote-1803841 +Ref: Explaining gettext-Footnote-2804025 +Node: Programmer i18n804190 +Node: Translator i18n808415 +Node: String Extraction809209 +Ref: String Extraction-Footnote-1810170 +Node: Printf Ordering810256 +Ref: Printf Ordering-Footnote-1813038 +Node: I18N Portability813102 +Ref: I18N Portability-Footnote-1815551 +Node: I18N Example815614 +Ref: I18N Example-Footnote-1818336 +Node: Gawk I18N818408 +Node: I18N Summary819046 +Node: Debugger820385 +Node: Debugging821407 +Node: Debugging Concepts821848 +Node: Debugging Terms823704 +Node: Awk Debugging826301 +Node: Sample Debugging Session827193 +Node: Debugger Invocation827713 +Node: Finding The Bug829046 +Node: List of Debugger Commands835528 +Node: Breakpoint Control836860 +Node: Debugger Execution Control840524 +Node: Viewing And Changing Data843884 +Node: Execution Stack847242 +Node: Debugger Info848755 +Node: Miscellaneous Debugger Commands852749 +Node: Readline Support857933 +Node: Limitations858825 +Node: Debugging Summary861099 +Node: Arbitrary Precision Arithmetic862263 +Node: Computer Arithmetic863592 +Ref: Computer Arithmetic-Footnote-1867979 +Node: Math Definitions868036 +Ref: table-ieee-formats870920 +Node: MPFR features871424 +Node: FP Math Caution873066 +Ref: FP Math Caution-Footnote-1874107 +Node: Inexactness of computations874476 +Node: Inexact representation875424 +Node: Comparing FP Values876779 +Node: Errors accumulate877743 +Node: Getting Accuracy879176 +Node: Try To Round881835 +Node: Setting precision882734 +Ref: table-predefined-precision-strings883416 +Node: Setting the rounding mode885209 +Ref: table-gawk-rounding-modes885573 +Ref: Setting the rounding mode-Footnote-1889027 +Node: Arbitrary Precision Integers889206 +Ref: Arbitrary Precision Integers-Footnote-1893001 +Node: POSIX Floating Point Problems893150 +Ref: POSIX Floating Point Problems-Footnote-1897026 +Node: Floating point summary897064 +Node: Dynamic Extensions899281 +Node: Extension Intro900833 +Node: Plugin License902098 +Node: Extension Mechanism Outline902783 +Ref: figure-load-extension903207 +Ref: figure-load-new-function904692 +Ref: figure-call-new-function905694 +Node: Extension API Description907678 +Node: Extension API Functions Introduction909128 +Node: General Data Types913993 +Ref: General Data Types-Footnote-1919686 +Node: Requesting Values919985 +Ref: table-value-types-returned920722 +Node: Memory Allocation Functions921680 +Ref: Memory Allocation Functions-Footnote-1924427 +Node: Constructor Functions924523 +Node: Registration Functions926281 +Node: Extension Functions926966 +Node: Exit Callback Functions929268 +Node: Extension Version String930517 +Node: Input Parsers931167 +Node: Output Wrappers940970 +Node: Two-way processors945486 +Node: Printing Messages947690 +Ref: Printing Messages-Footnote-1948767 +Node: Updating `ERRNO'948919 +Node: Accessing Parameters949658 +Node: Symbol Table Access950888 +Node: Symbol table by name951402 +Node: Symbol table by cookie953378 +Ref: Symbol table by cookie-Footnote-1957511 +Node: Cached values957574 +Ref: Cached values-Footnote-1961078 +Node: Array Manipulation961169 +Ref: Array Manipulation-Footnote-1962267 +Node: Array Data Types962306 +Ref: Array Data Types-Footnote-1965009 +Node: Array Functions965101 +Node: Flattening Arrays968975 +Node: Creating Arrays975827 +Node: Extension API Variables980558 +Node: Extension Versioning981194 +Node: Extension API Informational Variables983095 +Node: Extension API Boilerplate984181 +Node: Finding Extensions987985 +Node: Extension Example988545 +Node: Internal File Description989275 +Node: Internal File Ops993366 +Ref: Internal File Ops-Footnote-11004798 +Node: Using Internal File Ops1004938 +Ref: Using Internal File Ops-Footnote-11007285 +Node: Extension Samples1007553 +Node: Extension Sample File Functions1009077 +Node: Extension Sample Fnmatch1016645 +Node: Extension Sample Fork1018127 +Node: Extension Sample Inplace1019340 +Node: Extension Sample Ord1021015 +Node: Extension Sample Readdir1021851 +Ref: table-readdir-file-types1022707 +Node: Extension Sample Revout1023506 +Node: Extension Sample Rev2way1024097 +Node: Extension Sample Read write array1024838 +Node: Extension Sample Readfile1026717 +Node: Extension Sample API Tests1027817 +Node: Extension Sample Time1028342 +Node: gawkextlib1029657 +Node: Extension summary1032470 +Node: Extension Exercises1036163 +Node: Language History1036885 +Node: V7/SVR3.11038528 +Node: SVR41040848 +Node: POSIX1042290 +Node: BTL1043676 +Node: POSIX/GNU1044410 +Node: Feature History1050009 +Node: Common Extensions1063139 +Node: Ranges and Locales1064451 +Ref: Ranges and Locales-Footnote-11069068 +Ref: Ranges and Locales-Footnote-21069095 +Ref: Ranges and Locales-Footnote-31069329 +Node: Contributors1069550 +Node: History summary1074975 +Node: Installation1076344 +Node: Gawk Distribution1077295 +Node: Getting1077779 +Node: Extracting1078603 +Node: Distribution contents1080245 +Node: Unix Installation1086015 +Node: Quick Installation1086632 +Node: Additional Configuration Options1089074 +Node: Configuration Philosophy1090812 +Node: Non-Unix Installation1093163 +Node: PC Installation1093621 +Node: PC Binary Installation1094932 +Node: PC Compiling1096780 +Ref: PC Compiling-Footnote-11099779 +Node: PC Testing1099884 +Node: PC Using1101060 +Node: Cygwin1105218 +Node: MSYS1106027 +Node: VMS Installation1106541 +Node: VMS Compilation1107337 +Ref: VMS Compilation-Footnote-11108559 +Node: VMS Dynamic Extensions1108617 +Node: VMS Installation Details1109990 +Node: VMS Running1112242 +Node: VMS GNV1115076 +Node: VMS Old Gawk1115799 +Node: Bugs1116269 +Node: Other Versions1120273 +Node: Installation summary1126528 +Node: Notes1127584 +Node: Compatibility Mode1128449 +Node: Additions1129231 +Node: Accessing The Source1130156 +Node: Adding Code1131592 +Node: New Ports1137770 +Node: Derived Files1142251 +Ref: Derived Files-Footnote-11147332 +Ref: Derived Files-Footnote-21147366 +Ref: Derived Files-Footnote-31147962 +Node: Future Extensions1148076 +Node: Implementation Limitations1148682 +Node: Extension Design1149930 +Node: Old Extension Problems1151084 +Ref: Old Extension Problems-Footnote-11152601 +Node: Extension New Mechanism Goals1152658 +Ref: Extension New Mechanism Goals-Footnote-11156018 +Node: Extension Other Design Decisions1156207 +Node: Extension Future Growth1158313 +Node: Old Extension Mechanism1159149 +Node: Notes summary1160911 +Node: Basic Concepts1162097 +Node: Basic High Level1162778 +Ref: figure-general-flow1163050 +Ref: figure-process-flow1163649 +Ref: Basic High Level-Footnote-11166878 +Node: Basic Data Typing1167063 +Node: Glossary1170391 +Node: Copying1195543 +Node: GNU Free Documentation License1233099 +Node: Index1258235  End Tag Table -- cgit v1.2.3 From c0bea6b83a4e9e8bd8fb1e7dc700a5cf1ec4c0c5 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 24 Jul 2014 18:12:46 -0400 Subject: Clarify doc on div(). --- doc/gawk.info | 687 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 344 insertions(+), 343 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index e7854caf..e6c9a5d4 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -11682,14 +11682,15 @@ brackets ([ ]): `div(NUMERATOR, DENOMINATOR, RESULT)' Perform integer division, similar to the standard C function of the - same name. First, truncate `numerator' and `denominator' to - integers. Clear the `result' array, and then set - `result["quotient"]' to the result of `numerator / denominator', - truncated to an integer, and set `result["remainder"]' to the - result of `numerator % denominator', truncated to an integer. - This function is primarily intended for use with arbitrary length - integers; it avoids creating MPFR arbitrary precision - floating-point values (*note Arbitrary Precision Integers::). + same name. First, truncate `numerator' and `denominator' towards + zero, creating integer values. Clear the `result' array, and then + set `result["quotient"]' to the result of `numerator / + denominator', truncated towards zero to an integer, and set + `result["remainder"]' to the result of `numerator % denominator', + truncated towards zero to an integer. This function is primarily + intended for use with arbitrary length integers; it avoids + creating MPFR arbitrary precision floating-point values (*note + Arbitrary Precision Integers::). This function is a `gawk' extension. It is not available in compatibility mode (*note Options::). @@ -32163,10 +32164,10 @@ Index * exit status, of VMS: VMS Running. (line 29) * exit the debugger: Miscellaneous Debugger Commands. (line 99) -* exp: Numeric Functions. (line 32) +* exp: Numeric Functions. (line 33) * expand utility: Very Simple. (line 69) * Expat XML parser library: gawkextlib. (line 35) -* exponent: Numeric Functions. (line 32) +* exponent: Numeric Functions. (line 33) * expressions: Expressions. (line 6) * expressions, as patterns: Expression Patterns. (line 6) * expressions, assignment: Assignment Ops. (line 6) @@ -32702,7 +32703,7 @@ Index * installation, VMS: VMS Installation. (line 6) * installing gawk: Installation. (line 6) * instruction tracing, in debugger: Debugger Info. (line 89) -* int: Numeric Functions. (line 37) +* int: Numeric Functions. (line 38) * INT signal (MS-Windows): Profiling. (line 214) * integer array indices: Numeric Array Subscripts. (line 31) @@ -32851,9 +32852,9 @@ Index * localization: I18N and L10N. (line 6) * localization, See internationalization, localization: I18N and L10N. (line 6) -* log: Numeric Functions. (line 44) +* log: Numeric Functions. (line 45) * log files, timestamps in: Time Functions. (line 6) -* logarithm: Numeric Functions. (line 44) +* logarithm: Numeric Functions. (line 45) * logical false/true: Truth Values. (line 6) * logical operators, See Boolean expressions: Boolean Ops. (line 6) * login information: Passwd Functions. (line 16) @@ -33310,12 +33311,12 @@ Index * Rakitzis, Byron: History Sorting. (line 25) * Ramey, Chet <1>: General Data Types. (line 6) * Ramey, Chet: Acknowledgments. (line 60) -* rand: Numeric Functions. (line 48) +* rand: Numeric Functions. (line 49) * random numbers, Cliff: Cliff Random Function. (line 6) * random numbers, rand()/srand() functions: Numeric Functions. - (line 48) -* random numbers, seed of: Numeric Functions. (line 78) + (line 49) +* random numbers, seed of: Numeric Functions. (line 79) * range expressions (regexps): Bracket Expressions. (line 6) * range patterns: Ranges. (line 6) * range patterns, line continuation and: Ranges. (line 65) @@ -33443,7 +33444,7 @@ Index * Robbins, Miriam <2>: Getline/Pipe. (line 39) * Robbins, Miriam: Acknowledgments. (line 82) * Rommel, Kai Uwe: Contributors. (line 42) -* round to nearest integer: Numeric Functions. (line 37) +* round to nearest integer: Numeric Functions. (line 38) * round() user-defined function: Round Function. (line 16) * rounding numbers: Round Function. (line 6) * ROUNDMODE variable: User-modified. (line 128) @@ -33493,7 +33494,7 @@ Index * sed utility <2>: Simple Sed. (line 6) * sed utility: Field Splitting Summary. (line 46) -* seeding random number generator: Numeric Functions. (line 78) +* seeding random number generator: Numeric Functions. (line 79) * semicolon (;), AWKPATH variable and: PC Using. (line 10) * semicolon (;), separating statements in actions <1>: Statements. (line 10) @@ -33595,8 +33596,8 @@ Index * SIGUSR1 signal, for dynamic profiling: Profiling. (line 188) * silent debugger command: Debugger Execution Control. (line 10) -* sin: Numeric Functions. (line 89) -* sine: Numeric Functions. (line 89) +* sin: Numeric Functions. (line 90) +* sine: Numeric Functions. (line 90) * single quote ('): One-shot. (line 15) * single quote (') in gawk command lines: Long. (line 33) * single quote ('), in shell commands: Quoting. (line 48) @@ -33646,10 +33647,10 @@ Index * sprintf() function, OFMT variable and: User-modified. (line 114) * sprintf() function, print/printf statements and: Round Function. (line 6) -* sqrt: Numeric Functions. (line 92) +* sqrt: Numeric Functions. (line 93) * square brackets ([]), regexp operator: Regexp Operators. (line 56) -* square root: Numeric Functions. (line 92) -* srand: Numeric Functions. (line 96) +* square root: Numeric Functions. (line 93) +* srand: Numeric Functions. (line 97) * stack frame: Debugging Terms. (line 10) * Stallman, Richard <1>: Glossary. (line 296) * Stallman, Richard <2>: Contributors. (line 23) @@ -34218,325 +34219,325 @@ Node: Functions489801 Node: Built-in490674 Node: Calling Built-in491752 Node: Numeric Functions493740 -Ref: Numeric Functions-Footnote-1498318 -Ref: Numeric Functions-Footnote-2498675 -Ref: Numeric Functions-Footnote-3498723 -Node: String Functions498992 -Ref: String Functions-Footnote-1522003 -Ref: String Functions-Footnote-2522132 -Ref: String Functions-Footnote-3522380 -Node: Gory Details522467 -Ref: table-sub-escapes524136 -Ref: table-sub-posix-92525490 -Ref: table-sub-proposed526841 -Ref: table-posix-sub528195 -Ref: table-gensub-escapes529740 -Ref: Gory Details-Footnote-1530916 -Ref: Gory Details-Footnote-2530967 -Node: I/O Functions531118 -Ref: I/O Functions-Footnote-1538241 -Node: Time Functions538388 -Ref: Time Functions-Footnote-1548852 -Ref: Time Functions-Footnote-2548920 -Ref: Time Functions-Footnote-3549078 -Ref: Time Functions-Footnote-4549189 -Ref: Time Functions-Footnote-5549301 -Ref: Time Functions-Footnote-6549528 -Node: Bitwise Functions549794 -Ref: table-bitwise-ops550356 -Ref: Bitwise Functions-Footnote-1554601 -Node: Type Functions554785 -Node: I18N Functions555927 -Node: User-defined557572 -Node: Definition Syntax558376 -Ref: Definition Syntax-Footnote-1563555 -Node: Function Example563624 -Ref: Function Example-Footnote-1566268 -Node: Function Caveats566290 -Node: Calling A Function566808 -Node: Variable Scope567763 -Node: Pass By Value/Reference570751 -Node: Return Statement574259 -Node: Dynamic Typing577243 -Node: Indirect Calls578172 -Node: Functions Summary587885 -Node: Library Functions590424 -Ref: Library Functions-Footnote-1594042 -Ref: Library Functions-Footnote-2594185 -Node: Library Names594356 -Ref: Library Names-Footnote-1597829 -Ref: Library Names-Footnote-2598049 -Node: General Functions598135 -Node: Strtonum Function599163 -Node: Assert Function601943 -Node: Round Function605269 -Node: Cliff Random Function606810 -Node: Ordinal Functions607826 -Ref: Ordinal Functions-Footnote-1610903 -Ref: Ordinal Functions-Footnote-2611155 -Node: Join Function611366 -Ref: Join Function-Footnote-1613137 -Node: Getlocaltime Function613337 -Node: Readfile Function617073 -Node: Data File Management618912 -Node: Filetrans Function619544 -Node: Rewind Function623613 -Node: File Checking625000 -Ref: File Checking-Footnote-1626132 -Node: Empty Files626333 -Node: Ignoring Assigns628312 -Node: Getopt Function629866 -Ref: Getopt Function-Footnote-1641169 -Node: Passwd Functions641372 -Ref: Passwd Functions-Footnote-1650351 -Node: Group Functions650439 -Ref: Group Functions-Footnote-1658380 -Node: Walking Arrays658593 -Node: Library Functions Summary660196 -Node: Library exercises661584 -Node: Sample Programs662864 -Node: Running Examples663634 -Node: Clones664362 -Node: Cut Program665586 -Node: Egrep Program675454 -Ref: Egrep Program-Footnote-1683425 -Node: Id Program683535 -Node: Split Program687199 -Ref: Split Program-Footnote-1690737 -Node: Tee Program690865 -Node: Uniq Program693672 -Node: Wc Program701102 -Ref: Wc Program-Footnote-1705367 -Node: Miscellaneous Programs705459 -Node: Dupword Program706672 -Node: Alarm Program708703 -Node: Translate Program713517 -Ref: Translate Program-Footnote-1717908 -Ref: Translate Program-Footnote-2718178 -Node: Labels Program718312 -Ref: Labels Program-Footnote-1721683 -Node: Word Sorting721767 -Node: History Sorting725810 -Node: Extract Program727646 -Node: Simple Sed735182 -Node: Igawk Program738244 -Ref: Igawk Program-Footnote-1752555 -Ref: Igawk Program-Footnote-2752756 -Node: Anagram Program752894 -Node: Signature Program755962 -Node: Programs Summary757209 -Node: Programs Exercises758424 -Node: Advanced Features762075 -Node: Nondecimal Data764023 -Node: Array Sorting765600 -Node: Controlling Array Traversal766297 -Node: Array Sorting Functions774577 -Ref: Array Sorting Functions-Footnote-1778484 -Node: Two-way I/O778678 -Ref: Two-way I/O-Footnote-1784194 -Node: TCP/IP Networking784276 -Node: Profiling787120 -Node: Advanced Features Summary794671 -Node: Internationalization796535 -Node: I18N and L10N798015 -Node: Explaining gettext798701 -Ref: Explaining gettext-Footnote-1803841 -Ref: Explaining gettext-Footnote-2804025 -Node: Programmer i18n804190 -Node: Translator i18n808415 -Node: String Extraction809209 -Ref: String Extraction-Footnote-1810170 -Node: Printf Ordering810256 -Ref: Printf Ordering-Footnote-1813038 -Node: I18N Portability813102 -Ref: I18N Portability-Footnote-1815551 -Node: I18N Example815614 -Ref: I18N Example-Footnote-1818336 -Node: Gawk I18N818408 -Node: I18N Summary819046 -Node: Debugger820385 -Node: Debugging821407 -Node: Debugging Concepts821848 -Node: Debugging Terms823704 -Node: Awk Debugging826301 -Node: Sample Debugging Session827193 -Node: Debugger Invocation827713 -Node: Finding The Bug829046 -Node: List of Debugger Commands835528 -Node: Breakpoint Control836860 -Node: Debugger Execution Control840524 -Node: Viewing And Changing Data843884 -Node: Execution Stack847242 -Node: Debugger Info848755 -Node: Miscellaneous Debugger Commands852749 -Node: Readline Support857933 -Node: Limitations858825 -Node: Debugging Summary861099 -Node: Arbitrary Precision Arithmetic862263 -Node: Computer Arithmetic863592 -Ref: Computer Arithmetic-Footnote-1867979 -Node: Math Definitions868036 -Ref: table-ieee-formats870920 -Node: MPFR features871424 -Node: FP Math Caution873066 -Ref: FP Math Caution-Footnote-1874107 -Node: Inexactness of computations874476 -Node: Inexact representation875424 -Node: Comparing FP Values876779 -Node: Errors accumulate877743 -Node: Getting Accuracy879176 -Node: Try To Round881835 -Node: Setting precision882734 -Ref: table-predefined-precision-strings883416 -Node: Setting the rounding mode885209 -Ref: table-gawk-rounding-modes885573 -Ref: Setting the rounding mode-Footnote-1889027 -Node: Arbitrary Precision Integers889206 -Ref: Arbitrary Precision Integers-Footnote-1893001 -Node: POSIX Floating Point Problems893150 -Ref: POSIX Floating Point Problems-Footnote-1897026 -Node: Floating point summary897064 -Node: Dynamic Extensions899281 -Node: Extension Intro900833 -Node: Plugin License902098 -Node: Extension Mechanism Outline902783 -Ref: figure-load-extension903207 -Ref: figure-load-new-function904692 -Ref: figure-call-new-function905694 -Node: Extension API Description907678 -Node: Extension API Functions Introduction909128 -Node: General Data Types913993 -Ref: General Data Types-Footnote-1919686 -Node: Requesting Values919985 -Ref: table-value-types-returned920722 -Node: Memory Allocation Functions921680 -Ref: Memory Allocation Functions-Footnote-1924427 -Node: Constructor Functions924523 -Node: Registration Functions926281 -Node: Extension Functions926966 -Node: Exit Callback Functions929268 -Node: Extension Version String930517 -Node: Input Parsers931167 -Node: Output Wrappers940970 -Node: Two-way processors945486 -Node: Printing Messages947690 -Ref: Printing Messages-Footnote-1948767 -Node: Updating `ERRNO'948919 -Node: Accessing Parameters949658 -Node: Symbol Table Access950888 -Node: Symbol table by name951402 -Node: Symbol table by cookie953378 -Ref: Symbol table by cookie-Footnote-1957511 -Node: Cached values957574 -Ref: Cached values-Footnote-1961078 -Node: Array Manipulation961169 -Ref: Array Manipulation-Footnote-1962267 -Node: Array Data Types962306 -Ref: Array Data Types-Footnote-1965009 -Node: Array Functions965101 -Node: Flattening Arrays968975 -Node: Creating Arrays975827 -Node: Extension API Variables980558 -Node: Extension Versioning981194 -Node: Extension API Informational Variables983095 -Node: Extension API Boilerplate984181 -Node: Finding Extensions987985 -Node: Extension Example988545 -Node: Internal File Description989275 -Node: Internal File Ops993366 -Ref: Internal File Ops-Footnote-11004798 -Node: Using Internal File Ops1004938 -Ref: Using Internal File Ops-Footnote-11007285 -Node: Extension Samples1007553 -Node: Extension Sample File Functions1009077 -Node: Extension Sample Fnmatch1016645 -Node: Extension Sample Fork1018127 -Node: Extension Sample Inplace1019340 -Node: Extension Sample Ord1021015 -Node: Extension Sample Readdir1021851 -Ref: table-readdir-file-types1022707 -Node: Extension Sample Revout1023506 -Node: Extension Sample Rev2way1024097 -Node: Extension Sample Read write array1024838 -Node: Extension Sample Readfile1026717 -Node: Extension Sample API Tests1027817 -Node: Extension Sample Time1028342 -Node: gawkextlib1029657 -Node: Extension summary1032470 -Node: Extension Exercises1036163 -Node: Language History1036885 -Node: V7/SVR3.11038528 -Node: SVR41040848 -Node: POSIX1042290 -Node: BTL1043676 -Node: POSIX/GNU1044410 -Node: Feature History1050009 -Node: Common Extensions1063139 -Node: Ranges and Locales1064451 -Ref: Ranges and Locales-Footnote-11069068 -Ref: Ranges and Locales-Footnote-21069095 -Ref: Ranges and Locales-Footnote-31069329 -Node: Contributors1069550 -Node: History summary1074975 -Node: Installation1076344 -Node: Gawk Distribution1077295 -Node: Getting1077779 -Node: Extracting1078603 -Node: Distribution contents1080245 -Node: Unix Installation1086015 -Node: Quick Installation1086632 -Node: Additional Configuration Options1089074 -Node: Configuration Philosophy1090812 -Node: Non-Unix Installation1093163 -Node: PC Installation1093621 -Node: PC Binary Installation1094932 -Node: PC Compiling1096780 -Ref: PC Compiling-Footnote-11099779 -Node: PC Testing1099884 -Node: PC Using1101060 -Node: Cygwin1105218 -Node: MSYS1106027 -Node: VMS Installation1106541 -Node: VMS Compilation1107337 -Ref: VMS Compilation-Footnote-11108559 -Node: VMS Dynamic Extensions1108617 -Node: VMS Installation Details1109990 -Node: VMS Running1112242 -Node: VMS GNV1115076 -Node: VMS Old Gawk1115799 -Node: Bugs1116269 -Node: Other Versions1120273 -Node: Installation summary1126528 -Node: Notes1127584 -Node: Compatibility Mode1128449 -Node: Additions1129231 -Node: Accessing The Source1130156 -Node: Adding Code1131592 -Node: New Ports1137770 -Node: Derived Files1142251 -Ref: Derived Files-Footnote-11147332 -Ref: Derived Files-Footnote-21147366 -Ref: Derived Files-Footnote-31147962 -Node: Future Extensions1148076 -Node: Implementation Limitations1148682 -Node: Extension Design1149930 -Node: Old Extension Problems1151084 -Ref: Old Extension Problems-Footnote-11152601 -Node: Extension New Mechanism Goals1152658 -Ref: Extension New Mechanism Goals-Footnote-11156018 -Node: Extension Other Design Decisions1156207 -Node: Extension Future Growth1158313 -Node: Old Extension Mechanism1159149 -Node: Notes summary1160911 -Node: Basic Concepts1162097 -Node: Basic High Level1162778 -Ref: figure-general-flow1163050 -Ref: figure-process-flow1163649 -Ref: Basic High Level-Footnote-11166878 -Node: Basic Data Typing1167063 -Node: Glossary1170391 -Node: Copying1195543 -Node: GNU Free Documentation License1233099 -Node: Index1258235 +Ref: Numeric Functions-Footnote-1498376 +Ref: Numeric Functions-Footnote-2498733 +Ref: Numeric Functions-Footnote-3498781 +Node: String Functions499050 +Ref: String Functions-Footnote-1522061 +Ref: String Functions-Footnote-2522190 +Ref: String Functions-Footnote-3522438 +Node: Gory Details522525 +Ref: table-sub-escapes524194 +Ref: table-sub-posix-92525548 +Ref: table-sub-proposed526899 +Ref: table-posix-sub528253 +Ref: table-gensub-escapes529798 +Ref: Gory Details-Footnote-1530974 +Ref: Gory Details-Footnote-2531025 +Node: I/O Functions531176 +Ref: I/O Functions-Footnote-1538299 +Node: Time Functions538446 +Ref: Time Functions-Footnote-1548910 +Ref: Time Functions-Footnote-2548978 +Ref: Time Functions-Footnote-3549136 +Ref: Time Functions-Footnote-4549247 +Ref: Time Functions-Footnote-5549359 +Ref: Time Functions-Footnote-6549586 +Node: Bitwise Functions549852 +Ref: table-bitwise-ops550414 +Ref: Bitwise Functions-Footnote-1554659 +Node: Type Functions554843 +Node: I18N Functions555985 +Node: User-defined557630 +Node: Definition Syntax558434 +Ref: Definition Syntax-Footnote-1563613 +Node: Function Example563682 +Ref: Function Example-Footnote-1566326 +Node: Function Caveats566348 +Node: Calling A Function566866 +Node: Variable Scope567821 +Node: Pass By Value/Reference570809 +Node: Return Statement574317 +Node: Dynamic Typing577301 +Node: Indirect Calls578230 +Node: Functions Summary587943 +Node: Library Functions590482 +Ref: Library Functions-Footnote-1594100 +Ref: Library Functions-Footnote-2594243 +Node: Library Names594414 +Ref: Library Names-Footnote-1597887 +Ref: Library Names-Footnote-2598107 +Node: General Functions598193 +Node: Strtonum Function599221 +Node: Assert Function602001 +Node: Round Function605327 +Node: Cliff Random Function606868 +Node: Ordinal Functions607884 +Ref: Ordinal Functions-Footnote-1610961 +Ref: Ordinal Functions-Footnote-2611213 +Node: Join Function611424 +Ref: Join Function-Footnote-1613195 +Node: Getlocaltime Function613395 +Node: Readfile Function617131 +Node: Data File Management618970 +Node: Filetrans Function619602 +Node: Rewind Function623671 +Node: File Checking625058 +Ref: File Checking-Footnote-1626190 +Node: Empty Files626391 +Node: Ignoring Assigns628370 +Node: Getopt Function629924 +Ref: Getopt Function-Footnote-1641227 +Node: Passwd Functions641430 +Ref: Passwd Functions-Footnote-1650409 +Node: Group Functions650497 +Ref: Group Functions-Footnote-1658438 +Node: Walking Arrays658651 +Node: Library Functions Summary660254 +Node: Library exercises661642 +Node: Sample Programs662922 +Node: Running Examples663692 +Node: Clones664420 +Node: Cut Program665644 +Node: Egrep Program675512 +Ref: Egrep Program-Footnote-1683483 +Node: Id Program683593 +Node: Split Program687257 +Ref: Split Program-Footnote-1690795 +Node: Tee Program690923 +Node: Uniq Program693730 +Node: Wc Program701160 +Ref: Wc Program-Footnote-1705425 +Node: Miscellaneous Programs705517 +Node: Dupword Program706730 +Node: Alarm Program708761 +Node: Translate Program713575 +Ref: Translate Program-Footnote-1717966 +Ref: Translate Program-Footnote-2718236 +Node: Labels Program718370 +Ref: Labels Program-Footnote-1721741 +Node: Word Sorting721825 +Node: History Sorting725868 +Node: Extract Program727704 +Node: Simple Sed735240 +Node: Igawk Program738302 +Ref: Igawk Program-Footnote-1752613 +Ref: Igawk Program-Footnote-2752814 +Node: Anagram Program752952 +Node: Signature Program756020 +Node: Programs Summary757267 +Node: Programs Exercises758482 +Node: Advanced Features762133 +Node: Nondecimal Data764081 +Node: Array Sorting765658 +Node: Controlling Array Traversal766355 +Node: Array Sorting Functions774635 +Ref: Array Sorting Functions-Footnote-1778542 +Node: Two-way I/O778736 +Ref: Two-way I/O-Footnote-1784252 +Node: TCP/IP Networking784334 +Node: Profiling787178 +Node: Advanced Features Summary794729 +Node: Internationalization796593 +Node: I18N and L10N798073 +Node: Explaining gettext798759 +Ref: Explaining gettext-Footnote-1803899 +Ref: Explaining gettext-Footnote-2804083 +Node: Programmer i18n804248 +Node: Translator i18n808473 +Node: String Extraction809267 +Ref: String Extraction-Footnote-1810228 +Node: Printf Ordering810314 +Ref: Printf Ordering-Footnote-1813096 +Node: I18N Portability813160 +Ref: I18N Portability-Footnote-1815609 +Node: I18N Example815672 +Ref: I18N Example-Footnote-1818394 +Node: Gawk I18N818466 +Node: I18N Summary819104 +Node: Debugger820443 +Node: Debugging821465 +Node: Debugging Concepts821906 +Node: Debugging Terms823762 +Node: Awk Debugging826359 +Node: Sample Debugging Session827251 +Node: Debugger Invocation827771 +Node: Finding The Bug829104 +Node: List of Debugger Commands835586 +Node: Breakpoint Control836918 +Node: Debugger Execution Control840582 +Node: Viewing And Changing Data843942 +Node: Execution Stack847300 +Node: Debugger Info848813 +Node: Miscellaneous Debugger Commands852807 +Node: Readline Support857991 +Node: Limitations858883 +Node: Debugging Summary861157 +Node: Arbitrary Precision Arithmetic862321 +Node: Computer Arithmetic863650 +Ref: Computer Arithmetic-Footnote-1868037 +Node: Math Definitions868094 +Ref: table-ieee-formats870978 +Node: MPFR features871482 +Node: FP Math Caution873124 +Ref: FP Math Caution-Footnote-1874165 +Node: Inexactness of computations874534 +Node: Inexact representation875482 +Node: Comparing FP Values876837 +Node: Errors accumulate877801 +Node: Getting Accuracy879234 +Node: Try To Round881893 +Node: Setting precision882792 +Ref: table-predefined-precision-strings883474 +Node: Setting the rounding mode885267 +Ref: table-gawk-rounding-modes885631 +Ref: Setting the rounding mode-Footnote-1889085 +Node: Arbitrary Precision Integers889264 +Ref: Arbitrary Precision Integers-Footnote-1893059 +Node: POSIX Floating Point Problems893208 +Ref: POSIX Floating Point Problems-Footnote-1897084 +Node: Floating point summary897122 +Node: Dynamic Extensions899339 +Node: Extension Intro900891 +Node: Plugin License902156 +Node: Extension Mechanism Outline902841 +Ref: figure-load-extension903265 +Ref: figure-load-new-function904750 +Ref: figure-call-new-function905752 +Node: Extension API Description907736 +Node: Extension API Functions Introduction909186 +Node: General Data Types914051 +Ref: General Data Types-Footnote-1919744 +Node: Requesting Values920043 +Ref: table-value-types-returned920780 +Node: Memory Allocation Functions921738 +Ref: Memory Allocation Functions-Footnote-1924485 +Node: Constructor Functions924581 +Node: Registration Functions926339 +Node: Extension Functions927024 +Node: Exit Callback Functions929326 +Node: Extension Version String930575 +Node: Input Parsers931225 +Node: Output Wrappers941028 +Node: Two-way processors945544 +Node: Printing Messages947748 +Ref: Printing Messages-Footnote-1948825 +Node: Updating `ERRNO'948977 +Node: Accessing Parameters949716 +Node: Symbol Table Access950946 +Node: Symbol table by name951460 +Node: Symbol table by cookie953436 +Ref: Symbol table by cookie-Footnote-1957569 +Node: Cached values957632 +Ref: Cached values-Footnote-1961136 +Node: Array Manipulation961227 +Ref: Array Manipulation-Footnote-1962325 +Node: Array Data Types962364 +Ref: Array Data Types-Footnote-1965067 +Node: Array Functions965159 +Node: Flattening Arrays969033 +Node: Creating Arrays975885 +Node: Extension API Variables980616 +Node: Extension Versioning981252 +Node: Extension API Informational Variables983153 +Node: Extension API Boilerplate984239 +Node: Finding Extensions988043 +Node: Extension Example988603 +Node: Internal File Description989333 +Node: Internal File Ops993424 +Ref: Internal File Ops-Footnote-11004856 +Node: Using Internal File Ops1004996 +Ref: Using Internal File Ops-Footnote-11007343 +Node: Extension Samples1007611 +Node: Extension Sample File Functions1009135 +Node: Extension Sample Fnmatch1016703 +Node: Extension Sample Fork1018185 +Node: Extension Sample Inplace1019398 +Node: Extension Sample Ord1021073 +Node: Extension Sample Readdir1021909 +Ref: table-readdir-file-types1022765 +Node: Extension Sample Revout1023564 +Node: Extension Sample Rev2way1024155 +Node: Extension Sample Read write array1024896 +Node: Extension Sample Readfile1026775 +Node: Extension Sample API Tests1027875 +Node: Extension Sample Time1028400 +Node: gawkextlib1029715 +Node: Extension summary1032528 +Node: Extension Exercises1036221 +Node: Language History1036943 +Node: V7/SVR3.11038586 +Node: SVR41040906 +Node: POSIX1042348 +Node: BTL1043734 +Node: POSIX/GNU1044468 +Node: Feature History1050067 +Node: Common Extensions1063197 +Node: Ranges and Locales1064509 +Ref: Ranges and Locales-Footnote-11069126 +Ref: Ranges and Locales-Footnote-21069153 +Ref: Ranges and Locales-Footnote-31069387 +Node: Contributors1069608 +Node: History summary1075033 +Node: Installation1076402 +Node: Gawk Distribution1077353 +Node: Getting1077837 +Node: Extracting1078661 +Node: Distribution contents1080303 +Node: Unix Installation1086073 +Node: Quick Installation1086690 +Node: Additional Configuration Options1089132 +Node: Configuration Philosophy1090870 +Node: Non-Unix Installation1093221 +Node: PC Installation1093679 +Node: PC Binary Installation1094990 +Node: PC Compiling1096838 +Ref: PC Compiling-Footnote-11099837 +Node: PC Testing1099942 +Node: PC Using1101118 +Node: Cygwin1105276 +Node: MSYS1106085 +Node: VMS Installation1106599 +Node: VMS Compilation1107395 +Ref: VMS Compilation-Footnote-11108617 +Node: VMS Dynamic Extensions1108675 +Node: VMS Installation Details1110048 +Node: VMS Running1112300 +Node: VMS GNV1115134 +Node: VMS Old Gawk1115857 +Node: Bugs1116327 +Node: Other Versions1120331 +Node: Installation summary1126586 +Node: Notes1127642 +Node: Compatibility Mode1128507 +Node: Additions1129289 +Node: Accessing The Source1130214 +Node: Adding Code1131650 +Node: New Ports1137828 +Node: Derived Files1142309 +Ref: Derived Files-Footnote-11147390 +Ref: Derived Files-Footnote-21147424 +Ref: Derived Files-Footnote-31148020 +Node: Future Extensions1148134 +Node: Implementation Limitations1148740 +Node: Extension Design1149988 +Node: Old Extension Problems1151142 +Ref: Old Extension Problems-Footnote-11152659 +Node: Extension New Mechanism Goals1152716 +Ref: Extension New Mechanism Goals-Footnote-11156076 +Node: Extension Other Design Decisions1156265 +Node: Extension Future Growth1158371 +Node: Old Extension Mechanism1159207 +Node: Notes summary1160969 +Node: Basic Concepts1162155 +Node: Basic High Level1162836 +Ref: figure-general-flow1163108 +Ref: figure-process-flow1163707 +Ref: Basic High Level-Footnote-11166936 +Node: Basic Data Typing1167121 +Node: Glossary1170449 +Node: Copying1195601 +Node: GNU Free Documentation License1233157 +Node: Index1258293  End Tag Table -- cgit v1.2.3 From 831486481c397e13dc164524e54eddbc017fade3 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sun, 3 Aug 2014 22:02:41 +0300 Subject: Document more about sprintf %c. --- doc/gawk.info | 856 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 429 insertions(+), 427 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 8b5e572f..e1b07c80 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -6282,7 +6282,9 @@ width. Here is a list of the format-control letters: valid wide character and then to print the multibyte encoding of that character. Similarly, when printing a numeric value, `gawk' allows the value to be within the numeric range of - values that can be held in a wide character. + values that can be held in a wide character. If the + conversion to multibyte encoding fails, `gawk' uses the low + eight bits of the value as the character to print. Other `awk' versions generally restrict themselves to printing the first byte of a string or to numeric values within the @@ -34072,431 +34074,431 @@ Node: OFMT271992 Node: Printf273350 Node: Basic Printf274256 Node: Control Letters275795 -Node: Format Modifiers279647 -Node: Printf Examples285674 -Node: Redirection288138 -Node: Special Files295110 -Node: Special FD295641 -Ref: Special FD-Footnote-1299265 -Node: Special Network299339 -Node: Special Caveats300189 -Node: Close Files And Pipes300985 -Ref: Close Files And Pipes-Footnote-1308146 -Ref: Close Files And Pipes-Footnote-2308294 -Node: Output Summary308444 -Node: Output exercises309441 -Node: Expressions310121 -Node: Values311306 -Node: Constants311982 -Node: Scalar Constants312662 -Ref: Scalar Constants-Footnote-1313521 -Node: Nondecimal-numbers313771 -Node: Regexp Constants316771 -Node: Using Constant Regexps317246 -Node: Variables320316 -Node: Using Variables320971 -Node: Assignment Options322695 -Node: Conversion324570 -Node: Strings And Numbers325094 -Ref: Strings And Numbers-Footnote-1328156 -Node: Locale influences conversions328265 -Ref: table-locale-affects330982 -Node: All Operators331570 -Node: Arithmetic Ops332200 -Node: Concatenation334705 -Ref: Concatenation-Footnote-1337501 -Node: Assignment Ops337621 -Ref: table-assign-ops342604 -Node: Increment Ops343921 -Node: Truth Values and Conditions347359 -Node: Truth Values348442 -Node: Typing and Comparison349491 -Node: Variable Typing350284 -Ref: Variable Typing-Footnote-1354184 -Node: Comparison Operators354306 -Ref: table-relational-ops354716 -Node: POSIX String Comparison358266 -Ref: POSIX String Comparison-Footnote-1359350 -Node: Boolean Ops359488 -Ref: Boolean Ops-Footnote-1363558 -Node: Conditional Exp363649 -Node: Function Calls365376 -Node: Precedence369256 -Node: Locales372925 -Node: Expressions Summary374556 -Node: Patterns and Actions377097 -Node: Pattern Overview378213 -Node: Regexp Patterns379890 -Node: Expression Patterns380433 -Node: Ranges384214 -Node: BEGIN/END387320 -Node: Using BEGIN/END388082 -Ref: Using BEGIN/END-Footnote-1390818 -Node: I/O And BEGIN/END390924 -Node: BEGINFILE/ENDFILE393209 -Node: Empty396140 -Node: Using Shell Variables396457 -Node: Action Overview398740 -Node: Statements401067 -Node: If Statement402915 -Node: While Statement404413 -Node: Do Statement406457 -Node: For Statement407613 -Node: Switch Statement410765 -Node: Break Statement412868 -Node: Continue Statement414923 -Node: Next Statement416716 -Node: Nextfile Statement419106 -Node: Exit Statement421761 -Node: Built-in Variables424165 -Node: User-modified425292 -Ref: User-modified-Footnote-1432981 -Node: Auto-set433043 -Ref: Auto-set-Footnote-1445625 -Ref: Auto-set-Footnote-2445830 -Node: ARGC and ARGV445886 -Node: Pattern Action Summary449740 -Node: Arrays451963 -Node: Array Basics453512 -Node: Array Intro454338 -Ref: figure-array-elements456311 -Node: Reference to Elements458718 -Node: Assigning Elements460991 -Node: Array Example461482 -Node: Scanning an Array463214 -Node: Controlling Scanning466229 -Ref: Controlling Scanning-Footnote-1471402 -Node: Delete471718 -Ref: Delete-Footnote-1474483 -Node: Numeric Array Subscripts474540 -Node: Uninitialized Subscripts476723 -Node: Multidimensional478348 -Node: Multiscanning481441 -Node: Arrays of Arrays483030 -Node: Arrays Summary487693 -Node: Functions489798 -Node: Built-in490671 -Node: Calling Built-in491749 -Node: Numeric Functions493737 -Ref: Numeric Functions-Footnote-1497571 -Ref: Numeric Functions-Footnote-2497928 -Ref: Numeric Functions-Footnote-3497976 -Node: String Functions498245 -Ref: String Functions-Footnote-1521256 -Ref: String Functions-Footnote-2521385 -Ref: String Functions-Footnote-3521633 -Node: Gory Details521720 -Ref: table-sub-escapes523389 -Ref: table-sub-posix-92524743 -Ref: table-sub-proposed526094 -Ref: table-posix-sub527448 -Ref: table-gensub-escapes528993 -Ref: Gory Details-Footnote-1530169 -Ref: Gory Details-Footnote-2530220 -Node: I/O Functions530371 -Ref: I/O Functions-Footnote-1537494 -Node: Time Functions537641 -Ref: Time Functions-Footnote-1548105 -Ref: Time Functions-Footnote-2548173 -Ref: Time Functions-Footnote-3548331 -Ref: Time Functions-Footnote-4548442 -Ref: Time Functions-Footnote-5548554 -Ref: Time Functions-Footnote-6548781 -Node: Bitwise Functions549047 -Ref: table-bitwise-ops549609 -Ref: Bitwise Functions-Footnote-1553854 -Node: Type Functions554038 -Node: I18N Functions555180 -Node: User-defined556825 -Node: Definition Syntax557629 -Ref: Definition Syntax-Footnote-1562808 -Node: Function Example562877 -Ref: Function Example-Footnote-1565521 -Node: Function Caveats565543 -Node: Calling A Function566061 -Node: Variable Scope567016 -Node: Pass By Value/Reference570004 -Node: Return Statement573512 -Node: Dynamic Typing576496 -Node: Indirect Calls577425 -Node: Functions Summary587138 -Node: Library Functions589677 -Ref: Library Functions-Footnote-1593295 -Ref: Library Functions-Footnote-2593438 -Node: Library Names593609 -Ref: Library Names-Footnote-1597082 -Ref: Library Names-Footnote-2597302 -Node: General Functions597388 -Node: Strtonum Function598416 -Node: Assert Function601196 -Node: Round Function604522 -Node: Cliff Random Function606063 -Node: Ordinal Functions607079 -Ref: Ordinal Functions-Footnote-1610156 -Ref: Ordinal Functions-Footnote-2610408 -Node: Join Function610619 -Ref: Join Function-Footnote-1612390 -Node: Getlocaltime Function612590 -Node: Readfile Function616326 -Node: Data File Management618165 -Node: Filetrans Function618797 -Node: Rewind Function622866 -Node: File Checking624253 -Ref: File Checking-Footnote-1625385 -Node: Empty Files625586 -Node: Ignoring Assigns627565 -Node: Getopt Function629119 -Ref: Getopt Function-Footnote-1640422 -Node: Passwd Functions640625 -Ref: Passwd Functions-Footnote-1649604 -Node: Group Functions649692 -Ref: Group Functions-Footnote-1657633 -Node: Walking Arrays657846 -Node: Library Functions Summary659449 -Node: Library exercises660837 -Node: Sample Programs662117 -Node: Running Examples662887 -Node: Clones663615 -Node: Cut Program664839 -Node: Egrep Program674707 -Ref: Egrep Program-Footnote-1682678 -Node: Id Program682788 -Node: Split Program686452 -Ref: Split Program-Footnote-1689990 -Node: Tee Program690118 -Node: Uniq Program692925 -Node: Wc Program700355 -Ref: Wc Program-Footnote-1704620 -Node: Miscellaneous Programs704712 -Node: Dupword Program705925 -Node: Alarm Program707956 -Node: Translate Program712770 -Ref: Translate Program-Footnote-1717161 -Ref: Translate Program-Footnote-2717431 -Node: Labels Program717565 -Ref: Labels Program-Footnote-1720936 -Node: Word Sorting721020 -Node: History Sorting725063 -Node: Extract Program726899 -Node: Simple Sed734435 -Node: Igawk Program737497 -Ref: Igawk Program-Footnote-1751808 -Ref: Igawk Program-Footnote-2752009 -Node: Anagram Program752147 -Node: Signature Program755215 -Node: Programs Summary756462 -Node: Programs Exercises757677 -Node: Advanced Features761328 -Node: Nondecimal Data763276 -Node: Array Sorting764853 -Node: Controlling Array Traversal765550 -Node: Array Sorting Functions773830 -Ref: Array Sorting Functions-Footnote-1777737 -Node: Two-way I/O777931 -Ref: Two-way I/O-Footnote-1783447 -Node: TCP/IP Networking783529 -Node: Profiling786373 -Node: Advanced Features Summary793915 -Node: Internationalization795779 -Node: I18N and L10N797259 -Node: Explaining gettext797945 -Ref: Explaining gettext-Footnote-1803085 -Ref: Explaining gettext-Footnote-2803269 -Node: Programmer i18n803434 -Node: Translator i18n807659 -Node: String Extraction808453 -Ref: String Extraction-Footnote-1809414 -Node: Printf Ordering809500 -Ref: Printf Ordering-Footnote-1812282 -Node: I18N Portability812346 -Ref: I18N Portability-Footnote-1814795 -Node: I18N Example814858 -Ref: I18N Example-Footnote-1817580 -Node: Gawk I18N817652 -Node: I18N Summary818290 -Node: Debugger819629 -Node: Debugging820651 -Node: Debugging Concepts821092 -Node: Debugging Terms822948 -Node: Awk Debugging825545 -Node: Sample Debugging Session826437 -Node: Debugger Invocation826957 -Node: Finding The Bug828290 -Node: List of Debugger Commands834772 -Node: Breakpoint Control836104 -Node: Debugger Execution Control839768 -Node: Viewing And Changing Data843128 -Node: Execution Stack846486 -Node: Debugger Info847999 -Node: Miscellaneous Debugger Commands851993 -Node: Readline Support857177 -Node: Limitations858069 -Node: Debugging Summary860343 -Node: Arbitrary Precision Arithmetic861507 -Node: Computer Arithmetic862836 -Ref: Computer Arithmetic-Footnote-1867223 -Node: Math Definitions867280 -Ref: table-ieee-formats870164 -Node: MPFR features870668 -Node: FP Math Caution872310 -Ref: FP Math Caution-Footnote-1873351 -Node: Inexactness of computations873720 -Node: Inexact representation874668 -Node: Comparing FP Values876023 -Node: Errors accumulate876987 -Node: Getting Accuracy878420 -Node: Try To Round881079 -Node: Setting precision881978 -Ref: table-predefined-precision-strings882660 -Node: Setting the rounding mode884453 -Ref: table-gawk-rounding-modes884817 -Ref: Setting the rounding mode-Footnote-1888271 -Node: Arbitrary Precision Integers888450 -Ref: Arbitrary Precision Integers-Footnote-1891453 -Node: POSIX Floating Point Problems891602 -Ref: POSIX Floating Point Problems-Footnote-1895478 -Node: Floating point summary895516 -Node: Dynamic Extensions897733 -Node: Extension Intro899285 -Node: Plugin License900550 -Node: Extension Mechanism Outline901235 -Ref: figure-load-extension901659 -Ref: figure-load-new-function903144 -Ref: figure-call-new-function904146 -Node: Extension API Description906130 -Node: Extension API Functions Introduction907580 -Node: General Data Types912445 -Ref: General Data Types-Footnote-1918138 -Node: Requesting Values918437 -Ref: table-value-types-returned919174 -Node: Memory Allocation Functions920132 -Ref: Memory Allocation Functions-Footnote-1922879 -Node: Constructor Functions922975 -Node: Registration Functions924733 -Node: Extension Functions925418 -Node: Exit Callback Functions927720 -Node: Extension Version String928969 -Node: Input Parsers929619 -Node: Output Wrappers939422 -Node: Two-way processors943938 -Node: Printing Messages946142 -Ref: Printing Messages-Footnote-1947219 -Node: Updating `ERRNO'947371 -Node: Accessing Parameters948110 -Node: Symbol Table Access949340 -Node: Symbol table by name949854 -Node: Symbol table by cookie951830 -Ref: Symbol table by cookie-Footnote-1955963 -Node: Cached values956026 -Ref: Cached values-Footnote-1959530 -Node: Array Manipulation959621 -Ref: Array Manipulation-Footnote-1960719 -Node: Array Data Types960758 -Ref: Array Data Types-Footnote-1963461 -Node: Array Functions963553 -Node: Flattening Arrays967427 -Node: Creating Arrays974279 -Node: Extension API Variables979010 -Node: Extension Versioning979646 -Node: Extension API Informational Variables981547 -Node: Extension API Boilerplate982633 -Node: Finding Extensions986437 -Node: Extension Example986997 -Node: Internal File Description987727 -Node: Internal File Ops991818 -Ref: Internal File Ops-Footnote-11003250 -Node: Using Internal File Ops1003390 -Ref: Using Internal File Ops-Footnote-11005737 -Node: Extension Samples1006005 -Node: Extension Sample File Functions1007529 -Node: Extension Sample Fnmatch1015097 -Node: Extension Sample Fork1016579 -Node: Extension Sample Inplace1017792 -Node: Extension Sample Ord1019467 -Node: Extension Sample Readdir1020303 -Ref: table-readdir-file-types1021159 -Node: Extension Sample Revout1021958 -Node: Extension Sample Rev2way1022549 -Node: Extension Sample Read write array1023290 -Node: Extension Sample Readfile1025169 -Node: Extension Sample API Tests1026269 -Node: Extension Sample Time1026794 -Node: gawkextlib1028109 -Node: Extension summary1030922 -Node: Extension Exercises1034615 -Node: Language History1035337 -Node: V7/SVR3.11036980 -Node: SVR41039300 -Node: POSIX1040742 -Node: BTL1042128 -Node: POSIX/GNU1042862 -Node: Feature History1048461 -Node: Common Extensions1061591 -Node: Ranges and Locales1062903 -Ref: Ranges and Locales-Footnote-11067520 -Ref: Ranges and Locales-Footnote-21067547 -Ref: Ranges and Locales-Footnote-31067781 -Node: Contributors1068002 -Node: History summary1073427 -Node: Installation1074796 -Node: Gawk Distribution1075747 -Node: Getting1076231 -Node: Extracting1077055 -Node: Distribution contents1078697 -Node: Unix Installation1084414 -Node: Quick Installation1085031 -Node: Additional Configuration Options1087473 -Node: Configuration Philosophy1089211 -Node: Non-Unix Installation1091562 -Node: PC Installation1092020 -Node: PC Binary Installation1093331 -Node: PC Compiling1095179 -Ref: PC Compiling-Footnote-11098178 -Node: PC Testing1098283 -Node: PC Using1099459 -Node: Cygwin1103617 -Node: MSYS1104426 -Node: VMS Installation1104940 -Node: VMS Compilation1105736 -Ref: VMS Compilation-Footnote-11106958 -Node: VMS Dynamic Extensions1107016 -Node: VMS Installation Details1108389 -Node: VMS Running1110641 -Node: VMS GNV1113475 -Node: VMS Old Gawk1114198 -Node: Bugs1114668 -Node: Other Versions1118672 -Node: Installation summary1124927 -Node: Notes1125983 -Node: Compatibility Mode1126848 -Node: Additions1127630 -Node: Accessing The Source1128555 -Node: Adding Code1129991 -Node: New Ports1136169 -Node: Derived Files1140650 -Ref: Derived Files-Footnote-11145731 -Ref: Derived Files-Footnote-21145765 -Ref: Derived Files-Footnote-31146361 -Node: Future Extensions1146475 -Node: Implementation Limitations1147081 -Node: Extension Design1148329 -Node: Old Extension Problems1149483 -Ref: Old Extension Problems-Footnote-11151000 -Node: Extension New Mechanism Goals1151057 -Ref: Extension New Mechanism Goals-Footnote-11154417 -Node: Extension Other Design Decisions1154606 -Node: Extension Future Growth1156712 -Node: Old Extension Mechanism1157548 -Node: Notes summary1159310 -Node: Basic Concepts1160496 -Node: Basic High Level1161177 -Ref: figure-general-flow1161449 -Ref: figure-process-flow1162048 -Ref: Basic High Level-Footnote-11165277 -Node: Basic Data Typing1165462 -Node: Glossary1168790 -Node: Copying1193942 -Node: GNU Free Documentation License1231498 -Node: Index1256634 +Node: Format Modifiers279786 +Node: Printf Examples285813 +Node: Redirection288277 +Node: Special Files295249 +Node: Special FD295780 +Ref: Special FD-Footnote-1299404 +Node: Special Network299478 +Node: Special Caveats300328 +Node: Close Files And Pipes301124 +Ref: Close Files And Pipes-Footnote-1308285 +Ref: Close Files And Pipes-Footnote-2308433 +Node: Output Summary308583 +Node: Output exercises309580 +Node: Expressions310260 +Node: Values311445 +Node: Constants312121 +Node: Scalar Constants312801 +Ref: Scalar Constants-Footnote-1313660 +Node: Nondecimal-numbers313910 +Node: Regexp Constants316910 +Node: Using Constant Regexps317385 +Node: Variables320455 +Node: Using Variables321110 +Node: Assignment Options322834 +Node: Conversion324709 +Node: Strings And Numbers325233 +Ref: Strings And Numbers-Footnote-1328295 +Node: Locale influences conversions328404 +Ref: table-locale-affects331121 +Node: All Operators331709 +Node: Arithmetic Ops332339 +Node: Concatenation334844 +Ref: Concatenation-Footnote-1337640 +Node: Assignment Ops337760 +Ref: table-assign-ops342743 +Node: Increment Ops344060 +Node: Truth Values and Conditions347498 +Node: Truth Values348581 +Node: Typing and Comparison349630 +Node: Variable Typing350423 +Ref: Variable Typing-Footnote-1354323 +Node: Comparison Operators354445 +Ref: table-relational-ops354855 +Node: POSIX String Comparison358405 +Ref: POSIX String Comparison-Footnote-1359489 +Node: Boolean Ops359627 +Ref: Boolean Ops-Footnote-1363697 +Node: Conditional Exp363788 +Node: Function Calls365515 +Node: Precedence369395 +Node: Locales373064 +Node: Expressions Summary374695 +Node: Patterns and Actions377236 +Node: Pattern Overview378352 +Node: Regexp Patterns380029 +Node: Expression Patterns380572 +Node: Ranges384353 +Node: BEGIN/END387459 +Node: Using BEGIN/END388221 +Ref: Using BEGIN/END-Footnote-1390957 +Node: I/O And BEGIN/END391063 +Node: BEGINFILE/ENDFILE393348 +Node: Empty396279 +Node: Using Shell Variables396596 +Node: Action Overview398879 +Node: Statements401206 +Node: If Statement403054 +Node: While Statement404552 +Node: Do Statement406596 +Node: For Statement407752 +Node: Switch Statement410904 +Node: Break Statement413007 +Node: Continue Statement415062 +Node: Next Statement416855 +Node: Nextfile Statement419245 +Node: Exit Statement421900 +Node: Built-in Variables424304 +Node: User-modified425431 +Ref: User-modified-Footnote-1433120 +Node: Auto-set433182 +Ref: Auto-set-Footnote-1445764 +Ref: Auto-set-Footnote-2445969 +Node: ARGC and ARGV446025 +Node: Pattern Action Summary449879 +Node: Arrays452102 +Node: Array Basics453651 +Node: Array Intro454477 +Ref: figure-array-elements456450 +Node: Reference to Elements458857 +Node: Assigning Elements461130 +Node: Array Example461621 +Node: Scanning an Array463353 +Node: Controlling Scanning466368 +Ref: Controlling Scanning-Footnote-1471541 +Node: Delete471857 +Ref: Delete-Footnote-1474622 +Node: Numeric Array Subscripts474679 +Node: Uninitialized Subscripts476862 +Node: Multidimensional478487 +Node: Multiscanning481580 +Node: Arrays of Arrays483169 +Node: Arrays Summary487832 +Node: Functions489937 +Node: Built-in490810 +Node: Calling Built-in491888 +Node: Numeric Functions493876 +Ref: Numeric Functions-Footnote-1497710 +Ref: Numeric Functions-Footnote-2498067 +Ref: Numeric Functions-Footnote-3498115 +Node: String Functions498384 +Ref: String Functions-Footnote-1521395 +Ref: String Functions-Footnote-2521524 +Ref: String Functions-Footnote-3521772 +Node: Gory Details521859 +Ref: table-sub-escapes523528 +Ref: table-sub-posix-92524882 +Ref: table-sub-proposed526233 +Ref: table-posix-sub527587 +Ref: table-gensub-escapes529132 +Ref: Gory Details-Footnote-1530308 +Ref: Gory Details-Footnote-2530359 +Node: I/O Functions530510 +Ref: I/O Functions-Footnote-1537633 +Node: Time Functions537780 +Ref: Time Functions-Footnote-1548244 +Ref: Time Functions-Footnote-2548312 +Ref: Time Functions-Footnote-3548470 +Ref: Time Functions-Footnote-4548581 +Ref: Time Functions-Footnote-5548693 +Ref: Time Functions-Footnote-6548920 +Node: Bitwise Functions549186 +Ref: table-bitwise-ops549748 +Ref: Bitwise Functions-Footnote-1553993 +Node: Type Functions554177 +Node: I18N Functions555319 +Node: User-defined556964 +Node: Definition Syntax557768 +Ref: Definition Syntax-Footnote-1562947 +Node: Function Example563016 +Ref: Function Example-Footnote-1565660 +Node: Function Caveats565682 +Node: Calling A Function566200 +Node: Variable Scope567155 +Node: Pass By Value/Reference570143 +Node: Return Statement573651 +Node: Dynamic Typing576635 +Node: Indirect Calls577564 +Node: Functions Summary587277 +Node: Library Functions589816 +Ref: Library Functions-Footnote-1593434 +Ref: Library Functions-Footnote-2593577 +Node: Library Names593748 +Ref: Library Names-Footnote-1597221 +Ref: Library Names-Footnote-2597441 +Node: General Functions597527 +Node: Strtonum Function598555 +Node: Assert Function601335 +Node: Round Function604661 +Node: Cliff Random Function606202 +Node: Ordinal Functions607218 +Ref: Ordinal Functions-Footnote-1610295 +Ref: Ordinal Functions-Footnote-2610547 +Node: Join Function610758 +Ref: Join Function-Footnote-1612529 +Node: Getlocaltime Function612729 +Node: Readfile Function616465 +Node: Data File Management618304 +Node: Filetrans Function618936 +Node: Rewind Function623005 +Node: File Checking624392 +Ref: File Checking-Footnote-1625524 +Node: Empty Files625725 +Node: Ignoring Assigns627704 +Node: Getopt Function629258 +Ref: Getopt Function-Footnote-1640561 +Node: Passwd Functions640764 +Ref: Passwd Functions-Footnote-1649743 +Node: Group Functions649831 +Ref: Group Functions-Footnote-1657772 +Node: Walking Arrays657985 +Node: Library Functions Summary659588 +Node: Library exercises660976 +Node: Sample Programs662256 +Node: Running Examples663026 +Node: Clones663754 +Node: Cut Program664978 +Node: Egrep Program674846 +Ref: Egrep Program-Footnote-1682817 +Node: Id Program682927 +Node: Split Program686591 +Ref: Split Program-Footnote-1690129 +Node: Tee Program690257 +Node: Uniq Program693064 +Node: Wc Program700494 +Ref: Wc Program-Footnote-1704759 +Node: Miscellaneous Programs704851 +Node: Dupword Program706064 +Node: Alarm Program708095 +Node: Translate Program712909 +Ref: Translate Program-Footnote-1717300 +Ref: Translate Program-Footnote-2717570 +Node: Labels Program717704 +Ref: Labels Program-Footnote-1721075 +Node: Word Sorting721159 +Node: History Sorting725202 +Node: Extract Program727038 +Node: Simple Sed734574 +Node: Igawk Program737636 +Ref: Igawk Program-Footnote-1751947 +Ref: Igawk Program-Footnote-2752148 +Node: Anagram Program752286 +Node: Signature Program755354 +Node: Programs Summary756601 +Node: Programs Exercises757816 +Node: Advanced Features761467 +Node: Nondecimal Data763415 +Node: Array Sorting764992 +Node: Controlling Array Traversal765689 +Node: Array Sorting Functions773969 +Ref: Array Sorting Functions-Footnote-1777876 +Node: Two-way I/O778070 +Ref: Two-way I/O-Footnote-1783586 +Node: TCP/IP Networking783668 +Node: Profiling786512 +Node: Advanced Features Summary794054 +Node: Internationalization795918 +Node: I18N and L10N797398 +Node: Explaining gettext798084 +Ref: Explaining gettext-Footnote-1803224 +Ref: Explaining gettext-Footnote-2803408 +Node: Programmer i18n803573 +Node: Translator i18n807798 +Node: String Extraction808592 +Ref: String Extraction-Footnote-1809553 +Node: Printf Ordering809639 +Ref: Printf Ordering-Footnote-1812421 +Node: I18N Portability812485 +Ref: I18N Portability-Footnote-1814934 +Node: I18N Example814997 +Ref: I18N Example-Footnote-1817719 +Node: Gawk I18N817791 +Node: I18N Summary818429 +Node: Debugger819768 +Node: Debugging820790 +Node: Debugging Concepts821231 +Node: Debugging Terms823087 +Node: Awk Debugging825684 +Node: Sample Debugging Session826576 +Node: Debugger Invocation827096 +Node: Finding The Bug828429 +Node: List of Debugger Commands834911 +Node: Breakpoint Control836243 +Node: Debugger Execution Control839907 +Node: Viewing And Changing Data843267 +Node: Execution Stack846625 +Node: Debugger Info848138 +Node: Miscellaneous Debugger Commands852132 +Node: Readline Support857316 +Node: Limitations858208 +Node: Debugging Summary860482 +Node: Arbitrary Precision Arithmetic861646 +Node: Computer Arithmetic862975 +Ref: Computer Arithmetic-Footnote-1867362 +Node: Math Definitions867419 +Ref: table-ieee-formats870303 +Node: MPFR features870807 +Node: FP Math Caution872449 +Ref: FP Math Caution-Footnote-1873490 +Node: Inexactness of computations873859 +Node: Inexact representation874807 +Node: Comparing FP Values876162 +Node: Errors accumulate877126 +Node: Getting Accuracy878559 +Node: Try To Round881218 +Node: Setting precision882117 +Ref: table-predefined-precision-strings882799 +Node: Setting the rounding mode884592 +Ref: table-gawk-rounding-modes884956 +Ref: Setting the rounding mode-Footnote-1888410 +Node: Arbitrary Precision Integers888589 +Ref: Arbitrary Precision Integers-Footnote-1891592 +Node: POSIX Floating Point Problems891741 +Ref: POSIX Floating Point Problems-Footnote-1895617 +Node: Floating point summary895655 +Node: Dynamic Extensions897872 +Node: Extension Intro899424 +Node: Plugin License900689 +Node: Extension Mechanism Outline901374 +Ref: figure-load-extension901798 +Ref: figure-load-new-function903283 +Ref: figure-call-new-function904285 +Node: Extension API Description906269 +Node: Extension API Functions Introduction907719 +Node: General Data Types912584 +Ref: General Data Types-Footnote-1918277 +Node: Requesting Values918576 +Ref: table-value-types-returned919313 +Node: Memory Allocation Functions920271 +Ref: Memory Allocation Functions-Footnote-1923018 +Node: Constructor Functions923114 +Node: Registration Functions924872 +Node: Extension Functions925557 +Node: Exit Callback Functions927859 +Node: Extension Version String929108 +Node: Input Parsers929758 +Node: Output Wrappers939561 +Node: Two-way processors944077 +Node: Printing Messages946281 +Ref: Printing Messages-Footnote-1947358 +Node: Updating `ERRNO'947510 +Node: Accessing Parameters948249 +Node: Symbol Table Access949479 +Node: Symbol table by name949993 +Node: Symbol table by cookie951969 +Ref: Symbol table by cookie-Footnote-1956102 +Node: Cached values956165 +Ref: Cached values-Footnote-1959669 +Node: Array Manipulation959760 +Ref: Array Manipulation-Footnote-1960858 +Node: Array Data Types960897 +Ref: Array Data Types-Footnote-1963600 +Node: Array Functions963692 +Node: Flattening Arrays967566 +Node: Creating Arrays974418 +Node: Extension API Variables979149 +Node: Extension Versioning979785 +Node: Extension API Informational Variables981686 +Node: Extension API Boilerplate982772 +Node: Finding Extensions986576 +Node: Extension Example987136 +Node: Internal File Description987866 +Node: Internal File Ops991957 +Ref: Internal File Ops-Footnote-11003389 +Node: Using Internal File Ops1003529 +Ref: Using Internal File Ops-Footnote-11005876 +Node: Extension Samples1006144 +Node: Extension Sample File Functions1007668 +Node: Extension Sample Fnmatch1015236 +Node: Extension Sample Fork1016718 +Node: Extension Sample Inplace1017931 +Node: Extension Sample Ord1019606 +Node: Extension Sample Readdir1020442 +Ref: table-readdir-file-types1021298 +Node: Extension Sample Revout1022097 +Node: Extension Sample Rev2way1022688 +Node: Extension Sample Read write array1023429 +Node: Extension Sample Readfile1025308 +Node: Extension Sample API Tests1026408 +Node: Extension Sample Time1026933 +Node: gawkextlib1028248 +Node: Extension summary1031061 +Node: Extension Exercises1034754 +Node: Language History1035476 +Node: V7/SVR3.11037119 +Node: SVR41039439 +Node: POSIX1040881 +Node: BTL1042267 +Node: POSIX/GNU1043001 +Node: Feature History1048600 +Node: Common Extensions1061730 +Node: Ranges and Locales1063042 +Ref: Ranges and Locales-Footnote-11067659 +Ref: Ranges and Locales-Footnote-21067686 +Ref: Ranges and Locales-Footnote-31067920 +Node: Contributors1068141 +Node: History summary1073566 +Node: Installation1074935 +Node: Gawk Distribution1075886 +Node: Getting1076370 +Node: Extracting1077194 +Node: Distribution contents1078836 +Node: Unix Installation1084553 +Node: Quick Installation1085170 +Node: Additional Configuration Options1087612 +Node: Configuration Philosophy1089350 +Node: Non-Unix Installation1091701 +Node: PC Installation1092159 +Node: PC Binary Installation1093470 +Node: PC Compiling1095318 +Ref: PC Compiling-Footnote-11098317 +Node: PC Testing1098422 +Node: PC Using1099598 +Node: Cygwin1103756 +Node: MSYS1104565 +Node: VMS Installation1105079 +Node: VMS Compilation1105875 +Ref: VMS Compilation-Footnote-11107097 +Node: VMS Dynamic Extensions1107155 +Node: VMS Installation Details1108528 +Node: VMS Running1110780 +Node: VMS GNV1113614 +Node: VMS Old Gawk1114337 +Node: Bugs1114807 +Node: Other Versions1118811 +Node: Installation summary1125066 +Node: Notes1126122 +Node: Compatibility Mode1126987 +Node: Additions1127769 +Node: Accessing The Source1128694 +Node: Adding Code1130130 +Node: New Ports1136308 +Node: Derived Files1140789 +Ref: Derived Files-Footnote-11145870 +Ref: Derived Files-Footnote-21145904 +Ref: Derived Files-Footnote-31146500 +Node: Future Extensions1146614 +Node: Implementation Limitations1147220 +Node: Extension Design1148468 +Node: Old Extension Problems1149622 +Ref: Old Extension Problems-Footnote-11151139 +Node: Extension New Mechanism Goals1151196 +Ref: Extension New Mechanism Goals-Footnote-11154556 +Node: Extension Other Design Decisions1154745 +Node: Extension Future Growth1156851 +Node: Old Extension Mechanism1157687 +Node: Notes summary1159449 +Node: Basic Concepts1160635 +Node: Basic High Level1161316 +Ref: figure-general-flow1161588 +Ref: figure-process-flow1162187 +Ref: Basic High Level-Footnote-11165416 +Node: Basic Data Typing1165601 +Node: Glossary1168929 +Node: Copying1194081 +Node: GNU Free Documentation License1231637 +Node: Index1256773  End Tag Table -- cgit v1.2.3 From 8f2f7ef2872a9a95dc1506504b60225ef98944f1 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sun, 3 Aug 2014 22:06:51 +0300 Subject: Improve inrec setting ERRNO, doc of API get_record for errors. --- doc/gawk.info | 250 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 125 insertions(+), 125 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index e1b07c80..8ca20ccc 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -23161,10 +23161,10 @@ need to test for a `NULL' value. `gawk' sets `*errcode' to zero, so there is no need to set it unless an error occurs. If an error does occur, the function should return `EOF' and set -`*errcode' to a non-zero value. In that case, if `*errcode' does not -equal -1, `gawk' automatically updates the `ERRNO' variable based on -the value of `*errcode'. (In general, setting `*errcode = errno' -should do the right thing.) +`*errcode' to a value greater than zero. In that case, if `*errcode' +does not equal zero, `gawk' automatically updates the `ERRNO' variable +based on the value of `*errcode'. (In general, setting `*errcode = +errno' should do the right thing.) As an alternative to supplying a function that returns an input record, you may instead supply a function that simply reads bytes, and @@ -34379,126 +34379,126 @@ Node: Extension Functions925557 Node: Exit Callback Functions927859 Node: Extension Version String929108 Node: Input Parsers929758 -Node: Output Wrappers939561 -Node: Two-way processors944077 -Node: Printing Messages946281 -Ref: Printing Messages-Footnote-1947358 -Node: Updating `ERRNO'947510 -Node: Accessing Parameters948249 -Node: Symbol Table Access949479 -Node: Symbol table by name949993 -Node: Symbol table by cookie951969 -Ref: Symbol table by cookie-Footnote-1956102 -Node: Cached values956165 -Ref: Cached values-Footnote-1959669 -Node: Array Manipulation959760 -Ref: Array Manipulation-Footnote-1960858 -Node: Array Data Types960897 -Ref: Array Data Types-Footnote-1963600 -Node: Array Functions963692 -Node: Flattening Arrays967566 -Node: Creating Arrays974418 -Node: Extension API Variables979149 -Node: Extension Versioning979785 -Node: Extension API Informational Variables981686 -Node: Extension API Boilerplate982772 -Node: Finding Extensions986576 -Node: Extension Example987136 -Node: Internal File Description987866 -Node: Internal File Ops991957 -Ref: Internal File Ops-Footnote-11003389 -Node: Using Internal File Ops1003529 -Ref: Using Internal File Ops-Footnote-11005876 -Node: Extension Samples1006144 -Node: Extension Sample File Functions1007668 -Node: Extension Sample Fnmatch1015236 -Node: Extension Sample Fork1016718 -Node: Extension Sample Inplace1017931 -Node: Extension Sample Ord1019606 -Node: Extension Sample Readdir1020442 -Ref: table-readdir-file-types1021298 -Node: Extension Sample Revout1022097 -Node: Extension Sample Rev2way1022688 -Node: Extension Sample Read write array1023429 -Node: Extension Sample Readfile1025308 -Node: Extension Sample API Tests1026408 -Node: Extension Sample Time1026933 -Node: gawkextlib1028248 -Node: Extension summary1031061 -Node: Extension Exercises1034754 -Node: Language History1035476 -Node: V7/SVR3.11037119 -Node: SVR41039439 -Node: POSIX1040881 -Node: BTL1042267 -Node: POSIX/GNU1043001 -Node: Feature History1048600 -Node: Common Extensions1061730 -Node: Ranges and Locales1063042 -Ref: Ranges and Locales-Footnote-11067659 -Ref: Ranges and Locales-Footnote-21067686 -Ref: Ranges and Locales-Footnote-31067920 -Node: Contributors1068141 -Node: History summary1073566 -Node: Installation1074935 -Node: Gawk Distribution1075886 -Node: Getting1076370 -Node: Extracting1077194 -Node: Distribution contents1078836 -Node: Unix Installation1084553 -Node: Quick Installation1085170 -Node: Additional Configuration Options1087612 -Node: Configuration Philosophy1089350 -Node: Non-Unix Installation1091701 -Node: PC Installation1092159 -Node: PC Binary Installation1093470 -Node: PC Compiling1095318 -Ref: PC Compiling-Footnote-11098317 -Node: PC Testing1098422 -Node: PC Using1099598 -Node: Cygwin1103756 -Node: MSYS1104565 -Node: VMS Installation1105079 -Node: VMS Compilation1105875 -Ref: VMS Compilation-Footnote-11107097 -Node: VMS Dynamic Extensions1107155 -Node: VMS Installation Details1108528 -Node: VMS Running1110780 -Node: VMS GNV1113614 -Node: VMS Old Gawk1114337 -Node: Bugs1114807 -Node: Other Versions1118811 -Node: Installation summary1125066 -Node: Notes1126122 -Node: Compatibility Mode1126987 -Node: Additions1127769 -Node: Accessing The Source1128694 -Node: Adding Code1130130 -Node: New Ports1136308 -Node: Derived Files1140789 -Ref: Derived Files-Footnote-11145870 -Ref: Derived Files-Footnote-21145904 -Ref: Derived Files-Footnote-31146500 -Node: Future Extensions1146614 -Node: Implementation Limitations1147220 -Node: Extension Design1148468 -Node: Old Extension Problems1149622 -Ref: Old Extension Problems-Footnote-11151139 -Node: Extension New Mechanism Goals1151196 -Ref: Extension New Mechanism Goals-Footnote-11154556 -Node: Extension Other Design Decisions1154745 -Node: Extension Future Growth1156851 -Node: Old Extension Mechanism1157687 -Node: Notes summary1159449 -Node: Basic Concepts1160635 -Node: Basic High Level1161316 -Ref: figure-general-flow1161588 -Ref: figure-process-flow1162187 -Ref: Basic High Level-Footnote-11165416 -Node: Basic Data Typing1165601 -Node: Glossary1168929 -Node: Copying1194081 -Node: GNU Free Documentation License1231637 -Node: Index1256773 +Node: Output Wrappers939572 +Node: Two-way processors944088 +Node: Printing Messages946292 +Ref: Printing Messages-Footnote-1947369 +Node: Updating `ERRNO'947521 +Node: Accessing Parameters948260 +Node: Symbol Table Access949490 +Node: Symbol table by name950004 +Node: Symbol table by cookie951980 +Ref: Symbol table by cookie-Footnote-1956113 +Node: Cached values956176 +Ref: Cached values-Footnote-1959680 +Node: Array Manipulation959771 +Ref: Array Manipulation-Footnote-1960869 +Node: Array Data Types960908 +Ref: Array Data Types-Footnote-1963611 +Node: Array Functions963703 +Node: Flattening Arrays967577 +Node: Creating Arrays974429 +Node: Extension API Variables979160 +Node: Extension Versioning979796 +Node: Extension API Informational Variables981697 +Node: Extension API Boilerplate982783 +Node: Finding Extensions986587 +Node: Extension Example987147 +Node: Internal File Description987877 +Node: Internal File Ops991968 +Ref: Internal File Ops-Footnote-11003400 +Node: Using Internal File Ops1003540 +Ref: Using Internal File Ops-Footnote-11005887 +Node: Extension Samples1006155 +Node: Extension Sample File Functions1007679 +Node: Extension Sample Fnmatch1015247 +Node: Extension Sample Fork1016729 +Node: Extension Sample Inplace1017942 +Node: Extension Sample Ord1019617 +Node: Extension Sample Readdir1020453 +Ref: table-readdir-file-types1021309 +Node: Extension Sample Revout1022108 +Node: Extension Sample Rev2way1022699 +Node: Extension Sample Read write array1023440 +Node: Extension Sample Readfile1025319 +Node: Extension Sample API Tests1026419 +Node: Extension Sample Time1026944 +Node: gawkextlib1028259 +Node: Extension summary1031072 +Node: Extension Exercises1034765 +Node: Language History1035487 +Node: V7/SVR3.11037130 +Node: SVR41039450 +Node: POSIX1040892 +Node: BTL1042278 +Node: POSIX/GNU1043012 +Node: Feature History1048611 +Node: Common Extensions1061741 +Node: Ranges and Locales1063053 +Ref: Ranges and Locales-Footnote-11067670 +Ref: Ranges and Locales-Footnote-21067697 +Ref: Ranges and Locales-Footnote-31067931 +Node: Contributors1068152 +Node: History summary1073577 +Node: Installation1074946 +Node: Gawk Distribution1075897 +Node: Getting1076381 +Node: Extracting1077205 +Node: Distribution contents1078847 +Node: Unix Installation1084564 +Node: Quick Installation1085181 +Node: Additional Configuration Options1087623 +Node: Configuration Philosophy1089361 +Node: Non-Unix Installation1091712 +Node: PC Installation1092170 +Node: PC Binary Installation1093481 +Node: PC Compiling1095329 +Ref: PC Compiling-Footnote-11098328 +Node: PC Testing1098433 +Node: PC Using1099609 +Node: Cygwin1103767 +Node: MSYS1104576 +Node: VMS Installation1105090 +Node: VMS Compilation1105886 +Ref: VMS Compilation-Footnote-11107108 +Node: VMS Dynamic Extensions1107166 +Node: VMS Installation Details1108539 +Node: VMS Running1110791 +Node: VMS GNV1113625 +Node: VMS Old Gawk1114348 +Node: Bugs1114818 +Node: Other Versions1118822 +Node: Installation summary1125077 +Node: Notes1126133 +Node: Compatibility Mode1126998 +Node: Additions1127780 +Node: Accessing The Source1128705 +Node: Adding Code1130141 +Node: New Ports1136319 +Node: Derived Files1140800 +Ref: Derived Files-Footnote-11145881 +Ref: Derived Files-Footnote-21145915 +Ref: Derived Files-Footnote-31146511 +Node: Future Extensions1146625 +Node: Implementation Limitations1147231 +Node: Extension Design1148479 +Node: Old Extension Problems1149633 +Ref: Old Extension Problems-Footnote-11151150 +Node: Extension New Mechanism Goals1151207 +Ref: Extension New Mechanism Goals-Footnote-11154567 +Node: Extension Other Design Decisions1154756 +Node: Extension Future Growth1156862 +Node: Old Extension Mechanism1157698 +Node: Notes summary1159460 +Node: Basic Concepts1160646 +Node: Basic High Level1161327 +Ref: figure-general-flow1161599 +Ref: figure-process-flow1162198 +Ref: Basic High Level-Footnote-11165427 +Node: Basic Data Typing1165612 +Node: Glossary1168940 +Node: Copying1194092 +Node: GNU Free Documentation License1231648 +Node: Index1256784  End Tag Table -- cgit v1.2.3 From 7cc33dc5325181f26ded26b745229147e130bab1 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 6 Aug 2014 22:24:06 +0300 Subject: Minor doc updates. --- doc/gawk.info | 523 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 265 insertions(+), 258 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 8ca20ccc..5a07d84d 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -15018,7 +15018,9 @@ presented in *note Filetrans Function::, to either update `ARGIND' on your own or modify this code as appropriate. The `rewind()' function also relies on the `nextfile' keyword (*note -Nextfile Statement::). +Nextfile Statement::). Because of this, you should not call it from an +`ENDFILE' rule. (This isn't necessary anyway, since as soon as an +`ENDFILE' rule finishes `gawk' goes to the next file!)  File: gawk.info, Node: File Checking, Next: Empty Files, Prev: Rewind Function, Up: Data File Management @@ -26104,6 +26106,11 @@ the current version of `gawk'. - GCC for VAX and Alpha has not been tested for a while. + * Support for the following obsolete systems was removed from the + code and the documentation for `gawk' version 4.1: + + - Ultrix +  File: gawk.info, Node: Feature History, Next: Common Extensions, Prev: POSIX/GNU, Up: Language History @@ -34243,262 +34250,262 @@ Node: Readfile Function616465 Node: Data File Management618304 Node: Filetrans Function618936 Node: Rewind Function623005 -Node: File Checking624392 -Ref: File Checking-Footnote-1625524 -Node: Empty Files625725 -Node: Ignoring Assigns627704 -Node: Getopt Function629258 -Ref: Getopt Function-Footnote-1640561 -Node: Passwd Functions640764 -Ref: Passwd Functions-Footnote-1649743 -Node: Group Functions649831 -Ref: Group Functions-Footnote-1657772 -Node: Walking Arrays657985 -Node: Library Functions Summary659588 -Node: Library exercises660976 -Node: Sample Programs662256 -Node: Running Examples663026 -Node: Clones663754 -Node: Cut Program664978 -Node: Egrep Program674846 -Ref: Egrep Program-Footnote-1682817 -Node: Id Program682927 -Node: Split Program686591 -Ref: Split Program-Footnote-1690129 -Node: Tee Program690257 -Node: Uniq Program693064 -Node: Wc Program700494 -Ref: Wc Program-Footnote-1704759 -Node: Miscellaneous Programs704851 -Node: Dupword Program706064 -Node: Alarm Program708095 -Node: Translate Program712909 -Ref: Translate Program-Footnote-1717300 -Ref: Translate Program-Footnote-2717570 -Node: Labels Program717704 -Ref: Labels Program-Footnote-1721075 -Node: Word Sorting721159 -Node: History Sorting725202 -Node: Extract Program727038 -Node: Simple Sed734574 -Node: Igawk Program737636 -Ref: Igawk Program-Footnote-1751947 -Ref: Igawk Program-Footnote-2752148 -Node: Anagram Program752286 -Node: Signature Program755354 -Node: Programs Summary756601 -Node: Programs Exercises757816 -Node: Advanced Features761467 -Node: Nondecimal Data763415 -Node: Array Sorting764992 -Node: Controlling Array Traversal765689 -Node: Array Sorting Functions773969 -Ref: Array Sorting Functions-Footnote-1777876 -Node: Two-way I/O778070 -Ref: Two-way I/O-Footnote-1783586 -Node: TCP/IP Networking783668 -Node: Profiling786512 -Node: Advanced Features Summary794054 -Node: Internationalization795918 -Node: I18N and L10N797398 -Node: Explaining gettext798084 -Ref: Explaining gettext-Footnote-1803224 -Ref: Explaining gettext-Footnote-2803408 -Node: Programmer i18n803573 -Node: Translator i18n807798 -Node: String Extraction808592 -Ref: String Extraction-Footnote-1809553 -Node: Printf Ordering809639 -Ref: Printf Ordering-Footnote-1812421 -Node: I18N Portability812485 -Ref: I18N Portability-Footnote-1814934 -Node: I18N Example814997 -Ref: I18N Example-Footnote-1817719 -Node: Gawk I18N817791 -Node: I18N Summary818429 -Node: Debugger819768 -Node: Debugging820790 -Node: Debugging Concepts821231 -Node: Debugging Terms823087 -Node: Awk Debugging825684 -Node: Sample Debugging Session826576 -Node: Debugger Invocation827096 -Node: Finding The Bug828429 -Node: List of Debugger Commands834911 -Node: Breakpoint Control836243 -Node: Debugger Execution Control839907 -Node: Viewing And Changing Data843267 -Node: Execution Stack846625 -Node: Debugger Info848138 -Node: Miscellaneous Debugger Commands852132 -Node: Readline Support857316 -Node: Limitations858208 -Node: Debugging Summary860482 -Node: Arbitrary Precision Arithmetic861646 -Node: Computer Arithmetic862975 -Ref: Computer Arithmetic-Footnote-1867362 -Node: Math Definitions867419 -Ref: table-ieee-formats870303 -Node: MPFR features870807 -Node: FP Math Caution872449 -Ref: FP Math Caution-Footnote-1873490 -Node: Inexactness of computations873859 -Node: Inexact representation874807 -Node: Comparing FP Values876162 -Node: Errors accumulate877126 -Node: Getting Accuracy878559 -Node: Try To Round881218 -Node: Setting precision882117 -Ref: table-predefined-precision-strings882799 -Node: Setting the rounding mode884592 -Ref: table-gawk-rounding-modes884956 -Ref: Setting the rounding mode-Footnote-1888410 -Node: Arbitrary Precision Integers888589 -Ref: Arbitrary Precision Integers-Footnote-1891592 -Node: POSIX Floating Point Problems891741 -Ref: POSIX Floating Point Problems-Footnote-1895617 -Node: Floating point summary895655 -Node: Dynamic Extensions897872 -Node: Extension Intro899424 -Node: Plugin License900689 -Node: Extension Mechanism Outline901374 -Ref: figure-load-extension901798 -Ref: figure-load-new-function903283 -Ref: figure-call-new-function904285 -Node: Extension API Description906269 -Node: Extension API Functions Introduction907719 -Node: General Data Types912584 -Ref: General Data Types-Footnote-1918277 -Node: Requesting Values918576 -Ref: table-value-types-returned919313 -Node: Memory Allocation Functions920271 -Ref: Memory Allocation Functions-Footnote-1923018 -Node: Constructor Functions923114 -Node: Registration Functions924872 -Node: Extension Functions925557 -Node: Exit Callback Functions927859 -Node: Extension Version String929108 -Node: Input Parsers929758 -Node: Output Wrappers939572 -Node: Two-way processors944088 -Node: Printing Messages946292 -Ref: Printing Messages-Footnote-1947369 -Node: Updating `ERRNO'947521 -Node: Accessing Parameters948260 -Node: Symbol Table Access949490 -Node: Symbol table by name950004 -Node: Symbol table by cookie951980 -Ref: Symbol table by cookie-Footnote-1956113 -Node: Cached values956176 -Ref: Cached values-Footnote-1959680 -Node: Array Manipulation959771 -Ref: Array Manipulation-Footnote-1960869 -Node: Array Data Types960908 -Ref: Array Data Types-Footnote-1963611 -Node: Array Functions963703 -Node: Flattening Arrays967577 -Node: Creating Arrays974429 -Node: Extension API Variables979160 -Node: Extension Versioning979796 -Node: Extension API Informational Variables981697 -Node: Extension API Boilerplate982783 -Node: Finding Extensions986587 -Node: Extension Example987147 -Node: Internal File Description987877 -Node: Internal File Ops991968 -Ref: Internal File Ops-Footnote-11003400 -Node: Using Internal File Ops1003540 -Ref: Using Internal File Ops-Footnote-11005887 -Node: Extension Samples1006155 -Node: Extension Sample File Functions1007679 -Node: Extension Sample Fnmatch1015247 -Node: Extension Sample Fork1016729 -Node: Extension Sample Inplace1017942 -Node: Extension Sample Ord1019617 -Node: Extension Sample Readdir1020453 -Ref: table-readdir-file-types1021309 -Node: Extension Sample Revout1022108 -Node: Extension Sample Rev2way1022699 -Node: Extension Sample Read write array1023440 -Node: Extension Sample Readfile1025319 -Node: Extension Sample API Tests1026419 -Node: Extension Sample Time1026944 -Node: gawkextlib1028259 -Node: Extension summary1031072 -Node: Extension Exercises1034765 -Node: Language History1035487 -Node: V7/SVR3.11037130 -Node: SVR41039450 -Node: POSIX1040892 -Node: BTL1042278 -Node: POSIX/GNU1043012 -Node: Feature History1048611 -Node: Common Extensions1061741 -Node: Ranges and Locales1063053 -Ref: Ranges and Locales-Footnote-11067670 -Ref: Ranges and Locales-Footnote-21067697 -Ref: Ranges and Locales-Footnote-31067931 -Node: Contributors1068152 -Node: History summary1073577 -Node: Installation1074946 -Node: Gawk Distribution1075897 -Node: Getting1076381 -Node: Extracting1077205 -Node: Distribution contents1078847 -Node: Unix Installation1084564 -Node: Quick Installation1085181 -Node: Additional Configuration Options1087623 -Node: Configuration Philosophy1089361 -Node: Non-Unix Installation1091712 -Node: PC Installation1092170 -Node: PC Binary Installation1093481 -Node: PC Compiling1095329 -Ref: PC Compiling-Footnote-11098328 -Node: PC Testing1098433 -Node: PC Using1099609 -Node: Cygwin1103767 -Node: MSYS1104576 -Node: VMS Installation1105090 -Node: VMS Compilation1105886 -Ref: VMS Compilation-Footnote-11107108 -Node: VMS Dynamic Extensions1107166 -Node: VMS Installation Details1108539 -Node: VMS Running1110791 -Node: VMS GNV1113625 -Node: VMS Old Gawk1114348 -Node: Bugs1114818 -Node: Other Versions1118822 -Node: Installation summary1125077 -Node: Notes1126133 -Node: Compatibility Mode1126998 -Node: Additions1127780 -Node: Accessing The Source1128705 -Node: Adding Code1130141 -Node: New Ports1136319 -Node: Derived Files1140800 -Ref: Derived Files-Footnote-11145881 -Ref: Derived Files-Footnote-21145915 -Ref: Derived Files-Footnote-31146511 -Node: Future Extensions1146625 -Node: Implementation Limitations1147231 -Node: Extension Design1148479 -Node: Old Extension Problems1149633 -Ref: Old Extension Problems-Footnote-11151150 -Node: Extension New Mechanism Goals1151207 -Ref: Extension New Mechanism Goals-Footnote-11154567 -Node: Extension Other Design Decisions1154756 -Node: Extension Future Growth1156862 -Node: Old Extension Mechanism1157698 -Node: Notes summary1159460 -Node: Basic Concepts1160646 -Node: Basic High Level1161327 -Ref: figure-general-flow1161599 -Ref: figure-process-flow1162198 -Ref: Basic High Level-Footnote-11165427 -Node: Basic Data Typing1165612 -Node: Glossary1168940 -Node: Copying1194092 -Node: GNU Free Documentation License1231648 -Node: Index1256784 +Node: File Checking624563 +Ref: File Checking-Footnote-1625695 +Node: Empty Files625896 +Node: Ignoring Assigns627875 +Node: Getopt Function629429 +Ref: Getopt Function-Footnote-1640732 +Node: Passwd Functions640935 +Ref: Passwd Functions-Footnote-1649914 +Node: Group Functions650002 +Ref: Group Functions-Footnote-1657943 +Node: Walking Arrays658156 +Node: Library Functions Summary659759 +Node: Library exercises661147 +Node: Sample Programs662427 +Node: Running Examples663197 +Node: Clones663925 +Node: Cut Program665149 +Node: Egrep Program675017 +Ref: Egrep Program-Footnote-1682988 +Node: Id Program683098 +Node: Split Program686762 +Ref: Split Program-Footnote-1690300 +Node: Tee Program690428 +Node: Uniq Program693235 +Node: Wc Program700665 +Ref: Wc Program-Footnote-1704930 +Node: Miscellaneous Programs705022 +Node: Dupword Program706235 +Node: Alarm Program708266 +Node: Translate Program713080 +Ref: Translate Program-Footnote-1717471 +Ref: Translate Program-Footnote-2717741 +Node: Labels Program717875 +Ref: Labels Program-Footnote-1721246 +Node: Word Sorting721330 +Node: History Sorting725373 +Node: Extract Program727209 +Node: Simple Sed734745 +Node: Igawk Program737807 +Ref: Igawk Program-Footnote-1752118 +Ref: Igawk Program-Footnote-2752319 +Node: Anagram Program752457 +Node: Signature Program755525 +Node: Programs Summary756772 +Node: Programs Exercises757987 +Node: Advanced Features761638 +Node: Nondecimal Data763586 +Node: Array Sorting765163 +Node: Controlling Array Traversal765860 +Node: Array Sorting Functions774140 +Ref: Array Sorting Functions-Footnote-1778047 +Node: Two-way I/O778241 +Ref: Two-way I/O-Footnote-1783757 +Node: TCP/IP Networking783839 +Node: Profiling786683 +Node: Advanced Features Summary794225 +Node: Internationalization796089 +Node: I18N and L10N797569 +Node: Explaining gettext798255 +Ref: Explaining gettext-Footnote-1803395 +Ref: Explaining gettext-Footnote-2803579 +Node: Programmer i18n803744 +Node: Translator i18n807969 +Node: String Extraction808763 +Ref: String Extraction-Footnote-1809724 +Node: Printf Ordering809810 +Ref: Printf Ordering-Footnote-1812592 +Node: I18N Portability812656 +Ref: I18N Portability-Footnote-1815105 +Node: I18N Example815168 +Ref: I18N Example-Footnote-1817890 +Node: Gawk I18N817962 +Node: I18N Summary818600 +Node: Debugger819939 +Node: Debugging820961 +Node: Debugging Concepts821402 +Node: Debugging Terms823258 +Node: Awk Debugging825855 +Node: Sample Debugging Session826747 +Node: Debugger Invocation827267 +Node: Finding The Bug828600 +Node: List of Debugger Commands835082 +Node: Breakpoint Control836414 +Node: Debugger Execution Control840078 +Node: Viewing And Changing Data843438 +Node: Execution Stack846796 +Node: Debugger Info848309 +Node: Miscellaneous Debugger Commands852303 +Node: Readline Support857487 +Node: Limitations858379 +Node: Debugging Summary860653 +Node: Arbitrary Precision Arithmetic861817 +Node: Computer Arithmetic863146 +Ref: Computer Arithmetic-Footnote-1867533 +Node: Math Definitions867590 +Ref: table-ieee-formats870474 +Node: MPFR features870978 +Node: FP Math Caution872620 +Ref: FP Math Caution-Footnote-1873661 +Node: Inexactness of computations874030 +Node: Inexact representation874978 +Node: Comparing FP Values876333 +Node: Errors accumulate877297 +Node: Getting Accuracy878730 +Node: Try To Round881389 +Node: Setting precision882288 +Ref: table-predefined-precision-strings882970 +Node: Setting the rounding mode884763 +Ref: table-gawk-rounding-modes885127 +Ref: Setting the rounding mode-Footnote-1888581 +Node: Arbitrary Precision Integers888760 +Ref: Arbitrary Precision Integers-Footnote-1891763 +Node: POSIX Floating Point Problems891912 +Ref: POSIX Floating Point Problems-Footnote-1895788 +Node: Floating point summary895826 +Node: Dynamic Extensions898043 +Node: Extension Intro899595 +Node: Plugin License900860 +Node: Extension Mechanism Outline901545 +Ref: figure-load-extension901969 +Ref: figure-load-new-function903454 +Ref: figure-call-new-function904456 +Node: Extension API Description906440 +Node: Extension API Functions Introduction907890 +Node: General Data Types912755 +Ref: General Data Types-Footnote-1918448 +Node: Requesting Values918747 +Ref: table-value-types-returned919484 +Node: Memory Allocation Functions920442 +Ref: Memory Allocation Functions-Footnote-1923189 +Node: Constructor Functions923285 +Node: Registration Functions925043 +Node: Extension Functions925728 +Node: Exit Callback Functions928030 +Node: Extension Version String929279 +Node: Input Parsers929929 +Node: Output Wrappers939743 +Node: Two-way processors944259 +Node: Printing Messages946463 +Ref: Printing Messages-Footnote-1947540 +Node: Updating `ERRNO'947692 +Node: Accessing Parameters948431 +Node: Symbol Table Access949661 +Node: Symbol table by name950175 +Node: Symbol table by cookie952151 +Ref: Symbol table by cookie-Footnote-1956284 +Node: Cached values956347 +Ref: Cached values-Footnote-1959851 +Node: Array Manipulation959942 +Ref: Array Manipulation-Footnote-1961040 +Node: Array Data Types961079 +Ref: Array Data Types-Footnote-1963782 +Node: Array Functions963874 +Node: Flattening Arrays967748 +Node: Creating Arrays974600 +Node: Extension API Variables979331 +Node: Extension Versioning979967 +Node: Extension API Informational Variables981868 +Node: Extension API Boilerplate982954 +Node: Finding Extensions986758 +Node: Extension Example987318 +Node: Internal File Description988048 +Node: Internal File Ops992139 +Ref: Internal File Ops-Footnote-11003571 +Node: Using Internal File Ops1003711 +Ref: Using Internal File Ops-Footnote-11006058 +Node: Extension Samples1006326 +Node: Extension Sample File Functions1007850 +Node: Extension Sample Fnmatch1015418 +Node: Extension Sample Fork1016900 +Node: Extension Sample Inplace1018113 +Node: Extension Sample Ord1019788 +Node: Extension Sample Readdir1020624 +Ref: table-readdir-file-types1021480 +Node: Extension Sample Revout1022279 +Node: Extension Sample Rev2way1022870 +Node: Extension Sample Read write array1023611 +Node: Extension Sample Readfile1025490 +Node: Extension Sample API Tests1026590 +Node: Extension Sample Time1027115 +Node: gawkextlib1028430 +Node: Extension summary1031243 +Node: Extension Exercises1034936 +Node: Language History1035658 +Node: V7/SVR3.11037301 +Node: SVR41039621 +Node: POSIX1041063 +Node: BTL1042449 +Node: POSIX/GNU1043183 +Node: Feature History1048926 +Node: Common Extensions1062056 +Node: Ranges and Locales1063368 +Ref: Ranges and Locales-Footnote-11067985 +Ref: Ranges and Locales-Footnote-21068012 +Ref: Ranges and Locales-Footnote-31068246 +Node: Contributors1068467 +Node: History summary1073892 +Node: Installation1075261 +Node: Gawk Distribution1076212 +Node: Getting1076696 +Node: Extracting1077520 +Node: Distribution contents1079162 +Node: Unix Installation1084879 +Node: Quick Installation1085496 +Node: Additional Configuration Options1087938 +Node: Configuration Philosophy1089676 +Node: Non-Unix Installation1092027 +Node: PC Installation1092485 +Node: PC Binary Installation1093796 +Node: PC Compiling1095644 +Ref: PC Compiling-Footnote-11098643 +Node: PC Testing1098748 +Node: PC Using1099924 +Node: Cygwin1104082 +Node: MSYS1104891 +Node: VMS Installation1105405 +Node: VMS Compilation1106201 +Ref: VMS Compilation-Footnote-11107423 +Node: VMS Dynamic Extensions1107481 +Node: VMS Installation Details1108854 +Node: VMS Running1111106 +Node: VMS GNV1113940 +Node: VMS Old Gawk1114663 +Node: Bugs1115133 +Node: Other Versions1119137 +Node: Installation summary1125392 +Node: Notes1126448 +Node: Compatibility Mode1127313 +Node: Additions1128095 +Node: Accessing The Source1129020 +Node: Adding Code1130456 +Node: New Ports1136634 +Node: Derived Files1141115 +Ref: Derived Files-Footnote-11146196 +Ref: Derived Files-Footnote-21146230 +Ref: Derived Files-Footnote-31146826 +Node: Future Extensions1146940 +Node: Implementation Limitations1147546 +Node: Extension Design1148794 +Node: Old Extension Problems1149948 +Ref: Old Extension Problems-Footnote-11151465 +Node: Extension New Mechanism Goals1151522 +Ref: Extension New Mechanism Goals-Footnote-11154882 +Node: Extension Other Design Decisions1155071 +Node: Extension Future Growth1157177 +Node: Old Extension Mechanism1158013 +Node: Notes summary1159775 +Node: Basic Concepts1160961 +Node: Basic High Level1161642 +Ref: figure-general-flow1161914 +Ref: figure-process-flow1162513 +Ref: Basic High Level-Footnote-11165742 +Node: Basic Data Typing1165927 +Node: Glossary1169255 +Node: Copying1194407 +Node: GNU Free Documentation License1231963 +Node: Index1257099  End Tag Table -- cgit v1.2.3 From 1059680510215830da7e2eb91e72e4623d460d19 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 13 Aug 2014 06:30:39 +0300 Subject: Doc updates. Start on reviewer comments. --- doc/gawk.info | 1160 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 577 insertions(+), 583 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 5a07d84d..8035803b 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1159,13 +1159,6 @@ system for Intel(R), Power Architecture, Sun SPARC, IBM S/390, and other systems.(2) Many GNU/Linux distributions are available for download from the Internet. - (There are numerous other freely available, Unix-like operating -systems based on the Berkeley Software Distribution, and some of them -use recent versions of `gawk' for their versions of `awk'. NetBSD -(http://www.netbsd.org), FreeBSD (http://www.freebsd.org), and OpenBSD -(http://www.openbsd.org) are three of the most popular ones, but there -are others.) - The Info file itself has gone through a number of previous editions. Paul Rubin wrote the very first draft of `The GAWK Manual'; it was around 40 pages in size. Diane Close and Richard Stallman improved it, @@ -1300,16 +1293,26 @@ be a pleasure working with this team of fine people. Notable code and documentation contributions were made by a number of people. *Note Contributors::, for the full list. - Thanks to Patrice Dumas for the new `makeinfo' program. Thanks to + Thanks to Patrice Dumas for the new `makeinfo' program. Thanks to Karl Berry who continues to work to keep the Texinfo markup language sane. + Robert P.J. Day, Michael Brennan and Brian Kernighan kindly acted as +reviewers for the 2015 edition of this Info file. Their feedback helped +improve the final work. + I would like to thank Brian Kernighan for invaluable assistance during the testing and debugging of `gawk', and for ongoing help and advice in clarifying numerous points about the language. We could not have done nearly as good a job on either `gawk' or its documentation without his help. + Brian is in a class by himself as a programmer and technical author. +I have to thank him (yet again) for his ongoing friendship and the +role-model he has been for me for close to 30 years! Having him as a +reviewer is an exciting privilege. It has also been extremely +humbling... + I must thank my wonderful wife, Miriam, for her patience through the many versions of this project, for her proofreading, and for sharing me with the computer. I would like to thank my parents for their love, @@ -1927,12 +1930,13 @@ different ways to do the same things shown here: * Print the length of the longest line in `data': - expand data | awk '{ if (x < length()) x = length() } + expand data | awk '{ if (x < length($0)) x = length($0) } END { print "maximum line length is " x }' + This example differs slightly from the first example in this list: The input is processed by the `expand' utility to change TABs into spaces, so the widths compared are actually the right-margin - columns. + columns, as opposed to the number of input characters on each line. * Print every line that has at least one field: @@ -6786,9 +6790,9 @@ message to standard error in an `awk' program is as follows: This works by opening a pipeline to a shell command that can access the standard error stream that it inherits from the `awk' process. This is -far from elegant, and it is also inefficient, because it requires a -separate process. So people writing `awk' programs often don't do -this. Instead, they send the error messages to the screen, like this: +far from elegant, and it also requires a separate process. So people +writing `awk' programs often don't do this. Instead, they send the +error messages to the screen, like this: print "Serious error detected!" > "/dev/tty" @@ -7803,8 +7807,9 @@ Otherwise, it's parsed as follows: => -12 (-24) => -12-24 - As mentioned earlier, when doing concatenation, _parenthesize_. -Otherwise, you're never quite sure what you'll get. + As mentioned earlier, when mixing concatenation with other +operators, _parenthesize_. Otherwise, you're never quite sure what +you'll get. ---------- Footnotes ---------- @@ -8138,16 +8143,11 @@ File: gawk.info, Node: Variable Typing, Next: Comparison Operators, Up: Typin 6.3.2.1 String Type Versus Numeric Type ....................................... -The 1992 POSIX standard introduced the concept of a "numeric string", -which is simply a string that looks like a number--for example, -`" +2"'. This concept is used for determining the type of a variable. -The type of the variable is important because the types of two variables -determine how they are compared. - - The various versions of the POSIX standard did not get the rules -quite right for several editions. Fortunately, as of at least the 2008 -standard (and possibly earlier), the standard has been fixed, and -variable typing follows these rules:(1) +The POSIX standard introduced the concept of a "numeric string", which +is simply a string that looks like a number--for example, `" +2"'. +This concept is used for determining the type of a variable. The type +of the variable is important because the types of two variables +determine how they are compared. Variable typing follows these rules: * A numeric constant or the result of a numeric operation has the NUMERIC attribute. @@ -8225,11 +8225,6 @@ comparison between the two different constants is true, `0' otherwise: $ echo ' +3.14' | gawk '{ print $1 == 3.14 }' True -| 1 - ---------- Footnotes ---------- - - (1) `gawk' has followed these rules for many years, and it is -gratifying that the POSIX standard is also now correct. -  File: gawk.info, Node: Comparison Operators, Next: POSIX String Comparison, Prev: Variable Typing, Up: Typing and Comparison @@ -11695,7 +11690,8 @@ brackets ([ ]): `log(X)' Return the natural logarithm of X, if X is positive; otherwise, - report an error. + return `NaN' ("not a number") on IEEE 754 systems. Additionally, + `gawk' prints a warning message when `x' is negative. `rand()' Return a random number. The values of `rand()' are uniformly @@ -31198,7 +31194,6 @@ Index * algorithms: Basic High Level. (line 68) * allocating memory for extensions: Memory Allocation Functions. (line 6) -* Alpha (DEC): Manual History. (line 28) * amazing awk assembler (aaa): Glossary. (line 11) * amazingly workable formatter (awf): Glossary. (line 24) * ambiguity, syntactic: /= operator vs. /=.../ regexp constant: Assignment Ops. @@ -31614,7 +31609,7 @@ Index (line 131) * close() function, two-way pipes and: Two-way I/O. (line 77) * Close, Diane <1>: Contributors. (line 20) -* Close, Diane: Manual History. (line 41) +* Close, Diane: Manual History. (line 34) * Collado, Manuel: Acknowledgments. (line 60) * collating elements: Bracket Expressions. (line 77) * collating symbols: Bracket Expressions. (line 84) @@ -32399,7 +32394,7 @@ Index (line 47) * functions, user-defined, next/nextfile statements and: Next Statement. (line 45) -* G-d: Acknowledgments. (line 82) +* G-d: Acknowledgments. (line 92) * Garfinkle, Scott: Contributors. (line 34) * gawk program, dynamic profiling: Profiling. (line 179) * gawk version: Auto-set. (line 199) @@ -32725,7 +32720,7 @@ Index * Kernighan, Brian <6>: Library Functions. (line 12) * Kernighan, Brian <7>: Concatenation. (line 6) * Kernighan, Brian <8>: Getline/Pipe. (line 6) -* Kernighan, Brian <9>: Acknowledgments. (line 76) +* Kernighan, Brian <9>: Acknowledgments. (line 80) * Kernighan, Brian <10>: Conventions. (line 34) * Kernighan, Brian: History. (line 17) * kill command, dynamic profiling: Profiling. (line 188) @@ -33279,12 +33274,12 @@ Index * Rakitzis, Byron: History Sorting. (line 25) * Ramey, Chet <1>: General Data Types. (line 6) * Ramey, Chet: Acknowledgments. (line 60) -* rand: Numeric Functions. (line 34) +* rand: Numeric Functions. (line 35) * random numbers, Cliff: Cliff Random Function. (line 6) * random numbers, rand()/srand() functions: Numeric Functions. - (line 34) -* random numbers, seed of: Numeric Functions. (line 64) + (line 35) +* random numbers, seed of: Numeric Functions. (line 65) * range expressions (regexps): Bracket Expressions. (line 6) * range patterns: Ranges. (line 6) * range patterns, line continuation and: Ranges. (line 65) @@ -33406,11 +33401,11 @@ Index * Robbins, Arnold: Command Line Field Separator. (line 73) * Robbins, Bill: Getline/Pipe. (line 39) -* Robbins, Harry: Acknowledgments. (line 82) -* Robbins, Jean: Acknowledgments. (line 82) +* Robbins, Harry: Acknowledgments. (line 92) +* Robbins, Jean: Acknowledgments. (line 92) * Robbins, Miriam <1>: Passwd Functions. (line 90) * Robbins, Miriam <2>: Getline/Pipe. (line 39) -* Robbins, Miriam: Acknowledgments. (line 82) +* Robbins, Miriam: Acknowledgments. (line 92) * Rommel, Kai Uwe: Contributors. (line 42) * round to nearest integer: Numeric Functions. (line 23) * round() user-defined function: Round Function. (line 16) @@ -33462,7 +33457,7 @@ Index * sed utility <2>: Simple Sed. (line 6) * sed utility: Field Splitting Summary. (line 46) -* seeding random number generator: Numeric Functions. (line 64) +* seeding random number generator: Numeric Functions. (line 65) * semicolon (;), AWKPATH variable and: PC Using. (line 10) * semicolon (;), separating statements in actions <1>: Statements. (line 10) @@ -33564,8 +33559,8 @@ Index * SIGUSR1 signal, for dynamic profiling: Profiling. (line 188) * silent debugger command: Debugger Execution Control. (line 10) -* sin: Numeric Functions. (line 75) -* sine: Numeric Functions. (line 75) +* sin: Numeric Functions. (line 76) +* sine: Numeric Functions. (line 76) * single quote ('): One-shot. (line 15) * single quote (') in gawk command lines: Long. (line 33) * single quote ('), in shell commands: Quoting. (line 48) @@ -33615,10 +33610,10 @@ Index * sprintf() function, OFMT variable and: User-modified. (line 114) * sprintf() function, print/printf statements and: Round Function. (line 6) -* sqrt: Numeric Functions. (line 78) +* sqrt: Numeric Functions. (line 79) * square brackets ([]), regexp operator: Regexp Operators. (line 56) -* square root: Numeric Functions. (line 78) -* srand: Numeric Functions. (line 82) +* square root: Numeric Functions. (line 79) +* srand: Numeric Functions. (line 83) * stack frame: Debugging Terms. (line 10) * Stallman, Richard <1>: Glossary. (line 296) * Stallman, Richard <2>: Contributors. (line 23) @@ -33971,541 +33966,540 @@ Node: This Manual53600 Ref: This Manual-Footnote-159379 Node: Conventions59479 Node: Manual History61635 -Ref: Manual History-Footnote-165074 -Ref: Manual History-Footnote-265115 -Node: How To Contribute65189 -Node: Acknowledgments66428 -Node: Getting Started70724 -Node: Running gawk73158 -Node: One-shot74348 -Node: Read Terminal75573 -Ref: Read Terminal-Footnote-177223 -Ref: Read Terminal-Footnote-277499 -Node: Long77670 -Node: Executable Scripts79046 -Ref: Executable Scripts-Footnote-180879 -Ref: Executable Scripts-Footnote-280981 -Node: Comments81528 -Node: Quoting84001 -Node: DOS Quoting89317 -Node: Sample Data Files89992 -Node: Very Simple92507 -Node: Two Rules97145 -Node: More Complex99039 -Ref: More Complex-Footnote-1101971 -Node: Statements/Lines102056 -Ref: Statements/Lines-Footnote-1106512 -Node: Other Features106777 -Node: When107705 -Node: Intro Summary109875 -Node: Invoking Gawk110641 -Node: Command Line112156 -Node: Options112947 -Ref: Options-Footnote-1128776 -Node: Other Arguments128801 -Node: Naming Standard Input131463 -Node: Environment Variables132557 -Node: AWKPATH Variable133115 -Ref: AWKPATH Variable-Footnote-1135987 -Ref: AWKPATH Variable-Footnote-2136032 -Node: AWKLIBPATH Variable136292 -Node: Other Environment Variables137051 -Node: Exit Status140706 -Node: Include Files141381 -Node: Loading Shared Libraries144959 -Node: Obsolete146343 -Node: Undocumented147040 -Node: Invoking Summary147307 -Node: Regexp148887 -Node: Regexp Usage150337 -Node: Escape Sequences152370 -Node: Regexp Operators158037 -Ref: Regexp Operators-Footnote-1165517 -Ref: Regexp Operators-Footnote-2165664 -Node: Bracket Expressions165762 -Ref: table-char-classes167652 -Node: GNU Regexp Operators170592 -Node: Case-sensitivity174315 -Ref: Case-sensitivity-Footnote-1177207 -Ref: Case-sensitivity-Footnote-2177442 -Node: Leftmost Longest177550 -Node: Computed Regexps178751 -Node: Regexp Summary182123 -Node: Reading Files183594 -Node: Records185686 -Node: awk split records186429 -Node: gawk split records191287 -Ref: gawk split records-Footnote-1195808 -Node: Fields195845 -Ref: Fields-Footnote-1198809 -Node: Nonconstant Fields198895 -Ref: Nonconstant Fields-Footnote-1201125 -Node: Changing Fields201327 -Node: Field Separators207281 -Node: Default Field Splitting209983 -Node: Regexp Field Splitting211100 -Node: Single Character Fields214441 -Node: Command Line Field Separator215500 -Node: Full Line Fields218842 -Ref: Full Line Fields-Footnote-1219350 -Node: Field Splitting Summary219396 -Ref: Field Splitting Summary-Footnote-1222495 -Node: Constant Size222596 -Node: Splitting By Content227203 -Ref: Splitting By Content-Footnote-1230953 -Node: Multiple Line230993 -Ref: Multiple Line-Footnote-1236849 -Node: Getline237028 -Node: Plain Getline239244 -Node: Getline/Variable241339 -Node: Getline/File242486 -Node: Getline/Variable/File243870 -Ref: Getline/Variable/File-Footnote-1245469 -Node: Getline/Pipe245556 -Node: Getline/Variable/Pipe248255 -Node: Getline/Coprocess249362 -Node: Getline/Variable/Coprocess250614 -Node: Getline Notes251351 -Node: Getline Summary254155 -Ref: table-getline-variants254563 -Node: Read Timeout255475 -Ref: Read Timeout-Footnote-1259302 -Node: Command line directories259360 -Node: Input Summary260264 -Node: Input Exercises263401 -Node: Printing264134 -Node: Print265856 -Node: Print Examples267197 -Node: Output Separators269976 -Node: OFMT271992 -Node: Printf273350 -Node: Basic Printf274256 -Node: Control Letters275795 -Node: Format Modifiers279786 -Node: Printf Examples285813 -Node: Redirection288277 -Node: Special Files295249 -Node: Special FD295780 -Ref: Special FD-Footnote-1299404 -Node: Special Network299478 -Node: Special Caveats300328 -Node: Close Files And Pipes301124 -Ref: Close Files And Pipes-Footnote-1308285 -Ref: Close Files And Pipes-Footnote-2308433 -Node: Output Summary308583 -Node: Output exercises309580 -Node: Expressions310260 -Node: Values311445 -Node: Constants312121 -Node: Scalar Constants312801 -Ref: Scalar Constants-Footnote-1313660 -Node: Nondecimal-numbers313910 -Node: Regexp Constants316910 -Node: Using Constant Regexps317385 -Node: Variables320455 -Node: Using Variables321110 -Node: Assignment Options322834 -Node: Conversion324709 -Node: Strings And Numbers325233 -Ref: Strings And Numbers-Footnote-1328295 -Node: Locale influences conversions328404 -Ref: table-locale-affects331121 -Node: All Operators331709 -Node: Arithmetic Ops332339 -Node: Concatenation334844 -Ref: Concatenation-Footnote-1337640 -Node: Assignment Ops337760 -Ref: table-assign-ops342743 -Node: Increment Ops344060 -Node: Truth Values and Conditions347498 -Node: Truth Values348581 -Node: Typing and Comparison349630 -Node: Variable Typing350423 -Ref: Variable Typing-Footnote-1354323 -Node: Comparison Operators354445 -Ref: table-relational-ops354855 -Node: POSIX String Comparison358405 -Ref: POSIX String Comparison-Footnote-1359489 -Node: Boolean Ops359627 -Ref: Boolean Ops-Footnote-1363697 -Node: Conditional Exp363788 -Node: Function Calls365515 -Node: Precedence369395 -Node: Locales373064 -Node: Expressions Summary374695 -Node: Patterns and Actions377236 -Node: Pattern Overview378352 -Node: Regexp Patterns380029 -Node: Expression Patterns380572 -Node: Ranges384353 -Node: BEGIN/END387459 -Node: Using BEGIN/END388221 -Ref: Using BEGIN/END-Footnote-1390957 -Node: I/O And BEGIN/END391063 -Node: BEGINFILE/ENDFILE393348 -Node: Empty396279 -Node: Using Shell Variables396596 -Node: Action Overview398879 -Node: Statements401206 -Node: If Statement403054 -Node: While Statement404552 -Node: Do Statement406596 -Node: For Statement407752 -Node: Switch Statement410904 -Node: Break Statement413007 -Node: Continue Statement415062 -Node: Next Statement416855 -Node: Nextfile Statement419245 -Node: Exit Statement421900 -Node: Built-in Variables424304 -Node: User-modified425431 -Ref: User-modified-Footnote-1433120 -Node: Auto-set433182 -Ref: Auto-set-Footnote-1445764 -Ref: Auto-set-Footnote-2445969 -Node: ARGC and ARGV446025 -Node: Pattern Action Summary449879 -Node: Arrays452102 -Node: Array Basics453651 -Node: Array Intro454477 -Ref: figure-array-elements456450 -Node: Reference to Elements458857 -Node: Assigning Elements461130 -Node: Array Example461621 -Node: Scanning an Array463353 -Node: Controlling Scanning466368 -Ref: Controlling Scanning-Footnote-1471541 -Node: Delete471857 -Ref: Delete-Footnote-1474622 -Node: Numeric Array Subscripts474679 -Node: Uninitialized Subscripts476862 -Node: Multidimensional478487 -Node: Multiscanning481580 -Node: Arrays of Arrays483169 -Node: Arrays Summary487832 -Node: Functions489937 -Node: Built-in490810 -Node: Calling Built-in491888 -Node: Numeric Functions493876 -Ref: Numeric Functions-Footnote-1497710 -Ref: Numeric Functions-Footnote-2498067 -Ref: Numeric Functions-Footnote-3498115 -Node: String Functions498384 -Ref: String Functions-Footnote-1521395 -Ref: String Functions-Footnote-2521524 -Ref: String Functions-Footnote-3521772 -Node: Gory Details521859 -Ref: table-sub-escapes523528 -Ref: table-sub-posix-92524882 -Ref: table-sub-proposed526233 -Ref: table-posix-sub527587 -Ref: table-gensub-escapes529132 -Ref: Gory Details-Footnote-1530308 -Ref: Gory Details-Footnote-2530359 -Node: I/O Functions530510 -Ref: I/O Functions-Footnote-1537633 -Node: Time Functions537780 -Ref: Time Functions-Footnote-1548244 -Ref: Time Functions-Footnote-2548312 -Ref: Time Functions-Footnote-3548470 -Ref: Time Functions-Footnote-4548581 -Ref: Time Functions-Footnote-5548693 -Ref: Time Functions-Footnote-6548920 -Node: Bitwise Functions549186 -Ref: table-bitwise-ops549748 -Ref: Bitwise Functions-Footnote-1553993 -Node: Type Functions554177 -Node: I18N Functions555319 -Node: User-defined556964 -Node: Definition Syntax557768 -Ref: Definition Syntax-Footnote-1562947 -Node: Function Example563016 -Ref: Function Example-Footnote-1565660 -Node: Function Caveats565682 -Node: Calling A Function566200 -Node: Variable Scope567155 -Node: Pass By Value/Reference570143 -Node: Return Statement573651 -Node: Dynamic Typing576635 -Node: Indirect Calls577564 -Node: Functions Summary587277 -Node: Library Functions589816 -Ref: Library Functions-Footnote-1593434 -Ref: Library Functions-Footnote-2593577 -Node: Library Names593748 -Ref: Library Names-Footnote-1597221 -Ref: Library Names-Footnote-2597441 -Node: General Functions597527 -Node: Strtonum Function598555 -Node: Assert Function601335 -Node: Round Function604661 -Node: Cliff Random Function606202 -Node: Ordinal Functions607218 -Ref: Ordinal Functions-Footnote-1610295 -Ref: Ordinal Functions-Footnote-2610547 -Node: Join Function610758 -Ref: Join Function-Footnote-1612529 -Node: Getlocaltime Function612729 -Node: Readfile Function616465 -Node: Data File Management618304 -Node: Filetrans Function618936 -Node: Rewind Function623005 -Node: File Checking624563 -Ref: File Checking-Footnote-1625695 -Node: Empty Files625896 -Node: Ignoring Assigns627875 -Node: Getopt Function629429 -Ref: Getopt Function-Footnote-1640732 -Node: Passwd Functions640935 -Ref: Passwd Functions-Footnote-1649914 -Node: Group Functions650002 -Ref: Group Functions-Footnote-1657943 -Node: Walking Arrays658156 -Node: Library Functions Summary659759 -Node: Library exercises661147 -Node: Sample Programs662427 -Node: Running Examples663197 -Node: Clones663925 -Node: Cut Program665149 -Node: Egrep Program675017 -Ref: Egrep Program-Footnote-1682988 -Node: Id Program683098 -Node: Split Program686762 -Ref: Split Program-Footnote-1690300 -Node: Tee Program690428 -Node: Uniq Program693235 -Node: Wc Program700665 -Ref: Wc Program-Footnote-1704930 -Node: Miscellaneous Programs705022 -Node: Dupword Program706235 -Node: Alarm Program708266 -Node: Translate Program713080 -Ref: Translate Program-Footnote-1717471 -Ref: Translate Program-Footnote-2717741 -Node: Labels Program717875 -Ref: Labels Program-Footnote-1721246 -Node: Word Sorting721330 -Node: History Sorting725373 -Node: Extract Program727209 -Node: Simple Sed734745 -Node: Igawk Program737807 -Ref: Igawk Program-Footnote-1752118 -Ref: Igawk Program-Footnote-2752319 -Node: Anagram Program752457 -Node: Signature Program755525 -Node: Programs Summary756772 -Node: Programs Exercises757987 -Node: Advanced Features761638 -Node: Nondecimal Data763586 -Node: Array Sorting765163 -Node: Controlling Array Traversal765860 -Node: Array Sorting Functions774140 -Ref: Array Sorting Functions-Footnote-1778047 -Node: Two-way I/O778241 -Ref: Two-way I/O-Footnote-1783757 -Node: TCP/IP Networking783839 -Node: Profiling786683 -Node: Advanced Features Summary794225 -Node: Internationalization796089 -Node: I18N and L10N797569 -Node: Explaining gettext798255 -Ref: Explaining gettext-Footnote-1803395 -Ref: Explaining gettext-Footnote-2803579 -Node: Programmer i18n803744 -Node: Translator i18n807969 -Node: String Extraction808763 -Ref: String Extraction-Footnote-1809724 -Node: Printf Ordering809810 -Ref: Printf Ordering-Footnote-1812592 -Node: I18N Portability812656 -Ref: I18N Portability-Footnote-1815105 -Node: I18N Example815168 -Ref: I18N Example-Footnote-1817890 -Node: Gawk I18N817962 -Node: I18N Summary818600 -Node: Debugger819939 -Node: Debugging820961 -Node: Debugging Concepts821402 -Node: Debugging Terms823258 -Node: Awk Debugging825855 -Node: Sample Debugging Session826747 -Node: Debugger Invocation827267 -Node: Finding The Bug828600 -Node: List of Debugger Commands835082 -Node: Breakpoint Control836414 -Node: Debugger Execution Control840078 -Node: Viewing And Changing Data843438 -Node: Execution Stack846796 -Node: Debugger Info848309 -Node: Miscellaneous Debugger Commands852303 -Node: Readline Support857487 -Node: Limitations858379 -Node: Debugging Summary860653 -Node: Arbitrary Precision Arithmetic861817 -Node: Computer Arithmetic863146 -Ref: Computer Arithmetic-Footnote-1867533 -Node: Math Definitions867590 -Ref: table-ieee-formats870474 -Node: MPFR features870978 -Node: FP Math Caution872620 -Ref: FP Math Caution-Footnote-1873661 -Node: Inexactness of computations874030 -Node: Inexact representation874978 -Node: Comparing FP Values876333 -Node: Errors accumulate877297 -Node: Getting Accuracy878730 -Node: Try To Round881389 -Node: Setting precision882288 -Ref: table-predefined-precision-strings882970 -Node: Setting the rounding mode884763 -Ref: table-gawk-rounding-modes885127 -Ref: Setting the rounding mode-Footnote-1888581 -Node: Arbitrary Precision Integers888760 -Ref: Arbitrary Precision Integers-Footnote-1891763 -Node: POSIX Floating Point Problems891912 -Ref: POSIX Floating Point Problems-Footnote-1895788 -Node: Floating point summary895826 -Node: Dynamic Extensions898043 -Node: Extension Intro899595 -Node: Plugin License900860 -Node: Extension Mechanism Outline901545 -Ref: figure-load-extension901969 -Ref: figure-load-new-function903454 -Ref: figure-call-new-function904456 -Node: Extension API Description906440 -Node: Extension API Functions Introduction907890 -Node: General Data Types912755 -Ref: General Data Types-Footnote-1918448 -Node: Requesting Values918747 -Ref: table-value-types-returned919484 -Node: Memory Allocation Functions920442 -Ref: Memory Allocation Functions-Footnote-1923189 -Node: Constructor Functions923285 -Node: Registration Functions925043 -Node: Extension Functions925728 -Node: Exit Callback Functions928030 -Node: Extension Version String929279 -Node: Input Parsers929929 -Node: Output Wrappers939743 -Node: Two-way processors944259 -Node: Printing Messages946463 -Ref: Printing Messages-Footnote-1947540 -Node: Updating `ERRNO'947692 -Node: Accessing Parameters948431 -Node: Symbol Table Access949661 -Node: Symbol table by name950175 -Node: Symbol table by cookie952151 -Ref: Symbol table by cookie-Footnote-1956284 -Node: Cached values956347 -Ref: Cached values-Footnote-1959851 -Node: Array Manipulation959942 -Ref: Array Manipulation-Footnote-1961040 -Node: Array Data Types961079 -Ref: Array Data Types-Footnote-1963782 -Node: Array Functions963874 -Node: Flattening Arrays967748 -Node: Creating Arrays974600 -Node: Extension API Variables979331 -Node: Extension Versioning979967 -Node: Extension API Informational Variables981868 -Node: Extension API Boilerplate982954 -Node: Finding Extensions986758 -Node: Extension Example987318 -Node: Internal File Description988048 -Node: Internal File Ops992139 -Ref: Internal File Ops-Footnote-11003571 -Node: Using Internal File Ops1003711 -Ref: Using Internal File Ops-Footnote-11006058 -Node: Extension Samples1006326 -Node: Extension Sample File Functions1007850 -Node: Extension Sample Fnmatch1015418 -Node: Extension Sample Fork1016900 -Node: Extension Sample Inplace1018113 -Node: Extension Sample Ord1019788 -Node: Extension Sample Readdir1020624 -Ref: table-readdir-file-types1021480 -Node: Extension Sample Revout1022279 -Node: Extension Sample Rev2way1022870 -Node: Extension Sample Read write array1023611 -Node: Extension Sample Readfile1025490 -Node: Extension Sample API Tests1026590 -Node: Extension Sample Time1027115 -Node: gawkextlib1028430 -Node: Extension summary1031243 -Node: Extension Exercises1034936 -Node: Language History1035658 -Node: V7/SVR3.11037301 -Node: SVR41039621 -Node: POSIX1041063 -Node: BTL1042449 -Node: POSIX/GNU1043183 -Node: Feature History1048926 -Node: Common Extensions1062056 -Node: Ranges and Locales1063368 -Ref: Ranges and Locales-Footnote-11067985 -Ref: Ranges and Locales-Footnote-21068012 -Ref: Ranges and Locales-Footnote-31068246 -Node: Contributors1068467 -Node: History summary1073892 -Node: Installation1075261 -Node: Gawk Distribution1076212 -Node: Getting1076696 -Node: Extracting1077520 -Node: Distribution contents1079162 -Node: Unix Installation1084879 -Node: Quick Installation1085496 -Node: Additional Configuration Options1087938 -Node: Configuration Philosophy1089676 -Node: Non-Unix Installation1092027 -Node: PC Installation1092485 -Node: PC Binary Installation1093796 -Node: PC Compiling1095644 -Ref: PC Compiling-Footnote-11098643 -Node: PC Testing1098748 -Node: PC Using1099924 -Node: Cygwin1104082 -Node: MSYS1104891 -Node: VMS Installation1105405 -Node: VMS Compilation1106201 -Ref: VMS Compilation-Footnote-11107423 -Node: VMS Dynamic Extensions1107481 -Node: VMS Installation Details1108854 -Node: VMS Running1111106 -Node: VMS GNV1113940 -Node: VMS Old Gawk1114663 -Node: Bugs1115133 -Node: Other Versions1119137 -Node: Installation summary1125392 -Node: Notes1126448 -Node: Compatibility Mode1127313 -Node: Additions1128095 -Node: Accessing The Source1129020 -Node: Adding Code1130456 -Node: New Ports1136634 -Node: Derived Files1141115 -Ref: Derived Files-Footnote-11146196 -Ref: Derived Files-Footnote-21146230 -Ref: Derived Files-Footnote-31146826 -Node: Future Extensions1146940 -Node: Implementation Limitations1147546 -Node: Extension Design1148794 -Node: Old Extension Problems1149948 -Ref: Old Extension Problems-Footnote-11151465 -Node: Extension New Mechanism Goals1151522 -Ref: Extension New Mechanism Goals-Footnote-11154882 -Node: Extension Other Design Decisions1155071 -Node: Extension Future Growth1157177 -Node: Old Extension Mechanism1158013 -Node: Notes summary1159775 -Node: Basic Concepts1160961 -Node: Basic High Level1161642 -Ref: figure-general-flow1161914 -Ref: figure-process-flow1162513 -Ref: Basic High Level-Footnote-11165742 -Node: Basic Data Typing1165927 -Node: Glossary1169255 -Node: Copying1194407 -Node: GNU Free Documentation License1231963 -Node: Index1257099 +Ref: Manual History-Footnote-164714 +Ref: Manual History-Footnote-264755 +Node: How To Contribute64829 +Node: Acknowledgments66068 +Node: Getting Started70816 +Node: Running gawk73250 +Node: One-shot74440 +Node: Read Terminal75665 +Ref: Read Terminal-Footnote-177315 +Ref: Read Terminal-Footnote-277591 +Node: Long77762 +Node: Executable Scripts79138 +Ref: Executable Scripts-Footnote-180971 +Ref: Executable Scripts-Footnote-281073 +Node: Comments81620 +Node: Quoting84093 +Node: DOS Quoting89409 +Node: Sample Data Files90084 +Node: Very Simple92599 +Node: Two Rules97372 +Node: More Complex99266 +Ref: More Complex-Footnote-1102198 +Node: Statements/Lines102283 +Ref: Statements/Lines-Footnote-1106739 +Node: Other Features107004 +Node: When107932 +Node: Intro Summary110102 +Node: Invoking Gawk110868 +Node: Command Line112383 +Node: Options113174 +Ref: Options-Footnote-1129003 +Node: Other Arguments129028 +Node: Naming Standard Input131690 +Node: Environment Variables132784 +Node: AWKPATH Variable133342 +Ref: AWKPATH Variable-Footnote-1136214 +Ref: AWKPATH Variable-Footnote-2136259 +Node: AWKLIBPATH Variable136519 +Node: Other Environment Variables137278 +Node: Exit Status140933 +Node: Include Files141608 +Node: Loading Shared Libraries145186 +Node: Obsolete146570 +Node: Undocumented147267 +Node: Invoking Summary147534 +Node: Regexp149114 +Node: Regexp Usage150564 +Node: Escape Sequences152597 +Node: Regexp Operators158264 +Ref: Regexp Operators-Footnote-1165744 +Ref: Regexp Operators-Footnote-2165891 +Node: Bracket Expressions165989 +Ref: table-char-classes167879 +Node: GNU Regexp Operators170819 +Node: Case-sensitivity174542 +Ref: Case-sensitivity-Footnote-1177434 +Ref: Case-sensitivity-Footnote-2177669 +Node: Leftmost Longest177777 +Node: Computed Regexps178978 +Node: Regexp Summary182350 +Node: Reading Files183821 +Node: Records185913 +Node: awk split records186656 +Node: gawk split records191514 +Ref: gawk split records-Footnote-1196035 +Node: Fields196072 +Ref: Fields-Footnote-1199036 +Node: Nonconstant Fields199122 +Ref: Nonconstant Fields-Footnote-1201352 +Node: Changing Fields201554 +Node: Field Separators207508 +Node: Default Field Splitting210210 +Node: Regexp Field Splitting211327 +Node: Single Character Fields214668 +Node: Command Line Field Separator215727 +Node: Full Line Fields219069 +Ref: Full Line Fields-Footnote-1219577 +Node: Field Splitting Summary219623 +Ref: Field Splitting Summary-Footnote-1222722 +Node: Constant Size222823 +Node: Splitting By Content227430 +Ref: Splitting By Content-Footnote-1231180 +Node: Multiple Line231220 +Ref: Multiple Line-Footnote-1237076 +Node: Getline237255 +Node: Plain Getline239471 +Node: Getline/Variable241566 +Node: Getline/File242713 +Node: Getline/Variable/File244097 +Ref: Getline/Variable/File-Footnote-1245696 +Node: Getline/Pipe245783 +Node: Getline/Variable/Pipe248482 +Node: Getline/Coprocess249589 +Node: Getline/Variable/Coprocess250841 +Node: Getline Notes251578 +Node: Getline Summary254382 +Ref: table-getline-variants254790 +Node: Read Timeout255702 +Ref: Read Timeout-Footnote-1259529 +Node: Command line directories259587 +Node: Input Summary260491 +Node: Input Exercises263628 +Node: Printing264361 +Node: Print266083 +Node: Print Examples267424 +Node: Output Separators270203 +Node: OFMT272219 +Node: Printf273577 +Node: Basic Printf274483 +Node: Control Letters276022 +Node: Format Modifiers280013 +Node: Printf Examples286040 +Node: Redirection288504 +Node: Special Files295476 +Node: Special FD296007 +Ref: Special FD-Footnote-1299604 +Node: Special Network299678 +Node: Special Caveats300528 +Node: Close Files And Pipes301324 +Ref: Close Files And Pipes-Footnote-1308485 +Ref: Close Files And Pipes-Footnote-2308633 +Node: Output Summary308783 +Node: Output exercises309780 +Node: Expressions310460 +Node: Values311645 +Node: Constants312321 +Node: Scalar Constants313001 +Ref: Scalar Constants-Footnote-1313860 +Node: Nondecimal-numbers314110 +Node: Regexp Constants317110 +Node: Using Constant Regexps317585 +Node: Variables320655 +Node: Using Variables321310 +Node: Assignment Options323034 +Node: Conversion324909 +Node: Strings And Numbers325433 +Ref: Strings And Numbers-Footnote-1328495 +Node: Locale influences conversions328604 +Ref: table-locale-affects331321 +Node: All Operators331909 +Node: Arithmetic Ops332539 +Node: Concatenation335044 +Ref: Concatenation-Footnote-1337863 +Node: Assignment Ops337983 +Ref: table-assign-ops342966 +Node: Increment Ops344283 +Node: Truth Values and Conditions347721 +Node: Truth Values348804 +Node: Typing and Comparison349853 +Node: Variable Typing350646 +Node: Comparison Operators354296 +Ref: table-relational-ops354706 +Node: POSIX String Comparison358256 +Ref: POSIX String Comparison-Footnote-1359340 +Node: Boolean Ops359478 +Ref: Boolean Ops-Footnote-1363548 +Node: Conditional Exp363639 +Node: Function Calls365366 +Node: Precedence369246 +Node: Locales372915 +Node: Expressions Summary374546 +Node: Patterns and Actions377087 +Node: Pattern Overview378203 +Node: Regexp Patterns379880 +Node: Expression Patterns380423 +Node: Ranges384204 +Node: BEGIN/END387310 +Node: Using BEGIN/END388072 +Ref: Using BEGIN/END-Footnote-1390808 +Node: I/O And BEGIN/END390914 +Node: BEGINFILE/ENDFILE393199 +Node: Empty396130 +Node: Using Shell Variables396447 +Node: Action Overview398730 +Node: Statements401057 +Node: If Statement402905 +Node: While Statement404403 +Node: Do Statement406447 +Node: For Statement407603 +Node: Switch Statement410755 +Node: Break Statement412858 +Node: Continue Statement414913 +Node: Next Statement416706 +Node: Nextfile Statement419096 +Node: Exit Statement421751 +Node: Built-in Variables424155 +Node: User-modified425282 +Ref: User-modified-Footnote-1432971 +Node: Auto-set433033 +Ref: Auto-set-Footnote-1445615 +Ref: Auto-set-Footnote-2445820 +Node: ARGC and ARGV445876 +Node: Pattern Action Summary449730 +Node: Arrays451953 +Node: Array Basics453502 +Node: Array Intro454328 +Ref: figure-array-elements456301 +Node: Reference to Elements458708 +Node: Assigning Elements460981 +Node: Array Example461472 +Node: Scanning an Array463204 +Node: Controlling Scanning466219 +Ref: Controlling Scanning-Footnote-1471392 +Node: Delete471708 +Ref: Delete-Footnote-1474473 +Node: Numeric Array Subscripts474530 +Node: Uninitialized Subscripts476713 +Node: Multidimensional478338 +Node: Multiscanning481431 +Node: Arrays of Arrays483020 +Node: Arrays Summary487683 +Node: Functions489788 +Node: Built-in490661 +Node: Calling Built-in491739 +Node: Numeric Functions493727 +Ref: Numeric Functions-Footnote-1497669 +Ref: Numeric Functions-Footnote-2498026 +Ref: Numeric Functions-Footnote-3498074 +Node: String Functions498343 +Ref: String Functions-Footnote-1521354 +Ref: String Functions-Footnote-2521483 +Ref: String Functions-Footnote-3521731 +Node: Gory Details521818 +Ref: table-sub-escapes523487 +Ref: table-sub-posix-92524841 +Ref: table-sub-proposed526192 +Ref: table-posix-sub527546 +Ref: table-gensub-escapes529091 +Ref: Gory Details-Footnote-1530267 +Ref: Gory Details-Footnote-2530318 +Node: I/O Functions530469 +Ref: I/O Functions-Footnote-1537592 +Node: Time Functions537739 +Ref: Time Functions-Footnote-1548203 +Ref: Time Functions-Footnote-2548271 +Ref: Time Functions-Footnote-3548429 +Ref: Time Functions-Footnote-4548540 +Ref: Time Functions-Footnote-5548652 +Ref: Time Functions-Footnote-6548879 +Node: Bitwise Functions549145 +Ref: table-bitwise-ops549707 +Ref: Bitwise Functions-Footnote-1553952 +Node: Type Functions554136 +Node: I18N Functions555278 +Node: User-defined556923 +Node: Definition Syntax557727 +Ref: Definition Syntax-Footnote-1562906 +Node: Function Example562975 +Ref: Function Example-Footnote-1565619 +Node: Function Caveats565641 +Node: Calling A Function566159 +Node: Variable Scope567114 +Node: Pass By Value/Reference570102 +Node: Return Statement573610 +Node: Dynamic Typing576594 +Node: Indirect Calls577523 +Node: Functions Summary587236 +Node: Library Functions589775 +Ref: Library Functions-Footnote-1593393 +Ref: Library Functions-Footnote-2593536 +Node: Library Names593707 +Ref: Library Names-Footnote-1597180 +Ref: Library Names-Footnote-2597400 +Node: General Functions597486 +Node: Strtonum Function598514 +Node: Assert Function601294 +Node: Round Function604620 +Node: Cliff Random Function606161 +Node: Ordinal Functions607177 +Ref: Ordinal Functions-Footnote-1610254 +Ref: Ordinal Functions-Footnote-2610506 +Node: Join Function610717 +Ref: Join Function-Footnote-1612488 +Node: Getlocaltime Function612688 +Node: Readfile Function616424 +Node: Data File Management618263 +Node: Filetrans Function618895 +Node: Rewind Function622964 +Node: File Checking624522 +Ref: File Checking-Footnote-1625654 +Node: Empty Files625855 +Node: Ignoring Assigns627834 +Node: Getopt Function629388 +Ref: Getopt Function-Footnote-1640691 +Node: Passwd Functions640894 +Ref: Passwd Functions-Footnote-1649873 +Node: Group Functions649961 +Ref: Group Functions-Footnote-1657902 +Node: Walking Arrays658115 +Node: Library Functions Summary659718 +Node: Library exercises661106 +Node: Sample Programs662386 +Node: Running Examples663156 +Node: Clones663884 +Node: Cut Program665108 +Node: Egrep Program674976 +Ref: Egrep Program-Footnote-1682947 +Node: Id Program683057 +Node: Split Program686721 +Ref: Split Program-Footnote-1690259 +Node: Tee Program690387 +Node: Uniq Program693194 +Node: Wc Program700624 +Ref: Wc Program-Footnote-1704889 +Node: Miscellaneous Programs704981 +Node: Dupword Program706194 +Node: Alarm Program708225 +Node: Translate Program713039 +Ref: Translate Program-Footnote-1717430 +Ref: Translate Program-Footnote-2717700 +Node: Labels Program717834 +Ref: Labels Program-Footnote-1721205 +Node: Word Sorting721289 +Node: History Sorting725332 +Node: Extract Program727168 +Node: Simple Sed734704 +Node: Igawk Program737766 +Ref: Igawk Program-Footnote-1752077 +Ref: Igawk Program-Footnote-2752278 +Node: Anagram Program752416 +Node: Signature Program755484 +Node: Programs Summary756731 +Node: Programs Exercises757946 +Node: Advanced Features761597 +Node: Nondecimal Data763545 +Node: Array Sorting765122 +Node: Controlling Array Traversal765819 +Node: Array Sorting Functions774099 +Ref: Array Sorting Functions-Footnote-1778006 +Node: Two-way I/O778200 +Ref: Two-way I/O-Footnote-1783716 +Node: TCP/IP Networking783798 +Node: Profiling786642 +Node: Advanced Features Summary794184 +Node: Internationalization796048 +Node: I18N and L10N797528 +Node: Explaining gettext798214 +Ref: Explaining gettext-Footnote-1803354 +Ref: Explaining gettext-Footnote-2803538 +Node: Programmer i18n803703 +Node: Translator i18n807928 +Node: String Extraction808722 +Ref: String Extraction-Footnote-1809683 +Node: Printf Ordering809769 +Ref: Printf Ordering-Footnote-1812551 +Node: I18N Portability812615 +Ref: I18N Portability-Footnote-1815064 +Node: I18N Example815127 +Ref: I18N Example-Footnote-1817849 +Node: Gawk I18N817921 +Node: I18N Summary818559 +Node: Debugger819898 +Node: Debugging820920 +Node: Debugging Concepts821361 +Node: Debugging Terms823217 +Node: Awk Debugging825814 +Node: Sample Debugging Session826706 +Node: Debugger Invocation827226 +Node: Finding The Bug828559 +Node: List of Debugger Commands835041 +Node: Breakpoint Control836373 +Node: Debugger Execution Control840037 +Node: Viewing And Changing Data843397 +Node: Execution Stack846755 +Node: Debugger Info848268 +Node: Miscellaneous Debugger Commands852262 +Node: Readline Support857446 +Node: Limitations858338 +Node: Debugging Summary860612 +Node: Arbitrary Precision Arithmetic861776 +Node: Computer Arithmetic863105 +Ref: Computer Arithmetic-Footnote-1867492 +Node: Math Definitions867549 +Ref: table-ieee-formats870433 +Node: MPFR features870937 +Node: FP Math Caution872579 +Ref: FP Math Caution-Footnote-1873620 +Node: Inexactness of computations873989 +Node: Inexact representation874937 +Node: Comparing FP Values876292 +Node: Errors accumulate877256 +Node: Getting Accuracy878689 +Node: Try To Round881348 +Node: Setting precision882247 +Ref: table-predefined-precision-strings882929 +Node: Setting the rounding mode884722 +Ref: table-gawk-rounding-modes885086 +Ref: Setting the rounding mode-Footnote-1888540 +Node: Arbitrary Precision Integers888719 +Ref: Arbitrary Precision Integers-Footnote-1891722 +Node: POSIX Floating Point Problems891871 +Ref: POSIX Floating Point Problems-Footnote-1895747 +Node: Floating point summary895785 +Node: Dynamic Extensions898002 +Node: Extension Intro899554 +Node: Plugin License900819 +Node: Extension Mechanism Outline901504 +Ref: figure-load-extension901928 +Ref: figure-load-new-function903413 +Ref: figure-call-new-function904415 +Node: Extension API Description906399 +Node: Extension API Functions Introduction907849 +Node: General Data Types912714 +Ref: General Data Types-Footnote-1918407 +Node: Requesting Values918706 +Ref: table-value-types-returned919443 +Node: Memory Allocation Functions920401 +Ref: Memory Allocation Functions-Footnote-1923148 +Node: Constructor Functions923244 +Node: Registration Functions925002 +Node: Extension Functions925687 +Node: Exit Callback Functions927989 +Node: Extension Version String929238 +Node: Input Parsers929888 +Node: Output Wrappers939702 +Node: Two-way processors944218 +Node: Printing Messages946422 +Ref: Printing Messages-Footnote-1947499 +Node: Updating `ERRNO'947651 +Node: Accessing Parameters948390 +Node: Symbol Table Access949620 +Node: Symbol table by name950134 +Node: Symbol table by cookie952110 +Ref: Symbol table by cookie-Footnote-1956243 +Node: Cached values956306 +Ref: Cached values-Footnote-1959810 +Node: Array Manipulation959901 +Ref: Array Manipulation-Footnote-1960999 +Node: Array Data Types961038 +Ref: Array Data Types-Footnote-1963741 +Node: Array Functions963833 +Node: Flattening Arrays967707 +Node: Creating Arrays974559 +Node: Extension API Variables979290 +Node: Extension Versioning979926 +Node: Extension API Informational Variables981827 +Node: Extension API Boilerplate982913 +Node: Finding Extensions986717 +Node: Extension Example987277 +Node: Internal File Description988007 +Node: Internal File Ops992098 +Ref: Internal File Ops-Footnote-11003530 +Node: Using Internal File Ops1003670 +Ref: Using Internal File Ops-Footnote-11006017 +Node: Extension Samples1006285 +Node: Extension Sample File Functions1007809 +Node: Extension Sample Fnmatch1015377 +Node: Extension Sample Fork1016859 +Node: Extension Sample Inplace1018072 +Node: Extension Sample Ord1019747 +Node: Extension Sample Readdir1020583 +Ref: table-readdir-file-types1021439 +Node: Extension Sample Revout1022238 +Node: Extension Sample Rev2way1022829 +Node: Extension Sample Read write array1023570 +Node: Extension Sample Readfile1025449 +Node: Extension Sample API Tests1026549 +Node: Extension Sample Time1027074 +Node: gawkextlib1028389 +Node: Extension summary1031202 +Node: Extension Exercises1034895 +Node: Language History1035617 +Node: V7/SVR3.11037260 +Node: SVR41039580 +Node: POSIX1041022 +Node: BTL1042408 +Node: POSIX/GNU1043142 +Node: Feature History1048885 +Node: Common Extensions1062015 +Node: Ranges and Locales1063327 +Ref: Ranges and Locales-Footnote-11067944 +Ref: Ranges and Locales-Footnote-21067971 +Ref: Ranges and Locales-Footnote-31068205 +Node: Contributors1068426 +Node: History summary1073851 +Node: Installation1075220 +Node: Gawk Distribution1076171 +Node: Getting1076655 +Node: Extracting1077479 +Node: Distribution contents1079121 +Node: Unix Installation1084838 +Node: Quick Installation1085455 +Node: Additional Configuration Options1087897 +Node: Configuration Philosophy1089635 +Node: Non-Unix Installation1091986 +Node: PC Installation1092444 +Node: PC Binary Installation1093755 +Node: PC Compiling1095603 +Ref: PC Compiling-Footnote-11098602 +Node: PC Testing1098707 +Node: PC Using1099883 +Node: Cygwin1104041 +Node: MSYS1104850 +Node: VMS Installation1105364 +Node: VMS Compilation1106160 +Ref: VMS Compilation-Footnote-11107382 +Node: VMS Dynamic Extensions1107440 +Node: VMS Installation Details1108813 +Node: VMS Running1111065 +Node: VMS GNV1113899 +Node: VMS Old Gawk1114622 +Node: Bugs1115092 +Node: Other Versions1119096 +Node: Installation summary1125351 +Node: Notes1126407 +Node: Compatibility Mode1127272 +Node: Additions1128054 +Node: Accessing The Source1128979 +Node: Adding Code1130415 +Node: New Ports1136593 +Node: Derived Files1141074 +Ref: Derived Files-Footnote-11146155 +Ref: Derived Files-Footnote-21146189 +Ref: Derived Files-Footnote-31146785 +Node: Future Extensions1146899 +Node: Implementation Limitations1147505 +Node: Extension Design1148753 +Node: Old Extension Problems1149907 +Ref: Old Extension Problems-Footnote-11151424 +Node: Extension New Mechanism Goals1151481 +Ref: Extension New Mechanism Goals-Footnote-11154841 +Node: Extension Other Design Decisions1155030 +Node: Extension Future Growth1157136 +Node: Old Extension Mechanism1157972 +Node: Notes summary1159734 +Node: Basic Concepts1160920 +Node: Basic High Level1161601 +Ref: figure-general-flow1161873 +Ref: figure-process-flow1162472 +Ref: Basic High Level-Footnote-11165701 +Node: Basic Data Typing1165886 +Node: Glossary1169214 +Node: Copying1194366 +Node: GNU Free Documentation License1231922 +Node: Index1257058  End Tag Table -- cgit v1.2.3 From c9b1f9189625a8dab6092cbd46f8496537af227c Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 15 Aug 2014 14:01:11 +0300 Subject: Continue on reviewer comments. --- doc/gawk.info | 1437 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 708 insertions(+), 729 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 8035803b..8f91f3c0 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -190,7 +190,7 @@ entitled "GNU Free Documentation License". * Single Character Fields:: Making each character a separate field. * Command Line Field Separator:: Setting `FS' from the - command-line. + command line. * Full Line Fields:: Making the full line be a single field. * Field Splitting Summary:: Some final points and a summary table. @@ -216,7 +216,7 @@ entitled "GNU Free Documentation License". `getline'. * Getline Summary:: Summary of `getline' Variants. * Read Timeout:: Reading input with a timeout. -* Command line directories:: What happens if you put a directory on +* Command-line directories:: What happens if you put a directory on the command line. * Input Summary:: Input summary. * Input Exercises:: Exercises. @@ -255,7 +255,7 @@ entitled "GNU Free Documentation License". * Variables:: Variables give names to values for later use. * Using Variables:: Using variables in your programs. -* Assignment Options:: Setting variables on the command-line +* Assignment Options:: Setting variables on the command line and a summary of command-line syntax. This is an advanced method of input. * Conversion:: The conversion of strings to numbers @@ -884,7 +884,7 @@ contributed parts of the code as well. In 1988 and 1989, David Trueman, with help from me, thoroughly reworked `gawk' for compatibility with the newer `awk'. Circa 1994, I became the primary maintainer. Current development focuses on bug fixes, performance improvements, -standards compliance, and occasionally, new features. +standards compliance and, occasionally, new features. In May of 1997, Ju"rgen Kahrs felt the need for network access from `awk', and with a little help from me, set about adding features to do @@ -1086,7 +1086,7 @@ formatting language. A single Texinfo source file is used to produce both the printed and online versions of the documentation. This minor node briefly documents the typographical conventions used in Texinfo. - Examples you would type at the command-line are preceded by the + Examples you would type at the command line are preceded by the common shell primary and secondary prompts, `$' and `>'. Input that you type is shown `like this'. Output from the command is preceded by the glyph "-|". This typically represents the command's standard @@ -1456,7 +1456,7 @@ end-of-file character may be different. For example, on OS/2, it is As an example, the following program prints a friendly piece of advice (from Douglas Adams's `The Hitchhiker's Guide to the Galaxy'), to keep you from worrying about the complexities of computer -programming(1) (`BEGIN' is a feature we haven't discussed yet): +programming (`BEGIN' is a feature we haven't discussed yet): $ awk "BEGIN { print \"Don't Panic!\" }" -| Don't Panic! @@ -1464,7 +1464,13 @@ programming(1) (`BEGIN' is a feature we haven't discussed yet): This program does not read any input. The `\' before each of the inner double quotes is necessary because of the shell's quoting rules--in particular because it mixes both single quotes and double -quotes.(2) +quotes.(1) + + NOTE: As a side note, if you use Bash as your shell, you should + execute the command `set +H' before running this program + interactively, to disable the C shell-style command history, which + treats `!' as a special character. We recommend putting this + command into your personal startup file. This next simple `awk' program emulates the `cat' utility; it copies whatever you type on the keyboard to its standard output (why this @@ -1483,12 +1489,7 @@ works is explained shortly). ---------- Footnotes ---------- - (1) If you use Bash as your shell, you should execute the command -`set +H' before running this program interactively, to disable the C -shell-style command history, which treats `!' as a special character. -We recommend putting this command into your personal startup file. - - (2) Although we generally recommend the use of single quotes around + (1) Although we generally recommend the use of single quotes around the program text, double quotes are needed here in order to put the single quote into the message. @@ -1719,9 +1720,9 @@ the quoting rules. Note that the single quote is not special within double quotes. * Null strings are removed when they occur as part of a non-null - command-line argument, while explicit non-null objects are kept. - For example, to specify that the field separator `FS' should be - set to the null string, use: + command-line argument, while explicit null objects are kept. For + example, to specify that the field separator `FS' should be set to + the null string, use: awk -F "" 'PROGRAM' FILES # correct @@ -1814,10 +1815,10 @@ one "record". In the data file `mail-list', each record contains the name of a person, his/her phone number, his/her email-address, and a code for -their relationship with the author of the list. An `A' in the last -column means that the person is an acquaintance. An `F' in the last -column means that the person is a friend. An `R' means that the person -is a relative: +their relationship with the author of the list. The columns are +aligned using spaces. An `A' in the last column means that the person +is an acquaintance. An `F' in the last column means that the person is +a friend. An `R' means that the person is a relative: Amelia 555-5553 amelia.zodiacusque@gmail.com F Anthony 555-3412 anthony.asserturo@hotmail.com A @@ -2505,8 +2506,8 @@ The following list describes options mandated by the POSIX standard: this option is intended to be used with code libraries, `gawk' does not recognize such files as constituting main program input. Thus, after processing an `-i' argument, `gawk' still expects to - find the main source code via the `-f' option or on the - command-line. + find the main source code via the `-f' option or on the command + line. `-l' EXT `--load' EXT @@ -2523,7 +2524,7 @@ The following list describes options mandated by the POSIX standard: `-L'[VALUE] `--lint'[`='VALUE] Warn about constructs that are dubious or nonportable to other - `awk' implementations. No space is allowed between the `-D' and + `awk' implementations. No space is allowed between the `-L' and VALUE, if VALUE is supplied. Some warnings are issued when `gawk' first reads your program. Others are issued at runtime, as your program executes. With an optional argument of `fatal', lint @@ -2603,7 +2604,7 @@ The following list describes options mandated by the POSIX standard: * Newlines are not allowed after `?' or `:' (*note Conditional Exp::). - * Specifying `-Ft' on the command-line does not set the value + * Specifying `-Ft' on the command line does not set the value of `FS' to be a single TAB character (*note Field Separators::). @@ -2785,7 +2786,7 @@ with `getline' (*note Getline/File::). In addition, `gawk' allows you to specify the special file name `/dev/stdin', both on the command line and with `getline'. Some other versions of `awk' also support this, but it is not standard. (Some -operating systems provide a `/dev/stdin' file in the file system; +operating systems provide a `/dev/stdin' file in the filesystem; however, `gawk' always processes this file name itself.)  @@ -2811,7 +2812,7 @@ File: gawk.info, Node: AWKPATH Variable, Next: AWKLIBPATH Variable, Up: Envir ---------------------------------------- The previous minor node described how `awk' program files can be named -on the command-line with the `-f' option. In most `awk' +on the command line with the `-f' option. In most `awk' implementations, you must supply a precise path name for each program file, unless the file is in the current directory. But in `gawk', if the file name supplied to the `-f' or `-i' options does not contain a @@ -2898,7 +2899,7 @@ they are more specialized. Those in the following list are meant to be used by regular users. `POSIXLY_CORRECT' - Causes `gawk' to switch POSIX compatibility mode, disabling all + Causes `gawk' to switch to POSIX compatibility mode, disabling all traditional and GNU extensions. *Note Options::. `GAWK_SOCK_RETRIES' @@ -2926,7 +2927,7 @@ change. The variables are: the value should be a number, and `gawk' uses that number as the size of the buffer to allocate. (When this variable is not set, `gawk' uses the smaller of the file's size and the "default" - blocksize, which is usually the file systems I/O blocksize.) + blocksize, which is usually the filesystems I/O blocksize.) `AWK_HASH' If this variable exists with a value of `gst', `gawk' switches to @@ -3160,9 +3161,9 @@ File: gawk.info, Node: Invoking Summary, Prev: Undocumented, Up: Invoking Gaw * Use either `awk 'PROGRAM' FILES' or `awk -f PROGRAM-FILE FILES' to run `awk'. - * The three standard `awk' options are `-f', `-F' and `-v'. `gawk' - supplies these and many others, as well as corresponding GNU-style - long options. + * The three standard options for all versions of `awk' are `-f', + `-F' and `-v'. `gawk' supplies these and many others, as well as + corresponding GNU-style long options. * Non-option command-line arguments are usually treated as file names, unless they have the form `VAR=VALUE', in which case they @@ -3998,7 +3999,7 @@ File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp `awk', regular expression constants are written enclosed between slashes: `/'...`/'. - * Regexp constants may be used by standalone in patterns and in + * Regexp constants may be used standalone in patterns and in conditional expressions, or as part of matching expressions using the `~' and `!~' operators. @@ -4022,8 +4023,8 @@ File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp extent of the match, such as for text substitution and when the record separator is a regexp. - * Matching expressions may use dynamic regexps; that is string values - treated as regular expressions. + * Matching expressions may use dynamic regexps; that is, string + values treated as regular expressions.  @@ -4064,7 +4065,7 @@ have to be named on the `awk' command line (*note Getline::). * Getline:: Reading files under explicit program control using the `getline' function. * Read Timeout:: Reading input with a timeout. -* Command line directories:: What happens if you put a directory on the +* Command-line directories:: What happens if you put a directory on the command line. * Input Summary:: Input summary. * Input Exercises:: Exercises. @@ -4246,16 +4247,16 @@ trailing whitespace: $ echo record 1 AAAA record 2 BBBB record 3 | > gawk 'BEGIN { RS = "\n|( *[[:upper:]]+ *)" } - > { print "Record =", $0, "and RT =", RT }' - -| Record = record 1 and RT = AAAA - -| Record = record 2 and RT = BBBB - -| Record = record 3 and RT = - -| + > { print "Record =", $0,"and RT = [" RT "]" }' + -| Record = record 1 and RT = [ AAAA ] + -| Record = record 2 and RT = [ BBBB ] + -| Record = record 3 and RT = [ + -| ] -The final line of output has an extra blank line. This is because the -value of `RT' is a newline, and the `print' statement supplies its own -terminating newline. *Note Simple Sed::, for a more useful example of -`RS' as a regexp and `RT'. +The square brackets delineate the contents of `RT', letting you see the +leading and trailing whitespace. The final value of `RT' `RT' is a +newline. *Note Simple Sed::, for a more useful example of `RS' as a +regexp and `RT'. If you set `RS' to a regular expression that allows optional trailing text, such as `RS = "abc(XYZ)?"' it is possible, due to @@ -4597,7 +4598,7 @@ File: gawk.info, Node: Field Separators, Next: Constant Size, Prev: Changing * Default Field Splitting:: How fields are normally separated. * Regexp Field Splitting:: Using regexps as the field separator. * Single Character Fields:: Making each character a separate field. -* Command Line Field Separator:: Setting `FS' from the command-line. +* Command Line Field Separator:: Setting `FS' from the command line. * Full Line Fields:: Making the full line be a single field. * Field Splitting Summary:: Some final points and a summary table. @@ -5761,7 +5762,7 @@ VAR Table 4.1: `getline' Variants and What They Set  -File: gawk.info, Node: Read Timeout, Next: Command line directories, Prev: Getline, Up: Reading Files +File: gawk.info, Node: Read Timeout, Next: Command-line directories, Prev: Getline, Up: Reading Files 4.10 Reading Input With A Timeout ================================= @@ -5855,7 +5856,7 @@ writing. (1) This assumes that standard input is the keyboard.  -File: gawk.info, Node: Command line directories, Next: Input Summary, Prev: Read Timeout, Up: Reading Files +File: gawk.info, Node: Command-line directories, Next: Input Summary, Prev: Read Timeout, Up: Reading Files 4.11 Directories On The Command Line ==================================== @@ -5878,7 +5879,7 @@ error. usable data from an `awk' program.  -File: gawk.info, Node: Input Summary, Next: Input Exercises, Prev: Command line directories, Up: Reading Files +File: gawk.info, Node: Input Summary, Next: Input Exercises, Prev: Command-line directories, Up: Reading Files 4.12 Summary ============ @@ -7362,12 +7363,12 @@ For example: } In this example, the programmer wants to pass a regexp constant to -the user-defined function `mysub', which in turn passes it on to either -`sub()' or `gsub()'. However, what really happens is that the `pat' -parameter is either one or zero, depending upon whether or not `$0' -matches `/hi/'. `gawk' issues a warning when it sees a regexp constant -used as a parameter to a user-defined function, since passing a truth -value in this way is probably not what was intended. +the user-defined function `mysub()', which in turn passes it on to +either `sub()' or `gsub()'. However, what really happens is that the +`pat' parameter is either one or zero, depending upon whether or not +`$0' matches `/hi/'. `gawk' issues a warning when it sees a regexp +constant used as a parameter to a user-defined function, since passing +a truth value in this way is probably not what was intended.  File: gawk.info, Node: Variables, Next: Conversion, Prev: Using Constant Regexps, Up: Values @@ -7383,7 +7384,7 @@ on the `awk' command line. * Menu: * Using Variables:: Using variables in your programs. -* Assignment Options:: Setting variables on the command-line and a +* Assignment Options:: Setting variables on the command line and a summary of command-line syntax. This is an advanced method of input. @@ -12329,9 +12330,13 @@ File: gawk.info, Node: Gory Details, Up: String Functions 9.1.3.1 More About `\' and `&' with `sub()', `gsub()', and `gensub()' ..................................................................... -When using `sub()', `gsub()', or `gensub()', and trying to get literal -backslashes and ampersands into the replacement text, you need to -remember that there are several levels of "escape processing" going on. + CAUTION: This section has been known to cause headaches. You + might want to skip it upon first reading. + + When using `sub()', `gsub()', or `gensub()', and trying to get +literal backslashes and ampersands into the replacement text, you need +to remember that there are several levels of "escape processing" going +on. First, there is the "lexical" level, which is when `awk' reads your program and builds an internal copy of it to execute. Then there is @@ -12357,13 +12362,13 @@ is illustrated in *note table-sub-escapes::. You type `sub()' sees `sub()' generates ------- --------- -------------- - `\&' `&' the matched text - `\\&' `\&' a literal `&' - `\\\&' `\&' a literal `&' - `\\\\&' `\\&' a literal `\&' - `\\\\\&' `\\&' a literal `\&' - `\\\\\\&' `\\\&' a literal `\\&' - `\\q' `\q' a literal `\q' + `\&' `&' The matched text + `\\&' `\&' A literal `&' + `\\\&' `\&' A literal `&' + `\\\\&' `\\&' A literal `\&' + `\\\\\&' `\\&' A literal `\&' + `\\\\\\&' `\\\&' A literal `\\&' + `\\q' `\q' A literal `\q' Table 9.1: Historical Escape Sequence Processing for `sub()' and `gsub()' @@ -12377,50 +12382,25 @@ backslashes entered at the lexical level.) The problem with the historical approach is that there is no way to get a literal `\' followed by the matched text. - The 1992 POSIX standard attempted to fix this problem. That standard -says that `sub()' and `gsub()' look for either a `\' or an `&' after -the `\'. If either one follows a `\', that character is output -literally. The interpretation of `\' and `&' then becomes as shown in -*note table-sub-posix-92::. + Several editions of the POSIX standard attempted to fix this problem +but weren't successful. The details are irrelevant at this point in +time. - You type `sub()' sees `sub()' generates - ------- --------- -------------- - `&' `&' the matched text - `\\&' `\&' a literal `&' - `\\\\&' `\\&' a literal `\', then the matched text - `\\\\\\&' `\\\&' a literal `\&' - -Table 9.2: 1992 POSIX Rules for `sub()' and `gsub()' Escape Sequence -Processing - -This appears to solve the problem. Unfortunately, the phrasing of the -standard is unusual. It says, in effect, that `\' turns off the special -meaning of any following character, but for anything other than `\' and -`&', such special meaning is undefined. This wording leads to two -problems: - - * Backslashes must now be doubled in the REPLACEMENT string, breaking - historical `awk' programs. - - * To make sure that an `awk' program is portable, _every_ character - in the REPLACEMENT string must be preceded with a backslash.(1) - - Because of the problems just listed, in 1996, the `gawk' maintainer -submitted proposed text for a revised standard that reverts to rules -that correspond more closely to the original existing practice. The -proposed rules have special cases that make it possible to produce a -`\' preceding the matched text. This is shown in *note -table-sub-proposed::. + At one point, the `gawk' maintainer submitted proposed text for a +revised standard that reverts to rules that correspond more closely to +the original existing practice. The proposed rules have special cases +that make it possible to produce a `\' preceding the matched text. +This is shown in *note table-sub-proposed::. You type `sub()' sees `sub()' generates ------- --------- -------------- - `\\\\\\&' `\\\&' a literal `\&' - `\\\\&' `\\&' a literal `\', followed by the matched text - `\\&' `\&' a literal `&' - `\\q' `\q' a literal `\q' + `\\\\\\&' `\\\&' A literal `\&' + `\\\\&' `\\&' A literal `\', followed by the matched text + `\\&' `\&' A literal `&' + `\\q' `\q' A literal `\q' `\\\\' `\\' `\\' -Table 9.3: Proposed Rules For `sub()' And Backslash +Table 9.2: GNU `awk' Rules For `sub()' And Backslash In a nutshell, at the runtime level, there are now three special sequences of characters (`\\\&', `\\&' and `\&') whereas historically @@ -12428,11 +12408,11 @@ there was only one. However, as in the historical case, any `\' that is not part of one of these three sequences is not special and appears in the output literally. - `gawk' 3.0 and 3.1 follow these proposed POSIX rules for `sub()' and -`gsub()'. The POSIX standard took much longer to be revised than was -expected in 1996. The 2001 standard does not follow the above rules. -Instead, the rules there are somewhat simpler. The results are similar -except for one case. + `gawk' 3.0 and 3.1 follow these rules for `sub()' and `gsub()'. The +POSIX standard took much longer to be revised than was expected. In +addition, the `gawk' maintainer's proposal was lost during the +standardization process. The final rules are somewhat simpler. The +results are similar except for one case. The POSIX rules state that `\&' in the replacement string produces a literal `&', `\\' produces a literal `\', and `\' followed by anything @@ -12441,25 +12421,25 @@ rules are presented in *note table-posix-sub::. You type `sub()' sees `sub()' generates ------- --------- -------------- - `\\\\\\&' `\\\&' a literal `\&' - `\\\\&' `\\&' a literal `\', followed by the matched text - `\\&' `\&' a literal `&' - `\\q' `\q' a literal `\q' + `\\\\\\&' `\\\&' A literal `\&' + `\\\\&' `\\&' A literal `\', followed by the matched text + `\\&' `\&' A literal `&' + `\\q' `\q' A literal `\q' `\\\\' `\\' `\' -Table 9.4: POSIX Rules For `sub()' And `gsub()' +Table 9.3: POSIX Rules For `sub()' And `gsub()' The only case where the difference is noticeable is the last one: `\\\\' is seen as `\\' and produces `\' instead of `\\'. Starting with version 3.1.4, `gawk' followed the POSIX rules when `--posix' is specified (*note Options::). Otherwise, it continued to -follow the 1996 proposed rules, since that had been its behavior for -many years. +follow the proposed rules, since that had been its behavior for many +years. When version 4.0.0 was released, the `gawk' maintainer made the POSIX rules the default, breaking well over a decade's worth of -backwards compatibility.(2) Needless to say, this was a bad idea, and +backwards compatibility.(1) Needless to say, this was a bad idea, and as of version 4.0.1, `gawk' resumed its historical behavior, and only follows the POSIX rules when `--posix' is given. @@ -12472,14 +12452,14 @@ the `\' does not, as shown in *note table-gensub-escapes::. You type `gensub()' sees `gensub()' generates ------- ------------ ----------------- - `&' `&' the matched text - `\\&' `\&' a literal `&' - `\\\\' `\\' a literal `\' - `\\\\&' `\\&' a literal `\', then the matched text - `\\\\\\&' `\\\&' a literal `\&' - `\\q' `\q' a literal `q' + `&' `&' The matched text + `\\&' `\&' A literal `&' + `\\\\' `\\' A literal `\' + `\\\\&' `\\&' A literal `\', then the matched text + `\\\\\\&' `\\\&' A literal `\&' + `\\q' `\q' A literal `q' -Table 9.5: Escape Sequence Processing For `gensub()' +Table 9.4: Escape Sequence Processing For `gensub()' Because of the complexity of the lexical and runtime level processing and the special cases for `sub()' and `gsub()', we recommend the use of @@ -12498,9 +12478,7 @@ Although this makes a certain amount of sense, it can be surprising. ---------- Footnotes ---------- - (1) This consequence was certainly unintended. - - (2) This was rather naive of him, despite there being a note in this + (1) This was rather naive of him, despite there being a note in this section indicating that the next major version would move to the POSIX rules. @@ -13031,7 +13009,7 @@ table-bitwise-ops::. 0 | 0 0 | 0 1 | 0 1 1 | 0 1 | 1 1 | 1 0 -Table 9.6: Bitwise Operations +Table 9.5: Bitwise Operations As you can see, the result of an AND operation is 1 only when _both_ bits are 1. The result of an OR operation is 1 if _either_ bit is 1. @@ -13385,22 +13363,22 @@ standard.) The following is an example of a recursive function. It takes a string as an input parameter and returns the string in backwards order. Recursive functions must always have a test that stops the recursion. -In this case, the recursion terminates when the starting position is -zero, i.e., when there are no more characters left in the string. +In this case, the recursion terminates when the input string is already +empty. - function rev(str, start) + function rev(str) { - if (start == 0) + if (str == "") return "" - return (substr(str, start, 1) rev(str, start - 1)) + return (rev(substr(str, 2)) substr(str, 1, 1)) } If this function is in a file named `rev.awk', it can be tested this way: $ echo "Don't Panic!" | - > gawk --source '{ print rev($0, length($0)) }' -f rev.awk + > gawk --source '{ print rev($0) }' -f rev.awk -| !cinaP t'noD The C `ctime()' function takes a timestamp and returns it in a @@ -13650,8 +13628,8 @@ function _are_ visible outside that function. a[1], a[2], a[3] } - prints `a[1] = 1, a[2] = two, a[3] = 3', because `changeit' stores - `"two"' in the second element of `a'. + prints `a[1] = 1, a[2] = two, a[3] = 3', because `changeit()' + stores `"two"' in the second element of `a'. Some `awk' implementations allow you to call a function that has not been defined. They only report a problem at runtime when the program @@ -19201,24 +19179,7 @@ File: gawk.info, Node: Two-way I/O, Next: TCP/IP Networking, Prev: Array Sort 12.3 Two-Way Communications with Another Process ================================================ - From: brennan@whidbey.com (Mike Brennan) - Newsgroups: comp.lang.awk - Subject: Re: Learn the SECRET to Attract Women Easily - Date: 4 Aug 1997 17:34:46 GMT - Message-ID: <5s53rm$eca@news.whidbey.com> - - On 3 Aug 1997 13:17:43 GMT, Want More Dates??? - wrote: - >Learn the SECRET to Attract Women Easily - > - >The SCENT(tm) Pheromone Sex Attractant For Men to Attract Women - - The scent of awk programmers is a lot more attractive to women than - the scent of perl programmers. - -- - Mike Brennan - - It is often useful to be able to send data to a separate program for +It is often useful to be able to send data to a separate program for processing and then read the result. This can always be done with temporary files: @@ -19237,12 +19198,11 @@ temporary files: This works, but not elegantly. Among other things, it requires that the program be run in a directory that cannot be shared among users; for example, `/tmp' will not do, as another user might happen to be -using a temporary file with the same name. - - However, with `gawk', it is possible to open a _two-way_ pipe to -another process. The second process is termed a "coprocess", since it -runs in parallel with `gawk'. The two-way connection is created using -the `|&' operator (borrowed from the Korn shell, `ksh'):(1) +using a temporary file with the same name.(1) However, with `gawk', it +is possible to open a _two-way_ pipe to another process. The second +process is termed a "coprocess", since it runs in parallel with `gawk'. +The two-way connection is created using the `|&' operator (borrowed +from the Korn shell, `ksh'):(2) do { print DATA |& "subprogram" @@ -19329,7 +19289,11 @@ using regular pipes. ---------- Footnotes ---------- - (1) This is very different from the same operator in the C shell and + (1) Michael Brennan suggests the use of `rand()' to generate unique +file names. This is a valid point; nevertheless, temporary files remain +more difficult than two-way pipes. + + (2) This is very different from the same operator in the C shell and in Bash.  @@ -19352,7 +19316,7 @@ network connection. You can think of this as just a _very long_ two-way pipeline to a coprocess. The way `gawk' decides that you want to use TCP/IP networking is by recognizing special file names that begin with one of -`/inet/', `/inet4/' or `/inet6'. +`/inet/', `/inet4/' or `/inet6/'. The full syntax of the special file name is `/NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT'. The @@ -21389,6 +21353,10 @@ in `gawk'. It continues on to present arbitrary precision integers, and concludes with a description of some points where `gawk' and the POSIX standard are not quite in agreement. + NOTE: Most users of `gawk' can safely skip this chapter. But if + you want to do scientific calculations with `gawk', this is the + place to be. + * Menu: * Computer Arithmetic:: A quick intro to computer math. @@ -21519,9 +21487,18 @@ material here. number and infinity produce infinity. "NaN" - "Not A Number." A special value indicating a result that can't - happen in real math, but that can happen in floating-point - computations. + "Not A Number."(1). A special value that results from attempting a + calculation that has no answer as a real number. In such a case, + programs can either receive a floating-point exception, or get + `NaN' back as the result. The IEEE 754 standard recommends that + systems return `NaN'. Some examples: + + `sqrt(-1)' + This makes sense in the range of complex numbers, but not in + the range of real numbers, so the result is `NaN'. + + `log(-8)' + -8 is out of the domain of `log()', so the result is `NaN'. "Normalized" How the significand (see later in this list) is usually stored. The @@ -21579,6 +21556,11 @@ Table 15.1: Basic IEEE Format Context Values NOTE: The precision numbers include the implied leading one that gives them one extra bit of significand. + ---------- Footnotes ---------- + + (1) Thanks to Michael Brennan for this description, which I have +paraphrased, and for the examples +  File: gawk.info, Node: MPFR features, Next: FP Math Caution, Prev: Math Definitions, Up: Arbitrary Precision Arithmetic @@ -21906,7 +21888,7 @@ on arithmetic operations: of a constant. If you need to represent a floating-point constant at a higher - precision than the default and cannot use a command line + precision than the default and cannot use a command-line assignment to `PREC', you should either specify the constant as a string, or as a rational number, whenever possible. The following example illustrates the differences among various ways to print a @@ -22401,7 +22383,7 @@ Example::) and also the `testext.c' code for testing the APIs. Some other bits and pieces: * The API provides access to `gawk''s `do_XXX' values, reflecting - command line options, like `do_lint', `do_profiling' and so on + command-line options, like `do_lint', `do_profiling' and so on (*note Extension API Variables::). These are informational: an extension cannot affect their values inside `gawk'. In addition, attempting to assign to them produces a compile-time error. @@ -25995,7 +25977,7 @@ the current version of `gawk'. - Indirect function calls (*note Indirect Calls::). - Directories on the command line produce a warning and are - skipped (*note Command line directories::). + skipped (*note Command-line directories::). * New keywords: @@ -26165,7 +26147,7 @@ in POSIX `awk', in the order they were added to `gawk'. * The ability to delete all of an array at once with `delete ARRAY' (*note Delete::). - * Command line option changes (*note Options::): + * Command-line option changes (*note Options::): - The ability to use GNU-style long-named options that start with `--'. @@ -26202,7 +26184,7 @@ in POSIX `awk', in the order they were added to `gawk'. * The `fflush()' function from Brian Kernighan's `awk' (then at Bell Laboratories; *note I/O Functions::). - * New command line options: + * New command-line options: - The `--lint-old' option to warn about constructs that are not available in the original Version 7 Unix version of `awk' @@ -26395,7 +26377,7 @@ in POSIX `awk', in the order they were added to `gawk'. * `switch' / `case' are enabled by default (*note Switch Statement::). - * Command line option changes (*note Options::): + * Command-line option changes (*note Options::): - The `-b' and `--characters-as-bytes' options which prevent `gawk' from treating input as a multibyte string. @@ -26413,7 +26395,7 @@ in POSIX `awk', in the order they were added to `gawk'. * Directories named on the command line now produce a warning, not a fatal error, unless `--posix' or `--traditional' are used (*note - Command line directories::). + Command-line directories::). * The `gawk' internals were rewritten, bringing the `dgawk' debugger and possibly improved performance (*note Debugger::). @@ -26462,10 +26444,10 @@ in POSIX `awk', in the order they were added to `gawk'. `PROCINFO["identifiers"]' (*note Auto-set::). * The three executables `gawk', `pgawk', and `dgawk', were merged - into one, named just `gawk'. As a result the command line options + into one, named just `gawk'. As a result the command-line options changed. - * Command line option changes (*note Options::): + * Command-line option changes (*note Options::): - The `-D' option invokes the debugger. @@ -30945,7 +30927,7 @@ Index * * (asterisk), * operator, as regexp operator: Regexp Operators. (line 88) * * (asterisk), * operator, null strings, matching: Gory Details. - (line 164) + (line 143) * * (asterisk), ** operator <1>: Precedence. (line 49) * * (asterisk), ** operator: Arithmetic Ops. (line 81) * * (asterisk), **= operator <1>: Precedence. (line 95) @@ -31026,7 +31008,7 @@ Index * -F option: Options. (line 21) * -f option: Long. (line 12) * -F option, -Ft sets FS to TAB: Options. (line 308) -* -F option, command line: Command Line Field Separator. +* -F option, command-line: Command Line Field Separator. (line 6) * -f option, multiple uses: Options. (line 313) * -g option: Options. (line 147) @@ -31184,7 +31166,7 @@ Index * advanced features, network programming: TCP/IP Networking. (line 6) * advanced features, nondecimal input data: Nondecimal Data. (line 6) * advanced features, processes, communicating with: Two-way I/O. - (line 23) + (line 6) * advanced features, specifying field content: Splitting By Content. (line 10) * Aho, Alfred <1>: Contributors. (line 11) @@ -31304,7 +31286,7 @@ Index * asterisk (*), * operator, as regexp operator: Regexp Operators. (line 88) * asterisk (*), * operator, null strings, matching: Gory Details. - (line 164) + (line 143) * asterisk (*), ** operator <1>: Precedence. (line 49) * asterisk (*), ** operator: Arithmetic Ops. (line 81) * asterisk (*), **= operator <1>: Precedence. (line 95) @@ -31507,12 +31489,11 @@ Index * breakpoint, how to disable or enable: Breakpoint Control. (line 69) * breakpoint, setting: Breakpoint Control. (line 11) * Brennan, Michael <1>: Other Versions. (line 6) -* Brennan, Michael <2>: Two-way I/O. (line 6) -* Brennan, Michael <3>: Simple Sed. (line 25) -* Brennan, Michael <4>: Delete. (line 56) +* Brennan, Michael <2>: Simple Sed. (line 25) +* Brennan, Michael <3>: Delete. (line 56) * Brennan, Michael: Foreword. (line 83) * Brian Kernighan's awk <1>: I/O Functions. (line 43) -* Brian Kernighan's awk <2>: Gory Details. (line 15) +* Brian Kernighan's awk <2>: Gory Details. (line 19) * Brian Kernighan's awk <3>: String Functions. (line 490) * Brian Kernighan's awk <4>: Delete. (line 48) * Brian Kernighan's awk <5>: Nextfile Statement. (line 47) @@ -31539,7 +31520,7 @@ Index * Buening, Andreas <1>: Bugs. (line 71) * Buening, Andreas <2>: Contributors. (line 92) * Buening, Andreas: Acknowledgments. (line 60) -* buffering, input/output <1>: Two-way I/O. (line 70) +* buffering, input/output <1>: Two-way I/O. (line 52) * buffering, input/output: I/O Functions. (line 140) * buffering, interactive vs. noninteractive: I/O Functions. (line 109) * buffers, flushing: I/O Functions. (line 32) @@ -31607,7 +31588,7 @@ Index (line 81) * close() function, return value: Close Files And Pipes. (line 131) -* close() function, two-way pipes and: Two-way I/O. (line 77) +* close() function, two-way pipes and: Two-way I/O. (line 59) * Close, Diane <1>: Contributors. (line 20) * Close, Diane: Manual History. (line 34) * Collado, Manuel: Acknowledgments. (line 60) @@ -31622,7 +31603,7 @@ Index * command line, arguments <1>: ARGC and ARGV. (line 6) * command line, arguments <2>: Auto-set. (line 15) * command line, arguments: Other Arguments. (line 6) -* command line, directories on: Command line directories. +* command line, directories on: Command-line directories. (line 6) * command line, formats: Running gawk. (line 12) * command line, FS on, setting: Command Line Field Separator. @@ -31714,7 +31695,7 @@ Index * CONVFMT variable, and array subscripts: Numeric Array Subscripts. (line 6) * cookie: Glossary. (line 149) -* coprocesses <1>: Two-way I/O. (line 44) +* coprocesses <1>: Two-way I/O. (line 25) * coprocesses: Redirection. (line 102) * coprocesses, closing: Close Files And Pipes. (line 6) @@ -31724,7 +31705,7 @@ Index * counting: Wc Program. (line 6) * csh utility: Statements/Lines. (line 44) * csh utility, POSIXLY_CORRECT environment variable: Options. (line 355) -* csh utility, |& operator, comparison with: Two-way I/O. (line 44) +* csh utility, |& operator, comparison with: Two-way I/O. (line 25) * ctime() user-defined function: Function Example. (line 73) * currency symbols, localization: Explaining gettext. (line 104) * current system time: Time Functions. (line 66) @@ -31800,7 +31781,7 @@ Index * dcngettext: I18N Functions. (line 28) * dcngettext() function (gawk), portability and: I18N Portability. (line 33) -* deadlocks: Two-way I/O. (line 70) +* deadlocks: Two-way I/O. (line 52) * debugger commands, b (break): Breakpoint Control. (line 11) * debugger commands, backtrace: Execution Stack. (line 13) * debugger commands, break: Breakpoint Control. (line 11) @@ -31943,7 +31924,7 @@ Index (line 15) * differences in awk and gawk, close() function: Close Files And Pipes. (line 81) -* differences in awk and gawk, command line directories: Command line directories. +* differences in awk and gawk, command-line directories: Command-line directories. (line 6) * differences in awk and gawk, ERRNO variable: Auto-set. (line 74) * differences in awk and gawk, error messages: Special FD. (line 16) @@ -31996,7 +31977,7 @@ Index (line 152) * differences in awk and gawk, trunc-mod operation: Arithmetic Ops. (line 66) -* directories, command line: Command line directories. +* directories, command-line: Command-line directories. (line 6) * directories, searching: Programs Exercises. (line 63) * directories, searching for loadable extensions: AWKLIBPATH Variable. @@ -32464,7 +32445,7 @@ Index * gawk, newlines in: Statements/Lines. (line 12) * gawk, octal numbers and: Nondecimal-numbers. (line 42) * gawk, OS/2 version of: PC Using. (line 16) -* gawk, PROCINFO array in <1>: Two-way I/O. (line 117) +* gawk, PROCINFO array in <1>: Two-way I/O. (line 99) * gawk, PROCINFO array in <2>: Time Functions. (line 47) * gawk, PROCINFO array in: Auto-set. (line 128) * gawk, regexp constants and: Using Constant Regexps. @@ -32515,7 +32496,7 @@ Index (line 6) * getline command, coprocesses, using from: Getline/Coprocess. (line 6) -* getline command, deadlock and: Two-way I/O. (line 70) +* getline command, deadlock and: Two-way I/O. (line 52) * getline command, explicit input with: Getline. (line 6) * getline command, FILENAME variable and: Getline Notes. (line 19) * getline command, return values: Getline. (line 19) @@ -32661,7 +32642,7 @@ Index * input/output functions: I/O Functions. (line 6) * input/output, binary: User-modified. (line 15) * input/output, from BEGIN and END: I/O And BEGIN/END. (line 6) -* input/output, two-way: Two-way I/O. (line 44) +* input/output, two-way: Two-way I/O. (line 25) * insomnia, cure for: Alarm Program. (line 6) * installation, VMS: VMS Installation. (line 6) * installing gawk: Installation. (line 6) @@ -32852,7 +32833,7 @@ Index * matching, expressions, See comparison expressions: Typing and Comparison. (line 9) * matching, leftmost longest: Multiple Line. (line 26) -* matching, null strings: Gory Details. (line 164) +* matching, null strings: Gory Details. (line 143) * mawk utility <1>: Other Versions. (line 44) * mawk utility <2>: Nextfile Statement. (line 47) * mawk utility <3>: Concatenation. (line 36) @@ -32946,7 +32927,7 @@ Index (line 43) * null strings, converting numbers to strings: Strings And Numbers. (line 21) -* null strings, matching: Gory Details. (line 164) +* null strings, matching: Gory Details. (line 143) * number as string of bits: Bitwise Functions. (line 109) * number of array elements: String Functions. (line 197) * number sign (#), #! (executable scripts): Executable Scripts. @@ -33152,7 +33133,7 @@ Index * POSIX awk, field separators and: Fields. (line 6) * POSIX awk, FS variable and: User-modified. (line 60) * POSIX awk, function keyword in: Definition Syntax. (line 89) -* POSIX awk, functions and, gsub()/sub(): Gory Details. (line 54) +* POSIX awk, functions and, gsub()/sub(): Gory Details. (line 90) * POSIX awk, functions and, length(): String Functions. (line 176) * POSIX awk, GNU long options and: Options. (line 15) * POSIX awk, interval expressions in: Regexp Operators. (line 136) @@ -33214,12 +33195,12 @@ Index * private variables: Library Names. (line 11) * process group idIDof gawk process: Auto-set. (line 175) * process ID of gawk process: Auto-set. (line 178) -* processes, two-way communications with: Two-way I/O. (line 23) +* processes, two-way communications with: Two-way I/O. (line 6) * processing data: Basic High Level. (line 6) * PROCINFO array <1>: Passwd Functions. (line 6) * PROCINFO array <2>: Time Functions. (line 47) * PROCINFO array: Auto-set. (line 128) -* PROCINFO array, and communications via ptys: Two-way I/O. (line 117) +* PROCINFO array, and communications via ptys: Two-way I/O. (line 99) * PROCINFO array, and group membership: Group Functions. (line 6) * PROCINFO array, and user and group ID numbers: Id Program. (line 15) * PROCINFO array, testing the field splitting: Passwd Functions. @@ -33231,7 +33212,6 @@ Index * profiling awk programs, dynamically: Profiling. (line 179) * program identifiers: Auto-set. (line 146) * program, definition of: Getting Started. (line 21) -* programmers, attractiveness of: Two-way I/O. (line 6) * programming conventions, --non-decimal-data option: Nondecimal Data. (line 36) * programming conventions, ARGC/ARGV variables: Auto-set. (line 35) @@ -33531,7 +33511,7 @@ Index (line 64) * sidebar, Interactive Versus Noninteractive Buffering: I/O Functions. (line 107) -* sidebar, Matching the Null String: Gory Details. (line 162) +* sidebar, Matching the Null String: Gory Details. (line 141) * sidebar, Operator Evaluation Order: Increment Ops. (line 58) * sidebar, Piping into sh: Redirection. (line 140) * sidebar, Portability Issues with #!: Executable Scripts. (line 31) @@ -33580,7 +33560,7 @@ Index * sort function, arrays, sorting: Array Sorting Functions. (line 6) * sort utility: Word Sorting. (line 50) -* sort utility, coprocesses and: Two-way I/O. (line 83) +* sort utility, coprocesses and: Two-way I/O. (line 65) * sorting characters in different languages: Explaining gettext. (line 94) * source code, awka: Other Versions. (line 64) @@ -33872,7 +33852,7 @@ Index * vertical bar (|): Regexp Operators. (line 70) * vertical bar (|), | operator (I/O) <1>: Precedence. (line 65) * vertical bar (|), | operator (I/O): Getline/Pipe. (line 9) -* vertical bar (|), |& operator (I/O) <1>: Two-way I/O. (line 44) +* vertical bar (|), |& operator (I/O) <1>: Two-way I/O. (line 25) * vertical bar (|), |& operator (I/O) <2>: Precedence. (line 65) * vertical bar (|), |& operator (I/O): Getline/Coprocess. (line 6) * vertical bar (|), || operator <1>: Precedence. (line 89) @@ -33934,7 +33914,7 @@ Index * | (vertical bar), | operator (I/O) <1>: Precedence. (line 65) * | (vertical bar), | operator (I/O) <2>: Redirection. (line 57) * | (vertical bar), | operator (I/O): Getline/Pipe. (line 9) -* | (vertical bar), |& operator (I/O) <1>: Two-way I/O. (line 44) +* | (vertical bar), |& operator (I/O) <1>: Two-way I/O. (line 25) * | (vertical bar), |& operator (I/O) <2>: Precedence. (line 65) * | (vertical bar), |& operator (I/O) <3>: Redirection. (line 102) * | (vertical bar), |& operator (I/O): Getline/Coprocess. (line 6) @@ -33974,532 +33954,531 @@ Node: Getting Started70816 Node: Running gawk73250 Node: One-shot74440 Node: Read Terminal75665 -Ref: Read Terminal-Footnote-177315 -Ref: Read Terminal-Footnote-277591 -Node: Long77762 -Node: Executable Scripts79138 -Ref: Executable Scripts-Footnote-180971 -Ref: Executable Scripts-Footnote-281073 -Node: Comments81620 -Node: Quoting84093 -Node: DOS Quoting89409 -Node: Sample Data Files90084 -Node: Very Simple92599 -Node: Two Rules97372 -Node: More Complex99266 -Ref: More Complex-Footnote-1102198 -Node: Statements/Lines102283 -Ref: Statements/Lines-Footnote-1106739 -Node: Other Features107004 -Node: When107932 -Node: Intro Summary110102 -Node: Invoking Gawk110868 -Node: Command Line112383 -Node: Options113174 -Ref: Options-Footnote-1129003 -Node: Other Arguments129028 -Node: Naming Standard Input131690 -Node: Environment Variables132784 -Node: AWKPATH Variable133342 -Ref: AWKPATH Variable-Footnote-1136214 -Ref: AWKPATH Variable-Footnote-2136259 -Node: AWKLIBPATH Variable136519 -Node: Other Environment Variables137278 -Node: Exit Status140933 -Node: Include Files141608 -Node: Loading Shared Libraries145186 -Node: Obsolete146570 -Node: Undocumented147267 -Node: Invoking Summary147534 -Node: Regexp149114 -Node: Regexp Usage150564 -Node: Escape Sequences152597 -Node: Regexp Operators158264 -Ref: Regexp Operators-Footnote-1165744 -Ref: Regexp Operators-Footnote-2165891 -Node: Bracket Expressions165989 -Ref: table-char-classes167879 -Node: GNU Regexp Operators170819 -Node: Case-sensitivity174542 -Ref: Case-sensitivity-Footnote-1177434 -Ref: Case-sensitivity-Footnote-2177669 -Node: Leftmost Longest177777 -Node: Computed Regexps178978 -Node: Regexp Summary182350 -Node: Reading Files183821 -Node: Records185913 -Node: awk split records186656 -Node: gawk split records191514 -Ref: gawk split records-Footnote-1196035 -Node: Fields196072 -Ref: Fields-Footnote-1199036 -Node: Nonconstant Fields199122 -Ref: Nonconstant Fields-Footnote-1201352 -Node: Changing Fields201554 -Node: Field Separators207508 -Node: Default Field Splitting210210 -Node: Regexp Field Splitting211327 -Node: Single Character Fields214668 -Node: Command Line Field Separator215727 -Node: Full Line Fields219069 -Ref: Full Line Fields-Footnote-1219577 -Node: Field Splitting Summary219623 -Ref: Field Splitting Summary-Footnote-1222722 -Node: Constant Size222823 -Node: Splitting By Content227430 -Ref: Splitting By Content-Footnote-1231180 -Node: Multiple Line231220 -Ref: Multiple Line-Footnote-1237076 -Node: Getline237255 -Node: Plain Getline239471 -Node: Getline/Variable241566 -Node: Getline/File242713 -Node: Getline/Variable/File244097 -Ref: Getline/Variable/File-Footnote-1245696 -Node: Getline/Pipe245783 -Node: Getline/Variable/Pipe248482 -Node: Getline/Coprocess249589 -Node: Getline/Variable/Coprocess250841 -Node: Getline Notes251578 -Node: Getline Summary254382 -Ref: table-getline-variants254790 -Node: Read Timeout255702 -Ref: Read Timeout-Footnote-1259529 -Node: Command line directories259587 -Node: Input Summary260491 -Node: Input Exercises263628 -Node: Printing264361 -Node: Print266083 -Node: Print Examples267424 -Node: Output Separators270203 -Node: OFMT272219 -Node: Printf273577 -Node: Basic Printf274483 -Node: Control Letters276022 -Node: Format Modifiers280013 -Node: Printf Examples286040 -Node: Redirection288504 -Node: Special Files295476 -Node: Special FD296007 -Ref: Special FD-Footnote-1299604 -Node: Special Network299678 -Node: Special Caveats300528 -Node: Close Files And Pipes301324 -Ref: Close Files And Pipes-Footnote-1308485 -Ref: Close Files And Pipes-Footnote-2308633 -Node: Output Summary308783 -Node: Output exercises309780 -Node: Expressions310460 -Node: Values311645 -Node: Constants312321 -Node: Scalar Constants313001 -Ref: Scalar Constants-Footnote-1313860 -Node: Nondecimal-numbers314110 -Node: Regexp Constants317110 -Node: Using Constant Regexps317585 -Node: Variables320655 -Node: Using Variables321310 -Node: Assignment Options323034 -Node: Conversion324909 -Node: Strings And Numbers325433 -Ref: Strings And Numbers-Footnote-1328495 -Node: Locale influences conversions328604 -Ref: table-locale-affects331321 -Node: All Operators331909 -Node: Arithmetic Ops332539 -Node: Concatenation335044 -Ref: Concatenation-Footnote-1337863 -Node: Assignment Ops337983 -Ref: table-assign-ops342966 -Node: Increment Ops344283 -Node: Truth Values and Conditions347721 -Node: Truth Values348804 -Node: Typing and Comparison349853 -Node: Variable Typing350646 -Node: Comparison Operators354296 -Ref: table-relational-ops354706 -Node: POSIX String Comparison358256 -Ref: POSIX String Comparison-Footnote-1359340 -Node: Boolean Ops359478 -Ref: Boolean Ops-Footnote-1363548 -Node: Conditional Exp363639 -Node: Function Calls365366 -Node: Precedence369246 -Node: Locales372915 -Node: Expressions Summary374546 -Node: Patterns and Actions377087 -Node: Pattern Overview378203 -Node: Regexp Patterns379880 -Node: Expression Patterns380423 -Node: Ranges384204 -Node: BEGIN/END387310 -Node: Using BEGIN/END388072 -Ref: Using BEGIN/END-Footnote-1390808 -Node: I/O And BEGIN/END390914 -Node: BEGINFILE/ENDFILE393199 -Node: Empty396130 -Node: Using Shell Variables396447 -Node: Action Overview398730 -Node: Statements401057 -Node: If Statement402905 -Node: While Statement404403 -Node: Do Statement406447 -Node: For Statement407603 -Node: Switch Statement410755 -Node: Break Statement412858 -Node: Continue Statement414913 -Node: Next Statement416706 -Node: Nextfile Statement419096 -Node: Exit Statement421751 -Node: Built-in Variables424155 -Node: User-modified425282 -Ref: User-modified-Footnote-1432971 -Node: Auto-set433033 -Ref: Auto-set-Footnote-1445615 -Ref: Auto-set-Footnote-2445820 -Node: ARGC and ARGV445876 -Node: Pattern Action Summary449730 -Node: Arrays451953 -Node: Array Basics453502 -Node: Array Intro454328 -Ref: figure-array-elements456301 -Node: Reference to Elements458708 -Node: Assigning Elements460981 -Node: Array Example461472 -Node: Scanning an Array463204 -Node: Controlling Scanning466219 -Ref: Controlling Scanning-Footnote-1471392 -Node: Delete471708 -Ref: Delete-Footnote-1474473 -Node: Numeric Array Subscripts474530 -Node: Uninitialized Subscripts476713 -Node: Multidimensional478338 -Node: Multiscanning481431 -Node: Arrays of Arrays483020 -Node: Arrays Summary487683 -Node: Functions489788 -Node: Built-in490661 -Node: Calling Built-in491739 -Node: Numeric Functions493727 -Ref: Numeric Functions-Footnote-1497669 -Ref: Numeric Functions-Footnote-2498026 -Ref: Numeric Functions-Footnote-3498074 -Node: String Functions498343 -Ref: String Functions-Footnote-1521354 -Ref: String Functions-Footnote-2521483 -Ref: String Functions-Footnote-3521731 -Node: Gory Details521818 -Ref: table-sub-escapes523487 -Ref: table-sub-posix-92524841 -Ref: table-sub-proposed526192 -Ref: table-posix-sub527546 -Ref: table-gensub-escapes529091 -Ref: Gory Details-Footnote-1530267 -Ref: Gory Details-Footnote-2530318 -Node: I/O Functions530469 -Ref: I/O Functions-Footnote-1537592 -Node: Time Functions537739 -Ref: Time Functions-Footnote-1548203 -Ref: Time Functions-Footnote-2548271 -Ref: Time Functions-Footnote-3548429 -Ref: Time Functions-Footnote-4548540 -Ref: Time Functions-Footnote-5548652 -Ref: Time Functions-Footnote-6548879 -Node: Bitwise Functions549145 -Ref: table-bitwise-ops549707 -Ref: Bitwise Functions-Footnote-1553952 -Node: Type Functions554136 -Node: I18N Functions555278 -Node: User-defined556923 -Node: Definition Syntax557727 -Ref: Definition Syntax-Footnote-1562906 -Node: Function Example562975 -Ref: Function Example-Footnote-1565619 -Node: Function Caveats565641 -Node: Calling A Function566159 -Node: Variable Scope567114 -Node: Pass By Value/Reference570102 -Node: Return Statement573610 -Node: Dynamic Typing576594 -Node: Indirect Calls577523 -Node: Functions Summary587236 -Node: Library Functions589775 -Ref: Library Functions-Footnote-1593393 -Ref: Library Functions-Footnote-2593536 -Node: Library Names593707 -Ref: Library Names-Footnote-1597180 -Ref: Library Names-Footnote-2597400 -Node: General Functions597486 -Node: Strtonum Function598514 -Node: Assert Function601294 -Node: Round Function604620 -Node: Cliff Random Function606161 -Node: Ordinal Functions607177 -Ref: Ordinal Functions-Footnote-1610254 -Ref: Ordinal Functions-Footnote-2610506 -Node: Join Function610717 -Ref: Join Function-Footnote-1612488 -Node: Getlocaltime Function612688 -Node: Readfile Function616424 -Node: Data File Management618263 -Node: Filetrans Function618895 -Node: Rewind Function622964 -Node: File Checking624522 -Ref: File Checking-Footnote-1625654 -Node: Empty Files625855 -Node: Ignoring Assigns627834 -Node: Getopt Function629388 -Ref: Getopt Function-Footnote-1640691 -Node: Passwd Functions640894 -Ref: Passwd Functions-Footnote-1649873 -Node: Group Functions649961 -Ref: Group Functions-Footnote-1657902 -Node: Walking Arrays658115 -Node: Library Functions Summary659718 -Node: Library exercises661106 -Node: Sample Programs662386 -Node: Running Examples663156 -Node: Clones663884 -Node: Cut Program665108 -Node: Egrep Program674976 -Ref: Egrep Program-Footnote-1682947 -Node: Id Program683057 -Node: Split Program686721 -Ref: Split Program-Footnote-1690259 -Node: Tee Program690387 -Node: Uniq Program693194 -Node: Wc Program700624 -Ref: Wc Program-Footnote-1704889 -Node: Miscellaneous Programs704981 -Node: Dupword Program706194 -Node: Alarm Program708225 -Node: Translate Program713039 -Ref: Translate Program-Footnote-1717430 -Ref: Translate Program-Footnote-2717700 -Node: Labels Program717834 -Ref: Labels Program-Footnote-1721205 -Node: Word Sorting721289 -Node: History Sorting725332 -Node: Extract Program727168 -Node: Simple Sed734704 -Node: Igawk Program737766 -Ref: Igawk Program-Footnote-1752077 -Ref: Igawk Program-Footnote-2752278 -Node: Anagram Program752416 -Node: Signature Program755484 -Node: Programs Summary756731 -Node: Programs Exercises757946 -Node: Advanced Features761597 -Node: Nondecimal Data763545 -Node: Array Sorting765122 -Node: Controlling Array Traversal765819 -Node: Array Sorting Functions774099 -Ref: Array Sorting Functions-Footnote-1778006 -Node: Two-way I/O778200 -Ref: Two-way I/O-Footnote-1783716 -Node: TCP/IP Networking783798 -Node: Profiling786642 -Node: Advanced Features Summary794184 -Node: Internationalization796048 -Node: I18N and L10N797528 -Node: Explaining gettext798214 -Ref: Explaining gettext-Footnote-1803354 -Ref: Explaining gettext-Footnote-2803538 -Node: Programmer i18n803703 -Node: Translator i18n807928 -Node: String Extraction808722 -Ref: String Extraction-Footnote-1809683 -Node: Printf Ordering809769 -Ref: Printf Ordering-Footnote-1812551 -Node: I18N Portability812615 -Ref: I18N Portability-Footnote-1815064 -Node: I18N Example815127 -Ref: I18N Example-Footnote-1817849 -Node: Gawk I18N817921 -Node: I18N Summary818559 -Node: Debugger819898 -Node: Debugging820920 -Node: Debugging Concepts821361 -Node: Debugging Terms823217 -Node: Awk Debugging825814 -Node: Sample Debugging Session826706 -Node: Debugger Invocation827226 -Node: Finding The Bug828559 -Node: List of Debugger Commands835041 -Node: Breakpoint Control836373 -Node: Debugger Execution Control840037 -Node: Viewing And Changing Data843397 -Node: Execution Stack846755 -Node: Debugger Info848268 -Node: Miscellaneous Debugger Commands852262 -Node: Readline Support857446 -Node: Limitations858338 -Node: Debugging Summary860612 -Node: Arbitrary Precision Arithmetic861776 -Node: Computer Arithmetic863105 -Ref: Computer Arithmetic-Footnote-1867492 -Node: Math Definitions867549 -Ref: table-ieee-formats870433 -Node: MPFR features870937 -Node: FP Math Caution872579 -Ref: FP Math Caution-Footnote-1873620 -Node: Inexactness of computations873989 -Node: Inexact representation874937 -Node: Comparing FP Values876292 -Node: Errors accumulate877256 -Node: Getting Accuracy878689 -Node: Try To Round881348 -Node: Setting precision882247 -Ref: table-predefined-precision-strings882929 -Node: Setting the rounding mode884722 -Ref: table-gawk-rounding-modes885086 -Ref: Setting the rounding mode-Footnote-1888540 -Node: Arbitrary Precision Integers888719 -Ref: Arbitrary Precision Integers-Footnote-1891722 -Node: POSIX Floating Point Problems891871 -Ref: POSIX Floating Point Problems-Footnote-1895747 -Node: Floating point summary895785 -Node: Dynamic Extensions898002 -Node: Extension Intro899554 -Node: Plugin License900819 -Node: Extension Mechanism Outline901504 -Ref: figure-load-extension901928 -Ref: figure-load-new-function903413 -Ref: figure-call-new-function904415 -Node: Extension API Description906399 -Node: Extension API Functions Introduction907849 -Node: General Data Types912714 -Ref: General Data Types-Footnote-1918407 -Node: Requesting Values918706 -Ref: table-value-types-returned919443 -Node: Memory Allocation Functions920401 -Ref: Memory Allocation Functions-Footnote-1923148 -Node: Constructor Functions923244 -Node: Registration Functions925002 -Node: Extension Functions925687 -Node: Exit Callback Functions927989 -Node: Extension Version String929238 -Node: Input Parsers929888 -Node: Output Wrappers939702 -Node: Two-way processors944218 -Node: Printing Messages946422 -Ref: Printing Messages-Footnote-1947499 -Node: Updating `ERRNO'947651 -Node: Accessing Parameters948390 -Node: Symbol Table Access949620 -Node: Symbol table by name950134 -Node: Symbol table by cookie952110 -Ref: Symbol table by cookie-Footnote-1956243 -Node: Cached values956306 -Ref: Cached values-Footnote-1959810 -Node: Array Manipulation959901 -Ref: Array Manipulation-Footnote-1960999 -Node: Array Data Types961038 -Ref: Array Data Types-Footnote-1963741 -Node: Array Functions963833 -Node: Flattening Arrays967707 -Node: Creating Arrays974559 -Node: Extension API Variables979290 -Node: Extension Versioning979926 -Node: Extension API Informational Variables981827 -Node: Extension API Boilerplate982913 -Node: Finding Extensions986717 -Node: Extension Example987277 -Node: Internal File Description988007 -Node: Internal File Ops992098 -Ref: Internal File Ops-Footnote-11003530 -Node: Using Internal File Ops1003670 -Ref: Using Internal File Ops-Footnote-11006017 -Node: Extension Samples1006285 -Node: Extension Sample File Functions1007809 -Node: Extension Sample Fnmatch1015377 -Node: Extension Sample Fork1016859 -Node: Extension Sample Inplace1018072 -Node: Extension Sample Ord1019747 -Node: Extension Sample Readdir1020583 -Ref: table-readdir-file-types1021439 -Node: Extension Sample Revout1022238 -Node: Extension Sample Rev2way1022829 -Node: Extension Sample Read write array1023570 -Node: Extension Sample Readfile1025449 -Node: Extension Sample API Tests1026549 -Node: Extension Sample Time1027074 -Node: gawkextlib1028389 -Node: Extension summary1031202 -Node: Extension Exercises1034895 -Node: Language History1035617 -Node: V7/SVR3.11037260 -Node: SVR41039580 -Node: POSIX1041022 -Node: BTL1042408 -Node: POSIX/GNU1043142 -Node: Feature History1048885 -Node: Common Extensions1062015 -Node: Ranges and Locales1063327 -Ref: Ranges and Locales-Footnote-11067944 -Ref: Ranges and Locales-Footnote-21067971 -Ref: Ranges and Locales-Footnote-31068205 -Node: Contributors1068426 -Node: History summary1073851 -Node: Installation1075220 -Node: Gawk Distribution1076171 -Node: Getting1076655 -Node: Extracting1077479 -Node: Distribution contents1079121 -Node: Unix Installation1084838 -Node: Quick Installation1085455 -Node: Additional Configuration Options1087897 -Node: Configuration Philosophy1089635 -Node: Non-Unix Installation1091986 -Node: PC Installation1092444 -Node: PC Binary Installation1093755 -Node: PC Compiling1095603 -Ref: PC Compiling-Footnote-11098602 -Node: PC Testing1098707 -Node: PC Using1099883 -Node: Cygwin1104041 -Node: MSYS1104850 -Node: VMS Installation1105364 -Node: VMS Compilation1106160 -Ref: VMS Compilation-Footnote-11107382 -Node: VMS Dynamic Extensions1107440 -Node: VMS Installation Details1108813 -Node: VMS Running1111065 -Node: VMS GNV1113899 -Node: VMS Old Gawk1114622 -Node: Bugs1115092 -Node: Other Versions1119096 -Node: Installation summary1125351 -Node: Notes1126407 -Node: Compatibility Mode1127272 -Node: Additions1128054 -Node: Accessing The Source1128979 -Node: Adding Code1130415 -Node: New Ports1136593 -Node: Derived Files1141074 -Ref: Derived Files-Footnote-11146155 -Ref: Derived Files-Footnote-21146189 -Ref: Derived Files-Footnote-31146785 -Node: Future Extensions1146899 -Node: Implementation Limitations1147505 -Node: Extension Design1148753 -Node: Old Extension Problems1149907 -Ref: Old Extension Problems-Footnote-11151424 -Node: Extension New Mechanism Goals1151481 -Ref: Extension New Mechanism Goals-Footnote-11154841 -Node: Extension Other Design Decisions1155030 -Node: Extension Future Growth1157136 -Node: Old Extension Mechanism1157972 -Node: Notes summary1159734 -Node: Basic Concepts1160920 -Node: Basic High Level1161601 -Ref: figure-general-flow1161873 -Ref: figure-process-flow1162472 -Ref: Basic High Level-Footnote-11165701 -Node: Basic Data Typing1165886 -Node: Glossary1169214 -Node: Copying1194366 -Node: GNU Free Documentation License1231922 -Node: Index1257058 +Ref: Read Terminal-Footnote-177628 +Node: Long77799 +Node: Executable Scripts79175 +Ref: Executable Scripts-Footnote-181008 +Ref: Executable Scripts-Footnote-281110 +Node: Comments81657 +Node: Quoting84130 +Node: DOS Quoting89443 +Node: Sample Data Files90118 +Node: Very Simple92672 +Node: Two Rules97445 +Node: More Complex99339 +Ref: More Complex-Footnote-1102271 +Node: Statements/Lines102356 +Ref: Statements/Lines-Footnote-1106812 +Node: Other Features107077 +Node: When108005 +Node: Intro Summary110175 +Node: Invoking Gawk110941 +Node: Command Line112456 +Node: Options113247 +Ref: Options-Footnote-1129076 +Node: Other Arguments129101 +Node: Naming Standard Input131763 +Node: Environment Variables132856 +Node: AWKPATH Variable133414 +Ref: AWKPATH Variable-Footnote-1136286 +Ref: AWKPATH Variable-Footnote-2136331 +Node: AWKLIBPATH Variable136591 +Node: Other Environment Variables137350 +Node: Exit Status141007 +Node: Include Files141682 +Node: Loading Shared Libraries145260 +Node: Obsolete146644 +Node: Undocumented147341 +Node: Invoking Summary147608 +Node: Regexp149208 +Node: Regexp Usage150658 +Node: Escape Sequences152691 +Node: Regexp Operators158358 +Ref: Regexp Operators-Footnote-1165838 +Ref: Regexp Operators-Footnote-2165985 +Node: Bracket Expressions166083 +Ref: table-char-classes167973 +Node: GNU Regexp Operators170913 +Node: Case-sensitivity174636 +Ref: Case-sensitivity-Footnote-1177528 +Ref: Case-sensitivity-Footnote-2177763 +Node: Leftmost Longest177871 +Node: Computed Regexps179072 +Node: Regexp Summary182444 +Node: Reading Files183913 +Node: Records186005 +Node: awk split records186748 +Node: gawk split records191606 +Ref: gawk split records-Footnote-1196127 +Node: Fields196164 +Ref: Fields-Footnote-1199128 +Node: Nonconstant Fields199214 +Ref: Nonconstant Fields-Footnote-1201444 +Node: Changing Fields201646 +Node: Field Separators207600 +Node: Default Field Splitting210302 +Node: Regexp Field Splitting211419 +Node: Single Character Fields214760 +Node: Command Line Field Separator215819 +Node: Full Line Fields219161 +Ref: Full Line Fields-Footnote-1219669 +Node: Field Splitting Summary219715 +Ref: Field Splitting Summary-Footnote-1222814 +Node: Constant Size222915 +Node: Splitting By Content227522 +Ref: Splitting By Content-Footnote-1231272 +Node: Multiple Line231312 +Ref: Multiple Line-Footnote-1237168 +Node: Getline237347 +Node: Plain Getline239563 +Node: Getline/Variable241658 +Node: Getline/File242805 +Node: Getline/Variable/File244189 +Ref: Getline/Variable/File-Footnote-1245788 +Node: Getline/Pipe245875 +Node: Getline/Variable/Pipe248574 +Node: Getline/Coprocess249681 +Node: Getline/Variable/Coprocess250933 +Node: Getline Notes251670 +Node: Getline Summary254474 +Ref: table-getline-variants254882 +Node: Read Timeout255794 +Ref: Read Timeout-Footnote-1259621 +Node: Command-line directories259679 +Node: Input Summary260583 +Node: Input Exercises263720 +Node: Printing264453 +Node: Print266175 +Node: Print Examples267516 +Node: Output Separators270295 +Node: OFMT272311 +Node: Printf273669 +Node: Basic Printf274575 +Node: Control Letters276114 +Node: Format Modifiers280105 +Node: Printf Examples286132 +Node: Redirection288596 +Node: Special Files295568 +Node: Special FD296099 +Ref: Special FD-Footnote-1299696 +Node: Special Network299770 +Node: Special Caveats300620 +Node: Close Files And Pipes301416 +Ref: Close Files And Pipes-Footnote-1308577 +Ref: Close Files And Pipes-Footnote-2308725 +Node: Output Summary308875 +Node: Output exercises309872 +Node: Expressions310552 +Node: Values311737 +Node: Constants312413 +Node: Scalar Constants313093 +Ref: Scalar Constants-Footnote-1313952 +Node: Nondecimal-numbers314202 +Node: Regexp Constants317202 +Node: Using Constant Regexps317677 +Node: Variables320749 +Node: Using Variables321404 +Node: Assignment Options323128 +Node: Conversion325003 +Node: Strings And Numbers325527 +Ref: Strings And Numbers-Footnote-1328589 +Node: Locale influences conversions328698 +Ref: table-locale-affects331415 +Node: All Operators332003 +Node: Arithmetic Ops332633 +Node: Concatenation335138 +Ref: Concatenation-Footnote-1337957 +Node: Assignment Ops338077 +Ref: table-assign-ops343060 +Node: Increment Ops344377 +Node: Truth Values and Conditions347815 +Node: Truth Values348898 +Node: Typing and Comparison349947 +Node: Variable Typing350740 +Node: Comparison Operators354390 +Ref: table-relational-ops354800 +Node: POSIX String Comparison358350 +Ref: POSIX String Comparison-Footnote-1359434 +Node: Boolean Ops359572 +Ref: Boolean Ops-Footnote-1363642 +Node: Conditional Exp363733 +Node: Function Calls365460 +Node: Precedence369340 +Node: Locales373009 +Node: Expressions Summary374640 +Node: Patterns and Actions377181 +Node: Pattern Overview378297 +Node: Regexp Patterns379974 +Node: Expression Patterns380517 +Node: Ranges384298 +Node: BEGIN/END387404 +Node: Using BEGIN/END388166 +Ref: Using BEGIN/END-Footnote-1390902 +Node: I/O And BEGIN/END391008 +Node: BEGINFILE/ENDFILE393293 +Node: Empty396224 +Node: Using Shell Variables396541 +Node: Action Overview398824 +Node: Statements401151 +Node: If Statement402999 +Node: While Statement404497 +Node: Do Statement406541 +Node: For Statement407697 +Node: Switch Statement410849 +Node: Break Statement412952 +Node: Continue Statement415007 +Node: Next Statement416800 +Node: Nextfile Statement419190 +Node: Exit Statement421845 +Node: Built-in Variables424249 +Node: User-modified425376 +Ref: User-modified-Footnote-1433065 +Node: Auto-set433127 +Ref: Auto-set-Footnote-1445709 +Ref: Auto-set-Footnote-2445914 +Node: ARGC and ARGV445970 +Node: Pattern Action Summary449824 +Node: Arrays452047 +Node: Array Basics453596 +Node: Array Intro454422 +Ref: figure-array-elements456395 +Node: Reference to Elements458802 +Node: Assigning Elements461075 +Node: Array Example461566 +Node: Scanning an Array463298 +Node: Controlling Scanning466313 +Ref: Controlling Scanning-Footnote-1471486 +Node: Delete471802 +Ref: Delete-Footnote-1474567 +Node: Numeric Array Subscripts474624 +Node: Uninitialized Subscripts476807 +Node: Multidimensional478432 +Node: Multiscanning481525 +Node: Arrays of Arrays483114 +Node: Arrays Summary487777 +Node: Functions489882 +Node: Built-in490755 +Node: Calling Built-in491833 +Node: Numeric Functions493821 +Ref: Numeric Functions-Footnote-1497763 +Ref: Numeric Functions-Footnote-2498120 +Ref: Numeric Functions-Footnote-3498168 +Node: String Functions498437 +Ref: String Functions-Footnote-1521448 +Ref: String Functions-Footnote-2521577 +Ref: String Functions-Footnote-3521825 +Node: Gory Details521912 +Ref: table-sub-escapes523699 +Ref: table-sub-proposed525219 +Ref: table-posix-sub526583 +Ref: table-gensub-escapes528123 +Ref: Gory Details-Footnote-1529299 +Node: I/O Functions529450 +Ref: I/O Functions-Footnote-1536573 +Node: Time Functions536720 +Ref: Time Functions-Footnote-1547184 +Ref: Time Functions-Footnote-2547252 +Ref: Time Functions-Footnote-3547410 +Ref: Time Functions-Footnote-4547521 +Ref: Time Functions-Footnote-5547633 +Ref: Time Functions-Footnote-6547860 +Node: Bitwise Functions548126 +Ref: table-bitwise-ops548688 +Ref: Bitwise Functions-Footnote-1552933 +Node: Type Functions553117 +Node: I18N Functions554259 +Node: User-defined555904 +Node: Definition Syntax556708 +Ref: Definition Syntax-Footnote-1561887 +Node: Function Example561956 +Ref: Function Example-Footnote-1564520 +Node: Function Caveats564542 +Node: Calling A Function565060 +Node: Variable Scope566015 +Node: Pass By Value/Reference569003 +Node: Return Statement572513 +Node: Dynamic Typing575497 +Node: Indirect Calls576426 +Node: Functions Summary586139 +Node: Library Functions588678 +Ref: Library Functions-Footnote-1592296 +Ref: Library Functions-Footnote-2592439 +Node: Library Names592610 +Ref: Library Names-Footnote-1596083 +Ref: Library Names-Footnote-2596303 +Node: General Functions596389 +Node: Strtonum Function597417 +Node: Assert Function600197 +Node: Round Function603523 +Node: Cliff Random Function605064 +Node: Ordinal Functions606080 +Ref: Ordinal Functions-Footnote-1609157 +Ref: Ordinal Functions-Footnote-2609409 +Node: Join Function609620 +Ref: Join Function-Footnote-1611391 +Node: Getlocaltime Function611591 +Node: Readfile Function615327 +Node: Data File Management617166 +Node: Filetrans Function617798 +Node: Rewind Function621867 +Node: File Checking623425 +Ref: File Checking-Footnote-1624557 +Node: Empty Files624758 +Node: Ignoring Assigns626737 +Node: Getopt Function628291 +Ref: Getopt Function-Footnote-1639594 +Node: Passwd Functions639797 +Ref: Passwd Functions-Footnote-1648776 +Node: Group Functions648864 +Ref: Group Functions-Footnote-1656805 +Node: Walking Arrays657018 +Node: Library Functions Summary658621 +Node: Library exercises660009 +Node: Sample Programs661289 +Node: Running Examples662059 +Node: Clones662787 +Node: Cut Program664011 +Node: Egrep Program673879 +Ref: Egrep Program-Footnote-1681850 +Node: Id Program681960 +Node: Split Program685624 +Ref: Split Program-Footnote-1689162 +Node: Tee Program689290 +Node: Uniq Program692097 +Node: Wc Program699527 +Ref: Wc Program-Footnote-1703792 +Node: Miscellaneous Programs703884 +Node: Dupword Program705097 +Node: Alarm Program707128 +Node: Translate Program711942 +Ref: Translate Program-Footnote-1716333 +Ref: Translate Program-Footnote-2716603 +Node: Labels Program716737 +Ref: Labels Program-Footnote-1720108 +Node: Word Sorting720192 +Node: History Sorting724235 +Node: Extract Program726071 +Node: Simple Sed733607 +Node: Igawk Program736669 +Ref: Igawk Program-Footnote-1750980 +Ref: Igawk Program-Footnote-2751181 +Node: Anagram Program751319 +Node: Signature Program754387 +Node: Programs Summary755634 +Node: Programs Exercises756849 +Node: Advanced Features760500 +Node: Nondecimal Data762448 +Node: Array Sorting764025 +Node: Controlling Array Traversal764722 +Node: Array Sorting Functions773002 +Ref: Array Sorting Functions-Footnote-1776909 +Node: Two-way I/O777103 +Ref: Two-way I/O-Footnote-1782047 +Ref: Two-way I/O-Footnote-2782226 +Node: TCP/IP Networking782308 +Node: Profiling785153 +Node: Advanced Features Summary792695 +Node: Internationalization794559 +Node: I18N and L10N796039 +Node: Explaining gettext796725 +Ref: Explaining gettext-Footnote-1801865 +Ref: Explaining gettext-Footnote-2802049 +Node: Programmer i18n802214 +Node: Translator i18n806439 +Node: String Extraction807233 +Ref: String Extraction-Footnote-1808194 +Node: Printf Ordering808280 +Ref: Printf Ordering-Footnote-1811062 +Node: I18N Portability811126 +Ref: I18N Portability-Footnote-1813575 +Node: I18N Example813638 +Ref: I18N Example-Footnote-1816360 +Node: Gawk I18N816432 +Node: I18N Summary817070 +Node: Debugger818409 +Node: Debugging819431 +Node: Debugging Concepts819872 +Node: Debugging Terms821728 +Node: Awk Debugging824325 +Node: Sample Debugging Session825217 +Node: Debugger Invocation825737 +Node: Finding The Bug827070 +Node: List of Debugger Commands833552 +Node: Breakpoint Control834884 +Node: Debugger Execution Control838548 +Node: Viewing And Changing Data841908 +Node: Execution Stack845266 +Node: Debugger Info846779 +Node: Miscellaneous Debugger Commands850773 +Node: Readline Support855957 +Node: Limitations856849 +Node: Debugging Summary859123 +Node: Arbitrary Precision Arithmetic860287 +Node: Computer Arithmetic861774 +Ref: Computer Arithmetic-Footnote-1866161 +Node: Math Definitions866218 +Ref: table-ieee-formats869507 +Ref: Math Definitions-Footnote-1870047 +Node: MPFR features870150 +Node: FP Math Caution871792 +Ref: FP Math Caution-Footnote-1872833 +Node: Inexactness of computations873202 +Node: Inexact representation874150 +Node: Comparing FP Values875505 +Node: Errors accumulate876469 +Node: Getting Accuracy877902 +Node: Try To Round880561 +Node: Setting precision881460 +Ref: table-predefined-precision-strings882142 +Node: Setting the rounding mode883935 +Ref: table-gawk-rounding-modes884299 +Ref: Setting the rounding mode-Footnote-1887753 +Node: Arbitrary Precision Integers887932 +Ref: Arbitrary Precision Integers-Footnote-1890935 +Node: POSIX Floating Point Problems891084 +Ref: POSIX Floating Point Problems-Footnote-1894960 +Node: Floating point summary894998 +Node: Dynamic Extensions897215 +Node: Extension Intro898767 +Node: Plugin License900032 +Node: Extension Mechanism Outline900717 +Ref: figure-load-extension901141 +Ref: figure-load-new-function902626 +Ref: figure-call-new-function903628 +Node: Extension API Description905612 +Node: Extension API Functions Introduction907062 +Node: General Data Types911927 +Ref: General Data Types-Footnote-1917620 +Node: Requesting Values917919 +Ref: table-value-types-returned918656 +Node: Memory Allocation Functions919614 +Ref: Memory Allocation Functions-Footnote-1922361 +Node: Constructor Functions922457 +Node: Registration Functions924215 +Node: Extension Functions924900 +Node: Exit Callback Functions927202 +Node: Extension Version String928451 +Node: Input Parsers929101 +Node: Output Wrappers938915 +Node: Two-way processors943431 +Node: Printing Messages945635 +Ref: Printing Messages-Footnote-1946712 +Node: Updating `ERRNO'946864 +Node: Accessing Parameters947603 +Node: Symbol Table Access948833 +Node: Symbol table by name949347 +Node: Symbol table by cookie951323 +Ref: Symbol table by cookie-Footnote-1955456 +Node: Cached values955519 +Ref: Cached values-Footnote-1959023 +Node: Array Manipulation959114 +Ref: Array Manipulation-Footnote-1960212 +Node: Array Data Types960251 +Ref: Array Data Types-Footnote-1962954 +Node: Array Functions963046 +Node: Flattening Arrays966920 +Node: Creating Arrays973772 +Node: Extension API Variables978503 +Node: Extension Versioning979139 +Node: Extension API Informational Variables981040 +Node: Extension API Boilerplate982126 +Node: Finding Extensions985930 +Node: Extension Example986490 +Node: Internal File Description987220 +Node: Internal File Ops991311 +Ref: Internal File Ops-Footnote-11002743 +Node: Using Internal File Ops1002883 +Ref: Using Internal File Ops-Footnote-11005230 +Node: Extension Samples1005498 +Node: Extension Sample File Functions1007022 +Node: Extension Sample Fnmatch1014590 +Node: Extension Sample Fork1016072 +Node: Extension Sample Inplace1017285 +Node: Extension Sample Ord1018960 +Node: Extension Sample Readdir1019796 +Ref: table-readdir-file-types1020652 +Node: Extension Sample Revout1021451 +Node: Extension Sample Rev2way1022042 +Node: Extension Sample Read write array1022783 +Node: Extension Sample Readfile1024662 +Node: Extension Sample API Tests1025762 +Node: Extension Sample Time1026287 +Node: gawkextlib1027602 +Node: Extension summary1030415 +Node: Extension Exercises1034108 +Node: Language History1034830 +Node: V7/SVR3.11036473 +Node: SVR41038793 +Node: POSIX1040235 +Node: BTL1041621 +Node: POSIX/GNU1042355 +Node: Feature History1048098 +Node: Common Extensions1061228 +Node: Ranges and Locales1062540 +Ref: Ranges and Locales-Footnote-11067157 +Ref: Ranges and Locales-Footnote-21067184 +Ref: Ranges and Locales-Footnote-31067418 +Node: Contributors1067639 +Node: History summary1073064 +Node: Installation1074433 +Node: Gawk Distribution1075384 +Node: Getting1075868 +Node: Extracting1076692 +Node: Distribution contents1078334 +Node: Unix Installation1084051 +Node: Quick Installation1084668 +Node: Additional Configuration Options1087110 +Node: Configuration Philosophy1088848 +Node: Non-Unix Installation1091199 +Node: PC Installation1091657 +Node: PC Binary Installation1092968 +Node: PC Compiling1094816 +Ref: PC Compiling-Footnote-11097815 +Node: PC Testing1097920 +Node: PC Using1099096 +Node: Cygwin1103254 +Node: MSYS1104063 +Node: VMS Installation1104577 +Node: VMS Compilation1105373 +Ref: VMS Compilation-Footnote-11106595 +Node: VMS Dynamic Extensions1106653 +Node: VMS Installation Details1108026 +Node: VMS Running1110278 +Node: VMS GNV1113112 +Node: VMS Old Gawk1113835 +Node: Bugs1114305 +Node: Other Versions1118309 +Node: Installation summary1124564 +Node: Notes1125620 +Node: Compatibility Mode1126485 +Node: Additions1127267 +Node: Accessing The Source1128192 +Node: Adding Code1129628 +Node: New Ports1135806 +Node: Derived Files1140287 +Ref: Derived Files-Footnote-11145368 +Ref: Derived Files-Footnote-21145402 +Ref: Derived Files-Footnote-31145998 +Node: Future Extensions1146112 +Node: Implementation Limitations1146718 +Node: Extension Design1147966 +Node: Old Extension Problems1149120 +Ref: Old Extension Problems-Footnote-11150637 +Node: Extension New Mechanism Goals1150694 +Ref: Extension New Mechanism Goals-Footnote-11154054 +Node: Extension Other Design Decisions1154243 +Node: Extension Future Growth1156349 +Node: Old Extension Mechanism1157185 +Node: Notes summary1158947 +Node: Basic Concepts1160133 +Node: Basic High Level1160814 +Ref: figure-general-flow1161086 +Ref: figure-process-flow1161685 +Ref: Basic High Level-Footnote-11164914 +Node: Basic Data Typing1165099 +Node: Glossary1168427 +Node: Copying1193579 +Node: GNU Free Documentation License1231135 +Node: Index1256271  End Tag Table -- cgit v1.2.3 From 44f0c70e04a1beef988cde4950aabe29139e789a Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sat, 16 Aug 2014 22:08:24 +0300 Subject: More reviewer comments. --- doc/gawk.info | 954 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 481 insertions(+), 473 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 8f91f3c0..501b8136 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -4817,7 +4817,8 @@ argument to `-F' is `t', then `FS' is set to the TAB character. If you type `-F\t' at the shell, without any quotes, the `\' gets deleted, so `awk' figures that you really want your fields to be separated with TABs and not `t's. Use `-v FS="t"' or `-F"[t]"' on the command line if -you really do want to separate your fields with `t's. +you really do want to separate your fields with `t's. Use `-F '\t'' +when not in compatibility mode to specify that TABs separate fields. As an example, let's use an `awk' program file called `edu.awk' that contains the pattern `/edu/' and the action `print $1': @@ -4937,8 +4938,8 @@ which usually prints: root -on an incorrect implementation of `awk', while `gawk' prints something -like: +on an incorrect implementation of `awk', while `gawk' prints the full +first line of the file, something like: root:nSijPlPhZZwgE:0:0:Root:/: @@ -5018,7 +5019,7 @@ calculated idle time: BEGIN { FIELDWIDTHS = "9 6 10 6 7 7 35" } NR > 2 { idle = $4 - sub(/^ */, "", idle) # strip leading spaces + sub(/^ +/, "", idle) # strip leading spaces if (idle == "") idle = 0 if (idle ~ /:/) { @@ -5149,8 +5150,10 @@ would be to remove the quotes when they occur, with something like this: As with `FS', the `IGNORECASE' variable (*note User-modified::) affects field splitting with `FPAT'. - Similar to `FIELDWIDTHS', the value of `PROCINFO["FS"]' will be -`"FPAT"' if content-based field splitting is being used. + Assigning a value to `FPAT' overrides field splitting with `FS' and +with `FIELDWIDTHS'. Similar to `FIELDWIDTHS', the value of +`PROCINFO["FS"]' will be `"FPAT"' if content-based field splitting is +being used. NOTE: Some programs export CSV data that contains embedded newlines between the double quotes. `gawk' provides no way to @@ -5168,6 +5171,11 @@ changed the first `+' to `*') allows fields to be empty: Finally, the `patsplit()' function makes the same functionality available for splitting regular strings (*note String Functions::). + To recap, `gawk' provides three independent methods to split input +records into fields. `gawk' uses whichever mechanism was last chosen +based on which of the three variables--`FS', `FIELDWIDTHS', and +`FPAT'--was last assigned to. + ---------- Footnotes ---------- (1) At least, we don't know of one. @@ -6755,8 +6763,8 @@ to rename the files. It then sends the list to the shell for execution.  File: gawk.info, Node: Special Files, Next: Close Files And Pipes, Prev: Redirection, Up: Printing -5.7 Special File Name in `gawk' -=============================== +5.7 Special File Names in `gawk' +================================ `gawk' provides a number of special file names that it interprets internally. These file names provide access to standard file @@ -8194,7 +8202,7 @@ operands, according to the following symmetric matrix: user input--should be treated as numeric, even though it is actually made of characters and is therefore also a string. Thus, for example, the string constant `" +3.14"', when it appears in program source code, -is a string--even though it looks numeric--and is _never_ treated as +is a string--even though it looks numeric--and is _never_ treated as a number for comparison purposes. In short, when one operand is a "pure" string, such as a string @@ -21605,7 +21613,7 @@ File: gawk.info, Node: FP Math Caution, Next: Arbitrary Precision Integers, P 15.4 Floating Point Arithmetic: Caveat Emptor! ============================================== - Math class is tough! -- Late 1980's Barbie + Math class is tough! -- Teen Talk Barbie (July, 1992) This minor node provides a high level overview of the issues involved when doing lots of floating-point arithmetic.(1) The @@ -22167,7 +22175,7 @@ File: gawk.info, Node: Floating point summary, Prev: POSIX Floating Point Prob floating-point values. The default for `awk' is to use double-precision floating-point values. - * In the 1980's, Barbie mistakenly said "Math class is tough!" + * In the early 1990's, Barbie mistakenly said "Math class is tough!" While math isn't tough, floating-point arithmetic isn't the same as pencil and paper math, and care must be taken: @@ -33379,7 +33387,7 @@ Index * Robbins, Arnold <6>: Passwd Functions. (line 90) * Robbins, Arnold <7>: Getline/Pipe. (line 39) * Robbins, Arnold: Command Line Field Separator. - (line 73) + (line 74) * Robbins, Bill: Getline/Pipe. (line 39) * Robbins, Harry: Acknowledgments. (line 92) * Robbins, Jean: Acknowledgments. (line 92) @@ -33794,7 +33802,7 @@ Index * Unix awk, close() function and: Close Files And Pipes. (line 131) * Unix awk, password files, field separators and: Command Line Field Separator. - (line 64) + (line 65) * Unix, awk scripts and: Executable Scripts. (line 6) * UNIXROOT variable, on OS/2 systems: PC Using. (line 16) * unsigned integers: Computer Arithmetic. (line 41) @@ -34020,465 +34028,465 @@ Node: Default Field Splitting210302 Node: Regexp Field Splitting211419 Node: Single Character Fields214760 Node: Command Line Field Separator215819 -Node: Full Line Fields219161 -Ref: Full Line Fields-Footnote-1219669 -Node: Field Splitting Summary219715 -Ref: Field Splitting Summary-Footnote-1222814 -Node: Constant Size222915 -Node: Splitting By Content227522 -Ref: Splitting By Content-Footnote-1231272 -Node: Multiple Line231312 -Ref: Multiple Line-Footnote-1237168 -Node: Getline237347 -Node: Plain Getline239563 -Node: Getline/Variable241658 -Node: Getline/File242805 -Node: Getline/Variable/File244189 -Ref: Getline/Variable/File-Footnote-1245788 -Node: Getline/Pipe245875 -Node: Getline/Variable/Pipe248574 -Node: Getline/Coprocess249681 -Node: Getline/Variable/Coprocess250933 -Node: Getline Notes251670 -Node: Getline Summary254474 -Ref: table-getline-variants254882 -Node: Read Timeout255794 -Ref: Read Timeout-Footnote-1259621 -Node: Command-line directories259679 -Node: Input Summary260583 -Node: Input Exercises263720 -Node: Printing264453 -Node: Print266175 -Node: Print Examples267516 -Node: Output Separators270295 -Node: OFMT272311 -Node: Printf273669 -Node: Basic Printf274575 -Node: Control Letters276114 -Node: Format Modifiers280105 -Node: Printf Examples286132 -Node: Redirection288596 -Node: Special Files295568 -Node: Special FD296099 -Ref: Special FD-Footnote-1299696 -Node: Special Network299770 -Node: Special Caveats300620 -Node: Close Files And Pipes301416 -Ref: Close Files And Pipes-Footnote-1308577 -Ref: Close Files And Pipes-Footnote-2308725 -Node: Output Summary308875 -Node: Output exercises309872 -Node: Expressions310552 -Node: Values311737 -Node: Constants312413 -Node: Scalar Constants313093 -Ref: Scalar Constants-Footnote-1313952 -Node: Nondecimal-numbers314202 -Node: Regexp Constants317202 -Node: Using Constant Regexps317677 -Node: Variables320749 -Node: Using Variables321404 -Node: Assignment Options323128 -Node: Conversion325003 -Node: Strings And Numbers325527 -Ref: Strings And Numbers-Footnote-1328589 -Node: Locale influences conversions328698 -Ref: table-locale-affects331415 -Node: All Operators332003 -Node: Arithmetic Ops332633 -Node: Concatenation335138 -Ref: Concatenation-Footnote-1337957 -Node: Assignment Ops338077 -Ref: table-assign-ops343060 -Node: Increment Ops344377 -Node: Truth Values and Conditions347815 -Node: Truth Values348898 -Node: Typing and Comparison349947 -Node: Variable Typing350740 -Node: Comparison Operators354390 -Ref: table-relational-ops354800 -Node: POSIX String Comparison358350 -Ref: POSIX String Comparison-Footnote-1359434 -Node: Boolean Ops359572 -Ref: Boolean Ops-Footnote-1363642 -Node: Conditional Exp363733 -Node: Function Calls365460 -Node: Precedence369340 -Node: Locales373009 -Node: Expressions Summary374640 -Node: Patterns and Actions377181 -Node: Pattern Overview378297 -Node: Regexp Patterns379974 -Node: Expression Patterns380517 -Node: Ranges384298 -Node: BEGIN/END387404 -Node: Using BEGIN/END388166 -Ref: Using BEGIN/END-Footnote-1390902 -Node: I/O And BEGIN/END391008 -Node: BEGINFILE/ENDFILE393293 -Node: Empty396224 -Node: Using Shell Variables396541 -Node: Action Overview398824 -Node: Statements401151 -Node: If Statement402999 -Node: While Statement404497 -Node: Do Statement406541 -Node: For Statement407697 -Node: Switch Statement410849 -Node: Break Statement412952 -Node: Continue Statement415007 -Node: Next Statement416800 -Node: Nextfile Statement419190 -Node: Exit Statement421845 -Node: Built-in Variables424249 -Node: User-modified425376 -Ref: User-modified-Footnote-1433065 -Node: Auto-set433127 -Ref: Auto-set-Footnote-1445709 -Ref: Auto-set-Footnote-2445914 -Node: ARGC and ARGV445970 -Node: Pattern Action Summary449824 -Node: Arrays452047 -Node: Array Basics453596 -Node: Array Intro454422 -Ref: figure-array-elements456395 -Node: Reference to Elements458802 -Node: Assigning Elements461075 -Node: Array Example461566 -Node: Scanning an Array463298 -Node: Controlling Scanning466313 -Ref: Controlling Scanning-Footnote-1471486 -Node: Delete471802 -Ref: Delete-Footnote-1474567 -Node: Numeric Array Subscripts474624 -Node: Uninitialized Subscripts476807 -Node: Multidimensional478432 -Node: Multiscanning481525 -Node: Arrays of Arrays483114 -Node: Arrays Summary487777 -Node: Functions489882 -Node: Built-in490755 -Node: Calling Built-in491833 -Node: Numeric Functions493821 -Ref: Numeric Functions-Footnote-1497763 -Ref: Numeric Functions-Footnote-2498120 -Ref: Numeric Functions-Footnote-3498168 -Node: String Functions498437 -Ref: String Functions-Footnote-1521448 -Ref: String Functions-Footnote-2521577 -Ref: String Functions-Footnote-3521825 -Node: Gory Details521912 -Ref: table-sub-escapes523699 -Ref: table-sub-proposed525219 -Ref: table-posix-sub526583 -Ref: table-gensub-escapes528123 -Ref: Gory Details-Footnote-1529299 -Node: I/O Functions529450 -Ref: I/O Functions-Footnote-1536573 -Node: Time Functions536720 -Ref: Time Functions-Footnote-1547184 -Ref: Time Functions-Footnote-2547252 -Ref: Time Functions-Footnote-3547410 -Ref: Time Functions-Footnote-4547521 -Ref: Time Functions-Footnote-5547633 -Ref: Time Functions-Footnote-6547860 -Node: Bitwise Functions548126 -Ref: table-bitwise-ops548688 -Ref: Bitwise Functions-Footnote-1552933 -Node: Type Functions553117 -Node: I18N Functions554259 -Node: User-defined555904 -Node: Definition Syntax556708 -Ref: Definition Syntax-Footnote-1561887 -Node: Function Example561956 -Ref: Function Example-Footnote-1564520 -Node: Function Caveats564542 -Node: Calling A Function565060 -Node: Variable Scope566015 -Node: Pass By Value/Reference569003 -Node: Return Statement572513 -Node: Dynamic Typing575497 -Node: Indirect Calls576426 -Node: Functions Summary586139 -Node: Library Functions588678 -Ref: Library Functions-Footnote-1592296 -Ref: Library Functions-Footnote-2592439 -Node: Library Names592610 -Ref: Library Names-Footnote-1596083 -Ref: Library Names-Footnote-2596303 -Node: General Functions596389 -Node: Strtonum Function597417 -Node: Assert Function600197 -Node: Round Function603523 -Node: Cliff Random Function605064 -Node: Ordinal Functions606080 -Ref: Ordinal Functions-Footnote-1609157 -Ref: Ordinal Functions-Footnote-2609409 -Node: Join Function609620 -Ref: Join Function-Footnote-1611391 -Node: Getlocaltime Function611591 -Node: Readfile Function615327 -Node: Data File Management617166 -Node: Filetrans Function617798 -Node: Rewind Function621867 -Node: File Checking623425 -Ref: File Checking-Footnote-1624557 -Node: Empty Files624758 -Node: Ignoring Assigns626737 -Node: Getopt Function628291 -Ref: Getopt Function-Footnote-1639594 -Node: Passwd Functions639797 -Ref: Passwd Functions-Footnote-1648776 -Node: Group Functions648864 -Ref: Group Functions-Footnote-1656805 -Node: Walking Arrays657018 -Node: Library Functions Summary658621 -Node: Library exercises660009 -Node: Sample Programs661289 -Node: Running Examples662059 -Node: Clones662787 -Node: Cut Program664011 -Node: Egrep Program673879 -Ref: Egrep Program-Footnote-1681850 -Node: Id Program681960 -Node: Split Program685624 -Ref: Split Program-Footnote-1689162 -Node: Tee Program689290 -Node: Uniq Program692097 -Node: Wc Program699527 -Ref: Wc Program-Footnote-1703792 -Node: Miscellaneous Programs703884 -Node: Dupword Program705097 -Node: Alarm Program707128 -Node: Translate Program711942 -Ref: Translate Program-Footnote-1716333 -Ref: Translate Program-Footnote-2716603 -Node: Labels Program716737 -Ref: Labels Program-Footnote-1720108 -Node: Word Sorting720192 -Node: History Sorting724235 -Node: Extract Program726071 -Node: Simple Sed733607 -Node: Igawk Program736669 -Ref: Igawk Program-Footnote-1750980 -Ref: Igawk Program-Footnote-2751181 -Node: Anagram Program751319 -Node: Signature Program754387 -Node: Programs Summary755634 -Node: Programs Exercises756849 -Node: Advanced Features760500 -Node: Nondecimal Data762448 -Node: Array Sorting764025 -Node: Controlling Array Traversal764722 -Node: Array Sorting Functions773002 -Ref: Array Sorting Functions-Footnote-1776909 -Node: Two-way I/O777103 -Ref: Two-way I/O-Footnote-1782047 -Ref: Two-way I/O-Footnote-2782226 -Node: TCP/IP Networking782308 -Node: Profiling785153 -Node: Advanced Features Summary792695 -Node: Internationalization794559 -Node: I18N and L10N796039 -Node: Explaining gettext796725 -Ref: Explaining gettext-Footnote-1801865 -Ref: Explaining gettext-Footnote-2802049 -Node: Programmer i18n802214 -Node: Translator i18n806439 -Node: String Extraction807233 -Ref: String Extraction-Footnote-1808194 -Node: Printf Ordering808280 -Ref: Printf Ordering-Footnote-1811062 -Node: I18N Portability811126 -Ref: I18N Portability-Footnote-1813575 -Node: I18N Example813638 -Ref: I18N Example-Footnote-1816360 -Node: Gawk I18N816432 -Node: I18N Summary817070 -Node: Debugger818409 -Node: Debugging819431 -Node: Debugging Concepts819872 -Node: Debugging Terms821728 -Node: Awk Debugging824325 -Node: Sample Debugging Session825217 -Node: Debugger Invocation825737 -Node: Finding The Bug827070 -Node: List of Debugger Commands833552 -Node: Breakpoint Control834884 -Node: Debugger Execution Control838548 -Node: Viewing And Changing Data841908 -Node: Execution Stack845266 -Node: Debugger Info846779 -Node: Miscellaneous Debugger Commands850773 -Node: Readline Support855957 -Node: Limitations856849 -Node: Debugging Summary859123 -Node: Arbitrary Precision Arithmetic860287 -Node: Computer Arithmetic861774 -Ref: Computer Arithmetic-Footnote-1866161 -Node: Math Definitions866218 -Ref: table-ieee-formats869507 -Ref: Math Definitions-Footnote-1870047 -Node: MPFR features870150 -Node: FP Math Caution871792 -Ref: FP Math Caution-Footnote-1872833 -Node: Inexactness of computations873202 -Node: Inexact representation874150 -Node: Comparing FP Values875505 -Node: Errors accumulate876469 -Node: Getting Accuracy877902 -Node: Try To Round880561 -Node: Setting precision881460 -Ref: table-predefined-precision-strings882142 -Node: Setting the rounding mode883935 -Ref: table-gawk-rounding-modes884299 -Ref: Setting the rounding mode-Footnote-1887753 -Node: Arbitrary Precision Integers887932 -Ref: Arbitrary Precision Integers-Footnote-1890935 -Node: POSIX Floating Point Problems891084 -Ref: POSIX Floating Point Problems-Footnote-1894960 -Node: Floating point summary894998 -Node: Dynamic Extensions897215 -Node: Extension Intro898767 -Node: Plugin License900032 -Node: Extension Mechanism Outline900717 -Ref: figure-load-extension901141 -Ref: figure-load-new-function902626 -Ref: figure-call-new-function903628 -Node: Extension API Description905612 -Node: Extension API Functions Introduction907062 -Node: General Data Types911927 -Ref: General Data Types-Footnote-1917620 -Node: Requesting Values917919 -Ref: table-value-types-returned918656 -Node: Memory Allocation Functions919614 -Ref: Memory Allocation Functions-Footnote-1922361 -Node: Constructor Functions922457 -Node: Registration Functions924215 -Node: Extension Functions924900 -Node: Exit Callback Functions927202 -Node: Extension Version String928451 -Node: Input Parsers929101 -Node: Output Wrappers938915 -Node: Two-way processors943431 -Node: Printing Messages945635 -Ref: Printing Messages-Footnote-1946712 -Node: Updating `ERRNO'946864 -Node: Accessing Parameters947603 -Node: Symbol Table Access948833 -Node: Symbol table by name949347 -Node: Symbol table by cookie951323 -Ref: Symbol table by cookie-Footnote-1955456 -Node: Cached values955519 -Ref: Cached values-Footnote-1959023 -Node: Array Manipulation959114 -Ref: Array Manipulation-Footnote-1960212 -Node: Array Data Types960251 -Ref: Array Data Types-Footnote-1962954 -Node: Array Functions963046 -Node: Flattening Arrays966920 -Node: Creating Arrays973772 -Node: Extension API Variables978503 -Node: Extension Versioning979139 -Node: Extension API Informational Variables981040 -Node: Extension API Boilerplate982126 -Node: Finding Extensions985930 -Node: Extension Example986490 -Node: Internal File Description987220 -Node: Internal File Ops991311 -Ref: Internal File Ops-Footnote-11002743 -Node: Using Internal File Ops1002883 -Ref: Using Internal File Ops-Footnote-11005230 -Node: Extension Samples1005498 -Node: Extension Sample File Functions1007022 -Node: Extension Sample Fnmatch1014590 -Node: Extension Sample Fork1016072 -Node: Extension Sample Inplace1017285 -Node: Extension Sample Ord1018960 -Node: Extension Sample Readdir1019796 -Ref: table-readdir-file-types1020652 -Node: Extension Sample Revout1021451 -Node: Extension Sample Rev2way1022042 -Node: Extension Sample Read write array1022783 -Node: Extension Sample Readfile1024662 -Node: Extension Sample API Tests1025762 -Node: Extension Sample Time1026287 -Node: gawkextlib1027602 -Node: Extension summary1030415 -Node: Extension Exercises1034108 -Node: Language History1034830 -Node: V7/SVR3.11036473 -Node: SVR41038793 -Node: POSIX1040235 -Node: BTL1041621 -Node: POSIX/GNU1042355 -Node: Feature History1048098 -Node: Common Extensions1061228 -Node: Ranges and Locales1062540 -Ref: Ranges and Locales-Footnote-11067157 -Ref: Ranges and Locales-Footnote-21067184 -Ref: Ranges and Locales-Footnote-31067418 -Node: Contributors1067639 -Node: History summary1073064 -Node: Installation1074433 -Node: Gawk Distribution1075384 -Node: Getting1075868 -Node: Extracting1076692 -Node: Distribution contents1078334 -Node: Unix Installation1084051 -Node: Quick Installation1084668 -Node: Additional Configuration Options1087110 -Node: Configuration Philosophy1088848 -Node: Non-Unix Installation1091199 -Node: PC Installation1091657 -Node: PC Binary Installation1092968 -Node: PC Compiling1094816 -Ref: PC Compiling-Footnote-11097815 -Node: PC Testing1097920 -Node: PC Using1099096 -Node: Cygwin1103254 -Node: MSYS1104063 -Node: VMS Installation1104577 -Node: VMS Compilation1105373 -Ref: VMS Compilation-Footnote-11106595 -Node: VMS Dynamic Extensions1106653 -Node: VMS Installation Details1108026 -Node: VMS Running1110278 -Node: VMS GNV1113112 -Node: VMS Old Gawk1113835 -Node: Bugs1114305 -Node: Other Versions1118309 -Node: Installation summary1124564 -Node: Notes1125620 -Node: Compatibility Mode1126485 -Node: Additions1127267 -Node: Accessing The Source1128192 -Node: Adding Code1129628 -Node: New Ports1135806 -Node: Derived Files1140287 -Ref: Derived Files-Footnote-11145368 -Ref: Derived Files-Footnote-21145402 -Ref: Derived Files-Footnote-31145998 -Node: Future Extensions1146112 -Node: Implementation Limitations1146718 -Node: Extension Design1147966 -Node: Old Extension Problems1149120 -Ref: Old Extension Problems-Footnote-11150637 -Node: Extension New Mechanism Goals1150694 -Ref: Extension New Mechanism Goals-Footnote-11154054 -Node: Extension Other Design Decisions1154243 -Node: Extension Future Growth1156349 -Node: Old Extension Mechanism1157185 -Node: Notes summary1158947 -Node: Basic Concepts1160133 -Node: Basic High Level1160814 -Ref: figure-general-flow1161086 -Ref: figure-process-flow1161685 -Ref: Basic High Level-Footnote-11164914 -Node: Basic Data Typing1165099 -Node: Glossary1168427 -Node: Copying1193579 -Node: GNU Free Documentation License1231135 -Node: Index1256271 +Node: Full Line Fields219245 +Ref: Full Line Fields-Footnote-1219753 +Node: Field Splitting Summary219799 +Ref: Field Splitting Summary-Footnote-1222931 +Node: Constant Size223032 +Node: Splitting By Content227638 +Ref: Splitting By Content-Footnote-1231711 +Node: Multiple Line231751 +Ref: Multiple Line-Footnote-1237607 +Node: Getline237786 +Node: Plain Getline240002 +Node: Getline/Variable242097 +Node: Getline/File243244 +Node: Getline/Variable/File244628 +Ref: Getline/Variable/File-Footnote-1246227 +Node: Getline/Pipe246314 +Node: Getline/Variable/Pipe249013 +Node: Getline/Coprocess250120 +Node: Getline/Variable/Coprocess251372 +Node: Getline Notes252109 +Node: Getline Summary254913 +Ref: table-getline-variants255321 +Node: Read Timeout256233 +Ref: Read Timeout-Footnote-1260060 +Node: Command-line directories260118 +Node: Input Summary261022 +Node: Input Exercises264159 +Node: Printing264892 +Node: Print266614 +Node: Print Examples267955 +Node: Output Separators270734 +Node: OFMT272750 +Node: Printf274108 +Node: Basic Printf275014 +Node: Control Letters276553 +Node: Format Modifiers280544 +Node: Printf Examples286571 +Node: Redirection289035 +Node: Special Files296007 +Node: Special FD296540 +Ref: Special FD-Footnote-1300137 +Node: Special Network300211 +Node: Special Caveats301061 +Node: Close Files And Pipes301857 +Ref: Close Files And Pipes-Footnote-1309018 +Ref: Close Files And Pipes-Footnote-2309166 +Node: Output Summary309316 +Node: Output exercises310313 +Node: Expressions310993 +Node: Values312178 +Node: Constants312854 +Node: Scalar Constants313534 +Ref: Scalar Constants-Footnote-1314393 +Node: Nondecimal-numbers314643 +Node: Regexp Constants317643 +Node: Using Constant Regexps318118 +Node: Variables321190 +Node: Using Variables321845 +Node: Assignment Options323569 +Node: Conversion325444 +Node: Strings And Numbers325968 +Ref: Strings And Numbers-Footnote-1329030 +Node: Locale influences conversions329139 +Ref: table-locale-affects331856 +Node: All Operators332444 +Node: Arithmetic Ops333074 +Node: Concatenation335579 +Ref: Concatenation-Footnote-1338398 +Node: Assignment Ops338518 +Ref: table-assign-ops343501 +Node: Increment Ops344818 +Node: Truth Values and Conditions348256 +Node: Truth Values349339 +Node: Typing and Comparison350388 +Node: Variable Typing351181 +Node: Comparison Operators354833 +Ref: table-relational-ops355243 +Node: POSIX String Comparison358793 +Ref: POSIX String Comparison-Footnote-1359877 +Node: Boolean Ops360015 +Ref: Boolean Ops-Footnote-1364085 +Node: Conditional Exp364176 +Node: Function Calls365903 +Node: Precedence369783 +Node: Locales373452 +Node: Expressions Summary375083 +Node: Patterns and Actions377624 +Node: Pattern Overview378740 +Node: Regexp Patterns380417 +Node: Expression Patterns380960 +Node: Ranges384741 +Node: BEGIN/END387847 +Node: Using BEGIN/END388609 +Ref: Using BEGIN/END-Footnote-1391345 +Node: I/O And BEGIN/END391451 +Node: BEGINFILE/ENDFILE393736 +Node: Empty396667 +Node: Using Shell Variables396984 +Node: Action Overview399267 +Node: Statements401594 +Node: If Statement403442 +Node: While Statement404940 +Node: Do Statement406984 +Node: For Statement408140 +Node: Switch Statement411292 +Node: Break Statement413395 +Node: Continue Statement415450 +Node: Next Statement417243 +Node: Nextfile Statement419633 +Node: Exit Statement422288 +Node: Built-in Variables424692 +Node: User-modified425819 +Ref: User-modified-Footnote-1433508 +Node: Auto-set433570 +Ref: Auto-set-Footnote-1446152 +Ref: Auto-set-Footnote-2446357 +Node: ARGC and ARGV446413 +Node: Pattern Action Summary450267 +Node: Arrays452490 +Node: Array Basics454039 +Node: Array Intro454865 +Ref: figure-array-elements456838 +Node: Reference to Elements459245 +Node: Assigning Elements461518 +Node: Array Example462009 +Node: Scanning an Array463741 +Node: Controlling Scanning466756 +Ref: Controlling Scanning-Footnote-1471929 +Node: Delete472245 +Ref: Delete-Footnote-1475010 +Node: Numeric Array Subscripts475067 +Node: Uninitialized Subscripts477250 +Node: Multidimensional478875 +Node: Multiscanning481968 +Node: Arrays of Arrays483557 +Node: Arrays Summary488220 +Node: Functions490325 +Node: Built-in491198 +Node: Calling Built-in492276 +Node: Numeric Functions494264 +Ref: Numeric Functions-Footnote-1498206 +Ref: Numeric Functions-Footnote-2498563 +Ref: Numeric Functions-Footnote-3498611 +Node: String Functions498880 +Ref: String Functions-Footnote-1521891 +Ref: String Functions-Footnote-2522020 +Ref: String Functions-Footnote-3522268 +Node: Gory Details522355 +Ref: table-sub-escapes524142 +Ref: table-sub-proposed525662 +Ref: table-posix-sub527026 +Ref: table-gensub-escapes528566 +Ref: Gory Details-Footnote-1529742 +Node: I/O Functions529893 +Ref: I/O Functions-Footnote-1537016 +Node: Time Functions537163 +Ref: Time Functions-Footnote-1547627 +Ref: Time Functions-Footnote-2547695 +Ref: Time Functions-Footnote-3547853 +Ref: Time Functions-Footnote-4547964 +Ref: Time Functions-Footnote-5548076 +Ref: Time Functions-Footnote-6548303 +Node: Bitwise Functions548569 +Ref: table-bitwise-ops549131 +Ref: Bitwise Functions-Footnote-1553376 +Node: Type Functions553560 +Node: I18N Functions554702 +Node: User-defined556347 +Node: Definition Syntax557151 +Ref: Definition Syntax-Footnote-1562330 +Node: Function Example562399 +Ref: Function Example-Footnote-1564963 +Node: Function Caveats564985 +Node: Calling A Function565503 +Node: Variable Scope566458 +Node: Pass By Value/Reference569446 +Node: Return Statement572956 +Node: Dynamic Typing575940 +Node: Indirect Calls576869 +Node: Functions Summary586582 +Node: Library Functions589121 +Ref: Library Functions-Footnote-1592739 +Ref: Library Functions-Footnote-2592882 +Node: Library Names593053 +Ref: Library Names-Footnote-1596526 +Ref: Library Names-Footnote-2596746 +Node: General Functions596832 +Node: Strtonum Function597860 +Node: Assert Function600640 +Node: Round Function603966 +Node: Cliff Random Function605507 +Node: Ordinal Functions606523 +Ref: Ordinal Functions-Footnote-1609600 +Ref: Ordinal Functions-Footnote-2609852 +Node: Join Function610063 +Ref: Join Function-Footnote-1611834 +Node: Getlocaltime Function612034 +Node: Readfile Function615770 +Node: Data File Management617609 +Node: Filetrans Function618241 +Node: Rewind Function622310 +Node: File Checking623868 +Ref: File Checking-Footnote-1625000 +Node: Empty Files625201 +Node: Ignoring Assigns627180 +Node: Getopt Function628734 +Ref: Getopt Function-Footnote-1640037 +Node: Passwd Functions640240 +Ref: Passwd Functions-Footnote-1649219 +Node: Group Functions649307 +Ref: Group Functions-Footnote-1657248 +Node: Walking Arrays657461 +Node: Library Functions Summary659064 +Node: Library exercises660452 +Node: Sample Programs661732 +Node: Running Examples662502 +Node: Clones663230 +Node: Cut Program664454 +Node: Egrep Program674322 +Ref: Egrep Program-Footnote-1682293 +Node: Id Program682403 +Node: Split Program686067 +Ref: Split Program-Footnote-1689605 +Node: Tee Program689733 +Node: Uniq Program692540 +Node: Wc Program699970 +Ref: Wc Program-Footnote-1704235 +Node: Miscellaneous Programs704327 +Node: Dupword Program705540 +Node: Alarm Program707571 +Node: Translate Program712385 +Ref: Translate Program-Footnote-1716776 +Ref: Translate Program-Footnote-2717046 +Node: Labels Program717180 +Ref: Labels Program-Footnote-1720551 +Node: Word Sorting720635 +Node: History Sorting724678 +Node: Extract Program726514 +Node: Simple Sed734050 +Node: Igawk Program737112 +Ref: Igawk Program-Footnote-1751423 +Ref: Igawk Program-Footnote-2751624 +Node: Anagram Program751762 +Node: Signature Program754830 +Node: Programs Summary756077 +Node: Programs Exercises757292 +Node: Advanced Features760943 +Node: Nondecimal Data762891 +Node: Array Sorting764468 +Node: Controlling Array Traversal765165 +Node: Array Sorting Functions773445 +Ref: Array Sorting Functions-Footnote-1777352 +Node: Two-way I/O777546 +Ref: Two-way I/O-Footnote-1782490 +Ref: Two-way I/O-Footnote-2782669 +Node: TCP/IP Networking782751 +Node: Profiling785596 +Node: Advanced Features Summary793138 +Node: Internationalization795002 +Node: I18N and L10N796482 +Node: Explaining gettext797168 +Ref: Explaining gettext-Footnote-1802308 +Ref: Explaining gettext-Footnote-2802492 +Node: Programmer i18n802657 +Node: Translator i18n806882 +Node: String Extraction807676 +Ref: String Extraction-Footnote-1808637 +Node: Printf Ordering808723 +Ref: Printf Ordering-Footnote-1811505 +Node: I18N Portability811569 +Ref: I18N Portability-Footnote-1814018 +Node: I18N Example814081 +Ref: I18N Example-Footnote-1816803 +Node: Gawk I18N816875 +Node: I18N Summary817513 +Node: Debugger818852 +Node: Debugging819874 +Node: Debugging Concepts820315 +Node: Debugging Terms822171 +Node: Awk Debugging824768 +Node: Sample Debugging Session825660 +Node: Debugger Invocation826180 +Node: Finding The Bug827513 +Node: List of Debugger Commands833995 +Node: Breakpoint Control835327 +Node: Debugger Execution Control838991 +Node: Viewing And Changing Data842351 +Node: Execution Stack845709 +Node: Debugger Info847222 +Node: Miscellaneous Debugger Commands851216 +Node: Readline Support856400 +Node: Limitations857292 +Node: Debugging Summary859566 +Node: Arbitrary Precision Arithmetic860730 +Node: Computer Arithmetic862217 +Ref: Computer Arithmetic-Footnote-1866604 +Node: Math Definitions866661 +Ref: table-ieee-formats869950 +Ref: Math Definitions-Footnote-1870490 +Node: MPFR features870593 +Node: FP Math Caution872235 +Ref: FP Math Caution-Footnote-1873287 +Node: Inexactness of computations873656 +Node: Inexact representation874604 +Node: Comparing FP Values875959 +Node: Errors accumulate876923 +Node: Getting Accuracy878356 +Node: Try To Round881015 +Node: Setting precision881914 +Ref: table-predefined-precision-strings882596 +Node: Setting the rounding mode884389 +Ref: table-gawk-rounding-modes884753 +Ref: Setting the rounding mode-Footnote-1888207 +Node: Arbitrary Precision Integers888386 +Ref: Arbitrary Precision Integers-Footnote-1891389 +Node: POSIX Floating Point Problems891538 +Ref: POSIX Floating Point Problems-Footnote-1895414 +Node: Floating point summary895452 +Node: Dynamic Extensions897675 +Node: Extension Intro899227 +Node: Plugin License900492 +Node: Extension Mechanism Outline901177 +Ref: figure-load-extension901601 +Ref: figure-load-new-function903086 +Ref: figure-call-new-function904088 +Node: Extension API Description906072 +Node: Extension API Functions Introduction907522 +Node: General Data Types912387 +Ref: General Data Types-Footnote-1918080 +Node: Requesting Values918379 +Ref: table-value-types-returned919116 +Node: Memory Allocation Functions920074 +Ref: Memory Allocation Functions-Footnote-1922821 +Node: Constructor Functions922917 +Node: Registration Functions924675 +Node: Extension Functions925360 +Node: Exit Callback Functions927662 +Node: Extension Version String928911 +Node: Input Parsers929561 +Node: Output Wrappers939375 +Node: Two-way processors943891 +Node: Printing Messages946095 +Ref: Printing Messages-Footnote-1947172 +Node: Updating `ERRNO'947324 +Node: Accessing Parameters948063 +Node: Symbol Table Access949293 +Node: Symbol table by name949807 +Node: Symbol table by cookie951783 +Ref: Symbol table by cookie-Footnote-1955916 +Node: Cached values955979 +Ref: Cached values-Footnote-1959483 +Node: Array Manipulation959574 +Ref: Array Manipulation-Footnote-1960672 +Node: Array Data Types960711 +Ref: Array Data Types-Footnote-1963414 +Node: Array Functions963506 +Node: Flattening Arrays967380 +Node: Creating Arrays974232 +Node: Extension API Variables978963 +Node: Extension Versioning979599 +Node: Extension API Informational Variables981500 +Node: Extension API Boilerplate982586 +Node: Finding Extensions986390 +Node: Extension Example986950 +Node: Internal File Description987680 +Node: Internal File Ops991771 +Ref: Internal File Ops-Footnote-11003203 +Node: Using Internal File Ops1003343 +Ref: Using Internal File Ops-Footnote-11005690 +Node: Extension Samples1005958 +Node: Extension Sample File Functions1007482 +Node: Extension Sample Fnmatch1015050 +Node: Extension Sample Fork1016532 +Node: Extension Sample Inplace1017745 +Node: Extension Sample Ord1019420 +Node: Extension Sample Readdir1020256 +Ref: table-readdir-file-types1021112 +Node: Extension Sample Revout1021911 +Node: Extension Sample Rev2way1022502 +Node: Extension Sample Read write array1023243 +Node: Extension Sample Readfile1025122 +Node: Extension Sample API Tests1026222 +Node: Extension Sample Time1026747 +Node: gawkextlib1028062 +Node: Extension summary1030875 +Node: Extension Exercises1034568 +Node: Language History1035290 +Node: V7/SVR3.11036933 +Node: SVR41039253 +Node: POSIX1040695 +Node: BTL1042081 +Node: POSIX/GNU1042815 +Node: Feature History1048558 +Node: Common Extensions1061688 +Node: Ranges and Locales1063000 +Ref: Ranges and Locales-Footnote-11067617 +Ref: Ranges and Locales-Footnote-21067644 +Ref: Ranges and Locales-Footnote-31067878 +Node: Contributors1068099 +Node: History summary1073524 +Node: Installation1074893 +Node: Gawk Distribution1075844 +Node: Getting1076328 +Node: Extracting1077152 +Node: Distribution contents1078794 +Node: Unix Installation1084511 +Node: Quick Installation1085128 +Node: Additional Configuration Options1087570 +Node: Configuration Philosophy1089308 +Node: Non-Unix Installation1091659 +Node: PC Installation1092117 +Node: PC Binary Installation1093428 +Node: PC Compiling1095276 +Ref: PC Compiling-Footnote-11098275 +Node: PC Testing1098380 +Node: PC Using1099556 +Node: Cygwin1103714 +Node: MSYS1104523 +Node: VMS Installation1105037 +Node: VMS Compilation1105833 +Ref: VMS Compilation-Footnote-11107055 +Node: VMS Dynamic Extensions1107113 +Node: VMS Installation Details1108486 +Node: VMS Running1110738 +Node: VMS GNV1113572 +Node: VMS Old Gawk1114295 +Node: Bugs1114765 +Node: Other Versions1118769 +Node: Installation summary1125024 +Node: Notes1126080 +Node: Compatibility Mode1126945 +Node: Additions1127727 +Node: Accessing The Source1128652 +Node: Adding Code1130088 +Node: New Ports1136266 +Node: Derived Files1140747 +Ref: Derived Files-Footnote-11145828 +Ref: Derived Files-Footnote-21145862 +Ref: Derived Files-Footnote-31146458 +Node: Future Extensions1146572 +Node: Implementation Limitations1147178 +Node: Extension Design1148426 +Node: Old Extension Problems1149580 +Ref: Old Extension Problems-Footnote-11151097 +Node: Extension New Mechanism Goals1151154 +Ref: Extension New Mechanism Goals-Footnote-11154514 +Node: Extension Other Design Decisions1154703 +Node: Extension Future Growth1156809 +Node: Old Extension Mechanism1157645 +Node: Notes summary1159407 +Node: Basic Concepts1160593 +Node: Basic High Level1161274 +Ref: figure-general-flow1161546 +Ref: figure-process-flow1162145 +Ref: Basic High Level-Footnote-11165374 +Node: Basic Data Typing1165559 +Node: Glossary1168887 +Node: Copying1194039 +Node: GNU Free Documentation License1231595 +Node: Index1256731  End Tag Table -- cgit v1.2.3 From e909ea8295f5556db159ec28fdc566f504f9cb9a Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 20 Aug 2014 06:17:10 +0300 Subject: More fixes from reviewer comments. --- doc/gawk.info | 1394 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 705 insertions(+), 689 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 501b8136..7c97a5c9 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -769,12 +769,10 @@ Preface Several kinds of tasks occur repeatedly when working with text files. You might want to extract certain lines and discard the rest. Or you -may need to make changes wherever certain patterns appear, but leave -the rest of the file alone. Writing single-use programs for these -tasks in languages such as C, C++, or Java is time-consuming and -inconvenient. Such jobs are often easier with `awk'. The `awk' -utility interprets a special-purpose programming language that makes it -easy to handle simple data-reformatting jobs. +may need to make changes wherever certain patterns appear, but leave the +rest of the file alone. Such jobs are often easy with `awk'. The +`awk' utility interprets a special-purpose programming language that +makes it easy to handle simple data-reformatting jobs. The GNU implementation of `awk' is called `gawk'; if you invoke it with the proper options or environment variables (*note Options::), it @@ -818,12 +816,11 @@ such as input/output (I/O) redirection and pipes. different computing environments. This Info file, while describing the `awk' language in general, also describes the particular implementation of `awk' called `gawk' (which stands for "GNU `awk'"). `gawk' runs on -a broad range of Unix systems, ranging from Intel(R)-architecture -PC-based computers up through large-scale systems. `gawk' has also -been ported to Mac OS X, Microsoft Windows (all versions) and OS/2 PCs, -and OpenVMS. (Some other, obsolete systems to which `gawk' was once -ported are no longer supported and the code for those systems has been -removed.) +a broad range of Unix systems, ranging from Intel-architecture PC-based +computers up through large-scale systems. `gawk' has also been ported +to Mac OS X, Microsoft Windows (all versions) and OS/2 PCs, and OpenVMS. +(Some other, obsolete systems to which `gawk' was once ported are no +longer supported and the code for those systems has been removed.) * Menu: @@ -840,7 +837,7 @@ removed.) ---------- Footnotes ---------- - (1) The 2008 POSIX standard is accessable online at + (1) The 2008 POSIX standard is accessible online at `http://www.opengroup.org/onlinepubs/9699919799/'. (2) These commands are available on POSIX-compliant systems, as well @@ -1155,7 +1152,7 @@ released but remains in an early stage of development. Until the GNU operating system is more fully developed, you should consider using GNU/Linux, a freely distributable, Unix-like operating -system for Intel(R), Power Architecture, Sun SPARC, IBM S/390, and other +system for Intel, Power Architecture, Sun SPARC, IBM S/390, and other systems.(2) Many GNU/Linux distributions are available for download from the Internet. @@ -2249,14 +2246,13 @@ those that it has are much larger than they used to be. If you find yourself writing `awk' scripts of more than, say, a few hundred lines, you might consider using a different programming language. The shell is good at string and pattern matching; in -addition, it allows powerful use of the system utilities. More -conventional languages, such as C, C++, and Java, offer better -facilities for system programming and for managing the complexity of -large programs. Python offers a nice balance between high-level ease -of programming and access to system facilities. Programs in these -languages may require more lines of source code than the equivalent -`awk' programs, but they are easier to maintain and usually run more -efficiently. +addition, it allows powerful use of the system utilities. Python +offers a nice balance between high-level ease of programming and access +to system facilities.(1) + + ---------- Footnotes ---------- + + (1) Other popular scripting languages include Ruby and Perl.  File: gawk.info, Node: Intro Summary, Prev: When, Up: Getting Started @@ -2475,9 +2471,9 @@ The following list describes options mandated by the POSIX standard: This option is particularly necessary for World Wide Web CGI applications that pass arguments through the URL; using this option prevents a malicious (or other) user from passing in - options, assignments, or `awk' source code (via `--source') to the - CGI application. This option should be used with `#!' scripts - (*note Executable Scripts::), like so: + options, assignments, or `awk' source code (via `-e') to the CGI + application. This option should be used with `#!' scripts (*note + Executable Scripts::), like so: #! /usr/local/bin/gawk -E @@ -2667,16 +2663,14 @@ standard input but then you will not be able to also use the standard input as a source of data.) Because it is clumsy using the standard `awk' mechanisms to mix -source file and command-line `awk' programs, `gawk' provides the -`--source' option. This does not require you to pre-empt the standard -input for your source code; it allows you to easily mix command-line -and library source code (*note AWKPATH Variable::). As with `-f', the -`--source' and `--include' options may also be used multiple times on -the command line. +source file and command-line `awk' programs, `gawk' provides the `-e' +option. This does not require you to pre-empt the standard input for +your source code; it allows you to easily mix command-line and library +source code (*note AWKPATH Variable::). As with `-f', the `-e' and `-i' +options may also be used multiple times on the command line. - If no `-f' or `--source' option is specified, then `gawk' uses the -first non-option command-line argument as the text of the program -source code. + If no `-f' or `-e' option is specified, then `gawk' uses the first +non-option command-line argument as the text of the program source code. If the environment variable `POSIXLY_CORRECT' exists, then `gawk' behaves in strict POSIX mode, exactly as if you had supplied `--posix'. @@ -2831,7 +2825,7 @@ in a standard directory in the default path and then specified on the command line with a short file name. Otherwise, the full file name would have to be typed for each file. - By using the `-i' option, or the `--source' and `-f' options, your + By using the `-i' option, or the `-e' and `-f' options, your command-line `awk' programs can use facilities in `awk' library files (*note Library Functions::). Path searching is not done if `gawk' is in compatibility mode. This is true for both `--traditional' and @@ -3355,6 +3349,10 @@ apply to both string constants and regexp constants: more than two hexadecimal digits produces undefined results. (The `\x' escape sequence is not allowed in POSIX `awk'.) + CAUTION: The next major relase of `gawk' will change, such + that a maximum of two hexadecimal digits following the `\x' + will be used. + `\/' A literal slash (necessary for regexp constants only). This sequence is used when you want to write a regexp constant that @@ -9618,29 +9616,36 @@ match to a given case is made, the case statement bodies execute until a `break', `continue', `next', `nextfile' or `exit' is encountered, or the end of the `switch' statement itself. For example: - switch (NR * 2 + 1) { - case 3: - case "11": - print NR - 1 - break - - case /2[[:digit:]]+/: - print NR - - default: - print NR + 1 - - case -1: - print NR * -1 + while ((c = getopt(ARGC, ARGV, "aksx")) != -1) { + switch (c) { + case "a": + # report size of all files + all_files = TRUE; + break + case "k": + BLOCK_SIZE = 1024 # 1K block size + break + case "s": + # do sums only + sum_only = TRUE + break + case "x": + # don't cross filesystems + fts_flags = or(fts_flags, FTS_XDEV) + break + case "?": + default: + usage() + break + } } Note that if none of the statements specified above halt execution of a matched `case' statement, execution falls through to the next -`case' until execution halts. In the above example, for any case value -starting with `2' followed by one or more digits, the `print' statement -is executed and then falls through into the `default' section, -executing its `print' statement. In turn, the -1 case will also be -executed since the `default' does not halt execution. +`case' until execution halts. In the above example, the `case' for +`"?"' falls through to the `default' case, which is to call a function +named `usage()'. (The `getopt()' function being called here is +described in *note Getopt Function::.)  File: gawk.info, Node: Break Statement, Next: Continue Statement, Prev: Switch Statement, Up: Statements @@ -9741,7 +9746,8 @@ the previous example with the following `while' loop: print "" } -This program loops forever once `x' reaches 5. +This program loops forever once `x' reaches 5, since the increment +(`x++') is never reached. The `continue' statement has no special meaning with respect to the `switch' statement, nor does it have any meaning when used outside the @@ -10497,8 +10503,16 @@ elements from `ARGV' (*note Delete::). All of these actions are typically done in the `BEGIN' rule, before actual processing of the input begins. *Note Split Program::, and see *note Tee Program::, for examples of each way of removing elements from -`ARGV'. The following fragment processes `ARGV' in order to examine, -and then remove, command-line options: +`ARGV'. + + To actually get options into an `awk' program, end the `awk' options +with `--' and then supply the `awk' program's options, in the following +manner: + + awk -f myprog.awk -- -v -q file1 file2 ... + + The following fragment processes `ARGV' in order to examine, and +then remove, the above command-line options: BEGIN { for (i = 1; i < ARGC; i++) { @@ -10516,19 +10530,14 @@ and then remove, command-line options: } } - To actually get the options into the `awk' program, end the `awk' -options with `--' and then supply the `awk' program's options, in the -following manner: - - awk -f myprog -- -v -q file1 file2 ... - - This is not necessary in `gawk'. Unless `--posix' has been -specified, `gawk' silently puts any unrecognized options into `ARGV' -for the `awk' program to deal with. As soon as it sees an unknown -option, `gawk' stops looking for other options that it might otherwise -recognize. The previous example with `gawk' would be: + Ending the `awk' options with `--' isn't necessary in `gawk'. Unless +`--posix' has been specified, `gawk' silently puts any unrecognized +options into `ARGV' for the `awk' program to deal with. As soon as it +sees an unknown option, `gawk' stops looking for other options that it +might otherwise recognize. The previous command line with `gawk' would +be: - gawk -f myprog -q -v file1 file2 ... + gawk -f myprog.awk -q -v file1 file2 ... Because `-q' is not a valid `gawk' option, it and the following `-v' are passed on to the `awk' program. (*Note Getopt Function::, for an @@ -10775,8 +10784,9 @@ been assigned any value as well as elements that have been deleted # Check if "foo" exists in a: Incorrect! if (a["foo"] != "") ... - This is incorrect, since this will _create_ `a["foo"]' if it - didn't exist before! + This is incorrect for two reasons. First, it _creates_ `a["foo"]' + if it didn't exist before! Second, it is valid (if a bit unusual) + to set an array element equal to the empty string. To determine whether an element exists in an array at a certain index, use the following expression: @@ -11329,10 +11339,11 @@ multidimensional array, use the same operator (`in') that is used for single dimensional arrays. Write the whole sequence of indices in parentheses, separated by commas, as the left operand: - (SUBSCRIPT1, SUBSCRIPT2, ...) in ARRAY + if ((SUBSCRIPT1, SUBSCRIPT2, ...) in ARRAY) + ... - The following example treats its input as a two-dimensional array of -fields; it rotates this array 90 degrees clockwise and prints the + Here is an example that treats its input as a two-dimensional array +of fields; it rotates this array 90 degrees clockwise and prints the result. It assumes that all lines have the same number of elements: { @@ -11771,6 +11782,9 @@ brackets ([ ]): easy to keep track of the seeds in case you need to consistently reproduce sequences of random numbers. + POSIX does not specify the initial seed; it differs among `awk' + implementations. + ---------- Footnotes ---------- (1) The C version of `rand()' on many Unix systems is known to @@ -13352,7 +13366,8 @@ this program, using our function to format the results, prints: 5.6 21.2 - This function deletes all the elements in an array: + This function deletes all the elements in an array (recall that the +extra whitespace signifies the start of the local variable list): function delarray(a, i) { @@ -13386,7 +13401,7 @@ empty. way: $ echo "Don't Panic!" | - > gawk --source '{ print rev($0) }' -f rev.awk + > gawk -e '{ print rev($0) }' -f rev.awk -| !cinaP t'noD The C `ctime()' function takes a timestamp and returns it in a @@ -14150,7 +14165,7 @@ P.J. Plauger wrote: In fact, they felt this idea was so important that they placed this statement on the cover of their book. Because we believe strongly that their statement is correct, this major node and *note Sample -Programs::, provide a good-sized body of code for you to read, and we +Programs::, provide a good-sized body of code for you to read and, we hope, to learn from. This major node presents a library of useful `awk' functions. Many @@ -18187,8 +18202,8 @@ language.(1) It works as follows: 2. For any arguments that do represent `awk' text, put the arguments into a shell variable that will be expanded. There are two cases: - a. Literal text, provided with `--source' or `--source='. This - text is just appended directly. + a. Literal text, provided with `-e' or `--source'. This text is + just appended directly. b. Source file names, provided with `-f'. We use a neat trick and append `@include FILENAME' to the shell variable's @@ -21329,8 +21344,8 @@ File: gawk.info, Node: Debugging Summary, Prev: Limitations, Up: Debugger * Debuggers let you step through your program one statement at a time, examine and change variable and array values, and do a - number of other things that let understand what your program is - actually doing (as opposed to what it is supposed to do). + number of other things that let you understand what your program + is actually doing (as opposed to what it is supposed to do). * Like most debuggers, the `gawk' debugger works in terms of stack frames, and lets you set both breakpoints (stop at a point in the @@ -21597,10 +21612,9 @@ Auto-set::). The MPFR library provides precise control over precisions and rounding modes, and gives correctly rounded, reproducible, -platform-independent results. With either of the command-line options -`--bignum' or `-M', all floating-point arithmetic operators and numeric -functions can yield results to any desired precision level supported by -MPFR. +platform-independent results. With the `-M' command-line option, all +floating-point arithmetic operators and numeric functions can yield +results to any desired precision level supported by MPFR. Two built-in variables, `PREC' and `ROUNDMODE', provide control over the working precision and the rounding mode. The precision and the @@ -21613,7 +21627,7 @@ File: gawk.info, Node: FP Math Caution, Next: Arbitrary Precision Integers, P 15.4 Floating Point Arithmetic: Caveat Emptor! ============================================== - Math class is tough! -- Teen Talk Barbie (July, 1992) + Math class is tough! -- Teen Talk Barbie, July 1992 This minor node provides a high level overview of the issues involved when doing lots of floating-point arithmetic.(1) The @@ -22007,13 +22021,13 @@ File: gawk.info, Node: Arbitrary Precision Integers, Next: POSIX Floating Poin 15.5 Arbitrary Precision Integer Arithmetic with `gawk' ======================================================= -When given one of the options `--bignum' or `-M', `gawk' performs all -integer arithmetic using GMP arbitrary precision integers. Any number -that looks like an integer in a source or data file is stored as an -arbitrary precision integer. The size of the integer is limited only -by the available memory. For example, the following computes 5^4^3^2, -the result of which is beyond the limits of ordinary hardware -double-precision floating point values: +When given the `-M' option, `gawk' performs all integer arithmetic +using GMP arbitrary precision integers. Any number that looks like an +integer in a source or data file is stored as an arbitrary precision +integer. The size of the integer is limited only by the available +memory. For example, the following computes 5^4^3^2, the result of +which is beyond the limits of ordinary hardware double-precision +floating point values: $ gawk -M 'BEGIN { > x = 5^4^3^2 @@ -22193,13 +22207,13 @@ File: gawk.info, Node: Floating point summary, Prev: POSIX Floating Point Prob * Often, increasing the accuracy and then rounding to the desired number of digits produces reasonable results. - * Use either `-M' or `--bignum' to enable MPFR arithmetic. Use - `PREC' to set the precision in bits, and `ROUNDMODE' to set the - IEEE 754 rounding mode. + * Use `-M' (or `--bignum') to enable MPFR arithmetic. Use `PREC' to + set the precision in bits, and `ROUNDMODE' to set the IEEE 754 + rounding mode. - * With `-M' or `--bignum', `gawk' performs arbitrary precision - integer arithmetic using the GMP library. This is faster and more - space efficient than using MPFR for the same calculations. + * With `-M', `gawk' performs arbitrary precision integer arithmetic + using the GMP library. This is faster and more space efficient + than using MPFR for the same calculations. * There are several "dark corners" with respect to floating-point numbers where `gawk' disagrees with the POSIX standard. It pays @@ -22519,7 +22533,7 @@ operations: place `-Dinline=''' on your command line, or use the GNU Autotools and include a `config.h' file in your extensions. - * All pointers filled in by `gawk' are to memory managed by `gawk' + * All pointers filled in by `gawk' point to memory managed by `gawk' and should be treated by the extension as read-only. Memory for _all_ strings passed into `gawk' from the extension _must_ come from calling the API-provided function pointers `api_malloc()', @@ -22929,7 +22943,7 @@ File: gawk.info, Node: Exit Callback Functions, Next: Extension Version String An "exit callback" function is a function that `gawk' calls before it exits. Such functions are useful if you have general "cleanup" tasks -that should be performed in your extension (such as closing data base +that should be performed in your extension (such as closing database connections or other resource deallocations). You can register such a function with `gawk' using the following function. @@ -26056,7 +26070,7 @@ the current version of `gawk'. `-r', `-S', `-t', and `-V' short options. Also, the ability to use GNU-style long-named options that start with `--' and the `--assign', `--bignum', `--characters-as-bytes', - `--copyright', `--debug', `--dump-variables', `--execle', + `--copyright', `--debug', `--dump-variables', `--exec', `--field-separator', `--file', `--gen-pot', `--help', `--include', `--lint', `--lint-old', `--load', `--non-decimal-data', `--optimize', `--posix', @@ -27502,7 +27516,7 @@ These give the same result as the `-W BINMODE=2' option in `mawk'. The following changes the record separator to `"\r\n"' and sets binary mode on reads, but does not affect the mode on standard input: - gawk -v RS="\r\n" --source "BEGIN { BINMODE = 1 }" ... + gawk -v RS="\r\n" -e "BEGIN { BINMODE = 1 }" ... or: @@ -28841,7 +28855,7 @@ C.7 Summary `--parsedebug' option is available if `gawk' is compiled with `-DDEBUG'. - * The source code for `gawk' is maintained in a publicly accessable + * The source code for `gawk' is maintained in a publicly accessible Git repository. Anyone may check it out and view the source. * Contributions to `gawk' are welcome. Following the steps outlined @@ -31010,6 +31024,7 @@ Index * -c option: Options. (line 81) * -D option: Options. (line 108) * -d option: Options. (line 93) +* -e option: Options. (line 335) * -E option: Options. (line 125) * -e option: Options. (line 117) * -f option: Options. (line 25) @@ -31093,10 +31108,10 @@ Index * [] (square brackets), regexp operator: Regexp Operators. (line 56) * \ (backslash): Comments. (line 50) * \ (backslash) in shell commands: Read Terminal. (line 25) -* \ (backslash), \" escape sequence: Escape Sequences. (line 76) +* \ (backslash), \" escape sequence: Escape Sequences. (line 80) * \ (backslash), \' operator (gawk): GNU Regexp Operators. (line 56) -* \ (backslash), \/ escape sequence: Escape Sequences. (line 69) +* \ (backslash), \/ escape sequence: Escape Sequences. (line 73) * \ (backslash), \< operator (gawk): GNU Regexp Operators. (line 30) * \ (backslash), \> operator (gawk): GNU Regexp Operators. @@ -31137,7 +31152,7 @@ Index * \ (backslash), in bracket expressions: Bracket Expressions. (line 17) * \ (backslash), in escape sequences: Escape Sequences. (line 6) * \ (backslash), in escape sequences, POSIX and: Escape Sequences. - (line 112) + (line 116) * \ (backslash), in regexp constants: Computed Regexps. (line 29) * \ (backslash), in shell commands: Quoting. (line 48) * \ (backslash), regexp operator: Regexp Operators. (line 18) @@ -31330,7 +31345,7 @@ Index (line 6) * awk, function of: Getting Started. (line 6) * awk, gawk and <1>: This Manual. (line 14) -* awk, gawk and: Preface. (line 23) +* awk, gawk and: Preface. (line 21) * awk, history of: History. (line 17) * awk, implementation issues, pipes: Redirection. (line 135) * awk, implementations: Other Versions. (line 6) @@ -31338,15 +31353,15 @@ Index * awk, invoking: Command Line. (line 6) * awk, new vs. old: Names. (line 6) * awk, new vs. old, OFMT variable: Strings And Numbers. (line 57) -* awk, POSIX and: Preface. (line 23) -* awk, POSIX and, See Also POSIX awk: Preface. (line 23) +* awk, POSIX and: Preface. (line 21) +* awk, POSIX and, See Also POSIX awk: Preface. (line 21) * awk, regexp constants and: Comparison Operators. (line 102) -* awk, See Also gawk: Preface. (line 36) +* awk, See Also gawk: Preface. (line 34) * awk, terms describing: This Manual. (line 6) * awk, uses for <1>: When. (line 6) * awk, uses for <2>: Getting Started. (line 12) -* awk, uses for: Preface. (line 23) +* awk, uses for: Preface. (line 21) * awk, versions of <1>: V7/SVR3.1. (line 6) * awk, versions of: Names. (line 10) * awk, versions of, changes between SVR3.1 and SVR4: SVR4. (line 6) @@ -31366,10 +31381,10 @@ Index * b debugger command (alias for break): Breakpoint Control. (line 11) * backslash (\): Comments. (line 50) * backslash (\) in shell commands: Read Terminal. (line 25) -* backslash (\), \" escape sequence: Escape Sequences. (line 76) +* backslash (\), \" escape sequence: Escape Sequences. (line 80) * backslash (\), \' operator (gawk): GNU Regexp Operators. (line 56) -* backslash (\), \/ escape sequence: Escape Sequences. (line 69) +* backslash (\), \/ escape sequence: Escape Sequences. (line 73) * backslash (\), \< operator (gawk): GNU Regexp Operators. (line 30) * backslash (\), \> operator (gawk): GNU Regexp Operators. @@ -31410,7 +31425,7 @@ Index * backslash (\), in bracket expressions: Bracket Expressions. (line 17) * backslash (\), in escape sequences: Escape Sequences. (line 6) * backslash (\), in escape sequences, POSIX and: Escape Sequences. - (line 112) + (line 116) * backslash (\), in regexp constants: Computed Regexps. (line 29) * backslash (\), in shell commands: Quoting. (line 48) * backslash (\), regexp operator: Regexp Operators. (line 18) @@ -31505,7 +31520,7 @@ Index * Brian Kernighan's awk <3>: String Functions. (line 490) * Brian Kernighan's awk <4>: Delete. (line 48) * Brian Kernighan's awk <5>: Nextfile Statement. (line 47) -* Brian Kernighan's awk <6>: Continue Statement. (line 43) +* Brian Kernighan's awk <6>: Continue Statement. (line 44) * Brian Kernighan's awk <7>: Break Statement. (line 51) * Brian Kernighan's awk <8>: I/O And BEGIN/END. (line 16) * Brian Kernighan's awk <9>: Concatenation. (line 36) @@ -31514,9 +31529,9 @@ Index (line 67) * Brian Kernighan's awk <12>: GNU Regexp Operators. (line 83) -* Brian Kernighan's awk <13>: Escape Sequences. (line 116) +* Brian Kernighan's awk <13>: Escape Sequences. (line 120) * Brian Kernighan's awk <14>: When. (line 21) -* Brian Kernighan's awk: Preface. (line 15) +* Brian Kernighan's awk: Preface. (line 13) * Brian Kernighan's awk, extensions: BTL. (line 6) * Brian Kernighan's awk, source code: Other Versions. (line 13) * Brini, Davide: Signature Program. (line 6) @@ -31712,9 +31727,9 @@ Index * cosine: Numeric Functions. (line 15) * counting: Wc Program. (line 6) * csh utility: Statements/Lines. (line 44) -* csh utility, POSIXLY_CORRECT environment variable: Options. (line 355) +* csh utility, POSIXLY_CORRECT environment variable: Options. (line 353) * csh utility, |& operator, comparison with: Two-way I/O. (line 25) -* ctime() user-defined function: Function Example. (line 73) +* ctime() user-defined function: Function Example. (line 74) * currency symbols, localization: Explaining gettext. (line 104) * current system time: Time Functions. (line 66) * custom.h file: Configuration Philosophy. @@ -31739,11 +31754,11 @@ Index * dark corner, close() function: Close Files And Pipes. (line 131) * dark corner, command-line arguments: Assignment Options. (line 43) -* dark corner, continue statement: Continue Statement. (line 43) +* dark corner, continue statement: Continue Statement. (line 44) * dark corner, CONVFMT variable: Strings And Numbers. (line 40) * dark corner, escape sequences: Other Arguments. (line 31) * dark corner, escape sequences, for metacharacters: Escape Sequences. - (line 134) + (line 138) * dark corner, exit statement: Exit Statement. (line 30) * dark corner, field separators: Field Splitting Summary. (line 46) @@ -31914,7 +31929,7 @@ Index * describe call stack frame, in debugger: Debugger Info. (line 27) * differences between gawk and awk: String Functions. (line 197) * differences in awk and gawk, ARGC/ARGV variables: ARGC and ARGV. - (line 88) + (line 90) * differences in awk and gawk, ARGIND variable: Auto-set. (line 44) * differences in awk and gawk, array elements, deleting: Delete. (line 39) @@ -32389,7 +32404,7 @@ Index * gawk version: Auto-set. (line 199) * gawk, ARGIND variable in: Other Arguments. (line 12) * gawk, awk and <1>: This Manual. (line 14) -* gawk, awk and: Preface. (line 23) +* gawk, awk and: Preface. (line 21) * gawk, bitwise operations in: Bitwise Functions. (line 39) * gawk, break statement in: Break Statement. (line 51) * gawk, built-in variables and: Built-in Variables. (line 14) @@ -32403,7 +32418,7 @@ Index (line 6) * gawk, configuring, options: Additional Configuration Options. (line 6) -* gawk, continue statement in: Continue Statement. (line 43) +* gawk, continue statement in: Continue Statement. (line 44) * gawk, distribution: Distribution contents. (line 6) * gawk, ERRNO variable in <1>: TCP/IP Networking. (line 54) @@ -32412,7 +32427,7 @@ Index * gawk, ERRNO variable in <4>: Close Files And Pipes. (line 139) * gawk, ERRNO variable in: Getline. (line 19) -* gawk, escape sequences: Escape Sequences. (line 124) +* gawk, escape sequences: Escape Sequences. (line 128) * gawk, extensions, disabling: Options. (line 254) * gawk, features, adding: Adding Code. (line 6) * gawk, features, advanced: Advanced Features. (line 6) @@ -32466,14 +32481,14 @@ Index * gawk, RT variable in <1>: Auto-set. (line 257) * gawk, RT variable in <2>: Multiple Line. (line 129) * gawk, RT variable in: awk split records. (line 124) -* gawk, See Also awk: Preface. (line 36) +* gawk, See Also awk: Preface. (line 34) * gawk, source code, obtaining: Getting. (line 6) * gawk, splitting fields and: Constant Size. (line 88) * gawk, string-translation functions: I18N Functions. (line 6) * gawk, SYMTAB array in: Auto-set. (line 261) * gawk, TEXTDOMAIN variable in: User-modified. (line 152) * gawk, timestamps: Time Functions. (line 6) -* gawk, uses for: Preface. (line 36) +* gawk, uses for: Preface. (line 34) * gawk, versions of, information about, printing: Options. (line 300) * gawk, VMS version of: VMS Installation. (line 6) * gawk, word-boundary operator: GNU Regexp Operators. @@ -32535,7 +32550,7 @@ Index * git utility: gawkextlib. (line 29) * Git, use of for gawk source code: Derived Files. (line 6) * GNITS mailing list: Acknowledgments. (line 52) -* GNU awk, See gawk: Preface. (line 53) +* GNU awk, See gawk: Preface. (line 51) * GNU Free Documentation License: GNU Free Documentation License. (line 7) * GNU General Public License: Glossary. (line 305) @@ -32617,7 +32632,7 @@ Index (line 43) * in operator, order of array access: Scanning an Array. (line 48) * in operator, testing if array element exists: Reference to Elements. - (line 37) + (line 38) * in operator, use in loops: Scanning an Array. (line 17) * increment operators: Increment Ops. (line 6) * index: String Functions. (line 155) @@ -32785,7 +32800,7 @@ Index * lint checking, empty programs: Command Line. (line 16) * lint checking, issuing warnings: Options. (line 185) * lint checking, POSIXLY_CORRECT environment variable: Options. - (line 340) + (line 338) * lint checking, undefined functions: Pass By Value/Reference. (line 88) * LINT variable: User-modified. (line 88) @@ -32846,7 +32861,7 @@ Index * mawk utility <2>: Nextfile Statement. (line 47) * mawk utility <3>: Concatenation. (line 36) * mawk utility <4>: Getline/Pipe. (line 62) -* mawk utility: Escape Sequences. (line 124) +* mawk utility: Escape Sequences. (line 128) * maximum precision supported by MPFR library: Auto-set. (line 213) * McIlroy, Doug: Glossary. (line 149) * McPhee, Patrick: Contributors. (line 100) @@ -32859,7 +32874,7 @@ Index (line 54) * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) -* metacharacters, escape sequences for: Escape Sequences. (line 130) +* metacharacters, escape sequences for: Escape Sequences. (line 134) * minimum precision supported by MPFR library: Auto-set. (line 216) * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) @@ -33080,14 +33095,14 @@ Index * plus sign (+), += operator: Assignment Ops. (line 82) * plus sign (+), regexp operator: Regexp Operators. (line 103) * pointers to functions: Indirect Calls. (line 6) -* portability: Escape Sequences. (line 94) +* portability: Escape Sequences. (line 98) * portability, #! (executable scripts): Executable Scripts. (line 33) * portability, ** operator and: Arithmetic Ops. (line 81) * portability, **= operator and: Assignment Ops. (line 143) * portability, ARGV variable: Executable Scripts. (line 42) * portability, backslash continuation and: Statements/Lines. (line 30) * portability, backslash in escape sequences: Escape Sequences. - (line 112) + (line 116) * portability, close() function and: Close Files And Pipes. (line 81) * portability, data files as single record: gawk split records. @@ -33105,7 +33120,7 @@ Index * portability, NF variable, decrementing: Changing Fields. (line 115) * portability, operators: Increment Ops. (line 60) * portability, operators, not in POSIX awk: Precedence. (line 98) -* portability, POSIXLY_CORRECT environment variable: Options. (line 360) +* portability, POSIXLY_CORRECT environment variable: Options. (line 358) * portability, substr() function: String Functions. (line 510) * portable object files <1>: Translator i18n. (line 6) * portable object files: Explaining gettext. (line 37) @@ -33126,14 +33141,14 @@ Index * POSIX awk, < operator and: Getline/File. (line 26) * POSIX awk, arithmetic operators and: Arithmetic Ops. (line 30) * POSIX awk, backslashes in string constants: Escape Sequences. - (line 112) + (line 116) * POSIX awk, BEGIN/END patterns: I/O And BEGIN/END. (line 16) * POSIX awk, bracket expressions and: Bracket Expressions. (line 24) * POSIX awk, bracket expressions and, character classes: Bracket Expressions. (line 30) * POSIX awk, break statement and: Break Statement. (line 51) * POSIX awk, changes in awk versions: POSIX. (line 6) -* POSIX awk, continue statement and: Continue Statement. (line 43) +* POSIX awk, continue statement and: Continue Statement. (line 44) * POSIX awk, CONVFMT variable and: User-modified. (line 30) * POSIX awk, date utility and: Time Functions. (line 254) * POSIX awk, field separators and <1>: Field Splitting Summary. @@ -33155,10 +33170,10 @@ Index * POSIX awk, timestamps and: Time Functions. (line 6) * POSIX awk, | I/O operator and: Getline/Pipe. (line 55) * POSIX mode: Options. (line 254) -* POSIX, awk and: Preface. (line 23) +* POSIX, awk and: Preface. (line 21) * POSIX, gawk extensions not included in: POSIX/GNU. (line 6) * POSIX, programs, implementing in awk: Clones. (line 6) -* POSIXLY_CORRECT environment variable: Options. (line 340) +* POSIXLY_CORRECT environment variable: Options. (line 338) * PREC variable: User-modified. (line 124) * precedence <1>: Precedence. (line 6) * precedence: Increment Ops. (line 60) @@ -33359,7 +33374,7 @@ Index * return statement, user-defined functions: Return Statement. (line 6) * return value, close() function: Close Files And Pipes. (line 131) -* rev() user-defined function: Function Example. (line 53) +* rev() user-defined function: Function Example. (line 54) * revoutput extension: Extension Sample Revout. (line 11) * revtwoway extension: Extension Sample Rev2way. @@ -33494,7 +33509,7 @@ Index * side effects <1>: Increment Ops. (line 11) * side effects: Concatenation. (line 41) * side effects, array indexing: Reference to Elements. - (line 42) + (line 43) * side effects, asort() function: Array Sorting Functions. (line 24) * side effects, assignment expressions: Assignment Ops. (line 23) @@ -33507,14 +33522,14 @@ Index * sidebar, A Constant's Base Does Not Affect Its Value: Nondecimal-numbers. (line 64) * sidebar, Backslash Before Regular Characters: Escape Sequences. - (line 110) + (line 114) * sidebar, Changing FS Does Not Affect the Fields: Field Splitting Summary. (line 38) * sidebar, Changing NR and FNR: Auto-set. (line 299) * sidebar, Controlling Output Buffering with system(): I/O Functions. (line 138) * sidebar, Escape Sequences for Metacharacters: Escape Sequences. - (line 128) + (line 132) * sidebar, FS and IGNORECASE: Field Splitting Summary. (line 64) * sidebar, Interactive Versus Noninteractive Buffering: I/O Functions. @@ -33742,7 +33757,7 @@ Index (line 37) * troubleshooting, awk uses FS not IFS: Field Separators. (line 30) * troubleshooting, backslash before nonspecial character: Escape Sequences. - (line 112) + (line 116) * troubleshooting, division: Arithmetic Ops. (line 44) * troubleshooting, fatal errors, field widths, specifying: Constant Size. (line 23) @@ -33798,7 +33813,7 @@ Index * uniq.awk program: Uniq Program. (line 65) * Unix: Glossary. (line 611) * Unix awk, backslashes in escape sequences: Escape Sequences. - (line 124) + (line 128) * Unix awk, close() function and: Close Files And Pipes. (line 131) * Unix awk, password files, field separators and: Command Line Field Separator. @@ -33945,548 +33960,549 @@ Tag Table: Node: Top1204 Node: Foreword41858 Node: Preface46203 -Ref: Preface-Footnote-149350 -Ref: Preface-Footnote-249457 -Node: History49689 -Node: Names52063 -Ref: Names-Footnote-153527 -Node: This Manual53600 -Ref: This Manual-Footnote-159379 -Node: Conventions59479 -Node: Manual History61635 -Ref: Manual History-Footnote-164714 -Ref: Manual History-Footnote-264755 -Node: How To Contribute64829 -Node: Acknowledgments66068 -Node: Getting Started70816 -Node: Running gawk73250 -Node: One-shot74440 -Node: Read Terminal75665 -Ref: Read Terminal-Footnote-177628 -Node: Long77799 -Node: Executable Scripts79175 -Ref: Executable Scripts-Footnote-181008 -Ref: Executable Scripts-Footnote-281110 -Node: Comments81657 -Node: Quoting84130 -Node: DOS Quoting89443 -Node: Sample Data Files90118 -Node: Very Simple92672 -Node: Two Rules97445 -Node: More Complex99339 -Ref: More Complex-Footnote-1102271 -Node: Statements/Lines102356 -Ref: Statements/Lines-Footnote-1106812 -Node: Other Features107077 -Node: When108005 -Node: Intro Summary110175 -Node: Invoking Gawk110941 -Node: Command Line112456 -Node: Options113247 -Ref: Options-Footnote-1129076 -Node: Other Arguments129101 -Node: Naming Standard Input131763 -Node: Environment Variables132856 -Node: AWKPATH Variable133414 -Ref: AWKPATH Variable-Footnote-1136286 -Ref: AWKPATH Variable-Footnote-2136331 -Node: AWKLIBPATH Variable136591 -Node: Other Environment Variables137350 -Node: Exit Status141007 -Node: Include Files141682 -Node: Loading Shared Libraries145260 -Node: Obsolete146644 -Node: Undocumented147341 -Node: Invoking Summary147608 -Node: Regexp149208 -Node: Regexp Usage150658 -Node: Escape Sequences152691 -Node: Regexp Operators158358 -Ref: Regexp Operators-Footnote-1165838 -Ref: Regexp Operators-Footnote-2165985 -Node: Bracket Expressions166083 -Ref: table-char-classes167973 -Node: GNU Regexp Operators170913 -Node: Case-sensitivity174636 -Ref: Case-sensitivity-Footnote-1177528 -Ref: Case-sensitivity-Footnote-2177763 -Node: Leftmost Longest177871 -Node: Computed Regexps179072 -Node: Regexp Summary182444 -Node: Reading Files183913 -Node: Records186005 -Node: awk split records186748 -Node: gawk split records191606 -Ref: gawk split records-Footnote-1196127 -Node: Fields196164 -Ref: Fields-Footnote-1199128 -Node: Nonconstant Fields199214 -Ref: Nonconstant Fields-Footnote-1201444 -Node: Changing Fields201646 -Node: Field Separators207600 -Node: Default Field Splitting210302 -Node: Regexp Field Splitting211419 -Node: Single Character Fields214760 -Node: Command Line Field Separator215819 -Node: Full Line Fields219245 -Ref: Full Line Fields-Footnote-1219753 -Node: Field Splitting Summary219799 -Ref: Field Splitting Summary-Footnote-1222931 -Node: Constant Size223032 -Node: Splitting By Content227638 -Ref: Splitting By Content-Footnote-1231711 -Node: Multiple Line231751 -Ref: Multiple Line-Footnote-1237607 -Node: Getline237786 -Node: Plain Getline240002 -Node: Getline/Variable242097 -Node: Getline/File243244 -Node: Getline/Variable/File244628 -Ref: Getline/Variable/File-Footnote-1246227 -Node: Getline/Pipe246314 -Node: Getline/Variable/Pipe249013 -Node: Getline/Coprocess250120 -Node: Getline/Variable/Coprocess251372 -Node: Getline Notes252109 -Node: Getline Summary254913 -Ref: table-getline-variants255321 -Node: Read Timeout256233 -Ref: Read Timeout-Footnote-1260060 -Node: Command-line directories260118 -Node: Input Summary261022 -Node: Input Exercises264159 -Node: Printing264892 -Node: Print266614 -Node: Print Examples267955 -Node: Output Separators270734 -Node: OFMT272750 -Node: Printf274108 -Node: Basic Printf275014 -Node: Control Letters276553 -Node: Format Modifiers280544 -Node: Printf Examples286571 -Node: Redirection289035 -Node: Special Files296007 -Node: Special FD296540 -Ref: Special FD-Footnote-1300137 -Node: Special Network300211 -Node: Special Caveats301061 -Node: Close Files And Pipes301857 -Ref: Close Files And Pipes-Footnote-1309018 -Ref: Close Files And Pipes-Footnote-2309166 -Node: Output Summary309316 -Node: Output exercises310313 -Node: Expressions310993 -Node: Values312178 -Node: Constants312854 -Node: Scalar Constants313534 -Ref: Scalar Constants-Footnote-1314393 -Node: Nondecimal-numbers314643 -Node: Regexp Constants317643 -Node: Using Constant Regexps318118 -Node: Variables321190 -Node: Using Variables321845 -Node: Assignment Options323569 -Node: Conversion325444 -Node: Strings And Numbers325968 -Ref: Strings And Numbers-Footnote-1329030 -Node: Locale influences conversions329139 -Ref: table-locale-affects331856 -Node: All Operators332444 -Node: Arithmetic Ops333074 -Node: Concatenation335579 -Ref: Concatenation-Footnote-1338398 -Node: Assignment Ops338518 -Ref: table-assign-ops343501 -Node: Increment Ops344818 -Node: Truth Values and Conditions348256 -Node: Truth Values349339 -Node: Typing and Comparison350388 -Node: Variable Typing351181 -Node: Comparison Operators354833 -Ref: table-relational-ops355243 -Node: POSIX String Comparison358793 -Ref: POSIX String Comparison-Footnote-1359877 -Node: Boolean Ops360015 -Ref: Boolean Ops-Footnote-1364085 -Node: Conditional Exp364176 -Node: Function Calls365903 -Node: Precedence369783 -Node: Locales373452 -Node: Expressions Summary375083 -Node: Patterns and Actions377624 -Node: Pattern Overview378740 -Node: Regexp Patterns380417 -Node: Expression Patterns380960 -Node: Ranges384741 -Node: BEGIN/END387847 -Node: Using BEGIN/END388609 -Ref: Using BEGIN/END-Footnote-1391345 -Node: I/O And BEGIN/END391451 -Node: BEGINFILE/ENDFILE393736 -Node: Empty396667 -Node: Using Shell Variables396984 -Node: Action Overview399267 -Node: Statements401594 -Node: If Statement403442 -Node: While Statement404940 -Node: Do Statement406984 -Node: For Statement408140 -Node: Switch Statement411292 -Node: Break Statement413395 -Node: Continue Statement415450 -Node: Next Statement417243 -Node: Nextfile Statement419633 -Node: Exit Statement422288 -Node: Built-in Variables424692 -Node: User-modified425819 -Ref: User-modified-Footnote-1433508 -Node: Auto-set433570 -Ref: Auto-set-Footnote-1446152 -Ref: Auto-set-Footnote-2446357 -Node: ARGC and ARGV446413 -Node: Pattern Action Summary450267 -Node: Arrays452490 -Node: Array Basics454039 -Node: Array Intro454865 -Ref: figure-array-elements456838 -Node: Reference to Elements459245 -Node: Assigning Elements461518 -Node: Array Example462009 -Node: Scanning an Array463741 -Node: Controlling Scanning466756 -Ref: Controlling Scanning-Footnote-1471929 -Node: Delete472245 -Ref: Delete-Footnote-1475010 -Node: Numeric Array Subscripts475067 -Node: Uninitialized Subscripts477250 -Node: Multidimensional478875 -Node: Multiscanning481968 -Node: Arrays of Arrays483557 -Node: Arrays Summary488220 -Node: Functions490325 -Node: Built-in491198 -Node: Calling Built-in492276 -Node: Numeric Functions494264 -Ref: Numeric Functions-Footnote-1498206 -Ref: Numeric Functions-Footnote-2498563 -Ref: Numeric Functions-Footnote-3498611 -Node: String Functions498880 -Ref: String Functions-Footnote-1521891 -Ref: String Functions-Footnote-2522020 -Ref: String Functions-Footnote-3522268 -Node: Gory Details522355 -Ref: table-sub-escapes524142 -Ref: table-sub-proposed525662 -Ref: table-posix-sub527026 -Ref: table-gensub-escapes528566 -Ref: Gory Details-Footnote-1529742 -Node: I/O Functions529893 -Ref: I/O Functions-Footnote-1537016 -Node: Time Functions537163 -Ref: Time Functions-Footnote-1547627 -Ref: Time Functions-Footnote-2547695 -Ref: Time Functions-Footnote-3547853 -Ref: Time Functions-Footnote-4547964 -Ref: Time Functions-Footnote-5548076 -Ref: Time Functions-Footnote-6548303 -Node: Bitwise Functions548569 -Ref: table-bitwise-ops549131 -Ref: Bitwise Functions-Footnote-1553376 -Node: Type Functions553560 -Node: I18N Functions554702 -Node: User-defined556347 -Node: Definition Syntax557151 -Ref: Definition Syntax-Footnote-1562330 -Node: Function Example562399 -Ref: Function Example-Footnote-1564963 -Node: Function Caveats564985 -Node: Calling A Function565503 -Node: Variable Scope566458 -Node: Pass By Value/Reference569446 -Node: Return Statement572956 -Node: Dynamic Typing575940 -Node: Indirect Calls576869 -Node: Functions Summary586582 -Node: Library Functions589121 -Ref: Library Functions-Footnote-1592739 -Ref: Library Functions-Footnote-2592882 -Node: Library Names593053 -Ref: Library Names-Footnote-1596526 -Ref: Library Names-Footnote-2596746 -Node: General Functions596832 -Node: Strtonum Function597860 -Node: Assert Function600640 -Node: Round Function603966 -Node: Cliff Random Function605507 -Node: Ordinal Functions606523 -Ref: Ordinal Functions-Footnote-1609600 -Ref: Ordinal Functions-Footnote-2609852 -Node: Join Function610063 -Ref: Join Function-Footnote-1611834 -Node: Getlocaltime Function612034 -Node: Readfile Function615770 -Node: Data File Management617609 -Node: Filetrans Function618241 -Node: Rewind Function622310 -Node: File Checking623868 -Ref: File Checking-Footnote-1625000 -Node: Empty Files625201 -Node: Ignoring Assigns627180 -Node: Getopt Function628734 -Ref: Getopt Function-Footnote-1640037 -Node: Passwd Functions640240 -Ref: Passwd Functions-Footnote-1649219 -Node: Group Functions649307 -Ref: Group Functions-Footnote-1657248 -Node: Walking Arrays657461 -Node: Library Functions Summary659064 -Node: Library exercises660452 -Node: Sample Programs661732 -Node: Running Examples662502 -Node: Clones663230 -Node: Cut Program664454 -Node: Egrep Program674322 -Ref: Egrep Program-Footnote-1682293 -Node: Id Program682403 -Node: Split Program686067 -Ref: Split Program-Footnote-1689605 -Node: Tee Program689733 -Node: Uniq Program692540 -Node: Wc Program699970 -Ref: Wc Program-Footnote-1704235 -Node: Miscellaneous Programs704327 -Node: Dupword Program705540 -Node: Alarm Program707571 -Node: Translate Program712385 -Ref: Translate Program-Footnote-1716776 -Ref: Translate Program-Footnote-2717046 -Node: Labels Program717180 -Ref: Labels Program-Footnote-1720551 -Node: Word Sorting720635 -Node: History Sorting724678 -Node: Extract Program726514 -Node: Simple Sed734050 -Node: Igawk Program737112 -Ref: Igawk Program-Footnote-1751423 -Ref: Igawk Program-Footnote-2751624 -Node: Anagram Program751762 -Node: Signature Program754830 -Node: Programs Summary756077 -Node: Programs Exercises757292 -Node: Advanced Features760943 -Node: Nondecimal Data762891 -Node: Array Sorting764468 -Node: Controlling Array Traversal765165 -Node: Array Sorting Functions773445 -Ref: Array Sorting Functions-Footnote-1777352 -Node: Two-way I/O777546 -Ref: Two-way I/O-Footnote-1782490 -Ref: Two-way I/O-Footnote-2782669 -Node: TCP/IP Networking782751 -Node: Profiling785596 -Node: Advanced Features Summary793138 -Node: Internationalization795002 -Node: I18N and L10N796482 -Node: Explaining gettext797168 -Ref: Explaining gettext-Footnote-1802308 -Ref: Explaining gettext-Footnote-2802492 -Node: Programmer i18n802657 -Node: Translator i18n806882 -Node: String Extraction807676 -Ref: String Extraction-Footnote-1808637 -Node: Printf Ordering808723 -Ref: Printf Ordering-Footnote-1811505 -Node: I18N Portability811569 -Ref: I18N Portability-Footnote-1814018 -Node: I18N Example814081 -Ref: I18N Example-Footnote-1816803 -Node: Gawk I18N816875 -Node: I18N Summary817513 -Node: Debugger818852 -Node: Debugging819874 -Node: Debugging Concepts820315 -Node: Debugging Terms822171 -Node: Awk Debugging824768 -Node: Sample Debugging Session825660 -Node: Debugger Invocation826180 -Node: Finding The Bug827513 -Node: List of Debugger Commands833995 -Node: Breakpoint Control835327 -Node: Debugger Execution Control838991 -Node: Viewing And Changing Data842351 -Node: Execution Stack845709 -Node: Debugger Info847222 -Node: Miscellaneous Debugger Commands851216 -Node: Readline Support856400 -Node: Limitations857292 -Node: Debugging Summary859566 -Node: Arbitrary Precision Arithmetic860730 -Node: Computer Arithmetic862217 -Ref: Computer Arithmetic-Footnote-1866604 -Node: Math Definitions866661 -Ref: table-ieee-formats869950 -Ref: Math Definitions-Footnote-1870490 -Node: MPFR features870593 -Node: FP Math Caution872235 -Ref: FP Math Caution-Footnote-1873287 -Node: Inexactness of computations873656 -Node: Inexact representation874604 -Node: Comparing FP Values875959 -Node: Errors accumulate876923 -Node: Getting Accuracy878356 -Node: Try To Round881015 -Node: Setting precision881914 -Ref: table-predefined-precision-strings882596 -Node: Setting the rounding mode884389 -Ref: table-gawk-rounding-modes884753 -Ref: Setting the rounding mode-Footnote-1888207 -Node: Arbitrary Precision Integers888386 -Ref: Arbitrary Precision Integers-Footnote-1891389 -Node: POSIX Floating Point Problems891538 -Ref: POSIX Floating Point Problems-Footnote-1895414 -Node: Floating point summary895452 -Node: Dynamic Extensions897675 -Node: Extension Intro899227 -Node: Plugin License900492 -Node: Extension Mechanism Outline901177 -Ref: figure-load-extension901601 -Ref: figure-load-new-function903086 -Ref: figure-call-new-function904088 -Node: Extension API Description906072 -Node: Extension API Functions Introduction907522 -Node: General Data Types912387 -Ref: General Data Types-Footnote-1918080 -Node: Requesting Values918379 -Ref: table-value-types-returned919116 -Node: Memory Allocation Functions920074 -Ref: Memory Allocation Functions-Footnote-1922821 -Node: Constructor Functions922917 -Node: Registration Functions924675 -Node: Extension Functions925360 -Node: Exit Callback Functions927662 -Node: Extension Version String928911 -Node: Input Parsers929561 -Node: Output Wrappers939375 -Node: Two-way processors943891 -Node: Printing Messages946095 -Ref: Printing Messages-Footnote-1947172 -Node: Updating `ERRNO'947324 -Node: Accessing Parameters948063 -Node: Symbol Table Access949293 -Node: Symbol table by name949807 -Node: Symbol table by cookie951783 -Ref: Symbol table by cookie-Footnote-1955916 -Node: Cached values955979 -Ref: Cached values-Footnote-1959483 -Node: Array Manipulation959574 -Ref: Array Manipulation-Footnote-1960672 -Node: Array Data Types960711 -Ref: Array Data Types-Footnote-1963414 -Node: Array Functions963506 -Node: Flattening Arrays967380 -Node: Creating Arrays974232 -Node: Extension API Variables978963 -Node: Extension Versioning979599 -Node: Extension API Informational Variables981500 -Node: Extension API Boilerplate982586 -Node: Finding Extensions986390 -Node: Extension Example986950 -Node: Internal File Description987680 -Node: Internal File Ops991771 -Ref: Internal File Ops-Footnote-11003203 -Node: Using Internal File Ops1003343 -Ref: Using Internal File Ops-Footnote-11005690 -Node: Extension Samples1005958 -Node: Extension Sample File Functions1007482 -Node: Extension Sample Fnmatch1015050 -Node: Extension Sample Fork1016532 -Node: Extension Sample Inplace1017745 -Node: Extension Sample Ord1019420 -Node: Extension Sample Readdir1020256 -Ref: table-readdir-file-types1021112 -Node: Extension Sample Revout1021911 -Node: Extension Sample Rev2way1022502 -Node: Extension Sample Read write array1023243 -Node: Extension Sample Readfile1025122 -Node: Extension Sample API Tests1026222 -Node: Extension Sample Time1026747 -Node: gawkextlib1028062 -Node: Extension summary1030875 -Node: Extension Exercises1034568 -Node: Language History1035290 -Node: V7/SVR3.11036933 -Node: SVR41039253 -Node: POSIX1040695 -Node: BTL1042081 -Node: POSIX/GNU1042815 -Node: Feature History1048558 -Node: Common Extensions1061688 -Node: Ranges and Locales1063000 -Ref: Ranges and Locales-Footnote-11067617 -Ref: Ranges and Locales-Footnote-21067644 -Ref: Ranges and Locales-Footnote-31067878 -Node: Contributors1068099 -Node: History summary1073524 -Node: Installation1074893 -Node: Gawk Distribution1075844 -Node: Getting1076328 -Node: Extracting1077152 -Node: Distribution contents1078794 -Node: Unix Installation1084511 -Node: Quick Installation1085128 -Node: Additional Configuration Options1087570 -Node: Configuration Philosophy1089308 -Node: Non-Unix Installation1091659 -Node: PC Installation1092117 -Node: PC Binary Installation1093428 -Node: PC Compiling1095276 -Ref: PC Compiling-Footnote-11098275 -Node: PC Testing1098380 -Node: PC Using1099556 -Node: Cygwin1103714 -Node: MSYS1104523 -Node: VMS Installation1105037 -Node: VMS Compilation1105833 -Ref: VMS Compilation-Footnote-11107055 -Node: VMS Dynamic Extensions1107113 -Node: VMS Installation Details1108486 -Node: VMS Running1110738 -Node: VMS GNV1113572 -Node: VMS Old Gawk1114295 -Node: Bugs1114765 -Node: Other Versions1118769 -Node: Installation summary1125024 -Node: Notes1126080 -Node: Compatibility Mode1126945 -Node: Additions1127727 -Node: Accessing The Source1128652 -Node: Adding Code1130088 -Node: New Ports1136266 -Node: Derived Files1140747 -Ref: Derived Files-Footnote-11145828 -Ref: Derived Files-Footnote-21145862 -Ref: Derived Files-Footnote-31146458 -Node: Future Extensions1146572 -Node: Implementation Limitations1147178 -Node: Extension Design1148426 -Node: Old Extension Problems1149580 -Ref: Old Extension Problems-Footnote-11151097 -Node: Extension New Mechanism Goals1151154 -Ref: Extension New Mechanism Goals-Footnote-11154514 -Node: Extension Other Design Decisions1154703 -Node: Extension Future Growth1156809 -Node: Old Extension Mechanism1157645 -Node: Notes summary1159407 -Node: Basic Concepts1160593 -Node: Basic High Level1161274 -Ref: figure-general-flow1161546 -Ref: figure-process-flow1162145 -Ref: Basic High Level-Footnote-11165374 -Node: Basic Data Typing1165559 -Node: Glossary1168887 -Node: Copying1194039 -Node: GNU Free Documentation License1231595 -Node: Index1256731 +Ref: Preface-Footnote-149226 +Ref: Preface-Footnote-249333 +Node: History49565 +Node: Names51939 +Ref: Names-Footnote-153403 +Node: This Manual53476 +Ref: This Manual-Footnote-159255 +Node: Conventions59355 +Node: Manual History61511 +Ref: Manual History-Footnote-164587 +Ref: Manual History-Footnote-264628 +Node: How To Contribute64702 +Node: Acknowledgments65941 +Node: Getting Started70689 +Node: Running gawk73123 +Node: One-shot74313 +Node: Read Terminal75538 +Ref: Read Terminal-Footnote-177501 +Node: Long77672 +Node: Executable Scripts79048 +Ref: Executable Scripts-Footnote-180881 +Ref: Executable Scripts-Footnote-280983 +Node: Comments81530 +Node: Quoting84003 +Node: DOS Quoting89316 +Node: Sample Data Files89991 +Node: Very Simple92545 +Node: Two Rules97318 +Node: More Complex99212 +Ref: More Complex-Footnote-1102144 +Node: Statements/Lines102229 +Ref: Statements/Lines-Footnote-1106685 +Node: Other Features106950 +Node: When107878 +Ref: When-Footnote-1109764 +Node: Intro Summary109829 +Node: Invoking Gawk110595 +Node: Command Line112110 +Node: Options112901 +Ref: Options-Footnote-1128699 +Node: Other Arguments128724 +Node: Naming Standard Input131386 +Node: Environment Variables132479 +Node: AWKPATH Variable133037 +Ref: AWKPATH Variable-Footnote-1135903 +Ref: AWKPATH Variable-Footnote-2135948 +Node: AWKLIBPATH Variable136208 +Node: Other Environment Variables136967 +Node: Exit Status140624 +Node: Include Files141299 +Node: Loading Shared Libraries144877 +Node: Obsolete146261 +Node: Undocumented146958 +Node: Invoking Summary147225 +Node: Regexp148825 +Node: Regexp Usage150275 +Node: Escape Sequences152308 +Node: Regexp Operators158139 +Ref: Regexp Operators-Footnote-1165619 +Ref: Regexp Operators-Footnote-2165766 +Node: Bracket Expressions165864 +Ref: table-char-classes167754 +Node: GNU Regexp Operators170694 +Node: Case-sensitivity174417 +Ref: Case-sensitivity-Footnote-1177309 +Ref: Case-sensitivity-Footnote-2177544 +Node: Leftmost Longest177652 +Node: Computed Regexps178853 +Node: Regexp Summary182225 +Node: Reading Files183694 +Node: Records185786 +Node: awk split records186529 +Node: gawk split records191387 +Ref: gawk split records-Footnote-1195908 +Node: Fields195945 +Ref: Fields-Footnote-1198909 +Node: Nonconstant Fields198995 +Ref: Nonconstant Fields-Footnote-1201225 +Node: Changing Fields201427 +Node: Field Separators207381 +Node: Default Field Splitting210083 +Node: Regexp Field Splitting211200 +Node: Single Character Fields214541 +Node: Command Line Field Separator215600 +Node: Full Line Fields219026 +Ref: Full Line Fields-Footnote-1219534 +Node: Field Splitting Summary219580 +Ref: Field Splitting Summary-Footnote-1222712 +Node: Constant Size222813 +Node: Splitting By Content227419 +Ref: Splitting By Content-Footnote-1231492 +Node: Multiple Line231532 +Ref: Multiple Line-Footnote-1237388 +Node: Getline237567 +Node: Plain Getline239783 +Node: Getline/Variable241878 +Node: Getline/File243025 +Node: Getline/Variable/File244409 +Ref: Getline/Variable/File-Footnote-1246008 +Node: Getline/Pipe246095 +Node: Getline/Variable/Pipe248794 +Node: Getline/Coprocess249901 +Node: Getline/Variable/Coprocess251153 +Node: Getline Notes251890 +Node: Getline Summary254694 +Ref: table-getline-variants255102 +Node: Read Timeout256014 +Ref: Read Timeout-Footnote-1259841 +Node: Command-line directories259899 +Node: Input Summary260803 +Node: Input Exercises263940 +Node: Printing264673 +Node: Print266395 +Node: Print Examples267736 +Node: Output Separators270515 +Node: OFMT272531 +Node: Printf273889 +Node: Basic Printf274795 +Node: Control Letters276334 +Node: Format Modifiers280325 +Node: Printf Examples286352 +Node: Redirection288816 +Node: Special Files295788 +Node: Special FD296321 +Ref: Special FD-Footnote-1299918 +Node: Special Network299992 +Node: Special Caveats300842 +Node: Close Files And Pipes301638 +Ref: Close Files And Pipes-Footnote-1308799 +Ref: Close Files And Pipes-Footnote-2308947 +Node: Output Summary309097 +Node: Output exercises310094 +Node: Expressions310774 +Node: Values311959 +Node: Constants312635 +Node: Scalar Constants313315 +Ref: Scalar Constants-Footnote-1314174 +Node: Nondecimal-numbers314424 +Node: Regexp Constants317424 +Node: Using Constant Regexps317899 +Node: Variables320971 +Node: Using Variables321626 +Node: Assignment Options323350 +Node: Conversion325225 +Node: Strings And Numbers325749 +Ref: Strings And Numbers-Footnote-1328811 +Node: Locale influences conversions328920 +Ref: table-locale-affects331637 +Node: All Operators332225 +Node: Arithmetic Ops332855 +Node: Concatenation335360 +Ref: Concatenation-Footnote-1338179 +Node: Assignment Ops338299 +Ref: table-assign-ops343282 +Node: Increment Ops344599 +Node: Truth Values and Conditions348037 +Node: Truth Values349120 +Node: Typing and Comparison350169 +Node: Variable Typing350962 +Node: Comparison Operators354614 +Ref: table-relational-ops355024 +Node: POSIX String Comparison358574 +Ref: POSIX String Comparison-Footnote-1359658 +Node: Boolean Ops359796 +Ref: Boolean Ops-Footnote-1363866 +Node: Conditional Exp363957 +Node: Function Calls365684 +Node: Precedence369564 +Node: Locales373233 +Node: Expressions Summary374864 +Node: Patterns and Actions377405 +Node: Pattern Overview378521 +Node: Regexp Patterns380198 +Node: Expression Patterns380741 +Node: Ranges384522 +Node: BEGIN/END387628 +Node: Using BEGIN/END388390 +Ref: Using BEGIN/END-Footnote-1391126 +Node: I/O And BEGIN/END391232 +Node: BEGINFILE/ENDFILE393517 +Node: Empty396448 +Node: Using Shell Variables396765 +Node: Action Overview399048 +Node: Statements401375 +Node: If Statement403223 +Node: While Statement404721 +Node: Do Statement406765 +Node: For Statement407921 +Node: Switch Statement411073 +Node: Break Statement413461 +Node: Continue Statement415516 +Node: Next Statement417355 +Node: Nextfile Statement419745 +Node: Exit Statement422400 +Node: Built-in Variables424804 +Node: User-modified425931 +Ref: User-modified-Footnote-1433620 +Node: Auto-set433682 +Ref: Auto-set-Footnote-1446264 +Ref: Auto-set-Footnote-2446469 +Node: ARGC and ARGV446525 +Node: Pattern Action Summary450429 +Node: Arrays452652 +Node: Array Basics454201 +Node: Array Intro455027 +Ref: figure-array-elements457000 +Node: Reference to Elements459407 +Node: Assigning Elements461786 +Node: Array Example462277 +Node: Scanning an Array464009 +Node: Controlling Scanning467024 +Ref: Controlling Scanning-Footnote-1472197 +Node: Delete472513 +Ref: Delete-Footnote-1475278 +Node: Numeric Array Subscripts475335 +Node: Uninitialized Subscripts477518 +Node: Multidimensional479143 +Node: Multiscanning482256 +Node: Arrays of Arrays483845 +Node: Arrays Summary488508 +Node: Functions490613 +Node: Built-in491486 +Node: Calling Built-in492564 +Node: Numeric Functions494552 +Ref: Numeric Functions-Footnote-1498586 +Ref: Numeric Functions-Footnote-2498943 +Ref: Numeric Functions-Footnote-3498991 +Node: String Functions499260 +Ref: String Functions-Footnote-1522271 +Ref: String Functions-Footnote-2522400 +Ref: String Functions-Footnote-3522648 +Node: Gory Details522735 +Ref: table-sub-escapes524522 +Ref: table-sub-proposed526042 +Ref: table-posix-sub527406 +Ref: table-gensub-escapes528946 +Ref: Gory Details-Footnote-1530122 +Node: I/O Functions530273 +Ref: I/O Functions-Footnote-1537396 +Node: Time Functions537543 +Ref: Time Functions-Footnote-1548007 +Ref: Time Functions-Footnote-2548075 +Ref: Time Functions-Footnote-3548233 +Ref: Time Functions-Footnote-4548344 +Ref: Time Functions-Footnote-5548456 +Ref: Time Functions-Footnote-6548683 +Node: Bitwise Functions548949 +Ref: table-bitwise-ops549511 +Ref: Bitwise Functions-Footnote-1553756 +Node: Type Functions553940 +Node: I18N Functions555082 +Node: User-defined556727 +Node: Definition Syntax557531 +Ref: Definition Syntax-Footnote-1562710 +Node: Function Example562779 +Ref: Function Example-Footnote-1565419 +Node: Function Caveats565441 +Node: Calling A Function565959 +Node: Variable Scope566914 +Node: Pass By Value/Reference569902 +Node: Return Statement573412 +Node: Dynamic Typing576396 +Node: Indirect Calls577325 +Node: Functions Summary587038 +Node: Library Functions589577 +Ref: Library Functions-Footnote-1593195 +Ref: Library Functions-Footnote-2593338 +Node: Library Names593509 +Ref: Library Names-Footnote-1596982 +Ref: Library Names-Footnote-2597202 +Node: General Functions597288 +Node: Strtonum Function598316 +Node: Assert Function601096 +Node: Round Function604422 +Node: Cliff Random Function605963 +Node: Ordinal Functions606979 +Ref: Ordinal Functions-Footnote-1610056 +Ref: Ordinal Functions-Footnote-2610308 +Node: Join Function610519 +Ref: Join Function-Footnote-1612290 +Node: Getlocaltime Function612490 +Node: Readfile Function616226 +Node: Data File Management618065 +Node: Filetrans Function618697 +Node: Rewind Function622766 +Node: File Checking624324 +Ref: File Checking-Footnote-1625456 +Node: Empty Files625657 +Node: Ignoring Assigns627636 +Node: Getopt Function629190 +Ref: Getopt Function-Footnote-1640493 +Node: Passwd Functions640696 +Ref: Passwd Functions-Footnote-1649675 +Node: Group Functions649763 +Ref: Group Functions-Footnote-1657704 +Node: Walking Arrays657917 +Node: Library Functions Summary659520 +Node: Library exercises660908 +Node: Sample Programs662188 +Node: Running Examples662958 +Node: Clones663686 +Node: Cut Program664910 +Node: Egrep Program674778 +Ref: Egrep Program-Footnote-1682749 +Node: Id Program682859 +Node: Split Program686523 +Ref: Split Program-Footnote-1690061 +Node: Tee Program690189 +Node: Uniq Program692996 +Node: Wc Program700426 +Ref: Wc Program-Footnote-1704691 +Node: Miscellaneous Programs704783 +Node: Dupword Program705996 +Node: Alarm Program708027 +Node: Translate Program712841 +Ref: Translate Program-Footnote-1717232 +Ref: Translate Program-Footnote-2717502 +Node: Labels Program717636 +Ref: Labels Program-Footnote-1721007 +Node: Word Sorting721091 +Node: History Sorting725134 +Node: Extract Program726970 +Node: Simple Sed734506 +Node: Igawk Program737568 +Ref: Igawk Program-Footnote-1751872 +Ref: Igawk Program-Footnote-2752073 +Node: Anagram Program752211 +Node: Signature Program755279 +Node: Programs Summary756526 +Node: Programs Exercises757741 +Node: Advanced Features761392 +Node: Nondecimal Data763340 +Node: Array Sorting764917 +Node: Controlling Array Traversal765614 +Node: Array Sorting Functions773894 +Ref: Array Sorting Functions-Footnote-1777801 +Node: Two-way I/O777995 +Ref: Two-way I/O-Footnote-1782939 +Ref: Two-way I/O-Footnote-2783118 +Node: TCP/IP Networking783200 +Node: Profiling786045 +Node: Advanced Features Summary793587 +Node: Internationalization795451 +Node: I18N and L10N796931 +Node: Explaining gettext797617 +Ref: Explaining gettext-Footnote-1802757 +Ref: Explaining gettext-Footnote-2802941 +Node: Programmer i18n803106 +Node: Translator i18n807331 +Node: String Extraction808125 +Ref: String Extraction-Footnote-1809086 +Node: Printf Ordering809172 +Ref: Printf Ordering-Footnote-1811954 +Node: I18N Portability812018 +Ref: I18N Portability-Footnote-1814467 +Node: I18N Example814530 +Ref: I18N Example-Footnote-1817252 +Node: Gawk I18N817324 +Node: I18N Summary817962 +Node: Debugger819301 +Node: Debugging820323 +Node: Debugging Concepts820764 +Node: Debugging Terms822620 +Node: Awk Debugging825217 +Node: Sample Debugging Session826109 +Node: Debugger Invocation826629 +Node: Finding The Bug827962 +Node: List of Debugger Commands834444 +Node: Breakpoint Control835776 +Node: Debugger Execution Control839440 +Node: Viewing And Changing Data842800 +Node: Execution Stack846158 +Node: Debugger Info847671 +Node: Miscellaneous Debugger Commands851665 +Node: Readline Support856849 +Node: Limitations857741 +Node: Debugging Summary860015 +Node: Arbitrary Precision Arithmetic861183 +Node: Computer Arithmetic862670 +Ref: Computer Arithmetic-Footnote-1867057 +Node: Math Definitions867114 +Ref: table-ieee-formats870403 +Ref: Math Definitions-Footnote-1870943 +Node: MPFR features871046 +Node: FP Math Caution872663 +Ref: FP Math Caution-Footnote-1873713 +Node: Inexactness of computations874082 +Node: Inexact representation875030 +Node: Comparing FP Values876385 +Node: Errors accumulate877349 +Node: Getting Accuracy878782 +Node: Try To Round881441 +Node: Setting precision882340 +Ref: table-predefined-precision-strings883022 +Node: Setting the rounding mode884815 +Ref: table-gawk-rounding-modes885179 +Ref: Setting the rounding mode-Footnote-1888633 +Node: Arbitrary Precision Integers888812 +Ref: Arbitrary Precision Integers-Footnote-1891793 +Node: POSIX Floating Point Problems891942 +Ref: POSIX Floating Point Problems-Footnote-1895818 +Node: Floating point summary895856 +Node: Dynamic Extensions898060 +Node: Extension Intro899612 +Node: Plugin License900877 +Node: Extension Mechanism Outline901562 +Ref: figure-load-extension901986 +Ref: figure-load-new-function903471 +Ref: figure-call-new-function904473 +Node: Extension API Description906457 +Node: Extension API Functions Introduction907907 +Node: General Data Types912774 +Ref: General Data Types-Footnote-1918467 +Node: Requesting Values918766 +Ref: table-value-types-returned919503 +Node: Memory Allocation Functions920461 +Ref: Memory Allocation Functions-Footnote-1923208 +Node: Constructor Functions923304 +Node: Registration Functions925062 +Node: Extension Functions925747 +Node: Exit Callback Functions928049 +Node: Extension Version String929297 +Node: Input Parsers929947 +Node: Output Wrappers939761 +Node: Two-way processors944277 +Node: Printing Messages946481 +Ref: Printing Messages-Footnote-1947558 +Node: Updating `ERRNO'947710 +Node: Accessing Parameters948449 +Node: Symbol Table Access949679 +Node: Symbol table by name950193 +Node: Symbol table by cookie952169 +Ref: Symbol table by cookie-Footnote-1956302 +Node: Cached values956365 +Ref: Cached values-Footnote-1959869 +Node: Array Manipulation959960 +Ref: Array Manipulation-Footnote-1961058 +Node: Array Data Types961097 +Ref: Array Data Types-Footnote-1963800 +Node: Array Functions963892 +Node: Flattening Arrays967766 +Node: Creating Arrays974618 +Node: Extension API Variables979349 +Node: Extension Versioning979985 +Node: Extension API Informational Variables981886 +Node: Extension API Boilerplate982972 +Node: Finding Extensions986776 +Node: Extension Example987336 +Node: Internal File Description988066 +Node: Internal File Ops992157 +Ref: Internal File Ops-Footnote-11003589 +Node: Using Internal File Ops1003729 +Ref: Using Internal File Ops-Footnote-11006076 +Node: Extension Samples1006344 +Node: Extension Sample File Functions1007868 +Node: Extension Sample Fnmatch1015436 +Node: Extension Sample Fork1016918 +Node: Extension Sample Inplace1018131 +Node: Extension Sample Ord1019806 +Node: Extension Sample Readdir1020642 +Ref: table-readdir-file-types1021498 +Node: Extension Sample Revout1022297 +Node: Extension Sample Rev2way1022888 +Node: Extension Sample Read write array1023629 +Node: Extension Sample Readfile1025508 +Node: Extension Sample API Tests1026608 +Node: Extension Sample Time1027133 +Node: gawkextlib1028448 +Node: Extension summary1031261 +Node: Extension Exercises1034954 +Node: Language History1035676 +Node: V7/SVR3.11037319 +Node: SVR41039639 +Node: POSIX1041081 +Node: BTL1042467 +Node: POSIX/GNU1043201 +Node: Feature History1048942 +Node: Common Extensions1062072 +Node: Ranges and Locales1063384 +Ref: Ranges and Locales-Footnote-11068001 +Ref: Ranges and Locales-Footnote-21068028 +Ref: Ranges and Locales-Footnote-31068262 +Node: Contributors1068483 +Node: History summary1073908 +Node: Installation1075277 +Node: Gawk Distribution1076228 +Node: Getting1076712 +Node: Extracting1077536 +Node: Distribution contents1079178 +Node: Unix Installation1084895 +Node: Quick Installation1085512 +Node: Additional Configuration Options1087954 +Node: Configuration Philosophy1089692 +Node: Non-Unix Installation1092043 +Node: PC Installation1092501 +Node: PC Binary Installation1093812 +Node: PC Compiling1095660 +Ref: PC Compiling-Footnote-11098659 +Node: PC Testing1098764 +Node: PC Using1099940 +Node: Cygwin1104092 +Node: MSYS1104901 +Node: VMS Installation1105415 +Node: VMS Compilation1106211 +Ref: VMS Compilation-Footnote-11107433 +Node: VMS Dynamic Extensions1107491 +Node: VMS Installation Details1108864 +Node: VMS Running1111116 +Node: VMS GNV1113950 +Node: VMS Old Gawk1114673 +Node: Bugs1115143 +Node: Other Versions1119147 +Node: Installation summary1125402 +Node: Notes1126458 +Node: Compatibility Mode1127323 +Node: Additions1128105 +Node: Accessing The Source1129030 +Node: Adding Code1130466 +Node: New Ports1136644 +Node: Derived Files1141125 +Ref: Derived Files-Footnote-11146206 +Ref: Derived Files-Footnote-21146240 +Ref: Derived Files-Footnote-31146836 +Node: Future Extensions1146950 +Node: Implementation Limitations1147556 +Node: Extension Design1148804 +Node: Old Extension Problems1149958 +Ref: Old Extension Problems-Footnote-11151475 +Node: Extension New Mechanism Goals1151532 +Ref: Extension New Mechanism Goals-Footnote-11154892 +Node: Extension Other Design Decisions1155081 +Node: Extension Future Growth1157187 +Node: Old Extension Mechanism1158023 +Node: Notes summary1159785 +Node: Basic Concepts1160971 +Node: Basic High Level1161652 +Ref: figure-general-flow1161924 +Ref: figure-process-flow1162523 +Ref: Basic High Level-Footnote-11165752 +Node: Basic Data Typing1165937 +Node: Glossary1169265 +Node: Copying1194417 +Node: GNU Free Documentation License1231973 +Node: Index1257109  End Tag Table -- cgit v1.2.3 From 0a8f56def1597bd886d7c9095c1f73e157d1197b Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Wed, 20 Aug 2014 06:23:01 +0300 Subject: \x escape sequences now process a maximum of 2 digits. --- doc/gawk.info | 1028 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 515 insertions(+), 513 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index a3195bb5..a4f52a54 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -3336,15 +3336,17 @@ apply to both string constants and regexp constants: `\xHH...' The hexadecimal value HH, where HH stands for a sequence of - hexadecimal digits (`0'-`9', and either `A'-`F' or `a'-`f'). Like - the same construct in ISO C, the escape sequence continues until - the first nonhexadecimal digit is seen. (c.e.) However, using - more than two hexadecimal digits produces undefined results. (The - `\x' escape sequence is not allowed in POSIX `awk'.) + hexadecimal digits (`0'-`9', and either `A'-`F' or `a'-`f'). A + maximum of two digts are allowed after the `\x'. Any further + hexadecimal digits are treated as simple letters or numbers. + (c.e.) - CAUTION: The next major relase of `gawk' will change, such - that a maximum of two hexadecimal digits following the `\x' - will be used. + CAUTION: In ISO C, the escape sequence continues until the + first nonhexadecimal digit is seen. For many years, `gawk' + would continue incorporating hexadecimal digits into the + value until a non-hexadecimal digit or the end of the string + was encountered. However, using more than two hexadecimal + digits produces `\/' A literal slash (necessary for regexp constants only). This @@ -31148,10 +31150,10 @@ Index * [] (square brackets), regexp operator: Regexp Operators. (line 56) * \ (backslash): Comments. (line 50) * \ (backslash) in shell commands: Read Terminal. (line 25) -* \ (backslash), \" escape sequence: Escape Sequences. (line 80) +* \ (backslash), \" escape sequence: Escape Sequences. (line 82) * \ (backslash), \' operator (gawk): GNU Regexp Operators. (line 56) -* \ (backslash), \/ escape sequence: Escape Sequences. (line 73) +* \ (backslash), \/ escape sequence: Escape Sequences. (line 75) * \ (backslash), \< operator (gawk): GNU Regexp Operators. (line 30) * \ (backslash), \> operator (gawk): GNU Regexp Operators. @@ -31192,7 +31194,7 @@ Index * \ (backslash), in bracket expressions: Bracket Expressions. (line 17) * \ (backslash), in escape sequences: Escape Sequences. (line 6) * \ (backslash), in escape sequences, POSIX and: Escape Sequences. - (line 116) + (line 118) * \ (backslash), in regexp constants: Computed Regexps. (line 29) * \ (backslash), in shell commands: Quoting. (line 48) * \ (backslash), regexp operator: Regexp Operators. (line 18) @@ -31421,10 +31423,10 @@ Index * b debugger command (alias for break): Breakpoint Control. (line 11) * backslash (\): Comments. (line 50) * backslash (\) in shell commands: Read Terminal. (line 25) -* backslash (\), \" escape sequence: Escape Sequences. (line 80) +* backslash (\), \" escape sequence: Escape Sequences. (line 82) * backslash (\), \' operator (gawk): GNU Regexp Operators. (line 56) -* backslash (\), \/ escape sequence: Escape Sequences. (line 73) +* backslash (\), \/ escape sequence: Escape Sequences. (line 75) * backslash (\), \< operator (gawk): GNU Regexp Operators. (line 30) * backslash (\), \> operator (gawk): GNU Regexp Operators. @@ -31465,7 +31467,7 @@ Index * backslash (\), in bracket expressions: Bracket Expressions. (line 17) * backslash (\), in escape sequences: Escape Sequences. (line 6) * backslash (\), in escape sequences, POSIX and: Escape Sequences. - (line 116) + (line 118) * backslash (\), in regexp constants: Computed Regexps. (line 29) * backslash (\), in shell commands: Quoting. (line 48) * backslash (\), regexp operator: Regexp Operators. (line 18) @@ -31569,7 +31571,7 @@ Index (line 67) * Brian Kernighan's awk <12>: GNU Regexp Operators. (line 83) -* Brian Kernighan's awk <13>: Escape Sequences. (line 120) +* Brian Kernighan's awk <13>: Escape Sequences. (line 122) * Brian Kernighan's awk <14>: When. (line 21) * Brian Kernighan's awk: Preface. (line 13) * Brian Kernighan's awk, extensions: BTL. (line 6) @@ -31798,7 +31800,7 @@ Index * dark corner, CONVFMT variable: Strings And Numbers. (line 40) * dark corner, escape sequences: Other Arguments. (line 31) * dark corner, escape sequences, for metacharacters: Escape Sequences. - (line 138) + (line 140) * dark corner, exit statement: Exit Statement. (line 30) * dark corner, field separators: Field Splitting Summary. (line 46) @@ -32468,7 +32470,7 @@ Index * gawk, ERRNO variable in <4>: Close Files And Pipes. (line 139) * gawk, ERRNO variable in: Getline. (line 19) -* gawk, escape sequences: Escape Sequences. (line 128) +* gawk, escape sequences: Escape Sequences. (line 130) * gawk, extensions, disabling: Options. (line 252) * gawk, features, adding: Adding Code. (line 6) * gawk, features, advanced: Advanced Features. (line 6) @@ -32902,7 +32904,7 @@ Index * mawk utility <2>: Nextfile Statement. (line 47) * mawk utility <3>: Concatenation. (line 36) * mawk utility <4>: Getline/Pipe. (line 62) -* mawk utility: Escape Sequences. (line 128) +* mawk utility: Escape Sequences. (line 130) * maximum precision supported by MPFR library: Auto-set. (line 221) * McIlroy, Doug: Glossary. (line 149) * McPhee, Patrick: Contributors. (line 100) @@ -32915,7 +32917,7 @@ Index (line 54) * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) -* metacharacters, escape sequences for: Escape Sequences. (line 134) +* metacharacters, escape sequences for: Escape Sequences. (line 136) * minimum precision supported by MPFR library: Auto-set. (line 224) * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) @@ -33136,14 +33138,14 @@ Index * plus sign (+), += operator: Assignment Ops. (line 82) * plus sign (+), regexp operator: Regexp Operators. (line 103) * pointers to functions: Indirect Calls. (line 6) -* portability: Escape Sequences. (line 98) +* portability: Escape Sequences. (line 100) * portability, #! (executable scripts): Executable Scripts. (line 33) * portability, ** operator and: Arithmetic Ops. (line 81) * portability, **= operator and: Assignment Ops. (line 143) * portability, ARGV variable: Executable Scripts. (line 42) * portability, backslash continuation and: Statements/Lines. (line 30) * portability, backslash in escape sequences: Escape Sequences. - (line 116) + (line 118) * portability, close() function and: Close Files And Pipes. (line 81) * portability, data files as single record: gawk split records. @@ -33182,7 +33184,7 @@ Index * POSIX awk, < operator and: Getline/File. (line 26) * POSIX awk, arithmetic operators and: Arithmetic Ops. (line 30) * POSIX awk, backslashes in string constants: Escape Sequences. - (line 116) + (line 118) * POSIX awk, BEGIN/END patterns: I/O And BEGIN/END. (line 16) * POSIX awk, bracket expressions and: Bracket Expressions. (line 24) * POSIX awk, bracket expressions and, character classes: Bracket Expressions. @@ -33563,14 +33565,14 @@ Index * sidebar, A Constant's Base Does Not Affect Its Value: Nondecimal-numbers. (line 64) * sidebar, Backslash Before Regular Characters: Escape Sequences. - (line 114) + (line 116) * sidebar, Changing FS Does Not Affect the Fields: Field Splitting Summary. (line 38) * sidebar, Changing NR and FNR: Auto-set. (line 307) * sidebar, Controlling Output Buffering with system(): I/O Functions. (line 138) * sidebar, Escape Sequences for Metacharacters: Escape Sequences. - (line 132) + (line 134) * sidebar, FS and IGNORECASE: Field Splitting Summary. (line 64) * sidebar, Interactive Versus Noninteractive Buffering: I/O Functions. @@ -33798,7 +33800,7 @@ Index (line 37) * troubleshooting, awk uses FS not IFS: Field Separators. (line 30) * troubleshooting, backslash before nonspecial character: Escape Sequences. - (line 116) + (line 118) * troubleshooting, division: Arithmetic Ops. (line 44) * troubleshooting, fatal errors, field widths, specifying: Constant Size. (line 23) @@ -33854,7 +33856,7 @@ Index * uniq.awk program: Uniq Program. (line 65) * Unix: Glossary. (line 611) * Unix awk, backslashes in escape sequences: Escape Sequences. - (line 128) + (line 130) * Unix awk, close() function and: Close Files And Pipes. (line 131) * Unix awk, password files, field separators and: Command Line Field Separator. @@ -34058,492 +34060,492 @@ Node: Invoking Summary146891 Node: Regexp148491 Node: Regexp Usage149941 Node: Escape Sequences151974 -Node: Regexp Operators157805 -Ref: Regexp Operators-Footnote-1165285 -Ref: Regexp Operators-Footnote-2165432 -Node: Bracket Expressions165530 -Ref: table-char-classes167420 -Node: GNU Regexp Operators170360 -Node: Case-sensitivity174083 -Ref: Case-sensitivity-Footnote-1176975 -Ref: Case-sensitivity-Footnote-2177210 -Node: Leftmost Longest177318 -Node: Computed Regexps178519 -Node: Regexp Summary181891 -Node: Reading Files183360 -Node: Records185452 -Node: awk split records186195 -Node: gawk split records191053 -Ref: gawk split records-Footnote-1195574 -Node: Fields195611 -Ref: Fields-Footnote-1198575 -Node: Nonconstant Fields198661 -Ref: Nonconstant Fields-Footnote-1200891 -Node: Changing Fields201093 -Node: Field Separators207047 -Node: Default Field Splitting209749 -Node: Regexp Field Splitting210866 -Node: Single Character Fields214207 -Node: Command Line Field Separator215266 -Node: Full Line Fields218692 -Ref: Full Line Fields-Footnote-1219200 -Node: Field Splitting Summary219246 -Ref: Field Splitting Summary-Footnote-1222378 -Node: Constant Size222479 -Node: Splitting By Content227085 -Ref: Splitting By Content-Footnote-1231158 -Node: Multiple Line231198 -Ref: Multiple Line-Footnote-1237054 -Node: Getline237233 -Node: Plain Getline239449 -Node: Getline/Variable241544 -Node: Getline/File242691 -Node: Getline/Variable/File244075 -Ref: Getline/Variable/File-Footnote-1245674 -Node: Getline/Pipe245761 -Node: Getline/Variable/Pipe248460 -Node: Getline/Coprocess249567 -Node: Getline/Variable/Coprocess250819 -Node: Getline Notes251556 -Node: Getline Summary254360 -Ref: table-getline-variants254768 -Node: Read Timeout255680 -Ref: Read Timeout-Footnote-1259507 -Node: Command-line directories259565 -Node: Input Summary260469 -Node: Input Exercises263606 -Node: Printing264339 -Node: Print266061 -Node: Print Examples267402 -Node: Output Separators270181 -Node: OFMT272197 -Node: Printf273555 -Node: Basic Printf274461 -Node: Control Letters276000 -Node: Format Modifiers279991 -Node: Printf Examples286018 -Node: Redirection288482 -Node: Special Files295454 -Node: Special FD295987 -Ref: Special FD-Footnote-1299584 -Node: Special Network299658 -Node: Special Caveats300508 -Node: Close Files And Pipes301304 -Ref: Close Files And Pipes-Footnote-1308465 -Ref: Close Files And Pipes-Footnote-2308613 -Node: Output Summary308763 -Node: Output exercises309760 -Node: Expressions310440 -Node: Values311625 -Node: Constants312301 -Node: Scalar Constants312981 -Ref: Scalar Constants-Footnote-1313840 -Node: Nondecimal-numbers314090 -Node: Regexp Constants317090 -Node: Using Constant Regexps317565 -Node: Variables320637 -Node: Using Variables321292 -Node: Assignment Options323016 -Node: Conversion324891 -Node: Strings And Numbers325415 -Ref: Strings And Numbers-Footnote-1328477 -Node: Locale influences conversions328586 -Ref: table-locale-affects331303 -Node: All Operators331891 -Node: Arithmetic Ops332521 -Node: Concatenation335026 -Ref: Concatenation-Footnote-1337845 -Node: Assignment Ops337965 -Ref: table-assign-ops342948 -Node: Increment Ops344265 -Node: Truth Values and Conditions347703 -Node: Truth Values348786 -Node: Typing and Comparison349835 -Node: Variable Typing350628 -Node: Comparison Operators354280 -Ref: table-relational-ops354690 -Node: POSIX String Comparison358240 -Ref: POSIX String Comparison-Footnote-1359324 -Node: Boolean Ops359462 -Ref: Boolean Ops-Footnote-1363532 -Node: Conditional Exp363623 -Node: Function Calls365350 -Node: Precedence369230 -Node: Locales372899 -Node: Expressions Summary374530 -Node: Patterns and Actions377071 -Node: Pattern Overview378187 -Node: Regexp Patterns379864 -Node: Expression Patterns380407 -Node: Ranges384188 -Node: BEGIN/END387294 -Node: Using BEGIN/END388056 -Ref: Using BEGIN/END-Footnote-1390792 -Node: I/O And BEGIN/END390898 -Node: BEGINFILE/ENDFILE393183 -Node: Empty396114 -Node: Using Shell Variables396431 -Node: Action Overview398714 -Node: Statements401041 -Node: If Statement402889 -Node: While Statement404387 -Node: Do Statement406431 -Node: For Statement407587 -Node: Switch Statement410739 -Node: Break Statement413127 -Node: Continue Statement415182 -Node: Next Statement417021 -Node: Nextfile Statement419411 -Node: Exit Statement422066 -Node: Built-in Variables424470 -Node: User-modified425597 -Ref: User-modified-Footnote-1433286 -Node: Auto-set433348 -Ref: Auto-set-Footnote-1446267 -Ref: Auto-set-Footnote-2446472 -Node: ARGC and ARGV446528 -Node: Pattern Action Summary450432 -Node: Arrays452655 -Node: Array Basics454204 -Node: Array Intro455030 -Ref: figure-array-elements457003 -Node: Reference to Elements459410 -Node: Assigning Elements461789 -Node: Array Example462280 -Node: Scanning an Array464012 -Node: Controlling Scanning467027 -Ref: Controlling Scanning-Footnote-1472200 -Node: Delete472516 -Ref: Delete-Footnote-1475281 -Node: Numeric Array Subscripts475338 -Node: Uninitialized Subscripts477521 -Node: Multidimensional479146 -Node: Multiscanning482259 -Node: Arrays of Arrays483848 -Node: Arrays Summary488511 -Node: Functions490616 -Node: Built-in491489 -Node: Calling Built-in492567 -Node: Numeric Functions494555 -Ref: Numeric Functions-Footnote-1499391 -Ref: Numeric Functions-Footnote-2499748 -Ref: Numeric Functions-Footnote-3499796 -Node: String Functions500065 -Ref: String Functions-Footnote-1523076 -Ref: String Functions-Footnote-2523205 -Ref: String Functions-Footnote-3523453 -Node: Gory Details523540 -Ref: table-sub-escapes525327 -Ref: table-sub-proposed526847 -Ref: table-posix-sub528211 -Ref: table-gensub-escapes529751 -Ref: Gory Details-Footnote-1530927 -Node: I/O Functions531078 -Ref: I/O Functions-Footnote-1538201 -Node: Time Functions538348 -Ref: Time Functions-Footnote-1548812 -Ref: Time Functions-Footnote-2548880 -Ref: Time Functions-Footnote-3549038 -Ref: Time Functions-Footnote-4549149 -Ref: Time Functions-Footnote-5549261 -Ref: Time Functions-Footnote-6549488 -Node: Bitwise Functions549754 -Ref: table-bitwise-ops550316 -Ref: Bitwise Functions-Footnote-1554561 -Node: Type Functions554745 -Node: I18N Functions555887 -Node: User-defined557532 -Node: Definition Syntax558336 -Ref: Definition Syntax-Footnote-1563515 -Node: Function Example563584 -Ref: Function Example-Footnote-1566224 -Node: Function Caveats566246 -Node: Calling A Function566764 -Node: Variable Scope567719 -Node: Pass By Value/Reference570707 -Node: Return Statement574217 -Node: Dynamic Typing577201 -Node: Indirect Calls578130 -Node: Functions Summary587843 -Node: Library Functions590382 -Ref: Library Functions-Footnote-1594000 -Ref: Library Functions-Footnote-2594143 -Node: Library Names594314 -Ref: Library Names-Footnote-1597787 -Ref: Library Names-Footnote-2598007 -Node: General Functions598093 -Node: Strtonum Function599121 -Node: Assert Function601901 -Node: Round Function605227 -Node: Cliff Random Function606768 -Node: Ordinal Functions607784 -Ref: Ordinal Functions-Footnote-1610861 -Ref: Ordinal Functions-Footnote-2611113 -Node: Join Function611324 -Ref: Join Function-Footnote-1613095 -Node: Getlocaltime Function613295 -Node: Readfile Function617031 -Node: Data File Management618870 -Node: Filetrans Function619502 -Node: Rewind Function623571 -Node: File Checking625129 -Ref: File Checking-Footnote-1626261 -Node: Empty Files626462 -Node: Ignoring Assigns628441 -Node: Getopt Function629995 -Ref: Getopt Function-Footnote-1641298 -Node: Passwd Functions641501 -Ref: Passwd Functions-Footnote-1650480 -Node: Group Functions650568 -Ref: Group Functions-Footnote-1658509 -Node: Walking Arrays658722 -Node: Library Functions Summary660325 -Node: Library exercises661713 -Node: Sample Programs662993 -Node: Running Examples663763 -Node: Clones664491 -Node: Cut Program665715 -Node: Egrep Program675583 -Ref: Egrep Program-Footnote-1683554 -Node: Id Program683664 -Node: Split Program687328 -Ref: Split Program-Footnote-1690866 -Node: Tee Program690994 -Node: Uniq Program693801 -Node: Wc Program701231 -Ref: Wc Program-Footnote-1705496 -Node: Miscellaneous Programs705588 -Node: Dupword Program706801 -Node: Alarm Program708832 -Node: Translate Program713646 -Ref: Translate Program-Footnote-1718037 -Ref: Translate Program-Footnote-2718307 -Node: Labels Program718441 -Ref: Labels Program-Footnote-1721812 -Node: Word Sorting721896 -Node: History Sorting725939 -Node: Extract Program727775 -Node: Simple Sed735311 -Node: Igawk Program738373 -Ref: Igawk Program-Footnote-1752677 -Ref: Igawk Program-Footnote-2752878 -Node: Anagram Program753016 -Node: Signature Program756084 -Node: Programs Summary757331 -Node: Programs Exercises758546 -Node: Advanced Features762197 -Node: Nondecimal Data764145 -Node: Array Sorting765722 -Node: Controlling Array Traversal766419 -Node: Array Sorting Functions774699 -Ref: Array Sorting Functions-Footnote-1778606 -Node: Two-way I/O778800 -Ref: Two-way I/O-Footnote-1783744 -Ref: Two-way I/O-Footnote-2783923 -Node: TCP/IP Networking784005 -Node: Profiling786850 -Node: Advanced Features Summary794401 -Node: Internationalization796265 -Node: I18N and L10N797745 -Node: Explaining gettext798431 -Ref: Explaining gettext-Footnote-1803571 -Ref: Explaining gettext-Footnote-2803755 -Node: Programmer i18n803920 -Node: Translator i18n808145 -Node: String Extraction808939 -Ref: String Extraction-Footnote-1809900 -Node: Printf Ordering809986 -Ref: Printf Ordering-Footnote-1812768 -Node: I18N Portability812832 -Ref: I18N Portability-Footnote-1815281 -Node: I18N Example815344 -Ref: I18N Example-Footnote-1818066 -Node: Gawk I18N818138 -Node: I18N Summary818776 -Node: Debugger820115 -Node: Debugging821137 -Node: Debugging Concepts821578 -Node: Debugging Terms823434 -Node: Awk Debugging826031 -Node: Sample Debugging Session826923 -Node: Debugger Invocation827443 -Node: Finding The Bug828776 -Node: List of Debugger Commands835258 -Node: Breakpoint Control836590 -Node: Debugger Execution Control840254 -Node: Viewing And Changing Data843614 -Node: Execution Stack846972 -Node: Debugger Info848485 -Node: Miscellaneous Debugger Commands852479 -Node: Readline Support857663 -Node: Limitations858555 -Node: Debugging Summary860829 -Node: Arbitrary Precision Arithmetic861997 -Node: Computer Arithmetic863484 -Ref: Computer Arithmetic-Footnote-1867871 -Node: Math Definitions867928 -Ref: table-ieee-formats871217 -Ref: Math Definitions-Footnote-1871757 -Node: MPFR features871860 -Node: FP Math Caution873477 -Ref: FP Math Caution-Footnote-1874527 -Node: Inexactness of computations874896 -Node: Inexact representation875844 -Node: Comparing FP Values877199 -Node: Errors accumulate878163 -Node: Getting Accuracy879596 -Node: Try To Round882255 -Node: Setting precision883154 -Ref: table-predefined-precision-strings883836 -Node: Setting the rounding mode885629 -Ref: table-gawk-rounding-modes885993 -Ref: Setting the rounding mode-Footnote-1889447 -Node: Arbitrary Precision Integers889626 -Ref: Arbitrary Precision Integers-Footnote-1893399 -Node: POSIX Floating Point Problems893548 -Ref: POSIX Floating Point Problems-Footnote-1897424 -Node: Floating point summary897462 -Node: Dynamic Extensions899666 -Node: Extension Intro901218 -Node: Plugin License902483 -Node: Extension Mechanism Outline903168 -Ref: figure-load-extension903592 -Ref: figure-load-new-function905077 -Ref: figure-call-new-function906079 -Node: Extension API Description908063 -Node: Extension API Functions Introduction909513 -Node: General Data Types914380 -Ref: General Data Types-Footnote-1920073 -Node: Requesting Values920372 -Ref: table-value-types-returned921109 -Node: Memory Allocation Functions922067 -Ref: Memory Allocation Functions-Footnote-1924814 -Node: Constructor Functions924910 -Node: Registration Functions926668 -Node: Extension Functions927353 -Node: Exit Callback Functions929655 -Node: Extension Version String930903 -Node: Input Parsers931553 -Node: Output Wrappers941367 -Node: Two-way processors945883 -Node: Printing Messages948087 -Ref: Printing Messages-Footnote-1949164 -Node: Updating `ERRNO'949316 -Node: Accessing Parameters950055 -Node: Symbol Table Access951285 -Node: Symbol table by name951799 -Node: Symbol table by cookie953775 -Ref: Symbol table by cookie-Footnote-1957908 -Node: Cached values957971 -Ref: Cached values-Footnote-1961475 -Node: Array Manipulation961566 -Ref: Array Manipulation-Footnote-1962664 -Node: Array Data Types962703 -Ref: Array Data Types-Footnote-1965406 -Node: Array Functions965498 -Node: Flattening Arrays969372 -Node: Creating Arrays976224 -Node: Extension API Variables980955 -Node: Extension Versioning981591 -Node: Extension API Informational Variables983492 -Node: Extension API Boilerplate984578 -Node: Finding Extensions988382 -Node: Extension Example988942 -Node: Internal File Description989672 -Node: Internal File Ops993763 -Ref: Internal File Ops-Footnote-11005195 -Node: Using Internal File Ops1005335 -Ref: Using Internal File Ops-Footnote-11007682 -Node: Extension Samples1007950 -Node: Extension Sample File Functions1009474 -Node: Extension Sample Fnmatch1017042 -Node: Extension Sample Fork1018524 -Node: Extension Sample Inplace1019737 -Node: Extension Sample Ord1021412 -Node: Extension Sample Readdir1022248 -Ref: table-readdir-file-types1023104 -Node: Extension Sample Revout1023903 -Node: Extension Sample Rev2way1024494 -Node: Extension Sample Read write array1025235 -Node: Extension Sample Readfile1027114 -Node: Extension Sample API Tests1028214 -Node: Extension Sample Time1028739 -Node: gawkextlib1030054 -Node: Extension summary1032867 -Node: Extension Exercises1036560 -Node: Language History1037282 -Node: V7/SVR3.11038925 -Node: SVR41041245 -Node: POSIX1042687 -Node: BTL1044073 -Node: POSIX/GNU1044807 -Node: Feature History1050548 -Node: Common Extensions1063678 -Node: Ranges and Locales1064990 -Ref: Ranges and Locales-Footnote-11069607 -Ref: Ranges and Locales-Footnote-21069634 -Ref: Ranges and Locales-Footnote-31069868 -Node: Contributors1070089 -Node: History summary1075514 -Node: Installation1076883 -Node: Gawk Distribution1077834 -Node: Getting1078318 -Node: Extracting1079142 -Node: Distribution contents1080784 -Node: Unix Installation1086554 -Node: Quick Installation1087171 -Node: Additional Configuration Options1089613 -Node: Configuration Philosophy1091351 -Node: Non-Unix Installation1093702 -Node: PC Installation1094160 -Node: PC Binary Installation1095471 -Node: PC Compiling1097319 -Ref: PC Compiling-Footnote-11100318 -Node: PC Testing1100423 -Node: PC Using1101599 -Node: Cygwin1105751 -Node: MSYS1106560 -Node: VMS Installation1107074 -Node: VMS Compilation1107870 -Ref: VMS Compilation-Footnote-11109092 -Node: VMS Dynamic Extensions1109150 -Node: VMS Installation Details1110523 -Node: VMS Running1112775 -Node: VMS GNV1115609 -Node: VMS Old Gawk1116332 -Node: Bugs1116802 -Node: Other Versions1120806 -Node: Installation summary1127061 -Node: Notes1128117 -Node: Compatibility Mode1128982 -Node: Additions1129764 -Node: Accessing The Source1130689 -Node: Adding Code1132125 -Node: New Ports1138303 -Node: Derived Files1142784 -Ref: Derived Files-Footnote-11147865 -Ref: Derived Files-Footnote-21147899 -Ref: Derived Files-Footnote-31148495 -Node: Future Extensions1148609 -Node: Implementation Limitations1149215 -Node: Extension Design1150463 -Node: Old Extension Problems1151617 -Ref: Old Extension Problems-Footnote-11153134 -Node: Extension New Mechanism Goals1153191 -Ref: Extension New Mechanism Goals-Footnote-11156551 -Node: Extension Other Design Decisions1156740 -Node: Extension Future Growth1158846 -Node: Old Extension Mechanism1159682 -Node: Notes summary1161444 -Node: Basic Concepts1162630 -Node: Basic High Level1163311 -Ref: figure-general-flow1163583 -Ref: figure-process-flow1164182 -Ref: Basic High Level-Footnote-11167411 -Node: Basic Data Typing1167596 -Node: Glossary1170924 -Node: Copying1196076 -Node: GNU Free Documentation License1233632 -Node: Index1258768 +Node: Regexp Operators157888 +Ref: Regexp Operators-Footnote-1165368 +Ref: Regexp Operators-Footnote-2165515 +Node: Bracket Expressions165613 +Ref: table-char-classes167503 +Node: GNU Regexp Operators170443 +Node: Case-sensitivity174166 +Ref: Case-sensitivity-Footnote-1177058 +Ref: Case-sensitivity-Footnote-2177293 +Node: Leftmost Longest177401 +Node: Computed Regexps178602 +Node: Regexp Summary181974 +Node: Reading Files183443 +Node: Records185535 +Node: awk split records186278 +Node: gawk split records191136 +Ref: gawk split records-Footnote-1195657 +Node: Fields195694 +Ref: Fields-Footnote-1198658 +Node: Nonconstant Fields198744 +Ref: Nonconstant Fields-Footnote-1200974 +Node: Changing Fields201176 +Node: Field Separators207130 +Node: Default Field Splitting209832 +Node: Regexp Field Splitting210949 +Node: Single Character Fields214290 +Node: Command Line Field Separator215349 +Node: Full Line Fields218775 +Ref: Full Line Fields-Footnote-1219283 +Node: Field Splitting Summary219329 +Ref: Field Splitting Summary-Footnote-1222461 +Node: Constant Size222562 +Node: Splitting By Content227168 +Ref: Splitting By Content-Footnote-1231241 +Node: Multiple Line231281 +Ref: Multiple Line-Footnote-1237137 +Node: Getline237316 +Node: Plain Getline239532 +Node: Getline/Variable241627 +Node: Getline/File242774 +Node: Getline/Variable/File244158 +Ref: Getline/Variable/File-Footnote-1245757 +Node: Getline/Pipe245844 +Node: Getline/Variable/Pipe248543 +Node: Getline/Coprocess249650 +Node: Getline/Variable/Coprocess250902 +Node: Getline Notes251639 +Node: Getline Summary254443 +Ref: table-getline-variants254851 +Node: Read Timeout255763 +Ref: Read Timeout-Footnote-1259590 +Node: Command-line directories259648 +Node: Input Summary260552 +Node: Input Exercises263689 +Node: Printing264422 +Node: Print266144 +Node: Print Examples267485 +Node: Output Separators270264 +Node: OFMT272280 +Node: Printf273638 +Node: Basic Printf274544 +Node: Control Letters276083 +Node: Format Modifiers280074 +Node: Printf Examples286101 +Node: Redirection288565 +Node: Special Files295537 +Node: Special FD296070 +Ref: Special FD-Footnote-1299667 +Node: Special Network299741 +Node: Special Caveats300591 +Node: Close Files And Pipes301387 +Ref: Close Files And Pipes-Footnote-1308548 +Ref: Close Files And Pipes-Footnote-2308696 +Node: Output Summary308846 +Node: Output exercises309843 +Node: Expressions310523 +Node: Values311708 +Node: Constants312384 +Node: Scalar Constants313064 +Ref: Scalar Constants-Footnote-1313923 +Node: Nondecimal-numbers314173 +Node: Regexp Constants317173 +Node: Using Constant Regexps317648 +Node: Variables320720 +Node: Using Variables321375 +Node: Assignment Options323099 +Node: Conversion324974 +Node: Strings And Numbers325498 +Ref: Strings And Numbers-Footnote-1328560 +Node: Locale influences conversions328669 +Ref: table-locale-affects331386 +Node: All Operators331974 +Node: Arithmetic Ops332604 +Node: Concatenation335109 +Ref: Concatenation-Footnote-1337928 +Node: Assignment Ops338048 +Ref: table-assign-ops343031 +Node: Increment Ops344348 +Node: Truth Values and Conditions347786 +Node: Truth Values348869 +Node: Typing and Comparison349918 +Node: Variable Typing350711 +Node: Comparison Operators354363 +Ref: table-relational-ops354773 +Node: POSIX String Comparison358323 +Ref: POSIX String Comparison-Footnote-1359407 +Node: Boolean Ops359545 +Ref: Boolean Ops-Footnote-1363615 +Node: Conditional Exp363706 +Node: Function Calls365433 +Node: Precedence369313 +Node: Locales372982 +Node: Expressions Summary374613 +Node: Patterns and Actions377154 +Node: Pattern Overview378270 +Node: Regexp Patterns379947 +Node: Expression Patterns380490 +Node: Ranges384271 +Node: BEGIN/END387377 +Node: Using BEGIN/END388139 +Ref: Using BEGIN/END-Footnote-1390875 +Node: I/O And BEGIN/END390981 +Node: BEGINFILE/ENDFILE393266 +Node: Empty396197 +Node: Using Shell Variables396514 +Node: Action Overview398797 +Node: Statements401124 +Node: If Statement402972 +Node: While Statement404470 +Node: Do Statement406514 +Node: For Statement407670 +Node: Switch Statement410822 +Node: Break Statement413210 +Node: Continue Statement415265 +Node: Next Statement417104 +Node: Nextfile Statement419494 +Node: Exit Statement422149 +Node: Built-in Variables424553 +Node: User-modified425680 +Ref: User-modified-Footnote-1433369 +Node: Auto-set433431 +Ref: Auto-set-Footnote-1446350 +Ref: Auto-set-Footnote-2446555 +Node: ARGC and ARGV446611 +Node: Pattern Action Summary450515 +Node: Arrays452738 +Node: Array Basics454287 +Node: Array Intro455113 +Ref: figure-array-elements457086 +Node: Reference to Elements459493 +Node: Assigning Elements461872 +Node: Array Example462363 +Node: Scanning an Array464095 +Node: Controlling Scanning467110 +Ref: Controlling Scanning-Footnote-1472283 +Node: Delete472599 +Ref: Delete-Footnote-1475364 +Node: Numeric Array Subscripts475421 +Node: Uninitialized Subscripts477604 +Node: Multidimensional479229 +Node: Multiscanning482342 +Node: Arrays of Arrays483931 +Node: Arrays Summary488594 +Node: Functions490699 +Node: Built-in491572 +Node: Calling Built-in492650 +Node: Numeric Functions494638 +Ref: Numeric Functions-Footnote-1499474 +Ref: Numeric Functions-Footnote-2499831 +Ref: Numeric Functions-Footnote-3499879 +Node: String Functions500148 +Ref: String Functions-Footnote-1523159 +Ref: String Functions-Footnote-2523288 +Ref: String Functions-Footnote-3523536 +Node: Gory Details523623 +Ref: table-sub-escapes525410 +Ref: table-sub-proposed526930 +Ref: table-posix-sub528294 +Ref: table-gensub-escapes529834 +Ref: Gory Details-Footnote-1531010 +Node: I/O Functions531161 +Ref: I/O Functions-Footnote-1538284 +Node: Time Functions538431 +Ref: Time Functions-Footnote-1548895 +Ref: Time Functions-Footnote-2548963 +Ref: Time Functions-Footnote-3549121 +Ref: Time Functions-Footnote-4549232 +Ref: Time Functions-Footnote-5549344 +Ref: Time Functions-Footnote-6549571 +Node: Bitwise Functions549837 +Ref: table-bitwise-ops550399 +Ref: Bitwise Functions-Footnote-1554644 +Node: Type Functions554828 +Node: I18N Functions555970 +Node: User-defined557615 +Node: Definition Syntax558419 +Ref: Definition Syntax-Footnote-1563598 +Node: Function Example563667 +Ref: Function Example-Footnote-1566307 +Node: Function Caveats566329 +Node: Calling A Function566847 +Node: Variable Scope567802 +Node: Pass By Value/Reference570790 +Node: Return Statement574300 +Node: Dynamic Typing577284 +Node: Indirect Calls578213 +Node: Functions Summary587926 +Node: Library Functions590465 +Ref: Library Functions-Footnote-1594083 +Ref: Library Functions-Footnote-2594226 +Node: Library Names594397 +Ref: Library Names-Footnote-1597870 +Ref: Library Names-Footnote-2598090 +Node: General Functions598176 +Node: Strtonum Function599204 +Node: Assert Function601984 +Node: Round Function605310 +Node: Cliff Random Function606851 +Node: Ordinal Functions607867 +Ref: Ordinal Functions-Footnote-1610944 +Ref: Ordinal Functions-Footnote-2611196 +Node: Join Function611407 +Ref: Join Function-Footnote-1613178 +Node: Getlocaltime Function613378 +Node: Readfile Function617114 +Node: Data File Management618953 +Node: Filetrans Function619585 +Node: Rewind Function623654 +Node: File Checking625212 +Ref: File Checking-Footnote-1626344 +Node: Empty Files626545 +Node: Ignoring Assigns628524 +Node: Getopt Function630078 +Ref: Getopt Function-Footnote-1641381 +Node: Passwd Functions641584 +Ref: Passwd Functions-Footnote-1650563 +Node: Group Functions650651 +Ref: Group Functions-Footnote-1658592 +Node: Walking Arrays658805 +Node: Library Functions Summary660408 +Node: Library exercises661796 +Node: Sample Programs663076 +Node: Running Examples663846 +Node: Clones664574 +Node: Cut Program665798 +Node: Egrep Program675666 +Ref: Egrep Program-Footnote-1683637 +Node: Id Program683747 +Node: Split Program687411 +Ref: Split Program-Footnote-1690949 +Node: Tee Program691077 +Node: Uniq Program693884 +Node: Wc Program701314 +Ref: Wc Program-Footnote-1705579 +Node: Miscellaneous Programs705671 +Node: Dupword Program706884 +Node: Alarm Program708915 +Node: Translate Program713729 +Ref: Translate Program-Footnote-1718120 +Ref: Translate Program-Footnote-2718390 +Node: Labels Program718524 +Ref: Labels Program-Footnote-1721895 +Node: Word Sorting721979 +Node: History Sorting726022 +Node: Extract Program727858 +Node: Simple Sed735394 +Node: Igawk Program738456 +Ref: Igawk Program-Footnote-1752760 +Ref: Igawk Program-Footnote-2752961 +Node: Anagram Program753099 +Node: Signature Program756167 +Node: Programs Summary757414 +Node: Programs Exercises758629 +Node: Advanced Features762280 +Node: Nondecimal Data764228 +Node: Array Sorting765805 +Node: Controlling Array Traversal766502 +Node: Array Sorting Functions774782 +Ref: Array Sorting Functions-Footnote-1778689 +Node: Two-way I/O778883 +Ref: Two-way I/O-Footnote-1783827 +Ref: Two-way I/O-Footnote-2784006 +Node: TCP/IP Networking784088 +Node: Profiling786933 +Node: Advanced Features Summary794484 +Node: Internationalization796348 +Node: I18N and L10N797828 +Node: Explaining gettext798514 +Ref: Explaining gettext-Footnote-1803654 +Ref: Explaining gettext-Footnote-2803838 +Node: Programmer i18n804003 +Node: Translator i18n808228 +Node: String Extraction809022 +Ref: String Extraction-Footnote-1809983 +Node: Printf Ordering810069 +Ref: Printf Ordering-Footnote-1812851 +Node: I18N Portability812915 +Ref: I18N Portability-Footnote-1815364 +Node: I18N Example815427 +Ref: I18N Example-Footnote-1818149 +Node: Gawk I18N818221 +Node: I18N Summary818859 +Node: Debugger820198 +Node: Debugging821220 +Node: Debugging Concepts821661 +Node: Debugging Terms823517 +Node: Awk Debugging826114 +Node: Sample Debugging Session827006 +Node: Debugger Invocation827526 +Node: Finding The Bug828859 +Node: List of Debugger Commands835341 +Node: Breakpoint Control836673 +Node: Debugger Execution Control840337 +Node: Viewing And Changing Data843697 +Node: Execution Stack847055 +Node: Debugger Info848568 +Node: Miscellaneous Debugger Commands852562 +Node: Readline Support857746 +Node: Limitations858638 +Node: Debugging Summary860912 +Node: Arbitrary Precision Arithmetic862080 +Node: Computer Arithmetic863567 +Ref: Computer Arithmetic-Footnote-1867954 +Node: Math Definitions868011 +Ref: table-ieee-formats871300 +Ref: Math Definitions-Footnote-1871840 +Node: MPFR features871943 +Node: FP Math Caution873560 +Ref: FP Math Caution-Footnote-1874610 +Node: Inexactness of computations874979 +Node: Inexact representation875927 +Node: Comparing FP Values877282 +Node: Errors accumulate878246 +Node: Getting Accuracy879679 +Node: Try To Round882338 +Node: Setting precision883237 +Ref: table-predefined-precision-strings883919 +Node: Setting the rounding mode885712 +Ref: table-gawk-rounding-modes886076 +Ref: Setting the rounding mode-Footnote-1889530 +Node: Arbitrary Precision Integers889709 +Ref: Arbitrary Precision Integers-Footnote-1893482 +Node: POSIX Floating Point Problems893631 +Ref: POSIX Floating Point Problems-Footnote-1897507 +Node: Floating point summary897545 +Node: Dynamic Extensions899749 +Node: Extension Intro901301 +Node: Plugin License902566 +Node: Extension Mechanism Outline903251 +Ref: figure-load-extension903675 +Ref: figure-load-new-function905160 +Ref: figure-call-new-function906162 +Node: Extension API Description908146 +Node: Extension API Functions Introduction909596 +Node: General Data Types914463 +Ref: General Data Types-Footnote-1920156 +Node: Requesting Values920455 +Ref: table-value-types-returned921192 +Node: Memory Allocation Functions922150 +Ref: Memory Allocation Functions-Footnote-1924897 +Node: Constructor Functions924993 +Node: Registration Functions926751 +Node: Extension Functions927436 +Node: Exit Callback Functions929738 +Node: Extension Version String930986 +Node: Input Parsers931636 +Node: Output Wrappers941450 +Node: Two-way processors945966 +Node: Printing Messages948170 +Ref: Printing Messages-Footnote-1949247 +Node: Updating `ERRNO'949399 +Node: Accessing Parameters950138 +Node: Symbol Table Access951368 +Node: Symbol table by name951882 +Node: Symbol table by cookie953858 +Ref: Symbol table by cookie-Footnote-1957991 +Node: Cached values958054 +Ref: Cached values-Footnote-1961558 +Node: Array Manipulation961649 +Ref: Array Manipulation-Footnote-1962747 +Node: Array Data Types962786 +Ref: Array Data Types-Footnote-1965489 +Node: Array Functions965581 +Node: Flattening Arrays969455 +Node: Creating Arrays976307 +Node: Extension API Variables981038 +Node: Extension Versioning981674 +Node: Extension API Informational Variables983575 +Node: Extension API Boilerplate984661 +Node: Finding Extensions988465 +Node: Extension Example989025 +Node: Internal File Description989755 +Node: Internal File Ops993846 +Ref: Internal File Ops-Footnote-11005278 +Node: Using Internal File Ops1005418 +Ref: Using Internal File Ops-Footnote-11007765 +Node: Extension Samples1008033 +Node: Extension Sample File Functions1009557 +Node: Extension Sample Fnmatch1017125 +Node: Extension Sample Fork1018607 +Node: Extension Sample Inplace1019820 +Node: Extension Sample Ord1021495 +Node: Extension Sample Readdir1022331 +Ref: table-readdir-file-types1023187 +Node: Extension Sample Revout1023986 +Node: Extension Sample Rev2way1024577 +Node: Extension Sample Read write array1025318 +Node: Extension Sample Readfile1027197 +Node: Extension Sample API Tests1028297 +Node: Extension Sample Time1028822 +Node: gawkextlib1030137 +Node: Extension summary1032950 +Node: Extension Exercises1036643 +Node: Language History1037365 +Node: V7/SVR3.11039008 +Node: SVR41041328 +Node: POSIX1042770 +Node: BTL1044156 +Node: POSIX/GNU1044890 +Node: Feature History1050631 +Node: Common Extensions1063761 +Node: Ranges and Locales1065073 +Ref: Ranges and Locales-Footnote-11069690 +Ref: Ranges and Locales-Footnote-21069717 +Ref: Ranges and Locales-Footnote-31069951 +Node: Contributors1070172 +Node: History summary1075597 +Node: Installation1076966 +Node: Gawk Distribution1077917 +Node: Getting1078401 +Node: Extracting1079225 +Node: Distribution contents1080867 +Node: Unix Installation1086637 +Node: Quick Installation1087254 +Node: Additional Configuration Options1089696 +Node: Configuration Philosophy1091434 +Node: Non-Unix Installation1093785 +Node: PC Installation1094243 +Node: PC Binary Installation1095554 +Node: PC Compiling1097402 +Ref: PC Compiling-Footnote-11100401 +Node: PC Testing1100506 +Node: PC Using1101682 +Node: Cygwin1105834 +Node: MSYS1106643 +Node: VMS Installation1107157 +Node: VMS Compilation1107953 +Ref: VMS Compilation-Footnote-11109175 +Node: VMS Dynamic Extensions1109233 +Node: VMS Installation Details1110606 +Node: VMS Running1112858 +Node: VMS GNV1115692 +Node: VMS Old Gawk1116415 +Node: Bugs1116885 +Node: Other Versions1120889 +Node: Installation summary1127144 +Node: Notes1128200 +Node: Compatibility Mode1129065 +Node: Additions1129847 +Node: Accessing The Source1130772 +Node: Adding Code1132208 +Node: New Ports1138386 +Node: Derived Files1142867 +Ref: Derived Files-Footnote-11147948 +Ref: Derived Files-Footnote-21147982 +Ref: Derived Files-Footnote-31148578 +Node: Future Extensions1148692 +Node: Implementation Limitations1149298 +Node: Extension Design1150546 +Node: Old Extension Problems1151700 +Ref: Old Extension Problems-Footnote-11153217 +Node: Extension New Mechanism Goals1153274 +Ref: Extension New Mechanism Goals-Footnote-11156634 +Node: Extension Other Design Decisions1156823 +Node: Extension Future Growth1158929 +Node: Old Extension Mechanism1159765 +Node: Notes summary1161527 +Node: Basic Concepts1162713 +Node: Basic High Level1163394 +Ref: figure-general-flow1163666 +Ref: figure-process-flow1164265 +Ref: Basic High Level-Footnote-11167494 +Node: Basic Data Typing1167679 +Node: Glossary1171007 +Node: Copying1196159 +Node: GNU Free Documentation License1233715 +Node: Index1258851  End Tag Table -- cgit v1.2.3 From f215e2b823693103796cd71493b90300f54adba4 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 22 Aug 2014 16:02:18 +0300 Subject: More reviewer comments. --- doc/gawk.info | 1304 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 662 insertions(+), 642 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 7c97a5c9..39da4897 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1102,6 +1102,10 @@ key and another key, at the same time. For example, a `Ctrl-d' is typed by first pressing and holding the `CONTROL' key, next pressing the `d' key and finally releasing both keys. + For the sake of brevity, throughout this Info file, we refer to +Brian Kernighan's version of `awk' as "BWK `awk'." (*Note Other +Versions::, for information on his and other versions.) + Dark Corners ------------ @@ -1305,8 +1309,8 @@ have done nearly as good a job on either `gawk' or its documentation without his help. Brian is in a class by himself as a programmer and technical author. -I have to thank him (yet again) for his ongoing friendship and the -role-model he has been for me for close to 30 years! Having him as a +I have to thank him (yet again) for his ongoing friendship and the role +model he has been for me for close to 30 years! Having him as a reviewer is an exciting privilege. It has also been extremely humbling... @@ -1503,8 +1507,8 @@ tell `awk' to use that file for its program, you type: awk -f SOURCE-FILE INPUT-FILE1 INPUT-FILE2 ... The `-f' instructs the `awk' utility to get the `awk' program from -the file SOURCE-FILE. Any file name can be used for SOURCE-FILE. For -example, you could put the program: +the file SOURCE-FILE (*note Options::). Any file name can be used for +SOURCE-FILE. For example, you could put the program: BEGIN { print "Don't Panic!" } @@ -1582,8 +1586,8 @@ the name of your script (`advice'). (d.c.) Don't rely on the value of and commercial Unix systems. (2) The line beginning with `#!' lists the full file name of an -interpreter to run and an optional initial command-line argument to -pass to that interpreter. The operating system then runs the +interpreter to run and a single optional initial command-line argument +to pass to that interpreter. The operating system then runs the interpreter with the given argument and the full argument list of the executed program. The first argument in the list is the full file name of the `awk' program. The rest of the argument list contains either @@ -2240,8 +2244,8 @@ retargetable assembler for eight-bit microprocessors (*note Glossary::, for more information), and a microcode assembler for a special-purpose Prolog computer. While the original `awk''s capabilities were strained by tasks of such complexity, modern versions are more capable. Even -Brian Kernighan's version of `awk' has fewer predefined limits, and -those that it has are much larger than they used to be. +BWK `awk' has fewer predefined limits, and those that it has are much +larger than they used to be. If you find yourself writing `awk' scripts of more than, say, a few hundred lines, you might consider using a different programming @@ -2416,9 +2420,9 @@ The following list describes options mandated by the POSIX standard: `-c' `--traditional' Specify "compatibility mode", in which the GNU extensions to the - `awk' language are disabled, so that `gawk' behaves just like - Brian Kernighan's version `awk'. *Note POSIX/GNU::, which - summarizes the extensions. Also see *note Compatibility Mode::. + `awk' language are disabled, so that `gawk' behaves just like BWK + `awk'. *Note POSIX/GNU::, which summarizes the extensions. Also + see *note Compatibility Mode::. `-C' `--copyright' @@ -3401,12 +3405,12 @@ is not one of the characters previously listed, POSIX `awk' purposely leaves what happens as undefined. There are two choices: Strip the backslash out - This is what Brian Kernighan's `awk' and `gawk' both do. For - example, `"a\qc"' is the same as `"aqc"'. (Because this is such - an easy bug both to introduce and to miss, `gawk' warns you about - it.) Consider `FS = "[ \t]+\|[ \t]+"' to use vertical bars - surrounded by whitespace as the field separator. There should be - two backslashes in the string: `FS = "[ \t]+\\|[ \t]+"'.) + This is what BWK `awk' and `gawk' both do. For example, `"a\qc"' + is the same as `"aqc"'. (Because this is such an easy bug both to + introduce and to miss, `gawk' warns you about it.) Consider `FS = + "[ \t]+\|[ \t]+"' to use vertical bars surrounded by whitespace as + the field separator. There should be two backslashes in the + string: `FS = "[ \t]+\\|[ \t]+"'.) Leave the backslash alone Some other `awk' implementations do this. In such @@ -3794,9 +3798,9 @@ No options Traditional Unix `awk' regexps are matched. The GNU operators are not special, and interval expressions are not available. The POSIX character classes (`[[:alnum:]]', etc.) are supported, as - Brian Kernighan's `awk' does support them. Characters described - by octal and hexadecimal escape sequences are treated literally, - even if they represent regexp metacharacters. + BWK `awk' does support them. Characters described by octal and + hexadecimal escape sequences are treated literally, even if they + represent regexp metacharacters. `--re-interval' Allow interval expressions in regexps, if `--traditional' has been @@ -4740,9 +4744,8 @@ field separator a new string? It turns out that different `awk' versions answer this question differently, and you should not rely on any specific behavior in your programs. (d.c.) - As a point of information, Brian Kernighan's `awk' allows `^' to -match only at the beginning of the record. `gawk' also works this way. -For example: + As a point of information, BWK `awk' allows `^' to match only at the +beginning of the record. `gawk' also works this way. For example: $ echo 'xxAA xxBxx C' | > gawk -F '(^x+)|( +)' '{ for (i = 1; i <= NF; i++) @@ -5599,10 +5602,10 @@ all `awk' implementations. NOTE: Unfortunately, `gawk' has not been consistent in its treatment of a construct like `"echo " "date" | getline'. Most versions, including the current version, treat it at as `("echo " - "date") | getline'. (This how Brian Kernighan's `awk' behaves.) - Some versions changed and treated it as `"echo " ("date" | - getline)'. (This is how `mawk' behaves.) In short, _always_ use - explicit parentheses, and then you won't have to worry. + "date") | getline'. (This how BWK `awk' behaves.) Some versions + changed and treated it as `"echo " ("date" | getline)'. (This is + how `mawk' behaves.) In short, _always_ use explicit parentheses, + and then you won't have to worry.  File: gawk.info, Node: Getline/Variable/Pipe, Next: Getline/Coprocess, Prev: Getline/Pipe, Up: Getline @@ -6039,6 +6042,10 @@ you forget to use the double-quote characters, your text is taken as an `awk' expression, and you will probably get an error. Keep in mind that a space is printed between any two items. + Note that the `print' statement is a statement and not an +expression--you can't use it the pattern part of a pattern-action +statement, for example. +  File: gawk.info, Node: Print Examples, Next: Output Separators, Prev: Print, Up: Printing @@ -7820,8 +7827,8 @@ you'll get. ---------- Footnotes ---------- - (1) It happens that Brian Kernighan's `awk', `gawk' and `mawk' all -"get it right," but you should not rely on this. + (1) It happens that BWK `awk', `gawk' and `mawk' all "get it right," +but you should not rely on this.  File: gawk.info, Node: Assignment Ops, Next: Increment Ops, Prev: Concatenation, Up: All Operators @@ -7985,8 +7992,8 @@ A workaround is: awk '/[=]=/' /dev/null - `gawk' does not have this problem; Brian Kernighan's `awk' and -`mawk' also do not (*note Other Versions::). + `gawk' does not have this problem; BWK `awk' and `mawk' also do not +(*note Other Versions::).  File: gawk.info, Node: Increment Ops, Prev: Assignment Ops, Up: All Operators @@ -9133,8 +9140,7 @@ number of fields from the last input record. Most probably due to an oversight, the standard does not say that `$0' is also preserved, although logically one would think that it should be. In fact, `gawk' does preserve the value of `$0' for use in `END' rules. Be aware, -however, that Brian Kernighan's `awk', and possibly other -implementations, do not. +however, that BWK `awk', and possibly other implementations, do not. The third point follows from the first two. The meaning of `print' inside a `BEGIN' or `END' rule is the same as always: `print $0'. If @@ -9702,8 +9708,8 @@ statement. This is discussed in *note Switch Statement::. loop or `switch'. However, although it was never documented, historical implementations of `awk' treated the `break' statement outside of a loop as if it were a `next' statement (*note Next -Statement::). (d.c.) Recent versions of Brian Kernighan's `awk' no -longer allow this usage, nor does `gawk'. +Statement::). (d.c.) Recent versions of BWK `awk' no longer allow +this usage, nor does `gawk'.  File: gawk.info, Node: Continue Statement, Next: Next Statement, Prev: Break Statement, Up: Statements @@ -9754,8 +9760,8 @@ This program loops forever once `x' reaches 5, since the increment body of a loop. Historical versions of `awk' treated a `continue' statement outside a loop the same way they treated a `break' statement outside a loop: as if it were a `next' statement (*note Next -Statement::). (d.c.) Recent versions of Brian Kernighan's `awk' no -longer work this way, nor does `gawk'. +Statement::). (d.c.) Recent versions of BWK `awk' no longer work this +way, nor does `gawk'.  File: gawk.info, Node: Next Statement, Next: Nextfile Statement, Prev: Continue Statement, Up: Statements @@ -9857,12 +9863,12 @@ listed in `ARGV'. standard. See the Austin Group website (http://austingroupbugs.net/view.php?id=607). - The current version of the Brian Kernighan's `awk', and `mawk' -(*note Other Versions::) also support `nextfile'. However, they don't -allow the `nextfile' statement inside function bodies (*note -User-defined::). `gawk' does; a `nextfile' inside a function body -reads the next record and starts processing it with the first rule in -the program, just as any other `nextfile' statement. + The current version of BWK `awk', and `mawk' (*note Other +Versions::) also support `nextfile'. However, they don't allow the +`nextfile' statement inside function bodies (*note User-defined::). +`gawk' does; a `nextfile' inside a function body reads the next record +and starts processing it with the first rule in the program, just as +any other `nextfile' statement.  File: gawk.info, Node: Exit Statement, Prev: Nextfile Statement, Up: Statements @@ -10960,7 +10966,7 @@ all `awk' versions do so. Consider this program, named `loopcheck.awk': -| a -| is - Contrast this to Brian Kernighan's `awk': + Contrast this to BWK `awk': $ nawk -f loopcheck.awk -| loop @@ -11166,9 +11172,9 @@ at a time. `gawk' extension. As of September, 2012, it was accepted for inclusion into the POSIX standard. See the Austin Group website (http://austingroupbugs.net/view.php?id=544). This form of the - `delete' statement is also supported by Brian Kernighan's `awk' - and `mawk', as well as by a number of other implementations (*note - Other Versions::). + `delete' statement is also supported by BWK `awk' and `mawk', as + well as by a number of other implementations (*note Other + Versions::). The following statement provides a portable but nonobvious way to clear out an array:(1) @@ -12292,11 +12298,11 @@ Options::): remaining in the string, counting from character START. If START is less than one, `substr()' treats it as if it was one. - (POSIX doesn't specify what to do in this case: Brian Kernighan's - `awk' acts this way, and therefore `gawk' does too.) If START is - greater than the number of characters in the string, `substr()' - returns the null string. Similarly, if LENGTH is present but less - than or equal to zero, the null string is returned. + (POSIX doesn't specify what to do in this case: BWK `awk' acts + this way, and therefore `gawk' does too.) If START is greater + than the number of characters in the string, `substr()' returns + the null string. Similarly, if LENGTH is present but less than or + equal to zero, the null string is returned. The string returned by `substr()' _cannot_ be assigned. Thus, it is a mistake to attempt to change a portion of a string, as shown @@ -12370,9 +12376,9 @@ come after a backslash. At the lexical level, it looks for the escape sequences listed in *note Escape Sequences::. Thus, for every `\' that `awk' processes at the runtime level, you must type two backslashes at the lexical level. When a character that is not valid for an escape -sequence follows the `\', Brian Kernighan's `awk' and `gawk' both -simply remove the initial `\' and put the next character into the -string. Thus, for example, `"a\qb"' is treated as `"aqb"'. +sequence follows the `\', BWK `awk' and `gawk' both simply remove the +initial `\' and put the next character into the string. Thus, for +example, `"a\qb"' is treated as `"aqb"'. At the runtime level, the various functions handle sequences of `\' and `&' differently. The situation is (sadly) somewhat complex. @@ -12547,10 +12553,10 @@ parameters are enclosed in square brackets ([ ]): function--`gawk' also buffers its output and the `fflush()' function forces `gawk' to flush its buffers. - `fflush()' was added to Brian Kernighan's `awk' in April of 1992. - For two decades, it was not part of the POSIX standard. As of - December, 2012, it was accepted for inclusion into the POSIX - standard. See the Austin Group website + `fflush()' was added to BWK `awk' in April of 1992. For two + decades, it was not part of the POSIX standard. As of December, + 2012, it was accepted for inclusion into the POSIX standard. See + the Austin Group website (http://austingroupbugs.net/view.php?id=634). POSIX standardizes `fflush()' as follows: If there is no argument, @@ -19814,9 +19820,9 @@ are: `LC_CTYPE' Character-type information (alphabetic, digit, upper- or - lowercase, and so on). This information is accessed via the POSIX - character classes in regular expressions, such as `/[[:alnum:]]/' - (*note Regexp Operators::). + lowercase, and so on) as well as character encoding. This + information is accessed via the POSIX character classes in regular + expressions, such as `/[[:alnum:]]/' (*note Regexp Operators::). `LC_MONETARY' Monetary information, such as the currency symbol, and whether the @@ -19826,10 +19832,6 @@ are: Numeric information, such as which characters to use for the decimal point and the thousands separator.(2) -`LC_RESPONSE' - Response information, such as how "yes" and "no" appear in the - local language, and possibly other information as well. - `LC_TIME' Time- and date-related information, such as 12- or 24-hour clock, month printed before or after the day in a date, local month @@ -19926,16 +19928,27 @@ outlined in *note Explaining gettext::, like so: printf(_"Number of users is %d\n", nusers) 3. If you are creating strings dynamically, you can still translate - them, using the `dcgettext()' built-in function: + them, using the `dcgettext()' built-in function:(1) - message = nusers " users logged in" - message = dcgettext(message, "adminprog") - print message + if (groggy) + message = dcgettext("%d customers disturbing me\n", "adminprog") + else + message = dcgettext("enjoying %d customers\n", "adminprog") + printf(message, ncustomers) Here, the call to `dcgettext()' supplies a different text domain (`"adminprog"') in which to find the message, but it uses the default `"LC_MESSAGES"' category. + The previous example only works if `ncustomers' is greater than + one. This example would be better done with `dcngettext()': + + if (groggy) + message = dcngettext("%d customer disturbing me\n", "%d customers disturbing me\n", "adminprog") + else + message = dcngettext("enjoying %d customer\n", "enjoying %d customers\n", "adminprog") + printf(message, ncustomers) + 4. During development, you might want to put the `.gmo' file in a private directory for testing. This is done with the `bindtextdomain()' built-in function: @@ -19955,6 +19968,10 @@ outlined in *note Explaining gettext::, like so: *Note I18N Example::, for an example program showing the steps to create and use translations from `awk'. + ---------- Footnotes ---------- + + (1) Thanks to Bruno Haible for this example. +  File: gawk.info, Node: Translator i18n, Next: I18N Example, Prev: Programmer i18n, Up: Internationalization @@ -19994,8 +20011,11 @@ Instead, it parses it as usual and prints all marked strings to standard output in the format of a GNU `gettext' Portable Object file. Also included in the output are any constant strings that appear as the first argument to `dcgettext()' or as the first and second argument to -`dcngettext()'.(1) *Note I18N Example::, for the full list of steps to -go through to create and test translations for `guide'. +`dcngettext()'.(1) You should distribute the generated `.pot' file with +your `awk' program; translators will eventually use it to provide you +translations that you can also then distribute. *Note I18N Example::, +for the full list of steps to go through to create and test +translations for `guide'. ---------- Footnotes ---------- @@ -20212,8 +20232,7 @@ file to machine-readable `.mo' file. By default, `msgfmt' creates a file named `messages'. This file must be renamed and placed in the proper directory so that `gawk' can find it: - $ msgfmt guide-mellow.po - $ mv messages en_US.UTF-8/LC_MESSAGES/guide.mo + $ msgfmt guide-mellow.po -o en_US.UTF-8/LC_MESSAGES/guide.mo Finally, we run the program to test it: @@ -26048,8 +26067,8 @@ the current version of `gawk'. - The `bindtextdomain()', `dcgettext()' and `dcngettext()' functions for internationalization (*note Programmer i18n::). - - The `fflush()' function from Brian Kernighan's version of - `awk' (*note I/O Functions::). + - The `fflush()' function from BWK `awk' (*note I/O + Functions::). - The `gensub()', `patsplit()', and `strtonum()' functions for more powerful text manipulation (*note String Functions::). @@ -26203,8 +26222,8 @@ in POSIX `awk', in the order they were added to `gawk'. * The `next file' statement became `nextfile' (*note Nextfile Statement::). - * The `fflush()' function from Brian Kernighan's `awk' (then at Bell - Laboratories; *note I/O Functions::). + * The `fflush()' function from BWK `awk' (then at Bell Laboratories; + *note I/O Functions::). * New command-line options: @@ -26212,9 +26231,9 @@ in POSIX `awk', in the order they were added to `gawk'. available in the original Version 7 Unix version of `awk' (*note V7/SVR3.1::). - - The `-m' option from Brian Kernighan's `awk'. (He was still - at Bell Laboratories at the time.) This was later removed - from both his `awk' and from `gawk'. + - The `-m' option from BWK `awk'. (Brian was still at Bell + Laboratories at the time.) This was later removed from both + his `awk' and from `gawk'. - The `--re-interval' option to provide interval expressions in regexps (*note Regexp Operators::). @@ -26374,9 +26393,9 @@ in POSIX `awk', in the order they were added to `gawk'. * An optional third argument to `asort()' and `asorti()', specifying how to sort (*note String Functions::). - * The behavior of `fflush()' changed to match Brian Kernighan's `awk' - and for POSIX; now both `fflush()' and `fflush("")' flush all open - output redirections (*note I/O Functions::). + * The behavior of `fflush()' changed to match BWK `awk' and for + POSIX; now both `fflush()' and `fflush("")' flush all open output + redirections (*note I/O Functions::). * The `isarray()' function which distinguishes if an item is an array or not, to make it possible to traverse arrays of arrays (*note @@ -27984,11 +28003,11 @@ Unix `awk' since approximately 2003. `pawk' - Nelson H.F. Beebe at the University of Utah has modified Brian - Kernighan's `awk' to provide timing and profiling information. It - is different from `gawk' with the `--profile' option. (*note - Profiling::), in that it uses CPU-based profiling, not line-count - profiling. You may find it at either + Nelson H.F. Beebe at the University of Utah has modified BWK `awk' + to provide timing and profiling information. It is different from + `gawk' with the `--profile' option. (*note Profiling::), in that + it uses CPU-based profiling, not line-count profiling. You may + find it at either `ftp://ftp.math.utah.edu/pub/pawk/pawk-20030606.tar.gz' or `http://www.math.utah.edu/pub/pawk/pawk-20030606.tar.gz'. @@ -28033,7 +28052,7 @@ Libmawk This is a Python module that claims to bring `awk'-like features to Python. See `https://github.com/alecthomas/pawk' for more information. (This is not related to Nelson Beebe's modified - version of Brian Kernighan's `awk', described earlier.) + version of BWK `awk', described earlier.) QSE Awk This is an embeddable `awk' interpreter. For more information see @@ -31445,7 +31464,7 @@ Index * BEGIN pattern, next/nextfile statements and <1>: Next Statement. (line 45) * BEGIN pattern, next/nextfile statements and: I/O And BEGIN/END. - (line 37) + (line 36) * BEGIN pattern, OFS/ORS variables, assigning values to: Output Separators. (line 20) * BEGIN pattern, operators and: Using BEGIN/END. (line 17) @@ -31514,6 +31533,7 @@ Index * Brennan, Michael <1>: Other Versions. (line 6) * Brennan, Michael <2>: Simple Sed. (line 25) * Brennan, Michael <3>: Delete. (line 56) +* Brennan, Michael <4>: Acknowledgments. (line 76) * Brennan, Michael: Foreword. (line 83) * Brian Kernighan's awk <1>: I/O Functions. (line 43) * Brian Kernighan's awk <2>: Gory Details. (line 19) @@ -31530,8 +31550,7 @@ Index * Brian Kernighan's awk <12>: GNU Regexp Operators. (line 83) * Brian Kernighan's awk <13>: Escape Sequences. (line 120) -* Brian Kernighan's awk <14>: When. (line 21) -* Brian Kernighan's awk: Preface. (line 13) +* Brian Kernighan's awk: When. (line 21) * Brian Kernighan's awk, extensions: BTL. (line 6) * Brian Kernighan's awk, source code: Other Versions. (line 13) * Brini, Davide: Signature Program. (line 6) @@ -31740,9 +31759,9 @@ Index * cut utility: Cut Program. (line 6) * cut.awk program: Cut Program. (line 45) * d debugger command (alias for delete): Breakpoint Control. (line 64) -* d.c., See dark corner: Conventions. (line 38) +* d.c., See dark corner: Conventions. (line 42) * dark corner <1>: Glossary. (line 188) -* dark corner: Conventions. (line 38) +* dark corner: Conventions. (line 42) * dark corner, "0" is actually true: Truth Values. (line 24) * dark corner, /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) @@ -31793,9 +31812,10 @@ Index * date utility, POSIX: Time Functions. (line 254) * dates, converting to timestamps: Time Functions. (line 76) * dates, information related to, localization: Explaining gettext. - (line 116) + (line 112) * Davies, Stephen <1>: Contributors. (line 74) * Davies, Stephen: Acknowledgments. (line 60) +* Day, Robert P.J.: Acknowledgments. (line 76) * dcgettext <1>: Programmer i18n. (line 19) * dcgettext: I18N Functions. (line 22) * dcgettext() function (gawk), portability and: I18N Portability. @@ -32070,7 +32090,7 @@ Index * END pattern, next/nextfile statements and <1>: Next Statement. (line 45) * END pattern, next/nextfile statements and: I/O And BEGIN/END. - (line 37) + (line 36) * END pattern, operators and: Using BEGIN/END. (line 17) * END pattern, print statement and: I/O And BEGIN/END. (line 16) * ENDFILE pattern: BEGINFILE/ENDFILE. (line 6) @@ -32724,8 +32744,8 @@ Index * Kernighan, Brian <6>: Library Functions. (line 12) * Kernighan, Brian <7>: Concatenation. (line 6) * Kernighan, Brian <8>: Getline/Pipe. (line 6) -* Kernighan, Brian <9>: Acknowledgments. (line 80) -* Kernighan, Brian <10>: Conventions. (line 34) +* Kernighan, Brian <9>: Acknowledgments. (line 76) +* Kernighan, Brian <10>: Conventions. (line 38) * Kernighan, Brian: History. (line 17) * kill command, dynamic profiling: Profiling. (line 188) * Knights, jedi: Undocumented. (line 6) @@ -32735,16 +32755,15 @@ Index * labels.awk program: Labels Program. (line 51) * Langston, Peter: Advanced Features. (line 6) * languages, data-driven: Basic High Level. (line 85) -* LC_ALL locale category: Explaining gettext. (line 121) +* LC_ALL locale category: Explaining gettext. (line 117) * LC_COLLATE locale category: Explaining gettext. (line 94) * LC_CTYPE locale category: Explaining gettext. (line 98) * LC_MESSAGES locale category: Explaining gettext. (line 88) * LC_MESSAGES locale category, bindtextdomain() function (gawk): Programmer i18n. - (line 88) + (line 99) * LC_MONETARY locale category: Explaining gettext. (line 104) * LC_NUMERIC locale category: Explaining gettext. (line 108) -* LC_RESPONSE locale category: Explaining gettext. (line 112) -* LC_TIME locale category: Explaining gettext. (line 116) +* LC_TIME locale category: Explaining gettext. (line 112) * left angle bracket (<), < operator <1>: Precedence. (line 65) * left angle bracket (<), < operator: Comparison Operators. (line 11) @@ -32914,13 +32933,13 @@ Index * next file statement: Feature History. (line 169) * next statement <1>: Next Statement. (line 6) * next statement: Boolean Ops. (line 85) -* next statement, BEGIN/END patterns and: I/O And BEGIN/END. (line 37) +* next statement, BEGIN/END patterns and: I/O And BEGIN/END. (line 36) * next statement, BEGINFILE/ENDFILE patterns and: BEGINFILE/ENDFILE. (line 49) * next statement, user-defined functions and: Next Statement. (line 45) * nextfile statement: Nextfile Statement. (line 6) * nextfile statement, BEGIN/END patterns and: I/O And BEGIN/END. - (line 37) + (line 36) * nextfile statement, BEGINFILE/ENDFILE patterns and: BEGINFILE/ENDFILE. (line 26) * nextfile statement, user-defined functions and: Nextfile Statement. @@ -33734,7 +33753,7 @@ Index * tilde (~), ~ operator: Regexp Usage. (line 19) * time functions: Time Functions. (line 6) * time, alarm clock example program: Alarm Program. (line 11) -* time, localization and: Explaining gettext. (line 116) +* time, localization and: Explaining gettext. (line 112) * time, managing: Getlocaltime Function. (line 6) * time, retrieving: Time Functions. (line 17) @@ -33968,541 +33987,542 @@ Ref: Names-Footnote-153403 Node: This Manual53476 Ref: This Manual-Footnote-159255 Node: Conventions59355 -Node: Manual History61511 -Ref: Manual History-Footnote-164587 -Ref: Manual History-Footnote-264628 -Node: How To Contribute64702 -Node: Acknowledgments65941 -Node: Getting Started70689 -Node: Running gawk73123 -Node: One-shot74313 -Node: Read Terminal75538 -Ref: Read Terminal-Footnote-177501 -Node: Long77672 -Node: Executable Scripts79048 -Ref: Executable Scripts-Footnote-180881 -Ref: Executable Scripts-Footnote-280983 -Node: Comments81530 -Node: Quoting84003 -Node: DOS Quoting89316 -Node: Sample Data Files89991 -Node: Very Simple92545 -Node: Two Rules97318 -Node: More Complex99212 -Ref: More Complex-Footnote-1102144 -Node: Statements/Lines102229 -Ref: Statements/Lines-Footnote-1106685 -Node: Other Features106950 -Node: When107878 -Ref: When-Footnote-1109764 -Node: Intro Summary109829 -Node: Invoking Gawk110595 -Node: Command Line112110 -Node: Options112901 -Ref: Options-Footnote-1128699 -Node: Other Arguments128724 -Node: Naming Standard Input131386 -Node: Environment Variables132479 -Node: AWKPATH Variable133037 -Ref: AWKPATH Variable-Footnote-1135903 -Ref: AWKPATH Variable-Footnote-2135948 -Node: AWKLIBPATH Variable136208 -Node: Other Environment Variables136967 -Node: Exit Status140624 -Node: Include Files141299 -Node: Loading Shared Libraries144877 -Node: Obsolete146261 -Node: Undocumented146958 -Node: Invoking Summary147225 -Node: Regexp148825 -Node: Regexp Usage150275 -Node: Escape Sequences152308 -Node: Regexp Operators158139 -Ref: Regexp Operators-Footnote-1165619 -Ref: Regexp Operators-Footnote-2165766 -Node: Bracket Expressions165864 -Ref: table-char-classes167754 -Node: GNU Regexp Operators170694 -Node: Case-sensitivity174417 -Ref: Case-sensitivity-Footnote-1177309 -Ref: Case-sensitivity-Footnote-2177544 -Node: Leftmost Longest177652 -Node: Computed Regexps178853 -Node: Regexp Summary182225 -Node: Reading Files183694 -Node: Records185786 -Node: awk split records186529 -Node: gawk split records191387 -Ref: gawk split records-Footnote-1195908 -Node: Fields195945 -Ref: Fields-Footnote-1198909 -Node: Nonconstant Fields198995 -Ref: Nonconstant Fields-Footnote-1201225 -Node: Changing Fields201427 -Node: Field Separators207381 -Node: Default Field Splitting210083 -Node: Regexp Field Splitting211200 -Node: Single Character Fields214541 -Node: Command Line Field Separator215600 -Node: Full Line Fields219026 -Ref: Full Line Fields-Footnote-1219534 -Node: Field Splitting Summary219580 -Ref: Field Splitting Summary-Footnote-1222712 -Node: Constant Size222813 -Node: Splitting By Content227419 -Ref: Splitting By Content-Footnote-1231492 -Node: Multiple Line231532 -Ref: Multiple Line-Footnote-1237388 -Node: Getline237567 -Node: Plain Getline239783 -Node: Getline/Variable241878 -Node: Getline/File243025 -Node: Getline/Variable/File244409 -Ref: Getline/Variable/File-Footnote-1246008 -Node: Getline/Pipe246095 -Node: Getline/Variable/Pipe248794 -Node: Getline/Coprocess249901 -Node: Getline/Variable/Coprocess251153 -Node: Getline Notes251890 -Node: Getline Summary254694 -Ref: table-getline-variants255102 -Node: Read Timeout256014 -Ref: Read Timeout-Footnote-1259841 -Node: Command-line directories259899 -Node: Input Summary260803 -Node: Input Exercises263940 -Node: Printing264673 -Node: Print266395 -Node: Print Examples267736 -Node: Output Separators270515 -Node: OFMT272531 -Node: Printf273889 -Node: Basic Printf274795 -Node: Control Letters276334 -Node: Format Modifiers280325 -Node: Printf Examples286352 -Node: Redirection288816 -Node: Special Files295788 -Node: Special FD296321 -Ref: Special FD-Footnote-1299918 -Node: Special Network299992 -Node: Special Caveats300842 -Node: Close Files And Pipes301638 -Ref: Close Files And Pipes-Footnote-1308799 -Ref: Close Files And Pipes-Footnote-2308947 -Node: Output Summary309097 -Node: Output exercises310094 -Node: Expressions310774 -Node: Values311959 -Node: Constants312635 -Node: Scalar Constants313315 -Ref: Scalar Constants-Footnote-1314174 -Node: Nondecimal-numbers314424 -Node: Regexp Constants317424 -Node: Using Constant Regexps317899 -Node: Variables320971 -Node: Using Variables321626 -Node: Assignment Options323350 -Node: Conversion325225 -Node: Strings And Numbers325749 -Ref: Strings And Numbers-Footnote-1328811 -Node: Locale influences conversions328920 -Ref: table-locale-affects331637 -Node: All Operators332225 -Node: Arithmetic Ops332855 -Node: Concatenation335360 -Ref: Concatenation-Footnote-1338179 -Node: Assignment Ops338299 -Ref: table-assign-ops343282 -Node: Increment Ops344599 -Node: Truth Values and Conditions348037 -Node: Truth Values349120 -Node: Typing and Comparison350169 -Node: Variable Typing350962 -Node: Comparison Operators354614 -Ref: table-relational-ops355024 -Node: POSIX String Comparison358574 -Ref: POSIX String Comparison-Footnote-1359658 -Node: Boolean Ops359796 -Ref: Boolean Ops-Footnote-1363866 -Node: Conditional Exp363957 -Node: Function Calls365684 -Node: Precedence369564 -Node: Locales373233 -Node: Expressions Summary374864 -Node: Patterns and Actions377405 -Node: Pattern Overview378521 -Node: Regexp Patterns380198 -Node: Expression Patterns380741 -Node: Ranges384522 -Node: BEGIN/END387628 -Node: Using BEGIN/END388390 -Ref: Using BEGIN/END-Footnote-1391126 -Node: I/O And BEGIN/END391232 -Node: BEGINFILE/ENDFILE393517 -Node: Empty396448 -Node: Using Shell Variables396765 -Node: Action Overview399048 -Node: Statements401375 -Node: If Statement403223 -Node: While Statement404721 -Node: Do Statement406765 -Node: For Statement407921 -Node: Switch Statement411073 -Node: Break Statement413461 -Node: Continue Statement415516 -Node: Next Statement417355 -Node: Nextfile Statement419745 -Node: Exit Statement422400 -Node: Built-in Variables424804 -Node: User-modified425931 -Ref: User-modified-Footnote-1433620 -Node: Auto-set433682 -Ref: Auto-set-Footnote-1446264 -Ref: Auto-set-Footnote-2446469 -Node: ARGC and ARGV446525 -Node: Pattern Action Summary450429 -Node: Arrays452652 -Node: Array Basics454201 -Node: Array Intro455027 -Ref: figure-array-elements457000 -Node: Reference to Elements459407 -Node: Assigning Elements461786 -Node: Array Example462277 -Node: Scanning an Array464009 -Node: Controlling Scanning467024 -Ref: Controlling Scanning-Footnote-1472197 -Node: Delete472513 -Ref: Delete-Footnote-1475278 -Node: Numeric Array Subscripts475335 -Node: Uninitialized Subscripts477518 -Node: Multidimensional479143 -Node: Multiscanning482256 -Node: Arrays of Arrays483845 -Node: Arrays Summary488508 -Node: Functions490613 -Node: Built-in491486 -Node: Calling Built-in492564 -Node: Numeric Functions494552 -Ref: Numeric Functions-Footnote-1498586 -Ref: Numeric Functions-Footnote-2498943 -Ref: Numeric Functions-Footnote-3498991 -Node: String Functions499260 -Ref: String Functions-Footnote-1522271 -Ref: String Functions-Footnote-2522400 -Ref: String Functions-Footnote-3522648 -Node: Gory Details522735 -Ref: table-sub-escapes524522 -Ref: table-sub-proposed526042 -Ref: table-posix-sub527406 -Ref: table-gensub-escapes528946 -Ref: Gory Details-Footnote-1530122 -Node: I/O Functions530273 -Ref: I/O Functions-Footnote-1537396 -Node: Time Functions537543 -Ref: Time Functions-Footnote-1548007 -Ref: Time Functions-Footnote-2548075 -Ref: Time Functions-Footnote-3548233 -Ref: Time Functions-Footnote-4548344 -Ref: Time Functions-Footnote-5548456 -Ref: Time Functions-Footnote-6548683 -Node: Bitwise Functions548949 -Ref: table-bitwise-ops549511 -Ref: Bitwise Functions-Footnote-1553756 -Node: Type Functions553940 -Node: I18N Functions555082 -Node: User-defined556727 -Node: Definition Syntax557531 -Ref: Definition Syntax-Footnote-1562710 -Node: Function Example562779 -Ref: Function Example-Footnote-1565419 -Node: Function Caveats565441 -Node: Calling A Function565959 -Node: Variable Scope566914 -Node: Pass By Value/Reference569902 -Node: Return Statement573412 -Node: Dynamic Typing576396 -Node: Indirect Calls577325 -Node: Functions Summary587038 -Node: Library Functions589577 -Ref: Library Functions-Footnote-1593195 -Ref: Library Functions-Footnote-2593338 -Node: Library Names593509 -Ref: Library Names-Footnote-1596982 -Ref: Library Names-Footnote-2597202 -Node: General Functions597288 -Node: Strtonum Function598316 -Node: Assert Function601096 -Node: Round Function604422 -Node: Cliff Random Function605963 -Node: Ordinal Functions606979 -Ref: Ordinal Functions-Footnote-1610056 -Ref: Ordinal Functions-Footnote-2610308 -Node: Join Function610519 -Ref: Join Function-Footnote-1612290 -Node: Getlocaltime Function612490 -Node: Readfile Function616226 -Node: Data File Management618065 -Node: Filetrans Function618697 -Node: Rewind Function622766 -Node: File Checking624324 -Ref: File Checking-Footnote-1625456 -Node: Empty Files625657 -Node: Ignoring Assigns627636 -Node: Getopt Function629190 -Ref: Getopt Function-Footnote-1640493 -Node: Passwd Functions640696 -Ref: Passwd Functions-Footnote-1649675 -Node: Group Functions649763 -Ref: Group Functions-Footnote-1657704 -Node: Walking Arrays657917 -Node: Library Functions Summary659520 -Node: Library exercises660908 -Node: Sample Programs662188 -Node: Running Examples662958 -Node: Clones663686 -Node: Cut Program664910 -Node: Egrep Program674778 -Ref: Egrep Program-Footnote-1682749 -Node: Id Program682859 -Node: Split Program686523 -Ref: Split Program-Footnote-1690061 -Node: Tee Program690189 -Node: Uniq Program692996 -Node: Wc Program700426 -Ref: Wc Program-Footnote-1704691 -Node: Miscellaneous Programs704783 -Node: Dupword Program705996 -Node: Alarm Program708027 -Node: Translate Program712841 -Ref: Translate Program-Footnote-1717232 -Ref: Translate Program-Footnote-2717502 -Node: Labels Program717636 -Ref: Labels Program-Footnote-1721007 -Node: Word Sorting721091 -Node: History Sorting725134 -Node: Extract Program726970 -Node: Simple Sed734506 -Node: Igawk Program737568 -Ref: Igawk Program-Footnote-1751872 -Ref: Igawk Program-Footnote-2752073 -Node: Anagram Program752211 -Node: Signature Program755279 -Node: Programs Summary756526 -Node: Programs Exercises757741 -Node: Advanced Features761392 -Node: Nondecimal Data763340 -Node: Array Sorting764917 -Node: Controlling Array Traversal765614 -Node: Array Sorting Functions773894 -Ref: Array Sorting Functions-Footnote-1777801 -Node: Two-way I/O777995 -Ref: Two-way I/O-Footnote-1782939 -Ref: Two-way I/O-Footnote-2783118 -Node: TCP/IP Networking783200 -Node: Profiling786045 -Node: Advanced Features Summary793587 -Node: Internationalization795451 -Node: I18N and L10N796931 -Node: Explaining gettext797617 -Ref: Explaining gettext-Footnote-1802757 -Ref: Explaining gettext-Footnote-2802941 -Node: Programmer i18n803106 -Node: Translator i18n807331 -Node: String Extraction808125 -Ref: String Extraction-Footnote-1809086 -Node: Printf Ordering809172 -Ref: Printf Ordering-Footnote-1811954 -Node: I18N Portability812018 -Ref: I18N Portability-Footnote-1814467 -Node: I18N Example814530 -Ref: I18N Example-Footnote-1817252 -Node: Gawk I18N817324 -Node: I18N Summary817962 -Node: Debugger819301 -Node: Debugging820323 -Node: Debugging Concepts820764 -Node: Debugging Terms822620 -Node: Awk Debugging825217 -Node: Sample Debugging Session826109 -Node: Debugger Invocation826629 -Node: Finding The Bug827962 -Node: List of Debugger Commands834444 -Node: Breakpoint Control835776 -Node: Debugger Execution Control839440 -Node: Viewing And Changing Data842800 -Node: Execution Stack846158 -Node: Debugger Info847671 -Node: Miscellaneous Debugger Commands851665 -Node: Readline Support856849 -Node: Limitations857741 -Node: Debugging Summary860015 -Node: Arbitrary Precision Arithmetic861183 -Node: Computer Arithmetic862670 -Ref: Computer Arithmetic-Footnote-1867057 -Node: Math Definitions867114 -Ref: table-ieee-formats870403 -Ref: Math Definitions-Footnote-1870943 -Node: MPFR features871046 -Node: FP Math Caution872663 -Ref: FP Math Caution-Footnote-1873713 -Node: Inexactness of computations874082 -Node: Inexact representation875030 -Node: Comparing FP Values876385 -Node: Errors accumulate877349 -Node: Getting Accuracy878782 -Node: Try To Round881441 -Node: Setting precision882340 -Ref: table-predefined-precision-strings883022 -Node: Setting the rounding mode884815 -Ref: table-gawk-rounding-modes885179 -Ref: Setting the rounding mode-Footnote-1888633 -Node: Arbitrary Precision Integers888812 -Ref: Arbitrary Precision Integers-Footnote-1891793 -Node: POSIX Floating Point Problems891942 -Ref: POSIX Floating Point Problems-Footnote-1895818 -Node: Floating point summary895856 -Node: Dynamic Extensions898060 -Node: Extension Intro899612 -Node: Plugin License900877 -Node: Extension Mechanism Outline901562 -Ref: figure-load-extension901986 -Ref: figure-load-new-function903471 -Ref: figure-call-new-function904473 -Node: Extension API Description906457 -Node: Extension API Functions Introduction907907 -Node: General Data Types912774 -Ref: General Data Types-Footnote-1918467 -Node: Requesting Values918766 -Ref: table-value-types-returned919503 -Node: Memory Allocation Functions920461 -Ref: Memory Allocation Functions-Footnote-1923208 -Node: Constructor Functions923304 -Node: Registration Functions925062 -Node: Extension Functions925747 -Node: Exit Callback Functions928049 -Node: Extension Version String929297 -Node: Input Parsers929947 -Node: Output Wrappers939761 -Node: Two-way processors944277 -Node: Printing Messages946481 -Ref: Printing Messages-Footnote-1947558 -Node: Updating `ERRNO'947710 -Node: Accessing Parameters948449 -Node: Symbol Table Access949679 -Node: Symbol table by name950193 -Node: Symbol table by cookie952169 -Ref: Symbol table by cookie-Footnote-1956302 -Node: Cached values956365 -Ref: Cached values-Footnote-1959869 -Node: Array Manipulation959960 -Ref: Array Manipulation-Footnote-1961058 -Node: Array Data Types961097 -Ref: Array Data Types-Footnote-1963800 -Node: Array Functions963892 -Node: Flattening Arrays967766 -Node: Creating Arrays974618 -Node: Extension API Variables979349 -Node: Extension Versioning979985 -Node: Extension API Informational Variables981886 -Node: Extension API Boilerplate982972 -Node: Finding Extensions986776 -Node: Extension Example987336 -Node: Internal File Description988066 -Node: Internal File Ops992157 -Ref: Internal File Ops-Footnote-11003589 -Node: Using Internal File Ops1003729 -Ref: Using Internal File Ops-Footnote-11006076 -Node: Extension Samples1006344 -Node: Extension Sample File Functions1007868 -Node: Extension Sample Fnmatch1015436 -Node: Extension Sample Fork1016918 -Node: Extension Sample Inplace1018131 -Node: Extension Sample Ord1019806 -Node: Extension Sample Readdir1020642 -Ref: table-readdir-file-types1021498 -Node: Extension Sample Revout1022297 -Node: Extension Sample Rev2way1022888 -Node: Extension Sample Read write array1023629 -Node: Extension Sample Readfile1025508 -Node: Extension Sample API Tests1026608 -Node: Extension Sample Time1027133 -Node: gawkextlib1028448 -Node: Extension summary1031261 -Node: Extension Exercises1034954 -Node: Language History1035676 -Node: V7/SVR3.11037319 -Node: SVR41039639 -Node: POSIX1041081 -Node: BTL1042467 -Node: POSIX/GNU1043201 -Node: Feature History1048942 -Node: Common Extensions1062072 -Node: Ranges and Locales1063384 -Ref: Ranges and Locales-Footnote-11068001 -Ref: Ranges and Locales-Footnote-21068028 -Ref: Ranges and Locales-Footnote-31068262 -Node: Contributors1068483 -Node: History summary1073908 -Node: Installation1075277 -Node: Gawk Distribution1076228 -Node: Getting1076712 -Node: Extracting1077536 -Node: Distribution contents1079178 -Node: Unix Installation1084895 -Node: Quick Installation1085512 -Node: Additional Configuration Options1087954 -Node: Configuration Philosophy1089692 -Node: Non-Unix Installation1092043 -Node: PC Installation1092501 -Node: PC Binary Installation1093812 -Node: PC Compiling1095660 -Ref: PC Compiling-Footnote-11098659 -Node: PC Testing1098764 -Node: PC Using1099940 -Node: Cygwin1104092 -Node: MSYS1104901 -Node: VMS Installation1105415 -Node: VMS Compilation1106211 -Ref: VMS Compilation-Footnote-11107433 -Node: VMS Dynamic Extensions1107491 -Node: VMS Installation Details1108864 -Node: VMS Running1111116 -Node: VMS GNV1113950 -Node: VMS Old Gawk1114673 -Node: Bugs1115143 -Node: Other Versions1119147 -Node: Installation summary1125402 -Node: Notes1126458 -Node: Compatibility Mode1127323 -Node: Additions1128105 -Node: Accessing The Source1129030 -Node: Adding Code1130466 -Node: New Ports1136644 -Node: Derived Files1141125 -Ref: Derived Files-Footnote-11146206 -Ref: Derived Files-Footnote-21146240 -Ref: Derived Files-Footnote-31146836 -Node: Future Extensions1146950 -Node: Implementation Limitations1147556 -Node: Extension Design1148804 -Node: Old Extension Problems1149958 -Ref: Old Extension Problems-Footnote-11151475 -Node: Extension New Mechanism Goals1151532 -Ref: Extension New Mechanism Goals-Footnote-11154892 -Node: Extension Other Design Decisions1155081 -Node: Extension Future Growth1157187 -Node: Old Extension Mechanism1158023 -Node: Notes summary1159785 -Node: Basic Concepts1160971 -Node: Basic High Level1161652 -Ref: figure-general-flow1161924 -Ref: figure-process-flow1162523 -Ref: Basic High Level-Footnote-11165752 -Node: Basic Data Typing1165937 -Node: Glossary1169265 -Node: Copying1194417 -Node: GNU Free Documentation License1231973 -Node: Index1257109 +Node: Manual History61700 +Ref: Manual History-Footnote-164776 +Ref: Manual History-Footnote-264817 +Node: How To Contribute64891 +Node: Acknowledgments66130 +Node: Getting Started70878 +Node: Running gawk73312 +Node: One-shot74502 +Node: Read Terminal75727 +Ref: Read Terminal-Footnote-177690 +Node: Long77861 +Node: Executable Scripts79255 +Ref: Executable Scripts-Footnote-181088 +Ref: Executable Scripts-Footnote-281190 +Node: Comments81743 +Node: Quoting84216 +Node: DOS Quoting89529 +Node: Sample Data Files90204 +Node: Very Simple92758 +Node: Two Rules97531 +Node: More Complex99425 +Ref: More Complex-Footnote-1102357 +Node: Statements/Lines102442 +Ref: Statements/Lines-Footnote-1106898 +Node: Other Features107163 +Node: When108091 +Ref: When-Footnote-1109952 +Node: Intro Summary110017 +Node: Invoking Gawk110783 +Node: Command Line112298 +Node: Options113089 +Ref: Options-Footnote-1128865 +Node: Other Arguments128890 +Node: Naming Standard Input131552 +Node: Environment Variables132645 +Node: AWKPATH Variable133203 +Ref: AWKPATH Variable-Footnote-1136069 +Ref: AWKPATH Variable-Footnote-2136114 +Node: AWKLIBPATH Variable136374 +Node: Other Environment Variables137133 +Node: Exit Status140790 +Node: Include Files141465 +Node: Loading Shared Libraries145043 +Node: Obsolete146427 +Node: Undocumented147124 +Node: Invoking Summary147391 +Node: Regexp148991 +Node: Regexp Usage150441 +Node: Escape Sequences152474 +Node: Regexp Operators158291 +Ref: Regexp Operators-Footnote-1165771 +Ref: Regexp Operators-Footnote-2165918 +Node: Bracket Expressions166016 +Ref: table-char-classes167906 +Node: GNU Regexp Operators170846 +Node: Case-sensitivity174555 +Ref: Case-sensitivity-Footnote-1177447 +Ref: Case-sensitivity-Footnote-2177682 +Node: Leftmost Longest177790 +Node: Computed Regexps178991 +Node: Regexp Summary182363 +Node: Reading Files183832 +Node: Records185924 +Node: awk split records186667 +Node: gawk split records191525 +Ref: gawk split records-Footnote-1196046 +Node: Fields196083 +Ref: Fields-Footnote-1199047 +Node: Nonconstant Fields199133 +Ref: Nonconstant Fields-Footnote-1201363 +Node: Changing Fields201565 +Node: Field Separators207519 +Node: Default Field Splitting210221 +Node: Regexp Field Splitting211338 +Node: Single Character Fields214665 +Node: Command Line Field Separator215724 +Node: Full Line Fields219150 +Ref: Full Line Fields-Footnote-1219658 +Node: Field Splitting Summary219704 +Ref: Field Splitting Summary-Footnote-1222836 +Node: Constant Size222937 +Node: Splitting By Content227543 +Ref: Splitting By Content-Footnote-1231616 +Node: Multiple Line231656 +Ref: Multiple Line-Footnote-1237512 +Node: Getline237691 +Node: Plain Getline239907 +Node: Getline/Variable242002 +Node: Getline/File243149 +Node: Getline/Variable/File244533 +Ref: Getline/Variable/File-Footnote-1246132 +Node: Getline/Pipe246219 +Node: Getline/Variable/Pipe248905 +Node: Getline/Coprocess250012 +Node: Getline/Variable/Coprocess251264 +Node: Getline Notes252001 +Node: Getline Summary254805 +Ref: table-getline-variants255213 +Node: Read Timeout256125 +Ref: Read Timeout-Footnote-1259952 +Node: Command-line directories260010 +Node: Input Summary260914 +Node: Input Exercises264051 +Node: Printing264784 +Node: Print266506 +Node: Print Examples267999 +Node: Output Separators270778 +Node: OFMT272794 +Node: Printf274152 +Node: Basic Printf275058 +Node: Control Letters276597 +Node: Format Modifiers280588 +Node: Printf Examples286615 +Node: Redirection289079 +Node: Special Files296051 +Node: Special FD296584 +Ref: Special FD-Footnote-1300181 +Node: Special Network300255 +Node: Special Caveats301105 +Node: Close Files And Pipes301901 +Ref: Close Files And Pipes-Footnote-1309062 +Ref: Close Files And Pipes-Footnote-2309210 +Node: Output Summary309360 +Node: Output exercises310357 +Node: Expressions311037 +Node: Values312222 +Node: Constants312898 +Node: Scalar Constants313578 +Ref: Scalar Constants-Footnote-1314437 +Node: Nondecimal-numbers314687 +Node: Regexp Constants317687 +Node: Using Constant Regexps318162 +Node: Variables321234 +Node: Using Variables321889 +Node: Assignment Options323613 +Node: Conversion325488 +Node: Strings And Numbers326012 +Ref: Strings And Numbers-Footnote-1329074 +Node: Locale influences conversions329183 +Ref: table-locale-affects331900 +Node: All Operators332488 +Node: Arithmetic Ops333118 +Node: Concatenation335623 +Ref: Concatenation-Footnote-1338442 +Node: Assignment Ops338548 +Ref: table-assign-ops343531 +Node: Increment Ops344834 +Node: Truth Values and Conditions348272 +Node: Truth Values349355 +Node: Typing and Comparison350404 +Node: Variable Typing351197 +Node: Comparison Operators354849 +Ref: table-relational-ops355259 +Node: POSIX String Comparison358809 +Ref: POSIX String Comparison-Footnote-1359893 +Node: Boolean Ops360031 +Ref: Boolean Ops-Footnote-1364101 +Node: Conditional Exp364192 +Node: Function Calls365919 +Node: Precedence369799 +Node: Locales373468 +Node: Expressions Summary375099 +Node: Patterns and Actions377640 +Node: Pattern Overview378756 +Node: Regexp Patterns380433 +Node: Expression Patterns380976 +Node: Ranges384757 +Node: BEGIN/END387863 +Node: Using BEGIN/END388625 +Ref: Using BEGIN/END-Footnote-1391361 +Node: I/O And BEGIN/END391467 +Node: BEGINFILE/ENDFILE393738 +Node: Empty396669 +Node: Using Shell Variables396986 +Node: Action Overview399269 +Node: Statements401596 +Node: If Statement403444 +Node: While Statement404942 +Node: Do Statement406986 +Node: For Statement408142 +Node: Switch Statement411294 +Node: Break Statement413682 +Node: Continue Statement415723 +Node: Next Statement417548 +Node: Nextfile Statement419938 +Node: Exit Statement422574 +Node: Built-in Variables424978 +Node: User-modified426105 +Ref: User-modified-Footnote-1433794 +Node: Auto-set433856 +Ref: Auto-set-Footnote-1446438 +Ref: Auto-set-Footnote-2446643 +Node: ARGC and ARGV446699 +Node: Pattern Action Summary450603 +Node: Arrays452826 +Node: Array Basics454375 +Node: Array Intro455201 +Ref: figure-array-elements457174 +Node: Reference to Elements459581 +Node: Assigning Elements461960 +Node: Array Example462451 +Node: Scanning an Array464183 +Node: Controlling Scanning467184 +Ref: Controlling Scanning-Footnote-1472357 +Node: Delete472673 +Ref: Delete-Footnote-1475424 +Node: Numeric Array Subscripts475481 +Node: Uninitialized Subscripts477664 +Node: Multidimensional479289 +Node: Multiscanning482402 +Node: Arrays of Arrays483991 +Node: Arrays Summary488654 +Node: Functions490759 +Node: Built-in491632 +Node: Calling Built-in492710 +Node: Numeric Functions494698 +Ref: Numeric Functions-Footnote-1498732 +Ref: Numeric Functions-Footnote-2499089 +Ref: Numeric Functions-Footnote-3499137 +Node: String Functions499406 +Ref: String Functions-Footnote-1522403 +Ref: String Functions-Footnote-2522532 +Ref: String Functions-Footnote-3522780 +Node: Gory Details522867 +Ref: table-sub-escapes524640 +Ref: table-sub-proposed526160 +Ref: table-posix-sub527524 +Ref: table-gensub-escapes529064 +Ref: Gory Details-Footnote-1530240 +Node: I/O Functions530391 +Ref: I/O Functions-Footnote-1537501 +Node: Time Functions537648 +Ref: Time Functions-Footnote-1548112 +Ref: Time Functions-Footnote-2548180 +Ref: Time Functions-Footnote-3548338 +Ref: Time Functions-Footnote-4548449 +Ref: Time Functions-Footnote-5548561 +Ref: Time Functions-Footnote-6548788 +Node: Bitwise Functions549054 +Ref: table-bitwise-ops549616 +Ref: Bitwise Functions-Footnote-1553861 +Node: Type Functions554045 +Node: I18N Functions555187 +Node: User-defined556832 +Node: Definition Syntax557636 +Ref: Definition Syntax-Footnote-1562815 +Node: Function Example562884 +Ref: Function Example-Footnote-1565524 +Node: Function Caveats565546 +Node: Calling A Function566064 +Node: Variable Scope567019 +Node: Pass By Value/Reference570007 +Node: Return Statement573517 +Node: Dynamic Typing576501 +Node: Indirect Calls577430 +Node: Functions Summary587143 +Node: Library Functions589682 +Ref: Library Functions-Footnote-1593300 +Ref: Library Functions-Footnote-2593443 +Node: Library Names593614 +Ref: Library Names-Footnote-1597087 +Ref: Library Names-Footnote-2597307 +Node: General Functions597393 +Node: Strtonum Function598421 +Node: Assert Function601201 +Node: Round Function604527 +Node: Cliff Random Function606068 +Node: Ordinal Functions607084 +Ref: Ordinal Functions-Footnote-1610161 +Ref: Ordinal Functions-Footnote-2610413 +Node: Join Function610624 +Ref: Join Function-Footnote-1612395 +Node: Getlocaltime Function612595 +Node: Readfile Function616331 +Node: Data File Management618170 +Node: Filetrans Function618802 +Node: Rewind Function622871 +Node: File Checking624429 +Ref: File Checking-Footnote-1625561 +Node: Empty Files625762 +Node: Ignoring Assigns627741 +Node: Getopt Function629295 +Ref: Getopt Function-Footnote-1640598 +Node: Passwd Functions640801 +Ref: Passwd Functions-Footnote-1649780 +Node: Group Functions649868 +Ref: Group Functions-Footnote-1657809 +Node: Walking Arrays658022 +Node: Library Functions Summary659625 +Node: Library exercises661013 +Node: Sample Programs662293 +Node: Running Examples663063 +Node: Clones663791 +Node: Cut Program665015 +Node: Egrep Program674883 +Ref: Egrep Program-Footnote-1682854 +Node: Id Program682964 +Node: Split Program686628 +Ref: Split Program-Footnote-1690166 +Node: Tee Program690294 +Node: Uniq Program693101 +Node: Wc Program700531 +Ref: Wc Program-Footnote-1704796 +Node: Miscellaneous Programs704888 +Node: Dupword Program706101 +Node: Alarm Program708132 +Node: Translate Program712946 +Ref: Translate Program-Footnote-1717337 +Ref: Translate Program-Footnote-2717607 +Node: Labels Program717741 +Ref: Labels Program-Footnote-1721112 +Node: Word Sorting721196 +Node: History Sorting725239 +Node: Extract Program727075 +Node: Simple Sed734611 +Node: Igawk Program737673 +Ref: Igawk Program-Footnote-1751977 +Ref: Igawk Program-Footnote-2752178 +Node: Anagram Program752316 +Node: Signature Program755384 +Node: Programs Summary756631 +Node: Programs Exercises757846 +Node: Advanced Features761497 +Node: Nondecimal Data763445 +Node: Array Sorting765022 +Node: Controlling Array Traversal765719 +Node: Array Sorting Functions773999 +Ref: Array Sorting Functions-Footnote-1777906 +Node: Two-way I/O778100 +Ref: Two-way I/O-Footnote-1783044 +Ref: Two-way I/O-Footnote-2783223 +Node: TCP/IP Networking783305 +Node: Profiling786150 +Node: Advanced Features Summary793692 +Node: Internationalization795556 +Node: I18N and L10N797036 +Node: Explaining gettext797722 +Ref: Explaining gettext-Footnote-1802748 +Ref: Explaining gettext-Footnote-2802932 +Node: Programmer i18n803097 +Ref: Programmer i18n-Footnote-1807891 +Node: Translator i18n807940 +Node: String Extraction808734 +Ref: String Extraction-Footnote-1809867 +Node: Printf Ordering809953 +Ref: Printf Ordering-Footnote-1812735 +Node: I18N Portability812799 +Ref: I18N Portability-Footnote-1815248 +Node: I18N Example815311 +Ref: I18N Example-Footnote-1818017 +Node: Gawk I18N818089 +Node: I18N Summary818727 +Node: Debugger820066 +Node: Debugging821088 +Node: Debugging Concepts821529 +Node: Debugging Terms823385 +Node: Awk Debugging825982 +Node: Sample Debugging Session826874 +Node: Debugger Invocation827394 +Node: Finding The Bug828727 +Node: List of Debugger Commands835209 +Node: Breakpoint Control836541 +Node: Debugger Execution Control840205 +Node: Viewing And Changing Data843565 +Node: Execution Stack846923 +Node: Debugger Info848436 +Node: Miscellaneous Debugger Commands852430 +Node: Readline Support857614 +Node: Limitations858506 +Node: Debugging Summary860780 +Node: Arbitrary Precision Arithmetic861948 +Node: Computer Arithmetic863435 +Ref: Computer Arithmetic-Footnote-1867822 +Node: Math Definitions867879 +Ref: table-ieee-formats871168 +Ref: Math Definitions-Footnote-1871708 +Node: MPFR features871811 +Node: FP Math Caution873428 +Ref: FP Math Caution-Footnote-1874478 +Node: Inexactness of computations874847 +Node: Inexact representation875795 +Node: Comparing FP Values877150 +Node: Errors accumulate878114 +Node: Getting Accuracy879547 +Node: Try To Round882206 +Node: Setting precision883105 +Ref: table-predefined-precision-strings883787 +Node: Setting the rounding mode885580 +Ref: table-gawk-rounding-modes885944 +Ref: Setting the rounding mode-Footnote-1889398 +Node: Arbitrary Precision Integers889577 +Ref: Arbitrary Precision Integers-Footnote-1892558 +Node: POSIX Floating Point Problems892707 +Ref: POSIX Floating Point Problems-Footnote-1896583 +Node: Floating point summary896621 +Node: Dynamic Extensions898825 +Node: Extension Intro900377 +Node: Plugin License901642 +Node: Extension Mechanism Outline902327 +Ref: figure-load-extension902751 +Ref: figure-load-new-function904236 +Ref: figure-call-new-function905238 +Node: Extension API Description907222 +Node: Extension API Functions Introduction908672 +Node: General Data Types913539 +Ref: General Data Types-Footnote-1919232 +Node: Requesting Values919531 +Ref: table-value-types-returned920268 +Node: Memory Allocation Functions921226 +Ref: Memory Allocation Functions-Footnote-1923973 +Node: Constructor Functions924069 +Node: Registration Functions925827 +Node: Extension Functions926512 +Node: Exit Callback Functions928814 +Node: Extension Version String930062 +Node: Input Parsers930712 +Node: Output Wrappers940526 +Node: Two-way processors945042 +Node: Printing Messages947246 +Ref: Printing Messages-Footnote-1948323 +Node: Updating `ERRNO'948475 +Node: Accessing Parameters949214 +Node: Symbol Table Access950444 +Node: Symbol table by name950958 +Node: Symbol table by cookie952934 +Ref: Symbol table by cookie-Footnote-1957067 +Node: Cached values957130 +Ref: Cached values-Footnote-1960634 +Node: Array Manipulation960725 +Ref: Array Manipulation-Footnote-1961823 +Node: Array Data Types961862 +Ref: Array Data Types-Footnote-1964565 +Node: Array Functions964657 +Node: Flattening Arrays968531 +Node: Creating Arrays975383 +Node: Extension API Variables980114 +Node: Extension Versioning980750 +Node: Extension API Informational Variables982651 +Node: Extension API Boilerplate983737 +Node: Finding Extensions987541 +Node: Extension Example988101 +Node: Internal File Description988831 +Node: Internal File Ops992922 +Ref: Internal File Ops-Footnote-11004354 +Node: Using Internal File Ops1004494 +Ref: Using Internal File Ops-Footnote-11006841 +Node: Extension Samples1007109 +Node: Extension Sample File Functions1008633 +Node: Extension Sample Fnmatch1016201 +Node: Extension Sample Fork1017683 +Node: Extension Sample Inplace1018896 +Node: Extension Sample Ord1020571 +Node: Extension Sample Readdir1021407 +Ref: table-readdir-file-types1022263 +Node: Extension Sample Revout1023062 +Node: Extension Sample Rev2way1023653 +Node: Extension Sample Read write array1024394 +Node: Extension Sample Readfile1026273 +Node: Extension Sample API Tests1027373 +Node: Extension Sample Time1027898 +Node: gawkextlib1029213 +Node: Extension summary1032026 +Node: Extension Exercises1035719 +Node: Language History1036441 +Node: V7/SVR3.11038084 +Node: SVR41040404 +Node: POSIX1041846 +Node: BTL1043232 +Node: POSIX/GNU1043966 +Node: Feature History1049682 +Node: Common Extensions1062773 +Node: Ranges and Locales1064085 +Ref: Ranges and Locales-Footnote-11068702 +Ref: Ranges and Locales-Footnote-21068729 +Ref: Ranges and Locales-Footnote-31068963 +Node: Contributors1069184 +Node: History summary1074609 +Node: Installation1075978 +Node: Gawk Distribution1076929 +Node: Getting1077413 +Node: Extracting1078237 +Node: Distribution contents1079879 +Node: Unix Installation1085596 +Node: Quick Installation1086213 +Node: Additional Configuration Options1088655 +Node: Configuration Philosophy1090393 +Node: Non-Unix Installation1092744 +Node: PC Installation1093202 +Node: PC Binary Installation1094513 +Node: PC Compiling1096361 +Ref: PC Compiling-Footnote-11099360 +Node: PC Testing1099465 +Node: PC Using1100641 +Node: Cygwin1104793 +Node: MSYS1105602 +Node: VMS Installation1106116 +Node: VMS Compilation1106912 +Ref: VMS Compilation-Footnote-11108134 +Node: VMS Dynamic Extensions1108192 +Node: VMS Installation Details1109565 +Node: VMS Running1111817 +Node: VMS GNV1114651 +Node: VMS Old Gawk1115374 +Node: Bugs1115844 +Node: Other Versions1119848 +Node: Installation summary1126075 +Node: Notes1127131 +Node: Compatibility Mode1127996 +Node: Additions1128778 +Node: Accessing The Source1129703 +Node: Adding Code1131139 +Node: New Ports1137317 +Node: Derived Files1141798 +Ref: Derived Files-Footnote-11146879 +Ref: Derived Files-Footnote-21146913 +Ref: Derived Files-Footnote-31147509 +Node: Future Extensions1147623 +Node: Implementation Limitations1148229 +Node: Extension Design1149477 +Node: Old Extension Problems1150631 +Ref: Old Extension Problems-Footnote-11152148 +Node: Extension New Mechanism Goals1152205 +Ref: Extension New Mechanism Goals-Footnote-11155565 +Node: Extension Other Design Decisions1155754 +Node: Extension Future Growth1157860 +Node: Old Extension Mechanism1158696 +Node: Notes summary1160458 +Node: Basic Concepts1161644 +Node: Basic High Level1162325 +Ref: figure-general-flow1162597 +Ref: figure-process-flow1163196 +Ref: Basic High Level-Footnote-11166425 +Node: Basic Data Typing1166610 +Node: Glossary1169938 +Node: Copying1195090 +Node: GNU Free Documentation License1232646 +Node: Index1257782  End Tag Table -- cgit v1.2.3 From 3defec04e39c4ca6987a21f79686576d9823c653 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sat, 23 Aug 2014 22:40:59 +0300 Subject: More reviewer comments. --- doc/gawk.info | 1193 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 589 insertions(+), 604 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 39da4897..9e4f3ec7 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -2243,9 +2243,7 @@ edit-compile-test-debug cycle of software development. retargetable assembler for eight-bit microprocessors (*note Glossary::, for more information), and a microcode assembler for a special-purpose Prolog computer. While the original `awk''s capabilities were strained -by tasks of such complexity, modern versions are more capable. Even -BWK `awk' has fewer predefined limits, and those that it has are much -larger than they used to be. +by tasks of such complexity, modern versions are more capable. If you find yourself writing `awk' scripts of more than, say, a few hundred lines, you might consider using a different programming @@ -2266,6 +2264,9 @@ File: gawk.info, Node: Intro Summary, Prev: When, Up: Getting Started * Programs in `awk' consist of PATTERN-ACTION pairs. + * An ACTION without a PATTERN always runs. The default ACTION for a + pattern without one is `{ print $0 }'. + * Use either `awk 'PROGRAM' FILES' or `awk -f PROGRAM-FILE FILES' to run `awk'. @@ -3207,7 +3208,7 @@ that matches every input record whose text belongs to that set. The simplest regular expression is a sequence of letters, numbers, or both. Such a regexp matches any string that contains that sequence. Thus, the regexp `foo' matches any string containing `foo'. Therefore, the -pattern `/foo/' matches any input record containing the three +pattern `/foo/' matches any input record containing the three adjacent characters `foo' _anywhere_ in the record. Other kinds of regexps let you specify more complicated classes of strings. @@ -3502,9 +3503,10 @@ sequences and that are not listed in the table stand for themselves: `|' This is the "alternation operator" and it is used to specify alternatives. The `|' has the lowest precedence of all the regular - expression operators. For example, `^P|[[:digit:]]' matches any - string that matches either `^P' or `[[:digit:]]'. This means it - matches any string that starts with `P' or contains a digit. + expression operators. For example, `^P|[aeiouy]' matches any + string that matches either `^P' or `[aeiouy]'. This means it + matches any string that starts with `P' or contains (anywhere + within it) a lowercase English vowel. The alternation applies to the largest possible regexps on either side. @@ -3630,7 +3632,9 @@ expression, put a `\' in front of it. For example: [d\]] -matches either `d' or `]'. +matches either `d' or `]'. Additionally, if you place `]' right after +the opening `[', the closing bracket is treated as one of the +characters to be matched. This treatment of `\' in bracket expressions is compatible with other `awk' implementations and is also mandated by POSIX. The regular @@ -4025,7 +4029,7 @@ File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp extent of the match, such as for text substitution and when the record separator is a regexp. - * Matching expressions may use dynamic regexps; that is, string + * Matching expressions may use dynamic regexps, that is, string values treated as regular expressions. @@ -4078,13 +4082,13 @@ File: gawk.info, Node: Records, Next: Fields, Up: Reading Files 4.1 How Input Is Split into Records =================================== -The `awk' utility divides the input for your `awk' program into records -and fields. `awk' keeps track of the number of records that have been -read so far from the current input file. This value is stored in a -built-in variable called `FNR'. It is reset to zero when a new file is -started. Another built-in variable, `NR', records the total number of -input records read so far from all data files. It starts at zero, but -is never automatically reset to zero. +`awk' divides the input for your program into records and fields. It +keeps track of the number of records that have been read so far from +the current input file. This value is stored in a built-in variable +called `FNR' which is reset to zero when a new file is started. +Another built-in variable, `NR', records the total number of input +records read so far from all data files. It starts at zero, but is +never automatically reset to zero. * Menu: @@ -5339,8 +5343,8 @@ yet. Therefore, come back and study the `getline' command _after_ you have reviewed the rest of this Info file and have a good knowledge of how `awk' works. - The `getline' command returns one if it finds a record and zero if -it encounters the end of the file. If there is some error in getting a + The `getline' command returns 1 if it finds a record and 0 if it +encounters the end of the file. If there is some error in getting a record, such as a file that cannot be opened, then `getline' returns -1. In this case, `gawk' sets the variable `ERRNO' to a string describing the error that occurred. @@ -8441,9 +8445,9 @@ because of the way they work. Evaluation of the full expression is "short-circuited" if the result can be determined part way through its evaluation. - Statements that use `&&' or `||' can be continued simply by putting -a newline after them. But you cannot put a newline in front of either -of these operators without using backslash continuation (*note + Statements that end with `&&' or `||' can be continued simply by +putting a newline after them. But you cannot put a newline in front of +either of these operators without using backslash continuation (*note Statements/Lines::). The actual value of an expression using the `!' operator is either @@ -8919,7 +8923,7 @@ precisely `li': `li'.) Contrast this with the following regular expression match, which accepts any record with a first field that contains `li': - $ awk '$1 ~ /foo/ { print $2 }' mail-list + $ awk '$1 ~ /li/ { print $2 }' mail-list -| 555-5553 -| 555-6699 @@ -10802,7 +10806,8 @@ index, use the following expression: This expression tests whether the particular index INDX exists, without the side effect of creating that element if it is not present. The expression has the value one (true) if `ARRAY[INDX]' exists and zero -(false) if it does not exist. For example, this statement tests +(false) if it does not exist. (We use INDX here, since `index' is the +name of a built-in function.) For example, this statement tests whether the array `frequencies' contains the index `2': if (2 in frequencies) @@ -14651,8 +14656,7 @@ worrying about: } #### test code #### - # BEGIN \ - # { + # BEGIN { # for (;;) { # printf("enter a character: ") # if (getline var <= 0) @@ -15775,8 +15779,7 @@ the same names: # group.awk --- functions for dealing with the group file - BEGIN \ - { + BEGIN { # Change to suit your system _gr_awklib = "/usr/local/libexec/awk/" } @@ -16199,8 +16202,7 @@ through the command-line options. Exactly one of the variables should be done by fields or by characters, respectively. When cutting by characters, the output field separator is set to the null string: - BEGIN \ - { + BEGIN { FS = "\t" # default OFS = FS while ((c = getopt(ARGC, ARGV, "sf:c:d:")) != -1) { @@ -16585,8 +16587,7 @@ line is printed, with a leading file name and colon if necessary: The `END' rule takes care of producing the correct exit status. If there are no matches, the exit status is one; otherwise it is zero: - END \ - { + END { exit (total == 0) } @@ -16604,13 +16605,6 @@ options, and then exits: The variable `e' is used so that the function fits nicely on the printed page. - Just a note on programming style: you may have noticed that the `END' -rule uses backslash continuation, with the open brace on a line by -itself. This is so that it more closely resembles the way functions -are written. Many of the examples in this major node use this style. -You can decide for yourself if you like writing your `BEGIN' and `END' -rules this way or not. - ---------- Footnotes ---------- (1) It also introduces a subtle bug; if a match happens, we output @@ -16653,8 +16647,7 @@ and the group numbers: # uid=12(foo) euid=34(bar) gid=3(baz) \ # egid=5(blat) groups=9(nine),2(two),1(one) - BEGIN \ - { + BEGIN { uid = PROCINFO["uid"] euid = PROCINFO["euid"] gid = PROCINFO["gid"] @@ -16862,8 +16855,7 @@ input by setting `ARGV[1]' to `"-"' and `ARGC' to two: # Copy standard input to all named output files. # Append content if -a option is supplied. # - BEGIN \ - { + BEGIN { for (i = 1; i < ARGC; i++) copy[i] = ARGV[i] @@ -16913,8 +16905,7 @@ N input records and M output files, the first method only executes N Finally, the `END' rule cleans up by closing all the output files: - END \ - { + END { for (i in copy) close(copy[i]) } @@ -17001,8 +16992,7 @@ standard output, `/dev/stdout': # -n skip n fields # +n skip n characters, skip fields first - BEGIN \ - { + BEGIN { count = 1 outputfile = "/dev/stdout" opts = "udc0:1:2:3:4:5:6:7:8:9:" @@ -17390,8 +17380,7 @@ Statement::), but the processing could be done with a series of # Requires getlocaltime() library function # usage: alarm time [ "message" [ count [ delay ] ] ] - BEGIN \ - { + BEGIN { # Initial argument sanity checking usage1 = "usage: alarm time ['message' [count [delay]]]" usage2 = sprintf("\t(%s) time ::= hh:mm", ARGV[1]) @@ -17712,8 +17701,7 @@ not have been an even multiple of 20 labels in the data: Count++ } - END \ - { + END { printpage() } @@ -30962,11 +30950,11 @@ Index * ' (single quote), vs. apostrophe: Comments. (line 27) * ' (single quote), with double quotes: Quoting. (line 70) * () (parentheses), in a profile: Profiling. (line 146) -* () (parentheses), regexp operator: Regexp Operators. (line 80) +* () (parentheses), regexp operator: Regexp Operators. (line 81) * * (asterisk), * operator, as multiplication operator: Precedence. (line 55) * * (asterisk), * operator, as regexp operator: Regexp Operators. - (line 88) + (line 89) * * (asterisk), * operator, null strings, matching: Gory Details. (line 143) * * (asterisk), ** operator <1>: Precedence. (line 49) @@ -30980,7 +30968,7 @@ Index * + (plus sign), ++ operator: Increment Ops. (line 11) * + (plus sign), += operator <1>: Precedence. (line 95) * + (plus sign), += operator: Assignment Ops. (line 82) -* + (plus sign), regexp operator: Regexp Operators. (line 103) +* + (plus sign), regexp operator: Regexp Operators. (line 104) * , (comma), in range patterns: Ranges. (line 6) * - (hyphen), - operator: Precedence. (line 52) * - (hyphen), -- operator <1>: Precedence. (line 46) @@ -31123,7 +31111,7 @@ Index * ? (question mark), ?: operator: Precedence. (line 92) * ? (question mark), regexp operator <1>: GNU Regexp Operators. (line 59) -* ? (question mark), regexp operator: Regexp Operators. (line 112) +* ? (question mark), regexp operator: Regexp Operators. (line 113) * [] (square brackets), regexp operator: Regexp Operators. (line 56) * \ (backslash): Comments. (line 50) * \ (backslash) in shell commands: Read Terminal. (line 25) @@ -31160,7 +31148,6 @@ Index (line 38) * \ (backslash), as field separator: Command Line Field Separator. (line 27) -* \ (backslash), continuing lines and <1>: Egrep Program. (line 223) * \ (backslash), continuing lines and: Statements/Lines. (line 19) * \ (backslash), continuing lines and, comments and: Statements/Lines. (line 76) @@ -31326,7 +31313,7 @@ Index * asterisk (*), * operator, as multiplication operator: Precedence. (line 55) * asterisk (*), * operator, as regexp operator: Regexp Operators. - (line 88) + (line 89) * asterisk (*), * operator, null strings, matching: Gory Details. (line 143) * asterisk (*), ** operator <1>: Precedence. (line 49) @@ -31344,7 +31331,7 @@ Index * awk programs <1>: Two Rules. (line 6) * awk programs <2>: Executable Scripts. (line 6) * awk programs: Getting Started. (line 12) -* awk programs, complex: When. (line 29) +* awk programs, complex: When. (line 27) * awk programs, documenting <1>: Library Names. (line 6) * awk programs, documenting: Comments. (line 6) * awk programs, examples of: Sample Programs. (line 6) @@ -31433,7 +31420,6 @@ Index (line 38) * backslash (\), as field separator: Command Line Field Separator. (line 27) -* backslash (\), continuing lines and <1>: Egrep Program. (line 223) * backslash (\), continuing lines and: Statements/Lines. (line 19) * backslash (\), continuing lines and, comments and: Statements/Lines. (line 76) @@ -31509,15 +31495,15 @@ Index * bracket expressions <1>: Bracket Expressions. (line 6) * bracket expressions: Regexp Operators. (line 56) * bracket expressions, character classes: Bracket Expressions. - (line 30) + (line 32) * bracket expressions, collating elements: Bracket Expressions. - (line 77) + (line 79) * bracket expressions, collating symbols: Bracket Expressions. - (line 84) + (line 86) * bracket expressions, complemented: Regexp Operators. (line 64) * bracket expressions, equivalence classes: Bracket Expressions. - (line 90) -* bracket expressions, non-ASCII: Bracket Expressions. (line 77) + (line 92) +* bracket expressions, non-ASCII: Bracket Expressions. (line 79) * bracket expressions, range expressions: Bracket Expressions. (line 6) * break debugger command: Breakpoint Control. (line 11) @@ -31634,8 +31620,8 @@ Index * Close, Diane <1>: Contributors. (line 20) * Close, Diane: Manual History. (line 34) * Collado, Manuel: Acknowledgments. (line 60) -* collating elements: Bracket Expressions. (line 77) -* collating symbols: Bracket Expressions. (line 84) +* collating elements: Bracket Expressions. (line 79) +* collating symbols: Bracket Expressions. (line 86) * Colombo, Antonio <1>: Contributors. (line 137) * Colombo, Antonio: Acknowledgments. (line 60) * columns, aligning: Print Examples. (line 70) @@ -32058,7 +32044,7 @@ Index * effective group ID of gawk user: Auto-set. (line 133) * effective user ID of gawk user: Auto-set. (line 137) * egrep utility <1>: Egrep Program. (line 6) -* egrep utility: Bracket Expressions. (line 24) +* egrep utility: Bracket Expressions. (line 26) * egrep.awk program: Egrep Program. (line 54) * elements in arrays, assigning values: Assigning Elements. (line 6) * elements in arrays, deleting: Delete. (line 6) @@ -32084,7 +32070,6 @@ Index * END pattern, and profiling: Profiling. (line 62) * END pattern, assert() user-defined function and: Assert Function. (line 75) -* END pattern, backslash continuation and: Egrep Program. (line 223) * END pattern, Boolean patterns and: Expression Patterns. (line 70) * END pattern, exit statement and: Exit Statement. (line 12) * END pattern, next/nextfile statements and <1>: Next Statement. @@ -32096,8 +32081,8 @@ Index * ENDFILE pattern: BEGINFILE/ENDFILE. (line 6) * ENDFILE pattern, Boolean patterns and: Expression Patterns. (line 70) * endfile() user-defined function: Filetrans Function. (line 62) -* endgrent() function (C library): Group Functions. (line 213) -* endgrent() user-defined function: Group Functions. (line 216) +* endgrent() function (C library): Group Functions. (line 212) +* endgrent() user-defined function: Group Functions. (line 215) * endpwent() function (C library): Passwd Functions. (line 210) * endpwent() user-defined function: Passwd Functions. (line 213) * English, Steve: Advanced Features. (line 6) @@ -32110,7 +32095,7 @@ Index * equals sign (=), == operator <1>: Precedence. (line 65) * equals sign (=), == operator: Comparison Operators. (line 11) -* EREs (Extended Regular Expressions): Bracket Expressions. (line 24) +* EREs (Extended Regular Expressions): Bracket Expressions. (line 26) * ERRNO variable <1>: TCP/IP Networking. (line 54) * ERRNO variable: Auto-set. (line 74) * ERRNO variable, with BEGINFILE pattern: BEGINFILE/ENDFILE. (line 26) @@ -32165,7 +32150,7 @@ Index * expressions, matching, See comparison expressions: Typing and Comparison. (line 9) * expressions, selecting: Conditional Exp. (line 6) -* Extended Regular Expressions (EREs): Bracket Expressions. (line 24) +* Extended Regular Expressions (EREs): Bracket Expressions. (line 26) * extension API: Extension API Description. (line 6) * extension API informational variables: Extension API Informational Variables. @@ -32231,7 +32216,7 @@ Index (line 6) * field separators, regular expressions as: Field Separators. (line 51) * field separators, See Also OFS: Changing Fields. (line 64) -* field separators, spaces as: Cut Program. (line 109) +* field separators, spaces as: Cut Program. (line 108) * fields <1>: Basic High Level. (line 73) * fields <2>: Fields. (line 6) * fields: Reading Files. (line 14) @@ -32428,7 +32413,7 @@ Index * gawk, bitwise operations in: Bitwise Functions. (line 39) * gawk, break statement in: Break Statement. (line 51) * gawk, built-in variables and: Built-in Variables. (line 14) -* gawk, character classes and: Bracket Expressions. (line 98) +* gawk, character classes and: Bracket Expressions. (line 100) * gawk, coding style in: Adding Code. (line 39) * gawk, command-line options, and regular expressions: GNU Regexp Operators. (line 70) @@ -32479,7 +32464,7 @@ Index (line 13) * gawk, interpreter, adding code to: Using Internal File Ops. (line 6) -* gawk, interval expressions and: Regexp Operators. (line 140) +* gawk, interval expressions and: Regexp Operators. (line 141) * gawk, line continuation in: Conditional Exp. (line 34) * gawk, LINT variable in: User-modified. (line 88) * gawk, list of contributors to: Contributors. (line 6) @@ -32497,7 +32482,7 @@ Index (line 26) * gawk, regular expressions, operators: GNU Regexp Operators. (line 6) -* gawk, regular expressions, precedence: Regexp Operators. (line 162) +* gawk, regular expressions, precedence: Regexp Operators. (line 163) * gawk, RT variable in <1>: Auto-set. (line 257) * gawk, RT variable in <2>: Multiple Line. (line 129) * gawk, RT variable in: awk split records. (line 124) @@ -32525,12 +32510,12 @@ Index * getaddrinfo() function (C library): TCP/IP Networking. (line 38) * getgrent() function (C library): Group Functions. (line 6) * getgrent() user-defined function: Group Functions. (line 6) -* getgrgid() function (C library): Group Functions. (line 184) -* getgrgid() user-defined function: Group Functions. (line 187) -* getgrnam() function (C library): Group Functions. (line 173) -* getgrnam() user-defined function: Group Functions. (line 178) -* getgruser() function (C library): Group Functions. (line 193) -* getgruser() function, user-defined: Group Functions. (line 196) +* getgrgid() function (C library): Group Functions. (line 183) +* getgrgid() user-defined function: Group Functions. (line 186) +* getgrnam() function (C library): Group Functions. (line 172) +* getgrnam() user-defined function: Group Functions. (line 177) +* getgruser() function (C library): Group Functions. (line 192) +* getgruser() function, user-defined: Group Functions. (line 195) * getline command: Reading Files. (line 20) * getline command, _gr_init() user-defined function: Group Functions. (line 83) @@ -32704,7 +32689,7 @@ Index (line 13) * internationalization, localization: User-modified. (line 152) * internationalization, localization, character classes: Bracket Expressions. - (line 98) + (line 100) * internationalization, localization, gawk and: Internationalization. (line 13) * internationalization, localization, locale categories: Explaining gettext. @@ -32716,7 +32701,7 @@ Index * internationalizing a program: Explaining gettext. (line 6) * interpreted programs <1>: Glossary. (line 356) * interpreted programs: Basic High Level. (line 15) -* interval expressions, regexp operator: Regexp Operators. (line 117) +* interval expressions, regexp operator: Regexp Operators. (line 118) * inventory-shipped file: Sample Data Files. (line 32) * invoke shell command: I/O Functions. (line 75) * isarray: Type Functions. (line 11) @@ -33074,7 +33059,7 @@ Index * Papadopoulos, Panos: Contributors. (line 128) * parent process ID of gawk process: Auto-set. (line 181) * parentheses (), in a profile: Profiling. (line 146) -* parentheses (), regexp operator: Regexp Operators. (line 80) +* parentheses (), regexp operator: Regexp Operators. (line 81) * password file: Passwd Functions. (line 16) * patsplit: String Functions. (line 294) * patterns: Patterns and Actions. @@ -33112,7 +33097,7 @@ Index * plus sign (+), ++ operator: Increment Ops. (line 11) * plus sign (+), += operator <1>: Precedence. (line 95) * plus sign (+), += operator: Assignment Ops. (line 82) -* plus sign (+), regexp operator: Regexp Operators. (line 103) +* plus sign (+), regexp operator: Regexp Operators. (line 104) * pointers to functions: Indirect Calls. (line 6) * portability: Escape Sequences. (line 98) * portability, #! (executable scripts): Executable Scripts. (line 33) @@ -33162,9 +33147,9 @@ Index * POSIX awk, backslashes in string constants: Escape Sequences. (line 116) * POSIX awk, BEGIN/END patterns: I/O And BEGIN/END. (line 16) -* POSIX awk, bracket expressions and: Bracket Expressions. (line 24) +* POSIX awk, bracket expressions and: Bracket Expressions. (line 26) * POSIX awk, bracket expressions and, character classes: Bracket Expressions. - (line 30) + (line 32) * POSIX awk, break statement and: Break Statement. (line 51) * POSIX awk, changes in awk versions: POSIX. (line 6) * POSIX awk, continue statement and: Continue Statement. (line 44) @@ -33178,14 +33163,14 @@ Index * POSIX awk, functions and, gsub()/sub(): Gory Details. (line 90) * POSIX awk, functions and, length(): String Functions. (line 176) * POSIX awk, GNU long options and: Options. (line 15) -* POSIX awk, interval expressions in: Regexp Operators. (line 136) +* POSIX awk, interval expressions in: Regexp Operators. (line 137) * POSIX awk, next/nextfile statements and: Next Statement. (line 45) * POSIX awk, numeric strings and: Variable Typing. (line 6) * POSIX awk, OFMT variable and <1>: Strings And Numbers. (line 57) * POSIX awk, OFMT variable and: OFMT. (line 27) * POSIX awk, period (.), using: Regexp Operators. (line 51) * POSIX awk, printf format strings and: Format Modifiers. (line 159) -* POSIX awk, regular expressions and: Regexp Operators. (line 162) +* POSIX awk, regular expressions and: Regexp Operators. (line 163) * POSIX awk, timestamps and: Time Functions. (line 6) * POSIX awk, | I/O operator and: Getline/Pipe. (line 55) * POSIX mode: Options. (line 254) @@ -33196,7 +33181,7 @@ Index * PREC variable: User-modified. (line 124) * precedence <1>: Precedence. (line 6) * precedence: Increment Ops. (line 60) -* precedence, regexp operators: Regexp Operators. (line 157) +* precedence, regexp operators: Regexp Operators. (line 158) * print debugger command: Viewing And Changing Data. (line 36) * print statement: Printing. (line 16) @@ -33283,7 +33268,7 @@ Index * question mark (?), ?: operator: Precedence. (line 92) * question mark (?), regexp operator <1>: GNU Regexp Operators. (line 59) -* question mark (?), regexp operator: Regexp Operators. (line 112) +* question mark (?), regexp operator: Regexp Operators. (line 113) * QuikTrim Awk: Other Versions. (line 135) * quit debugger command: Miscellaneous Debugger Commands. (line 99) @@ -33383,7 +33368,7 @@ Index * regular expressions, operators, gawk: GNU Regexp Operators. (line 6) * regular expressions, operators, precedence of: Regexp Operators. - (line 157) + (line 158) * regular expressions, searching for: Egrep Program. (line 6) * relational operators, See comparison operators: Typing and Comparison. (line 9) @@ -33593,7 +33578,7 @@ Index * single-step execution, in the debugger: Debugger Execution Control. (line 43) * Skywalker, Luke: Undocumented. (line 6) -* sleep utility: Alarm Program. (line 111) +* sleep utility: Alarm Program. (line 110) * sleep() extension function: Extension Sample Time. (line 22) * Solaris, POSIX-compliant awk: Other Versions. (line 96) @@ -34013,516 +33998,516 @@ Node: Statements/Lines102442 Ref: Statements/Lines-Footnote-1106898 Node: Other Features107163 Node: When108091 -Ref: When-Footnote-1109952 -Node: Intro Summary110017 -Node: Invoking Gawk110783 -Node: Command Line112298 -Node: Options113089 -Ref: Options-Footnote-1128865 -Node: Other Arguments128890 -Node: Naming Standard Input131552 -Node: Environment Variables132645 -Node: AWKPATH Variable133203 -Ref: AWKPATH Variable-Footnote-1136069 -Ref: AWKPATH Variable-Footnote-2136114 -Node: AWKLIBPATH Variable136374 -Node: Other Environment Variables137133 -Node: Exit Status140790 -Node: Include Files141465 -Node: Loading Shared Libraries145043 -Node: Obsolete146427 -Node: Undocumented147124 -Node: Invoking Summary147391 -Node: Regexp148991 -Node: Regexp Usage150441 -Node: Escape Sequences152474 -Node: Regexp Operators158291 -Ref: Regexp Operators-Footnote-1165771 -Ref: Regexp Operators-Footnote-2165918 -Node: Bracket Expressions166016 -Ref: table-char-classes167906 -Node: GNU Regexp Operators170846 -Node: Case-sensitivity174555 -Ref: Case-sensitivity-Footnote-1177447 -Ref: Case-sensitivity-Footnote-2177682 -Node: Leftmost Longest177790 -Node: Computed Regexps178991 -Node: Regexp Summary182363 -Node: Reading Files183832 -Node: Records185924 -Node: awk split records186667 -Node: gawk split records191525 -Ref: gawk split records-Footnote-1196046 -Node: Fields196083 -Ref: Fields-Footnote-1199047 -Node: Nonconstant Fields199133 -Ref: Nonconstant Fields-Footnote-1201363 -Node: Changing Fields201565 -Node: Field Separators207519 -Node: Default Field Splitting210221 -Node: Regexp Field Splitting211338 -Node: Single Character Fields214665 -Node: Command Line Field Separator215724 -Node: Full Line Fields219150 -Ref: Full Line Fields-Footnote-1219658 -Node: Field Splitting Summary219704 -Ref: Field Splitting Summary-Footnote-1222836 -Node: Constant Size222937 -Node: Splitting By Content227543 -Ref: Splitting By Content-Footnote-1231616 -Node: Multiple Line231656 -Ref: Multiple Line-Footnote-1237512 -Node: Getline237691 -Node: Plain Getline239907 -Node: Getline/Variable242002 -Node: Getline/File243149 -Node: Getline/Variable/File244533 -Ref: Getline/Variable/File-Footnote-1246132 -Node: Getline/Pipe246219 -Node: Getline/Variable/Pipe248905 -Node: Getline/Coprocess250012 -Node: Getline/Variable/Coprocess251264 -Node: Getline Notes252001 -Node: Getline Summary254805 -Ref: table-getline-variants255213 -Node: Read Timeout256125 -Ref: Read Timeout-Footnote-1259952 -Node: Command-line directories260010 -Node: Input Summary260914 -Node: Input Exercises264051 -Node: Printing264784 -Node: Print266506 -Node: Print Examples267999 -Node: Output Separators270778 -Node: OFMT272794 -Node: Printf274152 -Node: Basic Printf275058 -Node: Control Letters276597 -Node: Format Modifiers280588 -Node: Printf Examples286615 -Node: Redirection289079 -Node: Special Files296051 -Node: Special FD296584 -Ref: Special FD-Footnote-1300181 -Node: Special Network300255 -Node: Special Caveats301105 -Node: Close Files And Pipes301901 -Ref: Close Files And Pipes-Footnote-1309062 -Ref: Close Files And Pipes-Footnote-2309210 -Node: Output Summary309360 -Node: Output exercises310357 -Node: Expressions311037 -Node: Values312222 -Node: Constants312898 -Node: Scalar Constants313578 -Ref: Scalar Constants-Footnote-1314437 -Node: Nondecimal-numbers314687 -Node: Regexp Constants317687 -Node: Using Constant Regexps318162 -Node: Variables321234 -Node: Using Variables321889 -Node: Assignment Options323613 -Node: Conversion325488 -Node: Strings And Numbers326012 -Ref: Strings And Numbers-Footnote-1329074 -Node: Locale influences conversions329183 -Ref: table-locale-affects331900 -Node: All Operators332488 -Node: Arithmetic Ops333118 -Node: Concatenation335623 -Ref: Concatenation-Footnote-1338442 -Node: Assignment Ops338548 -Ref: table-assign-ops343531 -Node: Increment Ops344834 -Node: Truth Values and Conditions348272 -Node: Truth Values349355 -Node: Typing and Comparison350404 -Node: Variable Typing351197 -Node: Comparison Operators354849 -Ref: table-relational-ops355259 -Node: POSIX String Comparison358809 -Ref: POSIX String Comparison-Footnote-1359893 -Node: Boolean Ops360031 -Ref: Boolean Ops-Footnote-1364101 -Node: Conditional Exp364192 -Node: Function Calls365919 -Node: Precedence369799 -Node: Locales373468 -Node: Expressions Summary375099 -Node: Patterns and Actions377640 -Node: Pattern Overview378756 -Node: Regexp Patterns380433 -Node: Expression Patterns380976 -Node: Ranges384757 -Node: BEGIN/END387863 -Node: Using BEGIN/END388625 -Ref: Using BEGIN/END-Footnote-1391361 -Node: I/O And BEGIN/END391467 -Node: BEGINFILE/ENDFILE393738 -Node: Empty396669 -Node: Using Shell Variables396986 -Node: Action Overview399269 -Node: Statements401596 -Node: If Statement403444 -Node: While Statement404942 -Node: Do Statement406986 -Node: For Statement408142 -Node: Switch Statement411294 -Node: Break Statement413682 -Node: Continue Statement415723 -Node: Next Statement417548 -Node: Nextfile Statement419938 -Node: Exit Statement422574 -Node: Built-in Variables424978 -Node: User-modified426105 -Ref: User-modified-Footnote-1433794 -Node: Auto-set433856 -Ref: Auto-set-Footnote-1446438 -Ref: Auto-set-Footnote-2446643 -Node: ARGC and ARGV446699 -Node: Pattern Action Summary450603 -Node: Arrays452826 -Node: Array Basics454375 -Node: Array Intro455201 -Ref: figure-array-elements457174 -Node: Reference to Elements459581 -Node: Assigning Elements461960 -Node: Array Example462451 -Node: Scanning an Array464183 -Node: Controlling Scanning467184 -Ref: Controlling Scanning-Footnote-1472357 -Node: Delete472673 -Ref: Delete-Footnote-1475424 -Node: Numeric Array Subscripts475481 -Node: Uninitialized Subscripts477664 -Node: Multidimensional479289 -Node: Multiscanning482402 -Node: Arrays of Arrays483991 -Node: Arrays Summary488654 -Node: Functions490759 -Node: Built-in491632 -Node: Calling Built-in492710 -Node: Numeric Functions494698 -Ref: Numeric Functions-Footnote-1498732 -Ref: Numeric Functions-Footnote-2499089 -Ref: Numeric Functions-Footnote-3499137 -Node: String Functions499406 -Ref: String Functions-Footnote-1522403 -Ref: String Functions-Footnote-2522532 -Ref: String Functions-Footnote-3522780 -Node: Gory Details522867 -Ref: table-sub-escapes524640 -Ref: table-sub-proposed526160 -Ref: table-posix-sub527524 -Ref: table-gensub-escapes529064 -Ref: Gory Details-Footnote-1530240 -Node: I/O Functions530391 -Ref: I/O Functions-Footnote-1537501 -Node: Time Functions537648 -Ref: Time Functions-Footnote-1548112 -Ref: Time Functions-Footnote-2548180 -Ref: Time Functions-Footnote-3548338 -Ref: Time Functions-Footnote-4548449 -Ref: Time Functions-Footnote-5548561 -Ref: Time Functions-Footnote-6548788 -Node: Bitwise Functions549054 -Ref: table-bitwise-ops549616 -Ref: Bitwise Functions-Footnote-1553861 -Node: Type Functions554045 -Node: I18N Functions555187 -Node: User-defined556832 -Node: Definition Syntax557636 -Ref: Definition Syntax-Footnote-1562815 -Node: Function Example562884 -Ref: Function Example-Footnote-1565524 -Node: Function Caveats565546 -Node: Calling A Function566064 -Node: Variable Scope567019 -Node: Pass By Value/Reference570007 -Node: Return Statement573517 -Node: Dynamic Typing576501 -Node: Indirect Calls577430 -Node: Functions Summary587143 -Node: Library Functions589682 -Ref: Library Functions-Footnote-1593300 -Ref: Library Functions-Footnote-2593443 -Node: Library Names593614 -Ref: Library Names-Footnote-1597087 -Ref: Library Names-Footnote-2597307 -Node: General Functions597393 -Node: Strtonum Function598421 -Node: Assert Function601201 -Node: Round Function604527 -Node: Cliff Random Function606068 -Node: Ordinal Functions607084 -Ref: Ordinal Functions-Footnote-1610161 -Ref: Ordinal Functions-Footnote-2610413 -Node: Join Function610624 -Ref: Join Function-Footnote-1612395 -Node: Getlocaltime Function612595 -Node: Readfile Function616331 -Node: Data File Management618170 -Node: Filetrans Function618802 -Node: Rewind Function622871 -Node: File Checking624429 -Ref: File Checking-Footnote-1625561 -Node: Empty Files625762 -Node: Ignoring Assigns627741 -Node: Getopt Function629295 -Ref: Getopt Function-Footnote-1640598 -Node: Passwd Functions640801 -Ref: Passwd Functions-Footnote-1649780 -Node: Group Functions649868 -Ref: Group Functions-Footnote-1657809 -Node: Walking Arrays658022 -Node: Library Functions Summary659625 -Node: Library exercises661013 -Node: Sample Programs662293 -Node: Running Examples663063 -Node: Clones663791 -Node: Cut Program665015 -Node: Egrep Program674883 -Ref: Egrep Program-Footnote-1682854 -Node: Id Program682964 -Node: Split Program686628 -Ref: Split Program-Footnote-1690166 -Node: Tee Program690294 -Node: Uniq Program693101 -Node: Wc Program700531 -Ref: Wc Program-Footnote-1704796 -Node: Miscellaneous Programs704888 -Node: Dupword Program706101 -Node: Alarm Program708132 -Node: Translate Program712946 -Ref: Translate Program-Footnote-1717337 -Ref: Translate Program-Footnote-2717607 -Node: Labels Program717741 -Ref: Labels Program-Footnote-1721112 -Node: Word Sorting721196 -Node: History Sorting725239 -Node: Extract Program727075 -Node: Simple Sed734611 -Node: Igawk Program737673 -Ref: Igawk Program-Footnote-1751977 -Ref: Igawk Program-Footnote-2752178 -Node: Anagram Program752316 -Node: Signature Program755384 -Node: Programs Summary756631 -Node: Programs Exercises757846 -Node: Advanced Features761497 -Node: Nondecimal Data763445 -Node: Array Sorting765022 -Node: Controlling Array Traversal765719 -Node: Array Sorting Functions773999 -Ref: Array Sorting Functions-Footnote-1777906 -Node: Two-way I/O778100 -Ref: Two-way I/O-Footnote-1783044 -Ref: Two-way I/O-Footnote-2783223 -Node: TCP/IP Networking783305 -Node: Profiling786150 -Node: Advanced Features Summary793692 -Node: Internationalization795556 -Node: I18N and L10N797036 -Node: Explaining gettext797722 -Ref: Explaining gettext-Footnote-1802748 -Ref: Explaining gettext-Footnote-2802932 -Node: Programmer i18n803097 -Ref: Programmer i18n-Footnote-1807891 -Node: Translator i18n807940 -Node: String Extraction808734 -Ref: String Extraction-Footnote-1809867 -Node: Printf Ordering809953 -Ref: Printf Ordering-Footnote-1812735 -Node: I18N Portability812799 -Ref: I18N Portability-Footnote-1815248 -Node: I18N Example815311 -Ref: I18N Example-Footnote-1818017 -Node: Gawk I18N818089 -Node: I18N Summary818727 -Node: Debugger820066 -Node: Debugging821088 -Node: Debugging Concepts821529 -Node: Debugging Terms823385 -Node: Awk Debugging825982 -Node: Sample Debugging Session826874 -Node: Debugger Invocation827394 -Node: Finding The Bug828727 -Node: List of Debugger Commands835209 -Node: Breakpoint Control836541 -Node: Debugger Execution Control840205 -Node: Viewing And Changing Data843565 -Node: Execution Stack846923 -Node: Debugger Info848436 -Node: Miscellaneous Debugger Commands852430 -Node: Readline Support857614 -Node: Limitations858506 -Node: Debugging Summary860780 -Node: Arbitrary Precision Arithmetic861948 -Node: Computer Arithmetic863435 -Ref: Computer Arithmetic-Footnote-1867822 -Node: Math Definitions867879 -Ref: table-ieee-formats871168 -Ref: Math Definitions-Footnote-1871708 -Node: MPFR features871811 -Node: FP Math Caution873428 -Ref: FP Math Caution-Footnote-1874478 -Node: Inexactness of computations874847 -Node: Inexact representation875795 -Node: Comparing FP Values877150 -Node: Errors accumulate878114 -Node: Getting Accuracy879547 -Node: Try To Round882206 -Node: Setting precision883105 -Ref: table-predefined-precision-strings883787 -Node: Setting the rounding mode885580 -Ref: table-gawk-rounding-modes885944 -Ref: Setting the rounding mode-Footnote-1889398 -Node: Arbitrary Precision Integers889577 -Ref: Arbitrary Precision Integers-Footnote-1892558 -Node: POSIX Floating Point Problems892707 -Ref: POSIX Floating Point Problems-Footnote-1896583 -Node: Floating point summary896621 -Node: Dynamic Extensions898825 -Node: Extension Intro900377 -Node: Plugin License901642 -Node: Extension Mechanism Outline902327 -Ref: figure-load-extension902751 -Ref: figure-load-new-function904236 -Ref: figure-call-new-function905238 -Node: Extension API Description907222 -Node: Extension API Functions Introduction908672 -Node: General Data Types913539 -Ref: General Data Types-Footnote-1919232 -Node: Requesting Values919531 -Ref: table-value-types-returned920268 -Node: Memory Allocation Functions921226 -Ref: Memory Allocation Functions-Footnote-1923973 -Node: Constructor Functions924069 -Node: Registration Functions925827 -Node: Extension Functions926512 -Node: Exit Callback Functions928814 -Node: Extension Version String930062 -Node: Input Parsers930712 -Node: Output Wrappers940526 -Node: Two-way processors945042 -Node: Printing Messages947246 -Ref: Printing Messages-Footnote-1948323 -Node: Updating `ERRNO'948475 -Node: Accessing Parameters949214 -Node: Symbol Table Access950444 -Node: Symbol table by name950958 -Node: Symbol table by cookie952934 -Ref: Symbol table by cookie-Footnote-1957067 -Node: Cached values957130 -Ref: Cached values-Footnote-1960634 -Node: Array Manipulation960725 -Ref: Array Manipulation-Footnote-1961823 -Node: Array Data Types961862 -Ref: Array Data Types-Footnote-1964565 -Node: Array Functions964657 -Node: Flattening Arrays968531 -Node: Creating Arrays975383 -Node: Extension API Variables980114 -Node: Extension Versioning980750 -Node: Extension API Informational Variables982651 -Node: Extension API Boilerplate983737 -Node: Finding Extensions987541 -Node: Extension Example988101 -Node: Internal File Description988831 -Node: Internal File Ops992922 -Ref: Internal File Ops-Footnote-11004354 -Node: Using Internal File Ops1004494 -Ref: Using Internal File Ops-Footnote-11006841 -Node: Extension Samples1007109 -Node: Extension Sample File Functions1008633 -Node: Extension Sample Fnmatch1016201 -Node: Extension Sample Fork1017683 -Node: Extension Sample Inplace1018896 -Node: Extension Sample Ord1020571 -Node: Extension Sample Readdir1021407 -Ref: table-readdir-file-types1022263 -Node: Extension Sample Revout1023062 -Node: Extension Sample Rev2way1023653 -Node: Extension Sample Read write array1024394 -Node: Extension Sample Readfile1026273 -Node: Extension Sample API Tests1027373 -Node: Extension Sample Time1027898 -Node: gawkextlib1029213 -Node: Extension summary1032026 -Node: Extension Exercises1035719 -Node: Language History1036441 -Node: V7/SVR3.11038084 -Node: SVR41040404 -Node: POSIX1041846 -Node: BTL1043232 -Node: POSIX/GNU1043966 -Node: Feature History1049682 -Node: Common Extensions1062773 -Node: Ranges and Locales1064085 -Ref: Ranges and Locales-Footnote-11068702 -Ref: Ranges and Locales-Footnote-21068729 -Ref: Ranges and Locales-Footnote-31068963 -Node: Contributors1069184 -Node: History summary1074609 -Node: Installation1075978 -Node: Gawk Distribution1076929 -Node: Getting1077413 -Node: Extracting1078237 -Node: Distribution contents1079879 -Node: Unix Installation1085596 -Node: Quick Installation1086213 -Node: Additional Configuration Options1088655 -Node: Configuration Philosophy1090393 -Node: Non-Unix Installation1092744 -Node: PC Installation1093202 -Node: PC Binary Installation1094513 -Node: PC Compiling1096361 -Ref: PC Compiling-Footnote-11099360 -Node: PC Testing1099465 -Node: PC Using1100641 -Node: Cygwin1104793 -Node: MSYS1105602 -Node: VMS Installation1106116 -Node: VMS Compilation1106912 -Ref: VMS Compilation-Footnote-11108134 -Node: VMS Dynamic Extensions1108192 -Node: VMS Installation Details1109565 -Node: VMS Running1111817 -Node: VMS GNV1114651 -Node: VMS Old Gawk1115374 -Node: Bugs1115844 -Node: Other Versions1119848 -Node: Installation summary1126075 -Node: Notes1127131 -Node: Compatibility Mode1127996 -Node: Additions1128778 -Node: Accessing The Source1129703 -Node: Adding Code1131139 -Node: New Ports1137317 -Node: Derived Files1141798 -Ref: Derived Files-Footnote-11146879 -Ref: Derived Files-Footnote-21146913 -Ref: Derived Files-Footnote-31147509 -Node: Future Extensions1147623 -Node: Implementation Limitations1148229 -Node: Extension Design1149477 -Node: Old Extension Problems1150631 -Ref: Old Extension Problems-Footnote-11152148 -Node: Extension New Mechanism Goals1152205 -Ref: Extension New Mechanism Goals-Footnote-11155565 -Node: Extension Other Design Decisions1155754 -Node: Extension Future Growth1157860 -Node: Old Extension Mechanism1158696 -Node: Notes summary1160458 -Node: Basic Concepts1161644 -Node: Basic High Level1162325 -Ref: figure-general-flow1162597 -Ref: figure-process-flow1163196 -Ref: Basic High Level-Footnote-11166425 -Node: Basic Data Typing1166610 -Node: Glossary1169938 -Node: Copying1195090 -Node: GNU Free Documentation License1232646 -Node: Index1257782 +Ref: When-Footnote-1109847 +Node: Intro Summary109912 +Node: Invoking Gawk110795 +Node: Command Line112310 +Node: Options113101 +Ref: Options-Footnote-1128877 +Node: Other Arguments128902 +Node: Naming Standard Input131564 +Node: Environment Variables132657 +Node: AWKPATH Variable133215 +Ref: AWKPATH Variable-Footnote-1136081 +Ref: AWKPATH Variable-Footnote-2136126 +Node: AWKLIBPATH Variable136386 +Node: Other Environment Variables137145 +Node: Exit Status140802 +Node: Include Files141477 +Node: Loading Shared Libraries145055 +Node: Obsolete146439 +Node: Undocumented147136 +Node: Invoking Summary147403 +Node: Regexp149003 +Node: Regexp Usage150462 +Node: Escape Sequences152495 +Node: Regexp Operators158312 +Ref: Regexp Operators-Footnote-1165830 +Ref: Regexp Operators-Footnote-2165977 +Node: Bracket Expressions166075 +Ref: table-char-classes168097 +Node: GNU Regexp Operators171037 +Node: Case-sensitivity174746 +Ref: Case-sensitivity-Footnote-1177638 +Ref: Case-sensitivity-Footnote-2177873 +Node: Leftmost Longest177981 +Node: Computed Regexps179182 +Node: Regexp Summary182554 +Node: Reading Files184023 +Node: Records186115 +Node: awk split records186837 +Node: gawk split records191695 +Ref: gawk split records-Footnote-1196216 +Node: Fields196253 +Ref: Fields-Footnote-1199217 +Node: Nonconstant Fields199303 +Ref: Nonconstant Fields-Footnote-1201533 +Node: Changing Fields201735 +Node: Field Separators207689 +Node: Default Field Splitting210391 +Node: Regexp Field Splitting211508 +Node: Single Character Fields214835 +Node: Command Line Field Separator215894 +Node: Full Line Fields219320 +Ref: Full Line Fields-Footnote-1219828 +Node: Field Splitting Summary219874 +Ref: Field Splitting Summary-Footnote-1223006 +Node: Constant Size223107 +Node: Splitting By Content227713 +Ref: Splitting By Content-Footnote-1231786 +Node: Multiple Line231826 +Ref: Multiple Line-Footnote-1237682 +Node: Getline237861 +Node: Plain Getline240072 +Node: Getline/Variable242167 +Node: Getline/File243314 +Node: Getline/Variable/File244698 +Ref: Getline/Variable/File-Footnote-1246297 +Node: Getline/Pipe246384 +Node: Getline/Variable/Pipe249070 +Node: Getline/Coprocess250177 +Node: Getline/Variable/Coprocess251429 +Node: Getline Notes252166 +Node: Getline Summary254970 +Ref: table-getline-variants255378 +Node: Read Timeout256290 +Ref: Read Timeout-Footnote-1260117 +Node: Command-line directories260175 +Node: Input Summary261079 +Node: Input Exercises264216 +Node: Printing264949 +Node: Print266671 +Node: Print Examples268164 +Node: Output Separators270943 +Node: OFMT272959 +Node: Printf274317 +Node: Basic Printf275223 +Node: Control Letters276762 +Node: Format Modifiers280753 +Node: Printf Examples286780 +Node: Redirection289244 +Node: Special Files296216 +Node: Special FD296749 +Ref: Special FD-Footnote-1300346 +Node: Special Network300420 +Node: Special Caveats301270 +Node: Close Files And Pipes302066 +Ref: Close Files And Pipes-Footnote-1309227 +Ref: Close Files And Pipes-Footnote-2309375 +Node: Output Summary309525 +Node: Output exercises310522 +Node: Expressions311202 +Node: Values312387 +Node: Constants313063 +Node: Scalar Constants313743 +Ref: Scalar Constants-Footnote-1314602 +Node: Nondecimal-numbers314852 +Node: Regexp Constants317852 +Node: Using Constant Regexps318327 +Node: Variables321399 +Node: Using Variables322054 +Node: Assignment Options323778 +Node: Conversion325653 +Node: Strings And Numbers326177 +Ref: Strings And Numbers-Footnote-1329239 +Node: Locale influences conversions329348 +Ref: table-locale-affects332065 +Node: All Operators332653 +Node: Arithmetic Ops333283 +Node: Concatenation335788 +Ref: Concatenation-Footnote-1338607 +Node: Assignment Ops338713 +Ref: table-assign-ops343696 +Node: Increment Ops344999 +Node: Truth Values and Conditions348437 +Node: Truth Values349520 +Node: Typing and Comparison350569 +Node: Variable Typing351362 +Node: Comparison Operators355014 +Ref: table-relational-ops355424 +Node: POSIX String Comparison358974 +Ref: POSIX String Comparison-Footnote-1360058 +Node: Boolean Ops360196 +Ref: Boolean Ops-Footnote-1364271 +Node: Conditional Exp364362 +Node: Function Calls366089 +Node: Precedence369969 +Node: Locales373638 +Node: Expressions Summary375269 +Node: Patterns and Actions377810 +Node: Pattern Overview378926 +Node: Regexp Patterns380603 +Node: Expression Patterns381146 +Node: Ranges384926 +Node: BEGIN/END388032 +Node: Using BEGIN/END388794 +Ref: Using BEGIN/END-Footnote-1391530 +Node: I/O And BEGIN/END391636 +Node: BEGINFILE/ENDFILE393907 +Node: Empty396838 +Node: Using Shell Variables397155 +Node: Action Overview399438 +Node: Statements401765 +Node: If Statement403613 +Node: While Statement405111 +Node: Do Statement407155 +Node: For Statement408311 +Node: Switch Statement411463 +Node: Break Statement413851 +Node: Continue Statement415892 +Node: Next Statement417717 +Node: Nextfile Statement420107 +Node: Exit Statement422743 +Node: Built-in Variables425147 +Node: User-modified426274 +Ref: User-modified-Footnote-1433963 +Node: Auto-set434025 +Ref: Auto-set-Footnote-1446607 +Ref: Auto-set-Footnote-2446812 +Node: ARGC and ARGV446868 +Node: Pattern Action Summary450772 +Node: Arrays452995 +Node: Array Basics454544 +Node: Array Intro455370 +Ref: figure-array-elements457343 +Node: Reference to Elements459750 +Node: Assigning Elements462200 +Node: Array Example462691 +Node: Scanning an Array464423 +Node: Controlling Scanning467424 +Ref: Controlling Scanning-Footnote-1472597 +Node: Delete472913 +Ref: Delete-Footnote-1475664 +Node: Numeric Array Subscripts475721 +Node: Uninitialized Subscripts477904 +Node: Multidimensional479529 +Node: Multiscanning482642 +Node: Arrays of Arrays484231 +Node: Arrays Summary488894 +Node: Functions490999 +Node: Built-in491872 +Node: Calling Built-in492950 +Node: Numeric Functions494938 +Ref: Numeric Functions-Footnote-1498972 +Ref: Numeric Functions-Footnote-2499329 +Ref: Numeric Functions-Footnote-3499377 +Node: String Functions499646 +Ref: String Functions-Footnote-1522643 +Ref: String Functions-Footnote-2522772 +Ref: String Functions-Footnote-3523020 +Node: Gory Details523107 +Ref: table-sub-escapes524880 +Ref: table-sub-proposed526400 +Ref: table-posix-sub527764 +Ref: table-gensub-escapes529304 +Ref: Gory Details-Footnote-1530480 +Node: I/O Functions530631 +Ref: I/O Functions-Footnote-1537741 +Node: Time Functions537888 +Ref: Time Functions-Footnote-1548352 +Ref: Time Functions-Footnote-2548420 +Ref: Time Functions-Footnote-3548578 +Ref: Time Functions-Footnote-4548689 +Ref: Time Functions-Footnote-5548801 +Ref: Time Functions-Footnote-6549028 +Node: Bitwise Functions549294 +Ref: table-bitwise-ops549856 +Ref: Bitwise Functions-Footnote-1554101 +Node: Type Functions554285 +Node: I18N Functions555427 +Node: User-defined557072 +Node: Definition Syntax557876 +Ref: Definition Syntax-Footnote-1563055 +Node: Function Example563124 +Ref: Function Example-Footnote-1565764 +Node: Function Caveats565786 +Node: Calling A Function566304 +Node: Variable Scope567259 +Node: Pass By Value/Reference570247 +Node: Return Statement573757 +Node: Dynamic Typing576741 +Node: Indirect Calls577670 +Node: Functions Summary587383 +Node: Library Functions589922 +Ref: Library Functions-Footnote-1593540 +Ref: Library Functions-Footnote-2593683 +Node: Library Names593854 +Ref: Library Names-Footnote-1597327 +Ref: Library Names-Footnote-2597547 +Node: General Functions597633 +Node: Strtonum Function598661 +Node: Assert Function601441 +Node: Round Function604767 +Node: Cliff Random Function606308 +Node: Ordinal Functions607324 +Ref: Ordinal Functions-Footnote-1610389 +Ref: Ordinal Functions-Footnote-2610641 +Node: Join Function610852 +Ref: Join Function-Footnote-1612623 +Node: Getlocaltime Function612823 +Node: Readfile Function616559 +Node: Data File Management618398 +Node: Filetrans Function619030 +Node: Rewind Function623099 +Node: File Checking624657 +Ref: File Checking-Footnote-1625789 +Node: Empty Files625990 +Node: Ignoring Assigns627969 +Node: Getopt Function629523 +Ref: Getopt Function-Footnote-1640826 +Node: Passwd Functions641029 +Ref: Passwd Functions-Footnote-1650008 +Node: Group Functions650096 +Ref: Group Functions-Footnote-1658027 +Node: Walking Arrays658240 +Node: Library Functions Summary659843 +Node: Library exercises661231 +Node: Sample Programs662511 +Node: Running Examples663281 +Node: Clones664009 +Node: Cut Program665233 +Node: Egrep Program675091 +Ref: Egrep Program-Footnote-1682678 +Node: Id Program682788 +Node: Split Program686442 +Ref: Split Program-Footnote-1689980 +Node: Tee Program690108 +Node: Uniq Program692895 +Node: Wc Program700316 +Ref: Wc Program-Footnote-1704581 +Node: Miscellaneous Programs704673 +Node: Dupword Program705886 +Node: Alarm Program707917 +Node: Translate Program712721 +Ref: Translate Program-Footnote-1717112 +Ref: Translate Program-Footnote-2717382 +Node: Labels Program717516 +Ref: Labels Program-Footnote-1720877 +Node: Word Sorting720961 +Node: History Sorting725004 +Node: Extract Program726840 +Node: Simple Sed734376 +Node: Igawk Program737438 +Ref: Igawk Program-Footnote-1751742 +Ref: Igawk Program-Footnote-2751943 +Node: Anagram Program752081 +Node: Signature Program755149 +Node: Programs Summary756396 +Node: Programs Exercises757611 +Node: Advanced Features761262 +Node: Nondecimal Data763210 +Node: Array Sorting764787 +Node: Controlling Array Traversal765484 +Node: Array Sorting Functions773764 +Ref: Array Sorting Functions-Footnote-1777671 +Node: Two-way I/O777865 +Ref: Two-way I/O-Footnote-1782809 +Ref: Two-way I/O-Footnote-2782988 +Node: TCP/IP Networking783070 +Node: Profiling785915 +Node: Advanced Features Summary793457 +Node: Internationalization795321 +Node: I18N and L10N796801 +Node: Explaining gettext797487 +Ref: Explaining gettext-Footnote-1802513 +Ref: Explaining gettext-Footnote-2802697 +Node: Programmer i18n802862 +Ref: Programmer i18n-Footnote-1807656 +Node: Translator i18n807705 +Node: String Extraction808499 +Ref: String Extraction-Footnote-1809632 +Node: Printf Ordering809718 +Ref: Printf Ordering-Footnote-1812500 +Node: I18N Portability812564 +Ref: I18N Portability-Footnote-1815013 +Node: I18N Example815076 +Ref: I18N Example-Footnote-1817782 +Node: Gawk I18N817854 +Node: I18N Summary818492 +Node: Debugger819831 +Node: Debugging820853 +Node: Debugging Concepts821294 +Node: Debugging Terms823150 +Node: Awk Debugging825747 +Node: Sample Debugging Session826639 +Node: Debugger Invocation827159 +Node: Finding The Bug828492 +Node: List of Debugger Commands834974 +Node: Breakpoint Control836306 +Node: Debugger Execution Control839970 +Node: Viewing And Changing Data843330 +Node: Execution Stack846688 +Node: Debugger Info848201 +Node: Miscellaneous Debugger Commands852195 +Node: Readline Support857379 +Node: Limitations858271 +Node: Debugging Summary860545 +Node: Arbitrary Precision Arithmetic861713 +Node: Computer Arithmetic863200 +Ref: Computer Arithmetic-Footnote-1867587 +Node: Math Definitions867644 +Ref: table-ieee-formats870933 +Ref: Math Definitions-Footnote-1871473 +Node: MPFR features871576 +Node: FP Math Caution873193 +Ref: FP Math Caution-Footnote-1874243 +Node: Inexactness of computations874612 +Node: Inexact representation875560 +Node: Comparing FP Values876915 +Node: Errors accumulate877879 +Node: Getting Accuracy879312 +Node: Try To Round881971 +Node: Setting precision882870 +Ref: table-predefined-precision-strings883552 +Node: Setting the rounding mode885345 +Ref: table-gawk-rounding-modes885709 +Ref: Setting the rounding mode-Footnote-1889163 +Node: Arbitrary Precision Integers889342 +Ref: Arbitrary Precision Integers-Footnote-1892323 +Node: POSIX Floating Point Problems892472 +Ref: POSIX Floating Point Problems-Footnote-1896348 +Node: Floating point summary896386 +Node: Dynamic Extensions898590 +Node: Extension Intro900142 +Node: Plugin License901407 +Node: Extension Mechanism Outline902092 +Ref: figure-load-extension902516 +Ref: figure-load-new-function904001 +Ref: figure-call-new-function905003 +Node: Extension API Description906987 +Node: Extension API Functions Introduction908437 +Node: General Data Types913304 +Ref: General Data Types-Footnote-1918997 +Node: Requesting Values919296 +Ref: table-value-types-returned920033 +Node: Memory Allocation Functions920991 +Ref: Memory Allocation Functions-Footnote-1923738 +Node: Constructor Functions923834 +Node: Registration Functions925592 +Node: Extension Functions926277 +Node: Exit Callback Functions928579 +Node: Extension Version String929827 +Node: Input Parsers930477 +Node: Output Wrappers940291 +Node: Two-way processors944807 +Node: Printing Messages947011 +Ref: Printing Messages-Footnote-1948088 +Node: Updating `ERRNO'948240 +Node: Accessing Parameters948979 +Node: Symbol Table Access950209 +Node: Symbol table by name950723 +Node: Symbol table by cookie952699 +Ref: Symbol table by cookie-Footnote-1956832 +Node: Cached values956895 +Ref: Cached values-Footnote-1960399 +Node: Array Manipulation960490 +Ref: Array Manipulation-Footnote-1961588 +Node: Array Data Types961627 +Ref: Array Data Types-Footnote-1964330 +Node: Array Functions964422 +Node: Flattening Arrays968296 +Node: Creating Arrays975148 +Node: Extension API Variables979879 +Node: Extension Versioning980515 +Node: Extension API Informational Variables982416 +Node: Extension API Boilerplate983502 +Node: Finding Extensions987306 +Node: Extension Example987866 +Node: Internal File Description988596 +Node: Internal File Ops992687 +Ref: Internal File Ops-Footnote-11004119 +Node: Using Internal File Ops1004259 +Ref: Using Internal File Ops-Footnote-11006606 +Node: Extension Samples1006874 +Node: Extension Sample File Functions1008398 +Node: Extension Sample Fnmatch1015966 +Node: Extension Sample Fork1017448 +Node: Extension Sample Inplace1018661 +Node: Extension Sample Ord1020336 +Node: Extension Sample Readdir1021172 +Ref: table-readdir-file-types1022028 +Node: Extension Sample Revout1022827 +Node: Extension Sample Rev2way1023418 +Node: Extension Sample Read write array1024159 +Node: Extension Sample Readfile1026038 +Node: Extension Sample API Tests1027138 +Node: Extension Sample Time1027663 +Node: gawkextlib1028978 +Node: Extension summary1031791 +Node: Extension Exercises1035484 +Node: Language History1036206 +Node: V7/SVR3.11037849 +Node: SVR41040169 +Node: POSIX1041611 +Node: BTL1042997 +Node: POSIX/GNU1043731 +Node: Feature History1049447 +Node: Common Extensions1062538 +Node: Ranges and Locales1063850 +Ref: Ranges and Locales-Footnote-11068467 +Ref: Ranges and Locales-Footnote-21068494 +Ref: Ranges and Locales-Footnote-31068728 +Node: Contributors1068949 +Node: History summary1074374 +Node: Installation1075743 +Node: Gawk Distribution1076694 +Node: Getting1077178 +Node: Extracting1078002 +Node: Distribution contents1079644 +Node: Unix Installation1085361 +Node: Quick Installation1085978 +Node: Additional Configuration Options1088420 +Node: Configuration Philosophy1090158 +Node: Non-Unix Installation1092509 +Node: PC Installation1092967 +Node: PC Binary Installation1094278 +Node: PC Compiling1096126 +Ref: PC Compiling-Footnote-11099125 +Node: PC Testing1099230 +Node: PC Using1100406 +Node: Cygwin1104558 +Node: MSYS1105367 +Node: VMS Installation1105881 +Node: VMS Compilation1106677 +Ref: VMS Compilation-Footnote-11107899 +Node: VMS Dynamic Extensions1107957 +Node: VMS Installation Details1109330 +Node: VMS Running1111582 +Node: VMS GNV1114416 +Node: VMS Old Gawk1115139 +Node: Bugs1115609 +Node: Other Versions1119613 +Node: Installation summary1125840 +Node: Notes1126896 +Node: Compatibility Mode1127761 +Node: Additions1128543 +Node: Accessing The Source1129468 +Node: Adding Code1130904 +Node: New Ports1137082 +Node: Derived Files1141563 +Ref: Derived Files-Footnote-11146644 +Ref: Derived Files-Footnote-21146678 +Ref: Derived Files-Footnote-31147274 +Node: Future Extensions1147388 +Node: Implementation Limitations1147994 +Node: Extension Design1149242 +Node: Old Extension Problems1150396 +Ref: Old Extension Problems-Footnote-11151913 +Node: Extension New Mechanism Goals1151970 +Ref: Extension New Mechanism Goals-Footnote-11155330 +Node: Extension Other Design Decisions1155519 +Node: Extension Future Growth1157625 +Node: Old Extension Mechanism1158461 +Node: Notes summary1160223 +Node: Basic Concepts1161409 +Node: Basic High Level1162090 +Ref: figure-general-flow1162362 +Ref: figure-process-flow1162961 +Ref: Basic High Level-Footnote-11166190 +Node: Basic Data Typing1166375 +Node: Glossary1169703 +Node: Copying1194855 +Node: GNU Free Documentation License1232411 +Node: Index1257547  End Tag Table -- cgit v1.2.3 From cd3f4b04ef1a3a0027e72ed6d7af2fcab5ca64df Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sun, 24 Aug 2014 22:16:12 +0300 Subject: More reviewer comments. This is getting harder. --- doc/gawk.info | 1276 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 644 insertions(+), 632 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 9e4f3ec7..caf36e31 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -905,23 +905,19 @@ A Rose by Any Other Name The `awk' language has evolved over the years. Full details are provided in *note Language History::. The language described in this -Info file is often referred to as "new `awk'" (`nawk'). +Info file is often referred to as "new `awk'". By analogy, the +original version of `awk' is referred to as "old `awk'." - For some time after new `awk' was introduced, there were systems -with multiple versions of `awk'. Some systems had an `awk' utility -that implemented the original version of the `awk' language and a -`nawk' utility for the new version. Others had an `oawk' version for -the "old `awk'" language and plain `awk' for the new one. Still others -only had one version, which is usually the new one. + Today, on most systems, when you run the `awk' utility, you get some +version of new `awk'.(1) If your system's standard `awk' is the old +one, you will see something like this if you try the test program: - Today, only Solaris systems still use an old `awk' for the default -`awk' utility. (A more modern `awk' lives in `/usr/xpg6/bin' on these -systems.) All other modern systems use some version of new `awk'.(1) + $ awk 1 /dev/null + error--> awk: syntax error near line 1 + error--> awk: bailing out near line 1 - It is likely that you already have some version of new `awk' on your -system, which is what you should use when running your programs. (Of -course, if you're reading this Info file, chances are good that you -have `gawk'!) +In this case, you should find a version of new `awk', or just install +`gawk'! Throughout this Info file, whenever we refer to a language feature that should be available in any complete implementation of POSIX `awk', @@ -930,7 +926,9 @@ specific to the GNU implementation, we use the term `gawk'. ---------- Footnotes ---------- - (1) Many of these systems use `gawk' for their `awk' implementation! + (1) Only Solaris systems still use an old `awk' for the default +`awk' utility. A more modern `awk' lives in `/usr/xpg6/bin' on these +systems.  File: gawk.info, Node: This Manual, Next: Conventions, Prev: Names, Up: Preface @@ -1548,8 +1546,8 @@ like this: BEGIN { print "Don't Panic!" } After making this file executable (with the `chmod' utility), simply -type `advice' at the shell and the system arranges to run `awk'(2) as -if you had typed `awk -f advice': +type `advice' at the shell and the system arranges to run `awk' as if +you had typed `awk -f advice': $ chmod +x advice $ advice @@ -1563,7 +1561,24 @@ at the shell.) program that users can invoke without their having to know that the program is written in `awk'. - Portability Issues with `#!' + Understanding `#!' + + `awk' is an "interpreted" language. This means that the `awk' +utility reads your program and then processes your data according to +the instructions in your program. (This is different from a "compiled" +language such as C, where your program is first compiled into machine +code that is executed directly by your system's hardware.) The `awk' +utility is thus termed an "interpreter". Many modern languages are +interperted. + + The line beginning with `#!' lists the full file name of an +interpreter to run and a single optional initial command-line argument +to pass to that interpreter. The operating system then runs the +interpreter with the given argument and the full argument list of the +executed program. The first argument in the list is the full file name +of the `awk' program. The rest of the argument list contains either +options to `awk', or data files, or both. Note that on many systems +`awk' may be found in `/usr/bin' instead of in `/bin'. Caveat Emptor. Some systems limit the length of the interpreter name to 32 characters. Often, this can be dealt with by using a symbolic link. @@ -1585,15 +1600,6 @@ the name of your script (`advice'). (d.c.) Don't rely on the value of (1) The `#!' mechanism works on GNU/Linux systems, BSD-based systems and commercial Unix systems. - (2) The line beginning with `#!' lists the full file name of an -interpreter to run and a single optional initial command-line argument -to pass to that interpreter. The operating system then runs the -interpreter with the given argument and the full argument list of the -executed program. The first argument in the list is the full file name -of the `awk' program. The rest of the argument list contains either -options to `awk', or data files, or both. Note that on many systems -`awk' may be found in `/usr/bin' instead of in `/bin'. Caveat Emptor. -  File: gawk.info, Node: Comments, Next: Quoting, Prev: Executable Scripts, Up: Running gawk @@ -1838,7 +1844,8 @@ shipments during the year. Each record contains the month, the number of green crates shipped, the number of red boxes shipped, the number of orange bags shipped, and the number of blue packages shipped, respectively. There are 16 entries, covering the 12 months of last year -and the first four months of the current year. +and the first four months of the current year. An empty line separates +the data for the two years. Jan 13 25 15 115 Feb 15 32 24 226 @@ -1918,11 +1925,6 @@ often more than one way to do things in `awk'. At some point, you may want to look back at these examples and see if you can come up with different ways to do the same things shown here: - * Print the length of the longest input line: - - awk '{ if (length($0) > max) max = length($0) } - END { print max }' data - * Print every line that is longer than 80 characters: awk 'length($0) > 80' data @@ -1930,15 +1932,20 @@ different ways to do the same things shown here: The sole rule has a relational expression as its pattern and it has no action--so it uses the default action, printing the record. + * Print the length of the longest input line: + + awk '{ if (length($0) > max) max = length($0) } + END { print max }' data + * Print the length of the longest line in `data': expand data | awk '{ if (x < length($0)) x = length($0) } END { print "maximum line length is " x }' - This example differs slightly from the first example in this list: - The input is processed by the `expand' utility to change TABs into - spaces, so the widths compared are actually the right-margin - columns, as opposed to the number of input characters on each line. + This example differs slightly from the previous one: The input is + processed by the `expand' utility to change TABs into spaces, so + the widths compared are actually the right-margin columns, as + opposed to the number of input characters on each line. * Print every line that has at least one field: @@ -3526,22 +3533,20 @@ sequences and that are not listed in the table stand for themselves: matches of one `p' followed by any number of `h's. This also matches just `p' if no `h's are present. - The `*' repeats the _smallest_ possible preceding expression. - (Use parentheses if you want to repeat a larger expression.) It - finds as many repetitions as possible. For example, `awk - '/\(c[ad][ad]*r x\)/ { print }' sample' prints every record in - `sample' containing a string of the form `(car x)', `(cdr x)', - `(cadr x)', and so on. Notice the escaping of the parentheses by - preceding them with backslashes. + There are two subtle points to understand about how `*' works. + First, the `*' applies only to the single preceding regular + expression component (e.g., in `ph*', it applies just to the `h'). + To cause `*' to apply to a larger sub-expression, use parentheses: + `(ph)*' matches `ph', `phph', `phphph' and so on. + + Second, `*' finds as many repetititons as possible. If the text to + be matched is `phhhhhhhhhhhhhhooey', `ph*' matches all of the `h's. `+' This symbol is similar to `*', except that the preceding expression must be matched at least once. This means that `wh+y' would match `why' and `whhy', but not `wy', whereas `wh*y' would - match all three. The following is a simpler way of writing the - last `*' example: - - awk '/\(c[ad]+r x\)/ { print }' sample + match all three. `?' This symbol is similar to `*', except that the preceding @@ -10718,7 +10723,8 @@ array element value: Index 0 Value 8 Index 2 Value "" -The pairs are shown in jumbled order because their order is irrelevant. +The pairs are shown in jumbled order because their order is +irrelevant.(1) One advantage of associative arrays is that new pairs can be added at any time. For example, suppose a tenth element is added to the array @@ -10747,9 +10753,10 @@ from English to French: Here we decided to translate the number one in both spelled-out and numeric form--thus illustrating that a single array can have both numbers and strings as indices. (In fact, array subscripts are always -strings; this is discussed in more detail in *note Numeric Array -Subscripts::.) Here, the number `1' isn't double-quoted, since `awk' -automatically converts it to a string. +strings. There are some subtleties to how numbers work when used as +array subscripts; this is discussed in more detail in *note Numeric +Array Subscripts::.) Here, the number `1' isn't double-quoted, since +`awk' automatically converts it to a string. The value of `IGNORECASE' has no effect upon array subscripting. The identical string value used to store an array element must be used @@ -10760,6 +10767,11 @@ starting at one. (*Note String Functions::.) `awk''s arrays are efficient--the time to access an element is independent of the number of elements in the array. + ---------- Footnotes ---------- + + (1) The ordering will vary among `awk' implementations, which +typically use hash tables to store array elements and values. +  File: gawk.info, Node: Reference to Elements, Next: Assigning Elements, Prev: Array Intro, Up: Array Basics @@ -13240,7 +13252,10 @@ File: gawk.info, Node: Definition Syntax, Next: Function Example, Up: User-de 9.2.1 Function Definition Syntax -------------------------------- -Definitions of functions can appear anywhere between the rules of an + It's entirely fair to say that the `awk' syntax for local variable + definitions is appallingly awful -- Brian Kernighan + + Definitions of functions can appear anywhere between the rules of an `awk' program. Thus, the general form of an `awk' program is extended to include sequences of rules _and_ user-defined function definitions. There is no need to put the definition of a function before all uses of @@ -13270,7 +13285,7 @@ have a parameter with the same name as the function itself. In addition, according to the POSIX standard, function parameters cannot have the same name as one of the special built-in variables (*note Built-in Variables::). Not all versions of `awk' enforce this -restriction.) +restriction. Local variables act like the empty string if referenced where a string value is required, and like zero if referenced where a numeric @@ -30968,7 +30983,7 @@ Index * + (plus sign), ++ operator: Increment Ops. (line 11) * + (plus sign), += operator <1>: Precedence. (line 95) * + (plus sign), += operator: Assignment Ops. (line 82) -* + (plus sign), regexp operator: Regexp Operators. (line 104) +* + (plus sign), regexp operator: Regexp Operators. (line 105) * , (comma), in range patterns: Ranges. (line 6) * - (hyphen), - operator: Precedence. (line 52) * - (hyphen), -- operator <1>: Precedence. (line 46) @@ -31111,7 +31126,7 @@ Index * ? (question mark), ?: operator: Precedence. (line 92) * ? (question mark), regexp operator <1>: GNU Regexp Operators. (line 59) -* ? (question mark), regexp operator: Regexp Operators. (line 113) +* ? (question mark), regexp operator: Regexp Operators. (line 111) * [] (square brackets), regexp operator: Regexp Operators. (line 56) * \ (backslash): Comments. (line 50) * \ (backslash) in shell commands: Read Terminal. (line 25) @@ -31233,7 +31248,7 @@ Index * ARGC/ARGV variables, command-line arguments: Other Arguments. (line 12) * ARGC/ARGV variables, how to use: ARGC and ARGV. (line 6) -* ARGC/ARGV variables, portability and: Executable Scripts. (line 42) +* ARGC/ARGV variables, portability and: Executable Scripts. (line 59) * ARGIND variable: Auto-set. (line 44) * ARGIND variable, command-line arguments: Other Arguments. (line 12) * arguments, command-line <1>: ARGC and ARGV. (line 6) @@ -31253,7 +31268,7 @@ Index * arrays: Arrays. (line 6) * arrays of arrays: Arrays of Arrays. (line 6) * arrays, an example of using: Array Example. (line 6) -* arrays, and IGNORECASE variable: Array Intro. (line 92) +* arrays, and IGNORECASE variable: Array Intro. (line 94) * arrays, as parameters to functions: Pass By Value/Reference. (line 47) * arrays, associative: Array Intro. (line 50) @@ -31281,7 +31296,7 @@ Index (line 6) * arrays, sorting, and IGNORECASE variable: Array Sorting Functions. (line 83) -* arrays, sparse: Array Intro. (line 71) +* arrays, sparse: Array Intro. (line 72) * arrays, subscripts, uninitialized variables as: Uninitialized Subscripts. (line 6) * arrays, unassigned elements: Reference to Elements. @@ -31368,8 +31383,7 @@ Index * awk, uses for <1>: When. (line 6) * awk, uses for <2>: Getting Started. (line 12) * awk, uses for: Preface. (line 21) -* awk, versions of <1>: V7/SVR3.1. (line 6) -* awk, versions of: Names. (line 10) +* awk, versions of: V7/SVR3.1. (line 6) * awk, versions of, changes between SVR3.1 and SVR4: SVR4. (line 6) * awk, versions of, changes between SVR4 and POSIX awk: POSIX. (line 6) @@ -31578,7 +31592,7 @@ Index * case keyword: Switch Statement. (line 6) * case sensitivity, and regexps: User-modified. (line 76) * case sensitivity, and string comparisons: User-modified. (line 76) -* case sensitivity, array indices and: Array Intro. (line 92) +* case sensitivity, array indices and: Array Intro. (line 94) * case sensitivity, converting case: String Functions. (line 520) * case sensitivity, example programs: Library Functions. (line 53) * case sensitivity, gawk: Case-sensitivity. (line 26) @@ -31657,7 +31671,7 @@ Index * common extensions, \x escape sequence: Escape Sequences. (line 61) * common extensions, BINMODE variable: PC Using. (line 33) * common extensions, delete to delete entire arrays: Delete. (line 39) -* common extensions, func keyword: Definition Syntax. (line 89) +* common extensions, func keyword: Definition Syntax. (line 92) * common extensions, length() applied to an array: String Functions. (line 197) * common extensions, RS as a regexp: gawk split records. (line 6) @@ -32176,7 +32190,7 @@ Index * extensions, common, BINMODE variable: PC Using. (line 33) * extensions, common, delete to delete entire arrays: Delete. (line 39) * extensions, common, fflush() function: I/O Functions. (line 43) -* extensions, common, func keyword: Definition Syntax. (line 89) +* extensions, common, func keyword: Definition Syntax. (line 92) * extensions, common, length() applied to an array: String Functions. (line 197) * extensions, common, RS as a regexp: gawk split records. (line 6) @@ -32366,7 +32380,7 @@ Index * functions, built-in <1>: Functions. (line 6) * functions, built-in: Function Calls. (line 10) * functions, built-in, evaluation order: Calling Built-in. (line 30) -* functions, defining: Definition Syntax. (line 6) +* functions, defining: Definition Syntax. (line 9) * functions, library: Library Functions. (line 6) * functions, library, assertions: Assert Function. (line 6) * functions, library, associative arrays and: Library Names. (line 57) @@ -32389,9 +32403,9 @@ Index * functions, library, rounding numbers: Round Function. (line 6) * functions, library, user database, reading: Passwd Functions. (line 6) -* functions, names of <1>: Definition Syntax. (line 20) +* functions, names of <1>: Definition Syntax. (line 23) * functions, names of: Arrays. (line 18) -* functions, recursive: Definition Syntax. (line 79) +* functions, recursive: Definition Syntax. (line 82) * functions, string-translation: I18N Functions. (line 6) * functions, undefined: Pass By Value/Reference. (line 71) @@ -32450,7 +32464,7 @@ Index * gawk, IGNORECASE variable in <1>: Array Sorting Functions. (line 83) * gawk, IGNORECASE variable in <2>: String Functions. (line 58) -* gawk, IGNORECASE variable in <3>: Array Intro. (line 92) +* gawk, IGNORECASE variable in <3>: Array Intro. (line 94) * gawk, IGNORECASE variable in <4>: User-modified. (line 76) * gawk, IGNORECASE variable in: Case-sensitivity. (line 26) * gawk, implementation issues: Notes. (line 6) @@ -32464,7 +32478,7 @@ Index (line 13) * gawk, interpreter, adding code to: Using Internal File Ops. (line 6) -* gawk, interval expressions and: Regexp Operators. (line 141) +* gawk, interval expressions and: Regexp Operators. (line 139) * gawk, line continuation in: Conditional Exp. (line 34) * gawk, LINT variable in: User-modified. (line 88) * gawk, list of contributors to: Contributors. (line 6) @@ -32482,7 +32496,7 @@ Index (line 26) * gawk, regular expressions, operators: GNU Regexp Operators. (line 6) -* gawk, regular expressions, precedence: Regexp Operators. (line 163) +* gawk, regular expressions, precedence: Regexp Operators. (line 161) * gawk, RT variable in <1>: Auto-set. (line 257) * gawk, RT variable in <2>: Multiple Line. (line 129) * gawk, RT variable in: awk split records. (line 124) @@ -32616,7 +32630,7 @@ Index * ignore breakpoint: Breakpoint Control. (line 87) * ignore debugger command: Breakpoint Control. (line 87) * IGNORECASE variable: User-modified. (line 76) -* IGNORECASE variable, and array indices: Array Intro. (line 92) +* IGNORECASE variable, and array indices: Array Intro. (line 94) * IGNORECASE variable, and array sorting functions: Array Sorting Functions. (line 83) * IGNORECASE variable, in example programs: Library Functions. @@ -32701,7 +32715,7 @@ Index * internationalizing a program: Explaining gettext. (line 6) * interpreted programs <1>: Glossary. (line 356) * interpreted programs: Basic High Level. (line 15) -* interval expressions, regexp operator: Regexp Operators. (line 118) +* interval expressions, regexp operator: Regexp Operators. (line 116) * inventory-shipped file: Sample Data Files. (line 32) * invoke shell command: I/O Functions. (line 75) * isarray: Type Functions. (line 11) @@ -32893,11 +32907,10 @@ Index * names, arrays/variables <1>: Library Names. (line 6) * names, arrays/variables: Arrays. (line 18) * names, functions <1>: Library Names. (line 6) -* names, functions: Definition Syntax. (line 20) +* names, functions: Definition Syntax. (line 23) * namespace issues <1>: Library Names. (line 6) * namespace issues: Arrays. (line 18) -* namespace issues, functions: Definition Syntax. (line 20) -* nawk utility: Names. (line 10) +* namespace issues, functions: Definition Syntax. (line 23) * NetBSD: Glossary. (line 611) * networks, programming: TCP/IP Networking. (line 6) * networks, support for: Special Network. (line 6) @@ -32976,7 +32989,6 @@ Index * numeric, output format: OFMT. (line 6) * numeric, strings: Variable Typing. (line 6) * o debugger command (alias for option): Debugger Info. (line 57) -* oawk utility: Names. (line 10) * obsolete features: Obsolete. (line 6) * octal numbers: Nondecimal-numbers. (line 6) * octal values, enabling interpretation of: Options. (line 211) @@ -33097,13 +33109,13 @@ Index * plus sign (+), ++ operator: Increment Ops. (line 11) * plus sign (+), += operator <1>: Precedence. (line 95) * plus sign (+), += operator: Assignment Ops. (line 82) -* plus sign (+), regexp operator: Regexp Operators. (line 104) +* plus sign (+), regexp operator: Regexp Operators. (line 105) * pointers to functions: Indirect Calls. (line 6) * portability: Escape Sequences. (line 98) * portability, #! (executable scripts): Executable Scripts. (line 33) * portability, ** operator and: Arithmetic Ops. (line 81) * portability, **= operator and: Assignment Ops. (line 143) -* portability, ARGV variable: Executable Scripts. (line 42) +* portability, ARGV variable: Executable Scripts. (line 59) * portability, backslash continuation and: Statements/Lines. (line 30) * portability, backslash in escape sequences: Escape Sequences. (line 116) @@ -33113,7 +33125,7 @@ Index (line 65) * portability, deleting array elements: Delete. (line 56) * portability, example programs: Library Functions. (line 42) -* portability, functions, defining: Definition Syntax. (line 105) +* portability, functions, defining: Definition Syntax. (line 108) * portability, gawk: New Ports. (line 6) * portability, gettext library and: Explaining gettext. (line 11) * portability, internationalization and: I18N Portability. (line 6) @@ -33159,18 +33171,18 @@ Index (line 40) * POSIX awk, field separators and: Fields. (line 6) * POSIX awk, FS variable and: User-modified. (line 60) -* POSIX awk, function keyword in: Definition Syntax. (line 89) +* POSIX awk, function keyword in: Definition Syntax. (line 92) * POSIX awk, functions and, gsub()/sub(): Gory Details. (line 90) * POSIX awk, functions and, length(): String Functions. (line 176) * POSIX awk, GNU long options and: Options. (line 15) -* POSIX awk, interval expressions in: Regexp Operators. (line 137) +* POSIX awk, interval expressions in: Regexp Operators. (line 135) * POSIX awk, next/nextfile statements and: Next Statement. (line 45) * POSIX awk, numeric strings and: Variable Typing. (line 6) * POSIX awk, OFMT variable and <1>: Strings And Numbers. (line 57) * POSIX awk, OFMT variable and: OFMT. (line 27) * POSIX awk, period (.), using: Regexp Operators. (line 51) * POSIX awk, printf format strings and: Format Modifiers. (line 159) -* POSIX awk, regular expressions and: Regexp Operators. (line 163) +* POSIX awk, regular expressions and: Regexp Operators. (line 161) * POSIX awk, timestamps and: Time Functions. (line 6) * POSIX awk, | I/O operator and: Getline/Pipe. (line 55) * POSIX mode: Options. (line 254) @@ -33181,7 +33193,7 @@ Index * PREC variable: User-modified. (line 124) * precedence <1>: Precedence. (line 6) * precedence: Increment Ops. (line 60) -* precedence, regexp operators: Regexp Operators. (line 158) +* precedence, regexp operators: Regexp Operators. (line 156) * print debugger command: Viewing And Changing Data. (line 36) * print statement: Printing. (line 16) @@ -33248,7 +33260,7 @@ Index * programming conventions, functions, calling: Calling Built-in. (line 10) * programming conventions, functions, writing: Definition Syntax. - (line 61) + (line 64) * programming conventions, gawk extensions: Internal File Ops. (line 45) * programming conventions, private variable names: Library Names. @@ -33268,7 +33280,7 @@ Index * question mark (?), ?: operator: Precedence. (line 92) * question mark (?), regexp operator <1>: GNU Regexp Operators. (line 59) -* question mark (?), regexp operator: Regexp Operators. (line 113) +* question mark (?), regexp operator: Regexp Operators. (line 111) * QuikTrim Awk: Other Versions. (line 135) * quit debugger command: Miscellaneous Debugger Commands. (line 99) @@ -33318,7 +33330,7 @@ Index * records, splitting input into: Records. (line 6) * records, terminating: awk split records. (line 124) * records, treating files as: gawk split records. (line 92) -* recursive functions: Definition Syntax. (line 79) +* recursive functions: Definition Syntax. (line 82) * redirect gawk output, in debugger: Debugger Info. (line 72) * redirection of input: Getline/File. (line 6) * redirection of output: Redirection. (line 6) @@ -33368,7 +33380,7 @@ Index * regular expressions, operators, gawk: GNU Regexp Operators. (line 6) * regular expressions, operators, precedence of: Regexp Operators. - (line 158) + (line 156) * regular expressions, searching for: Egrep Program. (line 6) * relational operators, See comparison operators: Typing and Comparison. (line 9) @@ -33488,7 +33500,7 @@ Index * set directory of message catalogs: I18N Functions. (line 12) * set watchpoint: Viewing And Changing Data. (line 67) -* shadowing of variable values: Definition Syntax. (line 67) +* shadowing of variable values: Definition Syntax. (line 70) * shell quoting, double quote: Read Terminal. (line 25) * shell quoting, rules for: Quoting. (line 6) * shells, piping commands into: Redirection. (line 142) @@ -33541,7 +33553,6 @@ Index * sidebar, Matching the Null String: Gory Details. (line 141) * sidebar, Operator Evaluation Order: Increment Ops. (line 58) * sidebar, Piping into sh: Redirection. (line 140) -* sidebar, Portability Issues with #!: Executable Scripts. (line 31) * sidebar, Pre-POSIX awk Used OFMT For String Conversion: Strings And Numbers. (line 55) * sidebar, Recipe For A Programming Language: History. (line 6) @@ -33550,6 +33561,7 @@ Index (line 83) * sidebar, Syntactic Ambiguities Between /= and Regular Expressions: Assignment Ops. (line 146) +* sidebar, Understanding #!: Executable Scripts. (line 31) * sidebar, Understanding $0: Changing Fields. (line 134) * sidebar, Using \n in Bracket Expressions of Dynamic Regexps: Computed Regexps. (line 57) @@ -33605,7 +33617,7 @@ Index * source code, QuikTrim Awk: Other Versions. (line 135) * source code, Solaris awk: Other Versions. (line 96) * source files, search path for: Programs Exercises. (line 63) -* sparse arrays: Array Intro. (line 71) +* sparse arrays: Array Intro. (line 72) * Spencer, Henry: Glossary. (line 11) * split: String Functions. (line 313) * split string into array: String Functions. (line 294) @@ -33865,7 +33877,7 @@ Index * variables, names of: Arrays. (line 18) * variables, private: Library Names. (line 11) * variables, setting: Options. (line 32) -* variables, shadowing: Definition Syntax. (line 67) +* variables, shadowing: Definition Syntax. (line 70) * variables, types of: Assignment Ops. (line 40) * variables, types of, comparison expressions and: Typing and Comparison. (line 9) @@ -33968,546 +33980,546 @@ Ref: Preface-Footnote-149226 Ref: Preface-Footnote-249333 Node: History49565 Node: Names51939 -Ref: Names-Footnote-153403 -Node: This Manual53476 -Ref: This Manual-Footnote-159255 -Node: Conventions59355 -Node: Manual History61700 -Ref: Manual History-Footnote-164776 -Ref: Manual History-Footnote-264817 -Node: How To Contribute64891 -Node: Acknowledgments66130 -Node: Getting Started70878 -Node: Running gawk73312 -Node: One-shot74502 -Node: Read Terminal75727 -Ref: Read Terminal-Footnote-177690 -Node: Long77861 -Node: Executable Scripts79255 -Ref: Executable Scripts-Footnote-181088 -Ref: Executable Scripts-Footnote-281190 -Node: Comments81743 -Node: Quoting84216 -Node: DOS Quoting89529 -Node: Sample Data Files90204 -Node: Very Simple92758 -Node: Two Rules97531 -Node: More Complex99425 -Ref: More Complex-Footnote-1102357 -Node: Statements/Lines102442 -Ref: Statements/Lines-Footnote-1106898 -Node: Other Features107163 -Node: When108091 -Ref: When-Footnote-1109847 -Node: Intro Summary109912 -Node: Invoking Gawk110795 -Node: Command Line112310 -Node: Options113101 -Ref: Options-Footnote-1128877 -Node: Other Arguments128902 -Node: Naming Standard Input131564 -Node: Environment Variables132657 -Node: AWKPATH Variable133215 -Ref: AWKPATH Variable-Footnote-1136081 -Ref: AWKPATH Variable-Footnote-2136126 -Node: AWKLIBPATH Variable136386 -Node: Other Environment Variables137145 -Node: Exit Status140802 -Node: Include Files141477 -Node: Loading Shared Libraries145055 -Node: Obsolete146439 -Node: Undocumented147136 -Node: Invoking Summary147403 -Node: Regexp149003 -Node: Regexp Usage150462 -Node: Escape Sequences152495 -Node: Regexp Operators158312 -Ref: Regexp Operators-Footnote-1165830 -Ref: Regexp Operators-Footnote-2165977 -Node: Bracket Expressions166075 -Ref: table-char-classes168097 -Node: GNU Regexp Operators171037 -Node: Case-sensitivity174746 -Ref: Case-sensitivity-Footnote-1177638 -Ref: Case-sensitivity-Footnote-2177873 -Node: Leftmost Longest177981 -Node: Computed Regexps179182 -Node: Regexp Summary182554 -Node: Reading Files184023 -Node: Records186115 -Node: awk split records186837 -Node: gawk split records191695 -Ref: gawk split records-Footnote-1196216 -Node: Fields196253 -Ref: Fields-Footnote-1199217 -Node: Nonconstant Fields199303 -Ref: Nonconstant Fields-Footnote-1201533 -Node: Changing Fields201735 -Node: Field Separators207689 -Node: Default Field Splitting210391 -Node: Regexp Field Splitting211508 -Node: Single Character Fields214835 -Node: Command Line Field Separator215894 -Node: Full Line Fields219320 -Ref: Full Line Fields-Footnote-1219828 -Node: Field Splitting Summary219874 -Ref: Field Splitting Summary-Footnote-1223006 -Node: Constant Size223107 -Node: Splitting By Content227713 -Ref: Splitting By Content-Footnote-1231786 -Node: Multiple Line231826 -Ref: Multiple Line-Footnote-1237682 -Node: Getline237861 -Node: Plain Getline240072 -Node: Getline/Variable242167 -Node: Getline/File243314 -Node: Getline/Variable/File244698 -Ref: Getline/Variable/File-Footnote-1246297 -Node: Getline/Pipe246384 -Node: Getline/Variable/Pipe249070 -Node: Getline/Coprocess250177 -Node: Getline/Variable/Coprocess251429 -Node: Getline Notes252166 -Node: Getline Summary254970 -Ref: table-getline-variants255378 -Node: Read Timeout256290 -Ref: Read Timeout-Footnote-1260117 -Node: Command-line directories260175 -Node: Input Summary261079 -Node: Input Exercises264216 -Node: Printing264949 -Node: Print266671 -Node: Print Examples268164 -Node: Output Separators270943 -Node: OFMT272959 -Node: Printf274317 -Node: Basic Printf275223 -Node: Control Letters276762 -Node: Format Modifiers280753 -Node: Printf Examples286780 -Node: Redirection289244 -Node: Special Files296216 -Node: Special FD296749 -Ref: Special FD-Footnote-1300346 -Node: Special Network300420 -Node: Special Caveats301270 -Node: Close Files And Pipes302066 -Ref: Close Files And Pipes-Footnote-1309227 -Ref: Close Files And Pipes-Footnote-2309375 -Node: Output Summary309525 -Node: Output exercises310522 -Node: Expressions311202 -Node: Values312387 -Node: Constants313063 -Node: Scalar Constants313743 -Ref: Scalar Constants-Footnote-1314602 -Node: Nondecimal-numbers314852 -Node: Regexp Constants317852 -Node: Using Constant Regexps318327 -Node: Variables321399 -Node: Using Variables322054 -Node: Assignment Options323778 -Node: Conversion325653 -Node: Strings And Numbers326177 -Ref: Strings And Numbers-Footnote-1329239 -Node: Locale influences conversions329348 -Ref: table-locale-affects332065 -Node: All Operators332653 -Node: Arithmetic Ops333283 -Node: Concatenation335788 -Ref: Concatenation-Footnote-1338607 -Node: Assignment Ops338713 -Ref: table-assign-ops343696 -Node: Increment Ops344999 -Node: Truth Values and Conditions348437 -Node: Truth Values349520 -Node: Typing and Comparison350569 -Node: Variable Typing351362 -Node: Comparison Operators355014 -Ref: table-relational-ops355424 -Node: POSIX String Comparison358974 -Ref: POSIX String Comparison-Footnote-1360058 -Node: Boolean Ops360196 -Ref: Boolean Ops-Footnote-1364271 -Node: Conditional Exp364362 -Node: Function Calls366089 -Node: Precedence369969 -Node: Locales373638 -Node: Expressions Summary375269 -Node: Patterns and Actions377810 -Node: Pattern Overview378926 -Node: Regexp Patterns380603 -Node: Expression Patterns381146 -Node: Ranges384926 -Node: BEGIN/END388032 -Node: Using BEGIN/END388794 -Ref: Using BEGIN/END-Footnote-1391530 -Node: I/O And BEGIN/END391636 -Node: BEGINFILE/ENDFILE393907 -Node: Empty396838 -Node: Using Shell Variables397155 -Node: Action Overview399438 -Node: Statements401765 -Node: If Statement403613 -Node: While Statement405111 -Node: Do Statement407155 -Node: For Statement408311 -Node: Switch Statement411463 -Node: Break Statement413851 -Node: Continue Statement415892 -Node: Next Statement417717 -Node: Nextfile Statement420107 -Node: Exit Statement422743 -Node: Built-in Variables425147 -Node: User-modified426274 -Ref: User-modified-Footnote-1433963 -Node: Auto-set434025 -Ref: Auto-set-Footnote-1446607 -Ref: Auto-set-Footnote-2446812 -Node: ARGC and ARGV446868 -Node: Pattern Action Summary450772 -Node: Arrays452995 -Node: Array Basics454544 -Node: Array Intro455370 -Ref: figure-array-elements457343 -Node: Reference to Elements459750 -Node: Assigning Elements462200 -Node: Array Example462691 -Node: Scanning an Array464423 -Node: Controlling Scanning467424 -Ref: Controlling Scanning-Footnote-1472597 -Node: Delete472913 -Ref: Delete-Footnote-1475664 -Node: Numeric Array Subscripts475721 -Node: Uninitialized Subscripts477904 -Node: Multidimensional479529 -Node: Multiscanning482642 -Node: Arrays of Arrays484231 -Node: Arrays Summary488894 -Node: Functions490999 -Node: Built-in491872 -Node: Calling Built-in492950 -Node: Numeric Functions494938 -Ref: Numeric Functions-Footnote-1498972 -Ref: Numeric Functions-Footnote-2499329 -Ref: Numeric Functions-Footnote-3499377 -Node: String Functions499646 -Ref: String Functions-Footnote-1522643 -Ref: String Functions-Footnote-2522772 -Ref: String Functions-Footnote-3523020 -Node: Gory Details523107 -Ref: table-sub-escapes524880 -Ref: table-sub-proposed526400 -Ref: table-posix-sub527764 -Ref: table-gensub-escapes529304 -Ref: Gory Details-Footnote-1530480 -Node: I/O Functions530631 -Ref: I/O Functions-Footnote-1537741 -Node: Time Functions537888 -Ref: Time Functions-Footnote-1548352 -Ref: Time Functions-Footnote-2548420 -Ref: Time Functions-Footnote-3548578 -Ref: Time Functions-Footnote-4548689 -Ref: Time Functions-Footnote-5548801 -Ref: Time Functions-Footnote-6549028 -Node: Bitwise Functions549294 -Ref: table-bitwise-ops549856 -Ref: Bitwise Functions-Footnote-1554101 -Node: Type Functions554285 -Node: I18N Functions555427 -Node: User-defined557072 -Node: Definition Syntax557876 -Ref: Definition Syntax-Footnote-1563055 -Node: Function Example563124 -Ref: Function Example-Footnote-1565764 -Node: Function Caveats565786 -Node: Calling A Function566304 -Node: Variable Scope567259 -Node: Pass By Value/Reference570247 -Node: Return Statement573757 -Node: Dynamic Typing576741 -Node: Indirect Calls577670 -Node: Functions Summary587383 -Node: Library Functions589922 -Ref: Library Functions-Footnote-1593540 -Ref: Library Functions-Footnote-2593683 -Node: Library Names593854 -Ref: Library Names-Footnote-1597327 -Ref: Library Names-Footnote-2597547 -Node: General Functions597633 -Node: Strtonum Function598661 -Node: Assert Function601441 -Node: Round Function604767 -Node: Cliff Random Function606308 -Node: Ordinal Functions607324 -Ref: Ordinal Functions-Footnote-1610389 -Ref: Ordinal Functions-Footnote-2610641 -Node: Join Function610852 -Ref: Join Function-Footnote-1612623 -Node: Getlocaltime Function612823 -Node: Readfile Function616559 -Node: Data File Management618398 -Node: Filetrans Function619030 -Node: Rewind Function623099 -Node: File Checking624657 -Ref: File Checking-Footnote-1625789 -Node: Empty Files625990 -Node: Ignoring Assigns627969 -Node: Getopt Function629523 -Ref: Getopt Function-Footnote-1640826 -Node: Passwd Functions641029 -Ref: Passwd Functions-Footnote-1650008 -Node: Group Functions650096 -Ref: Group Functions-Footnote-1658027 -Node: Walking Arrays658240 -Node: Library Functions Summary659843 -Node: Library exercises661231 -Node: Sample Programs662511 -Node: Running Examples663281 -Node: Clones664009 -Node: Cut Program665233 -Node: Egrep Program675091 -Ref: Egrep Program-Footnote-1682678 -Node: Id Program682788 -Node: Split Program686442 -Ref: Split Program-Footnote-1689980 -Node: Tee Program690108 -Node: Uniq Program692895 -Node: Wc Program700316 -Ref: Wc Program-Footnote-1704581 -Node: Miscellaneous Programs704673 -Node: Dupword Program705886 -Node: Alarm Program707917 -Node: Translate Program712721 -Ref: Translate Program-Footnote-1717112 -Ref: Translate Program-Footnote-2717382 -Node: Labels Program717516 -Ref: Labels Program-Footnote-1720877 -Node: Word Sorting720961 -Node: History Sorting725004 -Node: Extract Program726840 -Node: Simple Sed734376 -Node: Igawk Program737438 -Ref: Igawk Program-Footnote-1751742 -Ref: Igawk Program-Footnote-2751943 -Node: Anagram Program752081 -Node: Signature Program755149 -Node: Programs Summary756396 -Node: Programs Exercises757611 -Node: Advanced Features761262 -Node: Nondecimal Data763210 -Node: Array Sorting764787 -Node: Controlling Array Traversal765484 -Node: Array Sorting Functions773764 -Ref: Array Sorting Functions-Footnote-1777671 -Node: Two-way I/O777865 -Ref: Two-way I/O-Footnote-1782809 -Ref: Two-way I/O-Footnote-2782988 -Node: TCP/IP Networking783070 -Node: Profiling785915 -Node: Advanced Features Summary793457 -Node: Internationalization795321 -Node: I18N and L10N796801 -Node: Explaining gettext797487 -Ref: Explaining gettext-Footnote-1802513 -Ref: Explaining gettext-Footnote-2802697 -Node: Programmer i18n802862 -Ref: Programmer i18n-Footnote-1807656 -Node: Translator i18n807705 -Node: String Extraction808499 -Ref: String Extraction-Footnote-1809632 -Node: Printf Ordering809718 -Ref: Printf Ordering-Footnote-1812500 -Node: I18N Portability812564 -Ref: I18N Portability-Footnote-1815013 -Node: I18N Example815076 -Ref: I18N Example-Footnote-1817782 -Node: Gawk I18N817854 -Node: I18N Summary818492 -Node: Debugger819831 -Node: Debugging820853 -Node: Debugging Concepts821294 -Node: Debugging Terms823150 -Node: Awk Debugging825747 -Node: Sample Debugging Session826639 -Node: Debugger Invocation827159 -Node: Finding The Bug828492 -Node: List of Debugger Commands834974 -Node: Breakpoint Control836306 -Node: Debugger Execution Control839970 -Node: Viewing And Changing Data843330 -Node: Execution Stack846688 -Node: Debugger Info848201 -Node: Miscellaneous Debugger Commands852195 -Node: Readline Support857379 -Node: Limitations858271 -Node: Debugging Summary860545 -Node: Arbitrary Precision Arithmetic861713 -Node: Computer Arithmetic863200 -Ref: Computer Arithmetic-Footnote-1867587 -Node: Math Definitions867644 -Ref: table-ieee-formats870933 -Ref: Math Definitions-Footnote-1871473 -Node: MPFR features871576 -Node: FP Math Caution873193 -Ref: FP Math Caution-Footnote-1874243 -Node: Inexactness of computations874612 -Node: Inexact representation875560 -Node: Comparing FP Values876915 -Node: Errors accumulate877879 -Node: Getting Accuracy879312 -Node: Try To Round881971 -Node: Setting precision882870 -Ref: table-predefined-precision-strings883552 -Node: Setting the rounding mode885345 -Ref: table-gawk-rounding-modes885709 -Ref: Setting the rounding mode-Footnote-1889163 -Node: Arbitrary Precision Integers889342 -Ref: Arbitrary Precision Integers-Footnote-1892323 -Node: POSIX Floating Point Problems892472 -Ref: POSIX Floating Point Problems-Footnote-1896348 -Node: Floating point summary896386 -Node: Dynamic Extensions898590 -Node: Extension Intro900142 -Node: Plugin License901407 -Node: Extension Mechanism Outline902092 -Ref: figure-load-extension902516 -Ref: figure-load-new-function904001 -Ref: figure-call-new-function905003 -Node: Extension API Description906987 -Node: Extension API Functions Introduction908437 -Node: General Data Types913304 -Ref: General Data Types-Footnote-1918997 -Node: Requesting Values919296 -Ref: table-value-types-returned920033 -Node: Memory Allocation Functions920991 -Ref: Memory Allocation Functions-Footnote-1923738 -Node: Constructor Functions923834 -Node: Registration Functions925592 -Node: Extension Functions926277 -Node: Exit Callback Functions928579 -Node: Extension Version String929827 -Node: Input Parsers930477 -Node: Output Wrappers940291 -Node: Two-way processors944807 -Node: Printing Messages947011 -Ref: Printing Messages-Footnote-1948088 -Node: Updating `ERRNO'948240 -Node: Accessing Parameters948979 -Node: Symbol Table Access950209 -Node: Symbol table by name950723 -Node: Symbol table by cookie952699 -Ref: Symbol table by cookie-Footnote-1956832 -Node: Cached values956895 -Ref: Cached values-Footnote-1960399 -Node: Array Manipulation960490 -Ref: Array Manipulation-Footnote-1961588 -Node: Array Data Types961627 -Ref: Array Data Types-Footnote-1964330 -Node: Array Functions964422 -Node: Flattening Arrays968296 -Node: Creating Arrays975148 -Node: Extension API Variables979879 -Node: Extension Versioning980515 -Node: Extension API Informational Variables982416 -Node: Extension API Boilerplate983502 -Node: Finding Extensions987306 -Node: Extension Example987866 -Node: Internal File Description988596 -Node: Internal File Ops992687 -Ref: Internal File Ops-Footnote-11004119 -Node: Using Internal File Ops1004259 -Ref: Using Internal File Ops-Footnote-11006606 -Node: Extension Samples1006874 -Node: Extension Sample File Functions1008398 -Node: Extension Sample Fnmatch1015966 -Node: Extension Sample Fork1017448 -Node: Extension Sample Inplace1018661 -Node: Extension Sample Ord1020336 -Node: Extension Sample Readdir1021172 -Ref: table-readdir-file-types1022028 -Node: Extension Sample Revout1022827 -Node: Extension Sample Rev2way1023418 -Node: Extension Sample Read write array1024159 -Node: Extension Sample Readfile1026038 -Node: Extension Sample API Tests1027138 -Node: Extension Sample Time1027663 -Node: gawkextlib1028978 -Node: Extension summary1031791 -Node: Extension Exercises1035484 -Node: Language History1036206 -Node: V7/SVR3.11037849 -Node: SVR41040169 -Node: POSIX1041611 -Node: BTL1042997 -Node: POSIX/GNU1043731 -Node: Feature History1049447 -Node: Common Extensions1062538 -Node: Ranges and Locales1063850 -Ref: Ranges and Locales-Footnote-11068467 -Ref: Ranges and Locales-Footnote-21068494 -Ref: Ranges and Locales-Footnote-31068728 -Node: Contributors1068949 -Node: History summary1074374 -Node: Installation1075743 -Node: Gawk Distribution1076694 -Node: Getting1077178 -Node: Extracting1078002 -Node: Distribution contents1079644 -Node: Unix Installation1085361 -Node: Quick Installation1085978 -Node: Additional Configuration Options1088420 -Node: Configuration Philosophy1090158 -Node: Non-Unix Installation1092509 -Node: PC Installation1092967 -Node: PC Binary Installation1094278 -Node: PC Compiling1096126 -Ref: PC Compiling-Footnote-11099125 -Node: PC Testing1099230 -Node: PC Using1100406 -Node: Cygwin1104558 -Node: MSYS1105367 -Node: VMS Installation1105881 -Node: VMS Compilation1106677 -Ref: VMS Compilation-Footnote-11107899 -Node: VMS Dynamic Extensions1107957 -Node: VMS Installation Details1109330 -Node: VMS Running1111582 -Node: VMS GNV1114416 -Node: VMS Old Gawk1115139 -Node: Bugs1115609 -Node: Other Versions1119613 -Node: Installation summary1125840 -Node: Notes1126896 -Node: Compatibility Mode1127761 -Node: Additions1128543 -Node: Accessing The Source1129468 -Node: Adding Code1130904 -Node: New Ports1137082 -Node: Derived Files1141563 -Ref: Derived Files-Footnote-11146644 -Ref: Derived Files-Footnote-21146678 -Ref: Derived Files-Footnote-31147274 -Node: Future Extensions1147388 -Node: Implementation Limitations1147994 -Node: Extension Design1149242 -Node: Old Extension Problems1150396 -Ref: Old Extension Problems-Footnote-11151913 -Node: Extension New Mechanism Goals1151970 -Ref: Extension New Mechanism Goals-Footnote-11155330 -Node: Extension Other Design Decisions1155519 -Node: Extension Future Growth1157625 -Node: Old Extension Mechanism1158461 -Node: Notes summary1160223 -Node: Basic Concepts1161409 -Node: Basic High Level1162090 -Ref: figure-general-flow1162362 -Ref: figure-process-flow1162961 -Ref: Basic High Level-Footnote-11166190 -Node: Basic Data Typing1166375 -Node: Glossary1169703 -Node: Copying1194855 -Node: GNU Free Documentation License1232411 -Node: Index1257547 +Ref: Names-Footnote-153033 +Node: This Manual53179 +Ref: This Manual-Footnote-158958 +Node: Conventions59058 +Node: Manual History61403 +Ref: Manual History-Footnote-164479 +Ref: Manual History-Footnote-264520 +Node: How To Contribute64594 +Node: Acknowledgments65833 +Node: Getting Started70581 +Node: Running gawk73015 +Node: One-shot74205 +Node: Read Terminal75430 +Ref: Read Terminal-Footnote-177393 +Node: Long77564 +Node: Executable Scripts78958 +Ref: Executable Scripts-Footnote-181759 +Node: Comments81861 +Node: Quoting84334 +Node: DOS Quoting89647 +Node: Sample Data Files90322 +Node: Very Simple92929 +Node: Two Rules97688 +Node: More Complex99582 +Ref: More Complex-Footnote-1102514 +Node: Statements/Lines102599 +Ref: Statements/Lines-Footnote-1107055 +Node: Other Features107320 +Node: When108248 +Ref: When-Footnote-1110004 +Node: Intro Summary110069 +Node: Invoking Gawk110952 +Node: Command Line112467 +Node: Options113258 +Ref: Options-Footnote-1129034 +Node: Other Arguments129059 +Node: Naming Standard Input131721 +Node: Environment Variables132814 +Node: AWKPATH Variable133372 +Ref: AWKPATH Variable-Footnote-1136238 +Ref: AWKPATH Variable-Footnote-2136283 +Node: AWKLIBPATH Variable136543 +Node: Other Environment Variables137302 +Node: Exit Status140959 +Node: Include Files141634 +Node: Loading Shared Libraries145212 +Node: Obsolete146596 +Node: Undocumented147293 +Node: Invoking Summary147560 +Node: Regexp149160 +Node: Regexp Usage150619 +Node: Escape Sequences152652 +Node: Regexp Operators158469 +Ref: Regexp Operators-Footnote-1165900 +Ref: Regexp Operators-Footnote-2166047 +Node: Bracket Expressions166145 +Ref: table-char-classes168167 +Node: GNU Regexp Operators171107 +Node: Case-sensitivity174816 +Ref: Case-sensitivity-Footnote-1177708 +Ref: Case-sensitivity-Footnote-2177943 +Node: Leftmost Longest178051 +Node: Computed Regexps179252 +Node: Regexp Summary182624 +Node: Reading Files184093 +Node: Records186185 +Node: awk split records186907 +Node: gawk split records191765 +Ref: gawk split records-Footnote-1196286 +Node: Fields196323 +Ref: Fields-Footnote-1199287 +Node: Nonconstant Fields199373 +Ref: Nonconstant Fields-Footnote-1201603 +Node: Changing Fields201805 +Node: Field Separators207759 +Node: Default Field Splitting210461 +Node: Regexp Field Splitting211578 +Node: Single Character Fields214905 +Node: Command Line Field Separator215964 +Node: Full Line Fields219390 +Ref: Full Line Fields-Footnote-1219898 +Node: Field Splitting Summary219944 +Ref: Field Splitting Summary-Footnote-1223076 +Node: Constant Size223177 +Node: Splitting By Content227783 +Ref: Splitting By Content-Footnote-1231856 +Node: Multiple Line231896 +Ref: Multiple Line-Footnote-1237752 +Node: Getline237931 +Node: Plain Getline240142 +Node: Getline/Variable242237 +Node: Getline/File243384 +Node: Getline/Variable/File244768 +Ref: Getline/Variable/File-Footnote-1246367 +Node: Getline/Pipe246454 +Node: Getline/Variable/Pipe249140 +Node: Getline/Coprocess250247 +Node: Getline/Variable/Coprocess251499 +Node: Getline Notes252236 +Node: Getline Summary255040 +Ref: table-getline-variants255448 +Node: Read Timeout256360 +Ref: Read Timeout-Footnote-1260187 +Node: Command-line directories260245 +Node: Input Summary261149 +Node: Input Exercises264286 +Node: Printing265019 +Node: Print266741 +Node: Print Examples268234 +Node: Output Separators271013 +Node: OFMT273029 +Node: Printf274387 +Node: Basic Printf275293 +Node: Control Letters276832 +Node: Format Modifiers280823 +Node: Printf Examples286850 +Node: Redirection289314 +Node: Special Files296286 +Node: Special FD296819 +Ref: Special FD-Footnote-1300416 +Node: Special Network300490 +Node: Special Caveats301340 +Node: Close Files And Pipes302136 +Ref: Close Files And Pipes-Footnote-1309297 +Ref: Close Files And Pipes-Footnote-2309445 +Node: Output Summary309595 +Node: Output exercises310592 +Node: Expressions311272 +Node: Values312457 +Node: Constants313133 +Node: Scalar Constants313813 +Ref: Scalar Constants-Footnote-1314672 +Node: Nondecimal-numbers314922 +Node: Regexp Constants317922 +Node: Using Constant Regexps318397 +Node: Variables321469 +Node: Using Variables322124 +Node: Assignment Options323848 +Node: Conversion325723 +Node: Strings And Numbers326247 +Ref: Strings And Numbers-Footnote-1329309 +Node: Locale influences conversions329418 +Ref: table-locale-affects332135 +Node: All Operators332723 +Node: Arithmetic Ops333353 +Node: Concatenation335858 +Ref: Concatenation-Footnote-1338677 +Node: Assignment Ops338783 +Ref: table-assign-ops343766 +Node: Increment Ops345069 +Node: Truth Values and Conditions348507 +Node: Truth Values349590 +Node: Typing and Comparison350639 +Node: Variable Typing351432 +Node: Comparison Operators355084 +Ref: table-relational-ops355494 +Node: POSIX String Comparison359044 +Ref: POSIX String Comparison-Footnote-1360128 +Node: Boolean Ops360266 +Ref: Boolean Ops-Footnote-1364341 +Node: Conditional Exp364432 +Node: Function Calls366159 +Node: Precedence370039 +Node: Locales373708 +Node: Expressions Summary375339 +Node: Patterns and Actions377880 +Node: Pattern Overview378996 +Node: Regexp Patterns380673 +Node: Expression Patterns381216 +Node: Ranges384996 +Node: BEGIN/END388102 +Node: Using BEGIN/END388864 +Ref: Using BEGIN/END-Footnote-1391600 +Node: I/O And BEGIN/END391706 +Node: BEGINFILE/ENDFILE393977 +Node: Empty396908 +Node: Using Shell Variables397225 +Node: Action Overview399508 +Node: Statements401835 +Node: If Statement403683 +Node: While Statement405181 +Node: Do Statement407225 +Node: For Statement408381 +Node: Switch Statement411533 +Node: Break Statement413921 +Node: Continue Statement415962 +Node: Next Statement417787 +Node: Nextfile Statement420177 +Node: Exit Statement422813 +Node: Built-in Variables425217 +Node: User-modified426344 +Ref: User-modified-Footnote-1434033 +Node: Auto-set434095 +Ref: Auto-set-Footnote-1446677 +Ref: Auto-set-Footnote-2446882 +Node: ARGC and ARGV446938 +Node: Pattern Action Summary450842 +Node: Arrays453065 +Node: Array Basics454614 +Node: Array Intro455440 +Ref: figure-array-elements457413 +Ref: Array Intro-Footnote-1459937 +Node: Reference to Elements460065 +Node: Assigning Elements462515 +Node: Array Example463006 +Node: Scanning an Array464738 +Node: Controlling Scanning467739 +Ref: Controlling Scanning-Footnote-1472912 +Node: Delete473228 +Ref: Delete-Footnote-1475979 +Node: Numeric Array Subscripts476036 +Node: Uninitialized Subscripts478219 +Node: Multidimensional479844 +Node: Multiscanning482957 +Node: Arrays of Arrays484546 +Node: Arrays Summary489209 +Node: Functions491314 +Node: Built-in492187 +Node: Calling Built-in493265 +Node: Numeric Functions495253 +Ref: Numeric Functions-Footnote-1499287 +Ref: Numeric Functions-Footnote-2499644 +Ref: Numeric Functions-Footnote-3499692 +Node: String Functions499961 +Ref: String Functions-Footnote-1522958 +Ref: String Functions-Footnote-2523087 +Ref: String Functions-Footnote-3523335 +Node: Gory Details523422 +Ref: table-sub-escapes525195 +Ref: table-sub-proposed526715 +Ref: table-posix-sub528079 +Ref: table-gensub-escapes529619 +Ref: Gory Details-Footnote-1530795 +Node: I/O Functions530946 +Ref: I/O Functions-Footnote-1538056 +Node: Time Functions538203 +Ref: Time Functions-Footnote-1548667 +Ref: Time Functions-Footnote-2548735 +Ref: Time Functions-Footnote-3548893 +Ref: Time Functions-Footnote-4549004 +Ref: Time Functions-Footnote-5549116 +Ref: Time Functions-Footnote-6549343 +Node: Bitwise Functions549609 +Ref: table-bitwise-ops550171 +Ref: Bitwise Functions-Footnote-1554416 +Node: Type Functions554600 +Node: I18N Functions555742 +Node: User-defined557387 +Node: Definition Syntax558191 +Ref: Definition Syntax-Footnote-1563502 +Node: Function Example563571 +Ref: Function Example-Footnote-1566211 +Node: Function Caveats566233 +Node: Calling A Function566751 +Node: Variable Scope567706 +Node: Pass By Value/Reference570694 +Node: Return Statement574204 +Node: Dynamic Typing577188 +Node: Indirect Calls578117 +Node: Functions Summary587830 +Node: Library Functions590369 +Ref: Library Functions-Footnote-1593987 +Ref: Library Functions-Footnote-2594130 +Node: Library Names594301 +Ref: Library Names-Footnote-1597774 +Ref: Library Names-Footnote-2597994 +Node: General Functions598080 +Node: Strtonum Function599108 +Node: Assert Function601888 +Node: Round Function605214 +Node: Cliff Random Function606755 +Node: Ordinal Functions607771 +Ref: Ordinal Functions-Footnote-1610836 +Ref: Ordinal Functions-Footnote-2611088 +Node: Join Function611299 +Ref: Join Function-Footnote-1613070 +Node: Getlocaltime Function613270 +Node: Readfile Function617006 +Node: Data File Management618845 +Node: Filetrans Function619477 +Node: Rewind Function623546 +Node: File Checking625104 +Ref: File Checking-Footnote-1626236 +Node: Empty Files626437 +Node: Ignoring Assigns628416 +Node: Getopt Function629970 +Ref: Getopt Function-Footnote-1641273 +Node: Passwd Functions641476 +Ref: Passwd Functions-Footnote-1650455 +Node: Group Functions650543 +Ref: Group Functions-Footnote-1658474 +Node: Walking Arrays658687 +Node: Library Functions Summary660290 +Node: Library exercises661678 +Node: Sample Programs662958 +Node: Running Examples663728 +Node: Clones664456 +Node: Cut Program665680 +Node: Egrep Program675538 +Ref: Egrep Program-Footnote-1683125 +Node: Id Program683235 +Node: Split Program686889 +Ref: Split Program-Footnote-1690427 +Node: Tee Program690555 +Node: Uniq Program693342 +Node: Wc Program700763 +Ref: Wc Program-Footnote-1705028 +Node: Miscellaneous Programs705120 +Node: Dupword Program706333 +Node: Alarm Program708364 +Node: Translate Program713168 +Ref: Translate Program-Footnote-1717559 +Ref: Translate Program-Footnote-2717829 +Node: Labels Program717963 +Ref: Labels Program-Footnote-1721324 +Node: Word Sorting721408 +Node: History Sorting725451 +Node: Extract Program727287 +Node: Simple Sed734823 +Node: Igawk Program737885 +Ref: Igawk Program-Footnote-1752189 +Ref: Igawk Program-Footnote-2752390 +Node: Anagram Program752528 +Node: Signature Program755596 +Node: Programs Summary756843 +Node: Programs Exercises758058 +Node: Advanced Features761709 +Node: Nondecimal Data763657 +Node: Array Sorting765234 +Node: Controlling Array Traversal765931 +Node: Array Sorting Functions774211 +Ref: Array Sorting Functions-Footnote-1778118 +Node: Two-way I/O778312 +Ref: Two-way I/O-Footnote-1783256 +Ref: Two-way I/O-Footnote-2783435 +Node: TCP/IP Networking783517 +Node: Profiling786362 +Node: Advanced Features Summary793904 +Node: Internationalization795768 +Node: I18N and L10N797248 +Node: Explaining gettext797934 +Ref: Explaining gettext-Footnote-1802960 +Ref: Explaining gettext-Footnote-2803144 +Node: Programmer i18n803309 +Ref: Programmer i18n-Footnote-1808103 +Node: Translator i18n808152 +Node: String Extraction808946 +Ref: String Extraction-Footnote-1810079 +Node: Printf Ordering810165 +Ref: Printf Ordering-Footnote-1812947 +Node: I18N Portability813011 +Ref: I18N Portability-Footnote-1815460 +Node: I18N Example815523 +Ref: I18N Example-Footnote-1818229 +Node: Gawk I18N818301 +Node: I18N Summary818939 +Node: Debugger820278 +Node: Debugging821300 +Node: Debugging Concepts821741 +Node: Debugging Terms823597 +Node: Awk Debugging826194 +Node: Sample Debugging Session827086 +Node: Debugger Invocation827606 +Node: Finding The Bug828939 +Node: List of Debugger Commands835421 +Node: Breakpoint Control836753 +Node: Debugger Execution Control840417 +Node: Viewing And Changing Data843777 +Node: Execution Stack847135 +Node: Debugger Info848648 +Node: Miscellaneous Debugger Commands852642 +Node: Readline Support857826 +Node: Limitations858718 +Node: Debugging Summary860992 +Node: Arbitrary Precision Arithmetic862160 +Node: Computer Arithmetic863647 +Ref: Computer Arithmetic-Footnote-1868034 +Node: Math Definitions868091 +Ref: table-ieee-formats871380 +Ref: Math Definitions-Footnote-1871920 +Node: MPFR features872023 +Node: FP Math Caution873640 +Ref: FP Math Caution-Footnote-1874690 +Node: Inexactness of computations875059 +Node: Inexact representation876007 +Node: Comparing FP Values877362 +Node: Errors accumulate878326 +Node: Getting Accuracy879759 +Node: Try To Round882418 +Node: Setting precision883317 +Ref: table-predefined-precision-strings883999 +Node: Setting the rounding mode885792 +Ref: table-gawk-rounding-modes886156 +Ref: Setting the rounding mode-Footnote-1889610 +Node: Arbitrary Precision Integers889789 +Ref: Arbitrary Precision Integers-Footnote-1892770 +Node: POSIX Floating Point Problems892919 +Ref: POSIX Floating Point Problems-Footnote-1896795 +Node: Floating point summary896833 +Node: Dynamic Extensions899037 +Node: Extension Intro900589 +Node: Plugin License901854 +Node: Extension Mechanism Outline902539 +Ref: figure-load-extension902963 +Ref: figure-load-new-function904448 +Ref: figure-call-new-function905450 +Node: Extension API Description907434 +Node: Extension API Functions Introduction908884 +Node: General Data Types913751 +Ref: General Data Types-Footnote-1919444 +Node: Requesting Values919743 +Ref: table-value-types-returned920480 +Node: Memory Allocation Functions921438 +Ref: Memory Allocation Functions-Footnote-1924185 +Node: Constructor Functions924281 +Node: Registration Functions926039 +Node: Extension Functions926724 +Node: Exit Callback Functions929026 +Node: Extension Version String930274 +Node: Input Parsers930924 +Node: Output Wrappers940738 +Node: Two-way processors945254 +Node: Printing Messages947458 +Ref: Printing Messages-Footnote-1948535 +Node: Updating `ERRNO'948687 +Node: Accessing Parameters949426 +Node: Symbol Table Access950656 +Node: Symbol table by name951170 +Node: Symbol table by cookie953146 +Ref: Symbol table by cookie-Footnote-1957279 +Node: Cached values957342 +Ref: Cached values-Footnote-1960846 +Node: Array Manipulation960937 +Ref: Array Manipulation-Footnote-1962035 +Node: Array Data Types962074 +Ref: Array Data Types-Footnote-1964777 +Node: Array Functions964869 +Node: Flattening Arrays968743 +Node: Creating Arrays975595 +Node: Extension API Variables980326 +Node: Extension Versioning980962 +Node: Extension API Informational Variables982863 +Node: Extension API Boilerplate983949 +Node: Finding Extensions987753 +Node: Extension Example988313 +Node: Internal File Description989043 +Node: Internal File Ops993134 +Ref: Internal File Ops-Footnote-11004566 +Node: Using Internal File Ops1004706 +Ref: Using Internal File Ops-Footnote-11007053 +Node: Extension Samples1007321 +Node: Extension Sample File Functions1008845 +Node: Extension Sample Fnmatch1016413 +Node: Extension Sample Fork1017895 +Node: Extension Sample Inplace1019108 +Node: Extension Sample Ord1020783 +Node: Extension Sample Readdir1021619 +Ref: table-readdir-file-types1022475 +Node: Extension Sample Revout1023274 +Node: Extension Sample Rev2way1023865 +Node: Extension Sample Read write array1024606 +Node: Extension Sample Readfile1026485 +Node: Extension Sample API Tests1027585 +Node: Extension Sample Time1028110 +Node: gawkextlib1029425 +Node: Extension summary1032238 +Node: Extension Exercises1035931 +Node: Language History1036653 +Node: V7/SVR3.11038296 +Node: SVR41040616 +Node: POSIX1042058 +Node: BTL1043444 +Node: POSIX/GNU1044178 +Node: Feature History1049894 +Node: Common Extensions1062985 +Node: Ranges and Locales1064297 +Ref: Ranges and Locales-Footnote-11068914 +Ref: Ranges and Locales-Footnote-21068941 +Ref: Ranges and Locales-Footnote-31069175 +Node: Contributors1069396 +Node: History summary1074821 +Node: Installation1076190 +Node: Gawk Distribution1077141 +Node: Getting1077625 +Node: Extracting1078449 +Node: Distribution contents1080091 +Node: Unix Installation1085808 +Node: Quick Installation1086425 +Node: Additional Configuration Options1088867 +Node: Configuration Philosophy1090605 +Node: Non-Unix Installation1092956 +Node: PC Installation1093414 +Node: PC Binary Installation1094725 +Node: PC Compiling1096573 +Ref: PC Compiling-Footnote-11099572 +Node: PC Testing1099677 +Node: PC Using1100853 +Node: Cygwin1105005 +Node: MSYS1105814 +Node: VMS Installation1106328 +Node: VMS Compilation1107124 +Ref: VMS Compilation-Footnote-11108346 +Node: VMS Dynamic Extensions1108404 +Node: VMS Installation Details1109777 +Node: VMS Running1112029 +Node: VMS GNV1114863 +Node: VMS Old Gawk1115586 +Node: Bugs1116056 +Node: Other Versions1120060 +Node: Installation summary1126287 +Node: Notes1127343 +Node: Compatibility Mode1128208 +Node: Additions1128990 +Node: Accessing The Source1129915 +Node: Adding Code1131351 +Node: New Ports1137529 +Node: Derived Files1142010 +Ref: Derived Files-Footnote-11147091 +Ref: Derived Files-Footnote-21147125 +Ref: Derived Files-Footnote-31147721 +Node: Future Extensions1147835 +Node: Implementation Limitations1148441 +Node: Extension Design1149689 +Node: Old Extension Problems1150843 +Ref: Old Extension Problems-Footnote-11152360 +Node: Extension New Mechanism Goals1152417 +Ref: Extension New Mechanism Goals-Footnote-11155777 +Node: Extension Other Design Decisions1155966 +Node: Extension Future Growth1158072 +Node: Old Extension Mechanism1158908 +Node: Notes summary1160670 +Node: Basic Concepts1161856 +Node: Basic High Level1162537 +Ref: figure-general-flow1162809 +Ref: figure-process-flow1163408 +Ref: Basic High Level-Footnote-11166637 +Node: Basic Data Typing1166822 +Node: Glossary1170150 +Node: Copying1195302 +Node: GNU Free Documentation License1232858 +Node: Index1257994  End Tag Table -- cgit v1.2.3 From 5167f5aaabb5adb4801be9f46ba3ba16596014c3 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Mon, 25 Aug 2014 22:29:27 +0300 Subject: Exclude exercises from print edition. --- doc/gawk.info | 1122 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 566 insertions(+), 556 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index caf36e31..850c8e73 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -219,6 +219,7 @@ entitled "GNU Free Documentation License". * Command-line directories:: What happens if you put a directory on the command line. * Input Summary:: Input summary. + * Input Exercises:: Exercises. * Print:: The `print' statement. * Print Examples:: Simple examples of `print' @@ -244,7 +245,8 @@ entitled "GNU Free Documentation License". * Close Files And Pipes:: Closing Input and Output Files and Pipes. * Output Summary:: Output summary. -* Output exercises:: Exercises. + +* Output Exercises:: Exercises. * Values:: Constants, Variables, and Regular Expressions. * Constants:: String, numeric and regexp constants. @@ -431,7 +433,8 @@ entitled "GNU Free Documentation License". information. * Walking Arrays:: A function to walk arrays of arrays. * Library Functions Summary:: Summary of library functions. -* Library exercises:: Exercises. + +* Library Exercises:: Exercises. * Running Examples:: How to run these examples. * Clones:: Clones of common utilities. * Cut Program:: The `cut' utility. @@ -462,6 +465,7 @@ entitled "GNU Free Documentation License". * Signature Program:: People do amazing things with too much time on their hands. * Programs Summary:: Summary of programs. + * Programs Exercises:: Exercises. * Nondecimal Data:: Allowing nondecimal input data. * Array Sorting:: Facilities for controlling array @@ -584,6 +588,7 @@ entitled "GNU Free Documentation License". and `sleep()'. * gawkextlib:: The `gawkextlib' project. * Extension summary:: Extension summary. + * Extension Exercises:: Exercises. * V7/SVR3.1:: The major changes between V7 and System V Release 3.1. @@ -4079,6 +4084,7 @@ have to be named on the `awk' command line (*note Getline::). * Command-line directories:: What happens if you put a directory on the command line. * Input Summary:: Input summary. + * Input Exercises:: Exercises.  @@ -6019,7 +6025,8 @@ function. descriptors. * Close Files And Pipes:: Closing Input and Output Files and Pipes. * Output Summary:: Output summary. -* Output exercises:: Exercises. + +* Output Exercises:: Exercises.  File: gawk.info, Node: Print, Next: Print Examples, Up: Printing @@ -7081,7 +7088,7 @@ call. See the system manual pages for information on how to decode this value.  -File: gawk.info, Node: Output Summary, Next: Output exercises, Prev: Close Files And Pipes, Up: Printing +File: gawk.info, Node: Output Summary, Next: Output Exercises, Prev: Close Files And Pipes, Up: Printing 5.9 Summary =========== @@ -7107,7 +7114,7 @@ File: gawk.info, Node: Output Summary, Next: Output exercises, Prev: Close Fi  -File: gawk.info, Node: Output exercises, Prev: Output Summary, Up: Printing +File: gawk.info, Node: Output Exercises, Prev: Output Summary, Up: Printing 5.10 Exercises ============== @@ -13253,7 +13260,7 @@ File: gawk.info, Node: Definition Syntax, Next: Function Example, Up: User-de -------------------------------- It's entirely fair to say that the `awk' syntax for local variable - definitions is appallingly awful -- Brian Kernighan + definitions is appallingly awful. -- Brian Kernighan Definitions of functions can appear anywhere between the rules of an `awk' program. Thus, the general form of an `awk' program is extended @@ -14243,7 +14250,8 @@ for different implementations of `awk' is pretty straightforward. * Group Functions:: Functions for getting group information. * Walking Arrays:: A function to walk arrays of arrays. * Library Functions Summary:: Summary of library functions. -* Library exercises:: Exercises. + +* Library Exercises:: Exercises. ---------- Footnotes ---------- @@ -15998,7 +16006,7 @@ value. Here is a main program to demonstrate: -| a[3] = 3  -File: gawk.info, Node: Library Functions Summary, Next: Library exercises, Prev: Walking Arrays, Up: Library Functions +File: gawk.info, Node: Library Functions Summary, Next: Library Exercises, Prev: Walking Arrays, Up: Library Functions 10.8 Summary ============ @@ -16035,7 +16043,7 @@ File: gawk.info, Node: Library Functions Summary, Next: Library exercises, Pr  -File: gawk.info, Node: Library exercises, Prev: Library Functions Summary, Up: Library Functions +File: gawk.info, Node: Library Exercises, Prev: Library Functions Summary, Up: Library Functions 10.9 Exercises ============== @@ -16085,6 +16093,7 @@ Library Functions::. * Clones:: Clones of common utilities. * Miscellaneous Programs:: Some interesting `awk' programs. * Programs Summary:: Summary of programs. + * Programs Exercises:: Exercises.  @@ -22287,6 +22296,7 @@ sample extensions are automatically built and installed when `gawk' is. `gawk'. * gawkextlib:: The `gawkextlib' project. * Extension summary:: Extension summary. + * Extension Exercises:: Exercises.  @@ -33974,552 +33984,552 @@ Index  Tag Table: Node: Top1204 -Node: Foreword41858 -Node: Preface46203 -Ref: Preface-Footnote-149226 -Ref: Preface-Footnote-249333 -Node: History49565 -Node: Names51939 -Ref: Names-Footnote-153033 -Node: This Manual53179 -Ref: This Manual-Footnote-158958 -Node: Conventions59058 -Node: Manual History61403 -Ref: Manual History-Footnote-164479 -Ref: Manual History-Footnote-264520 -Node: How To Contribute64594 -Node: Acknowledgments65833 -Node: Getting Started70581 -Node: Running gawk73015 -Node: One-shot74205 -Node: Read Terminal75430 -Ref: Read Terminal-Footnote-177393 -Node: Long77564 -Node: Executable Scripts78958 -Ref: Executable Scripts-Footnote-181759 -Node: Comments81861 -Node: Quoting84334 -Node: DOS Quoting89647 -Node: Sample Data Files90322 -Node: Very Simple92929 -Node: Two Rules97688 -Node: More Complex99582 -Ref: More Complex-Footnote-1102514 -Node: Statements/Lines102599 -Ref: Statements/Lines-Footnote-1107055 -Node: Other Features107320 -Node: When108248 -Ref: When-Footnote-1110004 -Node: Intro Summary110069 -Node: Invoking Gawk110952 -Node: Command Line112467 -Node: Options113258 -Ref: Options-Footnote-1129034 -Node: Other Arguments129059 -Node: Naming Standard Input131721 -Node: Environment Variables132814 -Node: AWKPATH Variable133372 -Ref: AWKPATH Variable-Footnote-1136238 -Ref: AWKPATH Variable-Footnote-2136283 -Node: AWKLIBPATH Variable136543 -Node: Other Environment Variables137302 -Node: Exit Status140959 -Node: Include Files141634 -Node: Loading Shared Libraries145212 -Node: Obsolete146596 -Node: Undocumented147293 -Node: Invoking Summary147560 -Node: Regexp149160 -Node: Regexp Usage150619 -Node: Escape Sequences152652 -Node: Regexp Operators158469 -Ref: Regexp Operators-Footnote-1165900 -Ref: Regexp Operators-Footnote-2166047 -Node: Bracket Expressions166145 -Ref: table-char-classes168167 -Node: GNU Regexp Operators171107 -Node: Case-sensitivity174816 -Ref: Case-sensitivity-Footnote-1177708 -Ref: Case-sensitivity-Footnote-2177943 -Node: Leftmost Longest178051 -Node: Computed Regexps179252 -Node: Regexp Summary182624 -Node: Reading Files184093 -Node: Records186185 -Node: awk split records186907 -Node: gawk split records191765 -Ref: gawk split records-Footnote-1196286 -Node: Fields196323 -Ref: Fields-Footnote-1199287 -Node: Nonconstant Fields199373 -Ref: Nonconstant Fields-Footnote-1201603 -Node: Changing Fields201805 -Node: Field Separators207759 -Node: Default Field Splitting210461 -Node: Regexp Field Splitting211578 -Node: Single Character Fields214905 -Node: Command Line Field Separator215964 -Node: Full Line Fields219390 -Ref: Full Line Fields-Footnote-1219898 -Node: Field Splitting Summary219944 -Ref: Field Splitting Summary-Footnote-1223076 -Node: Constant Size223177 -Node: Splitting By Content227783 -Ref: Splitting By Content-Footnote-1231856 -Node: Multiple Line231896 -Ref: Multiple Line-Footnote-1237752 -Node: Getline237931 -Node: Plain Getline240142 -Node: Getline/Variable242237 -Node: Getline/File243384 -Node: Getline/Variable/File244768 -Ref: Getline/Variable/File-Footnote-1246367 -Node: Getline/Pipe246454 -Node: Getline/Variable/Pipe249140 -Node: Getline/Coprocess250247 -Node: Getline/Variable/Coprocess251499 -Node: Getline Notes252236 -Node: Getline Summary255040 -Ref: table-getline-variants255448 -Node: Read Timeout256360 -Ref: Read Timeout-Footnote-1260187 -Node: Command-line directories260245 -Node: Input Summary261149 -Node: Input Exercises264286 -Node: Printing265019 -Node: Print266741 -Node: Print Examples268234 -Node: Output Separators271013 -Node: OFMT273029 -Node: Printf274387 -Node: Basic Printf275293 -Node: Control Letters276832 -Node: Format Modifiers280823 -Node: Printf Examples286850 -Node: Redirection289314 -Node: Special Files296286 -Node: Special FD296819 -Ref: Special FD-Footnote-1300416 -Node: Special Network300490 -Node: Special Caveats301340 -Node: Close Files And Pipes302136 -Ref: Close Files And Pipes-Footnote-1309297 -Ref: Close Files And Pipes-Footnote-2309445 -Node: Output Summary309595 -Node: Output exercises310592 -Node: Expressions311272 -Node: Values312457 -Node: Constants313133 -Node: Scalar Constants313813 -Ref: Scalar Constants-Footnote-1314672 -Node: Nondecimal-numbers314922 -Node: Regexp Constants317922 -Node: Using Constant Regexps318397 -Node: Variables321469 -Node: Using Variables322124 -Node: Assignment Options323848 -Node: Conversion325723 -Node: Strings And Numbers326247 -Ref: Strings And Numbers-Footnote-1329309 -Node: Locale influences conversions329418 -Ref: table-locale-affects332135 -Node: All Operators332723 -Node: Arithmetic Ops333353 -Node: Concatenation335858 -Ref: Concatenation-Footnote-1338677 -Node: Assignment Ops338783 -Ref: table-assign-ops343766 -Node: Increment Ops345069 -Node: Truth Values and Conditions348507 -Node: Truth Values349590 -Node: Typing and Comparison350639 -Node: Variable Typing351432 -Node: Comparison Operators355084 -Ref: table-relational-ops355494 -Node: POSIX String Comparison359044 -Ref: POSIX String Comparison-Footnote-1360128 -Node: Boolean Ops360266 -Ref: Boolean Ops-Footnote-1364341 -Node: Conditional Exp364432 -Node: Function Calls366159 -Node: Precedence370039 -Node: Locales373708 -Node: Expressions Summary375339 -Node: Patterns and Actions377880 -Node: Pattern Overview378996 -Node: Regexp Patterns380673 -Node: Expression Patterns381216 -Node: Ranges384996 -Node: BEGIN/END388102 -Node: Using BEGIN/END388864 -Ref: Using BEGIN/END-Footnote-1391600 -Node: I/O And BEGIN/END391706 -Node: BEGINFILE/ENDFILE393977 -Node: Empty396908 -Node: Using Shell Variables397225 -Node: Action Overview399508 -Node: Statements401835 -Node: If Statement403683 -Node: While Statement405181 -Node: Do Statement407225 -Node: For Statement408381 -Node: Switch Statement411533 -Node: Break Statement413921 -Node: Continue Statement415962 -Node: Next Statement417787 -Node: Nextfile Statement420177 -Node: Exit Statement422813 -Node: Built-in Variables425217 -Node: User-modified426344 -Ref: User-modified-Footnote-1434033 -Node: Auto-set434095 -Ref: Auto-set-Footnote-1446677 -Ref: Auto-set-Footnote-2446882 -Node: ARGC and ARGV446938 -Node: Pattern Action Summary450842 -Node: Arrays453065 -Node: Array Basics454614 -Node: Array Intro455440 -Ref: figure-array-elements457413 -Ref: Array Intro-Footnote-1459937 -Node: Reference to Elements460065 -Node: Assigning Elements462515 -Node: Array Example463006 -Node: Scanning an Array464738 -Node: Controlling Scanning467739 -Ref: Controlling Scanning-Footnote-1472912 -Node: Delete473228 -Ref: Delete-Footnote-1475979 -Node: Numeric Array Subscripts476036 -Node: Uninitialized Subscripts478219 -Node: Multidimensional479844 -Node: Multiscanning482957 -Node: Arrays of Arrays484546 -Node: Arrays Summary489209 -Node: Functions491314 -Node: Built-in492187 -Node: Calling Built-in493265 -Node: Numeric Functions495253 -Ref: Numeric Functions-Footnote-1499287 -Ref: Numeric Functions-Footnote-2499644 -Ref: Numeric Functions-Footnote-3499692 -Node: String Functions499961 -Ref: String Functions-Footnote-1522958 -Ref: String Functions-Footnote-2523087 -Ref: String Functions-Footnote-3523335 -Node: Gory Details523422 -Ref: table-sub-escapes525195 -Ref: table-sub-proposed526715 -Ref: table-posix-sub528079 -Ref: table-gensub-escapes529619 -Ref: Gory Details-Footnote-1530795 -Node: I/O Functions530946 -Ref: I/O Functions-Footnote-1538056 -Node: Time Functions538203 -Ref: Time Functions-Footnote-1548667 -Ref: Time Functions-Footnote-2548735 -Ref: Time Functions-Footnote-3548893 -Ref: Time Functions-Footnote-4549004 -Ref: Time Functions-Footnote-5549116 -Ref: Time Functions-Footnote-6549343 -Node: Bitwise Functions549609 -Ref: table-bitwise-ops550171 -Ref: Bitwise Functions-Footnote-1554416 -Node: Type Functions554600 -Node: I18N Functions555742 -Node: User-defined557387 -Node: Definition Syntax558191 -Ref: Definition Syntax-Footnote-1563502 -Node: Function Example563571 -Ref: Function Example-Footnote-1566211 -Node: Function Caveats566233 -Node: Calling A Function566751 -Node: Variable Scope567706 -Node: Pass By Value/Reference570694 -Node: Return Statement574204 -Node: Dynamic Typing577188 -Node: Indirect Calls578117 -Node: Functions Summary587830 -Node: Library Functions590369 -Ref: Library Functions-Footnote-1593987 -Ref: Library Functions-Footnote-2594130 -Node: Library Names594301 -Ref: Library Names-Footnote-1597774 -Ref: Library Names-Footnote-2597994 -Node: General Functions598080 -Node: Strtonum Function599108 -Node: Assert Function601888 -Node: Round Function605214 -Node: Cliff Random Function606755 -Node: Ordinal Functions607771 -Ref: Ordinal Functions-Footnote-1610836 -Ref: Ordinal Functions-Footnote-2611088 -Node: Join Function611299 -Ref: Join Function-Footnote-1613070 -Node: Getlocaltime Function613270 -Node: Readfile Function617006 -Node: Data File Management618845 -Node: Filetrans Function619477 -Node: Rewind Function623546 -Node: File Checking625104 -Ref: File Checking-Footnote-1626236 -Node: Empty Files626437 -Node: Ignoring Assigns628416 -Node: Getopt Function629970 -Ref: Getopt Function-Footnote-1641273 -Node: Passwd Functions641476 -Ref: Passwd Functions-Footnote-1650455 -Node: Group Functions650543 -Ref: Group Functions-Footnote-1658474 -Node: Walking Arrays658687 -Node: Library Functions Summary660290 -Node: Library exercises661678 -Node: Sample Programs662958 -Node: Running Examples663728 -Node: Clones664456 -Node: Cut Program665680 -Node: Egrep Program675538 -Ref: Egrep Program-Footnote-1683125 -Node: Id Program683235 -Node: Split Program686889 -Ref: Split Program-Footnote-1690427 -Node: Tee Program690555 -Node: Uniq Program693342 -Node: Wc Program700763 -Ref: Wc Program-Footnote-1705028 -Node: Miscellaneous Programs705120 -Node: Dupword Program706333 -Node: Alarm Program708364 -Node: Translate Program713168 -Ref: Translate Program-Footnote-1717559 -Ref: Translate Program-Footnote-2717829 -Node: Labels Program717963 -Ref: Labels Program-Footnote-1721324 -Node: Word Sorting721408 -Node: History Sorting725451 -Node: Extract Program727287 -Node: Simple Sed734823 -Node: Igawk Program737885 -Ref: Igawk Program-Footnote-1752189 -Ref: Igawk Program-Footnote-2752390 -Node: Anagram Program752528 -Node: Signature Program755596 -Node: Programs Summary756843 -Node: Programs Exercises758058 -Node: Advanced Features761709 -Node: Nondecimal Data763657 -Node: Array Sorting765234 -Node: Controlling Array Traversal765931 -Node: Array Sorting Functions774211 -Ref: Array Sorting Functions-Footnote-1778118 -Node: Two-way I/O778312 -Ref: Two-way I/O-Footnote-1783256 -Ref: Two-way I/O-Footnote-2783435 -Node: TCP/IP Networking783517 -Node: Profiling786362 -Node: Advanced Features Summary793904 -Node: Internationalization795768 -Node: I18N and L10N797248 -Node: Explaining gettext797934 -Ref: Explaining gettext-Footnote-1802960 -Ref: Explaining gettext-Footnote-2803144 -Node: Programmer i18n803309 -Ref: Programmer i18n-Footnote-1808103 -Node: Translator i18n808152 -Node: String Extraction808946 -Ref: String Extraction-Footnote-1810079 -Node: Printf Ordering810165 -Ref: Printf Ordering-Footnote-1812947 -Node: I18N Portability813011 -Ref: I18N Portability-Footnote-1815460 -Node: I18N Example815523 -Ref: I18N Example-Footnote-1818229 -Node: Gawk I18N818301 -Node: I18N Summary818939 -Node: Debugger820278 -Node: Debugging821300 -Node: Debugging Concepts821741 -Node: Debugging Terms823597 -Node: Awk Debugging826194 -Node: Sample Debugging Session827086 -Node: Debugger Invocation827606 -Node: Finding The Bug828939 -Node: List of Debugger Commands835421 -Node: Breakpoint Control836753 -Node: Debugger Execution Control840417 -Node: Viewing And Changing Data843777 -Node: Execution Stack847135 -Node: Debugger Info848648 -Node: Miscellaneous Debugger Commands852642 -Node: Readline Support857826 -Node: Limitations858718 -Node: Debugging Summary860992 -Node: Arbitrary Precision Arithmetic862160 -Node: Computer Arithmetic863647 -Ref: Computer Arithmetic-Footnote-1868034 -Node: Math Definitions868091 -Ref: table-ieee-formats871380 -Ref: Math Definitions-Footnote-1871920 -Node: MPFR features872023 -Node: FP Math Caution873640 -Ref: FP Math Caution-Footnote-1874690 -Node: Inexactness of computations875059 -Node: Inexact representation876007 -Node: Comparing FP Values877362 -Node: Errors accumulate878326 -Node: Getting Accuracy879759 -Node: Try To Round882418 -Node: Setting precision883317 -Ref: table-predefined-precision-strings883999 -Node: Setting the rounding mode885792 -Ref: table-gawk-rounding-modes886156 -Ref: Setting the rounding mode-Footnote-1889610 -Node: Arbitrary Precision Integers889789 -Ref: Arbitrary Precision Integers-Footnote-1892770 -Node: POSIX Floating Point Problems892919 -Ref: POSIX Floating Point Problems-Footnote-1896795 -Node: Floating point summary896833 -Node: Dynamic Extensions899037 -Node: Extension Intro900589 -Node: Plugin License901854 -Node: Extension Mechanism Outline902539 -Ref: figure-load-extension902963 -Ref: figure-load-new-function904448 -Ref: figure-call-new-function905450 -Node: Extension API Description907434 -Node: Extension API Functions Introduction908884 -Node: General Data Types913751 -Ref: General Data Types-Footnote-1919444 -Node: Requesting Values919743 -Ref: table-value-types-returned920480 -Node: Memory Allocation Functions921438 -Ref: Memory Allocation Functions-Footnote-1924185 -Node: Constructor Functions924281 -Node: Registration Functions926039 -Node: Extension Functions926724 -Node: Exit Callback Functions929026 -Node: Extension Version String930274 -Node: Input Parsers930924 -Node: Output Wrappers940738 -Node: Two-way processors945254 -Node: Printing Messages947458 -Ref: Printing Messages-Footnote-1948535 -Node: Updating `ERRNO'948687 -Node: Accessing Parameters949426 -Node: Symbol Table Access950656 -Node: Symbol table by name951170 -Node: Symbol table by cookie953146 -Ref: Symbol table by cookie-Footnote-1957279 -Node: Cached values957342 -Ref: Cached values-Footnote-1960846 -Node: Array Manipulation960937 -Ref: Array Manipulation-Footnote-1962035 -Node: Array Data Types962074 -Ref: Array Data Types-Footnote-1964777 -Node: Array Functions964869 -Node: Flattening Arrays968743 -Node: Creating Arrays975595 -Node: Extension API Variables980326 -Node: Extension Versioning980962 -Node: Extension API Informational Variables982863 -Node: Extension API Boilerplate983949 -Node: Finding Extensions987753 -Node: Extension Example988313 -Node: Internal File Description989043 -Node: Internal File Ops993134 -Ref: Internal File Ops-Footnote-11004566 -Node: Using Internal File Ops1004706 -Ref: Using Internal File Ops-Footnote-11007053 -Node: Extension Samples1007321 -Node: Extension Sample File Functions1008845 -Node: Extension Sample Fnmatch1016413 -Node: Extension Sample Fork1017895 -Node: Extension Sample Inplace1019108 -Node: Extension Sample Ord1020783 -Node: Extension Sample Readdir1021619 -Ref: table-readdir-file-types1022475 -Node: Extension Sample Revout1023274 -Node: Extension Sample Rev2way1023865 -Node: Extension Sample Read write array1024606 -Node: Extension Sample Readfile1026485 -Node: Extension Sample API Tests1027585 -Node: Extension Sample Time1028110 -Node: gawkextlib1029425 -Node: Extension summary1032238 -Node: Extension Exercises1035931 -Node: Language History1036653 -Node: V7/SVR3.11038296 -Node: SVR41040616 -Node: POSIX1042058 -Node: BTL1043444 -Node: POSIX/GNU1044178 -Node: Feature History1049894 -Node: Common Extensions1062985 -Node: Ranges and Locales1064297 -Ref: Ranges and Locales-Footnote-11068914 -Ref: Ranges and Locales-Footnote-21068941 -Ref: Ranges and Locales-Footnote-31069175 -Node: Contributors1069396 -Node: History summary1074821 -Node: Installation1076190 -Node: Gawk Distribution1077141 -Node: Getting1077625 -Node: Extracting1078449 -Node: Distribution contents1080091 -Node: Unix Installation1085808 -Node: Quick Installation1086425 -Node: Additional Configuration Options1088867 -Node: Configuration Philosophy1090605 -Node: Non-Unix Installation1092956 -Node: PC Installation1093414 -Node: PC Binary Installation1094725 -Node: PC Compiling1096573 -Ref: PC Compiling-Footnote-11099572 -Node: PC Testing1099677 -Node: PC Using1100853 -Node: Cygwin1105005 -Node: MSYS1105814 -Node: VMS Installation1106328 -Node: VMS Compilation1107124 -Ref: VMS Compilation-Footnote-11108346 -Node: VMS Dynamic Extensions1108404 -Node: VMS Installation Details1109777 -Node: VMS Running1112029 -Node: VMS GNV1114863 -Node: VMS Old Gawk1115586 -Node: Bugs1116056 -Node: Other Versions1120060 -Node: Installation summary1126287 -Node: Notes1127343 -Node: Compatibility Mode1128208 -Node: Additions1128990 -Node: Accessing The Source1129915 -Node: Adding Code1131351 -Node: New Ports1137529 -Node: Derived Files1142010 -Ref: Derived Files-Footnote-11147091 -Ref: Derived Files-Footnote-21147125 -Ref: Derived Files-Footnote-31147721 -Node: Future Extensions1147835 -Node: Implementation Limitations1148441 -Node: Extension Design1149689 -Node: Old Extension Problems1150843 -Ref: Old Extension Problems-Footnote-11152360 -Node: Extension New Mechanism Goals1152417 -Ref: Extension New Mechanism Goals-Footnote-11155777 -Node: Extension Other Design Decisions1155966 -Node: Extension Future Growth1158072 -Node: Old Extension Mechanism1158908 -Node: Notes summary1160670 -Node: Basic Concepts1161856 -Node: Basic High Level1162537 -Ref: figure-general-flow1162809 -Ref: figure-process-flow1163408 -Ref: Basic High Level-Footnote-11166637 -Node: Basic Data Typing1166822 -Node: Glossary1170150 -Node: Copying1195302 -Node: GNU Free Documentation License1232858 -Node: Index1257994 +Node: Foreword41863 +Node: Preface46208 +Ref: Preface-Footnote-149231 +Ref: Preface-Footnote-249338 +Node: History49570 +Node: Names51944 +Ref: Names-Footnote-153038 +Node: This Manual53184 +Ref: This Manual-Footnote-158963 +Node: Conventions59063 +Node: Manual History61408 +Ref: Manual History-Footnote-164484 +Ref: Manual History-Footnote-264525 +Node: How To Contribute64599 +Node: Acknowledgments65838 +Node: Getting Started70586 +Node: Running gawk73020 +Node: One-shot74210 +Node: Read Terminal75435 +Ref: Read Terminal-Footnote-177398 +Node: Long77569 +Node: Executable Scripts78963 +Ref: Executable Scripts-Footnote-181764 +Node: Comments81866 +Node: Quoting84339 +Node: DOS Quoting89652 +Node: Sample Data Files90327 +Node: Very Simple92934 +Node: Two Rules97693 +Node: More Complex99587 +Ref: More Complex-Footnote-1102519 +Node: Statements/Lines102604 +Ref: Statements/Lines-Footnote-1107060 +Node: Other Features107325 +Node: When108253 +Ref: When-Footnote-1110009 +Node: Intro Summary110074 +Node: Invoking Gawk110957 +Node: Command Line112472 +Node: Options113263 +Ref: Options-Footnote-1129039 +Node: Other Arguments129064 +Node: Naming Standard Input131726 +Node: Environment Variables132819 +Node: AWKPATH Variable133377 +Ref: AWKPATH Variable-Footnote-1136243 +Ref: AWKPATH Variable-Footnote-2136288 +Node: AWKLIBPATH Variable136548 +Node: Other Environment Variables137307 +Node: Exit Status140964 +Node: Include Files141639 +Node: Loading Shared Libraries145217 +Node: Obsolete146601 +Node: Undocumented147298 +Node: Invoking Summary147565 +Node: Regexp149165 +Node: Regexp Usage150624 +Node: Escape Sequences152657 +Node: Regexp Operators158474 +Ref: Regexp Operators-Footnote-1165905 +Ref: Regexp Operators-Footnote-2166052 +Node: Bracket Expressions166150 +Ref: table-char-classes168172 +Node: GNU Regexp Operators171112 +Node: Case-sensitivity174821 +Ref: Case-sensitivity-Footnote-1177713 +Ref: Case-sensitivity-Footnote-2177948 +Node: Leftmost Longest178056 +Node: Computed Regexps179257 +Node: Regexp Summary182629 +Node: Reading Files184098 +Node: Records186191 +Node: awk split records186913 +Node: gawk split records191771 +Ref: gawk split records-Footnote-1196292 +Node: Fields196329 +Ref: Fields-Footnote-1199293 +Node: Nonconstant Fields199379 +Ref: Nonconstant Fields-Footnote-1201609 +Node: Changing Fields201811 +Node: Field Separators207765 +Node: Default Field Splitting210467 +Node: Regexp Field Splitting211584 +Node: Single Character Fields214911 +Node: Command Line Field Separator215970 +Node: Full Line Fields219396 +Ref: Full Line Fields-Footnote-1219904 +Node: Field Splitting Summary219950 +Ref: Field Splitting Summary-Footnote-1223082 +Node: Constant Size223183 +Node: Splitting By Content227789 +Ref: Splitting By Content-Footnote-1231862 +Node: Multiple Line231902 +Ref: Multiple Line-Footnote-1237758 +Node: Getline237937 +Node: Plain Getline240148 +Node: Getline/Variable242243 +Node: Getline/File243390 +Node: Getline/Variable/File244774 +Ref: Getline/Variable/File-Footnote-1246373 +Node: Getline/Pipe246460 +Node: Getline/Variable/Pipe249146 +Node: Getline/Coprocess250253 +Node: Getline/Variable/Coprocess251505 +Node: Getline Notes252242 +Node: Getline Summary255046 +Ref: table-getline-variants255454 +Node: Read Timeout256366 +Ref: Read Timeout-Footnote-1260193 +Node: Command-line directories260251 +Node: Input Summary261155 +Node: Input Exercises264292 +Node: Printing265025 +Node: Print266748 +Node: Print Examples268241 +Node: Output Separators271020 +Node: OFMT273036 +Node: Printf274394 +Node: Basic Printf275300 +Node: Control Letters276839 +Node: Format Modifiers280830 +Node: Printf Examples286857 +Node: Redirection289321 +Node: Special Files296293 +Node: Special FD296826 +Ref: Special FD-Footnote-1300423 +Node: Special Network300497 +Node: Special Caveats301347 +Node: Close Files And Pipes302143 +Ref: Close Files And Pipes-Footnote-1309304 +Ref: Close Files And Pipes-Footnote-2309452 +Node: Output Summary309602 +Node: Output Exercises310599 +Node: Expressions311279 +Node: Values312464 +Node: Constants313140 +Node: Scalar Constants313820 +Ref: Scalar Constants-Footnote-1314679 +Node: Nondecimal-numbers314929 +Node: Regexp Constants317929 +Node: Using Constant Regexps318404 +Node: Variables321476 +Node: Using Variables322131 +Node: Assignment Options323855 +Node: Conversion325730 +Node: Strings And Numbers326254 +Ref: Strings And Numbers-Footnote-1329316 +Node: Locale influences conversions329425 +Ref: table-locale-affects332142 +Node: All Operators332730 +Node: Arithmetic Ops333360 +Node: Concatenation335865 +Ref: Concatenation-Footnote-1338684 +Node: Assignment Ops338790 +Ref: table-assign-ops343773 +Node: Increment Ops345076 +Node: Truth Values and Conditions348514 +Node: Truth Values349597 +Node: Typing and Comparison350646 +Node: Variable Typing351439 +Node: Comparison Operators355091 +Ref: table-relational-ops355501 +Node: POSIX String Comparison359051 +Ref: POSIX String Comparison-Footnote-1360135 +Node: Boolean Ops360273 +Ref: Boolean Ops-Footnote-1364348 +Node: Conditional Exp364439 +Node: Function Calls366166 +Node: Precedence370046 +Node: Locales373715 +Node: Expressions Summary375346 +Node: Patterns and Actions377887 +Node: Pattern Overview379003 +Node: Regexp Patterns380680 +Node: Expression Patterns381223 +Node: Ranges385003 +Node: BEGIN/END388109 +Node: Using BEGIN/END388871 +Ref: Using BEGIN/END-Footnote-1391607 +Node: I/O And BEGIN/END391713 +Node: BEGINFILE/ENDFILE393984 +Node: Empty396915 +Node: Using Shell Variables397232 +Node: Action Overview399515 +Node: Statements401842 +Node: If Statement403690 +Node: While Statement405188 +Node: Do Statement407232 +Node: For Statement408388 +Node: Switch Statement411540 +Node: Break Statement413928 +Node: Continue Statement415969 +Node: Next Statement417794 +Node: Nextfile Statement420184 +Node: Exit Statement422820 +Node: Built-in Variables425224 +Node: User-modified426351 +Ref: User-modified-Footnote-1434040 +Node: Auto-set434102 +Ref: Auto-set-Footnote-1446684 +Ref: Auto-set-Footnote-2446889 +Node: ARGC and ARGV446945 +Node: Pattern Action Summary450849 +Node: Arrays453072 +Node: Array Basics454621 +Node: Array Intro455447 +Ref: figure-array-elements457420 +Ref: Array Intro-Footnote-1459944 +Node: Reference to Elements460072 +Node: Assigning Elements462522 +Node: Array Example463013 +Node: Scanning an Array464745 +Node: Controlling Scanning467746 +Ref: Controlling Scanning-Footnote-1472919 +Node: Delete473235 +Ref: Delete-Footnote-1475986 +Node: Numeric Array Subscripts476043 +Node: Uninitialized Subscripts478226 +Node: Multidimensional479851 +Node: Multiscanning482964 +Node: Arrays of Arrays484553 +Node: Arrays Summary489216 +Node: Functions491321 +Node: Built-in492194 +Node: Calling Built-in493272 +Node: Numeric Functions495260 +Ref: Numeric Functions-Footnote-1499294 +Ref: Numeric Functions-Footnote-2499651 +Ref: Numeric Functions-Footnote-3499699 +Node: String Functions499968 +Ref: String Functions-Footnote-1522965 +Ref: String Functions-Footnote-2523094 +Ref: String Functions-Footnote-3523342 +Node: Gory Details523429 +Ref: table-sub-escapes525202 +Ref: table-sub-proposed526722 +Ref: table-posix-sub528086 +Ref: table-gensub-escapes529626 +Ref: Gory Details-Footnote-1530802 +Node: I/O Functions530953 +Ref: I/O Functions-Footnote-1538063 +Node: Time Functions538210 +Ref: Time Functions-Footnote-1548674 +Ref: Time Functions-Footnote-2548742 +Ref: Time Functions-Footnote-3548900 +Ref: Time Functions-Footnote-4549011 +Ref: Time Functions-Footnote-5549123 +Ref: Time Functions-Footnote-6549350 +Node: Bitwise Functions549616 +Ref: table-bitwise-ops550178 +Ref: Bitwise Functions-Footnote-1554423 +Node: Type Functions554607 +Node: I18N Functions555749 +Node: User-defined557394 +Node: Definition Syntax558198 +Ref: Definition Syntax-Footnote-1563511 +Node: Function Example563580 +Ref: Function Example-Footnote-1566220 +Node: Function Caveats566242 +Node: Calling A Function566760 +Node: Variable Scope567715 +Node: Pass By Value/Reference570703 +Node: Return Statement574213 +Node: Dynamic Typing577197 +Node: Indirect Calls578126 +Node: Functions Summary587839 +Node: Library Functions590378 +Ref: Library Functions-Footnote-1593997 +Ref: Library Functions-Footnote-2594140 +Node: Library Names594311 +Ref: Library Names-Footnote-1597784 +Ref: Library Names-Footnote-2598004 +Node: General Functions598090 +Node: Strtonum Function599118 +Node: Assert Function601898 +Node: Round Function605224 +Node: Cliff Random Function606765 +Node: Ordinal Functions607781 +Ref: Ordinal Functions-Footnote-1610846 +Ref: Ordinal Functions-Footnote-2611098 +Node: Join Function611309 +Ref: Join Function-Footnote-1613080 +Node: Getlocaltime Function613280 +Node: Readfile Function617016 +Node: Data File Management618855 +Node: Filetrans Function619487 +Node: Rewind Function623556 +Node: File Checking625114 +Ref: File Checking-Footnote-1626246 +Node: Empty Files626447 +Node: Ignoring Assigns628426 +Node: Getopt Function629980 +Ref: Getopt Function-Footnote-1641283 +Node: Passwd Functions641486 +Ref: Passwd Functions-Footnote-1650465 +Node: Group Functions650553 +Ref: Group Functions-Footnote-1658484 +Node: Walking Arrays658697 +Node: Library Functions Summary660300 +Node: Library Exercises661688 +Node: Sample Programs662968 +Node: Running Examples663739 +Node: Clones664467 +Node: Cut Program665691 +Node: Egrep Program675549 +Ref: Egrep Program-Footnote-1683136 +Node: Id Program683246 +Node: Split Program686900 +Ref: Split Program-Footnote-1690438 +Node: Tee Program690566 +Node: Uniq Program693353 +Node: Wc Program700774 +Ref: Wc Program-Footnote-1705039 +Node: Miscellaneous Programs705131 +Node: Dupword Program706344 +Node: Alarm Program708375 +Node: Translate Program713179 +Ref: Translate Program-Footnote-1717570 +Ref: Translate Program-Footnote-2717840 +Node: Labels Program717974 +Ref: Labels Program-Footnote-1721335 +Node: Word Sorting721419 +Node: History Sorting725462 +Node: Extract Program727298 +Node: Simple Sed734834 +Node: Igawk Program737896 +Ref: Igawk Program-Footnote-1752200 +Ref: Igawk Program-Footnote-2752401 +Node: Anagram Program752539 +Node: Signature Program755607 +Node: Programs Summary756854 +Node: Programs Exercises758069 +Node: Advanced Features761720 +Node: Nondecimal Data763668 +Node: Array Sorting765245 +Node: Controlling Array Traversal765942 +Node: Array Sorting Functions774222 +Ref: Array Sorting Functions-Footnote-1778129 +Node: Two-way I/O778323 +Ref: Two-way I/O-Footnote-1783267 +Ref: Two-way I/O-Footnote-2783446 +Node: TCP/IP Networking783528 +Node: Profiling786373 +Node: Advanced Features Summary793915 +Node: Internationalization795779 +Node: I18N and L10N797259 +Node: Explaining gettext797945 +Ref: Explaining gettext-Footnote-1802971 +Ref: Explaining gettext-Footnote-2803155 +Node: Programmer i18n803320 +Ref: Programmer i18n-Footnote-1808114 +Node: Translator i18n808163 +Node: String Extraction808957 +Ref: String Extraction-Footnote-1810090 +Node: Printf Ordering810176 +Ref: Printf Ordering-Footnote-1812958 +Node: I18N Portability813022 +Ref: I18N Portability-Footnote-1815471 +Node: I18N Example815534 +Ref: I18N Example-Footnote-1818240 +Node: Gawk I18N818312 +Node: I18N Summary818950 +Node: Debugger820289 +Node: Debugging821311 +Node: Debugging Concepts821752 +Node: Debugging Terms823608 +Node: Awk Debugging826205 +Node: Sample Debugging Session827097 +Node: Debugger Invocation827617 +Node: Finding The Bug828950 +Node: List of Debugger Commands835432 +Node: Breakpoint Control836764 +Node: Debugger Execution Control840428 +Node: Viewing And Changing Data843788 +Node: Execution Stack847146 +Node: Debugger Info848659 +Node: Miscellaneous Debugger Commands852653 +Node: Readline Support857837 +Node: Limitations858729 +Node: Debugging Summary861003 +Node: Arbitrary Precision Arithmetic862171 +Node: Computer Arithmetic863658 +Ref: Computer Arithmetic-Footnote-1868045 +Node: Math Definitions868102 +Ref: table-ieee-formats871391 +Ref: Math Definitions-Footnote-1871931 +Node: MPFR features872034 +Node: FP Math Caution873651 +Ref: FP Math Caution-Footnote-1874701 +Node: Inexactness of computations875070 +Node: Inexact representation876018 +Node: Comparing FP Values877373 +Node: Errors accumulate878337 +Node: Getting Accuracy879770 +Node: Try To Round882429 +Node: Setting precision883328 +Ref: table-predefined-precision-strings884010 +Node: Setting the rounding mode885803 +Ref: table-gawk-rounding-modes886167 +Ref: Setting the rounding mode-Footnote-1889621 +Node: Arbitrary Precision Integers889800 +Ref: Arbitrary Precision Integers-Footnote-1892781 +Node: POSIX Floating Point Problems892930 +Ref: POSIX Floating Point Problems-Footnote-1896806 +Node: Floating point summary896844 +Node: Dynamic Extensions899048 +Node: Extension Intro900601 +Node: Plugin License901866 +Node: Extension Mechanism Outline902551 +Ref: figure-load-extension902975 +Ref: figure-load-new-function904460 +Ref: figure-call-new-function905462 +Node: Extension API Description907446 +Node: Extension API Functions Introduction908896 +Node: General Data Types913763 +Ref: General Data Types-Footnote-1919456 +Node: Requesting Values919755 +Ref: table-value-types-returned920492 +Node: Memory Allocation Functions921450 +Ref: Memory Allocation Functions-Footnote-1924197 +Node: Constructor Functions924293 +Node: Registration Functions926051 +Node: Extension Functions926736 +Node: Exit Callback Functions929038 +Node: Extension Version String930286 +Node: Input Parsers930936 +Node: Output Wrappers940750 +Node: Two-way processors945266 +Node: Printing Messages947470 +Ref: Printing Messages-Footnote-1948547 +Node: Updating `ERRNO'948699 +Node: Accessing Parameters949438 +Node: Symbol Table Access950668 +Node: Symbol table by name951182 +Node: Symbol table by cookie953158 +Ref: Symbol table by cookie-Footnote-1957291 +Node: Cached values957354 +Ref: Cached values-Footnote-1960858 +Node: Array Manipulation960949 +Ref: Array Manipulation-Footnote-1962047 +Node: Array Data Types962086 +Ref: Array Data Types-Footnote-1964789 +Node: Array Functions964881 +Node: Flattening Arrays968755 +Node: Creating Arrays975607 +Node: Extension API Variables980338 +Node: Extension Versioning980974 +Node: Extension API Informational Variables982875 +Node: Extension API Boilerplate983961 +Node: Finding Extensions987765 +Node: Extension Example988325 +Node: Internal File Description989055 +Node: Internal File Ops993146 +Ref: Internal File Ops-Footnote-11004578 +Node: Using Internal File Ops1004718 +Ref: Using Internal File Ops-Footnote-11007065 +Node: Extension Samples1007333 +Node: Extension Sample File Functions1008857 +Node: Extension Sample Fnmatch1016425 +Node: Extension Sample Fork1017907 +Node: Extension Sample Inplace1019120 +Node: Extension Sample Ord1020795 +Node: Extension Sample Readdir1021631 +Ref: table-readdir-file-types1022487 +Node: Extension Sample Revout1023286 +Node: Extension Sample Rev2way1023877 +Node: Extension Sample Read write array1024618 +Node: Extension Sample Readfile1026497 +Node: Extension Sample API Tests1027597 +Node: Extension Sample Time1028122 +Node: gawkextlib1029437 +Node: Extension summary1032250 +Node: Extension Exercises1035943 +Node: Language History1036665 +Node: V7/SVR3.11038308 +Node: SVR41040628 +Node: POSIX1042070 +Node: BTL1043456 +Node: POSIX/GNU1044190 +Node: Feature History1049906 +Node: Common Extensions1062997 +Node: Ranges and Locales1064309 +Ref: Ranges and Locales-Footnote-11068926 +Ref: Ranges and Locales-Footnote-21068953 +Ref: Ranges and Locales-Footnote-31069187 +Node: Contributors1069408 +Node: History summary1074833 +Node: Installation1076202 +Node: Gawk Distribution1077153 +Node: Getting1077637 +Node: Extracting1078461 +Node: Distribution contents1080103 +Node: Unix Installation1085820 +Node: Quick Installation1086437 +Node: Additional Configuration Options1088879 +Node: Configuration Philosophy1090617 +Node: Non-Unix Installation1092968 +Node: PC Installation1093426 +Node: PC Binary Installation1094737 +Node: PC Compiling1096585 +Ref: PC Compiling-Footnote-11099584 +Node: PC Testing1099689 +Node: PC Using1100865 +Node: Cygwin1105017 +Node: MSYS1105826 +Node: VMS Installation1106340 +Node: VMS Compilation1107136 +Ref: VMS Compilation-Footnote-11108358 +Node: VMS Dynamic Extensions1108416 +Node: VMS Installation Details1109789 +Node: VMS Running1112041 +Node: VMS GNV1114875 +Node: VMS Old Gawk1115598 +Node: Bugs1116068 +Node: Other Versions1120072 +Node: Installation summary1126299 +Node: Notes1127355 +Node: Compatibility Mode1128220 +Node: Additions1129002 +Node: Accessing The Source1129927 +Node: Adding Code1131363 +Node: New Ports1137541 +Node: Derived Files1142022 +Ref: Derived Files-Footnote-11147103 +Ref: Derived Files-Footnote-21147137 +Ref: Derived Files-Footnote-31147733 +Node: Future Extensions1147847 +Node: Implementation Limitations1148453 +Node: Extension Design1149701 +Node: Old Extension Problems1150855 +Ref: Old Extension Problems-Footnote-11152372 +Node: Extension New Mechanism Goals1152429 +Ref: Extension New Mechanism Goals-Footnote-11155789 +Node: Extension Other Design Decisions1155978 +Node: Extension Future Growth1158084 +Node: Old Extension Mechanism1158920 +Node: Notes summary1160682 +Node: Basic Concepts1161868 +Node: Basic High Level1162549 +Ref: figure-general-flow1162821 +Ref: figure-process-flow1163420 +Ref: Basic High Level-Footnote-11166649 +Node: Basic Data Typing1166834 +Node: Glossary1170162 +Node: Copying1195314 +Node: GNU Free Documentation License1232870 +Node: Index1258006  End Tag Table -- cgit v1.2.3 From 12e05615041147de61658bda8f5e7d5a4acd87c3 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 26 Aug 2014 21:18:03 +0300 Subject: Remove support for MirBSD. Yay! --- doc/gawk.info | 138 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 70 insertions(+), 68 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index b1a3cbdb..ef7847df 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -26184,6 +26184,8 @@ the current version of `gawk'. - Ultrix + * Support for MirBSD was removed at `gawk' version 4.2. +  File: gawk.info, Node: Feature History, Next: Common Extensions, Prev: POSIX/GNU, Up: Language History @@ -34506,73 +34508,73 @@ Node: SVR41042317 Node: POSIX1043759 Node: BTL1045145 Node: POSIX/GNU1045879 -Node: Feature History1051595 -Node: Common Extensions1064686 -Node: Ranges and Locales1065998 -Ref: Ranges and Locales-Footnote-11070615 -Ref: Ranges and Locales-Footnote-21070642 -Ref: Ranges and Locales-Footnote-31070876 -Node: Contributors1071097 -Node: History summary1076522 -Node: Installation1077891 -Node: Gawk Distribution1078842 -Node: Getting1079326 -Node: Extracting1080150 -Node: Distribution contents1081792 -Node: Unix Installation1087562 -Node: Quick Installation1088179 -Node: Additional Configuration Options1090621 -Node: Configuration Philosophy1092359 -Node: Non-Unix Installation1094710 -Node: PC Installation1095168 -Node: PC Binary Installation1096479 -Node: PC Compiling1098327 -Ref: PC Compiling-Footnote-11101326 -Node: PC Testing1101431 -Node: PC Using1102607 -Node: Cygwin1106759 -Node: MSYS1107568 -Node: VMS Installation1108082 -Node: VMS Compilation1108878 -Ref: VMS Compilation-Footnote-11110100 -Node: VMS Dynamic Extensions1110158 -Node: VMS Installation Details1111531 -Node: VMS Running1113783 -Node: VMS GNV1116617 -Node: VMS Old Gawk1117340 -Node: Bugs1117810 -Node: Other Versions1121814 -Node: Installation summary1128041 -Node: Notes1129097 -Node: Compatibility Mode1129962 -Node: Additions1130744 -Node: Accessing The Source1131669 -Node: Adding Code1133105 -Node: New Ports1139283 -Node: Derived Files1143764 -Ref: Derived Files-Footnote-11148845 -Ref: Derived Files-Footnote-21148879 -Ref: Derived Files-Footnote-31149475 -Node: Future Extensions1149589 -Node: Implementation Limitations1150195 -Node: Extension Design1151443 -Node: Old Extension Problems1152597 -Ref: Old Extension Problems-Footnote-11154114 -Node: Extension New Mechanism Goals1154171 -Ref: Extension New Mechanism Goals-Footnote-11157531 -Node: Extension Other Design Decisions1157720 -Node: Extension Future Growth1159826 -Node: Old Extension Mechanism1160662 -Node: Notes summary1162424 -Node: Basic Concepts1163610 -Node: Basic High Level1164291 -Ref: figure-general-flow1164563 -Ref: figure-process-flow1165162 -Ref: Basic High Level-Footnote-11168391 -Node: Basic Data Typing1168576 -Node: Glossary1171904 -Node: Copying1197056 -Node: GNU Free Documentation License1234612 -Node: Index1259748 +Node: Feature History1051655 +Node: Common Extensions1064746 +Node: Ranges and Locales1066058 +Ref: Ranges and Locales-Footnote-11070675 +Ref: Ranges and Locales-Footnote-21070702 +Ref: Ranges and Locales-Footnote-31070936 +Node: Contributors1071157 +Node: History summary1076582 +Node: Installation1077951 +Node: Gawk Distribution1078902 +Node: Getting1079386 +Node: Extracting1080210 +Node: Distribution contents1081852 +Node: Unix Installation1087622 +Node: Quick Installation1088239 +Node: Additional Configuration Options1090681 +Node: Configuration Philosophy1092419 +Node: Non-Unix Installation1094770 +Node: PC Installation1095228 +Node: PC Binary Installation1096539 +Node: PC Compiling1098387 +Ref: PC Compiling-Footnote-11101386 +Node: PC Testing1101491 +Node: PC Using1102667 +Node: Cygwin1106819 +Node: MSYS1107628 +Node: VMS Installation1108142 +Node: VMS Compilation1108938 +Ref: VMS Compilation-Footnote-11110160 +Node: VMS Dynamic Extensions1110218 +Node: VMS Installation Details1111591 +Node: VMS Running1113843 +Node: VMS GNV1116677 +Node: VMS Old Gawk1117400 +Node: Bugs1117870 +Node: Other Versions1121874 +Node: Installation summary1128101 +Node: Notes1129157 +Node: Compatibility Mode1130022 +Node: Additions1130804 +Node: Accessing The Source1131729 +Node: Adding Code1133165 +Node: New Ports1139343 +Node: Derived Files1143824 +Ref: Derived Files-Footnote-11148905 +Ref: Derived Files-Footnote-21148939 +Ref: Derived Files-Footnote-31149535 +Node: Future Extensions1149649 +Node: Implementation Limitations1150255 +Node: Extension Design1151503 +Node: Old Extension Problems1152657 +Ref: Old Extension Problems-Footnote-11154174 +Node: Extension New Mechanism Goals1154231 +Ref: Extension New Mechanism Goals-Footnote-11157591 +Node: Extension Other Design Decisions1157780 +Node: Extension Future Growth1159886 +Node: Old Extension Mechanism1160722 +Node: Notes summary1162484 +Node: Basic Concepts1163670 +Node: Basic High Level1164351 +Ref: figure-general-flow1164623 +Ref: figure-process-flow1165222 +Ref: Basic High Level-Footnote-11168451 +Node: Basic Data Typing1168636 +Node: Glossary1171964 +Node: Copying1197116 +Node: GNU Free Documentation License1234672 +Node: Index1259808  End Tag Table -- cgit v1.2.3 From a5847cb0a97b093cd0f23b65c72370af836c9748 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 26 Aug 2014 21:32:45 +0300 Subject: Change exclusion of exercises. --- doc/gawk.info | 1108 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 549 insertions(+), 559 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 850c8e73..7e6e1b89 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -219,7 +219,6 @@ entitled "GNU Free Documentation License". * Command-line directories:: What happens if you put a directory on the command line. * Input Summary:: Input summary. - * Input Exercises:: Exercises. * Print:: The `print' statement. * Print Examples:: Simple examples of `print' @@ -245,7 +244,6 @@ entitled "GNU Free Documentation License". * Close Files And Pipes:: Closing Input and Output Files and Pipes. * Output Summary:: Output summary. - * Output Exercises:: Exercises. * Values:: Constants, Variables, and Regular Expressions. @@ -433,7 +431,6 @@ entitled "GNU Free Documentation License". information. * Walking Arrays:: A function to walk arrays of arrays. * Library Functions Summary:: Summary of library functions. - * Library Exercises:: Exercises. * Running Examples:: How to run these examples. * Clones:: Clones of common utilities. @@ -465,7 +462,6 @@ entitled "GNU Free Documentation License". * Signature Program:: People do amazing things with too much time on their hands. * Programs Summary:: Summary of programs. - * Programs Exercises:: Exercises. * Nondecimal Data:: Allowing nondecimal input data. * Array Sorting:: Facilities for controlling array @@ -588,7 +584,6 @@ entitled "GNU Free Documentation License". and `sleep()'. * gawkextlib:: The `gawkextlib' project. * Extension summary:: Extension summary. - * Extension Exercises:: Exercises. * V7/SVR3.1:: The major changes between V7 and System V Release 3.1. @@ -2047,8 +2042,8 @@ summarize, select, and rearrange the output of another utility. It uses features that haven't been covered yet, so don't worry if you don't understand all the details: - LC_ALL=C ls -l | awk '$6 == "Nov" { sum += $5 } - END { print sum }' + ls -l | awk '$6 == "Nov" { sum += $5 } + END { print sum }' This command prints the total number of bytes in all the files in the current directory that were last modified in November (of any year). @@ -4084,7 +4079,6 @@ have to be named on the `awk' command line (*note Getline::). * Command-line directories:: What happens if you put a directory on the command line. * Input Summary:: Input summary. - * Input Exercises:: Exercises.  @@ -6025,7 +6019,6 @@ function. descriptors. * Close Files And Pipes:: Closing Input and Output Files and Pipes. * Output Summary:: Output summary. - * Output Exercises:: Exercises.  @@ -14250,7 +14243,6 @@ for different implementations of `awk' is pretty straightforward. * Group Functions:: Functions for getting group information. * Walking Arrays:: A function to walk arrays of arrays. * Library Functions Summary:: Summary of library functions. - * Library Exercises:: Exercises. ---------- Footnotes ---------- @@ -16093,7 +16085,6 @@ Library Functions::. * Clones:: Clones of common utilities. * Miscellaneous Programs:: Some interesting `awk' programs. * Programs Summary:: Summary of programs. - * Programs Exercises:: Exercises.  @@ -22296,7 +22287,6 @@ sample extensions are automatically built and installed when `gawk' is. `gawk'. * gawkextlib:: The `gawkextlib' project. * Extension summary:: Extension summary. - * Extension Exercises:: Exercises.  @@ -33984,552 +33974,552 @@ Index  Tag Table: Node: Top1204 -Node: Foreword41863 -Node: Preface46208 -Ref: Preface-Footnote-149231 -Ref: Preface-Footnote-249338 -Node: History49570 -Node: Names51944 -Ref: Names-Footnote-153038 -Node: This Manual53184 -Ref: This Manual-Footnote-158963 -Node: Conventions59063 -Node: Manual History61408 -Ref: Manual History-Footnote-164484 -Ref: Manual History-Footnote-264525 -Node: How To Contribute64599 -Node: Acknowledgments65838 -Node: Getting Started70586 -Node: Running gawk73020 -Node: One-shot74210 -Node: Read Terminal75435 -Ref: Read Terminal-Footnote-177398 -Node: Long77569 -Node: Executable Scripts78963 -Ref: Executable Scripts-Footnote-181764 -Node: Comments81866 -Node: Quoting84339 -Node: DOS Quoting89652 -Node: Sample Data Files90327 -Node: Very Simple92934 -Node: Two Rules97693 -Node: More Complex99587 -Ref: More Complex-Footnote-1102519 -Node: Statements/Lines102604 -Ref: Statements/Lines-Footnote-1107060 -Node: Other Features107325 -Node: When108253 -Ref: When-Footnote-1110009 -Node: Intro Summary110074 -Node: Invoking Gawk110957 -Node: Command Line112472 -Node: Options113263 -Ref: Options-Footnote-1129039 -Node: Other Arguments129064 -Node: Naming Standard Input131726 -Node: Environment Variables132819 -Node: AWKPATH Variable133377 -Ref: AWKPATH Variable-Footnote-1136243 -Ref: AWKPATH Variable-Footnote-2136288 -Node: AWKLIBPATH Variable136548 -Node: Other Environment Variables137307 -Node: Exit Status140964 -Node: Include Files141639 -Node: Loading Shared Libraries145217 -Node: Obsolete146601 -Node: Undocumented147298 -Node: Invoking Summary147565 -Node: Regexp149165 -Node: Regexp Usage150624 -Node: Escape Sequences152657 -Node: Regexp Operators158474 -Ref: Regexp Operators-Footnote-1165905 -Ref: Regexp Operators-Footnote-2166052 -Node: Bracket Expressions166150 -Ref: table-char-classes168172 -Node: GNU Regexp Operators171112 -Node: Case-sensitivity174821 -Ref: Case-sensitivity-Footnote-1177713 -Ref: Case-sensitivity-Footnote-2177948 -Node: Leftmost Longest178056 -Node: Computed Regexps179257 -Node: Regexp Summary182629 -Node: Reading Files184098 -Node: Records186191 -Node: awk split records186913 -Node: gawk split records191771 -Ref: gawk split records-Footnote-1196292 -Node: Fields196329 -Ref: Fields-Footnote-1199293 -Node: Nonconstant Fields199379 -Ref: Nonconstant Fields-Footnote-1201609 -Node: Changing Fields201811 -Node: Field Separators207765 -Node: Default Field Splitting210467 -Node: Regexp Field Splitting211584 -Node: Single Character Fields214911 -Node: Command Line Field Separator215970 -Node: Full Line Fields219396 -Ref: Full Line Fields-Footnote-1219904 -Node: Field Splitting Summary219950 -Ref: Field Splitting Summary-Footnote-1223082 -Node: Constant Size223183 -Node: Splitting By Content227789 -Ref: Splitting By Content-Footnote-1231862 -Node: Multiple Line231902 -Ref: Multiple Line-Footnote-1237758 -Node: Getline237937 -Node: Plain Getline240148 -Node: Getline/Variable242243 -Node: Getline/File243390 -Node: Getline/Variable/File244774 -Ref: Getline/Variable/File-Footnote-1246373 -Node: Getline/Pipe246460 -Node: Getline/Variable/Pipe249146 -Node: Getline/Coprocess250253 -Node: Getline/Variable/Coprocess251505 -Node: Getline Notes252242 -Node: Getline Summary255046 -Ref: table-getline-variants255454 -Node: Read Timeout256366 -Ref: Read Timeout-Footnote-1260193 -Node: Command-line directories260251 -Node: Input Summary261155 -Node: Input Exercises264292 -Node: Printing265025 -Node: Print266748 -Node: Print Examples268241 -Node: Output Separators271020 -Node: OFMT273036 -Node: Printf274394 -Node: Basic Printf275300 -Node: Control Letters276839 -Node: Format Modifiers280830 -Node: Printf Examples286857 -Node: Redirection289321 -Node: Special Files296293 -Node: Special FD296826 -Ref: Special FD-Footnote-1300423 -Node: Special Network300497 -Node: Special Caveats301347 -Node: Close Files And Pipes302143 -Ref: Close Files And Pipes-Footnote-1309304 -Ref: Close Files And Pipes-Footnote-2309452 -Node: Output Summary309602 -Node: Output Exercises310599 -Node: Expressions311279 -Node: Values312464 -Node: Constants313140 -Node: Scalar Constants313820 -Ref: Scalar Constants-Footnote-1314679 -Node: Nondecimal-numbers314929 -Node: Regexp Constants317929 -Node: Using Constant Regexps318404 -Node: Variables321476 -Node: Using Variables322131 -Node: Assignment Options323855 -Node: Conversion325730 -Node: Strings And Numbers326254 -Ref: Strings And Numbers-Footnote-1329316 -Node: Locale influences conversions329425 -Ref: table-locale-affects332142 -Node: All Operators332730 -Node: Arithmetic Ops333360 -Node: Concatenation335865 -Ref: Concatenation-Footnote-1338684 -Node: Assignment Ops338790 -Ref: table-assign-ops343773 -Node: Increment Ops345076 -Node: Truth Values and Conditions348514 -Node: Truth Values349597 -Node: Typing and Comparison350646 -Node: Variable Typing351439 -Node: Comparison Operators355091 -Ref: table-relational-ops355501 -Node: POSIX String Comparison359051 -Ref: POSIX String Comparison-Footnote-1360135 -Node: Boolean Ops360273 -Ref: Boolean Ops-Footnote-1364348 -Node: Conditional Exp364439 -Node: Function Calls366166 -Node: Precedence370046 -Node: Locales373715 -Node: Expressions Summary375346 -Node: Patterns and Actions377887 -Node: Pattern Overview379003 -Node: Regexp Patterns380680 -Node: Expression Patterns381223 -Node: Ranges385003 -Node: BEGIN/END388109 -Node: Using BEGIN/END388871 -Ref: Using BEGIN/END-Footnote-1391607 -Node: I/O And BEGIN/END391713 -Node: BEGINFILE/ENDFILE393984 -Node: Empty396915 -Node: Using Shell Variables397232 -Node: Action Overview399515 -Node: Statements401842 -Node: If Statement403690 -Node: While Statement405188 -Node: Do Statement407232 -Node: For Statement408388 -Node: Switch Statement411540 -Node: Break Statement413928 -Node: Continue Statement415969 -Node: Next Statement417794 -Node: Nextfile Statement420184 -Node: Exit Statement422820 -Node: Built-in Variables425224 -Node: User-modified426351 -Ref: User-modified-Footnote-1434040 -Node: Auto-set434102 -Ref: Auto-set-Footnote-1446684 -Ref: Auto-set-Footnote-2446889 -Node: ARGC and ARGV446945 -Node: Pattern Action Summary450849 -Node: Arrays453072 -Node: Array Basics454621 -Node: Array Intro455447 -Ref: figure-array-elements457420 -Ref: Array Intro-Footnote-1459944 -Node: Reference to Elements460072 -Node: Assigning Elements462522 -Node: Array Example463013 -Node: Scanning an Array464745 -Node: Controlling Scanning467746 -Ref: Controlling Scanning-Footnote-1472919 -Node: Delete473235 -Ref: Delete-Footnote-1475986 -Node: Numeric Array Subscripts476043 -Node: Uninitialized Subscripts478226 -Node: Multidimensional479851 -Node: Multiscanning482964 -Node: Arrays of Arrays484553 -Node: Arrays Summary489216 -Node: Functions491321 -Node: Built-in492194 -Node: Calling Built-in493272 -Node: Numeric Functions495260 -Ref: Numeric Functions-Footnote-1499294 -Ref: Numeric Functions-Footnote-2499651 -Ref: Numeric Functions-Footnote-3499699 -Node: String Functions499968 -Ref: String Functions-Footnote-1522965 -Ref: String Functions-Footnote-2523094 -Ref: String Functions-Footnote-3523342 -Node: Gory Details523429 -Ref: table-sub-escapes525202 -Ref: table-sub-proposed526722 -Ref: table-posix-sub528086 -Ref: table-gensub-escapes529626 -Ref: Gory Details-Footnote-1530802 -Node: I/O Functions530953 -Ref: I/O Functions-Footnote-1538063 -Node: Time Functions538210 -Ref: Time Functions-Footnote-1548674 -Ref: Time Functions-Footnote-2548742 -Ref: Time Functions-Footnote-3548900 -Ref: Time Functions-Footnote-4549011 -Ref: Time Functions-Footnote-5549123 -Ref: Time Functions-Footnote-6549350 -Node: Bitwise Functions549616 -Ref: table-bitwise-ops550178 -Ref: Bitwise Functions-Footnote-1554423 -Node: Type Functions554607 -Node: I18N Functions555749 -Node: User-defined557394 -Node: Definition Syntax558198 -Ref: Definition Syntax-Footnote-1563511 -Node: Function Example563580 -Ref: Function Example-Footnote-1566220 -Node: Function Caveats566242 -Node: Calling A Function566760 -Node: Variable Scope567715 -Node: Pass By Value/Reference570703 -Node: Return Statement574213 -Node: Dynamic Typing577197 -Node: Indirect Calls578126 -Node: Functions Summary587839 -Node: Library Functions590378 -Ref: Library Functions-Footnote-1593997 -Ref: Library Functions-Footnote-2594140 -Node: Library Names594311 -Ref: Library Names-Footnote-1597784 -Ref: Library Names-Footnote-2598004 -Node: General Functions598090 -Node: Strtonum Function599118 -Node: Assert Function601898 -Node: Round Function605224 -Node: Cliff Random Function606765 -Node: Ordinal Functions607781 -Ref: Ordinal Functions-Footnote-1610846 -Ref: Ordinal Functions-Footnote-2611098 -Node: Join Function611309 -Ref: Join Function-Footnote-1613080 -Node: Getlocaltime Function613280 -Node: Readfile Function617016 -Node: Data File Management618855 -Node: Filetrans Function619487 -Node: Rewind Function623556 -Node: File Checking625114 -Ref: File Checking-Footnote-1626246 -Node: Empty Files626447 -Node: Ignoring Assigns628426 -Node: Getopt Function629980 -Ref: Getopt Function-Footnote-1641283 -Node: Passwd Functions641486 -Ref: Passwd Functions-Footnote-1650465 -Node: Group Functions650553 -Ref: Group Functions-Footnote-1658484 -Node: Walking Arrays658697 -Node: Library Functions Summary660300 -Node: Library Exercises661688 -Node: Sample Programs662968 -Node: Running Examples663739 -Node: Clones664467 -Node: Cut Program665691 -Node: Egrep Program675549 -Ref: Egrep Program-Footnote-1683136 -Node: Id Program683246 -Node: Split Program686900 -Ref: Split Program-Footnote-1690438 -Node: Tee Program690566 -Node: Uniq Program693353 -Node: Wc Program700774 -Ref: Wc Program-Footnote-1705039 -Node: Miscellaneous Programs705131 -Node: Dupword Program706344 -Node: Alarm Program708375 -Node: Translate Program713179 -Ref: Translate Program-Footnote-1717570 -Ref: Translate Program-Footnote-2717840 -Node: Labels Program717974 -Ref: Labels Program-Footnote-1721335 -Node: Word Sorting721419 -Node: History Sorting725462 -Node: Extract Program727298 -Node: Simple Sed734834 -Node: Igawk Program737896 -Ref: Igawk Program-Footnote-1752200 -Ref: Igawk Program-Footnote-2752401 -Node: Anagram Program752539 -Node: Signature Program755607 -Node: Programs Summary756854 -Node: Programs Exercises758069 -Node: Advanced Features761720 -Node: Nondecimal Data763668 -Node: Array Sorting765245 -Node: Controlling Array Traversal765942 -Node: Array Sorting Functions774222 -Ref: Array Sorting Functions-Footnote-1778129 -Node: Two-way I/O778323 -Ref: Two-way I/O-Footnote-1783267 -Ref: Two-way I/O-Footnote-2783446 -Node: TCP/IP Networking783528 -Node: Profiling786373 -Node: Advanced Features Summary793915 -Node: Internationalization795779 -Node: I18N and L10N797259 -Node: Explaining gettext797945 -Ref: Explaining gettext-Footnote-1802971 -Ref: Explaining gettext-Footnote-2803155 -Node: Programmer i18n803320 -Ref: Programmer i18n-Footnote-1808114 -Node: Translator i18n808163 -Node: String Extraction808957 -Ref: String Extraction-Footnote-1810090 -Node: Printf Ordering810176 -Ref: Printf Ordering-Footnote-1812958 -Node: I18N Portability813022 -Ref: I18N Portability-Footnote-1815471 -Node: I18N Example815534 -Ref: I18N Example-Footnote-1818240 -Node: Gawk I18N818312 -Node: I18N Summary818950 -Node: Debugger820289 -Node: Debugging821311 -Node: Debugging Concepts821752 -Node: Debugging Terms823608 -Node: Awk Debugging826205 -Node: Sample Debugging Session827097 -Node: Debugger Invocation827617 -Node: Finding The Bug828950 -Node: List of Debugger Commands835432 -Node: Breakpoint Control836764 -Node: Debugger Execution Control840428 -Node: Viewing And Changing Data843788 -Node: Execution Stack847146 -Node: Debugger Info848659 -Node: Miscellaneous Debugger Commands852653 -Node: Readline Support857837 -Node: Limitations858729 -Node: Debugging Summary861003 -Node: Arbitrary Precision Arithmetic862171 -Node: Computer Arithmetic863658 -Ref: Computer Arithmetic-Footnote-1868045 -Node: Math Definitions868102 -Ref: table-ieee-formats871391 -Ref: Math Definitions-Footnote-1871931 -Node: MPFR features872034 -Node: FP Math Caution873651 -Ref: FP Math Caution-Footnote-1874701 -Node: Inexactness of computations875070 -Node: Inexact representation876018 -Node: Comparing FP Values877373 -Node: Errors accumulate878337 -Node: Getting Accuracy879770 -Node: Try To Round882429 -Node: Setting precision883328 -Ref: table-predefined-precision-strings884010 -Node: Setting the rounding mode885803 -Ref: table-gawk-rounding-modes886167 -Ref: Setting the rounding mode-Footnote-1889621 -Node: Arbitrary Precision Integers889800 -Ref: Arbitrary Precision Integers-Footnote-1892781 -Node: POSIX Floating Point Problems892930 -Ref: POSIX Floating Point Problems-Footnote-1896806 -Node: Floating point summary896844 -Node: Dynamic Extensions899048 -Node: Extension Intro900601 -Node: Plugin License901866 -Node: Extension Mechanism Outline902551 -Ref: figure-load-extension902975 -Ref: figure-load-new-function904460 -Ref: figure-call-new-function905462 -Node: Extension API Description907446 -Node: Extension API Functions Introduction908896 -Node: General Data Types913763 -Ref: General Data Types-Footnote-1919456 -Node: Requesting Values919755 -Ref: table-value-types-returned920492 -Node: Memory Allocation Functions921450 -Ref: Memory Allocation Functions-Footnote-1924197 -Node: Constructor Functions924293 -Node: Registration Functions926051 -Node: Extension Functions926736 -Node: Exit Callback Functions929038 -Node: Extension Version String930286 -Node: Input Parsers930936 -Node: Output Wrappers940750 -Node: Two-way processors945266 -Node: Printing Messages947470 -Ref: Printing Messages-Footnote-1948547 -Node: Updating `ERRNO'948699 -Node: Accessing Parameters949438 -Node: Symbol Table Access950668 -Node: Symbol table by name951182 -Node: Symbol table by cookie953158 -Ref: Symbol table by cookie-Footnote-1957291 -Node: Cached values957354 -Ref: Cached values-Footnote-1960858 -Node: Array Manipulation960949 -Ref: Array Manipulation-Footnote-1962047 -Node: Array Data Types962086 -Ref: Array Data Types-Footnote-1964789 -Node: Array Functions964881 -Node: Flattening Arrays968755 -Node: Creating Arrays975607 -Node: Extension API Variables980338 -Node: Extension Versioning980974 -Node: Extension API Informational Variables982875 -Node: Extension API Boilerplate983961 -Node: Finding Extensions987765 -Node: Extension Example988325 -Node: Internal File Description989055 -Node: Internal File Ops993146 -Ref: Internal File Ops-Footnote-11004578 -Node: Using Internal File Ops1004718 -Ref: Using Internal File Ops-Footnote-11007065 -Node: Extension Samples1007333 -Node: Extension Sample File Functions1008857 -Node: Extension Sample Fnmatch1016425 -Node: Extension Sample Fork1017907 -Node: Extension Sample Inplace1019120 -Node: Extension Sample Ord1020795 -Node: Extension Sample Readdir1021631 -Ref: table-readdir-file-types1022487 -Node: Extension Sample Revout1023286 -Node: Extension Sample Rev2way1023877 -Node: Extension Sample Read write array1024618 -Node: Extension Sample Readfile1026497 -Node: Extension Sample API Tests1027597 -Node: Extension Sample Time1028122 -Node: gawkextlib1029437 -Node: Extension summary1032250 -Node: Extension Exercises1035943 -Node: Language History1036665 -Node: V7/SVR3.11038308 -Node: SVR41040628 -Node: POSIX1042070 -Node: BTL1043456 -Node: POSIX/GNU1044190 -Node: Feature History1049906 -Node: Common Extensions1062997 -Node: Ranges and Locales1064309 -Ref: Ranges and Locales-Footnote-11068926 -Ref: Ranges and Locales-Footnote-21068953 -Ref: Ranges and Locales-Footnote-31069187 -Node: Contributors1069408 -Node: History summary1074833 -Node: Installation1076202 -Node: Gawk Distribution1077153 -Node: Getting1077637 -Node: Extracting1078461 -Node: Distribution contents1080103 -Node: Unix Installation1085820 -Node: Quick Installation1086437 -Node: Additional Configuration Options1088879 -Node: Configuration Philosophy1090617 -Node: Non-Unix Installation1092968 -Node: PC Installation1093426 -Node: PC Binary Installation1094737 -Node: PC Compiling1096585 -Ref: PC Compiling-Footnote-11099584 -Node: PC Testing1099689 -Node: PC Using1100865 -Node: Cygwin1105017 -Node: MSYS1105826 -Node: VMS Installation1106340 -Node: VMS Compilation1107136 -Ref: VMS Compilation-Footnote-11108358 -Node: VMS Dynamic Extensions1108416 -Node: VMS Installation Details1109789 -Node: VMS Running1112041 -Node: VMS GNV1114875 -Node: VMS Old Gawk1115598 -Node: Bugs1116068 -Node: Other Versions1120072 -Node: Installation summary1126299 -Node: Notes1127355 -Node: Compatibility Mode1128220 -Node: Additions1129002 -Node: Accessing The Source1129927 -Node: Adding Code1131363 -Node: New Ports1137541 -Node: Derived Files1142022 -Ref: Derived Files-Footnote-11147103 -Ref: Derived Files-Footnote-21147137 -Ref: Derived Files-Footnote-31147733 -Node: Future Extensions1147847 -Node: Implementation Limitations1148453 -Node: Extension Design1149701 -Node: Old Extension Problems1150855 -Ref: Old Extension Problems-Footnote-11152372 -Node: Extension New Mechanism Goals1152429 -Ref: Extension New Mechanism Goals-Footnote-11155789 -Node: Extension Other Design Decisions1155978 -Node: Extension Future Growth1158084 -Node: Old Extension Mechanism1158920 -Node: Notes summary1160682 -Node: Basic Concepts1161868 -Node: Basic High Level1162549 -Ref: figure-general-flow1162821 -Ref: figure-process-flow1163420 -Ref: Basic High Level-Footnote-11166649 -Node: Basic Data Typing1166834 -Node: Glossary1170162 -Node: Copying1195314 -Node: GNU Free Documentation License1232870 -Node: Index1258006 +Node: Foreword41858 +Node: Preface46203 +Ref: Preface-Footnote-149226 +Ref: Preface-Footnote-249333 +Node: History49565 +Node: Names51939 +Ref: Names-Footnote-153033 +Node: This Manual53179 +Ref: This Manual-Footnote-158958 +Node: Conventions59058 +Node: Manual History61403 +Ref: Manual History-Footnote-164479 +Ref: Manual History-Footnote-264520 +Node: How To Contribute64594 +Node: Acknowledgments65833 +Node: Getting Started70581 +Node: Running gawk73015 +Node: One-shot74205 +Node: Read Terminal75430 +Ref: Read Terminal-Footnote-177393 +Node: Long77564 +Node: Executable Scripts78958 +Ref: Executable Scripts-Footnote-181759 +Node: Comments81861 +Node: Quoting84334 +Node: DOS Quoting89647 +Node: Sample Data Files90322 +Node: Very Simple92929 +Node: Two Rules97688 +Node: More Complex99582 +Ref: More Complex-Footnote-1102496 +Node: Statements/Lines102581 +Ref: Statements/Lines-Footnote-1107037 +Node: Other Features107302 +Node: When108230 +Ref: When-Footnote-1109986 +Node: Intro Summary110051 +Node: Invoking Gawk110934 +Node: Command Line112449 +Node: Options113240 +Ref: Options-Footnote-1129016 +Node: Other Arguments129041 +Node: Naming Standard Input131703 +Node: Environment Variables132796 +Node: AWKPATH Variable133354 +Ref: AWKPATH Variable-Footnote-1136220 +Ref: AWKPATH Variable-Footnote-2136265 +Node: AWKLIBPATH Variable136525 +Node: Other Environment Variables137284 +Node: Exit Status140941 +Node: Include Files141616 +Node: Loading Shared Libraries145194 +Node: Obsolete146578 +Node: Undocumented147275 +Node: Invoking Summary147542 +Node: Regexp149142 +Node: Regexp Usage150601 +Node: Escape Sequences152634 +Node: Regexp Operators158451 +Ref: Regexp Operators-Footnote-1165882 +Ref: Regexp Operators-Footnote-2166029 +Node: Bracket Expressions166127 +Ref: table-char-classes168149 +Node: GNU Regexp Operators171089 +Node: Case-sensitivity174798 +Ref: Case-sensitivity-Footnote-1177690 +Ref: Case-sensitivity-Footnote-2177925 +Node: Leftmost Longest178033 +Node: Computed Regexps179234 +Node: Regexp Summary182606 +Node: Reading Files184075 +Node: Records186167 +Node: awk split records186889 +Node: gawk split records191747 +Ref: gawk split records-Footnote-1196268 +Node: Fields196305 +Ref: Fields-Footnote-1199269 +Node: Nonconstant Fields199355 +Ref: Nonconstant Fields-Footnote-1201585 +Node: Changing Fields201787 +Node: Field Separators207741 +Node: Default Field Splitting210443 +Node: Regexp Field Splitting211560 +Node: Single Character Fields214887 +Node: Command Line Field Separator215946 +Node: Full Line Fields219372 +Ref: Full Line Fields-Footnote-1219880 +Node: Field Splitting Summary219926 +Ref: Field Splitting Summary-Footnote-1223058 +Node: Constant Size223159 +Node: Splitting By Content227765 +Ref: Splitting By Content-Footnote-1231838 +Node: Multiple Line231878 +Ref: Multiple Line-Footnote-1237734 +Node: Getline237913 +Node: Plain Getline240124 +Node: Getline/Variable242219 +Node: Getline/File243366 +Node: Getline/Variable/File244750 +Ref: Getline/Variable/File-Footnote-1246349 +Node: Getline/Pipe246436 +Node: Getline/Variable/Pipe249122 +Node: Getline/Coprocess250229 +Node: Getline/Variable/Coprocess251481 +Node: Getline Notes252218 +Node: Getline Summary255022 +Ref: table-getline-variants255430 +Node: Read Timeout256342 +Ref: Read Timeout-Footnote-1260169 +Node: Command-line directories260227 +Node: Input Summary261131 +Node: Input Exercises264268 +Node: Printing265001 +Node: Print266723 +Node: Print Examples268216 +Node: Output Separators270995 +Node: OFMT273011 +Node: Printf274369 +Node: Basic Printf275275 +Node: Control Letters276814 +Node: Format Modifiers280805 +Node: Printf Examples286832 +Node: Redirection289296 +Node: Special Files296268 +Node: Special FD296801 +Ref: Special FD-Footnote-1300398 +Node: Special Network300472 +Node: Special Caveats301322 +Node: Close Files And Pipes302118 +Ref: Close Files And Pipes-Footnote-1309279 +Ref: Close Files And Pipes-Footnote-2309427 +Node: Output Summary309577 +Node: Output Exercises310574 +Node: Expressions311254 +Node: Values312439 +Node: Constants313115 +Node: Scalar Constants313795 +Ref: Scalar Constants-Footnote-1314654 +Node: Nondecimal-numbers314904 +Node: Regexp Constants317904 +Node: Using Constant Regexps318379 +Node: Variables321451 +Node: Using Variables322106 +Node: Assignment Options323830 +Node: Conversion325705 +Node: Strings And Numbers326229 +Ref: Strings And Numbers-Footnote-1329291 +Node: Locale influences conversions329400 +Ref: table-locale-affects332117 +Node: All Operators332705 +Node: Arithmetic Ops333335 +Node: Concatenation335840 +Ref: Concatenation-Footnote-1338659 +Node: Assignment Ops338765 +Ref: table-assign-ops343748 +Node: Increment Ops345051 +Node: Truth Values and Conditions348489 +Node: Truth Values349572 +Node: Typing and Comparison350621 +Node: Variable Typing351414 +Node: Comparison Operators355066 +Ref: table-relational-ops355476 +Node: POSIX String Comparison359026 +Ref: POSIX String Comparison-Footnote-1360110 +Node: Boolean Ops360248 +Ref: Boolean Ops-Footnote-1364323 +Node: Conditional Exp364414 +Node: Function Calls366141 +Node: Precedence370021 +Node: Locales373690 +Node: Expressions Summary375321 +Node: Patterns and Actions377862 +Node: Pattern Overview378978 +Node: Regexp Patterns380655 +Node: Expression Patterns381198 +Node: Ranges384978 +Node: BEGIN/END388084 +Node: Using BEGIN/END388846 +Ref: Using BEGIN/END-Footnote-1391582 +Node: I/O And BEGIN/END391688 +Node: BEGINFILE/ENDFILE393959 +Node: Empty396890 +Node: Using Shell Variables397207 +Node: Action Overview399490 +Node: Statements401817 +Node: If Statement403665 +Node: While Statement405163 +Node: Do Statement407207 +Node: For Statement408363 +Node: Switch Statement411515 +Node: Break Statement413903 +Node: Continue Statement415944 +Node: Next Statement417769 +Node: Nextfile Statement420159 +Node: Exit Statement422795 +Node: Built-in Variables425199 +Node: User-modified426326 +Ref: User-modified-Footnote-1434015 +Node: Auto-set434077 +Ref: Auto-set-Footnote-1446659 +Ref: Auto-set-Footnote-2446864 +Node: ARGC and ARGV446920 +Node: Pattern Action Summary450824 +Node: Arrays453047 +Node: Array Basics454596 +Node: Array Intro455422 +Ref: figure-array-elements457395 +Ref: Array Intro-Footnote-1459919 +Node: Reference to Elements460047 +Node: Assigning Elements462497 +Node: Array Example462988 +Node: Scanning an Array464720 +Node: Controlling Scanning467721 +Ref: Controlling Scanning-Footnote-1472894 +Node: Delete473210 +Ref: Delete-Footnote-1475961 +Node: Numeric Array Subscripts476018 +Node: Uninitialized Subscripts478201 +Node: Multidimensional479826 +Node: Multiscanning482939 +Node: Arrays of Arrays484528 +Node: Arrays Summary489191 +Node: Functions491296 +Node: Built-in492169 +Node: Calling Built-in493247 +Node: Numeric Functions495235 +Ref: Numeric Functions-Footnote-1499269 +Ref: Numeric Functions-Footnote-2499626 +Ref: Numeric Functions-Footnote-3499674 +Node: String Functions499943 +Ref: String Functions-Footnote-1522940 +Ref: String Functions-Footnote-2523069 +Ref: String Functions-Footnote-3523317 +Node: Gory Details523404 +Ref: table-sub-escapes525177 +Ref: table-sub-proposed526697 +Ref: table-posix-sub528061 +Ref: table-gensub-escapes529601 +Ref: Gory Details-Footnote-1530777 +Node: I/O Functions530928 +Ref: I/O Functions-Footnote-1538038 +Node: Time Functions538185 +Ref: Time Functions-Footnote-1548649 +Ref: Time Functions-Footnote-2548717 +Ref: Time Functions-Footnote-3548875 +Ref: Time Functions-Footnote-4548986 +Ref: Time Functions-Footnote-5549098 +Ref: Time Functions-Footnote-6549325 +Node: Bitwise Functions549591 +Ref: table-bitwise-ops550153 +Ref: Bitwise Functions-Footnote-1554398 +Node: Type Functions554582 +Node: I18N Functions555724 +Node: User-defined557369 +Node: Definition Syntax558173 +Ref: Definition Syntax-Footnote-1563486 +Node: Function Example563555 +Ref: Function Example-Footnote-1566195 +Node: Function Caveats566217 +Node: Calling A Function566735 +Node: Variable Scope567690 +Node: Pass By Value/Reference570678 +Node: Return Statement574188 +Node: Dynamic Typing577172 +Node: Indirect Calls578101 +Node: Functions Summary587814 +Node: Library Functions590353 +Ref: Library Functions-Footnote-1593971 +Ref: Library Functions-Footnote-2594114 +Node: Library Names594285 +Ref: Library Names-Footnote-1597758 +Ref: Library Names-Footnote-2597978 +Node: General Functions598064 +Node: Strtonum Function599092 +Node: Assert Function601872 +Node: Round Function605198 +Node: Cliff Random Function606739 +Node: Ordinal Functions607755 +Ref: Ordinal Functions-Footnote-1610820 +Ref: Ordinal Functions-Footnote-2611072 +Node: Join Function611283 +Ref: Join Function-Footnote-1613054 +Node: Getlocaltime Function613254 +Node: Readfile Function616990 +Node: Data File Management618829 +Node: Filetrans Function619461 +Node: Rewind Function623530 +Node: File Checking625088 +Ref: File Checking-Footnote-1626220 +Node: Empty Files626421 +Node: Ignoring Assigns628400 +Node: Getopt Function629954 +Ref: Getopt Function-Footnote-1641257 +Node: Passwd Functions641460 +Ref: Passwd Functions-Footnote-1650439 +Node: Group Functions650527 +Ref: Group Functions-Footnote-1658458 +Node: Walking Arrays658671 +Node: Library Functions Summary660274 +Node: Library Exercises661662 +Node: Sample Programs662942 +Node: Running Examples663712 +Node: Clones664440 +Node: Cut Program665664 +Node: Egrep Program675522 +Ref: Egrep Program-Footnote-1683109 +Node: Id Program683219 +Node: Split Program686873 +Ref: Split Program-Footnote-1690411 +Node: Tee Program690539 +Node: Uniq Program693326 +Node: Wc Program700747 +Ref: Wc Program-Footnote-1705012 +Node: Miscellaneous Programs705104 +Node: Dupword Program706317 +Node: Alarm Program708348 +Node: Translate Program713152 +Ref: Translate Program-Footnote-1717543 +Ref: Translate Program-Footnote-2717813 +Node: Labels Program717947 +Ref: Labels Program-Footnote-1721308 +Node: Word Sorting721392 +Node: History Sorting725435 +Node: Extract Program727271 +Node: Simple Sed734807 +Node: Igawk Program737869 +Ref: Igawk Program-Footnote-1752173 +Ref: Igawk Program-Footnote-2752374 +Node: Anagram Program752512 +Node: Signature Program755580 +Node: Programs Summary756827 +Node: Programs Exercises758042 +Node: Advanced Features761693 +Node: Nondecimal Data763641 +Node: Array Sorting765218 +Node: Controlling Array Traversal765915 +Node: Array Sorting Functions774195 +Ref: Array Sorting Functions-Footnote-1778102 +Node: Two-way I/O778296 +Ref: Two-way I/O-Footnote-1783240 +Ref: Two-way I/O-Footnote-2783419 +Node: TCP/IP Networking783501 +Node: Profiling786346 +Node: Advanced Features Summary793888 +Node: Internationalization795752 +Node: I18N and L10N797232 +Node: Explaining gettext797918 +Ref: Explaining gettext-Footnote-1802944 +Ref: Explaining gettext-Footnote-2803128 +Node: Programmer i18n803293 +Ref: Programmer i18n-Footnote-1808087 +Node: Translator i18n808136 +Node: String Extraction808930 +Ref: String Extraction-Footnote-1810063 +Node: Printf Ordering810149 +Ref: Printf Ordering-Footnote-1812931 +Node: I18N Portability812995 +Ref: I18N Portability-Footnote-1815444 +Node: I18N Example815507 +Ref: I18N Example-Footnote-1818213 +Node: Gawk I18N818285 +Node: I18N Summary818923 +Node: Debugger820262 +Node: Debugging821284 +Node: Debugging Concepts821725 +Node: Debugging Terms823581 +Node: Awk Debugging826178 +Node: Sample Debugging Session827070 +Node: Debugger Invocation827590 +Node: Finding The Bug828923 +Node: List of Debugger Commands835405 +Node: Breakpoint Control836737 +Node: Debugger Execution Control840401 +Node: Viewing And Changing Data843761 +Node: Execution Stack847119 +Node: Debugger Info848632 +Node: Miscellaneous Debugger Commands852626 +Node: Readline Support857810 +Node: Limitations858702 +Node: Debugging Summary860976 +Node: Arbitrary Precision Arithmetic862144 +Node: Computer Arithmetic863631 +Ref: Computer Arithmetic-Footnote-1868018 +Node: Math Definitions868075 +Ref: table-ieee-formats871364 +Ref: Math Definitions-Footnote-1871904 +Node: MPFR features872007 +Node: FP Math Caution873624 +Ref: FP Math Caution-Footnote-1874674 +Node: Inexactness of computations875043 +Node: Inexact representation875991 +Node: Comparing FP Values877346 +Node: Errors accumulate878310 +Node: Getting Accuracy879743 +Node: Try To Round882402 +Node: Setting precision883301 +Ref: table-predefined-precision-strings883983 +Node: Setting the rounding mode885776 +Ref: table-gawk-rounding-modes886140 +Ref: Setting the rounding mode-Footnote-1889594 +Node: Arbitrary Precision Integers889773 +Ref: Arbitrary Precision Integers-Footnote-1892754 +Node: POSIX Floating Point Problems892903 +Ref: POSIX Floating Point Problems-Footnote-1896779 +Node: Floating point summary896817 +Node: Dynamic Extensions899021 +Node: Extension Intro900573 +Node: Plugin License901838 +Node: Extension Mechanism Outline902523 +Ref: figure-load-extension902947 +Ref: figure-load-new-function904432 +Ref: figure-call-new-function905434 +Node: Extension API Description907418 +Node: Extension API Functions Introduction908868 +Node: General Data Types913735 +Ref: General Data Types-Footnote-1919428 +Node: Requesting Values919727 +Ref: table-value-types-returned920464 +Node: Memory Allocation Functions921422 +Ref: Memory Allocation Functions-Footnote-1924169 +Node: Constructor Functions924265 +Node: Registration Functions926023 +Node: Extension Functions926708 +Node: Exit Callback Functions929010 +Node: Extension Version String930258 +Node: Input Parsers930908 +Node: Output Wrappers940722 +Node: Two-way processors945238 +Node: Printing Messages947442 +Ref: Printing Messages-Footnote-1948519 +Node: Updating `ERRNO'948671 +Node: Accessing Parameters949410 +Node: Symbol Table Access950640 +Node: Symbol table by name951154 +Node: Symbol table by cookie953130 +Ref: Symbol table by cookie-Footnote-1957263 +Node: Cached values957326 +Ref: Cached values-Footnote-1960830 +Node: Array Manipulation960921 +Ref: Array Manipulation-Footnote-1962019 +Node: Array Data Types962058 +Ref: Array Data Types-Footnote-1964761 +Node: Array Functions964853 +Node: Flattening Arrays968727 +Node: Creating Arrays975579 +Node: Extension API Variables980310 +Node: Extension Versioning980946 +Node: Extension API Informational Variables982847 +Node: Extension API Boilerplate983933 +Node: Finding Extensions987737 +Node: Extension Example988297 +Node: Internal File Description989027 +Node: Internal File Ops993118 +Ref: Internal File Ops-Footnote-11004550 +Node: Using Internal File Ops1004690 +Ref: Using Internal File Ops-Footnote-11007037 +Node: Extension Samples1007305 +Node: Extension Sample File Functions1008829 +Node: Extension Sample Fnmatch1016397 +Node: Extension Sample Fork1017879 +Node: Extension Sample Inplace1019092 +Node: Extension Sample Ord1020767 +Node: Extension Sample Readdir1021603 +Ref: table-readdir-file-types1022459 +Node: Extension Sample Revout1023258 +Node: Extension Sample Rev2way1023849 +Node: Extension Sample Read write array1024590 +Node: Extension Sample Readfile1026469 +Node: Extension Sample API Tests1027569 +Node: Extension Sample Time1028094 +Node: gawkextlib1029409 +Node: Extension summary1032222 +Node: Extension Exercises1035915 +Node: Language History1036637 +Node: V7/SVR3.11038280 +Node: SVR41040600 +Node: POSIX1042042 +Node: BTL1043428 +Node: POSIX/GNU1044162 +Node: Feature History1049878 +Node: Common Extensions1062969 +Node: Ranges and Locales1064281 +Ref: Ranges and Locales-Footnote-11068898 +Ref: Ranges and Locales-Footnote-21068925 +Ref: Ranges and Locales-Footnote-31069159 +Node: Contributors1069380 +Node: History summary1074805 +Node: Installation1076174 +Node: Gawk Distribution1077125 +Node: Getting1077609 +Node: Extracting1078433 +Node: Distribution contents1080075 +Node: Unix Installation1085792 +Node: Quick Installation1086409 +Node: Additional Configuration Options1088851 +Node: Configuration Philosophy1090589 +Node: Non-Unix Installation1092940 +Node: PC Installation1093398 +Node: PC Binary Installation1094709 +Node: PC Compiling1096557 +Ref: PC Compiling-Footnote-11099556 +Node: PC Testing1099661 +Node: PC Using1100837 +Node: Cygwin1104989 +Node: MSYS1105798 +Node: VMS Installation1106312 +Node: VMS Compilation1107108 +Ref: VMS Compilation-Footnote-11108330 +Node: VMS Dynamic Extensions1108388 +Node: VMS Installation Details1109761 +Node: VMS Running1112013 +Node: VMS GNV1114847 +Node: VMS Old Gawk1115570 +Node: Bugs1116040 +Node: Other Versions1120044 +Node: Installation summary1126271 +Node: Notes1127327 +Node: Compatibility Mode1128192 +Node: Additions1128974 +Node: Accessing The Source1129899 +Node: Adding Code1131335 +Node: New Ports1137513 +Node: Derived Files1141994 +Ref: Derived Files-Footnote-11147075 +Ref: Derived Files-Footnote-21147109 +Ref: Derived Files-Footnote-31147705 +Node: Future Extensions1147819 +Node: Implementation Limitations1148425 +Node: Extension Design1149673 +Node: Old Extension Problems1150827 +Ref: Old Extension Problems-Footnote-11152344 +Node: Extension New Mechanism Goals1152401 +Ref: Extension New Mechanism Goals-Footnote-11155761 +Node: Extension Other Design Decisions1155950 +Node: Extension Future Growth1158056 +Node: Old Extension Mechanism1158892 +Node: Notes summary1160654 +Node: Basic Concepts1161840 +Node: Basic High Level1162521 +Ref: figure-general-flow1162793 +Ref: figure-process-flow1163392 +Ref: Basic High Level-Footnote-11166621 +Node: Basic Data Typing1166806 +Node: Glossary1170134 +Node: Copying1195286 +Node: GNU Free Documentation License1232842 +Node: Index1257978  End Tag Table -- cgit v1.2.3 From 6c541fd0f75cd328dd80afec757ecccc833719af Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 29 Aug 2014 13:11:45 +0300 Subject: More doc updates. --- doc/gawk.info | 1507 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 769 insertions(+), 738 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 7e6e1b89..2841d21e 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -170,10 +170,10 @@ entitled "GNU Free Documentation License". * Escape Sequences:: How to write nonprinting characters. * Regexp Operators:: Regular Expression Operators. * Bracket Expressions:: What can go between `[...]'. -* GNU Regexp Operators:: Operators specific to GNU software. -* Case-sensitivity:: How to do case-insensitive matching. * Leftmost Longest:: How much text matches. * Computed Regexps:: Using Dynamic Regexps. +* GNU Regexp Operators:: Operators specific to GNU software. +* Case-sensitivity:: How to do case-insensitive matching. * Regexp Summary:: Regular expressions summary. * Records:: Controlling how data is split into records. @@ -1455,15 +1455,17 @@ end-of-file character may be different. For example, on OS/2, it is As an example, the following program prints a friendly piece of advice (from Douglas Adams's `The Hitchhiker's Guide to the Galaxy'), to keep you from worrying about the complexities of computer -programming (`BEGIN' is a feature we haven't discussed yet): +programming: - $ awk "BEGIN { print \"Don't Panic!\" }" + $ awk "BEGIN { print "Don\47t Panic!" }" -| Don't Panic! - This program does not read any input. The `\' before each of the -inner double quotes is necessary because of the shell's quoting -rules--in particular because it mixes both single quotes and double -quotes.(1) + `awk' executes statements associated with `BEGIN' before reading any +input. If there are no other statements in your program, as is the +case here, `awk' just stops, instead of trying to read input it doesn't +know how to process. The `\47' is a magic way of getting a single +quote into the program, without having to engage in ugly shell quoting +tricks. NOTE: As a side note, if you use Bash as your shell, you should execute the command `set +H' before running this program @@ -1486,12 +1488,6 @@ works is explained shortly). -| What, me worry? Ctrl-d - ---------- Footnotes ---------- - - (1) Although we generally recommend the use of single quotes around -the program text, double quotes are needed here in order to put the -single quote into the message. -  File: gawk.info, Node: Long, Next: Executable Scripts, Prev: Read Terminal, Up: Running gawk @@ -1937,6 +1933,9 @@ different ways to do the same things shown here: awk '{ if (length($0) > max) max = length($0) } END { print max }' data + The code associated with `END' executes after all input has been + read; it's the other side of the coin to `BEGIN'. + * Print the length of the longest line in `data': expand data | awk '{ if (x < length($0)) x = length($0) } @@ -2731,6 +2730,10 @@ arguments, including variable assignments, are included. As each element of `ARGV' is processed, `gawk' sets the variable `ARGIND' to the index in `ARGV' of the current element. + Changing `ARGC' and `ARGV' in your `awk' program lets you control +how `awk' processes the input files; this is described in more detail +in *note ARGC and ARGV::. + The distinction between file name arguments and variable-assignment arguments is made when `awk' is about to open the next input file. At that point in execution, it checks the file name to see whether it is @@ -3225,10 +3228,10 @@ you specify more complicated classes of strings. * Escape Sequences:: How to write nonprinting characters. * Regexp Operators:: Regular Expression Operators. * Bracket Expressions:: What can go between `[...]'. -* GNU Regexp Operators:: Operators specific to GNU software. -* Case-sensitivity:: How to do case-insensitive matching. * Leftmost Longest:: How much text matches. * Computed Regexps:: Using Dynamic Regexps. +* GNU Regexp Operators:: Operators specific to GNU software. +* Case-sensitivity:: How to do case-insensitive matching. * Regexp Summary:: Regular expressions summary.  @@ -3368,17 +3371,19 @@ apply to both string constants and regexp constants: `\/' A literal slash (necessary for regexp constants only). This sequence is used when you want to write a regexp constant that - contains a slash. Because the regexp is delimited by slashes, you - need to escape the slash that is part of the pattern, in order to + contains a slash (such as `/.*:\/home\/[[:alnum:]]+:.*/'; the + `[[:alnum:]]' notation is discussed shortly, in *note Bracket + Expressions::). Because the regexp is delimited by slashes, you + need to escape any slash that is part of the pattern, in order to tell `awk' to keep processing the rest of the regexp. `\"' A literal double quote (necessary for string constants only). This sequence is used when you want to write a string constant - that contains a double quote. Because the string is delimited by - double quotes, you need to escape the quote that is part of the - string, in order to tell `awk' to keep processing the rest of the - string. + that contains a double quote (such as `"He said \"hi!\" to her."'). + Because the string is delimited by double quotes, you need to + escape any quote that is part of the string, in order to tell + `awk' to keep processing the rest of the string. In `gawk', a number of additional two-character sequences that begin with a backslash have special meaning in regexps. *Note GNU Regexp @@ -3616,7 +3621,7 @@ list". regexp operator or function.  -File: gawk.info, Node: Bracket Expressions, Next: GNU Regexp Operators, Prev: Regexp Operators, Up: Regexp +File: gawk.info, Node: Bracket Expressions, Next: Leftmost Longest, Prev: Regexp Operators, Up: Regexp 3.4 Using Bracket Expressions ============================= @@ -3721,9 +3726,118 @@ Equivalence classes classes.  -File: gawk.info, Node: GNU Regexp Operators, Next: Case-sensitivity, Prev: Bracket Expressions, Up: Regexp +File: gawk.info, Node: Leftmost Longest, Next: Computed Regexps, Prev: Bracket Expressions, Up: Regexp + +3.5 How Much Text Matches? +========================== + +Consider the following: + + echo aaaabcd | awk '{ sub(/a+/, ""); print }' + + This example uses the `sub()' function (which we haven't discussed +yet; *note String Functions::) to make a change to the input record. +Here, the regexp `/a+/' indicates "one or more `a' characters," and the +replacement text is `'. + + The input contains four `a' characters. `awk' (and POSIX) regular +expressions always match the leftmost, _longest_ sequence of input +characters that can match. Thus, all four `a' characters are replaced +with `' in this example: + + $ echo aaaabcd | awk '{ sub(/a+/, ""); print }' + -| bcd + + For simple match/no-match tests, this is not so important. But when +doing text matching and substitutions with the `match()', `sub()', +`gsub()', and `gensub()' functions, it is very important. *Note String +Functions::, for more information on these functions. Understanding +this principle is also important for regexp-based record and field +splitting (*note Records::, and also *note Field Separators::). + + +File: gawk.info, Node: Computed Regexps, Next: GNU Regexp Operators, Prev: Leftmost Longest, Up: Regexp + +3.6 Using Dynamic Regexps +========================= + +The righthand side of a `~' or `!~' operator need not be a regexp +constant (i.e., a string of characters between slashes). It may be any +expression. The expression is evaluated and converted to a string if +necessary; the contents of the string are then used as the regexp. A +regexp computed in this way is called a "dynamic regexp" or a "computed +regexp": + + BEGIN { digits_regexp = "[[:digit:]]+" } + $0 ~ digits_regexp { print } + +This sets `digits_regexp' to a regexp that describes one or more digits, +and tests whether the input record matches this regexp. + + NOTE: When using the `~' and `!~' operators, there is a difference + between a regexp constant enclosed in slashes and a string + constant enclosed in double quotes. If you are going to use a + string constant, you have to understand that the string is, in + essence, scanned _twice_: the first time when `awk' reads your + program, and the second time when it goes to match the string on + the lefthand side of the operator with the pattern on the right. + This is true of any string-valued expression (such as + `digits_regexp', shown previously), not just string constants. + + What difference does it make if the string is scanned twice? The +answer has to do with escape sequences, and particularly with +backslashes. To get a backslash into a regular expression inside a +string, you have to type two backslashes. + + For example, `/\*/' is a regexp constant for a literal `*'. Only +one backslash is needed. To do the same thing with a string, you have +to type `"\\*"'. The first backslash escapes the second one so that +the string actually contains the two characters `\' and `*'. + + Given that you can use both regexp and string constants to describe +regular expressions, which should you use? The answer is "regexp +constants," for several reasons: + + * String constants are more complicated to write and more difficult + to read. Using regexp constants makes your programs less + error-prone. Not understanding the difference between the two + kinds of constants is a common source of errors. + + * It is more efficient to use regexp constants. `awk' can note that + you have supplied a regexp and store it internally in a form that + makes pattern matching more efficient. When using a string + constant, `awk' must first convert the string into this internal + form and then perform the pattern matching. + + * Using regexp constants is better form; it shows clearly that you + intend a regexp match. + + Using `\n' in Bracket Expressions of Dynamic Regexps + + Some versions of `awk' do not allow the newline character to be used +inside a bracket expression for a dynamic regexp: + + $ awk '$0 ~ "[ \t\n]"' + error--> awk: newline in character class [ + error--> ]... + error--> source line number 1 + error--> context is + error--> >>> <<< + + But a newline in a regexp constant works with no problem: + + $ awk '$0 ~ /[ \t\n]/' + here is a sample line + -| here is a sample line + Ctrl-d + + `gawk' does not have this problem, and it isn't likely to occur +often in practice, but it's worth noting for future reference. + + +File: gawk.info, Node: GNU Regexp Operators, Next: Case-sensitivity, Prev: Computed Regexps, Up: Regexp -3.5 `gawk'-Specific Regexp Operators +3.7 `gawk'-Specific Regexp Operators ==================================== GNU software that deals with regular expressions provides a number of @@ -3817,9 +3931,9 @@ No options default.  -File: gawk.info, Node: Case-sensitivity, Next: Leftmost Longest, Prev: GNU Regexp Operators, Up: Regexp +File: gawk.info, Node: Case-sensitivity, Next: Regexp Summary, Prev: GNU Regexp Operators, Up: Regexp -3.6 Case Sensitivity in Matching +3.8 Case Sensitivity in Matching ================================ Case is normally significant in regular expressions, both when matching @@ -3892,116 +4006,7 @@ obscure and we don't recommend it. means that `gawk' does the right thing.  -File: gawk.info, Node: Leftmost Longest, Next: Computed Regexps, Prev: Case-sensitivity, Up: Regexp - -3.7 How Much Text Matches? -========================== - -Consider the following: - - echo aaaabcd | awk '{ sub(/a+/, ""); print }' - - This example uses the `sub()' function (which we haven't discussed -yet; *note String Functions::) to make a change to the input record. -Here, the regexp `/a+/' indicates "one or more `a' characters," and the -replacement text is `'. - - The input contains four `a' characters. `awk' (and POSIX) regular -expressions always match the leftmost, _longest_ sequence of input -characters that can match. Thus, all four `a' characters are replaced -with `' in this example: - - $ echo aaaabcd | awk '{ sub(/a+/, ""); print }' - -| bcd - - For simple match/no-match tests, this is not so important. But when -doing text matching and substitutions with the `match()', `sub()', -`gsub()', and `gensub()' functions, it is very important. *Note String -Functions::, for more information on these functions. Understanding -this principle is also important for regexp-based record and field -splitting (*note Records::, and also *note Field Separators::). - - -File: gawk.info, Node: Computed Regexps, Next: Regexp Summary, Prev: Leftmost Longest, Up: Regexp - -3.8 Using Dynamic Regexps -========================= - -The righthand side of a `~' or `!~' operator need not be a regexp -constant (i.e., a string of characters between slashes). It may be any -expression. The expression is evaluated and converted to a string if -necessary; the contents of the string are then used as the regexp. A -regexp computed in this way is called a "dynamic regexp" or a "computed -regexp": - - BEGIN { digits_regexp = "[[:digit:]]+" } - $0 ~ digits_regexp { print } - -This sets `digits_regexp' to a regexp that describes one or more digits, -and tests whether the input record matches this regexp. - - NOTE: When using the `~' and `!~' operators, there is a difference - between a regexp constant enclosed in slashes and a string - constant enclosed in double quotes. If you are going to use a - string constant, you have to understand that the string is, in - essence, scanned _twice_: the first time when `awk' reads your - program, and the second time when it goes to match the string on - the lefthand side of the operator with the pattern on the right. - This is true of any string-valued expression (such as - `digits_regexp', shown previously), not just string constants. - - What difference does it make if the string is scanned twice? The -answer has to do with escape sequences, and particularly with -backslashes. To get a backslash into a regular expression inside a -string, you have to type two backslashes. - - For example, `/\*/' is a regexp constant for a literal `*'. Only -one backslash is needed. To do the same thing with a string, you have -to type `"\\*"'. The first backslash escapes the second one so that -the string actually contains the two characters `\' and `*'. - - Given that you can use both regexp and string constants to describe -regular expressions, which should you use? The answer is "regexp -constants," for several reasons: - - * String constants are more complicated to write and more difficult - to read. Using regexp constants makes your programs less - error-prone. Not understanding the difference between the two - kinds of constants is a common source of errors. - - * It is more efficient to use regexp constants. `awk' can note that - you have supplied a regexp and store it internally in a form that - makes pattern matching more efficient. When using a string - constant, `awk' must first convert the string into this internal - form and then perform the pattern matching. - - * Using regexp constants is better form; it shows clearly that you - intend a regexp match. - - Using `\n' in Bracket Expressions of Dynamic Regexps - - Some versions of `awk' do not allow the newline character to be used -inside a bracket expression for a dynamic regexp: - - $ awk '$0 ~ "[ \t\n]"' - error--> awk: newline in character class [ - error--> ]... - error--> source line number 1 - error--> context is - error--> >>> <<< - - But a newline in a regexp constant works with no problem: - - $ awk '$0 ~ /[ \t\n]/' - here is a sample line - -| here is a sample line - Ctrl-d - - `gawk' does not have this problem, and it isn't likely to occur -often in practice, but it's worth noting for future reference. - - -File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp +File: gawk.info, Node: Regexp Summary, Prev: Case-sensitivity, Up: Regexp 3.9 Summary =========== @@ -5388,35 +5393,47 @@ input record and split it up into fields. This is useful if you've finished processing the current record, but want to do some special processing on the next record _right now_. For example: + # Remove text between /* and */, inclusive { - if ((t = index($0, "/*")) != 0) { - # value of `tmp' will be "" if t is 1 - tmp = substr($0, 1, t - 1) - u = index(substr($0, t + 2), "*/") - offset = t + 2 - while (u == 0) { - if (getline <= 0) { + if ((i = index($0, "/*")) != 0) { + out = substr($0, 1, i - 1) # leading part of the string + rest = substr($0, i + 2) # ... */ ... + j = index(rest, "*/") # is */ in trailing part? + if (j > 0) { + rest = substr(rest, j + 2) # remove comment + } else { + while (j == 0) { + # get more text + if (getline <= 0) { m = "unexpected EOF or error" m = (m ": " ERRNO) print m > "/dev/stderr" exit - } - u = index($0, "*/") - offset = 0 - } - # substr() expression will be "" if */ - # occurred at end of line - $0 = tmp substr($0, offset + u + 2) - } - print $0 + } + # build up the line using string concatenation + rest = rest $0 + j = index(rest, "*/") # is */ in trailing part? + if (j != 0) { + rest = substr(rest, j + 2) + break + } + } + } + # build up the output line using string concatenation + $0 = out rest + } + print $0 } This `awk' program deletes C-style comments (`/* ... */') from the -input. By replacing the `print $0' with other statements, you could -perform more complicated processing on the decommented input, such as -searching for matches of a regular expression. (This program has a -subtle problem--it does not work if one comment ends and another begins -on the same line.) +input. It uses a number of features we haven't covered yet, including +string concatenation (*note Concatenation::) and the `index()' and +`substr()' built-in functions (*note String Functions::). By replacing +the `print $0' with other statements, you could perform more +complicated processing on the decommented input, such as searching for +matches of a regular expression. (This program has a subtle +problem--it does not work if one comment ends and another begins on the +same line.) This form of the `getline' command sets `NF', `NR', `FNR', `RT', and the value of `$0'. @@ -5980,8 +5997,8 @@ File: gawk.info, Node: Input Exercises, Prev: Input Summary, Up: Reading File 2. *note Plain Getline::, presented a program to remove C-style comments (`/* ... */') from the input. That program does not work if one comment ends on one line and another one starts later on - the same line. Write a program that does handle multiple comments - on the line. + the same line. That can be fixed by making one simple change. + What is it?  @@ -7312,8 +7329,9 @@ File: gawk.info, Node: Regexp Constants, Prev: Nondecimal-numbers, Up: Consta A regexp constant is a regular expression description enclosed in slashes, such as `/^beginning and end$/'. Most regexps used in `awk' programs are constant, but the `~' and `!~' matching operators can also -match computed or dynamic regexps (which are just ordinary strings or -variables that contain a regexp). +match computed or dynamic regexps (which are typically just ordinary +strings or variables that contain a regexp, but could be a more complex +expression).  File: gawk.info, Node: Using Constant Regexps, Next: Variables, Prev: Constants, Up: Values @@ -8463,7 +8481,7 @@ following program is one way to print lines in between special bracketing lines: $1 == "START" { interested = ! interested; next } - interested == 1 { print } + interested { print } $1 == "END" { interested = ! interested; next } The variable `interested', as with all `awk' variables, starts out @@ -8473,6 +8491,14 @@ using `!'. The next rule prints lines as long as `interested' is true. When a line is seen whose first field is `END', `interested' is toggled back to false.(1) + Most commonly, the `!' operator is used in the conditions of `if' +and `while' statements, where it often makes more sense to phrase the +logic in the negative: + + if (! SOME CONDITION || SOME OTHER CONDITION) { + ... DO WHATEVER PROCESSING ... + } + NOTE: The `next' statement is discussed in *note Next Statement::. `next' tells `awk' to skip the rest of the rules, get the next record, and start processing the rules over again at the top. The @@ -9841,7 +9867,7 @@ reset to one, and processing starts over with the first rule in the program. If the `nextfile' statement causes the end of the input to be reached, then the code in any `END' rules is executed. An exception to this is when `nextfile' is invoked during execution of any statement in -an `END' rule; In this case, it causes the program to stop immediately. +an `END' rule; in this case, it causes the program to stop immediately. *Note BEGIN/END::. The `nextfile' statement is useful when there are many data files to @@ -9851,10 +9877,10 @@ would have to continue scanning the unwanted records. The `nextfile' statement accomplishes this much more efficiently. In `gawk', execution of `nextfile' causes additional things to -happen: any `ENDFILE' rules are executed except in the case as -mentioned below, `ARGIND' is incremented, and any `BEGINFILE' rules are -executed. (`ARGIND' hasn't been introduced yet. *Note Built-in -Variables::.) +happen: any `ENDFILE' rules are executed if `gawk' is not currently in +an `END' or `BEGINFILE' rule, `ARGIND' is incremented, and any +`BEGINFILE' rules are executed. (`ARGIND' hasn't been introduced yet. +*Note Built-in Variables::.) With `gawk', `nextfile' is useful inside a `BEGINFILE' rule to skip over a file that would otherwise cause `gawk' to exit with a fatal @@ -11280,7 +11306,7 @@ might look like this: > line 2 > line 3' | awk '{ l[lines] = $0; ++lines } > END { - > for (i = lines-1; i >= 0; --i) + > for (i = lines - 1; i >= 0; i--) > print l[i] > }' -| line 3 @@ -11301,7 +11327,7 @@ following version of the program works correctly: { l[lines++] = $0 } END { - for (i = lines - 1; i >= 0; --i) + for (i = lines - 1; i >= 0; i--) print l[i] } @@ -14378,8 +14404,9 @@ versions of `awk': ret = 0 for (i = 1; i <= n; i++) { c = substr(str, i, 1) - if ((k = index("01234567", c)) > 0) - k-- # adjust for 1-basing in awk + # index() returns 0 if c not in string, + # includes c == "0" + k = index("1234567", c) ret = ret * 8 + k } @@ -14391,6 +14418,8 @@ versions of `awk': for (i = 1; i <= n; i++) { c = substr(str, i, 1) c = tolower(c) + # index() returns 0 if c not in string, + # includes c == "0" k = index("123456789abcdef", c) ret = ret * 16 + k @@ -14851,7 +14880,7 @@ that might be as follows: This function reads from `file' one record at a time, building up the full contents of the file in the local variable `contents'. It -works, but is not necessarily efficient. +works, but is not necessarily efficient.(1) The following function, based on a suggestion by Denis Shirokov, reads the entire contents of the named file in one shot: @@ -14886,6 +14915,13 @@ string. Thus calling code may use something like: This tests the result to see if it is empty or not. An equivalent test would be `contents == ""'. + ---------- Footnotes ---------- + + (1) Execution time grows quadratically in the size of the input; for +each record, `awk' has to allocate a bigger internal buffer for +`contents', copy the old contents into it, and then append the contents +of the new record. +  File: gawk.info, Node: Data File Management, Next: Getopt Function, Prev: General Functions, Up: Library Functions @@ -15339,8 +15375,7 @@ not an option, and it ends option processing. Continuing on: i = index(options, thisopt) if (i == 0) { if (Opterr) - printf("%c -- invalid option\n", - thisopt) > "/dev/stderr" + printf("%c -- invalid option\n", thisopt) > "/dev/stderr" if (_opti >= length(argv[Optind])) { Optind++ _opti = 0 @@ -30938,10 +30973,9 @@ Index * ! (exclamation point), !~ operator <3>: Comparison Operators. (line 11) * ! (exclamation point), !~ operator <4>: Regexp Constants. (line 6) -* ! (exclamation point), !~ operator <5>: Computed Regexps. (line 6) -* ! (exclamation point), !~ operator <6>: Case-sensitivity. (line 26) +* ! (exclamation point), !~ operator <5>: Case-sensitivity. (line 26) +* ! (exclamation point), !~ operator <6>: Computed Regexps. (line 6) * ! (exclamation point), !~ operator: Regexp Usage. (line 19) -* " (double quote) in shell commands: Read Terminal. (line 25) * " (double quote), in regexp constants: Computed Regexps. (line 29) * " (double quote), in shell commands: Quoting. (line 54) * # (number sign), #! (executable scripts): Executable Scripts. @@ -31129,8 +31163,7 @@ Index * ? (question mark), regexp operator: Regexp Operators. (line 111) * [] (square brackets), regexp operator: Regexp Operators. (line 56) * \ (backslash): Comments. (line 50) -* \ (backslash) in shell commands: Read Terminal. (line 25) -* \ (backslash), \" escape sequence: Escape Sequences. (line 80) +* \ (backslash), \" escape sequence: Escape Sequences. (line 82) * \ (backslash), \' operator (gawk): GNU Regexp Operators. (line 56) * \ (backslash), \/ escape sequence: Escape Sequences. (line 73) @@ -31173,7 +31206,7 @@ Index * \ (backslash), in bracket expressions: Bracket Expressions. (line 17) * \ (backslash), in escape sequences: Escape Sequences. (line 6) * \ (backslash), in escape sequences, POSIX and: Escape Sequences. - (line 116) + (line 118) * \ (backslash), in regexp constants: Computed Regexps. (line 29) * \ (backslash), in shell commands: Quoting. (line 48) * \ (backslash), regexp operator: Regexp Operators. (line 18) @@ -31400,8 +31433,7 @@ Index * awkvars.out file: Options. (line 93) * b debugger command (alias for break): Breakpoint Control. (line 11) * backslash (\): Comments. (line 50) -* backslash (\) in shell commands: Read Terminal. (line 25) -* backslash (\), \" escape sequence: Escape Sequences. (line 80) +* backslash (\), \" escape sequence: Escape Sequences. (line 82) * backslash (\), \' operator (gawk): GNU Regexp Operators. (line 56) * backslash (\), \/ escape sequence: Escape Sequences. (line 73) @@ -31444,7 +31476,7 @@ Index * backslash (\), in bracket expressions: Bracket Expressions. (line 17) * backslash (\), in escape sequences: Escape Sequences. (line 6) * backslash (\), in escape sequences, POSIX and: Escape Sequences. - (line 116) + (line 118) * backslash (\), in regexp constants: Computed Regexps. (line 29) * backslash (\), in shell commands: Quoting. (line 48) * backslash (\), regexp operator: Regexp Operators. (line 18) @@ -31549,7 +31581,7 @@ Index (line 67) * Brian Kernighan's awk <12>: GNU Regexp Operators. (line 83) -* Brian Kernighan's awk <13>: Escape Sequences. (line 120) +* Brian Kernighan's awk <13>: Escape Sequences. (line 122) * Brian Kernighan's awk: When. (line 21) * Brian Kernighan's awk, extensions: BTL. (line 6) * Brian Kernighan's awk, source code: Other Versions. (line 13) @@ -31577,6 +31609,7 @@ Index * built-in variables, conveying information: Auto-set. (line 6) * built-in variables, user-modifiable: User-modified. (line 6) * Busybox Awk: Other Versions. (line 88) +* c.e., See common extensions: Conventions. (line 51) * call by reference: Pass By Value/Reference. (line 47) * call by value: Pass By Value/Reference. @@ -31775,9 +31808,9 @@ Index * dark corner, command-line arguments: Assignment Options. (line 43) * dark corner, continue statement: Continue Statement. (line 44) * dark corner, CONVFMT variable: Strings And Numbers. (line 40) -* dark corner, escape sequences: Other Arguments. (line 31) +* dark corner, escape sequences: Other Arguments. (line 35) * dark corner, escape sequences, for metacharacters: Escape Sequences. - (line 138) + (line 140) * dark corner, exit statement: Exit Statement. (line 30) * dark corner, field separators: Field Splitting Summary. (line 46) @@ -32042,7 +32075,6 @@ Index * dollar sign ($), incrementing fields and arrays: Increment Ops. (line 30) * dollar sign ($), regexp operator: Regexp Operators. (line 35) -* double quote (") in shell commands: Read Terminal. (line 25) * double quote ("), in regexp constants: Computed Regexps. (line 29) * double quote ("), in shell commands: Quoting. (line 54) * down debugger command: Execution Stack. (line 21) @@ -32142,8 +32174,8 @@ Index * exclamation point (!), !~ operator <3>: Comparison Operators. (line 11) * exclamation point (!), !~ operator <4>: Regexp Constants. (line 6) -* exclamation point (!), !~ operator <5>: Computed Regexps. (line 6) -* exclamation point (!), !~ operator <6>: Case-sensitivity. (line 26) +* exclamation point (!), !~ operator <5>: Case-sensitivity. (line 26) +* exclamation point (!), !~ operator <6>: Computed Regexps. (line 6) * exclamation point (!), !~ operator: Regexp Usage. (line 19) * exit statement: Exit Statement. (line 6) * exit status, of gawk: Exit Status. (line 6) @@ -32151,7 +32183,7 @@ Index * exit the debugger: Miscellaneous Debugger Commands. (line 99) * exp: Numeric Functions. (line 18) -* expand utility: Very Simple. (line 69) +* expand utility: Very Simple. (line 72) * Expat XML parser library: gawkextlib. (line 35) * exponent: Numeric Functions. (line 18) * expressions: Expressions. (line 6) @@ -32285,7 +32317,7 @@ Index (line 47) * files, message object, specifying directory of: Explaining gettext. (line 54) -* files, multiple passes over: Other Arguments. (line 49) +* files, multiple passes over: Other Arguments. (line 53) * files, multiple, duplicating output into: Tee Program. (line 6) * files, output, See output files: Close Files And Pipes. (line 6) @@ -32446,7 +32478,7 @@ Index * gawk, ERRNO variable in <4>: Close Files And Pipes. (line 139) * gawk, ERRNO variable in: Getline. (line 19) -* gawk, escape sequences: Escape Sequences. (line 128) +* gawk, escape sequences: Escape Sequences. (line 130) * gawk, extensions, disabling: Options. (line 254) * gawk, features, adding: Adding Code. (line 6) * gawk, features, advanced: Advanced Features. (line 6) @@ -32670,7 +32702,7 @@ Index * input files, examples: Sample Data Files. (line 6) * input files, reading: Reading Files. (line 6) * input files, running awk without: Read Terminal. (line 6) -* input files, variable assignments and: Other Arguments. (line 19) +* input files, variable assignments and: Other Arguments. (line 23) * input pipeline: Getline/Pipe. (line 9) * input record, length of: String Functions. (line 174) * input redirection: Getline/File. (line 6) @@ -32879,7 +32911,7 @@ Index * mawk utility <2>: Nextfile Statement. (line 47) * mawk utility <3>: Concatenation. (line 36) * mawk utility <4>: Getline/Pipe. (line 62) -* mawk utility: Escape Sequences. (line 128) +* mawk utility: Escape Sequences. (line 130) * maximum precision supported by MPFR library: Auto-set. (line 213) * McIlroy, Doug: Glossary. (line 149) * McPhee, Patrick: Contributors. (line 100) @@ -32892,7 +32924,7 @@ Index (line 54) * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) -* metacharacters, escape sequences for: Escape Sequences. (line 134) +* metacharacters, escape sequences for: Escape Sequences. (line 136) * minimum precision supported by MPFR library: Auto-set. (line 216) * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) @@ -32930,7 +32962,7 @@ Index (line 43) * next file statement: Feature History. (line 169) * next statement <1>: Next Statement. (line 6) -* next statement: Boolean Ops. (line 85) +* next statement: Boolean Ops. (line 93) * next statement, BEGIN/END patterns and: I/O And BEGIN/END. (line 36) * next statement, BEGINFILE/ENDFILE patterns and: BEGINFILE/ENDFILE. (line 49) @@ -33111,14 +33143,14 @@ Index * plus sign (+), += operator: Assignment Ops. (line 82) * plus sign (+), regexp operator: Regexp Operators. (line 105) * pointers to functions: Indirect Calls. (line 6) -* portability: Escape Sequences. (line 98) +* portability: Escape Sequences. (line 100) * portability, #! (executable scripts): Executable Scripts. (line 33) * portability, ** operator and: Arithmetic Ops. (line 81) * portability, **= operator and: Assignment Ops. (line 143) * portability, ARGV variable: Executable Scripts. (line 59) * portability, backslash continuation and: Statements/Lines. (line 30) * portability, backslash in escape sequences: Escape Sequences. - (line 116) + (line 118) * portability, close() function and: Close Files And Pipes. (line 81) * portability, data files as single record: gawk split records. @@ -33157,7 +33189,7 @@ Index * POSIX awk, < operator and: Getline/File. (line 26) * POSIX awk, arithmetic operators and: Arithmetic Ops. (line 30) * POSIX awk, backslashes in string constants: Escape Sequences. - (line 116) + (line 118) * POSIX awk, BEGIN/END patterns: I/O And BEGIN/END. (line 16) * POSIX awk, bracket expressions and: Bracket Expressions. (line 26) * POSIX awk, bracket expressions and, character classes: Bracket Expressions. @@ -33501,7 +33533,6 @@ Index * set watchpoint: Viewing And Changing Data. (line 67) * shadowing of variable values: Definition Syntax. (line 70) -* shell quoting, double quote: Read Terminal. (line 25) * shell quoting, rules for: Quoting. (line 6) * shells, piping commands into: Redirection. (line 142) * shells, quoting: Using Shell Variables. @@ -33538,14 +33569,14 @@ Index * sidebar, A Constant's Base Does Not Affect Its Value: Nondecimal-numbers. (line 64) * sidebar, Backslash Before Regular Characters: Escape Sequences. - (line 114) + (line 116) * sidebar, Changing FS Does Not Affect the Fields: Field Splitting Summary. (line 38) * sidebar, Changing NR and FNR: Auto-set. (line 299) * sidebar, Controlling Output Buffering with system(): I/O Functions. (line 138) * sidebar, Escape Sequences for Metacharacters: Escape Sequences. - (line 132) + (line 134) * sidebar, FS and IGNORECASE: Field Splitting Summary. (line 64) * sidebar, Interactive Versus Noninteractive Buffering: I/O Functions. @@ -33745,8 +33776,8 @@ Index * tilde (~), ~ operator <3>: Comparison Operators. (line 11) * tilde (~), ~ operator <4>: Regexp Constants. (line 6) -* tilde (~), ~ operator <5>: Computed Regexps. (line 6) -* tilde (~), ~ operator <6>: Case-sensitivity. (line 26) +* tilde (~), ~ operator <5>: Case-sensitivity. (line 26) +* tilde (~), ~ operator <6>: Computed Regexps. (line 6) * tilde (~), ~ operator: Regexp Usage. (line 19) * time functions: Time Functions. (line 6) * time, alarm clock example program: Alarm Program. (line 11) @@ -33773,7 +33804,7 @@ Index (line 37) * troubleshooting, awk uses FS not IFS: Field Separators. (line 30) * troubleshooting, backslash before nonspecial character: Escape Sequences. - (line 116) + (line 118) * troubleshooting, division: Arithmetic Ops. (line 44) * troubleshooting, fatal errors, field widths, specifying: Constant Size. (line 23) @@ -33829,7 +33860,7 @@ Index * uniq.awk program: Uniq Program. (line 65) * Unix: Glossary. (line 611) * Unix awk, backslashes in escape sequences: Escape Sequences. - (line 128) + (line 130) * Unix awk, close() function and: Close Files And Pipes. (line 131) * Unix awk, password files, field separators and: Command Line Field Separator. @@ -33852,7 +33883,7 @@ Index * USR1 signal, for dynamic profiling: Profiling. (line 188) * values, numeric: Basic Data Typing. (line 13) * values, string: Basic Data Typing. (line 13) -* variable assignments and input files: Other Arguments. (line 19) +* variable assignments and input files: Other Arguments. (line 23) * variable typing: Typing and Comparison. (line 9) * variables <1>: Basic Data Typing. (line 6) @@ -33966,8 +33997,8 @@ Index * ~ (tilde), ~ operator <3>: Comparison Operators. (line 11) * ~ (tilde), ~ operator <4>: Regexp Constants. (line 6) -* ~ (tilde), ~ operator <5>: Computed Regexps. (line 6) -* ~ (tilde), ~ operator <6>: Case-sensitivity. (line 26) +* ~ (tilde), ~ operator <5>: Case-sensitivity. (line 26) +* ~ (tilde), ~ operator <6>: Computed Regexps. (line 6) * ~ (tilde), ~ operator: Regexp Usage. (line 19) @@ -33993,533 +34024,533 @@ Node: Getting Started70581 Node: Running gawk73015 Node: One-shot74205 Node: Read Terminal75430 -Ref: Read Terminal-Footnote-177393 -Node: Long77564 -Node: Executable Scripts78958 -Ref: Executable Scripts-Footnote-181759 -Node: Comments81861 -Node: Quoting84334 -Node: DOS Quoting89647 -Node: Sample Data Files90322 -Node: Very Simple92929 -Node: Two Rules97688 -Node: More Complex99582 -Ref: More Complex-Footnote-1102496 -Node: Statements/Lines102581 -Ref: Statements/Lines-Footnote-1107037 -Node: Other Features107302 -Node: When108230 -Ref: When-Footnote-1109986 -Node: Intro Summary110051 -Node: Invoking Gawk110934 -Node: Command Line112449 -Node: Options113240 -Ref: Options-Footnote-1129016 -Node: Other Arguments129041 -Node: Naming Standard Input131703 -Node: Environment Variables132796 -Node: AWKPATH Variable133354 -Ref: AWKPATH Variable-Footnote-1136220 -Ref: AWKPATH Variable-Footnote-2136265 -Node: AWKLIBPATH Variable136525 -Node: Other Environment Variables137284 -Node: Exit Status140941 -Node: Include Files141616 -Node: Loading Shared Libraries145194 -Node: Obsolete146578 -Node: Undocumented147275 -Node: Invoking Summary147542 -Node: Regexp149142 -Node: Regexp Usage150601 -Node: Escape Sequences152634 -Node: Regexp Operators158451 -Ref: Regexp Operators-Footnote-1165882 -Ref: Regexp Operators-Footnote-2166029 -Node: Bracket Expressions166127 -Ref: table-char-classes168149 -Node: GNU Regexp Operators171089 -Node: Case-sensitivity174798 -Ref: Case-sensitivity-Footnote-1177690 -Ref: Case-sensitivity-Footnote-2177925 -Node: Leftmost Longest178033 -Node: Computed Regexps179234 -Node: Regexp Summary182606 -Node: Reading Files184075 -Node: Records186167 -Node: awk split records186889 -Node: gawk split records191747 -Ref: gawk split records-Footnote-1196268 -Node: Fields196305 -Ref: Fields-Footnote-1199269 -Node: Nonconstant Fields199355 -Ref: Nonconstant Fields-Footnote-1201585 -Node: Changing Fields201787 -Node: Field Separators207741 -Node: Default Field Splitting210443 -Node: Regexp Field Splitting211560 -Node: Single Character Fields214887 -Node: Command Line Field Separator215946 -Node: Full Line Fields219372 -Ref: Full Line Fields-Footnote-1219880 -Node: Field Splitting Summary219926 -Ref: Field Splitting Summary-Footnote-1223058 -Node: Constant Size223159 -Node: Splitting By Content227765 -Ref: Splitting By Content-Footnote-1231838 -Node: Multiple Line231878 -Ref: Multiple Line-Footnote-1237734 -Node: Getline237913 -Node: Plain Getline240124 -Node: Getline/Variable242219 -Node: Getline/File243366 -Node: Getline/Variable/File244750 -Ref: Getline/Variable/File-Footnote-1246349 -Node: Getline/Pipe246436 -Node: Getline/Variable/Pipe249122 -Node: Getline/Coprocess250229 -Node: Getline/Variable/Coprocess251481 -Node: Getline Notes252218 -Node: Getline Summary255022 -Ref: table-getline-variants255430 -Node: Read Timeout256342 -Ref: Read Timeout-Footnote-1260169 -Node: Command-line directories260227 -Node: Input Summary261131 -Node: Input Exercises264268 -Node: Printing265001 -Node: Print266723 -Node: Print Examples268216 -Node: Output Separators270995 -Node: OFMT273011 -Node: Printf274369 -Node: Basic Printf275275 -Node: Control Letters276814 -Node: Format Modifiers280805 -Node: Printf Examples286832 -Node: Redirection289296 -Node: Special Files296268 -Node: Special FD296801 -Ref: Special FD-Footnote-1300398 -Node: Special Network300472 -Node: Special Caveats301322 -Node: Close Files And Pipes302118 -Ref: Close Files And Pipes-Footnote-1309279 -Ref: Close Files And Pipes-Footnote-2309427 -Node: Output Summary309577 -Node: Output Exercises310574 -Node: Expressions311254 -Node: Values312439 -Node: Constants313115 -Node: Scalar Constants313795 -Ref: Scalar Constants-Footnote-1314654 -Node: Nondecimal-numbers314904 -Node: Regexp Constants317904 -Node: Using Constant Regexps318379 -Node: Variables321451 -Node: Using Variables322106 -Node: Assignment Options323830 -Node: Conversion325705 -Node: Strings And Numbers326229 -Ref: Strings And Numbers-Footnote-1329291 -Node: Locale influences conversions329400 -Ref: table-locale-affects332117 -Node: All Operators332705 -Node: Arithmetic Ops333335 -Node: Concatenation335840 -Ref: Concatenation-Footnote-1338659 -Node: Assignment Ops338765 -Ref: table-assign-ops343748 -Node: Increment Ops345051 -Node: Truth Values and Conditions348489 -Node: Truth Values349572 -Node: Typing and Comparison350621 -Node: Variable Typing351414 -Node: Comparison Operators355066 -Ref: table-relational-ops355476 -Node: POSIX String Comparison359026 -Ref: POSIX String Comparison-Footnote-1360110 -Node: Boolean Ops360248 -Ref: Boolean Ops-Footnote-1364323 -Node: Conditional Exp364414 -Node: Function Calls366141 -Node: Precedence370021 -Node: Locales373690 -Node: Expressions Summary375321 -Node: Patterns and Actions377862 -Node: Pattern Overview378978 -Node: Regexp Patterns380655 -Node: Expression Patterns381198 -Node: Ranges384978 -Node: BEGIN/END388084 -Node: Using BEGIN/END388846 -Ref: Using BEGIN/END-Footnote-1391582 -Node: I/O And BEGIN/END391688 -Node: BEGINFILE/ENDFILE393959 -Node: Empty396890 -Node: Using Shell Variables397207 -Node: Action Overview399490 -Node: Statements401817 -Node: If Statement403665 -Node: While Statement405163 -Node: Do Statement407207 -Node: For Statement408363 -Node: Switch Statement411515 -Node: Break Statement413903 -Node: Continue Statement415944 -Node: Next Statement417769 -Node: Nextfile Statement420159 -Node: Exit Statement422795 -Node: Built-in Variables425199 -Node: User-modified426326 -Ref: User-modified-Footnote-1434015 -Node: Auto-set434077 -Ref: Auto-set-Footnote-1446659 -Ref: Auto-set-Footnote-2446864 -Node: ARGC and ARGV446920 -Node: Pattern Action Summary450824 -Node: Arrays453047 -Node: Array Basics454596 -Node: Array Intro455422 -Ref: figure-array-elements457395 -Ref: Array Intro-Footnote-1459919 -Node: Reference to Elements460047 -Node: Assigning Elements462497 -Node: Array Example462988 -Node: Scanning an Array464720 -Node: Controlling Scanning467721 -Ref: Controlling Scanning-Footnote-1472894 -Node: Delete473210 -Ref: Delete-Footnote-1475961 -Node: Numeric Array Subscripts476018 -Node: Uninitialized Subscripts478201 -Node: Multidimensional479826 -Node: Multiscanning482939 -Node: Arrays of Arrays484528 -Node: Arrays Summary489191 -Node: Functions491296 -Node: Built-in492169 -Node: Calling Built-in493247 -Node: Numeric Functions495235 -Ref: Numeric Functions-Footnote-1499269 -Ref: Numeric Functions-Footnote-2499626 -Ref: Numeric Functions-Footnote-3499674 -Node: String Functions499943 -Ref: String Functions-Footnote-1522940 -Ref: String Functions-Footnote-2523069 -Ref: String Functions-Footnote-3523317 -Node: Gory Details523404 -Ref: table-sub-escapes525177 -Ref: table-sub-proposed526697 -Ref: table-posix-sub528061 -Ref: table-gensub-escapes529601 -Ref: Gory Details-Footnote-1530777 -Node: I/O Functions530928 -Ref: I/O Functions-Footnote-1538038 -Node: Time Functions538185 -Ref: Time Functions-Footnote-1548649 -Ref: Time Functions-Footnote-2548717 -Ref: Time Functions-Footnote-3548875 -Ref: Time Functions-Footnote-4548986 -Ref: Time Functions-Footnote-5549098 -Ref: Time Functions-Footnote-6549325 -Node: Bitwise Functions549591 -Ref: table-bitwise-ops550153 -Ref: Bitwise Functions-Footnote-1554398 -Node: Type Functions554582 -Node: I18N Functions555724 -Node: User-defined557369 -Node: Definition Syntax558173 -Ref: Definition Syntax-Footnote-1563486 -Node: Function Example563555 -Ref: Function Example-Footnote-1566195 -Node: Function Caveats566217 -Node: Calling A Function566735 -Node: Variable Scope567690 -Node: Pass By Value/Reference570678 -Node: Return Statement574188 -Node: Dynamic Typing577172 -Node: Indirect Calls578101 -Node: Functions Summary587814 -Node: Library Functions590353 -Ref: Library Functions-Footnote-1593971 -Ref: Library Functions-Footnote-2594114 -Node: Library Names594285 -Ref: Library Names-Footnote-1597758 -Ref: Library Names-Footnote-2597978 -Node: General Functions598064 -Node: Strtonum Function599092 -Node: Assert Function601872 -Node: Round Function605198 -Node: Cliff Random Function606739 -Node: Ordinal Functions607755 -Ref: Ordinal Functions-Footnote-1610820 -Ref: Ordinal Functions-Footnote-2611072 -Node: Join Function611283 -Ref: Join Function-Footnote-1613054 -Node: Getlocaltime Function613254 -Node: Readfile Function616990 -Node: Data File Management618829 -Node: Filetrans Function619461 -Node: Rewind Function623530 -Node: File Checking625088 -Ref: File Checking-Footnote-1626220 -Node: Empty Files626421 -Node: Ignoring Assigns628400 -Node: Getopt Function629954 -Ref: Getopt Function-Footnote-1641257 -Node: Passwd Functions641460 -Ref: Passwd Functions-Footnote-1650439 -Node: Group Functions650527 -Ref: Group Functions-Footnote-1658458 -Node: Walking Arrays658671 -Node: Library Functions Summary660274 -Node: Library Exercises661662 -Node: Sample Programs662942 -Node: Running Examples663712 -Node: Clones664440 -Node: Cut Program665664 -Node: Egrep Program675522 -Ref: Egrep Program-Footnote-1683109 -Node: Id Program683219 -Node: Split Program686873 -Ref: Split Program-Footnote-1690411 -Node: Tee Program690539 -Node: Uniq Program693326 -Node: Wc Program700747 -Ref: Wc Program-Footnote-1705012 -Node: Miscellaneous Programs705104 -Node: Dupword Program706317 -Node: Alarm Program708348 -Node: Translate Program713152 -Ref: Translate Program-Footnote-1717543 -Ref: Translate Program-Footnote-2717813 -Node: Labels Program717947 -Ref: Labels Program-Footnote-1721308 -Node: Word Sorting721392 -Node: History Sorting725435 -Node: Extract Program727271 -Node: Simple Sed734807 -Node: Igawk Program737869 -Ref: Igawk Program-Footnote-1752173 -Ref: Igawk Program-Footnote-2752374 -Node: Anagram Program752512 -Node: Signature Program755580 -Node: Programs Summary756827 -Node: Programs Exercises758042 -Node: Advanced Features761693 -Node: Nondecimal Data763641 -Node: Array Sorting765218 -Node: Controlling Array Traversal765915 -Node: Array Sorting Functions774195 -Ref: Array Sorting Functions-Footnote-1778102 -Node: Two-way I/O778296 -Ref: Two-way I/O-Footnote-1783240 -Ref: Two-way I/O-Footnote-2783419 -Node: TCP/IP Networking783501 -Node: Profiling786346 -Node: Advanced Features Summary793888 -Node: Internationalization795752 -Node: I18N and L10N797232 -Node: Explaining gettext797918 -Ref: Explaining gettext-Footnote-1802944 -Ref: Explaining gettext-Footnote-2803128 -Node: Programmer i18n803293 -Ref: Programmer i18n-Footnote-1808087 -Node: Translator i18n808136 -Node: String Extraction808930 -Ref: String Extraction-Footnote-1810063 -Node: Printf Ordering810149 -Ref: Printf Ordering-Footnote-1812931 -Node: I18N Portability812995 -Ref: I18N Portability-Footnote-1815444 -Node: I18N Example815507 -Ref: I18N Example-Footnote-1818213 -Node: Gawk I18N818285 -Node: I18N Summary818923 -Node: Debugger820262 -Node: Debugging821284 -Node: Debugging Concepts821725 -Node: Debugging Terms823581 -Node: Awk Debugging826178 -Node: Sample Debugging Session827070 -Node: Debugger Invocation827590 -Node: Finding The Bug828923 -Node: List of Debugger Commands835405 -Node: Breakpoint Control836737 -Node: Debugger Execution Control840401 -Node: Viewing And Changing Data843761 -Node: Execution Stack847119 -Node: Debugger Info848632 -Node: Miscellaneous Debugger Commands852626 -Node: Readline Support857810 -Node: Limitations858702 -Node: Debugging Summary860976 -Node: Arbitrary Precision Arithmetic862144 -Node: Computer Arithmetic863631 -Ref: Computer Arithmetic-Footnote-1868018 -Node: Math Definitions868075 -Ref: table-ieee-formats871364 -Ref: Math Definitions-Footnote-1871904 -Node: MPFR features872007 -Node: FP Math Caution873624 -Ref: FP Math Caution-Footnote-1874674 -Node: Inexactness of computations875043 -Node: Inexact representation875991 -Node: Comparing FP Values877346 -Node: Errors accumulate878310 -Node: Getting Accuracy879743 -Node: Try To Round882402 -Node: Setting precision883301 -Ref: table-predefined-precision-strings883983 -Node: Setting the rounding mode885776 -Ref: table-gawk-rounding-modes886140 -Ref: Setting the rounding mode-Footnote-1889594 -Node: Arbitrary Precision Integers889773 -Ref: Arbitrary Precision Integers-Footnote-1892754 -Node: POSIX Floating Point Problems892903 -Ref: POSIX Floating Point Problems-Footnote-1896779 -Node: Floating point summary896817 -Node: Dynamic Extensions899021 -Node: Extension Intro900573 -Node: Plugin License901838 -Node: Extension Mechanism Outline902523 -Ref: figure-load-extension902947 -Ref: figure-load-new-function904432 -Ref: figure-call-new-function905434 -Node: Extension API Description907418 -Node: Extension API Functions Introduction908868 -Node: General Data Types913735 -Ref: General Data Types-Footnote-1919428 -Node: Requesting Values919727 -Ref: table-value-types-returned920464 -Node: Memory Allocation Functions921422 -Ref: Memory Allocation Functions-Footnote-1924169 -Node: Constructor Functions924265 -Node: Registration Functions926023 -Node: Extension Functions926708 -Node: Exit Callback Functions929010 -Node: Extension Version String930258 -Node: Input Parsers930908 -Node: Output Wrappers940722 -Node: Two-way processors945238 -Node: Printing Messages947442 -Ref: Printing Messages-Footnote-1948519 -Node: Updating `ERRNO'948671 -Node: Accessing Parameters949410 -Node: Symbol Table Access950640 -Node: Symbol table by name951154 -Node: Symbol table by cookie953130 -Ref: Symbol table by cookie-Footnote-1957263 -Node: Cached values957326 -Ref: Cached values-Footnote-1960830 -Node: Array Manipulation960921 -Ref: Array Manipulation-Footnote-1962019 -Node: Array Data Types962058 -Ref: Array Data Types-Footnote-1964761 -Node: Array Functions964853 -Node: Flattening Arrays968727 -Node: Creating Arrays975579 -Node: Extension API Variables980310 -Node: Extension Versioning980946 -Node: Extension API Informational Variables982847 -Node: Extension API Boilerplate983933 -Node: Finding Extensions987737 -Node: Extension Example988297 -Node: Internal File Description989027 -Node: Internal File Ops993118 -Ref: Internal File Ops-Footnote-11004550 -Node: Using Internal File Ops1004690 -Ref: Using Internal File Ops-Footnote-11007037 -Node: Extension Samples1007305 -Node: Extension Sample File Functions1008829 -Node: Extension Sample Fnmatch1016397 -Node: Extension Sample Fork1017879 -Node: Extension Sample Inplace1019092 -Node: Extension Sample Ord1020767 -Node: Extension Sample Readdir1021603 -Ref: table-readdir-file-types1022459 -Node: Extension Sample Revout1023258 -Node: Extension Sample Rev2way1023849 -Node: Extension Sample Read write array1024590 -Node: Extension Sample Readfile1026469 -Node: Extension Sample API Tests1027569 -Node: Extension Sample Time1028094 -Node: gawkextlib1029409 -Node: Extension summary1032222 -Node: Extension Exercises1035915 -Node: Language History1036637 -Node: V7/SVR3.11038280 -Node: SVR41040600 -Node: POSIX1042042 -Node: BTL1043428 -Node: POSIX/GNU1044162 -Node: Feature History1049878 -Node: Common Extensions1062969 -Node: Ranges and Locales1064281 -Ref: Ranges and Locales-Footnote-11068898 -Ref: Ranges and Locales-Footnote-21068925 -Ref: Ranges and Locales-Footnote-31069159 -Node: Contributors1069380 -Node: History summary1074805 -Node: Installation1076174 -Node: Gawk Distribution1077125 -Node: Getting1077609 -Node: Extracting1078433 -Node: Distribution contents1080075 -Node: Unix Installation1085792 -Node: Quick Installation1086409 -Node: Additional Configuration Options1088851 -Node: Configuration Philosophy1090589 -Node: Non-Unix Installation1092940 -Node: PC Installation1093398 -Node: PC Binary Installation1094709 -Node: PC Compiling1096557 -Ref: PC Compiling-Footnote-11099556 -Node: PC Testing1099661 -Node: PC Using1100837 -Node: Cygwin1104989 -Node: MSYS1105798 -Node: VMS Installation1106312 -Node: VMS Compilation1107108 -Ref: VMS Compilation-Footnote-11108330 -Node: VMS Dynamic Extensions1108388 -Node: VMS Installation Details1109761 -Node: VMS Running1112013 -Node: VMS GNV1114847 -Node: VMS Old Gawk1115570 -Node: Bugs1116040 -Node: Other Versions1120044 -Node: Installation summary1126271 -Node: Notes1127327 -Node: Compatibility Mode1128192 -Node: Additions1128974 -Node: Accessing The Source1129899 -Node: Adding Code1131335 -Node: New Ports1137513 -Node: Derived Files1141994 -Ref: Derived Files-Footnote-11147075 -Ref: Derived Files-Footnote-21147109 -Ref: Derived Files-Footnote-31147705 -Node: Future Extensions1147819 -Node: Implementation Limitations1148425 -Node: Extension Design1149673 -Node: Old Extension Problems1150827 -Ref: Old Extension Problems-Footnote-11152344 -Node: Extension New Mechanism Goals1152401 -Ref: Extension New Mechanism Goals-Footnote-11155761 -Node: Extension Other Design Decisions1155950 -Node: Extension Future Growth1158056 -Node: Old Extension Mechanism1158892 -Node: Notes summary1160654 -Node: Basic Concepts1161840 -Node: Basic High Level1162521 -Ref: figure-general-flow1162793 -Ref: figure-process-flow1163392 -Ref: Basic High Level-Footnote-11166621 -Node: Basic Data Typing1166806 -Node: Glossary1170134 -Node: Copying1195286 -Node: GNU Free Documentation License1232842 -Node: Index1257978 +Node: Long77455 +Node: Executable Scripts78849 +Ref: Executable Scripts-Footnote-181650 +Node: Comments81752 +Node: Quoting84225 +Node: DOS Quoting89538 +Node: Sample Data Files90213 +Node: Very Simple92820 +Node: Two Rules97705 +Node: More Complex99599 +Ref: More Complex-Footnote-1102513 +Node: Statements/Lines102598 +Ref: Statements/Lines-Footnote-1107054 +Node: Other Features107319 +Node: When108247 +Ref: When-Footnote-1110003 +Node: Intro Summary110068 +Node: Invoking Gawk110951 +Node: Command Line112466 +Node: Options113257 +Ref: Options-Footnote-1129033 +Node: Other Arguments129058 +Node: Naming Standard Input131886 +Node: Environment Variables132979 +Node: AWKPATH Variable133537 +Ref: AWKPATH Variable-Footnote-1136403 +Ref: AWKPATH Variable-Footnote-2136448 +Node: AWKLIBPATH Variable136708 +Node: Other Environment Variables137467 +Node: Exit Status141124 +Node: Include Files141799 +Node: Loading Shared Libraries145377 +Node: Obsolete146761 +Node: Undocumented147458 +Node: Invoking Summary147725 +Node: Regexp149325 +Node: Regexp Usage150784 +Node: Escape Sequences152817 +Node: Regexp Operators158805 +Ref: Regexp Operators-Footnote-1166236 +Ref: Regexp Operators-Footnote-2166383 +Node: Bracket Expressions166481 +Ref: table-char-classes168499 +Node: Leftmost Longest171439 +Node: Computed Regexps172643 +Node: GNU Regexp Operators176021 +Node: Case-sensitivity179727 +Ref: Case-sensitivity-Footnote-1182617 +Ref: Case-sensitivity-Footnote-2182852 +Node: Regexp Summary182960 +Node: Reading Files184429 +Node: Records186521 +Node: awk split records187243 +Node: gawk split records192101 +Ref: gawk split records-Footnote-1196622 +Node: Fields196659 +Ref: Fields-Footnote-1199623 +Node: Nonconstant Fields199709 +Ref: Nonconstant Fields-Footnote-1201939 +Node: Changing Fields202141 +Node: Field Separators208095 +Node: Default Field Splitting210797 +Node: Regexp Field Splitting211914 +Node: Single Character Fields215241 +Node: Command Line Field Separator216300 +Node: Full Line Fields219726 +Ref: Full Line Fields-Footnote-1220234 +Node: Field Splitting Summary220280 +Ref: Field Splitting Summary-Footnote-1223412 +Node: Constant Size223513 +Node: Splitting By Content228119 +Ref: Splitting By Content-Footnote-1232192 +Node: Multiple Line232232 +Ref: Multiple Line-Footnote-1238088 +Node: Getline238267 +Node: Plain Getline240478 +Node: Getline/Variable243184 +Node: Getline/File244331 +Node: Getline/Variable/File245715 +Ref: Getline/Variable/File-Footnote-1247314 +Node: Getline/Pipe247401 +Node: Getline/Variable/Pipe250087 +Node: Getline/Coprocess251194 +Node: Getline/Variable/Coprocess252446 +Node: Getline Notes253183 +Node: Getline Summary255987 +Ref: table-getline-variants256395 +Node: Read Timeout257307 +Ref: Read Timeout-Footnote-1261134 +Node: Command-line directories261192 +Node: Input Summary262096 +Node: Input Exercises265233 +Node: Printing265961 +Node: Print267683 +Node: Print Examples269176 +Node: Output Separators271955 +Node: OFMT273971 +Node: Printf275329 +Node: Basic Printf276235 +Node: Control Letters277774 +Node: Format Modifiers281765 +Node: Printf Examples287792 +Node: Redirection290256 +Node: Special Files297228 +Node: Special FD297761 +Ref: Special FD-Footnote-1301358 +Node: Special Network301432 +Node: Special Caveats302282 +Node: Close Files And Pipes303078 +Ref: Close Files And Pipes-Footnote-1310239 +Ref: Close Files And Pipes-Footnote-2310387 +Node: Output Summary310537 +Node: Output Exercises311534 +Node: Expressions312214 +Node: Values313399 +Node: Constants314075 +Node: Scalar Constants314755 +Ref: Scalar Constants-Footnote-1315614 +Node: Nondecimal-numbers315864 +Node: Regexp Constants318864 +Node: Using Constant Regexps319389 +Node: Variables322461 +Node: Using Variables323116 +Node: Assignment Options324840 +Node: Conversion326715 +Node: Strings And Numbers327239 +Ref: Strings And Numbers-Footnote-1330301 +Node: Locale influences conversions330410 +Ref: table-locale-affects333127 +Node: All Operators333715 +Node: Arithmetic Ops334345 +Node: Concatenation336850 +Ref: Concatenation-Footnote-1339669 +Node: Assignment Ops339775 +Ref: table-assign-ops344758 +Node: Increment Ops346061 +Node: Truth Values and Conditions349499 +Node: Truth Values350582 +Node: Typing and Comparison351631 +Node: Variable Typing352424 +Node: Comparison Operators356076 +Ref: table-relational-ops356486 +Node: POSIX String Comparison360036 +Ref: POSIX String Comparison-Footnote-1361120 +Node: Boolean Ops361258 +Ref: Boolean Ops-Footnote-1365597 +Node: Conditional Exp365688 +Node: Function Calls367415 +Node: Precedence371295 +Node: Locales374964 +Node: Expressions Summary376595 +Node: Patterns and Actions379136 +Node: Pattern Overview380252 +Node: Regexp Patterns381929 +Node: Expression Patterns382472 +Node: Ranges386252 +Node: BEGIN/END389358 +Node: Using BEGIN/END390120 +Ref: Using BEGIN/END-Footnote-1392856 +Node: I/O And BEGIN/END392962 +Node: BEGINFILE/ENDFILE395233 +Node: Empty398164 +Node: Using Shell Variables398481 +Node: Action Overview400764 +Node: Statements403091 +Node: If Statement404939 +Node: While Statement406437 +Node: Do Statement408481 +Node: For Statement409637 +Node: Switch Statement412789 +Node: Break Statement415177 +Node: Continue Statement417218 +Node: Next Statement419043 +Node: Nextfile Statement421433 +Node: Exit Statement424090 +Node: Built-in Variables426494 +Node: User-modified427621 +Ref: User-modified-Footnote-1435310 +Node: Auto-set435372 +Ref: Auto-set-Footnote-1447954 +Ref: Auto-set-Footnote-2448159 +Node: ARGC and ARGV448215 +Node: Pattern Action Summary452119 +Node: Arrays454342 +Node: Array Basics455891 +Node: Array Intro456717 +Ref: figure-array-elements458690 +Ref: Array Intro-Footnote-1461214 +Node: Reference to Elements461342 +Node: Assigning Elements463792 +Node: Array Example464283 +Node: Scanning an Array466015 +Node: Controlling Scanning469016 +Ref: Controlling Scanning-Footnote-1474189 +Node: Delete474505 +Ref: Delete-Footnote-1477256 +Node: Numeric Array Subscripts477313 +Node: Uninitialized Subscripts479496 +Node: Multidimensional481123 +Node: Multiscanning484236 +Node: Arrays of Arrays485825 +Node: Arrays Summary490488 +Node: Functions492593 +Node: Built-in493466 +Node: Calling Built-in494544 +Node: Numeric Functions496532 +Ref: Numeric Functions-Footnote-1500566 +Ref: Numeric Functions-Footnote-2500923 +Ref: Numeric Functions-Footnote-3500971 +Node: String Functions501240 +Ref: String Functions-Footnote-1524237 +Ref: String Functions-Footnote-2524366 +Ref: String Functions-Footnote-3524614 +Node: Gory Details524701 +Ref: table-sub-escapes526474 +Ref: table-sub-proposed527994 +Ref: table-posix-sub529358 +Ref: table-gensub-escapes530898 +Ref: Gory Details-Footnote-1532074 +Node: I/O Functions532225 +Ref: I/O Functions-Footnote-1539335 +Node: Time Functions539482 +Ref: Time Functions-Footnote-1549946 +Ref: Time Functions-Footnote-2550014 +Ref: Time Functions-Footnote-3550172 +Ref: Time Functions-Footnote-4550283 +Ref: Time Functions-Footnote-5550395 +Ref: Time Functions-Footnote-6550622 +Node: Bitwise Functions550888 +Ref: table-bitwise-ops551450 +Ref: Bitwise Functions-Footnote-1555695 +Node: Type Functions555879 +Node: I18N Functions557021 +Node: User-defined558666 +Node: Definition Syntax559470 +Ref: Definition Syntax-Footnote-1564783 +Node: Function Example564852 +Ref: Function Example-Footnote-1567492 +Node: Function Caveats567514 +Node: Calling A Function568032 +Node: Variable Scope568987 +Node: Pass By Value/Reference571975 +Node: Return Statement575485 +Node: Dynamic Typing578469 +Node: Indirect Calls579398 +Node: Functions Summary589111 +Node: Library Functions591650 +Ref: Library Functions-Footnote-1595268 +Ref: Library Functions-Footnote-2595411 +Node: Library Names595582 +Ref: Library Names-Footnote-1599055 +Ref: Library Names-Footnote-2599275 +Node: General Functions599361 +Node: Strtonum Function600389 +Node: Assert Function603263 +Node: Round Function606589 +Node: Cliff Random Function608130 +Node: Ordinal Functions609146 +Ref: Ordinal Functions-Footnote-1612211 +Ref: Ordinal Functions-Footnote-2612463 +Node: Join Function612674 +Ref: Join Function-Footnote-1614445 +Node: Getlocaltime Function614645 +Node: Readfile Function618381 +Ref: Readfile Function-Footnote-1620259 +Node: Data File Management620487 +Node: Filetrans Function621119 +Node: Rewind Function625188 +Node: File Checking626746 +Ref: File Checking-Footnote-1627878 +Node: Empty Files628079 +Node: Ignoring Assigns630058 +Node: Getopt Function631612 +Ref: Getopt Function-Footnote-1642876 +Node: Passwd Functions643079 +Ref: Passwd Functions-Footnote-1652058 +Node: Group Functions652146 +Ref: Group Functions-Footnote-1660077 +Node: Walking Arrays660290 +Node: Library Functions Summary661893 +Node: Library Exercises663281 +Node: Sample Programs664561 +Node: Running Examples665331 +Node: Clones666059 +Node: Cut Program667283 +Node: Egrep Program677141 +Ref: Egrep Program-Footnote-1684728 +Node: Id Program684838 +Node: Split Program688492 +Ref: Split Program-Footnote-1692030 +Node: Tee Program692158 +Node: Uniq Program694945 +Node: Wc Program702366 +Ref: Wc Program-Footnote-1706631 +Node: Miscellaneous Programs706723 +Node: Dupword Program707936 +Node: Alarm Program709967 +Node: Translate Program714771 +Ref: Translate Program-Footnote-1719162 +Ref: Translate Program-Footnote-2719432 +Node: Labels Program719566 +Ref: Labels Program-Footnote-1722927 +Node: Word Sorting723011 +Node: History Sorting727054 +Node: Extract Program728890 +Node: Simple Sed736426 +Node: Igawk Program739488 +Ref: Igawk Program-Footnote-1753792 +Ref: Igawk Program-Footnote-2753993 +Node: Anagram Program754131 +Node: Signature Program757199 +Node: Programs Summary758446 +Node: Programs Exercises759661 +Node: Advanced Features763312 +Node: Nondecimal Data765260 +Node: Array Sorting766837 +Node: Controlling Array Traversal767534 +Node: Array Sorting Functions775814 +Ref: Array Sorting Functions-Footnote-1779721 +Node: Two-way I/O779915 +Ref: Two-way I/O-Footnote-1784859 +Ref: Two-way I/O-Footnote-2785038 +Node: TCP/IP Networking785120 +Node: Profiling787965 +Node: Advanced Features Summary795507 +Node: Internationalization797371 +Node: I18N and L10N798851 +Node: Explaining gettext799537 +Ref: Explaining gettext-Footnote-1804563 +Ref: Explaining gettext-Footnote-2804747 +Node: Programmer i18n804912 +Ref: Programmer i18n-Footnote-1809706 +Node: Translator i18n809755 +Node: String Extraction810549 +Ref: String Extraction-Footnote-1811682 +Node: Printf Ordering811768 +Ref: Printf Ordering-Footnote-1814550 +Node: I18N Portability814614 +Ref: I18N Portability-Footnote-1817063 +Node: I18N Example817126 +Ref: I18N Example-Footnote-1819832 +Node: Gawk I18N819904 +Node: I18N Summary820542 +Node: Debugger821881 +Node: Debugging822903 +Node: Debugging Concepts823344 +Node: Debugging Terms825200 +Node: Awk Debugging827797 +Node: Sample Debugging Session828689 +Node: Debugger Invocation829209 +Node: Finding The Bug830542 +Node: List of Debugger Commands837024 +Node: Breakpoint Control838356 +Node: Debugger Execution Control842020 +Node: Viewing And Changing Data845380 +Node: Execution Stack848738 +Node: Debugger Info850251 +Node: Miscellaneous Debugger Commands854245 +Node: Readline Support859429 +Node: Limitations860321 +Node: Debugging Summary862595 +Node: Arbitrary Precision Arithmetic863763 +Node: Computer Arithmetic865250 +Ref: Computer Arithmetic-Footnote-1869637 +Node: Math Definitions869694 +Ref: table-ieee-formats872983 +Ref: Math Definitions-Footnote-1873523 +Node: MPFR features873626 +Node: FP Math Caution875243 +Ref: FP Math Caution-Footnote-1876293 +Node: Inexactness of computations876662 +Node: Inexact representation877610 +Node: Comparing FP Values878965 +Node: Errors accumulate879929 +Node: Getting Accuracy881362 +Node: Try To Round884021 +Node: Setting precision884920 +Ref: table-predefined-precision-strings885602 +Node: Setting the rounding mode887395 +Ref: table-gawk-rounding-modes887759 +Ref: Setting the rounding mode-Footnote-1891213 +Node: Arbitrary Precision Integers891392 +Ref: Arbitrary Precision Integers-Footnote-1894373 +Node: POSIX Floating Point Problems894522 +Ref: POSIX Floating Point Problems-Footnote-1898398 +Node: Floating point summary898436 +Node: Dynamic Extensions900640 +Node: Extension Intro902192 +Node: Plugin License903457 +Node: Extension Mechanism Outline904142 +Ref: figure-load-extension904566 +Ref: figure-load-new-function906051 +Ref: figure-call-new-function907053 +Node: Extension API Description909037 +Node: Extension API Functions Introduction910487 +Node: General Data Types915354 +Ref: General Data Types-Footnote-1921047 +Node: Requesting Values921346 +Ref: table-value-types-returned922083 +Node: Memory Allocation Functions923041 +Ref: Memory Allocation Functions-Footnote-1925788 +Node: Constructor Functions925884 +Node: Registration Functions927642 +Node: Extension Functions928327 +Node: Exit Callback Functions930629 +Node: Extension Version String931877 +Node: Input Parsers932527 +Node: Output Wrappers942341 +Node: Two-way processors946857 +Node: Printing Messages949061 +Ref: Printing Messages-Footnote-1950138 +Node: Updating `ERRNO'950290 +Node: Accessing Parameters951029 +Node: Symbol Table Access952259 +Node: Symbol table by name952773 +Node: Symbol table by cookie954749 +Ref: Symbol table by cookie-Footnote-1958882 +Node: Cached values958945 +Ref: Cached values-Footnote-1962449 +Node: Array Manipulation962540 +Ref: Array Manipulation-Footnote-1963638 +Node: Array Data Types963677 +Ref: Array Data Types-Footnote-1966380 +Node: Array Functions966472 +Node: Flattening Arrays970346 +Node: Creating Arrays977198 +Node: Extension API Variables981929 +Node: Extension Versioning982565 +Node: Extension API Informational Variables984466 +Node: Extension API Boilerplate985552 +Node: Finding Extensions989356 +Node: Extension Example989916 +Node: Internal File Description990646 +Node: Internal File Ops994737 +Ref: Internal File Ops-Footnote-11006169 +Node: Using Internal File Ops1006309 +Ref: Using Internal File Ops-Footnote-11008656 +Node: Extension Samples1008924 +Node: Extension Sample File Functions1010448 +Node: Extension Sample Fnmatch1018016 +Node: Extension Sample Fork1019498 +Node: Extension Sample Inplace1020711 +Node: Extension Sample Ord1022386 +Node: Extension Sample Readdir1023222 +Ref: table-readdir-file-types1024078 +Node: Extension Sample Revout1024877 +Node: Extension Sample Rev2way1025468 +Node: Extension Sample Read write array1026209 +Node: Extension Sample Readfile1028088 +Node: Extension Sample API Tests1029188 +Node: Extension Sample Time1029713 +Node: gawkextlib1031028 +Node: Extension summary1033841 +Node: Extension Exercises1037534 +Node: Language History1038256 +Node: V7/SVR3.11039899 +Node: SVR41042219 +Node: POSIX1043661 +Node: BTL1045047 +Node: POSIX/GNU1045781 +Node: Feature History1051497 +Node: Common Extensions1064588 +Node: Ranges and Locales1065900 +Ref: Ranges and Locales-Footnote-11070517 +Ref: Ranges and Locales-Footnote-21070544 +Ref: Ranges and Locales-Footnote-31070778 +Node: Contributors1070999 +Node: History summary1076424 +Node: Installation1077793 +Node: Gawk Distribution1078744 +Node: Getting1079228 +Node: Extracting1080052 +Node: Distribution contents1081694 +Node: Unix Installation1087411 +Node: Quick Installation1088028 +Node: Additional Configuration Options1090470 +Node: Configuration Philosophy1092208 +Node: Non-Unix Installation1094559 +Node: PC Installation1095017 +Node: PC Binary Installation1096328 +Node: PC Compiling1098176 +Ref: PC Compiling-Footnote-11101175 +Node: PC Testing1101280 +Node: PC Using1102456 +Node: Cygwin1106608 +Node: MSYS1107417 +Node: VMS Installation1107931 +Node: VMS Compilation1108727 +Ref: VMS Compilation-Footnote-11109949 +Node: VMS Dynamic Extensions1110007 +Node: VMS Installation Details1111380 +Node: VMS Running1113632 +Node: VMS GNV1116466 +Node: VMS Old Gawk1117189 +Node: Bugs1117659 +Node: Other Versions1121663 +Node: Installation summary1127890 +Node: Notes1128946 +Node: Compatibility Mode1129811 +Node: Additions1130593 +Node: Accessing The Source1131518 +Node: Adding Code1132954 +Node: New Ports1139132 +Node: Derived Files1143613 +Ref: Derived Files-Footnote-11148694 +Ref: Derived Files-Footnote-21148728 +Ref: Derived Files-Footnote-31149324 +Node: Future Extensions1149438 +Node: Implementation Limitations1150044 +Node: Extension Design1151292 +Node: Old Extension Problems1152446 +Ref: Old Extension Problems-Footnote-11153963 +Node: Extension New Mechanism Goals1154020 +Ref: Extension New Mechanism Goals-Footnote-11157380 +Node: Extension Other Design Decisions1157569 +Node: Extension Future Growth1159675 +Node: Old Extension Mechanism1160511 +Node: Notes summary1162273 +Node: Basic Concepts1163459 +Node: Basic High Level1164140 +Ref: figure-general-flow1164412 +Ref: figure-process-flow1165011 +Ref: Basic High Level-Footnote-11168240 +Node: Basic Data Typing1168425 +Node: Glossary1171753 +Node: Copying1196905 +Node: GNU Free Documentation License1234461 +Node: Index1259597  End Tag Table -- cgit v1.2.3 From 00f86a1d837f838a715dc879076325f772c4c5c9 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Mon, 1 Sep 2014 22:40:55 +0300 Subject: Index @ stuff in doc. --- doc/gawk.info | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 2841d21e..8d71f77c 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -31161,6 +31161,10 @@ Index * ? (question mark), regexp operator <1>: GNU Regexp Operators. (line 59) * ? (question mark), regexp operator: Regexp Operators. (line 111) +* @-notation for indirect function calls: Indirect Calls. (line 47) +* @include directive: Include Files. (line 8) +* @load directive: Loading Shared Libraries. + (line 8) * [] (square brackets), regexp operator: Regexp Operators. (line 56) * \ (backslash): Comments. (line 50) * \ (backslash), \" escape sequence: Escape Sequences. (line 82) @@ -32229,6 +32233,8 @@ Index * extensions, common, single character fields: Single Character Fields. (line 6) * extensions, in gawk, not in POSIX awk: POSIX/GNU. (line 6) +* extensions, loading, @load directive: Loading Shared Libraries. + (line 8) * extensions, mawk: Common Extensions. (line 6) * extensions, where to find: gawkextlib. (line 6) * extract.awk program: Extract Program. (line 79) @@ -32279,6 +32285,7 @@ Index * FIELDWIDTHS variable <1>: User-modified. (line 37) * FIELDWIDTHS variable: Constant Size. (line 23) * file descriptors: Special FD. (line 6) +* file inclusion, @include directive: Include Files. (line 8) * file names, distinguishing: Auto-set. (line 56) * file names, in compatibility mode: Special Caveats. (line 9) * file names, standard streams in gawk: Special FD. (line 46) @@ -32405,6 +32412,7 @@ Index * FUNCTAB array: Auto-set. (line 115) * function calls: Function Calls. (line 6) * function calls, indirect: Indirect Calls. (line 6) +* function calls, indirect, @-notation for: Indirect Calls. (line 47) * function definition example: Function Example. (line 6) * function pointers: Indirect Calls. (line 6) * functions, arrays as parameters to: Pass By Value/Reference. @@ -32685,10 +32693,12 @@ Index * in operator, testing if array element exists: Reference to Elements. (line 38) * in operator, use in loops: Scanning an Array. (line 17) +* including files, @include directive: Include Files. (line 8) * increment operators: Increment Ops. (line 6) * index: String Functions. (line 155) * indexing arrays: Array Intro. (line 50) * indirect function calls: Indirect Calls. (line 6) +* indirect function calls, @-notation: Indirect Calls. (line 47) * infinite precision: Arbitrary Precision Arithmetic. (line 6) * info debugger command: Debugger Info. (line 13) @@ -32861,6 +32871,8 @@ Index * list debugger command: Miscellaneous Debugger Commands. (line 72) * list function definitions, in debugger: Debugger Info. (line 30) +* loading extensions, @load directive: Loading Shared Libraries. + (line 8) * loading, extensions: Options. (line 173) * local variables, in a function: Variable Scope. (line 6) * locale categories: Explaining gettext. (line 81) -- cgit v1.2.3 From f84a4ffb830e5f9ce138cb74fae99ad930805723 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Tue, 2 Sep 2014 06:03:05 +0300 Subject: Fix debugger walkthrough. --- doc/gawk.info | 69 ++++++++++++++++++++++++++++++----------------------------- 1 file changed, 35 insertions(+), 34 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 8d71f77c..c8212732 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -20524,7 +20524,7 @@ options. (`gawk' is not designed to debug command-line programs, only programs contained in files.) In our case, we invoke the debugger like this: - $ gawk -D -f getopt.awk -f join.awk -f uniq.awk inputfile + $ gawk -D -f getopt.awk -f join.awk -f uniq.awk -1 inputfile where both `getopt.awk' and `uniq.awk' are in `$AWKPATH'. (Experienced users of GDB or similar debuggers should note that this syntax is @@ -20576,7 +20576,7 @@ for a breakpoint in `uniq.awk' is at the beginning of the function To set the breakpoint, use the `b' (breakpoint) command: gawk> b are_equal - -| Breakpoint 1 set at file `awklib/eg/prog/uniq.awk', line 64 + -| Breakpoint 1 set at file `awklib/eg/prog/uniq.awk', line 63 The debugger tells us the file and line number where the breakpoint is. Now type `r' or `run' and the program runs until it hits the @@ -20586,8 +20586,8 @@ breakpoint for the first time: -| Starting program: -| Stopping in Rule ... -| Breakpoint 1, are_equal(n, m, clast, cline, alast, aline) - at `awklib/eg/prog/uniq.awk':64 - -| 64 if (fcount == 0 && charcount == 0) + at `awklib/eg/prog/uniq.awk':63 + -| 63 if (fcount == 0 && charcount == 0) gawk> Now we can look at what's going on inside our program. First of all, @@ -20597,11 +20597,11 @@ the current stack frames: gawk> bt -| #0 are_equal(n, m, clast, cline, alast, aline) - at `awklib/eg/prog/uniq.awk':69 - -| #1 in main() at `awklib/eg/prog/uniq.awk':89 + at `awklib/eg/prog/uniq.awk':68 + -| #1 in main() at `awklib/eg/prog/uniq.awk':88 This tells us that `are_equal()' was called by the main program at -line 89 of `uniq.awk'. (This is not a big surprise, since this is the +line 88 of `uniq.awk'. (This is not a big surprise, since this is the only call to `are_equal()' in the program, but in more complex programs, knowing who called a function and with what parameters can be the key to finding the source of the problem.) @@ -20620,13 +20620,13 @@ function was called without arguments (*note Function Calls::). A more useful variable to display might be the current record: gawk> p $0 - -| $0 = string ("gawk is a wonderful program!") + -| $0 = "gawk is a wonderful program!" This might be a bit puzzling at first since this is the second line of our test input above. Let's look at `NR': gawk> p NR - -| NR = number (2) + -| NR = 2 So we can see that `are_equal()' was only called for the second record of the file. Of course, this is because our program contains a rule for @@ -20640,7 +20640,7 @@ of the file. Of course, this is because our program contains a rule for OK, let's just check that that rule worked correctly: gawk> p last - -| last = string ("awk is a wonderful program!") + -| last = "awk is a wonderful program!" Everything we have done so far has verified that the program has worked as planned, up to and including the call to `are_equal()', so @@ -20649,38 +20649,39 @@ must begin "stepping through" the lines of `are_equal()'. We start by typing `n' (for "next"): gawk> n - -| 67 if (fcount > 0) { + -| 66 if (fcount > 0) { - This tells us that `gawk' is now ready to execute line 67, which + This tells us that `gawk' is now ready to execute line 66, which decides whether to give the lines the special "field skipping" treatment -indicated by the `-f' command-line option. (Notice that we skipped -from where we were before at line 64 to here, since the condition in -line 64 `if (fcount == 0 && charcount == 0)' was false.) +indicated by the `-1' command-line option. (Notice that we skipped +from where we were before at line 63 to here, since the condition in +line 63 `if (fcount == 0 && charcount == 0)' was false.) Continuing to step, we now get to the splitting of the current and last records: gawk> n - -| 68 n = split(last, alast) + -| 67 n = split(last, alast) gawk> n - -| 69 m = split($0, aline) + -| 68 m = split($0, aline) At this point, we should be curious to see what our records were split into, so we try to look: gawk> p n m alast aline - -| n = number (5) - -| m = number (5) + -| n = 5 + -| m = untyped variable -| alast = array, 5 elements - -| aline = array, 5 elements + -| aline = untyped variable (The `p' command can take more than one argument, similar to `awk''s `print' statement.) This is kind of disappointing, though. All we found out is that -there are five elements in each of our arrays. Useful enough (we now -know that none of the words were accidentally left out), but what if we -want to see inside the array? +there are five elements in `alast'; `m' and `aline' don't have values +yet since we are at line 68 but haven't executed it yet. This +information is useful enough (we now know that none of the words were +accidentally left out), but what if we want to see inside the array? The first choice would be to use subscripts: @@ -20690,25 +20691,25 @@ want to see inside the array? Oops! gawk> p alast[1] - -| alast["1"] = string ("awk") + -| alast["1"] = "awk" This would be kind of slow for a 100-member array, though, so `gawk' provides a shortcut (reminiscent of another language not to be mentioned): gawk> p @alast - -| alast["1"] = string ("awk") - -| alast["2"] = string ("is") - -| alast["3"] = string ("a") - -| alast["4"] = string ("wonderful") - -| alast["5"] = string ("program!") + -| alast["1"] = "awk" + -| alast["2"] = "is" + -| alast["3"] = "a" + -| alast["4"] = "wonderful" + -| alast["5"] = "program!" It looks like we got this far OK. Let's take another step or two: gawk> n - -| 70 clast = join(alast, fcount, n) + -| 69 clast = join(alast, fcount, n) gawk> n - -| 71 cline = join(aline, fcount, m) + -| 70 cline = join(aline, fcount, m) Well, here we are at our error (sorry to spoil the suspense). What we had in mind was to join the fields starting from the second one to @@ -20716,8 +20717,8 @@ make the virtual record to compare, and if the first field was numbered zero, this would work. Let's look at what we've got: gawk> p cline clast - -| cline = string ("gawk is a wonderful program!") - -| clast = string ("awk is a wonderful program!") + -| cline = "gawk is a wonderful program!" + -| clast = "awk is a wonderful program!" Hey, those look pretty familiar! They're just our original, unaltered, input records. A little thinking (the human brain is still @@ -34386,7 +34387,7 @@ Node: Debugging Terms825200 Node: Awk Debugging827797 Node: Sample Debugging Session828689 Node: Debugger Invocation829209 -Node: Finding The Bug830542 +Node: Finding The Bug830545 Node: List of Debugger Commands837024 Node: Breakpoint Control838356 Node: Debugger Execution Control842020 -- cgit v1.2.3 From a0d7edfff1b489e50ae8751429ebf925948b746f Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 4 Sep 2014 08:49:02 +0300 Subject: Documentation fixes and improvements. --- doc/gawk.info | 1094 +++++++++++++++++++++++++++++---------------------------- 1 file changed, 552 insertions(+), 542 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index c8212732..1e6e93f5 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -2222,7 +2222,7 @@ determining the type of a variable, and array sorting. As we develop our presentation of the `awk' language, we introduce most of the variables and many of the functions. They are described -systematically in *note Built-in Variables::, and *note Built-in::. +systematically in *note Built-in Variables::, and in *note Built-in::.  File: gawk.info, Node: When, Next: Intro Summary, Prev: Other Features, Up: Getting Started @@ -14880,7 +14880,7 @@ that might be as follows: This function reads from `file' one record at a time, building up the full contents of the file in the local variable `contents'. It -works, but is not necessarily efficient.(1) +works, but is not necessarily efficient. The following function, based on a suggestion by Denis Shirokov, reads the entire contents of the named file in one shot: @@ -14915,13 +14915,6 @@ string. Thus calling code may use something like: This tests the result to see if it is empty or not. An equivalent test would be `contents == ""'. - ---------- Footnotes ---------- - - (1) Execution time grows quadratically in the size of the input; for -each record, `awk' has to allocate a bigger internal buffer for -`contents', copy the old contents into it, and then append the contents -of the new record. -  File: gawk.info, Node: Data File Management, Next: Getopt Function, Prev: General Functions, Up: Library Functions @@ -17054,7 +17047,7 @@ standard output, `/dev/stdout': else if (c == "c") do_count++ else if (index("0123456789", c) != 0) { - # getopt requires args to options + # getopt() requires args to options # this messes us up for things like -5 if (Optarg ~ /^[[:digit:]]+$/) fcount = (c Optarg) + 0 @@ -17651,8 +17644,8 @@ program. enclosed in square brackets (`[a-z]') and quoted, to prevent the shell from attempting a file name expansion. This is not a feature. - (2) This program was written before `gawk' acquired the ability to -split each character in a string into separate array elements. + (2) This program was also written before `gawk' acquired the ability +to split each character in a string into separate array elements.  File: gawk.info, Node: Labels Program, Next: Word Sorting, Prev: Translate Program, Up: Miscellaneous Programs @@ -18745,23 +18738,35 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample 5. The `split.awk' program (*note Split Program::) assumes that letters are contiguous in the character set, which isn't true for - EBCDIC systems. Fix this problem. - - 6. Why can't the `wc.awk' program (*note Wc Program::) just use the + EBCDIC systems. Fix this problem. (Hint: Consider a different + way to work through the alphabet, without relying on `ord()' and + `chr()'.) + + 6. In `uniq.awk' (*note Uniq Program::, the logic for choosing which + lines to print represents a "state machine", which is "a device + that can be in one of a set number of stable conditions depending + on its previous condition and on the present values of its + inputs."(1) Brian Kernighan suggests that "an alternative approach + to state mechines is to just read the input into an array, then + use indexing. It's almost always easier code, and for most inputs + where you would use this, just as fast." Rewrite the logic to + follow this suggestion. + + 7. Why can't the `wc.awk' program (*note Wc Program::) just use the value of `FNR' in `endfile()'? Hint: Examine the code in *note Filetrans Function::. - 7. Manipulation of individual characters in the `translate' program + 8. Manipulation of individual characters in the `translate' program (*note Translate Program::) is painful using standard `awk' functions. Given that `gawk' can split strings into individual characters using `""' as the separator, how might you use this feature to simplify the program? - 8. The `extract.awk' program (*note Extract Program::) was written + 9. The `extract.awk' program (*note Extract Program::) was written before `gawk' had the `gensub()' function. Use it to simplify the code. - 9. Compare the performance of the `awksed.awk' program (*note Simple + 10. Compare the performance of the `awksed.awk' program (*note Simple Sed::) with the more straightforward: BEGIN { @@ -18772,16 +18777,16 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample { gsub(pat, repl); print } - 10. What are the advantages and disadvantages of `awksed.awk' versus + 11. What are the advantages and disadvantages of `awksed.awk' versus the real `sed' utility? - 11. In *note Igawk Program::, we mentioned that not trying to save the + 12. In *note Igawk Program::, we mentioned that not trying to save the line read with `getline' in the `pathto()' function when testing for the file's accessibility for use with the main program simplifies things considerably. What problem does this engender though? - 12. As an additional example of the idea that it is not always + 13. As an additional example of the idea that it is not always necessary to add new features to a program, consider the idea of having two files in a directory in the search path: @@ -18804,10 +18809,15 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample `@include' statements for the desired library functions. Make this change. - 13. Modify `anagram.awk' (*note Anagram Program::), to avoid the use + 14. Modify `anagram.awk' (*note Anagram Program::), to avoid the use of the external `sort' utility. + ---------- Footnotes ---------- + + (1) This is the definition returned from entering `define: state +machine' into Google. +  File: gawk.info, Node: Advanced Features, Next: Internationalization, Prev: Sample Programs, Up: Top @@ -21358,7 +21368,7 @@ some limitations. A few which are worth being aware of are: what your mistake was, though, you'll feel like a real guru. * If you perused the dump of opcodes in *note Miscellaneous Debugger - Commands::, (or if you are already familiar with `gawk' internals), + Commands:: (or if you are already familiar with `gawk' internals), you will realize that much of the internal manipulation of data in `gawk', as in many interpreters, is done on a stack. `Op_push', `Op_pop', etc., are the "bread and butter" of most `gawk' code. @@ -32060,7 +32070,7 @@ Index (line 66) * directories, command-line: Command-line directories. (line 6) -* directories, searching: Programs Exercises. (line 63) +* directories, searching: Programs Exercises. (line 75) * directories, searching for loadable extensions: AWKLIBPATH Variable. (line 6) * directories, searching for source files: AWKPATH Variable. (line 6) @@ -32341,7 +32351,7 @@ Index * files, reading, multiline records: Multiple Line. (line 6) * files, searching for regular expressions: Egrep Program. (line 6) * files, skipping: File Checking. (line 6) -* files, source, search path for: Programs Exercises. (line 63) +* files, source, search path for: Programs Exercises. (line 75) * files, splitting: Split Program. (line 6) * files, Texinfo, extracting programs from: Extract Program. (line 6) * find substring in string: String Functions. (line 155) @@ -33509,11 +33519,11 @@ Index * search in string: String Functions. (line 155) * search paths <1>: VMS Running. (line 58) * search paths <2>: PC Using. (line 10) -* search paths: Programs Exercises. (line 63) +* search paths: Programs Exercises. (line 75) * search paths, for loadable extensions: AWKLIBPATH Variable. (line 6) * search paths, for source files <1>: VMS Running. (line 58) * search paths, for source files <2>: PC Using. (line 10) -* search paths, for source files <3>: Programs Exercises. (line 63) +* search paths, for source files <3>: Programs Exercises. (line 75) * search paths, for source files: AWKPATH Variable. (line 6) * searching, files for regular expressions: Egrep Program. (line 6) * searching, for words: Dupword Program. (line 6) @@ -33660,7 +33670,7 @@ Index * source code, QSE Awk: Other Versions. (line 131) * source code, QuikTrim Awk: Other Versions. (line 135) * source code, Solaris awk: Other Versions. (line 96) -* source files, search path for: Programs Exercises. (line 63) +* source files, search path for: Programs Exercises. (line 75) * sparse arrays: Array Intro. (line 72) * Spencer, Henry: Glossary. (line 11) * split: String Functions. (line 313) @@ -34051,519 +34061,519 @@ Ref: More Complex-Footnote-1102513 Node: Statements/Lines102598 Ref: Statements/Lines-Footnote-1107054 Node: Other Features107319 -Node: When108247 -Ref: When-Footnote-1110003 -Node: Intro Summary110068 -Node: Invoking Gawk110951 -Node: Command Line112466 -Node: Options113257 -Ref: Options-Footnote-1129033 -Node: Other Arguments129058 -Node: Naming Standard Input131886 -Node: Environment Variables132979 -Node: AWKPATH Variable133537 -Ref: AWKPATH Variable-Footnote-1136403 -Ref: AWKPATH Variable-Footnote-2136448 -Node: AWKLIBPATH Variable136708 -Node: Other Environment Variables137467 -Node: Exit Status141124 -Node: Include Files141799 -Node: Loading Shared Libraries145377 -Node: Obsolete146761 -Node: Undocumented147458 -Node: Invoking Summary147725 -Node: Regexp149325 -Node: Regexp Usage150784 -Node: Escape Sequences152817 -Node: Regexp Operators158805 -Ref: Regexp Operators-Footnote-1166236 -Ref: Regexp Operators-Footnote-2166383 -Node: Bracket Expressions166481 -Ref: table-char-classes168499 -Node: Leftmost Longest171439 -Node: Computed Regexps172643 -Node: GNU Regexp Operators176021 -Node: Case-sensitivity179727 -Ref: Case-sensitivity-Footnote-1182617 -Ref: Case-sensitivity-Footnote-2182852 -Node: Regexp Summary182960 -Node: Reading Files184429 -Node: Records186521 -Node: awk split records187243 -Node: gawk split records192101 -Ref: gawk split records-Footnote-1196622 -Node: Fields196659 -Ref: Fields-Footnote-1199623 -Node: Nonconstant Fields199709 -Ref: Nonconstant Fields-Footnote-1201939 -Node: Changing Fields202141 -Node: Field Separators208095 -Node: Default Field Splitting210797 -Node: Regexp Field Splitting211914 -Node: Single Character Fields215241 -Node: Command Line Field Separator216300 -Node: Full Line Fields219726 -Ref: Full Line Fields-Footnote-1220234 -Node: Field Splitting Summary220280 -Ref: Field Splitting Summary-Footnote-1223412 -Node: Constant Size223513 -Node: Splitting By Content228119 -Ref: Splitting By Content-Footnote-1232192 -Node: Multiple Line232232 -Ref: Multiple Line-Footnote-1238088 -Node: Getline238267 -Node: Plain Getline240478 -Node: Getline/Variable243184 -Node: Getline/File244331 -Node: Getline/Variable/File245715 -Ref: Getline/Variable/File-Footnote-1247314 -Node: Getline/Pipe247401 -Node: Getline/Variable/Pipe250087 -Node: Getline/Coprocess251194 -Node: Getline/Variable/Coprocess252446 -Node: Getline Notes253183 -Node: Getline Summary255987 -Ref: table-getline-variants256395 -Node: Read Timeout257307 -Ref: Read Timeout-Footnote-1261134 -Node: Command-line directories261192 -Node: Input Summary262096 -Node: Input Exercises265233 -Node: Printing265961 -Node: Print267683 -Node: Print Examples269176 -Node: Output Separators271955 -Node: OFMT273971 -Node: Printf275329 -Node: Basic Printf276235 -Node: Control Letters277774 -Node: Format Modifiers281765 -Node: Printf Examples287792 -Node: Redirection290256 -Node: Special Files297228 -Node: Special FD297761 -Ref: Special FD-Footnote-1301358 -Node: Special Network301432 -Node: Special Caveats302282 -Node: Close Files And Pipes303078 -Ref: Close Files And Pipes-Footnote-1310239 -Ref: Close Files And Pipes-Footnote-2310387 -Node: Output Summary310537 -Node: Output Exercises311534 -Node: Expressions312214 -Node: Values313399 -Node: Constants314075 -Node: Scalar Constants314755 -Ref: Scalar Constants-Footnote-1315614 -Node: Nondecimal-numbers315864 -Node: Regexp Constants318864 -Node: Using Constant Regexps319389 -Node: Variables322461 -Node: Using Variables323116 -Node: Assignment Options324840 -Node: Conversion326715 -Node: Strings And Numbers327239 -Ref: Strings And Numbers-Footnote-1330301 -Node: Locale influences conversions330410 -Ref: table-locale-affects333127 -Node: All Operators333715 -Node: Arithmetic Ops334345 -Node: Concatenation336850 -Ref: Concatenation-Footnote-1339669 -Node: Assignment Ops339775 -Ref: table-assign-ops344758 -Node: Increment Ops346061 -Node: Truth Values and Conditions349499 -Node: Truth Values350582 -Node: Typing and Comparison351631 -Node: Variable Typing352424 -Node: Comparison Operators356076 -Ref: table-relational-ops356486 -Node: POSIX String Comparison360036 -Ref: POSIX String Comparison-Footnote-1361120 -Node: Boolean Ops361258 -Ref: Boolean Ops-Footnote-1365597 -Node: Conditional Exp365688 -Node: Function Calls367415 -Node: Precedence371295 -Node: Locales374964 -Node: Expressions Summary376595 -Node: Patterns and Actions379136 -Node: Pattern Overview380252 -Node: Regexp Patterns381929 -Node: Expression Patterns382472 -Node: Ranges386252 -Node: BEGIN/END389358 -Node: Using BEGIN/END390120 -Ref: Using BEGIN/END-Footnote-1392856 -Node: I/O And BEGIN/END392962 -Node: BEGINFILE/ENDFILE395233 -Node: Empty398164 -Node: Using Shell Variables398481 -Node: Action Overview400764 -Node: Statements403091 -Node: If Statement404939 -Node: While Statement406437 -Node: Do Statement408481 -Node: For Statement409637 -Node: Switch Statement412789 -Node: Break Statement415177 -Node: Continue Statement417218 -Node: Next Statement419043 -Node: Nextfile Statement421433 -Node: Exit Statement424090 -Node: Built-in Variables426494 -Node: User-modified427621 -Ref: User-modified-Footnote-1435310 -Node: Auto-set435372 -Ref: Auto-set-Footnote-1447954 -Ref: Auto-set-Footnote-2448159 -Node: ARGC and ARGV448215 -Node: Pattern Action Summary452119 -Node: Arrays454342 -Node: Array Basics455891 -Node: Array Intro456717 -Ref: figure-array-elements458690 -Ref: Array Intro-Footnote-1461214 -Node: Reference to Elements461342 -Node: Assigning Elements463792 -Node: Array Example464283 -Node: Scanning an Array466015 -Node: Controlling Scanning469016 -Ref: Controlling Scanning-Footnote-1474189 -Node: Delete474505 -Ref: Delete-Footnote-1477256 -Node: Numeric Array Subscripts477313 -Node: Uninitialized Subscripts479496 -Node: Multidimensional481123 -Node: Multiscanning484236 -Node: Arrays of Arrays485825 -Node: Arrays Summary490488 -Node: Functions492593 -Node: Built-in493466 -Node: Calling Built-in494544 -Node: Numeric Functions496532 -Ref: Numeric Functions-Footnote-1500566 -Ref: Numeric Functions-Footnote-2500923 -Ref: Numeric Functions-Footnote-3500971 -Node: String Functions501240 -Ref: String Functions-Footnote-1524237 -Ref: String Functions-Footnote-2524366 -Ref: String Functions-Footnote-3524614 -Node: Gory Details524701 -Ref: table-sub-escapes526474 -Ref: table-sub-proposed527994 -Ref: table-posix-sub529358 -Ref: table-gensub-escapes530898 -Ref: Gory Details-Footnote-1532074 -Node: I/O Functions532225 -Ref: I/O Functions-Footnote-1539335 -Node: Time Functions539482 -Ref: Time Functions-Footnote-1549946 -Ref: Time Functions-Footnote-2550014 -Ref: Time Functions-Footnote-3550172 -Ref: Time Functions-Footnote-4550283 -Ref: Time Functions-Footnote-5550395 -Ref: Time Functions-Footnote-6550622 -Node: Bitwise Functions550888 -Ref: table-bitwise-ops551450 -Ref: Bitwise Functions-Footnote-1555695 -Node: Type Functions555879 -Node: I18N Functions557021 -Node: User-defined558666 -Node: Definition Syntax559470 -Ref: Definition Syntax-Footnote-1564783 -Node: Function Example564852 -Ref: Function Example-Footnote-1567492 -Node: Function Caveats567514 -Node: Calling A Function568032 -Node: Variable Scope568987 -Node: Pass By Value/Reference571975 -Node: Return Statement575485 -Node: Dynamic Typing578469 -Node: Indirect Calls579398 -Node: Functions Summary589111 -Node: Library Functions591650 -Ref: Library Functions-Footnote-1595268 -Ref: Library Functions-Footnote-2595411 -Node: Library Names595582 -Ref: Library Names-Footnote-1599055 -Ref: Library Names-Footnote-2599275 -Node: General Functions599361 -Node: Strtonum Function600389 -Node: Assert Function603263 -Node: Round Function606589 -Node: Cliff Random Function608130 -Node: Ordinal Functions609146 -Ref: Ordinal Functions-Footnote-1612211 -Ref: Ordinal Functions-Footnote-2612463 -Node: Join Function612674 -Ref: Join Function-Footnote-1614445 -Node: Getlocaltime Function614645 -Node: Readfile Function618381 -Ref: Readfile Function-Footnote-1620259 -Node: Data File Management620487 -Node: Filetrans Function621119 -Node: Rewind Function625188 -Node: File Checking626746 -Ref: File Checking-Footnote-1627878 -Node: Empty Files628079 -Node: Ignoring Assigns630058 -Node: Getopt Function631612 -Ref: Getopt Function-Footnote-1642876 -Node: Passwd Functions643079 -Ref: Passwd Functions-Footnote-1652058 -Node: Group Functions652146 -Ref: Group Functions-Footnote-1660077 -Node: Walking Arrays660290 -Node: Library Functions Summary661893 -Node: Library Exercises663281 -Node: Sample Programs664561 -Node: Running Examples665331 -Node: Clones666059 -Node: Cut Program667283 -Node: Egrep Program677141 -Ref: Egrep Program-Footnote-1684728 -Node: Id Program684838 -Node: Split Program688492 -Ref: Split Program-Footnote-1692030 -Node: Tee Program692158 -Node: Uniq Program694945 -Node: Wc Program702366 -Ref: Wc Program-Footnote-1706631 -Node: Miscellaneous Programs706723 -Node: Dupword Program707936 -Node: Alarm Program709967 -Node: Translate Program714771 -Ref: Translate Program-Footnote-1719162 -Ref: Translate Program-Footnote-2719432 -Node: Labels Program719566 -Ref: Labels Program-Footnote-1722927 -Node: Word Sorting723011 -Node: History Sorting727054 -Node: Extract Program728890 -Node: Simple Sed736426 -Node: Igawk Program739488 -Ref: Igawk Program-Footnote-1753792 -Ref: Igawk Program-Footnote-2753993 -Node: Anagram Program754131 -Node: Signature Program757199 -Node: Programs Summary758446 -Node: Programs Exercises759661 -Node: Advanced Features763312 -Node: Nondecimal Data765260 -Node: Array Sorting766837 -Node: Controlling Array Traversal767534 -Node: Array Sorting Functions775814 -Ref: Array Sorting Functions-Footnote-1779721 -Node: Two-way I/O779915 -Ref: Two-way I/O-Footnote-1784859 -Ref: Two-way I/O-Footnote-2785038 -Node: TCP/IP Networking785120 -Node: Profiling787965 -Node: Advanced Features Summary795507 -Node: Internationalization797371 -Node: I18N and L10N798851 -Node: Explaining gettext799537 -Ref: Explaining gettext-Footnote-1804563 -Ref: Explaining gettext-Footnote-2804747 -Node: Programmer i18n804912 -Ref: Programmer i18n-Footnote-1809706 -Node: Translator i18n809755 -Node: String Extraction810549 -Ref: String Extraction-Footnote-1811682 -Node: Printf Ordering811768 -Ref: Printf Ordering-Footnote-1814550 -Node: I18N Portability814614 -Ref: I18N Portability-Footnote-1817063 -Node: I18N Example817126 -Ref: I18N Example-Footnote-1819832 -Node: Gawk I18N819904 -Node: I18N Summary820542 -Node: Debugger821881 -Node: Debugging822903 -Node: Debugging Concepts823344 -Node: Debugging Terms825200 -Node: Awk Debugging827797 -Node: Sample Debugging Session828689 -Node: Debugger Invocation829209 -Node: Finding The Bug830545 -Node: List of Debugger Commands837024 -Node: Breakpoint Control838356 -Node: Debugger Execution Control842020 -Node: Viewing And Changing Data845380 -Node: Execution Stack848738 -Node: Debugger Info850251 -Node: Miscellaneous Debugger Commands854245 -Node: Readline Support859429 -Node: Limitations860321 -Node: Debugging Summary862595 -Node: Arbitrary Precision Arithmetic863763 -Node: Computer Arithmetic865250 -Ref: Computer Arithmetic-Footnote-1869637 -Node: Math Definitions869694 -Ref: table-ieee-formats872983 -Ref: Math Definitions-Footnote-1873523 -Node: MPFR features873626 -Node: FP Math Caution875243 -Ref: FP Math Caution-Footnote-1876293 -Node: Inexactness of computations876662 -Node: Inexact representation877610 -Node: Comparing FP Values878965 -Node: Errors accumulate879929 -Node: Getting Accuracy881362 -Node: Try To Round884021 -Node: Setting precision884920 -Ref: table-predefined-precision-strings885602 -Node: Setting the rounding mode887395 -Ref: table-gawk-rounding-modes887759 -Ref: Setting the rounding mode-Footnote-1891213 -Node: Arbitrary Precision Integers891392 -Ref: Arbitrary Precision Integers-Footnote-1894373 -Node: POSIX Floating Point Problems894522 -Ref: POSIX Floating Point Problems-Footnote-1898398 -Node: Floating point summary898436 -Node: Dynamic Extensions900640 -Node: Extension Intro902192 -Node: Plugin License903457 -Node: Extension Mechanism Outline904142 -Ref: figure-load-extension904566 -Ref: figure-load-new-function906051 -Ref: figure-call-new-function907053 -Node: Extension API Description909037 -Node: Extension API Functions Introduction910487 -Node: General Data Types915354 -Ref: General Data Types-Footnote-1921047 -Node: Requesting Values921346 -Ref: table-value-types-returned922083 -Node: Memory Allocation Functions923041 -Ref: Memory Allocation Functions-Footnote-1925788 -Node: Constructor Functions925884 -Node: Registration Functions927642 -Node: Extension Functions928327 -Node: Exit Callback Functions930629 -Node: Extension Version String931877 -Node: Input Parsers932527 -Node: Output Wrappers942341 -Node: Two-way processors946857 -Node: Printing Messages949061 -Ref: Printing Messages-Footnote-1950138 -Node: Updating `ERRNO'950290 -Node: Accessing Parameters951029 -Node: Symbol Table Access952259 -Node: Symbol table by name952773 -Node: Symbol table by cookie954749 -Ref: Symbol table by cookie-Footnote-1958882 -Node: Cached values958945 -Ref: Cached values-Footnote-1962449 -Node: Array Manipulation962540 -Ref: Array Manipulation-Footnote-1963638 -Node: Array Data Types963677 -Ref: Array Data Types-Footnote-1966380 -Node: Array Functions966472 -Node: Flattening Arrays970346 -Node: Creating Arrays977198 -Node: Extension API Variables981929 -Node: Extension Versioning982565 -Node: Extension API Informational Variables984466 -Node: Extension API Boilerplate985552 -Node: Finding Extensions989356 -Node: Extension Example989916 -Node: Internal File Description990646 -Node: Internal File Ops994737 -Ref: Internal File Ops-Footnote-11006169 -Node: Using Internal File Ops1006309 -Ref: Using Internal File Ops-Footnote-11008656 -Node: Extension Samples1008924 -Node: Extension Sample File Functions1010448 -Node: Extension Sample Fnmatch1018016 -Node: Extension Sample Fork1019498 -Node: Extension Sample Inplace1020711 -Node: Extension Sample Ord1022386 -Node: Extension Sample Readdir1023222 -Ref: table-readdir-file-types1024078 -Node: Extension Sample Revout1024877 -Node: Extension Sample Rev2way1025468 -Node: Extension Sample Read write array1026209 -Node: Extension Sample Readfile1028088 -Node: Extension Sample API Tests1029188 -Node: Extension Sample Time1029713 -Node: gawkextlib1031028 -Node: Extension summary1033841 -Node: Extension Exercises1037534 -Node: Language History1038256 -Node: V7/SVR3.11039899 -Node: SVR41042219 -Node: POSIX1043661 -Node: BTL1045047 -Node: POSIX/GNU1045781 -Node: Feature History1051497 -Node: Common Extensions1064588 -Node: Ranges and Locales1065900 -Ref: Ranges and Locales-Footnote-11070517 -Ref: Ranges and Locales-Footnote-21070544 -Ref: Ranges and Locales-Footnote-31070778 -Node: Contributors1070999 -Node: History summary1076424 -Node: Installation1077793 -Node: Gawk Distribution1078744 -Node: Getting1079228 -Node: Extracting1080052 -Node: Distribution contents1081694 -Node: Unix Installation1087411 -Node: Quick Installation1088028 -Node: Additional Configuration Options1090470 -Node: Configuration Philosophy1092208 -Node: Non-Unix Installation1094559 -Node: PC Installation1095017 -Node: PC Binary Installation1096328 -Node: PC Compiling1098176 -Ref: PC Compiling-Footnote-11101175 -Node: PC Testing1101280 -Node: PC Using1102456 -Node: Cygwin1106608 -Node: MSYS1107417 -Node: VMS Installation1107931 -Node: VMS Compilation1108727 -Ref: VMS Compilation-Footnote-11109949 -Node: VMS Dynamic Extensions1110007 -Node: VMS Installation Details1111380 -Node: VMS Running1113632 -Node: VMS GNV1116466 -Node: VMS Old Gawk1117189 -Node: Bugs1117659 -Node: Other Versions1121663 -Node: Installation summary1127890 -Node: Notes1128946 -Node: Compatibility Mode1129811 -Node: Additions1130593 -Node: Accessing The Source1131518 -Node: Adding Code1132954 -Node: New Ports1139132 -Node: Derived Files1143613 -Ref: Derived Files-Footnote-11148694 -Ref: Derived Files-Footnote-21148728 -Ref: Derived Files-Footnote-31149324 -Node: Future Extensions1149438 -Node: Implementation Limitations1150044 -Node: Extension Design1151292 -Node: Old Extension Problems1152446 -Ref: Old Extension Problems-Footnote-11153963 -Node: Extension New Mechanism Goals1154020 -Ref: Extension New Mechanism Goals-Footnote-11157380 -Node: Extension Other Design Decisions1157569 -Node: Extension Future Growth1159675 -Node: Old Extension Mechanism1160511 -Node: Notes summary1162273 -Node: Basic Concepts1163459 -Node: Basic High Level1164140 -Ref: figure-general-flow1164412 -Ref: figure-process-flow1165011 -Ref: Basic High Level-Footnote-11168240 -Node: Basic Data Typing1168425 -Node: Glossary1171753 -Node: Copying1196905 -Node: GNU Free Documentation License1234461 -Node: Index1259597 +Node: When108250 +Ref: When-Footnote-1110006 +Node: Intro Summary110071 +Node: Invoking Gawk110954 +Node: Command Line112469 +Node: Options113260 +Ref: Options-Footnote-1129036 +Node: Other Arguments129061 +Node: Naming Standard Input131889 +Node: Environment Variables132982 +Node: AWKPATH Variable133540 +Ref: AWKPATH Variable-Footnote-1136406 +Ref: AWKPATH Variable-Footnote-2136451 +Node: AWKLIBPATH Variable136711 +Node: Other Environment Variables137470 +Node: Exit Status141127 +Node: Include Files141802 +Node: Loading Shared Libraries145380 +Node: Obsolete146764 +Node: Undocumented147461 +Node: Invoking Summary147728 +Node: Regexp149328 +Node: Regexp Usage150787 +Node: Escape Sequences152820 +Node: Regexp Operators158808 +Ref: Regexp Operators-Footnote-1166239 +Ref: Regexp Operators-Footnote-2166386 +Node: Bracket Expressions166484 +Ref: table-char-classes168502 +Node: Leftmost Longest171442 +Node: Computed Regexps172646 +Node: GNU Regexp Operators176024 +Node: Case-sensitivity179730 +Ref: Case-sensitivity-Footnote-1182620 +Ref: Case-sensitivity-Footnote-2182855 +Node: Regexp Summary182963 +Node: Reading Files184432 +Node: Records186524 +Node: awk split records187246 +Node: gawk split records192104 +Ref: gawk split records-Footnote-1196625 +Node: Fields196662 +Ref: Fields-Footnote-1199626 +Node: Nonconstant Fields199712 +Ref: Nonconstant Fields-Footnote-1201942 +Node: Changing Fields202144 +Node: Field Separators208098 +Node: Default Field Splitting210800 +Node: Regexp Field Splitting211917 +Node: Single Character Fields215244 +Node: Command Line Field Separator216303 +Node: Full Line Fields219729 +Ref: Full Line Fields-Footnote-1220237 +Node: Field Splitting Summary220283 +Ref: Field Splitting Summary-Footnote-1223415 +Node: Constant Size223516 +Node: Splitting By Content228122 +Ref: Splitting By Content-Footnote-1232195 +Node: Multiple Line232235 +Ref: Multiple Line-Footnote-1238091 +Node: Getline238270 +Node: Plain Getline240481 +Node: Getline/Variable243187 +Node: Getline/File244334 +Node: Getline/Variable/File245718 +Ref: Getline/Variable/File-Footnote-1247317 +Node: Getline/Pipe247404 +Node: Getline/Variable/Pipe250090 +Node: Getline/Coprocess251197 +Node: Getline/Variable/Coprocess252449 +Node: Getline Notes253186 +Node: Getline Summary255990 +Ref: table-getline-variants256398 +Node: Read Timeout257310 +Ref: Read Timeout-Footnote-1261137 +Node: Command-line directories261195 +Node: Input Summary262099 +Node: Input Exercises265236 +Node: Printing265964 +Node: Print267686 +Node: Print Examples269179 +Node: Output Separators271958 +Node: OFMT273974 +Node: Printf275332 +Node: Basic Printf276238 +Node: Control Letters277777 +Node: Format Modifiers281768 +Node: Printf Examples287795 +Node: Redirection290259 +Node: Special Files297231 +Node: Special FD297764 +Ref: Special FD-Footnote-1301361 +Node: Special Network301435 +Node: Special Caveats302285 +Node: Close Files And Pipes303081 +Ref: Close Files And Pipes-Footnote-1310242 +Ref: Close Files And Pipes-Footnote-2310390 +Node: Output Summary310540 +Node: Output Exercises311537 +Node: Expressions312217 +Node: Values313402 +Node: Constants314078 +Node: Scalar Constants314758 +Ref: Scalar Constants-Footnote-1315617 +Node: Nondecimal-numbers315867 +Node: Regexp Constants318867 +Node: Using Constant Regexps319392 +Node: Variables322464 +Node: Using Variables323119 +Node: Assignment Options324843 +Node: Conversion326718 +Node: Strings And Numbers327242 +Ref: Strings And Numbers-Footnote-1330304 +Node: Locale influences conversions330413 +Ref: table-locale-affects333130 +Node: All Operators333718 +Node: Arithmetic Ops334348 +Node: Concatenation336853 +Ref: Concatenation-Footnote-1339672 +Node: Assignment Ops339778 +Ref: table-assign-ops344761 +Node: Increment Ops346064 +Node: Truth Values and Conditions349502 +Node: Truth Values350585 +Node: Typing and Comparison351634 +Node: Variable Typing352427 +Node: Comparison Operators356079 +Ref: table-relational-ops356489 +Node: POSIX String Comparison360039 +Ref: POSIX String Comparison-Footnote-1361123 +Node: Boolean Ops361261 +Ref: Boolean Ops-Footnote-1365600 +Node: Conditional Exp365691 +Node: Function Calls367418 +Node: Precedence371298 +Node: Locales374967 +Node: Expressions Summary376598 +Node: Patterns and Actions379139 +Node: Pattern Overview380255 +Node: Regexp Patterns381932 +Node: Expression Patterns382475 +Node: Ranges386255 +Node: BEGIN/END389361 +Node: Using BEGIN/END390123 +Ref: Using BEGIN/END-Footnote-1392859 +Node: I/O And BEGIN/END392965 +Node: BEGINFILE/ENDFILE395236 +Node: Empty398167 +Node: Using Shell Variables398484 +Node: Action Overview400767 +Node: Statements403094 +Node: If Statement404942 +Node: While Statement406440 +Node: Do Statement408484 +Node: For Statement409640 +Node: Switch Statement412792 +Node: Break Statement415180 +Node: Continue Statement417221 +Node: Next Statement419046 +Node: Nextfile Statement421436 +Node: Exit Statement424093 +Node: Built-in Variables426497 +Node: User-modified427624 +Ref: User-modified-Footnote-1435313 +Node: Auto-set435375 +Ref: Auto-set-Footnote-1447957 +Ref: Auto-set-Footnote-2448162 +Node: ARGC and ARGV448218 +Node: Pattern Action Summary452122 +Node: Arrays454345 +Node: Array Basics455894 +Node: Array Intro456720 +Ref: figure-array-elements458693 +Ref: Array Intro-Footnote-1461217 +Node: Reference to Elements461345 +Node: Assigning Elements463795 +Node: Array Example464286 +Node: Scanning an Array466018 +Node: Controlling Scanning469019 +Ref: Controlling Scanning-Footnote-1474192 +Node: Delete474508 +Ref: Delete-Footnote-1477259 +Node: Numeric Array Subscripts477316 +Node: Uninitialized Subscripts479499 +Node: Multidimensional481126 +Node: Multiscanning484239 +Node: Arrays of Arrays485828 +Node: Arrays Summary490491 +Node: Functions492596 +Node: Built-in493469 +Node: Calling Built-in494547 +Node: Numeric Functions496535 +Ref: Numeric Functions-Footnote-1500569 +Ref: Numeric Functions-Footnote-2500926 +Ref: Numeric Functions-Footnote-3500974 +Node: String Functions501243 +Ref: String Functions-Footnote-1524240 +Ref: String Functions-Footnote-2524369 +Ref: String Functions-Footnote-3524617 +Node: Gory Details524704 +Ref: table-sub-escapes526477 +Ref: table-sub-proposed527997 +Ref: table-posix-sub529361 +Ref: table-gensub-escapes530901 +Ref: Gory Details-Footnote-1532077 +Node: I/O Functions532228 +Ref: I/O Functions-Footnote-1539338 +Node: Time Functions539485 +Ref: Time Functions-Footnote-1549949 +Ref: Time Functions-Footnote-2550017 +Ref: Time Functions-Footnote-3550175 +Ref: Time Functions-Footnote-4550286 +Ref: Time Functions-Footnote-5550398 +Ref: Time Functions-Footnote-6550625 +Node: Bitwise Functions550891 +Ref: table-bitwise-ops551453 +Ref: Bitwise Functions-Footnote-1555698 +Node: Type Functions555882 +Node: I18N Functions557024 +Node: User-defined558669 +Node: Definition Syntax559473 +Ref: Definition Syntax-Footnote-1564786 +Node: Function Example564855 +Ref: Function Example-Footnote-1567495 +Node: Function Caveats567517 +Node: Calling A Function568035 +Node: Variable Scope568990 +Node: Pass By Value/Reference571978 +Node: Return Statement575488 +Node: Dynamic Typing578472 +Node: Indirect Calls579401 +Node: Functions Summary589114 +Node: Library Functions591653 +Ref: Library Functions-Footnote-1595271 +Ref: Library Functions-Footnote-2595414 +Node: Library Names595585 +Ref: Library Names-Footnote-1599058 +Ref: Library Names-Footnote-2599278 +Node: General Functions599364 +Node: Strtonum Function600392 +Node: Assert Function603266 +Node: Round Function606592 +Node: Cliff Random Function608133 +Node: Ordinal Functions609149 +Ref: Ordinal Functions-Footnote-1612214 +Ref: Ordinal Functions-Footnote-2612466 +Node: Join Function612677 +Ref: Join Function-Footnote-1614448 +Node: Getlocaltime Function614648 +Node: Readfile Function618384 +Node: Data File Management620223 +Node: Filetrans Function620855 +Node: Rewind Function624924 +Node: File Checking626482 +Ref: File Checking-Footnote-1627614 +Node: Empty Files627815 +Node: Ignoring Assigns629794 +Node: Getopt Function631348 +Ref: Getopt Function-Footnote-1642612 +Node: Passwd Functions642815 +Ref: Passwd Functions-Footnote-1651794 +Node: Group Functions651882 +Ref: Group Functions-Footnote-1659813 +Node: Walking Arrays660026 +Node: Library Functions Summary661629 +Node: Library Exercises663017 +Node: Sample Programs664297 +Node: Running Examples665067 +Node: Clones665795 +Node: Cut Program667019 +Node: Egrep Program676877 +Ref: Egrep Program-Footnote-1684464 +Node: Id Program684574 +Node: Split Program688228 +Ref: Split Program-Footnote-1691766 +Node: Tee Program691894 +Node: Uniq Program694681 +Node: Wc Program702104 +Ref: Wc Program-Footnote-1706369 +Node: Miscellaneous Programs706461 +Node: Dupword Program707674 +Node: Alarm Program709705 +Node: Translate Program714509 +Ref: Translate Program-Footnote-1718900 +Ref: Translate Program-Footnote-2719170 +Node: Labels Program719309 +Ref: Labels Program-Footnote-1722670 +Node: Word Sorting722754 +Node: History Sorting726797 +Node: Extract Program728633 +Node: Simple Sed736169 +Node: Igawk Program739231 +Ref: Igawk Program-Footnote-1753535 +Ref: Igawk Program-Footnote-2753736 +Node: Anagram Program753874 +Node: Signature Program756942 +Node: Programs Summary758189 +Node: Programs Exercises759404 +Ref: Programs Exercises-Footnote-1763791 +Node: Advanced Features763882 +Node: Nondecimal Data765830 +Node: Array Sorting767407 +Node: Controlling Array Traversal768104 +Node: Array Sorting Functions776384 +Ref: Array Sorting Functions-Footnote-1780291 +Node: Two-way I/O780485 +Ref: Two-way I/O-Footnote-1785429 +Ref: Two-way I/O-Footnote-2785608 +Node: TCP/IP Networking785690 +Node: Profiling788535 +Node: Advanced Features Summary796077 +Node: Internationalization797941 +Node: I18N and L10N799421 +Node: Explaining gettext800107 +Ref: Explaining gettext-Footnote-1805133 +Ref: Explaining gettext-Footnote-2805317 +Node: Programmer i18n805482 +Ref: Programmer i18n-Footnote-1810276 +Node: Translator i18n810325 +Node: String Extraction811119 +Ref: String Extraction-Footnote-1812252 +Node: Printf Ordering812338 +Ref: Printf Ordering-Footnote-1815120 +Node: I18N Portability815184 +Ref: I18N Portability-Footnote-1817633 +Node: I18N Example817696 +Ref: I18N Example-Footnote-1820402 +Node: Gawk I18N820474 +Node: I18N Summary821112 +Node: Debugger822451 +Node: Debugging823473 +Node: Debugging Concepts823914 +Node: Debugging Terms825770 +Node: Awk Debugging828367 +Node: Sample Debugging Session829259 +Node: Debugger Invocation829779 +Node: Finding The Bug831115 +Node: List of Debugger Commands837594 +Node: Breakpoint Control838926 +Node: Debugger Execution Control842590 +Node: Viewing And Changing Data845950 +Node: Execution Stack849308 +Node: Debugger Info850821 +Node: Miscellaneous Debugger Commands854815 +Node: Readline Support859999 +Node: Limitations860891 +Node: Debugging Summary863164 +Node: Arbitrary Precision Arithmetic864332 +Node: Computer Arithmetic865819 +Ref: Computer Arithmetic-Footnote-1870206 +Node: Math Definitions870263 +Ref: table-ieee-formats873552 +Ref: Math Definitions-Footnote-1874092 +Node: MPFR features874195 +Node: FP Math Caution875812 +Ref: FP Math Caution-Footnote-1876862 +Node: Inexactness of computations877231 +Node: Inexact representation878179 +Node: Comparing FP Values879534 +Node: Errors accumulate880498 +Node: Getting Accuracy881931 +Node: Try To Round884590 +Node: Setting precision885489 +Ref: table-predefined-precision-strings886171 +Node: Setting the rounding mode887964 +Ref: table-gawk-rounding-modes888328 +Ref: Setting the rounding mode-Footnote-1891782 +Node: Arbitrary Precision Integers891961 +Ref: Arbitrary Precision Integers-Footnote-1894942 +Node: POSIX Floating Point Problems895091 +Ref: POSIX Floating Point Problems-Footnote-1898967 +Node: Floating point summary899005 +Node: Dynamic Extensions901209 +Node: Extension Intro902761 +Node: Plugin License904026 +Node: Extension Mechanism Outline904711 +Ref: figure-load-extension905135 +Ref: figure-load-new-function906620 +Ref: figure-call-new-function907622 +Node: Extension API Description909606 +Node: Extension API Functions Introduction911056 +Node: General Data Types915923 +Ref: General Data Types-Footnote-1921616 +Node: Requesting Values921915 +Ref: table-value-types-returned922652 +Node: Memory Allocation Functions923610 +Ref: Memory Allocation Functions-Footnote-1926357 +Node: Constructor Functions926453 +Node: Registration Functions928211 +Node: Extension Functions928896 +Node: Exit Callback Functions931198 +Node: Extension Version String932446 +Node: Input Parsers933096 +Node: Output Wrappers942910 +Node: Two-way processors947426 +Node: Printing Messages949630 +Ref: Printing Messages-Footnote-1950707 +Node: Updating `ERRNO'950859 +Node: Accessing Parameters951598 +Node: Symbol Table Access952828 +Node: Symbol table by name953342 +Node: Symbol table by cookie955318 +Ref: Symbol table by cookie-Footnote-1959451 +Node: Cached values959514 +Ref: Cached values-Footnote-1963018 +Node: Array Manipulation963109 +Ref: Array Manipulation-Footnote-1964207 +Node: Array Data Types964246 +Ref: Array Data Types-Footnote-1966949 +Node: Array Functions967041 +Node: Flattening Arrays970915 +Node: Creating Arrays977767 +Node: Extension API Variables982498 +Node: Extension Versioning983134 +Node: Extension API Informational Variables985035 +Node: Extension API Boilerplate986121 +Node: Finding Extensions989925 +Node: Extension Example990485 +Node: Internal File Description991215 +Node: Internal File Ops995306 +Ref: Internal File Ops-Footnote-11006738 +Node: Using Internal File Ops1006878 +Ref: Using Internal File Ops-Footnote-11009225 +Node: Extension Samples1009493 +Node: Extension Sample File Functions1011017 +Node: Extension Sample Fnmatch1018585 +Node: Extension Sample Fork1020067 +Node: Extension Sample Inplace1021280 +Node: Extension Sample Ord1022955 +Node: Extension Sample Readdir1023791 +Ref: table-readdir-file-types1024647 +Node: Extension Sample Revout1025446 +Node: Extension Sample Rev2way1026037 +Node: Extension Sample Read write array1026778 +Node: Extension Sample Readfile1028657 +Node: Extension Sample API Tests1029757 +Node: Extension Sample Time1030282 +Node: gawkextlib1031597 +Node: Extension summary1034410 +Node: Extension Exercises1038103 +Node: Language History1038825 +Node: V7/SVR3.11040468 +Node: SVR41042788 +Node: POSIX1044230 +Node: BTL1045616 +Node: POSIX/GNU1046350 +Node: Feature History1052066 +Node: Common Extensions1065157 +Node: Ranges and Locales1066469 +Ref: Ranges and Locales-Footnote-11071086 +Ref: Ranges and Locales-Footnote-21071113 +Ref: Ranges and Locales-Footnote-31071347 +Node: Contributors1071568 +Node: History summary1076993 +Node: Installation1078362 +Node: Gawk Distribution1079313 +Node: Getting1079797 +Node: Extracting1080621 +Node: Distribution contents1082263 +Node: Unix Installation1087980 +Node: Quick Installation1088597 +Node: Additional Configuration Options1091039 +Node: Configuration Philosophy1092777 +Node: Non-Unix Installation1095128 +Node: PC Installation1095586 +Node: PC Binary Installation1096897 +Node: PC Compiling1098745 +Ref: PC Compiling-Footnote-11101744 +Node: PC Testing1101849 +Node: PC Using1103025 +Node: Cygwin1107177 +Node: MSYS1107986 +Node: VMS Installation1108500 +Node: VMS Compilation1109296 +Ref: VMS Compilation-Footnote-11110518 +Node: VMS Dynamic Extensions1110576 +Node: VMS Installation Details1111949 +Node: VMS Running1114201 +Node: VMS GNV1117035 +Node: VMS Old Gawk1117758 +Node: Bugs1118228 +Node: Other Versions1122232 +Node: Installation summary1128459 +Node: Notes1129515 +Node: Compatibility Mode1130380 +Node: Additions1131162 +Node: Accessing The Source1132087 +Node: Adding Code1133523 +Node: New Ports1139701 +Node: Derived Files1144182 +Ref: Derived Files-Footnote-11149263 +Ref: Derived Files-Footnote-21149297 +Ref: Derived Files-Footnote-31149893 +Node: Future Extensions1150007 +Node: Implementation Limitations1150613 +Node: Extension Design1151861 +Node: Old Extension Problems1153015 +Ref: Old Extension Problems-Footnote-11154532 +Node: Extension New Mechanism Goals1154589 +Ref: Extension New Mechanism Goals-Footnote-11157949 +Node: Extension Other Design Decisions1158138 +Node: Extension Future Growth1160244 +Node: Old Extension Mechanism1161080 +Node: Notes summary1162842 +Node: Basic Concepts1164028 +Node: Basic High Level1164709 +Ref: figure-general-flow1164981 +Ref: figure-process-flow1165580 +Ref: Basic High Level-Footnote-11168809 +Node: Basic Data Typing1168994 +Node: Glossary1172322 +Node: Copying1197474 +Node: GNU Free Documentation License1235030 +Node: Index1260166  End Tag Table -- cgit v1.2.3 From 611353597e20081bd0c72617e24fa5ff4c63dac1 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 4 Sep 2014 09:38:08 +0300 Subject: Make indirect calls work on built-in and extension functions. --- doc/gawk.info | 600 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 303 insertions(+), 297 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 1e6e93f5..f008ecfa 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -13853,7 +13853,7 @@ File: gawk.info, Node: Indirect Calls, Next: Functions Summary, Prev: User-de 9.3 Indirect Function Calls =========================== -This section describes a `gawk'-specific extension. +This section describes an advanced, `gawk'-specific extension. Often, you may wish to defer the choice of function to call until runtime. For example, you may have different kinds of records, each of @@ -13892,7 +13892,7 @@ your test scores: This style of programming works, but can be awkward. With "indirect" function calls, you tell `gawk' to use the _value_ of a variable as the -name of the function to call. +_name_ of the function to call. The syntax is similar to that of a regular function call: an identifier immediately followed by a left parenthesis, any arguments, @@ -13934,7 +13934,6 @@ using indirect function calls. Otherwise they perform the expected computations and are not unusual. # For each record, print the class name and the requested statistics - { class_name = $1 gsub(/_/, " ", class_name) # Replace _ with spaces @@ -14121,11 +14120,11 @@ names of the two comparison functions: Remember that you must supply a leading `@' in front of an indirect function call. - Unfortunately, indirect function calls cannot be used with the -built-in functions. However, you can generally write "wrapper" -functions which call the built-in ones, and those can be called -indirectly. (Other than, perhaps, the mathematical functions, there is -not a lot of reason to try to call the built-in functions indirectly.) + Starting with version 4.1.2 of `gawk', indirect function calls may +also be used with built-in functions and with extension functions +(*note Dynamic Extensions::). The only thing you cannot do is pass a +regular expression constant to a built-in function through an indirect +function call.(1) `gawk' does its best to make indirect function calls efficient. For example, in the following case: @@ -14133,7 +14132,12 @@ example, in the following case: for (i = 1; i <= n; i++) @the_func() -`gawk' will look up the actual function to call only once. +`gawk' looks up the actual function to call only once. + + ---------- Footnotes ---------- + + (1) This may change in a future version; recheck the documentation +that comes with your version of `gawk' to see if it has.  File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions @@ -14170,7 +14174,9 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions * User-defined functions may call other user-defined (and built-in) functions and may call themselves recursively. Function parameters - "hide" any global variables of the same names. + "hide" any global variables of the same names. You cannot use the + name of a reserved variable (such as `ARGC') as the name of a + parameter in user-defined functions. * Scalar values are passed to user-defined functions by value. Array parameters are passed by reference; any changes made by the @@ -14186,10 +14192,9 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions either scalar or array. * `gawk' provides indirect function calls using a special syntax. - By setting a variable to the name of a user-defined function, you - can determine at runtime what function will be called at that - point in the program. This is equivalent to function pointers in C - and C++. + By setting a variable to the name of a function, you can determine + at runtime what function will be called at that point in the + program. This is equivalent to function pointers in C and C++.  @@ -34292,288 +34297,289 @@ Node: Pass By Value/Reference571978 Node: Return Statement575488 Node: Dynamic Typing578472 Node: Indirect Calls579401 -Node: Functions Summary589114 -Node: Library Functions591653 -Ref: Library Functions-Footnote-1595271 -Ref: Library Functions-Footnote-2595414 -Node: Library Names595585 -Ref: Library Names-Footnote-1599058 -Ref: Library Names-Footnote-2599278 -Node: General Functions599364 -Node: Strtonum Function600392 -Node: Assert Function603266 -Node: Round Function606592 -Node: Cliff Random Function608133 -Node: Ordinal Functions609149 -Ref: Ordinal Functions-Footnote-1612214 -Ref: Ordinal Functions-Footnote-2612466 -Node: Join Function612677 -Ref: Join Function-Footnote-1614448 -Node: Getlocaltime Function614648 -Node: Readfile Function618384 -Node: Data File Management620223 -Node: Filetrans Function620855 -Node: Rewind Function624924 -Node: File Checking626482 -Ref: File Checking-Footnote-1627614 -Node: Empty Files627815 -Node: Ignoring Assigns629794 -Node: Getopt Function631348 -Ref: Getopt Function-Footnote-1642612 -Node: Passwd Functions642815 -Ref: Passwd Functions-Footnote-1651794 -Node: Group Functions651882 -Ref: Group Functions-Footnote-1659813 -Node: Walking Arrays660026 -Node: Library Functions Summary661629 -Node: Library Exercises663017 -Node: Sample Programs664297 -Node: Running Examples665067 -Node: Clones665795 -Node: Cut Program667019 -Node: Egrep Program676877 -Ref: Egrep Program-Footnote-1684464 -Node: Id Program684574 -Node: Split Program688228 -Ref: Split Program-Footnote-1691766 -Node: Tee Program691894 -Node: Uniq Program694681 -Node: Wc Program702104 -Ref: Wc Program-Footnote-1706369 -Node: Miscellaneous Programs706461 -Node: Dupword Program707674 -Node: Alarm Program709705 -Node: Translate Program714509 -Ref: Translate Program-Footnote-1718900 -Ref: Translate Program-Footnote-2719170 -Node: Labels Program719309 -Ref: Labels Program-Footnote-1722670 -Node: Word Sorting722754 -Node: History Sorting726797 -Node: Extract Program728633 -Node: Simple Sed736169 -Node: Igawk Program739231 -Ref: Igawk Program-Footnote-1753535 -Ref: Igawk Program-Footnote-2753736 -Node: Anagram Program753874 -Node: Signature Program756942 -Node: Programs Summary758189 -Node: Programs Exercises759404 -Ref: Programs Exercises-Footnote-1763791 -Node: Advanced Features763882 -Node: Nondecimal Data765830 -Node: Array Sorting767407 -Node: Controlling Array Traversal768104 -Node: Array Sorting Functions776384 -Ref: Array Sorting Functions-Footnote-1780291 -Node: Two-way I/O780485 -Ref: Two-way I/O-Footnote-1785429 -Ref: Two-way I/O-Footnote-2785608 -Node: TCP/IP Networking785690 -Node: Profiling788535 -Node: Advanced Features Summary796077 -Node: Internationalization797941 -Node: I18N and L10N799421 -Node: Explaining gettext800107 -Ref: Explaining gettext-Footnote-1805133 -Ref: Explaining gettext-Footnote-2805317 -Node: Programmer i18n805482 -Ref: Programmer i18n-Footnote-1810276 -Node: Translator i18n810325 -Node: String Extraction811119 -Ref: String Extraction-Footnote-1812252 -Node: Printf Ordering812338 -Ref: Printf Ordering-Footnote-1815120 -Node: I18N Portability815184 -Ref: I18N Portability-Footnote-1817633 -Node: I18N Example817696 -Ref: I18N Example-Footnote-1820402 -Node: Gawk I18N820474 -Node: I18N Summary821112 -Node: Debugger822451 -Node: Debugging823473 -Node: Debugging Concepts823914 -Node: Debugging Terms825770 -Node: Awk Debugging828367 -Node: Sample Debugging Session829259 -Node: Debugger Invocation829779 -Node: Finding The Bug831115 -Node: List of Debugger Commands837594 -Node: Breakpoint Control838926 -Node: Debugger Execution Control842590 -Node: Viewing And Changing Data845950 -Node: Execution Stack849308 -Node: Debugger Info850821 -Node: Miscellaneous Debugger Commands854815 -Node: Readline Support859999 -Node: Limitations860891 -Node: Debugging Summary863164 -Node: Arbitrary Precision Arithmetic864332 -Node: Computer Arithmetic865819 -Ref: Computer Arithmetic-Footnote-1870206 -Node: Math Definitions870263 -Ref: table-ieee-formats873552 -Ref: Math Definitions-Footnote-1874092 -Node: MPFR features874195 -Node: FP Math Caution875812 -Ref: FP Math Caution-Footnote-1876862 -Node: Inexactness of computations877231 -Node: Inexact representation878179 -Node: Comparing FP Values879534 -Node: Errors accumulate880498 -Node: Getting Accuracy881931 -Node: Try To Round884590 -Node: Setting precision885489 -Ref: table-predefined-precision-strings886171 -Node: Setting the rounding mode887964 -Ref: table-gawk-rounding-modes888328 -Ref: Setting the rounding mode-Footnote-1891782 -Node: Arbitrary Precision Integers891961 -Ref: Arbitrary Precision Integers-Footnote-1894942 -Node: POSIX Floating Point Problems895091 -Ref: POSIX Floating Point Problems-Footnote-1898967 -Node: Floating point summary899005 -Node: Dynamic Extensions901209 -Node: Extension Intro902761 -Node: Plugin License904026 -Node: Extension Mechanism Outline904711 -Ref: figure-load-extension905135 -Ref: figure-load-new-function906620 -Ref: figure-call-new-function907622 -Node: Extension API Description909606 -Node: Extension API Functions Introduction911056 -Node: General Data Types915923 -Ref: General Data Types-Footnote-1921616 -Node: Requesting Values921915 -Ref: table-value-types-returned922652 -Node: Memory Allocation Functions923610 -Ref: Memory Allocation Functions-Footnote-1926357 -Node: Constructor Functions926453 -Node: Registration Functions928211 -Node: Extension Functions928896 -Node: Exit Callback Functions931198 -Node: Extension Version String932446 -Node: Input Parsers933096 -Node: Output Wrappers942910 -Node: Two-way processors947426 -Node: Printing Messages949630 -Ref: Printing Messages-Footnote-1950707 -Node: Updating `ERRNO'950859 -Node: Accessing Parameters951598 -Node: Symbol Table Access952828 -Node: Symbol table by name953342 -Node: Symbol table by cookie955318 -Ref: Symbol table by cookie-Footnote-1959451 -Node: Cached values959514 -Ref: Cached values-Footnote-1963018 -Node: Array Manipulation963109 -Ref: Array Manipulation-Footnote-1964207 -Node: Array Data Types964246 -Ref: Array Data Types-Footnote-1966949 -Node: Array Functions967041 -Node: Flattening Arrays970915 -Node: Creating Arrays977767 -Node: Extension API Variables982498 -Node: Extension Versioning983134 -Node: Extension API Informational Variables985035 -Node: Extension API Boilerplate986121 -Node: Finding Extensions989925 -Node: Extension Example990485 -Node: Internal File Description991215 -Node: Internal File Ops995306 -Ref: Internal File Ops-Footnote-11006738 -Node: Using Internal File Ops1006878 -Ref: Using Internal File Ops-Footnote-11009225 -Node: Extension Samples1009493 -Node: Extension Sample File Functions1011017 -Node: Extension Sample Fnmatch1018585 -Node: Extension Sample Fork1020067 -Node: Extension Sample Inplace1021280 -Node: Extension Sample Ord1022955 -Node: Extension Sample Readdir1023791 -Ref: table-readdir-file-types1024647 -Node: Extension Sample Revout1025446 -Node: Extension Sample Rev2way1026037 -Node: Extension Sample Read write array1026778 -Node: Extension Sample Readfile1028657 -Node: Extension Sample API Tests1029757 -Node: Extension Sample Time1030282 -Node: gawkextlib1031597 -Node: Extension summary1034410 -Node: Extension Exercises1038103 -Node: Language History1038825 -Node: V7/SVR3.11040468 -Node: SVR41042788 -Node: POSIX1044230 -Node: BTL1045616 -Node: POSIX/GNU1046350 -Node: Feature History1052066 -Node: Common Extensions1065157 -Node: Ranges and Locales1066469 -Ref: Ranges and Locales-Footnote-11071086 -Ref: Ranges and Locales-Footnote-21071113 -Ref: Ranges and Locales-Footnote-31071347 -Node: Contributors1071568 -Node: History summary1076993 -Node: Installation1078362 -Node: Gawk Distribution1079313 -Node: Getting1079797 -Node: Extracting1080621 -Node: Distribution contents1082263 -Node: Unix Installation1087980 -Node: Quick Installation1088597 -Node: Additional Configuration Options1091039 -Node: Configuration Philosophy1092777 -Node: Non-Unix Installation1095128 -Node: PC Installation1095586 -Node: PC Binary Installation1096897 -Node: PC Compiling1098745 -Ref: PC Compiling-Footnote-11101744 -Node: PC Testing1101849 -Node: PC Using1103025 -Node: Cygwin1107177 -Node: MSYS1107986 -Node: VMS Installation1108500 -Node: VMS Compilation1109296 -Ref: VMS Compilation-Footnote-11110518 -Node: VMS Dynamic Extensions1110576 -Node: VMS Installation Details1111949 -Node: VMS Running1114201 -Node: VMS GNV1117035 -Node: VMS Old Gawk1117758 -Node: Bugs1118228 -Node: Other Versions1122232 -Node: Installation summary1128459 -Node: Notes1129515 -Node: Compatibility Mode1130380 -Node: Additions1131162 -Node: Accessing The Source1132087 -Node: Adding Code1133523 -Node: New Ports1139701 -Node: Derived Files1144182 -Ref: Derived Files-Footnote-11149263 -Ref: Derived Files-Footnote-21149297 -Ref: Derived Files-Footnote-31149893 -Node: Future Extensions1150007 -Node: Implementation Limitations1150613 -Node: Extension Design1151861 -Node: Old Extension Problems1153015 -Ref: Old Extension Problems-Footnote-11154532 -Node: Extension New Mechanism Goals1154589 -Ref: Extension New Mechanism Goals-Footnote-11157949 -Node: Extension Other Design Decisions1158138 -Node: Extension Future Growth1160244 -Node: Old Extension Mechanism1161080 -Node: Notes summary1162842 -Node: Basic Concepts1164028 -Node: Basic High Level1164709 -Ref: figure-general-flow1164981 -Ref: figure-process-flow1165580 -Ref: Basic High Level-Footnote-11168809 -Node: Basic Data Typing1168994 -Node: Glossary1172322 -Node: Copying1197474 -Node: GNU Free Documentation License1235030 -Node: Index1260166 +Ref: Indirect Calls-Footnote-1589117 +Node: Functions Summary589245 +Node: Library Functions591895 +Ref: Library Functions-Footnote-1595513 +Ref: Library Functions-Footnote-2595656 +Node: Library Names595827 +Ref: Library Names-Footnote-1599300 +Ref: Library Names-Footnote-2599520 +Node: General Functions599606 +Node: Strtonum Function600634 +Node: Assert Function603508 +Node: Round Function606834 +Node: Cliff Random Function608375 +Node: Ordinal Functions609391 +Ref: Ordinal Functions-Footnote-1612456 +Ref: Ordinal Functions-Footnote-2612708 +Node: Join Function612919 +Ref: Join Function-Footnote-1614690 +Node: Getlocaltime Function614890 +Node: Readfile Function618626 +Node: Data File Management620465 +Node: Filetrans Function621097 +Node: Rewind Function625166 +Node: File Checking626724 +Ref: File Checking-Footnote-1627856 +Node: Empty Files628057 +Node: Ignoring Assigns630036 +Node: Getopt Function631590 +Ref: Getopt Function-Footnote-1642854 +Node: Passwd Functions643057 +Ref: Passwd Functions-Footnote-1652036 +Node: Group Functions652124 +Ref: Group Functions-Footnote-1660055 +Node: Walking Arrays660268 +Node: Library Functions Summary661871 +Node: Library Exercises663259 +Node: Sample Programs664539 +Node: Running Examples665309 +Node: Clones666037 +Node: Cut Program667261 +Node: Egrep Program677119 +Ref: Egrep Program-Footnote-1684706 +Node: Id Program684816 +Node: Split Program688470 +Ref: Split Program-Footnote-1692008 +Node: Tee Program692136 +Node: Uniq Program694923 +Node: Wc Program702346 +Ref: Wc Program-Footnote-1706611 +Node: Miscellaneous Programs706703 +Node: Dupword Program707916 +Node: Alarm Program709947 +Node: Translate Program714751 +Ref: Translate Program-Footnote-1719142 +Ref: Translate Program-Footnote-2719412 +Node: Labels Program719551 +Ref: Labels Program-Footnote-1722912 +Node: Word Sorting722996 +Node: History Sorting727039 +Node: Extract Program728875 +Node: Simple Sed736411 +Node: Igawk Program739473 +Ref: Igawk Program-Footnote-1753777 +Ref: Igawk Program-Footnote-2753978 +Node: Anagram Program754116 +Node: Signature Program757184 +Node: Programs Summary758431 +Node: Programs Exercises759646 +Ref: Programs Exercises-Footnote-1764033 +Node: Advanced Features764124 +Node: Nondecimal Data766072 +Node: Array Sorting767649 +Node: Controlling Array Traversal768346 +Node: Array Sorting Functions776626 +Ref: Array Sorting Functions-Footnote-1780533 +Node: Two-way I/O780727 +Ref: Two-way I/O-Footnote-1785671 +Ref: Two-way I/O-Footnote-2785850 +Node: TCP/IP Networking785932 +Node: Profiling788777 +Node: Advanced Features Summary796319 +Node: Internationalization798183 +Node: I18N and L10N799663 +Node: Explaining gettext800349 +Ref: Explaining gettext-Footnote-1805375 +Ref: Explaining gettext-Footnote-2805559 +Node: Programmer i18n805724 +Ref: Programmer i18n-Footnote-1810518 +Node: Translator i18n810567 +Node: String Extraction811361 +Ref: String Extraction-Footnote-1812494 +Node: Printf Ordering812580 +Ref: Printf Ordering-Footnote-1815362 +Node: I18N Portability815426 +Ref: I18N Portability-Footnote-1817875 +Node: I18N Example817938 +Ref: I18N Example-Footnote-1820644 +Node: Gawk I18N820716 +Node: I18N Summary821354 +Node: Debugger822693 +Node: Debugging823715 +Node: Debugging Concepts824156 +Node: Debugging Terms826012 +Node: Awk Debugging828609 +Node: Sample Debugging Session829501 +Node: Debugger Invocation830021 +Node: Finding The Bug831357 +Node: List of Debugger Commands837836 +Node: Breakpoint Control839168 +Node: Debugger Execution Control842832 +Node: Viewing And Changing Data846192 +Node: Execution Stack849550 +Node: Debugger Info851063 +Node: Miscellaneous Debugger Commands855057 +Node: Readline Support860241 +Node: Limitations861133 +Node: Debugging Summary863406 +Node: Arbitrary Precision Arithmetic864574 +Node: Computer Arithmetic866061 +Ref: Computer Arithmetic-Footnote-1870448 +Node: Math Definitions870505 +Ref: table-ieee-formats873794 +Ref: Math Definitions-Footnote-1874334 +Node: MPFR features874437 +Node: FP Math Caution876054 +Ref: FP Math Caution-Footnote-1877104 +Node: Inexactness of computations877473 +Node: Inexact representation878421 +Node: Comparing FP Values879776 +Node: Errors accumulate880740 +Node: Getting Accuracy882173 +Node: Try To Round884832 +Node: Setting precision885731 +Ref: table-predefined-precision-strings886413 +Node: Setting the rounding mode888206 +Ref: table-gawk-rounding-modes888570 +Ref: Setting the rounding mode-Footnote-1892024 +Node: Arbitrary Precision Integers892203 +Ref: Arbitrary Precision Integers-Footnote-1895184 +Node: POSIX Floating Point Problems895333 +Ref: POSIX Floating Point Problems-Footnote-1899209 +Node: Floating point summary899247 +Node: Dynamic Extensions901451 +Node: Extension Intro903003 +Node: Plugin License904268 +Node: Extension Mechanism Outline904953 +Ref: figure-load-extension905377 +Ref: figure-load-new-function906862 +Ref: figure-call-new-function907864 +Node: Extension API Description909848 +Node: Extension API Functions Introduction911298 +Node: General Data Types916165 +Ref: General Data Types-Footnote-1921858 +Node: Requesting Values922157 +Ref: table-value-types-returned922894 +Node: Memory Allocation Functions923852 +Ref: Memory Allocation Functions-Footnote-1926599 +Node: Constructor Functions926695 +Node: Registration Functions928453 +Node: Extension Functions929138 +Node: Exit Callback Functions931440 +Node: Extension Version String932688 +Node: Input Parsers933338 +Node: Output Wrappers943152 +Node: Two-way processors947668 +Node: Printing Messages949872 +Ref: Printing Messages-Footnote-1950949 +Node: Updating `ERRNO'951101 +Node: Accessing Parameters951840 +Node: Symbol Table Access953070 +Node: Symbol table by name953584 +Node: Symbol table by cookie955560 +Ref: Symbol table by cookie-Footnote-1959693 +Node: Cached values959756 +Ref: Cached values-Footnote-1963260 +Node: Array Manipulation963351 +Ref: Array Manipulation-Footnote-1964449 +Node: Array Data Types964488 +Ref: Array Data Types-Footnote-1967191 +Node: Array Functions967283 +Node: Flattening Arrays971157 +Node: Creating Arrays978009 +Node: Extension API Variables982740 +Node: Extension Versioning983376 +Node: Extension API Informational Variables985277 +Node: Extension API Boilerplate986363 +Node: Finding Extensions990167 +Node: Extension Example990727 +Node: Internal File Description991457 +Node: Internal File Ops995548 +Ref: Internal File Ops-Footnote-11006980 +Node: Using Internal File Ops1007120 +Ref: Using Internal File Ops-Footnote-11009467 +Node: Extension Samples1009735 +Node: Extension Sample File Functions1011259 +Node: Extension Sample Fnmatch1018827 +Node: Extension Sample Fork1020309 +Node: Extension Sample Inplace1021522 +Node: Extension Sample Ord1023197 +Node: Extension Sample Readdir1024033 +Ref: table-readdir-file-types1024889 +Node: Extension Sample Revout1025688 +Node: Extension Sample Rev2way1026279 +Node: Extension Sample Read write array1027020 +Node: Extension Sample Readfile1028899 +Node: Extension Sample API Tests1029999 +Node: Extension Sample Time1030524 +Node: gawkextlib1031839 +Node: Extension summary1034652 +Node: Extension Exercises1038345 +Node: Language History1039067 +Node: V7/SVR3.11040710 +Node: SVR41043030 +Node: POSIX1044472 +Node: BTL1045858 +Node: POSIX/GNU1046592 +Node: Feature History1052308 +Node: Common Extensions1065399 +Node: Ranges and Locales1066711 +Ref: Ranges and Locales-Footnote-11071328 +Ref: Ranges and Locales-Footnote-21071355 +Ref: Ranges and Locales-Footnote-31071589 +Node: Contributors1071810 +Node: History summary1077235 +Node: Installation1078604 +Node: Gawk Distribution1079555 +Node: Getting1080039 +Node: Extracting1080863 +Node: Distribution contents1082505 +Node: Unix Installation1088222 +Node: Quick Installation1088839 +Node: Additional Configuration Options1091281 +Node: Configuration Philosophy1093019 +Node: Non-Unix Installation1095370 +Node: PC Installation1095828 +Node: PC Binary Installation1097139 +Node: PC Compiling1098987 +Ref: PC Compiling-Footnote-11101986 +Node: PC Testing1102091 +Node: PC Using1103267 +Node: Cygwin1107419 +Node: MSYS1108228 +Node: VMS Installation1108742 +Node: VMS Compilation1109538 +Ref: VMS Compilation-Footnote-11110760 +Node: VMS Dynamic Extensions1110818 +Node: VMS Installation Details1112191 +Node: VMS Running1114443 +Node: VMS GNV1117277 +Node: VMS Old Gawk1118000 +Node: Bugs1118470 +Node: Other Versions1122474 +Node: Installation summary1128701 +Node: Notes1129757 +Node: Compatibility Mode1130622 +Node: Additions1131404 +Node: Accessing The Source1132329 +Node: Adding Code1133765 +Node: New Ports1139943 +Node: Derived Files1144424 +Ref: Derived Files-Footnote-11149505 +Ref: Derived Files-Footnote-21149539 +Ref: Derived Files-Footnote-31150135 +Node: Future Extensions1150249 +Node: Implementation Limitations1150855 +Node: Extension Design1152103 +Node: Old Extension Problems1153257 +Ref: Old Extension Problems-Footnote-11154774 +Node: Extension New Mechanism Goals1154831 +Ref: Extension New Mechanism Goals-Footnote-11158191 +Node: Extension Other Design Decisions1158380 +Node: Extension Future Growth1160486 +Node: Old Extension Mechanism1161322 +Node: Notes summary1163084 +Node: Basic Concepts1164270 +Node: Basic High Level1164951 +Ref: figure-general-flow1165223 +Ref: figure-process-flow1165822 +Ref: Basic High Level-Footnote-11169051 +Node: Basic Data Typing1169236 +Node: Glossary1172564 +Node: Copying1197716 +Node: GNU Free Documentation License1235272 +Node: Index1260408  End Tag Table -- cgit v1.2.3 From 0f5cb955662136ad4a93e35db5721dd986dfd55b Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 5 Sep 2014 11:21:38 +0300 Subject: Add builtin functions to FUNCTAB and PROCINFO["identifiers"] and doc. --- doc/gawk.info | 776 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 390 insertions(+), 386 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index f008ecfa..0d7505a5 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -10269,7 +10269,8 @@ Options::), they are not special. `FUNCTAB #' An array whose indices and corresponding values are the names of - all the user-defined or extension functions in the program. + all the built-in, user-defined and extension functions in the + program. NOTE: Attempting to use the `delete' statement with the `FUNCTAB' array causes a fatal error. Any attempt to assign @@ -10305,9 +10306,12 @@ Options::), they are not special. `"array"' The identifier is an array. + `"builtin"' + The identifier is a built-in function. + `"extension"' The identifier is an extension function loaded via - `@load'. + `@load' or `-l'. `"scalar"' The identifier is a scalar. @@ -31836,7 +31840,7 @@ Index (line 46) * dark corner, FILENAME variable <1>: Auto-set. (line 90) * dark corner, FILENAME variable: Getline Notes. (line 19) -* dark corner, FNR/NR variables: Auto-set. (line 301) +* dark corner, FNR/NR variables: Auto-set. (line 305) * dark corner, format-control characters: Control Letters. (line 18) * dark corner, FS as null string: Single Character Fields. (line 20) @@ -32050,7 +32054,7 @@ Index (line 260) * differences in awk and gawk, print/printf statements: Format Modifiers. (line 13) -* differences in awk and gawk, PROCINFO array: Auto-set. (line 128) +* differences in awk and gawk, PROCINFO array: Auto-set. (line 129) * differences in awk and gawk, read timeouts: Read Timeout. (line 6) * differences in awk and gawk, record separators: awk split records. (line 124) @@ -32060,7 +32064,7 @@ Index (line 26) * differences in awk and gawk, RS/RT variables: gawk split records. (line 58) -* differences in awk and gawk, RT variable: Auto-set. (line 257) +* differences in awk and gawk, RT variable: Auto-set. (line 261) * differences in awk and gawk, single-character fields: Single Character Fields. (line 6) * differences in awk and gawk, split() function: String Functions. @@ -32068,7 +32072,7 @@ Index * differences in awk and gawk, strings: Scalar Constants. (line 20) * differences in awk and gawk, strings, storing: gawk split records. (line 77) -* differences in awk and gawk, SYMTAB variable: Auto-set. (line 261) +* differences in awk and gawk, SYMTAB variable: Auto-set. (line 265) * differences in awk and gawk, TEXTDOMAIN variable: User-modified. (line 152) * differences in awk and gawk, trunc-mod operation: Arithmetic Ops. @@ -32107,8 +32111,8 @@ Index * dynamically loaded extensions: Dynamic Extensions. (line 6) * e debugger command (alias for enable): Breakpoint Control. (line 73) * EBCDIC: Ordinal Functions. (line 45) -* effective group ID of gawk user: Auto-set. (line 133) -* effective user ID of gawk user: Auto-set. (line 137) +* effective group ID of gawk user: Auto-set. (line 134) +* effective user ID of gawk user: Auto-set. (line 138) * egrep utility <1>: Egrep Program. (line 6) * egrep utility: Bracket Expressions. (line 26) * egrep.awk program: Egrep Program. (line 54) @@ -32223,7 +32227,7 @@ Index (line 6) * extension API version: Extension Versioning. (line 6) -* extension API, version number: Auto-set. (line 224) +* extension API, version number: Auto-set. (line 228) * extension example: Extension Example. (line 6) * extension registration: Registration Functions. (line 6) @@ -32375,7 +32379,7 @@ Index (line 12) * FNR variable <1>: Auto-set. (line 99) * FNR variable: Records. (line 6) -* FNR variable, changing: Auto-set. (line 301) +* FNR variable, changing: Auto-set. (line 305) * for statement: For Statement. (line 6) * for statement, looping over arrays: Scanning an Array. (line 20) * fork() extension function: Extension Sample Fork. @@ -32476,7 +32480,7 @@ Index * G-d: Acknowledgments. (line 92) * Garfinkle, Scott: Contributors. (line 34) * gawk program, dynamic profiling: Profiling. (line 179) -* gawk version: Auto-set. (line 199) +* gawk version: Auto-set. (line 203) * gawk, ARGIND variable in: Other Arguments. (line 12) * gawk, awk and <1>: This Manual. (line 14) * gawk, awk and: Preface. (line 21) @@ -32545,7 +32549,7 @@ Index * gawk, OS/2 version of: PC Using. (line 16) * gawk, PROCINFO array in <1>: Two-way I/O. (line 99) * gawk, PROCINFO array in <2>: Time Functions. (line 47) -* gawk, PROCINFO array in: Auto-set. (line 128) +* gawk, PROCINFO array in: Auto-set. (line 129) * gawk, regexp constants and: Using Constant Regexps. (line 28) * gawk, regular expressions, case sensitivity: Case-sensitivity. @@ -32553,14 +32557,14 @@ Index * gawk, regular expressions, operators: GNU Regexp Operators. (line 6) * gawk, regular expressions, precedence: Regexp Operators. (line 161) -* gawk, RT variable in <1>: Auto-set. (line 257) +* gawk, RT variable in <1>: Auto-set. (line 261) * gawk, RT variable in <2>: Multiple Line. (line 129) * gawk, RT variable in: awk split records. (line 124) * gawk, See Also awk: Preface. (line 34) * gawk, source code, obtaining: Getting. (line 6) * gawk, splitting fields and: Constant Size. (line 88) * gawk, string-translation functions: I18N Functions. (line 6) -* gawk, SYMTAB array in: Auto-set. (line 261) +* gawk, SYMTAB array in: Auto-set. (line 265) * gawk, TEXTDOMAIN variable in: User-modified. (line 152) * gawk, timestamps: Time Functions. (line 6) * gawk, uses for: Preface. (line 34) @@ -32646,7 +32650,7 @@ Index * Grigera, Juan: Contributors. (line 57) * group database, reading: Group Functions. (line 6) * group file: Group Functions. (line 6) -* group ID of gawk user: Auto-set. (line 172) +* group ID of gawk user: Auto-set. (line 176) * groups, information about: Group Functions. (line 6) * gsub <1>: String Functions. (line 139) * gsub: Using Constant Regexps. @@ -32940,7 +32944,7 @@ Index * mawk utility <3>: Concatenation. (line 36) * mawk utility <4>: Getline/Pipe. (line 62) * mawk utility: Escape Sequences. (line 130) -* maximum precision supported by MPFR library: Auto-set. (line 213) +* maximum precision supported by MPFR library: Auto-set. (line 217) * McIlroy, Doug: Glossary. (line 149) * McPhee, Patrick: Contributors. (line 100) * message object files: Explaining gettext. (line 42) @@ -32953,7 +32957,7 @@ Index * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) * metacharacters, escape sequences for: Escape Sequences. (line 136) -* minimum precision supported by MPFR library: Auto-set. (line 216) +* minimum precision supported by MPFR library: Auto-set. (line 220) * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) * monetary information, localization: Explaining gettext. (line 104) @@ -33013,9 +33017,9 @@ Index * non-existent array elements: Reference to Elements. (line 23) * not Boolean-logic operator: Boolean Ops. (line 6) -* NR variable <1>: Auto-set. (line 123) +* NR variable <1>: Auto-set. (line 124) * NR variable: Records. (line 6) -* NR variable, changing: Auto-set. (line 301) +* NR variable, changing: Auto-set. (line 305) * null strings <1>: Basic Data Typing. (line 26) * null strings <2>: Truth Values. (line 6) * null strings <3>: Regexp Field Splitting. @@ -33129,7 +33133,7 @@ Index * p debugger command (alias for print): Viewing And Changing Data. (line 36) * Papadopoulos, Panos: Contributors. (line 128) -* parent process ID of gawk process: Auto-set. (line 181) +* parent process ID of gawk process: Auto-set. (line 185) * parentheses (), in a profile: Profiling. (line 146) * parentheses (), regexp operator: Regexp Operators. (line 81) * password file: Passwd Functions. (line 16) @@ -33292,24 +33296,24 @@ Index * printing, unduplicated lines of text: Uniq Program. (line 6) * printing, user information: Id Program. (line 6) * private variables: Library Names. (line 11) -* process group idIDof gawk process: Auto-set. (line 175) -* process ID of gawk process: Auto-set. (line 178) +* process group idIDof gawk process: Auto-set. (line 179) +* process ID of gawk process: Auto-set. (line 182) * processes, two-way communications with: Two-way I/O. (line 6) * processing data: Basic High Level. (line 6) * PROCINFO array <1>: Passwd Functions. (line 6) * PROCINFO array <2>: Time Functions. (line 47) -* PROCINFO array: Auto-set. (line 128) +* PROCINFO array: Auto-set. (line 129) * PROCINFO array, and communications via ptys: Two-way I/O. (line 99) * PROCINFO array, and group membership: Group Functions. (line 6) * PROCINFO array, and user and group ID numbers: Id Program. (line 15) * PROCINFO array, testing the field splitting: Passwd Functions. (line 161) -* PROCINFO array, uses: Auto-set. (line 234) +* PROCINFO array, uses: Auto-set. (line 238) * PROCINFO, values of sorted_in: Controlling Scanning. (line 26) * profiling awk programs: Profiling. (line 6) * profiling awk programs, dynamically: Profiling. (line 179) -* program identifiers: Auto-set. (line 146) +* program identifiers: Auto-set. (line 147) * program, definition of: Getting Started. (line 21) * programming conventions, --non-decimal-data option: Nondecimal Data. (line 36) @@ -33468,7 +33472,7 @@ Index * right shift: Bitwise Functions. (line 52) * right shift, bitwise: Bitwise Functions. (line 32) * Ritchie, Dennis: Basic Data Typing. (line 54) -* RLENGTH variable: Auto-set. (line 244) +* RLENGTH variable: Auto-set. (line 248) * RLENGTH variable, match() function and: String Functions. (line 224) * Robbins, Arnold <1>: Future Extensions. (line 6) * Robbins, Arnold <2>: Bugs. (line 32) @@ -33494,9 +33498,9 @@ Index * RS variable: awk split records. (line 12) * RS variable, multiline records and: Multiple Line. (line 17) * rshift: Bitwise Functions. (line 52) -* RSTART variable: Auto-set. (line 250) +* RSTART variable: Auto-set. (line 254) * RSTART variable, match() function and: String Functions. (line 224) -* RT variable <1>: Auto-set. (line 257) +* RT variable <1>: Auto-set. (line 261) * RT variable <2>: Multiple Line. (line 129) * RT variable: awk split records. (line 124) * Rubin, Paul <1>: Contributors. (line 15) @@ -33516,7 +33520,7 @@ Index * scanning arrays: Scanning an Array. (line 6) * scanning multidimensional arrays: Multiscanning. (line 11) * Schorr, Andrew <1>: Contributors. (line 133) -* Schorr, Andrew <2>: Auto-set. (line 284) +* Schorr, Andrew <2>: Auto-set. (line 288) * Schorr, Andrew: Acknowledgments. (line 60) * Schreiber, Bert: Acknowledgments. (line 38) * Schreiber, Rita: Acknowledgments. (line 38) @@ -33600,7 +33604,7 @@ Index (line 116) * sidebar, Changing FS Does Not Affect the Fields: Field Splitting Summary. (line 38) -* sidebar, Changing NR and FNR: Auto-set. (line 299) +* sidebar, Changing NR and FNR: Auto-set. (line 303) * sidebar, Controlling Output Buffering with system(): I/O Functions. (line 138) * sidebar, Escape Sequences for Metacharacters: Escape Sequences. @@ -33763,9 +33767,9 @@ Index * substr: String Functions. (line 479) * substring: String Functions. (line 479) * Sumner, Andrew: Other Versions. (line 64) -* supplementary groups of gawk process: Auto-set. (line 229) +* supplementary groups of gawk process: Auto-set. (line 233) * switch statement: Switch Statement. (line 6) -* SYMTAB array: Auto-set. (line 261) +* SYMTAB array: Auto-set. (line 265) * syntactic ambiguity: /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) * system: I/O Functions. (line 75) @@ -33943,10 +33947,10 @@ Index * variables, uninitialized, as array subscripts: Uninitialized Subscripts. (line 6) * variables, user-defined: Variables. (line 6) -* version of gawk: Auto-set. (line 199) -* version of gawk extension API: Auto-set. (line 224) -* version of GNU MP library: Auto-set. (line 210) -* version of GNU MPFR library: Auto-set. (line 206) +* version of gawk: Auto-set. (line 203) +* version of gawk extension API: Auto-set. (line 228) +* version of GNU MP library: Auto-set. (line 214) +* version of GNU MPFR library: Auto-set. (line 210) * vertical bar (|): Regexp Operators. (line 70) * vertical bar (|), | operator (I/O) <1>: Precedence. (line 65) * vertical bar (|), | operator (I/O): Getline/Pipe. (line 9) @@ -34231,355 +34235,355 @@ Node: Built-in Variables426497 Node: User-modified427624 Ref: User-modified-Footnote-1435313 Node: Auto-set435375 -Ref: Auto-set-Footnote-1447957 -Ref: Auto-set-Footnote-2448162 -Node: ARGC and ARGV448218 -Node: Pattern Action Summary452122 -Node: Arrays454345 -Node: Array Basics455894 -Node: Array Intro456720 -Ref: figure-array-elements458693 -Ref: Array Intro-Footnote-1461217 -Node: Reference to Elements461345 -Node: Assigning Elements463795 -Node: Array Example464286 -Node: Scanning an Array466018 -Node: Controlling Scanning469019 -Ref: Controlling Scanning-Footnote-1474192 -Node: Delete474508 -Ref: Delete-Footnote-1477259 -Node: Numeric Array Subscripts477316 -Node: Uninitialized Subscripts479499 -Node: Multidimensional481126 -Node: Multiscanning484239 -Node: Arrays of Arrays485828 -Node: Arrays Summary490491 -Node: Functions492596 -Node: Built-in493469 -Node: Calling Built-in494547 -Node: Numeric Functions496535 -Ref: Numeric Functions-Footnote-1500569 -Ref: Numeric Functions-Footnote-2500926 -Ref: Numeric Functions-Footnote-3500974 -Node: String Functions501243 -Ref: String Functions-Footnote-1524240 -Ref: String Functions-Footnote-2524369 -Ref: String Functions-Footnote-3524617 -Node: Gory Details524704 -Ref: table-sub-escapes526477 -Ref: table-sub-proposed527997 -Ref: table-posix-sub529361 -Ref: table-gensub-escapes530901 -Ref: Gory Details-Footnote-1532077 -Node: I/O Functions532228 -Ref: I/O Functions-Footnote-1539338 -Node: Time Functions539485 -Ref: Time Functions-Footnote-1549949 -Ref: Time Functions-Footnote-2550017 -Ref: Time Functions-Footnote-3550175 -Ref: Time Functions-Footnote-4550286 -Ref: Time Functions-Footnote-5550398 -Ref: Time Functions-Footnote-6550625 -Node: Bitwise Functions550891 -Ref: table-bitwise-ops551453 -Ref: Bitwise Functions-Footnote-1555698 -Node: Type Functions555882 -Node: I18N Functions557024 -Node: User-defined558669 -Node: Definition Syntax559473 -Ref: Definition Syntax-Footnote-1564786 -Node: Function Example564855 -Ref: Function Example-Footnote-1567495 -Node: Function Caveats567517 -Node: Calling A Function568035 -Node: Variable Scope568990 -Node: Pass By Value/Reference571978 -Node: Return Statement575488 -Node: Dynamic Typing578472 -Node: Indirect Calls579401 -Ref: Indirect Calls-Footnote-1589117 -Node: Functions Summary589245 -Node: Library Functions591895 -Ref: Library Functions-Footnote-1595513 -Ref: Library Functions-Footnote-2595656 -Node: Library Names595827 -Ref: Library Names-Footnote-1599300 -Ref: Library Names-Footnote-2599520 -Node: General Functions599606 -Node: Strtonum Function600634 -Node: Assert Function603508 -Node: Round Function606834 -Node: Cliff Random Function608375 -Node: Ordinal Functions609391 -Ref: Ordinal Functions-Footnote-1612456 -Ref: Ordinal Functions-Footnote-2612708 -Node: Join Function612919 -Ref: Join Function-Footnote-1614690 -Node: Getlocaltime Function614890 -Node: Readfile Function618626 -Node: Data File Management620465 -Node: Filetrans Function621097 -Node: Rewind Function625166 -Node: File Checking626724 -Ref: File Checking-Footnote-1627856 -Node: Empty Files628057 -Node: Ignoring Assigns630036 -Node: Getopt Function631590 -Ref: Getopt Function-Footnote-1642854 -Node: Passwd Functions643057 -Ref: Passwd Functions-Footnote-1652036 -Node: Group Functions652124 -Ref: Group Functions-Footnote-1660055 -Node: Walking Arrays660268 -Node: Library Functions Summary661871 -Node: Library Exercises663259 -Node: Sample Programs664539 -Node: Running Examples665309 -Node: Clones666037 -Node: Cut Program667261 -Node: Egrep Program677119 -Ref: Egrep Program-Footnote-1684706 -Node: Id Program684816 -Node: Split Program688470 -Ref: Split Program-Footnote-1692008 -Node: Tee Program692136 -Node: Uniq Program694923 -Node: Wc Program702346 -Ref: Wc Program-Footnote-1706611 -Node: Miscellaneous Programs706703 -Node: Dupword Program707916 -Node: Alarm Program709947 -Node: Translate Program714751 -Ref: Translate Program-Footnote-1719142 -Ref: Translate Program-Footnote-2719412 -Node: Labels Program719551 -Ref: Labels Program-Footnote-1722912 -Node: Word Sorting722996 -Node: History Sorting727039 -Node: Extract Program728875 -Node: Simple Sed736411 -Node: Igawk Program739473 -Ref: Igawk Program-Footnote-1753777 -Ref: Igawk Program-Footnote-2753978 -Node: Anagram Program754116 -Node: Signature Program757184 -Node: Programs Summary758431 -Node: Programs Exercises759646 -Ref: Programs Exercises-Footnote-1764033 -Node: Advanced Features764124 -Node: Nondecimal Data766072 -Node: Array Sorting767649 -Node: Controlling Array Traversal768346 -Node: Array Sorting Functions776626 -Ref: Array Sorting Functions-Footnote-1780533 -Node: Two-way I/O780727 -Ref: Two-way I/O-Footnote-1785671 -Ref: Two-way I/O-Footnote-2785850 -Node: TCP/IP Networking785932 -Node: Profiling788777 -Node: Advanced Features Summary796319 -Node: Internationalization798183 -Node: I18N and L10N799663 -Node: Explaining gettext800349 -Ref: Explaining gettext-Footnote-1805375 -Ref: Explaining gettext-Footnote-2805559 -Node: Programmer i18n805724 -Ref: Programmer i18n-Footnote-1810518 -Node: Translator i18n810567 -Node: String Extraction811361 -Ref: String Extraction-Footnote-1812494 -Node: Printf Ordering812580 -Ref: Printf Ordering-Footnote-1815362 -Node: I18N Portability815426 -Ref: I18N Portability-Footnote-1817875 -Node: I18N Example817938 -Ref: I18N Example-Footnote-1820644 -Node: Gawk I18N820716 -Node: I18N Summary821354 -Node: Debugger822693 -Node: Debugging823715 -Node: Debugging Concepts824156 -Node: Debugging Terms826012 -Node: Awk Debugging828609 -Node: Sample Debugging Session829501 -Node: Debugger Invocation830021 -Node: Finding The Bug831357 -Node: List of Debugger Commands837836 -Node: Breakpoint Control839168 -Node: Debugger Execution Control842832 -Node: Viewing And Changing Data846192 -Node: Execution Stack849550 -Node: Debugger Info851063 -Node: Miscellaneous Debugger Commands855057 -Node: Readline Support860241 -Node: Limitations861133 -Node: Debugging Summary863406 -Node: Arbitrary Precision Arithmetic864574 -Node: Computer Arithmetic866061 -Ref: Computer Arithmetic-Footnote-1870448 -Node: Math Definitions870505 -Ref: table-ieee-formats873794 -Ref: Math Definitions-Footnote-1874334 -Node: MPFR features874437 -Node: FP Math Caution876054 -Ref: FP Math Caution-Footnote-1877104 -Node: Inexactness of computations877473 -Node: Inexact representation878421 -Node: Comparing FP Values879776 -Node: Errors accumulate880740 -Node: Getting Accuracy882173 -Node: Try To Round884832 -Node: Setting precision885731 -Ref: table-predefined-precision-strings886413 -Node: Setting the rounding mode888206 -Ref: table-gawk-rounding-modes888570 -Ref: Setting the rounding mode-Footnote-1892024 -Node: Arbitrary Precision Integers892203 -Ref: Arbitrary Precision Integers-Footnote-1895184 -Node: POSIX Floating Point Problems895333 -Ref: POSIX Floating Point Problems-Footnote-1899209 -Node: Floating point summary899247 -Node: Dynamic Extensions901451 -Node: Extension Intro903003 -Node: Plugin License904268 -Node: Extension Mechanism Outline904953 -Ref: figure-load-extension905377 -Ref: figure-load-new-function906862 -Ref: figure-call-new-function907864 -Node: Extension API Description909848 -Node: Extension API Functions Introduction911298 -Node: General Data Types916165 -Ref: General Data Types-Footnote-1921858 -Node: Requesting Values922157 -Ref: table-value-types-returned922894 -Node: Memory Allocation Functions923852 -Ref: Memory Allocation Functions-Footnote-1926599 -Node: Constructor Functions926695 -Node: Registration Functions928453 -Node: Extension Functions929138 -Node: Exit Callback Functions931440 -Node: Extension Version String932688 -Node: Input Parsers933338 -Node: Output Wrappers943152 -Node: Two-way processors947668 -Node: Printing Messages949872 -Ref: Printing Messages-Footnote-1950949 -Node: Updating `ERRNO'951101 -Node: Accessing Parameters951840 -Node: Symbol Table Access953070 -Node: Symbol table by name953584 -Node: Symbol table by cookie955560 -Ref: Symbol table by cookie-Footnote-1959693 -Node: Cached values959756 -Ref: Cached values-Footnote-1963260 -Node: Array Manipulation963351 -Ref: Array Manipulation-Footnote-1964449 -Node: Array Data Types964488 -Ref: Array Data Types-Footnote-1967191 -Node: Array Functions967283 -Node: Flattening Arrays971157 -Node: Creating Arrays978009 -Node: Extension API Variables982740 -Node: Extension Versioning983376 -Node: Extension API Informational Variables985277 -Node: Extension API Boilerplate986363 -Node: Finding Extensions990167 -Node: Extension Example990727 -Node: Internal File Description991457 -Node: Internal File Ops995548 -Ref: Internal File Ops-Footnote-11006980 -Node: Using Internal File Ops1007120 -Ref: Using Internal File Ops-Footnote-11009467 -Node: Extension Samples1009735 -Node: Extension Sample File Functions1011259 -Node: Extension Sample Fnmatch1018827 -Node: Extension Sample Fork1020309 -Node: Extension Sample Inplace1021522 -Node: Extension Sample Ord1023197 -Node: Extension Sample Readdir1024033 -Ref: table-readdir-file-types1024889 -Node: Extension Sample Revout1025688 -Node: Extension Sample Rev2way1026279 -Node: Extension Sample Read write array1027020 -Node: Extension Sample Readfile1028899 -Node: Extension Sample API Tests1029999 -Node: Extension Sample Time1030524 -Node: gawkextlib1031839 -Node: Extension summary1034652 -Node: Extension Exercises1038345 -Node: Language History1039067 -Node: V7/SVR3.11040710 -Node: SVR41043030 -Node: POSIX1044472 -Node: BTL1045858 -Node: POSIX/GNU1046592 -Node: Feature History1052308 -Node: Common Extensions1065399 -Node: Ranges and Locales1066711 -Ref: Ranges and Locales-Footnote-11071328 -Ref: Ranges and Locales-Footnote-21071355 -Ref: Ranges and Locales-Footnote-31071589 -Node: Contributors1071810 -Node: History summary1077235 -Node: Installation1078604 -Node: Gawk Distribution1079555 -Node: Getting1080039 -Node: Extracting1080863 -Node: Distribution contents1082505 -Node: Unix Installation1088222 -Node: Quick Installation1088839 -Node: Additional Configuration Options1091281 -Node: Configuration Philosophy1093019 -Node: Non-Unix Installation1095370 -Node: PC Installation1095828 -Node: PC Binary Installation1097139 -Node: PC Compiling1098987 -Ref: PC Compiling-Footnote-11101986 -Node: PC Testing1102091 -Node: PC Using1103267 -Node: Cygwin1107419 -Node: MSYS1108228 -Node: VMS Installation1108742 -Node: VMS Compilation1109538 -Ref: VMS Compilation-Footnote-11110760 -Node: VMS Dynamic Extensions1110818 -Node: VMS Installation Details1112191 -Node: VMS Running1114443 -Node: VMS GNV1117277 -Node: VMS Old Gawk1118000 -Node: Bugs1118470 -Node: Other Versions1122474 -Node: Installation summary1128701 -Node: Notes1129757 -Node: Compatibility Mode1130622 -Node: Additions1131404 -Node: Accessing The Source1132329 -Node: Adding Code1133765 -Node: New Ports1139943 -Node: Derived Files1144424 -Ref: Derived Files-Footnote-11149505 -Ref: Derived Files-Footnote-21149539 -Ref: Derived Files-Footnote-31150135 -Node: Future Extensions1150249 -Node: Implementation Limitations1150855 -Node: Extension Design1152103 -Node: Old Extension Problems1153257 -Ref: Old Extension Problems-Footnote-11154774 -Node: Extension New Mechanism Goals1154831 -Ref: Extension New Mechanism Goals-Footnote-11158191 -Node: Extension Other Design Decisions1158380 -Node: Extension Future Growth1160486 -Node: Old Extension Mechanism1161322 -Node: Notes summary1163084 -Node: Basic Concepts1164270 -Node: Basic High Level1164951 -Ref: figure-general-flow1165223 -Ref: figure-process-flow1165822 -Ref: Basic High Level-Footnote-11169051 -Node: Basic Data Typing1169236 -Node: Glossary1172564 -Node: Copying1197716 -Node: GNU Free Documentation License1235272 -Node: Index1260408 +Ref: Auto-set-Footnote-1448057 +Ref: Auto-set-Footnote-2448262 +Node: ARGC and ARGV448318 +Node: Pattern Action Summary452222 +Node: Arrays454445 +Node: Array Basics455994 +Node: Array Intro456820 +Ref: figure-array-elements458793 +Ref: Array Intro-Footnote-1461317 +Node: Reference to Elements461445 +Node: Assigning Elements463895 +Node: Array Example464386 +Node: Scanning an Array466118 +Node: Controlling Scanning469119 +Ref: Controlling Scanning-Footnote-1474292 +Node: Delete474608 +Ref: Delete-Footnote-1477359 +Node: Numeric Array Subscripts477416 +Node: Uninitialized Subscripts479599 +Node: Multidimensional481226 +Node: Multiscanning484339 +Node: Arrays of Arrays485928 +Node: Arrays Summary490591 +Node: Functions492696 +Node: Built-in493569 +Node: Calling Built-in494647 +Node: Numeric Functions496635 +Ref: Numeric Functions-Footnote-1500669 +Ref: Numeric Functions-Footnote-2501026 +Ref: Numeric Functions-Footnote-3501074 +Node: String Functions501343 +Ref: String Functions-Footnote-1524340 +Ref: String Functions-Footnote-2524469 +Ref: String Functions-Footnote-3524717 +Node: Gory Details524804 +Ref: table-sub-escapes526577 +Ref: table-sub-proposed528097 +Ref: table-posix-sub529461 +Ref: table-gensub-escapes531001 +Ref: Gory Details-Footnote-1532177 +Node: I/O Functions532328 +Ref: I/O Functions-Footnote-1539438 +Node: Time Functions539585 +Ref: Time Functions-Footnote-1550049 +Ref: Time Functions-Footnote-2550117 +Ref: Time Functions-Footnote-3550275 +Ref: Time Functions-Footnote-4550386 +Ref: Time Functions-Footnote-5550498 +Ref: Time Functions-Footnote-6550725 +Node: Bitwise Functions550991 +Ref: table-bitwise-ops551553 +Ref: Bitwise Functions-Footnote-1555798 +Node: Type Functions555982 +Node: I18N Functions557124 +Node: User-defined558769 +Node: Definition Syntax559573 +Ref: Definition Syntax-Footnote-1564886 +Node: Function Example564955 +Ref: Function Example-Footnote-1567595 +Node: Function Caveats567617 +Node: Calling A Function568135 +Node: Variable Scope569090 +Node: Pass By Value/Reference572078 +Node: Return Statement575588 +Node: Dynamic Typing578572 +Node: Indirect Calls579501 +Ref: Indirect Calls-Footnote-1589217 +Node: Functions Summary589345 +Node: Library Functions591995 +Ref: Library Functions-Footnote-1595613 +Ref: Library Functions-Footnote-2595756 +Node: Library Names595927 +Ref: Library Names-Footnote-1599400 +Ref: Library Names-Footnote-2599620 +Node: General Functions599706 +Node: Strtonum Function600734 +Node: Assert Function603608 +Node: Round Function606934 +Node: Cliff Random Function608475 +Node: Ordinal Functions609491 +Ref: Ordinal Functions-Footnote-1612556 +Ref: Ordinal Functions-Footnote-2612808 +Node: Join Function613019 +Ref: Join Function-Footnote-1614790 +Node: Getlocaltime Function614990 +Node: Readfile Function618726 +Node: Data File Management620565 +Node: Filetrans Function621197 +Node: Rewind Function625266 +Node: File Checking626824 +Ref: File Checking-Footnote-1627956 +Node: Empty Files628157 +Node: Ignoring Assigns630136 +Node: Getopt Function631690 +Ref: Getopt Function-Footnote-1642954 +Node: Passwd Functions643157 +Ref: Passwd Functions-Footnote-1652136 +Node: Group Functions652224 +Ref: Group Functions-Footnote-1660155 +Node: Walking Arrays660368 +Node: Library Functions Summary661971 +Node: Library Exercises663359 +Node: Sample Programs664639 +Node: Running Examples665409 +Node: Clones666137 +Node: Cut Program667361 +Node: Egrep Program677219 +Ref: Egrep Program-Footnote-1684806 +Node: Id Program684916 +Node: Split Program688570 +Ref: Split Program-Footnote-1692108 +Node: Tee Program692236 +Node: Uniq Program695023 +Node: Wc Program702446 +Ref: Wc Program-Footnote-1706711 +Node: Miscellaneous Programs706803 +Node: Dupword Program708016 +Node: Alarm Program710047 +Node: Translate Program714851 +Ref: Translate Program-Footnote-1719242 +Ref: Translate Program-Footnote-2719512 +Node: Labels Program719651 +Ref: Labels Program-Footnote-1723012 +Node: Word Sorting723096 +Node: History Sorting727139 +Node: Extract Program728975 +Node: Simple Sed736511 +Node: Igawk Program739573 +Ref: Igawk Program-Footnote-1753877 +Ref: Igawk Program-Footnote-2754078 +Node: Anagram Program754216 +Node: Signature Program757284 +Node: Programs Summary758531 +Node: Programs Exercises759746 +Ref: Programs Exercises-Footnote-1764133 +Node: Advanced Features764224 +Node: Nondecimal Data766172 +Node: Array Sorting767749 +Node: Controlling Array Traversal768446 +Node: Array Sorting Functions776726 +Ref: Array Sorting Functions-Footnote-1780633 +Node: Two-way I/O780827 +Ref: Two-way I/O-Footnote-1785771 +Ref: Two-way I/O-Footnote-2785950 +Node: TCP/IP Networking786032 +Node: Profiling788877 +Node: Advanced Features Summary796419 +Node: Internationalization798283 +Node: I18N and L10N799763 +Node: Explaining gettext800449 +Ref: Explaining gettext-Footnote-1805475 +Ref: Explaining gettext-Footnote-2805659 +Node: Programmer i18n805824 +Ref: Programmer i18n-Footnote-1810618 +Node: Translator i18n810667 +Node: String Extraction811461 +Ref: String Extraction-Footnote-1812594 +Node: Printf Ordering812680 +Ref: Printf Ordering-Footnote-1815462 +Node: I18N Portability815526 +Ref: I18N Portability-Footnote-1817975 +Node: I18N Example818038 +Ref: I18N Example-Footnote-1820744 +Node: Gawk I18N820816 +Node: I18N Summary821454 +Node: Debugger822793 +Node: Debugging823815 +Node: Debugging Concepts824256 +Node: Debugging Terms826112 +Node: Awk Debugging828709 +Node: Sample Debugging Session829601 +Node: Debugger Invocation830121 +Node: Finding The Bug831457 +Node: List of Debugger Commands837936 +Node: Breakpoint Control839268 +Node: Debugger Execution Control842932 +Node: Viewing And Changing Data846292 +Node: Execution Stack849650 +Node: Debugger Info851163 +Node: Miscellaneous Debugger Commands855157 +Node: Readline Support860341 +Node: Limitations861233 +Node: Debugging Summary863506 +Node: Arbitrary Precision Arithmetic864674 +Node: Computer Arithmetic866161 +Ref: Computer Arithmetic-Footnote-1870548 +Node: Math Definitions870605 +Ref: table-ieee-formats873894 +Ref: Math Definitions-Footnote-1874434 +Node: MPFR features874537 +Node: FP Math Caution876154 +Ref: FP Math Caution-Footnote-1877204 +Node: Inexactness of computations877573 +Node: Inexact representation878521 +Node: Comparing FP Values879876 +Node: Errors accumulate880840 +Node: Getting Accuracy882273 +Node: Try To Round884932 +Node: Setting precision885831 +Ref: table-predefined-precision-strings886513 +Node: Setting the rounding mode888306 +Ref: table-gawk-rounding-modes888670 +Ref: Setting the rounding mode-Footnote-1892124 +Node: Arbitrary Precision Integers892303 +Ref: Arbitrary Precision Integers-Footnote-1895284 +Node: POSIX Floating Point Problems895433 +Ref: POSIX Floating Point Problems-Footnote-1899309 +Node: Floating point summary899347 +Node: Dynamic Extensions901551 +Node: Extension Intro903103 +Node: Plugin License904368 +Node: Extension Mechanism Outline905053 +Ref: figure-load-extension905477 +Ref: figure-load-new-function906962 +Ref: figure-call-new-function907964 +Node: Extension API Description909948 +Node: Extension API Functions Introduction911398 +Node: General Data Types916265 +Ref: General Data Types-Footnote-1921958 +Node: Requesting Values922257 +Ref: table-value-types-returned922994 +Node: Memory Allocation Functions923952 +Ref: Memory Allocation Functions-Footnote-1926699 +Node: Constructor Functions926795 +Node: Registration Functions928553 +Node: Extension Functions929238 +Node: Exit Callback Functions931540 +Node: Extension Version String932788 +Node: Input Parsers933438 +Node: Output Wrappers943252 +Node: Two-way processors947768 +Node: Printing Messages949972 +Ref: Printing Messages-Footnote-1951049 +Node: Updating `ERRNO'951201 +Node: Accessing Parameters951940 +Node: Symbol Table Access953170 +Node: Symbol table by name953684 +Node: Symbol table by cookie955660 +Ref: Symbol table by cookie-Footnote-1959793 +Node: Cached values959856 +Ref: Cached values-Footnote-1963360 +Node: Array Manipulation963451 +Ref: Array Manipulation-Footnote-1964549 +Node: Array Data Types964588 +Ref: Array Data Types-Footnote-1967291 +Node: Array Functions967383 +Node: Flattening Arrays971257 +Node: Creating Arrays978109 +Node: Extension API Variables982840 +Node: Extension Versioning983476 +Node: Extension API Informational Variables985377 +Node: Extension API Boilerplate986463 +Node: Finding Extensions990267 +Node: Extension Example990827 +Node: Internal File Description991557 +Node: Internal File Ops995648 +Ref: Internal File Ops-Footnote-11007080 +Node: Using Internal File Ops1007220 +Ref: Using Internal File Ops-Footnote-11009567 +Node: Extension Samples1009835 +Node: Extension Sample File Functions1011359 +Node: Extension Sample Fnmatch1018927 +Node: Extension Sample Fork1020409 +Node: Extension Sample Inplace1021622 +Node: Extension Sample Ord1023297 +Node: Extension Sample Readdir1024133 +Ref: table-readdir-file-types1024989 +Node: Extension Sample Revout1025788 +Node: Extension Sample Rev2way1026379 +Node: Extension Sample Read write array1027120 +Node: Extension Sample Readfile1028999 +Node: Extension Sample API Tests1030099 +Node: Extension Sample Time1030624 +Node: gawkextlib1031939 +Node: Extension summary1034752 +Node: Extension Exercises1038445 +Node: Language History1039167 +Node: V7/SVR3.11040810 +Node: SVR41043130 +Node: POSIX1044572 +Node: BTL1045958 +Node: POSIX/GNU1046692 +Node: Feature History1052408 +Node: Common Extensions1065499 +Node: Ranges and Locales1066811 +Ref: Ranges and Locales-Footnote-11071428 +Ref: Ranges and Locales-Footnote-21071455 +Ref: Ranges and Locales-Footnote-31071689 +Node: Contributors1071910 +Node: History summary1077335 +Node: Installation1078704 +Node: Gawk Distribution1079655 +Node: Getting1080139 +Node: Extracting1080963 +Node: Distribution contents1082605 +Node: Unix Installation1088322 +Node: Quick Installation1088939 +Node: Additional Configuration Options1091381 +Node: Configuration Philosophy1093119 +Node: Non-Unix Installation1095470 +Node: PC Installation1095928 +Node: PC Binary Installation1097239 +Node: PC Compiling1099087 +Ref: PC Compiling-Footnote-11102086 +Node: PC Testing1102191 +Node: PC Using1103367 +Node: Cygwin1107519 +Node: MSYS1108328 +Node: VMS Installation1108842 +Node: VMS Compilation1109638 +Ref: VMS Compilation-Footnote-11110860 +Node: VMS Dynamic Extensions1110918 +Node: VMS Installation Details1112291 +Node: VMS Running1114543 +Node: VMS GNV1117377 +Node: VMS Old Gawk1118100 +Node: Bugs1118570 +Node: Other Versions1122574 +Node: Installation summary1128801 +Node: Notes1129857 +Node: Compatibility Mode1130722 +Node: Additions1131504 +Node: Accessing The Source1132429 +Node: Adding Code1133865 +Node: New Ports1140043 +Node: Derived Files1144524 +Ref: Derived Files-Footnote-11149605 +Ref: Derived Files-Footnote-21149639 +Ref: Derived Files-Footnote-31150235 +Node: Future Extensions1150349 +Node: Implementation Limitations1150955 +Node: Extension Design1152203 +Node: Old Extension Problems1153357 +Ref: Old Extension Problems-Footnote-11154874 +Node: Extension New Mechanism Goals1154931 +Ref: Extension New Mechanism Goals-Footnote-11158291 +Node: Extension Other Design Decisions1158480 +Node: Extension Future Growth1160586 +Node: Old Extension Mechanism1161422 +Node: Notes summary1163184 +Node: Basic Concepts1164370 +Node: Basic High Level1165051 +Ref: figure-general-flow1165323 +Ref: figure-process-flow1165922 +Ref: Basic High Level-Footnote-11169151 +Node: Basic Data Typing1169336 +Node: Glossary1172664 +Node: Copying1197816 +Node: GNU Free Documentation License1235372 +Node: Index1260508  End Tag Table -- cgit v1.2.3 From 4e463bfa0ca3d2e317a0d6afe0badd6b7ee4a001 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Fri, 5 Sep 2014 14:46:19 +0300 Subject: More reviewer comments. --- doc/gawk.info | 501 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 250 insertions(+), 251 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 0d7505a5..1ae776a6 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -17646,6 +17646,10 @@ array only once, in a `BEGIN' rule. However, this assumes that the "from" and "to" lists will never change throughout the lifetime of the program. + Another obvious improvement is to enable the use of ranges, such as +`a-z', as allowed by the `tr' utility. Look at the code for `cut.awk' +(*note Cut Program::) for inspiration. + ---------- Footnotes ---------- (1) On some older systems, including Solaris, the system version of @@ -18740,18 +18744,13 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample Program::) to accept the same arguments and perform in the same way. - 4. The `split.awk' program (*note Split Program::) uses the `chr()' - and `ord()' functions to move through the letters of the alphabet. - Modify the program to instead use only the `awk' built-in - functions, such as `index()' and `substr()'. - - 5. The `split.awk' program (*note Split Program::) assumes that + 4. The `split.awk' program (*note Split Program::) assumes that letters are contiguous in the character set, which isn't true for EBCDIC systems. Fix this problem. (Hint: Consider a different way to work through the alphabet, without relying on `ord()' and `chr()'.) - 6. In `uniq.awk' (*note Uniq Program::, the logic for choosing which + 5. In `uniq.awk' (*note Uniq Program::, the logic for choosing which lines to print represents a "state machine", which is "a device that can be in one of a set number of stable conditions depending on its previous condition and on the present values of its @@ -18761,21 +18760,21 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample where you would use this, just as fast." Rewrite the logic to follow this suggestion. - 7. Why can't the `wc.awk' program (*note Wc Program::) just use the + 6. Why can't the `wc.awk' program (*note Wc Program::) just use the value of `FNR' in `endfile()'? Hint: Examine the code in *note Filetrans Function::. - 8. Manipulation of individual characters in the `translate' program + 7. Manipulation of individual characters in the `translate' program (*note Translate Program::) is painful using standard `awk' functions. Given that `gawk' can split strings into individual characters using `""' as the separator, how might you use this feature to simplify the program? - 9. The `extract.awk' program (*note Extract Program::) was written + 8. The `extract.awk' program (*note Extract Program::) was written before `gawk' had the `gensub()' function. Use it to simplify the code. - 10. Compare the performance of the `awksed.awk' program (*note Simple + 9. Compare the performance of the `awksed.awk' program (*note Simple Sed::) with the more straightforward: BEGIN { @@ -18786,16 +18785,16 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample { gsub(pat, repl); print } - 11. What are the advantages and disadvantages of `awksed.awk' versus + 10. What are the advantages and disadvantages of `awksed.awk' versus the real `sed' utility? - 12. In *note Igawk Program::, we mentioned that not trying to save the + 11. In *note Igawk Program::, we mentioned that not trying to save the line read with `getline' in the `pathto()' function when testing for the file's accessibility for use with the main program simplifies things considerably. What problem does this engender though? - 13. As an additional example of the idea that it is not always + 12. As an additional example of the idea that it is not always necessary to add new features to a program, consider the idea of having two files in a directory in the search path: @@ -18818,7 +18817,7 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample `@include' statements for the desired library functions. Make this change. - 14. Modify `anagram.awk' (*note Anagram Program::), to avoid the use + 13. Modify `anagram.awk' (*note Anagram Program::), to avoid the use of the external `sort' utility. @@ -32079,7 +32078,7 @@ Index (line 66) * directories, command-line: Command-line directories. (line 6) -* directories, searching: Programs Exercises. (line 75) +* directories, searching: Programs Exercises. (line 70) * directories, searching for loadable extensions: AWKLIBPATH Variable. (line 6) * directories, searching for source files: AWKPATH Variable. (line 6) @@ -32360,7 +32359,7 @@ Index * files, reading, multiline records: Multiple Line. (line 6) * files, searching for regular expressions: Egrep Program. (line 6) * files, skipping: File Checking. (line 6) -* files, source, search path for: Programs Exercises. (line 75) +* files, source, search path for: Programs Exercises. (line 70) * files, splitting: Split Program. (line 6) * files, Texinfo, extracting programs from: Extract Program. (line 6) * find substring in string: String Functions. (line 155) @@ -33528,11 +33527,11 @@ Index * search in string: String Functions. (line 155) * search paths <1>: VMS Running. (line 58) * search paths <2>: PC Using. (line 10) -* search paths: Programs Exercises. (line 75) +* search paths: Programs Exercises. (line 70) * search paths, for loadable extensions: AWKLIBPATH Variable. (line 6) * search paths, for source files <1>: VMS Running. (line 58) * search paths, for source files <2>: PC Using. (line 10) -* search paths, for source files <3>: Programs Exercises. (line 75) +* search paths, for source files <3>: Programs Exercises. (line 70) * search paths, for source files: AWKPATH Variable. (line 6) * searching, files for regular expressions: Egrep Program. (line 6) * searching, for words: Dupword Program. (line 6) @@ -33679,7 +33678,7 @@ Index * source code, QSE Awk: Other Versions. (line 131) * source code, QuikTrim Awk: Other Versions. (line 135) * source code, Solaris awk: Other Versions. (line 96) -* source files, search path for: Programs Exercises. (line 75) +* source files, search path for: Programs Exercises. (line 70) * sparse arrays: Array Intro. (line 72) * Spencer, Henry: Glossary. (line 11) * split: String Functions. (line 313) @@ -34354,236 +34353,236 @@ Node: Miscellaneous Programs706803 Node: Dupword Program708016 Node: Alarm Program710047 Node: Translate Program714851 -Ref: Translate Program-Footnote-1719242 -Ref: Translate Program-Footnote-2719512 -Node: Labels Program719651 -Ref: Labels Program-Footnote-1723012 -Node: Word Sorting723096 -Node: History Sorting727139 -Node: Extract Program728975 -Node: Simple Sed736511 -Node: Igawk Program739573 -Ref: Igawk Program-Footnote-1753877 -Ref: Igawk Program-Footnote-2754078 -Node: Anagram Program754216 -Node: Signature Program757284 -Node: Programs Summary758531 -Node: Programs Exercises759746 -Ref: Programs Exercises-Footnote-1764133 -Node: Advanced Features764224 -Node: Nondecimal Data766172 -Node: Array Sorting767749 -Node: Controlling Array Traversal768446 -Node: Array Sorting Functions776726 -Ref: Array Sorting Functions-Footnote-1780633 -Node: Two-way I/O780827 -Ref: Two-way I/O-Footnote-1785771 -Ref: Two-way I/O-Footnote-2785950 -Node: TCP/IP Networking786032 -Node: Profiling788877 -Node: Advanced Features Summary796419 -Node: Internationalization798283 -Node: I18N and L10N799763 -Node: Explaining gettext800449 -Ref: Explaining gettext-Footnote-1805475 -Ref: Explaining gettext-Footnote-2805659 -Node: Programmer i18n805824 -Ref: Programmer i18n-Footnote-1810618 -Node: Translator i18n810667 -Node: String Extraction811461 -Ref: String Extraction-Footnote-1812594 -Node: Printf Ordering812680 -Ref: Printf Ordering-Footnote-1815462 -Node: I18N Portability815526 -Ref: I18N Portability-Footnote-1817975 -Node: I18N Example818038 -Ref: I18N Example-Footnote-1820744 -Node: Gawk I18N820816 -Node: I18N Summary821454 -Node: Debugger822793 -Node: Debugging823815 -Node: Debugging Concepts824256 -Node: Debugging Terms826112 -Node: Awk Debugging828709 -Node: Sample Debugging Session829601 -Node: Debugger Invocation830121 -Node: Finding The Bug831457 -Node: List of Debugger Commands837936 -Node: Breakpoint Control839268 -Node: Debugger Execution Control842932 -Node: Viewing And Changing Data846292 -Node: Execution Stack849650 -Node: Debugger Info851163 -Node: Miscellaneous Debugger Commands855157 -Node: Readline Support860341 -Node: Limitations861233 -Node: Debugging Summary863506 -Node: Arbitrary Precision Arithmetic864674 -Node: Computer Arithmetic866161 -Ref: Computer Arithmetic-Footnote-1870548 -Node: Math Definitions870605 -Ref: table-ieee-formats873894 -Ref: Math Definitions-Footnote-1874434 -Node: MPFR features874537 -Node: FP Math Caution876154 -Ref: FP Math Caution-Footnote-1877204 -Node: Inexactness of computations877573 -Node: Inexact representation878521 -Node: Comparing FP Values879876 -Node: Errors accumulate880840 -Node: Getting Accuracy882273 -Node: Try To Round884932 -Node: Setting precision885831 -Ref: table-predefined-precision-strings886513 -Node: Setting the rounding mode888306 -Ref: table-gawk-rounding-modes888670 -Ref: Setting the rounding mode-Footnote-1892124 -Node: Arbitrary Precision Integers892303 -Ref: Arbitrary Precision Integers-Footnote-1895284 -Node: POSIX Floating Point Problems895433 -Ref: POSIX Floating Point Problems-Footnote-1899309 -Node: Floating point summary899347 -Node: Dynamic Extensions901551 -Node: Extension Intro903103 -Node: Plugin License904368 -Node: Extension Mechanism Outline905053 -Ref: figure-load-extension905477 -Ref: figure-load-new-function906962 -Ref: figure-call-new-function907964 -Node: Extension API Description909948 -Node: Extension API Functions Introduction911398 -Node: General Data Types916265 -Ref: General Data Types-Footnote-1921958 -Node: Requesting Values922257 -Ref: table-value-types-returned922994 -Node: Memory Allocation Functions923952 -Ref: Memory Allocation Functions-Footnote-1926699 -Node: Constructor Functions926795 -Node: Registration Functions928553 -Node: Extension Functions929238 -Node: Exit Callback Functions931540 -Node: Extension Version String932788 -Node: Input Parsers933438 -Node: Output Wrappers943252 -Node: Two-way processors947768 -Node: Printing Messages949972 -Ref: Printing Messages-Footnote-1951049 -Node: Updating `ERRNO'951201 -Node: Accessing Parameters951940 -Node: Symbol Table Access953170 -Node: Symbol table by name953684 -Node: Symbol table by cookie955660 -Ref: Symbol table by cookie-Footnote-1959793 -Node: Cached values959856 -Ref: Cached values-Footnote-1963360 -Node: Array Manipulation963451 -Ref: Array Manipulation-Footnote-1964549 -Node: Array Data Types964588 -Ref: Array Data Types-Footnote-1967291 -Node: Array Functions967383 -Node: Flattening Arrays971257 -Node: Creating Arrays978109 -Node: Extension API Variables982840 -Node: Extension Versioning983476 -Node: Extension API Informational Variables985377 -Node: Extension API Boilerplate986463 -Node: Finding Extensions990267 -Node: Extension Example990827 -Node: Internal File Description991557 -Node: Internal File Ops995648 -Ref: Internal File Ops-Footnote-11007080 -Node: Using Internal File Ops1007220 -Ref: Using Internal File Ops-Footnote-11009567 -Node: Extension Samples1009835 -Node: Extension Sample File Functions1011359 -Node: Extension Sample Fnmatch1018927 -Node: Extension Sample Fork1020409 -Node: Extension Sample Inplace1021622 -Node: Extension Sample Ord1023297 -Node: Extension Sample Readdir1024133 -Ref: table-readdir-file-types1024989 -Node: Extension Sample Revout1025788 -Node: Extension Sample Rev2way1026379 -Node: Extension Sample Read write array1027120 -Node: Extension Sample Readfile1028999 -Node: Extension Sample API Tests1030099 -Node: Extension Sample Time1030624 -Node: gawkextlib1031939 -Node: Extension summary1034752 -Node: Extension Exercises1038445 -Node: Language History1039167 -Node: V7/SVR3.11040810 -Node: SVR41043130 -Node: POSIX1044572 -Node: BTL1045958 -Node: POSIX/GNU1046692 -Node: Feature History1052408 -Node: Common Extensions1065499 -Node: Ranges and Locales1066811 -Ref: Ranges and Locales-Footnote-11071428 -Ref: Ranges and Locales-Footnote-21071455 -Ref: Ranges and Locales-Footnote-31071689 -Node: Contributors1071910 -Node: History summary1077335 -Node: Installation1078704 -Node: Gawk Distribution1079655 -Node: Getting1080139 -Node: Extracting1080963 -Node: Distribution contents1082605 -Node: Unix Installation1088322 -Node: Quick Installation1088939 -Node: Additional Configuration Options1091381 -Node: Configuration Philosophy1093119 -Node: Non-Unix Installation1095470 -Node: PC Installation1095928 -Node: PC Binary Installation1097239 -Node: PC Compiling1099087 -Ref: PC Compiling-Footnote-11102086 -Node: PC Testing1102191 -Node: PC Using1103367 -Node: Cygwin1107519 -Node: MSYS1108328 -Node: VMS Installation1108842 -Node: VMS Compilation1109638 -Ref: VMS Compilation-Footnote-11110860 -Node: VMS Dynamic Extensions1110918 -Node: VMS Installation Details1112291 -Node: VMS Running1114543 -Node: VMS GNV1117377 -Node: VMS Old Gawk1118100 -Node: Bugs1118570 -Node: Other Versions1122574 -Node: Installation summary1128801 -Node: Notes1129857 -Node: Compatibility Mode1130722 -Node: Additions1131504 -Node: Accessing The Source1132429 -Node: Adding Code1133865 -Node: New Ports1140043 -Node: Derived Files1144524 -Ref: Derived Files-Footnote-11149605 -Ref: Derived Files-Footnote-21149639 -Ref: Derived Files-Footnote-31150235 -Node: Future Extensions1150349 -Node: Implementation Limitations1150955 -Node: Extension Design1152203 -Node: Old Extension Problems1153357 -Ref: Old Extension Problems-Footnote-11154874 -Node: Extension New Mechanism Goals1154931 -Ref: Extension New Mechanism Goals-Footnote-11158291 -Node: Extension Other Design Decisions1158480 -Node: Extension Future Growth1160586 -Node: Old Extension Mechanism1161422 -Node: Notes summary1163184 -Node: Basic Concepts1164370 -Node: Basic High Level1165051 -Ref: figure-general-flow1165323 -Ref: figure-process-flow1165922 -Ref: Basic High Level-Footnote-11169151 -Node: Basic Data Typing1169336 -Node: Glossary1172664 -Node: Copying1197816 -Node: GNU Free Documentation License1235372 -Node: Index1260508 +Ref: Translate Program-Footnote-1719424 +Ref: Translate Program-Footnote-2719694 +Node: Labels Program719833 +Ref: Labels Program-Footnote-1723194 +Node: Word Sorting723278 +Node: History Sorting727321 +Node: Extract Program729157 +Node: Simple Sed736693 +Node: Igawk Program739755 +Ref: Igawk Program-Footnote-1754059 +Ref: Igawk Program-Footnote-2754260 +Node: Anagram Program754398 +Node: Signature Program757466 +Node: Programs Summary758713 +Node: Programs Exercises759928 +Ref: Programs Exercises-Footnote-1764059 +Node: Advanced Features764150 +Node: Nondecimal Data766098 +Node: Array Sorting767675 +Node: Controlling Array Traversal768372 +Node: Array Sorting Functions776652 +Ref: Array Sorting Functions-Footnote-1780559 +Node: Two-way I/O780753 +Ref: Two-way I/O-Footnote-1785697 +Ref: Two-way I/O-Footnote-2785876 +Node: TCP/IP Networking785958 +Node: Profiling788803 +Node: Advanced Features Summary796345 +Node: Internationalization798209 +Node: I18N and L10N799689 +Node: Explaining gettext800375 +Ref: Explaining gettext-Footnote-1805401 +Ref: Explaining gettext-Footnote-2805585 +Node: Programmer i18n805750 +Ref: Programmer i18n-Footnote-1810544 +Node: Translator i18n810593 +Node: String Extraction811387 +Ref: String Extraction-Footnote-1812520 +Node: Printf Ordering812606 +Ref: Printf Ordering-Footnote-1815388 +Node: I18N Portability815452 +Ref: I18N Portability-Footnote-1817901 +Node: I18N Example817964 +Ref: I18N Example-Footnote-1820670 +Node: Gawk I18N820742 +Node: I18N Summary821380 +Node: Debugger822719 +Node: Debugging823741 +Node: Debugging Concepts824182 +Node: Debugging Terms826038 +Node: Awk Debugging828635 +Node: Sample Debugging Session829527 +Node: Debugger Invocation830047 +Node: Finding The Bug831383 +Node: List of Debugger Commands837862 +Node: Breakpoint Control839194 +Node: Debugger Execution Control842858 +Node: Viewing And Changing Data846218 +Node: Execution Stack849576 +Node: Debugger Info851089 +Node: Miscellaneous Debugger Commands855083 +Node: Readline Support860267 +Node: Limitations861159 +Node: Debugging Summary863432 +Node: Arbitrary Precision Arithmetic864600 +Node: Computer Arithmetic866087 +Ref: Computer Arithmetic-Footnote-1870474 +Node: Math Definitions870531 +Ref: table-ieee-formats873820 +Ref: Math Definitions-Footnote-1874360 +Node: MPFR features874463 +Node: FP Math Caution876080 +Ref: FP Math Caution-Footnote-1877130 +Node: Inexactness of computations877499 +Node: Inexact representation878447 +Node: Comparing FP Values879802 +Node: Errors accumulate880766 +Node: Getting Accuracy882199 +Node: Try To Round884858 +Node: Setting precision885757 +Ref: table-predefined-precision-strings886439 +Node: Setting the rounding mode888232 +Ref: table-gawk-rounding-modes888596 +Ref: Setting the rounding mode-Footnote-1892050 +Node: Arbitrary Precision Integers892229 +Ref: Arbitrary Precision Integers-Footnote-1895210 +Node: POSIX Floating Point Problems895359 +Ref: POSIX Floating Point Problems-Footnote-1899235 +Node: Floating point summary899273 +Node: Dynamic Extensions901477 +Node: Extension Intro903029 +Node: Plugin License904294 +Node: Extension Mechanism Outline904979 +Ref: figure-load-extension905403 +Ref: figure-load-new-function906888 +Ref: figure-call-new-function907890 +Node: Extension API Description909874 +Node: Extension API Functions Introduction911324 +Node: General Data Types916191 +Ref: General Data Types-Footnote-1921884 +Node: Requesting Values922183 +Ref: table-value-types-returned922920 +Node: Memory Allocation Functions923878 +Ref: Memory Allocation Functions-Footnote-1926625 +Node: Constructor Functions926721 +Node: Registration Functions928479 +Node: Extension Functions929164 +Node: Exit Callback Functions931466 +Node: Extension Version String932714 +Node: Input Parsers933364 +Node: Output Wrappers943178 +Node: Two-way processors947694 +Node: Printing Messages949898 +Ref: Printing Messages-Footnote-1950975 +Node: Updating `ERRNO'951127 +Node: Accessing Parameters951866 +Node: Symbol Table Access953096 +Node: Symbol table by name953610 +Node: Symbol table by cookie955586 +Ref: Symbol table by cookie-Footnote-1959719 +Node: Cached values959782 +Ref: Cached values-Footnote-1963286 +Node: Array Manipulation963377 +Ref: Array Manipulation-Footnote-1964475 +Node: Array Data Types964514 +Ref: Array Data Types-Footnote-1967217 +Node: Array Functions967309 +Node: Flattening Arrays971183 +Node: Creating Arrays978035 +Node: Extension API Variables982766 +Node: Extension Versioning983402 +Node: Extension API Informational Variables985303 +Node: Extension API Boilerplate986389 +Node: Finding Extensions990193 +Node: Extension Example990753 +Node: Internal File Description991483 +Node: Internal File Ops995574 +Ref: Internal File Ops-Footnote-11007006 +Node: Using Internal File Ops1007146 +Ref: Using Internal File Ops-Footnote-11009493 +Node: Extension Samples1009761 +Node: Extension Sample File Functions1011285 +Node: Extension Sample Fnmatch1018853 +Node: Extension Sample Fork1020335 +Node: Extension Sample Inplace1021548 +Node: Extension Sample Ord1023223 +Node: Extension Sample Readdir1024059 +Ref: table-readdir-file-types1024915 +Node: Extension Sample Revout1025714 +Node: Extension Sample Rev2way1026305 +Node: Extension Sample Read write array1027046 +Node: Extension Sample Readfile1028925 +Node: Extension Sample API Tests1030025 +Node: Extension Sample Time1030550 +Node: gawkextlib1031865 +Node: Extension summary1034678 +Node: Extension Exercises1038371 +Node: Language History1039093 +Node: V7/SVR3.11040736 +Node: SVR41043056 +Node: POSIX1044498 +Node: BTL1045884 +Node: POSIX/GNU1046618 +Node: Feature History1052334 +Node: Common Extensions1065425 +Node: Ranges and Locales1066737 +Ref: Ranges and Locales-Footnote-11071354 +Ref: Ranges and Locales-Footnote-21071381 +Ref: Ranges and Locales-Footnote-31071615 +Node: Contributors1071836 +Node: History summary1077261 +Node: Installation1078630 +Node: Gawk Distribution1079581 +Node: Getting1080065 +Node: Extracting1080889 +Node: Distribution contents1082531 +Node: Unix Installation1088248 +Node: Quick Installation1088865 +Node: Additional Configuration Options1091307 +Node: Configuration Philosophy1093045 +Node: Non-Unix Installation1095396 +Node: PC Installation1095854 +Node: PC Binary Installation1097165 +Node: PC Compiling1099013 +Ref: PC Compiling-Footnote-11102012 +Node: PC Testing1102117 +Node: PC Using1103293 +Node: Cygwin1107445 +Node: MSYS1108254 +Node: VMS Installation1108768 +Node: VMS Compilation1109564 +Ref: VMS Compilation-Footnote-11110786 +Node: VMS Dynamic Extensions1110844 +Node: VMS Installation Details1112217 +Node: VMS Running1114469 +Node: VMS GNV1117303 +Node: VMS Old Gawk1118026 +Node: Bugs1118496 +Node: Other Versions1122500 +Node: Installation summary1128727 +Node: Notes1129783 +Node: Compatibility Mode1130648 +Node: Additions1131430 +Node: Accessing The Source1132355 +Node: Adding Code1133791 +Node: New Ports1139969 +Node: Derived Files1144450 +Ref: Derived Files-Footnote-11149531 +Ref: Derived Files-Footnote-21149565 +Ref: Derived Files-Footnote-31150161 +Node: Future Extensions1150275 +Node: Implementation Limitations1150881 +Node: Extension Design1152129 +Node: Old Extension Problems1153283 +Ref: Old Extension Problems-Footnote-11154800 +Node: Extension New Mechanism Goals1154857 +Ref: Extension New Mechanism Goals-Footnote-11158217 +Node: Extension Other Design Decisions1158406 +Node: Extension Future Growth1160512 +Node: Old Extension Mechanism1161348 +Node: Notes summary1163110 +Node: Basic Concepts1164296 +Node: Basic High Level1164977 +Ref: figure-general-flow1165249 +Ref: figure-process-flow1165848 +Ref: Basic High Level-Footnote-11169077 +Node: Basic Data Typing1169262 +Node: Glossary1172590 +Node: Copying1197742 +Node: GNU Free Documentation License1235298 +Node: Index1260434  End Tag Table -- cgit v1.2.3 From 9b21de890a81179e951ffa5bea2099673f584b16 Mon Sep 17 00:00:00 2001 From: Stephen Davies Date: Wed, 10 Sep 2014 15:49:13 +0930 Subject: gawk.info? --- doc/gawk.info | 25168 ++++++++++++++++++++++++++++---------------------------- 1 file changed, 12580 insertions(+), 12588 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 076a2f34..ec16647a 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1,19 +1,10 @@ -This is gawk.info, produced by makeinfo version 4.13 from gawk.texi. +This is gawk.info, produced by makeinfo version 5.1 from gawk.texi. -INFO-DIR-SECTION Text creation and manipulation -START-INFO-DIR-ENTRY -* Gawk: (gawk). A text scanning and processing language. -END-INFO-DIR-ENTRY -INFO-DIR-SECTION Individual utilities -START-INFO-DIR-ENTRY -* awk: (gawk)Invoking gawk. Text scanning and processing. -END-INFO-DIR-ENTRY - - Copyright (C) 1989, 1991, 1992, 1993, 1996-2005, 2007, 2009-2014 +Copyright (C) 1989, 1991, 1992, 1993, 1996-2005, 2007, 2009-2014 Free Software Foundation, Inc. - This is Edition 4.1 of `GAWK: Effective AWK Programming: A User's + This is Edition 4.1 of 'GAWK: Effective AWK Programming: A User's Guide for GNU Awk', for the 4.1.1 (or later) version of the GNU implementation of AWK. @@ -21,12 +12,21 @@ implementation of AWK. under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being "GNU General Public License", with the -Front-Cover Texts being "A GNU Manual", and with the Back-Cover Texts -as in (a) below. A copy of the license is included in the section -entitled "GNU Free Documentation License". +Front-Cover Texts being "A GNU Manual", and with the Back-Cover Texts as +in (a) below. A copy of the license is included in the section entitled +"GNU Free Documentation License". a. The FSF's Back-Cover Text is: "You have the freedom to copy and modify this GNU manual." +INFO-DIR-SECTION Text creation and manipulation +START-INFO-DIR-ENTRY +* Gawk: (gawk). A text scanning and processing language. +END-INFO-DIR-ENTRY + +INFO-DIR-SECTION Individual utilities +START-INFO-DIR-ENTRY +* awk: (gawk)Invoking gawk. Text scanning and processing. +END-INFO-DIR-ENTRY  File: gawk.info, Node: Top, Next: Foreword, Up: (dir) @@ -34,14 +34,14 @@ File: gawk.info, Node: Top, Next: Foreword, Up: (dir) General Introduction ******************** -This file documents `awk', a program that you can use to select +This file documents 'awk', a program that you can use to select particular records in a file and perform operations upon them. Copyright (C) 1989, 1991, 1992, 1993, 1996-2005, 2007, 2009-2014 Free Software Foundation, Inc. - This is Edition 4.1 of `GAWK: Effective AWK Programming: A User's + This is Edition 4.1 of 'GAWK: Effective AWK Programming: A User's Guide for GNU Awk', for the 4.1.1 (or later) version of the GNU implementation of AWK. @@ -49,9 +49,9 @@ implementation of AWK. under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being "GNU General Public License", with the -Front-Cover Texts being "A GNU Manual", and with the Back-Cover Texts -as in (a) below. A copy of the license is included in the section -entitled "GNU Free Documentation License". +Front-Cover Texts being "A GNU Manual", and with the Back-Cover Texts as +in (a) below. A copy of the license is included in the section entitled +"GNU Free Documentation License". a. The FSF's Back-Cover Text is: "You have the freedom to copy and modify this GNU manual." @@ -63,14 +63,14 @@ entitled "GNU Free Documentation License". * Preface:: What this Info file is about; brief history and acknowledgments. * Getting Started:: A basic introduction to using - `awk'. How to run an `awk' + 'awk'. How to run an 'awk' program. Command-line syntax. -* Invoking Gawk:: How to run `gawk'. +* Invoking Gawk:: How to run 'gawk'. * Regexp:: All about matching things using regular expressions. * Reading Files:: How to read files and manipulate fields. -* Printing:: How to print using `awk'. Describes - the `print' and `printf' +* Printing:: How to print using 'awk'. Describes + the 'print' and 'printf' statements. Also describes redirection of output. * Expressions:: Expressions are the basic building blocks @@ -79,36 +79,36 @@ entitled "GNU Free Documentation License". * Arrays:: The description and use of arrays. Also includes array-oriented control statements. * Functions:: Built-in and user-defined functions. -* Library Functions:: A Library of `awk' Functions. -* Sample Programs:: Many `awk' programs with complete +* Library Functions:: A Library of 'awk' Functions. +* Sample Programs:: Many 'awk' programs with complete explanations. * Advanced Features:: Stuff for advanced users, specific to - `gawk'. -* Internationalization:: Getting `gawk' to speak your + 'gawk'. +* Internationalization:: Getting 'gawk' to speak your language. -* Debugger:: The `gawk' debugger. +* Debugger:: The 'gawk' debugger. * Arbitrary Precision Arithmetic:: Arbitrary precision arithmetic with - `gawk'. + 'gawk'. * Dynamic Extensions:: Adding new built-in functions to - `gawk'. -* Language History:: The evolution of the `awk' + 'gawk'. +* Language History:: The evolution of the 'awk' language. -* Installation:: Installing `gawk' under various +* Installation:: Installing 'gawk' under various operating systems. -* Notes:: Notes about adding things to `gawk' +* Notes:: Notes about adding things to 'gawk' and possible future work. * Basic Concepts:: A very quick introduction to programming concepts. * Glossary:: An explanation of some unfamiliar terms. * Copying:: Your right to copy and distribute - `gawk'. + 'gawk'. * GNU Free Documentation License:: The license for this Info file. * Index:: Concept and Variable Index. -* History:: The history of `gawk' and - `awk'. +* History:: The history of 'gawk' and + 'awk'. * Names:: What name to use to find - `awk'. + 'awk'. * This Manual:: Using this Info file. Includes sample input files that you can use. * Conventions:: Typographical Conventions. @@ -116,23 +116,23 @@ entitled "GNU Free Documentation License". this Info file. * How To Contribute:: Helping to save the world. * Acknowledgments:: Acknowledgments. -* Running gawk:: How to run `gawk' programs; +* Running gawk:: How to run 'gawk' programs; includes command-line syntax. * One-shot:: Running a short throwaway - `awk' program. + 'awk' program. * Read Terminal:: Using no input files (input from the keyboard instead). -* Long:: Putting permanent `awk' +* Long:: Putting permanent 'awk' programs in files. -* Executable Scripts:: Making self-contained `awk' +* Executable Scripts:: Making self-contained 'awk' programs. -* Comments:: Adding documentation to `gawk' +* Comments:: Adding documentation to 'gawk' programs. * Quoting:: More discussion of shell quoting issues. * DOS Quoting:: Quoting in Windows Batch Files. * Sample Data Files:: Sample data files for use in the - `awk' programs illustrated in + 'awk' programs illustrated in this Info file. * Very Simple:: A very simple example. * Two Rules:: A less simple one-line example using @@ -140,11 +140,11 @@ entitled "GNU Free Documentation License". * More Complex:: A more complex example. * Statements/Lines:: Subdividing or combining statements into lines. -* Other Features:: Other Features of `awk'. -* When:: When to use `gawk' and when to +* Other Features:: Other Features of 'awk'. +* When:: When to use 'gawk' and when to use other things. * Intro Summary:: Summary of the introduction. -* Command Line:: How to run `awk'. +* Command Line:: How to run 'awk'. * Options:: Command-line options and their meanings. * Other Arguments:: Input file names and variable @@ -152,13 +152,13 @@ entitled "GNU Free Documentation License". * Naming Standard Input:: How to specify standard input with other files. * Environment Variables:: The environment variables - `gawk' uses. + 'gawk' uses. * AWKPATH Variable:: Searching directories for - `awk' programs. + 'awk' programs. * AWKLIBPATH Variable:: Searching directories for - `awk' shared libraries. + 'awk' shared libraries. * Other Environment Variables:: The environment variables. -* Exit Status:: `gawk''s exit status. +* Exit Status:: 'gawk''s exit status. * Include Files:: Including other files into your program. * Loading Shared Libraries:: Loading shared libraries into your @@ -169,7 +169,7 @@ entitled "GNU Free Documentation License". * Regexp Usage:: How to Use Regular Expressions. * Escape Sequences:: How to write nonprinting characters. * Regexp Operators:: Regular Expression Operators. -* Bracket Expressions:: What can go between `[...]'. +* Bracket Expressions:: What can go between '[...]'. * GNU Regexp Operators:: Operators specific to GNU software. * Case-sensitivity:: How to do case-insensitive matching. * Leftmost Longest:: How much text matches. @@ -177,9 +177,9 @@ entitled "GNU Free Documentation License". * Regexp Summary:: Regular expressions summary. * Records:: Controlling how data is split into records. -* awk split records:: How standard `awk' splits +* awk split records:: How standard 'awk' splits records. -* gawk split records:: How `gawk' splits records. +* gawk split records:: How 'gawk' splits records. * Fields:: An introduction to fields. * Nonconstant Fields:: Nonconstant Field Numbers. * Changing Fields:: Changing the Contents of a Field. @@ -189,7 +189,7 @@ entitled "GNU Free Documentation License". * Regexp Field Splitting:: Using regexps as the field separator. * Single Character Fields:: Making each character a separate field. -* Command Line Field Separator:: Setting `FS' from the +* Command Line Field Separator:: Setting 'FS' from the command-line. * Full Line Fields:: Making the full line be a single field. @@ -198,44 +198,44 @@ entitled "GNU Free Documentation License". * Splitting By Content:: Defining Fields By Content * Multiple Line:: Reading multiline records. * Getline:: Reading files under explicit program - control using the `getline' + control using the 'getline' function. -* Plain Getline:: Using `getline' with no +* Plain Getline:: Using 'getline' with no arguments. -* Getline/Variable:: Using `getline' into a variable. -* Getline/File:: Using `getline' from a file. -* Getline/Variable/File:: Using `getline' into a variable +* Getline/Variable:: Using 'getline' into a variable. +* Getline/File:: Using 'getline' from a file. +* Getline/Variable/File:: Using 'getline' into a variable from a file. -* Getline/Pipe:: Using `getline' from a pipe. -* Getline/Variable/Pipe:: Using `getline' into a variable +* Getline/Pipe:: Using 'getline' from a pipe. +* Getline/Variable/Pipe:: Using 'getline' into a variable from a pipe. -* Getline/Coprocess:: Using `getline' from a coprocess. -* Getline/Variable/Coprocess:: Using `getline' into a variable +* Getline/Coprocess:: Using 'getline' from a coprocess. +* Getline/Variable/Coprocess:: Using 'getline' into a variable from a coprocess. * Getline Notes:: Important things to know about - `getline'. -* Getline Summary:: Summary of `getline' Variants. + 'getline'. +* Getline Summary:: Summary of 'getline' Variants. * Read Timeout:: Reading input with a timeout. * Command line directories:: What happens if you put a directory on the command line. * Input Summary:: Input summary. * Input Exercises:: Exercises. -* Print:: The `print' statement. -* Print Examples:: Simple examples of `print' +* Print:: The 'print' statement. +* Print Examples:: Simple examples of 'print' statements. * Output Separators:: The output separators and how to change them. * OFMT:: Controlling Numeric Output With - `print'. -* Printf:: The `printf' statement. -* Basic Printf:: Syntax of the `printf' statement. + 'print'. +* Printf:: The 'printf' statement. +* Basic Printf:: Syntax of the 'printf' statement. * Control Letters:: Format-control letters. * Format Modifiers:: Format-specification modifiers. * Printf Examples:: Several examples. * Redirection:: How to redirect output to multiple files and pipes. * Special Files:: File name interpretation in - `gawk'. `gawk' allows + 'gawk'. 'gawk' allows access to inherited file descriptors. * Special FD:: Special files for I/O. * Special Network:: Special files for network @@ -260,30 +260,30 @@ entitled "GNU Free Documentation License". This is an advanced method of input. * Conversion:: The conversion of strings to numbers and vice versa. -* Strings And Numbers:: How `awk' Converts Between +* Strings And Numbers:: How 'awk' Converts Between Strings And Numbers. * Locale influences conversions:: How the locale may affect conversions. -* All Operators:: `gawk''s operators. -* Arithmetic Ops:: Arithmetic operations (`+', - `-', etc.) +* All Operators:: 'gawk''s operators. +* Arithmetic Ops:: Arithmetic operations ('+', + '-', etc.) * Concatenation:: Concatenating strings. * Assignment Ops:: Changing the value of a variable or a field. * Increment Ops:: Incrementing the numeric value of a variable. * Truth Values and Conditions:: Testing for true and false. -* Truth Values:: What is ``true'' and what is - ``false''. +* Truth Values:: What is "true" and what is + "false". * Typing and Comparison:: How variables acquire types and how this affects comparison of numbers and - strings with `<', etc. + strings with '<', etc. * Variable Typing:: String type versus numeric type. * Comparison Operators:: The comparison operators. * POSIX String Comparison:: String comparison with POSIX rules. * Boolean Ops:: Combining comparison expressions using - boolean operators `||' (``or''), - `&&' (``and'') and `!' - (``not''). + boolean operators '||' ("or"), + '&&' ("and") and '!' + ("not"). * Conditional Exp:: Conditional expressions select between two subexpressions under control of a third subexpression. @@ -306,12 +306,12 @@ entitled "GNU Free Documentation License". * Empty:: The empty pattern, which matches every record. * Using Shell Variables:: How to use shell variables with - `awk'. + 'awk'. * Action Overview:: What goes into an action. * Statements:: Describes the various control statements in detail. * If Statement:: Conditionally execute some - `awk' statements. + 'awk' statements. * While Statement:: Loop until some condition is satisfied. * Do Statement:: Do specified action while looping @@ -329,14 +329,14 @@ entitled "GNU Free Documentation License". * Next Statement:: Stop processing the current input record. * Nextfile Statement:: Stop processing the current file. -* Exit Statement:: Stop execution of `awk'. +* Exit Statement:: Stop execution of 'awk'. * Built-in Variables:: Summarizes the built-in variables. * User-modified:: Built-in variables that you change to - control `awk'. -* Auto-set:: Built-in variables where `awk' + control 'awk'. +* Auto-set:: Built-in variables where 'awk' gives you information. -* ARGC and ARGV:: Ways to use `ARGC' and - `ARGV'. +* ARGC and ARGV:: Ways to use 'ARGC' and + 'ARGV'. * Pattern Action Summary:: Patterns and Actions summary. * Array Basics:: The basics of arrays. * Array Intro:: Introduction to Arrays @@ -344,35 +344,35 @@ entitled "GNU Free Documentation License". array. * Assigning Elements:: How to change an element of an array. * Array Example:: Basic Example of an Array -* Scanning an Array:: A variation of the `for' +* Scanning an Array:: A variation of the 'for' statement. It loops through the indices of an array's existing elements. * Controlling Scanning:: Controlling the order in which arrays are scanned. -* Delete:: The `delete' statement removes an +* Delete:: The 'delete' statement removes an element from an array. * Numeric Array Subscripts:: How to use numbers as subscripts in - `awk'. + 'awk'. * Uninitialized Subscripts:: Using Uninitialized variables as subscripts. * Multidimensional:: Emulating multidimensional arrays in - `awk'. + 'awk'. * Multiscanning:: Scanning multidimensional arrays. * Arrays of Arrays:: True multidimensional arrays. * Arrays Summary:: Summary of arrays. * Built-in:: Summarizes the built-in functions. * Calling Built-in:: How to call built-in functions. * Numeric Functions:: Functions that work with numbers, - including `int()', `sin()' - and `rand()'. + including 'int()', 'sin()' + and 'rand()'. * String Functions:: Functions for string manipulation, - such as `split()', `match()' - and `sprintf()'. + such as 'split()', 'match()' + and 'sprintf()'. * Gory Details:: More than you want to know about - `\' and `&' with - `sub()', `gsub()', and - `gensub()'. + '\' and '&' with + 'sub()', 'gsub()', and + 'gensub()'. * I/O Functions:: Functions for files and shell commands. * Time Functions:: Functions for dealing with timestamps. @@ -400,11 +400,11 @@ entitled "GNU Free Documentation License". variables in library functions. * General Functions:: Functions that are of general use. * Strtonum Function:: A replacement for the built-in - `strtonum()' function. + 'strtonum()' function. * Assert Function:: A function for assertions in - `awk' programs. + 'awk' programs. * Round Function:: A function for rounding if - `sprintf()' does not do it + 'sprintf()' does not do it correctly. * Cliff Random Function:: The Cliff Random Number Generator. * Ordinal Functions:: Functions for using characters as @@ -434,19 +434,19 @@ entitled "GNU Free Documentation License". * Library exercises:: Exercises. * Running Examples:: How to run these examples. * Clones:: Clones of common utilities. -* Cut Program:: The `cut' utility. -* Egrep Program:: The `egrep' utility. -* Id Program:: The `id' utility. -* Split Program:: The `split' utility. -* Tee Program:: The `tee' utility. -* Uniq Program:: The `uniq' utility. -* Wc Program:: The `wc' utility. -* Miscellaneous Programs:: Some interesting `awk' +* Cut Program:: The 'cut' utility. +* Egrep Program:: The 'egrep' utility. +* Id Program:: The 'id' utility. +* Split Program:: The 'split' utility. +* Tee Program:: The 'tee' utility. +* Uniq Program:: The 'uniq' utility. +* Wc Program:: The 'wc' utility. +* Miscellaneous Programs:: Some interesting 'awk' programs. * Dupword Program:: Finding duplicated words in a document. * Alarm Program:: An alarm clock. -* Translate Program:: A program similar to the `tr' +* Translate Program:: A program similar to the 'tr' utility. * Labels Program:: Printing mailing labels. * Word Sorting:: A program to produce a word usage @@ -456,7 +456,7 @@ entitled "GNU Free Documentation License". * Extract Program:: Pulling out programs from Texinfo source files. * Simple Sed:: A Simple Stream Editor. -* Igawk Program:: A wrapper for `awk' that +* Igawk Program:: A wrapper for 'awk' that includes files. * Anagram Program:: Finding anagrams from a dictionary. * Signature Program:: People do amazing things with too much @@ -467,27 +467,27 @@ entitled "GNU Free Documentation License". * Array Sorting:: Facilities for controlling array traversal and sorting arrays. * Controlling Array Traversal:: How to use PROCINFO["sorted_in"]. -* Array Sorting Functions:: How to use `asort()' and - `asorti()'. +* Array Sorting Functions:: How to use 'asort()' and + 'asorti()'. * Two-way I/O:: Two-way communications with another process. -* TCP/IP Networking:: Using `gawk' for network +* TCP/IP Networking:: Using 'gawk' for network programming. -* Profiling:: Profiling your `awk' programs. +* Profiling:: Profiling your 'awk' programs. * Advanced Features Summary:: Summary of advanced features. * I18N and L10N:: Internationalization and Localization. -* Explaining gettext:: How GNU `gettext' works. +* Explaining gettext:: How GNU 'gettext' works. * Programmer i18n:: Features for the programmer. * Translator i18n:: Features for the translator. * String Extraction:: Extracting marked strings. -* Printf Ordering:: Rearranging `printf' arguments. -* I18N Portability:: `awk'-level portability +* Printf Ordering:: Rearranging 'printf' arguments. +* I18N Portability:: 'awk'-level portability issues. * I18N Example:: A simple i18n example. -* Gawk I18N:: `gawk' is also +* Gawk I18N:: 'gawk' is also internationalized. * I18N Summary:: Summary of I18N stuff. -* Debugging:: Introduction to `gawk' +* Debugging:: Introduction to 'gawk' debugger. * Debugging Concepts:: Debugging in General. * Debugging Terms:: Additional Debugging Concepts. @@ -508,7 +508,7 @@ entitled "GNU Free Documentation License". * Debugging Summary:: Debugging summary. * Computer Arithmetic:: A quick intro to computer math. * Math Definitions:: Defining terms used. -* MPFR features:: The MPFR features in `gawk'. +* MPFR features:: The MPFR features in 'gawk'. * FP Math Caution:: Things to know. * Inexactness of computations:: Floating point math is not exact. * Inexact representation:: Numbers are not exactly represented. @@ -519,7 +519,7 @@ entitled "GNU Free Documentation License". * Setting precision:: How to set the precision. * Setting the rounding mode:: How to set the rounding mode. * Arbitrary Precision Integers:: Arbitrary Precision Integer Arithmetic - with `gawk'. + with 'gawk'. * POSIX Floating Point Problems:: Standards Versus Existing Practice. * Floating point summary:: Summary of floating point discussion. * Extension Intro:: What is an extension. @@ -532,7 +532,7 @@ entitled "GNU Free Documentation License". * Memory Allocation Functions:: Functions for allocating memory. * Constructor Functions:: Functions for creating values. * Registration Functions:: Functions to register things with - `gawk'. + 'gawk'. * Extension Functions:: Registering extension functions. * Exit Callback Functions:: Registering an exit callback. * Extension Version String:: Registering a version string. @@ -540,12 +540,12 @@ entitled "GNU Free Documentation License". * Output Wrappers:: Registering an output wrapper. * Two-way processors:: Registering a two-way processor. * Printing Messages:: Functions for printing messages. -* Updating `ERRNO':: Functions for updating `ERRNO'. +* Updating 'ERRNO':: Functions for updating 'ERRNO'. * Accessing Parameters:: Functions for accessing parameters. * Symbol Table Access:: Functions for accessing global variables. * Symbol table by name:: Accessing variables by name. -* Symbol table by cookie:: Accessing variables by ``cookie''. +* Symbol table by cookie:: Accessing variables by "cookie". * Cached values:: Creating and using cached values. * Array Manipulation:: Functions for working with arrays. * Array Data Types:: Data types for working with arrays. @@ -555,24 +555,24 @@ entitled "GNU Free Documentation License". * Extension API Variables:: Variables provided by the API. * Extension Versioning:: API Version information. * Extension API Informational Variables:: Variables providing information about - `gawk''s invocation. + 'gawk''s invocation. * Extension API Boilerplate:: Boilerplate code for using the API. -* Finding Extensions:: How `gawk' finds compiled +* Finding Extensions:: How 'gawk' finds compiled extensions. * Extension Example:: Example C code for an extension. * Internal File Description:: What the new functions will do. * Internal File Ops:: The code for internal file operations. * Using Internal File Ops:: How to use an external extension. * Extension Samples:: The sample extensions that ship with - `gawk'. + 'gawk'. * Extension Sample File Functions:: The file functions sample. -* Extension Sample Fnmatch:: An interface to `fnmatch()'. -* Extension Sample Fork:: An interface to `fork()' and +* Extension Sample Fnmatch:: An interface to 'fnmatch()'. +* Extension Sample Fork:: An interface to 'fork()' and other process functions. * Extension Sample Inplace:: Enabling in-place file editing. * Extension Sample Ord:: Character to value to character conversions. -* Extension Sample Readdir:: An interface to `readdir()'. +* Extension Sample Readdir:: An interface to 'readdir()'. * Extension Sample Revout:: Reversing output sample output wrapper. * Extension Sample Rev2way:: Reversing data sample two-way @@ -580,9 +580,9 @@ entitled "GNU Free Documentation License". * Extension Sample Read write array:: Serializing an array to a file. * Extension Sample Readfile:: Reading an entire file into a string. * Extension Sample API Tests:: Tests for the API. -* Extension Sample Time:: An interface to `gettimeofday()' - and `sleep()'. -* gawkextlib:: The `gawkextlib' project. +* Extension Sample Time:: An interface to 'gettimeofday()' + and 'sleep()'. +* gawkextlib:: The 'gawkextlib' project. * Extension summary:: Extension summary. * Extension Exercises:: Exercises. * V7/SVR3.1:: The major changes between V7 and @@ -591,63 +591,63 @@ entitled "GNU Free Documentation License". Releases 3.1 and 4. * POSIX:: New features from the POSIX standard. * BTL:: New features from Brian Kernighan's - version of `awk'. -* POSIX/GNU:: The extensions in `gawk' not - in POSIX `awk'. + version of 'awk'. +* POSIX/GNU:: The extensions in 'gawk' not + in POSIX 'awk'. * Feature History:: The history of the features in - `gawk'. + 'gawk'. * Common Extensions:: Common Extensions Summary. * Ranges and Locales:: How locales used to affect regexp ranges. * Contributors:: The major contributors to - `gawk'. + 'gawk'. * History summary:: History summary. -* Gawk Distribution:: What is in the `gawk' +* Gawk Distribution:: What is in the 'gawk' distribution. * Getting:: How to get the distribution. * Extracting:: How to extract the distribution. * Distribution contents:: What is in the distribution. -* Unix Installation:: Installing `gawk' under +* Unix Installation:: Installing 'gawk' under various versions of Unix. -* Quick Installation:: Compiling `gawk' under Unix. +* Quick Installation:: Compiling 'gawk' under Unix. * Additional Configuration Options:: Other compile-time options. * Configuration Philosophy:: How it's all supposed to work. * Non-Unix Installation:: Installation on Other Operating Systems. * PC Installation:: Installing and Compiling - `gawk' on MS-DOS and OS/2. + 'gawk' on MS-DOS and OS/2. * PC Binary Installation:: Installing a prepared distribution. -* PC Compiling:: Compiling `gawk' for MS-DOS, +* PC Compiling:: Compiling 'gawk' for MS-DOS, Windows32, and OS/2. -* PC Testing:: Testing `gawk' on PC systems. -* PC Using:: Running `gawk' on MS-DOS, +* PC Testing:: Testing 'gawk' on PC systems. +* PC Using:: Running 'gawk' on MS-DOS, Windows32 and OS/2. -* Cygwin:: Building and running `gawk' +* Cygwin:: Building and running 'gawk' for Cygwin. -* MSYS:: Using `gawk' In The MSYS +* MSYS:: Using 'gawk' In The MSYS Environment. -* VMS Installation:: Installing `gawk' on VMS. -* VMS Compilation:: How to compile `gawk' under +* VMS Installation:: Installing 'gawk' on VMS. +* VMS Compilation:: How to compile 'gawk' under VMS. -* VMS Dynamic Extensions:: Compiling `gawk' dynamic +* VMS Dynamic Extensions:: Compiling 'gawk' dynamic extensions on VMS. -* VMS Installation Details:: How to install `gawk' under +* VMS Installation Details:: How to install 'gawk' under VMS. -* VMS Running:: How to run `gawk' under VMS. +* VMS Running:: How to run 'gawk' under VMS. * VMS GNV:: The VMS GNV Project. * VMS Old Gawk:: An old version comes with some VMS systems. * Bugs:: Reporting Problems and Bugs. -* Other Versions:: Other freely available `awk' +* Other Versions:: Other freely available 'awk' implementations. * Installation summary:: Summary of installation. -* Compatibility Mode:: How to disable certain `gawk' +* Compatibility Mode:: How to disable certain 'gawk' extensions. -* Additions:: Making Additions To `gawk'. +* Additions:: Making Additions To 'gawk'. * Accessing The Source:: Accessing the Git repository. * Adding Code:: Adding code to the main body of - `gawk'. -* New Ports:: Porting `gawk' to a new + 'gawk'. +* New Ports:: Porting 'gawk' to a new operating system. * Derived Files:: Why derived files are kept in the Git repository. @@ -665,8 +665,8 @@ entitled "GNU Free Documentation License". * Basic High Level:: The high level view. * Basic Data Typing:: A very quick intro to data types. - To my parents, for their love, and for the wonderful example they -set for me. + To my parents, for their love, and for the wonderful example they set +for me. To my wife Miriam, for making me complete. Thank you for building your life together with me. @@ -680,85 +680,85 @@ File: gawk.info, Node: Foreword, Next: Preface, Prev: Top, Up: Top Foreword ******** -Arnold Robbins and I are good friends. We were introduced in 1990 by -circumstances--and our favorite programming language, AWK. The -circumstances started a couple of years earlier. I was working at a new +Arnold Robbins and I are good friends. We were introduced in 1990 by +circumstances--and our favorite programming language, AWK. The +circumstances started a couple of years earlier. I was working at a new job and noticed an unplugged Unix computer sitting in the corner. No -one knew how to use it, and neither did I. However, a couple of days -later it was running, and I was `root' and the one-and-only user. That +one knew how to use it, and neither did I. However, a couple of days +later it was running, and I was 'root' and the one-and-only user. That day, I began the transition from statistician to Unix programmer. On one of many trips to the library or bookstore in search of books on Unix, I found the gray AWK book, a.k.a. Aho, Kernighan and -Weinberger, `The AWK Programming Language', Addison-Wesley, 1988. -AWK's simple programming paradigm--find a pattern in the input and then +Weinberger, 'The AWK Programming Language', Addison-Wesley, 1988. AWK's +simple programming paradigm--find a pattern in the input and then perform an action--often reduced complex or tedious data manipulations to few lines of code. I was excited to try my hand at programming in AWK. - Alas, the `awk' on my computer was a limited version of the -language described in the AWK book. I discovered that my computer had -"old `awk'" and the AWK book described "new `awk'." I learned that -this was typical; the old version refused to step aside or relinquish -its name. If a system had a new `awk', it was invariably called -`nawk', and few systems had it. The best way to get a new `awk' was to -`ftp' the source code for `gawk' from `prep.ai.mit.edu'. `gawk' was a -version of new `awk' written by David Trueman and Arnold, and available -under the GNU General Public License. - - (Incidentally, it's no longer difficult to find a new `awk'. `gawk' + Alas, the 'awk' on my computer was a limited version of the language +described in the AWK book. I discovered that my computer had "old +'awk'" and the AWK book described "new 'awk'." I learned that this was +typical; the old version refused to step aside or relinquish its name. +If a system had a new 'awk', it was invariably called 'nawk', and few +systems had it. The best way to get a new 'awk' was to 'ftp' the source +code for 'gawk' from 'prep.ai.mit.edu'. 'gawk' was a version of new +'awk' written by David Trueman and Arnold, and available under the GNU +General Public License. + + (Incidentally, it's no longer difficult to find a new 'awk'. 'gawk' ships with GNU/Linux, and you can download binaries or source code for -almost any system; my wife uses `gawk' on her VMS box.) +almost any system; my wife uses 'gawk' on her VMS box.) My Unix system started out unplugged from the wall; it certainly was -not plugged into a network. So, oblivious to the existence of `gawk' -and the Unix community in general, and desiring a new `awk', I wrote my -own, called `mawk'. Before I was finished I knew about `gawk', but it -was too late to stop, so I eventually posted to a `comp.sources' +not plugged into a network. So, oblivious to the existence of 'gawk' +and the Unix community in general, and desiring a new 'awk', I wrote my +own, called 'mawk'. Before I was finished I knew about 'gawk', but it +was too late to stop, so I eventually posted to a 'comp.sources' newsgroup. A few days after my posting, I got a friendly email from Arnold -introducing himself. He suggested we share design and algorithms and -attached a draft of the POSIX standard so that I could update `mawk' to +introducing himself. He suggested we share design and algorithms and +attached a draft of the POSIX standard so that I could update 'mawk' to support language extensions added after publication of the AWK book. Frankly, if our roles had been reversed, I would not have been so -open and we probably would have never met. I'm glad we did meet. He -is an AWK expert's AWK expert and a genuinely nice person. Arnold +open and we probably would have never met. I'm glad we did meet. He is +an AWK expert's AWK expert and a genuinely nice person. Arnold contributes significant amounts of his expertise and time to the Free Software Foundation. - This book is the `gawk' reference manual, but at its core it is a -book about AWK programming that will appeal to a wide audience. It is -a definitive reference to the AWK language as defined by the 1987 Bell + This book is the 'gawk' reference manual, but at its core it is a +book about AWK programming that will appeal to a wide audience. It is a +definitive reference to the AWK language as defined by the 1987 Bell Laboratories release and codified in the 1992 POSIX Utilities standard. On the other hand, the novice AWK programmer can study a wealth of practical programs that emphasize the power of AWK's basic idioms: data driven control-flow, pattern matching with regular expressions, and associative arrays. Those looking for something new can try out -`gawk''s interface to network protocols via special `/inet' files. +'gawk''s interface to network protocols via special '/inet' files. - The programs in this book make clear that an AWK program is -typically much smaller and faster to develop than a counterpart written -in C. Consequently, there is often a payoff to prototype an algorithm -or design in AWK to get it running quickly and expose problems early. + The programs in this book make clear that an AWK program is typically +much smaller and faster to develop than a counterpart written in C. +Consequently, there is often a payoff to prototype an algorithm or +design in AWK to get it running quickly and expose problems early. Often, the interpreted performance is adequate and the AWK prototype becomes the product. - The new `pgawk' (profiling `gawk'), produces program execution + The new 'pgawk' (profiling 'gawk'), produces program execution counts. I recently experimented with an algorithm that for n lines of input, exhibited ~ C n^2 performance, while theory predicted ~ C n log n -behavior. A few minutes poring over the `awkprof.out' profile -pinpointed the problem to a single line of code. `pgawk' is a welcome +behavior. A few minutes poring over the 'awkprof.out' profile +pinpointed the problem to a single line of code. 'pgawk' is a welcome addition to my programmer's toolbox. Arnold has distilled over a decade of experience writing and using -AWK programs, and developing `gawk', into this book. If you use AWK or +AWK programs, and developing 'gawk', into this book. If you use AWK or want to learn how, then read this book. Michael Brennan - Author of `mawk' + Author of 'mawk' March, 2001  @@ -769,22 +769,22 @@ Preface Several kinds of tasks occur repeatedly when working with text files. You might want to extract certain lines and discard the rest. Or you -may need to make changes wherever certain patterns appear, but leave -the rest of the file alone. Writing single-use programs for these -tasks in languages such as C, C++, or Java is time-consuming and -inconvenient. Such jobs are often easier with `awk'. The `awk' -utility interprets a special-purpose programming language that makes it -easy to handle simple data-reformatting jobs. - - The GNU implementation of `awk' is called `gawk'; if you invoke it +may need to make changes wherever certain patterns appear, but leave the +rest of the file alone. Writing single-use programs for these tasks in +languages such as C, C++, or Java is time-consuming and inconvenient. +Such jobs are often easier with 'awk'. The 'awk' utility interprets a +special-purpose programming language that makes it easy to handle simple +data-reformatting jobs. + + The GNU implementation of 'awk' is called 'gawk'; if you invoke it with the proper options or environment variables (*note Options::), it -is fully compatible with the POSIX(1) specification of the `awk' -language and with the Unix version of `awk' maintained by Brian -Kernighan. This means that all properly written `awk' programs should -work with `gawk'. Thus, we usually don't distinguish between `gawk' -and other `awk' implementations. +is fully compatible with the POSIX(1) specification of the 'awk' +language and with the Unix version of 'awk' maintained by Brian +Kernighan. This means that all properly written 'awk' programs should +work with 'gawk'. Thus, we usually don't distinguish between 'gawk' and +other 'awk' implementations. - Using `awk' allows you to: + Using 'awk' allows you to: * Manage small, personal databases @@ -797,7 +797,7 @@ and other `awk' implementations. * Experiment with algorithms that you can adapt later to other computer languages - In addition, `gawk' provides facilities that make it easy to: + In addition, 'gawk' provides facilities that make it easy to: * Extract bits and pieces of data for processing @@ -805,31 +805,30 @@ and other `awk' implementations. * Perform simple network communications - * Profile and debug `awk' programs. + * Profile and debug 'awk' programs. * Extend the language with functions written in C or C++. - This Info file teaches you about the `awk' language and how you can + This Info file teaches you about the 'awk' language and how you can use it effectively. You should already be familiar with basic system -commands, such as `cat' and `ls',(2) as well as basic shell facilities, +commands, such as 'cat' and 'ls',(2) as well as basic shell facilities, such as input/output (I/O) redirection and pipes. - Implementations of the `awk' language are available for many + Implementations of the 'awk' language are available for many different computing environments. This Info file, while describing the -`awk' language in general, also describes the particular implementation -of `awk' called `gawk' (which stands for "GNU `awk'"). `gawk' runs on -a broad range of Unix systems, ranging from Intel(R)-architecture -PC-based computers up through large-scale systems. `gawk' has also -been ported to Mac OS X, Microsoft Windows (all versions) and OS/2 PCs, -and OpenVMS. (Some other, obsolete systems to which `gawk' was once -ported are no longer supported and the code for those systems has been -removed.) +'awk' language in general, also describes the particular implementation +of 'awk' called 'gawk' (which stands for "GNU 'awk'"). 'gawk' runs on a +broad range of Unix systems, ranging from Intel(R)-architecture PC-based +computers up through large-scale systems. 'gawk' has also been ported +to Mac OS X, Microsoft Windows (all versions) and OS/2 PCs, and OpenVMS. +(Some other, obsolete systems to which 'gawk' was once ported are no +longer supported and the code for those systems has been removed.) * Menu: -* History:: The history of `gawk' and - `awk'. -* Names:: What name to use to find `awk'. +* History:: The history of 'gawk' and + 'awk'. +* Names:: What name to use to find 'awk'. * This Manual:: Using this Info file. Includes sample input files that you can use. * Conventions:: Typographical Conventions. @@ -840,65 +839,64 @@ removed.) ---------- Footnotes ---------- - (1) The 2008 POSIX standard is accessable online at -`http://www.opengroup.org/onlinepubs/9699919799/'. + (1) The 2008 POSIX standard is accessable online at . (2) These commands are available on POSIX-compliant systems, as well -as on traditional Unix-based systems. If you are using some other +as on traditional Unix-based systems. If you are using some other operating system, you still need to be familiar with the ideas of I/O redirection and pipes.  File: gawk.info, Node: History, Next: Names, Up: Preface -History of `awk' and `gawk' +History of 'awk' and 'gawk' =========================== Recipe For A Programming Language - 1 part `egrep' 1 part `snobol' - 2 parts `ed' 3 parts C + 1 part 'egrep' 1 part 'snobol' + 2 parts 'ed' 3 parts C - Blend all parts well using `lex' and `yacc'. Document minimally and + Blend all parts well using 'lex' and 'yacc'. Document minimally and release. - After eight years, add another part `egrep' and two more parts C. + After eight years, add another part 'egrep' and two more parts C. Document very well and release. -The name `awk' comes from the initials of its designers: Alfred V. + The name 'awk' comes from the initials of its designers: Alfred V. Aho, Peter J. Weinberger and Brian W. Kernighan. The original version -of `awk' was written in 1977 at AT&T Bell Laboratories. In 1985, a new +of 'awk' was written in 1977 at AT&T Bell Laboratories. In 1985, a new version made the programming language more powerful, introducing user-defined functions, multiple input streams, and computed regular expressions. This new version became widely available with Unix System V Release 3.1 (1987). The version in System V Release 4 (1989) added some new features and cleaned up the behavior in some of the "dark -corners" of the language. The specification for `awk' in the POSIX +corners" of the language. The specification for 'awk' in the POSIX Command Language and Utilities standard further clarified the language. -Both the `gawk' designers and the original Bell Laboratories `awk' +Both the 'gawk' designers and the original Bell Laboratories 'awk' designers provided feedback for the POSIX specification. - Paul Rubin wrote the GNU implementation, `gawk', in 1986. Jay + Paul Rubin wrote the GNU implementation, 'gawk', in 1986. Jay Fenlason completed it, with advice from Richard Stallman. John Woods -contributed parts of the code as well. In 1988 and 1989, David -Trueman, with help from me, thoroughly reworked `gawk' for compatibility -with the newer `awk'. Circa 1994, I became the primary maintainer. -Current development focuses on bug fixes, performance improvements, -standards compliance, and occasionally, new features. +contributed parts of the code as well. In 1988 and 1989, David Trueman, +with help from me, thoroughly reworked 'gawk' for compatibility with the +newer 'awk'. Circa 1994, I became the primary maintainer. Current +development focuses on bug fixes, performance improvements, standards +compliance, and occasionally, new features. In May of 1997, Ju"rgen Kahrs felt the need for network access from -`awk', and with a little help from me, set about adding features to do -this for `gawk'. At that time, he also wrote the bulk of `TCP/IP -Internetworking with `gawk'' (a separate document, available as part of -the `gawk' distribution). His code finally became part of the main -`gawk' distribution with `gawk' version 3.1. - - John Haque rewrote the `gawk' internals, in the process providing an -`awk'-level debugger. This version became available as `gawk' version +'awk', and with a little help from me, set about adding features to do +this for 'gawk'. At that time, he also wrote the bulk of 'TCP/IP +Internetworking with 'gawk'' (a separate document, available as part of +the 'gawk' distribution). His code finally became part of the main +'gawk' distribution with 'gawk' version 3.1. + + John Haque rewrote the 'gawk' internals, in the process providing an +'awk'-level debugger. This version became available as 'gawk' version 4.0, in 2011. - *Note Contributors::, for a complete list of those who made -important contributions to `gawk'. + *Note Contributors::, for a complete list of those who made important +contributions to 'gawk'.  File: gawk.info, Node: Names, Next: This Manual, Prev: History, Up: Preface @@ -906,34 +904,34 @@ File: gawk.info, Node: Names, Next: This Manual, Prev: History, Up: Preface A Rose by Any Other Name ======================== -The `awk' language has evolved over the years. Full details are +The 'awk' language has evolved over the years. Full details are provided in *note Language History::. The language described in this -Info file is often referred to as "new `awk'" (`nawk'). +Info file is often referred to as "new 'awk'" ('nawk'). - For some time after new `awk' was introduced, there were systems -with multiple versions of `awk'. Some systems had an `awk' utility -that implemented the original version of the `awk' language and a -`nawk' utility for the new version. Others had an `oawk' version for -the "old `awk'" language and plain `awk' for the new one. Still others -only had one version, which is usually the new one. + For some time after new 'awk' was introduced, there were systems with +multiple versions of 'awk'. Some systems had an 'awk' utility that +implemented the original version of the 'awk' language and a 'nawk' +utility for the new version. Others had an 'oawk' version for the "old +'awk'" language and plain 'awk' for the new one. Still others only had +one version, which is usually the new one. - Today, only Solaris systems still use an old `awk' for the default -`awk' utility. (A more modern `awk' lives in `/usr/xpg6/bin' on these -systems.) All other modern systems use some version of new `awk'.(1) + Today, only Solaris systems still use an old 'awk' for the default +'awk' utility. (A more modern 'awk' lives in '/usr/xpg6/bin' on these +systems.) All other modern systems use some version of new 'awk'.(1) - It is likely that you already have some version of new `awk' on your + It is likely that you already have some version of new 'awk' on your system, which is what you should use when running your programs. (Of -course, if you're reading this Info file, chances are good that you -have `gawk'!) +course, if you're reading this Info file, chances are good that you have +'gawk'!) Throughout this Info file, whenever we refer to a language feature -that should be available in any complete implementation of POSIX `awk', -we simply use the term `awk'. When referring to a feature that is -specific to the GNU implementation, we use the term `gawk'. +that should be available in any complete implementation of POSIX 'awk', +we simply use the term 'awk'. When referring to a feature that is +specific to the GNU implementation, we use the term 'gawk'. ---------- Footnotes ---------- - (1) Many of these systems use `gawk' for their `awk' implementation! + (1) Many of these systems use 'gawk' for their 'awk' implementation!  File: gawk.info, Node: This Manual, Next: Conventions, Prev: Names, Up: Preface @@ -941,138 +939,138 @@ File: gawk.info, Node: This Manual, Next: Conventions, Prev: Names, Up: Pref Using This Book =============== -The term `awk' refers to a particular program as well as to the -language you use to tell this program what to do. When we need to be -careful, we call the language "the `awk' language," and the program -"the `awk' utility." This Info file explains both how to write -programs in the `awk' language and how to run the `awk' utility. The -term "`awk' program" refers to a program written by you in the `awk' -programming language. +The term 'awk' refers to a particular program as well as to the language +you use to tell this program what to do. When we need to be careful, we +call the language "the 'awk' language," and the program "the 'awk' +utility." This Info file explains both how to write programs in the +'awk' language and how to run the 'awk' utility. The term "'awk' +program" refers to a program written by you in the 'awk' programming +language. - Primarily, this Info file explains the features of `awk' as defined -in the POSIX standard. It does so in the context of the `gawk' + Primarily, this Info file explains the features of 'awk' as defined +in the POSIX standard. It does so in the context of the 'gawk' implementation. While doing so, it also attempts to describe important -differences between `gawk' and other `awk' implementations.(1) Finally, -any `gawk' features that are not in the POSIX standard for `awk' are +differences between 'gawk' and other 'awk' implementations.(1) Finally, +any 'gawk' features that are not in the POSIX standard for 'awk' are noted. There are sidebars scattered throughout the Info file. They add a -more complete explanation of points that are relevant, but not likely -to be of interest on first reading. All appear in the index, under the +more complete explanation of points that are relevant, but not likely to +be of interest on first reading. All appear in the index, under the heading "sidebar." - Most of the time, the examples use complete `awk' programs. Some of -the more advanced sections show only the part of the `awk' program that + Most of the time, the examples use complete 'awk' programs. Some of +the more advanced sections show only the part of the 'awk' program that illustrates the concept currently being described. While this Info file is aimed principally at people who have not been -exposed to `awk', there is a lot of information here that even the `awk' +exposed to 'awk', there is a lot of information here that even the 'awk' expert should find useful. In particular, the description of POSIX -`awk' and the example programs in *note Library Functions::, and in +'awk' and the example programs in *note Library Functions::, and in *note Sample Programs::, should be of interest. This Info file is split into several parts, as follows: - Part I describes the `awk' language and `gawk' program in detail. -It starts with the basics, and continues through all of the features of -`awk'. It contains the following chapters: + Part I describes the 'awk' language and 'gawk' program in detail. It +starts with the basics, and continues through all of the features of +'awk'. It contains the following chapters: *note Getting Started::, provides the essentials you need to know to -begin using `awk'. +begin using 'awk'. - *note Invoking Gawk::, describes how to run `gawk', the meaning of -its command-line options, and how it finds `awk' program source files. + *note Invoking Gawk::, describes how to run 'gawk', the meaning of +its command-line options, and how it finds 'awk' program source files. *note Regexp::, introduces regular expressions in general, and in -particular the flavors supported by POSIX `awk' and `gawk'. +particular the flavors supported by POSIX 'awk' and 'gawk'. - *note Reading Files::, describes how `awk' reads your data. It -introduces the concepts of records and fields, as well as the `getline' + *note Reading Files::, describes how 'awk' reads your data. It +introduces the concepts of records and fields, as well as the 'getline' command. I/O redirection is first described here. Network I/O is also briefly introduced here. - *note Printing::, describes how `awk' programs can produce output -with `print' and `printf'. + *note Printing::, describes how 'awk' programs can produce output +with 'print' and 'printf'. *note Expressions::, describes expressions, which are the basic building blocks for getting most things done in a program. *note Patterns and Actions::, describes how to write patterns for matching records, actions for doing something when a record is matched, -and the built-in variables `awk' and `gawk' use. +and the built-in variables 'awk' and 'gawk' use. - *note Arrays::, covers `awk''s one-and-only data structure: + *note Arrays::, covers 'awk''s one-and-only data structure: associative arrays. Deleting array elements and whole arrays is also -described, as well as sorting arrays in `gawk'. It also describes how -`gawk' provides arrays of arrays. +described, as well as sorting arrays in 'gawk'. It also describes how +'gawk' provides arrays of arrays. - *note Functions::, describes the built-in functions `awk' and `gawk' + *note Functions::, describes the built-in functions 'awk' and 'gawk' provide, as well as how to define your own functions. - Part II shows how to use `awk' and `gawk' for problem solving. -There is lots of code here for you to read and learn from. It contains -the following chapters: + Part II shows how to use 'awk' and 'gawk' for problem solving. There +is lots of code here for you to read and learn from. It contains the +following chapters: - *note Library Functions::, which provides a number of functions -meant to be used from main `awk' programs. + *note Library Functions::, which provides a number of functions meant +to be used from main 'awk' programs. - *note Sample Programs::, which provides many sample `awk' programs. + *note Sample Programs::, which provides many sample 'awk' programs. - Reading these two chapters allows you to see `awk' solving real + Reading these two chapters allows you to see 'awk' solving real problems. - Part III focuses on features specific to `gawk'. It contains the + Part III focuses on features specific to 'gawk'. It contains the following chapters: - *note Advanced Features::, describes a number of `gawk'-specific -advanced features. Of particular note are the abilities to have -two-way communications with another process, perform TCP/IP networking, -and profile your `awk' programs. + *note Advanced Features::, describes a number of 'gawk'-specific +advanced features. Of particular note are the abilities to have two-way +communications with another process, perform TCP/IP networking, and +profile your 'awk' programs. - *note Internationalization::, describes special features in `gawk' + *note Internationalization::, describes special features in 'gawk' for translating program messages into different languages at runtime. - *note Debugger::, describes the `awk' debugger. + *note Debugger::, describes the 'awk' debugger. - *note Arbitrary Precision Arithmetic::, describes advanced -arithmetic facilities provided by `gawk'. + *note Arbitrary Precision Arithmetic::, describes advanced arithmetic +facilities provided by 'gawk'. *note Dynamic Extensions::, describes how to add new variables and -functions to `gawk' by writing extensions in C or C++. +functions to 'gawk' by writing extensions in C or C++. Part IV provides the appendices, the Glossary, and two licenses that -cover the `gawk' source code and this Info file, respectively. It +cover the 'gawk' source code and this Info file, respectively. It contains the following appendices: - *note Language History::, describes how the `awk' language has + *note Language History::, describes how the 'awk' language has evolved since its first release to present. It also describes how -`gawk' has acquired features over time. +'gawk' has acquired features over time. - *note Installation::, describes how to get `gawk', how to compile it + *note Installation::, describes how to get 'gawk', how to compile it on POSIX-compatible systems, and how to compile and use it on different -non-POSIX systems. It also describes how to report bugs in `gawk' and -where to get other freely available `awk' implementations. +non-POSIX systems. It also describes how to report bugs in 'gawk' and +where to get other freely available 'awk' implementations. - *note Notes::, describes how to disable `gawk''s extensions, as well -as how to contribute new code to `gawk', and some possible future -directions for `gawk' development. + *note Notes::, describes how to disable 'gawk''s extensions, as well +as how to contribute new code to 'gawk', and some possible future +directions for 'gawk' development. *note Basic Concepts::, provides some very cursory background material for those who are completely unfamiliar with computer programming. - The *note Glossary::, defines most, if not all, the significant -terms used throughout the Info file. If you find terms that you aren't + The *note Glossary::, defines most, if not all, the significant terms +used throughout the Info file. If you find terms that you aren't familiar with, try looking them up here. *note Copying::, and *note GNU Free Documentation License::, present -the licenses that cover the `gawk' source code and this Info file, +the licenses that cover the 'gawk' source code and this Info file, respectively. ---------- Footnotes ---------- (1) All such differences appear in the index under the entry -"differences in `awk' and `gawk'." +"differences in 'awk' and 'gawk'."  File: gawk.info, Node: Conventions, Next: Manual History, Prev: This Manual, Up: Preface @@ -1081,48 +1079,48 @@ Typographical Conventions ========================= This Info file is written in Texinfo -(http://www.gnu.org/software/texinfo/), the GNU documentation -formatting language. A single Texinfo source file is used to produce -both the printed and online versions of the documentation. This minor -node briefly documents the typographical conventions used in Texinfo. +(http://www.gnu.org/software/texinfo/), the GNU documentation formatting +language. A single Texinfo source file is used to produce both the +printed and online versions of the documentation. This minor node +briefly documents the typographical conventions used in Texinfo. Examples you would type at the command-line are preceded by the -common shell primary and secondary prompts, `$' and `>'. Input that -you type is shown `like this'. Output from the command is preceded by -the glyph "-|". This typically represents the command's standard -output. Error messages, and other output on the command's standard -error, are preceded by the glyph "error-->". For example: +common shell primary and secondary prompts, '$' and '>'. Input that you +type is shown 'like this'. Output from the command is preceded by the +glyph "-|". This typically represents the command's standard output. +Error messages, and other output on the command's standard error, are +preceded by the glyph "error->". For example: $ echo hi on stdout -| hi on stdout $ echo hello on stderr 1>&2 - error--> hello on stderr + error-> hello on stderr - Characters that you type at the keyboard look `like this'. In + Characters that you type at the keyboard look 'like this'. In particular, there are special characters called "control characters." -These are characters that you type by holding down both the `CONTROL' -key and another key, at the same time. For example, a `Ctrl-d' is typed -by first pressing and holding the `CONTROL' key, next pressing the `d' +These are characters that you type by holding down both the 'CONTROL' +key and another key, at the same time. For example, a 'Ctrl-d' is typed +by first pressing and holding the 'CONTROL' key, next pressing the 'd' key and finally releasing both keys. Dark Corners ------------ Dark corners are basically fractal -- no matter how much you - illuminate, there's always a smaller but darker one. -- Brian - Kernighan + illuminate, there's always a smaller but darker one. + -- _Brian Kernighan_ - Until the POSIX standard (and `GAWK: Effective AWK Programming'), -many features of `awk' were either poorly documented or not documented -at all. Descriptions of such features (often called "dark corners") -are noted in this Info file with "(d.c.)". They also appear in the -index under the heading "dark corner." + Until the POSIX standard (and 'GAWK: Effective AWK Programming'), +many features of 'awk' were either poorly documented or not documented +at all. Descriptions of such features (often called "dark corners") are +noted in this Info file with "(d.c.)". They also appear in the index +under the heading "dark corner." As noted by the opening quote, though, any coverage of dark corners is, by definition, incomplete. - Extensions to the standard `awk' language that are supported by more -than one `awk' implementation are marked "(c.e.)," and listed in the + Extensions to the standard 'awk' language that are supported by more +than one 'awk' implementation are marked "(c.e.)," and listed in the index under "common extensions" and "extensions, common."  @@ -1132,8 +1130,8 @@ The GNU Project and This Book ============================= The Free Software Foundation (FSF) is a nonprofit organization dedicated -to the production and distribution of freely distributable software. -It was founded by Richard M. Stallman, the author of the original Emacs +to the production and distribution of freely distributable software. It +was founded by Richard M. Stallman, the author of the original Emacs editor. GNU Emacs is the most widely used version of Emacs today. The GNU(1) Project is an ongoing effort on the part of the Free @@ -1142,54 +1140,54 @@ POSIX-compliant computing environment. The FSF uses the "GNU General Public License" (GPL) to ensure that their software's source code is always available to the end user. A copy of the GPL is included for your reference (*note Copying::). The GPL applies to the C language -source code for `gawk'. To find out more about the FSF and the GNU +source code for 'gawk'. To find out more about the FSF and the GNU Project online, see the GNU Project's home page (http://www.gnu.org). This Info file may also be read from their web site (http://www.gnu.org/software/gawk/manual/). A shell, an editor (Emacs), highly portable optimizing C, C++, and -Objective-C compilers, a symbolic debugger and dozens of large and -small utilities (such as `gawk'), have all been completed and are -freely available. The GNU operating system kernel (the HURD), has been +Objective-C compilers, a symbolic debugger and dozens of large and small +utilities (such as 'gawk'), have all been completed and are freely +available. The GNU operating system kernel (the HURD), has been released but remains in an early stage of development. Until the GNU operating system is more fully developed, you should consider using GNU/Linux, a freely distributable, Unix-like operating system for Intel(R), Power Architecture, Sun SPARC, IBM S/390, and other -systems.(2) Many GNU/Linux distributions are available for download +systems.(2) Many GNU/Linux distributions are available for download from the Internet. (There are numerous other freely available, Unix-like operating systems based on the Berkeley Software Distribution, and some of them -use recent versions of `gawk' for their versions of `awk'. NetBSD +use recent versions of 'gawk' for their versions of 'awk'. NetBSD (http://www.netbsd.org), FreeBSD (http://www.freebsd.org), and OpenBSD (http://www.openbsd.org) are three of the most popular ones, but there are others.) The Info file itself has gone through a number of previous editions. -Paul Rubin wrote the very first draft of `The GAWK Manual'; it was +Paul Rubin wrote the very first draft of 'The GAWK Manual'; it was around 40 pages in size. Diane Close and Richard Stallman improved it, yielding a version that was around 90 pages long and barely described -the original, "old" version of `awk'. +the original, "old" version of 'awk'. I started working with that version in the fall of 1988. As work on it progressed, the FSF published several preliminary versions (numbered -0.X). In 1996, Edition 1.0 was released with `gawk' 3.0.0. The FSF -published the first two editions under the title `The GNU Awk User's +0.X). In 1996, Edition 1.0 was released with 'gawk' 3.0.0. The FSF +published the first two editions under the title 'The GNU Awk User's Guide'. This edition maintains the basic structure of the previous editions. For FSF edition 4.0, the content has been thoroughly reviewed and -updated. All references to `gawk' versions prior to 4.0 have been +updated. All references to 'gawk' versions prior to 4.0 have been removed. Of significant note for this edition was *note Debugger::. - For FSF edition 4.1, the content has been reorganized into parts, -and the major new additions are *note Arbitrary Precision Arithmetic::, -and *note Dynamic Extensions::. + For FSF edition 4.1, the content has been reorganized into parts, and +the major new additions are *note Arbitrary Precision Arithmetic::, and +*note Dynamic Extensions::. This Info file will undoubtedly continue to evolve. An electronic -version comes with the `gawk' distribution from the FSF. If you find -an error in this Info file, please report it! *Note Bugs::, for +version comes with the 'gawk' distribution from the FSF. If you find an +error in this Info file, please report it! *Note Bugs::, for information on submitting problem reports electronically. ---------- Footnotes ---------- @@ -1204,26 +1202,26 @@ File: gawk.info, Node: How To Contribute, Next: Acknowledgments, Prev: Manual How to Contribute ================= -As the maintainer of GNU `awk', I once thought that I would be able to -manage a collection of publicly available `awk' programs and I even +As the maintainer of GNU 'awk', I once thought that I would be able to +manage a collection of publicly available 'awk' programs and I even solicited contributions. Making things available on the Internet helps -keep the `gawk' distribution down to manageable size. +keep the 'gawk' distribution down to manageable size. The initial collection of material, such as it is, is still available -at `ftp://ftp.freefriends.org/arnold/Awkstuff'. In the hopes of doing -something more broad, I acquired the `awk.info' domain. +at . In the hopes of doing +something more broad, I acquired the 'awk.info' domain. However, I found that I could not dedicate enough time to managing contributed code: the archive did not grow and the domain went unused for several years. Late in 2008, a volunteer took on the task of setting up an -`awk'-related web site--`http://awk.info'--and did a very nice job. +'awk'-related web site----and did a very nice job. - If you have written an interesting `awk' program, or have written a -`gawk' extension that you would like to share with the rest of the -world, please see `http://awk.info/?contribute' for how to contribute -it to the web site. + If you have written an interesting 'awk' program, or have written a +'gawk' extension that you would like to share with the rest of the +world, please see for how to contribute it +to the web site. As of this writing, this website is in search of a maintainer; please contact me if you are interested. @@ -1234,15 +1232,15 @@ File: gawk.info, Node: Acknowledgments, Prev: How To Contribute, Up: Preface Acknowledgments =============== -The initial draft of `The GAWK Manual' had the following +The initial draft of 'The GAWK Manual' had the following acknowledgments: Many people need to be thanked for their assistance in producing this manual. Jay Fenlason contributed many ideas and sample programs. Richard Mlynarik and Robert Chassell gave helpful - comments on drafts of this manual. The paper `A Supplemental - Document for `awk'' by John W. Pierce of the Chemistry Department - at UC San Diego, pinpointed several issues relevant both to `awk' + comments on drafts of this manual. The paper 'A Supplemental + Document for 'awk'' by John W. Pierce of the Chemistry Department + at UC San Diego, pinpointed several issues relevant both to 'awk' implementation and to this manual, that would otherwise have escaped us. @@ -1263,21 +1261,21 @@ acknowledgements: Robert J. Chassell provided much valuable advice on the use of Texinfo. He also deserves special thanks for convincing me _not_ - to title this Info file `How To Gawk Politely'. Karl Berry helped + to title this Info file 'How To Gawk Politely'. Karl Berry helped significantly with the TeX part of Texinfo. I would like to thank Marshall and Elaine Hartholz of Seattle and Dr. Bert and Rita Schreiber of Detroit for large amounts of quiet vacation time in their homes, which allowed me to make significant - progress on this Info file and on `gawk' itself. + progress on this Info file and on 'gawk' itself. Phil Hughes of SSC contributed in a very important way by loaning me his laptop GNU/Linux system, not once, but twice, which allowed me to do a lot of work while away from home. David Trueman deserves special credit; he has done a yeoman job of - evolving `gawk' so that it performs well and without bugs. - Although he is no longer involved with `gawk', working with him on + evolving 'gawk' so that it performs well and without bugs. + Although he is no longer involved with 'gawk', working with him on this project was a significant pleasure. The intrepid members of the GNITS mailing list, and most notably @@ -1286,60 +1284,60 @@ acknowledgements: Chuck Toporek, Mary Sheehan, and Claire Cloutier of O'Reilly & Associates contributed significant editorial help for this Info - file for the 3.1 release of `gawk'. + file for the 3.1 release of 'gawk'. Dr. Nelson Beebe, Andreas Buening, Dr. Manuel Collado, Antonio Colombo, Stephen Davies, Scott Deifik, Akim Demaille, Darrel Hankerson, Michal Jaegermann, Ju"rgen Kahrs, Stepan Kasal, John Malmberg, Dave Pitts, Chet Ramey, Pat Rankin, Andrew Schorr, Corinna Vinschen, and Eli -Zaretskii (in alphabetical order) make up the current `gawk' "crack -portability team." Without their hard work and help, `gawk' would not -be nearly the fine program it is today. It has been and continues to -be a pleasure working with this team of fine people. +Zaretskii (in alphabetical order) make up the current 'gawk' "crack +portability team." Without their hard work and help, 'gawk' would not +be nearly the fine program it is today. It has been and continues to be +a pleasure working with this team of fine people. - Notable code and documentation contributions were made by a number -of people. *Note Contributors::, for the full list. + Notable code and documentation contributions were made by a number of +people. *Note Contributors::, for the full list. - Thanks to Patrice Dumas for the new `makeinfo' program. Thanks to + Thanks to Patrice Dumas for the new 'makeinfo' program. Thanks to Karl Berry who continues to work to keep the Texinfo markup language sane. I would like to thank Brian Kernighan for invaluable assistance -during the testing and debugging of `gawk', and for ongoing help and +during the testing and debugging of 'gawk', and for ongoing help and advice in clarifying numerous points about the language. We could not -have done nearly as good a job on either `gawk' or its documentation +have done nearly as good a job on either 'gawk' or its documentation without his help. I must thank my wonderful wife, Miriam, for her patience through the many versions of this project, for her proofreading, and for sharing me -with the computer. I would like to thank my parents for their love, -and for the grace with which they raised and educated me. Finally, I -also must acknowledge my gratitude to G-d, for the many opportunities -He has sent my way, as well as for the gifts He has given me with which -to take advantage of those opportunities. +with the computer. I would like to thank my parents for their love, and +for the grace with which they raised and educated me. Finally, I also +must acknowledge my gratitude to G-d, for the many opportunities He has +sent my way, as well as for the gifts He has given me with which to take +advantage of those opportunities.  File: gawk.info, Node: Getting Started, Next: Invoking Gawk, Prev: Preface, Up: Top -1 Getting Started with `awk' +1 Getting Started with 'awk' **************************** -The basic function of `awk' is to search files for lines (or other -units of text) that contain certain patterns. When a line matches one -of the patterns, `awk' performs specified actions on that line. `awk' -keeps processing input lines in this way until it reaches the end of -the input files. +The basic function of 'awk' is to search files for lines (or other units +of text) that contain certain patterns. When a line matches one of the +patterns, 'awk' performs specified actions on that line. 'awk' keeps +processing input lines in this way until it reaches the end of the input +files. - Programs in `awk' are different from programs in most other -languages, because `awk' programs are "data-driven"; that is, you + Programs in 'awk' are different from programs in most other +languages, because 'awk' programs are "data-driven"; that is, you describe the data you want to work with and then what to do when you find it. Most other languages are "procedural"; you have to describe, in great detail, every step the program is to take. When working with procedural languages, it is usually much harder to clearly describe the -data your program will process. For this reason, `awk' programs are +data your program will process. For this reason, 'awk' programs are often refreshingly easy to read and write. - When you run `awk', you specify an `awk' "program" that tells `awk' + When you run 'awk', you specify an 'awk' "program" that tells 'awk' what to do. The program consists of a series of "rules". (It may also contain "function definitions", an advanced feature that we will ignore for now. *Note User-defined::.) Each rule specifies one pattern to @@ -1347,8 +1345,8 @@ search for and one action to perform upon finding the pattern. Syntactically, a rule consists of a pattern followed by an action. The action is enclosed in braces to separate it from the pattern. -Newlines usually separate rules. Therefore, an `awk' program looks -like this: +Newlines usually separate rules. Therefore, an 'awk' program looks like +this: PATTERN { ACTION } PATTERN { ACTION } @@ -1356,9 +1354,9 @@ like this: * Menu: -* Running gawk:: How to run `gawk' programs; includes +* Running gawk:: How to run 'gawk' programs; includes command-line syntax. -* Sample Data Files:: Sample data files for use in the `awk' +* Sample Data Files:: Sample data files for use in the 'awk' programs illustrated in this Info file. * Very Simple:: A very simple example. * Two Rules:: A less simple one-line example using two @@ -1366,19 +1364,19 @@ like this: * More Complex:: A more complex example. * Statements/Lines:: Subdividing or combining statements into lines. -* Other Features:: Other Features of `awk'. -* When:: When to use `gawk' and when to use +* Other Features:: Other Features of 'awk'. +* When:: When to use 'gawk' and when to use other things. * Intro Summary:: Summary of the introduction.  File: gawk.info, Node: Running gawk, Next: Sample Data Files, Up: Getting Started -1.1 How to Run `awk' Programs +1.1 How to Run 'awk' Programs ============================= -There are several ways to run an `awk' program. If the program is -short, it is easiest to include it in the command that runs `awk', like +There are several ways to run an 'awk' program. If the program is +short, it is easiest to include it in the command that runs 'awk', like this: awk 'PROGRAM' INPUT-FILE1 INPUT-FILE2 ... @@ -1393,42 +1391,42 @@ variations of each. * Menu: -* One-shot:: Running a short throwaway `awk' +* One-shot:: Running a short throwaway 'awk' program. * Read Terminal:: Using no input files (input from the keyboard instead). -* Long:: Putting permanent `awk' programs in +* Long:: Putting permanent 'awk' programs in files. -* Executable Scripts:: Making self-contained `awk' programs. -* Comments:: Adding documentation to `gawk' +* Executable Scripts:: Making self-contained 'awk' programs. +* Comments:: Adding documentation to 'gawk' programs. * Quoting:: More discussion of shell quoting issues.  File: gawk.info, Node: One-shot, Next: Read Terminal, Up: Running gawk -1.1.1 One-Shot Throwaway `awk' Programs +1.1.1 One-Shot Throwaway 'awk' Programs --------------------------------------- -Once you are familiar with `awk', you will often type in simple -programs the moment you want to use them. Then you can write the -program as the first argument of the `awk' command, like this: +Once you are familiar with 'awk', you will often type in simple programs +the moment you want to use them. Then you can write the program as the +first argument of the 'awk' command, like this: awk 'PROGRAM' INPUT-FILE1 INPUT-FILE2 ... -where PROGRAM consists of a series of PATTERNS and ACTIONS, as -described earlier. +where PROGRAM consists of a series of PATTERNS and ACTIONS, as described +earlier. - This command format instructs the "shell", or command interpreter, -to start `awk' and use the PROGRAM to process records in the input -file(s). There are single quotes around PROGRAM so the shell won't -interpret any `awk' characters as special shell characters. The quotes -also cause the shell to treat all of PROGRAM as a single argument for -`awk', and allow PROGRAM to be more than one line long. + This command format instructs the "shell", or command interpreter, to +start 'awk' and use the PROGRAM to process records in the input file(s). +There are single quotes around PROGRAM so the shell won't interpret any +'awk' characters as special shell characters. The quotes also cause the +shell to treat all of PROGRAM as a single argument for 'awk', and allow +PROGRAM to be more than one line long. - This format is also useful for running short or medium-sized `awk' + This format is also useful for running short or medium-sized 'awk' programs from shell scripts, because it avoids the need for a separate -file for the `awk' program. A self-contained shell script is more +file for the 'awk' program. A self-contained shell script is more reliable because there are no other files to misplace. *note Very Simple::, presents several short, self-contained programs. @@ -1436,36 +1434,36 @@ reliable because there are no other files to misplace.  File: gawk.info, Node: Read Terminal, Next: Long, Prev: One-shot, Up: Running gawk -1.1.2 Running `awk' Without Input Files +1.1.2 Running 'awk' Without Input Files --------------------------------------- -You can also run `awk' without any input files. If you type the +You can also run 'awk' without any input files. If you type the following command line: awk 'PROGRAM' -`awk' applies the PROGRAM to the "standard input", which usually means +'awk' applies the PROGRAM to the "standard input", which usually means whatever you type on the keyboard. This continues until you indicate -end-of-file by typing `Ctrl-d'. (On other operating systems, the +end-of-file by typing 'Ctrl-d'. (On other operating systems, the end-of-file character may be different. For example, on OS/2, it is -`Ctrl-z'.) +'Ctrl-z'.) As an example, the following program prints a friendly piece of -advice (from Douglas Adams's `The Hitchhiker's Guide to the Galaxy'), -to keep you from worrying about the complexities of computer -programming(1) (`BEGIN' is a feature we haven't discussed yet): +advice (from Douglas Adams's 'The Hitchhiker's Guide to the Galaxy'), to +keep you from worrying about the complexities of computer programming(1) +('BEGIN' is a feature we haven't discussed yet): $ awk "BEGIN { print \"Don't Panic!\" }" -| Don't Panic! - This program does not read any input. The `\' before each of the + This program does not read any input. The '\' before each of the inner double quotes is necessary because of the shell's quoting rules--in particular because it mixes both single quotes and double quotes.(2) - This next simple `awk' program emulates the `cat' utility; it copies -whatever you type on the keyboard to its standard output (why this -works is explained shortly). + This next simple 'awk' program emulates the 'cat' utility; it copies +whatever you type on the keyboard to its standard output (why this works +is explained shortly). $ awk '{ print }' Now is the time for all good men @@ -1481,8 +1479,8 @@ works is explained shortly). ---------- Footnotes ---------- (1) If you use Bash as your shell, you should execute the command -`set +H' before running this program interactively, to disable the C -shell-style command history, which treats `!' as a special character. +'set +H' before running this program interactively, to disable the C +shell-style command history, which treats '!' as a special character. We recommend putting this command into your personal startup file. (2) Although we generally recommend the use of single quotes around @@ -1495,19 +1493,19 @@ File: gawk.info, Node: Long, Next: Executable Scripts, Prev: Read Terminal, 1.1.3 Running Long Programs --------------------------- -Sometimes your `awk' programs can be very long. In this case, it is +Sometimes your 'awk' programs can be very long. In this case, it is more convenient to put the program into a separate file. In order to -tell `awk' to use that file for its program, you type: +tell 'awk' to use that file for its program, you type: awk -f SOURCE-FILE INPUT-FILE1 INPUT-FILE2 ... - The `-f' instructs the `awk' utility to get the `awk' program from + The '-f' instructs the 'awk' utility to get the 'awk' program from the file SOURCE-FILE. Any file name can be used for SOURCE-FILE. For example, you could put the program: BEGIN { print "Don't Panic!" } -into the file `advice'. Then this command: +into the file 'advice'. Then this command: awk -f advice @@ -1515,84 +1513,83 @@ does the same thing as this one: awk "BEGIN { print \"Don't Panic!\" }" -This was explained earlier (*note Read Terminal::). Note that you -don't usually need single quotes around the file name that you specify -with `-f', because most file names don't contain any of the shell's -special characters. Notice that in `advice', the `awk' program did not -have single quotes around it. The quotes are only needed for programs -that are provided on the `awk' command line. +This was explained earlier (*note Read Terminal::). Note that you don't +usually need single quotes around the file name that you specify with +'-f', because most file names don't contain any of the shell's special +characters. Notice that in 'advice', the 'awk' program did not have +single quotes around it. The quotes are only needed for programs that +are provided on the 'awk' command line. - If you want to clearly identify your `awk' program files as such, -you can add the extension `.awk' to the file name. This doesn't affect -the execution of the `awk' program but it does make "housekeeping" -easier. + If you want to clearly identify your 'awk' program files as such, you +can add the extension '.awk' to the file name. This doesn't affect the +execution of the 'awk' program but it does make "housekeeping" easier.  File: gawk.info, Node: Executable Scripts, Next: Comments, Prev: Long, Up: Running gawk -1.1.4 Executable `awk' Programs +1.1.4 Executable 'awk' Programs ------------------------------- -Once you have learned `awk', you may want to write self-contained `awk' -scripts, using the `#!' script mechanism. You can do this on many -systems.(1) For example, you could update the file `advice' to look +Once you have learned 'awk', you may want to write self-contained 'awk' +scripts, using the '#!' script mechanism. You can do this on many +systems.(1) For example, you could update the file 'advice' to look like this: #! /bin/awk -f BEGIN { print "Don't Panic!" } -After making this file executable (with the `chmod' utility), simply -type `advice' at the shell and the system arranges to run `awk'(2) as -if you had typed `awk -f advice': +After making this file executable (with the 'chmod' utility), simply +type 'advice' at the shell and the system arranges to run 'awk'(2) as if +you had typed 'awk -f advice': $ chmod +x advice $ advice -| Don't Panic! (We assume you have the current directory in your shell's search path -variable [typically `$PATH']. If not, you may need to type `./advice' +variable [typically '$PATH']. If not, you may need to type './advice' at the shell.) - Self-contained `awk' scripts are useful when you want to write a + Self-contained 'awk' scripts are useful when you want to write a program that users can invoke without their having to know that the -program is written in `awk'. +program is written in 'awk'. - Portability Issues with `#!' + Portability Issues with '#!' Some systems limit the length of the interpreter name to 32 characters. Often, this can be dealt with by using a symbolic link. - You should not put more than one argument on the `#!' line after the -path to `awk'. It does not work. The operating system treats the rest -of the line as a single argument and passes it to `awk'. Doing this -leads to confusing behavior--most likely a usage diagnostic of some -sort from `awk'. + You should not put more than one argument on the '#!' line after the +path to 'awk'. It does not work. The operating system treats the rest +of the line as a single argument and passes it to 'awk'. Doing this +leads to confusing behavior--most likely a usage diagnostic of some sort +from 'awk'. - Finally, the value of `ARGV[0]' (*note Built-in Variables::) varies -depending upon your operating system. Some systems put `awk' there, -some put the full pathname of `awk' (such as `/bin/awk'), and some put -the name of your script (`advice'). (d.c.) Don't rely on the value of -`ARGV[0]' to provide your script name. + Finally, the value of 'ARGV[0]' (*note Built-in Variables::) varies +depending upon your operating system. Some systems put 'awk' there, +some put the full pathname of 'awk' (such as '/bin/awk'), and some put +the name of your script ('advice'). (d.c.) Don't rely on the value of +'ARGV[0]' to provide your script name. ---------- Footnotes ---------- - (1) The `#!' mechanism works on GNU/Linux systems, BSD-based systems + (1) The '#!' mechanism works on GNU/Linux systems, BSD-based systems and commercial Unix systems. - (2) The line beginning with `#!' lists the full file name of an -interpreter to run and an optional initial command-line argument to -pass to that interpreter. The operating system then runs the -interpreter with the given argument and the full argument list of the -executed program. The first argument in the list is the full file name -of the `awk' program. The rest of the argument list contains either -options to `awk', or data files, or both. Note that on many systems -`awk' may be found in `/usr/bin' instead of in `/bin'. Caveat Emptor. + (2) The line beginning with '#!' lists the full file name of an +interpreter to run and an optional initial command-line argument to pass +to that interpreter. The operating system then runs the interpreter +with the given argument and the full argument list of the executed +program. The first argument in the list is the full file name of the +'awk' program. The rest of the argument list contains either options to +'awk', or data files, or both. Note that on many systems 'awk' may be +found in '/usr/bin' instead of in '/bin'. Caveat Emptor.  File: gawk.info, Node: Comments, Next: Quoting, Prev: Executable Scripts, Up: Running gawk -1.1.5 Comments in `awk' Programs +1.1.5 Comments in 'awk' Programs -------------------------------- A "comment" is some text that is included in a program for the sake of @@ -1601,28 +1598,28 @@ Comments can explain what the program does and how it works. Nearly all programming languages have provisions for comments, as programs are typically hard to understand without them. - In the `awk' language, a comment starts with the sharp sign -character (`#') and continues to the end of the line. The `#' does not -have to be the first character on the line. The `awk' language ignores -the rest of a line following a sharp sign. For example, we could have -put the following into `advice': + In the 'awk' language, a comment starts with the sharp sign character +('#') and continues to the end of the line. The '#' does not have to be +the first character on the line. The 'awk' language ignores the rest of +a line following a sharp sign. For example, we could have put the +following into 'advice': # This program prints a nice friendly message. It helps # keep novice users from being afraid of the computer. BEGIN { print "Don't Panic!" } - You can put comment lines into keyboard-composed throwaway `awk' + You can put comment lines into keyboard-composed throwaway 'awk' programs, but this usually isn't very useful; the purpose of a comment is to help you or another person understand the program when reading it at a later time. - CAUTION: As mentioned in *note One-shot::, you can enclose small - to medium programs in single quotes, in order to keep your shell + CAUTION: As mentioned in *note One-shot::, you can enclose small to + medium programs in single quotes, in order to keep your shell scripts self-contained. When doing so, _don't_ put an apostrophe (i.e., a single quote) into a comment (or anywhere else in your - program). The shell interprets the quote as the closing quote for - the entire program. As a result, usually the shell prints a - message about mismatched quotes, and if `awk' actually runs, it + program). The shell interprets the quote as the closing quote for + the entire program. As a result, usually the shell prints a + message about mismatched quotes, and if 'awk' actually runs, it will probably print strange messages about syntax errors. For example, look at the following: @@ -1632,14 +1629,14 @@ at a later time. The shell sees that the first two quotes match, and that a new quoted object begins at the end of the command line. It therefore prompts with the secondary prompt, waiting for more input. With - Unix `awk', closing the quoted string produces this result: + Unix 'awk', closing the quoted string produces this result: $ awk '{ print "hello" } # let's be cute' > ' - error--> awk: can't open file be - error--> source line number 1 + error-> awk: can't open file be + error-> source line number 1 - Putting a backslash before the single quote in `let's' wouldn't + Putting a backslash before the single quote in 'let's' wouldn't help, since backslashes are not special inside single quotes. The next node describes the shell's quoting rules. @@ -1653,11 +1650,11 @@ File: gawk.info, Node: Quoting, Prev: Comments, Up: Running gawk * DOS Quoting:: Quoting in Windows Batch Files. - For short to medium length `awk' programs, it is most convenient to -enter the program on the `awk' command line. This is best done by -enclosing the entire program in single quotes. This is true whether -you are entering the program interactively at the shell prompt, or -writing it as part of a larger shell script: +For short to medium length 'awk' programs, it is most convenient to +enter the program on the 'awk' command line. This is best done by +enclosing the entire program in single quotes. This is true whether you +are entering the program interactively at the shell prompt, or writing +it as part of a larger shell script: awk 'PROGRAM TEXT' INPUT-FILE1 INPUT-FILE2 ... @@ -1670,16 +1667,16 @@ Shell). If you use the C shell, you're on your own. throughout this Info file, which is that of the "null", or empty, string. - The null string is character data that has no value. In other -words, it is empty. It is written in `awk' programs like this: `""'. -In the shell, it can be written using single or double quotes: `""' or -`'''. While the null string has no characters in it, it does exist. -Consider this command: + The null string is character data that has no value. In other words, +it is empty. It is written in 'awk' programs like this: '""'. In the +shell, it can be written using single or double quotes: '""' or ''''. +While the null string has no characters in it, it does exist. Consider +this command: $ echo "" -Here, the `echo' utility receives a single argument, even though that -argument has no characters in it. In the rest of this Info file, we use +Here, the 'echo' utility receives a single argument, even though that +argument has no characters in it. In the rest of this Info file, we use the terms "null string" and "empty string" interchangeably. Now, on to the quoting rules. @@ -1687,28 +1684,28 @@ the quoting rules. with other quoted items. The shell turns everything into one argument for the command. - * Preceding any single character with a backslash (`\') quotes that + * Preceding any single character with a backslash ('\') quotes that character. The shell removes the backslash and passes the quoted character on to the command. * Single quotes protect everything between the opening and closing quotes. The shell does no interpretation of the quoted text, - passing it on verbatim to the command. It is _impossible_ to - embed a single quote inside single-quoted text. Refer back to - *note Comments::, for an example of what happens if you try. + passing it on verbatim to the command. It is _impossible_ to embed + a single quote inside single-quoted text. Refer back to *note + Comments::, for an example of what happens if you try. * Double quotes protect most things between the opening and closing quotes. The shell does at least variable and command substitution on the quoted text. Different shells may do additional kinds of processing on double-quoted text. - Since certain characters within double-quoted text are processed - by the shell, they must be "escaped" within the text. Of note are - the characters `$', ``', `\', and `"', all of which must be - preceded by a backslash within double-quoted text if they are to - be passed on literally to the program. (The leading backslash is - stripped first.) Thus, the example seen in *note Read Terminal::, - is applicable: + Since certain characters within double-quoted text are processed by + the shell, they must be "escaped" within the text. Of note are the + characters '$', '`', '\', and '"', all of which must be preceded by + a backslash within double-quoted text if they are to be passed on + literally to the program. (The leading backslash is stripped + first.) Thus, the example seen in *note Read Terminal::, is + applicable: $ awk "BEGIN { print \"Don't Panic!\" }" -| Don't Panic! @@ -1717,8 +1714,8 @@ the quoting rules. * Null strings are removed when they occur as part of a non-null command-line argument, while explicit non-null objects are kept. - For example, to specify that the field separator `FS' should be - set to the null string, use: + For example, to specify that the field separator 'FS' should be set + to the null string, use: awk -F "" 'PROGRAM' FILES # correct @@ -1726,8 +1723,8 @@ the quoting rules. awk -F"" 'PROGRAM' FILES # wrong! - In the second case, `awk' will attempt to use the text of the - program as the value of `FS', and the first file name as the text + In the second case, 'awk' will attempt to use the text of the + program as the value of 'FS', and the first file name as the text of the program! This results in syntax errors at best, and confusing behavior at worst. @@ -1748,17 +1745,17 @@ and the third are single-quoted, the second is double-quoted. Judge for yourself which of these two is the more readable. Another option is to use double quotes, escaping the embedded, -`awk'-level double quotes: +'awk'-level double quotes: $ awk "BEGIN { print \"Here is a single quote <'>\" }" -| Here is a single quote <'> This option is also painful, because double quotes, backslashes, and -dollar signs are very common in more advanced `awk' programs. +dollar signs are very common in more advanced 'awk' programs. - A third option is to use the octal escape sequence equivalents -(*note Escape Sequences::) for the single- and double-quote characters, -like so: + A third option is to use the octal escape sequence equivalents (*note +Escape Sequences::) for the single- and double-quote characters, like +so: $ awk 'BEGIN { print "Here is a single quote <\47>" }' -| Here is a single quote <'> @@ -1774,7 +1771,7 @@ this: $ awk -v sq="'" 'BEGIN { print "Here is a single quote <" sq ">" }' -| Here is a single quote <'> - If you really need both single and double quotes in your `awk' + If you really need both single and double quotes in your 'awk' program, it is probably best to move it into a separate file, where the shell won't be part of the picture, and you can say what you mean. @@ -1803,17 +1800,17 @@ File: gawk.info, Node: Sample Data Files, Next: Very Simple, Prev: Running ga =============================== Many of the examples in this Info file take their input from two sample -data files. The first, `mail-list', represents a list of peoples' names +data files. The first, 'mail-list', represents a list of peoples' names together with their email addresses and information about those people. -The second data file, called `inventory-shipped', contains information +The second data file, called 'inventory-shipped', contains information about monthly shipments. In both files, each line is considered to be one "record". - In the data file `mail-list', each record contains the name of a + In the data file 'mail-list', each record contains the name of a person, his/her phone number, his/her email-address, and a code for -their relationship with the author of the list. An `A' in the last -column means that the person is an acquaintance. An `F' in the last -column means that the person is a friend. An `R' means that the person +their relationship with the author of the list. An 'A' in the last +column means that the person is an acquaintance. An 'F' in the last +column means that the person is a friend. An 'R' means that the person is a relative: Amelia 555-5553 amelia.zodiacusque@gmail.com F @@ -1828,7 +1825,7 @@ is a relative: Samuel 555-3430 samuel.lanceolis@shu.edu A Jean-Paul 555-2127 jeanpaul.campanorum@nyu.edu R - The data file `inventory-shipped' represents information about + The data file 'inventory-shipped' represents information about shipments during the year. Each record contains the month, the number of green crates shipped, the number of red boxes shipped, the number of orange bags shipped, and the number of blue packages shipped, @@ -1853,8 +1850,8 @@ and the first four months of the current year. Mar 24 75 70 495 Apr 21 70 74 514 - The sample files are included in the `gawk' distribution, in the -directory `awklib/eg/data'. + The sample files are included in the 'gawk' distribution, in the +directory 'awklib/eg/data'.  File: gawk.info, Node: Very Simple, Next: Two Rules, Prev: Sample Data Files, Up: Getting Started @@ -1862,23 +1859,23 @@ File: gawk.info, Node: Very Simple, Next: Two Rules, Prev: Sample Data Files, 1.3 Some Simple Examples ======================== -The following command runs a simple `awk' program that searches the -input file `mail-list' for the character string `li' (a grouping of +The following command runs a simple 'awk' program that searches the +input file 'mail-list' for the character string 'li' (a grouping of characters is usually called a "string"; the term "string" is based on similar usage in English, such as "a string of pearls," or "a string of cars in a train"): awk '/li/ { print $0 }' mail-list -When lines containing `li' are found, they are printed because -`print $0' means print the current line. (Just `print' by itself means -the same thing, so we could have written that instead.) +When lines containing 'li' are found, they are printed because 'print $0' +means print the current line. (Just 'print' by itself means the same +thing, so we could have written that instead.) - You will notice that slashes (`/') surround the string `li' in the -`awk' program. The slashes indicate that `li' is the pattern to search + You will notice that slashes ('/') surround the string 'li' in the +'awk' program. The slashes indicate that 'li' is the pattern to search for. This type of pattern is called a "regular expression", which is covered in more detail later (*note Regexp::). The pattern is allowed -to match parts of words. There are single quotes around the `awk' +to match parts of words. There are single quotes around the 'awk' program so that the shell won't interpret any of it as special shell characters. @@ -1890,26 +1887,26 @@ characters. -| Julie 555-6699 julie.perscrutabor@skeeve.com F -| Samuel 555-3430 samuel.lanceolis@shu.edu A - In an `awk' rule, either the pattern or the action can be omitted, + In an 'awk' rule, either the pattern or the action can be omitted, but not both. If the pattern is omitted, then the action is performed -for _every_ input line. If the action is omitted, the default action -is to print all lines that match the pattern. +for _every_ input line. If the action is omitted, the default action is +to print all lines that match the pattern. - Thus, we could leave out the action (the `print' statement and the -braces) in the previous example and the result would be the same: `awk' -prints all lines matching the pattern `li'. By comparison, omitting -the `print' statement but retaining the braces makes an empty action -that does nothing (i.e., no lines are printed). + Thus, we could leave out the action (the 'print' statement and the +braces) in the previous example and the result would be the same: 'awk' +prints all lines matching the pattern 'li'. By comparison, omitting the +'print' statement but retaining the braces makes an empty action that +does nothing (i.e., no lines are printed). - Many practical `awk' programs are just a line or two. Following is a + Many practical 'awk' programs are just a line or two. Following is a collection of useful, short programs to get you started. Some of these -programs contain constructs that haven't been covered yet. (The +programs contain constructs that haven't been covered yet. (The description of the program will give you a good idea of what is going -on, but please read the rest of the Info file to become an `awk' -expert!) Most of the examples use a data file named `data'. This is +on, but please read the rest of the Info file to become an 'awk' +expert!) Most of the examples use a data file named 'data'. This is just a placeholder; if you use these programs yourself, substitute your -own file names for `data'. For future reference, note that there is -often more than one way to do things in `awk'. At some point, you may +own file names for 'data'. For future reference, note that there is +often more than one way to do things in 'awk'. At some point, you may want to look back at these examples and see if you can come up with different ways to do the same things shown here: @@ -1922,15 +1919,15 @@ different ways to do the same things shown here: awk 'length($0) > 80' data - The sole rule has a relational expression as its pattern and it - has no action--so it uses the default action, printing the record. + The sole rule has a relational expression as its pattern and it has + no action--so it uses the default action, printing the record. - * Print the length of the longest line in `data': + * Print the length of the longest line in 'data': expand data | awk '{ if (x < length()) x = length() } END { print "maximum line length is " x }' - The input is processed by the `expand' utility to change TABs into + The input is processed by the 'expand' utility to change TABs into spaces, so the widths compared are actually the right-margin columns. @@ -1969,7 +1966,7 @@ different ways to do the same things shown here: awk 'NR % 2 == 0' data - If you use the expression `NR % 2 == 1' instead, the program would + If you use the expression 'NR % 2 == 1' instead, the program would print the odd-numbered lines.  @@ -1978,31 +1975,31 @@ File: gawk.info, Node: Two Rules, Next: More Complex, Prev: Very Simple, Up: 1.4 An Example with Two Rules ============================= -The `awk' utility reads the input files one line at a time. For each -line, `awk' tries the patterns of each of the rules. If several +The 'awk' utility reads the input files one line at a time. For each +line, 'awk' tries the patterns of each of the rules. If several patterns match, then several actions execute in the order in which they -appear in the `awk' program. If no patterns match, then no actions run. +appear in the 'awk' program. If no patterns match, then no actions run. - After processing all the rules that match the line (and perhaps -there are none), `awk' reads the next line. (However, *note Next -Statement::, and also *note Nextfile Statement::). This continues -until the program reaches the end of the file. For example, the -following `awk' program contains two rules: + After processing all the rules that match the line (and perhaps there +are none), 'awk' reads the next line. (However, *note Next Statement::, +and also *note Nextfile Statement::). This continues until the program +reaches the end of the file. For example, the following 'awk' program +contains two rules: /12/ { print $0 } /21/ { print $0 } -The first rule has the string `12' as the pattern and `print $0' as the -action. The second rule has the string `21' as the pattern and also -has `print $0' as the action. Each rule's action is enclosed in its -own pair of braces. +The first rule has the string '12' as the pattern and 'print $0' as the +action. The second rule has the string '21' as the pattern and also has +'print $0' as the action. Each rule's action is enclosed in its own +pair of braces. - This program prints every line that contains the string `12' _or_ -the string `21'. If a line contains both strings, it is printed twice, -once by each rule. + This program prints every line that contains the string '12' _or_ the +string '21'. If a line contains both strings, it is printed twice, once +by each rule. This is what happens if we run this program on our two sample data -files, `mail-list' and `inventory-shipped': +files, 'mail-list' and 'inventory-shipped': $ awk '/12/ { print $0 } > /21/ { print $0 }' mail-list inventory-shipped @@ -2014,7 +2011,7 @@ files, `mail-list' and `inventory-shipped': -| Jan 21 36 64 620 -| Apr 21 70 74 514 -Note how the line beginning with `Jean-Paul' in `mail-list' was printed +Note how the line beginning with 'Jean-Paul' in 'mail-list' was printed twice, once for each rule.  @@ -2024,7 +2021,7 @@ File: gawk.info, Node: More Complex, Next: Statements/Lines, Prev: Two Rules, ========================== Now that we've mastered some simple tasks, let's look at what typical -`awk' programs do. This example shows how `awk' can be used to +'awk' programs do. This example shows how 'awk' can be used to summarize, select, and rearrange the output of another utility. It uses features that haven't been covered yet, so don't worry if you don't understand all the details: @@ -2034,9 +2031,9 @@ understand all the details: This command prints the total number of bytes in all the files in the current directory that were last modified in November (of any year). -The `ls -l' part of this example is a system command that gives you a +The 'ls -l' part of this example is a system command that gives you a listing of the files in a directory, including each file's size and the -date the file was last modified. Its output looks like this: +date the file was last modified. Its output looks like this: -rw-r--r-- 1 arnold user 1933 Nov 7 13:05 Makefile -rw-r--r-- 1 arnold user 10809 Nov 7 13:03 awk.h @@ -2048,51 +2045,51 @@ date the file was last modified. Its output looks like this: -rw-r--r-- 1 arnold user 7989 Nov 7 13:03 awk4.c The first field contains read-write permissions, the second field -contains the number of links to the file, and the third field -identifies the owner of the file. The fourth field identifies the group -of the file. The fifth field contains the size of the file in bytes. -The sixth, seventh, and eighth fields contain the month, day, and time, +contains the number of links to the file, and the third field identifies +the owner of the file. The fourth field identifies the group of the +file. The fifth field contains the size of the file in bytes. The +sixth, seventh, and eighth fields contain the month, day, and time, respectively, that the file was last modified. Finally, the ninth field contains the file name.(1) - The `$6 == "Nov"' in our `awk' program is an expression that tests -whether the sixth field of the output from `ls -l' matches the string -`Nov'. Each time a line has the string `Nov' for its sixth field, -`awk' performs the action `sum += $5'. This adds the fifth field (the -file's size) to the variable `sum'. As a result, when `awk' has -finished reading all the input lines, `sum' is the total of the sizes -of the files whose lines matched the pattern. (This works because -`awk' variables are automatically initialized to zero.) + The '$6 == "Nov"' in our 'awk' program is an expression that tests +whether the sixth field of the output from 'ls -l' matches the string +'Nov'. Each time a line has the string 'Nov' for its sixth field, 'awk' +performs the action 'sum += $5'. This adds the fifth field (the file's +size) to the variable 'sum'. As a result, when 'awk' has finished +reading all the input lines, 'sum' is the total of the sizes of the +files whose lines matched the pattern. (This works because 'awk' +variables are automatically initialized to zero.) - After the last line of output from `ls' has been processed, the -`END' rule executes and prints the value of `sum'. In this example, -the value of `sum' is 80600. + After the last line of output from 'ls' has been processed, the 'END' +rule executes and prints the value of 'sum'. In this example, the value +of 'sum' is 80600. - These more advanced `awk' techniques are covered in later sections + These more advanced 'awk' techniques are covered in later sections (*note Action Overview::). Before you can move on to more advanced -`awk' programming, you have to know how `awk' interprets your input and -displays your output. By manipulating fields and using `print' +'awk' programming, you have to know how 'awk' interprets your input and +displays your output. By manipulating fields and using 'print' statements, you can produce some very useful and impressive-looking reports. ---------- Footnotes ---------- - (1) The `LC_ALL=C' is needed to produce this traditional-style -output from `ls'. + (1) The 'LC_ALL=C' is needed to produce this traditional-style output +from 'ls'.  File: gawk.info, Node: Statements/Lines, Next: Other Features, Prev: More Complex, Up: Getting Started -1.6 `awk' Statements Versus Lines +1.6 'awk' Statements Versus Lines ================================= -Most often, each line in an `awk' program is a separate statement or +Most often, each line in an 'awk' program is a separate statement or separate rule, like this: awk '/12/ { print $0 } /21/ { print $0 }' mail-list inventory-shipped - However, `gawk' ignores newlines after any of the following symbols + However, 'gawk' ignores newlines after any of the following symbols and keywords: , { ? : || && do else @@ -2101,7 +2098,7 @@ A newline at any other point is considered the end of the statement.(1) If you would like to split a single statement into two lines at a point where a newline would terminate it, you can "continue" it by -ending the first line with a backslash character (`\'). The backslash +ending the first line with a backslash character ('\'). The backslash must be the final character on the line in order to be recognized as a continuation character. A backslash is allowed anywhere in the statement, even in the middle of a string or regular expression. For @@ -2111,27 +2108,26 @@ example: on the next line/ { print $1 }' We have generally not used backslash continuation in our sample -programs. `gawk' places no limit on the length of a line, so backslash +programs. 'gawk' places no limit on the length of a line, so backslash continuation is never strictly necessary; it just makes programs more readable. For this same reason, as well as for clarity, we have kept most statements short in the programs presented throughout the Info -file. Backslash continuation is most useful when your `awk' program is -in a separate source file instead of entered from the command line. -You should also note that many `awk' implementations are more -particular about where you may use backslash continuation. For example, -they may not allow you to split a string constant using backslash -continuation. Thus, for maximum portability of your `awk' programs, it -is best not to split your lines in the middle of a regular expression -or a string. +file. Backslash continuation is most useful when your 'awk' program is +in a separate source file instead of entered from the command line. You +should also note that many 'awk' implementations are more particular +about where you may use backslash continuation. For example, they may +not allow you to split a string constant using backslash continuation. +Thus, for maximum portability of your 'awk' programs, it is best not to +split your lines in the middle of a regular expression or a string. CAUTION: _Backslash continuation does not work as described with - the C shell._ It works for `awk' programs in files and for + the C shell._ It works for 'awk' programs in files and for one-shot programs, _provided_ you are using a POSIX-compliant shell, such as the Unix Bourne shell or Bash. But the C shell - behaves differently! There, you must use two backslashes in a - row, followed by a newline. Note also that when using the C - shell, _every_ newline in your `awk' program must be escaped with - a backslash. To illustrate: + behaves differently! There, you must use two backslashes in a row, + followed by a newline. Note also that when using the C shell, + _every_ newline in your 'awk' program must be escaped with a + backslash. To illustrate: % awk 'BEGIN { \ ? print \\ @@ -2139,8 +2135,8 @@ or a string. ? }' -| hello, world - Here, the `%' and `?' are the C shell's primary and secondary - prompts, analogous to the standard shell's `$' and `>'. + Here, the '%' and '?' are the C shell's primary and secondary + prompts, analogous to the standard shell's '$' and '>'. Compare the previous example to how it is done with a POSIX-compliant shell: @@ -2151,106 +2147,106 @@ or a string. > }' -| hello, world - `awk' is a line-oriented language. Each rule's action has to begin + 'awk' is a line-oriented language. Each rule's action has to begin on the same line as the pattern. To have the pattern and action on -separate lines, you _must_ use backslash continuation; there is no -other option. +separate lines, you _must_ use backslash continuation; there is no other +option. Another thing to keep in mind is that backslash continuation and -comments do not mix. As soon as `awk' sees the `#' that starts a -comment, it ignores _everything_ on the rest of the line. For example: +comments do not mix. As soon as 'awk' sees the '#' that starts a +comment, it ignores _everything_ on the rest of the line. For example: $ gawk 'BEGIN { print "dont panic" # a friendly \ > BEGIN rule > }' - error--> gawk: cmd. line:2: BEGIN rule - error--> gawk: cmd. line:2: ^ syntax error + error-> gawk: cmd. line:2: BEGIN rule + error-> gawk: cmd. line:2: ^ syntax error In this case, it looks like the backslash would continue the comment -onto the next line. However, the backslash-newline combination is never -even noticed because it is "hidden" inside the comment. Thus, the -`BEGIN' is noted as a syntax error. +onto the next line. However, the backslash-newline combination is never +even noticed because it is "hidden" inside the comment. Thus, the +'BEGIN' is noted as a syntax error. - When `awk' statements within one rule are short, you might want to -put more than one of them on a line. This is accomplished by -separating the statements with a semicolon (`;'). This also applies to -the rules themselves. Thus, the program shown at the start of this -minor node could also be written this way: + When 'awk' statements within one rule are short, you might want to +put more than one of them on a line. This is accomplished by separating +the statements with a semicolon (';'). This also applies to the rules +themselves. Thus, the program shown at the start of this minor node +could also be written this way: /12/ { print $0 } ; /21/ { print $0 } NOTE: The requirement that states that rules on the same line must - be separated with a semicolon was not in the original `awk' + be separated with a semicolon was not in the original 'awk' language; it was added for consistency with the treatment of statements within an action. ---------- Footnotes ---------- - (1) The `?' and `:' referred to here is the three-operand -conditional expression described in *note Conditional Exp::. Splitting -lines after `?' and `:' is a minor `gawk' extension; if `--posix' is -specified (*note Options::), then this extension is disabled. + (1) The '?' and ':' referred to here is the three-operand conditional +expression described in *note Conditional Exp::. Splitting lines after +'?' and ':' is a minor 'gawk' extension; if '--posix' is specified +(*note Options::), then this extension is disabled.  File: gawk.info, Node: Other Features, Next: When, Prev: Statements/Lines, Up: Getting Started -1.7 Other Features of `awk' +1.7 Other Features of 'awk' =========================== -The `awk' language provides a number of predefined, or "built-in", -variables that your programs can use to get information from `awk'. +The 'awk' language provides a number of predefined, or "built-in", +variables that your programs can use to get information from 'awk'. There are other variables your program can set as well to control how -`awk' processes your data. +'awk' processes your data. - In addition, `awk' provides a number of built-in functions for doing -common computational and string-related operations. `gawk' provides + In addition, 'awk' provides a number of built-in functions for doing +common computational and string-related operations. 'gawk' provides built-in functions for working with timestamps, performing bit manipulation, for runtime string translation (internationalization), determining the type of a variable, and array sorting. - As we develop our presentation of the `awk' language, we introduce -most of the variables and many of the functions. They are described + As we develop our presentation of the 'awk' language, we introduce +most of the variables and many of the functions. They are described systematically in *note Built-in Variables::, and *note Built-in::.  File: gawk.info, Node: When, Next: Intro Summary, Prev: Other Features, Up: Getting Started -1.8 When to Use `awk' +1.8 When to Use 'awk' ===================== -Now that you've seen some of what `awk' can do, you might wonder how -`awk' could be useful for you. By using utility programs, advanced +Now that you've seen some of what 'awk' can do, you might wonder how +'awk' could be useful for you. By using utility programs, advanced patterns, field separators, arithmetic statements, and other selection -criteria, you can produce much more complex output. The `awk' language +criteria, you can produce much more complex output. The 'awk' language is very useful for producing reports from large amounts of raw data, such as summarizing information from the output of other utility -programs like `ls'. (*Note More Complex::.) +programs like 'ls'. (*Note More Complex::.) - Programs written with `awk' are usually much smaller than they would -be in other languages. This makes `awk' programs easy to compose and -use. Often, `awk' programs can be quickly composed at your keyboard, -used once, and thrown away. Because `awk' programs are interpreted, you + Programs written with 'awk' are usually much smaller than they would +be in other languages. This makes 'awk' programs easy to compose and +use. Often, 'awk' programs can be quickly composed at your keyboard, +used once, and thrown away. Because 'awk' programs are interpreted, you can avoid the (usually lengthy) compilation part of the typical edit-compile-test-debug cycle of software development. - Complex programs have been written in `awk', including a complete + Complex programs have been written in 'awk', including a complete retargetable assembler for eight-bit microprocessors (*note Glossary::, for more information), and a microcode assembler for a special-purpose -Prolog computer. While the original `awk''s capabilities were strained +Prolog computer. While the original 'awk''s capabilities were strained by tasks of such complexity, modern versions are more capable. Even -Brian Kernighan's version of `awk' has fewer predefined limits, and +Brian Kernighan's version of 'awk' has fewer predefined limits, and those that it has are much larger than they used to be. - If you find yourself writing `awk' scripts of more than, say, a few + If you find yourself writing 'awk' scripts of more than, say, a few hundred lines, you might consider using a different programming language. The shell is good at string and pattern matching; in addition, it allows powerful use of the system utilities. More conventional languages, such as C, C++, and Java, offer better facilities for system programming and for managing the complexity of -large programs. Python offers a nice balance between high-level ease -of programming and access to system facilities. Programs in these +large programs. Python offers a nice balance between high-level ease of +programming and access to system facilities. Programs in these languages may require more lines of source code than the equivalent -`awk' programs, but they are easier to maintain and usually run more +'awk' programs, but they are easier to maintain and usually run more efficiently.  @@ -2259,50 +2255,50 @@ File: gawk.info, Node: Intro Summary, Prev: When, Up: Getting Started 1.9 Summary =========== - * Programs in `awk' consist of PATTERN-ACTION pairs. + * Programs in 'awk' consist of PATTERN-ACTION pairs. - * Use either `awk 'PROGRAM' FILES' or `awk -f PROGRAM-FILE FILES' to - run `awk'. + * Use either 'awk 'PROGRAM' FILES' or 'awk -f PROGRAM-FILE FILES' to + run 'awk'. - * You may use the special `#!' header line to create `awk' programs + * You may use the special '#!' header line to create 'awk' programs that are directly executable. - * Comments in `awk' programs start with `#' and continue to the end + * Comments in 'awk' programs start with '#' and continue to the end of the same line. - * Be aware of quoting issues when writing `awk' programs as part of - a larger shell script (or MS-Windows batch file). + * Be aware of quoting issues when writing 'awk' programs as part of a + larger shell script (or MS-Windows batch file). * You may use backslash continuation to continue a source line. Lines are automatically continued after a comma, open brace, - question mark, colon, `||', `&&', `do' and `else'. + question mark, colon, '||', '&&', 'do' and 'else'.  File: gawk.info, Node: Invoking Gawk, Next: Regexp, Prev: Getting Started, Up: Top -2 Running `awk' and `gawk' +2 Running 'awk' and 'gawk' ************************** -This major node covers how to run `awk', both POSIX-standard and -`gawk'-specific command-line options, and what `awk' and `gawk' do with -non-option arguments. It then proceeds to cover how `gawk' searches -for source files, reading standard input along with other files, -`gawk''s environment variables, `gawk''s exit status, using include -files, and obsolete and undocumented options and/or features. +This major node covers how to run 'awk', both POSIX-standard and +'gawk'-specific command-line options, and what 'awk' and 'gawk' do with +non-option arguments. It then proceeds to cover how 'gawk' searches for +source files, reading standard input along with other files, 'gawk''s +environment variables, 'gawk''s exit status, using include files, and +obsolete and undocumented options and/or features. - Many of the options and features described here are discussed in -more detail later in the Info file; feel free to skip over things in -this major node that don't interest you right now. + Many of the options and features described here are discussed in more +detail later in the Info file; feel free to skip over things in this +major node that don't interest you right now. * Menu: -* Command Line:: How to run `awk'. +* Command Line:: How to run 'awk'. * Options:: Command-line options and their meanings. * Other Arguments:: Input file names and variable assignments. * Naming Standard Input:: How to specify standard input with other files. -* Environment Variables:: The environment variables `gawk' uses. -* Exit Status:: `gawk''s exit status. +* Environment Variables:: The environment variables 'gawk' uses. +* Exit Status:: 'gawk''s exit status. * Include Files:: Including other files into your program. * Loading Shared Libraries:: Loading shared libraries into your program. * Obsolete:: Obsolete Options and/or features. @@ -2312,26 +2308,26 @@ this major node that don't interest you right now.  File: gawk.info, Node: Command Line, Next: Options, Up: Invoking Gawk -2.1 Invoking `awk' +2.1 Invoking 'awk' ================== -There are two ways to run `awk'--with an explicit program or with one -or more program files. Here are templates for both of them; items -enclosed in [...] in these templates are optional: +There are two ways to run 'awk'--with an explicit program or with one or +more program files. Here are templates for both of them; items enclosed +in [...] in these templates are optional: - `awk' [OPTIONS] `-f' PROGFILE [`--'] FILE ... - `awk' [OPTIONS] [`--'] `'PROGRAM'' FILE ... + 'awk' [OPTIONS] '-f' PROGFILE ['--'] FILE ... + 'awk' [OPTIONS] ['--'] ''PROGRAM'' FILE ... - Besides traditional one-letter POSIX-style options, `gawk' also + Besides traditional one-letter POSIX-style options, 'gawk' also supports GNU long options. - It is possible to invoke `awk' with an empty program: + It is possible to invoke 'awk' with an empty program: awk '' datafile1 datafile2 -Doing so makes little sense, though; `awk' exits silently when given an -empty program. (d.c.) If `--lint' has been specified on the command -line, `gawk' issues a warning that the program is empty. +Doing so makes little sense, though; 'awk' exits silently when given an +empty program. (d.c.) If '--lint' has been specified on the command +line, 'gawk' issues a warning that the program is empty.  File: gawk.info, Node: Options, Next: Other Arguments, Prev: Command Line, Up: Invoking Gawk @@ -2343,356 +2339,352 @@ Options begin with a dash and consist of a single character. GNU-style long options consist of two dashes and a keyword. The keyword can be abbreviated, as long as the abbreviation allows the option to be uniquely identified. If the option takes an argument, then the keyword -is either immediately followed by an equals sign (`=') and the +is either immediately followed by an equals sign ('=') and the argument's value, or the keyword and the argument's value are separated by whitespace. If a particular option with a value is given more than once, it is the last value that counts. - Each long option for `gawk' has a corresponding POSIX-style short + Each long option for 'gawk' has a corresponding POSIX-style short option. The long and short options are interchangeable in all contexts. The following list describes options mandated by the POSIX standard: -`-F FS' -`--field-separator FS' - Set the `FS' variable to FS (*note Field Separators::). +'-F FS' +'--field-separator FS' + Set the 'FS' variable to FS (*note Field Separators::). -`-f SOURCE-FILE' -`--file SOURCE-FILE' - Read `awk' program source from SOURCE-FILE instead of in the first +'-f SOURCE-FILE' +'--file SOURCE-FILE' + Read 'awk' program source from SOURCE-FILE instead of in the first non-option argument. This option may be given multiple times; the - `awk' program consists of the concatenation of the contents of - each specified SOURCE-FILE. + 'awk' program consists of the concatenation of the contents of each + specified SOURCE-FILE. -`-v VAR=VAL' -`--assign VAR=VAL' +'-v VAR=VAL' +'--assign VAR=VAL' Set the variable VAR to the value VAL _before_ execution of the program begins. Such variable values are available inside the - `BEGIN' rule (*note Other Arguments::). + 'BEGIN' rule (*note Other Arguments::). - The `-v' option can only set one variable, but it can be used more - than once, setting another variable each time, like this: `awk - -v foo=1 -v bar=2 ...'. + The '-v' option can only set one variable, but it can be used more + than once, setting another variable each time, like this: 'awk -v foo=1 + -v bar=2 ...'. - CAUTION: Using `-v' to set the values of the built-in - variables may lead to surprising results. `awk' will reset + CAUTION: Using '-v' to set the values of the built-in + variables may lead to surprising results. 'awk' will reset the values of those variables as it needs to, possibly ignoring any predefined value you may have given. -`-W GAWK-OPT' +'-W GAWK-OPT' Provide an implementation-specific option. This is the POSIX convention for providing implementation-specific options. These options also have corresponding GNU-style long options. Note that the long options may be abbreviated, as long as the abbreviations - remain unique. The full list of `gawk'-specific options is + remain unique. The full list of 'gawk'-specific options is provided next. -`--' +'--' Signal the end of the command-line options. The following - arguments are not treated as options even if they begin with `-'. - This interpretation of `--' follows the POSIX argument parsing + arguments are not treated as options even if they begin with '-'. + This interpretation of '--' follows the POSIX argument parsing conventions. - This is useful if you have file names that start with `-', or in - shell scripts, if you have file names that will be specified by - the user that could start with `-'. It is also useful for passing - options on to the `awk' program; see *note Getopt Function::. + This is useful if you have file names that start with '-', or in + shell scripts, if you have file names that will be specified by the + user that could start with '-'. It is also useful for passing + options on to the 'awk' program; see *note Getopt Function::. - The following list describes `gawk'-specific options: + The following list describes 'gawk'-specific options: -`-b' -`--characters-as-bytes' - Cause `gawk' to treat all input data as single-byte characters. - In addition, all output written with `print' or `printf' are - treated as single-byte characters. +'-b' +'--characters-as-bytes' + Cause 'gawk' to treat all input data as single-byte characters. In + addition, all output written with 'print' or 'printf' are treated + as single-byte characters. - Normally, `gawk' follows the POSIX standard and attempts to process + Normally, 'gawk' follows the POSIX standard and attempts to process its input data according to the current locale (*note Locales::). This can often involve converting multibyte characters into wide characters (internally), and can lead to problems or confusion if - the input data does not contain valid multibyte characters. This - option is an easy way to tell `gawk': "hands off my data!". + the input data does not contain valid multibyte characters. This + option is an easy way to tell 'gawk': "hands off my data!". -`-c' -`--traditional' +'-c' +'--traditional' Specify "compatibility mode", in which the GNU extensions to the - `awk' language are disabled, so that `gawk' behaves just like - Brian Kernighan's version `awk'. *Note POSIX/GNU::, which - summarizes the extensions. Also see *note Compatibility Mode::. + 'awk' language are disabled, so that 'gawk' behaves just like Brian + Kernighan's version 'awk'. *Note POSIX/GNU::, which summarizes the + extensions. Also see *note Compatibility Mode::. -`-C' -`--copyright' +'-C' +'--copyright' Print the short version of the General Public License and then exit. -`-d'[FILE] -`--dump-variables'[`='FILE] +'-d'[FILE] +'--dump-variables'['='FILE] Print a sorted list of global variables, their types, and final values to FILE. If no FILE is provided, print this list to the - file named `awkvars.out' in the current directory. No space is - allowed between the `-d' and FILE, if FILE is supplied. + file named 'awkvars.out' in the current directory. No space is + allowed between the '-d' and FILE, if FILE is supplied. Having a list of all global variables is a good way to look for typographical errors in your programs. You would also use this - option if you have a large program with a lot of functions, and - you want to be sure that your functions don't inadvertently use - global variables that you meant to be local. (This is a - particularly easy mistake to make with simple variable names like - `i', `j', etc.) - -`-D'[FILE] -`--debug'[`='FILE] - Enable debugging of `awk' programs (*note Debugging::). By + option if you have a large program with a lot of functions, and you + want to be sure that your functions don't inadvertently use global + variables that you meant to be local. (This is a particularly easy + mistake to make with simple variable names like 'i', 'j', etc.) + +'-D'[FILE] +'--debug'['='FILE] + Enable debugging of 'awk' programs (*note Debugging::). By default, the debugger reads commands interactively from the keyboard. The optional FILE argument allows you to specify a file with a list of commands for the debugger to execute - non-interactively. No space is allowed between the `-D' and FILE, + non-interactively. No space is allowed between the '-D' and FILE, if FILE is supplied. -`-e' PROGRAM-TEXT -`--source' PROGRAM-TEXT +'-e' PROGRAM-TEXT +'--source' PROGRAM-TEXT Provide program source code in the PROGRAM-TEXT. This option allows you to mix source code in files with source code that you enter on the command line. This is particularly useful when you have library functions that you want to use from your command-line programs (*note AWKPATH Variable::). -`-E' FILE -`--exec' FILE - Similar to `-f', read `awk' program text from FILE. There are two - differences from `-f': +'-E' FILE +'--exec' FILE + Similar to '-f', read 'awk' program text from FILE. There are two + differences from '-f': - * This option terminates option processing; anything else on - the command line is passed on directly to the `awk' program. + * This option terminates option processing; anything else on the + command line is passed on directly to the 'awk' program. - * Command-line variable assignments of the form `VAR=VALUE' are + * Command-line variable assignments of the form 'VAR=VALUE' are disallowed. This option is particularly necessary for World Wide Web CGI - applications that pass arguments through the URL; using this - option prevents a malicious (or other) user from passing in - options, assignments, or `awk' source code (via `--source') to the - CGI application. This option should be used with `#!' scripts - (*note Executable Scripts::), like so: + applications that pass arguments through the URL; using this option + prevents a malicious (or other) user from passing in options, + assignments, or 'awk' source code (via '--source') to the CGI + application. This option should be used with '#!' scripts (*note + Executable Scripts::), like so: #! /usr/local/bin/gawk -E AWK PROGRAM HERE ... -`-g' -`--gen-pot' - Analyze the source program and generate a GNU `gettext' Portable +'-g' +'--gen-pot' + Analyze the source program and generate a GNU 'gettext' Portable Object Template file on standard output for all string constants that have been marked for translation. *Note Internationalization::, for information about this option. -`-h' -`--help' +'-h' +'--help' Print a "usage" message summarizing the short and long style - options that `gawk' accepts and then exit. - -`-i' SOURCE-FILE -`--include' SOURCE-FILE - Read `awk' source library from SOURCE-FILE. This option is - completely equivalent to using the `@include' directive inside - your program. This option is very similar to the `-f' option, but - there are two important differences. First, when `-i' is used, - the program source is not loaded if it has been previously loaded, - whereas with `-f', `gawk' always loads the file. Second, because - this option is intended to be used with code libraries, `gawk' - does not recognize such files as constituting main program input. - Thus, after processing an `-i' argument, `gawk' still expects to - find the main source code via the `-f' option or on the - command-line. - -`-l' EXT -`--load' EXT - Load a dynamic extension named EXT. Extensions are stored as + options that 'gawk' accepts and then exit. + +'-i' SOURCE-FILE +'--include' SOURCE-FILE + Read 'awk' source library from SOURCE-FILE. This option is + completely equivalent to using the '@include' directive inside your + program. This option is very similar to the '-f' option, but there + are two important differences. First, when '-i' is used, the + program source is not loaded if it has been previously loaded, + whereas with '-f', 'gawk' always loads the file. Second, because + this option is intended to be used with code libraries, 'gawk' does + not recognize such files as constituting main program input. Thus, + after processing an '-i' argument, 'gawk' still expects to find the + main source code via the '-f' option or on the command-line. + +'-l' EXT +'--load' EXT + Load a dynamic extension named EXT. Extensions are stored as system shared libraries. This option searches for the library - using the `AWKLIBPATH' environment variable. The correct library + using the 'AWKLIBPATH' environment variable. The correct library suffix for your platform will be supplied by default, so it need not be specified in the extension name. The extension - initialization routine should be named `dl_load()'. An - alternative is to use the `@load' keyword inside the program to - load a shared library. This feature is described in detail in - *note Dynamic Extensions::. + initialization routine should be named 'dl_load()'. An alternative + is to use the '@load' keyword inside the program to load a shared + library. This feature is described in detail in *note Dynamic + Extensions::. -`-L'[VALUE] -`--lint'[`='VALUE] +'-L'[VALUE] +'--lint'['='VALUE] Warn about constructs that are dubious or nonportable to other - `awk' implementations. No space is allowed between the `-D' and - VALUE, if VALUE is supplied. Some warnings are issued when `gawk' + 'awk' implementations. No space is allowed between the '-D' and + VALUE, if VALUE is supplied. Some warnings are issued when 'gawk' first reads your program. Others are issued at runtime, as your - program executes. With an optional argument of `fatal', lint + program executes. With an optional argument of 'fatal', lint warnings become fatal errors. This may be drastic, but its use - will certainly encourage the development of cleaner `awk' programs. - With an optional argument of `invalid', only warnings about things - that are actually invalid are issued. (This is not fully + will certainly encourage the development of cleaner 'awk' programs. + With an optional argument of 'invalid', only warnings about things + that are actually invalid are issued. (This is not fully implemented yet.) - Some warnings are only printed once, even if the dubious - constructs they warn about occur multiple times in your `awk' - program. Thus, when eliminating problems pointed out by `--lint', - you should take care to search for all occurrences of each - inappropriate construct. As `awk' programs are usually short, - doing so is not burdensome. - -`-M' -`--bignum' - Force arbitrary precision arithmetic on numbers. This option has - no effect if `gawk' is not compiled to use the GNU MPFR and MP + Some warnings are only printed once, even if the dubious constructs + they warn about occur multiple times in your 'awk' program. Thus, + when eliminating problems pointed out by '--lint', you should take + care to search for all occurrences of each inappropriate construct. + As 'awk' programs are usually short, doing so is not burdensome. + +'-M' +'--bignum' + Force arbitrary precision arithmetic on numbers. This option has + no effect if 'gawk' is not compiled to use the GNU MPFR and MP libraries (*note Arbitrary Precision Arithmetic::). -`-n' -`--non-decimal-data' +'-n' +'--non-decimal-data' Enable automatic interpretation of octal and hexadecimal values in input data (*note Nondecimal Data::). CAUTION: This option can severely break old programs. Use with care. -`-N' -`--use-lc-numeric' +'-N' +'--use-lc-numeric' Force the use of the locale's decimal point character when parsing numeric input data (*note Locales::). -`-o'[FILE] -`--pretty-print'[`='FILE] - Enable pretty-printing of `awk' programs. By default, output - program is created in a file named `awkprof.out' (*note +'-o'[FILE] +'--pretty-print'['='FILE] + Enable pretty-printing of 'awk' programs. By default, output + program is created in a file named 'awkprof.out' (*note Profiling::). The optional FILE argument allows you to specify a different file name for the output. No space is allowed between - the `-o' and FILE, if FILE is supplied. + the '-o' and FILE, if FILE is supplied. NOTE: In the past, this option would also execute your program. This is no longer the case. -`-O' -`--optimize' +'-O' +'--optimize' Enable some optimizations on the internal representation of the program. At the moment this includes just simple constant folding. -`-p'[FILE] -`--profile'[`='FILE] - Enable profiling of `awk' programs (*note Profiling::). By - default, profiles are created in a file named `awkprof.out'. The +'-p'[FILE] +'--profile'['='FILE] + Enable profiling of 'awk' programs (*note Profiling::). By + default, profiles are created in a file named 'awkprof.out'. The optional FILE argument allows you to specify a different file name - for the profile file. No space is allowed between the `-p' and + for the profile file. No space is allowed between the '-p' and FILE, if FILE is supplied. The profile contains execution counts for each statement in the program in the left margin, and function call counts for each function. -`-P' -`--posix' - Operate in strict POSIX mode. This disables all `gawk' extensions - (just like `--traditional') and disables all extensions not - allowed by POSIX. *Note Common Extensions::, for a summary of the - extensions in `gawk' that are disabled by this option. Also, the +'-P' +'--posix' + Operate in strict POSIX mode. This disables all 'gawk' extensions + (just like '--traditional') and disables all extensions not allowed + by POSIX. *Note Common Extensions::, for a summary of the + extensions in 'gawk' that are disabled by this option. Also, the following additional restrictions apply: - * Newlines do not act as whitespace to separate fields when - `FS' is equal to a single space (*note Fields::). + * Newlines do not act as whitespace to separate fields when 'FS' + is equal to a single space (*note Fields::). - * Newlines are not allowed after `?' or `:' (*note Conditional + * Newlines are not allowed after '?' or ':' (*note Conditional Exp::). - * Specifying `-Ft' on the command-line does not set the value - of `FS' to be a single TAB character (*note Field - Separators::). + * Specifying '-Ft' on the command-line does not set the value of + 'FS' to be a single TAB character (*note Field Separators::). * The locale's decimal point character is used for parsing input data (*note Locales::). - If you supply both `--traditional' and `--posix' on the command - line, `--posix' takes precedence. `gawk' issues a warning if both + If you supply both '--traditional' and '--posix' on the command + line, '--posix' takes precedence. 'gawk' issues a warning if both options are supplied. -`-r' -`--re-interval' +'-r' +'--re-interval' Allow interval expressions (*note Regexp Operators::) in regexps. - This is now `gawk''s default behavior. Nevertheless, this option - remains both for backward compatibility, and for use in - combination with `--traditional'. - -`-S' -`--sandbox' - Disable the `system()' function, input redirections with `getline', - output redirections with `print' and `printf', and dynamic - extensions. This is particularly useful when you want to run - `awk' scripts from questionable sources and need to make sure the - scripts can't access your system (other than the specified input - data file). - -`-t' -`--lint-old' + This is now 'gawk''s default behavior. Nevertheless, this option + remains both for backward compatibility, and for use in combination + with '--traditional'. + +'-S' +'--sandbox' + Disable the 'system()' function, input redirections with 'getline', + output redirections with 'print' and 'printf', and dynamic + extensions. This is particularly useful when you want to run 'awk' + scripts from questionable sources and need to make sure the scripts + can't access your system (other than the specified input data + file). + +'-t' +'--lint-old' Warn about constructs that are not available in the original - version of `awk' from Version 7 Unix (*note V7/SVR3.1::). + version of 'awk' from Version 7 Unix (*note V7/SVR3.1::). -`-V' -`--version' - Print version information for this particular copy of `gawk'. - This allows you to determine if your copy of `gawk' is up to date - with respect to whatever the Free Software Foundation is currently +'-V' +'--version' + Print version information for this particular copy of 'gawk'. This + allows you to determine if your copy of 'gawk' is up to date with + respect to whatever the Free Software Foundation is currently distributing. It is also useful for bug reports (*note Bugs::). As long as program text has been supplied, any other options are flagged as invalid with a warning message but are otherwise ignored. In compatibility mode, as a special case, if the value of FS supplied -to the `-F' option is `t', then `FS' is set to the TAB character -(`"\t"'). This is true only for `--traditional' and not for `--posix' +to the '-F' option is 't', then 'FS' is set to the TAB character +('"\t"'). This is true only for '--traditional' and not for '--posix' (*note Field Separators::). - The `-f' option may be used more than once on the command line. If -it is, `awk' reads its program source from all of the named files, as -if they had been concatenated together into one big file. This is -useful for creating libraries of `awk' functions. These functions can -be written once and then retrieved from a standard place, instead of -having to be included into each individual program. (As mentioned in -*note Definition Syntax::, function names must be unique.) - - With standard `awk', library functions can still be used, even if -the program is entered at the keyboard, by specifying `-f /dev/tty'. -After typing your program, type `Ctrl-d' (the end-of-file character) to -terminate it. (You may also use `-f -' to read program source from the + The '-f' option may be used more than once on the command line. If +it is, 'awk' reads its program source from all of the named files, as if +they had been concatenated together into one big file. This is useful +for creating libraries of 'awk' functions. These functions can be +written once and then retrieved from a standard place, instead of having +to be included into each individual program. (As mentioned in *note +Definition Syntax::, function names must be unique.) + + With standard 'awk', library functions can still be used, even if the +program is entered at the keyboard, by specifying '-f /dev/tty'. After +typing your program, type 'Ctrl-d' (the end-of-file character) to +terminate it. (You may also use '-f -' to read program source from the standard input but then you will not be able to also use the standard input as a source of data.) - Because it is clumsy using the standard `awk' mechanisms to mix -source file and command-line `awk' programs, `gawk' provides the -`--source' option. This does not require you to pre-empt the standard -input for your source code; it allows you to easily mix command-line -and library source code (*note AWKPATH Variable::). As with `-f', the -`--source' and `--include' options may also be used multiple times on + Because it is clumsy using the standard 'awk' mechanisms to mix +source file and command-line 'awk' programs, 'gawk' provides the +'--source' option. This does not require you to pre-empt the standard +input for your source code; it allows you to easily mix command-line and +library source code (*note AWKPATH Variable::). As with '-f', the +'--source' and '--include' options may also be used multiple times on the command line. - If no `-f' or `--source' option is specified, then `gawk' uses the -first non-option command-line argument as the text of the program -source code. + If no '-f' or '--source' option is specified, then 'gawk' uses the +first non-option command-line argument as the text of the program source +code. - If the environment variable `POSIXLY_CORRECT' exists, then `gawk' -behaves in strict POSIX mode, exactly as if you had supplied `--posix'. + If the environment variable 'POSIXLY_CORRECT' exists, then 'gawk' +behaves in strict POSIX mode, exactly as if you had supplied '--posix'. Many GNU programs look for this environment variable to suppress -extensions that conflict with POSIX, but `gawk' behaves differently: it +extensions that conflict with POSIX, but 'gawk' behaves differently: it suppresses all extensions, even those that do not conflict with POSIX, -and behaves in strict POSIX mode. If `--lint' is supplied on the -command line and `gawk' turns on POSIX mode because of -`POSIXLY_CORRECT', then it issues a warning message indicating that +and behaves in strict POSIX mode. If '--lint' is supplied on the +command line and 'gawk' turns on POSIX mode because of +'POSIXLY_CORRECT', then it issues a warning message indicating that POSIX mode is in effect. You would typically set this variable in your -shell's startup file. For a Bourne-compatible shell (such as Bash), -you would add these lines to the `.profile' file in your home directory: +shell's startup file. For a Bourne-compatible shell (such as Bash), you +would add these lines to the '.profile' file in your home directory: POSIXLY_CORRECT=true export POSIXLY_CORRECT For a C shell-compatible shell,(1) you would add this line to the -`.login' file in your home directory: +'.login' file in your home directory: setenv POSIXLY_CORRECT true - Having `POSIXLY_CORRECT' set is not recommended for daily use, but -it is good for testing the portability of your programs to other + Having 'POSIXLY_CORRECT' set is not recommended for daily use, but it +is good for testing the portability of your programs to other environments. ---------- Footnotes ---------- @@ -2706,53 +2698,53 @@ File: gawk.info, Node: Other Arguments, Next: Naming Standard Input, Prev: Op ================================ Any additional arguments on the command line are normally treated as -input files to be processed in the order specified. However, an -argument that has the form `VAR=VALUE', assigns the value VALUE to the +input files to be processed in the order specified. However, an +argument that has the form 'VAR=VALUE', assigns the value VALUE to the variable VAR--it does not specify a file at all. (See *note Assignment Options::.) - All these arguments are made available to your `awk' program in the -`ARGV' array (*note Built-in Variables::). Command-line options and -the program text (if present) are omitted from `ARGV'. All other -arguments, including variable assignments, are included. As each -element of `ARGV' is processed, `gawk' sets the variable `ARGIND' to -the index in `ARGV' of the current element. + All these arguments are made available to your 'awk' program in the +'ARGV' array (*note Built-in Variables::). Command-line options and the +program text (if present) are omitted from 'ARGV'. All other arguments, +including variable assignments, are included. As each element of 'ARGV' +is processed, 'gawk' sets the variable 'ARGIND' to the index in 'ARGV' +of the current element. The distinction between file name arguments and variable-assignment -arguments is made when `awk' is about to open the next input file. At +arguments is made when 'awk' is about to open the next input file. At that point in execution, it checks the file name to see whether it is -really a variable assignment; if so, `awk' sets the variable instead of +really a variable assignment; if so, 'awk' sets the variable instead of reading a file. Therefore, the variables actually receive the given values after all previously specified files have been read. In particular, the values of -variables assigned in this fashion are _not_ available inside a `BEGIN' -rule (*note BEGIN/END::), because such rules are run before `awk' -begins scanning the argument list. +variables assigned in this fashion are _not_ available inside a 'BEGIN' +rule (*note BEGIN/END::), because such rules are run before 'awk' begins +scanning the argument list. The variable values given on the command line are processed for escape sequences (*note Escape Sequences::). (d.c.) - In some very early implementations of `awk', when a variable + In some very early implementations of 'awk', when a variable assignment occurred before any file names, the assignment would happen -_before_ the `BEGIN' rule was executed. `awk''s behavior was thus +_before_ the 'BEGIN' rule was executed. 'awk''s behavior was thus inconsistent; some command-line assignments were available inside the -`BEGIN' rule, while others were not. Unfortunately, some applications -came to depend upon this "feature." When `awk' was changed to be more -consistent, the `-v' option was added to accommodate applications that +'BEGIN' rule, while others were not. Unfortunately, some applications +came to depend upon this "feature." When 'awk' was changed to be more +consistent, the '-v' option was added to accommodate applications that depended upon the old behavior. The variable assignment feature is most useful for assigning to -variables such as `RS', `OFS', and `ORS', which control input and -output formats, before scanning the data files. It is also useful for +variables such as 'RS', 'OFS', and 'ORS', which control input and output +formats, before scanning the data files. It is also useful for controlling state if multiple passes are needed over a data file. For example: awk 'pass == 1 { PASS 1 STUFF } pass == 2 { PASS 2 STUFF }' pass=1 mydata pass=2 mydata - Given the variable assignment feature, the `-F' option for setting -the value of `FS' is not strictly necessary. It remains for historical + Given the variable assignment feature, the '-F' option for setting +the value of 'FS' is not strictly necessary. It remains for historical compatibility.  @@ -2765,121 +2757,119 @@ Often, you may wish to read standard input together with other files. For example, you may wish to read one file, read standard input coming from a pipe, and then read another file. - The way to name the standard input, with all versions of `awk', is -to use a single, standalone minus sign or dash, `-'. For example: + The way to name the standard input, with all versions of 'awk', is to +use a single, standalone minus sign or dash, '-'. For example: SOME_COMMAND | awk -f myprog.awk file1 - file2 -Here, `awk' first reads `file1', then it reads the output of -SOME_COMMAND, and finally it reads `file2'. +Here, 'awk' first reads 'file1', then it reads the output of +SOME_COMMAND, and finally it reads 'file2'. - You may also use `"-"' to name standard input when reading files -with `getline' (*note Getline/File::). + You may also use '"-"' to name standard input when reading files with +'getline' (*note Getline/File::). - In addition, `gawk' allows you to specify the special file name -`/dev/stdin', both on the command line and with `getline'. Some other -versions of `awk' also support this, but it is not standard. (Some -operating systems provide a `/dev/stdin' file in the file system; -however, `gawk' always processes this file name itself.) + In addition, 'gawk' allows you to specify the special file name +'/dev/stdin', both on the command line and with 'getline'. Some other +versions of 'awk' also support this, but it is not standard. (Some +operating systems provide a '/dev/stdin' file in the file system; +however, 'gawk' always processes this file name itself.)  File: gawk.info, Node: Environment Variables, Next: Exit Status, Prev: Naming Standard Input, Up: Invoking Gawk -2.5 The Environment Variables `gawk' Uses +2.5 The Environment Variables 'gawk' Uses ========================================= -A number of environment variables influence how `gawk' behaves. +A number of environment variables influence how 'gawk' behaves. * Menu: -* AWKPATH Variable:: Searching directories for `awk' +* AWKPATH Variable:: Searching directories for 'awk' programs. -* AWKLIBPATH Variable:: Searching directories for `awk' shared +* AWKLIBPATH Variable:: Searching directories for 'awk' shared libraries. * Other Environment Variables:: The environment variables.  File: gawk.info, Node: AWKPATH Variable, Next: AWKLIBPATH Variable, Up: Environment Variables -2.5.1 The `AWKPATH' Environment Variable +2.5.1 The 'AWKPATH' Environment Variable ---------------------------------------- -The previous minor node described how `awk' program files can be named -on the command-line with the `-f' option. In most `awk' +The previous minor node described how 'awk' program files can be named +on the command-line with the '-f' option. In most 'awk' implementations, you must supply a precise path name for each program -file, unless the file is in the current directory. But in `gawk', if -the file name supplied to the `-f' or `-i' options does not contain a -directory separator `/', then `gawk' searches a list of directories +file, unless the file is in the current directory. But in 'gawk', if +the file name supplied to the '-f' or '-i' options does not contain a +directory separator '/', then 'gawk' searches a list of directories (called the "search path"), one by one, looking for a file with the specified name. -The search path is a string consisting of directory names separated by -colons(1). `gawk' gets its search path from the `AWKPATH' environment -variable. If that variable does not exist, `gawk' uses a default path, -`.:/usr/local/share/awk'.(2) + The search path is a string consisting of directory names separated +by colons(1). 'gawk' gets its search path from the 'AWKPATH' +environment variable. If that variable does not exist, 'gawk' uses a +default path, '.:/usr/local/share/awk'.(2) The search path feature is particularly helpful for building -libraries of useful `awk' functions. The library files can be placed -in a standard directory in the default path and then specified on the +libraries of useful 'awk' functions. The library files can be placed in +a standard directory in the default path and then specified on the command line with a short file name. Otherwise, the full file name would have to be typed for each file. - By using the `-i' option, or the `--source' and `-f' options, your -command-line `awk' programs can use facilities in `awk' library files -(*note Library Functions::). Path searching is not done if `gawk' is -in compatibility mode. This is true for both `--traditional' and -`--posix'. *Note Options::. + By using the '-i' option, or the '--source' and '-f' options, your +command-line 'awk' programs can use facilities in 'awk' library files +(*note Library Functions::). Path searching is not done if 'gawk' is in +compatibility mode. This is true for both '--traditional' and +'--posix'. *Note Options::. - If the source code is not found after the initial search, the path -is searched again after adding the default `.awk' suffix to the file -name. + If the source code is not found after the initial search, the path is +searched again after adding the default '.awk' suffix to the file name. NOTE: To include the current directory in the path, either place - `.' explicitly in the path or write a null entry in the path. (A - null entry is indicated by starting or ending the path with a - colon or by placing two colons next to each other [`::'].) This - path search mechanism is similar to the shell's. (See `The - Bourne-Again SHell manual'. - (http://www.gnu.org/software/bash/manual/)) - - However, `gawk' always looks in the current directory _before_ - searching `AWKPATH', so there is no real reason to include the + '.' explicitly in the path or write a null entry in the path. (A + null entry is indicated by starting or ending the path with a colon + or by placing two colons next to each other ['::'].) This path + search mechanism is similar to the shell's. (See 'The Bourne-Again + SHell manual'. (http://www.gnu.org/software/bash/manual/)) + + However, 'gawk' always looks in the current directory _before_ + searching 'AWKPATH', so there is no real reason to include the current directory in the search path. - If `AWKPATH' is not defined in the environment, `gawk' places its -default search path into `ENVIRON["AWKPATH"]'. This makes it easy to -determine the actual search path that `gawk' used from within an `awk' + If 'AWKPATH' is not defined in the environment, 'gawk' places its +default search path into 'ENVIRON["AWKPATH"]'. This makes it easy to +determine the actual search path that 'gawk' used from within an 'awk' program. - While you can change `ENVIRON["AWKPATH"]' within your `awk' program, -this has no effect on the running program's behavior. This makes -sense: the `AWKPATH' environment variable is used to find the program -source files. Once your program is running, all the files have been -found, and `gawk' no longer needs to use `AWKPATH'. + While you can change 'ENVIRON["AWKPATH"]' within your 'awk' program, +this has no effect on the running program's behavior. This makes sense: +the 'AWKPATH' environment variable is used to find the program source +files. Once your program is running, all the files have been found, and +'gawk' no longer needs to use 'AWKPATH'. ---------- Footnotes ---------- (1) Semicolons on MS-Windows and MS-DOS. - (2) Your version of `gawk' may use a different directory; it will -depend upon how `gawk' was built and installed. The actual directory is -the value of `$(datadir)' generated when `gawk' was configured. You + (2) Your version of 'gawk' may use a different directory; it will +depend upon how 'gawk' was built and installed. The actual directory is +the value of '$(datadir)' generated when 'gawk' was configured. You probably don't need to worry about this, though.  File: gawk.info, Node: AWKLIBPATH Variable, Next: Other Environment Variables, Prev: AWKPATH Variable, Up: Environment Variables -2.5.2 The `AWKLIBPATH' Environment Variable +2.5.2 The 'AWKLIBPATH' Environment Variable ------------------------------------------- -The `AWKLIBPATH' environment variable is similar to the `AWKPATH' +The 'AWKLIBPATH' environment variable is similar to the 'AWKPATH' variable, but it is used to search for loadable extensions (stored as -system shared libraries) specified with the `-l' option rather than for -source files. If the extension is not found, the path is searched -again after adding the appropriate shared library suffix for the -platform. For example, on GNU/Linux systems, the suffix `.so' is used. -The search path specified is also used for extensions loaded via the -`@load' keyword (*note Loading Shared Libraries::). +system shared libraries) specified with the '-l' option rather than for +source files. If the extension is not found, the path is searched again +after adding the appropriate shared library suffix for the platform. +For example, on GNU/Linux systems, the suffix '.so' is used. The search +path specified is also used for extensions loaded via the '@load' +keyword (*note Loading Shared Libraries::).  File: gawk.info, Node: Other Environment Variables, Prev: AWKLIBPATH Variable, Up: Environment Variables @@ -2887,100 +2877,100 @@ File: gawk.info, Node: Other Environment Variables, Prev: AWKLIBPATH Variable, 2.5.3 Other Environment Variables --------------------------------- -A number of other environment variables affect `gawk''s behavior, but -they are more specialized. Those in the following list are meant to be +A number of other environment variables affect 'gawk''s behavior, but +they are more specialized. Those in the following list are meant to be used by regular users. -`POSIXLY_CORRECT' - Causes `gawk' to switch POSIX compatibility mode, disabling all +'POSIXLY_CORRECT' + Causes 'gawk' to switch POSIX compatibility mode, disabling all traditional and GNU extensions. *Note Options::. -`GAWK_SOCK_RETRIES' - Controls the number of times `gawk' attempts to retry a two-way +'GAWK_SOCK_RETRIES' + Controls the number of times 'gawk' attempts to retry a two-way TCP/IP (socket) connection before giving up. *Note TCP/IP Networking::. -`GAWK_MSEC_SLEEP' - Specifies the interval between connection retries, in - milliseconds. On systems that do not support the `usleep()' system - call, the value is rounded up to an integral number of seconds. +'GAWK_MSEC_SLEEP' + Specifies the interval between connection retries, in milliseconds. + On systems that do not support the 'usleep()' system call, the + value is rounded up to an integral number of seconds. -`GAWK_READ_TIMEOUT' - Specifies the time, in milliseconds, for `gawk' to wait for input +'GAWK_READ_TIMEOUT' + Specifies the time, in milliseconds, for 'gawk' to wait for input before returning with an error. *Note Read Timeout::. The environment variables in the following list are meant for use by -the `gawk' developers for testing and tuning. They are subject to -change. The variables are: - -`AWKBUFSIZE' - This variable only affects `gawk' on POSIX-compliant systems. - With a value of `exact', `gawk' uses the size of each input file - as the size of the memory buffer to allocate for I/O. Otherwise, - the value should be a number, and `gawk' uses that number as the - size of the buffer to allocate. (When this variable is not set, - `gawk' uses the smaller of the file's size and the "default" - blocksize, which is usually the file systems I/O blocksize.) - -`AWK_HASH' - If this variable exists with a value of `gst', `gawk' switches to +the 'gawk' developers for testing and tuning. They are subject to +change. The variables are: + +'AWKBUFSIZE' + This variable only affects 'gawk' on POSIX-compliant systems. With + a value of 'exact', 'gawk' uses the size of each input file as the + size of the memory buffer to allocate for I/O. Otherwise, the value + should be a number, and 'gawk' uses that number as the size of the + buffer to allocate. (When this variable is not set, 'gawk' uses + the smaller of the file's size and the "default" blocksize, which + is usually the file systems I/O blocksize.) + +'AWK_HASH' + If this variable exists with a value of 'gst', 'gawk' switches to using the hash function from GNU Smalltalk for managing arrays. This function may be marginally faster than the standard function. -`AWKREADFUNC' - If this variable exists, `gawk' switches to reading source files - one line at a time, instead of reading in blocks. This exists for +'AWKREADFUNC' + If this variable exists, 'gawk' switches to reading source files + one line at a time, instead of reading in blocks. This exists for debugging problems on filesystems on non-POSIX operating systems where I/O is performed in records, not in blocks. -`GAWK_MSG_SRC' - If this variable exists, `gawk' includes the source file name and - line number from which warning and/or fatal messages are - generated. Its purpose is to help isolate the source of a - message, since there can be multiple places which produce the same - warning or error message. - -`GAWK_NO_DFA' - If this variable exists, `gawk' does not use the DFA regexp matcher - for "does it match" kinds of tests. This can cause `gawk' to be - slower. Its purpose is to help isolate differences between the two - regexp matchers that `gawk' uses internally. (There aren't +'GAWK_MSG_SRC' + If this variable exists, 'gawk' includes the source file name and + line number from which warning and/or fatal messages are generated. + Its purpose is to help isolate the source of a message, since there + can be multiple places which produce the same warning or error + message. + +'GAWK_NO_DFA' + If this variable exists, 'gawk' does not use the DFA regexp matcher + for "does it match" kinds of tests. This can cause 'gawk' to be + slower. Its purpose is to help isolate differences between the two + regexp matchers that 'gawk' uses internally. (There aren't supposed to be differences, but occasionally theory and practice don't coordinate with each other.) -`GAWK_STACKSIZE' - This specifies the amount by which `gawk' should grow its internal +'GAWK_STACKSIZE' + This specifies the amount by which 'gawk' should grow its internal evaluation stack, when needed. -`INT_CHAIN_MAX' - The average number of items `gawk' will maintain on a hash chain +'INT_CHAIN_MAX' + The average number of items 'gawk' will maintain on a hash chain for managing arrays indexed by integers. -`STR_CHAIN_MAX' - The average number of items `gawk' will maintain on a hash chain +'STR_CHAIN_MAX' + The average number of items 'gawk' will maintain on a hash chain for managing arrays indexed by strings. -`TIDYMEM' - If this variable exists, `gawk' uses the `mtrace()' library calls +'TIDYMEM' + If this variable exists, 'gawk' uses the 'mtrace()' library calls from GNU LIBC to help track down possible memory leaks.  File: gawk.info, Node: Exit Status, Next: Include Files, Prev: Environment Variables, Up: Invoking Gawk -2.6 `gawk''s Exit Status +2.6 'gawk''s Exit Status ======================== -If the `exit' statement is used with a value (*note Exit Statement::), -then `gawk' exits with the numeric value given to it. +If the 'exit' statement is used with a value (*note Exit Statement::), +then 'gawk' exits with the numeric value given to it. - Otherwise, if there were no problems during execution, `gawk' exits -with the value of the C constant `EXIT_SUCCESS'. This is usually zero. + Otherwise, if there were no problems during execution, 'gawk' exits +with the value of the C constant 'EXIT_SUCCESS'. This is usually zero. - If an error occurs, `gawk' exits with the value of the C constant -`EXIT_FAILURE'. This is usually one. + If an error occurs, 'gawk' exits with the value of the C constant +'EXIT_FAILURE'. This is usually one. - If `gawk' exits because of a fatal error, the exit status is 2. On -non-POSIX systems, this value may be mapped to `EXIT_FAILURE'. + If 'gawk' exits because of a fatal error, the exit status is 2. On +non-POSIX systems, this value may be mapped to 'EXIT_FAILURE'.  File: gawk.info, Node: Include Files, Next: Loading Shared Libraries, Prev: Exit Status, Up: Invoking Gawk @@ -2988,63 +2978,63 @@ File: gawk.info, Node: Include Files, Next: Loading Shared Libraries, Prev: E 2.7 Including Other Files Into Your Program =========================================== -This minor node describes a feature that is specific to `gawk'. +This minor node describes a feature that is specific to 'gawk'. - The `@include' keyword can be used to read external `awk' source -files. This gives you the ability to split large `awk' source files + The '@include' keyword can be used to read external 'awk' source +files. This gives you the ability to split large 'awk' source files into smaller, more manageable pieces, and also lets you reuse common -`awk' code from various `awk' scripts. In other words, you can group -together `awk' functions, used to carry out specific tasks, into -external files. These files can be used just like function libraries, -using the `@include' keyword in conjunction with the `AWKPATH' -environment variable. Note that source files may also be included -using the `-i' option. +'awk' code from various 'awk' scripts. In other words, you can group +together 'awk' functions, used to carry out specific tasks, into +external files. These files can be used just like function libraries, +using the '@include' keyword in conjunction with the 'AWKPATH' +environment variable. Note that source files may also be included using +the '-i' option. - Let's see an example. We'll start with two (trivial) `awk' scripts, -namely `test1' and `test2'. Here is the `test1' script: + Let's see an example. We'll start with two (trivial) 'awk' scripts, +namely 'test1' and 'test2'. Here is the 'test1' script: BEGIN { print "This is script test1." } -and here is `test2': +and here is 'test2': @include "test1" BEGIN { print "This is script test2." } - Running `gawk' with `test2' produces the following result: + Running 'gawk' with 'test2' produces the following result: $ gawk -f test2 -| This is file test1. -| This is file test2. - `gawk' runs the `test2' script which includes `test1' using the -`@include' keyword. So, to include external `awk' source files you just -use `@include' followed by the name of the file to be included, -enclosed in double quotes. + 'gawk' runs the 'test2' script which includes 'test1' using the +'@include' keyword. So, to include external 'awk' source files you just +use '@include' followed by the name of the file to be included, enclosed +in double quotes. NOTE: Keep in mind that this is a language construct and the file name cannot be a string variable, but rather just a literal string constant in double quotes. The files to be included may be nested; e.g., given a third script, -namely `test3': +namely 'test3': @include "test2" BEGIN { print "This is script test3." } -Running `gawk' with the `test3' script produces the following results: +Running 'gawk' with the 'test3' script produces the following results: $ gawk -f test3 -| This is file test1. -| This is file test2. -| This is file test3. - The file name can, of course, be a pathname. For example: + The file name can, of course, be a pathname. For example: @include "../io_funcs" @@ -3052,32 +3042,31 @@ or: @include "/usr/awklib/network" -are valid. The `AWKPATH' environment variable can be of great value -when using `@include'. The same rules for the use of the `AWKPATH' +are valid. The 'AWKPATH' environment variable can be of great value +when using '@include'. The same rules for the use of the 'AWKPATH' variable in command-line file searches (*note AWKPATH Variable::) apply -to `@include' also. +to '@include' also. - This is very helpful in constructing `gawk' function libraries. If -you have a large script with useful, general purpose `awk' functions, + This is very helpful in constructing 'gawk' function libraries. If +you have a large script with useful, general purpose 'awk' functions, you can break it down into library files and put those files in a -special directory. You can then include those "libraries," using -either the full pathnames of the files, or by setting the `AWKPATH' -environment variable accordingly and then using `@include' with just -the file part of the full pathname. Of course you can have more than -one directory to keep library files; the more complex the working -environment is, the more directories you may need to organize the files -to be included. - - Given the ability to specify multiple `-f' options, the `@include' -mechanism is not strictly necessary. However, the `@include' keyword -can help you in constructing self-contained `gawk' programs, thus +special directory. You can then include those "libraries," using either +the full pathnames of the files, or by setting the 'AWKPATH' environment +variable accordingly and then using '@include' with just the file part +of the full pathname. Of course you can have more than one directory to +keep library files; the more complex the working environment is, the +more directories you may need to organize the files to be included. + + Given the ability to specify multiple '-f' options, the '@include' +mechanism is not strictly necessary. However, the '@include' keyword +can help you in constructing self-contained 'gawk' programs, thus reducing the need for writing complex and tedious command lines. In -particular, `@include' is very useful for writing CGI scripts to be run +particular, '@include' is very useful for writing CGI scripts to be run from web pages. As mentioned in *note AWKPATH Variable::, the current directory is -always searched first for source files, before searching in `AWKPATH', -and this also applies to files named with `@include'. +always searched first for source files, before searching in 'AWKPATH', +and this also applies to files named with '@include'.  File: gawk.info, Node: Loading Shared Libraries, Next: Obsolete, Prev: Include Files, Up: Invoking Gawk @@ -3085,19 +3074,19 @@ File: gawk.info, Node: Loading Shared Libraries, Next: Obsolete, Prev: Includ 2.8 Loading Dynamic Extensions Into Your Program ================================================ -This minor node describes a feature that is specific to `gawk'. +This minor node describes a feature that is specific to 'gawk'. - The `@load' keyword can be used to read external `awk' extensions + The '@load' keyword can be used to read external 'awk' extensions (stored as system shared libraries). This allows you to link in -compiled code that may offer superior performance and/or give you -access to extended capabilities not supported by the `awk' language. -The `AWKLIBPATH' variable is used to search for the extension. Using -`@load' is completely equivalent to using the `-l' command-line option. +compiled code that may offer superior performance and/or give you access +to extended capabilities not supported by the 'awk' language. The +'AWKLIBPATH' variable is used to search for the extension. Using +'@load' is completely equivalent to using the '-l' command-line option. - If the extension is not initially found in `AWKLIBPATH', another + If the extension is not initially found in 'AWKLIBPATH', another search is conducted after appending the platform's default shared -library suffix to the file name. For example, on GNU/Linux systems, -the suffix `.so' is used. +library suffix to the file name. For example, on GNU/Linux systems, the +suffix '.so' is used. $ gawk '@load "ordchr"; BEGIN {print chr(65)}' -| A @@ -3107,12 +3096,12 @@ This is equivalent to the following example: $ gawk -lordchr 'BEGIN {print chr(65)}' -| A -For command-line usage, the `-l' option is more convenient, but `@load' -is useful for embedding inside an `awk' source file that requires -access to an extension. +For command-line usage, the '-l' option is more convenient, but '@load' +is useful for embedding inside an 'awk' source file that requires access +to an extension. *note Dynamic Extensions::, describes how to write extensions (in C -or C++) that can be loaded with either `@load' or the `-l' option. +or C++) that can be loaded with either '@load' or the '-l' option.  File: gawk.info, Node: Obsolete, Next: Undocumented, Prev: Loading Shared Libraries, Up: Invoking Gawk @@ -3121,14 +3110,14 @@ File: gawk.info, Node: Obsolete, Next: Undocumented, Prev: Loading Shared Lib ==================================== This minor node describes features and/or command-line options from -previous releases of `gawk' that are either not available in the -current version or that are still supported but deprecated (meaning that -they will _not_ be in the next release). +previous releases of 'gawk' that are either not available in the current +version or that are still supported but deprecated (meaning that they +will _not_ be in the next release). - The process-related special files `/dev/pid', `/dev/ppid', -`/dev/pgrpid', and `/dev/user' were deprecated in `gawk' 3.1, but still + The process-related special files '/dev/pid', '/dev/ppid', +'/dev/pgrpid', and '/dev/user' were deprecated in 'gawk' 3.1, but still worked. As of version 4.0, they are no longer interpreted specially by -`gawk'. (Use `PROCINFO' instead; see *note Auto-set::.) +'gawk'. (Use 'PROCINFO' instead; see *note Auto-set::.)  File: gawk.info, Node: Undocumented, Next: Invoking Summary, Prev: Obsolete, Up: Invoking Gawk @@ -3136,7 +3125,8 @@ File: gawk.info, Node: Undocumented, Next: Invoking Summary, Prev: Obsolete, 2.10 Undocumented Options and Features ====================================== - Use the Source, Luke! -- Obi-Wan + Use the Source, Luke! + -- _Obi-Wan_ This minor node intentionally left blank. @@ -3146,41 +3136,40 @@ File: gawk.info, Node: Invoking Summary, Prev: Undocumented, Up: Invoking Gaw 2.11 Summary ============ - * Use either `awk 'PROGRAM' FILES' or `awk -f PROGRAM-FILE FILES' to - run `awk'. + * Use either 'awk 'PROGRAM' FILES' or 'awk -f PROGRAM-FILE FILES' to + run 'awk'. - * The three standard `awk' options are `-f', `-F' and `-v'. `gawk' + * The three standard 'awk' options are '-f', '-F' and '-v'. 'gawk' supplies these and many others, as well as corresponding GNU-style long options. * Non-option command-line arguments are usually treated as file - names, unless they have the form `VAR=VALUE', in which case they + names, unless they have the form 'VAR=VALUE', in which case they are taken as variable assignments to be performed at that point in processing the input. * All non-option command-line arguments, excluding the program text, - are placed in the `ARGV' array. Adjusting `ARGC' and `ARGV' - affects how `awk' processes input. + are placed in the 'ARGV' array. Adjusting 'ARGC' and 'ARGV' + affects how 'awk' processes input. - * You can use a single minus sign (`-') to refer to standard input - on the command line. + * You can use a single minus sign ('-') to refer to standard input on + the command line. - * `gawk' pays attention to a number of environment variables. - `AWKPATH', `AWKLIBPATH', and `POSIXLY_CORRECT' are the most + * 'gawk' pays attention to a number of environment variables. + 'AWKPATH', 'AWKLIBPATH', and 'POSIXLY_CORRECT' are the most important ones. - * `gawk''s exit status conveys information to the program that - invoked it. Use the `exit' statement from within an `awk' program + * 'gawk''s exit status conveys information to the program that + invoked it. Use the 'exit' statement from within an 'awk' program to set the exit status. - * `gawk' allows you to include other `awk' source files into your - program using the `@include' statement and/or the `-i' and `-f' + * 'gawk' allows you to include other 'awk' source files into your + program using the '@include' statement and/or the '-i' and '-f' command-line options. - * `gawk' allows you to load additional functions written in C or C++ - using the `@load' statement and/or the `-l' option. (This - advanced feature is described later on in *note Dynamic - Extensions::.) + * 'gawk' allows you to load additional functions written in C or C++ + using the '@load' statement and/or the '-l' option. (This advanced + feature is described later on in *note Dynamic Extensions::.)  File: gawk.info, Node: Regexp, Next: Reading Files, Prev: Invoking Gawk, Up: Top @@ -3190,23 +3179,23 @@ File: gawk.info, Node: Regexp, Next: Reading Files, Prev: Invoking Gawk, Up: A "regular expression", or "regexp", is a way of describing a set of strings. Because regular expressions are such a fundamental part of -`awk' programming, their format and use deserve a separate major node. +'awk' programming, their format and use deserve a separate major node. - A regular expression enclosed in slashes (`/') is an `awk' pattern + A regular expression enclosed in slashes ('/') is an 'awk' pattern that matches every input record whose text belongs to that set. The simplest regular expression is a sequence of letters, numbers, or both. -Such a regexp matches any string that contains that sequence. Thus, -the regexp `foo' matches any string containing `foo'. Therefore, the -pattern `/foo/' matches any input record containing the three -characters `foo' _anywhere_ in the record. Other kinds of regexps let -you specify more complicated classes of strings. +Such a regexp matches any string that contains that sequence. Thus, the +regexp 'foo' matches any string containing 'foo'. Therefore, the +pattern '/foo/' matches any input record containing the three characters +'foo' _anywhere_ in the record. Other kinds of regexps let you specify +more complicated classes of strings. * Menu: * Regexp Usage:: How to Use Regular Expressions. * Escape Sequences:: How to write nonprinting characters. * Regexp Operators:: Regular Expression Operators. -* Bracket Expressions:: What can go between `[...]'. +* Bracket Expressions:: What can go between '[...]'. * GNU Regexp Operators:: Operators specific to GNU software. * Case-sensitivity:: How to do case-insensitive matching. * Leftmost Longest:: How much text matches. @@ -3221,10 +3210,10 @@ File: gawk.info, Node: Regexp Usage, Next: Escape Sequences, Up: Regexp A regular expression can be used as a pattern by enclosing it in slashes. Then the regular expression is tested against the entire text -of each record. (Normally, it only needs to match some part of the -text in order to succeed.) For example, the following prints the -second field of each record where the string `li' appears anywhere in -the record: +of each record. (Normally, it only needs to match some part of the text +in order to succeed.) For example, the following prints the second +field of each record where the string 'li' appears anywhere in the +record: $ awk '/li/ { print $2 }' mail-list -| 555-5553 @@ -3234,16 +3223,16 @@ the record: Regular expressions can also be used in matching expressions. These expressions allow you to specify the string to match against; it need -not be the entire current input record. The two operators `~' and `!~' +not be the entire current input record. The two operators '~' and '!~' perform regular expression comparisons. Expressions using these -operators can be used as patterns, or in `if', `while', `for', and `do' +operators can be used as patterns, or in 'if', 'while', 'for', and 'do' statements. (*Note Statements::.) For example: EXP ~ /REGEXP/ is true if the expression EXP (taken as a string) matches REGEXP. The following example matches, or selects, all input records with the -uppercase letter `J' somewhere in the first field: +uppercase letter 'J' somewhere in the first field: $ awk '$1 ~ /J/' inventory-shipped -| Jan 13 25 15 115 @@ -3255,13 +3244,13 @@ uppercase letter `J' somewhere in the first field: awk '{ if ($1 ~ /J/) print }' inventory-shipped - This next example is true if the expression EXP (taken as a -character string) does _not_ match REGEXP: + This next example is true if the expression EXP (taken as a character +string) does _not_ match REGEXP: EXP !~ /REGEXP/ The following example matches, or selects, all input records whose -first field _does not_ contain the uppercase letter `J': +first field _does not_ contain the uppercase letter 'J': $ awk '$1 !~ /J/' inventory-shipped -| Feb 15 32 24 226 @@ -3270,9 +3259,9 @@ first field _does not_ contain the uppercase letter `J': -| May 16 34 29 208 ... - When a regexp is enclosed in slashes, such as `/foo/', we call it a -"regexp constant", much like `5.27' is a numeric constant and `"foo"' -is a string constant. + When a regexp is enclosed in slashes, such as '/foo/', we call it a +"regexp constant", much like '5.27' is a numeric constant and '"foo"' is +a string constant.  File: gawk.info, Node: Escape Sequences, Next: Regexp Operators, Prev: Regexp Usage, Up: Regexp @@ -3281,103 +3270,102 @@ File: gawk.info, Node: Escape Sequences, Next: Regexp Operators, Prev: Regexp ==================== Some characters cannot be included literally in string constants -(`"foo"') or regexp constants (`/foo/'). Instead, they should be +('"foo"') or regexp constants ('/foo/'). Instead, they should be represented with "escape sequences", which are character sequences -beginning with a backslash (`\'). One use of an escape sequence is to +beginning with a backslash ('\'). One use of an escape sequence is to include a double-quote character in a string constant. Because a plain -double quote ends the string, you must use `\"' to represent an actual +double quote ends the string, you must use '\"' to represent an actual double-quote character as a part of the string. For example: $ awk 'BEGIN { print "He said \"hi!\" to her." }' -| He said "hi!" to her. - The backslash character itself is another character that cannot be -included normally; you must write `\\' to put one backslash in the + The backslash character itself is another character that cannot be +included normally; you must write '\\' to put one backslash in the string or regexp. Thus, the string whose contents are the two -characters `"' and `\' must be written `"\"\\"'. +characters '"' and '\' must be written '"\"\\"'. Other escape sequences represent unprintable characters such as TAB or newline. While there is nothing to stop you from entering most unprintable characters directly in a string constant or regexp constant, they may look ugly. - The following table lists all the escape sequences used in `awk' and -what they represent. Unless noted otherwise, all these escape sequences + The following table lists all the escape sequences used in 'awk' and +what they represent. Unless noted otherwise, all these escape sequences apply to both string constants and regexp constants: -`\\' - A literal backslash, `\'. +'\\' + A literal backslash, '\'. -`\a' - The "alert" character, `Ctrl-g', ASCII code 7 (BEL). (This often +'\a' + The "alert" character, 'Ctrl-g', ASCII code 7 (BEL). (This often makes some sort of audible noise.) -`\b' - Backspace, `Ctrl-h', ASCII code 8 (BS). +'\b' + Backspace, 'Ctrl-h', ASCII code 8 (BS). -`\f' - Formfeed, `Ctrl-l', ASCII code 12 (FF). +'\f' + Formfeed, 'Ctrl-l', ASCII code 12 (FF). -`\n' - Newline, `Ctrl-j', ASCII code 10 (LF). +'\n' + Newline, 'Ctrl-j', ASCII code 10 (LF). -`\r' - Carriage return, `Ctrl-m', ASCII code 13 (CR). +'\r' + Carriage return, 'Ctrl-m', ASCII code 13 (CR). -`\t' - Horizontal TAB, `Ctrl-i', ASCII code 9 (HT). +'\t' + Horizontal TAB, 'Ctrl-i', ASCII code 9 (HT). -`\v' - Vertical tab, `Ctrl-k', ASCII code 11 (VT). +'\v' + Vertical tab, 'Ctrl-k', ASCII code 11 (VT). -`\NNN' - The octal value NNN, where NNN stands for 1 to 3 digits between - `0' and `7'. For example, the code for the ASCII ESC (escape) - character is `\033'. +'\NNN' + The octal value NNN, where NNN stands for 1 to 3 digits between '0' + and '7'. For example, the code for the ASCII ESC (escape) + character is '\033'. -`\xHH...' +'\xHH...' The hexadecimal value HH, where HH stands for a sequence of - hexadecimal digits (`0'-`9', and either `A'-`F' or `a'-`f'). Like + hexadecimal digits ('0'-'9', and either 'A'-'F' or 'a'-'f'). Like the same construct in ISO C, the escape sequence continues until - the first nonhexadecimal digit is seen. (c.e.) However, using - more than two hexadecimal digits produces undefined results. (The - `\x' escape sequence is not allowed in POSIX `awk'.) + the first nonhexadecimal digit is seen. (c.e.) However, using + more than two hexadecimal digits produces undefined results. (The + '\x' escape sequence is not allowed in POSIX 'awk'.) -`\/' +'\/' A literal slash (necessary for regexp constants only). This sequence is used when you want to write a regexp constant that - contains a slash. Because the regexp is delimited by slashes, you + contains a slash. Because the regexp is delimited by slashes, you need to escape the slash that is part of the pattern, in order to - tell `awk' to keep processing the rest of the regexp. - -`\"' - A literal double quote (necessary for string constants only). - This sequence is used when you want to write a string constant - that contains a double quote. Because the string is delimited by - double quotes, you need to escape the quote that is part of the - string, in order to tell `awk' to keep processing the rest of the - string. + tell 'awk' to keep processing the rest of the regexp. + +'\"' + A literal double quote (necessary for string constants only). This + sequence is used when you want to write a string constant that + contains a double quote. Because the string is delimited by double + quotes, you need to escape the quote that is part of the string, in + order to tell 'awk' to keep processing the rest of the string. - In `gawk', a number of additional two-character sequences that begin + In 'gawk', a number of additional two-character sequences that begin with a backslash have special meaning in regexps. *Note GNU Regexp Operators::. In a regexp, a backslash before any character that is not in the -previous list and not listed in *note GNU Regexp Operators::, means -that the next character should be taken literally, even if it would -normally be a regexp operator. For example, `/a\+b/' matches the three -characters `a+b'. +previous list and not listed in *note GNU Regexp Operators::, means that +the next character should be taken literally, even if it would normally +be a regexp operator. For example, '/a\+b/' matches the three +characters 'a+b'. - For complete portability, do not use a backslash before any -character not shown in the previous list. + For complete portability, do not use a backslash before any character +not shown in the previous list. To summarize: * The escape sequences in the table above are always processed first, - for both string constants and regexp constants. This happens very - early, as soon as `awk' reads your program. + for both string constants and regexp constants. This happens very + early, as soon as 'awk' reads your program. - * `gawk' processes both regexp constants and dynamic regexps (*note + * 'gawk' processes both regexp constants and dynamic regexps (*note Computed Regexps::), for the special operators listed in *note GNU Regexp Operators::. @@ -3387,33 +3375,33 @@ character not shown in the previous list. Backslash Before Regular Characters If you place a backslash in a string constant before something that -is not one of the characters previously listed, POSIX `awk' purposely +is not one of the characters previously listed, POSIX 'awk' purposely leaves what happens as undefined. There are two choices: Strip the backslash out - This is what Brian Kernighan's `awk' and `gawk' both do. For - example, `"a\qc"' is the same as `"aqc"'. (Because this is such - an easy bug both to introduce and to miss, `gawk' warns you about - it.) Consider `FS = "[ \t]+\|[ \t]+"' to use vertical bars - surrounded by whitespace as the field separator. There should be - two backslashes in the string: `FS = "[ \t]+\\|[ \t]+"'.) + This is what Brian Kernighan's 'awk' and 'gawk' both do. For + example, '"a\qc"' is the same as '"aqc"'. (Because this is such an + easy bug both to introduce and to miss, 'gawk' warns you about it.) + Consider 'FS = "[ \t]+\|[ \t]+"' to use vertical bars surrounded by + whitespace as the field separator. There should be two backslashes + in the string: 'FS = "[ \t]+\\|[ \t]+"'.) Leave the backslash alone - Some other `awk' implementations do this. In such - implementations, typing `"a\qc"' is the same as typing `"a\\qc"'. + Some other 'awk' implementations do this. In such implementations, + typing '"a\qc"' is the same as typing '"a\\qc"'. Escape Sequences for Metacharacters Suppose you use an octal or hexadecimal escape to represent a regexp -metacharacter. (See *note Regexp Operators::.) Does `awk' treat the +metacharacter. (See *note Regexp Operators::.) Does 'awk' treat the character as a literal character or as a regexp operator? - Historically, such characters were taken literally. (d.c.) -However, the POSIX standard indicates that they should be treated as -real metacharacters, which is what `gawk' does. In compatibility mode -(*note Options::), `gawk' treats the characters represented by octal -and hexadecimal escape sequences literally when used in regexp -constants. Thus, `/a\52b/' is equivalent to `/a\*b/'. + Historically, such characters were taken literally. (d.c.) However, +the POSIX standard indicates that they should be treated as real +metacharacters, which is what 'gawk' does. In compatibility mode (*note +Options::), 'gawk' treats the characters represented by octal and +hexadecimal escape sequences literally when used in regexp constants. +Thus, '/a\52b/' is equivalent to '/a\*b/'.  File: gawk.info, Node: Regexp Operators, Next: Bracket Expressions, Prev: Escape Sequences, Up: Regexp @@ -3425,116 +3413,116 @@ You can combine regular expressions with special characters, called "regular expression operators" or "metacharacters", to increase the power and versatility of regular expressions. - The escape sequences described in *note Escape Sequences::, are -valid inside a regexp. They are introduced by a `\' and are recognized -and converted into corresponding real characters as the very first step -in processing regexps. + The escape sequences described in *note Escape Sequences::, are valid +inside a regexp. They are introduced by a '\' and are recognized and +converted into corresponding real characters as the very first step in +processing regexps. Here is a list of metacharacters. All characters that are not escape sequences and that are not listed in the table stand for themselves: -`\' +'\' This is used to suppress the special meaning of a character when - matching. For example, `\$' matches the character `$'. + matching. For example, '\$' matches the character '$'. -`^' - This matches the beginning of a string. For example, `^@chapter' - matches `@chapter' at the beginning of a string and can be used to - identify chapter beginnings in Texinfo source files. The `^' is +'^' + This matches the beginning of a string. For example, '^@chapter' + matches '@chapter' at the beginning of a string and can be used to + identify chapter beginnings in Texinfo source files. The '^' is known as an "anchor", because it anchors the pattern to match only at the beginning of the string. - It is important to realize that `^' does not match the beginning of - a line (the point right after a `\n' newline character) embedded - in a string. The condition is not true in the following example: + It is important to realize that '^' does not match the beginning of + a line (the point right after a '\n' newline character) embedded in + a string. The condition is not true in the following example: if ("line1\nLINE 2" ~ /^L/) ... -`$' - This is similar to `^', but it matches only at the end of a string. - For example, `p$' matches a record that ends with a `p'. The `$' +'$' + This is similar to '^', but it matches only at the end of a string. + For example, 'p$' matches a record that ends with a 'p'. The '$' is an anchor and does not match the end of a line (the point right - before a `\n' newline character) embedded in a string. The + before a '\n' newline character) embedded in a string. The condition in the following example is not true: if ("line1\nLINE 2" ~ /1$/) ... -`.' (period) +'.' (period) This matches any single character, _including_ the newline - character. For example, `.P' matches any single character - followed by a `P' in a string. Using concatenation, we can make a - regular expression such as `U.A', which matches any - three-character sequence that begins with `U' and ends with `A'. + character. For example, '.P' matches any single character followed + by a 'P' in a string. Using concatenation, we can make a regular + expression such as 'U.A', which matches any three-character + sequence that begins with 'U' and ends with 'A'. - In strict POSIX mode (*note Options::), `.' does not match the NUL + In strict POSIX mode (*note Options::), '.' does not match the NUL character, which is a character with all bits equal to zero. - Otherwise, NUL is just another character. Other versions of `awk' + Otherwise, NUL is just another character. Other versions of 'awk' may not be able to match the NUL character. -`['...`]' - This is called a "bracket expression".(1) It matches any _one_ of +'['...']' + This is called a "bracket expression".(1) It matches any _one_ of the characters that are enclosed in the square brackets. For - example, `[MVX]' matches any one of the characters `M', `V', or - `X' in a string. A full discussion of what can be inside the - square brackets of a bracket expression is given in *note Bracket + example, '[MVX]' matches any one of the characters 'M', 'V', or 'X' + in a string. A full discussion of what can be inside the square + brackets of a bracket expression is given in *note Bracket Expressions::. -`[^'...`]' +'[^'...']' This is a "complemented bracket expression". The first character - after the `[' _must_ be a `^'. It matches any characters _except_ - those in the square brackets. For example, `[^awk]' matches any - character that is not an `a', `w', or `k'. + after the '[' _must_ be a '^'. It matches any characters _except_ + those in the square brackets. For example, '[^awk]' matches any + character that is not an 'a', 'w', or 'k'. -`|' +'|' This is the "alternation operator" and it is used to specify - alternatives. The `|' has the lowest precedence of all the regular - expression operators. For example, `^P|[[:digit:]]' matches any - string that matches either `^P' or `[[:digit:]]'. This means it - matches any string that starts with `P' or contains a digit. + alternatives. The '|' has the lowest precedence of all the regular + expression operators. For example, '^P|[[:digit:]]' matches any + string that matches either '^P' or '[[:digit:]]'. This means it + matches any string that starts with 'P' or contains a digit. The alternation applies to the largest possible regexps on either side. -`('...`)' +'('...')' Parentheses are used for grouping in regular expressions, as in arithmetic. They can be used to concatenate regular expressions - containing the alternation operator, `|'. For example, - `@(samp|code)\{[^}]+\}' matches both `@code{foo}' and `@samp{bar}'. - (These are Texinfo formatting control sequences. The `+' is + containing the alternation operator, '|'. For example, + '@(samp|code)\{[^}]+\}' matches both '@code{foo}' and '@samp{bar}'. + (These are Texinfo formatting control sequences. The '+' is explained further on in this list.) -`*' +'*' This symbol means that the preceding regular expression should be repeated as many times as necessary to find a match. For example, - `ph*' applies the `*' symbol to the preceding `h' and looks for - matches of one `p' followed by any number of `h's. This also - matches just `p' if no `h's are present. - - The `*' repeats the _smallest_ possible preceding expression. - (Use parentheses if you want to repeat a larger expression.) It - finds as many repetitions as possible. For example, `awk - '/\(c[ad][ad]*r x\)/ { print }' sample' prints every record in - `sample' containing a string of the form `(car x)', `(cdr x)', - `(cadr x)', and so on. Notice the escaping of the parentheses by - preceding them with backslashes. - -`+' - This symbol is similar to `*', except that the preceding - expression must be matched at least once. This means that `wh+y' - would match `why' and `whhy', but not `wy', whereas `wh*y' would - match all three. The following is a simpler way of writing the - last `*' example: + 'ph*' applies the '*' symbol to the preceding 'h' and looks for + matches of one 'p' followed by any number of 'h's. This also + matches just 'p' if no 'h's are present. + + The '*' repeats the _smallest_ possible preceding expression. (Use + parentheses if you want to repeat a larger expression.) It finds + as many repetitions as possible. For example, 'awk '/\(c[ad][ad]*r + x\)/ { print }' sample' prints every record in 'sample' containing + a string of the form '(car x)', '(cdr x)', '(cadr x)', and so on. + Notice the escaping of the parentheses by preceding them with + backslashes. + +'+' + This symbol is similar to '*', except that the preceding expression + must be matched at least once. This means that 'wh+y' would match + 'why' and 'whhy', but not 'wy', whereas 'wh*y' would match all + three. The following is a simpler way of writing the last '*' + example: awk '/\(c[ad]+r x\)/ { print }' sample -`?' - This symbol is similar to `*', except that the preceding - expression can be matched either once or not at all. For example, - `fe?d' matches `fed' and `fd', but nothing else. +'?' + This symbol is similar to '*', except that the preceding expression + can be matched either once or not at all. For example, 'fe?d' + matches 'fed' and 'fd', but nothing else. -`{'N`}' -`{'N`,}' -`{'N`,'M`}' +'{'N'}' +'{'N',}' +'{'N','M'}' One or two numbers inside braces denote an "interval expression". If there is one number in the braces, the preceding regexp is repeated N times. If there are two numbers separated by a comma, @@ -3542,54 +3530,53 @@ sequences and that are not listed in the table stand for themselves: number followed by a comma, then the preceding regexp is repeated at least N times: - `wh{3}y' - Matches `whhhy', but not `why' or `whhhhy'. + 'wh{3}y' + Matches 'whhhy', but not 'why' or 'whhhhy'. - `wh{3,5}y' - Matches `whhhy', `whhhhy', or `whhhhhy', only. + 'wh{3,5}y' + Matches 'whhhy', 'whhhhy', or 'whhhhhy', only. - `wh{2,}y' - Matches `whhy' or `whhhy', and so on. + 'wh{2,}y' + Matches 'whhy' or 'whhhy', and so on. - Interval expressions were not traditionally available in `awk'. - They were added as part of the POSIX standard to make `awk' and - `egrep' consistent with each other. + Interval expressions were not traditionally available in 'awk'. + They were added as part of the POSIX standard to make 'awk' and + 'egrep' consistent with each other. - Initially, because old programs may use `{' and `}' in regexp - constants, `gawk' did _not_ match interval expressions in regexps. + Initially, because old programs may use '{' and '}' in regexp + constants, 'gawk' did _not_ match interval expressions in regexps. - However, beginning with version 4.0, `gawk' does match interval + However, beginning with version 4.0, 'gawk' does match interval expressions by default. This is because compatibility with POSIX - has become more important to most `gawk' users than compatibility + has become more important to most 'gawk' users than compatibility with old programs. - For programs that use `{' and `}' in regexp constants, it is good + For programs that use '{' and '}' in regexp constants, it is good practice to always escape them with a backslash. Then the regexp constants are valid and work the way you want them to, using any - version of `awk'.(2) + version of 'awk'.(2) - Finally, when `{' and `}' appear in regexp constants in a way that - cannot be interpreted as an interval expression (such as - `/q{a}/'), then they stand for themselves. + Finally, when '{' and '}' appear in regexp constants in a way that + cannot be interpreted as an interval expression (such as '/q{a}/'), + then they stand for themselves. - In regular expressions, the `*', `+', and `?' operators, as well as -the braces `{' and `}', have the highest precedence, followed by -concatenation, and finally by `|'. As in arithmetic, parentheses can + In regular expressions, the '*', '+', and '?' operators, as well as +the braces '{' and '}', have the highest precedence, followed by +concatenation, and finally by '|'. As in arithmetic, parentheses can change how operators are grouped. - In POSIX `awk' and `gawk', the `*', `+', and `?' operators stand for + In POSIX 'awk' and 'gawk', the '*', '+', and '?' operators stand for themselves when there is nothing in the regexp that precedes them. For -example, `/+/' matches a literal plus sign. However, many other -versions of `awk' treat such a usage as a syntax error. +example, '/+/' matches a literal plus sign. However, many other +versions of 'awk' treat such a usage as a syntax error. - If `gawk' is in compatibility mode (*note Options::), interval + If 'gawk' is in compatibility mode (*note Options::), interval expressions are not available in regular expressions. ---------- Footnotes ---------- - (1) In other literature, you may see a bracket expression referred -to as either a "character set", a "character class", or a "character -list". + (1) In other literature, you may see a bracket expression referred to +as either a "character set", a "character class", or a "character list". (2) Use two backslashes if you're using a string constant with a regexp operator or function. @@ -3606,93 +3593,92 @@ those listed between the opening and closing square brackets. Within a bracket expression, a "range expression" consists of two characters separated by a hyphen. It matches any single character that sorts between the two characters, based upon the system's native -character set. For example, `[0-9]' is equivalent to `[0123456789]'. +character set. For example, '[0-9]' is equivalent to '[0123456789]'. (See *note Ranges and Locales::, for an explanation of how the POSIX -standard and `gawk' have changed over time. This is mainly of +standard and 'gawk' have changed over time. This is mainly of historical interest.) - To include one of the characters `\', `]', `-', or `^' in a bracket -expression, put a `\' in front of it. For example: + To include one of the characters '\', ']', '-', or '^' in a bracket +expression, put a '\' in front of it. For example: [d\]] -matches either `d' or `]'. +matches either 'd' or ']'. - This treatment of `\' in bracket expressions is compatible with -other `awk' implementations and is also mandated by POSIX. The regular -expressions in `awk' are a superset of the POSIX specification for + This treatment of '\' in bracket expressions is compatible with other +'awk' implementations and is also mandated by POSIX. The regular +expressions in 'awk' are a superset of the POSIX specification for Extended Regular Expressions (EREs). POSIX EREs are based on the -regular expressions accepted by the traditional `egrep' utility. +regular expressions accepted by the traditional 'egrep' utility. "Character classes" are a feature introduced in the POSIX standard. A character class is a special notation for describing lists of -characters that have a specific attribute, but the actual characters -can vary from country to country and/or from character set to character -set. For example, the notion of what is an alphabetic character -differs between the United States and France. +characters that have a specific attribute, but the actual characters can +vary from country to country and/or from character set to character set. +For example, the notion of what is an alphabetic character differs +between the United States and France. A character class is only valid in a regexp _inside_ the brackets of -a bracket expression. Character classes consist of `[:', a keyword -denoting the class, and `:]'. *note table-char-classes:: lists the -character classes defined by the POSIX standard. +a bracket expression. Character classes consist of '[:', a keyword +denoting the class, and ':]'. *note Table 3.1: table-char-classes. +lists the character classes defined by the POSIX standard. Class Meaning --------------------------------------------------------------------------- -`[:alnum:]' Alphanumeric characters. -`[:alpha:]' Alphabetic characters. -`[:blank:]' Space and TAB characters. -`[:cntrl:]' Control characters. -`[:digit:]' Numeric characters. -`[:graph:]' Characters that are both printable and visible. (A space is - printable but not visible, whereas an `a' is both.) -`[:lower:]' Lowercase alphabetic characters. -`[:print:]' Printable characters (characters that are not control +-------------------------------------------------------------------------- +'[:alnum:]' Alphanumeric characters. +'[:alpha:]' Alphabetic characters. +'[:blank:]' Space and TAB characters. +'[:cntrl:]' Control characters. +'[:digit:]' Numeric characters. +'[:graph:]' Characters that are both printable and visible. (A space + is printable but not visible, whereas an 'a' is both.) +'[:lower:]' Lowercase alphabetic characters. +'[:print:]' Printable characters (characters that are not control characters). -`[:punct:]' Punctuation characters (characters that are not letters, +'[:punct:]' Punctuation characters (characters that are not letters, digits, control characters, or space characters). -`[:space:]' Space characters (such as space, TAB, and formfeed, to name +'[:space:]' Space characters (such as space, TAB, and formfeed, to name a few). -`[:upper:]' Uppercase alphabetic characters. -`[:xdigit:]'Characters that are hexadecimal digits. +'[:upper:]' Uppercase alphabetic characters. +'[:xdigit:]'Characters that are hexadecimal digits. Table 3.1: POSIX Character Classes For example, before the POSIX standard, you had to write -`/[A-Za-z0-9]/' to match alphanumeric characters. If your character -set had other alphabetic characters in it, this would not match them. -With the POSIX character classes, you can write `/[[:alnum:]]/' to -match the alphabetic and numeric characters in your character set. +'/[A-Za-z0-9]/' to match alphanumeric characters. If your character set +had other alphabetic characters in it, this would not match them. With +the POSIX character classes, you can write '/[[:alnum:]]/' to match the +alphabetic and numeric characters in your character set. Some utilities that match regular expressions provide a non-standard -`[:ascii:]' character class; `awk' does not. However, you can simulate -such a construct using `[\x00-\x7F]'. This matches all values +'[:ascii:]' character class; 'awk' does not. However, you can simulate +such a construct using '[\x00-\x7F]'. This matches all values numerically between zero and 127, which is the defined range of the -ASCII character set. Use a complemented character list -(`[^\x00-\x7F]') to match any single-byte characters that are not in -the ASCII range. +ASCII character set. Use a complemented character list ('[^\x00-\x7F]') +to match any single-byte characters that are not in the ASCII range. Two additional special sequences can appear in bracket expressions. These apply to non-ASCII character sets, which can have single symbols (called "collating elements") that are represented with more than one -character. They can also have several characters that are equivalent for -"collating", or sorting, purposes. (For example, in French, a plain "e" -and a grave-accented "e`" are equivalent.) These sequences are: +character. They can also have several characters that are equivalent +for "collating", or sorting, purposes. (For example, in French, a plain +"e" and a grave-accented "e`" are equivalent.) These sequences are: Collating symbols - Multicharacter collating elements enclosed between `[.' and `.]'. - For example, if `ch' is a collating element, then `[[.ch.]]' is a - regexp that matches this collating element, whereas `[ch]' is a - regexp that matches either `c' or `h'. + Multicharacter collating elements enclosed between '[.' and '.]'. + For example, if 'ch' is a collating element, then '[[.ch.]]' is a + regexp that matches this collating element, whereas '[ch]' is a + regexp that matches either 'c' or 'h'. Equivalence classes - Locale-specific names for a list of characters that are equal. The - name is enclosed between `[=' and `=]'. For example, the name `e' - might be used to represent all of "e," "e`," and "e'." In this - case, `[[=e=]]' is a regexp that matches any of `e', `e'', or `e`'. + Locale-specific names for a list of characters that are equal. The + name is enclosed between '[=' and '=]'. For example, the name 'e' + might be used to represent all of "e," "e`," and "e'." In this + case, '[[=e=]]' is a regexp that matches any of 'e', 'e'', or 'e`'. These features are very valuable in non-English-speaking locales. - CAUTION: The library functions that `gawk' uses for regular + CAUTION: The library functions that 'gawk' uses for regular expression matching currently recognize only POSIX character classes; they do not recognize collating symbols or equivalence classes. @@ -3700,96 +3686,96 @@ Equivalence classes  File: gawk.info, Node: GNU Regexp Operators, Next: Case-sensitivity, Prev: Bracket Expressions, Up: Regexp -3.5 `gawk'-Specific Regexp Operators +3.5 'gawk'-Specific Regexp Operators ==================================== GNU software that deals with regular expressions provides a number of additional regexp operators. These operators are described in this -minor node and are specific to `gawk'; they are not available in other -`awk' implementations. Most of the additional operators deal with word +minor node and are specific to 'gawk'; they are not available in other +'awk' implementations. Most of the additional operators deal with word matching. For our purposes, a "word" is a sequence of one or more -letters, digits, or underscores (`_'): +letters, digits, or underscores ('_'): -`\s' +'\s' Matches any whitespace character. Think of it as shorthand for - `[[:space:]]'. + '[[:space:]]'. -`\S' +'\S' Matches any character that is not whitespace. Think of it as - shorthand for `[^[:space:]]'. + shorthand for '[^[:space:]]'. -`\w' +'\w' Matches any word-constituent character--that is, it matches any - letter, digit, or underscore. Think of it as shorthand for - `[[:alnum:]_]'. + letter, digit, or underscore. Think of it as shorthand for + '[[:alnum:]_]'. -`\W' - Matches any character that is not word-constituent. Think of it - as shorthand for `[^[:alnum:]_]'. +'\W' + Matches any character that is not word-constituent. Think of it as + shorthand for '[^[:alnum:]_]'. -`\<' +'\<' Matches the empty string at the beginning of a word. For example, - `/\' +'\>' Matches the empty string at the end of a word. For example, - `/stow\>/' matches `stow' but not `stowaway'. + '/stow\>/' matches 'stow' but not 'stowaway'. -`\y' +'\y' Matches the empty string at either the beginning or the end of a - word (i.e., the word boundar*y*). For example, `\yballs?\y' - matches either `ball' or `balls', as a separate word. + word (i.e., the word boundar*y*). For example, '\yballs?\y' + matches either 'ball' or 'balls', as a separate word. -`\B' +'\B' Matches the empty string that occurs between two word-constituent - characters. For example, `/\Brat\B/' matches `crate' but it does - not match `dirty rat'. `\B' is essentially the opposite of `\y'. + characters. For example, '/\Brat\B/' matches 'crate' but it does + not match 'dirty rat'. '\B' is essentially the opposite of '\y'. There are two other operators that work on buffers. In Emacs, a -"buffer" is, naturally, an Emacs buffer. For other programs, `gawk''s +"buffer" is, naturally, an Emacs buffer. For other programs, 'gawk''s regexp library routines consider the entire string to match as the buffer. The operators are: -`\`' +'\`' Matches the empty string at the beginning of a buffer (string). -`\'' +'\'' Matches the empty string at the end of a buffer (string). - Because `^' and `$' always work in terms of the beginning and end of -strings, these operators don't add any new capabilities for `awk'. -They are provided for compatibility with other GNU software. + Because '^' and '$' always work in terms of the beginning and end of +strings, these operators don't add any new capabilities for 'awk'. They +are provided for compatibility with other GNU software. - In other GNU software, the word-boundary operator is `\b'. However, -that conflicts with the `awk' language's definition of `\b' as -backspace, so `gawk' uses a different letter. An alternative method + In other GNU software, the word-boundary operator is '\b'. However, +that conflicts with the 'awk' language's definition of '\b' as +backspace, so 'gawk' uses a different letter. An alternative method would have been to require two backslashes in the GNU operators, but -this was deemed too confusing. The current method of using `\y' for the -GNU `\b' appears to be the lesser of two evils. +this was deemed too confusing. The current method of using '\y' for the +GNU '\b' appears to be the lesser of two evils. - The various command-line options (*note Options::) control how -`gawk' interprets characters in regexps: + The various command-line options (*note Options::) control how 'gawk' +interprets characters in regexps: No options - In the default case, `gawk' provides all the facilities of POSIX + In the default case, 'gawk' provides all the facilities of POSIX regexps and the GNU regexp operators described in *note Regexp Operators::. -`--posix' +'--posix' Only POSIX regexps are supported; the GNU operators are not special - (e.g., `\w' matches a literal `w'). Interval expressions are + (e.g., '\w' matches a literal 'w'). Interval expressions are allowed. -`--traditional' - Traditional Unix `awk' regexps are matched. The GNU operators are - not special, and interval expressions are not available. The - POSIX character classes (`[[:alnum:]]', etc.) are supported, as - Brian Kernighan's `awk' does support them. Characters described - by octal and hexadecimal escape sequences are treated literally, - even if they represent regexp metacharacters. +'--traditional' + Traditional Unix 'awk' regexps are matched. The GNU operators are + not special, and interval expressions are not available. The POSIX + character classes ('[[:alnum:]]', etc.) are supported, as Brian + Kernighan's 'awk' does support them. Characters described by octal + and hexadecimal escape sequences are treated literally, even if + they represent regexp metacharacters. -`--re-interval' - Allow interval expressions in regexps, if `--traditional' has been +'--re-interval' + Allow interval expressions in regexps, if '--traditional' has been provided. Otherwise, interval expressions are available by default. @@ -3801,32 +3787,32 @@ File: gawk.info, Node: Case-sensitivity, Next: Leftmost Longest, Prev: GNU Re Case is normally significant in regular expressions, both when matching ordinary characters (i.e., not metacharacters) and inside bracket -expressions. Thus, a `w' in a regular expression matches only a -lowercase `w' and not an uppercase `W'. +expressions. Thus, a 'w' in a regular expression matches only a +lowercase 'w' and not an uppercase 'W'. The simplest way to do a case-independent match is to use a bracket -expression--for example, `[Ww]'. However, this can be cumbersome if -you need to use it often, and it can make the regular expressions harder -to read. There are two alternatives that you might prefer. +expression--for example, '[Ww]'. However, this can be cumbersome if you +need to use it often, and it can make the regular expressions harder to +read. There are two alternatives that you might prefer. One way to perform a case-insensitive match at a particular point in the program is to convert the data to a single case, using the -`tolower()' or `toupper()' built-in string functions (which we haven't +'tolower()' or 'toupper()' built-in string functions (which we haven't discussed yet; *note String Functions::). For example: tolower($1) ~ /foo/ { ... } converts the first field to lowercase before matching against it. This -works in any POSIX-compliant `awk'. +works in any POSIX-compliant 'awk'. - Another method, specific to `gawk', is to set the variable -`IGNORECASE' to a nonzero value (*note Built-in Variables::). When -`IGNORECASE' is not zero, _all_ regexp and string operations ignore + Another method, specific to 'gawk', is to set the variable +'IGNORECASE' to a nonzero value (*note Built-in Variables::). When +'IGNORECASE' is not zero, _all_ regexp and string operations ignore case. - Changing the value of `IGNORECASE' dynamically controls the + Changing the value of 'IGNORECASE' dynamically controls the case-sensitivity of the program as it runs. Case is significant by -default because `IGNORECASE' (like most variables) is initialized to +default because 'IGNORECASE' (like most variables) is initialized to zero: x = "aB" @@ -3835,38 +3821,38 @@ zero: IGNORECASE = 1 if (x ~ /ab/) ... # now it will succeed - In general, you cannot use `IGNORECASE' to make certain rules + In general, you cannot use 'IGNORECASE' to make certain rules case-insensitive and other rules case-sensitive, because there is no -straightforward way to set `IGNORECASE' just for the pattern of a -particular rule.(1) To do this, use either bracket expressions or -`tolower()'. However, one thing you can do with `IGNORECASE' only is +straightforward way to set 'IGNORECASE' just for the pattern of a +particular rule.(1) To do this, use either bracket expressions or +'tolower()'. However, one thing you can do with 'IGNORECASE' only is dynamically turn case-sensitivity on or off for all the rules at once. - `IGNORECASE' can be set on the command line or in a `BEGIN' rule + 'IGNORECASE' can be set on the command line or in a 'BEGIN' rule (*note Other Arguments::; also *note Using BEGIN/END::). Setting -`IGNORECASE' from the command line is a way to make a program +'IGNORECASE' from the command line is a way to make a program case-insensitive without having to edit it. In multibyte locales, the equivalences between upper- and lowercase -characters are tested based on the wide-character values of the -locale's character set. Otherwise, the characters are tested based on -the ISO-8859-1 (ISO Latin-1) character set. This character set is a +characters are tested based on the wide-character values of the locale's +character set. Otherwise, the characters are tested based on the +ISO-8859-1 (ISO Latin-1) character set. This character set is a superset of the traditional 128 ASCII characters, which also provides a number of characters suitable for use with European languages.(2) - The value of `IGNORECASE' has no effect if `gawk' is in -compatibility mode (*note Options::). Case is always significant in -compatibility mode. + The value of 'IGNORECASE' has no effect if 'gawk' is in compatibility +mode (*note Options::). Case is always significant in compatibility +mode. ---------- Footnotes ---------- (1) Experienced C and C++ programmers will note that it is possible, -using something like `IGNORECASE = 1 && /foObAr/ { ... }' and -`IGNORECASE = 0 || /foobar/ { ... }'. However, this is somewhat -obscure and we don't recommend it. +using something like 'IGNORECASE = 1 && /foObAr/ { ... }' and +'IGNORECASE = 0 || /foobar/ { ... }'. However, this is somewhat obscure +and we don't recommend it. - (2) If you don't understand this, don't worry about it; it just -means that `gawk' does the right thing. + (2) If you don't understand this, don't worry about it; it just means +that 'gawk' does the right thing.  File: gawk.info, Node: Leftmost Longest, Next: Computed Regexps, Prev: Case-sensitivity, Up: Regexp @@ -3878,22 +3864,22 @@ Consider the following: echo aaaabcd | awk '{ sub(/a+/, ""); print }' - This example uses the `sub()' function (which we haven't discussed + This example uses the 'sub()' function (which we haven't discussed yet; *note String Functions::) to make a change to the input record. -Here, the regexp `/a+/' indicates "one or more `a' characters," and the -replacement text is `'. +Here, the regexp '/a+/' indicates "one or more 'a' characters," and the +replacement text is ''. - The input contains four `a' characters. `awk' (and POSIX) regular + The input contains four 'a' characters. 'awk' (and POSIX) regular expressions always match the leftmost, _longest_ sequence of input -characters that can match. Thus, all four `a' characters are replaced -with `' in this example: +characters that can match. Thus, all four 'a' characters are replaced +with '' in this example: $ echo aaaabcd | awk '{ sub(/a+/, ""); print }' -| bcd - For simple match/no-match tests, this is not so important. But when -doing text matching and substitutions with the `match()', `sub()', -`gsub()', and `gensub()' functions, it is very important. *Note String + For simple match/no-match tests, this is not so important. But when +doing text matching and substitutions with the 'match()', 'sub()', +'gsub()', and 'gensub()' functions, it is very important. *Note String Functions::, for more information on these functions. Understanding this principle is also important for regexp-based record and field splitting (*note Records::, and also *note Field Separators::). @@ -3904,7 +3890,7 @@ File: gawk.info, Node: Computed Regexps, Next: Regexp Summary, Prev: Leftmost 3.8 Using Dynamic Regexps ========================= -The righthand side of a `~' or `!~' operator need not be a regexp +The righthand side of a '~' or '!~' operator need not be a regexp constant (i.e., a string of characters between slashes). It may be any expression. The expression is evaluated and converted to a string if necessary; the contents of the string are then used as the regexp. A @@ -3914,58 +3900,58 @@ regexp": BEGIN { digits_regexp = "[[:digit:]]+" } $0 ~ digits_regexp { print } -This sets `digits_regexp' to a regexp that describes one or more digits, +This sets 'digits_regexp' to a regexp that describes one or more digits, and tests whether the input record matches this regexp. - NOTE: When using the `~' and `!~' operators, there is a difference - between a regexp constant enclosed in slashes and a string - constant enclosed in double quotes. If you are going to use a - string constant, you have to understand that the string is, in - essence, scanned _twice_: the first time when `awk' reads your - program, and the second time when it goes to match the string on - the lefthand side of the operator with the pattern on the right. - This is true of any string-valued expression (such as - `digits_regexp', shown previously), not just string constants. - - What difference does it make if the string is scanned twice? The + NOTE: When using the '~' and '!~' operators, there is a difference + between a regexp constant enclosed in slashes and a string constant + enclosed in double quotes. If you are going to use a string + constant, you have to understand that the string is, in essence, + scanned _twice_: the first time when 'awk' reads your program, and + the second time when it goes to match the string on the lefthand + side of the operator with the pattern on the right. This is true + of any string-valued expression (such as 'digits_regexp', shown + previously), not just string constants. + + What difference does it make if the string is scanned twice? The answer has to do with escape sequences, and particularly with backslashes. To get a backslash into a regular expression inside a string, you have to type two backslashes. - For example, `/\*/' is a regexp constant for a literal `*'. Only -one backslash is needed. To do the same thing with a string, you have -to type `"\\*"'. The first backslash escapes the second one so that -the string actually contains the two characters `\' and `*'. + For example, '/\*/' is a regexp constant for a literal '*'. Only one +backslash is needed. To do the same thing with a string, you have to +type '"\\*"'. The first backslash escapes the second one so that the +string actually contains the two characters '\' and '*'. Given that you can use both regexp and string constants to describe regular expressions, which should you use? The answer is "regexp constants," for several reasons: * String constants are more complicated to write and more difficult - to read. Using regexp constants makes your programs less + to read. Using regexp constants makes your programs less error-prone. Not understanding the difference between the two kinds of constants is a common source of errors. - * It is more efficient to use regexp constants. `awk' can note that + * It is more efficient to use regexp constants. 'awk' can note that you have supplied a regexp and store it internally in a form that makes pattern matching more efficient. When using a string - constant, `awk' must first convert the string into this internal + constant, 'awk' must first convert the string into this internal form and then perform the pattern matching. * Using regexp constants is better form; it shows clearly that you intend a regexp match. - Using `\n' in Bracket Expressions of Dynamic Regexps + Using '\n' in Bracket Expressions of Dynamic Regexps - Some versions of `awk' do not allow the newline character to be used + Some versions of 'awk' do not allow the newline character to be used inside a bracket expression for a dynamic regexp: $ awk '$0 ~ "[ \t\n]"' - error--> awk: newline in character class [ - error--> ]... - error--> source line number 1 - error--> context is - error--> >>> <<< + error-> awk: newline in character class [ + error-> ]... + error-> source line number 1 + error-> context is + error-> >>> <<< But a newline in a regexp constant works with no problem: @@ -3974,8 +3960,8 @@ inside a bracket expression for a dynamic regexp: -| here is a sample line Ctrl-d - `gawk' does not have this problem, and it isn't likely to occur -often in practice, but it's worth noting for future reference. + 'gawk' does not have this problem, and it isn't likely to occur often +in practice, but it's worth noting for future reference.  File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp @@ -3984,12 +3970,12 @@ File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp =========== * Regular expressions describe sets of strings to be matched. In - `awk', regular expression constants are written enclosed between - slashes: `/'...`/'. + 'awk', regular expression constants are written enclosed between + slashes: '/'...'/'. * Regexp constants may be used by standalone in patterns and in conditional expressions, or as part of matching expressions using - the `~' and `!~' operators. + the '~' and '!~' operators. * Escape sequences let you represent non-printable characters and also let you represent regexp metacharacters as literal characters @@ -4002,9 +3988,9 @@ File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp Within bracket expressions, POSIX character classes let you specify certain groups of characters in a locale-independent fashion. - * `gawk''s `IGNORECASE' variable lets you control the case - sensitivity of regexp matching. In other `awk' versions, use - `tolower()' or `toupper()'. + * 'gawk''s 'IGNORECASE' variable lets you control the case + sensitivity of regexp matching. In other 'awk' versions, use + 'tolower()' or 'toupper()'. * Regular expressions match the leftmost longest text in the string being matched. This matters for cases where you need to know the @@ -4014,20 +4000,19 @@ File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp * Matching expressions may use dynamic regexps; that is string values treated as regular expressions. -  File: gawk.info, Node: Reading Files, Next: Printing, Prev: Regexp, Up: Top 4 Reading Input Files ********************* -In the typical `awk' program, `awk' reads all input either from the -standard input (by default, this is the keyboard, but often it is a -pipe from another command) or from files whose names you specify on the -`awk' command line. If you specify input files, `awk' reads them in -order, processing all the data from one before going on to the next. -The name of the current input file can be found in the built-in variable -`FILENAME' (*note Built-in Variables::). +In the typical 'awk' program, 'awk' reads all input either from the +standard input (by default, this is the keyboard, but often it is a pipe +from another command) or from files whose names you specify on the 'awk' +command line. If you specify input files, 'awk' reads them in order, +processing all the data from one before going on to the next. The name +of the current input file can be found in the built-in variable +'FILENAME' (*note Built-in Variables::). The input is read in units called "records", and is processed by the rules of your program one record at a time. By default, each record is @@ -4035,10 +4020,10 @@ one line. Each record is automatically split into chunks called "fields". This makes it more convenient for programs to work on the parts of a record. - On rare occasions, you may need to use the `getline' command. The -`getline' command is valuable, both because it can do explicit input -from any number of files, and because the files used with it do not -have to be named on the `awk' command line (*note Getline::). + On rare occasions, you may need to use the 'getline' command. The +'getline' command is valuable, both because it can do explicit input +from any number of files, and because the files used with it do not have +to be named on the 'awk' command line (*note Getline::). * Menu: @@ -4051,7 +4036,7 @@ have to be named on the `awk' command line (*note Getline::). * Splitting By Content:: Defining Fields By Content * Multiple Line:: Reading multiline records. * Getline:: Reading files under explicit program control - using the `getline' function. + using the 'getline' function. * Read Timeout:: Reading input with a timeout. * Command line directories:: What happens if you put a directory on the command line. @@ -4064,51 +4049,51 @@ File: gawk.info, Node: Records, Next: Fields, Up: Reading Files 4.1 How Input Is Split into Records =================================== -The `awk' utility divides the input for your `awk' program into records -and fields. `awk' keeps track of the number of records that have been +The 'awk' utility divides the input for your 'awk' program into records +and fields. 'awk' keeps track of the number of records that have been read so far from the current input file. This value is stored in a -built-in variable called `FNR'. It is reset to zero when a new file is -started. Another built-in variable, `NR', records the total number of +built-in variable called 'FNR'. It is reset to zero when a new file is +started. Another built-in variable, 'NR', records the total number of input records read so far from all data files. It starts at zero, but is never automatically reset to zero. * Menu: -* awk split records:: How standard `awk' splits records. -* gawk split records:: How `gawk' splits records. +* awk split records:: How standard 'awk' splits records. +* gawk split records:: How 'gawk' splits records.  File: gawk.info, Node: awk split records, Next: gawk split records, Up: Records -4.1.1 Record Splitting With Standard `awk' +4.1.1 Record Splitting With Standard 'awk' ------------------------------------------ Records are separated by a character called the "record separator". By default, the record separator is the newline character. This is why records are, by default, single lines. A different character can be -used for the record separator by assigning the character to the -built-in variable `RS'. +used for the record separator by assigning the character to the built-in +variable 'RS'. - Like any other variable, the value of `RS' can be changed in the -`awk' program with the assignment operator, `=' (*note Assignment + Like any other variable, the value of 'RS' can be changed in the +'awk' program with the assignment operator, '=' (*note Assignment Ops::). The new record-separator character should be enclosed in -quotation marks, which indicate a string constant. Often the right -time to do this is at the beginning of execution, before any input is +quotation marks, which indicate a string constant. Often the right time +to do this is at the beginning of execution, before any input is processed, so that the very first record is read with the proper -separator. To do this, use the special `BEGIN' pattern (*note +separator. To do this, use the special 'BEGIN' pattern (*note BEGIN/END::). For example: awk 'BEGIN { RS = "u" } { print $0 }' mail-list -changes the value of `RS' to `u', before reading any input. This is a -string whose first character is the letter "u;" as a result, records -are separated by the letter "u." Then the input file is read, and the -second rule in the `awk' program (the action with no pattern) prints -each record. Because each `print' statement adds a newline at the end -of its output, this `awk' program copies the input with each `u' -changed to a newline. Here are the results of running the program on -`mail-list': +changes the value of 'RS' to 'u', before reading any input. This is a +string whose first character is the letter "u;" as a result, records are +separated by the letter "u." Then the input file is read, and the +second rule in the 'awk' program (the action with no pattern) prints +each record. Because each 'print' statement adds a newline at the end +of its output, this 'awk' program copies the input with each 'u' changed +to a newline. Here are the results of running the program on +'mail-list': $ awk 'BEGIN { RS = "u" } > { print $0 }' mail-list @@ -4151,85 +4136,84 @@ changed to a newline. Here are the results of running the program on -| R -| -Note that the entry for the name `Bill' is not split. In the original +Note that the entry for the name 'Bill' is not split. In the original data file (*note Sample Data Files::), the line looks like this: Bill 555-1675 bill.drowning@hotmail.com A -It contains no `u' so there is no reason to split the record, unlike -the others which have one or more occurrences of the `u'. In fact, -this record is treated as part of the previous record; the newline -separating them in the output is the original newline in the data file, -not the one added by `awk' when it printed the record! +It contains no 'u' so there is no reason to split the record, unlike the +others which have one or more occurrences of the 'u'. In fact, this +record is treated as part of the previous record; the newline separating +them in the output is the original newline in the data file, not the one +added by 'awk' when it printed the record! Another way to change the record separator is on the command line, using the variable-assignment feature (*note Other Arguments::): awk '{ print $0 }' RS="u" mail-list -This sets `RS' to `u' before processing `mail-list'. +This sets 'RS' to 'u' before processing 'mail-list'. - Using an alphabetic character such as `u' for the record separator -is highly likely to produce strange results. Using an unusual -character such as `/' is more likely to produce correct behavior in the -majority of cases, but there are no guarantees. The moral is: Know Your -Data. + Using an alphabetic character such as 'u' for the record separator is +highly likely to produce strange results. Using an unusual character +such as '/' is more likely to produce correct behavior in the majority +of cases, but there are no guarantees. The moral is: Know Your Data. - There is one unusual case, that occurs when `gawk' is being fully + There is one unusual case, that occurs when 'gawk' is being fully POSIX-compliant (*note Options::). Then, the following (extreme) -pipeline prints a surprising `1': +pipeline prints a surprising '1': $ echo | gawk --posix 'BEGIN { RS = "a" } ; { print NF }' -| 1 There is one field, consisting of a newline. The value of the -built-in variable `NF' is the number of fields in the current record. -(In the normal case, `gawk' treats the newline as whitespace, printing -`0' as the result. Most other versions of `awk' also act this way.) +built-in variable 'NF' is the number of fields in the current record. +(In the normal case, 'gawk' treats the newline as whitespace, printing +'0' as the result. Most other versions of 'awk' also act this way.) Reaching the end of an input file terminates the current input record, even if the last character in the file is not the character in -`RS'. (d.c.) +'RS'. (d.c.) - The empty string `""' (a string without any characters) has a -special meaning as the value of `RS'. It means that records are -separated by one or more blank lines and nothing else. *Note Multiple -Line::, for more details. + The empty string '""' (a string without any characters) has a special +meaning as the value of 'RS'. It means that records are separated by +one or more blank lines and nothing else. *Note Multiple Line::, for +more details. - If you change the value of `RS' in the middle of an `awk' run, the + If you change the value of 'RS' in the middle of an 'awk' run, the new value is used to delimit subsequent records, but the record currently being processed, as well as records already processed, are not affected. - After the end of the record has been determined, `gawk' sets the -variable `RT' to the text in the input that matched `RS'. + After the end of the record has been determined, 'gawk' sets the +variable 'RT' to the text in the input that matched 'RS'.  File: gawk.info, Node: gawk split records, Prev: awk split records, Up: Records -4.1.2 Record Splitting With `gawk' +4.1.2 Record Splitting With 'gawk' ---------------------------------- -When using `gawk', the value of `RS' is not limited to a one-character -string. It can be any regular expression (*note Regexp::). (c.e.) In +When using 'gawk', the value of 'RS' is not limited to a one-character +string. It can be any regular expression (*note Regexp::). (c.e.) In general, each record ends at the next string that matches the regular expression; the next record starts at the end of the matching string. -This general rule is actually at work in the usual case, where `RS' +This general rule is actually at work in the usual case, where 'RS' contains just a newline: a record ends at the beginning of the next matching string (the next newline in the input), and the following record starts just after the end of this string (at the first character -of the following line). The newline, because it matches `RS', is not +of the following line). The newline, because it matches 'RS', is not part of either record. - When `RS' is a single character, `RT' contains the same single -character. However, when `RS' is a regular expression, `RT' contains + When 'RS' is a single character, 'RT' contains the same single +character. However, when 'RS' is a regular expression, 'RT' contains the actual input text that matched the regular expression. - If the input file ended without any text that matches `RS', `gawk' -sets `RT' to the null string. + If the input file ended without any text that matches 'RS', 'gawk' +sets 'RT' to the null string. The following example illustrates both of these features. It sets -`RS' equal to a regular expression that matches either a newline or a +'RS' equal to a regular expression that matches either a newline or a series of one or more uppercase letters with optional leading and/or trailing whitespace: @@ -4241,63 +4225,62 @@ trailing whitespace: -| Record = record 3 and RT = -| -The final line of output has an extra blank line. This is because the -value of `RT' is a newline, and the `print' statement supplies its own +The final line of output has an extra blank line. This is because the +value of 'RT' is a newline, and the 'print' statement supplies its own terminating newline. *Note Simple Sed::, for a more useful example of -`RS' as a regexp and `RT'. - - If you set `RS' to a regular expression that allows optional -trailing text, such as `RS = "abc(XYZ)?"' it is possible, due to -implementation constraints, that `gawk' may match the leading part of -the regular expression, but not the trailing part, particularly if the -input text that could match the trailing part is fairly long. `gawk' -attempts to avoid this problem, but currently, there's no guarantee -that this will never happen. - - NOTE: Remember that in `awk', the `^' and `$' anchor - metacharacters match the beginning and end of a _string_, and not - the beginning and end of a _line_. As a result, something like - `RS = "^[[:upper:]]"' can only match at the beginning of a file. - This is because `gawk' views the input file as one long string - that happens to contain newline characters in it. It is thus best - to avoid anchor characters in the value of `RS'. - - The use of `RS' as a regular expression and the `RT' variable are -`gawk' extensions; they are not available in compatibility mode (*note +'RS' as a regexp and 'RT'. + + If you set 'RS' to a regular expression that allows optional trailing +text, such as 'RS = "abc(XYZ)?"' it is possible, due to implementation +constraints, that 'gawk' may match the leading part of the regular +expression, but not the trailing part, particularly if the input text +that could match the trailing part is fairly long. 'gawk' attempts to +avoid this problem, but currently, there's no guarantee that this will +never happen. + + NOTE: Remember that in 'awk', the '^' and '$' anchor metacharacters + match the beginning and end of a _string_, and not the beginning + and end of a _line_. As a result, something like 'RS = + "^[[:upper:]]"' can only match at the beginning of a file. This is + because 'gawk' views the input file as one long string that happens + to contain newline characters in it. It is thus best to avoid + anchor characters in the value of 'RS'. + + The use of 'RS' as a regular expression and the 'RT' variable are +'gawk' extensions; they are not available in compatibility mode (*note Options::). In compatibility mode, only the first character of the -value of `RS' is used to determine the end of the record. +value of 'RS' is used to determine the end of the record. - `RS = "\0"' Is Not Portable + 'RS = "\0"' Is Not Portable There are times when you might want to treat an entire data file as a -single record. The only way to make this happen is to give `RS' a -value that you know doesn't occur in the input file. This is hard to -do in a general way, such that a program always works for arbitrary -input files. +single record. The only way to make this happen is to give 'RS' a value +that you know doesn't occur in the input file. This is hard to do in a +general way, such that a program always works for arbitrary input files. You might think that for text files, the NUL character, which consists of a character with all bits equal to zero, is a good value to -use for `RS' in this case: +use for 'RS' in this case: BEGIN { RS = "\0" } # whole file becomes one record? - `gawk' in fact accepts this, and uses the NUL character for the + 'gawk' in fact accepts this, and uses the NUL character for the record separator. This works for certain special files, such as -`/proc/environ' on GNU/Linux systems, where the NUL character is in -fact the record separator. However, this usage is _not_ portable to -most other `awk' implementations. +'/proc/environ' on GNU/Linux systems, where the NUL character is in fact +the record separator. However, this usage is _not_ portable to most +other 'awk' implementations. - Almost all other `awk' implementations(1) store strings internally -as C-style strings. C strings use the NUL character as the string -terminator. In effect, this means that `RS = "\0"' is the same as `RS -= ""'. (d.c.) + Almost all other 'awk' implementations(1) store strings internally as +C-style strings. C strings use the NUL character as the string +terminator. In effect, this means that 'RS = "\0"' is the same as 'RS = +""'. (d.c.) - It happens that recent versions of `mawk' can use the NUL character -as a record separator. However, this is a special case: `mawk' does not + It happens that recent versions of 'mawk' can use the NUL character +as a record separator. However, this is a special case: 'mawk' does not allow embedded NUL characters in strings. *Note Readfile Function::, for an interesting, portable way to read -whole files. If you are using `gawk', see *note Extension Sample +whole files. If you are using 'gawk', see *note Extension Sample Readfile::, for another option. ---------- Footnotes ---------- @@ -4310,56 +4293,55 @@ File: gawk.info, Node: Fields, Next: Nonconstant Fields, Prev: Records, Up: 4.2 Examining Fields ==================== -When `awk' reads an input record, the record is automatically "parsed" -or separated by the `awk' utility into chunks called "fields". By +When 'awk' reads an input record, the record is automatically "parsed" +or separated by the 'awk' utility into chunks called "fields". By default, fields are separated by "whitespace", like words in a line. -Whitespace in `awk' means any string of one or more spaces, TABs, or +Whitespace in 'awk' means any string of one or more spaces, TABs, or newlines;(1) other characters, such as formfeed, vertical tab, etc., that are considered whitespace by other languages, are _not_ considered -whitespace by `awk'. +whitespace by 'awk'. The purpose of fields is to make it more convenient for you to refer to these pieces of the record. You don't have to use them--you can -operate on the whole record if you want--but fields are what make -simple `awk' programs so powerful. +operate on the whole record if you want--but fields are what make simple +'awk' programs so powerful. - You use a dollar-sign (`$') to refer to a field in an `awk' program, -followed by the number of the field you want. Thus, `$1' refers to the -first field, `$2' to the second, and so on. (Unlike the Unix shells, -the field numbers are not limited to single digits. `$127' is the one + You use a dollar-sign ('$') to refer to a field in an 'awk' program, +followed by the number of the field you want. Thus, '$1' refers to the +first field, '$2' to the second, and so on. (Unlike the Unix shells, +the field numbers are not limited to single digits. '$127' is the one hundred twenty-seventh field in the record.) For example, suppose the following is a line of input: This seems like a pretty nice example. -Here the first field, or `$1', is `This', the second field, or `$2', is -`seems', and so on. Note that the last field, `$7', is `example.'. -Because there is no space between the `e' and the `.', the period is +Here the first field, or '$1', is 'This', the second field, or '$2', is +'seems', and so on. Note that the last field, '$7', is 'example.'. +Because there is no space between the 'e' and the '.', the period is considered part of the seventh field. - `NF' is a built-in variable whose value is the number of fields in -the current record. `awk' automatically updates the value of `NF' each + 'NF' is a built-in variable whose value is the number of fields in +the current record. 'awk' automatically updates the value of 'NF' each time it reads a record. No matter how many fields there are, the last -field in a record can be represented by `$NF'. So, `$NF' is the same -as `$7', which is `example.'. If you try to reference a field beyond -the last one (such as `$8' when the record has only seven fields), you -get the empty string. (If used in a numeric operation, you get zero.) +field in a record can be represented by '$NF'. So, '$NF' is the same as +'$7', which is 'example.'. If you try to reference a field beyond the +last one (such as '$8' when the record has only seven fields), you get +the empty string. (If used in a numeric operation, you get zero.) - The use of `$0', which looks like a reference to the "zero-th" -field, is a special case: it represents the whole input record. Use it -when you are not interested in specific fields. Here are some more -examples: + The use of '$0', which looks like a reference to the "zero-th" field, +is a special case: it represents the whole input record. Use it when +you are not interested in specific fields. Here are some more examples: $ awk '$1 ~ /li/ { print $0 }' mail-list -| Amelia 555-5553 amelia.zodiacusque@gmail.com F -| Julie 555-6699 julie.perscrutabor@skeeve.com F -This example prints each record in the file `mail-list' whose first -field contains the string `li'. The operator `~' is called a "matching +This example prints each record in the file 'mail-list' whose first +field contains the string 'li'. The operator '~' is called a "matching operator" (*note Regexp Usage::); it tests whether a string (here, the -field `$1') matches a given regular expression. +field '$1') matches a given regular expression. - By contrast, the following example looks for `li' in _the entire + By contrast, the following example looks for 'li' in _the entire record_ and prints the first field and the last field for each matching input record: @@ -4371,7 +4353,7 @@ input record: ---------- Footnotes ---------- - (1) In POSIX `awk', newlines are not considered whitespace for + (1) In POSIX 'awk', newlines are not considered whitespace for separating fields.  @@ -4380,15 +4362,14 @@ File: gawk.info, Node: Nonconstant Fields, Next: Changing Fields, Prev: Field 4.3 Nonconstant Field Numbers ============================= -A field number need not be a constant. Any expression in the `awk' -language can be used after a `$' to refer to a field. The value of the -expression specifies the field number. If the value is a string, -rather than a number, it is converted to a number. Consider this -example: +A field number need not be a constant. Any expression in the 'awk' +language can be used after a '$' to refer to a field. The value of the +expression specifies the field number. If the value is a string, rather +than a number, it is converted to a number. Consider this example: awk '{ print $NR }' -Recall that `NR' is the number of records read so far: one in the first +Recall that 'NR' is the number of records read so far: one in the first record, two in the second, etc. So this example prints the first field of the first record, the second field of the second record, and so on. For the twentieth record, field number 20 is printed; most likely, the @@ -4397,33 +4378,33 @@ another example of using expressions as field numbers: awk '{ print $(2*2) }' mail-list - `awk' evaluates the expression `(2*2)' and uses its value as the -number of the field to print. The `*' sign represents multiplication, -so the expression `2*2' evaluates to four. The parentheses are used so -that the multiplication is done before the `$' operation; they are + 'awk' evaluates the expression '(2*2)' and uses its value as the +number of the field to print. The '*' sign represents multiplication, +so the expression '2*2' evaluates to four. The parentheses are used so +that the multiplication is done before the '$' operation; they are necessary whenever there is a binary operator(1) in the field-number expression. This example, then, prints the type of relationship (the -fourth field) for every line of the file `mail-list'. (All of the -`awk' operators are listed, in order of decreasing precedence, in *note +fourth field) for every line of the file 'mail-list'. (All of the 'awk' +operators are listed, in order of decreasing precedence, in *note Precedence::.) If the field number you compute is zero, you get the entire record. -Thus, `$(2-2)' has the same value as `$0'. Negative field numbers are +Thus, '$(2-2)' has the same value as '$0'. Negative field numbers are not allowed; trying to reference one usually terminates the program. (The POSIX standard does not define what happens when you reference a -negative field number. `gawk' notices this and terminates your -program. Other `awk' implementations may behave differently.) +negative field number. 'gawk' notices this and terminates your program. +Other 'awk' implementations may behave differently.) - As mentioned in *note Fields::, `awk' stores the current record's -number of fields in the built-in variable `NF' (also *note Built-in -Variables::). The expression `$NF' is not a special feature--it is the -direct consequence of evaluating `NF' and using its value as a field + As mentioned in *note Fields::, 'awk' stores the current record's +number of fields in the built-in variable 'NF' (also *note Built-in +Variables::). The expression '$NF' is not a special feature--it is the +direct consequence of evaluating 'NF' and using its value as a field number. ---------- Footnotes ---------- - (1) A "binary operator", such as `*' for multiplication, is one that -takes two operands. The distinction is required, since `awk' also has + (1) A "binary operator", such as '*' for multiplication, is one that +takes two operands. The distinction is required, since 'awk' also has unary (one-operand) and ternary (three-operand) operators.  @@ -4432,9 +4413,9 @@ File: gawk.info, Node: Changing Fields, Next: Field Separators, Prev: Noncons 4.4 Changing the Contents of a Field ==================================== -The contents of a field, as seen by `awk', can be changed within an -`awk' program; this changes what `awk' perceives as the current input -record. (The actual input is untouched; `awk' _never_ modifies the +The contents of a field, as seen by 'awk', can be changed within an +'awk' program; this changes what 'awk' perceives as the current input +record. (The actual input is untouched; 'awk' _never_ modifies the input file.) Consider the following example and its output: $ awk '{ nboxes = $3 ; $3 = $3 - 10 @@ -4445,21 +4426,21 @@ input file.) Consider the following example and its output: ... The program first saves the original value of field three in the -variable `nboxes'. The `-' sign represents subtraction, so this -program reassigns field three, `$3', as the original value of field -three minus ten: `$3 - 10'. (*Note Arithmetic Ops::.) Then it prints -the original and new values for field three. (Someone in the warehouse -made a consistent mistake while inventorying the red boxes.) +variable 'nboxes'. The '-' sign represents subtraction, so this program +reassigns field three, '$3', as the original value of field three minus +ten: '$3 - 10'. (*Note Arithmetic Ops::.) Then it prints the original +and new values for field three. (Someone in the warehouse made a +consistent mistake while inventorying the red boxes.) - For this to work, the text in `$3' must make sense as a number; the + For this to work, the text in '$3' must make sense as a number; the string of characters must be converted to a number for the computer to do arithmetic on it. The number resulting from the subtraction is converted back to a string of characters that then becomes field three. *Note Conversion::. - When the value of a field is changed (as perceived by `awk'), the + When the value of a field is changed (as perceived by 'awk'), the text of the input record is recalculated to contain the new field where -the old one was. In other words, `$0' changes to reflect the altered +the old one was. In other words, '$0' changes to reflect the altered field. Thus, this program prints a copy of the input file, with 10 subtracted from the second field of each line: @@ -4469,8 +4450,8 @@ subtracted from the second field of each line: -| Mar 5 24 34 228 ... - It is also possible to also assign contents to fields that are out -of range. For example: + It is also possible to also assign contents to fields that are out of +range. For example: $ awk '{ $6 = ($5 + $4 + $3 + $2) > print $6 }' inventory-shipped @@ -4479,26 +4460,26 @@ of range. For example: -| 301 ... -We've just created `$6', whose value is the sum of fields `$2', `$3', -`$4', and `$5'. The `+' sign represents addition. For the file -`inventory-shipped', `$6' represents the total number of parcels -shipped for a particular month. +We've just created '$6', whose value is the sum of fields '$2', '$3', +'$4', and '$5'. The '+' sign represents addition. For the file +'inventory-shipped', '$6' represents the total number of parcels shipped +for a particular month. - Creating a new field changes `awk''s internal copy of the current -input record, which is the value of `$0'. Thus, if you do `print $0' + Creating a new field changes 'awk''s internal copy of the current +input record, which is the value of '$0'. Thus, if you do 'print $0' after adding a field, the record printed includes the new field, with the appropriate number of field separators between it and the previously existing fields. - This recomputation affects and is affected by `NF' (the number of -fields; *note Fields::). For example, the value of `NF' is set to the -number of the highest field you create. The exact format of `$0' is + This recomputation affects and is affected by 'NF' (the number of +fields; *note Fields::). For example, the value of 'NF' is set to the +number of the highest field you create. The exact format of '$0' is also affected by a feature that has not been discussed yet: the "output -field separator", `OFS', used to separate the fields (*note Output +field separator", 'OFS', used to separate the fields (*note Output Separators::). Note, however, that merely _referencing_ an out-of-range field does -_not_ change the value of either `$0' or `NF'. Referencing an +_not_ change the value of either '$0' or 'NF'. Referencing an out-of-range field only produces an empty string. For example: if ($(NF+1) != "") @@ -4506,13 +4487,13 @@ out-of-range field only produces an empty string. For example: else print "everything is normal" -should print `everything is normal', because `NF+1' is certain to be -out of range. (*Note If Statement::, for more information about -`awk''s `if-else' statements. *Note Typing and Comparison::, for more -information about the `!=' operator.) +should print 'everything is normal', because 'NF+1' is certain to be out +of range. (*Note If Statement::, for more information about 'awk''s +'if-else' statements. *Note Typing and Comparison::, for more +information about the '!=' operator.) It is important to note that making an assignment to an existing -field changes the value of `$0' but does not change the value of `NF', +field changes the value of '$0' but does not change the value of 'NF', even when you assign the empty string to a field. For example: $ echo a b c d | awk '{ OFS = ":"; $2 = "" @@ -4521,7 +4502,7 @@ even when you assign the empty string to a field. For example: -| 4 The field is still there; it just has an empty value, delimited by the -two colons between `a' and `c'. This example shows what happens if you +two colons between 'a' and 'c'. This example shows what happens if you create a new field: $ echo a b c d | awk '{ OFS = ":"; $2 = ""; $6 = "new" @@ -4529,51 +4510,51 @@ create a new field: -| a::c:d::new -| 6 -The intervening field, `$5', is created with an empty value (indicated -by the second pair of adjacent colons), and `NF' is updated with the +The intervening field, '$5', is created with an empty value (indicated +by the second pair of adjacent colons), and 'NF' is updated with the value six. - Decrementing `NF' throws away the values of the fields after the new -value of `NF' and recomputes `$0'. (d.c.) Here is an example: + Decrementing 'NF' throws away the values of the fields after the new +value of 'NF' and recomputes '$0'. (d.c.) Here is an example: $ echo a b c d e f | awk '{ print "NF =", NF; > NF = 3; print $0 }' -| NF = 6 -| a b c - CAUTION: Some versions of `awk' don't rebuild `$0' when `NF' is - decremented. Caveat emptor. + CAUTION: Some versions of 'awk' don't rebuild '$0' when 'NF' is + decremented. Caveat emptor. - Finally, there are times when it is convenient to force `awk' to + Finally, there are times when it is convenient to force 'awk' to rebuild the entire record, using the current value of the fields and -`OFS'. To do this, use the seemingly innocuous assignment: +'OFS'. To do this, use the seemingly innocuous assignment: $1 = $1 # force record to be reconstituted print $0 # or whatever else with $0 -This forces `awk' to rebuild the record. It does help to add a -comment, as we've shown here. +This forces 'awk' to rebuild the record. It does help to add a comment, +as we've shown here. - There is a flip side to the relationship between `$0' and the -fields. Any assignment to `$0' causes the record to be reparsed into -fields using the _current_ value of `FS'. This also applies to any -built-in function that updates `$0', such as `sub()' and `gsub()' -(*note String Functions::). + There is a flip side to the relationship between '$0' and the fields. +Any assignment to '$0' causes the record to be reparsed into fields +using the _current_ value of 'FS'. This also applies to any built-in +function that updates '$0', such as 'sub()' and 'gsub()' (*note String +Functions::). - Understanding `$0' + Understanding '$0' - It is important to remember that `$0' is the _full_ record, exactly + It is important to remember that '$0' is the _full_ record, exactly as it was read from the input. This includes any leading or trailing -whitespace, and the exact whitespace (or other characters) that -separate the fields. +whitespace, and the exact whitespace (or other characters) that separate +the fields. - It is a not-uncommon error to try to change the field separators in -a record simply by setting `FS' and `OFS', and then expecting a plain -`print' or `print $0' to print the modified record. + It is a not-uncommon error to try to change the field separators in a +record simply by setting 'FS' and 'OFS', and then expecting a plain +'print' or 'print $0' to print the modified record. But this does not work, since nothing was done to change the record itself. Instead, you must force the record to be rebuilt, typically -with a statement such as `$1 = $1', as described earlier. +with a statement such as '$1 = $1', as described earlier.  File: gawk.info, Node: Field Separators, Next: Constant Size, Prev: Changing Fields, Up: Reading Files @@ -4586,37 +4567,36 @@ File: gawk.info, Node: Field Separators, Next: Constant Size, Prev: Changing * Default Field Splitting:: How fields are normally separated. * Regexp Field Splitting:: Using regexps as the field separator. * Single Character Fields:: Making each character a separate field. -* Command Line Field Separator:: Setting `FS' from the command-line. +* Command Line Field Separator:: Setting 'FS' from the command-line. * Full Line Fields:: Making the full line be a single field. * Field Splitting Summary:: Some final points and a summary table. - The "field separator", which is either a single character or a -regular expression, controls the way `awk' splits an input record into -fields. `awk' scans the input record for character sequences that -match the separator; the fields themselves are the text between the -matches. +The "field separator", which is either a single character or a regular +expression, controls the way 'awk' splits an input record into fields. +'awk' scans the input record for character sequences that match the +separator; the fields themselves are the text between the matches. In the examples that follow, we use the bullet symbol (*) to -represent spaces in the output. If the field separator is `oo', then +represent spaces in the output. If the field separator is 'oo', then the following line: moo goo gai pan -is split into three fields: `m', `*g', and `*gai*pan'. Note the -leading spaces in the values of the second and third fields. +is split into three fields: 'm', '*g', and '*gai*pan'. Note the leading +spaces in the values of the second and third fields. - The field separator is represented by the built-in variable `FS'. -Shell programmers take note: `awk' does _not_ use the name `IFS' that -is used by the POSIX-compliant shells (such as the Unix Bourne shell, -`sh', or Bash). + The field separator is represented by the built-in variable 'FS'. +Shell programmers take note: 'awk' does _not_ use the name 'IFS' that is +used by the POSIX-compliant shells (such as the Unix Bourne shell, 'sh', +or Bash). - The value of `FS' can be changed in the `awk' program with the -assignment operator, `=' (*note Assignment Ops::). Often the right -time to do this is at the beginning of execution before any input has -been processed, so that the very first record is read with the proper -separator. To do this, use the special `BEGIN' pattern (*note -BEGIN/END::). For example, here we set the value of `FS' to the string -`","': + The value of 'FS' can be changed in the 'awk' program with the +assignment operator, '=' (*note Assignment Ops::). Often the right time +to do this is at the beginning of execution before any input has been +processed, so that the very first record is read with the proper +separator. To do this, use the special 'BEGIN' pattern (*note +BEGIN/END::). For example, here we set the value of 'FS' to the string +'","': awk 'BEGIN { FS = "," } ; { print $2 }' @@ -4624,7 +4604,7 @@ Given the input line: John Q. Smith, 29 Oak St., Walamazoo, MI 42139 -this `awk' program extracts and prints the string `*29*Oak*St.'. +this 'awk' program extracts and prints the string '*29*Oak*St.'. Sometimes the input data contains separator characters that don't separate fields the way you thought they would. For instance, the @@ -4633,12 +4613,12 @@ attached, such as: John Q. Smith, LXIX, 29 Oak St., Walamazoo, MI 42139 -The same program would extract `*LXIX', instead of `*29*Oak*St.'. If +The same program would extract '*LXIX', instead of '*29*Oak*St.'. If you were expecting the program to print the address, you would be surprised. The moral is to choose your data layout and separator -characters carefully to prevent such problems. (If the data is not in -a form that is easy to process, perhaps you can massage it first with a -separate `awk' program.) +characters carefully to prevent such problems. (If the data is not in a +form that is easy to process, perhaps you can massage it first with a +separate 'awk' program.)  File: gawk.info, Node: Default Field Splitting, Next: Regexp Field Splitting, Up: Field Separators @@ -4646,17 +4626,16 @@ File: gawk.info, Node: Default Field Splitting, Next: Regexp Field Splitting, 4.5.1 Whitespace Normally Separates Fields ------------------------------------------ -Fields are normally separated by whitespace sequences (spaces, TABs, -and newlines), not by single spaces. Two spaces in a row do not -delimit an empty field. The default value of the field separator `FS' -is a string containing a single space, `" "'. If `awk' interpreted -this value in the usual way, each space character would separate -fields, so two spaces in a row would make an empty field between them. -The reason this does not happen is that a single space as the value of -`FS' is a special case--it is taken to specify the default manner of -delimiting fields. - - If `FS' is any other single character, such as `","', then each +Fields are normally separated by whitespace sequences (spaces, TABs, and +newlines), not by single spaces. Two spaces in a row do not delimit an +empty field. The default value of the field separator 'FS' is a string +containing a single space, '" "'. If 'awk' interpreted this value in +the usual way, each space character would separate fields, so two spaces +in a row would make an empty field between them. The reason this does +not happen is that a single space as the value of 'FS' is a special +case--it is taken to specify the default manner of delimiting fields. + + If 'FS' is any other single character, such as '","', then each occurrence of that character separates two fields. Two consecutive occurrences delimit an empty field. If the character occurs at the beginning or the end of the line, that too delimits an empty field. The @@ -4670,36 +4649,35 @@ File: gawk.info, Node: Regexp Field Splitting, Next: Single Character Fields, -------------------------------------------------- The previous node discussed the use of single characters or simple -strings as the value of `FS'. More generally, the value of `FS' may be -a string containing any regular expression. In this case, each match -in the record for the regular expression separates fields. For -example, the assignment: +strings as the value of 'FS'. More generally, the value of 'FS' may be +a string containing any regular expression. In this case, each match in +the record for the regular expression separates fields. For example, +the assignment: FS = ", \t" makes every area of an input line that consists of a comma followed by a -space and a TAB into a field separator. (`\t' is an "escape sequence" +space and a TAB into a field separator. ('\t' is an "escape sequence" that stands for a TAB; *note Escape Sequences::, for the complete list of similar escape sequences.) For a less trivial example of a regular expression, try using single -spaces to separate fields the way single commas are used. `FS' can be -set to `"[ ]"' (left bracket, space, right bracket). This regular +spaces to separate fields the way single commas are used. 'FS' can be +set to '"[ ]"' (left bracket, space, right bracket). This regular expression matches a single space and nothing else (*note Regexp::). - There is an important difference between the two cases of `FS = " "' -(a single space) and `FS = "[ \t\n]+"' (a regular expression matching -one or more spaces, TABs, or newlines). For both values of `FS', -fields are separated by "runs" (multiple adjacent occurrences) of -spaces, TABs, and/or newlines. However, when the value of `FS' is -`" "', `awk' first strips leading and trailing whitespace from the -record and then decides where the fields are. For example, the -following pipeline prints `b': + There is an important difference between the two cases of 'FS = " "' +(a single space) and 'FS = "[ \t\n]+"' (a regular expression matching +one or more spaces, TABs, or newlines). For both values of 'FS', fields +are separated by "runs" (multiple adjacent occurrences) of spaces, TABs, +and/or newlines. However, when the value of 'FS' is '" "', 'awk' first +strips leading and trailing whitespace from the record and then decides +where the fields are. For example, the following pipeline prints 'b': $ echo ' a b c d ' | awk '{ print $2 }' -| b -However, this pipeline prints `a' (note the extra spaces around each +However, this pipeline prints 'a' (note the extra spaces around each letter): $ echo ' a b c d ' | awk 'BEGIN { FS = "[ \t\n]+" } @@ -4708,30 +4686,30 @@ letter): In this case, the first field is null, or empty. - The stripping of leading and trailing whitespace also comes into -play whenever `$0' is recomputed. For instance, study this pipeline: + The stripping of leading and trailing whitespace also comes into play +whenever '$0' is recomputed. For instance, study this pipeline: $ echo ' a b c d' | awk '{ print; $2 = $2; print }' -| a b c d -| a b c d -The first `print' statement prints the record as it was read, with -leading whitespace intact. The assignment to `$2' rebuilds `$0' by -concatenating `$1' through `$NF' together, separated by the value of -`OFS'. Because the leading whitespace was ignored when finding `$1', -it is not part of the new `$0'. Finally, the last `print' statement -prints the new `$0'. +The first 'print' statement prints the record as it was read, with +leading whitespace intact. The assignment to '$2' rebuilds '$0' by +concatenating '$1' through '$NF' together, separated by the value of +'OFS'. Because the leading whitespace was ignored when finding '$1', it +is not part of the new '$0'. Finally, the last 'print' statement prints +the new '$0'. There is an additional subtlety to be aware of when using regular expressions for field splitting. It is not well-specified in the POSIX -standard, or anywhere else, what `^' means when splitting fields. Does -the `^' match only at the beginning of the entire record? Or is each -field separator a new string? It turns out that different `awk' +standard, or anywhere else, what '^' means when splitting fields. Does +the '^' match only at the beginning of the entire record? Or is each +field separator a new string? It turns out that different 'awk' versions answer this question differently, and you should not rely on any specific behavior in your programs. (d.c.) - As a point of information, Brian Kernighan's `awk' allows `^' to -match only at the beginning of the record. `gawk' also works this way. + As a point of information, Brian Kernighan's 'awk' allows '^' to +match only at the beginning of the record. 'gawk' also works this way. For example: $ echo 'xxAA xxBxx C' | @@ -4749,8 +4727,8 @@ File: gawk.info, Node: Single Character Fields, Next: Command Line Field Separ -------------------------------------------- There are times when you may want to examine each character of a record -separately. This can be done in `gawk' by simply assigning the null -string (`""') to `FS'. (c.e.) In this case, each individual character +separately. This can be done in 'gawk' by simply assigning the null +string ('""') to 'FS'. (c.e.) In this case, each individual character in the record becomes a separate field. For example: $ echo a b | gawk 'BEGIN { FS = "" } @@ -4762,58 +4740,58 @@ in the record becomes a separate field. For example: -| Field 2 is -| Field 3 is b - Traditionally, the behavior of `FS' equal to `""' was not defined. -In this case, most versions of Unix `awk' simply treat the entire record + Traditionally, the behavior of 'FS' equal to '""' was not defined. +In this case, most versions of Unix 'awk' simply treat the entire record as only having one field. (d.c.) In compatibility mode (*note -Options::), if `FS' is the null string, then `gawk' also behaves this +Options::), if 'FS' is the null string, then 'gawk' also behaves this way.  File: gawk.info, Node: Command Line Field Separator, Next: Full Line Fields, Prev: Single Character Fields, Up: Field Separators -4.5.4 Setting `FS' from the Command Line +4.5.4 Setting 'FS' from the Command Line ---------------------------------------- -`FS' can be set on the command line. Use the `-F' option to do so. -For example: +'FS' can be set on the command line. Use the '-F' option to do so. For +example: awk -F, 'PROGRAM' INPUT-FILES -sets `FS' to the `,' character. Notice that the option uses an -uppercase `F' instead of a lowercase `f'. The latter option (`-f') -specifies a file containing an `awk' program. Case is significant in -command-line options: the `-F' and `-f' options have nothing to do with -each other. You can use both options at the same time to set the `FS' -variable _and_ get an `awk' program from a file. +sets 'FS' to the ',' character. Notice that the option uses an +uppercase 'F' instead of a lowercase 'f'. The latter option ('-f') +specifies a file containing an 'awk' program. Case is significant in +command-line options: the '-F' and '-f' options have nothing to do with +each other. You can use both options at the same time to set the 'FS' +variable _and_ get an 'awk' program from a file. - The value used for the argument to `-F' is processed in exactly the -same way as assignments to the built-in variable `FS'. Any special + The value used for the argument to '-F' is processed in exactly the +same way as assignments to the built-in variable 'FS'. Any special characters in the field separator must be escaped appropriately. For -example, to use a `\' as the field separator on the command line, you +example, to use a '\' as the field separator on the command line, you would have to type: # same as FS = "\\" awk -F\\\\ '...' files ... -Because `\' is used for quoting in the shell, `awk' sees `-F\\'. Then -`awk' processes the `\\' for escape characters (*note Escape -Sequences::), finally yielding a single `\' to use for the field +Because '\' is used for quoting in the shell, 'awk' sees '-F\\'. Then +'awk' processes the '\\' for escape characters (*note Escape +Sequences::), finally yielding a single '\' to use for the field separator. As a special case, in compatibility mode (*note Options::), if the -argument to `-F' is `t', then `FS' is set to the TAB character. If you -type `-F\t' at the shell, without any quotes, the `\' gets deleted, so -`awk' figures that you really want your fields to be separated with -TABs and not `t's. Use `-v FS="t"' or `-F"[t]"' on the command line if -you really do want to separate your fields with `t's. +argument to '-F' is 't', then 'FS' is set to the TAB character. If you +type '-F\t' at the shell, without any quotes, the '\' gets deleted, so +'awk' figures that you really want your fields to be separated with TABs +and not 't's. Use '-v FS="t"' or '-F"[t]"' on the command line if you +really do want to separate your fields with 't's. - As an example, let's use an `awk' program file called `edu.awk' that -contains the pattern `/edu/' and the action `print $1': + As an example, let's use an 'awk' program file called 'edu.awk' that +contains the pattern '/edu/' and the action 'print $1': /edu/ { print $1 } - Let's also set `FS' to be the `-' character and run the program on -the file `mail-list'. The following command prints a list of the names + Let's also set 'FS' to be the '-' character and run the program on +the file 'mail-list'. The following command prints a list of the names of the people that work at or attend a university, and the first three digits of their phone numbers: @@ -4827,19 +4805,19 @@ looked like this: Jean-Paul 555-2127 jeanpaul.campanorum@nyu.edu R - The `-' as part of the person's name was used as the field -separator, instead of the `-' in the phone number that was originally -intended. This demonstrates why you have to be careful in choosing -your field and record separators. + The '-' as part of the person's name was used as the field separator, +instead of the '-' in the phone number that was originally intended. +This demonstrates why you have to be careful in choosing your field and +record separators. Perhaps the most common use of a single character as the field -separator occurs when processing the Unix system password file. On -many Unix systems, each user has a separate entry in the system -password file, one line per user. The information in these lines is -separated by colons. The first field is the user's login name and the -second is the user's encrypted or shadow password. (A shadow password -is indicated by the presence of a single `x' in the second field.) A -password file entry might look like this: +separator occurs when processing the Unix system password file. On many +Unix systems, each user has a separate entry in the system password +file, one line per user. The information in these lines is separated by +colons. The first field is the user's login name and the second is the +user's encrypted or shadow password. (A shadow password is indicated by +the presence of a single 'x' in the second field.) A password file +entry might look like this: arnold:x:2076:10:Arnold Robbins:/home/arnold:/bin/bash @@ -4855,12 +4833,12 @@ File: gawk.info, Node: Full Line Fields, Next: Field Splitting Summary, Prev: -------------------------------------------- Occasionally, it's useful to treat the whole input line as a single -field. This can be done easily and portably simply by setting `FS' to -`"\n"' (a newline).(1) +field. This can be done easily and portably simply by setting 'FS' to +'"\n"' (a newline).(1) awk -F'\n' 'PROGRAM' FILES ... -When you do this, `$1' is the same as `$0'. +When you do this, '$1' is the same as '$0'. ---------- Footnotes ---------- @@ -4873,51 +4851,50 @@ File: gawk.info, Node: Field Splitting Summary, Prev: Full Line Fields, Up: F ----------------------------- It is important to remember that when you assign a string constant as -the value of `FS', it undergoes normal `awk' string processing. For -example, with Unix `awk' and `gawk', the assignment `FS = "\.."' -assigns the character string `".."' to `FS' (the backslash is -stripped). This creates a regexp meaning "fields are separated by -occurrences of any two characters." If instead you want fields to be -separated by a literal period followed by any single character, use `FS -= "\\.."'. +the value of 'FS', it undergoes normal 'awk' string processing. For +example, with Unix 'awk' and 'gawk', the assignment 'FS = "\.."' assigns +the character string '".."' to 'FS' (the backslash is stripped). This +creates a regexp meaning "fields are separated by occurrences of any two +characters." If instead you want fields to be separated by a literal +period followed by any single character, use 'FS = "\\.."'. The following table summarizes how fields are split, based on the -value of `FS' (`==' means "is equal to"): +value of 'FS' ('==' means "is equal to"): -`FS == " "' +'FS == " "' Fields are separated by runs of whitespace. Leading and trailing whitespace are ignored. This is the default. -`FS == ANY OTHER SINGLE CHARACTER' +'FS == ANY OTHER SINGLE CHARACTER' Fields are separated by each occurrence of the character. Multiple successive occurrences delimit empty fields, as do leading and trailing occurrences. The character can even be a regexp metacharacter; it does not need to be escaped. -`FS == REGEXP' +'FS == REGEXP' Fields are separated by occurrences of characters that match REGEXP. Leading and trailing matches of REGEXP delimit empty fields. -`FS == ""' +'FS == ""' Each individual character in the record becomes a separate field. - (This is a `gawk' extension; it is not specified by the POSIX + (This is a 'gawk' extension; it is not specified by the POSIX standard.) - Changing `FS' Does Not Affect the Fields + Changing 'FS' Does Not Affect the Fields - According to the POSIX standard, `awk' is supposed to behave as if -each record is split into fields at the time it is read. In -particular, this means that if you change the value of `FS' after a -record is read, the value of the fields (i.e., how they were split) -should reflect the old value of `FS', not the new one. + According to the POSIX standard, 'awk' is supposed to behave as if +each record is split into fields at the time it is read. In particular, +this means that if you change the value of 'FS' after a record is read, +the value of the fields (i.e., how they were split) should reflect the +old value of 'FS', not the new one. - However, many older implementations of `awk' do not work this way. + However, many older implementations of 'awk' do not work this way. Instead, they defer splitting the fields until a field is actually -referenced. The fields are split using the _current_ value of `FS'! -(d.c.) This behavior can be difficult to diagnose. The following +referenced. The fields are split using the _current_ value of 'FS'! +(d.c.) This behavior can be difficult to diagnose. The following example illustrates the difference between the two methods. (The -`sed'(1) command prints just the first line of `/etc/passwd'.) +'sed'(1) command prints just the first line of '/etc/passwd'.) sed 1q /etc/passwd | awk '{ FS = ":" ; print $1 }' @@ -4925,16 +4902,16 @@ which usually prints: root -on an incorrect implementation of `awk', while `gawk' prints something +on an incorrect implementation of 'awk', while 'gawk' prints something like: root:nSijPlPhZZwgE:0:0:Root:/: - `FS' and `IGNORECASE' + 'FS' and 'IGNORECASE' - The `IGNORECASE' variable (*note User-modified::) affects field -splitting _only_ when the value of `FS' is a regexp. It has no effect -when `FS' is a single character, even if that character is a letter. + The 'IGNORECASE' variable (*note User-modified::) affects field +splitting _only_ when the value of 'FS' is a regexp. It has no effect +when 'FS' is a single character, even if that character is a letter. Thus, in the following code: FS = "c" @@ -4942,14 +4919,14 @@ Thus, in the following code: $0 = "aCa" print $1 -The output is `aCa'. If you really want to split fields on an +The output is 'aCa'. If you really want to split fields on an alphabetic character while ignoring case, use a regexp that will do it -for you. E.g., `FS = "[c]"'. In this case, `IGNORECASE' will take +for you. E.g., 'FS = "[c]"'. In this case, 'IGNORECASE' will take effect. ---------- Footnotes ---------- - (1) The `sed' utility is a "stream editor." Its behavior is also + (1) The 'sed' utility is a "stream editor." Its behavior is also defined by the POSIX standard.  @@ -4958,32 +4935,31 @@ File: gawk.info, Node: Constant Size, Next: Splitting By Content, Prev: Field 4.6 Reading Fixed-Width Data ============================ - NOTE: This minor node discusses an advanced feature of `gawk'. If - you are a novice `awk' user, you might want to skip it on the - first reading. + NOTE: This minor node discusses an advanced feature of 'gawk'. If + you are a novice 'awk' user, you might want to skip it on the first + reading. - `gawk' provides a facility for dealing with fixed-width fields with -no distinctive field separator. For example, data of this nature -arises in the input for old Fortran programs where numbers are run -together, or in the output of programs that did not anticipate the use -of their output as input for other programs. + 'gawk' provides a facility for dealing with fixed-width fields with +no distinctive field separator. For example, data of this nature arises +in the input for old Fortran programs where numbers are run together, or +in the output of programs that did not anticipate the use of their +output as input for other programs. An example of the latter is a table where all the columns are lined up by the use of a variable number of spaces and _empty fields are just -spaces_. Clearly, `awk''s normal field splitting based on `FS' does -not work well in this case. Although a portable `awk' program can use -a series of `substr()' calls on `$0' (*note String Functions::), this -is awkward and inefficient for a large number of fields. - - The splitting of an input record into fixed-width fields is -specified by assigning a string containing space-separated numbers to -the built-in variable `FIELDWIDTHS'. Each number specifies the width -of the field, _including_ columns between fields. If you want to -ignore the columns between fields, you can specify the width as a -separate field that is subsequently ignored. It is a fatal error to -supply a field width that is not a positive number. The following data -is the output of the Unix `w' utility. It is useful to illustrate the -use of `FIELDWIDTHS': +spaces_. Clearly, 'awk''s normal field splitting based on 'FS' does not +work well in this case. Although a portable 'awk' program can use a +series of 'substr()' calls on '$0' (*note String Functions::), this is +awkward and inefficient for a large number of fields. + + The splitting of an input record into fixed-width fields is specified +by assigning a string containing space-separated numbers to the built-in +variable 'FIELDWIDTHS'. Each number specifies the width of the field, +_including_ columns between fields. If you want to ignore the columns +between fields, you can specify the width as a separate field that is +subsequently ignored. It is a fatal error to supply a field width that +is not a positive number. The following data is the output of the Unix +'w' utility. It is useful to illustrate the use of 'FIELDWIDTHS': 10:06pm up 21 days, 14:04, 23 users User tty login idle JCPU PCPU what @@ -5000,7 +4976,7 @@ use of `FIELDWIDTHS': to number of seconds, and prints out the first two fields and the calculated idle time: - NOTE: This program uses a number of `awk' features that haven't + NOTE: This program uses a number of 'awk' features that haven't been introduced yet. BEGIN { FIELDWIDTHS = "9 6 10 6 7 7 35" } @@ -5036,16 +5012,16 @@ United States, voters mark their choices by punching holes in computer cards. These cards are then processed to count the votes for any particular candidate or on any particular issue. Because a voter may choose not to vote on some issue, any column on the card may be empty. -An `awk' program for processing such data could use the `FIELDWIDTHS' -feature to simplify reading the data. (Of course, getting `gawk' to -run on a system with card readers is another story!) +An 'awk' program for processing such data could use the 'FIELDWIDTHS' +feature to simplify reading the data. (Of course, getting 'gawk' to run +on a system with card readers is another story!) - Assigning a value to `FS' causes `gawk' to use `FS' for field -splitting again. Use `FS = FS' to make this happen, without having to -know the current value of `FS'. In order to tell which kind of field -splitting is in effect, use `PROCINFO["FS"]' (*note Auto-set::). The -value is `"FS"' if regular field splitting is being used, or it is -`"FIELDWIDTHS"' if fixed-width field splitting is being used: + Assigning a value to 'FS' causes 'gawk' to use 'FS' for field +splitting again. Use 'FS = FS' to make this happen, without having to +know the current value of 'FS'. In order to tell which kind of field +splitting is in effect, use 'PROCINFO["FS"]' (*note Auto-set::). The +value is '"FS"' if regular field splitting is being used, or it is +'"FIELDWIDTHS"' if fixed-width field splitting is being used: if (PROCINFO["FS"] == "FS") REGULAR FIELD SPLITTING ... @@ -5055,7 +5031,7 @@ value is `"FS"' if regular field splitting is being used, or it is CONTENT-BASED FIELD SPLITTING ... (see next minor node) This information is useful when writing a function that needs to -temporarily change `FS' or `FIELDWIDTHS', read some records, and then +temporarily change 'FS' or 'FIELDWIDTHS', read some records, and then restore the original settings (*note Passwd Functions::, for an example of such a function). @@ -5065,36 +5041,36 @@ File: gawk.info, Node: Splitting By Content, Next: Multiple Line, Prev: Const 4.7 Defining Fields By Content ============================== - NOTE: This minor node discusses an advanced feature of `gawk'. If - you are a novice `awk' user, you might want to skip it on the - first reading. + NOTE: This minor node discusses an advanced feature of 'gawk'. If + you are a novice 'awk' user, you might want to skip it on the first + reading. - Normally, when using `FS', `gawk' defines the fields as the parts of -the record that occur in between each field separator. In other words, -`FS' defines what a field _is not_, instead of what a field _is_. + Normally, when using 'FS', 'gawk' defines the fields as the parts of +the record that occur in between each field separator. In other words, +'FS' defines what a field _is not_, instead of what a field _is_. However, there are times when you really want to define the fields by what they are, and not by what they are not. The most notorious such case is so-called "comma separated value" -(CSV) data. Many spreadsheet programs, for example, can export their +(CSV) data. Many spreadsheet programs, for example, can export their data into text files, where each record is terminated with a newline, -and fields are separated by commas. If only commas separated the data, -there wouldn't be an issue. The problem comes when one of the fields -contains an _embedded_ comma. While there is no formal standard +and fields are separated by commas. If only commas separated the data, +there wouldn't be an issue. The problem comes when one of the fields +contains an _embedded_ comma. While there is no formal standard specification for CSV data(1), in such cases, most programs embed the -field in double quotes. So we might have data like this: +field in double quotes. So we might have data like this: Robbins,Arnold,"1234 A Pretty Street, NE",MyTown,MyState,12345-6789,USA - The `FPAT' variable offers a solution for cases like this. The -value of `FPAT' should be a string that provides a regular expression. -This regular expression describes the contents of each field. + The 'FPAT' variable offers a solution for cases like this. The value +of 'FPAT' should be a string that provides a regular expression. This +regular expression describes the contents of each field. In the case of CSV data as presented above, each field is either -"anything that is not a comma," or "a double quote, anything that is -not a double quote, and a closing double quote." If written as a -regular expression constant (*note Regexp::), we would have -`/([^,]+)|("[^"]+")/'. Writing this as a string requires us to escape +"anything that is not a comma," or "a double quote, anything that is not +a double quote, and a closing double quote." If written as a regular +expression constant (*note Regexp::), we would have +'/([^,]+)|("[^"]+")/'. Writing this as a string requires us to escape the double quotes, leading to: FPAT = "([^,]+)|(\"[^\"]+\")" @@ -5124,7 +5100,7 @@ the double quotes, leading to: $6 = <12345-6789> $7 = - Note the embedded comma in the value of `$3'. + Note the embedded comma in the value of '$3'. A straightforward improvement when processing CSV data of this sort would be to remove the quotes when they occur, with something like this: @@ -5134,26 +5110,26 @@ would be to remove the quotes when they occur, with something like this: $i = substr($i, 2, len - 2) # Get text within the two quotes } - As with `FS', the `IGNORECASE' variable (*note User-modified::) -affects field splitting with `FPAT'. + As with 'FS', the 'IGNORECASE' variable (*note User-modified::) +affects field splitting with 'FPAT'. - Similar to `FIELDWIDTHS', the value of `PROCINFO["FS"]' will be -`"FPAT"' if content-based field splitting is being used. + Similar to 'FIELDWIDTHS', the value of 'PROCINFO["FS"]' will be +'"FPAT"' if content-based field splitting is being used. - NOTE: Some programs export CSV data that contains embedded - newlines between the double quotes. `gawk' provides no way to - deal with this. Since there is no formal specification for CSV - data, there isn't much more to be done; the `FPAT' mechanism - provides an elegant solution for the majority of cases, and the - `gawk' developers are satisfied with that. + NOTE: Some programs export CSV data that contains embedded newlines + between the double quotes. 'gawk' provides no way to deal with + this. Since there is no formal specification for CSV data, there + isn't much more to be done; the 'FPAT' mechanism provides an + elegant solution for the majority of cases, and the 'gawk' + developers are satisfied with that. - As written, the regexp used for `FPAT' requires that each field have -a least one character. A straightforward modification (changing -changed the first `+' to `*') allows fields to be empty: + As written, the regexp used for 'FPAT' requires that each field have +a least one character. A straightforward modification (changing changed +the first '+' to '*') allows fields to be empty: FPAT = "([^,]*)|(\"[^\"]+\")" - Finally, the `patsplit()' function makes the same functionality + Finally, the 'patsplit()' function makes the same functionality available for splitting regular strings (*note String Functions::). ---------- Footnotes ---------- @@ -5167,27 +5143,27 @@ File: gawk.info, Node: Multiple Line, Next: Getline, Prev: Splitting By Conte ========================= In some databases, a single line cannot conveniently hold all the -information in one entry. In such cases, you can use multiline -records. The first step in doing this is to choose your data format. +information in one entry. In such cases, you can use multiline records. +The first step in doing this is to choose your data format. One technique is to use an unusual character or string to separate records. For example, you could use the formfeed character (written -`\f' in `awk', as in C) to separate them, making each record a page of -the file. To do this, just set the variable `RS' to `"\f"' (a string +'\f' in 'awk', as in C) to separate them, making each record a page of +the file. To do this, just set the variable 'RS' to '"\f"' (a string containing the formfeed character). Any other character could equally well be used, as long as it won't be part of the data in a record. Another technique is to have blank lines separate records. By a -special dispensation, an empty string as the value of `RS' indicates -that records are separated by one or more blank lines. When `RS' is set +special dispensation, an empty string as the value of 'RS' indicates +that records are separated by one or more blank lines. When 'RS' is set to the empty string, each record always ends at the first blank line encountered. The next record doesn't start until the first nonblank line that follows. No matter how many blank lines appear in a row, they -all act as one record separator. (Blank lines must be completely -empty; lines that contain only whitespace do not count.) +all act as one record separator. (Blank lines must be completely empty; +lines that contain only whitespace do not count.) - You can achieve the same effect as `RS = ""' by assigning the string -`"\n\n+"' to `RS'. This regexp matches the newline at the end of the + You can achieve the same effect as 'RS = ""' by assigning the string +'"\n\n+"' to 'RS'. This regexp matches the newline at the end of the record and one or more blank lines after the record. In addition, a regular expression always matches the longest possible sequence when there is a choice (*note Leftmost Longest::). So the next record @@ -5195,37 +5171,37 @@ doesn't start until the first nonblank line that follows--no matter how many blank lines appear in a row, they are considered one record separator. - However, there is an important difference between `RS = ""' and `RS -= "\n\n+"'. In the first case, leading newlines in the input data file -are ignored, and if a file ends without extra blank lines after the -last record, the final newline is removed from the record. In the -second case, this special processing is not done. (d.c.) + However, there is an important difference between 'RS = ""' and 'RS = +"\n\n+"'. In the first case, leading newlines in the input data file +are ignored, and if a file ends without extra blank lines after the last +record, the final newline is removed from the record. In the second +case, this special processing is not done. (d.c.) Now that the input is separated into records, the second step is to separate the fields in the record. One way to do this is to divide each of the lines into fields in the normal manner. This happens by default -as the result of a special feature. When `RS' is set to the empty -string, _and_ `FS' is set to a single character, the newline character +as the result of a special feature. When 'RS' is set to the empty +string, _and_ 'FS' is set to a single character, the newline character _always_ acts as a field separator. This is in addition to whatever -field separations result from `FS'.(1) +field separations result from 'FS'.(1) The original motivation for this special exception was probably to -provide useful behavior in the default case (i.e., `FS' is equal to -`" "'). This feature can be a problem if you really don't want the -newline character to separate fields, because there is no way to -prevent it. However, you can work around this by using the `split()' -function to break up the record manually (*note String Functions::). -If you have a single character field separator, you can work around the -special feature in a different way, by making `FS' into a regexp for -that single character. For example, if the field separator is a -percent character, instead of `FS = "%"', use `FS = "[%]"'. +provide useful behavior in the default case (i.e., 'FS' is equal to +'" "'). This feature can be a problem if you really don't want the +newline character to separate fields, because there is no way to prevent +it. However, you can work around this by using the 'split()' function +to break up the record manually (*note String Functions::). If you have +a single character field separator, you can work around the special +feature in a different way, by making 'FS' into a regexp for that single +character. For example, if the field separator is a percent character, +instead of 'FS = "%"', use 'FS = "[%]"'. Another way to separate fields is to put each field on a separate -line: to do this, just set the variable `FS' to the string `"\n"'. -(This single character separator matches a single newline.) A -practical example of a data file organized this way might be a mailing -list, where each entry is separated by blank lines. Consider a mailing -list in a file named `addresses', which looks like this: +line: to do this, just set the variable 'FS' to the string '"\n"'. +(This single character separator matches a single newline.) A practical +example of a data file organized this way might be a mailing list, where +each entry is separated by blank lines. Consider a mailing list in a +file named 'addresses', which looks like this: Jane Doe 123 Main Street @@ -5266,97 +5242,97 @@ A simple program to process this file is as follows: *Note Labels Program::, for a more realistic program that deals with address lists. The following table summarizes how records are split, -based on the value of `RS'. (`==' means "is equal to.") +based on the value of 'RS'. ('==' means "is equal to.") -`RS == "\n"' - Records are separated by the newline character (`\n'). In effect, +'RS == "\n"' + Records are separated by the newline character ('\n'). In effect, every line in the data file is a separate record, including blank lines. This is the default. -`RS == ANY SINGLE CHARACTER' +'RS == ANY SINGLE CHARACTER' Records are separated by each occurrence of the character. Multiple successive occurrences delimit empty records. -`RS == ""' - Records are separated by runs of blank lines. When `FS' is a +'RS == ""' + Records are separated by runs of blank lines. When 'FS' is a single character, then the newline character always serves as a - field separator, in addition to whatever value `FS' may have. + field separator, in addition to whatever value 'FS' may have. Leading and trailing newlines in a file are ignored. -`RS == REGEXP' +'RS == REGEXP' Records are separated by occurrences of characters that match REGEXP. Leading and trailing matches of REGEXP delimit empty - records. (This is a `gawk' extension; it is not specified by the + records. (This is a 'gawk' extension; it is not specified by the POSIX standard.) - In all cases, `gawk' sets `RT' to the input text that matched the -value specified by `RS'. But if the input file ended without any text -that matches `RS', then `gawk' sets `RT' to the null string. + In all cases, 'gawk' sets 'RT' to the input text that matched the +value specified by 'RS'. But if the input file ended without any text +that matches 'RS', then 'gawk' sets 'RT' to the null string. ---------- Footnotes ---------- - (1) When `FS' is the null string (`""') or a regexp, this special -feature of `RS' does not apply. It does apply to the default field -separator of a single space: `FS = " "'. + (1) When 'FS' is the null string ('""') or a regexp, this special +feature of 'RS' does not apply. It does apply to the default field +separator of a single space: 'FS = " "'.  File: gawk.info, Node: Getline, Next: Read Timeout, Prev: Multiple Line, Up: Reading Files -4.9 Explicit Input with `getline' +4.9 Explicit Input with 'getline' ================================= -So far we have been getting our input data from `awk''s main input +So far we have been getting our input data from 'awk''s main input stream--either the standard input (usually your keyboard, sometimes the output from another program) or from the files specified on the command -line. The `awk' language has a special built-in command called -`getline' that can be used to read input under your explicit control. - - The `getline' command is used in several different ways and should -_not_ be used by beginners. The examples that follow the explanation -of the `getline' command include material that has not been covered -yet. Therefore, come back and study the `getline' command _after_ you -have reviewed the rest of this Info file and have a good knowledge of -how `awk' works. - - The `getline' command returns one if it finds a record and zero if -it encounters the end of the file. If there is some error in getting a -record, such as a file that cannot be opened, then `getline' returns --1. In this case, `gawk' sets the variable `ERRNO' to a string -describing the error that occurred. +line. The 'awk' language has a special built-in command called +'getline' that can be used to read input under your explicit control. + + The 'getline' command is used in several different ways and should +_not_ be used by beginners. The examples that follow the explanation of +the 'getline' command include material that has not been covered yet. +Therefore, come back and study the 'getline' command _after_ you have +reviewed the rest of this Info file and have a good knowledge of how +'awk' works. + + The 'getline' command returns one if it finds a record and zero if it +encounters the end of the file. If there is some error in getting a +record, such as a file that cannot be opened, then 'getline' returns -1. +In this case, 'gawk' sets the variable 'ERRNO' to a string describing +the error that occurred. In the following examples, COMMAND stands for a string value that represents a shell command. - NOTE: When `--sandbox' is specified (*note Options::), reading + NOTE: When '--sandbox' is specified (*note Options::), reading lines from files, pipes and coprocesses is disabled. * Menu: -* Plain Getline:: Using `getline' with no arguments. -* Getline/Variable:: Using `getline' into a variable. -* Getline/File:: Using `getline' from a file. -* Getline/Variable/File:: Using `getline' into a variable from a +* Plain Getline:: Using 'getline' with no arguments. +* Getline/Variable:: Using 'getline' into a variable. +* Getline/File:: Using 'getline' from a file. +* Getline/Variable/File:: Using 'getline' into a variable from a file. -* Getline/Pipe:: Using `getline' from a pipe. -* Getline/Variable/Pipe:: Using `getline' into a variable from a +* Getline/Pipe:: Using 'getline' from a pipe. +* Getline/Variable/Pipe:: Using 'getline' into a variable from a pipe. -* Getline/Coprocess:: Using `getline' from a coprocess. -* Getline/Variable/Coprocess:: Using `getline' into a variable from a +* Getline/Coprocess:: Using 'getline' from a coprocess. +* Getline/Variable/Coprocess:: Using 'getline' into a variable from a coprocess. -* Getline Notes:: Important things to know about `getline'. -* Getline Summary:: Summary of `getline' Variants. +* Getline Notes:: Important things to know about 'getline'. +* Getline Summary:: Summary of 'getline' Variants.  File: gawk.info, Node: Plain Getline, Next: Getline/Variable, Up: Getline -4.9.1 Using `getline' with No Arguments +4.9.1 Using 'getline' with No Arguments --------------------------------------- -The `getline' command can be used without arguments to read input from -the current input file. All it does in this case is read the next -input record and split it up into fields. This is useful if you've -finished processing the current record, but want to do some special -processing on the next record _right now_. For example: +The 'getline' command can be used without arguments to read input from +the current input file. All it does in this case is read the next input +record and split it up into fields. This is useful if you've finished +processing the current record, but want to do some special processing on +the next record _right now_. For example: { if ((t = index($0, "/*")) != 0) { @@ -5381,19 +5357,19 @@ processing on the next record _right now_. For example: print $0 } - This `awk' program deletes C-style comments (`/* ... */') from the -input. By replacing the `print $0' with other statements, you could + This 'awk' program deletes C-style comments ('/* ... */') from the +input. By replacing the 'print $0' with other statements, you could perform more complicated processing on the decommented input, such as searching for matches of a regular expression. (This program has a subtle problem--it does not work if one comment ends and another begins on the same line.) - This form of the `getline' command sets `NF', `NR', `FNR', `RT', and -the value of `$0'. + This form of the 'getline' command sets 'NF', 'NR', 'FNR', 'RT', and +the value of '$0'. - NOTE: The new value of `$0' is used to test the patterns of any - subsequent rules. The original value of `$0' that triggered the - rule that executed `getline' is lost. By contrast, the `next' + NOTE: The new value of '$0' is used to test the patterns of any + subsequent rules. The original value of '$0' that triggered the + rule that executed 'getline' is lost. By contrast, the 'next' statement reads a new record but immediately begins processing it normally, starting with the first rule in the program. *Note Next Statement::. @@ -5401,15 +5377,15 @@ the value of `$0'.  File: gawk.info, Node: Getline/Variable, Next: Getline/File, Prev: Plain Getline, Up: Getline -4.9.2 Using `getline' into a Variable +4.9.2 Using 'getline' into a Variable ------------------------------------- -You can use `getline VAR' to read the next record from `awk''s input +You can use 'getline VAR' to read the next record from 'awk''s input into the variable VAR. No other processing is done. For example, suppose the next line is a comment or a special string, and you want to -read it without triggering any rules. This form of `getline' allows -you to read that line and store it in a variable so that the main -read-a-line-and-check-each-rule loop of `awk' never sees it. The +read it without triggering any rules. This form of 'getline' allows you +to read that line and store it in a variable so that the main +read-a-line-and-check-each-rule loop of 'awk' never sees it. The following example swaps every two lines of input: { @@ -5434,23 +5410,23 @@ and produces these results: phore free - The `getline' command used in this way sets only the variables `NR', -`FNR' and `RT' (and of course, VAR). The record is not split into -fields, so the values of the fields (including `$0') and the value of -`NF' do not change. + The 'getline' command used in this way sets only the variables 'NR', +'FNR' and 'RT' (and of course, VAR). The record is not split into +fields, so the values of the fields (including '$0') and the value of +'NF' do not change.  File: gawk.info, Node: Getline/File, Next: Getline/Variable/File, Prev: Getline/Variable, Up: Getline -4.9.3 Using `getline' from a File +4.9.3 Using 'getline' from a File --------------------------------- -Use `getline < FILE' to read the next record from FILE. Here FILE is a -string-valued expression that specifies the file name. `< FILE' is -called a "redirection" because it directs input to come from a -different place. For example, the following program reads its input -record from the file `secondary.input' when it encounters a first field -with a value equal to 10 in the current input file: +Use 'getline < FILE' to read the next record from FILE. Here FILE is a +string-valued expression that specifies the file name. '< FILE' is +called a "redirection" because it directs input to come from a different +place. For example, the following program reads its input record from +the file 'secondary.input' when it encounters a first field with a value +equal to 10 in the current input file: { if ($1 == 10) { @@ -5460,33 +5436,33 @@ with a value equal to 10 in the current input file: print } - Because the main input stream is not used, the values of `NR' and -`FNR' are not changed. However, the record it reads is split into -fields in the normal manner, so the values of `$0' and the other fields -are changed, resulting in a new value of `NF'. `RT' is also set. + Because the main input stream is not used, the values of 'NR' and +'FNR' are not changed. However, the record it reads is split into +fields in the normal manner, so the values of '$0' and the other fields +are changed, resulting in a new value of 'NF'. 'RT' is also set. - According to POSIX, `getline < EXPRESSION' is ambiguous if -EXPRESSION contains unparenthesized operators other than `$'; for -example, `getline < dir "/" file' is ambiguous because the -concatenation operator (not discussed yet; *note Concatenation::) is -not parenthesized. You should write it as `getline < (dir "/" file)' if -you want your program to be portable to all `awk' implementations. + According to POSIX, 'getline < EXPRESSION' is ambiguous if EXPRESSION +contains unparenthesized operators other than '$'; for example, 'getline +< dir "/" file' is ambiguous because the concatenation operator (not +discussed yet; *note Concatenation::) is not parenthesized. You should +write it as 'getline < (dir "/" file)' if you want your program to be +portable to all 'awk' implementations.  File: gawk.info, Node: Getline/Variable/File, Next: Getline/Pipe, Prev: Getline/File, Up: Getline -4.9.4 Using `getline' into a Variable from a File +4.9.4 Using 'getline' into a Variable from a File ------------------------------------------------- -Use `getline VAR < FILE' to read input from the file FILE, and put it -in the variable VAR. As above, FILE is a string-valued expression that +Use 'getline VAR < FILE' to read input from the file FILE, and put it in +the variable VAR. As above, FILE is a string-valued expression that specifies the file from which to read. - In this version of `getline', none of the built-in variables are + In this version of 'getline', none of the built-in variables are changed and the record is not split into fields. The only variable -changed is VAR.(1) For example, the following program copies all the +changed is VAR.(1) For example, the following program copies all the input files to the output, except for records that say -`@include FILENAME'. Such a record is replaced by the contents of the +'@include FILENAME'. Such a record is replaced by the contents of the file FILENAME: { @@ -5500,37 +5476,38 @@ file FILENAME: Note here how the name of the extra input file is not built into the program; it is taken directly from the data, specifically from the -second field on the `@include' line. +second field on the '@include' line. - The `close()' function is called to ensure that if two identical -`@include' lines appear in the input, the entire specified file is + The 'close()' function is called to ensure that if two identical +'@include' lines appear in the input, the entire specified file is included twice. *Note Close Files And Pipes::. One deficiency of this program is that it does not process nested -`@include' statements (i.e., `@include' statements in included files) +'@include' statements (i.e., '@include' statements in included files) the way a true macro preprocessor would. *Note Igawk Program::, for a -program that does handle nested `@include' statements. +program that does handle nested '@include' statements. ---------- Footnotes ---------- - (1) This is not quite true. `RT' could be changed if `RS' is a + (1) This is not quite true. 'RT' could be changed if 'RS' is a regular expression.  File: gawk.info, Node: Getline/Pipe, Next: Getline/Variable/Pipe, Prev: Getline/Variable/File, Up: Getline -4.9.5 Using `getline' from a Pipe +4.9.5 Using 'getline' from a Pipe --------------------------------- Omniscience has much to recommend it. Failing that, attention to - details would be useful. -- Brian Kernighan + details would be useful. + -- _Brian Kernighan_ - The output of a command can also be piped into `getline', using -`COMMAND | getline'. In this case, the string COMMAND is run as a -shell command and its output is piped into `awk' to be used as input. -This form of `getline' reads one record at a time from the pipe. For + The output of a command can also be piped into 'getline', using +'COMMAND | getline'. In this case, the string COMMAND is run as a shell +command and its output is piped into 'awk' to be used as input. This +form of 'getline' reads one record at a time from the pipe. For example, the following program copies its input to its output, except -for lines that begin with `@execute', which are replaced by the output +for lines that begin with '@execute', which are replaced by the output produced by running the rest of the line as a shell command: { @@ -5543,8 +5520,8 @@ produced by running the rest of the line as a shell command: print } -The `close()' function is called to ensure that if two identical -`@execute' lines appear in the input, the command is run for each one. +The 'close()' function is called to ensure that if two identical +'@execute' lines appear in the input, the command is run for each one. *Note Close Files And Pipes::. Given the input: foo @@ -5563,39 +5540,38 @@ the program might produce: bill ttyp1 Jul 13 14:23 (murphy:0) bletch -Notice that this program ran the command `who' and printed the previous +Notice that this program ran the command 'who' and printed the previous result. (If you try this program yourself, you will of course get different results, depending upon who is logged in on your system.) - This variation of `getline' splits the record into fields, sets the -value of `NF', and recomputes the value of `$0'. The values of `NR' -and `FNR' are not changed. `RT' is set. - - According to POSIX, `EXPRESSION | getline' is ambiguous if -EXPRESSION contains unparenthesized operators other than `$'--for -example, `"echo " "date" | getline' is ambiguous because the -concatenation operator is not parenthesized. You should write it as -`("echo " "date") | getline' if you want your program to be portable to -all `awk' implementations. - - NOTE: Unfortunately, `gawk' has not been consistent in its - treatment of a construct like `"echo " "date" | getline'. Most - versions, including the current version, treat it at as `("echo " - "date") | getline'. (This how Brian Kernighan's `awk' behaves.) - Some versions changed and treated it as `"echo " ("date" | - getline)'. (This is how `mawk' behaves.) In short, _always_ use + This variation of 'getline' splits the record into fields, sets the +value of 'NF', and recomputes the value of '$0'. The values of 'NR' and +'FNR' are not changed. 'RT' is set. + + According to POSIX, 'EXPRESSION | getline' is ambiguous if EXPRESSION +contains unparenthesized operators other than '$'--for example, '"echo " +"date" | getline' is ambiguous because the concatenation operator is not +parenthesized. You should write it as '("echo " "date") | getline' if +you want your program to be portable to all 'awk' implementations. + + NOTE: Unfortunately, 'gawk' has not been consistent in its + treatment of a construct like '"echo " "date" | getline'. Most + versions, including the current version, treat it at as '("echo " + "date") | getline'. (This how Brian Kernighan's 'awk' behaves.) + Some versions changed and treated it as '"echo " ("date" | + getline)'. (This is how 'mawk' behaves.) In short, _always_ use explicit parentheses, and then you won't have to worry.  File: gawk.info, Node: Getline/Variable/Pipe, Next: Getline/Coprocess, Prev: Getline/Pipe, Up: Getline -4.9.6 Using `getline' into a Variable from a Pipe +4.9.6 Using 'getline' into a Variable from a Pipe ------------------------------------------------- -When you use `COMMAND | getline VAR', the output of COMMAND is sent -through a pipe to `getline' and into the variable VAR. For example, the +When you use 'COMMAND | getline VAR', the output of COMMAND is sent +through a pipe to 'getline' and into the variable VAR. For example, the following program reads the current date and time into the variable -`current_time', using the `date' utility, and then prints it: +'current_time', using the 'date' utility, and then prints it: BEGIN { "date" | getline current_time @@ -5603,108 +5579,108 @@ following program reads the current date and time into the variable print "Report printed on " current_time } - In this version of `getline', none of the built-in variables are + In this version of 'getline', none of the built-in variables are changed and the record is not split into fields. - According to POSIX, `EXPRESSION | getline VAR' is ambiguous if -EXPRESSION contains unparenthesized operators other than `$'; for -example, `"echo " "date" | getline VAR' is ambiguous because the -concatenation operator is not parenthesized. You should write it as -`("echo " "date") | getline VAR' if you want your program to be -portable to other `awk' implementations. + According to POSIX, 'EXPRESSION | getline VAR' is ambiguous if +EXPRESSION contains unparenthesized operators other than '$'; for +example, '"echo " "date" | getline VAR' is ambiguous because the +concatenation operator is not parenthesized. You should write it as '("echo " +"date") | getline VAR' if you want your program to be portable to other +'awk' implementations.  File: gawk.info, Node: Getline/Coprocess, Next: Getline/Variable/Coprocess, Prev: Getline/Variable/Pipe, Up: Getline -4.9.7 Using `getline' from a Coprocess +4.9.7 Using 'getline' from a Coprocess -------------------------------------- -Input into `getline' from a pipe is a one-way operation. The command -that is started with `COMMAND | getline' only sends data _to_ your -`awk' program. +Input into 'getline' from a pipe is a one-way operation. The command +that is started with 'COMMAND | getline' only sends data _to_ your 'awk' +program. On occasion, you might want to send data to another program for -processing and then read the results back. `gawk' allows you to start -a "coprocess", with which two-way communications are possible. This is -done with the `|&' operator. Typically, you write data to the -coprocess first and then read results back, as shown in the following: +processing and then read the results back. 'gawk' allows you to start a +"coprocess", with which two-way communications are possible. This is +done with the '|&' operator. Typically, you write data to the coprocess +first and then read results back, as shown in the following: print "SOME QUERY" |& "db_server" "db_server" |& getline -which sends a query to `db_server' and then reads the results. +which sends a query to 'db_server' and then reads the results. - The values of `NR' and `FNR' are not changed, because the main input + The values of 'NR' and 'FNR' are not changed, because the main input stream is not used. However, the record is split into fields in the -normal manner, thus changing the values of `$0', of the other fields, -and of `NF' and `RT'. +normal manner, thus changing the values of '$0', of the other fields, +and of 'NF' and 'RT'. - Coprocesses are an advanced feature. They are discussed here only -because this is the minor node on `getline'. *Note Two-way I/O::, -where coprocesses are discussed in more detail. + Coprocesses are an advanced feature. They are discussed here only +because this is the minor node on 'getline'. *Note Two-way I/O::, where +coprocesses are discussed in more detail.  File: gawk.info, Node: Getline/Variable/Coprocess, Next: Getline Notes, Prev: Getline/Coprocess, Up: Getline -4.9.8 Using `getline' into a Variable from a Coprocess +4.9.8 Using 'getline' into a Variable from a Coprocess ------------------------------------------------------ -When you use `COMMAND |& getline VAR', the output from the coprocess -COMMAND is sent through a two-way pipe to `getline' and into the +When you use 'COMMAND |& getline VAR', the output from the coprocess +COMMAND is sent through a two-way pipe to 'getline' and into the variable VAR. - In this version of `getline', none of the built-in variables are + In this version of 'getline', none of the built-in variables are changed and the record is not split into fields. The only variable -changed is VAR. However, `RT' is set. +changed is VAR. However, 'RT' is set. - Coprocesses are an advanced feature. They are discussed here only -because this is the minor node on `getline'. *Note Two-way I/O::, -where coprocesses are discussed in more detail. + Coprocesses are an advanced feature. They are discussed here only +because this is the minor node on 'getline'. *Note Two-way I/O::, where +coprocesses are discussed in more detail.  File: gawk.info, Node: Getline Notes, Next: Getline Summary, Prev: Getline/Variable/Coprocess, Up: Getline -4.9.9 Points to Remember About `getline' +4.9.9 Points to Remember About 'getline' ---------------------------------------- -Here are some miscellaneous points about `getline' that you should bear +Here are some miscellaneous points about 'getline' that you should bear in mind: - * When `getline' changes the value of `$0' and `NF', `awk' does - _not_ automatically jump to the start of the program and start - testing the new record against every pattern. However, the new - record is tested against any subsequent rules. - - * Some very old `awk' implementations limit the number of pipelines - that an `awk' program may have open to just one. In `gawk', there - is no such limit. You can open as many pipelines (and - coprocesses) as the underlying operating system permits. - - * An interesting side effect occurs if you use `getline' without a - redirection inside a `BEGIN' rule. Because an unredirected - `getline' reads from the command-line data files, the first - `getline' command causes `awk' to set the value of `FILENAME'. - Normally, `FILENAME' does not have a value inside `BEGIN' rules, + * When 'getline' changes the value of '$0' and 'NF', 'awk' does _not_ + automatically jump to the start of the program and start testing + the new record against every pattern. However, the new record is + tested against any subsequent rules. + + * Some very old 'awk' implementations limit the number of pipelines + that an 'awk' program may have open to just one. In 'gawk', there + is no such limit. You can open as many pipelines (and coprocesses) + as the underlying operating system permits. + + * An interesting side effect occurs if you use 'getline' without a + redirection inside a 'BEGIN' rule. Because an unredirected + 'getline' reads from the command-line data files, the first + 'getline' command causes 'awk' to set the value of 'FILENAME'. + Normally, 'FILENAME' does not have a value inside 'BEGIN' rules, because you have not yet started to process the command-line data files. (d.c.) (*Note BEGIN/END::, also *note Auto-set::.) - * Using `FILENAME' with `getline' (`getline < FILENAME') is likely - to be a source for confusion. `awk' opens a separate input stream + * Using 'FILENAME' with 'getline' ('getline < FILENAME') is likely to + be a source for confusion. 'awk' opens a separate input stream from the current input file. However, by not using a variable, - `$0' and `NR' are still updated. If you're doing this, it's + '$0' and 'NR' are still updated. If you're doing this, it's probably by accident, and you should reconsider what it is you're trying to accomplish. - * *note Getline Summary::, presents a table summarizing the - `getline' variants and which variables they can affect. It is - worth noting that those variants which do not use redirection can - cause `FILENAME' to be updated if they cause `awk' to start - reading a new input file. + * *note Getline Summary::, presents a table summarizing the 'getline' + variants and which variables they can affect. It is worth noting + that those variants which do not use redirection can cause + 'FILENAME' to be updated if they cause 'awk' to start reading a new + input file. * If the variable being assigned is an expression with side effects, - different versions of `awk' behave differently upon encountering + different versions of 'awk' behave differently upon encountering end-of-file. Some versions don't evaluate the expression; many - versions (including `gawk') do. Here is an example, due to Duncan + versions (including 'gawk') do. Here is an example, due to Duncan Moore: BEGIN { @@ -5713,41 +5689,42 @@ in mind: print c } - Here, the side effect is the `++c'. Is `c' incremented if end of - file is encountered, before the element in `a' is assigned? + Here, the side effect is the '++c'. Is 'c' incremented if end of + file is encountered, before the element in 'a' is assigned? - `gawk' treats `getline' like a function call, and evaluates the - expression `a[++c]' before attempting to read from `f'. However, - some versions of `awk' only evaluate the expression once they know + 'gawk' treats 'getline' like a function call, and evaluates the + expression 'a[++c]' before attempting to read from 'f'. However, + some versions of 'awk' only evaluate the expression once they know that there is a string value to be assigned. Caveat Emptor.  File: gawk.info, Node: Getline Summary, Prev: Getline Notes, Up: Getline -4.9.10 Summary of `getline' Variants +4.9.10 Summary of 'getline' Variants ------------------------------------ -*note table-getline-variants:: summarizes the eight variants of -`getline', listing which built-in variables are set by each one, and -whether the variant is standard or a `gawk' extension. Note: for each -variant, `gawk' sets the `RT' built-in variable. +*note Table 4.1: table-getline-variants. summarizes the eight variants +of 'getline', listing which built-in variables are set by each one, and +whether the variant is standard or a 'gawk' extension. Note: for each +variant, 'gawk' sets the 'RT' built-in variable. Variant Effect Standard / Extension -------------------------------------------------------------------------- -`getline' Sets `$0', `NF', `FNR', Standard - `NR', and `RT' -`getline' VAR Sets VAR, `FNR', `NR', and Standard - `RT' -`getline <' FILE Sets `$0', `NF', and `RT' Standard -`getline VAR < FILE' Sets VAR and `RT' Standard -COMMAND `| getline' Sets `$0', `NF', and `RT' Standard -COMMAND `| getline' VAR Sets VAR and `RT' Standard -COMMAND `|& getline' Sets `$0', `NF', and `RT' Extension -COMMAND `|& getline' Sets VAR and `RT' Extension -VAR - -Table 4.1: `getline' Variants and What They Set +------------------------------------------------------------------------- +'getline' Sets '$0', 'NF', 'FNR', Standard + 'NR', and 'RT' +'getline' VAR Sets VAR, 'FNR', 'NR', Standard + and 'RT' +'getline <' FILE Sets '$0', 'NF', and 'RT' Standard +'getline VAR < FILE' Sets VAR and 'RT' Standard +COMMAND '| getline' Sets '$0', 'NF', and 'RT' Standard +COMMAND '| getline' Sets VAR and 'RT' Standard +VAR +COMMAND '|& getline' Sets '$0', 'NF', and 'RT' Extension +COMMAND '|& getline' Sets VAR and 'RT' Extension +VAR + +Table 4.1: 'getline' Variants and What They Set  File: gawk.info, Node: Read Timeout, Next: Command line directories, Prev: Getline, Up: Reading Files @@ -5755,16 +5732,16 @@ File: gawk.info, Node: Read Timeout, Next: Command line directories, Prev: Ge 4.10 Reading Input With A Timeout ================================= -This minor node describes a feature that is specific to `gawk'. +This minor node describes a feature that is specific to 'gawk'. You may specify a timeout in milliseconds for reading input from the keyboard, a pipe, or two-way communication, including TCP/IP sockets. -This can be done on a per input, command or connection basis, by -setting a special element in the `PROCINFO' (*note Auto-set::) array: +This can be done on a per input, command or connection basis, by setting +a special element in the 'PROCINFO' (*note Auto-set::) array: PROCINFO["input_name", "READ_TIMEOUT"] = TIMEOUT IN MILLISECONDS - When set, this causes `gawk' to time out and return failure if no + When set, this causes 'gawk' to time out and return failure if no data is available to read within the specified timeout period. For example, a TCP client can decide to give up on receiving any response from the server after a certain amount of time: @@ -5783,8 +5760,8 @@ for more than five seconds: while ((getline < "/dev/stdin") > 0) print $0 - `gawk' terminates the read operation if input does not arrive after -waiting for the timeout period, returns failure and sets the `ERRNO' + 'gawk' terminates the read operation if input does not arrive after +waiting for the timeout period, returns failure and sets the 'ERRNO' variable to an appropriate string value. A negative or zero value for the timeout is the same as specifying no timeout at all. @@ -5800,10 +5777,10 @@ patterns, like so: In this case, failure to respond within five seconds results in the following error message: - error--> gawk: cmd. line:2: (FILENAME=- FNR=1) fatal: error reading input file `-': Connection timed out + error-> gawk: cmd. line:2: (FILENAME=- FNR=1) fatal: error reading input file `-': Connection timed out The timeout can be set or changed at any time, and will take effect -on the next attempt to read from the input device. In the following +on the next attempt to read from the input device. In the following example, we start with a timeout value of one second, and progressively reduce it by one-tenth of a second until we wait indefinitely for the input to arrive: @@ -5815,29 +5792,28 @@ input to arrive: } NOTE: You should not assume that the read operation will block - exactly after the tenth record has been printed. It is possible - that `gawk' will read and buffer more than one record's worth of - data the first time. Because of this, changing the value of + exactly after the tenth record has been printed. It is possible + that 'gawk' will read and buffer more than one record's worth of + data the first time. Because of this, changing the value of timeout like in the above example is not very useful. - If the `PROCINFO' element is not present and the environment -variable `GAWK_READ_TIMEOUT' exists, `gawk' uses its value to -initialize the timeout value. The exclusive use of the environment -variable to specify timeout has the disadvantage of not being able to -control it on a per command or connection basis. + If the 'PROCINFO' element is not present and the environment variable +'GAWK_READ_TIMEOUT' exists, 'gawk' uses its value to initialize the +timeout value. The exclusive use of the environment variable to specify +timeout has the disadvantage of not being able to control it on a per +command or connection basis. - `gawk' considers a timeout event to be an error even though the + 'gawk' considers a timeout event to be an error even though the attempt to read from the underlying device may succeed in a later -attempt. This is a limitation, and it also means that you cannot use +attempt. This is a limitation, and it also means that you cannot use this to multiplex input from two or more sources. Assigning a timeout value prevents read operations from blocking -indefinitely. But bear in mind that there are other ways `gawk' can +indefinitely. But bear in mind that there are other ways 'gawk' can stall waiting for an input device to be ready. A network client can -sometimes take a long time to establish a connection before it can -start reading any data, or the attempt to open a FIFO special file for -reading can block indefinitely until some other process opens it for -writing. +sometimes take a long time to establish a connection before it can start +reading any data, or the attempt to open a FIFO special file for reading +can block indefinitely until some other process opens it for writing. ---------- Footnotes ---------- @@ -5849,22 +5825,22 @@ File: gawk.info, Node: Command line directories, Next: Input Summary, Prev: R 4.11 Directories On The Command Line ==================================== -According to the POSIX standard, files named on the `awk' command line +According to the POSIX standard, files named on the 'awk' command line must be text files; it is a fatal error if they are not. Most versions -of `awk' treat a directory on the command line as a fatal error. +of 'awk' treat a directory on the command line as a fatal error. - By default, `gawk' produces a warning for a directory on the command + By default, 'gawk' produces a warning for a directory on the command line, but otherwise ignores it. This makes it easier to use shell -wildcards with your `awk' program: +wildcards with your 'awk' program: $ gawk -f whizprog.awk * Directories could kill this progam - If either of the `--posix' or `--traditional' options is given, then -`gawk' reverts to treating a directory on the command line as a fatal + If either of the '--posix' or '--traditional' options is given, then +'gawk' reverts to treating a directory on the command line as a fatal error. *Note Extension Sample Readdir::, for a way to treat directories as -usable data from an `awk' program. +usable data from an 'awk' program.  File: gawk.info, Node: Input Summary, Next: Input Exercises, Prev: Command line directories, Up: Reading Files @@ -5872,68 +5848,66 @@ File: gawk.info, Node: Input Summary, Next: Input Exercises, Prev: Command li 4.12 Summary ============ - * Input is split into records based on the value of `RS'. The + * Input is split into records based on the value of 'RS'. The possibilities are as follows: - Value of `RS' Records are split on `awk' / `gawk' - ---------------------------------------------------------------------- - Any single That character `awk' - character - The empty string Runs of two or more `awk' - (`""') newlines - A regexp Text that matches the `gawk' - regexp + Value of 'RS' Records are split on 'awk' / 'gawk' + --------------------------------------------------------------------------- + Any single That character 'awk' + character + The empty string Runs of two or more 'awk' + ('""') newlines + A regexp Text that matches the 'gawk' + regexp - * `gawk' sets `RT' to the text matched by `RS'. + * 'gawk' sets 'RT' to the text matched by 'RS'. - * After splitting the input into records, `awk' further splits the - record into individual fields, named `$1', `$2' and so on. `$0' is - the whole record, and `NF' indicates how many fields there are. + * After splitting the input into records, 'awk' further splits the + record into individual fields, named '$1', '$2' and so on. '$0' is + the whole record, and 'NF' indicates how many fields there are. The default way to split fields is between whitespace characters. - * Fields may be referenced using a variable, as in `$NF'. Fields - may also be assigned values, which causes the value of `$0' to be - recomputed when it is later referenced. Assigning to a field with - a number greater than `NF' creates the field and rebuilds the - record, using `OFS' to separate the fields. Incrementing `NF' - does the same thing. Decrementing `NF' throws away fields and - rebuilds the record. + * Fields may be referenced using a variable, as in '$NF'. Fields may + also be assigned values, which causes the value of '$0' to be + recomputed when it is later referenced. Assigning to a field with + a number greater than 'NF' creates the field and rebuilds the + record, using 'OFS' to separate the fields. Incrementing 'NF' does + the same thing. Decrementing 'NF' throws away fields and rebuilds + the record. * Field splitting is more complicated than record splitting. - Field separator value Fields are split ... `awk' / - `gawk' - ---------------------------------------------------------------------- - `FS == " "' On runs of whitespace `awk' - `FS == ANY SINGLE On that character `awk' - CHARACTER' - `FS == REGEXP' On text matching the `awk' - regexp - `FS == ""' Each individual character `gawk' - is a separate field - `FIELDWIDTHS == LIST OF Based on character `gawk' - COLUMNS' position - `FPAT == REGEXP' On text around text `gawk' - matching the regexp - - Using `FS = "\n"' causes the entire record to be a single field + Field separator value Fields are split ... 'awk' / + 'gawk' + --------------------------------------------------------------------------- + 'FS == " "' On runs of whitespace 'awk' + 'FS == ANY SINGLE On that character 'awk' + CHARACTER' + 'FS == REGEXP' On text matching the regexp 'awk' + 'FS == ""' Each individual character 'gawk' + is a separate field + 'FIELDWIDTHS == LIST OF Based on character position 'gawk' + COLUMNS' + 'FPAT == REGEXP' On text around text 'gawk' + matching the regexp + + Using 'FS = "\n"' causes the entire record to be a single field (assuming that newlines separate records). - * `FS' may be set from the command line using the `-F' option. This + * 'FS' may be set from the command line using the '-F' option. This can also be done using command-line variable assignment. - * `PROCINFO["FS"]' can be used to see how fields are being split. + * 'PROCINFO["FS"]' can be used to see how fields are being split. - * Use `getline' in its various forms to read additional records, - from the default input stream, from a file, or from a pipe or + * Use 'getline' in its various forms to read additional records, from + the default input stream, from a file, or from a pipe or co-process. - * Use `PROCINFO[FILE, "READ_TIMEOUT"]' to cause reads to timeout for + * Use 'PROCINFO[FILE, "READ_TIMEOUT"]' to cause reads to timeout for FILE. - * Directories on the command line are fatal for standard `awk'; - `gawk' ignores them if not in POSIX mode. - + * Directories on the command line are fatal for standard 'awk'; + 'gawk' ignores them if not in POSIX mode.  File: gawk.info, Node: Input Exercises, Prev: Input Summary, Up: Reading Files @@ -5941,18 +5915,17 @@ File: gawk.info, Node: Input Exercises, Prev: Input Summary, Up: Reading File 4.13 Exercises ============== - 1. Using the `FIELDWIDTHS' variable (*note Constant Size::), write a + 1. Using the 'FIELDWIDTHS' variable (*note Constant Size::), write a program to read election data, where each record represents one voter's votes. Come up with a way to define which columns are associated with each ballot item, and print the total votes, including abstentions, for each item. 2. *note Plain Getline::, presented a program to remove C-style - comments (`/* ... */') from the input. That program does not work - if one comment ends on one line and another one starts later on - the same line. Write a program that does handle multiple comments - on the line. - + comments ('/* ... */') from the input. That program does not work + if one comment ends on one line and another one starts later on the + same line. Write a program that does handle multiple comments on + the line.  File: gawk.info, Node: Printing, Next: Expressions, Prev: Reading Files, Up: Top @@ -5961,31 +5934,31 @@ File: gawk.info, Node: Printing, Next: Expressions, Prev: Reading Files, Up: ***************** One of the most common programming actions is to "print", or output, -some or all of the input. Use the `print' statement for simple output, -and the `printf' statement for fancier formatting. The `print' +some or all of the input. Use the 'print' statement for simple output, +and the 'printf' statement for fancier formatting. The 'print' statement is not limited when computing _which_ values to print. However, with two exceptions, you cannot specify _how_ to print them--how many columns, whether to use exponential notation or not, and so on. (For the exceptions, *note Output Separators::, and *note -OFMT::.) For printing with specifications, you need the `printf' +OFMT::.) For printing with specifications, you need the 'printf' statement (*note Printf::). - Besides basic and formatted printing, this major node also covers -I/O redirections to files and pipes, introduces the special file names -that `gawk' processes internally, and discusses the `close()' built-in + Besides basic and formatted printing, this major node also covers I/O +redirections to files and pipes, introduces the special file names that +'gawk' processes internally, and discusses the 'close()' built-in function. * Menu: -* Print:: The `print' statement. -* Print Examples:: Simple examples of `print' statements. +* Print:: The 'print' statement. +* Print Examples:: Simple examples of 'print' statements. * Output Separators:: The output separators and how to change them. -* OFMT:: Controlling Numeric Output With `print'. -* Printf:: The `printf' statement. +* OFMT:: Controlling Numeric Output With 'print'. +* Printf:: The 'printf' statement. * Redirection:: How to redirect output to multiple files and pipes. -* Special Files:: File name interpretation in `gawk'. - `gawk' allows access to inherited file +* Special Files:: File name interpretation in 'gawk'. + 'gawk' allows access to inherited file descriptors. * Close Files And Pipes:: Closing Input and Output Files and Pipes. * Output Summary:: Output summary. @@ -5994,10 +5967,10 @@ function.  File: gawk.info, Node: Print, Next: Print Examples, Up: Printing -5.1 The `print' Statement +5.1 The 'print' Statement ========================= -The `print' statement is used for producing output with simple, +The 'print' statement is used for producing output with simple, standardized formatting. You specify only the strings or numbers to print, in a list separated by commas. They are output, separated by single spaces, followed by a newline. The statement looks like this: @@ -6005,44 +5978,43 @@ single spaces, followed by a newline. The statement looks like this: print ITEM1, ITEM2, ... The entire list of items may be optionally enclosed in parentheses. The -parentheses are necessary if any of the item expressions uses the `>' +parentheses are necessary if any of the item expressions uses the '>' relational operator; otherwise it could be confused with an output redirection (*note Redirection::). The items to print can be constant strings or numbers, fields of the -current record (such as `$1'), variables, or any `awk' expression. +current record (such as '$1'), variables, or any 'awk' expression. Numeric values are converted to strings and then printed. - The simple statement `print' with no items is equivalent to `print + The simple statement 'print' with no items is equivalent to 'print $0': it prints the entire current record. To print a blank line, use -`print ""', where `""' is the empty string. To print a fixed piece of -text, use a string constant, such as `"Don't Panic"', as one item. If +'print ""', where '""' is the empty string. To print a fixed piece of +text, use a string constant, such as '"Don't Panic"', as one item. If you forget to use the double-quote characters, your text is taken as an -`awk' expression, and you will probably get an error. Keep in mind -that a space is printed between any two items. +'awk' expression, and you will probably get an error. Keep in mind that +a space is printed between any two items.  File: gawk.info, Node: Print Examples, Next: Output Separators, Prev: Print, Up: Printing -5.2 `print' Statement Examples +5.2 'print' Statement Examples ============================== -Each `print' statement makes at least one line of output. However, it -isn't limited to only one line. If an item value is a string -containing a newline, the newline is output along with the rest of the -string. A single `print' statement can make any number of lines this -way. +Each 'print' statement makes at least one line of output. However, it +isn't limited to only one line. If an item value is a string containing +a newline, the newline is output along with the rest of the string. A +single 'print' statement can make any number of lines this way. The following is an example of printing a string that contains -embedded newlines (the `\n' is an escape sequence, used to represent -the newline character; *note Escape Sequences::): +embedded newlines (the '\n' is an escape sequence, used to represent the +newline character; *note Escape Sequences::): $ awk 'BEGIN { print "line one\nline two\nline three" }' -| line one -| line two -| line three - The next example, which is run on the `inventory-shipped' file, + The next example, which is run on the 'inventory-shipped' file, prints the first two fields of each input record, with a space between them: @@ -6052,10 +6024,10 @@ them: -| Mar 15 ... - A common mistake in using the `print' statement is to omit the comma + A common mistake in using the 'print' statement is to omit the comma between two items. This often has the effect of making the items run together in the output, with no space. The reason for this is that -juxtaposing two string expressions in `awk' means to concatenate them. +juxtaposing two string expressions in 'awk' means to concatenate them. Here is the same program, without the comma: $ awk '{ print $1 $2 }' inventory-shipped @@ -6064,11 +6036,11 @@ Here is the same program, without the comma: -| Mar15 ... - To someone unfamiliar with the `inventory-shipped' file, neither + To someone unfamiliar with the 'inventory-shipped' file, neither example's output makes much sense. A heading line at the beginning would make it clearer. Let's add some headings to our table of months -(`$1') and green crates shipped (`$2'). We do this using a `BEGIN' -rule (*note BEGIN/END::) so that the headings are only printed once: +('$1') and green crates shipped ('$2'). We do this using a 'BEGIN' rule +(*note BEGIN/END::) so that the headings are only printed once: awk 'BEGIN { print "Month Crates" print "----- ------" } @@ -6083,8 +6055,8 @@ When run, the program prints the following: Mar 15 ... -The only problem, however, is that the headings and the table data -don't line up! We can fix this by printing some spaces between the two +The only problem, however, is that the headings and the table data don't +line up! We can fix this by printing some spaces between the two fields: awk 'BEGIN { print "Month Crates" @@ -6093,11 +6065,11 @@ fields: Lining up columns this way can get pretty complicated when there are many columns to fix. Counting spaces for two or three columns is -simple, but any more than this can take up a lot of time. This is why -the `printf' statement was created (*note Printf::); one of its +simple, but any more than this can take up a lot of time. This is why +the 'printf' statement was created (*note Printf::); one of its specialties is lining up columns of data. - NOTE: You can continue either a `print' or `printf' statement + NOTE: You can continue either a 'print' or 'printf' statement simply by putting a newline after any comma (*note Statements/Lines::). @@ -6107,28 +6079,28 @@ File: gawk.info, Node: Output Separators, Next: OFMT, Prev: Print Examples, 5.3 Output Separators ===================== -As mentioned previously, a `print' statement contains a list of items -separated by commas. In the output, the items are normally separated -by single spaces. However, this doesn't need to be the case; a single +As mentioned previously, a 'print' statement contains a list of items +separated by commas. In the output, the items are normally separated by +single spaces. However, this doesn't need to be the case; a single space is simply the default. Any string of characters may be used as -the "output field separator" by setting the built-in variable `OFS'. -The initial value of this variable is the string `" "'--that is, a +the "output field separator" by setting the built-in variable 'OFS'. +The initial value of this variable is the string '" "'--that is, a single space. - The output from an entire `print' statement is called an "output -record". Each `print' statement outputs one output record, and then -outputs a string called the "output record separator" (or `ORS'). The -initial value of `ORS' is the string `"\n"'; i.e., a newline character. -Thus, each `print' statement normally makes a separate line. + The output from an entire 'print' statement is called an "output +record". Each 'print' statement outputs one output record, and then +outputs a string called the "output record separator" (or 'ORS'). The +initial value of 'ORS' is the string '"\n"'; i.e., a newline character. +Thus, each 'print' statement normally makes a separate line. In order to change how output fields and records are separated, -assign new values to the variables `OFS' and `ORS'. The usual place to -do this is in the `BEGIN' rule (*note BEGIN/END::), so that it happens +assign new values to the variables 'OFS' and 'ORS'. The usual place to +do this is in the 'BEGIN' rule (*note BEGIN/END::), so that it happens before any input is processed. It can also be done with assignments on -the command line, before the names of the input files, or using the -`-v' command-line option (*note Options::). The following example -prints the first and second fields of each input record, separated by a -semicolon, with a blank line added after each newline: +the command line, before the names of the input files, or using the '-v' +command-line option (*note Options::). The following example prints the +first and second fields of each input record, separated by a semicolon, +with a blank line added after each newline: $ awk 'BEGIN { OFS = ";"; ORS = "\n\n" } > { print $1, $2 }' mail-list @@ -6155,57 +6127,56 @@ semicolon, with a blank line added after each newline: -| Jean-Paul;555-2127 -| - If the value of `ORS' does not contain a newline, the program's + If the value of 'ORS' does not contain a newline, the program's output runs together on a single line.  File: gawk.info, Node: OFMT, Next: Printf, Prev: Output Separators, Up: Printing -5.4 Controlling Numeric Output with `print' +5.4 Controlling Numeric Output with 'print' =========================================== -When printing numeric values with the `print' statement, `awk' -internally converts the number to a string of characters and prints -that string. `awk' uses the `sprintf()' function to do this conversion +When printing numeric values with the 'print' statement, 'awk' +internally converts the number to a string of characters and prints that +string. 'awk' uses the 'sprintf()' function to do this conversion (*note String Functions::). For now, it suffices to say that the -`sprintf()' function accepts a "format specification" that tells it how -to format numbers (or strings), and that there are a number of -different ways in which numbers can be formatted. The different format +'sprintf()' function accepts a "format specification" that tells it how +to format numbers (or strings), and that there are a number of different +ways in which numbers can be formatted. The different format specifications are discussed more fully in *note Control Letters::. - The built-in variable `OFMT' contains the default format -specification that `print' uses with `sprintf()' when it wants to -convert a number to a string for printing. The default value of `OFMT' -is `"%.6g"'. The way `print' prints numbers can be changed by -supplying different format specifications as the value of `OFMT', as -shown in the following example: + The built-in variable 'OFMT' contains the default format +specification that 'print' uses with 'sprintf()' when it wants to +convert a number to a string for printing. The default value of 'OFMT' +is '"%.6g"'. The way 'print' prints numbers can be changed by supplying +different format specifications as the value of 'OFMT', as shown in the +following example: $ awk 'BEGIN { > OFMT = "%.0f" # print numbers as integers (rounds) > print 17.23, 17.54 }' -| 17 18 -According to the POSIX standard, `awk''s behavior is undefined if -`OFMT' contains anything but a floating-point conversion specification. -(d.c.) +According to the POSIX standard, 'awk''s behavior is undefined if 'OFMT' +contains anything but a floating-point conversion specification. (d.c.)  File: gawk.info, Node: Printf, Next: Redirection, Prev: OFMT, Up: Printing -5.5 Using `printf' Statements for Fancier Printing +5.5 Using 'printf' Statements for Fancier Printing ================================================== -For more precise control over the output format than what is provided -by `print', use `printf'. With `printf' you can specify the width to -use for each item, as well as various formatting choices for numbers -(such as what output base to use, whether to print an exponent, whether -to print a sign, and how many digits to print after the decimal point). +For more precise control over the output format than what is provided by +'print', use 'printf'. With 'printf' you can specify the width to use +for each item, as well as various formatting choices for numbers (such +as what output base to use, whether to print an exponent, whether to +print a sign, and how many digits to print after the decimal point). You do this by supplying a string, called the "format string", that controls how and where to print the other arguments. * Menu: -* Basic Printf:: Syntax of the `printf' statement. +* Basic Printf:: Syntax of the 'printf' statement. * Control Letters:: Format-control letters. * Format Modifiers:: Format-specification modifiers. * Printf Examples:: Several examples. @@ -6213,34 +6184,34 @@ controls how and where to print the other arguments.  File: gawk.info, Node: Basic Printf, Next: Control Letters, Up: Printf -5.5.1 Introduction to the `printf' Statement +5.5.1 Introduction to the 'printf' Statement -------------------------------------------- -A simple `printf' statement looks like this: +A simple 'printf' statement looks like this: printf FORMAT, ITEM1, ITEM2, ... The entire list of arguments may optionally be enclosed in parentheses. -The parentheses are necessary if any of the item expressions use the `>' +The parentheses are necessary if any of the item expressions use the '>' relational operator; otherwise, it can be confused with an output redirection (*note Redirection::). - The difference between `printf' and `print' is the FORMAT argument. -This is an expression whose value is taken as a string; it specifies -how to output each of the other arguments. It is called the "format + The difference between 'printf' and 'print' is the FORMAT argument. +This is an expression whose value is taken as a string; it specifies how +to output each of the other arguments. It is called the "format string". The format string is very similar to that in the ISO C library -function `printf()'. Most of FORMAT is text to output verbatim. +function 'printf()'. Most of FORMAT is text to output verbatim. Scattered among this text are "format specifiers"--one per item. Each format specifier says to output the next item in the argument list at that place in the format. - The `printf' statement does not automatically append a newline to -its output. It outputs only what the format string specifies. So if a + The 'printf' statement does not automatically append a newline to its +output. It outputs only what the format string specifies. So if a newline is needed, you must include one in the format string. The -output separator variables `OFS' and `ORS' have no effect on `printf' -statements. For example: +output separator variables 'OFS' and 'ORS' have no effect on 'printf' +statements. For example: $ awk 'BEGIN { > ORS = "\nOUCH!\n"; OFS = "+" @@ -6249,7 +6220,7 @@ statements. For example: > }' -| Dont Panic! -Here, neither the `+' nor the `OUCH' appear in the output message. +Here, neither the '+' nor the 'OUCH' appear in the output message.  File: gawk.info, Node: Control Letters, Next: Format Modifiers, Prev: Basic Printf, Up: Printf @@ -6257,120 +6228,120 @@ File: gawk.info, Node: Control Letters, Next: Format Modifiers, Prev: Basic P 5.5.2 Format-Control Letters ---------------------------- -A format specifier starts with the character `%' and ends with a -"format-control letter"--it tells the `printf' statement how to output +A format specifier starts with the character '%' and ends with a +"format-control letter"--it tells the 'printf' statement how to output one item. The format-control letter specifies what _kind_ of value to print. The rest of the format specifier is made up of optional "modifiers" that control _how_ to print the value, such as the field width. Here is a list of the format-control letters: -`%c' - Print a number as an ASCII character; thus, `printf "%c", 65' - outputs the letter `A'. The output for a string value is the first +'%c' + Print a number as an ASCII character; thus, 'printf "%c", 65' + outputs the letter 'A'. The output for a string value is the first character of the string. NOTE: The POSIX standard says the first character of a string - is printed. In locales with multibyte characters, `gawk' + is printed. In locales with multibyte characters, 'gawk' attempts to convert the leading bytes of the string into a valid wide character and then to print the multibyte encoding of that character. Similarly, when printing a numeric value, - `gawk' allows the value to be within the numeric range of + 'gawk' allows the value to be within the numeric range of values that can be held in a wide character. If the - conversion to multibyte encoding fails, `gawk' uses the low + conversion to multibyte encoding fails, 'gawk' uses the low eight bits of the value as the character to print. - Other `awk' versions generally restrict themselves to printing + Other 'awk' versions generally restrict themselves to printing the first byte of a string or to numeric values within the range of a single byte (0-255). -`%d', `%i' +'%d', '%i' Print a decimal integer. The two control letters are equivalent. - (The `%i' specification is for compatibility with ISO C.) + (The '%i' specification is for compatibility with ISO C.) -`%e', `%E' +'%e', '%E' Print a number in scientific (exponential) notation; for example: printf "%4.3e\n", 1950 - prints `1.950e+03', with a total of four significant figures, - three of which follow the decimal point. (The `4.3' represents - two modifiers, discussed in the next node.) `%E' uses `E' instead - of `e' in the output. + prints '1.950e+03', with a total of four significant figures, three + of which follow the decimal point. (The '4.3' represents two + modifiers, discussed in the next node.) '%E' uses 'E' instead of + 'e' in the output. -`%f' +'%f' Print a number in floating-point notation. For example: printf "%4.3f", 1950 - prints `1950.000', with a total of four significant figures, three - of which follow the decimal point. (The `4.3' represents two + prints '1950.000', with a total of four significant figures, three + of which follow the decimal point. (The '4.3' represents two modifiers, discussed in the next node.) On systems supporting IEEE 754 floating point format, values - representing negative infinity are formatted as `-inf' or - `-infinity', and positive infinity as `inf' and `infinity'. The - special "not a number" value formats as `-nan' or `nan' (*note - Math Definitions::). + representing negative infinity are formatted as '-inf' or + '-infinity', and positive infinity as 'inf' and 'infinity'. The + special "not a number" value formats as '-nan' or 'nan' (*note Math + Definitions::). -`%F' - Like `%f' but the infinity and "not a number" values are spelled +'%F' + Like '%f' but the infinity and "not a number" values are spelled using uppercase letters. - The `%F' format is a POSIX extension to ISO C; not all systems - support it. On those that don't, `gawk' uses `%f' instead. + The '%F' format is a POSIX extension to ISO C; not all systems + support it. On those that don't, 'gawk' uses '%f' instead. -`%g', `%G' +'%g', '%G' Print a number in either scientific notation or in floating-point - notation, whichever uses fewer characters; if the result is - printed in scientific notation, `%G' uses `E' instead of `e'. + notation, whichever uses fewer characters; if the result is printed + in scientific notation, '%G' uses 'E' instead of 'e'. -`%o' +'%o' Print an unsigned octal integer (*note Nondecimal-numbers::). -`%s' +'%s' Print a string. -`%u' +'%u' Print an unsigned decimal integer. (This format is of marginal - use, because all numbers in `awk' are floating-point; it is + use, because all numbers in 'awk' are floating-point; it is provided primarily for compatibility with C.) -`%x', `%X' - Print an unsigned hexadecimal integer; `%X' uses the letters `A' - through `F' instead of `a' through `f' (*note +'%x', '%X' + Print an unsigned hexadecimal integer; '%X' uses the letters 'A' + through 'F' instead of 'a' through 'f' (*note Nondecimal-numbers::). -`%%' - Print a single `%'. This does not consume an argument and it +'%%' + Print a single '%'. This does not consume an argument and it ignores any modifiers. - NOTE: When using the integer format-control letters for values - that are outside the range of the widest C integer type, `gawk' - switches to the `%g' format specifier. If `--lint' is provided on - the command line (*note Options::), `gawk' warns about this. - Other versions of `awk' may print invalid values or do something - else entirely. (d.c.) + NOTE: When using the integer format-control letters for values that + are outside the range of the widest C integer type, 'gawk' switches + to the '%g' format specifier. If '--lint' is provided on the + command line (*note Options::), 'gawk' warns about this. Other + versions of 'awk' may print invalid values or do something else + entirely. (d.c.)  File: gawk.info, Node: Format Modifiers, Next: Printf Examples, Prev: Control Letters, Up: Printf -5.5.3 Modifiers for `printf' Formats +5.5.3 Modifiers for 'printf' Formats ------------------------------------ -A format specification can also include "modifiers" that can control -how much of the item's value is printed, as well as how much space it -gets. The modifiers come between the `%' and the format-control letter. -We will use the bullet symbol "*" in the following examples to represent -spaces in the output. Here are the possible modifiers, in the order in +A format specification can also include "modifiers" that can control how +much of the item's value is printed, as well as how much space it gets. +The modifiers come between the '%' and the format-control letter. We +will use the bullet symbol "*" in the following examples to represent +spaces in the output. Here are the possible modifiers, in the order in which they may appear: -`N$' - An integer constant followed by a `$' is a "positional specifier". +'N$' + An integer constant followed by a '$' is a "positional specifier". Normally, format specifications are applied to arguments in the - order given in the format string. With a positional specifier, - the format specification is applied to a specific argument, - instead of what would be the next argument in the list. - Positional specifiers begin counting with one. Thus: + order given in the format string. With a positional specifier, the + format specification is applied to a specific argument, instead of + what would be the next argument in the list. Positional specifiers + begin counting with one. Thus: printf "%s %s\n", "don't", "panic" printf "%2$s %1$s\n", "panic", "don't" @@ -6378,12 +6349,12 @@ which they may appear: prints the famous friendly message twice. At first glance, this feature doesn't seem to be of much use. It - is in fact a `gawk' extension, intended for use in translating + is in fact a 'gawk' extension, intended for use in translating messages at runtime. *Note Printf Ordering::, which describes how and why to use positional specifiers. For now, we will not use them. -`-' +'-' The minus sign, used before the width modifier (see later on in this list), says to left-justify the argument within its specified width. Normally, the argument is printed right-justified in the @@ -6391,35 +6362,35 @@ which they may appear: printf "%-4s", "foo" - prints `foo*'. + prints 'foo*'. -`SPACE' +'SPACE' For numeric conversions, prefix positive values with a space and negative values with a minus sign. -`+' - The plus sign, used before the width modifier (see later on in - this list), says to always supply a sign for numeric conversions, - even if the data to format is positive. The `+' overrides the - space modifier. - -`#' - Use an "alternate form" for certain control letters. For `%o', - supply a leading zero. For `%x' and `%X', supply a leading `0x' - or `0X' for a nonzero result. For `%e', `%E', `%f', and `%F', the - result always contains a decimal point. For `%g' and `%G', +'+' + The plus sign, used before the width modifier (see later on in this + list), says to always supply a sign for numeric conversions, even + if the data to format is positive. The '+' overrides the space + modifier. + +'#' + Use an "alternate form" for certain control letters. For '%o', + supply a leading zero. For '%x' and '%X', supply a leading '0x' or + '0X' for a nonzero result. For '%e', '%E', '%f', and '%F', the + result always contains a decimal point. For '%g' and '%G', trailing zeros are not removed from the result. -`0' - A leading `0' (zero) acts as a flag that indicates that output +'0' + A leading '0' (zero) acts as a flag that indicates that output should be padded with zeros instead of spaces. This applies only to the numeric output formats. This flag only has an effect when the field width is wider than the value to print. -`'' +''' A single quote or apostrophe character is a POSIX extension to ISO - C. It indicates that the integer part of a floating point value, - or the entire part of an integer decimal value, should have a + C. It indicates that the integer part of a floating point value, or + the entire part of an integer decimal value, should have a thousands-separator character in it. This only works in locales that support such characters. For example: @@ -6433,20 +6404,20 @@ which they may appear: For more information about locales and internationalization issues, see *note Locales::. - NOTE: The `'' flag is a nice feature, but its use complicates + NOTE: The ''' flag is a nice feature, but its use complicates things: it becomes difficult to use it in command-line programs. For information on appropriate quoting tricks, see *note Quoting::. -`WIDTH' +'WIDTH' This is a number specifying the desired minimum width of a field. - Inserting any number between the `%' sign and the format-control + Inserting any number between the '%' sign and the format-control character forces the field to expand to this width. The default way to do this is to pad with spaces on the left. For example: printf "%4s", "foo" - prints `*foo'. + prints '*foo'. The value of WIDTH is a minimum width, not a maximum. If the item value requires more than WIDTH characters, it can be as wide as @@ -6454,26 +6425,26 @@ which they may appear: printf "%4s", "foobar" - prints `foobar'. + prints 'foobar'. Preceding the WIDTH with a minus sign causes the output to be padded with spaces on the right, instead of on the left. -`.PREC' - A period followed by an integer constant specifies the precision - to use when printing. The meaning of the precision varies by - control letter: +'.PREC' + A period followed by an integer constant specifies the precision to + use when printing. The meaning of the precision varies by control + letter: - `%d', `%i', `%o', `%u', `%x', `%X' + '%d', '%i', '%o', '%u', '%x', '%X' Minimum number of digits to print. - `%e', `%E', `%f', `%F' + '%e', '%E', '%f', '%F' Number of digits to the right of the decimal point. - `%g', `%G' + '%g', '%G' Maximum number of significant digits. - `%s' + '%s' Maximum number of characters from the string that should print. @@ -6481,12 +6452,12 @@ which they may appear: printf "%.4s", "foobar" - prints `foob'. + prints 'foob'. - The C library `printf''s dynamic WIDTH and PREC capability (for -example, `"%*.*s"') is supported. Instead of supplying explicit WIDTH -and/or PREC values in the format string, they are passed in the -argument list. For example: + The C library 'printf''s dynamic WIDTH and PREC capability (for +example, '"%*.*s"') is supported. Instead of supplying explicit WIDTH +and/or PREC values in the format string, they are passed in the argument +list. For example: w = 5 p = 3 @@ -6498,10 +6469,9 @@ is exactly equivalent to: s = "abcdefg" printf "%5.3s\n", s -Both programs output `**abc'. Earlier versions of `awk' did not -support this capability. If you must use such a version, you may -simulate this feature by using concatenation to build up the format -string, like so: +Both programs output '**abc'. Earlier versions of 'awk' did not support +this capability. If you must use such a version, you may simulate this +feature by using concatenation to build up the format string, like so: w = 5 p = 3 @@ -6510,28 +6480,27 @@ string, like so: This is not particularly easy to read but it does work. - C programmers may be used to supplying additional modifiers (`h', -`j', `l', `L', `t', and `z') in `printf' format strings. These are not -valid in `awk'. Most `awk' implementations silently ignore them. If -`--lint' is provided on the command line (*note Options::), `gawk' -warns about their use. If `--posix' is supplied, their use is a fatal -error. + C programmers may be used to supplying additional modifiers ('h', +'j', 'l', 'L', 't', and 'z') in 'printf' format strings. These are not +valid in 'awk'. Most 'awk' implementations silently ignore them. If +'--lint' is provided on the command line (*note Options::), 'gawk' warns +about their use. If '--posix' is supplied, their use is a fatal error.  File: gawk.info, Node: Printf Examples, Prev: Format Modifiers, Up: Printf -5.5.4 Examples Using `printf' +5.5.4 Examples Using 'printf' ----------------------------- -The following simple example shows how to use `printf' to make an +The following simple example shows how to use 'printf' to make an aligned table: awk '{ printf "%-10s %s\n", $1, $2 }' mail-list -This command prints the names of the people (`$1') in the file -`mail-list' as a string of 10 characters that are left-justified. It -also prints the phone numbers (`$2') next on the line. This produces -an aligned two-column table of names and phone numbers, as shown here: +This command prints the names of the people ('$1') in the file +'mail-list' as a string of 10 characters that are left-justified. It +also prints the phone numbers ('$2') next on the line. This produces an +aligned two-column table of names and phone numbers, as shown here: $ awk '{ printf "%-10s %s\n", $1, $2 }' mail-list -| Amelia 555-5553 @@ -6548,7 +6517,7 @@ an aligned two-column table of names and phone numbers, as shown here: In this case, the phone numbers had to be printed as strings because the numbers are separated by a dash. Printing the phone numbers as -numbers would have produced just the first three digits: `555'. This +numbers would have produced just the first three digits: '555'. This would have been pretty confusing. It wasn't necessary to specify a width for the phone numbers because @@ -6556,24 +6525,24 @@ they are last on their lines. They don't need to have spaces after them. The table could be made to look even nicer by adding headings to the -tops of the columns. This is done using a `BEGIN' rule (*note -BEGIN/END::) so that the headers are only printed once, at the -beginning of the `awk' program: +tops of the columns. This is done using a 'BEGIN' rule (*note +BEGIN/END::) so that the headers are only printed once, at the beginning +of the 'awk' program: awk 'BEGIN { print "Name Number" print "---- ------" } { printf "%-10s %s\n", $1, $2 }' mail-list - The above example mixes `print' and `printf' statements in the same -program. Using just `printf' statements can produce the same results: + The above example mixes 'print' and 'printf' statements in the same +program. Using just 'printf' statements can produce the same results: awk 'BEGIN { printf "%-10s %s\n", "Name", "Number" printf "%-10s %s\n", "----", "------" } { printf "%-10s %s\n", $1, $2 }' mail-list -Printing each column heading with the same format specification used -for the column elements ensures that the headings are aligned just like -the columns. +Printing each column heading with the same format specification used for +the column elements ensures that the headings are aligned just like the +columns. The fact that the same format specification is used three times can be emphasized by storing it in a variable, like this: @@ -6586,39 +6555,39 @@ be emphasized by storing it in a variable, like this:  File: gawk.info, Node: Redirection, Next: Special Files, Prev: Printf, Up: Printing -5.6 Redirecting Output of `print' and `printf' +5.6 Redirecting Output of 'print' and 'printf' ============================================== -So far, the output from `print' and `printf' has gone to the standard -output, usually the screen. Both `print' and `printf' can also send +So far, the output from 'print' and 'printf' has gone to the standard +output, usually the screen. Both 'print' and 'printf' can also send their output to other places. This is called "redirection". - NOTE: When `--sandbox' is specified (*note Options::), redirecting + NOTE: When '--sandbox' is specified (*note Options::), redirecting output to files and pipes is disabled. - A redirection appears after the `print' or `printf' statement. -Redirections in `awk' are written just like redirections in shell -commands, except that they are written inside the `awk' program. + A redirection appears after the 'print' or 'printf' statement. +Redirections in 'awk' are written just like redirections in shell +commands, except that they are written inside the 'awk' program. There are four forms of output redirection: output to a file, output appended to a file, output through a pipe to another command, and output -to a coprocess. We show them all for the `print' statement, but they -work identically for `printf': +to a coprocess. We show them all for the 'print' statement, but they +work identically for 'printf': -`print ITEMS > OUTPUT-FILE' +'print ITEMS > OUTPUT-FILE' This redirection prints the items into the output file named - OUTPUT-FILE. The file name OUTPUT-FILE can be any expression. - Its value is changed to a string and then used as a file name - (*note Expressions::). + OUTPUT-FILE. The file name OUTPUT-FILE can be any expression. Its + value is changed to a string and then used as a file name (*note + Expressions::). When this type of redirection is used, the OUTPUT-FILE is erased - before the first output is written to it. Subsequent writes to - the same OUTPUT-FILE do not erase OUTPUT-FILE, but append to it. - (This is different from how you use redirections in shell scripts.) - If OUTPUT-FILE does not exist, it is created. For example, here - is how an `awk' program can write a list of peoples' names to one - file named `name-list', and a list of phone numbers to another file - named `phone-list': + before the first output is written to it. Subsequent writes to the + same OUTPUT-FILE do not erase OUTPUT-FILE, but append to it. (This + is different from how you use redirections in shell scripts.) If + OUTPUT-FILE does not exist, it is created. For example, here is + how an 'awk' program can write a list of peoples' names to one file + named 'name-list', and a list of phone numbers to another file + named 'phone-list': $ awk '{ print $2 > "phone-list" > print $1 > "name-list" }' mail-list @@ -6633,20 +6602,20 @@ work identically for `printf': Each output file contains one name or number per line. -`print ITEMS >> OUTPUT-FILE' +'print ITEMS >> OUTPUT-FILE' This redirection prints the items into the pre-existing output file - named OUTPUT-FILE. The difference between this and the single-`>' + named OUTPUT-FILE. The difference between this and the single-'>' redirection is that the old contents (if any) of OUTPUT-FILE are - not erased. Instead, the `awk' output is appended to the file. - If OUTPUT-FILE does not exist, then it is created. + not erased. Instead, the 'awk' output is appended to the file. If + OUTPUT-FILE does not exist, then it is created. -`print ITEMS | COMMAND' +'print ITEMS | COMMAND' It is possible to send output to another program through a pipe - instead of into a file. This redirection opens a pipe to - COMMAND, and writes the values of ITEMS through this pipe to - another process created to execute COMMAND. + instead of into a file. This redirection opens a pipe to COMMAND, + and writes the values of ITEMS through this pipe to another process + created to execute COMMAND. - The redirection argument COMMAND is actually an `awk' expression. + The redirection argument COMMAND is actually an 'awk' expression. Its value is converted to a string whose contents give the shell command to be run. For example, the following produces two files, one unsorted list of peoples' names, and one list sorted in reverse @@ -6657,11 +6626,11 @@ work identically for `printf': print $1 | command }' mail-list The unsorted list is written with an ordinary redirection, while - the sorted list is written by piping through the `sort' utility. + the sorted list is written by piping through the 'sort' utility. The next example uses redirection to mail a message to the mailing - list `bug-system'. This might be useful when trouble is - encountered in an `awk' script run periodically for system + list 'bug-system'. This might be useful when trouble is + encountered in an 'awk' script run periodically for system maintenance: report = "mail bug-system" @@ -6671,38 +6640,38 @@ work identically for `printf': close(report) The message is built using string concatenation and saved in the - variable `m'. It's then sent down the pipeline to the `mail' + variable 'm'. It's then sent down the pipeline to the 'mail' program. (The parentheses group the items to concatenate--see *note Concatenation::.) - The `close()' function is called here because it's a good idea to + The 'close()' function is called here because it's a good idea to close the pipe as soon as all the intended output has been sent to it. *Note Close Files And Pipes::, for more information. This example also illustrates the use of a variable to represent a FILE or COMMAND--it is not necessary to always use a string constant. Using a variable is generally a good idea, because (if - you mean to refer to that same file or command) `awk' requires - that the string value be written identically every time. + you mean to refer to that same file or command) 'awk' requires that + the string value be written identically every time. -`print ITEMS |& COMMAND' +'print ITEMS |& COMMAND' This redirection prints the items to the input of COMMAND. The - difference between this and the single-`|' redirection is that the - output from COMMAND can be read with `getline'. Thus COMMAND is a + difference between this and the single-'|' redirection is that the + output from COMMAND can be read with 'getline'. Thus COMMAND is a "coprocess", which works together with, but subsidiary to, the - `awk' program. + 'awk' program. - This feature is a `gawk' extension, and is not available in POSIX - `awk'. *Note Getline/Coprocess::, for a brief discussion. *Note + This feature is a 'gawk' extension, and is not available in POSIX + 'awk'. *Note Getline/Coprocess::, for a brief discussion. *Note Two-way I/O::, for a more complete discussion. - Redirecting output using `>', `>>', `|', or `|&' asks the system to + Redirecting output using '>', '>>', '|', or '|&' asks the system to open a file, pipe, or coprocess only if the particular FILE or COMMAND -you specify has not already been written to by your program or if it -has been closed since it was last written to. +you specify has not already been written to by your program or if it has +been closed since it was last written to. - It is a common error to use `>' redirection for the first `print' to -a file, and then to use `>>' for subsequent output: + It is a common error to use '>' redirection for the first 'print' to +a file, and then to use '>>' for subsequent output: # clear the file print "Don't panic" > "guide.txt" @@ -6711,42 +6680,41 @@ a file, and then to use `>>' for subsequent output: print "Avoid improbability generators" >> "guide.txt" This is indeed how redirections must be used from the shell. But in -`awk', it isn't necessary. In this kind of case, a program should use -`>' for all the `print' statements, since the output file is only -opened once. (It happens that if you mix `>' and `>>' that output is -produced in the expected order. However, mixing the operators for the -same file is definitely poor style, and is confusing to readers of your -program.) - - Many older `awk' implementations limit the number of pipelines that -an `awk' program may have open to just one! In `gawk', there is no -such limit. `gawk' allows a program to open as many pipelines as the +'awk', it isn't necessary. In this kind of case, a program should use +'>' for all the 'print' statements, since the output file is only opened +once. (It happens that if you mix '>' and '>>' that output is produced +in the expected order. However, mixing the operators for the same file +is definitely poor style, and is confusing to readers of your program.) + + Many older 'awk' implementations limit the number of pipelines that +an 'awk' program may have open to just one! In 'gawk', there is no such +limit. 'gawk' allows a program to open as many pipelines as the underlying operating system permits. - Piping into `sh' + Piping into 'sh' A particularly powerful way to use redirection is to build command -lines and pipe them into the shell, `sh'. For example, suppose you -have a list of files brought over from a system where all the file names -are stored in uppercase, and you wish to rename them to have names in -all lowercase. The following program is both simple and efficient: +lines and pipe them into the shell, 'sh'. For example, suppose you have +a list of files brought over from a system where all the file names are +stored in uppercase, and you wish to rename them to have names in all +lowercase. The following program is both simple and efficient: { printf("mv %s %s\n", $0, tolower($0)) | "sh" } END { close("sh") } - The `tolower()' function returns its argument string with all + The 'tolower()' function returns its argument string with all uppercase characters converted to lowercase (*note String Functions::). -The program builds up a list of command lines, using the `mv' utility -to rename the files. It then sends the list to the shell for execution. +The program builds up a list of command lines, using the 'mv' utility to +rename the files. It then sends the list to the shell for execution.  File: gawk.info, Node: Special Files, Next: Close Files And Pipes, Prev: Redirection, Up: Printing -5.7 Special File Name in `gawk' +5.7 Special File Name in 'gawk' =============================== -`gawk' provides a number of special file names that it interprets +'gawk' provides a number of special file names that it interprets internally. These file names provide access to standard file descriptors and TCP/IP networking. @@ -6766,61 +6734,61 @@ Running programs conventionally have three input and output streams already available to them for reading and writing. These are known as the "standard input", "standard output", and "standard error output". These streams are, by default, connected to your keyboard and screen, -but they are often redirected with the shell, via the `<', `<<', `>', -`>>', `>&', and `|' operators. Standard error is typically used for +but they are often redirected with the shell, via the '<', '<<', '>', +'>>', '>&', and '|' operators. Standard error is typically used for writing error messages; the reason there are two separate streams, standard output and standard error, is so that they can be redirected separately. - In other implementations of `awk', the only way to write an error -message to standard error in an `awk' program is as follows: + In other implementations of 'awk', the only way to write an error +message to standard error in an 'awk' program is as follows: print "Serious error detected!" | "cat 1>&2" This works by opening a pipeline to a shell command that can access the -standard error stream that it inherits from the `awk' process. This is +standard error stream that it inherits from the 'awk' process. This is far from elegant, and it is also inefficient, because it requires a -separate process. So people writing `awk' programs often don't do -this. Instead, they send the error messages to the screen, like this: +separate process. So people writing 'awk' programs often don't do this. +Instead, they send the error messages to the screen, like this: print "Serious error detected!" > "/dev/tty" -(`/dev/tty' is a special file supplied by the operating system that is -connected to your keyboard and screen. It represents the "terminal,"(1) +('/dev/tty' is a special file supplied by the operating system that is +connected to your keyboard and screen. It represents the "terminal,"(1) which on modern systems is a keyboard and screen, not a serial console.) This usually has the same effect but not always: although the standard error stream is usually the screen, it can be redirected; when that -happens, writing to the screen is not correct. In fact, if `awk' is -run from a background job, it may not have a terminal at all. Then -opening `/dev/tty' fails. +happens, writing to the screen is not correct. In fact, if 'awk' is run +from a background job, it may not have a terminal at all. Then opening +'/dev/tty' fails. - `gawk' provides special file names for accessing the three standard -streams. (c.e.) It also provides syntax for accessing any other + 'gawk' provides special file names for accessing the three standard +streams. (c.e.) It also provides syntax for accessing any other inherited open files. If the file name matches one of these special -names when `gawk' redirects input or output, then it directly uses the -stream that the file name stands for. These special file names work -for all operating systems that `gawk' has been ported to, not just -those that are POSIX-compliant: +names when 'gawk' redirects input or output, then it directly uses the +stream that the file name stands for. These special file names work for +all operating systems that 'gawk' has been ported to, not just those +that are POSIX-compliant: -`/dev/stdin' +'/dev/stdin' The standard input (file descriptor 0). -`/dev/stdout' +'/dev/stdout' The standard output (file descriptor 1). -`/dev/stderr' +'/dev/stderr' The standard error output (file descriptor 2). -`/dev/fd/N' +'/dev/fd/N' The file associated with file descriptor N. Such a file must be - opened by the program initiating the `awk' execution (typically - the shell). Unless special pains are taken in the shell from which - `gawk' is invoked, only descriptors 0, 1, and 2 are available. + opened by the program initiating the 'awk' execution (typically the + shell). Unless special pains are taken in the shell from which + 'gawk' is invoked, only descriptors 0, 1, and 2 are available. - The file names `/dev/stdin', `/dev/stdout', and `/dev/stderr' are -aliases for `/dev/fd/0', `/dev/fd/1', and `/dev/fd/2', respectively. + The file names '/dev/stdin', '/dev/stdout', and '/dev/stderr' are +aliases for '/dev/fd/0', '/dev/fd/1', and '/dev/fd/2', respectively. However, they are more self-explanatory. The proper way to write an -error message in a `gawk' program is to use `/dev/stderr', like this: +error message in a 'gawk' program is to use '/dev/stderr', like this: print "Serious error detected!" > "/dev/stderr" @@ -6828,16 +6796,16 @@ error message in a `gawk' program is to use `/dev/stderr', like this: redirection, the value must be a string. It is a common error to omit the quotes, which leads to confusing results. - Finally, using the `close()' function on a file name of the form -`"/dev/fd/N"', for file descriptor numbers above two, does actually + Finally, using the 'close()' function on a file name of the form +'"/dev/fd/N"', for file descriptor numbers above two, does actually close the given file descriptor. - The `/dev/stdin', `/dev/stdout', and `/dev/stderr' special files are -also recognized internally by several other versions of `awk'. + The '/dev/stdin', '/dev/stdout', and '/dev/stderr' special files are +also recognized internally by several other versions of 'awk'. ---------- Footnotes ---------- - (1) The "tty" in `/dev/tty' stands for "Teletype," a serial terminal. + (1) The "tty" in '/dev/tty' stands for "Teletype," a serial terminal.  File: gawk.info, Node: Special Network, Next: Special Caveats, Prev: Special FD, Up: Special Files @@ -6845,16 +6813,15 @@ File: gawk.info, Node: Special Network, Next: Special Caveats, Prev: Special 5.7.2 Special Files for Network Communications ---------------------------------------------- -`gawk' programs can open a two-way TCP/IP connection, acting as either -a client or a server. This is done using a special file name of the -form: +'gawk' programs can open a two-way TCP/IP connection, acting as either a +client or a server. This is done using a special file name of the form: - `/NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT' + /NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT - The NET-TYPE is one of `inet', `inet4' or `inet6'. The PROTOCOL is -one of `tcp' or `udp', and the other fields represent the other + The NET-TYPE is one of 'inet', 'inet4' or 'inet6'. The PROTOCOL is +one of 'tcp' or 'udp', and the other fields represent the other essential pieces of information for making a networking connection. -These file names are used with the `|&' operator for communicating with +These file names are used with the '|&' operator for communicating with a coprocess (*note Two-way I/O::). This is an advanced feature, mentioned here only for completeness. Full discussion is delayed until *note TCP/IP Networking::. @@ -6866,14 +6833,14 @@ File: gawk.info, Node: Special Caveats, Prev: Special Network, Up: Special Fi ------------------------------- Here is a list of things to bear in mind when using the special file -names that `gawk' provides: +names that 'gawk' provides: - * Recognition of these special file names is disabled if `gawk' is in + * Recognition of these special file names is disabled if 'gawk' is in compatibility mode (*note Options::). - * `gawk' _always_ interprets these special file names. For example, - using `/dev/fd/4' for output actually writes on file descriptor 4, - and not on a new file descriptor that is `dup()''ed from file + * 'gawk' _always_ interprets these special file names. For example, + using '/dev/fd/4' for output actually writes on file descriptor 4, + and not on a new file descriptor that is 'dup()''ed from file descriptor 4. Most of the time this does not matter; however, it is important to _not_ close any of the files related to file descriptors 0, 1, and 2. Doing so results in unpredictable @@ -6885,21 +6852,21 @@ File: gawk.info, Node: Close Files And Pipes, Next: Output Summary, Prev: Spe 5.8 Closing Input and Output Redirections ========================================= -If the same file name or the same shell command is used with `getline' -more than once during the execution of an `awk' program (*note +If the same file name or the same shell command is used with 'getline' +more than once during the execution of an 'awk' program (*note Getline::), the file is opened (or the command is executed) the first time only. At that time, the first record of input is read from that file or command. The next time the same file or command is used with -`getline', another record is read from it, and so on. +'getline', another record is read from it, and so on. - Similarly, when a file or pipe is opened for output, `awk' remembers + Similarly, when a file or pipe is opened for output, 'awk' remembers the file name or command associated with it, and subsequent writes to the same file or command are appended to the previous writes. The file -or pipe stays open until `awk' exits. +or pipe stays open until 'awk' exits. This implies that special steps are necessary in order to read the same file again from the beginning, or to rerun a shell command (rather -than reading more output from the same command). The `close()' function +than reading more output from the same command). The 'close()' function makes these things possible: close(FILENAME) @@ -6910,7 +6877,7 @@ or: The argument FILENAME or COMMAND can be any expression. Its value must _exactly_ match the string that was used to open the file or start -the command (spaces and other "irrelevant" characters included). For +the command (spaces and other "irrelevant" characters included). For example, if you open a pipe with this: "sort -r names" | getline foo @@ -6919,28 +6886,28 @@ then you must close it with this: close("sort -r names") - Once this function call is executed, the next `getline' from that -file or command, or the next `print' or `printf' to that file or -command, reopens the file or reruns the command. Because the -expression that you use to close a file or pipeline must exactly match -the expression used to open the file or run the command, it is good -practice to use a variable to store the file name or command. The -previous example becomes the following: + Once this function call is executed, the next 'getline' from that +file or command, or the next 'print' or 'printf' to that file or +command, reopens the file or reruns the command. Because the expression +that you use to close a file or pipeline must exactly match the +expression used to open the file or run the command, it is good practice +to use a variable to store the file name or command. The previous +example becomes the following: sortcom = "sort -r names" sortcom | getline foo ... close(sortcom) -This helps avoid hard-to-find typographical errors in your `awk' +This helps avoid hard-to-find typographical errors in your 'awk' programs. Here are some of the reasons for closing an output file: - * To write a file and read it back later on in the same `awk' + * To write a file and read it back later on in the same 'awk' program. Close the file after writing it, then begin reading it - with `getline'. + with 'getline'. - * To write numerous files, successively, in the same `awk' program. - If the files aren't closed, eventually `awk' may exceed a system + * To write numerous files, successively, in the same 'awk' program. + If the files aren't closed, eventually 'awk' may exceed a system limit on the number of open files in one process. It is best to close each one when the program has finished writing it. @@ -6948,25 +6915,25 @@ programs. Here are some of the reasons for closing an output file: pipe, the command reading the pipe normally continues to try to read input as long as the pipe is open. Often this means the command cannot really do its work until the pipe is closed. For - example, if output is redirected to the `mail' program, the - message is not actually sent until the pipe is closed. + example, if output is redirected to the 'mail' program, the message + is not actually sent until the pipe is closed. * To run the same program a second time, with the same arguments. This is not the same thing as giving more input to the first run! - For example, suppose a program pipes output to the `mail' program. + For example, suppose a program pipes output to the 'mail' program. If it outputs several lines redirected to this pipe without closing it, they make a single message of several lines. By contrast, if the program closes the pipe after each line of output, then each line makes a separate message. - If you use more files than the system allows you to have open, -`gawk' attempts to multiplex the available open files among your data -files. `gawk''s ability to do this depends upon the facilities of your + If you use more files than the system allows you to have open, 'gawk' +attempts to multiplex the available open files among your data files. +'gawk''s ability to do this depends upon the facilities of your operating system, so it may not always work. It is therefore both good -practice and good portability advice to always use `close()' on your +practice and good portability advice to always use 'close()' on your files when you are done with them. In fact, if you are using a lot of -pipes, it is essential that you close commands when done. For example, +pipes, it is essential that you close commands when done. For example, consider something like this: { @@ -6979,62 +6946,62 @@ consider something like this: } This example creates a new pipeline based on data in _each_ record. -Without the call to `close()' indicated in the comment, `awk' creates +Without the call to 'close()' indicated in the comment, 'awk' creates child processes to run the commands, until it eventually runs out of file descriptors for more pipelines. Even though each command has finished (as indicated by the -end-of-file return status from `getline'), the child process is not -terminated;(1) more importantly, the file descriptor for the pipe is -not closed and released until `close()' is called or `awk' exits. +end-of-file return status from 'getline'), the child process is not +terminated;(1) more importantly, the file descriptor for the pipe is not +closed and released until 'close()' is called or 'awk' exits. - `close()' silently does nothing if given an argument that does not + 'close()' silently does nothing if given an argument that does not represent a file, pipe or coprocess that was opened with a redirection. -In such a case, it returns a negative value, indicating an error. In -addition, `gawk' sets `ERRNO' to a string indicating the error. +In such a case, it returns a negative value, indicating an error. In +addition, 'gawk' sets 'ERRNO' to a string indicating the error. - Note also that `close(FILENAME)' has no "magic" effects on the + Note also that 'close(FILENAME)' has no "magic" effects on the implicit loop that reads through the files named on the command line. It is, more likely, a close of a file that was never opened with a -redirection, so `awk' silently does nothing. +redirection, so 'awk' silently does nothing. - When using the `|&' operator to communicate with a coprocess, it is + When using the '|&' operator to communicate with a coprocess, it is occasionally useful to be able to close one end of the two-way pipe without closing the other. This is done by supplying a second argument -to `close()'. As in any other call to `close()', the first argument is +to 'close()'. As in any other call to 'close()', the first argument is the name of the command or special file used to start the coprocess. -The second argument should be a string, with either of the values -`"to"' or `"from"'. Case does not matter. As this is an advanced -feature, a more complete discussion is delayed until *note Two-way -I/O::, which discusses it in more detail and gives an example. +The second argument should be a string, with either of the values '"to"' +or '"from"'. Case does not matter. As this is an advanced feature, a +more complete discussion is delayed until *note Two-way I/O::, which +discusses it in more detail and gives an example. - Using `close()''s Return Value + Using 'close()''s Return Value - In many older versions of Unix `awk', the `close()' function is + In many older versions of Unix 'awk', the 'close()' function is actually a statement. It is a syntax error to try and use the return -value from `close()': (d.c.) +value from 'close()': (d.c.) command = "..." command | getline info retval = close(command) # syntax error in many Unix awks - `gawk' treats `close()' as a function. The return value is -1 if -the argument names something that was never opened with a redirection, -or if there is a system problem closing the file or process. In these -cases, `gawk' sets the built-in variable `ERRNO' to a string describing -the problem. + 'gawk' treats 'close()' as a function. The return value is -1 if the +argument names something that was never opened with a redirection, or if +there is a system problem closing the file or process. In these cases, +'gawk' sets the built-in variable 'ERRNO' to a string describing the +problem. - In `gawk', when closing a pipe or coprocess (input or output), the -return value is the exit status of the command.(2) Otherwise, it is the -return value from the system's `close()' or `fclose()' C functions when + In 'gawk', when closing a pipe or coprocess (input or output), the +return value is the exit status of the command.(2) Otherwise, it is the +return value from the system's 'close()' or 'fclose()' C functions when closing input or output files, respectively. This value is zero if the close succeeds, or -1 if it fails. - The POSIX standard is very vague; it says that `close()' returns -zero on success and nonzero otherwise. In general, different -implementations vary in what they report when closing pipes; thus the -return value cannot be used portably. (d.c.) In POSIX mode (*note -Options::), `gawk' just returns zero when closing a pipe. + The POSIX standard is very vague; it says that 'close()' returns zero +on success and nonzero otherwise. In general, different implementations +vary in what they report when closing pipes; thus the return value +cannot be used portably. (d.c.) In POSIX mode (*note Options::), +'gawk' just returns zero when closing a pipe. ---------- Footnotes ---------- @@ -7042,8 +7009,8 @@ Options::), `gawk' just returns zero when closing a pipe. is called a "zombie," and cleaning up after it is referred to as "reaping." - (2) This is a full 16-bit value as returned by the `wait()' system -call. See the system manual pages for information on how to decode this + (2) This is a full 16-bit value as returned by the 'wait()' system +call. See the system manual pages for information on how to decode this value.  @@ -7052,26 +7019,25 @@ File: gawk.info, Node: Output Summary, Next: Output exercises, Prev: Close Fi 5.9 Summary =========== - * The `print' statement prints comma-separated expressions. Each - expression is separated by the value of `OFS' and terminated by - the value of `ORS'. `OFMT' provides the conversion format for - numeric values for the `print' statement. + * The 'print' statement prints comma-separated expressions. Each + expression is separated by the value of 'OFS' and terminated by the + value of 'ORS'. 'OFMT' provides the conversion format for numeric + values for the 'print' statement. - * The `printf' statement provides finer-grained control over output, + * The 'printf' statement provides finer-grained control over output, with format control letters for different data types and various flags that modify the behavior of the format control letters. - * Output from both `print' and `printf' may be redirected to files, + * Output from both 'print' and 'printf' may be redirected to files, pipes, and co-processes. - * `gawk' provides special file names for access to standard input, + * 'gawk' provides special file names for access to standard input, output and error, and for network communications. - * Use `close()' to close open file, pipe and co-process redirections. + * Use 'close()' to close open file, pipe and co-process redirections. For co-processes, it is possible to close only one direction of the communications. -  File: gawk.info, Node: Output exercises, Prev: Output Summary, Up: Printing @@ -7084,10 +7050,10 @@ File: gawk.info, Node: Output exercises, Prev: Output Summary, Up: Printing print "----- ------" } { print $1, " ", $2 }' inventory-shipped - from *note Output Separators::, by using a new value of `OFS'. + from *note Output Separators::, by using a new value of 'OFS'. - 2. Use the `printf' statement to line up the headings and table data - for the `inventory-shipped' example that was covered in *note + 2. Use the 'printf' statement to line up the headings and table data + for the 'inventory-shipped' example that was covered in *note Print::. 3. What happens if you forget the double quotes when redirecting @@ -7095,29 +7061,27 @@ File: gawk.info, Node: Output exercises, Prev: Output Summary, Up: Printing BEGIN { print "Serious error detected!" > /dev/stderr } -  File: gawk.info, Node: Expressions, Next: Patterns and Actions, Prev: Printing, Up: Top 6 Expressions ************* -Expressions are the basic building blocks of `awk' patterns and -actions. An expression evaluates to a value that you can print, test, -or pass to a function. Additionally, an expression can assign a new -value to a variable or a field by using an assignment operator. +Expressions are the basic building blocks of 'awk' patterns and actions. +An expression evaluates to a value that you can print, test, or pass to +a function. Additionally, an expression can assign a new value to a +variable or a field by using an assignment operator. An expression can serve as a pattern or action statement on its own. Most other kinds of statements contain one or more expressions that specify the data on which to operate. As in other languages, -expressions in `awk' include variables, array references, constants, -and function calls, as well as combinations of these with various -operators. +expressions in 'awk' include variables, array references, constants, and +function calls, as well as combinations of these with various operators. * Menu: * Values:: Constants, Variables, and Regular Expressions. -* All Operators:: `gawk''s operators. +* All Operators:: 'gawk''s operators. * Truth Values and Conditions:: Testing for true and false. * Function Calls:: A function call is an expression. * Precedence:: How various operators nest. @@ -7131,7 +7095,7 @@ File: gawk.info, Node: Values, Next: All Operators, Up: Expressions ======================================== Expressions are built up from values and the operations performed upon -them. This minor node describes the elementary objects which provide +them. This minor node describes the elementary objects which provide the values used in expressions. * Menu: @@ -7153,8 +7117,8 @@ same value. There are three types of constants: numeric, string, and regular expression. Each is used in the appropriate context when you need a data value -that isn't going to change. Numeric constants can have different -forms, but are stored identically internally. +that isn't going to change. Numeric constants can have different forms, +but are stored identically internally. * Menu: @@ -7170,7 +7134,7 @@ File: gawk.info, Node: Scalar Constants, Next: Nondecimal-numbers, Up: Consta A "numeric constant" stands for a number. This number can be an integer, a decimal fraction, or a number in scientific (exponential) -notation.(1) Here are some examples of numeric constants that all have +notation.(1) Here are some examples of numeric constants that all have the same value: 105 @@ -7182,11 +7146,10 @@ double-quotation marks. For example: "parrot" -represents the string whose contents are `parrot'. Strings in `gawk' -can be of any length, and they can contain any of the possible -eight-bit ASCII characters including ASCII NUL (character code zero). -Other `awk' implementations may have difficulty with some character -codes. +represents the string whose contents are 'parrot'. Strings in 'gawk' +can be of any length, and they can contain any of the possible eight-bit +ASCII characters including ASCII NUL (character code zero). Other 'awk' +implementations may have difficulty with some character codes. ---------- Footnotes ---------- @@ -7201,30 +7164,29 @@ File: gawk.info, Node: Nondecimal-numbers, Next: Regexp Constants, Prev: Scal 6.1.1.2 Octal and Hexadecimal Numbers ..................................... -In `awk', all numbers are in decimal; i.e., base 10. Many other +In 'awk', all numbers are in decimal; i.e., base 10. Many other programming languages allow you to specify numbers in other bases, often octal (base 8) and hexadecimal (base 16). In octal, the numbers go 0, -1, 2, 3, 4, 5, 6, 7, 10, 11, 12, etc. Just as `11', in decimal, is 1 -times 10 plus 1, so `11', in octal, is 1 times 8, plus 1. This equals 9 -in decimal. In hexadecimal, there are 16 digits. Since the everyday -decimal number system only has ten digits (`0'-`9'), the letters `a' -through `f' are used to represent the rest. (Case in the letters is -usually irrelevant; hexadecimal `a' and `A' have the same value.) -Thus, `11', in hexadecimal, is 1 times 16 plus 1, which equals 17 in -decimal. - - Just by looking at plain `11', you can't tell what base it's in. -So, in C, C++, and other languages derived from C, there is a special -notation to signify the base. Octal numbers start with a leading `0', -and hexadecimal numbers start with a leading `0x' or `0X': - -`11' +1, 2, 3, 4, 5, 6, 7, 10, 11, 12, etc. Just as '11', in decimal, is 1 +times 10 plus 1, so '11', in octal, is 1 times 8, plus 1. This equals 9 +in decimal. In hexadecimal, there are 16 digits. Since the everyday +decimal number system only has ten digits ('0'-'9'), the letters 'a' +through 'f' are used to represent the rest. (Case in the letters is +usually irrelevant; hexadecimal 'a' and 'A' have the same value.) Thus, +'11', in hexadecimal, is 1 times 16 plus 1, which equals 17 in decimal. + + Just by looking at plain '11', you can't tell what base it's in. So, +in C, C++, and other languages derived from C, there is a special +notation to signify the base. Octal numbers start with a leading '0', +and hexadecimal numbers start with a leading '0x' or '0X': + +'11' Decimal value 11. -`011' +'011' Octal 11, decimal value 9. -`0x11' +'0x11' Hexadecimal 11, decimal value 17. This example shows the difference: @@ -7232,39 +7194,39 @@ and hexadecimal numbers start with a leading `0x' or `0X': $ gawk 'BEGIN { printf "%d, %d, %d\n", 011, 11, 0x11 }' -| 9, 11, 17 - Being able to use octal and hexadecimal constants in your programs -is most useful when working with data that cannot be represented -conveniently as characters or as regular numbers, such as binary data -of various sorts. + Being able to use octal and hexadecimal constants in your programs is +most useful when working with data that cannot be represented +conveniently as characters or as regular numbers, such as binary data of +various sorts. - `gawk' allows the use of octal and hexadecimal constants in your + 'gawk' allows the use of octal and hexadecimal constants in your program text. However, such numbers in the input data are not treated differently; doing so by default would break old programs. (If you -really need to do this, use the `--non-decimal-data' command-line +really need to do this, use the '--non-decimal-data' command-line option; *note Nondecimal Data::.) If you have octal or hexadecimal -data, you can use the `strtonum()' function (*note String Functions::) +data, you can use the 'strtonum()' function (*note String Functions::) to convert the data into a number. Most of the time, you will want to use octal or hexadecimal constants when working with the built-in bit manipulation functions; see *note Bitwise Functions::, for more information. - Unlike some early C implementations, `8' and `9' are not valid in -octal constants; e.g., `gawk' treats `018' as decimal 18: + Unlike some early C implementations, '8' and '9' are not valid in +octal constants; e.g., 'gawk' treats '018' as decimal 18: $ gawk 'BEGIN { print "021 is", 021 ; print 018 }' -| 021 is 17 -| 18 - Octal and hexadecimal source code constants are a `gawk' extension. -If `gawk' is in compatibility mode (*note Options::), they are not + Octal and hexadecimal source code constants are a 'gawk' extension. +If 'gawk' is in compatibility mode (*note Options::), they are not available. A Constant's Base Does Not Affect Its Value Once a numeric constant has been converted internally into a number, -`gawk' no longer remembers what the original form of the constant was; -the internal value is always used. This has particular consequences -for conversion of numbers to strings: +'gawk' no longer remembers what the original form of the constant was; +the internal value is always used. This has particular consequences for +conversion of numbers to strings: $ gawk 'BEGIN { printf "0x11 is <%s>\n", 0x11 }' -| 0x11 is <17> @@ -7276,8 +7238,8 @@ File: gawk.info, Node: Regexp Constants, Prev: Nondecimal-numbers, Up: Consta .................................... A regexp constant is a regular expression description enclosed in -slashes, such as `/^beginning and end$/'. Most regexps used in `awk' -programs are constant, but the `~' and `!~' matching operators can also +slashes, such as '/^beginning and end$/'. Most regexps used in 'awk' +programs are constant, but the '~' and '!~' matching operators can also match computed or dynamic regexps (which are just ordinary strings or variables that contain a regexp). @@ -7287,11 +7249,11 @@ File: gawk.info, Node: Using Constant Regexps, Next: Variables, Prev: Constan 6.1.2 Using Regular Expression Constants ---------------------------------------- -When used on the righthand side of the `~' or `!~' operators, a regexp +When used on the righthand side of the '~' or '!~' operators, a regexp constant merely stands for the regexp that is to be matched. However, -regexp constants (such as `/foo/') may be used like simple expressions. +regexp constants (such as '/foo/') may be used like simple expressions. When a regexp constant appears by itself, it has the same meaning as if -it appeared in a pattern, i.e., `($0 ~ /foo/)' (d.c.) *Note Expression +it appeared in a pattern, i.e., '($0 ~ /foo/)' (d.c.) *Note Expression Patterns::. This means that the following two code segments: if ($0 ~ /barfly/ || $0 ~ /camelot/) @@ -7303,33 +7265,33 @@ and: print "found" are exactly equivalent. One rather bizarre consequence of this rule is -that the following Boolean expression is valid, but does not do what -the user probably intended: +that the following Boolean expression is valid, but does not do what the +user probably intended: # Note that /foo/ is on the left of the ~ if (/foo/ ~ $1) print "found foo" -This code is "obviously" testing `$1' for a match against the regexp -`/foo/'. But in fact, the expression `/foo/ ~ $1' really means `($0 ~ +This code is "obviously" testing '$1' for a match against the regexp +'/foo/'. But in fact, the expression '/foo/ ~ $1' really means '($0 ~ /foo/) ~ $1'. In other words, first match the input record against the -regexp `/foo/'. The result is either zero or one, depending upon the +regexp '/foo/'. The result is either zero or one, depending upon the success or failure of the match. That result is then matched against the first field in the record. Because it is unlikely that you would -ever really want to make this kind of test, `gawk' issues a warning -when it sees this construct in a program. Another consequence of this -rule is that the assignment statement: +ever really want to make this kind of test, 'gawk' issues a warning when +it sees this construct in a program. Another consequence of this rule +is that the assignment statement: matches = /foo/ -assigns either zero or one to the variable `matches', depending upon -the contents of the current input record. +assigns either zero or one to the variable 'matches', depending upon the +contents of the current input record. Constant regular expressions are also used as the first argument for -the `gensub()', `sub()', and `gsub()' functions, as the second argument -of the `match()' function, and as the third argument of the `split()' -and `patsplit()' functions (*note String Functions::). Modern -implementations of `awk', including `gawk', allow the third argument of -`split()' to be a regexp constant, but some older implementations do +the 'gensub()', 'sub()', and 'gsub()' functions, as the second argument +of the 'match()' function, and as the third argument of the 'split()' +and 'patsplit()' functions (*note String Functions::). Modern +implementations of 'awk', including 'gawk', allow the third argument of +'split()' to be a regexp constant, but some older implementations do not. (d.c.) This can lead to confusion when attempting to use regexp constants as arguments to user-defined functions (*note User-defined::). For example: @@ -7351,10 +7313,10 @@ For example: } In this example, the programmer wants to pass a regexp constant to -the user-defined function `mysub', which in turn passes it on to either -`sub()' or `gsub()'. However, what really happens is that the `pat' -parameter is either one or zero, depending upon whether or not `$0' -matches `/hi/'. `gawk' issues a warning when it sees a regexp constant +the user-defined function 'mysub', which in turn passes it on to either +'sub()' or 'gsub()'. However, what really happens is that the 'pat' +parameter is either one or zero, depending upon whether or not '$0' +matches '/hi/'. 'gawk' issues a warning when it sees a regexp constant used as a parameter to a user-defined function, since passing a truth value in this way is probably not what was intended. @@ -7367,7 +7329,7 @@ File: gawk.info, Node: Variables, Next: Conversion, Prev: Using Constant Rege Variables are ways of storing values at one point in your program for use later in another part of your program. They can be manipulated entirely within the program text, and they can also be assigned values -on the `awk' command line. +on the 'awk' command line. * Menu: @@ -7383,33 +7345,33 @@ File: gawk.info, Node: Using Variables, Next: Assignment Options, Up: Variabl .................................... Variables let you give names to values and refer to them later. -Variables have already been used in many of the examples. The name of -a variable must be a sequence of letters, digits, or underscores, and -it may not begin with a digit. Case is significant in variable names; -`a' and `A' are distinct variables. +Variables have already been used in many of the examples. The name of a +variable must be a sequence of letters, digits, or underscores, and it +may not begin with a digit. Case is significant in variable names; 'a' +and 'A' are distinct variables. A variable name is a valid expression by itself; it represents the variable's current value. Variables are given new values with "assignment operators", "increment operators", and "decrement -operators". *Note Assignment Ops::. In addition, the `sub()' and -`gsub()' functions can change a variable's value, and the `match()', -`patsplit()' and `split()' functions can change the contents of their -array parameters. *Note String Functions::. +operators". *Note Assignment Ops::. In addition, the 'sub()' and +'gsub()' functions can change a variable's value, and the 'match()', +'patsplit()' and 'split()' functions can change the contents of their +array parameters. *Note String Functions::. - A few variables have special built-in meanings, such as `FS' (the -field separator), and `NF' (the number of fields in the current input + A few variables have special built-in meanings, such as 'FS' (the +field separator), and 'NF' (the number of fields in the current input record). *Note Built-in Variables::, for a list of the built-in variables. These built-in variables can be used and assigned just like all other variables, but their values are also used or changed -automatically by `awk'. All built-in variables' names are entirely +automatically by 'awk'. All built-in variables' names are entirely uppercase. - Variables in `awk' can be assigned either numeric or string values. + Variables in 'awk' can be assigned either numeric or string values. The kind of value a variable holds can change over the life of a program. By default, variables are initialized to the empty string, which is zero if converted to a number. There is no need to explicitly -"initialize" a variable in `awk', which is what you would do in C and -in most other traditional languages. +"initialize" a variable in 'awk', which is what you would do in C and in +most other traditional languages.  File: gawk.info, Node: Assignment Options, Prev: Using Variables, Up: Variables @@ -7417,34 +7379,34 @@ File: gawk.info, Node: Assignment Options, Prev: Using Variables, Up: Variabl 6.1.3.2 Assigning Variables on the Command Line ............................................... -Any `awk' variable can be set by including a "variable assignment" -among the arguments on the command line when `awk' is invoked (*note -Other Arguments::). Such an assignment has the following form: +Any 'awk' variable can be set by including a "variable assignment" among +the arguments on the command line when 'awk' is invoked (*note Other +Arguments::). Such an assignment has the following form: VARIABLE=TEXT -With it, a variable is set either at the beginning of the `awk' run or -in between input files. When the assignment is preceded with the `-v' +With it, a variable is set either at the beginning of the 'awk' run or +in between input files. When the assignment is preceded with the '-v' option, as in the following: -v VARIABLE=TEXT -the variable is set at the very beginning, even before the `BEGIN' -rules execute. The `-v' option and its assignment must precede all the -file name arguments, as well as the program text. (*Note Options::, -for more information about the `-v' option.) Otherwise, the variable -assignment is performed at a time determined by its position among the -input file arguments--after the processing of the preceding input file -argument. For example: +the variable is set at the very beginning, even before the 'BEGIN' rules +execute. The '-v' option and its assignment must precede all the file +name arguments, as well as the program text. (*Note Options::, for more +information about the '-v' option.) Otherwise, the variable assignment +is performed at a time determined by its position among the input file +arguments--after the processing of the preceding input file argument. +For example: awk '{ print $n }' n=4 inventory-shipped n=2 mail-list -prints the value of field number `n' for all input records. Before the -first file is read, the command line sets the variable `n' equal to +prints the value of field number 'n' for all input records. Before the +first file is read, the command line sets the variable 'n' equal to four. This causes the fourth field to be printed in lines from -`inventory-shipped'. After the first file has finished, but before the -second file is started, `n' is set to two, so that the second field is -printed in lines from `mail-list': +'inventory-shipped'. After the first file has finished, but before the +second file is started, 'n' is set to two, so that the second field is +printed in lines from 'mail-list': $ awk '{ print $n }' n=4 inventory-shipped n=2 mail-list -| 15 @@ -7455,7 +7417,7 @@ printed in lines from `mail-list': ... Command-line arguments are made available for explicit examination by -the `awk' program in the `ARGV' array (*note ARGC and ARGV::). `awk' +the 'awk' program in the 'ARGV' array (*note ARGC and ARGV::). 'awk' processes the values of command-line assignments for escape sequences (*note Escape Sequences::). (d.c.) @@ -7467,23 +7429,23 @@ File: gawk.info, Node: Conversion, Prev: Variables, Up: Values Number to string and string to number conversion are generally straightforward. There can be subtleties to be aware of; this minor -node discusses this important facet of `awk'. +node discusses this important facet of 'awk'. * Menu: -* Strings And Numbers:: How `awk' Converts Between Strings And +* Strings And Numbers:: How 'awk' Converts Between Strings And Numbers. * Locale influences conversions:: How the locale may affect conversions.  File: gawk.info, Node: Strings And Numbers, Next: Locale influences conversions, Up: Conversion -6.1.4.1 How `awk' Converts Between Strings And Numbers +6.1.4.1 How 'awk' Converts Between Strings And Numbers ...................................................... Strings are converted to numbers and numbers are converted to strings, -if the context of the `awk' program demands it. For example, if the -value of either `foo' or `bar' in the expression `foo + bar' happens to +if the context of the 'awk' program demands it. For example, if the +value of either 'foo' or 'bar' in the expression 'foo + bar' happens to be a string, it is converted to a number before the addition is performed. If numeric values appear in string concatenation, they are converted to strings. Consider the following: @@ -7491,60 +7453,59 @@ converted to strings. Consider the following: two = 2; three = 3 print (two three) + 4 -This prints the (numeric) value 27. The numeric values of the -variables `two' and `three' are converted to strings and concatenated -together. The resulting string is converted back to the number 23, to -which 4 is then added. +This prints the (numeric) value 27. The numeric values of the variables +'two' and 'three' are converted to strings and concatenated together. +The resulting string is converted back to the number 23, to which 4 is +then added. If, for some reason, you need to force a number to be converted to a -string, concatenate that number with the empty string, `""'. To force -a string to be converted to a number, add zero to that string. A -string is converted to a number by interpreting any numeric prefix of -the string as numerals: `"2.5"' converts to 2.5, `"1e3"' converts to -1000, and `"25fix"' has a numeric value of 25. Strings that can't be +string, concatenate that number with the empty string, '""'. To force a +string to be converted to a number, add zero to that string. A string +is converted to a number by interpreting any numeric prefix of the +string as numerals: '"2.5"' converts to 2.5, '"1e3"' converts to 1000, +and '"25fix"' has a numeric value of 25. Strings that can't be interpreted as valid numbers convert to zero. The exact manner in which numbers are converted into strings is -controlled by the `awk' built-in variable `CONVFMT' (*note Built-in -Variables::). Numbers are converted using the `sprintf()' function -with `CONVFMT' as the format specifier (*note String Functions::). +controlled by the 'awk' built-in variable 'CONVFMT' (*note Built-in +Variables::). Numbers are converted using the 'sprintf()' function with +'CONVFMT' as the format specifier (*note String Functions::). - `CONVFMT''s default value is `"%.6g"', which creates a value with at + 'CONVFMT''s default value is '"%.6g"', which creates a value with at most six significant digits. For some applications, you might want to -change it to specify more precision. On most modern machines, 17 -digits is usually enough to capture a floating-point number's value -exactly.(1) +change it to specify more precision. On most modern machines, 17 digits +is usually enough to capture a floating-point number's value exactly.(1) - Strange results can occur if you set `CONVFMT' to a string that -doesn't tell `sprintf()' how to format floating-point numbers in a -useful way. For example, if you forget the `%' in the format, `awk' + Strange results can occur if you set 'CONVFMT' to a string that +doesn't tell 'sprintf()' how to format floating-point numbers in a +useful way. For example, if you forget the '%' in the format, 'awk' converts all numbers to the same constant string. As a special case, if a number is an integer, then the result of converting it to a string is _always_ an integer, no matter what the -value of `CONVFMT' may be. Given the following code fragment: +value of 'CONVFMT' may be. Given the following code fragment: CONVFMT = "%2.2f" a = 12 b = a "" -`b' has the value `"12"', not `"12.00"'. (d.c.) +'b' has the value '"12"', not '"12.00"'. (d.c.) - Pre-POSIX `awk' Used `OFMT' For String Conversion + Pre-POSIX 'awk' Used 'OFMT' For String Conversion - Prior to the POSIX standard, `awk' used the value of `OFMT' for -converting numbers to strings. `OFMT' specifies the output format to -use when printing numbers with `print'. `CONVFMT' was introduced in + Prior to the POSIX standard, 'awk' used the value of 'OFMT' for +converting numbers to strings. 'OFMT' specifies the output format to +use when printing numbers with 'print'. 'CONVFMT' was introduced in order to separate the semantics of conversion from the semantics of -printing. Both `CONVFMT' and `OFMT' have the same default value: -`"%.6g"'. In the vast majority of cases, old `awk' programs do not +printing. Both 'CONVFMT' and 'OFMT' have the same default value: +'"%.6g"'. In the vast majority of cases, old 'awk' programs do not change their behavior. *Note Print::, for more information on the -`print' statement. +'print' statement. ---------- Footnotes ---------- - (1) Pathological cases can require up to 752 digits (!), but we -doubt that you need to worry about this. + (1) Pathological cases can require up to 752 digits (!), but we doubt +that you need to worry about this.  File: gawk.info, Node: Locale influences conversions, Prev: Strings And Numbers, Up: Conversion @@ -7553,22 +7514,22 @@ File: gawk.info, Node: Locale influences conversions, Prev: Strings And Number ........................................ Where you are can matter when it comes to converting between numbers and -strings. The local character set and language--the "locale"--can -affect numeric formats. In particular, for `awk' programs, it affects -the decimal point character and the thousands-separator character. The -`"C"' locale, and most English-language locales, use the period -character (`.') as the decimal point and don't have a thousands -separator. However, many (if not most) European and non-English -locales use the comma (`,') as the decimal point character. European -locales often use either a space or a period as the thousands -separator, if they have one. - - The POSIX standard says that `awk' always uses the period as the -decimal point when reading the `awk' program source code, and for +strings. The local character set and language--the "locale"--can affect +numeric formats. In particular, for 'awk' programs, it affects the +decimal point character and the thousands-separator character. The +'"C"' locale, and most English-language locales, use the period +character ('.') as the decimal point and don't have a thousands +separator. However, many (if not most) European and non-English locales +use the comma (',') as the decimal point character. European locales +often use either a space or a period as the thousands separator, if they +have one. + + The POSIX standard says that 'awk' always uses the period as the +decimal point when reading the 'awk' program source code, and for command-line variable assignments (*note Other Arguments::). However, -when interpreting input data, for `print' and `printf' output, and for +when interpreting input data, for 'print' and 'printf' output, and for number to string conversion, the local decimal point character is used. -(d.c.) In all cases, numbers in source code and in input data cannot +(d.c.) In all cases, numbers in source code and in input data cannot have a thousands separator. Here are some examples indicating the difference in behavior, on a GNU/Linux system: @@ -7582,37 +7543,38 @@ difference in behavior, on a GNU/Linux system: $ echo 4,321 | LC_ALL=en_DK.utf-8 gawk '{ print $1 + 1 }' -| 5,321 -The `en_DK.utf-8' locale is for English in Denmark, where the comma -acts as the decimal point separator. In the normal `"C"' locale, `gawk' -treats `4,321' as `4', while in the Danish locale, it's treated as the +The 'en_DK.utf-8' locale is for English in Denmark, where the comma acts +as the decimal point separator. In the normal '"C"' locale, 'gawk' +treats '4,321' as '4', while in the Danish locale, it's treated as the full number, 4.321. - Some earlier versions of `gawk' fully complied with this aspect of + Some earlier versions of 'gawk' fully complied with this aspect of the standard. However, many users in non-English locales complained about this behavior, since their data used a period as the decimal point, so the default behavior was restored to use a period as the -decimal point character. You can use the `--use-lc-numeric' option -(*note Options::) to force `gawk' to use the locale's decimal point -character. (`gawk' also uses the locale's decimal point character when -in POSIX mode, either via `--posix', or the `POSIXLY_CORRECT' +decimal point character. You can use the '--use-lc-numeric' option +(*note Options::) to force 'gawk' to use the locale's decimal point +character. ('gawk' also uses the locale's decimal point character when +in POSIX mode, either via '--posix', or the 'POSIXLY_CORRECT' environment variable, as shown previously.) - *note table-locale-affects:: describes the cases in which the -locale's decimal point character is used and when a period is used. + *note Table 6.1: table-locale-affects. describes the cases in which +the locale's decimal point character is used and when a period is used. Some of these features have not been described yet. -Feature Default `--posix' or `--use-lc-numeric' ------------------------------------------------------------- -`%'g' Use locale Use locale -`%g' Use period Use locale +Feature Default '--posix' or + '--use-lc-numeric' +------------------------------------------------------------ +'%'g' Use locale Use locale +'%g' Use period Use locale Input Use period Use locale -`strtonum()'Use period Use locale +'strtonum()'Use period Use locale Table 6.1: Locale Decimal Point versus A Period Finally, modern day formal standards and IEEE standard floating point representation can have an unusual but important effect on the way -`gawk' converts some special string values to numbers. The details are +'gawk' converts some special string values to numbers. The details are presented in *note POSIX Floating Point Problems::.  @@ -7626,7 +7588,7 @@ provided by constants and variables. * Menu: -* Arithmetic Ops:: Arithmetic operations (`+', `-', +* Arithmetic Ops:: Arithmetic operations ('+', '-', etc.) * Concatenation:: Concatenating strings. * Assignment Ops:: Changing the value of a variable or a field. @@ -7638,11 +7600,11 @@ File: gawk.info, Node: Arithmetic Ops, Next: Concatenation, Up: All Operators 6.2.1 Arithmetic Operators -------------------------- -The `awk' language uses the common arithmetic operators when evaluating -expressions. All of these arithmetic operators follow normal -precedence rules and work as you would expect them to. +The 'awk' language uses the common arithmetic operators when evaluating +expressions. All of these arithmetic operators follow normal precedence +rules and work as you would expect them to. - The following example uses a file named `grades', which contains a + The following example uses a file named 'grades', which contains a list of student names as well as three test scores per student (it's a small class): @@ -7650,7 +7612,7 @@ small class): Sandy 84 72 93 Chris 72 92 89 -This program takes the file `grades' and prints the average of the +This program takes the file 'grades' and prints the average of the scores: $ awk '{ sum = $2 + $3 + $4 ; avg = sum / 3 @@ -7659,62 +7621,62 @@ scores: -| Sandy 83 -| Chris 84.3333 - The following list provides the arithmetic operators in `awk', in + The following list provides the arithmetic operators in 'awk', in order from the highest precedence to the lowest: -`X ^ Y' -`X ** Y' - Exponentiation; X raised to the Y power. `2 ^ 3' has the value - eight; the character sequence `**' is equivalent to `^'. (c.e.) +'X ^ Y' +'X ** Y' + Exponentiation; X raised to the Y power. '2 ^ 3' has the value + eight; the character sequence '**' is equivalent to '^'. (c.e.) -`- X' +'- X' Negation. -`+ X' +'+ X' Unary plus; the expression is converted to a number. -`X * Y' +'X * Y' Multiplication. -`X / Y' - Division; because all numbers in `awk' are floating-point - numbers, the result is _not_ rounded to an integer--`3 / 4' has - the value 0.75. (It is a common mistake, especially for C - programmers, to forget that _all_ numbers in `awk' are - floating-point, and that division of integer-looking constants - produces a real number, not an integer.) +'X / Y' + Division; because all numbers in 'awk' are floating-point numbers, + the result is _not_ rounded to an integer--'3 / 4' has the value + 0.75. (It is a common mistake, especially for C programmers, to + forget that _all_ numbers in 'awk' are floating-point, and that + division of integer-looking constants produces a real number, not + an integer.) -`X % Y' +'X % Y' Remainder; further discussion is provided in the text, just after this list. -`X + Y' +'X + Y' Addition. -`X - Y' +'X - Y' Subtraction. Unary plus and minus have the same precedence, the multiplication operators all have the same precedence, and addition and subtraction have the same precedence. - When computing the remainder of `X % Y', the quotient is rounded -toward zero to an integer and multiplied by Y. This result is + When computing the remainder of 'X % Y', the quotient is rounded +toward zero to an integer and multiplied by Y. This result is subtracted from X; this operation is sometimes known as "trunc-mod." The following relation always holds: b * int(a / b) + (a % b) == a One possibly undesirable effect of this definition of remainder is -that `X % Y' is negative if X is negative. Thus: +that 'X % Y' is negative if X is negative. Thus: -17 % 8 = -1 - In other `awk' implementations, the signedness of the remainder may + In other 'awk' implementations, the signedness of the remainder may be machine-dependent. - NOTE: The POSIX standard only specifies the use of `^' for - exponentiation. For maximum portability, do not use the `**' + NOTE: The POSIX standard only specifies the use of '^' for + exponentiation. For maximum portability, do not use the '**' operator.  @@ -7723,7 +7685,8 @@ File: gawk.info, Node: Concatenation, Next: Assignment Ops, Prev: Arithmetic 6.2.2 String Concatenation -------------------------- - It seemed like a good idea at the time. -- Brian Kernighan + It seemed like a good idea at the time. + -- _Brian Kernighan_ There is only one string operation: concatenation. It does not have a specific operator to represent it. Instead, concatenation is @@ -7735,8 +7698,8 @@ For example: -| Field number one: Anthony ... - Without the space in the string constant after the `:', the line -runs together. For example: + Without the space in the string constant after the ':', the line runs +together. For example: $ awk '{ print "Field number one:" $1 }' mail-list -| Field number one:Amelia @@ -7745,34 +7708,32 @@ runs together. For example: Because string concatenation does not have an explicit operator, it is often necessary to insure that it happens at the right time by using -parentheses to enclose the items to concatenate. For example, you -might expect that the following code fragment concatenates `file' and -`name': +parentheses to enclose the items to concatenate. For example, you might +expect that the following code fragment concatenates 'file' and 'name': file = "file" name = "name" print "something meaningful" > file name -This produces a syntax error with some versions of Unix `awk'.(1) It is +This produces a syntax error with some versions of Unix 'awk'.(1) It is necessary to use the following: print "something meaningful" > (file name) Parentheses should be used around concatenation in all but the most -common contexts, such as on the righthand side of `='. Be careful -about the kinds of expressions used in string concatenation. In -particular, the order of evaluation of expressions used for -concatenation is undefined in the `awk' language. Consider this -example: +common contexts, such as on the righthand side of '='. Be careful about +the kinds of expressions used in string concatenation. In particular, +the order of evaluation of expressions used for concatenation is +undefined in the 'awk' language. Consider this example: BEGIN { a = "don't" print (a " " (a = "panic")) } -It is not defined whether the second assignment to `a' happens before -or after the value of `a' is retrieved for producing the concatenated -value. The result could be either `don't panic', or `panic panic'. +It is not defined whether the second assignment to 'a' happens before or +after the value of 'a' is retrieved for producing the concatenated +value. The result could be either 'don't panic', or 'panic panic'. The precedence of concatenation, when mixed with other operators, is often counter-intuitive. Consider this example: @@ -7782,16 +7743,16 @@ often counter-intuitive. Consider this example: This "obviously" is concatenating -12, a space, and -24. But where did the space disappear to? The answer lies in the combination of -operator precedences and `awk''s automatic conversion rules. To get -the desired result, write the program this way: +operator precedences and 'awk''s automatic conversion rules. To get the +desired result, write the program this way: $ awk 'BEGIN { print -12 " " (-24) }' -| -12 -24 - This forces `awk' to treat the `-' on the `-24' as unary. -Otherwise, it's parsed as follows: + This forces 'awk' to treat the '-' on the '-24' as unary. Otherwise, +it's parsed as follows: - -12 (`" "' - 24) + -12 ('" "' - 24) => -12 (0 - 24) => -12 (-24) => -12-24 @@ -7801,7 +7762,7 @@ Otherwise, you're never quite sure what you'll get. ---------- Footnotes ---------- - (1) It happens that Brian Kernighan's `awk', `gawk' and `mawk' all + (1) It happens that Brian Kernighan's 'awk', 'gawk' and 'mawk' all "get it right," but you should not rely on this.  @@ -7810,24 +7771,23 @@ File: gawk.info, Node: Assignment Ops, Next: Increment Ops, Prev: Concatenati 6.2.3 Assignment Expressions ---------------------------- -An "assignment" is an expression that stores a (usually different) -value into a variable. For example, let's assign the value one to the -variable `z': +An "assignment" is an expression that stores a (usually different) value +into a variable. For example, let's assign the value one to the +variable 'z': z = 1 - After this expression is executed, the variable `z' has the value -one. Whatever old value `z' had before the assignment is forgotten. + After this expression is executed, the variable 'z' has the value +one. Whatever old value 'z' had before the assignment is forgotten. - Assignments can also store string values. For example, the -following stores the value `"this food is good"' in the variable -`message': + Assignments can also store string values. For example, the following +stores the value '"this food is good"' in the variable 'message': thing = "food" predicate = "good" message = "this " thing " is " predicate -This also illustrates string concatenation. The `=' sign is called an +This also illustrates string concatenation. The '=' sign is called an "assignment operator". It is the simplest assignment operator because the value of the righthand operand is stored unchanged. Most operators (addition, concatenation, and so on) have no effect except to compute a @@ -7842,11 +7802,11 @@ array element (*note Arrays::). These are all called "lvalues", which means they can appear on the lefthand side of an assignment operator. The righthand operand may be any expression; it produces the new value that the assignment stores in the specified variable, field, or array -element. (Such values are called "rvalues".) +element. (Such values are called "rvalues".) It is important to note that variables do _not_ have permanent types. A variable's type is simply the type of whatever value was last assigned -to it. In the following program fragment, the variable `foo' has a +to it. In the following program fragment, the variable 'foo' has a numeric value at first, and a string value later on: foo = 1 @@ -7854,43 +7814,43 @@ numeric value at first, and a string value later on: foo = "bar" print foo -When the second assignment gives `foo' a string value, the fact that it +When the second assignment gives 'foo' a string value, the fact that it previously had a numeric value is forgotten. String values that do not begin with a digit have a numeric value of -zero. After executing the following code, the value of `foo' is five: +zero. After executing the following code, the value of 'foo' is five: foo = "a string" foo = foo + 5 NOTE: Using a variable as a number and then later as a string can be confusing and is poor programming style. The previous two - examples illustrate how `awk' works, _not_ how you should write + examples illustrate how 'awk' works, _not_ how you should write your programs! An assignment is an expression, so it has a value--the same value -that is assigned. Thus, `z = 1' is an expression with the value one. +that is assigned. Thus, 'z = 1' is an expression with the value one. One consequence of this is that you can write multiple assignments together, such as: x = y = z = 5 -This example stores the value five in all three variables (`x', `y', -and `z'). It does so because the value of `z = 5', which is five, is -stored into `y' and then the value of `y = z = 5', which is five, is -stored into `x'. +This example stores the value five in all three variables ('x', 'y', and +'z'). It does so because the value of 'z = 5', which is five, is stored +into 'y' and then the value of 'y = z = 5', which is five, is stored +into 'x'. Assignments may be used anywhere an expression is called for. For -example, it is valid to write `x != (y = 1)' to set `y' to one, and -then test whether `x' equals one. But this style tends to make -programs hard to read; such nesting of assignments should be avoided, -except perhaps in a one-shot program. +example, it is valid to write 'x != (y = 1)' to set 'y' to one, and then +test whether 'x' equals one. But this style tends to make programs hard +to read; such nesting of assignments should be avoided, except perhaps +in a one-shot program. - Aside from `=', there are several other assignment operators that do + Aside from '=', there are several other assignment operators that do arithmetic with the old value of the variable. For example, the -operator `+=' computes a new value by adding the righthand value to the +operator '+=' computes a new value by adding the righthand value to the old value of the variable. Thus, the following assignment adds five to -the value of `foo': +the value of 'foo': foo += 5 @@ -7900,9 +7860,9 @@ This is equivalent to the following: Use whichever makes the meaning of your program clearer. - There are situations where using `+=' (or any assignment operator) -is _not_ the same as simply repeating the lefthand operand in the -righthand expression. For example: + There are situations where using '+=' (or any assignment operator) is +_not_ the same as simply repeating the lefthand operand in the righthand +expression. For example: # Thanks to Pat Rankin for this example BEGIN { @@ -7915,10 +7875,10 @@ righthand expression. For example: print x, bar[x] } -The indices of `bar' are practically guaranteed to be different, because -`rand()' returns different values each time it is called. (Arrays and -the `rand()' function haven't been covered yet. *Note Arrays::, and -see *note Numeric Functions::, for more information). This example +The indices of 'bar' are practically guaranteed to be different, because +'rand()' returns different values each time it is called. (Arrays and +the 'rand()' function haven't been covered yet. *Note Arrays::, and see +*note Numeric Functions::, for more information). This example illustrates an important fact about assignment operators: the lefthand expression is only evaluated _once_. @@ -7928,46 +7888,48 @@ first, the lefthand or the righthand. Consider this example: i = 1 a[i += 2] = i + 1 -The value of `a[3]' could be either two or four. +The value of 'a[3]' could be either two or four. - *note table-assign-ops:: lists the arithmetic assignment operators. -In each case, the righthand operand is an expression whose value is -converted to a number. + *note Table 6.2: table-assign-ops. lists the arithmetic assignment +operators. In each case, the righthand operand is an expression whose +value is converted to a number. Operator Effect --------------------------------------------------------------------------- -LVALUE `+=' INCREMENT Add INCREMENT to the value of LVALUE. -LVALUE `-=' DECREMENT Subtract DECREMENT from the value of LVALUE. -LVALUE `*=' Multiply the value of LVALUE by COEFFICIENT. -COEFFICIENT -LVALUE `/=' DIVISOR Divide the value of LVALUE by DIVISOR. -LVALUE `%=' MODULUS Set LVALUE to its remainder by MODULUS. -LVALUE `^=' POWER -LVALUE `**=' POWER Raise LVALUE to the power POWER. (c.e.) +-------------------------------------------------------------------------- +LVALUE '+=' Add INCREMENT to the value of LVALUE. +INCREMENT +LVALUE '-=' Subtract DECREMENT from the value of LVALUE. +DECREMENT +LVALUE '*=' Multiply the value of LVALUE by COEFFICIENT. +COEFFICIENT +LVALUE '/=' DIVISOR Divide the value of LVALUE by DIVISOR. +LVALUE '%=' MODULUS Set LVALUE to its remainder by MODULUS. +LVALUE '^=' POWER +LVALUE '**=' POWER Raise LVALUE to the power POWER. (c.e.) Table 6.2: Arithmetic Assignment Operators - NOTE: Only the `^=' operator is specified by POSIX. For maximum - portability, do not use the `**=' operator. + NOTE: Only the '^=' operator is specified by POSIX. For maximum + portability, do not use the '**=' operator. - Syntactic Ambiguities Between `/=' and Regular Expressions + Syntactic Ambiguities Between '/=' and Regular Expressions - There is a syntactic ambiguity between the `/=' assignment operator -and regexp constants whose first character is an `='. (d.c.) This is -most notable in some commercial `awk' versions. For example: + There is a syntactic ambiguity between the '/=' assignment operator +and regexp constants whose first character is an '='. (d.c.) This is +most notable in some commercial 'awk' versions. For example: $ awk /==/ /dev/null - error--> awk: syntax error at source line 1 - error--> context is - error--> >>> /= <<< - error--> awk: bailing out at source line 1 + error-> awk: syntax error at source line 1 + error-> context is + error-> >>> /= <<< + error-> awk: bailing out at source line 1 A workaround is: awk '/[=]=/' /dev/null - `gawk' does not have this problem; Brian Kernighan's `awk' and -`mawk' also do not (*note Other Versions::). + 'gawk' does not have this problem; Brian Kernighan's 'awk' and 'mawk' +also do not (*note Other Versions::).  File: gawk.info, Node: Increment Ops, Prev: Assignment Ops, Up: All Operators @@ -7976,61 +7938,62 @@ File: gawk.info, Node: Increment Ops, Prev: Assignment Ops, Up: All Operators --------------------------------------- "Increment" and "decrement operators" increase or decrease the value of -a variable by one. An assignment operator can do the same thing, so -the increment operators add no power to the `awk' language; however, -they are convenient abbreviations for very common operations. +a variable by one. An assignment operator can do the same thing, so the +increment operators add no power to the 'awk' language; however, they +are convenient abbreviations for very common operations. - The operator used for adding one is written `++'. It can be used to + The operator used for adding one is written '++'. It can be used to increment a variable either before or after taking its value. To -"pre-increment" a variable `v', write `++v'. This adds one to the -value of `v'--that new value is also the value of the expression. (The -assignment expression `v += 1' is completely equivalent.) Writing the -`++' after the variable specifies "post-increment". This increments -the variable value just the same; the difference is that the value of -the increment expression itself is the variable's _old_ value. Thus, -if `foo' has the value four, then the expression `foo++' has the value -four, but it changes the value of `foo' to five. In other words, the -operator returns the old value of the variable, but with the side -effect of incrementing it. - - The post-increment `foo++' is nearly the same as writing `(foo += 1) -- 1'. It is not perfectly equivalent because all numbers in `awk' are -floating-point--in floating-point, `foo + 1 - 1' does not necessarily -equal `foo'. But the difference is minute as long as you stick to +"pre-increment" a variable 'v', write '++v'. This adds one to the value +of 'v'--that new value is also the value of the expression. (The +assignment expression 'v += 1' is completely equivalent.) Writing the +'++' after the variable specifies "post-increment". This increments the +variable value just the same; the difference is that the value of the +increment expression itself is the variable's _old_ value. Thus, if +'foo' has the value four, then the expression 'foo++' has the value +four, but it changes the value of 'foo' to five. In other words, the +operator returns the old value of the variable, but with the side effect +of incrementing it. + + The post-increment 'foo++' is nearly the same as writing '(foo += 1) +- 1'. It is not perfectly equivalent because all numbers in 'awk' are +floating-point--in floating-point, 'foo + 1 - 1' does not necessarily +equal 'foo'. But the difference is minute as long as you stick to numbers that are fairly small (less than 10e12). Fields and array elements are incremented just like variables. (Use -`$(i++)' when you want to do a field reference and a variable increment +'$(i++)' when you want to do a field reference and a variable increment at the same time. The parentheses are necessary because of the -precedence of the field reference operator `$'.) +precedence of the field reference operator '$'.) - The decrement operator `--' works just like `++', except that it -subtracts one instead of adding it. As with `++', it can be used before -the lvalue to pre-decrement or after it to post-decrement. Following -is a summary of increment and decrement expressions: + The decrement operator '--' works just like '++', except that it +subtracts one instead of adding it. As with '++', it can be used before +the lvalue to pre-decrement or after it to post-decrement. Following is +a summary of increment and decrement expressions: -`++LVALUE' +'++LVALUE' Increment LVALUE, returning the new value as the value of the expression. -`LVALUE++' +'LVALUE++' Increment LVALUE, returning the _old_ value of LVALUE as the value of the expression. -`--LVALUE' +'--LVALUE' Decrement LVALUE, returning the new value as the value of the - expression. (This expression is like `++LVALUE', but instead of + expression. (This expression is like '++LVALUE', but instead of adding, it subtracts.) -`LVALUE--' +'LVALUE--' Decrement LVALUE, returning the _old_ value of LVALUE as the value - of the expression. (This expression is like `LVALUE++', but + of the expression. (This expression is like 'LVALUE++', but instead of adding, it subtracts.) Operator Evaluation Order Doctor, doctor! It hurts when I do this! - So don't do that! -- Groucho Marx + So don't do that! + -- _Groucho Marx_ What happens for something like the following? @@ -8044,10 +8007,10 @@ Or something even stranger? print b In other words, when do the various side effects prescribed by the -postfix operators (`b++') take effect? When side effects happen is +postfix operators ('b++') take effect? When side effects happen is "implementation defined". In other words, it is up to the particular -version of `awk'. The result for the first example may be 12 or 13, -and for the second, it may be 22 or 23. +version of 'awk'. The result for the first example may be 12 or 13, and +for the second, it may be 22 or 23. In short, doing things like this is not recommended and definitely not anything that you can rely upon for portability. You should avoid @@ -8060,19 +8023,19 @@ File: gawk.info, Node: Truth Values and Conditions, Next: Function Calls, Pre =============================== In certain contexts, expression values also serve as "truth values;" -i.e., they determine what should happen next as the program runs. This -minor node describes how `awk' defines "true" and "false" and how -values are compared. +i.e., they determine what should happen next as the program runs. This +minor node describes how 'awk' defines "true" and "false" and how values +are compared. * Menu: -* Truth Values:: What is ``true'' and what is ``false''. +* Truth Values:: What is "true" and what is "false". * Typing and Comparison:: How variables acquire types and how this affects comparison of numbers and strings with - `<', etc. + '<', etc. * Boolean Ops:: Combining comparison expressions using boolean - operators `||' (``or''), `&&' - (``and'') and `!' (``not''). + operators '||' ("or"), '&&' + ("and") and '!' ("not"). * Conditional Exp:: Conditional expressions select between two subexpressions under control of a third subexpression. @@ -8080,17 +8043,17 @@ values are compared.  File: gawk.info, Node: Truth Values, Next: Typing and Comparison, Up: Truth Values and Conditions -6.3.1 True and False in `awk' +6.3.1 True and False in 'awk' ----------------------------- Many programming languages have a special representation for the concepts of "true" and "false." Such languages usually use the special -constants `true' and `false', or perhaps their uppercase equivalents. -However, `awk' is different. It borrows a very simple concept of true -and false from C. In `awk', any nonzero numeric value _or_ any -nonempty string value is true. Any other value (zero or the null -string, `""') is false. The following program prints `A strange truth -value' three times: +constants 'true' and 'false', or perhaps their uppercase equivalents. +However, 'awk' is different. It borrows a very simple concept of true +and false from C. In 'awk', any nonzero numeric value _or_ any nonempty +string value is true. Any other value (zero or the null string, '""') +is false. The following program prints 'A strange truth value' three +times: BEGIN { if (3.1415927) @@ -8102,7 +8065,7 @@ value' three times: } There is a surprising consequence of the "nonzero or non-null" rule: -the string constant `"0"' is actually true, because it is non-null. +the string constant '"0"' is actually true, because it is non-null. (d.c.)  @@ -8111,13 +8074,13 @@ File: gawk.info, Node: Typing and Comparison, Next: Boolean Ops, Prev: Truth 6.3.2 Variable Typing and Comparison Expressions ------------------------------------------------ - The Guide is definitive. Reality is frequently inaccurate. -- The - Hitchhiker's Guide to the Galaxy + The Guide is definitive. Reality is frequently inaccurate. + -- _The Hitchhiker's Guide to the Galaxy_ - Unlike other programming languages, `awk' variables do not have a -fixed type. Instead, they can be either a number or a string, depending + Unlike other programming languages, 'awk' variables do not have a +fixed type. Instead, they can be either a number or a string, depending upon the value that is assigned to them. We look now at how variables -are typed, and how `awk' compares variables. +are typed, and how 'awk' compares variables. * Menu: @@ -8132,9 +8095,9 @@ File: gawk.info, Node: Variable Typing, Next: Comparison Operators, Up: Typin ....................................... The 1992 POSIX standard introduced the concept of a "numeric string", -which is simply a string that looks like a number--for example, -`" +2"'. This concept is used for determining the type of a variable. -The type of the variable is important because the types of two variables +which is simply a string that looks like a number--for example, '" +2"'. +This concept is used for determining the type of a variable. The type +of the variable is important because the types of two variables determine how they are compared. The various versions of the POSIX standard did not get the rules @@ -8148,17 +8111,17 @@ variable typing follows these rules:(1) * A string constant or the result of a string operation has the STRING attribute. - * Fields, `getline' input, `FILENAME', `ARGV' elements, `ENVIRON' - elements, and the elements of an array created by `patsplit()', - `split()' and `match()' that are numeric strings have the STRNUM + * Fields, 'getline' input, 'FILENAME', 'ARGV' elements, 'ENVIRON' + elements, and the elements of an array created by 'patsplit()', + 'split()' and 'match()' that are numeric strings have the STRNUM attribute. Otherwise, they have the STRING attribute. Uninitialized variables also have the STRNUM attribute. * Attributes propagate across assignments but are not changed by any use. - The last rule is particularly important. In the following program, -`a' has numeric type, even though it is later used in a string + The last rule is particularly important. In the following program, +'a' has numeric type, even though it is later used in a string operation: BEGIN { @@ -8168,26 +8131,26 @@ operation: } When two operands are compared, either string comparison or numeric -comparison may be used. This depends upon the attributes of the +comparison may be used. This depends upon the attributes of the operands, according to the following symmetric matrix: - +--------------------------------------------- + +------------------------------- | STRING NUMERIC STRNUM - -------+--------------------------------------------- + -----+------------------------------- | STRING | string string string | NUMERIC | string numeric numeric | STRNUM | string numeric numeric - -------+--------------------------------------------- + -----+------------------------------- - The basic idea is that user input that looks numeric--and _only_ -user input--should be treated as numeric, even though it is actually -made of characters and is therefore also a string. Thus, for example, -the string constant `" +3.14"', when it appears in program source code, -is a string--even though it looks numeric--and is _never_ treated as -number for comparison purposes. + The basic idea is that user input that looks numeric--and _only_ user +input--should be treated as numeric, even though it is actually made of +characters and is therefore also a string. Thus, for example, the +string constant '" +3.14"', when it appears in program source code, is a +string--even though it looks numeric--and is _never_ treated as number +for comparison purposes. In short, when one operand is a "pure" string, such as a string constant, then a string comparison is performed. Otherwise, a numeric @@ -8196,10 +8159,10 @@ comparison is performed. This point bears additional emphasis: All user input is made of characters, and so is first and foremost of STRING type; input strings that look numeric are additionally given the STRNUM attribute. Thus, -the six-character input string ` +3.14' receives the STRNUM attribute. -In contrast, the eight characters `" +3.14"' appearing in program text -comprise a string constant. The following examples print `1' when the -comparison between the two different constants is true, `0' otherwise: +the six-character input string ' +3.14' receives the STRNUM attribute. +In contrast, the eight characters '" +3.14"' appearing in program text +comprise a string constant. The following examples print '1' when the +comparison between the two different constants is true, '0' otherwise: $ echo ' +3.14' | gawk '{ print $0 == " +3.14" }' True -| 1 @@ -8220,7 +8183,7 @@ comparison between the two different constants is true, `0' otherwise: ---------- Footnotes ---------- - (1) `gawk' has followed these rules for many years, and it is + (1) 'gawk' has followed these rules for many years, and it is gratifying that the POSIX standard is also now correct.  @@ -8231,37 +8194,38 @@ File: gawk.info, Node: Comparison Operators, Next: POSIX String Comparison, P "Comparison expressions" compare strings or numbers for relationships such as equality. They are written using "relational operators", which -are a superset of those in C. *note table-relational-ops:: describes -them. +are a superset of those in C. *note Table 6.3: table-relational-ops. +describes them. Expression Result --------------------------------------------------------------------------- -X `<' Y True if X is less than Y. -X `<=' Y True if X is less than or equal to Y. -X `>' Y True if X is greater than Y. -X `>=' Y True if X is greater than or equal to Y. -X `==' Y True if X is equal to Y. -X `!=' Y True if X is not equal to Y. -X `~' Y True if the string X matches the regexp denoted by Y. -X `!~' Y True if the string X does not match the regexp +-------------------------------------------------------------------------- +X '<' Y True if X is less than Y. +X '<=' Y True if X is less than or equal to Y. +X '>' Y True if X is greater than Y. +X '>=' Y True if X is greater than or equal to Y. +X '==' Y True if X is equal to Y. +X '!=' Y True if X is not equal to Y. +X '~' Y True if the string X matches the regexp denoted by + Y. +X '!~' Y True if the string X does not match the regexp denoted by Y. -SUBSCRIPT `in' True if the array ARRAY has an element with the +SUBSCRIPT 'in' True if the array ARRAY has an element with the ARRAY subscript SUBSCRIPT. Table 6.3: Relational Operators Comparison expressions have the value one if true and zero if false. When comparing operands of mixed types, numeric operands are converted -to strings using the value of `CONVFMT' (*note Conversion::). +to strings using the value of 'CONVFMT' (*note Conversion::). Strings are compared by comparing the first character of each, then -the second character of each, and so on. Thus, `"10"' is less than -`"9"'. If there are two strings where one is a prefix of the other, -the shorter string is less than the longer one. Thus, `"abc"' is less -than `"abcd"'. +the second character of each, and so on. Thus, '"10"' is less than +'"9"'. If there are two strings where one is a prefix of the other, the +shorter string is less than the longer one. Thus, '"abc"' is less than +'"abcd"'. - It is very easy to accidentally mistype the `==' operator and leave -off one of the `=' characters. The result is still valid `awk' code, + It is very easy to accidentally mistype the '==' operator and leave +off one of the '=' characters. The result is still valid 'awk' code, but the program does not do what is intended: if (a = b) # oops! should be a == b @@ -8269,31 +8233,31 @@ but the program does not do what is intended: else ... -Unless `b' happens to be zero or the null string, the `if' part of the +Unless 'b' happens to be zero or the null string, the 'if' part of the test always succeeds. Because the operators are so similar, this kind of error is very difficult to spot when scanning the source code. The following table of expressions illustrates the kind of comparison -`gawk' performs, as well as what the result of the comparison is: +'gawk' performs, as well as what the result of the comparison is: -`1.5 <= 2.0' +'1.5 <= 2.0' numeric comparison (true) -`"abc" >= "xyz"' +'"abc" >= "xyz"' string comparison (false) -`1.5 != " +2"' +'1.5 != " +2"' string comparison (true) -`"1e2" < "3"' +'"1e2" < "3"' string comparison (true) -`a = 2; b = "2"' -`a == b' +'a = 2; b = "2"' +'a == b' string comparison (true) -`a = 2; b = " +2"' -`a == b' +'a = 2; b = " +2"' +'a == b' string comparison (false) In this example: @@ -8301,38 +8265,38 @@ of error is very difficult to spot when scanning the source code. $ echo 1e2 3 | awk '{ print ($1 < $2) ? "true" : "false" }' -| false -the result is `false' because both `$1' and `$2' are user input. They -are numeric strings--therefore both have the STRNUM attribute, -dictating a numeric comparison. The purpose of the comparison rules -and the use of numeric strings is to attempt to produce the behavior -that is "least surprising," while still "doing the right thing." +the result is 'false' because both '$1' and '$2' are user input. They +are numeric strings--therefore both have the STRNUM attribute, dictating +a numeric comparison. The purpose of the comparison rules and the use +of numeric strings is to attempt to produce the behavior that is "least +surprising," while still "doing the right thing." String comparisons and regular expression comparisons are very different. For example: x == "foo" -has the value one, or is true if the variable `x' is precisely `foo'. +has the value one, or is true if the variable 'x' is precisely 'foo'. By contrast: x ~ /foo/ -has the value one if `x' contains `foo', such as `"Oh, what a fool am +has the value one if 'x' contains 'foo', such as '"Oh, what a fool am I!"'. - The righthand operand of the `~' and `!~' operators may be either a -regexp constant (`/'...`/') or an ordinary expression. In the latter + The righthand operand of the '~' and '!~' operators may be either a +regexp constant ('/'...'/') or an ordinary expression. In the latter case, the value of the expression as a string is used as a dynamic regexp (*note Regexp Usage::; also *note Computed Regexps::). - In modern implementations of `awk', a constant regular expression in -slashes by itself is also an expression. The regexp `/REGEXP/' is an + In modern implementations of 'awk', a constant regular expression in +slashes by itself is also an expression. The regexp '/REGEXP/' is an abbreviation for the following comparison expression: $0 ~ /REGEXP/ - One special place where `/foo/' is _not_ an abbreviation for `$0 ~ -/foo/' is when it is the righthand operand of `~' or `!~'. *Note Using + One special place where '/foo/' is _not_ an abbreviation for '$0 ~ +/foo/' is when it is the righthand operand of '~' or '!~'. *Note Using Constant Regexps::, where this is discussed in more detail.  @@ -8341,15 +8305,15 @@ File: gawk.info, Node: POSIX String Comparison, Prev: Comparison Operators, U 6.3.2.3 String Comparison With POSIX Rules .......................................... -The POSIX standard says that string comparison is performed based on -the locale's "collating order". This is the order in which characters -sort, as defined by the locale (for more discussion, *note Ranges and +The POSIX standard says that string comparison is performed based on the +locale's "collating order". This is the order in which characters sort, +as defined by the locale (for more discussion, *note Ranges and Locales::). This order is usually very different from the results obtained when doing straight character-by-character comparison.(1) Because this behavior differs considerably from existing practice, -`gawk' only implements it when in POSIX mode (*note Options::). Here -is an example to illustrate the difference, in an `en_US.UTF-8' locale: +'gawk' only implements it when in POSIX mode (*note Options::). Here is +an example to illustrate the difference, in an 'en_US.UTF-8' locale: $ gawk 'BEGIN { printf("ABC < abc = %s\n", > ("ABC" < "abc" ? "TRUE" : "FALSE")) }' @@ -8360,8 +8324,8 @@ is an example to illustrate the difference, in an `en_US.UTF-8' locale: ---------- Footnotes ---------- - (1) Technically, string comparison is supposed to behave the same -way as if the strings are compared with the C `strcoll()' function. + (1) Technically, string comparison is supposed to behave the same way +as if the strings are compared with the C 'strcoll()' function.  File: gawk.info, Node: Boolean Ops, Next: Conditional Exp, Prev: Typing and Comparison, Up: Truth Values and Conditions @@ -8370,39 +8334,39 @@ File: gawk.info, Node: Boolean Ops, Next: Conditional Exp, Prev: Typing and C ------------------------- A "Boolean expression" is a combination of comparison expressions or -matching expressions, using the Boolean operators "or" (`||'), "and" -(`&&'), and "not" (`!'), along with parentheses to control nesting. -The truth value of the Boolean expression is computed by combining the -truth values of the component expressions. Boolean expressions are -also referred to as "logical expressions". The terms are equivalent. +matching expressions, using the Boolean operators "or" ('||'), "and" +('&&'), and "not" ('!'), along with parentheses to control nesting. The +truth value of the Boolean expression is computed by combining the truth +values of the component expressions. Boolean expressions are also +referred to as "logical expressions". The terms are equivalent. Boolean expressions can be used wherever comparison and matching -expressions can be used. They can be used in `if', `while', `do', and -`for' statements (*note Statements::). They have numeric values (one -if true, zero if false) that come into play if the result of the -Boolean expression is stored in a variable or used in arithmetic. +expressions can be used. They can be used in 'if', 'while', 'do', and +'for' statements (*note Statements::). They have numeric values (one if +true, zero if false) that come into play if the result of the Boolean +expression is stored in a variable or used in arithmetic. - In addition, every Boolean expression is also a valid pattern, so -you can use one as a pattern to control the execution of rules. The -Boolean operators are: + In addition, every Boolean expression is also a valid pattern, so you +can use one as a pattern to control the execution of rules. The Boolean +operators are: -`BOOLEAN1 && BOOLEAN2' +'BOOLEAN1 && BOOLEAN2' True if both BOOLEAN1 and BOOLEAN2 are true. For example, the following statement prints the current input record if it contains - both `edu' and `li': + both 'edu' and 'li': if ($0 ~ /edu/ && $0 ~ /li/) print The subexpression BOOLEAN2 is evaluated only if BOOLEAN1 is true. This can make a difference when BOOLEAN2 contains expressions that - have side effects. In the case of `$0 ~ /foo/ && ($2 == bar++)', - the variable `bar' is not incremented if there is no substring - `foo' in the record. + have side effects. In the case of '$0 ~ /foo/ && ($2 == bar++)', + the variable 'bar' is not incremented if there is no substring + 'foo' in the record. -`BOOLEAN1 || BOOLEAN2' - True if at least one of BOOLEAN1 or BOOLEAN2 is true. For - example, the following statement prints all records in the input - that contain _either_ `edu' or `li' or both: +'BOOLEAN1 || BOOLEAN2' + True if at least one of BOOLEAN1 or BOOLEAN2 is true. For example, + the following statement prints all records in the input that + contain _either_ 'edu' or 'li' or both: if ($0 ~ /edu/ || $0 ~ /li/) print @@ -8410,30 +8374,30 @@ Boolean operators are: This can make a difference when BOOLEAN2 contains expressions that have side effects. -`! BOOLEAN' +'! BOOLEAN' True if BOOLEAN is false. For example, the following program - prints `no home!' in the unusual event that the `HOME' environment + prints 'no home!' in the unusual event that the 'HOME' environment variable is not defined: BEGIN { if (! ("HOME" in ENVIRON)) print "no home!" } - (The `in' operator is described in *note Reference to Elements::.) + (The 'in' operator is described in *note Reference to Elements::.) - The `&&' and `||' operators are called "short-circuit" operators + The '&&' and '||' operators are called "short-circuit" operators because of the way they work. Evaluation of the full expression is "short-circuited" if the result can be determined part way through its evaluation. - Statements that use `&&' or `||' can be continued simply by putting -a newline after them. But you cannot put a newline in front of either -of these operators without using backslash continuation (*note + Statements that use '&&' or '||' can be continued simply by putting a +newline after them. But you cannot put a newline in front of either of +these operators without using backslash continuation (*note Statements/Lines::). - The actual value of an expression using the `!' operator is either + The actual value of an expression using the '!' operator is either one or zero, depending upon the truth value of the expression it is -applied to. The `!' operator is often useful for changing the sense of -a flag variable from false to true and back again. For example, the +applied to. The '!' operator is often useful for changing the sense of +a flag variable from false to true and back again. For example, the following program is one way to print lines in between special bracketing lines: @@ -8441,22 +8405,22 @@ bracketing lines: interested == 1 { print } $1 == "END" { interested = ! interested; next } -The variable `interested', as with all `awk' variables, starts out +The variable 'interested', as with all 'awk' variables, starts out initialized to zero, which is also false. When a line is seen whose -first field is `START', the value of `interested' is toggled to true, -using `!'. The next rule prints lines as long as `interested' is true. -When a line is seen whose first field is `END', `interested' is toggled +first field is 'START', the value of 'interested' is toggled to true, +using '!'. The next rule prints lines as long as 'interested' is true. +When a line is seen whose first field is 'END', 'interested' is toggled back to false.(1) - NOTE: The `next' statement is discussed in *note Next Statement::. - `next' tells `awk' to skip the rest of the rules, get the next + NOTE: The 'next' statement is discussed in *note Next Statement::. + 'next' tells 'awk' to skip the rest of the rules, get the next record, and start processing the rules over again at the top. The - reason it's there is to avoid printing the bracketing `START' and - `END' lines. + reason it's there is to avoid printing the bracketing 'START' and + 'END' lines. ---------- Footnotes ---------- - (1) This program has a bug; it prints lines starting with `END'. How + (1) This program has a bug; it prints lines starting with 'END'. How would you fix it?  @@ -8467,36 +8431,36 @@ File: gawk.info, Node: Conditional Exp, Prev: Boolean Ops, Up: Truth Values a A "conditional expression" is a special kind of expression that has three operands. It allows you to use one expression's value to select -one of two other expressions. The conditional expression is the same -as in the C language, as shown here: +one of two other expressions. The conditional expression is the same as +in the C language, as shown here: SELECTOR ? IF-TRUE-EXP : IF-FALSE-EXP -There are three subexpressions. The first, SELECTOR, is always -computed first. If it is "true" (not zero or not null), then -IF-TRUE-EXP is computed next and its value becomes the value of the -whole expression. Otherwise, IF-FALSE-EXP is computed next and its -value becomes the value of the whole expression. For example, the -following expression produces the absolute value of `x': +There are three subexpressions. The first, SELECTOR, is always computed +first. If it is "true" (not zero or not null), then IF-TRUE-EXP is +computed next and its value becomes the value of the whole expression. +Otherwise, IF-FALSE-EXP is computed next and its value becomes the value +of the whole expression. For example, the following expression produces +the absolute value of 'x': x >= 0 ? x : -x Each time the conditional expression is computed, only one of IF-TRUE-EXP and IF-FALSE-EXP is used; the other is ignored. This is important when the expressions have side effects. For example, this -conditional expression examines element `i' of either array `a' or -array `b', and increments `i': +conditional expression examines element 'i' of either array 'a' or array +'b', and increments 'i': x == y ? a[i++] : b[i++] -This is guaranteed to increment `i' exactly once, because each time -only one of the two increment expressions is executed and the other is -not. *Note Arrays::, for more information about arrays. +This is guaranteed to increment 'i' exactly once, because each time only +one of the two increment expressions is executed and the other is not. +*Note Arrays::, for more information about arrays. - As a minor `gawk' extension, a statement that uses `?:' can be + As a minor 'gawk' extension, a statement that uses '?:' can be continued simply by putting a newline after either character. However, putting a newline in front of either character does not work without -using backslash continuation (*note Statements/Lines::). If `--posix' +using backslash continuation (*note Statements/Lines::). If '--posix' is specified (*note Options::), this extension is disabled.  @@ -8507,22 +8471,22 @@ File: gawk.info, Node: Function Calls, Next: Precedence, Prev: Truth Values a A "function" is a name for a particular calculation. This enables you to ask for it by name at any point in the program. For example, the -function `sqrt()' computes the square root of a number. +function 'sqrt()' computes the square root of a number. A fixed set of functions are "built-in", which means they are -available in every `awk' program. The `sqrt()' function is one of +available in every 'awk' program. The 'sqrt()' function is one of these. *Note Built-in::, for a list of built-in functions and their descriptions. In addition, you can define functions for use in your program. *Note User-defined::, for instructions on how to do this. -Finally, `gawk' lets you write functions in C or C++ that may be called +Finally, 'gawk' lets you write functions in C or C++ that may be called from your program: see *note Dynamic Extensions::. - The way to use a function is with a "function call" expression, -which consists of the function name followed immediately by a list of + The way to use a function is with a "function call" expression, which +consists of the function name followed immediately by a list of "arguments" in parentheses. The arguments are expressions that provide the raw materials for the function's calculations. When there is more than one argument, they are separated by commas. If there are no -arguments, just write `()' after the function name. The following +arguments, just write '()' after the function name. The following examples show function calls with and without arguments: sqrt(x^2 + y^2) one argument @@ -8530,16 +8494,16 @@ examples show function calls with and without arguments: rand() no arguments CAUTION: Do not put any space between the function name and the - open-parenthesis! A user-defined function name looks just like - the name of a variable--a space would make the expression look - like concatenation of a variable with an expression inside - parentheses. With built-in functions, space before the - parenthesis is harmless, but it is best not to get into the habit - of using space to avoid mistakes with user-defined functions. + open-parenthesis! A user-defined function name looks just like the + name of a variable--a space would make the expression look like + concatenation of a variable with an expression inside parentheses. + With built-in functions, space before the parenthesis is harmless, + but it is best not to get into the habit of using space to avoid + mistakes with user-defined functions. - Each function expects a particular number of arguments. For -example, the `sqrt()' function must be called with a single argument, -the number of which to take the square root: + Each function expects a particular number of arguments. For example, +the 'sqrt()' function must be called with a single argument, the number +of which to take the square root: sqrt(ARGUMENT) @@ -8547,19 +8511,19 @@ the number of which to take the square root: If those arguments are not supplied, the functions use a reasonable default value. *Note Built-in::, for full details. If arguments are omitted in calls to user-defined functions, then those arguments are -treated as local variables. Such local variables act like the empty +treated as local variables. Such local variables act like the empty string if referenced where a string value is required, and like zero if referenced where a numeric value is required (*note User-defined::). - As an advanced feature, `gawk' provides indirect function calls, + As an advanced feature, 'gawk' provides indirect function calls, which is a way to choose the function to call at runtime, instead of -when you write the source code to your program. We defer discussion of +when you write the source code to your program. We defer discussion of this feature until later; see *note Indirect Calls::. Like every other expression, the function call has a value, often called the "return value", which is computed by the function based on the arguments you give it. In this example, the return value of -`sqrt(ARGUMENT)' is the square root of ARGUMENT. The following program +'sqrt(ARGUMENT)' is the square root of ARGUMENT. The following program reads numbers, one number per line, and prints the square root of each one: @@ -8573,9 +8537,9 @@ one: Ctrl-d A function can also have side effects, such as assigning values to -certain variables or doing I/O. This program shows how the `match()' -function (*note String Functions::) changes the variables `RSTART' and -`RLENGTH': +certain variables or doing I/O. This program shows how the 'match()' +function (*note String Functions::) changes the variables 'RSTART' and +'RLENGTH': { if (match($1, $2)) @@ -8601,9 +8565,9 @@ File: gawk.info, Node: Precedence, Next: Locales, Prev: Function Calls, Up: ============================================ "Operator precedence" determines how operators are grouped when -different operators appear close by in one expression. For example, -`*' has higher precedence than `+'; thus, `a + b * c' means to multiply -`b' and `c', and then add `a' to the product (i.e., `a + (b * c)'). +different operators appear close by in one expression. For example, '*' +has higher precedence than '+'; thus, 'a + b * c' means to multiply 'b' +and 'c', and then add 'a' to the product (i.e., 'a + (b * c)'). The normal precedence of the operators can be overruled by using parentheses. Think of the precedence rules as saying where the @@ -8616,84 +8580,83 @@ help prevent any such mistakes. When operators of equal precedence are used together, the leftmost operator groups first, except for the assignment, conditional, and -exponentiation operators, which group in the opposite order. Thus, `a -- b + c' groups as `(a - b) + c' and `a = b = c' groups as `a = (b = -c)'. +exponentiation operators, which group in the opposite order. Thus, 'a - +b + c' groups as '(a - b) + c' and 'a = b = c' groups as 'a = (b = c)'. Normally the precedence of prefix unary operators does not matter, -because there is only one way to interpret them: innermost first. -Thus, `$++i' means `$(++i)' and `++$x' means `++($x)'. However, when -another operator follows the operand, then the precedence of the unary -operators can matter. `$x^2' means `($x)^2', but `-x^2' means -`-(x^2)', because `-' has lower precedence than `^', whereas `$' has -higher precedence. Also, operators cannot be combined in a way that -violates the precedence rules; for example, `$$0++--' is not a valid -expression because the first `$' has higher precedence than the `++'; -to avoid the problem the expression can be rewritten as `$($0++)--'. - - This table presents `awk''s operators, in order of highest to lowest +because there is only one way to interpret them: innermost first. Thus, +'$++i' means '$(++i)' and '++$x' means '++($x)'. However, when another +operator follows the operand, then the precedence of the unary operators +can matter. '$x^2' means '($x)^2', but '-x^2' means '-(x^2)', because +'-' has lower precedence than '^', whereas '$' has higher precedence. +Also, operators cannot be combined in a way that violates the precedence +rules; for example, '$$0++--' is not a valid expression because the +first '$' has higher precedence than the '++'; to avoid the problem the +expression can be rewritten as '$($0++)--'. + + This table presents 'awk''s operators, in order of highest to lowest precedence: -`('...`)' +'('...')' Grouping. -`$' +'$' Field reference. -`++ --' +'++ --' Increment, decrement. -`^ **' +'^ **' Exponentiation. These operators group right-to-left. -`+ - !' +'+ - !' Unary plus, minus, logical "not." -`* / %' +'* / %' Multiplication, division, remainder. -`+ -' +'+ -' Addition, subtraction. String Concatenation There is no special symbol for concatenation. The operands are simply written side by side (*note Concatenation::). -`< <= == != > >= >> | |&' +'< <= == != > >= >> | |&' Relational and redirection. The relational operators and the redirections have the same precedence level. Characters such as - `>' serve both as relationals and as redirections; the context + '>' serve both as relationals and as redirections; the context distinguishes between the two meanings. - Note that the I/O redirection operators in `print' and `printf' + Note that the I/O redirection operators in 'print' and 'printf' statements belong to the statement level, not to expressions. The redirection does not produce an expression that could be the operand of another operator. As a result, it does not make sense to use a redirection operator near another operator of lower precedence without parentheses. Such combinations (for example, - `print foo > a ? b : c'), result in syntax errors. The correct - way to write this statement is `print foo > (a ? b : c)'. + 'print foo > a ? b : c'), result in syntax errors. The correct way + to write this statement is 'print foo > (a ? b : c)'. -`~ !~' +'~ !~' Matching, nonmatching. -`in' +'in' Array membership. -`&&' +'&&' Logical "and". -`||' +'||' Logical "or". -`?:' +'?:' Conditional. This operator groups right-to-left. -`= += -= *= /= %= ^= **=' +'= += -= *= /= %= ^= **=' Assignment. These operators group right-to-left. - NOTE: The `|&', `**', and `**=' operators are not specified by - POSIX. For maximum portability, do not use them. + NOTE: The '|&', '**', and '**=' operators are not specified by + POSIX. For maximum portability, do not use them.  File: gawk.info, Node: Locales, Next: Expressions Summary, Prev: Precedence, Up: Expressions @@ -8701,34 +8664,34 @@ File: gawk.info, Node: Locales, Next: Expressions Summary, Prev: Precedence, 6.6 Where You Are Makes A Difference ==================================== -Modern systems support the notion of "locales": a way to tell the -system about the local character set and language. The ISO C standard -defines a default `"C"' locale, which is an environment that is typical -of what many C programmers are used to. +Modern systems support the notion of "locales": a way to tell the system +about the local character set and language. The ISO C standard defines +a default '"C"' locale, which is an environment that is typical of what +many C programmers are used to. Once upon a time, the locale setting used to affect regexp matching (*note Ranges and Locales::), but this is no longer true. - Locales can affect record splitting. For the normal case of `RS = + Locales can affect record splitting. For the normal case of 'RS = "\n"', the locale is largely irrelevant. For other single-character -record separators, setting `LC_ALL=C' in the environment will give you -much better performance when reading records. Otherwise, `gawk' has to +record separators, setting 'LC_ALL=C' in the environment will give you +much better performance when reading records. Otherwise, 'gawk' has to make several function calls, _per input character_, to find the record terminator. Locales can affect how dates and times are formatted (*note Time Functions::). For example, a common way to abbreviate the date September 4, 2015 in the United States is "9/4/15." In many countries -in Europe, however, it is abbreviated "4.9.15." Thus, the `%x' -specification in a `"US"' locale might produce `9/4/15', while in a -`"EUROPE"' locale, it might produce `4.9.15'. +in Europe, however, it is abbreviated "4.9.15." Thus, the '%x' +specification in a '"US"' locale might produce '9/4/15', while in a +'"EUROPE"' locale, it might produce '4.9.15'. According to POSIX, string comparison is also affected by locales (similar to regular expressions). The details are presented in *note POSIX String Comparison::. Finally, the locale affects the value of the decimal point character -used when `gawk' parses input data. This is discussed in detail in +used when 'gawk' parses input data. This is discussed in detail in *note Conversion::.  @@ -8741,34 +8704,34 @@ File: gawk.info, Node: Expressions Summary, Prev: Locales, Up: Expressions They are built from constants, variables, function calls and combinations of the various kinds of values with operators. - * `awk' supplies three kinds of constants: numeric, string, and - regexp. `gawk' lets you specify numeric constants in octal and + * 'awk' supplies three kinds of constants: numeric, string, and + regexp. 'gawk' lets you specify numeric constants in octal and hexadecimal (bases 8 and 16) in addition to decimal (base 10). In - certain contexts, a standalone regexp constant such as `/foo/' has - the same meaning as `$0 ~ /foo/'. + certain contexts, a standalone regexp constant such as '/foo/' has + the same meaning as '$0 ~ /foo/'. - * Variables hold values between uses in computations. A number of - built-in variables provide information to your `awk' program, and - a number of others let you control how `awk' behaves. + * Variables hold values between uses in computations. A number of + built-in variables provide information to your 'awk' program, and a + number of others let you control how 'awk' behaves. * Numbers are automatically converted to strings, and strings to - numbers, as needed by `awk'. Numeric values are converted as if - they were formatted with `sprintf()' using the format in `CONVFMT'. + numbers, as needed by 'awk'. Numeric values are converted as if + they were formatted with 'sprintf()' using the format in 'CONVFMT'. Locales can influence the conversions. - * `awk' provides the usual arithmetic operators (addition, - subtraction, multiplication, division, modulus), and unary plus - and minus. It also provides comparison operators, boolean - operators, and regexp matching operators. String concatenation is + * 'awk' provides the usual arithmetic operators (addition, + subtraction, multiplication, division, modulus), and unary plus and + minus. It also provides comparison operators, boolean operators, + and regexp matching operators. String concatenation is accomplished by placing two expressions next to each other; there - is no explicit operator. The three-operand `?:' operator provides + is no explicit operator. The three-operand '?:' operator provides an "if-else" test within expressions. * Assignment operators provide convenient shorthands for common arithmetic operations. - * In `awk', a value is considered to be true if it is non-zero _or_ - non-null. Otherwise, the value is false. + * In 'awk', a value is considered to be true if it is non-zero _or_ + non-null. Otherwise, the value is false. * A value's type is set upon each assignment and may change over its lifetime. The type determines how it behaves in comparisons @@ -8776,38 +8739,37 @@ File: gawk.info, Node: Expressions Summary, Prev: Locales, Up: Expressions * Function calls return a value which may be used as part of a larger expression. Expressions used to pass parameter values are fully - evaluated before the function is called. `awk' provides built-in - and user-defined functions; this is described later on in this - Info file. + evaluated before the function is called. 'awk' provides built-in + and user-defined functions; this is described later on in this Info + file. * Operator precedence specifies the order in which operations are - performed, unless explicitly overridden by parentheses. `awk''s + performed, unless explicitly overridden by parentheses. 'awk''s operator precedence is compatible with that of C. - * Locales can affect the format of data as output by an `awk' + * Locales can affect the format of data as output by an 'awk' program, and occasionally the format for data read as input. -  File: gawk.info, Node: Patterns and Actions, Next: Arrays, Prev: Expressions, Up: Top 7 Patterns, Actions, and Variables ********************************** -As you have already seen, each `awk' statement consists of a pattern +As you have already seen, each 'awk' statement consists of a pattern with an associated action. This major node describes how you build patterns and actions, what kinds of things you can do within actions, -and `awk''s built-in variables. +and 'awk''s built-in variables. The pattern-action rules and the statements available for use within -actions form the core of `awk' programming. In a sense, everything +actions form the core of 'awk' programming. In a sense, everything covered up to here has been the foundation that programs are built on top of. Now it's time to start building something useful. * Menu: * Pattern Overview:: What goes into a pattern. -* Using Shell Variables:: How to use shell variables with `awk'. +* Using Shell Variables:: How to use shell variables with 'awk'. * Action Overview:: What goes into an action. * Statements:: Describes the various control statements in detail. @@ -8829,34 +8791,34 @@ File: gawk.info, Node: Pattern Overview, Next: Using Shell Variables, Up: Pat * BEGINFILE/ENDFILE:: Two special patterns for advanced control. * Empty:: The empty pattern, which matches every record. - Patterns in `awk' control the execution of rules--a rule is executed +Patterns in 'awk' control the execution of rules--a rule is executed when its pattern matches the current input record. The following is a -summary of the types of `awk' patterns: +summary of the types of 'awk' patterns: -`/REGULAR EXPRESSION/' - A regular expression. It matches when the text of the input record +'/REGULAR EXPRESSION/' + A regular expression. It matches when the text of the input record fits the regular expression. (*Note Regexp::.) -`EXPRESSION' +'EXPRESSION' A single expression. It matches when its value is nonzero (if a number) or non-null (if a string). (*Note Expression Patterns::.) -`BEGPAT, ENDPAT' +'BEGPAT, ENDPAT' A pair of patterns separated by a comma, specifying a range of records. The range includes both the initial record that matches BEGPAT and the final record that matches ENDPAT. (*Note Ranges::.) -`BEGIN' -`END' +'BEGIN' +'END' Special patterns for you to supply startup or cleanup actions for - your `awk' program. (*Note BEGIN/END::.) + your 'awk' program. (*Note BEGIN/END::.) -`BEGINFILE' -`ENDFILE' +'BEGINFILE' +'ENDFILE' Special patterns for you to supply startup or cleanup actions to be done on a per-file basis. (*Note BEGINFILE/ENDFILE::.) -`EMPTY' +'EMPTY' The empty pattern matches every input record. (*Note Empty::.)  @@ -8867,7 +8829,7 @@ File: gawk.info, Node: Regexp Patterns, Next: Expression Patterns, Up: Patter Regular expressions are one of the first kinds of patterns presented in this book. This kind of pattern is simply a regexp constant in the -pattern part of a rule. Its meaning is `$0 ~ /PATTERN/'. The pattern +pattern part of a rule. Its meaning is '$0 ~ /PATTERN/'. The pattern matches when the input record matches the regexp. For example: /foo|bar|baz/ { buzzwords++ } @@ -8879,49 +8841,49 @@ File: gawk.info, Node: Expression Patterns, Next: Ranges, Prev: Regexp Patter 7.1.2 Expressions as Patterns ----------------------------- -Any `awk' expression is valid as an `awk' pattern. The pattern matches +Any 'awk' expression is valid as an 'awk' pattern. The pattern matches if the expression's value is nonzero (if a number) or non-null (if a string). The expression is reevaluated each time the rule is tested -against a new input record. If the expression uses fields such as -`$1', the value depends directly on the new input record's text; -otherwise, it depends on only what has happened so far in the execution -of the `awk' program. +against a new input record. If the expression uses fields such as '$1', +the value depends directly on the new input record's text; otherwise, it +depends on only what has happened so far in the execution of the 'awk' +program. Comparison expressions, using the comparison operators described in *note Typing and Comparison::, are a very common kind of pattern. Regexp matching and nonmatching are also very common expressions. The -left operand of the `~' and `!~' operators is a string. The right +left operand of the '~' and '!~' operators is a string. The right operand is either a constant regular expression enclosed in slashes -(`/REGEXP/'), or any expression whose string value is used as a dynamic +('/REGEXP/'), or any expression whose string value is used as a dynamic regular expression (*note Computed Regexps::). The following example prints the second field of each input record whose first field is -precisely `li': +precisely 'li': $ awk '$1 == "li" { print $2 }' mail-list (There is no output, because there is no person with the exact name -`li'.) Contrast this with the following regular expression match, which -accepts any record with a first field that contains `li': +'li'.) Contrast this with the following regular expression match, which +accepts any record with a first field that contains 'li': $ awk '$1 ~ /foo/ { print $2 }' mail-list -| 555-5553 -| 555-6699 A regexp constant as a pattern is also a special case of an -expression pattern. The expression `/li/' has the value one if `li' -appears in the current input record. Thus, as a pattern, `/li/' matches -any record containing `li'. +expression pattern. The expression '/li/' has the value one if 'li' +appears in the current input record. Thus, as a pattern, '/li/' matches +any record containing 'li'. Boolean expressions are also commonly used as patterns. Whether the pattern matches an input record depends on whether its subexpressions match. For example, the following command prints all the records in -`mail-list' that contain both `edu' and `li': +'mail-list' that contain both 'edu' and 'li': $ awk '/edu/ && /li/' mail-list -| Samuel 555-3430 samuel.lanceolis@shu.edu A - The following command prints all records in `mail-list' that contain -_either_ `edu' or `li' (or both, of course): + The following command prints all records in 'mail-list' that contain +_either_ 'edu' or 'li' (or both, of course): $ awk '/edu/ || /li/' mail-list -| Amelia 555-5553 amelia.zodiacusque@gmail.com F @@ -8931,8 +8893,8 @@ _either_ `edu' or `li' (or both, of course): -| Samuel 555-3430 samuel.lanceolis@shu.edu A -| Jean-Paul 555-2127 jeanpaul.campanorum@nyu.edu R - The following command prints all records in `mail-list' that do -_not_ contain the string `li': + The following command prints all records in 'mail-list' that do _not_ +contain the string 'li': $ awk '! /li/' mail-list -| Anthony 555-3412 anthony.asserturo@hotmail.com A @@ -8943,12 +8905,12 @@ _not_ contain the string `li': -| Martin 555-6480 martin.codicibus@hotmail.com A -| Jean-Paul 555-2127 jeanpaul.campanorum@nyu.edu R - The subexpressions of a Boolean operator in a pattern can be -constant regular expressions, comparisons, or any other `awk' -expressions. Range patterns are not expressions, so they cannot appear -inside Boolean patterns. Likewise, the special patterns `BEGIN', `END', -`BEGINFILE' and `ENDFILE', which never match any input record, are not -expressions and cannot appear inside Boolean patterns. + The subexpressions of a Boolean operator in a pattern can be constant +regular expressions, comparisons, or any other 'awk' expressions. Range +patterns are not expressions, so they cannot appear inside Boolean +patterns. Likewise, the special patterns 'BEGIN', 'END', 'BEGINFILE' +and 'ENDFILE', which never match any input record, are not expressions +and cannot appear inside Boolean patterns. The precedence of the different operators which can appear in patterns is described in *note Precedence::. @@ -8960,80 +8922,78 @@ File: gawk.info, Node: Ranges, Next: BEGIN/END, Prev: Expression Patterns, U -------------------------------------------- A "range pattern" is made of two patterns separated by a comma, in the -form `BEGPAT, ENDPAT'. It is used to match ranges of consecutive input +form 'BEGPAT, ENDPAT'. It is used to match ranges of consecutive input records. The first pattern, BEGPAT, controls where the range begins, while ENDPAT controls where the pattern ends. For example, the following: awk '$1 == "on", $1 == "off"' myfile -prints every record in `myfile' between `on'/`off' pairs, inclusive. +prints every record in 'myfile' between 'on'/'off' pairs, inclusive. A range pattern starts out by matching BEGPAT against every input record. When a record matches BEGPAT, the range pattern is "turned on" -and the range pattern matches this record as well. As long as the -range pattern stays turned on, it automatically matches every input -record read. The range pattern also matches ENDPAT against every input -record; when this succeeds, the range pattern is "turned off" again for -the following record. Then the range pattern goes back to checking -BEGPAT against each record. +and the range pattern matches this record as well. As long as the range +pattern stays turned on, it automatically matches every input record +read. The range pattern also matches ENDPAT against every input record; +when this succeeds, the range pattern is "turned off" again for the +following record. Then the range pattern goes back to checking BEGPAT +against each record. The record that turns on the range pattern and the one that turns it -off both match the range pattern. If you don't want to operate on -these records, you can write `if' statements in the rule's action to +off both match the range pattern. If you don't want to operate on these +records, you can write 'if' statements in the rule's action to distinguish them from the records you are interested in. It is possible for a pattern to be turned on and off by the same -record. If the record satisfies both conditions, then the action is +record. If the record satisfies both conditions, then the action is executed for just that record. For example, suppose there is text -between two identical markers (e.g., the `%' symbol), each on its own +between two identical markers (e.g., the '%' symbol), each on its own line, that should be ignored. A first attempt would be to combine a -range pattern that describes the delimited text with the `next' +range pattern that describes the delimited text with the 'next' statement (not discussed yet, *note Next Statement::). This causes -`awk' to skip any further processing of the current record and start -over again with the next input record. Such a program looks like this: +'awk' to skip any further processing of the current record and start +over again with the next input record. Such a program looks like this: /^%$/,/^%$/ { next } { print } This program fails because the range pattern is both turned on and -turned off by the first line, which just has a `%' on it. To -accomplish this task, write the program in the following manner, using -a flag: +turned off by the first line, which just has a '%' on it. To accomplish +this task, write the program in the following manner, using a flag: /^%$/ { skip = ! skip; next } skip == 1 { next } # skip lines with `skip' set - In a range pattern, the comma (`,') has the lowest precedence of all -the operators (i.e., it is evaluated last). Thus, the following -program attempts to combine a range pattern with another, simpler test: + In a range pattern, the comma (',') has the lowest precedence of all +the operators (i.e., it is evaluated last). Thus, the following program +attempts to combine a range pattern with another, simpler test: echo Yes | awk '/1/,/2/ || /Yes/' - The intent of this program is `(/1/,/2/) || /Yes/'. However, `awk' -interprets this as `/1/, (/2/ || /Yes/)'. This cannot be changed or + The intent of this program is '(/1/,/2/) || /Yes/'. However, 'awk' +interprets this as '/1/, (/2/ || /Yes/)'. This cannot be changed or worked around; range patterns do not combine with other patterns: $ echo Yes | gawk '(/1/,/2/) || /Yes/' - error--> gawk: cmd. line:1: (/1/,/2/) || /Yes/ - error--> gawk: cmd. line:1: ^ syntax error + error-> gawk: cmd. line:1: (/1/,/2/) || /Yes/ + error-> gawk: cmd. line:1: ^ syntax error - As a minor point of interest, although it is poor style, POSIX -allows you to put a newline after the comma in a range pattern. -(d.c.) + As a minor point of interest, although it is poor style, POSIX allows +you to put a newline after the comma in a range pattern. (d.c.)  File: gawk.info, Node: BEGIN/END, Next: BEGINFILE/ENDFILE, Prev: Ranges, Up: Pattern Overview -7.1.4 The `BEGIN' and `END' Special Patterns +7.1.4 The 'BEGIN' and 'END' Special Patterns -------------------------------------------- All the patterns described so far are for matching input records. The -`BEGIN' and `END' special patterns are different. They supply startup -and cleanup actions for `awk' programs. `BEGIN' and `END' rules must +'BEGIN' and 'END' special patterns are different. They supply startup +and cleanup actions for 'awk' programs. 'BEGIN' and 'END' rules must have actions; there is no default action for these rules because there -is no current record when they run. `BEGIN' and `END' rules are often -referred to as "`BEGIN' and `END' blocks" by long-time `awk' +is no current record when they run. 'BEGIN' and 'END' rules are often +referred to as "'BEGIN' and 'END' blocks" by long-time 'awk' programmers. * Menu: @@ -9047,8 +9007,8 @@ File: gawk.info, Node: Using BEGIN/END, Next: I/O And BEGIN/END, Up: BEGIN/EN 7.1.4.1 Startup and Cleanup Actions ................................... -A `BEGIN' rule is executed once only, before the first input record is -read. Likewise, an `END' rule is executed once only, after all the +A 'BEGIN' rule is executed once only, before the first input record is +read. Likewise, an 'END' rule is executed once only, after all the input is read. For example: $ awk ' @@ -9059,110 +9019,109 @@ input is read. For example: -| "li" appears in 4 records. This program finds the number of records in the input file -`mail-list' that contain the string `li'. The `BEGIN' rule prints a -title for the report. There is no need to use the `BEGIN' rule to -initialize the counter `n' to zero, since `awk' does this automatically -(*note Variables::). The second rule increments the variable `n' every -time a record containing the pattern `li' is read. The `END' rule -prints the value of `n' at the end of the run. - - The special patterns `BEGIN' and `END' cannot be used in ranges or +'mail-list' that contain the string 'li'. The 'BEGIN' rule prints a +title for the report. There is no need to use the 'BEGIN' rule to +initialize the counter 'n' to zero, since 'awk' does this automatically +(*note Variables::). The second rule increments the variable 'n' every +time a record containing the pattern 'li' is read. The 'END' rule +prints the value of 'n' at the end of the run. + + The special patterns 'BEGIN' and 'END' cannot be used in ranges or with Boolean operators (indeed, they cannot be used with any operators). -An `awk' program may have multiple `BEGIN' and/or `END' rules. They -are executed in the order in which they appear: all the `BEGIN' rules -at startup and all the `END' rules at termination. `BEGIN' and `END' -rules may be intermixed with other rules. This feature was added in -the 1987 version of `awk' and is included in the POSIX standard. The -original (1978) version of `awk' required the `BEGIN' rule to be placed -at the beginning of the program, the `END' rule to be placed at the -end, and only allowed one of each. This is no longer required, but it -is a good idea to follow this template in terms of program organization -and readability. - - Multiple `BEGIN' and `END' rules are useful for writing library -functions, because each library file can have its own `BEGIN' and/or -`END' rule to do its own initialization and/or cleanup. The order in -which library functions are named on the command line controls the -order in which their `BEGIN' and `END' rules are executed. Therefore, -you have to be careful when writing such rules in library files so that -the order in which they are executed doesn't matter. *Note Options::, -for more information on using library functions. *Note Library -Functions::, for a number of useful library functions. - - If an `awk' program has only `BEGIN' rules and no other rules, then -the program exits after the `BEGIN' rule is run.(1) However, if an -`END' rule exists, then the input is read, even if there are no other -rules in the program. This is necessary in case the `END' rule checks -the `FNR' and `NR' variables. +An 'awk' program may have multiple 'BEGIN' and/or 'END' rules. They are +executed in the order in which they appear: all the 'BEGIN' rules at +startup and all the 'END' rules at termination. 'BEGIN' and 'END' rules +may be intermixed with other rules. This feature was added in the 1987 +version of 'awk' and is included in the POSIX standard. The original +(1978) version of 'awk' required the 'BEGIN' rule to be placed at the +beginning of the program, the 'END' rule to be placed at the end, and +only allowed one of each. This is no longer required, but it is a good +idea to follow this template in terms of program organization and +readability. + + Multiple 'BEGIN' and 'END' rules are useful for writing library +functions, because each library file can have its own 'BEGIN' and/or +'END' rule to do its own initialization and/or cleanup. The order in +which library functions are named on the command line controls the order +in which their 'BEGIN' and 'END' rules are executed. Therefore, you +have to be careful when writing such rules in library files so that the +order in which they are executed doesn't matter. *Note Options::, for +more information on using library functions. *Note Library Functions::, +for a number of useful library functions. + + If an 'awk' program has only 'BEGIN' rules and no other rules, then +the program exits after the 'BEGIN' rule is run.(1) However, if an +'END' rule exists, then the input is read, even if there are no other +rules in the program. This is necessary in case the 'END' rule checks +the 'FNR' and 'NR' variables. ---------- Footnotes ---------- - (1) The original version of `awk' kept reading and ignoring input + (1) The original version of 'awk' kept reading and ignoring input until the end of the file was seen.  File: gawk.info, Node: I/O And BEGIN/END, Prev: Using BEGIN/END, Up: BEGIN/END -7.1.4.2 Input/Output from `BEGIN' and `END' Rules +7.1.4.2 Input/Output from 'BEGIN' and 'END' Rules ................................................. There are several (sometimes subtle) points to be aware of when doing -I/O from a `BEGIN' or `END' rule. The first has to do with the value -of `$0' in a `BEGIN' rule. Because `BEGIN' rules are executed before -any input is read, there simply is no input record, and therefore no -fields, when executing `BEGIN' rules. References to `$0' and the fields -yield a null string or zero, depending upon the context. One way to -give `$0' a real value is to execute a `getline' command without a -variable (*note Getline::). Another way is simply to assign a value to -`$0'. +I/O from a 'BEGIN' or 'END' rule. The first has to do with the value of +'$0' in a 'BEGIN' rule. Because 'BEGIN' rules are executed before any +input is read, there simply is no input record, and therefore no fields, +when executing 'BEGIN' rules. References to '$0' and the fields yield a +null string or zero, depending upon the context. One way to give '$0' a +real value is to execute a 'getline' command without a variable (*note +Getline::). Another way is simply to assign a value to '$0'. The second point is similar to the first but from the other -direction. Traditionally, due largely to implementation issues, `$0' -and `NF' were _undefined_ inside an `END' rule. The POSIX standard -specifies that `NF' is available in an `END' rule. It contains the +direction. Traditionally, due largely to implementation issues, '$0' +and 'NF' were _undefined_ inside an 'END' rule. The POSIX standard +specifies that 'NF' is available in an 'END' rule. It contains the number of fields from the last input record. Most probably due to an -oversight, the standard does not say that `$0' is also preserved, -although logically one would think that it should be. In fact, `gawk' -does preserve the value of `$0' for use in `END' rules. Be aware, -however, that Brian Kernighan's `awk', and possibly other +oversight, the standard does not say that '$0' is also preserved, +although logically one would think that it should be. In fact, 'gawk' +does preserve the value of '$0' for use in 'END' rules. Be aware, +however, that Brian Kernighan's 'awk', and possibly other implementations, do not. - The third point follows from the first two. The meaning of `print' -inside a `BEGIN' or `END' rule is the same as always: `print $0'. If -`$0' is the null string, then this prints an empty record. Many long -time `awk' programmers use an unadorned `print' in `BEGIN' and `END' -rules, to mean `print ""', relying on `$0' being null. Although one -might generally get away with this in `BEGIN' rules, it is a very bad -idea in `END' rules, at least in `gawk'. It is also poor style, since + The third point follows from the first two. The meaning of 'print' +inside a 'BEGIN' or 'END' rule is the same as always: 'print $0'. If +'$0' is the null string, then this prints an empty record. Many long +time 'awk' programmers use an unadorned 'print' in 'BEGIN' and 'END' +rules, to mean 'print ""', relying on '$0' being null. Although one +might generally get away with this in 'BEGIN' rules, it is a very bad +idea in 'END' rules, at least in 'gawk'. It is also poor style, since if an empty line is needed in the output, the program should print one explicitly. - Finally, the `next' and `nextfile' statements are not allowed in a -`BEGIN' rule, because the implicit + Finally, the 'next' and 'nextfile' statements are not allowed in a +'BEGIN' rule, because the implicit read-a-record-and-match-against-the-rules loop has not started yet. -Similarly, those statements are not valid in an `END' rule, since all +Similarly, those statements are not valid in an 'END' rule, since all the input has been read. (*Note Next Statement::, and see *note Nextfile Statement::.)  File: gawk.info, Node: BEGINFILE/ENDFILE, Next: Empty, Prev: BEGIN/END, Up: Pattern Overview -7.1.5 The `BEGINFILE' and `ENDFILE' Special Patterns +7.1.5 The 'BEGINFILE' and 'ENDFILE' Special Patterns ---------------------------------------------------- -This minor node describes a `gawk'-specific feature. +This minor node describes a 'gawk'-specific feature. - Two special kinds of rule, `BEGINFILE' and `ENDFILE', give you -"hooks" into `gawk''s command-line file processing loop. As with the -`BEGIN' and `END' rules (*note BEGIN/END::), all `BEGINFILE' rules in a -program are merged, in the order they are read by `gawk', and all -`ENDFILE' rules are merged as well. + Two special kinds of rule, 'BEGINFILE' and 'ENDFILE', give you +"hooks" into 'gawk''s command-line file processing loop. As with the +'BEGIN' and 'END' rules (*note BEGIN/END::), all 'BEGINFILE' rules in a +program are merged, in the order they are read by 'gawk', and all +'ENDFILE' rules are merged as well. - The body of the `BEGINFILE' rules is executed just before `gawk' -reads the first record from a file. `FILENAME' is set to the name of -the current file, and `FNR' is set to zero. + The body of the 'BEGINFILE' rules is executed just before 'gawk' +reads the first record from a file. 'FILENAME' is set to the name of +the current file, and 'FNR' is set to zero. - The `BEGINFILE' rule provides you the opportunity to accomplish two + The 'BEGINFILE' rule provides you the opportunity to accomplish two tasks that would otherwise be difficult or impossible to perform: * You can test if the file is readable. Normally, it is a fatal @@ -9170,40 +9129,40 @@ tasks that would otherwise be difficult or impossible to perform: reading. However, you can bypass the fatal error and move on to the next file on the command line. - You do this by checking if the `ERRNO' variable is not the empty - string; if so, then `gawk' was not able to open the file. In this - case, your program can execute the `nextfile' statement (*note - Nextfile Statement::). This causes `gawk' to skip the file - entirely. Otherwise, `gawk' exits with the usual fatal error. + You do this by checking if the 'ERRNO' variable is not the empty + string; if so, then 'gawk' was not able to open the file. In this + case, your program can execute the 'nextfile' statement (*note + Nextfile Statement::). This causes 'gawk' to skip the file + entirely. Otherwise, 'gawk' exits with the usual fatal error. * If you have written extensions that modify the record handling (by inserting an "input parser," *note Input Parsers::), you can invoke - them at this point, before `gawk' has started processing the file. + them at this point, before 'gawk' has started processing the file. (This is a _very_ advanced feature, currently used only by the - `gawkextlib' project (http://gawkextlib.sourceforge.net).) + 'gawkextlib' project (http://gawkextlib.sourceforge.net).) - The `ENDFILE' rule is called when `gawk' has finished processing the + The 'ENDFILE' rule is called when 'gawk' has finished processing the last record in an input file. For the last input file, it will be -called before any `END' rules. The `ENDFILE' rule is executed even for +called before any 'END' rules. The 'ENDFILE' rule is executed even for empty input files. Normally, when an error occurs when reading input in the normal input -processing loop, the error is fatal. However, if an `ENDFILE' rule is -present, the error becomes non-fatal, and instead `ERRNO' is set. This +processing loop, the error is fatal. However, if an 'ENDFILE' rule is +present, the error becomes non-fatal, and instead 'ERRNO' is set. This makes it possible to catch and process I/O errors at the level of the -`awk' program. +'awk' program. - The `next' statement (*note Next Statement::) is not allowed inside -either a `BEGINFILE' or and `ENDFILE' rule. The `nextfile' statement -(*note Nextfile Statement::) is allowed only inside a `BEGINFILE' rule, -but not inside an `ENDFILE' rule. + The 'next' statement (*note Next Statement::) is not allowed inside +either a 'BEGINFILE' or and 'ENDFILE' rule. The 'nextfile' statement +(*note Nextfile Statement::) is allowed only inside a 'BEGINFILE' rule, +but not inside an 'ENDFILE' rule. - The `getline' statement (*note Getline::) is restricted inside both -`BEGINFILE' and `ENDFILE': only redirected forms of `getline' are + The 'getline' statement (*note Getline::) is restricted inside both +'BEGINFILE' and 'ENDFILE': only redirected forms of 'getline' are allowed. - `BEGINFILE' and `ENDFILE' are `gawk' extensions. In most other -`awk' implementations, or if `gawk' is in compatibility mode (*note + 'BEGINFILE' and 'ENDFILE' are 'gawk' extensions. In most other 'awk' +implementations, or if 'gawk' is in compatibility mode (*note Options::), they are not special.  @@ -9225,10 +9184,10 @@ File: gawk.info, Node: Using Shell Variables, Next: Action Overview, Prev: Pa 7.2 Using Shell Variables in Programs ===================================== -`awk' programs are often used as components in larger programs written +'awk' programs are often used as components in larger programs written in shell. For example, it is very common to use a shell variable to -hold a pattern that the `awk' program searches for. There are two ways -to get the value of the shell variable into the body of the `awk' +hold a pattern that the 'awk' program searches for. There are two ways +to get the value of the shell variable into the body of the 'awk' program. The most common method is to use shell quoting to substitute the @@ -9240,35 +9199,35 @@ consider the following program: awk "/$pattern/ "'{ nmatches++ } END { print nmatches, "found" }' /path/to/data -The `awk' program consists of two pieces of quoted text that are +The 'awk' program consists of two pieces of quoted text that are concatenated together to form the program. The first part is -double-quoted, which allows substitution of the `pattern' shell -variable inside the quotes. The second part is single-quoted. +double-quoted, which allows substitution of the 'pattern' shell variable +inside the quotes. The second part is single-quoted. Variable substitution via quoting works, but can be potentially messy. It requires a good understanding of the shell's quoting rules (*note Quoting::), and it's often difficult to correctly match up the quotes when reading the program. - A better method is to use `awk''s variable assignment feature (*note -Assignment Options::) to assign the shell variable's value to an `awk' -variable. Then use dynamic regexps to match the pattern (*note -Computed Regexps::). The following shows how to redo the previous -example using this technique: + A better method is to use 'awk''s variable assignment feature (*note +Assignment Options::) to assign the shell variable's value to an 'awk' +variable. Then use dynamic regexps to match the pattern (*note Computed +Regexps::). The following shows how to redo the previous example using +this technique: printf "Enter search pattern: " read pattern awk -v pat="$pattern" '$0 ~ pat { nmatches++ } END { print nmatches, "found" }' /path/to/data -Now, the `awk' program is just one single-quoted string. The -assignment `-v pat="$pattern"' still requires double quotes, in case -there is whitespace in the value of `$pattern'. The `awk' variable -`pat' could be named `pattern' too, but that would be more confusing. -Using a variable also provides more flexibility, since the variable can -be used anywhere inside the program--for printing, as an array -subscript, or for any other use--without requiring the quoting tricks -at every point in the program. +Now, the 'awk' program is just one single-quoted string. The assignment +'-v pat="$pattern"' still requires double quotes, in case there is +whitespace in the value of '$pattern'. The 'awk' variable 'pat' could +be named 'pattern' too, but that would be more confusing. Using a +variable also provides more flexibility, since the variable can be used +anywhere inside the program--for printing, as an array subscript, or for +any other use--without requiring the quoting tricks at every point in +the program.  File: gawk.info, Node: Action Overview, Next: Statements, Prev: Using Shell Variables, Up: Patterns and Actions @@ -9276,55 +9235,55 @@ File: gawk.info, Node: Action Overview, Next: Statements, Prev: Using Shell V 7.3 Actions =========== -An `awk' program or script consists of a series of rules and function +An 'awk' program or script consists of a series of rules and function definitions interspersed. (Functions are described later. *Note User-defined::.) A rule contains a pattern and an action, either of which (but not both) may be omitted. The purpose of the "action" is to -tell `awk' what to do once a match for the pattern is found. Thus, in -outline, an `awk' program generally looks like this: +tell 'awk' what to do once a match for the pattern is found. Thus, in +outline, an 'awk' program generally looks like this: - [PATTERN] `{ ACTION }' - PATTERN [`{ ACTION }'] + [PATTERN] '{ ACTION }' + PATTERN ['{ ACTION }'] ... - `function NAME(ARGS) { ... }' + 'function NAME(ARGS) { ... }' ... - An action consists of one or more `awk' "statements", enclosed in -braces (`{...}'). Each statement specifies one thing to do. The + An action consists of one or more 'awk' "statements", enclosed in +braces ('{...}'). Each statement specifies one thing to do. The statements are separated by newlines or semicolons. The braces around an action must be used even if the action contains only one statement, -or if it contains no statements at all. However, if you omit the -action entirely, omit the braces as well. An omitted action is -equivalent to `{ print $0 }': +or if it contains no statements at all. However, if you omit the action +entirely, omit the braces as well. An omitted action is equivalent to +'{ print $0 }': - /foo/ { } match `foo', do nothing -- empty action - /foo/ match `foo', print the record -- omitted action + /foo/ { } match 'foo', do nothing -- empty action + /foo/ match 'foo', print the record -- omitted action - The following types of statements are supported in `awk': + The following types of statements are supported in 'awk': Expressions - Call functions or assign values to variables (*note - Expressions::). Executing this kind of statement simply computes - the value of the expression. This is useful when the expression - has side effects (*note Assignment Ops::). + Call functions or assign values to variables (*note Expressions::). + Executing this kind of statement simply computes the value of the + expression. This is useful when the expression has side effects + (*note Assignment Ops::). Control statements - Specify the control flow of `awk' programs. The `awk' language - gives you C-like constructs (`if', `for', `while', and `do') as + Specify the control flow of 'awk' programs. The 'awk' language + gives you C-like constructs ('if', 'for', 'while', and 'do') as well as a few special ones (*note Statements::). Compound statements Enclose one or more statements in braces. A compound statement is used in order to put several statements together in the body of an - `if', `while', `do', or `for' statement. + 'if', 'while', 'do', or 'for' statement. Input statements - Use the `getline' command (*note Getline::). Also supplied in - `awk' are the `next' statement (*note Next Statement::), and the - `nextfile' statement (*note Nextfile Statement::). + Use the 'getline' command (*note Getline::). Also supplied in + 'awk' are the 'next' statement (*note Next Statement::), and the + 'nextfile' statement (*note Nextfile Statement::). Output statements - Such as `print' and `printf'. *Note Printing::. + Such as 'print' and 'printf'. *Note Printing::. Deletion statements For deleting array elements. *Note Delete::. @@ -9335,13 +9294,13 @@ File: gawk.info, Node: Statements, Next: Built-in Variables, Prev: Action Ove 7.4 Control Statements in Actions ================================= -"Control statements", such as `if', `while', and so on, control the -flow of execution in `awk' programs. Most of `awk''s control -statements are patterned after similar statements in C. +"Control statements", such as 'if', 'while', and so on, control the flow +of execution in 'awk' programs. Most of 'awk''s control statements are +patterned after similar statements in C. - All the control statements start with special keywords, such as `if' -and `while', to distinguish them from simple expressions. Many control -statements contain other statements. For example, the `if' statement + All the control statements start with special keywords, such as 'if' +and 'while', to distinguish them from simple expressions. Many control +statements contain other statements. For example, the 'if' statement contains another statement that may or may not be executed. The contained statement is called the "body". To include more than one statement in the body, group them into a single "compound statement" @@ -9349,7 +9308,7 @@ with braces, separating them with newlines or semicolons. * Menu: -* If Statement:: Conditionally execute some `awk' +* If Statement:: Conditionally execute some 'awk' statements. * While Statement:: Loop until some condition is satisfied. * Do Statement:: Do specified action while looping until some @@ -9363,56 +9322,55 @@ with braces, separating them with newlines or semicolons. loop. * Next Statement:: Stop processing the current input record. * Nextfile Statement:: Stop processing the current file. -* Exit Statement:: Stop execution of `awk'. +* Exit Statement:: Stop execution of 'awk'.  File: gawk.info, Node: If Statement, Next: While Statement, Up: Statements -7.4.1 The `if'-`else' Statement +7.4.1 The 'if'-'else' Statement ------------------------------- -The `if'-`else' statement is `awk''s decision-making statement. It +The 'if'-'else' statement is 'awk''s decision-making statement. It looks like this: - `if (CONDITION) THEN-BODY' [`else ELSE-BODY'] + 'if (CONDITION) THEN-BODY' ['else ELSE-BODY'] The CONDITION is an expression that controls what the rest of the statement does. If the CONDITION is true, THEN-BODY is executed; -otherwise, ELSE-BODY is executed. The `else' part of the statement is -optional. The condition is considered false if its value is zero or -the null string; otherwise, the condition is true. Refer to the -following: +otherwise, ELSE-BODY is executed. The 'else' part of the statement is +optional. The condition is considered false if its value is zero or the +null string; otherwise, the condition is true. Refer to the following: if (x % 2 == 0) print "x is even" else print "x is odd" - In this example, if the expression `x % 2 == 0' is true (that is, if -the value of `x' is evenly divisible by two), then the first `print' -statement is executed; otherwise, the second `print' statement is -executed. If the `else' keyword appears on the same line as THEN-BODY + In this example, if the expression 'x % 2 == 0' is true (that is, if +the value of 'x' is evenly divisible by two), then the first 'print' +statement is executed; otherwise, the second 'print' statement is +executed. If the 'else' keyword appears on the same line as THEN-BODY and THEN-BODY is not a compound statement (i.e., not surrounded by -braces), then a semicolon must separate THEN-BODY from the `else'. To +braces), then a semicolon must separate THEN-BODY from the 'else'. To illustrate this, the previous example can be rewritten as: if (x % 2 == 0) print "x is even"; else print "x is odd" -If the `;' is left out, `awk' can't interpret the statement and it +If the ';' is left out, 'awk' can't interpret the statement and it produces a syntax error. Don't actually write programs this way, -because a human reader might fail to see the `else' if it is not the +because a human reader might fail to see the 'else' if it is not the first thing on its line.  File: gawk.info, Node: While Statement, Next: Do Statement, Prev: If Statement, Up: Statements -7.4.2 The `while' Statement +7.4.2 The 'while' Statement --------------------------- -In programming, a "loop" is a part of a program that can be executed -two or more times in succession. The `while' statement is the simplest -looping statement in `awk'. It repeatedly executes a statement as long +In programming, a "loop" is a part of a program that can be executed two +or more times in succession. The 'while' statement is the simplest +looping statement in 'awk'. It repeatedly executes a statement as long as a condition is true. For example: while (CONDITION) @@ -9420,13 +9378,13 @@ as a condition is true. For example: BODY is a statement called the "body" of the loop, and CONDITION is an expression that controls how long the loop keeps running. The first -thing the `while' statement does is test the CONDITION. If the +thing the 'while' statement does is test the CONDITION. If the CONDITION is true, it executes the statement BODY. (The CONDITION is true when the value is not zero and not a null string.) After BODY has been executed, CONDITION is tested again, and if it is still true, BODY is executed again. This process repeats until the CONDITION is no longer true. If the CONDITION is initially false, the body of the loop -is never executed and `awk' continues with the statement following the +is never executed and 'awk' continues with the statement following the loop. This example prints the first three fields of each record, one per line: @@ -9440,27 +9398,27 @@ per line: The body of this loop is a compound statement enclosed in braces, containing two statements. The loop works in the following manner: -first, the value of `i' is set to one. Then, the `while' statement -tests whether `i' is less than or equal to three. This is true when -`i' equals one, so the `i'-th field is printed. Then the `i++' -increments the value of `i' and the loop repeats. The loop terminates -when `i' reaches four. +first, the value of 'i' is set to one. Then, the 'while' statement +tests whether 'i' is less than or equal to three. This is true when 'i' +equals one, so the 'i'-th field is printed. Then the 'i++' increments +the value of 'i' and the loop repeats. The loop terminates when 'i' +reaches four. - A newline is not required between the condition and the body; -however using one makes the program clearer unless the body is a -compound statement or else is very simple. The newline after the -open-brace that begins the compound statement is not required either, -but the program is harder to read without it. + A newline is not required between the condition and the body; however +using one makes the program clearer unless the body is a compound +statement or else is very simple. The newline after the open-brace that +begins the compound statement is not required either, but the program is +harder to read without it.  File: gawk.info, Node: Do Statement, Next: For Statement, Prev: While Statement, Up: Statements -7.4.3 The `do'-`while' Statement +7.4.3 The 'do'-'while' Statement -------------------------------- -The `do' loop is a variation of the `while' looping statement. The -`do' loop executes the BODY once and then repeats the BODY as long as -the CONDITION is true. It looks like this: +The 'do' loop is a variation of the 'while' looping statement. The 'do' +loop executes the BODY once and then repeats the BODY as long as the +CONDITION is true. It looks like this: do BODY @@ -9468,13 +9426,13 @@ the CONDITION is true. It looks like this: Even if the CONDITION is false at the start, the BODY is executed at least once (and only once, unless executing BODY makes CONDITION true). -Contrast this with the corresponding `while' statement: +Contrast this with the corresponding 'while' statement: while (CONDITION) BODY -This statement does not execute BODY even once if the CONDITION is -false to begin with. The following is an example of a `do' statement: +This statement does not execute BODY even once if the CONDITION is false +to begin with. The following is an example of a 'do' statement: { i = 1 @@ -9485,26 +9443,26 @@ false to begin with. The following is an example of a `do' statement: } This program prints each input record 10 times. However, it isn't a -very realistic example, since in this case an ordinary `while' would do +very realistic example, since in this case an ordinary 'while' would do just as well. This situation reflects actual experience; only -occasionally is there a real use for a `do' statement. +occasionally is there a real use for a 'do' statement.  File: gawk.info, Node: For Statement, Next: Switch Statement, Prev: Do Statement, Up: Statements -7.4.4 The `for' Statement +7.4.4 The 'for' Statement ------------------------- -The `for' statement makes it more convenient to count iterations of a -loop. The general form of the `for' statement looks like this: +The 'for' statement makes it more convenient to count iterations of a +loop. The general form of the 'for' statement looks like this: for (INITIALIZATION; CONDITION; INCREMENT) BODY -The INITIALIZATION, CONDITION, and INCREMENT parts are arbitrary `awk' -expressions, and BODY stands for any `awk' statement. +The INITIALIZATION, CONDITION, and INCREMENT parts are arbitrary 'awk' +expressions, and BODY stands for any 'awk' statement. - The `for' statement starts by executing INITIALIZATION. Then, as + The 'for' statement starts by executing INITIALIZATION. Then, as long as the CONDITION is true, it repeatedly executes BODY and then INCREMENT. Typically, INITIALIZATION sets a variable to either zero or one, INCREMENT adds one to it, and CONDITION compares it against the @@ -9518,34 +9476,33 @@ desired number of iterations. For example: This prints the first three fields of each input record, with one field per line. - It isn't possible to set more than one variable in the -INITIALIZATION part without using a multiple assignment statement such -as `x = y = 0'. This makes sense only if all the initial values are -equal. (But it is possible to initialize additional variables by -writing their assignments as separate statements preceding the `for' -loop.) + It isn't possible to set more than one variable in the INITIALIZATION +part without using a multiple assignment statement such as 'x = y = 0'. +This makes sense only if all the initial values are equal. (But it is +possible to initialize additional variables by writing their assignments +as separate statements preceding the 'for' loop.) - The same is true of the INCREMENT part. Incrementing additional + The same is true of the INCREMENT part. Incrementing additional variables requires separate statements at the end of the loop. The C -compound expression, using C's comma operator, is useful in this -context but it is not supported in `awk'. +compound expression, using C's comma operator, is useful in this context +but it is not supported in 'awk'. Most often, INCREMENT is an increment expression, as in the previous -example. But this is not required; it can be any expression -whatsoever. For example, the following statement prints all the powers -of two between 1 and 100: +example. But this is not required; it can be any expression whatsoever. +For example, the following statement prints all the powers of two +between 1 and 100: for (i = 1; i <= 100; i *= 2) print i If there is nothing to be done, any of the three expressions in the -parentheses following the `for' keyword may be omitted. Thus, -`for (; x > 0;)' is equivalent to `while (x > 0)'. If the CONDITION is -omitted, it is treated as true, effectively yielding an "infinite loop" -(i.e., a loop that never terminates). +parentheses following the 'for' keyword may be omitted. Thus, 'for (; x > 0;)' +is equivalent to 'while (x > 0)'. If the CONDITION is omitted, it is +treated as true, effectively yielding an "infinite loop" (i.e., a loop +that never terminates). - In most cases, a `for' loop is an abbreviation for a `while' loop, -as shown here: + In most cases, a 'for' loop is an abbreviation for a 'while' loop, as +shown here: INITIALIZATION while (CONDITION) { @@ -9553,46 +9510,46 @@ as shown here: INCREMENT } -The only exception is when the `continue' statement (*note Continue -Statement::) is used inside the loop. Changing a `for' statement to a -`while' statement in this way can change the effect of the `continue' +The only exception is when the 'continue' statement (*note Continue +Statement::) is used inside the loop. Changing a 'for' statement to a +'while' statement in this way can change the effect of the 'continue' statement inside the loop. - The `awk' language has a `for' statement in addition to a `while' -statement because a `for' loop is often both less work to type and more + The 'awk' language has a 'for' statement in addition to a 'while' +statement because a 'for' loop is often both less work to type and more natural to think of. Counting the number of iterations is very common -in loops. It can be easier to think of this counting as part of -looping rather than as something to do inside the loop. +in loops. It can be easier to think of this counting as part of looping +rather than as something to do inside the loop. - There is an alternate version of the `for' loop, for iterating over + There is an alternate version of the 'for' loop, for iterating over all the indices of an array: for (i in array) DO SOMETHING WITH array[i] *Note Scanning an Array::, for more information on this version of the -`for' loop. +'for' loop.  File: gawk.info, Node: Switch Statement, Next: Break Statement, Prev: For Statement, Up: Statements -7.4.5 The `switch' Statement +7.4.5 The 'switch' Statement ---------------------------- -This minor node describes a `gawk'-specific feature. If `gawk' is in +This minor node describes a 'gawk'-specific feature. If 'gawk' is in compatibility mode (*note Options::), it is not available. - The `switch' statement allows the evaluation of an expression and -the execution of statements based on a `case' match. Case statements -are checked for a match in the order they are defined. If no suitable -`case' is found, the `default' section is executed, if supplied. + The 'switch' statement allows the evaluation of an expression and the +execution of statements based on a 'case' match. Case statements are +checked for a match in the order they are defined. If no suitable +'case' is found, the 'default' section is executed, if supplied. - Each `case' contains a single constant, be it numeric, string, or -regexp. The `switch' expression is evaluated, and then each `case''s -constant is compared against the result in turn. The type of constant + Each 'case' contains a single constant, be it numeric, string, or +regexp. The 'switch' expression is evaluated, and then each 'case''s +constant is compared against the result in turn. The type of constant determines the comparison: numeric or string do the usual comparisons. A regexp constant does a regular expression match against the string -value of the original expression. The general form of the `switch' +value of the original expression. The general form of the 'switch' statement looks like this: switch (EXPRESSION) { @@ -9602,10 +9559,10 @@ statement looks like this: DEFAULT-BODY } - Control flow in the `switch' statement works as it does in C. Once a -match to a given case is made, the case statement bodies execute until -a `break', `continue', `next', `nextfile' or `exit' is encountered, or -the end of the `switch' statement itself. For example: + Control flow in the 'switch' statement works as it does in C. Once a +match to a given case is made, the case statement bodies execute until a +'break', 'continue', 'next', 'nextfile' or 'exit' is encountered, or the +end of the 'switch' statement itself. For example: switch (NR * 2 + 1) { case 3: @@ -9623,23 +9580,23 @@ the end of the `switch' statement itself. For example: print NR * -1 } - Note that if none of the statements specified above halt execution -of a matched `case' statement, execution falls through to the next -`case' until execution halts. In the above example, for any case value -starting with `2' followed by one or more digits, the `print' statement -is executed and then falls through into the `default' section, -executing its `print' statement. In turn, the -1 case will also be -executed since the `default' does not halt execution. + Note that if none of the statements specified above halt execution of +a matched 'case' statement, execution falls through to the next 'case' +until execution halts. In the above example, for any case value +starting with '2' followed by one or more digits, the 'print' statement +is executed and then falls through into the 'default' section, executing +its 'print' statement. In turn, the -1 case will also be executed since +the 'default' does not halt execution.  File: gawk.info, Node: Break Statement, Next: Continue Statement, Prev: Switch Statement, Up: Statements -7.4.6 The `break' Statement +7.4.6 The 'break' Statement --------------------------- -The `break' statement jumps out of the innermost `for', `while', or -`do' loop that encloses it. The following example finds the smallest -divisor of any integer, and also identifies prime numbers: +The 'break' statement jumps out of the innermost 'for', 'while', or 'do' +loop that encloses it. The following example finds the smallest divisor +of any integer, and also identifies prime numbers: # find smallest divisor of num { @@ -9654,15 +9611,15 @@ divisor of any integer, and also identifies prime numbers: printf "%d is prime\n", num } - When the remainder is zero in the first `if' statement, `awk' -immediately "breaks out" of the containing `for' loop. This means that -`awk' proceeds immediately to the statement following the loop and -continues processing. (This is very different from the `exit' -statement, which stops the entire `awk' program. *Note Exit + When the remainder is zero in the first 'if' statement, 'awk' +immediately "breaks out" of the containing 'for' loop. This means that +'awk' proceeds immediately to the statement following the loop and +continues processing. (This is very different from the 'exit' +statement, which stops the entire 'awk' program. *Note Exit Statement::.) - The following program illustrates how the CONDITION of a `for' or -`while' statement could be replaced with a `break' inside an `if': + The following program illustrates how the CONDITION of a 'for' or +'while' statement could be replaced with a 'break' inside an 'if': # find smallest divisor of num { @@ -9679,30 +9636,30 @@ Statement::.) } } - The `break' statement is also used to break out of the `switch' + The 'break' statement is also used to break out of the 'switch' statement. This is discussed in *note Switch Statement::. - The `break' statement has no meaning when used outside the body of a -loop or `switch'. However, although it was never documented, -historical implementations of `awk' treated the `break' statement -outside of a loop as if it were a `next' statement (*note Next -Statement::). (d.c.) Recent versions of Brian Kernighan's `awk' no -longer allow this usage, nor does `gawk'. + The 'break' statement has no meaning when used outside the body of a +loop or 'switch'. However, although it was never documented, historical +implementations of 'awk' treated the 'break' statement outside of a loop +as if it were a 'next' statement (*note Next Statement::). (d.c.) +Recent versions of Brian Kernighan's 'awk' no longer allow this usage, +nor does 'gawk'.  File: gawk.info, Node: Continue Statement, Next: Next Statement, Prev: Break Statement, Up: Statements -7.4.7 The `continue' Statement +7.4.7 The 'continue' Statement ------------------------------ -Similar to `break', the `continue' statement is used only inside `for', -`while', and `do' loops. It skips over the rest of the loop body, +Similar to 'break', the 'continue' statement is used only inside 'for', +'while', and 'do' loops. It skips over the rest of the loop body, causing the next cycle around the loop to begin immediately. Contrast -this with `break', which jumps out of the loop altogether. +this with 'break', which jumps out of the loop altogether. - The `continue' statement in a `for' loop directs `awk' to skip the + The 'continue' statement in a 'for' loop directs 'awk' to skip the rest of the body of the loop and resume execution with the -increment-expression of the `for' statement. The following program +increment-expression of the 'for' statement. The following program illustrates this fact: BEGIN { @@ -9715,9 +9672,9 @@ illustrates this fact: } This program prints all the numbers from 0 to 20--except for 5, for -which the `printf' is skipped. Because the increment `x++' is not -skipped, `x' does not remain stuck at 5. Contrast the `for' loop from -the previous example with the following `while' loop: +which the 'printf' is skipped. Because the increment 'x++' is not +skipped, 'x' does not remain stuck at 5. Contrast the 'for' loop from +the previous example with the following 'while' loop: BEGIN { x = 0 @@ -9730,41 +9687,41 @@ the previous example with the following `while' loop: print "" } -This program loops forever once `x' reaches 5. +This program loops forever once 'x' reaches 5. - The `continue' statement has no special meaning with respect to the -`switch' statement, nor does it have any meaning when used outside the -body of a loop. Historical versions of `awk' treated a `continue' -statement outside a loop the same way they treated a `break' statement -outside a loop: as if it were a `next' statement (*note Next -Statement::). (d.c.) Recent versions of Brian Kernighan's `awk' no -longer work this way, nor does `gawk'. + The 'continue' statement has no special meaning with respect to the +'switch' statement, nor does it have any meaning when used outside the +body of a loop. Historical versions of 'awk' treated a 'continue' +statement outside a loop the same way they treated a 'break' statement +outside a loop: as if it were a 'next' statement (*note Next +Statement::). (d.c.) Recent versions of Brian Kernighan's 'awk' no +longer work this way, nor does 'gawk'.  File: gawk.info, Node: Next Statement, Next: Nextfile Statement, Prev: Continue Statement, Up: Statements -7.4.8 The `next' Statement +7.4.8 The 'next' Statement -------------------------- -The `next' statement forces `awk' to immediately stop processing the -current record and go on to the next record. This means that no -further rules are executed for the current record, and the rest of the -current rule's action isn't executed. +The 'next' statement forces 'awk' to immediately stop processing the +current record and go on to the next record. This means that no further +rules are executed for the current record, and the rest of the current +rule's action isn't executed. - Contrast this with the effect of the `getline' function (*note -Getline::). That also causes `awk' to read the next record -immediately, but it does not alter the flow of control in any way -(i.e., the rest of the current action executes with a new input record). + Contrast this with the effect of the 'getline' function (*note +Getline::). That also causes 'awk' to read the next record immediately, +but it does not alter the flow of control in any way (i.e., the rest of +the current action executes with a new input record). - At the highest level, `awk' program execution is a loop that reads -an input record and then tests each rule's pattern against it. If you -think of this loop as a `for' statement whose body contains the rules, -then the `next' statement is analogous to a `continue' statement. It + At the highest level, 'awk' program execution is a loop that reads an +input record and then tests each rule's pattern against it. If you +think of this loop as a 'for' statement whose body contains the rules, +then the 'next' statement is analogous to a 'continue' statement. It skips to the end of the body of this implicit loop and executes the increment (which reads another record). - For example, suppose an `awk' program works only on records with -four fields, and it shouldn't fail when given bad input. To avoid + For example, suppose an 'awk' program works only on records with four +fields, and it shouldn't fail when given bad input. To avoid complicating the rest of the program, write a "weed out" rule near the beginning, in the following manner: @@ -9774,120 +9731,119 @@ beginning, in the following manner: next } -Because of the `next' statement, the program's subsequent rules won't +Because of the 'next' statement, the program's subsequent rules won't see the bad record. The error message is redirected to the standard error output stream, as error messages should be. For more detail see *note Special Files::. - If the `next' statement causes the end of the input to be reached, -then the code in any `END' rules is executed. *Note BEGIN/END::. + If the 'next' statement causes the end of the input to be reached, +then the code in any 'END' rules is executed. *Note BEGIN/END::. - The `next' statement is not allowed inside `BEGINFILE' and `ENDFILE' -rules. *Note BEGINFILE/ENDFILE::. + The 'next' statement is not allowed inside 'BEGINFILE' and 'ENDFILE' +rules. *Note BEGINFILE/ENDFILE::. According to the POSIX standard, the behavior is undefined if the -`next' statement is used in a `BEGIN' or `END' rule. `gawk' treats it -as a syntax error. Although POSIX permits it, most other `awk' -implementations don't allow the `next' statement inside function bodies -(*note User-defined::). Just as with any other `next' statement, a -`next' statement inside a function body reads the next record and -starts processing it with the first rule in the program. +'next' statement is used in a 'BEGIN' or 'END' rule. 'gawk' treats it +as a syntax error. Although POSIX permits it, most other 'awk' +implementations don't allow the 'next' statement inside function bodies +(*note User-defined::). Just as with any other 'next' statement, a +'next' statement inside a function body reads the next record and starts +processing it with the first rule in the program.  File: gawk.info, Node: Nextfile Statement, Next: Exit Statement, Prev: Next Statement, Up: Statements -7.4.9 The `nextfile' Statement +7.4.9 The 'nextfile' Statement ------------------------------ -The `nextfile' statement is similar to the `next' statement. However, -instead of abandoning processing of the current record, the `nextfile' -statement instructs `awk' to stop processing the current data file. +The 'nextfile' statement is similar to the 'next' statement. However, +instead of abandoning processing of the current record, the 'nextfile' +statement instructs 'awk' to stop processing the current data file. - Upon execution of the `nextfile' statement, `FILENAME' is updated to -the name of the next data file listed on the command line, `FNR' is + Upon execution of the 'nextfile' statement, 'FILENAME' is updated to +the name of the next data file listed on the command line, 'FNR' is reset to one, and processing starts over with the first rule in the -program. If the `nextfile' statement causes the end of the input to be -reached, then the code in any `END' rules is executed. An exception to -this is when `nextfile' is invoked during execution of any statement in -an `END' rule; In this case, it causes the program to stop immediately. +program. If the 'nextfile' statement causes the end of the input to be +reached, then the code in any 'END' rules is executed. An exception to +this is when 'nextfile' is invoked during execution of any statement in +an 'END' rule; In this case, it causes the program to stop immediately. *Note BEGIN/END::. - The `nextfile' statement is useful when there are many data files to + The 'nextfile' statement is useful when there are many data files to process but it isn't necessary to process every record in every file. -Without `nextfile', in order to move on to the next data file, a program -would have to continue scanning the unwanted records. The `nextfile' +Without 'nextfile', in order to move on to the next data file, a program +would have to continue scanning the unwanted records. The 'nextfile' statement accomplishes this much more efficiently. - In `gawk', execution of `nextfile' causes additional things to -happen: any `ENDFILE' rules are executed except in the case as -mentioned below, `ARGIND' is incremented, and any `BEGINFILE' rules are -executed. (`ARGIND' hasn't been introduced yet. *Note Built-in -Variables::.) + In 'gawk', execution of 'nextfile' causes additional things to +happen: any 'ENDFILE' rules are executed except in the case as mentioned +below, 'ARGIND' is incremented, and any 'BEGINFILE' rules are executed. +('ARGIND' hasn't been introduced yet. *Note Built-in Variables::.) - With `gawk', `nextfile' is useful inside a `BEGINFILE' rule to skip -over a file that would otherwise cause `gawk' to exit with a fatal -error. In this case, `ENDFILE' rules are not executed. *Note + With 'gawk', 'nextfile' is useful inside a 'BEGINFILE' rule to skip +over a file that would otherwise cause 'gawk' to exit with a fatal +error. In this case, 'ENDFILE' rules are not executed. *Note BEGINFILE/ENDFILE::. - While one might think that `close(FILENAME)' would accomplish the -same as `nextfile', this isn't true. `close()' is reserved for closing + While one might think that 'close(FILENAME)' would accomplish the +same as 'nextfile', this isn't true. 'close()' is reserved for closing files, pipes, and coprocesses that are opened with redirections. It is -not related to the main processing that `awk' does with the files -listed in `ARGV'. +not related to the main processing that 'awk' does with the files listed +in 'ARGV'. - NOTE: For many years, `nextfile' was a `gawk' extension. As of + NOTE: For many years, 'nextfile' was a 'gawk' extension. As of September, 2012, it was accepted for inclusion into the POSIX standard. See the Austin Group website (http://austingroupbugs.net/view.php?id=607). - The current version of the Brian Kernighan's `awk', and `mawk' -(*note Other Versions::) also support `nextfile'. However, they don't -allow the `nextfile' statement inside function bodies (*note -User-defined::). `gawk' does; a `nextfile' inside a function body -reads the next record and starts processing it with the first rule in -the program, just as any other `nextfile' statement. + The current version of the Brian Kernighan's 'awk', and 'mawk' (*note +Other Versions::) also support 'nextfile'. However, they don't allow +the 'nextfile' statement inside function bodies (*note User-defined::). +'gawk' does; a 'nextfile' inside a function body reads the next record +and starts processing it with the first rule in the program, just as any +other 'nextfile' statement.  File: gawk.info, Node: Exit Statement, Prev: Nextfile Statement, Up: Statements -7.4.10 The `exit' Statement +7.4.10 The 'exit' Statement --------------------------- -The `exit' statement causes `awk' to immediately stop executing the +The 'exit' statement causes 'awk' to immediately stop executing the current rule and to stop processing input; any remaining input is -ignored. The `exit' statement is written as follows: - - `exit' [RETURN CODE] - - When an `exit' statement is executed from a `BEGIN' rule, the -program stops processing everything immediately. No input records are -read. However, if an `END' rule is present, as part of executing the -`exit' statement, the `END' rule is executed (*note BEGIN/END::). If -`exit' is used in the body of an `END' rule, it causes the program to -stop immediately. - - An `exit' statement that is not part of a `BEGIN' or `END' rule -stops the execution of any further automatic rules for the current -record, skips reading any remaining input records, and executes the -`END' rule if there is one. Any `ENDFILE' rules are also skipped; they -are not executed. - - In such a case, if you don't want the `END' rule to do its job, set -a variable to nonzero before the `exit' statement and check that -variable in the `END' rule. *Note Assert Function::, for an example -that does this. - - If an argument is supplied to `exit', its value is used as the exit -status code for the `awk' process. If no argument is supplied, `exit' -causes `awk' to return a "success" status. In the case where an -argument is supplied to a first `exit' statement, and then `exit' is -called a second time from an `END' rule with no argument, `awk' uses -the previously supplied exit value. (d.c.) *Note Exit Status::, for -more information. +ignored. The 'exit' statement is written as follows: + + 'exit' [RETURN CODE] + + When an 'exit' statement is executed from a 'BEGIN' rule, the program +stops processing everything immediately. No input records are read. +However, if an 'END' rule is present, as part of executing the 'exit' +statement, the 'END' rule is executed (*note BEGIN/END::). If 'exit' is +used in the body of an 'END' rule, it causes the program to stop +immediately. + + An 'exit' statement that is not part of a 'BEGIN' or 'END' rule stops +the execution of any further automatic rules for the current record, +skips reading any remaining input records, and executes the 'END' rule +if there is one. Any 'ENDFILE' rules are also skipped; they are not +executed. + + In such a case, if you don't want the 'END' rule to do its job, set a +variable to nonzero before the 'exit' statement and check that variable +in the 'END' rule. *Note Assert Function::, for an example that does +this. + + If an argument is supplied to 'exit', its value is used as the exit +status code for the 'awk' process. If no argument is supplied, 'exit' +causes 'awk' to return a "success" status. In the case where an +argument is supplied to a first 'exit' statement, and then 'exit' is +called a second time from an 'END' rule with no argument, 'awk' uses the +previously supplied exit value. (d.c.) *Note Exit Status::, for more +information. For example, suppose an error condition occurs that is difficult or impossible to handle. Conventionally, programs report this by exiting -with a nonzero status. An `awk' program can do this using an `exit' +with a nonzero status. An 'awk' program can do this using an 'exit' statement with a nonzero argument, as shown in the following example: BEGIN { @@ -9900,9 +9856,8 @@ statement with a nonzero argument, as shown in the following example: } NOTE: For full portability, exit values should be between zero and - 126, inclusive. Negative values, and values of 127 or greater, - may not produce consistent results across different operating - systems. + 126, inclusive. Negative values, and values of 127 or greater, may + not produce consistent results across different operating systems.  File: gawk.info, Node: Built-in Variables, Next: Pattern Action Summary, Prev: Statements, Up: Patterns and Actions @@ -9910,160 +9865,159 @@ File: gawk.info, Node: Built-in Variables, Next: Pattern Action Summary, Prev 7.5 Built-in Variables ====================== -Most `awk' variables are available to use for your own purposes; they +Most 'awk' variables are available to use for your own purposes; they never change unless your program assigns values to them, and they never affect anything unless your program examines them. However, a few -variables in `awk' have special built-in meanings. `awk' examines some -of these automatically, so that they enable you to tell `awk' how to do -certain things. Others are set automatically by `awk', so that they -carry information from the internal workings of `awk' to your program. +variables in 'awk' have special built-in meanings. 'awk' examines some +of these automatically, so that they enable you to tell 'awk' how to do +certain things. Others are set automatically by 'awk', so that they +carry information from the internal workings of 'awk' to your program. - This minor node documents all of `gawk''s built-in variables, most -of which are also documented in the major nodes describing their areas -of activity. + This minor node documents all of 'gawk''s built-in variables, most of +which are also documented in the major nodes describing their areas of +activity. * Menu: * User-modified:: Built-in variables that you change to control - `awk'. -* Auto-set:: Built-in variables where `awk' gives + 'awk'. +* Auto-set:: Built-in variables where 'awk' gives you information. -* ARGC and ARGV:: Ways to use `ARGC' and `ARGV'. +* ARGC and ARGV:: Ways to use 'ARGC' and 'ARGV'.  File: gawk.info, Node: User-modified, Next: Auto-set, Up: Built-in Variables -7.5.1 Built-in Variables That Control `awk' +7.5.1 Built-in Variables That Control 'awk' ------------------------------------------- The following is an alphabetical list of variables that you can change -to control how `awk' does certain things. +to control how 'awk' does certain things. - The variables that are specific to `gawk' are marked with a pound -sign (`#'). These variables are `gawk' extensions. In other `awk' -implementations or if `gawk' is in compatibility mode (*note -Options::), they are not special. (Any exceptions are noted in the -description of each variable.) + The variables that are specific to 'gawk' are marked with a pound +sign ('#'). These variables are 'gawk' extensions. In other 'awk' +implementations or if 'gawk' is in compatibility mode (*note Options::), +they are not special. (Any exceptions are noted in the description of +each variable.) -`BINMODE #' +'BINMODE #' On non-POSIX systems, this variable specifies use of binary mode - for all I/O. Numeric values of one, two, or three specify that + for all I/O. Numeric values of one, two, or three specify that input files, output files, or all files, respectively, should use - binary I/O. A numeric value less than zero is treated as zero, - and a numeric value greater than three is treated as three. - Alternatively, string values of `"r"' or `"w"' specify that input - files and output files, respectively, should use binary I/O. A - string value of `"rw"' or `"wr"' indicates that all files should - use binary I/O. Any other string value is treated the same as - `"rw"', but causes `gawk' to generate a warning message. - `BINMODE' is described in more detail in *note PC Using::. `mawk' - *note Other Versions::), also supports this variable, but only - using numeric values. - -``CONVFMT'' + binary I/O. A numeric value less than zero is treated as zero, and + a numeric value greater than three is treated as three. + Alternatively, string values of '"r"' or '"w"' specify that input + files and output files, respectively, should use binary I/O. A + string value of '"rw"' or '"wr"' indicates that all files should + use binary I/O. Any other string value is treated the same as + '"rw"', but causes 'gawk' to generate a warning message. 'BINMODE' + is described in more detail in *note PC Using::. 'mawk' *note + Other Versions::), also supports this variable, but only using + numeric values. + +'CONVFMT' This string controls conversion of numbers to strings (*note Conversion::). It works by being passed, in effect, as the first - argument to the `sprintf()' function (*note String Functions::). - Its default value is `"%.6g"'. `CONVFMT' was introduced by the + argument to the 'sprintf()' function (*note String Functions::). + Its default value is '"%.6g"'. 'CONVFMT' was introduced by the POSIX standard. -`FIELDWIDTHS #' - A space-separated list of columns that tells `gawk' how to split +'FIELDWIDTHS #' + A space-separated list of columns that tells 'gawk' how to split input with fixed columnar boundaries. Assigning a value to - `FIELDWIDTHS' overrides the use of `FS' and `FPAT' for field + 'FIELDWIDTHS' overrides the use of 'FS' and 'FPAT' for field splitting. *Note Constant Size::, for more information. -`FPAT #' - A regular expression (as a string) that tells `gawk' to create the +'FPAT #' + A regular expression (as a string) that tells 'gawk' to create the fields based on text that matches the regular expression. - Assigning a value to `FPAT' overrides the use of `FS' and - `FIELDWIDTHS' for field splitting. *Note Splitting By Content::, + Assigning a value to 'FPAT' overrides the use of 'FS' and + 'FIELDWIDTHS' for field splitting. *Note Splitting By Content::, for more information. -`FS' - The input field separator (*note Field Separators::). The value - is a single-character string or a multicharacter regular - expression that matches the separations between fields in an input - record. If the value is the null string (`""'), then each - character in the record becomes a separate field. (This behavior - is a `gawk' extension. POSIX `awk' does not specify the behavior - when `FS' is the null string. Nonetheless, some other versions of - `awk' also treat `""' specially.) - - The default value is `" "', a string consisting of a single space. +'FS' + The input field separator (*note Field Separators::). The value is + a single-character string or a multicharacter regular expression + that matches the separations between fields in an input record. If + the value is the null string ('""'), then each character in the + record becomes a separate field. (This behavior is a 'gawk' + extension. POSIX 'awk' does not specify the behavior when 'FS' is + the null string. Nonetheless, some other versions of 'awk' also + treat '""' specially.) + + The default value is '" "', a string consisting of a single space. As a special exception, this value means that any sequence of spaces, TABs, and/or newlines is a single separator.(1) It also causes spaces, TABs, and newlines at the beginning and end of a record to be ignored. - You can set the value of `FS' on the command line using the `-F' + You can set the value of 'FS' on the command line using the '-F' option: awk -F, 'PROGRAM' INPUT-FILES - If `gawk' is using `FIELDWIDTHS' or `FPAT' for field splitting, - assigning a value to `FS' causes `gawk' to return to the normal, - `FS'-based field splitting. An easy way to do this is to simply - say `FS = FS', perhaps with an explanatory comment. + If 'gawk' is using 'FIELDWIDTHS' or 'FPAT' for field splitting, + assigning a value to 'FS' causes 'gawk' to return to the normal, + 'FS'-based field splitting. An easy way to do this is to simply + say 'FS = FS', perhaps with an explanatory comment. -`IGNORECASE #' - If `IGNORECASE' is nonzero or non-null, then all string comparisons +'IGNORECASE #' + If 'IGNORECASE' is nonzero or non-null, then all string comparisons and all regular expression matching are case independent. Thus, - regexp matching with `~' and `!~', as well as the `gensub()', - `gsub()', `index()', `match()', `patsplit()', `split()', and - `sub()' functions, record termination with `RS', and field - splitting with `FS' and `FPAT', all ignore case when doing their - particular regexp operations. However, the value of `IGNORECASE' + regexp matching with '~' and '!~', as well as the 'gensub()', + 'gsub()', 'index()', 'match()', 'patsplit()', 'split()', and + 'sub()' functions, record termination with 'RS', and field + splitting with 'FS' and 'FPAT', all ignore case when doing their + particular regexp operations. However, the value of 'IGNORECASE' does _not_ affect array subscripting and it does not affect field splitting when using a single-character field separator. *Note Case-sensitivity::. -`LINT #' - When this variable is true (nonzero or non-null), `gawk' behaves - as if the `--lint' command-line option is in effect (*note - Options::). With a value of `"fatal"', lint warnings become fatal - errors. With a value of `"invalid"', only warnings about things - that are actually invalid are issued. (This is not fully - implemented yet.) Any other true value prints nonfatal warnings. - Assigning a false value to `LINT' turns off the lint warnings. - - This variable is a `gawk' extension. It is not special in other - `awk' implementations. Unlike the other special variables, - changing `LINT' does affect the production of lint warnings, even - if `gawk' is in compatibility mode. Much as the `--lint' and - `--traditional' options independently control different aspects of - `gawk''s behavior, the control of lint warnings during program - execution is independent of the flavor of `awk' being executed. - -`OFMT' +'LINT #' + When this variable is true (nonzero or non-null), 'gawk' behaves as + if the '--lint' command-line option is in effect (*note Options::). + With a value of '"fatal"', lint warnings become fatal errors. With + a value of '"invalid"', only warnings about things that are + actually invalid are issued. (This is not fully implemented yet.) + Any other true value prints nonfatal warnings. Assigning a false + value to 'LINT' turns off the lint warnings. + + This variable is a 'gawk' extension. It is not special in other + 'awk' implementations. Unlike the other special variables, + changing 'LINT' does affect the production of lint warnings, even + if 'gawk' is in compatibility mode. Much as the '--lint' and + '--traditional' options independently control different aspects of + 'gawk''s behavior, the control of lint warnings during program + execution is independent of the flavor of 'awk' being executed. + +'OFMT' Controls conversion of numbers to strings (*note Conversion::) for - printing with the `print' statement. It works by being passed as - the first argument to the `sprintf()' function (*note String - Functions::). Its default value is `"%.6g"'. Earlier versions of - `awk' also used `OFMT' to specify the format for converting - numbers to strings in general expressions; this is now done by - `CONVFMT'. - -`OFS' - This is the output field separator (*note Output Separators::). - It is output between the fields printed by a `print' statement. - Its default value is `" "', a string consisting of a single space. - -`ORS' + printing with the 'print' statement. It works by being passed as + the first argument to the 'sprintf()' function (*note String + Functions::). Its default value is '"%.6g"'. Earlier versions of + 'awk' also used 'OFMT' to specify the format for converting numbers + to strings in general expressions; this is now done by 'CONVFMT'. + +'OFS' + This is the output field separator (*note Output Separators::). It + is output between the fields printed by a 'print' statement. Its + default value is '" "', a string consisting of a single space. + +'ORS' The output record separator. It is output at the end of every - `print' statement. Its default value is `"\n"', the newline + 'print' statement. Its default value is '"\n"', the newline character. (*Note Output Separators::.) -`PREC #' +'PREC #' The working precision of arbitrary precision floating-point numbers, 53 bits by default (*note Setting precision::). -`ROUNDMODE #' +'ROUNDMODE #' The rounding mode to use for arbitrary precision arithmetic on - numbers, by default `"N"' (`roundTiesToEven' in the IEEE 754 + numbers, by default '"N"' ('roundTiesToEven' in the IEEE 754 standard; *note Setting the rounding mode::). -``RS'' +'RS' The input record separator. Its default value is a string containing a single newline character, which means that an input record consists of a single line of text. It can also be the null @@ -10071,28 +10025,28 @@ description of each variable.) If it is a regexp, records are separated by matches of the regexp in the input text. (*Note Records::.) - The ability for `RS' to be a regular expression is a `gawk' - extension. In most other `awk' implementations, or if `gawk' is - in compatibility mode (*note Options::), just the first character - of `RS''s value is used. + The ability for 'RS' to be a regular expression is a 'gawk' + extension. In most other 'awk' implementations, or if 'gawk' is in + compatibility mode (*note Options::), just the first character of + 'RS''s value is used. -``SUBSEP'' - The subscript separator. It has the default value of `"\034"' and +'SUBSEP' + The subscript separator. It has the default value of '"\034"' and is used to separate the parts of the indices of a multidimensional - array. Thus, the expression `foo["A", "B"]' really accesses - `foo["A\034B"]' (*note Multidimensional::). + array. Thus, the expression 'foo["A", "B"]' really accesses + 'foo["A\034B"]' (*note Multidimensional::). -`TEXTDOMAIN #' - Used for internationalization of programs at the `awk' level. It +'TEXTDOMAIN #' + Used for internationalization of programs at the 'awk' level. It sets the default text domain for specially marked string constants - in the source text, as well as for the `dcgettext()', - `dcngettext()' and `bindtextdomain()' functions (*note - Internationalization::). The default value of `TEXTDOMAIN' is - `"messages"'. + in the source text, as well as for the 'dcgettext()', + 'dcngettext()' and 'bindtextdomain()' functions (*note + Internationalization::). The default value of 'TEXTDOMAIN' is + '"messages"'. ---------- Footnotes ---------- - (1) In POSIX `awk', newline does not count as whitespace. + (1) In POSIX 'awk', newline does not count as whitespace.  File: gawk.info, Node: Auto-set, Next: ARGC and ARGV, Prev: User-modified, Up: Built-in Variables @@ -10100,20 +10054,20 @@ File: gawk.info, Node: Auto-set, Next: ARGC and ARGV, Prev: User-modified, U 7.5.2 Built-in Variables That Convey Information ------------------------------------------------ -The following is an alphabetical list of variables that `awk' sets +The following is an alphabetical list of variables that 'awk' sets automatically on certain occasions in order to provide information to your program. - The variables that are specific to `gawk' are marked with a pound -sign (`#'). These variables are `gawk' extensions. In other `awk' -implementations or if `gawk' is in compatibility mode (*note -Options::), they are not special. + The variables that are specific to 'gawk' are marked with a pound +sign ('#'). These variables are 'gawk' extensions. In other 'awk' +implementations or if 'gawk' is in compatibility mode (*note Options::), +they are not special. -`ARGC', `ARGV' - The command-line arguments available to `awk' programs are stored - in an array called `ARGV'. `ARGC' is the number of command-line - arguments present. *Note Other Arguments::. Unlike most `awk' - arrays, `ARGV' is indexed from 0 to `ARGC' - 1. In the following +'ARGC', 'ARGV' + The command-line arguments available to 'awk' programs are stored + in an array called 'ARGV'. 'ARGC' is the number of command-line + arguments present. *Note Other Arguments::. Unlike most 'awk' + arrays, 'ARGV' is indexed from 0 to 'ARGC' - 1. In the following example: $ awk 'BEGIN { @@ -10124,246 +10078,245 @@ Options::), they are not special. -| inventory-shipped -| mail-list - `ARGV[0]' contains `awk', `ARGV[1]' contains `inventory-shipped', - and `ARGV[2]' contains `mail-list'. The value of `ARGC' is three, - one more than the index of the last element in `ARGV', because the + 'ARGV[0]' contains 'awk', 'ARGV[1]' contains 'inventory-shipped', + and 'ARGV[2]' contains 'mail-list'. The value of 'ARGC' is three, + one more than the index of the last element in 'ARGV', because the elements are numbered from zero. - The names `ARGC' and `ARGV', as well as the convention of indexing - the array from 0 to `ARGC' - 1, are derived from the C language's + The names 'ARGC' and 'ARGV', as well as the convention of indexing + the array from 0 to 'ARGC' - 1, are derived from the C language's method of accessing command-line arguments. - The value of `ARGV[0]' can vary from system to system. Also, you - should note that the program text is _not_ included in `ARGV', nor - are any of `awk''s command-line options. *Note ARGC and ARGV::, - for information about how `awk' uses these variables. (d.c.) + The value of 'ARGV[0]' can vary from system to system. Also, you + should note that the program text is _not_ included in 'ARGV', nor + are any of 'awk''s command-line options. *Note ARGC and ARGV::, + for information about how 'awk' uses these variables. (d.c.) -`ARGIND #' - The index in `ARGV' of the current file being processed. Every - time `gawk' opens a new data file for processing, it sets `ARGIND' - to the index in `ARGV' of the file name. When `gawk' is - processing the input files, `FILENAME == ARGV[ARGIND]' is always - true. +'ARGIND #' + The index in 'ARGV' of the current file being processed. Every + time 'gawk' opens a new data file for processing, it sets 'ARGIND' + to the index in 'ARGV' of the file name. When 'gawk' is processing + the input files, 'FILENAME == ARGV[ARGIND]' is always true. This variable is useful in file processing; it allows you to tell how far along you are in the list of data files as well as to distinguish between successive instances of the same file name on the command line. - While you can change the value of `ARGIND' within your `awk' - program, `gawk' automatically sets it to a new value when the next + While you can change the value of 'ARGIND' within your 'awk' + program, 'gawk' automatically sets it to a new value when the next file is opened. -`ENVIRON' - An associative array containing the values of the environment. - The array indices are the environment variable names; the elements - are the values of the particular environment variables. For - example, `ENVIRON["HOME"]' might be `/home/arnold'. +'ENVIRON' + An associative array containing the values of the environment. The + array indices are the environment variable names; the elements are + the values of the particular environment variables. For example, + 'ENVIRON["HOME"]' might be '/home/arnold'. - For POSIX `awk', changing this array does not affect the - environment passed on to any programs that `awk' may spawn via - redirection or the `system()' function. + For POSIX 'awk', changing this array does not affect the + environment passed on to any programs that 'awk' may spawn via + redirection or the 'system()' function. However, beginning with version 4.2, if not in POSIX compatibility - mode, `gawk' does update its own environment when `ENVIRON' is + mode, 'gawk' does update its own environment when 'ENVIRON' is changed, thus changing the environment seen by programs that it creates. You should therefore be especially careful if you modify - `ENVIRON["PATH"]"', which is the search path for finding - executable programs. + 'ENVIRON["PATH"]"', which is the search path for finding executable + programs. - Some operating systems may not have environment variables. On - such systems, the `ENVIRON' array is empty (except for - `ENVIRON["AWKPATH"]' and `ENVIRON["AWKLIBPATH"]'; *note AWKPATH - Variable::, and *note AWKLIBPATH Variable::). + Some operating systems may not have environment variables. On such + systems, the 'ENVIRON' array is empty (except for 'ENVIRON["AWKPATH"]' + and 'ENVIRON["AWKLIBPATH"]'; *note AWKPATH Variable::, and *note + AWKLIBPATH Variable::). -`ERRNO #' - If a system error occurs during a redirection for `getline', during - a read for `getline', or during a `close()' operation, then - `ERRNO' contains a string describing the error. +'ERRNO #' + If a system error occurs during a redirection for 'getline', during + a read for 'getline', or during a 'close()' operation, then 'ERRNO' + contains a string describing the error. - In addition, `gawk' clears `ERRNO' before opening each - command-line input file. This enables checking if the file is - readable inside a `BEGINFILE' pattern (*note BEGINFILE/ENDFILE::). + In addition, 'gawk' clears 'ERRNO' before opening each command-line + input file. This enables checking if the file is readable inside a + 'BEGINFILE' pattern (*note BEGINFILE/ENDFILE::). - Otherwise, `ERRNO' works similarly to the C variable `errno'. - Except for the case just mentioned, `gawk' _never_ clears it (sets - it to zero or `""'). Thus, you should only expect its value to be + Otherwise, 'ERRNO' works similarly to the C variable 'errno'. + Except for the case just mentioned, 'gawk' _never_ clears it (sets + it to zero or '""'). Thus, you should only expect its value to be meaningful when an I/O operation returns a failure value, such as - `getline' returning -1. You are, of course, free to clear it + 'getline' returning -1. You are, of course, free to clear it yourself before doing an I/O operation. -`FILENAME' +'FILENAME' The name of the current input file. When no data files are listed - on the command line, `awk' reads from the standard input and - `FILENAME' is set to `"-"'. `FILENAME' changes each time a new - file is read (*note Reading Files::). Inside a `BEGIN' rule, the - value of `FILENAME' is `""', since there are no input files being - processed yet.(1) (d.c.) Note, though, that using `getline' (*note - Getline::) inside a `BEGIN' rule can give `FILENAME' a value. - -`FNR' - The current record number in the current file. `FNR' is + on the command line, 'awk' reads from the standard input and + 'FILENAME' is set to '"-"'. 'FILENAME' changes each time a new + file is read (*note Reading Files::). Inside a 'BEGIN' rule, the + value of 'FILENAME' is '""', since there are no input files being + processed yet.(1) (d.c.) Note, though, that using 'getline' + (*note Getline::) inside a 'BEGIN' rule can give 'FILENAME' a + value. + +'FNR' + The current record number in the current file. 'FNR' is incremented each time a new record is read (*note Records::). It is reinitialized to zero each time a new input file is started. -`NF' - The number of fields in the current input record. `NF' is set - each time a new record is read, when a new field is created or - when `$0' changes (*note Fields::). +'NF' + The number of fields in the current input record. 'NF' is set each + time a new record is read, when a new field is created or when '$0' + changes (*note Fields::). Unlike most of the variables described in this node, assigning a - value to `NF' has the potential to affect `awk''s internal - workings. In particular, assignments to `NF' can be used to - create or remove fields from the current record. *Note Changing - Fields::. + value to 'NF' has the potential to affect 'awk''s internal + workings. In particular, assignments to 'NF' can be used to create + or remove fields from the current record. *Note Changing Fields::. -`FUNCTAB #' +'FUNCTAB #' An array whose indices and corresponding values are the names of all the user-defined or extension functions in the program. - NOTE: Attempting to use the `delete' statement with the - `FUNCTAB' array causes a fatal error. Any attempt to assign - to an element of `FUNCTAB' also causes a fatal error. + NOTE: Attempting to use the 'delete' statement with the + 'FUNCTAB' array causes a fatal error. Any attempt to assign + to an element of 'FUNCTAB' also causes a fatal error. -`NR' - The number of input records `awk' has processed since the - beginning of the program's execution (*note Records::). `NR' is - incremented each time a new record is read. +'NR' + The number of input records 'awk' has processed since the beginning + of the program's execution (*note Records::). 'NR' is incremented + each time a new record is read. -`PROCINFO #' +'PROCINFO #' The elements of this array provide access to information about the - running `awk' program. The following elements (listed + running 'awk' program. The following elements (listed alphabetically) are guaranteed to be available: - `PROCINFO["egid"]' - The value of the `getegid()' system call. + 'PROCINFO["egid"]' + The value of the 'getegid()' system call. - `PROCINFO["euid"]' - The value of the `geteuid()' system call. + 'PROCINFO["euid"]' + The value of the 'geteuid()' system call. - `PROCINFO["FS"]' - This is `"FS"' if field splitting with `FS' is in effect, - `"FIELDWIDTHS"' if field splitting with `FIELDWIDTHS' is in - effect, or `"FPAT"' if field matching with `FPAT' is in + 'PROCINFO["FS"]' + This is '"FS"' if field splitting with 'FS' is in effect, + '"FIELDWIDTHS"' if field splitting with 'FIELDWIDTHS' is in + effect, or '"FPAT"' if field matching with 'FPAT' is in effect. - `PROCINFO["identifiers"]' + 'PROCINFO["identifiers"]' A subarray, indexed by the names of all identifiers used in the text of the AWK program. For each identifier, the value of the element is one of the following: - `"array"' + '"array"' The identifier is an array. - `"extension"' + '"extension"' The identifier is an extension function loaded via - `@load'. + '@load'. - `"scalar"' + '"scalar"' The identifier is a scalar. - `"untyped"' + '"untyped"' The identifier is untyped (could be used as a scalar or - array, `gawk' doesn't know yet). + array, 'gawk' doesn't know yet). - `"user"' + '"user"' The identifier is a user-defined function. - The values indicate what `gawk' knows about the identifiers + The values indicate what 'gawk' knows about the identifiers after it has finished parsing the program; they are _not_ updated while the program runs. - `PROCINFO["gid"]' - The value of the `getgid()' system call. + 'PROCINFO["gid"]' + The value of the 'getgid()' system call. - `PROCINFO["pgrpid"]' + 'PROCINFO["pgrpid"]' The process group ID of the current process. - `PROCINFO["pid"]' + 'PROCINFO["pid"]' The process ID of the current process. - `PROCINFO["ppid"]' + 'PROCINFO["ppid"]' The parent process ID of the current process. - `PROCINFO["sorted_in"]' - If this element exists in `PROCINFO', its value controls the - order in which array indices will be processed by `for (INDEX - in ARRAY)' loops. Since this is an advanced feature, we - defer the full description until later; see *note Scanning an + 'PROCINFO["sorted_in"]' + If this element exists in 'PROCINFO', its value controls the + order in which array indices will be processed by 'for (INDEX + in ARRAY)' loops. Since this is an advanced feature, we defer + the full description until later; see *note Scanning an Array::. - `PROCINFO["strftime"]' - The default time format string for `strftime()'. Assigning a + 'PROCINFO["strftime"]' + The default time format string for 'strftime()'. Assigning a new value to this element changes the default. *Note Time Functions::. - `PROCINFO["uid"]' - The value of the `getuid()' system call. + 'PROCINFO["uid"]' + The value of the 'getuid()' system call. - `PROCINFO["version"]' - The version of `gawk'. + 'PROCINFO["version"]' + The version of 'gawk'. The following additional elements in the array are available to provide information about the MPFR and GMP libraries if your - version of `gawk' supports arbitrary precision numbers (*note + version of 'gawk' supports arbitrary precision numbers (*note Arbitrary Precision Arithmetic::): - `PROCINFO["mpfr_version"]' + 'PROCINFO["mpfr_version"]' The version of the GNU MPFR library. - `PROCINFO["gmp_version"]' + 'PROCINFO["gmp_version"]' The version of the GNU MP library. - `PROCINFO["prec_max"]' + 'PROCINFO["prec_max"]' The maximum precision supported by MPFR. - `PROCINFO["prec_min"]' + 'PROCINFO["prec_min"]' The minimum precision required by MPFR. The following additional elements in the array are available to - provide information about the version of the extension API, if - your version of `gawk' supports dynamic loading of extension - functions (*note Dynamic Extensions::): + provide information about the version of the extension API, if your + version of 'gawk' supports dynamic loading of extension functions + (*note Dynamic Extensions::): - `PROCINFO["api_major"]' + 'PROCINFO["api_major"]' The major version of the extension API. - `PROCINFO["api_minor"]' + 'PROCINFO["api_minor"]' The minor version of the extension API. - On some systems, there may be elements in the array, `"group1"' - through `"groupN"' for some N. N is the number of supplementary - groups that the process has. Use the `in' operator to test for + On some systems, there may be elements in the array, '"group1"' + through '"groupN"' for some N. N is the number of supplementary + groups that the process has. Use the 'in' operator to test for these elements (*note Reference to Elements::). - The `PROCINFO' array has the following additional uses: + The 'PROCINFO' array has the following additional uses: * It may be used to cause coprocesses to communicate over pseudo-ttys instead of through two-way pipes; this is discussed further in *note Two-way I/O::. - * It may be used to provide a timeout when reading from any - open input file, pipe, or coprocess. *Note Read Timeout::, - for more information. + * It may be used to provide a timeout when reading from any open + input file, pipe, or coprocess. *Note Read Timeout::, for + more information. -`RLENGTH' - The length of the substring matched by the `match()' function - (*note String Functions::). `RLENGTH' is set by invoking the - `match()' function. Its value is the length of the matched - string, or -1 if no match is found. +'RLENGTH' + The length of the substring matched by the 'match()' function + (*note String Functions::). 'RLENGTH' is set by invoking the + 'match()' function. Its value is the length of the matched string, + or -1 if no match is found. -`RSTART' +'RSTART' The start-index in characters of the substring that is matched by - the `match()' function (*note String Functions::). `RSTART' is - set by invoking the `match()' function. Its value is the position - of the string where the matched substring starts, or zero if no - match was found. + the 'match()' function (*note String Functions::). 'RSTART' is set + by invoking the 'match()' function. Its value is the position of + the string where the matched substring starts, or zero if no match + was found. -`RT #' - The input text that matched the text denoted by `RS', the record +'RT #' + The input text that matched the text denoted by 'RS', the record separator. It is set every time a record is read. -`SYMTAB #' +'SYMTAB #' An array whose indices are the names of all currently defined global variables and arrays in the program. The array may be used for indirect access to read or write the value of a variable: @@ -10372,23 +10325,23 @@ Options::), they are not special. SYMTAB["foo"] = 4 print foo # prints 4 - The `isarray()' function (*note Type Functions::) may be used to - test if an element in `SYMTAB' is an array. Also, you may not use - the `delete' statement with the `SYMTAB' array. + The 'isarray()' function (*note Type Functions::) may be used to + test if an element in 'SYMTAB' is an array. Also, you may not use + the 'delete' statement with the 'SYMTAB' array. - You may use an index for `SYMTAB' that is not a predefined + You may use an index for 'SYMTAB' that is not a predefined identifier: SYMTAB["xxx"] = 5 print SYMTAB["xxx"] - This works as expected: in this case `SYMTAB' acts just like a + This works as expected: in this case 'SYMTAB' acts just like a regular array. The only difference is that you can't then delete - `SYMTAB["xxx"]'. + 'SYMTAB["xxx"]'. - The `SYMTAB' array is more interesting than it looks. Andrew Schorr - points out that it effectively gives `awk' data pointers. Consider - his example: + The 'SYMTAB' array is more interesting than it looks. Andrew + Schorr points out that it effectively gives 'awk' data pointers. + Consider his example: # Indirect multiply of any variable by amount, return result @@ -10398,12 +10351,12 @@ Options::), they are not special. } NOTE: In order to avoid severe time-travel paradoxes,(2) - neither `FUNCTAB' nor `SYMTAB' are available as elements - within the `SYMTAB' array. + neither 'FUNCTAB' nor 'SYMTAB' are available as elements + within the 'SYMTAB' array. - Changing `NR' and `FNR' + Changing 'NR' and 'FNR' - `awk' increments `NR' and `FNR' each time it reads a record, instead + 'awk' increments 'NR' and 'FNR' each time it reads a record, instead of setting them to the absolute value of the number of records read. This means that a program can change these variables and their new values are incremented for each record. (d.c.) The following example @@ -10419,14 +10372,14 @@ shows this: -| 18 -| 19 -Before `FNR' was added to the `awk' language (*note V7/SVR3.1::), many -`awk' programs used this feature to track the number of records in a -file by resetting `NR' to zero when `FILENAME' changed. +Before 'FNR' was added to the 'awk' language (*note V7/SVR3.1::), many +'awk' programs used this feature to track the number of records in a +file by resetting 'NR' to zero when 'FILENAME' changed. ---------- Footnotes ---------- - (1) Some early implementations of Unix `awk' initialized `FILENAME' -to `"-"', even if there were data files to be processed. This behavior + (1) Some early implementations of Unix 'awk' initialized 'FILENAME' +to '"-"', even if there were data files to be processed. This behavior was incorrect and should not be relied upon in your programs. (2) Not to mention difficult implementation issues. @@ -10434,11 +10387,11 @@ was incorrect and should not be relied upon in your programs.  File: gawk.info, Node: ARGC and ARGV, Prev: Auto-set, Up: Built-in Variables -7.5.3 Using `ARGC' and `ARGV' +7.5.3 Using 'ARGC' and 'ARGV' ----------------------------- *note Auto-set::, presented the following program describing the -information contained in `ARGC' and `ARGV': +information contained in 'ARGC' and 'ARGV': $ awk 'BEGIN { > for (i = 0; i < ARGC; i++) @@ -10448,14 +10401,14 @@ information contained in `ARGC' and `ARGV': -| inventory-shipped -| mail-list -In this example, `ARGV[0]' contains `awk', `ARGV[1]' contains -`inventory-shipped', and `ARGV[2]' contains `mail-list'. Notice that -the `awk' program is not entered in `ARGV'. The other command-line +In this example, 'ARGV[0]' contains 'awk', 'ARGV[1]' contains +'inventory-shipped', and 'ARGV[2]' contains 'mail-list'. Notice that +the 'awk' program is not entered in 'ARGV'. The other command-line options, with their arguments, are also not entered. This includes -variable assignments done with the `-v' option (*note Options::). +variable assignments done with the '-v' option (*note Options::). Normal variable assignments on the command line _are_ treated as -arguments and do show up in the `ARGV' array. Given the following -program in a file named `showargs.awk': +arguments and do show up in the 'ARGV' array. Given the following +program in a file named 'showargs.awk': BEGIN { printf "A=%d, B=%d\n", A, B @@ -10473,28 +10426,28 @@ Running it produces the following: -| ARGV[2] = /dev/null -| A=1, B=2 - A program can alter `ARGC' and the elements of `ARGV'. Each time -`awk' reaches the end of an input file, it uses the next element of -`ARGV' as the name of the next input file. By storing a different -string there, a program can change which files are read. Use `"-"' to + A program can alter 'ARGC' and the elements of 'ARGV'. Each time +'awk' reaches the end of an input file, it uses the next element of +'ARGV' as the name of the next input file. By storing a different +string there, a program can change which files are read. Use '"-"' to represent the standard input. Storing additional elements and -incrementing `ARGC' causes additional files to be read. +incrementing 'ARGC' causes additional files to be read. - If the value of `ARGC' is decreased, that eliminates input files -from the end of the list. By recording the old value of `ARGC' -elsewhere, a program can treat the eliminated arguments as something -other than file names. + If the value of 'ARGC' is decreased, that eliminates input files from +the end of the list. By recording the old value of 'ARGC' elsewhere, a +program can treat the eliminated arguments as something other than file +names. To eliminate a file from the middle of the list, store the null -string (`""') into `ARGV' in place of the file's name. As a special -feature, `awk' ignores file names that have been replaced with the null -string. Another option is to use the `delete' statement to remove -elements from `ARGV' (*note Delete::). +string ('""') into 'ARGV' in place of the file's name. As a special +feature, 'awk' ignores file names that have been replaced with the null +string. Another option is to use the 'delete' statement to remove +elements from 'ARGV' (*note Delete::). - All of these actions are typically done in the `BEGIN' rule, before + All of these actions are typically done in the 'BEGIN' rule, before actual processing of the input begins. *Note Split Program::, and see *note Tee Program::, for examples of each way of removing elements from -`ARGV'. The following fragment processes `ARGV' in order to examine, +'ARGV'. The following fragment processes 'ARGV' in order to examine, and then remove, command-line options: BEGIN { @@ -10513,23 +10466,23 @@ and then remove, command-line options: } } - To actually get the options into the `awk' program, end the `awk' -options with `--' and then supply the `awk' program's options, in the + To actually get the options into the 'awk' program, end the 'awk' +options with '--' and then supply the 'awk' program's options, in the following manner: awk -f myprog -- -v -q file1 file2 ... - This is not necessary in `gawk'. Unless `--posix' has been -specified, `gawk' silently puts any unrecognized options into `ARGV' -for the `awk' program to deal with. As soon as it sees an unknown -option, `gawk' stops looking for other options that it might otherwise -recognize. The previous example with `gawk' would be: + This is not necessary in 'gawk'. Unless '--posix' has been +specified, 'gawk' silently puts any unrecognized options into 'ARGV' for +the 'awk' program to deal with. As soon as it sees an unknown option, +'gawk' stops looking for other options that it might otherwise +recognize. The previous example with 'gawk' would be: gawk -f myprog -q -v file1 file2 ... -Because `-q' is not a valid `gawk' option, it and the following `-v' -are passed on to the `awk' program. (*Note Getopt Function::, for an -`awk' library function that parses command-line options.) +Because '-q' is not a valid 'gawk' option, it and the following '-v' are +passed on to the 'awk' program. (*Note Getopt Function::, for an 'awk' +library function that parses command-line options.)  File: gawk.info, Node: Pattern Action Summary, Prev: Built-in Variables, Up: Patterns and Actions @@ -10537,82 +10490,81 @@ File: gawk.info, Node: Pattern Action Summary, Prev: Built-in Variables, Up: 7.6 Summary =========== - * Pattern-action pairs make up the basic elements of an `awk' + * Pattern-action pairs make up the basic elements of an 'awk' program. Patterns are either normal expressions, range - expressions, regexp constants, one of the special keywords - `BEGIN', `END', `BEGINFILE', `ENDFILE', or empty. The action - executes if the current record matches the pattern. Empty - (missing) patterns match all records. - - * I/O from `BEGIN' and `END' rules have certain constraints. This - is also true, only more so, for `BEGINFILE' and `ENDFILE' rules. - The latter two give you "hooks" into `gawk''s file processing, - allowing you to recover from a file that otherwise would cause a - fatal error (such as a file that cannot be opened). - - * Shell variables can be used in `awk' programs by careful use of - shell quoting. It is easier to pass a shell variable into `awk' - by using the `-v' option and an `awk' variable. - - * Actions consist of statements enclosed in curly braces. Statements + expressions, regexp constants, one of the special keywords 'BEGIN', + 'END', 'BEGINFILE', 'ENDFILE', or empty. The action executes if + the current record matches the pattern. Empty (missing) patterns + match all records. + + * I/O from 'BEGIN' and 'END' rules have certain constraints. This is + also true, only more so, for 'BEGINFILE' and 'ENDFILE' rules. The + latter two give you "hooks" into 'gawk''s file processing, allowing + you to recover from a file that otherwise would cause a fatal error + (such as a file that cannot be opened). + + * Shell variables can be used in 'awk' programs by careful use of + shell quoting. It is easier to pass a shell variable into 'awk' by + using the '-v' option and an 'awk' variable. + + * Actions consist of statements enclosed in curly braces. Statements are built up from expressions, control statements, compound statements, input and output statements, and deletion statements. - * The control statements in `awk' are `if'-`else', `while', `for', - and `do'-`while'. `gawk' adds the `switch' statement. There are - two flavors of `for' statement: one for for performing general + * The control statements in 'awk' are 'if'-'else', 'while', 'for', + and 'do'-'while'. 'gawk' adds the 'switch' statement. There are + two flavors of 'for' statement: one for for performing general looping, and the other iterating through an array. - * `break' and `continue' let you exit early or start the next - iteration of a loop (or get out of a `switch'). + * 'break' and 'continue' let you exit early or start the next + iteration of a loop (or get out of a 'switch'). - * `next' and `nextfile' let you read the next record and start over + * 'next' and 'nextfile' let you read the next record and start over at the top of your program, or skip to the next input file and start over, respectively. - * The `exit' statement terminates your program. When executed from - an action (or function body) it transfers control to the `END' - statements. From an `END' statement body, it exits immediately. - You may pass an optional numeric value to be used at `awk''s exit + * The 'exit' statement terminates your program. When executed from + an action (or function body) it transfers control to the 'END' + statements. From an 'END' statement body, it exits immediately. + You may pass an optional numeric value to be used at 'awk''s exit status. - * Some built-in variables provide control over `awk', mainly for I/O. - Other variables convey information from `awk' to your program. - + * Some built-in variables provide control over 'awk', mainly for I/O. + Other variables convey information from 'awk' to your program.  File: gawk.info, Node: Arrays, Next: Functions, Prev: Patterns and Actions, Up: Top -8 Arrays in `awk' +8 Arrays in 'awk' ***************** An "array" is a table of values called "elements". The elements of an array are distinguished by their "indices". Indices may be either numbers or strings. - This major node describes how arrays work in `awk', how to use array + This major node describes how arrays work in 'awk', how to use array elements, how to scan through every element in an array, and how to -remove array elements. It also describes how `awk' simulates +remove array elements. It also describes how 'awk' simulates multidimensional arrays, as well as some of the less obvious points -about array usage. The major node moves on to discuss `gawk''s facility -for sorting arrays, and ends with a brief description of `gawk''s +about array usage. The major node moves on to discuss 'gawk''s facility +for sorting arrays, and ends with a brief description of 'gawk''s ability to support true arrays of arrays. - `awk' maintains a single set of names that may be used for naming + 'awk' maintains a single set of names that may be used for naming variables, arrays, and functions (*note User-defined::). Thus, you -cannot have a variable and an array with the same name in the same -`awk' program. +cannot have a variable and an array with the same name in the same 'awk' +program. * Menu: * Array Basics:: The basics of arrays. -* Delete:: The `delete' statement removes an element +* Delete:: The 'delete' statement removes an element from an array. * Numeric Array Subscripts:: How to use numbers as subscripts in - `awk'. + 'awk'. * Uninitialized Subscripts:: Using Uninitialized variables as subscripts. * Multidimensional:: Emulating multidimensional arrays in - `awk'. + 'awk'. * Arrays of Arrays:: True multidimensional arrays. * Arrays Summary:: Summary of arrays. @@ -10622,8 +10574,8 @@ File: gawk.info, Node: Array Basics, Next: Delete, Up: Arrays 8.1 The Basics of Arrays ======================== -This minor node presents the basics: working with elements in arrays -one at a time, and traversing all of the elements in an array. +This minor node presents the basics: working with elements in arrays one +at a time, and traversing all of the elements in an array. * Menu: @@ -10631,7 +10583,7 @@ one at a time, and traversing all of the elements in an array. * Reference to Elements:: How to examine one element of an array. * Assigning Elements:: How to change an element of an array. * Array Example:: Basic Example of an Array -* Scanning an Array:: A variation of the `for' statement. It +* Scanning an Array:: A variation of the 'for' statement. It loops through the indices of an array's existing elements. * Controlling Scanning:: Controlling the order in which arrays are @@ -10643,20 +10595,20 @@ File: gawk.info, Node: Array Intro, Next: Reference to Elements, Up: Array Ba 8.1.1 Introduction to Arrays ---------------------------- - Doing linear scans over an associative array is like trying to - club someone to death with a loaded Uzi. -- Larry Wall + Doing linear scans over an associative array is like trying to club + someone to death with a loaded Uzi. + -- _Larry Wall_ - The `awk' language provides one-dimensional arrays for storing -groups of related strings or numbers. Every `awk' array must have a -name. Array names have the same syntax as variable names; any valid -variable name would also be a valid array name. But one name cannot be -used in both ways (as an array and as a variable) in the same `awk' -program. + The 'awk' language provides one-dimensional arrays for storing groups +of related strings or numbers. Every 'awk' array must have a name. +Array names have the same syntax as variable names; any valid variable +name would also be a valid array name. But one name cannot be used in +both ways (as an array and as a variable) in the same 'awk' program. - Arrays in `awk' superficially resemble arrays in other programming -languages, but there are fundamental differences. In `awk', it isn't + Arrays in 'awk' superficially resemble arrays in other programming +languages, but there are fundamental differences. In 'awk', it isn't necessary to specify the size of an array before starting to use it. -Additionally, any number or string in `awk', not just consecutive +Additionally, any number or string in 'awk', not just consecutive integers, may be used as an array index. In most other languages, arrays must be "declared" before use, @@ -10666,28 +10618,29 @@ of memory to be allocated for that many elements. Usually, an index in the array must be a positive integer. For example, the index zero specifies the first element in the array, which is actually stored at the beginning of the block of memory. Index one specifies the second -element, which is stored in memory right after the first element, and -so on. It is impossible to add more elements to the array, because it -has room only for as many elements as given in the declaration. (Some -languages allow arbitrary starting and ending indices--e.g., `15 .. +element, which is stored in memory right after the first element, and so +on. It is impossible to add more elements to the array, because it has +room only for as many elements as given in the declaration. (Some +languages allow arbitrary starting and ending indices--e.g., '15 .. 27'--but the size of the array is still fixed when the array is declared.) A contiguous array of four elements might look like the following -example, conceptually, if the element values are 8, `"foo"', `""', and -30 as shown in *note figure-array-elements::: +example, conceptually, if the element values are 8, '"foo"', '""', and +30 as shown in *note Figure 8.1: figure-array-elements.: +[image src="array-elements.txt" alt="Basic Program Stages" text="+---------+---------+--------+---------+ +| 8 | \"foo\" | \"\" | 30 | @r{Value} +---------+---------+--------+---------+ -| 8 | "foo" | "" | 30 | @r{Value} -+---------+---------+--------+---------+ - 0 1 2 3 @r{Index} + 0 1 2 3 @r{Index}"] + Figure 8.1: A Contiguous Array Only the values are stored; the indices are implicit from the order of -the values. Here, 8 is the value at index zero, because 8 appears in the -position with zero elements before it. +the values. Here, 8 is the value at index zero, because 8 appears in +the position with zero elements before it. - Arrays in `awk' are different--they are "associative". This means + Arrays in 'awk' are different--they are "associative". This means that each array is a collection of pairs: an index and its corresponding array element value: @@ -10698,9 +10651,9 @@ array element value: The pairs are shown in jumbled order because their order is irrelevant. - One advantage of associative arrays is that new pairs can be added -at any time. For example, suppose a tenth element is added to the array -whose value is `"number ten"'. The result is: + One advantage of associative arrays is that new pairs can be added at +any time. For example, suppose a tenth element is added to the array +whose value is '"number ten"'. The result is: Index 10 Value "number ten" Index 3 Value 30 @@ -10726,16 +10679,16 @@ Here we decided to translate the number one in both spelled-out and numeric form--thus illustrating that a single array can have both numbers and strings as indices. (In fact, array subscripts are always strings; this is discussed in more detail in *note Numeric Array -Subscripts::.) Here, the number `1' isn't double-quoted, since `awk' +Subscripts::.) Here, the number '1' isn't double-quoted, since 'awk' automatically converts it to a string. - The value of `IGNORECASE' has no effect upon array subscripting. -The identical string value used to store an array element must be used -to retrieve it. When `awk' creates an array (e.g., with the `split()' + The value of 'IGNORECASE' has no effect upon array subscripting. The +identical string value used to store an array element must be used to +retrieve it. When 'awk' creates an array (e.g., with the 'split()' built-in function), that array's indices are consecutive integers starting at one. (*Note String Functions::.) - `awk''s arrays are efficient--the time to access an element is + 'awk''s arrays are efficient--the time to access an element is independent of the number of elements in the array.  @@ -10753,27 +10706,27 @@ Here, ARRAY is the name of an array. The expression INDEX-EXPRESSION is the index of the desired element of the array. The value of the array reference is the current value of that array -element. For example, `foo[4.3]' is an expression for the element of -array `foo' at index `4.3'. +element. For example, 'foo[4.3]' is an expression for the element of +array 'foo' at index '4.3'. A reference to an array element that has no recorded value yields a -value of `""', the null string. This includes elements that have not +value of '""', the null string. This includes elements that have not been assigned any value as well as elements that have been deleted (*note Delete::). - NOTE: A reference to an element that does not exist - _automatically_ creates that array element, with the null string - as its value. (In some cases, this is unfortunate, because it - might waste memory inside `awk'.) + NOTE: A reference to an element that does not exist _automatically_ + creates that array element, with the null string as its value. (In + some cases, this is unfortunate, because it might waste memory + inside 'awk'.) - Novice `awk' programmers often make the mistake of checking if an + Novice 'awk' programmers often make the mistake of checking if an element exists by checking if the value is empty: # Check if "foo" exists in a: Incorrect! if (a["foo"] != "") ... - This is incorrect, since this will _create_ `a["foo"]' if it - didn't exist before! + This is incorrect, since this will _create_ 'a["foo"]' if it didn't + exist before! To determine whether an element exists in an array at a certain index, use the following expression: @@ -10782,17 +10735,17 @@ index, use the following expression: This expression tests whether the particular index INDX exists, without the side effect of creating that element if it is not present. The -expression has the value one (true) if `ARRAY[INDX]' exists and zero -(false) if it does not exist. For example, this statement tests -whether the array `frequencies' contains the index `2': +expression has the value one (true) if 'ARRAY[INDX]' exists and zero +(false) if it does not exist. For example, this statement tests whether +the array 'frequencies' contains the index '2': if (2 in frequencies) print "Subscript 2 is present." - Note that this is _not_ a test of whether the array `frequencies' + Note that this is _not_ a test of whether the array 'frequencies' contains an element whose _value_ is two. There is no way to do that except to scan all the elements. Also, this _does not_ create -`frequencies[2]', while the following (incorrect) alternative does: +'frequencies[2]', while the following (incorrect) alternative does: if (frequencies[2] != "") print "Subscript 2 is present." @@ -10803,7 +10756,7 @@ File: gawk.info, Node: Assigning Elements, Next: Array Example, Prev: Referen 8.1.3 Assigning Array Elements ------------------------------ -Array elements can be assigned values just like `awk' variables: +Array elements can be assigned values just like 'awk' variables: ARRAY[INDEX-EXPRESSION] = VALUE @@ -10821,8 +10774,8 @@ The following program takes a list of lines, each beginning with a line number, and prints them out in order of line number. The line numbers are not in order when they are first read--instead they are scrambled. This program sorts the lines by making an array using the line numbers -as subscripts. The program then prints out the lines in sorted order -of their numbers. It is a very simple program and gets confused upon +as subscripts. The program then prints out the lines in sorted order of +their numbers. It is a very simple program and gets confused upon encountering repeated numbers, gaps, or lines that don't begin with a number: @@ -10837,11 +10790,11 @@ number: print arr[x] } - The first rule keeps track of the largest line number seen so far; -it also stores each line into the array `arr', at an index that is the + The first rule keeps track of the largest line number seen so far; it +also stores each line into the array 'arr', at an index that is the line's number. The second rule runs after all the input has been read, -to print out all the lines. When this program is run with the -following input: +to print out all the lines. When this program is run with the following +input: 5 I am the Five man 2 Who are you? The new number two! @@ -10859,7 +10812,7 @@ Its output is: If a line number is repeated, the last line with a given number overrides the others. Gaps in the line numbers can be handled with an -easy improvement to the program's `END' rule, as follows: +easy improvement to the program's 'END' rule, as follows: END { for (x = 1; x <= max; x++) @@ -10875,11 +10828,11 @@ File: gawk.info, Node: Scanning an Array, Next: Controlling Scanning, Prev: A In programs that use arrays, it is often necessary to use a loop that executes once for each element of an array. In other languages, where -arrays are contiguous and indices are limited to positive integers, -this is easy: all the valid indices can be found by counting from the -lowest index up to the highest. This technique won't do the job in -`awk', because any number or string can be an array index. So `awk' -has a special kind of `for' statement for scanning an array: +arrays are contiguous and indices are limited to positive integers, this +is easy: all the valid indices can be found by counting from the lowest +index up to the highest. This technique won't do the job in 'awk', +because any number or string can be an array index. So 'awk' has a +special kind of 'for' statement for scanning an array: for (VAR in ARRAY) BODY @@ -10887,14 +10840,14 @@ has a special kind of `for' statement for scanning an array: This loop executes BODY once for each index in ARRAY that the program has previously used, with the variable VAR set to that index. - The following program uses this form of the `for' statement. The + The following program uses this form of the 'for' statement. The first rule scans the input records and notes which words appear (at -least once) in the input, by storing a one into the array `used' with -the word as index. The second rule scans the elements of `used' to -find all the distinct words that appear in the input. It prints each -word that is more than 10 characters long and also prints the number of -such words. *Note String Functions::, for more information on the -built-in function `length()'. +least once) in the input, by storing a one into the array 'used' with +the word as index. The second rule scans the elements of 'used' to find +all the distinct words that appear in the input. It prints each word +that is more than 10 characters long and also prints the number of such +words. *Note String Functions::, for more information on the built-in +function 'length()'. # Record a 1 for each word that is used at least once { @@ -10917,15 +10870,15 @@ built-in function `length()'. The order in which elements of the array are accessed by this statement is determined by the internal arrangement of the array -elements within `awk' and in standard `awk' cannot be controlled or +elements within 'awk' and in standard 'awk' cannot be controlled or changed. This can lead to problems if new elements are added to ARRAY -by statements in the loop body; it is not predictable whether the `for' +by statements in the loop body; it is not predictable whether the 'for' loop will reach them. Similarly, changing VAR inside the loop may produce strange results. It is best to avoid such things. - As a point of information, `gawk' sets up the list of elements to be + As a point of information, 'gawk' sets up the list of elements to be iterated over before the loop starts, and does not change it. But not -all `awk' versions do so. Consider this program, named `loopcheck.awk': +all 'awk' versions do so. Consider this program, named 'loopcheck.awk': BEGIN { a["here"] = "here" @@ -10939,7 +10892,7 @@ all `awk' versions do so. Consider this program, named `loopcheck.awk': } } - Here is what happens when run with `gawk': + Here is what happens when run with 'gawk': $ gawk -f loopcheck.awk -| here @@ -10947,7 +10900,7 @@ all `awk' versions do so. Consider this program, named `loopcheck.awk': -| a -| is - Contrast this to Brian Kernighan's `awk': + Contrast this to Brian Kernighan's 'awk': $ nawk -f loopcheck.awk -| loop @@ -10959,87 +10912,87 @@ all `awk' versions do so. Consider this program, named `loopcheck.awk':  File: gawk.info, Node: Controlling Scanning, Prev: Scanning an Array, Up: Array Basics -8.1.6 Using Predefined Array Scanning Orders With `gawk' +8.1.6 Using Predefined Array Scanning Orders With 'gawk' -------------------------------------------------------- -This node describes a feature that is specific to `gawk'. +This node describes a feature that is specific to 'gawk'. - By default, when a `for' loop traverses an array, the order is -undefined, meaning that the `awk' implementation determines the order -in which the array is traversed. This order is usually based on the + By default, when a 'for' loop traverses an array, the order is +undefined, meaning that the 'awk' implementation determines the order in +which the array is traversed. This order is usually based on the internal implementation of arrays and will vary from one version of -`awk' to the next. +'awk' to the next. - Often, though, you may wish to do something simple, such as -"traverse the array by comparing the indices in ascending order," or -"traverse the array by comparing the values in descending order." -`gawk' provides two mechanisms which give you this control. + Often, though, you may wish to do something simple, such as "traverse +the array by comparing the indices in ascending order," or "traverse the +array by comparing the values in descending order." 'gawk' provides two +mechanisms which give you this control. - * Set `PROCINFO["sorted_in"]' to one of a set of predefined values. + * Set 'PROCINFO["sorted_in"]' to one of a set of predefined values. We describe this now. - * Set `PROCINFO["sorted_in"]' to the name of a user-defined function - to use for comparison of array elements. This advanced feature is + * Set 'PROCINFO["sorted_in"]' to the name of a user-defined function + to use for comparison of array elements. This advanced feature is described later, in *note Array Sorting::. - The following special values for `PROCINFO["sorted_in"]' are + The following special values for 'PROCINFO["sorted_in"]' are available: -`"@unsorted"' +'"@unsorted"' Array elements are processed in arbitrary order, which is the - default `awk' behavior. + default 'awk' behavior. -`"@ind_str_asc"' +'"@ind_str_asc"' Order by indices in ascending order compared as strings; this is the most basic sort. (Internally, array indices are always - strings, so with `a[2*5] = 1' the index is `"10"' rather than + strings, so with 'a[2*5] = 1' the index is '"10"' rather than numeric 10.) -`"@ind_num_asc"' - Order by indices in ascending order but force them to be treated - as numbers in the process. Any index with a non-numeric value - will end up positioned as if it were zero. +'"@ind_num_asc"' + Order by indices in ascending order but force them to be treated as + numbers in the process. Any index with a non-numeric value will + end up positioned as if it were zero. -`"@val_type_asc"' +'"@val_type_asc"' Order by element values in ascending order (rather than by indices). Ordering is by the type assigned to the element (*note Typing and Comparison::). All numeric values come before all - string values, which in turn come before all subarrays. - (Subarrays have not been described yet; *note Arrays of Arrays::.) + string values, which in turn come before all subarrays. (Subarrays + have not been described yet; *note Arrays of Arrays::.) -`"@val_str_asc"' +'"@val_str_asc"' Order by element values in ascending order (rather than by indices). Scalar values are compared as strings. Subarrays, if present, come out last. -`"@val_num_asc"' +'"@val_num_asc"' Order by element values in ascending order (rather than by indices). Scalar values are compared as numbers. Subarrays, if present, come out last. When numeric values are equal, the string values are used to provide an ordering: this guarantees consistent - results across different versions of the C `qsort()' function,(1) - which `gawk' uses internally to perform the sorting. + results across different versions of the C 'qsort()' function,(1) + which 'gawk' uses internally to perform the sorting. -`"@ind_str_desc"' +'"@ind_str_desc"' String indices ordered from high to low. -`"@ind_num_desc"' +'"@ind_num_desc"' Numeric indices ordered from high to low. -`"@val_type_desc"' +'"@val_type_desc"' Element values, based on type, ordered from high to low. Subarrays, if present, come out first. -`"@val_str_desc"' +'"@val_str_desc"' Element values, treated as strings, ordered from high to low. Subarrays, if present, come out first. -`"@val_num_desc"' +'"@val_num_desc"' Element values, treated as numbers, ordered from high to low. Subarrays, if present, come out first. - The array traversal order is determined before the `for' loop starts -to run. Changing `PROCINFO["sorted_in"]' in the loop body does not + The array traversal order is determined before the 'for' loop starts +to run. Changing 'PROCINFO["sorted_in"]' in the loop body does not affect the loop. For example: $ gawk 'BEGIN { @@ -11069,10 +11022,10 @@ relative to each other is determined by their index strings. Here are some additional things to bear in mind about sorted array traversal. - * The value of `PROCINFO["sorted_in"]' is global. That is, it affects - all array traversal `for' loops. If you need to change it within - your own code, you should see if it's defined and save and restore - the value: + * The value of 'PROCINFO["sorted_in"]' is global. That is, it + affects all array traversal 'for' loops. If you need to change it + within your own code, you should see if it's defined and save and + restore the value: ... if ("sorted_in" in PROCINFO) { @@ -11084,77 +11037,77 @@ traversal. PROCINFO["sorted_in"] = save_sorted * As mentioned, the default array traversal order is represented by - `"@unsorted"'. You can also get the default behavior by assigning - the null string to `PROCINFO["sorted_in"]' or by just deleting the - `"sorted_in"' element from the `PROCINFO' array with the `delete' - statement. (The `delete' statement hasn't been described yet; + '"@unsorted"'. You can also get the default behavior by assigning + the null string to 'PROCINFO["sorted_in"]' or by just deleting the + '"sorted_in"' element from the 'PROCINFO' array with the 'delete' + statement. (The 'delete' statement hasn't been described yet; *note Delete::.) - In addition, `gawk' provides built-in functions for sorting arrays; + In addition, 'gawk' provides built-in functions for sorting arrays; see *note Array Sorting Functions::. ---------- Footnotes ---------- - (1) When two elements compare as equal, the C `qsort()' function -does not guarantee that they will maintain their original relative -order after sorting. Using the string value to provide a unique -ordering when the numeric values are equal ensures that `gawk' behaves -consistently across different environments. + (1) When two elements compare as equal, the C 'qsort()' function does +not guarantee that they will maintain their original relative order +after sorting. Using the string value to provide a unique ordering when +the numeric values are equal ensures that 'gawk' behaves consistently +across different environments.  File: gawk.info, Node: Delete, Next: Numeric Array Subscripts, Prev: Array Basics, Up: Arrays -8.2 The `delete' Statement +8.2 The 'delete' Statement ========================== -To remove an individual element of an array, use the `delete' statement: +To remove an individual element of an array, use the 'delete' statement: delete ARRAY[INDEX-EXPRESSION] Once an array element has been deleted, any value the element once -had is no longer available. It is as if the element had never been +had is no longer available. It is as if the element had never been referred to or been given a value. The following is an example of deleting elements in an array: for (i in frequencies) delete frequencies[i] -This example removes all the elements from the array `frequencies'. -Once an element is deleted, a subsequent `for' statement to scan the -array does not report that element and the `in' operator to check for +This example removes all the elements from the array 'frequencies'. +Once an element is deleted, a subsequent 'for' statement to scan the +array does not report that element and the 'in' operator to check for the presence of that element returns zero (i.e., false): delete foo[4] if (4 in foo) print "This will never be printed" - It is important to note that deleting an element is _not_ the same -as assigning it a null value (the empty string, `""'). For example: + It is important to note that deleting an element is _not_ the same as +assigning it a null value (the empty string, '""'). For example: foo[4] = "" if (4 in foo) print "This is printed, even though foo[4] is empty" It is not an error to delete an element that does not exist. -However, if `--lint' is provided on the command line (*note Options::), -`gawk' issues a warning message when an element that is not in the -array is deleted. +However, if '--lint' is provided on the command line (*note Options::), +'gawk' issues a warning message when an element that is not in the array +is deleted. All the elements of an array may be deleted with a single statement -by leaving off the subscript in the `delete' statement, as follows: +by leaving off the subscript in the 'delete' statement, as follows: delete ARRAY - Using this version of the `delete' statement is about three times -more efficient than the equivalent loop that deletes each element one -at a time. + Using this version of the 'delete' statement is about three times +more efficient than the equivalent loop that deletes each element one at +a time. - NOTE: For many years, using `delete' without a subscript was a - `gawk' extension. As of September, 2012, it was accepted for - inclusion into the POSIX standard. See the Austin Group website + NOTE: For many years, using 'delete' without a subscript was a + 'gawk' extension. As of September, 2012, it was accepted for + inclusion into the POSIX standard. See the Austin Group website (http://austingroupbugs.net/view.php?id=544). This form of the - `delete' statement is also supported by Brian Kernighan's `awk' - and `mawk', as well as by a number of other implementations (*note + 'delete' statement is also supported by Brian Kernighan's 'awk' and + 'mawk', as well as by a number of other implementations (*note Other Versions::). The following statement provides a portable but nonobvious way to @@ -11162,14 +11115,14 @@ clear out an array:(1) split("", array) - The `split()' function (*note String Functions::) clears out the -target array first. This call asks it to split apart the null string. + The 'split()' function (*note String Functions::) clears out the +target array first. This call asks it to split apart the null string. Because there is no data to split out, the function simply clears the array and then returns. CAUTION: Deleting an array does not change its type; you cannot delete an array and then use the array's name as a scalar (i.e., a - regular variable). For example, the following does not work: + regular variable). For example, the following does not work: a[1] = 3 delete a @@ -11186,11 +11139,11 @@ File: gawk.info, Node: Numeric Array Subscripts, Next: Uninitialized Subscript ===================================== An important aspect to remember about arrays is that _array subscripts -are always strings_. When a numeric value is used as a subscript, it -is converted to a string value before being used for subscripting -(*note Conversion::). This means that the value of the built-in -variable `CONVFMT' can affect how your program accesses elements of an -array. For example: +are always strings_. When a numeric value is used as a subscript, it is +converted to a string value before being used for subscripting (*note +Conversion::). This means that the value of the built-in variable +'CONVFMT' can affect how your program accesses elements of an array. +For example: xyz = 12.153 data[xyz] = 1 @@ -11200,20 +11153,20 @@ array. For example: else printf "%s is not in data\n", xyz -This prints `12.15 is not in data'. The first statement gives `xyz' a -numeric value. Assigning to `data[xyz]' subscripts `data' with the -string value `"12.153"' (using the default conversion value of -`CONVFMT', `"%.6g"'). Thus, the array element `data["12.153"]' is +This prints '12.15 is not in data'. The first statement gives 'xyz' a +numeric value. Assigning to 'data[xyz]' subscripts 'data' with the +string value '"12.153"' (using the default conversion value of +'CONVFMT', '"%.6g"'). Thus, the array element 'data["12.153"]' is assigned the value one. The program then changes the value of -`CONVFMT'. The test `(xyz in data)' generates a new string value from -`xyz'--this time `"12.15"'--because the value of `CONVFMT' only allows -two significant digits. This test fails, since `"12.15"' is different -from `"12.153"'. +'CONVFMT'. The test '(xyz in data)' generates a new string value from +'xyz'--this time '"12.15"'--because the value of 'CONVFMT' only allows +two significant digits. This test fails, since '"12.15"' is different +from '"12.153"'. According to the rules for conversions (*note Conversion::), integer values are always converted to strings as integers, no matter what the -value of `CONVFMT' may happen to be. So the usual case of the -following works: +value of 'CONVFMT' may happen to be. So the usual case of the following +works: for (i = 1; i <= maxsub; i++) do something with array[i] @@ -11221,14 +11174,14 @@ following works: The "integer values always convert to strings as integers" rule has an additional consequence for array indexing. Octal and hexadecimal constants (*note Nondecimal-numbers::) are converted internally into -numbers, and their original form is forgotten. This means, for -example, that `array[17]', `array[021]', and `array[0x11]' all refer to -the same element! +numbers, and their original form is forgotten. This means, for example, +that 'array[17]', 'array[021]', and 'array[0x11]' all refer to the same +element! - As with many things in `awk', the majority of the time things work -as one would expect them to. But it is useful to have a precise -knowledge of the actual rules since they can sometimes have a subtle -effect on your programs. + As with many things in 'awk', the majority of the time things work as +one would expect them to. But it is useful to have a precise knowledge +of the actual rules since they can sometimes have a subtle effect on +your programs.  File: gawk.info, Node: Uninitialized Subscripts, Next: Multidimensional, Prev: Numeric Array Subscripts, Up: Arrays @@ -11254,13 +11207,13 @@ might look like this: the output! Upon first glance, we would think that this program should have -worked. The variable `lines' is uninitialized, and uninitialized -variables have the numeric value zero. So, `awk' should have printed -the value of `l[0]'. +worked. The variable 'lines' is uninitialized, and uninitialized +variables have the numeric value zero. So, 'awk' should have printed +the value of 'l[0]'. - The issue here is that subscripts for `awk' arrays are _always_ -strings. Uninitialized variables, when used as strings, have the value -`""', not zero. Thus, `line 1' ends up stored in `l[""]'. The + The issue here is that subscripts for 'awk' arrays are _always_ +strings. Uninitialized variables, when used as strings, have the value +'""', not zero. Thus, 'line 1' ends up stored in 'l[""]'. The following version of the program works correctly: { l[lines++] = $0 } @@ -11269,14 +11222,14 @@ following version of the program works correctly: print l[i] } - Here, the `++' forces `lines' to be numeric, thus making the "old -value" numeric zero. This is then converted to `"0"' as the array + Here, the '++' forces 'lines' to be numeric, thus making the "old +value" numeric zero. This is then converted to '"0"' as the array subscript. - Even though it is somewhat unusual, the null string (`""') is a -valid array subscript. (d.c.) `gawk' warns about the use of the null -string as a subscript if `--lint' is provided on the command line -(*note Options::). + Even though it is somewhat unusual, the null string ('""') is a valid +array subscript. (d.c.) 'gawk' warns about the use of the null string +as a subscript if '--lint' is provided on the command line (*note +Options::).  File: gawk.info, Node: Multidimensional, Next: Arrays of Arrays, Prev: Uninitialized Subscripts, Up: Arrays @@ -11288,41 +11241,39 @@ File: gawk.info, Node: Multidimensional, Next: Arrays of Arrays, Prev: Uninit * Multiscanning:: Scanning multidimensional arrays. - A multidimensional array is an array in which an element is -identified by a sequence of indices instead of a single index. For -example, a two-dimensional array requires two indices. The usual way -(in most languages, including `awk') to refer to an element of a -two-dimensional array named `grid' is with `grid[X,Y]'. +A multidimensional array is an array in which an element is identified +by a sequence of indices instead of a single index. For example, a +two-dimensional array requires two indices. The usual way (in most +languages, including 'awk') to refer to an element of a two-dimensional +array named 'grid' is with 'grid[X,Y]'. - Multidimensional arrays are supported in `awk' through concatenation -of indices into one string. `awk' converts the indices into strings + Multidimensional arrays are supported in 'awk' through concatenation +of indices into one string. 'awk' converts the indices into strings (*note Conversion::) and concatenates them together, with a separator -between them. This creates a single string that describes the values -of the separate indices. The combined string is used as a single index +between them. This creates a single string that describes the values of +the separate indices. The combined string is used as a single index into an ordinary, one-dimensional array. The separator used is the -value of the built-in variable `SUBSEP'. - - For example, suppose we evaluate the expression `foo[5,12] = "value"' -when the value of `SUBSEP' is `"@"'. The numbers 5 and 12 are -converted to strings and concatenated with an `@' between them, -yielding `"5@12"'; thus, the array element `foo["5@12"]' is set to -`"value"'. - - Once the element's value is stored, `awk' has no record of whether -it was stored with a single index or a sequence of indices. The two -expressions `foo[5,12]' and `foo[5 SUBSEP 12]' are always equivalent. - - The default value of `SUBSEP' is the string `"\034"', which contains -a nonprinting character that is unlikely to appear in an `awk' program -or in most input data. The usefulness of choosing an unlikely -character comes from the fact that index values that contain a string -matching `SUBSEP' can lead to combined strings that are ambiguous. -Suppose that `SUBSEP' is `"@"'; then `foo["a@b", "c"]' and -`foo["a", "b@c"]' are indistinguishable because both are actually -stored as `foo["a@b@c"]'. +value of the built-in variable 'SUBSEP'. + + For example, suppose we evaluate the expression 'foo[5,12] = "value"' +when the value of 'SUBSEP' is '"@"'. The numbers 5 and 12 are converted +to strings and concatenated with an '@' between them, yielding '"5@12"'; +thus, the array element 'foo["5@12"]' is set to '"value"'. + + Once the element's value is stored, 'awk' has no record of whether it +was stored with a single index or a sequence of indices. The two +expressions 'foo[5,12]' and 'foo[5 SUBSEP 12]' are always equivalent. + + The default value of 'SUBSEP' is the string '"\034"', which contains +a nonprinting character that is unlikely to appear in an 'awk' program +or in most input data. The usefulness of choosing an unlikely character +comes from the fact that index values that contain a string matching +'SUBSEP' can lead to combined strings that are ambiguous. Suppose that +'SUBSEP' is '"@"'; then 'foo["a@b", "c"]' and 'foo["a", "b@c"]' are +indistinguishable because both are actually stored as 'foo["a@b@c"]'. To test whether a particular index sequence exists in a -multidimensional array, use the same operator (`in') that is used for +multidimensional array, use the same operator ('in') that is used for single dimensional arrays. Write the whole sequence of indices in parentheses, separated by commas, as the left operand: @@ -11370,38 +11321,38 @@ File: gawk.info, Node: Multiscanning, Up: Multidimensional 8.5.1 Scanning Multidimensional Arrays -------------------------------------- -There is no special `for' statement for scanning a "multidimensional" -array. There cannot be one, because, in truth, `awk' does not have +There is no special 'for' statement for scanning a "multidimensional" +array. There cannot be one, because, in truth, 'awk' does not have multidimensional arrays or elements--there is only a multidimensional _way of accessing_ an array. However, if your program has an array that is always accessed as -multidimensional, you can get the effect of scanning it by combining -the scanning `for' statement (*note Scanning an Array::) with the -built-in `split()' function (*note String Functions::). It works in -the following manner: +multidimensional, you can get the effect of scanning it by combining the +scanning 'for' statement (*note Scanning an Array::) with the built-in +'split()' function (*note String Functions::). It works in the +following manner: for (combined in array) { split(combined, separate, SUBSEP) ... } -This sets the variable `combined' to each concatenated combined index -in the array, and splits it into the individual indices by breaking it -apart where the value of `SUBSEP' appears. The individual indices then -become the elements of the array `separate'. +This sets the variable 'combined' to each concatenated combined index in +the array, and splits it into the individual indices by breaking it +apart where the value of 'SUBSEP' appears. The individual indices then +become the elements of the array 'separate'. - Thus, if a value is previously stored in `array[1, "foo"]', then an -element with index `"1\034foo"' exists in `array'. (Recall that the -default value of `SUBSEP' is the character with code 034.) Sooner or -later, the `for' statement finds that index and does an iteration with -the variable `combined' set to `"1\034foo"'. Then the `split()' + Thus, if a value is previously stored in 'array[1, "foo"]', then an +element with index '"1\034foo"' exists in 'array'. (Recall that the +default value of 'SUBSEP' is the character with code 034.) Sooner or +later, the 'for' statement finds that index and does an iteration with +the variable 'combined' set to '"1\034foo"'. Then the 'split()' function is called as follows: split("1\034foo", separate, "\034") -The result is to set `separate[1]' to `"1"' and `separate[2]' to -`"foo"'. Presto! The original sequence of separate indices is +The result is to set 'separate[1]' to '"1"' and 'separate[2]' to +'"foo"'. Presto! The original sequence of separate indices is recovered.  @@ -11410,72 +11361,72 @@ File: gawk.info, Node: Arrays of Arrays, Next: Arrays Summary, Prev: Multidim 8.6 Arrays of Arrays ==================== -`gawk' goes beyond standard `awk''s multidimensional array access and -provides true arrays of arrays. Elements of a subarray are referred to -by their own indices enclosed in square brackets, just like the -elements of the main array. For example, the following creates a -two-element subarray at index `1' of the main array `a': +'gawk' goes beyond standard 'awk''s multidimensional array access and +provides true arrays of arrays. Elements of a subarray are referred to +by their own indices enclosed in square brackets, just like the elements +of the main array. For example, the following creates a two-element +subarray at index '1' of the main array 'a': a[1][1] = 1 a[1][2] = 2 - This simulates a true two-dimensional array. Each subarray element + This simulates a true two-dimensional array. Each subarray element can contain another subarray as a value, which in turn can hold other -arrays as well. In this way, you can create arrays of three or more -dimensions. The indices can be any `awk' expression, including scalars -separated by commas (that is, a regular `awk' simulated -multidimensional subscript). So the following is valid in `gawk': +arrays as well. In this way, you can create arrays of three or more +dimensions. The indices can be any 'awk' expression, including scalars +separated by commas (that is, a regular 'awk' simulated multidimensional +subscript). So the following is valid in 'gawk': a[1][3][1, "name"] = "barney" - Each subarray and the main array can be of different length. In + Each subarray and the main array can be of different length. In fact, the elements of an array or its subarray do not all have to have -the same type. This means that the main array and any of its subarrays -can be non-rectangular, or jagged in structure. One can assign a scalar -value to the index `4' of the main array `a': +the same type. This means that the main array and any of its subarrays +can be non-rectangular, or jagged in structure. One can assign a scalar +value to the index '4' of the main array 'a': a[4] = "An element in a jagged array" The terms "dimension", "row" and "column" are meaningless when applied to such an array, but we will use "dimension" henceforth to imply the maximum number of indices needed to refer to an existing -element. The type of any element that has already been assigned cannot -be changed by assigning a value of a different type. You have to first -delete the current element, which effectively makes `gawk' forget about +element. The type of any element that has already been assigned cannot +be changed by assigning a value of a different type. You have to first +delete the current element, which effectively makes 'gawk' forget about the element at that index: delete a[4] a[4][5][6][7] = "An element in a four-dimensional array" -This removes the scalar value from index `4' and then inserts a -subarray of subarray of subarray containing a scalar. You can also -delete an entire subarray or subarray of subarrays: +This removes the scalar value from index '4' and then inserts a subarray +of subarray of subarray containing a scalar. You can also delete an +entire subarray or subarray of subarrays: delete a[4][5] a[4][5] = "An element in subarray a[4]" - But recall that you can not delete the main array `a' and then use it + But recall that you can not delete the main array 'a' and then use it as a scalar. The built-in functions which take array arguments can also be used -with subarrays. For example, the following code fragment uses `length()' -(*note String Functions::) to determine the number of elements in the -main array `a' and its subarrays: +with subarrays. For example, the following code fragment uses +'length()' (*note String Functions::) to determine the number of +elements in the main array 'a' and its subarrays: print length(a), length(a[1]), length(a[1][3]) -This results in the following output for our main array `a': +This results in the following output for our main array 'a': 2, 3, 1 -The `SUBSCRIPT in ARRAY' expression (*note Reference to Elements::) -works similarly for both regular `awk'-style arrays and arrays of -arrays. For example, the tests `1 in a', `3 in a[1]', and `(1, "name") -in a[1][3]' all evaluate to one (true) for our array `a'. +The 'SUBSCRIPT in ARRAY' expression (*note Reference to Elements::) +works similarly for both regular 'awk'-style arrays and arrays of +arrays. For example, the tests '1 in a', '3 in a[1]', and '(1, "name") +in a[1][3]' all evaluate to one (true) for our array 'a'. - The `for (item in array)' statement (*note Scanning an Array::) can + The 'for (item in array)' statement (*note Scanning an Array::) can be nested to scan all the elements of an array of arrays if it is -rectangular in structure. In order to print the contents (scalar +rectangular in structure. In order to print the contents (scalar values) of a two-dimensional array of arrays (i.e., in which each first-level element is itself an array, not necessarily of the same length) you could use the following code: @@ -11484,8 +11435,8 @@ length) you could use the following code: for (j in array[i]) print array[i][j] - The `isarray()' function (*note Type Functions::) lets you test if -an array element is itself an array: + The 'isarray()' function (*note Type Functions::) lets you test if an +array element is itself an array: for (i in array) { if (isarray(array[i]) { @@ -11495,9 +11446,9 @@ an array element is itself an array: } } - If the structure of a jagged array of arrays is known in advance, -you can often devise workarounds using control statements. For example, -the following code prints the elements of our main array `a': + If the structure of a jagged array of arrays is known in advance, you +can often devise workarounds using control statements. For example, the +following code prints the elements of our main array 'a': for (i in a) { for (j in a[i]) { @@ -11513,14 +11464,14 @@ the following code prints the elements of our main array `a': arbitrarily-dimensioned array of arrays. Recall that a reference to an uninitialized array element yields a -value of `""', the null string. This has one important implication when +value of '""', the null string. This has one important implication when you intend to use a subarray as an argument to a function, as illustrated by the following example: $ gawk 'BEGIN { split("a b c d", b[1]); print b[1][1] }' - error--> gawk: cmd. line:1: fatal: split: second argument is not an array + error-> gawk: cmd. line:1: fatal: split: second argument is not an array - The way to work around this is to first force `b[1]' to be an array + The way to work around this is to first force 'b[1]' to be an array by creating an arbitrary index: $ gawk 'BEGIN { b[1][1] = ""; split("a b c d", b[1]); print b[1][1] }' @@ -11532,60 +11483,59 @@ File: gawk.info, Node: Arrays Summary, Prev: Arrays of Arrays, Up: Arrays 8.7 Summary =========== - * Standard `awk' provides one-dimensional associative arrays (arrays + * Standard 'awk' provides one-dimensional associative arrays (arrays indexed by string values). All arrays are associative; numeric indices are converted automatically to strings. - * Array elements are referenced as `ARRAY[INDX]'. Referencing an + * Array elements are referenced as 'ARRAY[INDX]'. Referencing an element creates it if it did not exist previously. * The proper way to see if an array has an element with a given index - is to use the `in' operator: `INDX in ARRAY'. + is to use the 'in' operator: 'INDX in ARRAY'. - * Use `for (INDX in ARRAY) ...' to scan through all the individual - elements of an array. In the body of the loop, INDX takes on the + * Use 'for (INDX in ARRAY) ...' to scan through all the individual + elements of an array. In the body of the loop, INDX takes on the value of each element's index in turn. - * The order in which a `for (INDX in ARRAY)' loop traverses an array - is undefined in POSIX `awk' and varies among implementations. - `gawk' lets you control the order by assigning special predefined - values to `PROCINFO["sorted_in"]'. + * The order in which a 'for (INDX in ARRAY)' loop traverses an array + is undefined in POSIX 'awk' and varies among implementations. + 'gawk' lets you control the order by assigning special predefined + values to 'PROCINFO["sorted_in"]'. - * Use `delete ARRAY[INDX]' to delete an individual element. You may - also use `delete ARRAY' to delete all of the elements in the - array. This latter feature has been a common extension for many - years and is now standard, but may not be supported by all - commercial versions of `awk'. + * Use 'delete ARRAY[INDX]' to delete an individual element. You may + also use 'delete ARRAY' to delete all of the elements in the array. + This latter feature has been a common extension for many years and + is now standard, but may not be supported by all commercial + versions of 'awk'. - * Standard `awk' simulates multidimensional arrays by separating + * Standard 'awk' simulates multidimensional arrays by separating subscript values with a comma. The values are concatenated into a - single string, separated by the value of `SUBSEP'. The fact that + single string, separated by the value of 'SUBSEP'. The fact that such a subscript was created in this way is not retained; thus - changing `SUBSEP' may have unexpected consequences. You can use - `(SUB1, SUB2, ...) in ARRAY' to see if such a multidimensional + changing 'SUBSEP' may have unexpected consequences. You can use + '(SUB1, SUB2, ...) in ARRAY' to see if such a multidimensional subscript exists in ARRAY. - * `gawk' provides true arrays of arrays. You use a separate set of + * 'gawk' provides true arrays of arrays. You use a separate set of square brackets for each dimension in such an array: - `data[row][col]', for example. Array elements may thus be either + 'data[row][col]', for example. Array elements may thus be either scalar values (number or string) or another array. - * Use the `isarray()' built-in function to determine if an array + * Use the 'isarray()' built-in function to determine if an array element is itself a subarray. -  File: gawk.info, Node: Functions, Next: Library Functions, Prev: Arrays, Up: Top 9 Functions *********** -This major node describes `awk''s built-in functions, which fall into -three categories: numeric, string, and I/O. `gawk' provides additional +This major node describes 'awk''s built-in functions, which fall into +three categories: numeric, string, and I/O. 'gawk' provides additional groups of functions to work with values that represent time, do bit manipulation, sort arrays, and internationalize and localize programs. - Besides the built-in functions, `awk' has provisions for writing new + Besides the built-in functions, 'awk' has provisions for writing new functions that the rest of a program can use. The second half of this major node describes these "user-defined" functions. @@ -11602,19 +11552,19 @@ File: gawk.info, Node: Built-in, Next: User-defined, Up: Functions 9.1 Built-in Functions ====================== -"Built-in" functions are always available for your `awk' program to -call. This minor node defines all the built-in functions in `awk'; -some of these are mentioned in other sections but are summarized here -for your convenience. +"Built-in" functions are always available for your 'awk' program to +call. This minor node defines all the built-in functions in 'awk'; some +of these are mentioned in other sections but are summarized here for +your convenience. * Menu: * Calling Built-in:: How to call built-in functions. * Numeric Functions:: Functions that work with numbers, including - `int()', `sin()' and `rand()'. + 'int()', 'sin()' and 'rand()'. * String Functions:: Functions for string manipulation, such as - `split()', `match()' and - `sprintf()'. + 'split()', 'match()' and + 'sprintf()'. * I/O Functions:: Functions for files and shell commands. * Time Functions:: Functions for dealing with timestamps. * Bitwise Functions:: Functions for bitwise operations. @@ -11627,21 +11577,21 @@ File: gawk.info, Node: Calling Built-in, Next: Numeric Functions, Up: Built-i 9.1.1 Calling Built-in Functions -------------------------------- -To call one of `awk''s built-in functions, write the name of the -function followed by arguments in parentheses. For example, `atan2(y + -z, 1)' is a call to the function `atan2()' and has two arguments. +To call one of 'awk''s built-in functions, write the name of the +function followed by arguments in parentheses. For example, 'atan2(y + +z, 1)' is a call to the function 'atan2()' and has two arguments. - Whitespace is ignored between the built-in function name and the -open parenthesis, but nonetheless it is good practice to avoid using + Whitespace is ignored between the built-in function name and the open +parenthesis, but nonetheless it is good practice to avoid using whitespace there. User-defined functions do not permit whitespace in this way, and it is easier to avoid mistakes by following a simple convention that always works--no whitespace after a function name. Each built-in function accepts a certain number of arguments. In -some cases, arguments can be omitted. The defaults for omitted +some cases, arguments can be omitted. The defaults for omitted arguments vary from function to function and are described under the -individual functions. In some `awk' implementations, extra arguments -given to built-in functions are ignored. However, in `gawk', it is a +individual functions. In some 'awk' implementations, extra arguments +given to built-in functions are ignored. However, in 'gawk', it is a fatal error to give extra arguments to a built-in function. When a function is called, expressions that create the function's @@ -11651,19 +11601,19 @@ For example, in the following code fragment: i = 4 j = sqrt(i++) -the variable `i' is incremented to the value five before `sqrt()' is +the variable 'i' is incremented to the value five before 'sqrt()' is called with a value of four for its actual parameter. The order of evaluation of the expressions used for the function's parameters is -undefined. Thus, avoid writing programs that assume that parameters -are evaluated from left to right or from right to left. For example: +undefined. Thus, avoid writing programs that assume that parameters are +evaluated from left to right or from right to left. For example: i = 5 j = atan2(i++, i *= 2) - If the order of evaluation is left to right, then `i' first becomes -6, and then 12, and `atan2()' is called with the two arguments 6 and -12. But if the order of evaluation is right to left, `i' first becomes -10, then 11, and `atan2()' is called with the two arguments 11 and 10. + If the order of evaluation is left to right, then 'i' first becomes +6, and then 12, and 'atan2()' is called with the two arguments 6 and 12. +But if the order of evaluation is right to left, 'i' first becomes 10, +then 11, and 'atan2()' is called with the two arguments 11 and 10.  File: gawk.info, Node: Numeric Functions, Next: String Functions, Prev: Calling Built-in, Up: Built-in @@ -11672,49 +11622,48 @@ File: gawk.info, Node: Numeric Functions, Next: String Functions, Prev: Calli ----------------------- The following list describes all of the built-in functions that work -with numbers. Optional parameters are enclosed in square -brackets ([ ]): +with numbers. Optional parameters are enclosed in square brackets ([ ]): -`atan2(Y, X)' - Return the arctangent of `Y / X' in radians. You can use `pi = +'atan2(Y, X)' + Return the arctangent of 'Y / X' in radians. You can use 'pi = atan2(0, -1)' to retrieve the value of pi. -`cos(X)' +'cos(X)' Return the cosine of X, with X in radians. -`div(NUMERATOR, DENOMINATOR, RESULT)' +'div(NUMERATOR, DENOMINATOR, RESULT)' Perform integer division, similar to the standard C function of the - same name. First, truncate `numerator' and `denominator' towards - zero, creating integer values. Clear the `result' array, and then - set `result["quotient"]' to the result of `numerator / + same name. First, truncate 'numerator' and 'denominator' towards + zero, creating integer values. Clear the 'result' array, and then + set 'result["quotient"]' to the result of 'numerator / denominator', truncated towards zero to an integer, and set - `result["remainder"]' to the result of `numerator % denominator', + 'result["remainder"]' to the result of 'numerator % denominator', truncated towards zero to an integer. This function is primarily - intended for use with arbitrary length integers; it avoids - creating MPFR arbitrary precision floating-point values (*note - Arbitrary Precision Integers::). + intended for use with arbitrary length integers; it avoids creating + MPFR arbitrary precision floating-point values (*note Arbitrary + Precision Integers::). - This function is a `gawk' extension. It is not available in + This function is a 'gawk' extension. It is not available in compatibility mode (*note Options::). -`exp(X)' - Return the exponential of X (`e ^ X') or report an error if X is +'exp(X)' + Return the exponential of X ('e ^ X') or report an error if X is out of range. The range of values X can have depends on your machine's floating-point representation. -`int(X)' +'int(X)' Return the nearest integer to X, located between X and zero and truncated toward zero. - For example, `int(3)' is 3, `int(3.9)' is 3, `int(-3.9)' is -3, - and `int(-3)' is -3 as well. + For example, 'int(3)' is 3, 'int(3.9)' is 3, 'int(-3.9)' is -3, and + 'int(-3)' is -3 as well. -`log(X)' +'log(X)' Return the natural logarithm of X, if X is positive; otherwise, report an error. -`rand()' - Return a random number. The values of `rand()' are uniformly +'rand()' + Return a random number. The values of 'rand()' are uniformly distributed between zero and one. The value could be zero but is never one.(1) @@ -11727,8 +11676,8 @@ brackets ([ ]): } The multiplication produces a random number greater than zero and - less than `n'. Using `int()', this result is made into an integer - between zero and `n' - 1, inclusive. + less than 'n'. Using 'int()', this result is made into an integer + between zero and 'n' - 1, inclusive. The following example uses a similar function to produce random integers between one and N. This program prints a new random @@ -11744,59 +11693,59 @@ brackets ([ ]): roll(6)+roll(6)+roll(6)) } - CAUTION: In most `awk' implementations, including `gawk', - `rand()' starts generating numbers from the same starting - number, or "seed", each time you run `awk'.(2) Thus, a + CAUTION: In most 'awk' implementations, including 'gawk', + 'rand()' starts generating numbers from the same starting + number, or "seed", each time you run 'awk'.(2) Thus, a program generates the same results each time you run it. The - numbers are random within one `awk' run but predictable from + numbers are random within one 'awk' run but predictable from run to run. This is convenient for debugging, but if you want a program to do different things each time it is used, you - must change the seed to a value that is different in each - run. To do this, use `srand()'. + must change the seed to a value that is different in each run. + To do this, use 'srand()'. -`sin(X)' +'sin(X)' Return the sine of X, with X in radians. -`sqrt(X)' - Return the positive square root of X. `gawk' prints a warning - message if X is negative. Thus, `sqrt(4)' is 2. +'sqrt(X)' + Return the positive square root of X. 'gawk' prints a warning + message if X is negative. Thus, 'sqrt(4)' is 2. -`srand('[X]`)' +'srand('[X]')' Set the starting point, or seed, for generating random numbers to the value X. Each seed value leads to a particular sequence of random - numbers.(3) Thus, if the seed is set to the same value a second + numbers.(3) Thus, if the seed is set to the same value a second time, the same sequence of random numbers is produced again. - CAUTION: Different `awk' implementations use different + CAUTION: Different 'awk' implementations use different random-number generators internally. Don't expect the same - `awk' program to produce the same series of random numbers - when executed by different versions of `awk'. + 'awk' program to produce the same series of random numbers + when executed by different versions of 'awk'. - If the argument X is omitted, as in `srand()', then the current + If the argument X is omitted, as in 'srand()', then the current date and time of day are used for a seed. This is the way to get random numbers that are truly unpredictable. - The return value of `srand()' is the previous seed. This makes it + The return value of 'srand()' is the previous seed. This makes it easy to keep track of the seeds in case you need to consistently reproduce sequences of random numbers. ---------- Footnotes ---------- - (1) The C version of `rand()' on many Unix systems is known to + (1) The C version of 'rand()' on many Unix systems is known to produce fairly poor sequences of random numbers. However, nothing -requires that an `awk' implementation use the C `rand()' to implement -the `awk' version of `rand()'. In fact, `gawk' uses the BSD `random()' -function, which is considerably better than `rand()', to produce random +requires that an 'awk' implementation use the C 'rand()' to implement +the 'awk' version of 'rand()'. In fact, 'gawk' uses the BSD 'random()' +function, which is considerably better than 'rand()', to produce random numbers. - (2) `mawk' uses a different seed each time. + (2) 'mawk' uses a different seed each time. (3) Computer-generated random numbers really are not truly random. -They are technically known as "pseudorandom." This means that while -the numbers in a sequence appear to be random, you can in fact generate -the same sequence of random numbers over and over again. +They are technically known as "pseudorandom." This means that while the +numbers in a sequence appear to be random, you can in fact generate the +same sequence of random numbers over and over again.  File: gawk.info, Node: String Functions, Next: I/O Functions, Prev: Numeric Functions, Up: Built-in @@ -11807,102 +11756,101 @@ File: gawk.info, Node: String Functions, Next: I/O Functions, Prev: Numeric F The functions in this minor node look at or change the text of one or more strings. - `gawk' understands locales (*note Locales::), and does all string + 'gawk' understands locales (*note Locales::), and does all string processing in terms of _characters_, not _bytes_. This distinction is -particularly important to understand for locales where one character -may be represented by multiple bytes. Thus, for example, `length()' -returns the number of characters in a string, and not the number of -bytes used to represent those characters. Similarly, `index()' works -with character indices, and not byte indices. - - CAUTION: A number of functions deal with indices into strings. - For these functions, the first character of a string is at - position (index) one. This is different from C and the languages - descended from it, where the first character is at position zero. - You need to remember this when doing index calculations, - particularly if you are used to C. +particularly important to understand for locales where one character may +be represented by multiple bytes. Thus, for example, 'length()' returns +the number of characters in a string, and not the number of bytes used +to represent those characters. Similarly, 'index()' works with +character indices, and not byte indices. + + CAUTION: A number of functions deal with indices into strings. For + these functions, the first character of a string is at position + (index) one. This is different from C and the languages descended + from it, where the first character is at position zero. You need + to remember this when doing index calculations, particularly if you + are used to C. In the following list, optional parameters are enclosed in square -brackets ([ ]). Several functions perform string substitution; the -full discussion is provided in the description of the `sub()' function, -which comes towards the end since the list is presented in alphabetic -order. +brackets ([ ]). Several functions perform string substitution; the full +discussion is provided in the description of the 'sub()' function, which +comes towards the end since the list is presented in alphabetic order. - Those functions that are specific to `gawk' are marked with a pound -sign (`#'). They are not available in compatibility mode (*note + Those functions that are specific to 'gawk' are marked with a pound +sign ('#'). They are not available in compatibility mode (*note Options::): * Menu: -* Gory Details:: More than you want to know about `\' and - `&' with `sub()', `gsub()', and - `gensub()'. +* Gory Details:: More than you want to know about '\' and + '&' with 'sub()', 'gsub()', and + 'gensub()'. -`asort('SOURCE [`,' DEST [`,' HOW ] ]`) #' -`asorti('SOURCE [`,' DEST [`,' HOW ] ]`) #' +'asort('SOURCE [',' DEST [',' HOW ] ]') #' +'asorti('SOURCE [',' DEST [',' HOW ] ]') #' These two functions are similar in behavior, so they are described together. NOTE: The following description ignores the third argument, - HOW, since it requires understanding features that we have - not discussed yet. Thus, the discussion here is a deliberate + HOW, since it requires understanding features that we have not + discussed yet. Thus, the discussion here is a deliberate simplification. (We do provide all the details later on: *Note Array Sorting Functions::, for the full story.) Both functions return the number of elements in the array SOURCE. - For `asort()', `gawk' sorts the values of SOURCE and replaces the + For 'asort()', 'gawk' sorts the values of SOURCE and replaces the indices of the sorted values of SOURCE with sequential integers starting with one. If the optional array DEST is specified, then SOURCE is duplicated into DEST. DEST is then sorted, leaving the indices of SOURCE unchanged. - When comparing strings, `IGNORECASE' affects the sorting (*note - Array Sorting Functions::). If the SOURCE array contains - subarrays as values (*note Arrays of Arrays::), they will come - last, after all scalar values. + When comparing strings, 'IGNORECASE' affects the sorting (*note + Array Sorting Functions::). If the SOURCE array contains subarrays + as values (*note Arrays of Arrays::), they will come last, after + all scalar values. - For example, if the contents of `a' are as follows: + For example, if the contents of 'a' are as follows: a["last"] = "de" a["first"] = "sac" a["middle"] = "cul" - A call to `asort()': + A call to 'asort()': asort(a) - results in the following contents of `a': + results in the following contents of 'a': a[1] = "cul" a[2] = "de" a[3] = "sac" - The `asorti()' function works similarly to `asort()', however, the - _indices_ are sorted, instead of the values. Thus, in the previous + The 'asorti()' function works similarly to 'asort()', however, the + _indices_ are sorted, instead of the values. Thus, in the previous example, starting with the same initial set of indices and values - in `a', calling `asorti(a)' would yield: + in 'a', calling 'asorti(a)' would yield: a[1] = "first" a[2] = "last" a[3] = "middle" -`gensub(REGEXP, REPLACEMENT, HOW' [`, TARGET']`) #' +'gensub(REGEXP, REPLACEMENT, HOW' [', TARGET']') #' Search the target string TARGET for matches of the regular - expression REGEXP. If HOW is a string beginning with `g' or `G' + expression REGEXP. If HOW is a string beginning with 'g' or 'G' (short for "global"), then replace all matches of REGEXP with REPLACEMENT. Otherwise, HOW is treated as a number indicating - which match of REGEXP to replace. If no TARGET is supplied, use - `$0'. It returns the modified string as the result of the - function and the original target string is _not_ changed. + which match of REGEXP to replace. If no TARGET is supplied, use + '$0'. It returns the modified string as the result of the function + and the original target string is _not_ changed. - `gensub()' is a general substitution function. Its purpose is to - provide more features than the standard `sub()' and `gsub()' + 'gensub()' is a general substitution function. Its purpose is to + provide more features than the standard 'sub()' and 'gsub()' functions. - `gensub()' provides an additional feature that is not available in - `sub()' or `gsub()': the ability to specify components of a regexp + 'gensub()' provides an additional feature that is not available in + 'sub()' or 'gsub()': the ability to specify components of a regexp in the replacement text. This is done by using parentheses in the - regexp to mark the components and then specifying `\N' in the + regexp to mark the components and then specifying '\N' in the replacement text, where N is a digit from 1 to 9. For example: $ gawk ' @@ -11913,9 +11861,9 @@ Options::): > }' -| def abc - As with `sub()', you must type two backslashes in order to get one - into the string. In the replacement text, the sequence `\0' - represents the entire matched text, as does the character `&'. + As with 'sub()', you must type two backslashes in order to get one + into the string. In the replacement text, the sequence '\0' + represents the entire matched text, as does the character '&'. The following example shows how you can use the third argument to control which match of the regexp should be changed: @@ -11924,35 +11872,35 @@ Options::): > gawk '{ print gensub(/a/, "AA", 2) }' -| a b c AA b c - In this case, `$0' is the default target string. `gensub()' + In this case, '$0' is the default target string. 'gensub()' returns the new string as its result, which is passed directly to - `print' for printing. + 'print' for printing. - If the HOW argument is a string that does not begin with `g' or - `G', or if it is a number that is less than or equal to zero, only - one substitution is performed. If HOW is zero, `gawk' issues a + If the HOW argument is a string that does not begin with 'g' or + 'G', or if it is a number that is less than or equal to zero, only + one substitution is performed. If HOW is zero, 'gawk' issues a warning message. - If REGEXP does not match TARGET, `gensub()''s return value is the + If REGEXP does not match TARGET, 'gensub()''s return value is the original unchanged value of TARGET. -`gsub(REGEXP, REPLACEMENT' [`, TARGET']`)' +'gsub(REGEXP, REPLACEMENT' [', TARGET']')' Search TARGET for _all_ of the longest, leftmost, _nonoverlapping_ matching substrings it can find and replace them with REPLACEMENT. - The `g' in `gsub()' stands for "global," which means replace + The 'g' in 'gsub()' stands for "global," which means replace everywhere. For example: { gsub(/Britain/, "United Kingdom"); print } - replaces all occurrences of the string `Britain' with `United + replaces all occurrences of the string 'Britain' with 'United Kingdom' for all input records. - The `gsub()' function returns the number of substitutions made. If + The 'gsub()' function returns the number of substitutions made. If the variable to search and alter (TARGET) is omitted, then the - entire input record (`$0') is used. As in `sub()', the characters - `&' and `\' are special, and the third argument must be assignable. + entire input record ('$0') is used. As in 'sub()', the characters + '&' and '\' are special, and the third argument must be assignable. -`index(IN, FIND)' +'index(IN, FIND)' Search the string IN for the first occurrence of the string FIND, and return the position in characters where that occurrence begins in the string IN. Consider the following example: @@ -11960,72 +11908,72 @@ Options::): $ awk 'BEGIN { print index("peanut", "an") }' -| 3 - If FIND is not found, `index()' returns zero. + If FIND is not found, 'index()' returns zero. It is a fatal error to use a regexp constant for FIND. -`length('[STRING]`)' +'length('[STRING]')' Return the number of characters in STRING. If STRING is a number, the length of the digit string representing that number is - returned. For example, `length("abcde")' is five. By contrast, - `length(15 * 35)' works out to three. In this example, 15 * 35 = - 525, and 525 is then converted to the string `"525"', which has + returned. For example, 'length("abcde")' is five. By contrast, + 'length(15 * 35)' works out to three. In this example, 15 * 35 = + 525, and 525 is then converted to the string '"525"', which has three characters. - If no argument is supplied, `length()' returns the length of `$0'. + If no argument is supplied, 'length()' returns the length of '$0'. - NOTE: In older versions of `awk', the `length()' function + NOTE: In older versions of 'awk', the 'length()' function could be called without any parentheses. Doing so is considered poor practice, although the 2008 POSIX standard explicitly allows it, to support historical practice. For programs to be maximally portable, always supply the parentheses. - If `length()' is called with a variable that has not been used, - `gawk' forces the variable to be a scalar. Other implementations - of `awk' leave the variable without a type. (d.c.) Consider: + If 'length()' is called with a variable that has not been used, + 'gawk' forces the variable to be a scalar. Other implementations + of 'awk' leave the variable without a type. (d.c.) Consider: $ gawk 'BEGIN { print length(x) ; x[1] = 1 }' -| 0 - error--> gawk: fatal: attempt to use scalar `x' as array + error-> gawk: fatal: attempt to use scalar `x' as array $ nawk 'BEGIN { print length(x) ; x[1] = 1 }' -| 0 - If `--lint' has been specified on the command line, `gawk' issues a + If '--lint' has been specified on the command line, 'gawk' issues a warning about this. - With `gawk' and several other `awk' implementations, when given an - array argument, the `length()' function returns the number of - elements in the array. (c.e.) This is less useful than it might + With 'gawk' and several other 'awk' implementations, when given an + array argument, the 'length()' function returns the number of + elements in the array. (c.e.) This is less useful than it might seem at first, as the array is not guaranteed to be indexed from - one to the number of elements in it. If `--lint' is provided on - the command line (*note Options::), `gawk' warns that passing an - array argument is not portable. If `--posix' is supplied, using - an array argument is a fatal error (*note Arrays::). + one to the number of elements in it. If '--lint' is provided on + the command line (*note Options::), 'gawk' warns that passing an + array argument is not portable. If '--posix' is supplied, using an + array argument is a fatal error (*note Arrays::). -`match(STRING, REGEXP' [`, ARRAY']`)' +'match(STRING, REGEXP' [', ARRAY']')' Search STRING for the longest, leftmost substring matched by the regular expression, REGEXP and return the character position (index) at which that substring begins (one, if it starts at the beginning of STRING). If no match is found, return zero. - The REGEXP argument may be either a regexp constant (`/'...`/') or - a string constant (`"'...`"'). In the latter case, the string is + The REGEXP argument may be either a regexp constant ('/'...'/') or + a string constant ('"'...'"'). In the latter case, the string is treated as a regexp to be matched. *Note Computed Regexps::, for a discussion of the difference between the two forms, and the implications for writing your program correctly. The order of the first two arguments is backwards from most other string functions that work with regular expressions, such as - `sub()' and `gsub()'. It might help to remember that for - `match()', the order is the same as for the `~' operator: `STRING - ~ REGEXP'. + 'sub()' and 'gsub()'. It might help to remember that for + 'match()', the order is the same as for the '~' operator: 'STRING ~ + REGEXP'. - The `match()' function sets the built-in variable `RSTART' to the - index. It also sets the built-in variable `RLENGTH' to the length + The 'match()' function sets the built-in variable 'RSTART' to the + index. It also sets the built-in variable 'RLENGTH' to the length in characters of the matched substring. If no match is found, - `RSTART' is set to zero, and `RLENGTH' to -1. + 'RSTART' is set to zero, and 'RLENGTH' to -1. For example: @@ -12041,9 +11989,9 @@ Options::): } This program looks for lines that match the regular expression - stored in the variable `regex'. This regular expression can be - changed. If the first word on a line is `FIND', `regex' is - changed to be the second word on that line. Therefore, if given: + stored in the variable 'regex'. This regular expression can be + changed. If the first word on a line is 'FIND', 'regex' is changed + to be the second word on that line. Therefore, if given: FIND ru+n My program runs @@ -12053,16 +12001,16 @@ Options::): This line is property of Reality Engineering Co. Melvin was here. - `awk' prints: + 'awk' prints: Match of ru+n found at 12 in My program runs Match of Melvin found at 1 in Melvin was here. If ARRAY is present, it is cleared, and then the zeroth element of - ARRAY is set to the entire portion of STRING matched by REGEXP. - If REGEXP contains parentheses, the integer-indexed elements of - ARRAY are set to contain the portion of STRING matching the - corresponding parenthesized subexpression. For example: + ARRAY is set to the entire portion of STRING matched by REGEXP. If + REGEXP contains parentheses, the integer-indexed elements of ARRAY + are set to contain the portion of STRING matching the corresponding + parenthesized subexpression. For example: $ echo foooobazbarrrrr | > gawk '{ match($0, /(fo+).+(bar*)/, arr) @@ -12084,158 +12032,157 @@ Options::): There may not be subscripts for the start and index for every parenthesized subexpression, since they may not all have matched - text; thus they should be tested for with the `in' operator (*note + text; thus they should be tested for with the 'in' operator (*note Reference to Elements::). - The ARRAY argument to `match()' is a `gawk' extension. In + The ARRAY argument to 'match()' is a 'gawk' extension. In compatibility mode (*note Options::), using a third argument is a fatal error. -`patsplit(STRING, ARRAY' [`, FIELDPAT' [`, SEPS' ] ]`) #' +'patsplit(STRING, ARRAY' [', FIELDPAT' [', SEPS' ] ]') #' Divide STRING into pieces defined by FIELDPAT and store the pieces in ARRAY and the separator strings in the SEPS array. The first - piece is stored in `ARRAY[1]', the second piece in `ARRAY[2]', and - so forth. The third argument, FIELDPAT, is a regexp describing - the fields in STRING (just as `FPAT' is a regexp describing the - fields in input records). It may be either a regexp constant or a - string. If FIELDPAT is omitted, the value of `FPAT' is used. - `patsplit()' returns the number of elements created. `SEPS[I]' is - the separator string between `ARRAY[I]' and `ARRAY[I+1]'. Any - leading separator will be in `SEPS[0]'. - - The `patsplit()' function splits strings into pieces in a manner - similar to the way input lines are split into fields using `FPAT' + piece is stored in 'ARRAY[1]', the second piece in 'ARRAY[2]', and + so forth. The third argument, FIELDPAT, is a regexp describing the + fields in STRING (just as 'FPAT' is a regexp describing the fields + in input records). It may be either a regexp constant or a string. + If FIELDPAT is omitted, the value of 'FPAT' is used. 'patsplit()' + returns the number of elements created. 'SEPS[I]' is the separator + string between 'ARRAY[I]' and 'ARRAY[I+1]'. Any leading separator + will be in 'SEPS[0]'. + + The 'patsplit()' function splits strings into pieces in a manner + similar to the way input lines are split into fields using 'FPAT' (*note Splitting By Content::. - Before splitting the string, `patsplit()' deletes any previously + Before splitting the string, 'patsplit()' deletes any previously existing elements in the arrays ARRAY and SEPS. -`split(STRING, ARRAY' [`, FIELDSEP' [`, SEPS' ] ]`)' +'split(STRING, ARRAY' [', FIELDSEP' [', SEPS' ] ]')' Divide STRING into pieces separated by FIELDSEP and store the pieces in ARRAY and the separator strings in the SEPS array. The - first piece is stored in `ARRAY[1]', the second piece in - `ARRAY[2]', and so forth. The string value of the third argument, + first piece is stored in 'ARRAY[1]', the second piece in + 'ARRAY[2]', and so forth. The string value of the third argument, FIELDSEP, is a regexp describing where to split STRING (much as - `FS' can be a regexp describing where to split input records; - *note Regexp Field Splitting::). If FIELDSEP is omitted, the - value of `FS' is used. `split()' returns the number of elements - created. SEPS is a `gawk' extension with `SEPS[I]' being the - separator string between `ARRAY[I]' and `ARRAY[I+1]'. If FIELDSEP - is a single space then any leading whitespace goes into `SEPS[0]' - and any trailing whitespace goes into `SEPS[N]' where N is the - return value of `split()' (that is, the number of elements in - ARRAY). - - The `split()' function splits strings into pieces in a manner + 'FS' can be a regexp describing where to split input records; *note + Regexp Field Splitting::). If FIELDSEP is omitted, the value of + 'FS' is used. 'split()' returns the number of elements created. + SEPS is a 'gawk' extension with 'SEPS[I]' being the separator + string between 'ARRAY[I]' and 'ARRAY[I+1]'. If FIELDSEP is a + single space then any leading whitespace goes into 'SEPS[0]' and + any trailing whitespace goes into 'SEPS[N]' where N is the return + value of 'split()' (that is, the number of elements in ARRAY). + + The 'split()' function splits strings into pieces in a manner similar to the way input lines are split into fields. For example: split("cul-de-sac", a, "-", seps) - splits the string `cul-de-sac' into three fields using `-' as the - separator. It sets the contents of the array `a' as follows: + splits the string 'cul-de-sac' into three fields using '-' as the + separator. It sets the contents of the array 'a' as follows: a[1] = "cul" a[2] = "de" a[3] = "sac" - and sets the contents of the array `seps' as follows: + and sets the contents of the array 'seps' as follows: seps[1] = "-" seps[2] = "-" - The value returned by this call to `split()' is three. + The value returned by this call to 'split()' is three. - As with input field-splitting, when the value of FIELDSEP is - `" "', leading and trailing whitespace is ignored in values - assigned to the elements of ARRAY but not in SEPS, and the elements - are separated by runs of whitespace. Also as with input + As with input field-splitting, when the value of FIELDSEP is '" "', + leading and trailing whitespace is ignored in values assigned to + the elements of ARRAY but not in SEPS, and the elements are + separated by runs of whitespace. Also as with input field-splitting, if FIELDSEP is the null string, each individual character in the string is split into its own array element. (c.e.) - Note, however, that `RS' has no effect on the way `split()' works. - Even though `RS = ""' causes newline to also be an input field - separator, this does not affect how `split()' splits strings. + Note, however, that 'RS' has no effect on the way 'split()' works. + Even though 'RS = ""' causes newline to also be an input field + separator, this does not affect how 'split()' splits strings. - Modern implementations of `awk', including `gawk', allow the third - argument to be a regexp constant (`/abc/') as well as a string. + Modern implementations of 'awk', including 'gawk', allow the third + argument to be a regexp constant ('/abc/') as well as a string. (d.c.) The POSIX standard allows this as well. *Note Computed Regexps::, for a discussion of the difference between using a string constant or a regexp constant, and the implications for writing your program correctly. - Before splitting the string, `split()' deletes any previously + Before splitting the string, 'split()' deletes any previously existing elements in the arrays ARRAY and SEPS. - If STRING is null, the array has no elements. (So this is a + If STRING is null, the array has no elements. (So this is a portable way to delete an entire array with one statement. *Note Delete::.) If STRING does not match FIELDSEP at all (but is not null), ARRAY - has one element only. The value of that element is the original + has one element only. The value of that element is the original STRING. In POSIX mode (*note Options::), the fourth argument is not allowed. -`sprintf(FORMAT, EXPRESSION1, ...)' - Return (without printing) the string that `printf' would have +'sprintf(FORMAT, EXPRESSION1, ...)' + Return (without printing) the string that 'printf' would have printed out with the same arguments (*note Printf::). For example: pival = sprintf("pi = %.2f (approx.)", 22/7) - assigns the string `pi = 3.14 (approx.)' to the variable `pival'. + assigns the string 'pi = 3.14 (approx.)' to the variable 'pival'. -`strtonum(STR) #' +'strtonum(STR) #' Examine STR and return its numeric value. If STR begins with a - leading `0', `strtonum()' assumes that STR is an octal number. If - STR begins with a leading `0x' or `0X', `strtonum()' assumes that + leading '0', 'strtonum()' assumes that STR is an octal number. If + STR begins with a leading '0x' or '0X', 'strtonum()' assumes that STR is a hexadecimal number. For example: $ echo 0x11 | > gawk '{ printf "%d\n", strtonum($1) }' -| 17 - Using the `strtonum()' function is _not_ the same as adding zero - to a string value; the automatic coercion of strings to numbers - works only for decimal data, not for octal or hexadecimal.(1) + Using the 'strtonum()' function is _not_ the same as adding zero to + a string value; the automatic coercion of strings to numbers works + only for decimal data, not for octal or hexadecimal.(1) - Note also that `strtonum()' uses the current locale's decimal point + Note also that 'strtonum()' uses the current locale's decimal point for recognizing numbers (*note Locales::). -`sub(REGEXP, REPLACEMENT' [`, TARGET']`)' +'sub(REGEXP, REPLACEMENT' [', TARGET']')' Search TARGET, which is treated as a string, for the leftmost, - longest substring matched by the regular expression REGEXP. - Modify the entire string by replacing the matched text with - REPLACEMENT. The modified string becomes the new value of TARGET. - Return the number of substitutions made (zero or one). + longest substring matched by the regular expression REGEXP. Modify + the entire string by replacing the matched text with REPLACEMENT. + The modified string becomes the new value of TARGET. Return the + number of substitutions made (zero or one). - The REGEXP argument may be either a regexp constant (`/'...`/') or - a string constant (`"'...`"'). In the latter case, the string is + The REGEXP argument may be either a regexp constant ('/'...'/') or + a string constant ('"'...'"'). In the latter case, the string is treated as a regexp to be matched. *Note Computed Regexps::, for a discussion of the difference between the two forms, and the implications for writing your program correctly. This function is peculiar because TARGET is not simply used to compute a value, and not just any expression will do--it must be a - variable, field, or array element so that `sub()' can store a + variable, field, or array element so that 'sub()' can store a modified value there. If this argument is omitted, then the - default is to use and alter `$0'.(2) For example: + default is to use and alter '$0'.(2) For example: str = "water, water, everywhere" sub(/at/, "ith", str) - sets `str' to `wither, water, everywhere', by replacing the - leftmost longest occurrence of `at' with `ith'. + sets 'str' to 'wither, water, everywhere', by replacing the + leftmost longest occurrence of 'at' with 'ith'. - If the special character `&' appears in REPLACEMENT, it stands for + If the special character '&' appears in REPLACEMENT, it stands for the precise substring that was matched by REGEXP. (If the regexp can match more than one string, then this precise substring may vary.) For example: { sub(/candidate/, "& and his wife"); print } - changes the first occurrence of `candidate' to `candidate and his + changes the first occurrence of 'candidate' to 'candidate and his wife' on each input line. Here is another example: $ awk 'BEGIN { @@ -12245,30 +12192,30 @@ Options::): > }' -| dCaaCbaaa - This shows how `&' can represent a nonconstant string and also + This shows how '&' can represent a nonconstant string and also illustrates the "leftmost, longest" rule in regexp matching (*note Leftmost Longest::). - The effect of this special character (`&') can be turned off by + The effect of this special character ('&') can be turned off by putting a backslash before it in the string. As usual, to insert one backslash in the string, you must write two backslashes. - Therefore, write `\\&' in a string constant to include a literal - `&' in the replacement. For example, the following shows how to - replace the first `|' on each line with an `&': + Therefore, write '\\&' in a string constant to include a literal + '&' in the replacement. For example, the following shows how to + replace the first '|' on each line with an '&': { sub(/\|/, "\\&"); print } - As mentioned, the third argument to `sub()' must be a variable, - field or array element. Some versions of `awk' allow the third + As mentioned, the third argument to 'sub()' must be a variable, + field or array element. Some versions of 'awk' allow the third argument to be an expression that is not an lvalue. In such a - case, `sub()' still searches for the pattern and returns zero or + case, 'sub()' still searches for the pattern and returns zero or one, but the result of the substitution (if any) is thrown away - because there is no place to put it. Such versions of `awk' - accept expressions like the following: + because there is no place to put it. Such versions of 'awk' accept + expressions like the following: sub(/USA/, "United States", "the USA and Canada") - For historical compatibility, `gawk' accepts such erroneous code. + For historical compatibility, 'gawk' accepts such erroneous code. However, using any other nonchangeable object as the third parameter causes a fatal error and your program will not run. @@ -12276,26 +12223,26 @@ Options::): into a string, and then the value of that string is treated as the regexp to match. -`substr(STRING, START' [`, LENGTH' ]`)' +'substr(STRING, START' [', LENGTH' ]')' Return a LENGTH-character-long substring of STRING, starting at character number START. The first character of a string is - character number one.(3) For example, `substr("washington", 5, 3)' - returns `"ing"'. + character number one.(3) For example, 'substr("washington", 5, 3)' + returns '"ing"'. - If LENGTH is not present, `substr()' returns the whole suffix of + If LENGTH is not present, 'substr()' returns the whole suffix of STRING that begins at character number START. For example, - `substr("washington", 5)' returns `"ington"'. The whole suffix is + 'substr("washington", 5)' returns '"ington"'. The whole suffix is also returned if LENGTH is greater than the number of characters remaining in the string, counting from character START. - If START is less than one, `substr()' treats it as if it was one. + If START is less than one, 'substr()' treats it as if it was one. (POSIX doesn't specify what to do in this case: Brian Kernighan's - `awk' acts this way, and therefore `gawk' does too.) If START is - greater than the number of characters in the string, `substr()' + 'awk' acts this way, and therefore 'gawk' does too.) If START is + greater than the number of characters in the string, 'substr()' returns the null string. Similarly, if LENGTH is present but less than or equal to zero, the null string is returned. - The string returned by `substr()' _cannot_ be assigned. Thus, it + The string returned by 'substr()' _cannot_ be assigned. Thus, it is a mistake to attempt to change a portion of a string, as shown in the following example: @@ -12303,212 +12250,212 @@ Options::): # try to get "abCDEf", won't work substr(string, 3, 3) = "CDE" - It is also a mistake to use `substr()' as the third argument of - `sub()' or `gsub()': + It is also a mistake to use 'substr()' as the third argument of + 'sub()' or 'gsub()': gsub(/xyz/, "pdq", substr($0, 5, 20)) # WRONG - (Some commercial versions of `awk' treat `substr()' as assignable, + (Some commercial versions of 'awk' treat 'substr()' as assignable, but doing so is not portable.) If you need to replace bits and pieces of a string, combine - `substr()' with string concatenation, in the following manner: + 'substr()' with string concatenation, in the following manner: string = "abcdef" ... string = substr(string, 1, 2) "CDE" substr(string, 6) -`tolower(STRING)' +'tolower(STRING)' Return a copy of STRING, with each uppercase character in the string replaced with its corresponding lowercase character. Nonalphabetic characters are left unchanged. For example, - `tolower("MiXeD cAsE 123")' returns `"mixed case 123"'. + 'tolower("MiXeD cAsE 123")' returns '"mixed case 123"'. -`toupper(STRING)' +'toupper(STRING)' Return a copy of STRING, with each lowercase character in the string replaced with its corresponding uppercase character. Nonalphabetic characters are left unchanged. For example, - `toupper("MiXeD cAsE 123")' returns `"MIXED CASE 123"'. + 'toupper("MiXeD cAsE 123")' returns '"MIXED CASE 123"'. ---------- Footnotes ---------- - (1) Unless you use the `--non-decimal-data' option, which isn't + (1) Unless you use the '--non-decimal-data' option, which isn't recommended. *Note Nondecimal Data::, for more information. (2) Note that this means that the record will first be regenerated -using the value of `OFS' if any fields have been changed, and that the +using the value of 'OFS' if any fields have been changed, and that the fields will be updated after the substitution, even if the operation is -a "no-op" such as `sub(/^/, "")'. +a "no-op" such as 'sub(/^/, "")'. - (3) This is different from C and C++, in which the first character -is number zero. + (3) This is different from C and C++, in which the first character is +number zero.  File: gawk.info, Node: Gory Details, Up: String Functions -9.1.3.1 More About `\' and `&' with `sub()', `gsub()', and `gensub()' +9.1.3.1 More About '\' and '&' with 'sub()', 'gsub()', and 'gensub()' ..................................................................... -When using `sub()', `gsub()', or `gensub()', and trying to get literal +When using 'sub()', 'gsub()', or 'gensub()', and trying to get literal backslashes and ampersands into the replacement text, you need to remember that there are several levels of "escape processing" going on. - First, there is the "lexical" level, which is when `awk' reads your -program and builds an internal copy of it to execute. Then there is -the runtime level, which is when `awk' actually scans the replacement -string to determine what to generate. + First, there is the "lexical" level, which is when 'awk' reads your +program and builds an internal copy of it to execute. Then there is the +runtime level, which is when 'awk' actually scans the replacement string +to determine what to generate. - At both levels, `awk' looks for a defined set of characters that can + At both levels, 'awk' looks for a defined set of characters that can come after a backslash. At the lexical level, it looks for the escape -sequences listed in *note Escape Sequences::. Thus, for every `\' that -`awk' processes at the runtime level, you must type two backslashes at +sequences listed in *note Escape Sequences::. Thus, for every '\' that +'awk' processes at the runtime level, you must type two backslashes at the lexical level. When a character that is not valid for an escape -sequence follows the `\', Brian Kernighan's `awk' and `gawk' both -simply remove the initial `\' and put the next character into the -string. Thus, for example, `"a\qb"' is treated as `"aqb"'. - - At the runtime level, the various functions handle sequences of `\' -and `&' differently. The situation is (sadly) somewhat complex. -Historically, the `sub()' and `gsub()' functions treated the two -character sequence `\&' specially; this sequence was replaced in the -generated text with a single `&'. Any other `\' within the REPLACEMENT -string that did not precede an `&' was passed through unchanged. This -is illustrated in *note table-sub-escapes::. - - You type `sub()' sees `sub()' generates - ------- --------- -------------- - `\&' `&' the matched text - `\\&' `\&' a literal `&' - `\\\&' `\&' a literal `&' - `\\\\&' `\\&' a literal `\&' - `\\\\\&' `\\&' a literal `\&' - `\\\\\\&' `\\\&' a literal `\\&' - `\\q' `\q' a literal `\q' - -Table 9.1: Historical Escape Sequence Processing for `sub()' and -`gsub()' +sequence follows the '\', Brian Kernighan's 'awk' and 'gawk' both simply +remove the initial '\' and put the next character into the string. +Thus, for example, '"a\qb"' is treated as '"aqb"'. + + At the runtime level, the various functions handle sequences of '\' +and '&' differently. The situation is (sadly) somewhat complex. +Historically, the 'sub()' and 'gsub()' functions treated the two +character sequence '\&' specially; this sequence was replaced in the +generated text with a single '&'. Any other '\' within the REPLACEMENT +string that did not precede an '&' was passed through unchanged. This +is illustrated in *note Table 9.1: table-sub-escapes. + + You type 'sub()' sees 'sub()' generates + ----- ------- ---------- + '\&' '&' the matched text + '\\&' '\&' a literal '&' + '\\\&' '\&' a literal '&' + '\\\\&' '\\&' a literal '\&' + '\\\\\&' '\\&' a literal '\&' + '\\\\\\&' '\\\&' a literal '\\&' + '\\q' '\q' a literal '\q' + +Table 9.1: Historical Escape Sequence Processing for 'sub()' and +'gsub()' This table shows both the lexical-level processing, where an odd number of backslashes becomes an even number at the runtime level, as well as -the runtime processing done by `sub()'. (For the sake of simplicity, +the runtime processing done by 'sub()'. (For the sake of simplicity, the rest of the following tables only show the case of even numbers of backslashes entered at the lexical level.) The problem with the historical approach is that there is no way to -get a literal `\' followed by the matched text. - - The 1992 POSIX standard attempted to fix this problem. That standard -says that `sub()' and `gsub()' look for either a `\' or an `&' after -the `\'. If either one follows a `\', that character is output -literally. The interpretation of `\' and `&' then becomes as shown in -*note table-sub-posix-92::. - - You type `sub()' sees `sub()' generates - ------- --------- -------------- - `&' `&' the matched text - `\\&' `\&' a literal `&' - `\\\\&' `\\&' a literal `\', then the matched text - `\\\\\\&' `\\\&' a literal `\&' - -Table 9.2: 1992 POSIX Rules for `sub()' and `gsub()' Escape Sequence +get a literal '\' followed by the matched text. + + The 1992 POSIX standard attempted to fix this problem. That standard +says that 'sub()' and 'gsub()' look for either a '\' or an '&' after the +'\'. If either one follows a '\', that character is output literally. +The interpretation of '\' and '&' then becomes as shown in *note Table +9.2: table-sub-posix-92. + + You type 'sub()' sees 'sub()' generates + ----- ------- ---------- + '&' '&' the matched text + '\\&' '\&' a literal '&' + '\\\\&' '\\&' a literal '\', then the matched text + '\\\\\\&' '\\\&' a literal '\&' + +Table 9.2: 1992 POSIX Rules for 'sub()' and 'gsub()' Escape Sequence Processing This appears to solve the problem. Unfortunately, the phrasing of the -standard is unusual. It says, in effect, that `\' turns off the special -meaning of any following character, but for anything other than `\' and -`&', such special meaning is undefined. This wording leads to two +standard is unusual. It says, in effect, that '\' turns off the special +meaning of any following character, but for anything other than '\' and +'&', such special meaning is undefined. This wording leads to two problems: * Backslashes must now be doubled in the REPLACEMENT string, breaking - historical `awk' programs. + historical 'awk' programs. - * To make sure that an `awk' program is portable, _every_ character + * To make sure that an 'awk' program is portable, _every_ character in the REPLACEMENT string must be preceded with a backslash.(1) - Because of the problems just listed, in 1996, the `gawk' maintainer + Because of the problems just listed, in 1996, the 'gawk' maintainer submitted proposed text for a revised standard that reverts to rules -that correspond more closely to the original existing practice. The -proposed rules have special cases that make it possible to produce a -`\' preceding the matched text. This is shown in *note -table-sub-proposed::. +that correspond more closely to the original existing practice. The +proposed rules have special cases that make it possible to produce a '\' +preceding the matched text. This is shown in *note Table 9.3: +table-sub-proposed. - You type `sub()' sees `sub()' generates - ------- --------- -------------- - `\\\\\\&' `\\\&' a literal `\&' - `\\\\&' `\\&' a literal `\', followed by the matched text - `\\&' `\&' a literal `&' - `\\q' `\q' a literal `\q' - `\\\\' `\\' `\\' + You type 'sub()' sees 'sub()' generates + ----- ------- ---------- + '\\\\\\&' '\\\&' a literal '\&' + '\\\\&' '\\&' a literal '\', followed by the matched text + '\\&' '\&' a literal '&' + '\\q' '\q' a literal '\q' + '\\\\' '\\' '\\' -Table 9.3: Proposed Rules For `sub()' And Backslash +Table 9.3: Proposed Rules For 'sub()' And Backslash In a nutshell, at the runtime level, there are now three special -sequences of characters (`\\\&', `\\&' and `\&') whereas historically -there was only one. However, as in the historical case, any `\' that -is not part of one of these three sequences is not special and appears -in the output literally. +sequences of characters ('\\\&', '\\&' and '\&') whereas historically +there was only one. However, as in the historical case, any '\' that is +not part of one of these three sequences is not special and appears in +the output literally. - `gawk' 3.0 and 3.1 follow these proposed POSIX rules for `sub()' and -`gsub()'. The POSIX standard took much longer to be revised than was + 'gawk' 3.0 and 3.1 follow these proposed POSIX rules for 'sub()' and +'gsub()'. The POSIX standard took much longer to be revised than was expected in 1996. The 2001 standard does not follow the above rules. Instead, the rules there are somewhat simpler. The results are similar except for one case. - The POSIX rules state that `\&' in the replacement string produces a -literal `&', `\\' produces a literal `\', and `\' followed by anything -else is not special; the `\' is placed straight into the output. These -rules are presented in *note table-posix-sub::. + The POSIX rules state that '\&' in the replacement string produces a +literal '&', '\\' produces a literal '\', and '\' followed by anything +else is not special; the '\' is placed straight into the output. These +rules are presented in *note Table 9.4: table-posix-sub. - You type `sub()' sees `sub()' generates - ------- --------- -------------- - `\\\\\\&' `\\\&' a literal `\&' - `\\\\&' `\\&' a literal `\', followed by the matched text - `\\&' `\&' a literal `&' - `\\q' `\q' a literal `\q' - `\\\\' `\\' `\' + You type 'sub()' sees 'sub()' generates + ----- ------- ---------- + '\\\\\\&' '\\\&' a literal '\&' + '\\\\&' '\\&' a literal '\', followed by the matched text + '\\&' '\&' a literal '&' + '\\q' '\q' a literal '\q' + '\\\\' '\\' '\' -Table 9.4: POSIX Rules For `sub()' And `gsub()' +Table 9.4: POSIX Rules For 'sub()' And 'gsub()' The only case where the difference is noticeable is the last one: -`\\\\' is seen as `\\' and produces `\' instead of `\\'. +'\\\\' is seen as '\\' and produces '\' instead of '\\'. - Starting with version 3.1.4, `gawk' followed the POSIX rules when -`--posix' is specified (*note Options::). Otherwise, it continued to + Starting with version 3.1.4, 'gawk' followed the POSIX rules when +'--posix' is specified (*note Options::). Otherwise, it continued to follow the 1996 proposed rules, since that had been its behavior for many years. - When version 4.0.0 was released, the `gawk' maintainer made the -POSIX rules the default, breaking well over a decade's worth of -backwards compatibility.(2) Needless to say, this was a bad idea, and -as of version 4.0.1, `gawk' resumed its historical behavior, and only -follows the POSIX rules when `--posix' is given. + When version 4.0.0 was released, the 'gawk' maintainer made the POSIX +rules the default, breaking well over a decade's worth of backwards +compatibility.(2) Needless to say, this was a bad idea, and as of +version 4.0.1, 'gawk' resumed its historical behavior, and only follows +the POSIX rules when '--posix' is given. - The rules for `gensub()' are considerably simpler. At the runtime -level, whenever `gawk' sees a `\', if the following character is a + The rules for 'gensub()' are considerably simpler. At the runtime +level, whenever 'gawk' sees a '\', if the following character is a digit, then the text that matched the corresponding parenthesized subexpression is placed in the generated output. Otherwise, no matter -what character follows the `\', it appears in the generated text and -the `\' does not, as shown in *note table-gensub-escapes::. +what character follows the '\', it appears in the generated text and the +'\' does not, as shown in *note Table 9.5: table-gensub-escapes. - You type `gensub()' sees `gensub()' generates - ------- ------------ ----------------- - `&' `&' the matched text - `\\&' `\&' a literal `&' - `\\\\' `\\' a literal `\' - `\\\\&' `\\&' a literal `\', then the matched text - `\\\\\\&' `\\\&' a literal `\&' - `\\q' `\q' a literal `q' + You type 'gensub()' sees 'gensub()' generates + ----- --------- ------------ + '&' '&' the matched text + '\\&' '\&' a literal '&' + '\\\\' '\\' a literal '\' + '\\\\&' '\\&' a literal '\', then the matched text + '\\\\\\&' '\\\&' a literal '\&' + '\\q' '\q' a literal 'q' -Table 9.5: Escape Sequence Processing For `gensub()' +Table 9.5: Escape Sequence Processing For 'gensub()' Because of the complexity of the lexical and runtime level processing -and the special cases for `sub()' and `gsub()', we recommend the use of -`gawk' and `gensub()' when you have to do substitutions. +and the special cases for 'sub()' and 'gsub()', we recommend the use of +'gawk' and 'gensub()' when you have to do substitutions. Matching the Null String - In `awk', the `*' operator can match the null string. This is -particularly important for the `sub()', `gsub()', and `gensub()' + In 'awk', the '*' operator can match the null string. This is +particularly important for the 'sub()', 'gsub()', and 'gensub()' functions. For example: $ echo abc | awk '{ gsub(/m*/, "X"); print }' @@ -12530,31 +12477,31 @@ File: gawk.info, Node: I/O Functions, Next: Time Functions, Prev: String Func 9.1.4 Input/Output Functions ---------------------------- -The following functions relate to input/output (I/O). Optional +The following functions relate to input/output (I/O). Optional parameters are enclosed in square brackets ([ ]): -`close('FILENAME [`,' HOW]`)' - Close the file FILENAME for input or output. Alternatively, the +'close('FILENAME [',' HOW]')' + Close the file FILENAME for input or output. Alternatively, the argument may be a shell command that was used for creating a - coprocess, or for redirecting to or from a pipe; then the - coprocess or pipe is closed. *Note Close Files And Pipes::, for - more information. + coprocess, or for redirecting to or from a pipe; then the coprocess + or pipe is closed. *Note Close Files And Pipes::, for more + information. When closing a coprocess, it is occasionally useful to first close one end of the two-way pipe and then to close the other. This is - done by providing a second argument to `close()'. This second - argument should be one of the two string values `"to"' or `"from"', + done by providing a second argument to 'close()'. This second + argument should be one of the two string values '"to"' or '"from"', indicating which end of the pipe to close. Case in the string does not matter. *Note Two-way I/O::, which discusses this feature in more detail and gives an example. - Note that the second argument to `close()' is a `gawk' extension; + Note that the second argument to 'close()' is a 'gawk' extension; it is not available in compatibility mode (*note Options::). -`fflush('[FILENAME]`)' - Flush any buffered output associated with FILENAME, which is - either a file opened for writing or a shell command for - redirecting output to a pipe or coprocess. +'fflush('[FILENAME]')' + Flush any buffered output associated with FILENAME, which is either + a file opened for writing or a shell command for redirecting output + to a pipe or coprocess. Many utility programs "buffer" their output; i.e., they save information to write to a disk file or the screen in memory until @@ -12562,57 +12509,57 @@ parameters are enclosed in square brackets ([ ]): output device. This is often more efficient than writing every little bit of information as soon as it is ready. However, sometimes it is necessary to force a program to "flush" its - buffers; that is, write the information to its destination, even - if a buffer is not full. This is the purpose of the `fflush()' - function--`gawk' also buffers its output and the `fflush()' - function forces `gawk' to flush its buffers. + buffers; that is, write the information to its destination, even if + a buffer is not full. This is the purpose of the 'fflush()' + function--'gawk' also buffers its output and the 'fflush()' + function forces 'gawk' to flush its buffers. - `fflush()' was added to Brian Kernighan's `awk' in April of 1992. + 'fflush()' was added to Brian Kernighan's 'awk' in April of 1992. For two decades, it was not part of the POSIX standard. As of December, 2012, it was accepted for inclusion into the POSIX standard. See the Austin Group website (http://austingroupbugs.net/view.php?id=634). - POSIX standardizes `fflush()' as follows: If there is no argument, - or if the argument is the null string (`""'), then `awk' flushes + POSIX standardizes 'fflush()' as follows: If there is no argument, + or if the argument is the null string ('""'), then 'awk' flushes the buffers for _all_ open output files and pipes. - NOTE: Prior to version 4.0.2, `gawk' would flush only the - standard output if there was no argument, and flush all - output files and pipes if the argument was the null string. - This was changed in order to be compatible with Brian - Kernighan's `awk', in the hope that standardizing this - feature in POSIX would then be easier (which indeed helped). + NOTE: Prior to version 4.0.2, 'gawk' would flush only the + standard output if there was no argument, and flush all output + files and pipes if the argument was the null string. This was + changed in order to be compatible with Brian Kernighan's + 'awk', in the hope that standardizing this feature in POSIX + would then be easier (which indeed helped). - With `gawk', you can use `fflush("/dev/stdout")' if you wish + With 'gawk', you can use 'fflush("/dev/stdout")' if you wish to flush only the standard output. - `fflush()' returns zero if the buffer is successfully flushed; - otherwise, it returns non-zero. (`gawk' returns -1.) In the case - where all buffers are flushed, the return value is zero only if - all buffers were flushed successfully. Otherwise, it is -1, and - `gawk' warns about the problem FILENAME. + 'fflush()' returns zero if the buffer is successfully flushed; + otherwise, it returns non-zero. ('gawk' returns -1.) In the case + where all buffers are flushed, the return value is zero only if all + buffers were flushed successfully. Otherwise, it is -1, and 'gawk' + warns about the problem FILENAME. - `gawk' also issues a warning message if you attempt to flush a - file or pipe that was opened for reading (such as with `getline'), - or if FILENAME is not an open file, pipe, or coprocess. In such a - case, `fflush()' returns -1, as well. + 'gawk' also issues a warning message if you attempt to flush a file + or pipe that was opened for reading (such as with 'getline'), or if + FILENAME is not an open file, pipe, or coprocess. In such a case, + 'fflush()' returns -1, as well. -`system(COMMAND)' - Execute the operating-system command COMMAND and then return to - the `awk' program. Return COMMAND's exit status. +'system(COMMAND)' + Execute the operating-system command COMMAND and then return to the + 'awk' program. Return COMMAND's exit status. - For example, if the following fragment of code is put in your `awk' + For example, if the following fragment of code is put in your 'awk' program: END { system("date | mail -s 'awk run done' root") } - the system administrator is sent mail when the `awk' program + the system administrator is sent mail when the 'awk' program finishes processing input and begins its end-of-input processing. - Note that redirecting `print' or `printf' into a pipe is often + Note that redirecting 'print' or 'printf' into a pipe is often enough to accomplish your task. If you need to run many commands, it is more efficient to simply print them down a pipeline to the shell: @@ -12621,16 +12568,14 @@ parameters are enclosed in square brackets ([ ]): print COMMAND | "/bin/sh" close("/bin/sh") - However, if your `awk' program is interactive, `system()' is - useful for running large self-contained programs, such as a shell - or an editor. Some operating systems cannot implement the - `system()' function. `system()' causes a fatal error if it is not - supported. + However, if your 'awk' program is interactive, 'system()' is useful + for running large self-contained programs, such as a shell or an + editor. Some operating systems cannot implement the 'system()' + function. 'system()' causes a fatal error if it is not supported. - NOTE: When `--sandbox' is specified, the `system()' function + NOTE: When '--sandbox' is specified, the 'system()' function is disabled (*note Options::). - Interactive Versus Noninteractive Buffering As a side point, buffering issues can be even more confusing, @@ -12649,7 +12594,7 @@ the difference: -| 5 Ctrl-d -Each line of output is printed immediately. Compare that behavior with +Each line of output is printed immediately. Compare that behavior with this example: $ awk '{ print $1 + $2 }' | cat @@ -12659,30 +12604,30 @@ this example: -| 2 -| 5 -Here, no output is printed until after the `Ctrl-d' is typed, because -it is all buffered and sent down the pipe to `cat' in one shot. +Here, no output is printed until after the 'Ctrl-d' is typed, because it +is all buffered and sent down the pipe to 'cat' in one shot. - Controlling Output Buffering with `system()' + Controlling Output Buffering with 'system()' - The `fflush()' function provides explicit control over output + The 'fflush()' function provides explicit control over output buffering for individual files and pipes. However, its use is not -portable to many older `awk' implementations. An alternative method to -flush output buffers is to call `system()' with a null string as its +portable to many older 'awk' implementations. An alternative method to +flush output buffers is to call 'system()' with a null string as its argument: system("") # flush output -`gawk' treats this use of the `system()' function as a special case and +'gawk' treats this use of the 'system()' function as a special case and is smart enough not to run a shell (or other command interpreter) with -the empty command. Therefore, with `gawk', this idiom is not only +the empty command. Therefore, with 'gawk', this idiom is not only useful, it is also efficient. While this method should work with other -`awk' implementations, it does not necessarily avoid starting an +'awk' implementations, it does not necessarily avoid starting an unnecessary shell. (Other implementations may only flush the buffer associated with the standard output and not necessarily all buffered output.) If you think about what a programmer expects, it makes sense that -`system()' should flush any pending output. The following program: +'system()' should flush any pending output. The following program: BEGIN { print "first print" @@ -12702,13 +12647,13 @@ and not: first print second print - If `awk' did not flush its buffers before calling `system()', you + If 'awk' did not flush its buffers before calling 'system()', you would see the latter (undesirable) output. ---------- Footnotes ---------- - (1) A program is interactive if the standard output is connected to -a terminal device. On modern systems, this means your keyboard and + (1) A program is interactive if the standard output is connected to a +terminal device. On modern systems, this means your keyboard and screen.  @@ -12717,266 +12662,264 @@ File: gawk.info, Node: Time Functions, Next: Bitwise Functions, Prev: I/O Fun 9.1.5 Time Functions -------------------- -`awk' programs are commonly used to process log files containing +'awk' programs are commonly used to process log files containing timestamp information, indicating when a particular log record was written. Many programs log their timestamp in the form returned by the -`time()' system call, which is the number of seconds since a particular +'time()' system call, which is the number of seconds since a particular epoch. On POSIX-compliant systems, it is the number of seconds since -1970-01-01 00:00:00 UTC, not counting leap seconds.(1) All known +1970-01-01 00:00:00 UTC, not counting leap seconds.(1) All known POSIX-compliant systems support timestamps from 0 through 2^31 - 1, which is sufficient to represent times through 2038-01-19 03:14:07 UTC. Many systems support a wider range of timestamps, including negative timestamps that represent times before the epoch. In order to make it easier to process such log files and to produce -useful reports, `gawk' provides the following functions for working -with timestamps. They are `gawk' extensions; they are not specified in -the POSIX standard.(2) However, recent versions of `mawk' (*note Other +useful reports, 'gawk' provides the following functions for working with +timestamps. They are 'gawk' extensions; they are not specified in the +POSIX standard.(2) However, recent versions of 'mawk' (*note Other Versions::) also support these functions. Optional parameters are enclosed in square brackets ([ ]): -`mktime(DATESPEC)' +'mktime(DATESPEC)' Turn DATESPEC into a timestamp in the same form as is returned by - `systime()'. It is similar to the function of the same name in - ISO C. The argument, DATESPEC, is a string of the form - `"YYYY MM DD HH MM SS [DST]"'. The string consists of six or - seven numbers representing, respectively, the full year including - century, the month from 1 to 12, the day of the month from 1 to - 31, the hour of the day from 0 to 23, the minute from 0 to 59, the + 'systime()'. It is similar to the function of the same name in ISO + C. The argument, DATESPEC, is a string of the form + '"YYYY MM DD HH MM SS [DST]"'. The string consists of six or seven + numbers representing, respectively, the full year including + century, the month from 1 to 12, the day of the month from 1 to 31, + the hour of the day from 0 to 23, the minute from 0 to 59, the second from 0 to 60,(3) and an optional daylight-savings flag. The values of these numbers need not be within the ranges specified; for example, an hour of -1 means 1 hour before midnight. The origin-zero Gregorian calendar is assumed, with year 0 - preceding year 1 and year -1 preceding year 0. The time is - assumed to be in the local timezone. If the daylight-savings flag - is positive, the time is assumed to be daylight savings time; if - zero, the time is assumed to be standard time; and if negative - (the default), `mktime()' attempts to determine whether daylight - savings time is in effect for the specified time. + preceding year 1 and year -1 preceding year 0. The time is assumed + to be in the local timezone. If the daylight-savings flag is + positive, the time is assumed to be daylight savings time; if zero, + the time is assumed to be standard time; and if negative (the + default), 'mktime()' attempts to determine whether daylight savings + time is in effect for the specified time. If DATESPEC does not contain enough elements or if the resulting - time is out of range, `mktime()' returns -1. - -`strftime(' [FORMAT [`,' TIMESTAMP [`,' UTC-FLAG] ] ]`)' - Format the time specified by TIMESTAMP based on the contents of - the FORMAT string and return the result. It is similar to the - function of the same name in ISO C. If UTC-FLAG is present and is - either nonzero or non-null, the value is formatted as UTC - (Coordinated Universal Time, formerly GMT or Greenwich Mean Time). - Otherwise, the value is formatted for the local time zone. The - TIMESTAMP is in the same format as the value returned by the - `systime()' function. If no TIMESTAMP argument is supplied, - `gawk' uses the current time of day as the timestamp. If no - FORMAT argument is supplied, `strftime()' uses the value of - `PROCINFO["strftime"]' as the format string (*note Built-in - Variables::). The default string value is - `"%a %b %e %H:%M:%S %Z %Y"'. This format string produces output - that is equivalent to that of the `date' utility. You can assign - a new value to `PROCINFO["strftime"]' to change the default + time is out of range, 'mktime()' returns -1. + +'strftime(' [FORMAT [',' TIMESTAMP [',' UTC-FLAG] ] ]')' + Format the time specified by TIMESTAMP based on the contents of the + FORMAT string and return the result. It is similar to the function + of the same name in ISO C. If UTC-FLAG is present and is either + nonzero or non-null, the value is formatted as UTC (Coordinated + Universal Time, formerly GMT or Greenwich Mean Time). Otherwise, + the value is formatted for the local time zone. The TIMESTAMP is + in the same format as the value returned by the 'systime()' + function. If no TIMESTAMP argument is supplied, 'gawk' uses the + current time of day as the timestamp. If no FORMAT argument is + supplied, 'strftime()' uses the value of 'PROCINFO["strftime"]' as + the format string (*note Built-in Variables::). The default string + value is '"%a %b %e %H:%M:%S %Z %Y"'. This format string produces + output that is equivalent to that of the 'date' utility. You can + assign a new value to 'PROCINFO["strftime"]' to change the default format; see below for the various format directives. -`systime()' +'systime()' Return the current time as the number of seconds since the system epoch. On POSIX systems, this is the number of seconds since 1970-01-01 00:00:00 UTC, not counting leap seconds. It may be a different number on other systems. - The `systime()' function allows you to compare a timestamp from a -log file with the current time of day. In particular, it is easy to + The 'systime()' function allows you to compare a timestamp from a log +file with the current time of day. In particular, it is easy to determine how long ago a particular record was logged. It also allows you to produce log records using the "seconds since the epoch" format. - The `mktime()' function allows you to convert a textual -representation of a date and time into a timestamp. This makes it -easy to do before/after comparisons of dates and times, particularly -when dealing with date and time data coming from an external source, -such as a log file. + The 'mktime()' function allows you to convert a textual +representation of a date and time into a timestamp. This makes it easy +to do before/after comparisons of dates and times, particularly when +dealing with date and time data coming from an external source, such as +a log file. - The `strftime()' function allows you to easily turn a timestamp into -human-readable information. It is similar in nature to the `sprintf()' + The 'strftime()' function allows you to easily turn a timestamp into +human-readable information. It is similar in nature to the 'sprintf()' function (*note String Functions::), in that it copies nonformat specification characters verbatim to the returned string, while substituting date and time values for format specifications in the FORMAT string. - `strftime()' is guaranteed by the 1999 ISO C standard(4) to support + 'strftime()' is guaranteed by the 1999 ISO C standard(4) to support the following date format specifications: -`%a' +'%a' The locale's abbreviated weekday name. -`%A' +'%A' The locale's full weekday name. -`%b' +'%b' The locale's abbreviated month name. -`%B' +'%B' The locale's full month name. -`%c' +'%c' The locale's "appropriate" date and time representation. (This is - `%A %B %d %T %Y' in the `"C"' locale.) + '%A %B %d %T %Y' in the '"C"' locale.) -`%C' +'%C' The century part of the current year. This is the year divided by 100 and truncated to the next lower integer. -`%d' +'%d' The day of the month as a decimal number (01-31). -`%D' - Equivalent to specifying `%m/%d/%y'. +'%D' + Equivalent to specifying '%m/%d/%y'. -`%e' +'%e' The day of the month, padded with a space if it is only one digit. -`%F' - Equivalent to specifying `%Y-%m-%d'. This is the ISO 8601 date +'%F' + Equivalent to specifying '%Y-%m-%d'. This is the ISO 8601 date format. -`%g' +'%g' The year modulo 100 of the ISO 8601 week number, as a decimal number (00-99). For example, January 1, 2012 is in week 53 of - 2011. Thus, the year of its ISO 8601 week number is 2011, even - though its year is 2012. Similarly, December 31, 2012 is in week - 1 of 2013. Thus, the year of its ISO week number is 2013, even + 2011. Thus, the year of its ISO 8601 week number is 2011, even + though its year is 2012. Similarly, December 31, 2012 is in week 1 + of 2013. Thus, the year of its ISO week number is 2013, even though its year is 2012. -`%G' +'%G' The full year of the ISO week number, as a decimal number. -`%h' - Equivalent to `%b'. +'%h' + Equivalent to '%b'. -`%H' +'%H' The hour (24-hour clock) as a decimal number (00-23). -`%I' +'%I' The hour (12-hour clock) as a decimal number (01-12). -`%j' +'%j' The day of the year as a decimal number (001-366). -`%m' +'%m' The month as a decimal number (01-12). -`%M' +'%M' The minute as a decimal number (00-59). -`%n' +'%n' A newline character (ASCII LF). -`%p' - The locale's equivalent of the AM/PM designations associated with - a 12-hour clock. +'%p' + The locale's equivalent of the AM/PM designations associated with a + 12-hour clock. -`%r' - The locale's 12-hour clock time. (This is `%I:%M:%S %p' in the - `"C"' locale.) +'%r' + The locale's 12-hour clock time. (This is '%I:%M:%S %p' in the + '"C"' locale.) -`%R' - Equivalent to specifying `%H:%M'. +'%R' + Equivalent to specifying '%H:%M'. -`%S' +'%S' The second as a decimal number (00-60). -`%t' +'%t' A TAB character. -`%T' - Equivalent to specifying `%H:%M:%S'. +'%T' + Equivalent to specifying '%H:%M:%S'. -`%u' +'%u' The weekday as a decimal number (1-7). Monday is day one. -`%U' +'%U' The week number of the year (the first Sunday as the first day of week one) as a decimal number (00-53). -`%V' +'%V' The week number of the year (the first Monday as the first day of week one) as a decimal number (01-53). The method for determining the week number is as specified by ISO 8601. (To wit: if the week - containing January 1 has four or more days in the new year, then - it is week one; otherwise it is week 53 of the previous year and - the next week is week one.) + containing January 1 has four or more days in the new year, then it + is week one; otherwise it is week 53 of the previous year and the + next week is week one.) -`%w' +'%w' The weekday as a decimal number (0-6). Sunday is day zero. -`%W' +'%W' The week number of the year (the first Monday as the first day of week one) as a decimal number (00-53). -`%x' - The locale's "appropriate" date representation. (This is `%A %B - %d %Y' in the `"C"' locale.) +'%x' + The locale's "appropriate" date representation. (This is '%A %B %d + %Y' in the '"C"' locale.) -`%X' - The locale's "appropriate" time representation. (This is `%T' in - the `"C"' locale.) +'%X' + The locale's "appropriate" time representation. (This is '%T' in + the '"C"' locale.) -`%y' +'%y' The year modulo 100 as a decimal number (00-99). -`%Y' +'%Y' The full year as a decimal number (e.g., 2015). -`%z' +'%z' The timezone offset in a +HHMM format (e.g., the format necessary to produce RFC 822/RFC 1036 date headers). -`%Z' +'%Z' The time zone name or abbreviation; no characters if no time zone is determinable. -`%Ec %EC %Ex %EX %Ey %EY %Od %Oe %OH' -`%OI %Om %OM %OS %Ou %OU %OV %Ow %OW %Oy' +'%Ec %EC %Ex %EX %Ey %EY %Od %Oe %OH' +'%OI %Om %OM %OS %Ou %OU %OV %Ow %OW %Oy' "Alternate representations" for the specifications that use only - the second letter (`%c', `%C', and so on).(5) (These facilitate - compliance with the POSIX `date' utility.) + the second letter ('%c', '%C', and so on).(5) (These facilitate + compliance with the POSIX 'date' utility.) -`%%' - A literal `%'. +'%%' + A literal '%'. If a conversion specifier is not one of the above, the behavior is undefined.(6) - For systems that are not yet fully standards-compliant, `gawk' -supplies a copy of `strftime()' from the GNU C Library. It supports -all of the just-listed format specifications. If that version is used -to compile `gawk' (*note Installation::), then the following additional + For systems that are not yet fully standards-compliant, 'gawk' +supplies a copy of 'strftime()' from the GNU C Library. It supports all +of the just-listed format specifications. If that version is used to +compile 'gawk' (*note Installation::), then the following additional format specifications are available: -`%k' +'%k' The hour (24-hour clock) as a decimal number (0-23). Single-digit numbers are padded with a space. -`%l' +'%l' The hour (12-hour clock) as a decimal number (1-12). Single-digit numbers are padded with a space. -`%s' +'%s' The time as a decimal timestamp in seconds since the epoch. - Additionally, the alternate representations are recognized but their normal representations are used. - The following example is an `awk' implementation of the POSIX `date' -utility. Normally, the `date' utility prints the current date and time + The following example is an 'awk' implementation of the POSIX 'date' +utility. Normally, the 'date' utility prints the current date and time of day in a well-known format. However, if you provide an argument to -it that begins with a `+', `date' copies nonformat specifier characters +it that begins with a '+', 'date' copies nonformat specifier characters to the standard output and interprets the current time according to the format specifiers in the string. For example: $ date '+Today is %A, %B %d, %Y.' -| Today is Monday, May 05, 2014. - Here is the `gawk' version of the `date' utility. It has a shell -"wrapper" to handle the `-u' option, which requires that `date' run as + Here is the 'gawk' version of the 'date' utility. It has a shell +"wrapper" to handle the '-u' option, which requires that 'date' run as if the time zone is set to UTC: #! /bin/sh @@ -13008,14 +12951,14 @@ if the time zone is set to UTC: (1) *Note Glossary::, especially the entries "Epoch" and "UTC." - (2) The GNU `date' utility can also do many of the things described + (2) The GNU 'date' utility can also do many of the things described here. Its use may be preferable for simple time-related operations in shell scripts. (3) Occasionally there are minutes in a year with a leap second, which is why the seconds can go up to 60. - (4) Unfortunately, not every system's `strftime()' necessarily + (4) Unfortunately, not every system's 'strftime()' necessarily supports all of the conversions listed here. (5) If you don't understand any of this, don't worry about it; these @@ -13024,8 +12967,8 @@ Other internationalization features are described in *note Internationalization::. (6) This is because ISO C leaves the behavior of the C version of -`strftime()' undefined and `gawk' uses the system's version of -`strftime()' if it's there. Typically, the conversion specifier either +'strftime()' undefined and 'gawk' uses the system's version of +'strftime()' if it's there. Typically, the conversion specifier either does not appear in the returned string or appears literally.  @@ -13034,20 +12977,20 @@ File: gawk.info, Node: Bitwise Functions, Next: Type Functions, Prev: Time Fu 9.1.6 Bit-Manipulation Functions -------------------------------- - I can explain it for you, but I can't understand it for you. -- - Anonymous + I can explain it for you, but I can't understand it for you. + -- _Anonymous_ - Many languages provide the ability to perform "bitwise" operations -on two integer numbers. In other words, the operation is performed on -each successive pair of bits in the operands. Three common operations -are bitwise AND, OR, and XOR. The operations are described in *note -table-bitwise-ops::. + Many languages provide the ability to perform "bitwise" operations on +two integer numbers. In other words, the operation is performed on each +successive pair of bits in the operands. Three common operations are +bitwise AND, OR, and XOR. The operations are described in *note Table +9.6: table-bitwise-ops. Bit Operator | AND | OR | XOR |--+--+--+--+--+-- Operands | 0 | 1 | 0 | 1 | 0 | 1 - ---------+--+--+--+--+--+-- + -------+--+--+--+--+--+-- 0 | 0 0 | 0 1 | 0 1 1 | 0 1 | 1 1 | 1 0 @@ -13056,44 +12999,45 @@ Table 9.6: Bitwise Operations As you can see, the result of an AND operation is 1 only when _both_ bits are 1. The result of an OR operation is 1 if _either_ bit is 1. The result of an XOR operation is 1 if either bit is 1, but not both. -The next operation is the "complement"; the complement of 1 is 0 and -the complement of 0 is 1. Thus, this operation "flips" all the bits of -a given value. +The next operation is the "complement"; the complement of 1 is 0 and the +complement of 0 is 1. Thus, this operation "flips" all the bits of a +given value. Finally, two other common operations are to shift the bits left or -right. For example, if you have a bit string `10111001' and you shift -it right by three bits, you end up with `00010111'.(1) If you start over -again with `10111001' and shift it left by three bits, you end up with -`11001000'. `gawk' provides built-in functions that implement the -bitwise operations just described. They are: - -``and(V1, V2' [`,' ...]`)'' - Return the bitwise AND of the arguments. There must be at least +right. For example, if you have a bit string '10111001' and you shift +it right by three bits, you end up with '00010111'.(1) If you start +over again with '10111001' and shift it left by three bits, you end up +with '11001000'. 'gawk' provides built-in functions that implement the +bitwise operations just described. They are: + +'and(V1, V2 [, ...])' + Return the bitwise AND of the arguments. There must be at least two. -``compl(VAL)'' +'compl(VAL)' Return the bitwise complement of VAL. -``lshift(VAL, COUNT)'' +'lshift(VAL, COUNT)' Return the value of VAL, shifted left by COUNT bits. -``or(V1, V2' [`,' ...]`)'' - Return the bitwise OR of the arguments. There must be at least two. +'or(V1, V2 [, ...])' + Return the bitwise OR of the arguments. There must be at least + two. -``rshift(VAL, COUNT)'' +'rshift(VAL, COUNT)' Return the value of VAL, shifted right by COUNT bits. -``xor(V1, V2' [`,' ...]`)'' - Return the bitwise XOR of the arguments. There must be at least +'xor(V1, V2 [, ...])' + Return the bitwise XOR of the arguments. There must be at least two. - For all of these functions, first the double precision -floating-point value is converted to the widest C unsigned integer -type, then the bitwise operation is performed. If the result cannot be -represented exactly as a C `double', leading nonzero bits are removed -one by one until it can be represented exactly. The result is then -converted back into a C `double'. (If you don't understand this -paragraph, don't worry about it.) + For all of these functions, first the double precision floating-point +value is converted to the widest C unsigned integer type, then the +bitwise operation is performed. If the result cannot be represented +exactly as a C 'double', leading nonzero bits are removed one by one +until it can be represented exactly. The result is then converted back +into a C 'double'. (If you don't understand this paragraph, don't worry +about it.) Here is a user-defined function (*note User-defined::) that illustrates the use of these functions: @@ -13137,28 +13081,28 @@ This program produces the following output when run: -| lshift(0x99, 2) = 0x264 = 0000001001100100 -| rshift(0x99, 2) = 0x26 = 00100110 - The `bits2str()' function turns a binary number into a string. The -number `1' represents a binary value where the rightmost bit is set to + The 'bits2str()' function turns a binary number into a string. The +number '1' represents a binary value where the rightmost bit is set to 1. Using this mask, the function repeatedly checks the rightmost bit. ANDing the mask with the value indicates whether the rightmost bit is 1 -or not. If so, a `"1"' is concatenated onto the front of the string. -Otherwise, a `"0"' is added. The value is then shifted right by one -bit and the loop continues until there are no more 1 bits. +or not. If so, a '"1"' is concatenated onto the front of the string. +Otherwise, a '"0"' is added. The value is then shifted right by one bit +and the loop continues until there are no more 1 bits. - If the initial value is zero it returns a simple `"0"'. Otherwise, -at the end, it pads the value with zeros to represent multiples of -8-bit quantities. This is typical in modern computers. + If the initial value is zero it returns a simple '"0"'. Otherwise, +at the end, it pads the value with zeros to represent multiples of 8-bit +quantities. This is typical in modern computers. - The main code in the `BEGIN' rule shows the difference between the + The main code in the 'BEGIN' rule shows the difference between the decimal and octal values for the same numbers (*note Nondecimal-numbers::), and then demonstrates the results of the -`compl()', `lshift()', and `rshift()' functions. +'compl()', 'lshift()', and 'rshift()' functions. ---------- Footnotes ---------- - (1) This example shows that 0's come in on the left side. For -`gawk', this is always true, but in some languages, it's possible to -have the left side fill with 1's. Caveat emptor. + (1) This example shows that 0's come in on the left side. For +'gawk', this is always true, but in some languages, it's possible to +have the left side fill with 1's. Caveat emptor.  File: gawk.info, Node: Type Functions, Next: I18N Functions, Prev: Bitwise Functions, Up: Built-in @@ -13166,26 +13110,26 @@ File: gawk.info, Node: Type Functions, Next: I18N Functions, Prev: Bitwise Fu 9.1.7 Getting Type Information ------------------------------ -`gawk' provides a single function that lets you distinguish an array +'gawk' provides a single function that lets you distinguish an array from a scalar variable. This is necessary for writing code that traverses every element of an array of arrays. (*note Arrays of Arrays::). -`isarray(X)' - Return a true value if X is an array. Otherwise return false. +'isarray(X)' + Return a true value if X is an array. Otherwise return false. - `isarray()' is meant for use in two circumstances. The first is when + 'isarray()' is meant for use in two circumstances. The first is when traversing a multidimensional array: you can test if an element is -itself an array or not. The second is inside the body of a -user-defined function (not discussed yet; *note User-defined::), to -test if a parameter is an array or not. +itself an array or not. The second is inside the body of a user-defined +function (not discussed yet; *note User-defined::), to test if a +parameter is an array or not. - Note, however, that using `isarray()' at the global level to test -variables makes no sense. Since you are the one writing the program, you -are supposed to know if your variables are arrays or not. And in fact, -due to the way `gawk' works, if you pass the name of a variable that -has not been previously used to `isarray()', `gawk' will end up turning -it into a scalar. + Note, however, that using 'isarray()' at the global level to test +variables makes no sense. Since you are the one writing the program, +you are supposed to know if your variables are arrays or not. And in +fact, due to the way 'gawk' works, if you pass the name of a variable +that has not been previously used to 'isarray()', 'gawk' will end up +turning it into a scalar.  File: gawk.info, Node: I18N Functions, Prev: Type Functions, Up: Built-in @@ -13193,35 +13137,34 @@ File: gawk.info, Node: I18N Functions, Prev: Type Functions, Up: Built-in 9.1.8 String-Translation Functions ---------------------------------- -`gawk' provides facilities for internationalizing `awk' programs. -These include the functions described in the following list. The -descriptions here are purposely brief. *Note Internationalization::, -for the full story. Optional parameters are enclosed in square -brackets ([ ]): +'gawk' provides facilities for internationalizing 'awk' programs. These +include the functions described in the following list. The descriptions +here are purposely brief. *Note Internationalization::, for the full +story. Optional parameters are enclosed in square brackets ([ ]): -`bindtextdomain(DIRECTORY' [`,' DOMAIN]`)' - Set the directory in which `gawk' will look for message - translation files, in case they will not or cannot be placed in - the "standard" locations (e.g., during testing). It returns the - directory in which DOMAIN is "bound." +'bindtextdomain(DIRECTORY' [',' DOMAIN]')' + Set the directory in which 'gawk' will look for message translation + files, in case they will not or cannot be placed in the "standard" + locations (e.g., during testing). It returns the directory in + which DOMAIN is "bound." - The default DOMAIN is the value of `TEXTDOMAIN'. If DIRECTORY is - the null string (`""'), then `bindtextdomain()' returns the - current binding for the given DOMAIN. + The default DOMAIN is the value of 'TEXTDOMAIN'. If DIRECTORY is + the null string ('""'), then 'bindtextdomain()' returns the current + binding for the given DOMAIN. -`dcgettext(STRING' [`,' DOMAIN [`,' CATEGORY] ]`)' +'dcgettext(STRING' [',' DOMAIN [',' CATEGORY] ]')' Return the translation of STRING in text domain DOMAIN for locale category CATEGORY. The default value for DOMAIN is the current - value of `TEXTDOMAIN'. The default value for CATEGORY is - `"LC_MESSAGES"'. + value of 'TEXTDOMAIN'. The default value for CATEGORY is + '"LC_MESSAGES"'. -`dcngettext(STRING1, STRING2, NUMBER' [`,' DOMAIN [`,' CATEGORY] ]`)' +'dcngettext(STRING1, STRING2, NUMBER' [',' DOMAIN [',' CATEGORY] ]')' Return the plural form used for NUMBER of the translation of STRING1 and STRING2 in text domain DOMAIN for locale category - CATEGORY. STRING1 is the English singular variant of a message, + CATEGORY. STRING1 is the English singular variant of a message, and STRING2 the English plural variant of the same message. The - default value for DOMAIN is the current value of `TEXTDOMAIN'. - The default value for CATEGORY is `"LC_MESSAGES"'. + default value for DOMAIN is the current value of 'TEXTDOMAIN'. The + default value for CATEGORY is '"LC_MESSAGES"'.  File: gawk.info, Node: User-defined, Next: Indirect Calls, Prev: Built-in, Up: Functions @@ -13229,10 +13172,10 @@ File: gawk.info, Node: User-defined, Next: Indirect Calls, Prev: Built-in, U 9.2 User-Defined Functions ========================== -Complicated `awk' programs can often be simplified by defining your own -functions. User-defined functions can be called just like built-in -ones (*note Function Calls::), but it is up to you to define them, -i.e., to tell `awk' what they should do. +Complicated 'awk' programs can often be simplified by defining your own +functions. User-defined functions can be called just like built-in ones +(*note Function Calls::), but it is up to you to define them, i.e., to +tell 'awk' what they should do. * Menu: @@ -13250,22 +13193,22 @@ File: gawk.info, Node: Definition Syntax, Next: Function Example, Up: User-de -------------------------------- Definitions of functions can appear anywhere between the rules of an -`awk' program. Thus, the general form of an `awk' program is extended +'awk' program. Thus, the general form of an 'awk' program is extended to include sequences of rules _and_ user-defined function definitions. There is no need to put the definition of a function before all uses of -the function. This is because `awk' reads the entire program before +the function. This is because 'awk' reads the entire program before starting to execute any of it. The definition of a function named NAME looks like this: - `function' NAME`('[PARAMETER-LIST]`)' - `{' + 'function' NAME'('[PARAMETER-LIST]')' + '{' BODY-OF-FUNCTION - `}' + '}' -Here, NAME is the name of the function to define. A valid function -name is like a valid variable name: a sequence of letters, digits, and -underscores that doesn't start with a digit. Within a single `awk' +Here, NAME is the name of the function to define. A valid function name +is like a valid variable name: a sequence of letters, digits, and +underscores that doesn't start with a digit. Within a single 'awk' program, any particular name can only be used as a variable, array, or function. @@ -13278,23 +13221,23 @@ call. have a parameter with the same name as the function itself. In addition, according to the POSIX standard, function parameters cannot have the same name as one of the special built-in variables (*note -Built-in Variables::). Not all versions of `awk' enforce this +Built-in Variables::). Not all versions of 'awk' enforce this restriction.) Local variables act like the empty string if referenced where a string value is required, and like zero if referenced where a numeric -value is required. This is the same as regular variables that have +value is required. This is the same as regular variables that have never been assigned a value. (There is more to understand about local variables; *note Dynamic Typing::.) - The BODY-OF-FUNCTION consists of `awk' statements. It is the most + The BODY-OF-FUNCTION consists of 'awk' statements. It is the most important part of the definition, because it says what the function should actually _do_. The argument names exist to give the body a way to talk about the arguments; local variables exist to give the body places to keep temporary values. Argument names are not distinguished syntactically from local -variable names. Instead, the number of arguments supplied when the +variable names. Instead, the number of arguments supplied when the function is called determines how many argument variables there are. Thus, if three argument values are given, the first three names in PARAMETER-LIST are arguments and the rest are local variables. @@ -13304,19 +13247,19 @@ calls to the function, some of the names in PARAMETER-LIST may be arguments on some occasions and local variables on others. Another way to think of this is that omitted arguments default to the null string. - Usually when you write a function, you know how many names you -intend to use for arguments and how many you intend to use as local -variables. It is conventional to place some extra space between the -arguments and the local variables, in order to document how your -function is supposed to be used. + Usually when you write a function, you know how many names you intend +to use for arguments and how many you intend to use as local variables. +It is conventional to place some extra space between the arguments and +the local variables, in order to document how your function is supposed +to be used. During execution of the function body, the arguments and local variable values hide, or "shadow", any variables of the same names used in the rest of the program. The shadowed variables are not accessible in the function definition, because there is no way to name them while their names have been taken away for the local variables. All other -variables used in the `awk' program can be referenced or set normally -in the function's body. +variables used in the 'awk' program can be referenced or set normally in +the function's body. The arguments and local variables last only as long as the function body is executing. Once the body finishes, you can once again access @@ -13328,32 +13271,31 @@ function. When this happens, we say the function is "recursive". The act of a function calling itself is called "recursion". All the built-in functions return a value to their caller. -User-defined functions can do so also, using the `return' statement, +User-defined functions can do so also, using the 'return' statement, which is described in detail in *note Return Statement::. Many of the -subsequent examples in this minor node use the `return' statement. +subsequent examples in this minor node use the 'return' statement. - In many `awk' implementations, including `gawk', the keyword -`function' may be abbreviated `func'. (c.e.) However, POSIX only -specifies the use of the keyword `function'. This actually has some -practical implications. If `gawk' is in POSIX-compatibility mode -(*note Options::), then the following statement does _not_ define a -function: + In many 'awk' implementations, including 'gawk', the keyword +'function' may be abbreviated 'func'. (c.e.) However, POSIX only +specifies the use of the keyword 'function'. This actually has some +practical implications. If 'gawk' is in POSIX-compatibility mode (*note +Options::), then the following statement does _not_ define a function: func foo() { a = sqrt($1) ; print a } Instead it defines a rule that, for each record, concatenates the value -of the variable `func' with the return value of the function `foo'. If +of the variable 'func' with the return value of the function 'foo'. If the resulting string is non-null, the action is executed. This is -probably not what is desired. (`awk' accepts this input as +probably not what is desired. ('awk' accepts this input as syntactically valid, because functions may be used before they are -defined in `awk' programs.(1)) +defined in 'awk' programs.(1)) - To ensure that your `awk' programs are portable, always use the -keyword `function' when defining a function. + To ensure that your 'awk' programs are portable, always use the +keyword 'function' when defining a function. ---------- Footnotes ---------- - (1) This program won't actually run, since `foo()' is undefined. + (1) This program won't actually run, since 'foo()' is undefined.  File: gawk.info, Node: Function Example, Next: Function Caveats, Prev: Definition Syntax, Up: User-defined @@ -13361,7 +13303,7 @@ File: gawk.info, Node: Function Example, Next: Function Caveats, Prev: Defini 9.2.2 Function Definition Examples ---------------------------------- -Here is an example of a user-defined function, called `myprint()', that +Here is an example of a user-defined function, called 'myprint()', that takes a number and prints it in a specific format: function myprint(num) @@ -13369,7 +13311,7 @@ takes a number and prints it in a specific format: printf "%6.3g\n", num } -To illustrate, here is an `awk' rule that uses our `myprint' function: +To illustrate, here is an 'awk' rule that uses our 'myprint' function: $3 > 0 { myprint($3) } @@ -13397,8 +13339,8 @@ this program, using our function to format the results, prints: When working with arrays, it is often necessary to delete all the elements in an array and start over with a new list of elements (*note Delete::). Instead of having to repeat this loop everywhere that you -need to clear out an array, your program can just call `delarray'. -(This guarantees portability. The use of `delete ARRAY' to delete the +need to clear out an array, your program can just call 'delarray'. +(This guarantees portability. The use of 'delete ARRAY' to delete the contents of an entire array is a recent(1) addition to the POSIX standard.) @@ -13416,17 +13358,17 @@ zero, i.e., when there are no more characters left in the string. return (substr(str, start, 1) rev(str, start - 1)) } - If this function is in a file named `rev.awk', it can be tested this + If this function is in a file named 'rev.awk', it can be tested this way: $ echo "Don't Panic!" | > gawk --source '{ print rev($0, length($0)) }' -f rev.awk -| !cinaP t'noD - The C `ctime()' function takes a timestamp and returns it in a + The C 'ctime()' function takes a timestamp and returns it in a string, formatted in a well-known fashion. The following example uses -the built-in `strftime()' function (*note Time Functions::) to create -an `awk' version of `ctime()': +the built-in 'strftime()' function (*note Time Functions::) to create an +'awk' version of 'ctime()': # ctime.awk # @@ -13467,20 +13409,20 @@ File: gawk.info, Node: Calling A Function, Next: Variable Scope, Up: Function ............................... A function call consists of the function name followed by the arguments -in parentheses. `awk' expressions are what you write in the call for +in parentheses. 'awk' expressions are what you write in the call for the arguments. Each time the call is executed, these expressions are evaluated, and the values become the actual arguments. For example, -here is a call to `foo()' with three arguments (the first being a -string concatenation): +here is a call to 'foo()' with three arguments (the first being a string +concatenation): foo(x y, "lose", 4 * z) CAUTION: Whitespace characters (spaces and TABs) are not allowed between the function name and the open-parenthesis of the argument - list. If you write whitespace by mistake, `awk' might think that + list. If you write whitespace by mistake, 'awk' might think that you mean to concatenate a variable with an expression in - parentheses. However, it notices that you used a function name - and not a variable name, and reports an error. + parentheses. However, it notices that you used a function name and + not a variable name, and reports an error.  File: gawk.info, Node: Variable Scope, Next: Pass By Value/Reference, Prev: Calling A Function, Up: Function Caveats @@ -13488,15 +13430,15 @@ File: gawk.info, Node: Variable Scope, Next: Pass By Value/Reference, Prev: C 9.2.3.2 Controlling Variable Scope .................................. -Unlike many languages, there is no way to make a variable local to a -`{' ... `}' block in `awk', but you can make a variable local to a -function. It is good practice to do so whenever a variable is needed -only in that function. +Unlike many languages, there is no way to make a variable local to a '{' +... '}' block in 'awk', but you can make a variable local to a function. +It is good practice to do so whenever a variable is needed only in that +function. To make a variable local to a function, simply declare the variable as an argument after the actual function arguments (*note Definition -Syntax::). Look at the following example where variable `i' is a -global variable used by both functions `foo()' and `bar()': +Syntax::). Look at the following example where variable 'i' is a global +variable used by both functions 'foo()' and 'bar()': function bar() { @@ -13519,8 +13461,8 @@ global variable used by both functions `foo()' and `bar()': print "top's i=" i } - Running this script produces the following, because the `i' in -functions `foo()' and `bar()' and at the top level refer to the same + Running this script produces the following, because the 'i' in +functions 'foo()' and 'bar()' and at the top level refer to the same variable instance: top's i=10 @@ -13531,9 +13473,9 @@ variable instance: foo's i=3 top's i=3 - If you want `i' to be local to both `foo()' and `bar()' do as -follows (the extra-space before `i' is a coding convention to indicate -that `i' is a local variable, not an argument): + If you want 'i' to be local to both 'foo()' and 'bar()' do as follows +(the extra-space before 'i' is a coding convention to indicate that 'i' +is a local variable, not an argument): function bar( i) { @@ -13567,7 +13509,7 @@ that `i' is a local variable, not an argument): top's i=10 Besides scalar values (strings and numbers), you may also have local -arrays. By using a parameter name as an array, `awk' treats it as an +arrays. By using a parameter name as an array, 'awk' treats it as an array, and it is local to the function. In addition, recursive calls create new arrays. Consider this example: @@ -13608,7 +13550,7 @@ File: gawk.info, Node: Pass By Value/Reference, Prev: Variable Scope, Up: Fun 9.2.3.3 Passing Function Arguments By Value Or By Reference ........................................................... -In `awk', when you declare a function, there is no way to declare +In 'awk', when you declare a function, there is no way to declare explicitly whether the arguments are passed "by value" or "by reference". @@ -13617,7 +13559,6 @@ function is called according to the following rule: * If the argument is an array variable, then it is passed by reference, - * Otherwise the argument is passed by value. Passing an argument by value means that when a function is called, it @@ -13629,11 +13570,11 @@ example, if you write the following code: foo = "bar" z = myfunc(foo) -then you should not think of the argument to `myfunc()' as being "the -variable `foo'." Instead, think of the argument as the string value -`"bar"'. If the function `myfunc()' alters the values of its local +then you should not think of the argument to 'myfunc()' as being "the +variable 'foo'." Instead, think of the argument as the string value +'"bar"'. If the function 'myfunc()' alters the values of its local variables, this has no effect on any other variables. Thus, if -`myfunc()' does this: +'myfunc()' does this: function myfunc(str) { @@ -13642,11 +13583,11 @@ variables, this has no effect on any other variables. Thus, if print str } -to change its first argument variable `str', it does _not_ change the -value of `foo' in the caller. The role of `foo' in calling `myfunc()' -ended when its value (`"bar"') was computed. If `str' also exists -outside of `myfunc()', the function body cannot alter this outer value, -because it is shadowed during the execution of `myfunc()' and cannot be +to change its first argument variable 'str', it does _not_ change the +value of 'foo' in the caller. The role of 'foo' in calling 'myfunc()' +ended when its value ('"bar"') was computed. If 'str' also exists +outside of 'myfunc()', the function body cannot alter this outer value, +because it is shadowed during the execution of 'myfunc()' and cannot be seen or changed from there. However, when arrays are the parameters to functions, they are _not_ @@ -13670,12 +13611,12 @@ function _are_ visible outside that function. a[1], a[2], a[3] } - prints `a[1] = 1, a[2] = two, a[3] = 3', because `changeit' stores - `"two"' in the second element of `a'. + prints 'a[1] = 1, a[2] = two, a[3] = 3', because 'changeit' stores + '"two"' in the second element of 'a'. - Some `awk' implementations allow you to call a function that has not -been defined. They only report a problem at runtime when the program -actually tries to call the function. For example: + Some 'awk' implementations allow you to call a function that has not +been defined. They only report a problem at runtime when the program +actually tries to call the function. For example: BEGIN { if (0) @@ -13686,53 +13627,52 @@ actually tries to call the function. For example: function bar() { ... } # note that `foo' is not defined -Because the `if' statement will never be true, it is not really a -problem that `foo()' has not been defined. Usually, though, it is a +Because the 'if' statement will never be true, it is not really a +problem that 'foo()' has not been defined. Usually, though, it is a problem if a program calls an undefined function. - If `--lint' is specified (*note Options::), `gawk' reports calls to + If '--lint' is specified (*note Options::), 'gawk' reports calls to undefined functions. - Some `awk' implementations generate a runtime error if you use -either the `next' statement or the `nextfile' statement (*note Next + Some 'awk' implementations generate a runtime error if you use either +the 'next' statement or the 'nextfile' statement (*note Next Statement::, also *note Nextfile Statement::) inside a user-defined -function. `gawk' does not have this limitation. +function. 'gawk' does not have this limitation.  File: gawk.info, Node: Return Statement, Next: Dynamic Typing, Prev: Function Caveats, Up: User-defined -9.2.4 The `return' Statement +9.2.4 The 'return' Statement ---------------------------- -As seen in several earlier examples, the body of a user-defined -function can contain a `return' statement. This statement returns -control to the calling part of the `awk' program. It can also be used -to return a value for use in the rest of the `awk' program. It looks -like this: +As seen in several earlier examples, the body of a user-defined function +can contain a 'return' statement. This statement returns control to the +calling part of the 'awk' program. It can also be used to return a +value for use in the rest of the 'awk' program. It looks like this: - `return' [EXPRESSION] + 'return' [EXPRESSION] The EXPRESSION part is optional. Due most likely to an oversight, POSIX does not define what the return value is if you omit the EXPRESSION. Technically speaking, this makes the returned value undefined, and therefore, unpredictable. In practice, though, all -versions of `awk' simply return the null string, which acts like zero -if used in a numeric context. +versions of 'awk' simply return the null string, which acts like zero if +used in a numeric context. - A `return' statement with no value expression is assumed at the end + A 'return' statement with no value expression is assumed at the end of every function definition. So if control reaches the end of the function body, then technically, the function returns an unpredictable -value. In practice, it returns the empty string. `awk' does _not_ -warn you if you use the return value of such a function. +value. In practice, it returns the empty string. 'awk' does _not_ warn +you if you use the return value of such a function. Sometimes, you want to write a function for what it does, not for -what it returns. Such a function corresponds to a `void' function in -C, C++ or Java, or to a `procedure' in Ada. Thus, it may be -appropriate to not return any value; simply bear in mind that you -should not be using the return value of such a function. +what it returns. Such a function corresponds to a 'void' function in C, +C++ or Java, or to a 'procedure' in Ada. Thus, it may be appropriate to +not return any value; simply bear in mind that you should not be using +the return value of such a function. - The following is an example of a user-defined function that returns -a value for the largest number among the elements of an array: + The following is an example of a user-defined function that returns a +value for the largest number among the elements of an array: function maxelt(vec, i, ret) { @@ -13743,15 +13683,15 @@ a value for the largest number among the elements of an array: return ret } -You call `maxelt()' with one argument, which is an array name. The -local variables `i' and `ret' are not intended to be arguments; while +You call 'maxelt()' with one argument, which is an array name. The +local variables 'i' and 'ret' are not intended to be arguments; while there is nothing to stop you from passing more than one argument to -`maxelt()', the results would be strange. The extra space before `i' -in the function parameter list indicates that `i' and `ret' are local +'maxelt()', the results would be strange. The extra space before 'i' in +the function parameter list indicates that 'i' and 'ret' are local variables. You should follow this convention when defining functions. - The following program uses the `maxelt()' function. It loads an -array, calls `maxelt()', and then reports the maximum number in that + The following program uses the 'maxelt()' function. It loads an +array, calls 'maxelt()', and then reports the maximum number in that array: function maxelt(vec, i, ret) @@ -13790,8 +13730,8 @@ File: gawk.info, Node: Dynamic Typing, Prev: Return Statement, Up: User-defin 9.2.5 Functions and Their Effects on Variable Typing ---------------------------------------------------- -`awk' is a very fluid language. It is possible that `awk' can't tell -if an identifier represents a scalar variable or an array until runtime. +'awk' is a very fluid language. It is possible that 'awk' can't tell if +an identifier represents a scalar variable or an array until runtime. Here is an annotated sample program: function foo(a) @@ -13807,9 +13747,9 @@ Here is an annotated sample program: x = 1 # now not allowed, runtime error } - In this example, the first call to `foo()' generates a fatal error, -so `awk' will not report the second error. If you comment out that -call, though, then `awk' does report the second error. + In this example, the first call to 'foo()' generates a fatal error, +so 'awk' will not report the second error. If you comment out that +call, though, then 'awk' does report the second error. Usually, such things aren't a big issue, but it's worth being aware of them. @@ -13820,21 +13760,21 @@ File: gawk.info, Node: Indirect Calls, Next: Functions Summary, Prev: User-de 9.3 Indirect Function Calls =========================== -This section describes a `gawk'-specific extension. +This section describes a 'gawk'-specific extension. Often, you may wish to defer the choice of function to call until runtime. For example, you may have different kinds of records, each of which should be processed differently. - Normally, you would have to use a series of `if'-`else' statements -to decide which function to call. By using "indirect" function calls, -you can specify the name of the function to call as a string variable, -and then call the function. Let's look at an example. + Normally, you would have to use a series of 'if'-'else' statements to +decide which function to call. By using "indirect" function calls, you +can specify the name of the function to call as a string variable, and +then call the function. Let's look at an example. - Suppose you have a file with your test scores for the classes you -are taking. The first field is the class name. The following fields -are the functions to call to process the data, up to a "marker" field -`data:'. Following the marker, to the end of the record, are the + Suppose you have a file with your test scores for the classes you are +taking. The first field is the class name. The following fields are +the functions to call to process the data, up to a "marker" field +'data:'. Following the marker, to the end of the record, are the various numeric test scores. Here is the initial file; you wish to get the sum and the average of @@ -13858,12 +13798,12 @@ your test scores: } This style of programming works, but can be awkward. With "indirect" -function calls, you tell `gawk' to use the _value_ of a variable as the +function calls, you tell 'gawk' to use the _value_ of a variable as the name of the function to call. The syntax is similar to that of a regular function call: an identifier immediately followed by a left parenthesis, any arguments, -and then a closing right parenthesis, with the addition of a leading `@' +and then a closing right parenthesis, with the addition of a leading '@' character: the_func = "sum" @@ -13897,7 +13837,7 @@ using indirect function calls. } These two functions expect to work on fields; thus the parameters -`first' and `last' indicate where in the fields to start and end. +'first' and 'last' indicate where in the fields to start and end. Otherwise they perform the expected computations and are not unusual. # For each record, print the class name and the requested statistics @@ -13922,14 +13862,14 @@ Otherwise they perform the expected computations and are not unusual. print "" } - This is the main processing for each record. It prints the class -name (with underscores replaced with spaces). It then finds the start -of the actual data, saving it in `start'. The last part of the code -loops through each function name (from `$2' up to the marker, `data:'), -calling the function named by the field. The indirect function call -itself occurs as a parameter in the call to `printf'. (The `printf' -format string uses `%s' as the format specifier so that we can use -functions that return strings, as well as numbers. Note that the result + This is the main processing for each record. It prints the class +name (with underscores replaced with spaces). It then finds the start +of the actual data, saving it in 'start'. The last part of the code +loops through each function name (from '$2' up to the marker, 'data:'), +calling the function named by the field. The indirect function call +itself occurs as a parameter in the call to 'printf'. (The 'printf' +format string uses '%s' as the format specifier so that we can use +functions that return strings, as well as numbers. Note that the result from the indirect call is concatenated with the empty string, in order to force it to be a string value.) @@ -13952,13 +13892,13 @@ to force it to be a string value.) may think at first. The C and C++ languages provide "function pointers," which are a mechanism for calling a function chosen at runtime. One of the most well-known uses of this ability is the C -`qsort()' function, which sorts an array using the famous "quick sort" +'qsort()' function, which sorts an array using the famous "quick sort" algorithm (see the Wikipedia article -(http://en.wikipedia.org/wiki/Quick_sort) for more information). To -use this function, you supply a pointer to a comparison function. This +(http://en.wikipedia.org/wiki/Quick_sort) for more information). To use +this function, you supply a pointer to a comparison function. This mechanism allows you to sort arbitrary data in an arbitrary fashion. - We can do something similar using `gawk', like this: + We can do something similar using 'gawk', like this: # quicksort.awk --- Quicksort algorithm, with user-supplied # comparison function @@ -13989,13 +13929,13 @@ mechanism allows you to sort arbitrary data in an arbitrary fashion. data[j] = temp } - The `quicksort()' function receives the `data' array, the starting -and ending indices to sort (`left' and `right'), and the name of a -function that performs a "less than" comparison. It then implements -the quick sort algorithm. + The 'quicksort()' function receives the 'data' array, the starting +and ending indices to sort ('left' and 'right'), and the name of a +function that performs a "less than" comparison. It then implements the +quick sort algorithm. To make use of the sorting function, we return to our previous -example. The first thing to do is write some comparison functions: +example. The first thing to do is write some comparison functions: # num_lt --- do a numeric less than comparison @@ -14011,15 +13951,15 @@ example. The first thing to do is write some comparison functions: return ((left + 0) >= (right + 0)) } - The `num_ge()' function is needed to perform a descending sort; when + The 'num_ge()' function is needed to perform a descending sort; when used to perform a "less than" test, it actually does the opposite (greater than or equal to), which yields data sorted in descending order. - Next comes a sorting function. It is parameterized with the -starting and ending field numbers and the comparison function. It -builds an array with the data and calls `quicksort()' appropriately, -and then formats the results as a single string: + Next comes a sorting function. It is parameterized with the starting +and ending field numbers and the comparison function. It builds an +array with the data and calls 'quicksort()' appropriately, and then +formats the results as a single string: # do_sort --- sort the data according to `compare' # and return it as a string @@ -14041,7 +13981,7 @@ and then formats the results as a single string: return retval } - Finally, the two sorting functions call `do_sort()', passing in the + Finally, the two sorting functions call 'do_sort()', passing in the names of the two comparison functions: # sort --- sort the data in ascending order and return it as a string @@ -14085,22 +14025,22 @@ names of the two comparison functions: -| sort: <87.1 93.4 95.6 100.0> -| rsort: <100.0 95.6 93.4 87.1> - Remember that you must supply a leading `@' in front of an indirect + Remember that you must supply a leading '@' in front of an indirect function call. Unfortunately, indirect function calls cannot be used with the built-in functions. However, you can generally write "wrapper" functions which call the built-in ones, and those can be called -indirectly. (Other than, perhaps, the mathematical functions, there is +indirectly. (Other than, perhaps, the mathematical functions, there is not a lot of reason to try to call the built-in functions indirectly.) - `gawk' does its best to make indirect function calls efficient. For + 'gawk' does its best to make indirect function calls efficient. For example, in the following case: for (i = 1; i <= n; i++) @the_func() -`gawk' will look up the actual function to call only once. +'gawk' will look up the actual function to call only once.  File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions @@ -14108,27 +14048,27 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions 9.4 Summary =========== - * `awk' provides built-in functions and lets you define your own + * 'awk' provides built-in functions and lets you define your own functions. - * POSIX `awk' provides three kinds of built-in functions: numeric, - string, and I/O. `gawk' provides functions that work with values + * POSIX 'awk' provides three kinds of built-in functions: numeric, + string, and I/O. 'gawk' provides functions that work with values representing time, do bit manipulation, sort arrays, and - internationalize and localize programs. `gawk' also provides + internationalize and localize programs. 'gawk' also provides several extensions to some of standard functions, typically in the form of additional arguments. * Functions accept zero or more arguments and return a value. The expressions that provide the argument values are completely - evaluated before the function is called. Order of evaluation is + evaluated before the function is called. Order of evaluation is not defined. The return value can be ignored. - * The handling of backslash in `sub()' and `gsub()' is not simple. - It is more straightforward in `gawk''s `gensub()' function, but + * The handling of backslash in 'sub()' and 'gsub()' is not simple. + It is more straightforward in 'gawk''s 'gensub()' function, but that function still requires care in its use. * User-defined functions provide important capabilities but come with - some syntactic inelegancies. In a function call, there cannot be + some syntactic inelegancies. In a function call, there cannot be any space between the function name and the opening left parenthesis of the argument list. Also, there is no provision for local variables, so the convention is to add extra parameters, and @@ -14136,15 +14076,15 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions whitespace. * User-defined functions may call other user-defined (and built-in) - functions and may call themselves recursively. Function parameters + functions and may call themselves recursively. Function parameters "hide" any global variables of the same names. - * Scalar values are passed to user-defined functions by value. Array + * Scalar values are passed to user-defined functions by value. Array parameters are passed by reference; any changes made by the function to array parameters are thus visible after the function has returned. - * Use the `return' statement to return from a user-defined function. + * Use the 'return' statement to return from a user-defined function. An optional expression becomes the function's return value. Only scalar values may be returned by a function. @@ -14152,26 +14092,24 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions function, how that function treats the variable can set its nature: either scalar or array. - * `gawk' provides indirect function calls using a special syntax. - By setting a variable to the name of a user-defined function, you - can determine at runtime what function will be called at that - point in the program. This is equivalent to function pointers in C - and C++. - + * 'gawk' provides indirect function calls using a special syntax. By + setting a variable to the name of a user-defined function, you can + determine at runtime what function will be called at that point in + the program. This is equivalent to function pointers in C and C++.  File: gawk.info, Node: Library Functions, Next: Sample Programs, Prev: Functions, Up: Top -10 A Library of `awk' Functions +10 A Library of 'awk' Functions ******************************* -*note User-defined::, describes how to write your own `awk' functions. +*note User-defined::, describes how to write your own 'awk' functions. Writing functions is important, because it allows you to encapsulate algorithms and program tasks in a single place. It simplifies programming, making program development more manageable, and making programs more readable. - In their seminal 1976 book, `Software Tools',(1) Brian Kernighan and + In their seminal 1976 book, 'Software Tools',(1) Brian Kernighan and P.J. Plauger wrote: Good Programming is not learned from generalities, but by seeing @@ -14183,38 +14121,38 @@ P.J. Plauger wrote: In fact, they felt this idea was so important that they placed this statement on the cover of their book. Because we believe strongly that -their statement is correct, this major node and *note Sample -Programs::, provide a good-sized body of code for you to read, and we -hope, to learn from. +their statement is correct, this major node and *note Sample Programs::, +provide a good-sized body of code for you to read, and we hope, to learn +from. - This major node presents a library of useful `awk' functions. Many + This major node presents a library of useful 'awk' functions. Many of the sample programs presented later in this Info file use these functions. The functions are presented here in a progression from simple to complex. *note Extract Program::, presents a program that you can use to -extract the source code for these example library functions and -programs from the Texinfo source for this Info file. (This has already -been done as part of the `gawk' distribution.) +extract the source code for these example library functions and programs +from the Texinfo source for this Info file. (This has already been done +as part of the 'gawk' distribution.) - If you have written one or more useful, general-purpose `awk' -functions and would like to contribute them to the `awk' user -community, see *note How To Contribute::, for more information. + If you have written one or more useful, general-purpose 'awk' +functions and would like to contribute them to the 'awk' user community, +see *note How To Contribute::, for more information. The programs in this major node and in *note Sample Programs::, -freely use features that are `gawk'-specific. Rewriting these programs -for different implementations of `awk' is pretty straightforward. +freely use features that are 'gawk'-specific. Rewriting these programs +for different implementations of 'awk' is pretty straightforward. - * Diagnostic error messages are sent to `/dev/stderr'. Use `| "cat - 1>&2"' instead of `> "/dev/stderr"' if your system does not have a - `/dev/stderr', or if you cannot use `gawk'. + * Diagnostic error messages are sent to '/dev/stderr'. Use '| "cat + 1>&2"' instead of '> "/dev/stderr"' if your system does not have a + '/dev/stderr', or if you cannot use 'gawk'. - * A number of programs use `nextfile' (*note Nextfile Statement::) - to skip any remaining input in the input file. + * A number of programs use 'nextfile' (*note Nextfile Statement::) to + skip any remaining input in the input file. * Finally, some of the programs choose to ignore upper- and lowercase - distinctions in their input. They do so by assigning one to - `IGNORECASE'. You can achieve almost the same effect(2) by adding + distinctions in their input. They do so by assigning one to + 'IGNORECASE'. You can achieve almost the same effect(2) by adding the following rule to the beginning of the program: # ignore case @@ -14244,7 +14182,7 @@ for different implementations of `awk' is pretty straightforward. book have yet to be learned by a vast number of practicing programmers. (2) The effects are not identical. Output of the transformed record -will be in all lowercase, while `IGNORECASE' preserves the original +will be in all lowercase, while 'IGNORECASE' preserves the original contents of the input record.  @@ -14253,49 +14191,49 @@ File: gawk.info, Node: Library Names, Next: General Functions, Up: Library Fu 10.1 Naming Library Function Global Variables ============================================= -Due to the way the `awk' language evolved, variables are either -"global" (usable by the entire program) or "local" (usable just by a -specific function). There is no intermediate state analogous to -`static' variables in C. +Due to the way the 'awk' language evolved, variables are either "global" +(usable by the entire program) or "local" (usable just by a specific +function). There is no intermediate state analogous to 'static' +variables in C. Library functions often need to have global variables that they can use to preserve state information between calls to the function--for -example, `getopt()''s variable `_opti' (*note Getopt Function::). Such +example, 'getopt()''s variable '_opti' (*note Getopt Function::). Such variables are called "private", since the only functions that need to use them are the ones in the library. When writing a library function, you should try to choose names for your private variables that will not conflict with any variables used by either another library function or a user's main program. For example, -a name like `i' or `j' is not a good choice, because user programs -often use variable names like these for their own purposes. +a name like 'i' or 'j' is not a good choice, because user programs often +use variable names like these for their own purposes. The example programs shown in this major node all start the names of -their private variables with an underscore (`_'). Users generally -don't use leading underscores in their variable names, so this -convention immediately decreases the chances that the variable name -will be accidentally shared with the user's program. +their private variables with an underscore ('_'). Users generally don't +use leading underscores in their variable names, so this convention +immediately decreases the chances that the variable name will be +accidentally shared with the user's program. In addition, several of the library functions use a prefix that helps indicate what function or set of functions use the variables--for -example, `_pw_byname()' in the user database routines (*note Passwd +example, '_pw_byname()' in the user database routines (*note Passwd Functions::). This convention is recommended, since it even further -decreases the chance of inadvertent conflict among variable names. -Note that this convention is used equally well for variable names and -for private function names.(1) +decreases the chance of inadvertent conflict among variable names. Note +that this convention is used equally well for variable names and for +private function names.(1) As a final note on variable naming, if a function makes global variables available for use by a main program, it is a good convention to start that variable's name with a capital letter--for example, -`getopt()''s `Opterr' and `Optind' variables (*note Getopt Function::). +'getopt()''s 'Opterr' and 'Optind' variables (*note Getopt Function::). The leading capital letter indicates that it is global, while the fact that the variable name is not all capital letters indicates that the -variable is not one of `awk''s built-in variables, such as `FS'. +variable is not one of 'awk''s built-in variables, such as 'FS'. It is also important that _all_ variables in library functions that -do not need to save state are, in fact, declared local.(2) If this is -not done, the variable could accidentally be used in the user's -program, leading to bugs that are very difficult to track down: +do not need to save state are, in fact, declared local.(2) If this is +not done, the variable could accidentally be used in the user's program, +leading to bugs that are very difficult to track down: function lib_func(x, y, l1, l2) { @@ -14309,22 +14247,22 @@ single associative array to hold the values needed by the library function(s), or "package." This significantly decreases the number of actual global names in use. For example, the functions described in *note Passwd Functions::, might have used array elements -`PW_data["inited"]', `PW_data["total"]', `PW_data["count"]', and -`PW_data["awklib"]', instead of `_pw_inited', `_pw_awklib', `_pw_total', -and `_pw_count'. +'PW_data["inited"]', 'PW_data["total"]', 'PW_data["count"]', and +'PW_data["awklib"]', instead of '_pw_inited', '_pw_awklib', '_pw_total', +and '_pw_count'. The conventions presented in this minor node are exactly that: -conventions. You are not required to write your programs this way--we +conventions. You are not required to write your programs this way--we merely recommend that you do so. ---------- Footnotes ---------- (1) While all the library routines could have been rewritten to use -this convention, this was not done, in order to show how our own `awk' +this convention, this was not done, in order to show how our own 'awk' programming style has evolved and to provide some basis for this discussion. - (2) `gawk''s `--dump-variables' command-line option is useful for + (2) 'gawk''s '--dump-variables' command-line option is useful for verifying this.  @@ -14339,10 +14277,10 @@ programming use. * Menu: * Strtonum Function:: A replacement for the built-in - `strtonum()' function. -* Assert Function:: A function for assertions in `awk' + 'strtonum()' function. +* Assert Function:: A function for assertions in 'awk' programs. -* Round Function:: A function for rounding if `sprintf()' +* Round Function:: A function for rounding if 'sprintf()' does not do it correctly. * Cliff Random Function:: The Cliff Random Number Generator. * Ordinal Functions:: Functions for using characters as numbers and @@ -14357,9 +14295,9 @@ File: gawk.info, Node: Strtonum Function, Next: Assert Function, Up: General 10.2.1 Converting Strings To Numbers ------------------------------------ -The `strtonum()' function (*note String Functions::) is a `gawk' +The 'strtonum()' function (*note String Functions::) is a 'gawk' extension. The following function provides an implementation for other -versions of `awk': +versions of 'awk': # mystrtonum --- convert string to number @@ -14413,24 +14351,24 @@ versions of `awk': # } The function first looks for C-style octal numbers (base 8). If the -input string matches a regular expression describing octal numbers, -then `mystrtonum()' loops through each character in the string. It -sets `k' to the index in `"01234567"' of the current octal digit. -Since the return value is one-based, the `k--' adjusts `k' so it can be -used in computing the return value. +input string matches a regular expression describing octal numbers, then +'mystrtonum()' loops through each character in the string. It sets 'k' +to the index in '"01234567"' of the current octal digit. Since the +return value is one-based, the 'k--' adjusts 'k' so it can be used in +computing the return value. Similar logic applies to the code that checks for and converts a -hexadecimal value, which starts with `0x' or `0X'. The use of -`tolower()' simplifies the computation for finding the correct numeric +hexadecimal value, which starts with '0x' or '0X'. The use of +'tolower()' simplifies the computation for finding the correct numeric value for each hexadecimal digit. Finally, if the string matches the (rather complicated) regexp for a -regular decimal integer or floating-point number, the computation `ret -= str + 0' lets `awk' convert the value to a number. +regular decimal integer or floating-point number, the computation 'ret = +str + 0' lets 'awk' convert the value to a number. - A commented-out test program is included, so that the function can -be tested with `gawk' and the results compared to the built-in -`strtonum()' function. + A commented-out test program is included, so that the function can be +tested with 'gawk' and the results compared to the built-in 'strtonum()' +function.  File: gawk.info, Node: Assert Function, Next: Round Function, Prev: Strtonum Function, Up: General Functions @@ -14438,15 +14376,15 @@ File: gawk.info, Node: Assert Function, Next: Round Function, Prev: Strtonum 10.2.2 Assertions ----------------- -When writing large programs, it is often useful to know that a -condition or set of conditions is true. Before proceeding with a -particular computation, you make a statement about what you believe to -be the case. Such a statement is known as an "assertion". The C -language provides an `' header file and corresponding -`assert()' macro that the programmer can use to make assertions. If an -assertion fails, the `assert()' macro arranges to print a diagnostic -message describing the condition that should have been true but was -not, and then it kills the program. In C, using `assert()' looks this: +When writing large programs, it is often useful to know that a condition +or set of conditions is true. Before proceeding with a particular +computation, you make a statement about what you believe to be the case. +Such a statement is known as an "assertion". The C language provides an +'' header file and corresponding 'assert()' macro that the +programmer can use to make assertions. If an assertion fails, the +'assert()' macro arranges to print a diagnostic message describing the +condition that should have been true but was not, and then it kills the +program. In C, using 'assert()' looks this: #include @@ -14462,8 +14400,8 @@ not, and then it kills the program. In C, using `assert()' looks this: The C language makes it possible to turn the condition into a string for use in printing the diagnostic message. This is not possible in -`awk', so this `assert()' function also requires a string version of -the condition that is being tested. Following is the function: +'awk', so this 'assert()' function also requires a string version of the +condition that is being tested. Following is the function: # assert --- assert that a condition is true. Otherwise exit. @@ -14482,20 +14420,20 @@ the condition that is being tested. Following is the function: exit 1 } - The `assert()' function tests the `condition' parameter. If it is -false, it prints a message to standard error, using the `string' + The 'assert()' function tests the 'condition' parameter. If it is +false, it prints a message to standard error, using the 'string' parameter to describe the failed condition. It then sets the variable -`_assert_exit' to one and executes the `exit' statement. The `exit' -statement jumps to the `END' rule. If the `END' rules finds -`_assert_exit' to be true, it exits immediately. +'_assert_exit' to one and executes the 'exit' statement. The 'exit' +statement jumps to the 'END' rule. If the 'END' rules finds +'_assert_exit' to be true, it exits immediately. - The purpose of the test in the `END' rule is to keep any other `END' + The purpose of the test in the 'END' rule is to keep any other 'END' rules from running. When an assertion fails, the program should exit -immediately. If no assertions fail, then `_assert_exit' is still false -when the `END' rule is run normally, and the rest of the program's -`END' rules execute. For all of this to work correctly, `assert.awk' -must be the first source file read by `awk'. The function can be used -in a program in the following way: +immediately. If no assertions fail, then '_assert_exit' is still false +when the 'END' rule is run normally, and the rest of the program's 'END' +rules execute. For all of this to work correctly, 'assert.awk' must be +the first source file read by 'awk'. The function can be used in a +program in the following way: function myfunc(a, b) { @@ -14507,16 +14445,16 @@ If the assertion fails, you see a message similar to the following: mydata:1357: assertion failed: a <= 5 && b >= 17.1 - There is a small problem with this version of `assert()'. An `END' -rule is automatically added to the program calling `assert()'. -Normally, if a program consists of just a `BEGIN' rule, the input files -and/or standard input are not read. However, now that the program has -an `END' rule, `awk' attempts to read the input data files or standard -input (*note Using BEGIN/END::), most likely causing the program to -hang as it waits for input. + There is a small problem with this version of 'assert()'. An 'END' +rule is automatically added to the program calling 'assert()'. +Normally, if a program consists of just a 'BEGIN' rule, the input files +and/or standard input are not read. However, now that the program has +an 'END' rule, 'awk' attempts to read the input data files or standard +input (*note Using BEGIN/END::), most likely causing the program to hang +as it waits for input. - There is a simple workaround to this: make sure that such a `BEGIN' -rule always ends with an `exit' statement. + There is a simple workaround to this: make sure that such a 'BEGIN' +rule always ends with an 'exit' statement.  File: gawk.info, Node: Round Function, Next: Cliff Random Function, Prev: Assert Function, Up: General Functions @@ -14524,15 +14462,15 @@ File: gawk.info, Node: Round Function, Next: Cliff Random Function, Prev: Ass 10.2.3 Rounding Numbers ----------------------- -The way `printf' and `sprintf()' (*note Printf::) perform rounding -often depends upon the system's C `sprintf()' subroutine. On many -machines, `sprintf()' rounding is "unbiased", which means it doesn't -always round a trailing .5 up, contrary to naive expectations. In -unbiased rounding, .5 rounds to even, rather than always up, so 1.5 -rounds to 2 but 4.5 rounds to 4. This means that if you are using a -format that does rounding (e.g., `"%.0f"'), you should check what your -system does. The following function does traditional rounding; it -might be useful if your `awk''s `printf' does unbiased rounding: +The way 'printf' and 'sprintf()' (*note Printf::) perform rounding often +depends upon the system's C 'sprintf()' subroutine. On many machines, +'sprintf()' rounding is "unbiased", which means it doesn't always round +a trailing .5 up, contrary to naive expectations. In unbiased rounding, +.5 rounds to even, rather than always up, so 1.5 rounds to 2 but 4.5 +rounds to 4. This means that if you are using a format that does +rounding (e.g., '"%.0f"'), you should check what your system does. The +following function does traditional rounding; it might be useful if your +'awk''s 'printf' does unbiased rounding: # round.awk --- do normal rounding @@ -14571,10 +14509,10 @@ File: gawk.info, Node: Cliff Random Function, Next: Ordinal Functions, Prev: ---------------------------------------- The Cliff random number generator -(http://mathworld.wolfram.com/CliffRandomNumberGenerator.html) is a -very simple random number generator that "passes the noise sphere test -for randomness by showing no structure." It is easily programmed, in -less than 10 lines of `awk' code: +(http://mathworld.wolfram.com/CliffRandomNumberGenerator.html) is a very +simple random number generator that "passes the noise sphere test for +randomness by showing no structure." It is easily programmed, in less +than 10 lines of 'awk' code: # cliff_rand.awk --- generate Cliff random numbers @@ -14590,7 +14528,7 @@ less than 10 lines of `awk' code: This algorithm requires an initial "seed" of 0.1. Each new value uses the current seed as input for the calculation. If the built-in -`rand()' function (*note Numeric Functions::) isn't random enough, you +'rand()' function (*note Numeric Functions::) isn't random enough, you might try using this function instead.  @@ -14599,15 +14537,15 @@ File: gawk.info, Node: Ordinal Functions, Next: Join Function, Prev: Cliff Ra 10.2.5 Translating Between Characters and Numbers ------------------------------------------------- -One commercial implementation of `awk' supplies a built-in function, -`ord()', which takes a character and returns the numeric value for that +One commercial implementation of 'awk' supplies a built-in function, +'ord()', which takes a character and returns the numeric value for that character in the machine's character set. If the string passed to -`ord()' has more than one character, only the first one is used. +'ord()' has more than one character, only the first one is used. - The inverse of this function is `chr()' (from the function of the -same name in Pascal), which takes a number and returns the -corresponding character. Both functions are written very nicely in -`awk'; there is no real reason to build them into the `awk' interpreter: + The inverse of this function is 'chr()' (from the function of the +same name in Pascal), which takes a number and returns the corresponding +character. Both functions are written very nicely in 'awk'; there is no +real reason to build them into the 'awk' interpreter: # ord.awk --- do ord and chr @@ -14638,17 +14576,16 @@ corresponding character. Both functions are written very nicely in } } - Some explanation of the numbers used by `_ord_init()' is worthwhile. + Some explanation of the numbers used by '_ord_init()' is worthwhile. The most prominent character set in use today is ASCII.(1) Although an 8-bit byte can hold 256 distinct values (from 0 to 255), ASCII only -defines characters that use the values from 0 to 127.(2) In the now +defines characters that use the values from 0 to 127.(2) In the now distant past, at least one minicomputer manufacturer used ASCII, but -with mark parity, meaning that the leftmost bit in the byte is always -1. This means that on those systems, characters have numeric values -from 128 to 255. Finally, large mainframe systems use the EBCDIC -character set, which uses all 256 values. While there are other -character sets in use on some older systems, they are not really worth -worrying about: +with mark parity, meaning that the leftmost bit in the byte is always 1. +This means that on those systems, characters have numeric values from +128 to 255. Finally, large mainframe systems use the EBCDIC character +set, which uses all 256 values. While there are other character sets in +use on some older systems, they are not really worth worrying about: function ord(str, c) { @@ -14675,9 +14612,9 @@ worrying about: # } An obvious improvement to these functions is to move the code for the -`_ord_init' function into the body of the `BEGIN' rule. It was written +'_ord_init' function into the body of the 'BEGIN' rule. It was written this way initially for ease of development. There is a "test program" -in a `BEGIN' rule, to test the function. It is commented out for +in a 'BEGIN' rule, to test the function. It is commented out for production use. ---------- Footnotes ---------- @@ -14688,8 +14625,8 @@ Unicode support, a character can occupy up to 32 bits, making simple tests such as used here prohibitively expensive. (2) ASCII has been extended in many countries to use the values from -128 to 255 for country-specific characters. If your system uses these -extensions, you can simplify `_ord_init()' to loop from 0 to 255. +128 to 255 for country-specific characters. If your system uses these +extensions, you can simplify '_ord_init()' to loop from 0 to 255.  File: gawk.info, Node: Join Function, Next: Getlocaltime Function, Prev: Ordinal Functions, Up: General Functions @@ -14699,15 +14636,15 @@ File: gawk.info, Node: Join Function, Next: Getlocaltime Function, Prev: Ordi When doing string processing, it is often useful to be able to join all the strings in an array into one long string. The following function, -`join()', accomplishes this task. It is used later in several of the +'join()', accomplishes this task. It is used later in several of the application programs (*note Sample Programs::). Good function design is important; this function needs to be general but it should also have a reasonable default behavior. It is called with an array as well as the beginning and ending indices of the -elements in the array to be merged. This assumes that the array -indices are numeric--a reasonable assumption since the array was likely -created with `split()' (*note String Functions::): +elements in the array to be merged. This assumes that the array indices +are numeric--a reasonable assumption since the array was likely created +with 'split()' (*note String Functions::): # join.awk --- join an array into a string @@ -14725,18 +14662,18 @@ created with `split()' (*note String Functions::): An optional additional argument is the separator to use when joining the strings back together. If the caller supplies a nonempty value, -`join()' uses it; if it is not supplied, it has a null value. In this -case, `join()' uses a single space as a default separator for the -strings. If the value is equal to `SUBSEP', then `join()' joins the -strings with no separator between them. `SUBSEP' serves as a "magic" +'join()' uses it; if it is not supplied, it has a null value. In this +case, 'join()' uses a single space as a default separator for the +strings. If the value is equal to 'SUBSEP', then 'join()' joins the +strings with no separator between them. 'SUBSEP' serves as a "magic" value to indicate that there should be no separation between the component strings.(1) ---------- Footnotes ---------- - (1) It would be nice if `awk' had an assignment operator for -concatenation. The lack of an explicit operator for concatenation -makes string operations more difficult than they really need to be. + (1) It would be nice if 'awk' had an assignment operator for +concatenation. The lack of an explicit operator for concatenation makes +string operations more difficult than they really need to be.  File: gawk.info, Node: Getlocaltime Function, Next: Readfile Function, Prev: Join Function, Up: General Functions @@ -14744,15 +14681,15 @@ File: gawk.info, Node: Getlocaltime Function, Next: Readfile Function, Prev: 10.2.7 Managing the Time of Day ------------------------------- -The `systime()' and `strftime()' functions described in *note Time +The 'systime()' and 'strftime()' functions described in *note Time Functions::, provide the minimum functionality necessary for dealing -with the time of day in human readable form. While `strftime()' is +with the time of day in human readable form. While 'strftime()' is extensive, the control formats are not necessarily easy to remember or intuitively obvious when reading a program. - The following function, `getlocaltime()', populates a user-supplied + The following function, 'getlocaltime()', populates a user-supplied array with preformatted time information. It returns a string with the -current time formatted in the same way as the `date' utility: +current time formatted in the same way as the 'date' utility: # getlocaltime.awk --- get the time of day in a usable format @@ -14815,9 +14752,9 @@ current time formatted in the same way as the `date' utility: } The string indices are easier to use and read than the various -formats required by `strftime()'. The `alarm' program presented in +formats required by 'strftime()'. The 'alarm' program presented in *note Alarm Program::, uses this function. A more general design for -the `getlocaltime()' function would have allowed the user to supply an +the 'getlocaltime()' function would have allowed the user to supply an optional timestamp value to use instead of the current time.  @@ -14827,7 +14764,7 @@ File: gawk.info, Node: Readfile Function, Prev: Getlocaltime Function, Up: Ge ----------------------------------- Often, it is convenient to have the entire contents of a file available -in memory as a single string. A straightforward but naive way to do +in memory as a single string. A straightforward but naive way to do that might be as follows: function readfile(file, tmp, contents) @@ -14843,9 +14780,9 @@ that might be as follows: return contents } - This function reads from `file' one record at a time, building up -the full contents of the file in the local variable `contents'. It -works, but is not necessarily efficient. + This function reads from 'file' one record at a time, building up the +full contents of the file in the local variable 'contents'. It works, +but is not necessarily efficient. The following function, based on a suggestion by Denis Shirokov, reads the entire contents of the named file in one shot: @@ -14863,22 +14800,21 @@ reads the entire contents of the named file in one shot: return tmp } - It works by setting `RS' to `^$', a regular expression that will -never match if the file has contents. `gawk' reads data from the file -into `tmp' attempting to match `RS'. The match fails after each read, -but fails quickly, such that `gawk' fills `tmp' with the entire -contents of the file. (*Note Records::, for information on `RT' and -`RS'.) + It works by setting 'RS' to '^$', a regular expression that will +never match if the file has contents. 'gawk' reads data from the file +into 'tmp' attempting to match 'RS'. The match fails after each read, +but fails quickly, such that 'gawk' fills 'tmp' with the entire contents +of the file. (*Note Records::, for information on 'RT' and 'RS'.) - In the case that `file' is empty, the return value is the null + In the case that 'file' is empty, the return value is the null string. Thus calling code may use something like: contents = readfile("/some/path") if (length(contents) == 0) # file was empty ... - This tests the result to see if it is empty or not. An equivalent -test would be `contents == ""'. + This tests the result to see if it is empty or not. An equivalent +test would be 'contents == ""'.  File: gawk.info, Node: Data File Management, Next: Getopt Function, Prev: General Functions, Up: Library Functions @@ -14903,23 +14839,23 @@ File: gawk.info, Node: Filetrans Function, Next: Rewind Function, Up: Data Fi 10.3.1 Noting Data File Boundaries ---------------------------------- -The `BEGIN' and `END' rules are each executed exactly once at the -beginning and end of your `awk' program, respectively (*note -BEGIN/END::). We (the `gawk' authors) once had a user who mistakenly -thought that the `BEGIN' rule is executed at the beginning of each data -file and the `END' rule is executed at the end of each data file. +The 'BEGIN' and 'END' rules are each executed exactly once at the +beginning and end of your 'awk' program, respectively (*note +BEGIN/END::). We (the 'gawk' authors) once had a user who mistakenly +thought that the 'BEGIN' rule is executed at the beginning of each data +file and the 'END' rule is executed at the end of each data file. When informed that this was not the case, the user requested that we -add new special patterns to `gawk', named `BEGIN_FILE' and `END_FILE', +add new special patterns to 'gawk', named 'BEGIN_FILE' and 'END_FILE', that would have the desired behavior. He even supplied us the code to do so. - Adding these special patterns to `gawk' wasn't necessary; the job -can be done cleanly in `awk' itself, as illustrated by the following -library program. It arranges to call two user-supplied functions, -`beginfile()' and `endfile()', at the beginning and end of each data -file. Besides solving the problem in only nine(!) lines of code, it -does so _portably_; this works with any implementation of `awk': + Adding these special patterns to 'gawk' wasn't necessary; the job can +be done cleanly in 'awk' itself, as illustrated by the following library +program. It arranges to call two user-supplied functions, 'beginfile()' +and 'endfile()', at the beginning and end of each data file. Besides +solving the problem in only nine(!) lines of code, it does so +_portably_; this works with any implementation of 'awk': # transfile.awk # @@ -14942,25 +14878,25 @@ does so _portably_; this works with any implementation of `awk': This file must be loaded before the user's "main" program, so that the rule it supplies is executed first. - This rule relies on `awk''s `FILENAME' variable that automatically + This rule relies on 'awk''s 'FILENAME' variable that automatically changes for each new data file. The current file name is saved in a -private variable, `_oldfilename'. If `FILENAME' does not equal -`_oldfilename', then a new data file is being processed and it is -necessary to call `endfile()' for the old file. Because `endfile()' +private variable, '_oldfilename'. If 'FILENAME' does not equal +'_oldfilename', then a new data file is being processed and it is +necessary to call 'endfile()' for the old file. Because 'endfile()' should only be called if a file has been processed, the program first -checks to make sure that `_oldfilename' is not the null string. The -program then assigns the current file name to `_oldfilename' and calls -`beginfile()' for the file. Because, like all `awk' variables, -`_oldfilename' is initialized to the null string, this rule executes +checks to make sure that '_oldfilename' is not the null string. The +program then assigns the current file name to '_oldfilename' and calls +'beginfile()' for the file. Because, like all 'awk' variables, +'_oldfilename' is initialized to the null string, this rule executes correctly even for the first data file. - The program also supplies an `END' rule to do the final processing -for the last file. Because this `END' rule comes before any `END' rules -supplied in the "main" program, `endfile()' is called first. Once -again the value of multiple `BEGIN' and `END' rules should be clear. + The program also supplies an 'END' rule to do the final processing +for the last file. Because this 'END' rule comes before any 'END' rules +supplied in the "main" program, 'endfile()' is called first. Once again +the value of multiple 'BEGIN' and 'END' rules should be clear. If the same data file occurs twice in a row on the command line, then -`endfile()' and `beginfile()' are not executed at the end of the first +'endfile()' and 'beginfile()' are not executed at the end of the first pass and at the beginning of the second pass. The following version solves the problem: @@ -14980,19 +14916,19 @@ solves the problem: *note Wc Program::, shows how this library function can be used and how it simplifies writing the main program. - So Why Does `gawk' have `BEGINFILE' and `ENDFILE'? + So Why Does 'gawk' have 'BEGINFILE' and 'ENDFILE'? - You are probably wondering, if `beginfile()' and `endfile()' -functions can do the job, why does `gawk' have `BEGINFILE' and -`ENDFILE' patterns (*note BEGINFILE/ENDFILE::)? + You are probably wondering, if 'beginfile()' and 'endfile()' +functions can do the job, why does 'gawk' have 'BEGINFILE' and 'ENDFILE' +patterns (*note BEGINFILE/ENDFILE::)? - Good question. Normally, if `awk' cannot open a file, this causes -an immediate fatal error. In this case, there is no way for a -user-defined function to deal with the problem, since the mechanism for -calling it relies on the file being open and at the first record. Thus, -the main reason for `BEGINFILE' is to give you a "hook" to catch files -that cannot be processed. `ENDFILE' exists for symmetry, and because -it provides an easy way to do per-file cleanup processing. + Good question. Normally, if 'awk' cannot open a file, this causes an +immediate fatal error. In this case, there is no way for a user-defined +function to deal with the problem, since the mechanism for calling it +relies on the file being open and at the first record. Thus, the main +reason for 'BEGINFILE' is to give you a "hook" to catch files that +cannot be processed. 'ENDFILE' exists for symmetry, and because it +provides an easy way to do per-file cleanup processing.  File: gawk.info, Node: Rewind Function, Next: File Checking, Prev: Filetrans Function, Up: Data File Management @@ -15000,15 +14936,15 @@ File: gawk.info, Node: Rewind Function, Next: File Checking, Prev: Filetrans 10.3.2 Rereading the Current File --------------------------------- -Another request for a new built-in function was for a `rewind()' +Another request for a new built-in function was for a 'rewind()' function that would make it possible to reread the current file. The -requesting user didn't want to have to use `getline' (*note Getline::) +requesting user didn't want to have to use 'getline' (*note Getline::) inside a loop. - However, as long as you are not in the `END' rule, it is quite easy + However, as long as you are not in the 'END' rule, it is quite easy to arrange to immediately close the current input file and then start over with it from the top. For lack of a better name, we'll call it -`rewind()': +'rewind()': # rewind.awk --- rewind the current file and start over @@ -15028,15 +14964,15 @@ over with it from the top. For lack of a better name, we'll call it nextfile } - This code relies on the `ARGIND' variable (*note Auto-set::), which -is specific to `gawk'. If you are not using `gawk', you can use ideas -presented in *note Filetrans Function::, to either update `ARGIND' on + This code relies on the 'ARGIND' variable (*note Auto-set::), which +is specific to 'gawk'. If you are not using 'gawk', you can use ideas +presented in *note Filetrans Function::, to either update 'ARGIND' on your own or modify this code as appropriate. - The `rewind()' function also relies on the `nextfile' keyword (*note + The 'rewind()' function also relies on the 'nextfile' keyword (*note Nextfile Statement::). Because of this, you should not call it from an -`ENDFILE' rule. (This isn't necessary anyway, since as soon as an -`ENDFILE' rule finishes `gawk' goes to the next file!) +'ENDFILE' rule. (This isn't necessary anyway, since as soon as an +'ENDFILE' rule finishes 'gawk' goes to the next file!)  File: gawk.info, Node: File Checking, Next: Empty Files, Prev: Rewind Function, Up: Data File Management @@ -15044,10 +14980,10 @@ File: gawk.info, Node: File Checking, Next: Empty Files, Prev: Rewind Functio 10.3.3 Checking for Readable Data Files --------------------------------------- -Normally, if you give `awk' a data file that isn't readable, it stops +Normally, if you give 'awk' a data file that isn't readable, it stops with a fatal error. There are times when you might want to just ignore -such files and keep going.(1) You can do this by prepending the -following program to your `awk' program: +such files and keep going.(1) You can do this by prepending the +following program to your 'awk' program: # readable.awk --- library file to skip over unreadable files @@ -15063,13 +14999,13 @@ following program to your `awk' program: } } - This works, because the `getline' won't be fatal. Removing the -element from `ARGV' with `delete' skips the file (since it's no longer + This works, because the 'getline' won't be fatal. Removing the +element from 'ARGV' with 'delete' skips the file (since it's no longer in the list). See also *note ARGC and ARGV::. ---------- Footnotes ---------- - (1) The `BEGINFILE' special pattern (*note BEGINFILE/ENDFILE::) + (1) The 'BEGINFILE' special pattern (*note BEGINFILE/ENDFILE::) provides an alternative mechanism for dealing with files that can't be opened. However, the code here provides a portable solution. @@ -15079,20 +15015,19 @@ File: gawk.info, Node: Empty Files, Next: Ignoring Assigns, Prev: File Checki 10.3.4 Checking for Zero-length Files ------------------------------------- -All known `awk' implementations silently skip over zero-length files. -This is a by-product of `awk''s implicit -read-a-record-and-match-against-the-rules loop: when `awk' tries to -read a record from an empty file, it immediately receives an end of -file indication, closes the file, and proceeds on to the next -command-line data file, _without_ executing any user-level `awk' -program code. - - Using `gawk''s `ARGIND' variable (*note Built-in Variables::), it is -possible to detect when an empty data file has been skipped. Similar -to the library file presented in *note Filetrans Function::, the -following library file calls a function named `zerofile()' that the -user must provide. The arguments passed are the file name and the -position in `ARGV' where it was found: +All known 'awk' implementations silently skip over zero-length files. +This is a by-product of 'awk''s implicit +read-a-record-and-match-against-the-rules loop: when 'awk' tries to read +a record from an empty file, it immediately receives an end of file +indication, closes the file, and proceeds on to the next command-line +data file, _without_ executing any user-level 'awk' program code. + + Using 'gawk''s 'ARGIND' variable (*note Built-in Variables::), it is +possible to detect when an empty data file has been skipped. Similar to +the library file presented in *note Filetrans Function::, the following +library file calls a function named 'zerofile()' that the user must +provide. The arguments passed are the file name and the position in +'ARGV' where it was found: # zerofile.awk --- library file to process empty input files @@ -15111,18 +15046,18 @@ position in `ARGV' where it was found: zerofile(ARGV[Argind], Argind) } - The user-level variable `Argind' allows the `awk' program to track -its progress through `ARGV'. Whenever the program detects that -`ARGIND' is greater than `Argind + 1', it means that one or more empty -files were skipped. The action then calls `zerofile()' for each such -file, incrementing `Argind' along the way. + The user-level variable 'Argind' allows the 'awk' program to track +its progress through 'ARGV'. Whenever the program detects that 'ARGIND' +is greater than 'Argind + 1', it means that one or more empty files were +skipped. The action then calls 'zerofile()' for each such file, +incrementing 'Argind' along the way. - The `Argind != ARGIND' rule simply keeps `Argind' up to date in the + The 'Argind != ARGIND' rule simply keeps 'Argind' up to date in the normal case. - Finally, the `END' rule catches the case of any empty files at the + Finally, the 'END' rule catches the case of any empty files at the end of the command-line arguments. Note that the test in the condition -of the `for' loop uses the `<=' operator, not `<'. +of the 'for' loop uses the '<=' operator, not '<'.  File: gawk.info, Node: Ignoring Assigns, Prev: Empty Files, Up: Data File Management @@ -15130,13 +15065,13 @@ File: gawk.info, Node: Ignoring Assigns, Prev: Empty Files, Up: Data File Man 10.3.5 Treating Assignments as File Names ----------------------------------------- -Occasionally, you might not want `awk' to process command-line variable +Occasionally, you might not want 'awk' to process command-line variable assignments (*note Assignment Options::). In particular, if you have a -file name that contains an `=' character, `awk' treats the file name as +file name that contains an '=' character, 'awk' treats the file name as an assignment, and does not process it. Some users have suggested an additional command-line option for -`gawk' to disable command-line assignments. However, some simple +'gawk' to disable command-line assignments. However, some simple programming with a library file does the trick: # noassign.awk --- library file to avoid the need for a @@ -15159,10 +15094,10 @@ programming with a library file does the trick: awk -v No_command_assign=1 -f noassign.awk -f yourprog.awk * The function works by looping through the arguments. It prepends -`./' to any argument that matches the form of a variable assignment, +'./' to any argument that matches the form of a variable assignment, turning that argument into a file name. - The use of `No_command_assign' allows you to disable command-line + The use of 'No_command_assign' allows you to disable command-line assignments at invocation time, by giving the variable a true value. When not set, it is initially zero (i.e., false), so the command-line arguments are left alone. @@ -15174,32 +15109,32 @@ File: gawk.info, Node: Getopt Function, Next: Passwd Functions, Prev: Data Fi ==================================== Most utilities on POSIX compatible systems take options on the command -line that can be used to change the way a program behaves. `awk' is an +line that can be used to change the way a program behaves. 'awk' is an example of such a program (*note Options::). Often, options take "arguments"; i.e., data that the program needs to correctly obey the -command-line option. For example, `awk''s `-F' option requires a -string to use as the field separator. The first occurrence on the -command line of either `--' or a string that does not begin with `-' -ends the options. +command-line option. For example, 'awk''s '-F' option requires a string +to use as the field separator. The first occurrence on the command line +of either '--' or a string that does not begin with '-' ends the +options. - Modern Unix systems provide a C function named `getopt()' for + Modern Unix systems provide a C function named 'getopt()' for processing command-line arguments. The programmer provides a string -describing the one-letter options. If an option requires an argument, -it is followed in the string with a colon. `getopt()' is also passed +describing the one-letter options. If an option requires an argument, +it is followed in the string with a colon. 'getopt()' is also passed the count and values of the command-line arguments and is called in a -loop. `getopt()' processes the command-line arguments for option +loop. 'getopt()' processes the command-line arguments for option letters. Each time around the loop, it returns a single character -representing the next option letter that it finds, or `?' if it finds -an invalid option. When it returns -1, there are no options left on -the command line. +representing the next option letter that it finds, or '?' if it finds an +invalid option. When it returns -1, there are no options left on the +command line. - When using `getopt()', options that do not take arguments can be -grouped together. Furthermore, options that take arguments require -that the argument be present. The argument can immediately follow the -option letter, or it can be a separate command-line argument. + When using 'getopt()', options that do not take arguments can be +grouped together. Furthermore, options that take arguments require that +the argument be present. The argument can immediately follow the option +letter, or it can be a separate command-line argument. Given a hypothetical program that takes three command-line options, -`-a', `-b', and `-c', where `-b' requires an argument, all of the +'-a', '-b', and '-c', where '-b' requires an argument, all of the following are valid ways of invoking the program: prog -a -b foo -c data1 data2 data3 @@ -15208,30 +15143,30 @@ following are valid ways of invoking the program: Notice that when the argument is grouped with its option, the rest of the argument is considered to be the option's argument. In this -example, `-acbfoo' indicates that all of the `-a', `-b', and `-c' -options were supplied, and that `foo' is the argument to the `-b' +example, '-acbfoo' indicates that all of the '-a', '-b', and '-c' +options were supplied, and that 'foo' is the argument to the '-b' option. - `getopt()' provides four external variables that the programmer can + 'getopt()' provides four external variables that the programmer can use: -`optind' - The index in the argument value array (`argv') where the first +'optind' + The index in the argument value array ('argv') where the first nonoption command-line argument can be found. -`optarg' +'optarg' The string value of the argument to an option. -`opterr' - Usually `getopt()' prints an error message when it finds an invalid - option. Setting `opterr' to zero disables this feature. (An +'opterr' + Usually 'getopt()' prints an error message when it finds an invalid + option. Setting 'opterr' to zero disables this feature. (An application might want to print its own error message.) -`optopt' +'optopt' The letter representing the command-line option. - The following C fragment shows how `getopt()' might process -command-line arguments for `awk': + The following C fragment shows how 'getopt()' might process +command-line arguments for 'awk': int main(int argc, char *argv[]) @@ -15262,15 +15197,15 @@ command-line arguments for `awk': ... } - As a side point, `gawk' actually uses the GNU `getopt_long()' + As a side point, 'gawk' actually uses the GNU 'getopt_long()' function to process both normal and GNU-style long options (*note Options::). - The abstraction provided by `getopt()' is very useful and is quite -handy in `awk' programs as well. Following is an `awk' version of -`getopt()'. This function highlights one of the greatest weaknesses in -`awk', which is that it is very poor at manipulating single characters. -Repeated calls to `substr()' are necessary for accessing individual + The abstraction provided by 'getopt()' is very useful and is quite +handy in 'awk' programs as well. Following is an 'awk' version of +'getopt()'. This function highlights one of the greatest weaknesses in +'awk', which is that it is very poor at manipulating single characters. +Repeated calls to 'substr()' are necessary for accessing individual characters (*note String Functions::).(1) The discussion that follows walks through the code a bit at a time: @@ -15291,15 +15226,15 @@ characters (*note String Functions::).(1) # Private Data: # _opti -- index in multiflag option, e.g., -abc - The function starts out with comments presenting a list of the -global variables it uses, what the return values are, what they mean, -and any global variables that are "private" to this library function. -Such documentation is essential for any program, and particularly for -library functions. + The function starts out with comments presenting a list of the global +variables it uses, what the return values are, what they mean, and any +global variables that are "private" to this library function. Such +documentation is essential for any program, and particularly for library +functions. - The `getopt()' function first checks that it was indeed called with -a string of options (the `options' parameter). If `options' has a zero -length, `getopt()' immediately returns -1: + The 'getopt()' function first checks that it was indeed called with a +string of options (the 'options' parameter). If 'options' has a zero +length, 'getopt()' immediately returns -1: function getopt(argc, argv, options, thisopt, i) { @@ -15315,16 +15250,16 @@ length, `getopt()' immediately returns -1: return -1 } - The next thing to check for is the end of the options. A `--' ends + The next thing to check for is the end of the options. A '--' ends the command-line options, as does any command-line argument that does -not begin with a `-'. `Optind' is used to step through the array of -command-line arguments; it retains its value across calls to -`getopt()', because it is a global variable. +not begin with a '-'. 'Optind' is used to step through the array of +command-line arguments; it retains its value across calls to 'getopt()', +because it is a global variable. - The regular expression that is used, `/^-[^:[:space:]/', checks for -a `-' followed by anything that is not whitespace and not a colon. If -the current command-line argument does not match this pattern, it is -not an option, and it ends option processing. Continuing on: + The regular expression that is used, '/^-[^:[:space:]/', checks for a +'-' followed by anything that is not whitespace and not a colon. If the +current command-line argument does not match this pattern, it is not an +option, and it ends option processing. Continuing on: if (_opti == 0) _opti = 2 @@ -15343,31 +15278,31 @@ not an option, and it ends option processing. Continuing on: return "?" } - The `_opti' variable tracks the position in the current command-line -argument (`argv[Optind]'). If multiple options are grouped together -with one `-' (e.g., `-abx'), it is necessary to return them to the user + The '_opti' variable tracks the position in the current command-line +argument ('argv[Optind]'). If multiple options are grouped together +with one '-' (e.g., '-abx'), it is necessary to return them to the user one at a time. - If `_opti' is equal to zero, it is set to two, which is the index in -the string of the next character to look at (we skip the `-', which is -at position one). The variable `thisopt' holds the character, obtained -with `substr()'. It is saved in `Optopt' for the main program to use. + If '_opti' is equal to zero, it is set to two, which is the index in +the string of the next character to look at (we skip the '-', which is +at position one). The variable 'thisopt' holds the character, obtained +with 'substr()'. It is saved in 'Optopt' for the main program to use. - If `thisopt' is not in the `options' string, then it is an invalid -option. If `Opterr' is nonzero, `getopt()' prints an error message on + If 'thisopt' is not in the 'options' string, then it is an invalid +option. If 'Opterr' is nonzero, 'getopt()' prints an error message on the standard error that is similar to the message from the C version of -`getopt()'. +'getopt()'. - Because the option is invalid, it is necessary to skip it and move -on to the next option character. If `_opti' is greater than or equal -to the length of the current command-line argument, it is necessary to -move on to the next argument, so `Optind' is incremented and `_opti' is -reset to zero. Otherwise, `Optind' is left alone and `_opti' is merely + Because the option is invalid, it is necessary to skip it and move on +to the next option character. If '_opti' is greater than or equal to +the length of the current command-line argument, it is necessary to move +on to the next argument, so 'Optind' is incremented and '_opti' is reset +to zero. Otherwise, 'Optind' is left alone and '_opti' is merely incremented. - In any case, because the option is invalid, `getopt()' returns `"?"'. -The main program can examine `Optopt' if it needs to know what the -invalid option letter actually is. Continuing on: + In any case, because the option is invalid, 'getopt()' returns '"?"'. +The main program can examine 'Optopt' if it needs to know what the +invalid option letter actually is. Continuing on: if (substr(options, i + 1, 1) == ":") { # get option argument @@ -15380,12 +15315,12 @@ invalid option letter actually is. Continuing on: Optarg = "" If the option requires an argument, the option letter is followed by -a colon in the `options' string. If there are remaining characters in -the current command-line argument (`argv[Optind]'), then the rest of -that string is assigned to `Optarg'. Otherwise, the next command-line -argument is used (`-xFOO' versus `-x FOO'). In either case, `_opti' is +a colon in the 'options' string. If there are remaining characters in +the current command-line argument ('argv[Optind]'), then the rest of +that string is assigned to 'Optarg'. Otherwise, the next command-line +argument is used ('-xFOO' versus '-x FOO'). In either case, '_opti' is reset to zero, because there are no more characters left to examine in -the current command-line argument. Continuing: +the current command-line argument. Continuing: if (_opti == 0 || _opti >= length(argv[Optind])) { Optind++ @@ -15395,18 +15330,18 @@ the current command-line argument. Continuing: return thisopt } - Finally, if `_opti' is either zero or greater than the length of the -current command-line argument, it means this element in `argv' is -through being processed, so `Optind' is incremented to point to the -next element in `argv'. If neither condition is true, then only -`_opti' is incremented, so that the next option letter can be processed -on the next call to `getopt()'. + Finally, if '_opti' is either zero or greater than the length of the +current command-line argument, it means this element in 'argv' is +through being processed, so 'Optind' is incremented to point to the next +element in 'argv'. If neither condition is true, then only '_opti' is +incremented, so that the next option letter can be processed on the next +call to 'getopt()'. - The `BEGIN' rule initializes both `Opterr' and `Optind' to one. -`Opterr' is set to one, since the default behavior is for `getopt()' to -print a diagnostic message upon seeing an invalid option. `Optind' is + The 'BEGIN' rule initializes both 'Opterr' and 'Optind' to one. +'Opterr' is set to one, since the default behavior is for 'getopt()' to +print a diagnostic message upon seeing an invalid option. 'Optind' is set to one, since there's no reason to look at the program name, which -is in `ARGV[0]': +is in 'ARGV[0]': BEGIN { Opterr = 1 # default is to diagnose @@ -15424,7 +15359,7 @@ is in `ARGV[0]': } } - The rest of the `BEGIN' rule is a simple test program. Here is the + The rest of the 'BEGIN' rule is a simple test program. Here is the result of two sample runs of the test program: $ awk -f getopt.awk -v _getopt_test=1 -- -a -cbARG bax -x @@ -15437,28 +15372,28 @@ result of two sample runs of the test program: $ awk -f getopt.awk -v _getopt_test=1 -- -a -x -- xyz abc -| c = , Optarg = <> - error--> x -- invalid option + error-> x -- invalid option -| c = , Optarg = <> -| non-option arguments: -| ARGV[4] = -| ARGV[5] = - In both runs, the first `--' terminates the arguments to `awk', so -that it does not try to interpret the `-a', etc., as its own options. + In both runs, the first '--' terminates the arguments to 'awk', so +that it does not try to interpret the '-a', etc., as its own options. - NOTE: After `getopt()' is through, it is the responsibility of the - user level code to clear out all the elements of `ARGV' from 1 to - `Optind', so that `awk' does not try to process the command-line + NOTE: After 'getopt()' is through, it is the responsibility of the + user level code to clear out all the elements of 'ARGV' from 1 to + 'Optind', so that 'awk' does not try to process the command-line options as file names. Several of the sample programs presented in *note Sample Programs::, -use `getopt()' to process their arguments. +use 'getopt()' to process their arguments. ---------- Footnotes ---------- - (1) This function was written before `gawk' acquired the ability to -split strings into single characters using `""' as the separator. We -have left it alone, since using `substr()' is more portable. + (1) This function was written before 'gawk' acquired the ability to +split strings into single characters using '""' as the separator. We +have left it alone, since using 'substr()' is more portable.  File: gawk.info, Node: Passwd Functions, Next: Group Functions, Prev: Getopt Function, Up: Library Functions @@ -15466,33 +15401,33 @@ File: gawk.info, Node: Passwd Functions, Next: Group Functions, Prev: Getopt 10.5 Reading the User Database ============================== -The `PROCINFO' array (*note Built-in Variables::) provides access to -the current user's real and effective user and group ID numbers, and if +The 'PROCINFO' array (*note Built-in Variables::) provides access to the +current user's real and effective user and group ID numbers, and if available, the user's supplementary group set. However, because these are numbers, they do not provide very useful information to the average user. There needs to be some way to find the user information -associated with the user and group ID numbers. This minor node -presents a suite of functions for retrieving information from the user -database. *Note Group Functions::, for a similar suite that retrieves -information from the group database. +associated with the user and group ID numbers. This minor node presents +a suite of functions for retrieving information from the user database. +*Note Group Functions::, for a similar suite that retrieves information +from the group database. The POSIX standard does not define the file where user information is -kept. Instead, it provides the `' header file and several C +kept. Instead, it provides the '' header file and several C language subroutines for obtaining user information. The primary -function is `getpwent()', for "get password entry." The "password" -comes from the original user database file, `/etc/passwd', which stores +function is 'getpwent()', for "get password entry." The "password" +comes from the original user database file, '/etc/passwd', which stores user information, along with the encrypted passwords (hence the name). - While an `awk' program could simply read `/etc/passwd' directly, -this file may not contain complete information about the system's set -of users.(1) To be sure you are able to produce a readable and complete -version of the user database, it is necessary to write a small C -program that calls `getpwent()'. `getpwent()' is defined as returning -a pointer to a `struct passwd'. Each time it is called, it returns the -next entry in the database. When there are no more entries, it returns -`NULL', the null pointer. When this happens, the C program should call -`endpwent()' to close the database. Following is `pwcat', a C program -that "cats" the password database: + While an 'awk' program could simply read '/etc/passwd' directly, this +file may not contain complete information about the system's set of +users.(1) To be sure you are able to produce a readable and complete +version of the user database, it is necessary to write a small C program +that calls 'getpwent()'. 'getpwent()' is defined as returning a pointer +to a 'struct passwd'. Each time it is called, it returns the next entry +in the database. When there are no more entries, it returns 'NULL', the +null pointer. When this happens, the C program should call 'endpwent()' +to close the database. Following is 'pwcat', a C program that "cats" +the password database: /* * pwcat.c @@ -15517,8 +15452,8 @@ that "cats" the password database: } If you don't understand C, don't worry about it. The output from -`pwcat' is the user database, in the traditional `/etc/passwd' format -of colon-separated fields. The fields are: +'pwcat' is the user database, in the traditional '/etc/passwd' format of +colon-separated fields. The fields are: Login name The user's login name. @@ -15529,26 +15464,26 @@ Encrypted password User-ID The user's numeric user ID number. (On some systems it's a C - `long', and not an `int'. Thus we cast it to `long' for all + 'long', and not an 'int'. Thus we cast it to 'long' for all cases.) Group-ID - The user's numeric group ID number. (Similar comments about - `long' vs. `int' apply here.) + The user's numeric group ID number. (Similar comments about 'long' + vs. 'int' apply here.) Full name - The user's full name, and perhaps other information associated - with the user. + The user's full name, and perhaps other information associated with + the user. Home directory The user's login (or "home") directory (familiar to shell - programmers as `$HOME'). + programmers as '$HOME'). Login shell The program that is run when the user logs in. This is usually a shell, such as Bash. - A few lines representative of `pwcat''s output are as follows: + A few lines representative of 'pwcat''s output are as follows: $ pwcat -| root:3Ov02d5VaUPB6:0:1:Operator:/:/bin/sh @@ -15561,9 +15496,9 @@ Login shell -| andy:abcca2:113:10:Andy Jacobs:/home/andy:/bin/sh ... - With that introduction, following is a group of functions for -getting user information. There are several functions here, -corresponding to the C functions of the same names: + With that introduction, following is a group of functions for getting +user information. There are several functions here, corresponding to +the C functions of the same names: # passwd.awk --- access password file information @@ -15603,41 +15538,41 @@ corresponding to the C functions of the same names: $0 = olddol0 } - The `BEGIN' rule sets a private variable to the directory where -`pwcat' is stored. Because it is used to help out an `awk' library -routine, we have chosen to put it in `/usr/local/libexec/awk'; however, + The 'BEGIN' rule sets a private variable to the directory where +'pwcat' is stored. Because it is used to help out an 'awk' library +routine, we have chosen to put it in '/usr/local/libexec/awk'; however, you might want it to be in a different directory on your system. - The function `_pw_init()' keeps three copies of the user information + The function '_pw_init()' keeps three copies of the user information in three associative arrays. The arrays are indexed by username -(`_pw_byname'), by user ID number (`_pw_byuid'), and by order of -occurrence (`_pw_bycount'). The variable `_pw_inited' is used for -efficiency, since `_pw_init()' needs to be called only once. - - Because this function uses `getline' to read information from -`pwcat', it first saves the values of `FS', `RS', and `$0'. It notes -in the variable `using_fw' whether field splitting with `FIELDWIDTHS' -is in effect or not. Doing so is necessary, since these functions -could be called from anywhere within a user's program, and the user may -have his or her own way of splitting records and fields. - - The `using_fw' variable checks `PROCINFO["FS"]', which is -`"FIELDWIDTHS"' if field splitting is being done with `FIELDWIDTHS'. +('_pw_byname'), by user ID number ('_pw_byuid'), and by order of +occurrence ('_pw_bycount'). The variable '_pw_inited' is used for +efficiency, since '_pw_init()' needs to be called only once. + + Because this function uses 'getline' to read information from +'pwcat', it first saves the values of 'FS', 'RS', and '$0'. It notes in +the variable 'using_fw' whether field splitting with 'FIELDWIDTHS' is in +effect or not. Doing so is necessary, since these functions could be +called from anywhere within a user's program, and the user may have his +or her own way of splitting records and fields. + + The 'using_fw' variable checks 'PROCINFO["FS"]', which is +'"FIELDWIDTHS"' if field splitting is being done with 'FIELDWIDTHS'. This makes it possible to restore the correct field-splitting mechanism -later. The test can only be true for `gawk'. It is false if using -`FS' or `FPAT', or on some other `awk' implementation. +later. The test can only be true for 'gawk'. It is false if using 'FS' +or 'FPAT', or on some other 'awk' implementation. - The code that checks for using `FPAT', using `using_fpat' and -`PROCINFO["FS"]', is similar. + The code that checks for using 'FPAT', using 'using_fpat' and +'PROCINFO["FS"]', is similar. The main part of the function uses a loop to read database lines, split the line into fields, and then store the line into each array as -necessary. When the loop is done, `_pw_init()' cleans up by closing -the pipeline, setting `_pw_inited' to one, and restoring `FS' (and -`FIELDWIDTHS' or `FPAT' if necessary), `RS', and `$0'. The use of -`_pw_count' is explained shortly. +necessary. When the loop is done, '_pw_init()' cleans up by closing the +pipeline, setting '_pw_inited' to one, and restoring 'FS' (and +'FIELDWIDTHS' or 'FPAT' if necessary), 'RS', and '$0'. The use of +'_pw_count' is explained shortly. - The `getpwnam()' function takes a username as a string argument. If + The 'getpwnam()' function takes a username as a string argument. If that user is in the database, it returns the appropriate line. Otherwise, it relies on the array reference to a nonexistent element to create the element with the null string as its value: @@ -15648,9 +15583,9 @@ create the element with the null string as its value: return _pw_byname[name] } - Similarly, the `getpwuid()' function takes a user ID number -argument. If that user number is in the database, it returns the -appropriate line. Otherwise, it returns the null string: + Similarly, the 'getpwuid()' function takes a user ID number argument. +If that user number is in the database, it returns the appropriate line. +Otherwise, it returns the null string: function getpwuid(uid) { @@ -15658,9 +15593,9 @@ appropriate line. Otherwise, it returns the null string: return _pw_byuid[uid] } - The `getpwent()' function simply steps through the database, one -entry at a time. It uses `_pw_count' to track its current position in -the `_pw_bycount' array: + The 'getpwent()' function simply steps through the database, one +entry at a time. It uses '_pw_count' to track its current position in +the '_pw_bycount' array: function getpwent() { @@ -15670,8 +15605,8 @@ the `_pw_bycount' array: return "" } - The `endpwent()' function resets `_pw_count' to zero, so that -subsequent calls to `getpwent()' start over again: + The 'endpwent()' function resets '_pw_count' to zero, so that +subsequent calls to 'getpwent()' start over again: function endpwent() { @@ -15679,24 +15614,24 @@ subsequent calls to `getpwent()' start over again: } A conscious design decision in this suite is that each subroutine -calls `_pw_init()' to initialize the database arrays. The overhead of -running a separate process to generate the user database, and the I/O -to scan it, are only incurred if the user's main program actually calls -one of these functions. If this library file is loaded along with a -user's program, but none of the routines are ever called, then there is -no extra runtime overhead. (The alternative is move the body of -`_pw_init()' into a `BEGIN' rule, which always runs `pwcat'. This +calls '_pw_init()' to initialize the database arrays. The overhead of +running a separate process to generate the user database, and the I/O to +scan it, are only incurred if the user's main program actually calls one +of these functions. If this library file is loaded along with a user's +program, but none of the routines are ever called, then there is no +extra runtime overhead. (The alternative is move the body of +'_pw_init()' into a 'BEGIN' rule, which always runs 'pwcat'. This simplifies the code but runs an extra process that may never be needed.) - In turn, calling `_pw_init()' is not too expensive, because the -`_pw_inited' variable keeps the program from reading the data more than + In turn, calling '_pw_init()' is not too expensive, because the +'_pw_inited' variable keeps the program from reading the data more than once. If you are worried about squeezing every last cycle out of your -`awk' program, the check of `_pw_inited' could be moved out of -`_pw_init()' and duplicated in all the other functions. In practice, -this is not necessary, since most `awk' programs are I/O-bound, and -such a change would clutter up the code. +'awk' program, the check of '_pw_inited' could be moved out of +'_pw_init()' and duplicated in all the other functions. In practice, +this is not necessary, since most 'awk' programs are I/O-bound, and such +a change would clutter up the code. - The `id' program in *note Id Program::, uses these functions. + The 'id' program in *note Id Program::, uses these functions. ---------- Footnotes ---------- @@ -15709,14 +15644,14 @@ File: gawk.info, Node: Group Functions, Next: Walking Arrays, Prev: Passwd Fu 10.6 Reading the Group Database =============================== -Much of the discussion presented in *note Passwd Functions::, applies -to the group database as well. Although there has traditionally been a -well-known file (`/etc/group') in a well-known format, the POSIX -standard only provides a set of C library routines (`' and -`getgrent()') for accessing the information. Even though this file may +Much of the discussion presented in *note Passwd Functions::, applies to +the group database as well. Although there has traditionally been a +well-known file ('/etc/group') in a well-known format, the POSIX +standard only provides a set of C library routines ('' and +'getgrent()') for accessing the information. Even though this file may exist, it may not have complete information. Therefore, as with the user database, it is necessary to have a small C program that generates -the group database as its output. `grcat', a C program that "cats" the +the group database as its output. 'grcat', a C program that "cats" the group database, is as follows: /* @@ -15754,24 +15689,24 @@ Group Name The group's name. Group Password - The group's encrypted password. In practice, this field is never - used; it is usually empty or set to `*'. + The group's encrypted password. In practice, this field is never + used; it is usually empty or set to '*'. Group ID Number The group's numeric group ID number; the association of name to number must be unique within the file. (On some systems it's a C - `long', and not an `int'. Thus we cast it to `long' for all + 'long', and not an 'int'. Thus we cast it to 'long' for all cases.) Group Member List A comma-separated list of user names. These users are members of the group. Modern Unix systems allow users to be members of - several groups simultaneously. If your system does, then there - are elements `"group1"' through `"groupN"' in `PROCINFO' for those - group ID numbers. (Note that `PROCINFO' is a `gawk' extension; + several groups simultaneously. If your system does, then there are + elements '"group1"' through '"groupN"' in 'PROCINFO' for those + group ID numbers. (Note that 'PROCINFO' is a 'gawk' extension; *note Built-in Variables::.) - Here is what running `grcat' might produce: + Here is what running 'grcat' might produce: $ grcat -| wheel:*:0:arnold @@ -15841,23 +15776,23 @@ the same names: $0 = olddol0 } - The `BEGIN' rule sets a private variable to the directory where -`grcat' is stored. Because it is used to help out an `awk' library -routine, we have chosen to put it in `/usr/local/libexec/awk'. You + The 'BEGIN' rule sets a private variable to the directory where +'grcat' is stored. Because it is used to help out an 'awk' library +routine, we have chosen to put it in '/usr/local/libexec/awk'. You might want it to be in a different directory on your system. These routines follow the same general outline as the user database -routines (*note Passwd Functions::). The `_gr_inited' variable is used +routines (*note Passwd Functions::). The '_gr_inited' variable is used to ensure that the database is scanned no more than once. The -`_gr_init()' function first saves `FS', `RS', and `$0', and then sets -`FS' and `RS' to the correct values for scanning the group information. -It also takes care to note whether `FIELDWIDTHS' or `FPAT' is being +'_gr_init()' function first saves 'FS', 'RS', and '$0', and then sets +'FS' and 'RS' to the correct values for scanning the group information. +It also takes care to note whether 'FIELDWIDTHS' or 'FPAT' is being used, and to restore the appropriate field splitting mechanism. The group information is stored is several associative arrays. The -arrays are indexed by group name (`_gr_byname'), by group ID number -(`_gr_bygid'), and by position in the database (`_gr_bycount'). There -is an additional array indexed by user name (`_gr_groupsbyuser'), which +arrays are indexed by group name ('_gr_byname'), by group ID number +('_gr_bygid'), and by position in the database ('_gr_bycount'). There +is an additional array indexed by user name ('_gr_groupsbyuser'), which is a space-separated list of groups to which each user belongs. Unlike the user database, it is possible to have multiple records in @@ -15868,15 +15803,15 @@ following: tvpeople:*:101:johny,jay,arsenio tvpeople:*:101:david,conan,tom,joan - For this reason, `_gr_init()' looks to see if a group name or group + For this reason, '_gr_init()' looks to see if a group name or group ID number is already seen. If it is, then the user names are simply concatenated onto the previous list of users.(1) - Finally, `_gr_init()' closes the pipeline to `grcat', restores `FS' -(and `FIELDWIDTHS' or `FPAT' if necessary), `RS', and `$0', initializes -`_gr_count' to zero (it is used later), and makes `_gr_inited' nonzero. + Finally, '_gr_init()' closes the pipeline to 'grcat', restores 'FS' +(and 'FIELDWIDTHS' or 'FPAT' if necessary), 'RS', and '$0', initializes +'_gr_count' to zero (it is used later), and makes '_gr_inited' nonzero. - The `getgrnam()' function takes a group name as its argument, and if + The 'getgrnam()' function takes a group name as its argument, and if that group exists, it is returned. Otherwise, it relies on the array reference to a nonexistent element to create the element with the null string as its value: @@ -15887,7 +15822,7 @@ string as its value: return _gr_byname[group] } - The `getgrgid()' function is similar; it takes a numeric group ID and + The 'getgrgid()' function is similar; it takes a numeric group ID and looks up the information associated with that group ID: function getgrgid(gid) @@ -15896,7 +15831,7 @@ looks up the information associated with that group ID: return _gr_bygid[gid] } - The `getgruser()' function does not have a C counterpart. It takes a + The 'getgruser()' function does not have a C counterpart. It takes a user name and returns the list of groups that have the user as a member: function getgruser(user) @@ -15905,8 +15840,8 @@ user name and returns the list of groups that have the user as a member: return _gr_groupsbyuser[user] } - The `getgrent()' function steps through the database one entry at a -time. It uses `_gr_count' to track its position in the list: + The 'getgrent()' function steps through the database one entry at a +time. It uses '_gr_count' to track its position in the list: function getgrent() { @@ -15916,30 +15851,30 @@ time. It uses `_gr_count' to track its position in the list: return "" } - The `endgrent()' function resets `_gr_count' to zero so that -`getgrent()' can start over again: + The 'endgrent()' function resets '_gr_count' to zero so that +'getgrent()' can start over again: function endgrent() { _gr_count = 0 } - As with the user database routines, each function calls `_gr_init()' + As with the user database routines, each function calls '_gr_init()' to initialize the arrays. Doing so only incurs the extra overhead of -running `grcat' if these functions are used (as opposed to moving the -body of `_gr_init()' into a `BEGIN' rule). +running 'grcat' if these functions are used (as opposed to moving the +body of '_gr_init()' into a 'BEGIN' rule). Most of the work is in scanning the database and building the various associative arrays. The functions that the user calls are themselves -very simple, relying on `awk''s associative arrays to do work. +very simple, relying on 'awk''s associative arrays to do work. - The `id' program in *note Id Program::, uses these functions. + The 'id' program in *note Id Program::, uses these functions. ---------- Footnotes ---------- (1) There is actually a subtle problem with the code just presented. -Suppose that the first time there were no names. This code adds the -names with a leading comma. It also doesn't check that there is a `$4'. +Suppose that the first time there were no names. This code adds the +names with a leading comma. It also doesn't check that there is a '$4'.  File: gawk.info, Node: Walking Arrays, Next: Library Functions Summary, Prev: Group Functions, Up: Library Functions @@ -15947,13 +15882,13 @@ File: gawk.info, Node: Walking Arrays, Next: Library Functions Summary, Prev: 10.7 Traversing Arrays of Arrays ================================ -*note Arrays of Arrays::, described how `gawk' provides arrays of +*note Arrays of Arrays::, described how 'gawk' provides arrays of arrays. In particular, any element of an array may be either a scalar, -or another array. The `isarray()' function (*note Type Functions::) +or another array. The 'isarray()' function (*note Type Functions::) lets you distinguish an array from a scalar. The following function, -`walk_array()', recursively traverses an array, printing each element's -indices and value. You call it with the array and a string -representing the name of the array: +'walk_array()', recursively traverses an array, printing each element's +indices and value. You call it with the array and a string representing +the name of the array: function walk_array(arr, name, i) { @@ -15965,7 +15900,7 @@ representing the name of the array: } } -It works by looping over each element of the array. If any given +It works by looping over each element of the array. If any given element is itself an array, the function calls itself recursively, passing the subarray and a new string representing the current index. Otherwise, the function simply prints the element's name, index, and @@ -16008,67 +15943,65 @@ File: gawk.info, Node: Library Functions Summary, Next: Library exercises, Pr * The functions presented here fit into the following categories: - General problems + General problems Number to string conversion, assertions, rounding, random number generation, converting characters to numbers, joining strings, getting easily usable time-of-day information, and reading a whole file in one shot. - Managing data files + Managing data files Noting data file boundaries, rereading the current file, checking for readable files, checking for zero-length files, and treating assignments as file names. - Processing command-line options - An `awk' version of the standard C `getopt()' function. + Processing command-line options + An 'awk' version of the standard C 'getopt()' function. - Reading the user and group databases + Reading the user and group databases Two sets of routines that parallel the C library versions. - Traversing arrays of arrays + Traversing arrays of arrays A simple function to traverse an array of arrays to any depth. -  File: gawk.info, Node: Library exercises, Prev: Library Functions Summary, Up: Library Functions 10.9 Exercises ============== - 1. In *note Empty Files::, we presented the `zerofile.awk' program, - which made use of `gawk''s `ARGIND' variable. Can this problem be - solved without relying on `ARGIND'? If so, how? + 1. In *note Empty Files::, we presented the 'zerofile.awk' program, + which made use of 'gawk''s 'ARGIND' variable. Can this problem be + solved without relying on 'ARGIND'? If so, how? 2. As a related challenge, revise that code to handle the case where - an intervening value in `ARGV' is a variable assignment. + an intervening value in 'ARGV' is a variable assignment. 3. *note Walking Arrays::, presented a function that walked a multidimensional array to print it out. However, walking an array and processing each element is a general-purpose operation. - Generalize the `walk_array()' function by adding an additional - parameter named `process'. + Generalize the 'walk_array()' function by adding an additional + parameter named 'process'. Then, inside the loop, instead of printing the array element's index and value, use the indirect function call syntax (*note - Indirect Calls::) on `process', passing it the index and the value. + Indirect Calls::) on 'process', passing it the index and the value. - When calling `walk_array()', you would pass the name of a + When calling 'walk_array()', you would pass the name of a user-defined function that expects to receive an index and a value, and then processes the element. Test your new version by printing the array; you should end up with output identical to that of the original version. -  File: gawk.info, Node: Sample Programs, Next: Advanced Features, Prev: Library Functions, Up: Top -11 Practical `awk' Programs +11 Practical 'awk' Programs *************************** *note Library Functions::, presents the idea that reading programs in a language contributes to learning that language. This major node -continues that theme, presenting a potpourri of `awk' programs for your +continues that theme, presenting a potpourri of 'awk' programs for your reading enjoyment. Many of these programs use library functions presented in *note @@ -16078,7 +16011,7 @@ Library Functions::. * Running Examples:: How to run these examples. * Clones:: Clones of common utilities. -* Miscellaneous Programs:: Some interesting `awk' programs. +* Miscellaneous Programs:: Some interesting 'awk' programs. * Programs Summary:: Summary of programs. * Programs Exercises:: Exercises. @@ -16092,16 +16025,16 @@ To run a given program, you would typically do something like this: awk -f PROGRAM -- OPTIONS FILES -Here, PROGRAM is the name of the `awk' program (such as `cut.awk'), +Here, PROGRAM is the name of the 'awk' program (such as 'cut.awk'), OPTIONS are any command-line options for the program that start with a -`-', and FILES are the actual data files. +'-', and FILES are the actual data files. - If your system supports the `#!' executable interpreter mechanism + If your system supports the '#!' executable interpreter mechanism (*note Executable Scripts::), you can instead run your program directly: cut.awk -c1-8 myfiles > results - If your `awk' is not `gawk', you may instead need to use this: + If your 'awk' is not 'gawk', you may instead need to use this: cut.awk -- -c1-8 myfiles > results @@ -16112,28 +16045,28 @@ File: gawk.info, Node: Clones, Next: Miscellaneous Programs, Prev: Running Ex ========================================== This minor node presents a number of POSIX utilities implemented in -`awk'. Reinventing these programs in `awk' is often enjoyable, because +'awk'. Reinventing these programs in 'awk' is often enjoyable, because the algorithms can be very clearly expressed, and the code is usually -very concise and simple. This is true because `awk' does so much for +very concise and simple. This is true because 'awk' does so much for you. It should be noted that these programs are not necessarily intended to replace the installed versions on your system. Nor may all of these programs be fully compliant with the most recent POSIX standard. This -is not a problem; their purpose is to illustrate `awk' language +is not a problem; their purpose is to illustrate 'awk' language programming for "real world" tasks. The programs are presented in alphabetical order. * Menu: -* Cut Program:: The `cut' utility. -* Egrep Program:: The `egrep' utility. -* Id Program:: The `id' utility. -* Split Program:: The `split' utility. -* Tee Program:: The `tee' utility. -* Uniq Program:: The `uniq' utility. -* Wc Program:: The `wc' utility. +* Cut Program:: The 'cut' utility. +* Egrep Program:: The 'egrep' utility. +* Id Program:: The 'id' utility. +* Split Program:: The 'split' utility. +* Tee Program:: The 'tee' utility. +* Uniq Program:: The 'uniq' utility. +* Wc Program:: The 'wc' utility.  File: gawk.info, Node: Cut Program, Next: Egrep Program, Up: Clones @@ -16141,43 +16074,43 @@ File: gawk.info, Node: Cut Program, Next: Egrep Program, Up: Clones 11.2.1 Cutting out Fields and Columns ------------------------------------- -The `cut' utility selects, or "cuts," characters or fields from its +The 'cut' utility selects, or "cuts," characters or fields from its standard input and sends them to its standard output. Fields are separated by TABs by default, but you may supply a command-line option to change the field "delimiter" (i.e., the field-separator character). -`cut''s definition of fields is less general than `awk''s. +'cut''s definition of fields is less general than 'awk''s. - A common use of `cut' might be to pull out just the login name of -logged-on users from the output of `who'. For example, the following + A common use of 'cut' might be to pull out just the login name of +logged-on users from the output of 'who'. For example, the following pipeline generates a sorted, unique list of the logged-on users: who | cut -c1-8 | sort | uniq - The options for `cut' are: + The options for 'cut' are: -`-c LIST' +'-c LIST' Use LIST as the list of characters to cut out. Items within the list may be separated by commas, and ranges of characters can be - separated with dashes. The list `1-8,15,22-35' specifies + separated with dashes. The list '1-8,15,22-35' specifies characters 1 through 8, 15, and 22 through 35. -`-f LIST' +'-f LIST' Use LIST as the list of fields to cut out. -`-d DELIM' +'-d DELIM' Use DELIM as the field-separator character instead of the TAB character. -`-s' +'-s' Suppress printing of lines that do not contain the field delimiter. - The `awk' implementation of `cut' uses the `getopt()' library -function (*note Getopt Function::) and the `join()' library function + The 'awk' implementation of 'cut' uses the 'getopt()' library +function (*note Getopt Function::) and the 'join()' library function (*note Join Function::). The program begins with a comment describing the options, the library -functions needed, and a `usage()' function that prints out a usage -message and exits. `usage()' is called if invalid arguments are +functions needed, and a 'usage()' function that prints out a usage +message and exits. 'usage()' is called if invalid arguments are supplied: # cut.awk --- implement cut in awk @@ -16200,15 +16133,15 @@ supplied: exit 1 } -The variables `e1' and `e2' are used so that the function fits nicely -on the screen. +The variables 'e1' and 'e2' are used so that the function fits nicely on +the screen. - Next comes a `BEGIN' rule that parses the command-line options. It -sets `FS' to a single TAB character, because that is `cut''s default -field separator. The rule then sets the output field separator to be the -same as the input field separator. A loop using `getopt()' steps + Next comes a 'BEGIN' rule that parses the command-line options. It +sets 'FS' to a single TAB character, because that is 'cut''s default +field separator. The rule then sets the output field separator to be +the same as the input field separator. A loop using 'getopt()' steps through the command-line options. Exactly one of the variables -`by_fields' or `by_chars' is set to true, to indicate that processing +'by_fields' or 'by_chars' is set to true, to indicate that processing should be done by fields or by characters, respectively. When cutting by characters, the output field separator is set to the null string: @@ -16245,18 +16178,18 @@ by characters, the output field separator is set to the null string: ARGV[i] = "" The code must take special care when the field delimiter is a space. -Using a single space (`" "') for the value of `FS' is incorrect--`awk' -would separate fields with runs of spaces, TABs, and/or newlines, and -we want them to be separated with individual spaces. Also remember -that after `getopt()' is through (as described in *note Getopt -Function::), we have to clear out all the elements of `ARGV' from 1 to -`Optind', so that `awk' does not try to process the command-line options -as file names. +Using a single space ('" "') for the value of 'FS' is incorrect--'awk' +would separate fields with runs of spaces, TABs, and/or newlines, and we +want them to be separated with individual spaces. Also remember that +after 'getopt()' is through (as described in *note Getopt Function::), +we have to clear out all the elements of 'ARGV' from 1 to 'Optind', so +that 'awk' does not try to process the command-line options as file +names. After dealing with the command-line options, the program verifies -that the options make sense. Only one or the other of `-c' and `-f' +that the options make sense. Only one or the other of '-c' and '-f' should be used, and both require a field list. Then the program calls -either `set_fieldlist()' or `set_charlist()' to pull apart the list of +either 'set_fieldlist()' or 'set_charlist()' to pull apart the list of fields or characters: if (by_fields && by_chars) @@ -16276,13 +16209,13 @@ fields or characters: set_charlist() } - `set_fieldlist()' splits the field list apart at the commas into an + 'set_fieldlist()' splits the field list apart at the commas into an array. Then, for each element of the array, it looks to see if the element is actually a range, and if so, splits it apart. The function checks the range to make sure that the first number is smaller than the -second. Each number in the list is added to the `flist' array, which -simply lists the fields that will be printed. Normal field splitting -is used. The program lets `awk' handle the job of doing the field +second. Each number in the list is added to the 'flist' array, which +simply lists the fields that will be printed. Normal field splitting is +used. The program lets 'awk' handle the job of doing the field splitting: function set_fieldlist( n, m, i, j, k, f, g) @@ -16305,20 +16238,20 @@ splitting: nfields = j - 1 } - The `set_charlist()' function is more complicated than -`set_fieldlist()'. The idea here is to use `gawk''s `FIELDWIDTHS' + The 'set_charlist()' function is more complicated than +'set_fieldlist()'. The idea here is to use 'gawk''s 'FIELDWIDTHS' variable (*note Constant Size::), which describes constant-width input. When using a character list, that is exactly what we have. - Setting up `FIELDWIDTHS' is more complicated than simply listing the + Setting up 'FIELDWIDTHS' is more complicated than simply listing the fields that need to be printed. We have to keep track of the fields to print and also the intervening characters that have to be skipped. For example, suppose you wanted characters 1 through 8, 15, and 22 through -35. You would use `-c 1-8,15,22-35'. The necessary value for -`FIELDWIDTHS' is `"8 6 1 6 14"'. This yields five fields, and the -fields to print are `$1', `$3', and `$5'. The intermediate fields are -"filler", which is stuff in between the desired data. `flist' lists -the fields to print, and `t' tracks the complete field list, including +35. You would use '-c 1-8,15,22-35'. The necessary value for +'FIELDWIDTHS' is '"8 6 1 6 14"'. This yields five fields, and the +fields to print are '$1', '$3', and '$5'. The intermediate fields are +"filler", which is stuff in between the desired data. 'flist' lists the +fields to print, and 't' tracks the complete field list, including filler fields: function set_charlist( field, i, j, f, g, n, m, t, @@ -16361,15 +16294,15 @@ filler fields: nfields = j - 1 } - Next is the rule that actually processes the data. If the `-s' -option is given, then `suppress' is true. The first `if' statement + Next is the rule that actually processes the data. If the '-s' +option is given, then 'suppress' is true. The first 'if' statement makes sure that the input record does have the field separator. If -`cut' is processing fields, `suppress' is true, and the field separator +'cut' is processing fields, 'suppress' is true, and the field separator character is not in the record, then the record is skipped. - If the record is valid, then `gawk' has split the data into fields, -either using the character in `FS' or using fixed-length fields and -`FIELDWIDTHS'. The loop goes through the list of fields that should be + If the record is valid, then 'gawk' has split the data into fields, +either using the character in 'FS' or using fixed-length fields and +'FIELDWIDTHS'. The loop goes through the list of fields that should be printed. The corresponding field is printed if it contains data. If the next field also has data, then the separator character is written out between the fields: @@ -16388,10 +16321,10 @@ out between the fields: print "" } - This version of `cut' relies on `gawk''s `FIELDWIDTHS' variable to -do the character-based cutting. While it is possible in other `awk' -implementations to use `substr()' (*note String Functions::), it is -also extremely painful. The `FIELDWIDTHS' variable supplies an elegant + This version of 'cut' relies on 'gawk''s 'FIELDWIDTHS' variable to do +the character-based cutting. While it is possible in other 'awk' +implementations to use 'substr()' (*note String Functions::), it is also +extremely painful. The 'FIELDWIDTHS' variable supplies an elegant solution to the problem of picking the input line apart by characters.  @@ -16400,53 +16333,52 @@ File: gawk.info, Node: Egrep Program, Next: Id Program, Prev: Cut Program, U 11.2.2 Searching for Regular Expressions in Files ------------------------------------------------- -The `egrep' utility searches files for patterns. It uses regular -expressions that are almost identical to those available in `awk' -(*note Regexp::). You invoke it as follows: +The 'egrep' utility searches files for patterns. It uses regular +expressions that are almost identical to those available in 'awk' (*note +Regexp::). You invoke it as follows: - `egrep' [OPTIONS] `'PATTERN'' FILES ... + 'egrep' [OPTIONS] ''PATTERN'' FILES ... The PATTERN is a regular expression. In typical usage, the regular expression is quoted to prevent the shell from expanding any of the -special characters as file name wildcards. Normally, `egrep' prints -the lines that matched. If multiple file names are provided on the -command line, each output line is preceded by the name of the file and -a colon. +special characters as file name wildcards. Normally, 'egrep' prints the +lines that matched. If multiple file names are provided on the command +line, each output line is preceded by the name of the file and a colon. - The options to `egrep' are as follows: + The options to 'egrep' are as follows: -`-c' - Print out a count of the lines that matched the pattern, instead - of the lines themselves. +'-c' + Print out a count of the lines that matched the pattern, instead of + the lines themselves. -`-s' +'-s' Be silent. No output is produced and the exit value indicates whether the pattern was matched. -`-v' - Invert the sense of the test. `egrep' prints the lines that do +'-v' + Invert the sense of the test. 'egrep' prints the lines that do _not_ match the pattern and exits successfully if the pattern is not matched. -`-i' +'-i' Ignore case distinctions in both the pattern and the input data. -`-l' +'-l' Only print (list) the names of the files that matched, not the lines that matched. -`-e PATTERN' - Use PATTERN as the regexp to match. The purpose of the `-e' - option is to allow patterns that start with a `-'. +'-e PATTERN' + Use PATTERN as the regexp to match. The purpose of the '-e' option + is to allow patterns that start with a '-'. - This version uses the `getopt()' library function (*note Getopt + This version uses the 'getopt()' library function (*note Getopt Function::) and the file transition library program (*note Filetrans Function::). - The program begins with a descriptive comment and then a `BEGIN' rule -that processes the command-line arguments with `getopt()'. The `-i' -(ignore case) option is particularly easy with `gawk'; we just use the -`IGNORECASE' built-in variable (*note Built-in Variables::): + The program begins with a descriptive comment and then a 'BEGIN' rule +that processes the command-line arguments with 'getopt()'. The '-i' +(ignore case) option is particularly easy with 'gawk'; we just use the +'IGNORECASE' built-in variable (*note Built-in Variables::): # egrep.awk --- simulate egrep in awk # @@ -16478,10 +16410,10 @@ that processes the command-line arguments with `getopt()'. The `-i' usage() } - Next comes the code that handles the `egrep'-specific behavior. If no -pattern is supplied with `-e', the first nonoption on the command line -is used. The `awk' command-line arguments up to `ARGV[Optind]' are -cleared, so that `awk' won't try to process them as files. If no files + Next comes the code that handles the 'egrep'-specific behavior. If +no pattern is supplied with '-e', the first nonoption on the command +line is used. The 'awk' command-line arguments up to 'ARGV[Optind]' are +cleared, so that 'awk' won't try to process them as files. If no files are specified, the standard input is used, and if multiple files are specified, we make sure to note this so that the file names can precede the matched lines in the output: @@ -16502,24 +16434,24 @@ the matched lines in the output: } The last two lines are commented out, since they are not needed in -`gawk'. They should be uncommented if you have to use another version -of `awk'. +'gawk'. They should be uncommented if you have to use another version +of 'awk'. The next set of lines should be uncommented if you are not using -`gawk'. This rule translates all the characters in the input line into -lowercase if the `-i' option is specified.(1) The rule is commented out -since it is not necessary with `gawk': +'gawk'. This rule translates all the characters in the input line into +lowercase if the '-i' option is specified.(1) The rule is commented out +since it is not necessary with 'gawk': #{ # if (IGNORECASE) # $0 = tolower($0) #} - The `beginfile()' function is called by the rule in `ftrans.awk' -when each new file is processed. In this case, it is very simple; all -it does is initialize a variable `fcount' to zero. `fcount' tracks how + The 'beginfile()' function is called by the rule in 'ftrans.awk' when +each new file is processed. In this case, it is very simple; all it +does is initialize a variable 'fcount' to zero. 'fcount' tracks how many lines in the current file matched the pattern. Naming the -parameter `junk' shows we know that `beginfile()' is called with a +parameter 'junk' shows we know that 'beginfile()' is called with a parameter, but that we're not interested in its value: function beginfile(junk) @@ -16527,13 +16459,13 @@ parameter, but that we're not interested in its value: fcount = 0 } - The `endfile()' function is called after each file has been + The 'endfile()' function is called after each file has been processed. It affects the output only when the user wants a count of -the number of lines that matched. `no_print' is true only if the exit -status is desired. `count_only' is true if line counts are desired. -`egrep' therefore only prints line counts if printing and counting are +the number of lines that matched. 'no_print' is true only if the exit +status is desired. 'count_only' is true if line counts are desired. +'egrep' therefore only prints line counts if printing and counting are enabled. The output format must be adjusted depending upon the number -of files to process. Finally, `fcount' is added to `total', so that we +of files to process. Finally, 'fcount' is added to 'total', so that we know the total number of lines that matched the pattern: function endfile(file) @@ -16548,25 +16480,25 @@ know the total number of lines that matched the pattern: total += fcount } - The `BEGINFILE' and `ENDFILE' special patterns (*note + The 'BEGINFILE' and 'ENDFILE' special patterns (*note BEGINFILE/ENDFILE::) could be used, but then the program would be -`gawk'-specific. Additionally, this example was written before `gawk' -acquired `BEGINFILE' and `ENDFILE'. +'gawk'-specific. Additionally, this example was written before 'gawk' +acquired 'BEGINFILE' and 'ENDFILE'. - The following rule does most of the work of matching lines. The -variable `matches' is true if the line matched the pattern. If the user -wants lines that did not match, the sense of `matches' is inverted -using the `!' operator. `fcount' is incremented with the value of -`matches', which is either one or zero, depending upon a successful or -unsuccessful match. If the line does not match, the `next' statement -just moves on to the next record. + The following rule does most of the work of matching lines. The +variable 'matches' is true if the line matched the pattern. If the user +wants lines that did not match, the sense of 'matches' is inverted using +the '!' operator. 'fcount' is incremented with the value of 'matches', +which is either one or zero, depending upon a successful or unsuccessful +match. If the line does not match, the 'next' statement just moves on +to the next record. A number of additional tests are made, but they are only done if we are not counting lines. First, if the user only wants exit status -(`no_print' is true), then it is enough to know that _one_ line in this -file matched, and we can skip on to the next file with `nextfile'. +('no_print' is true), then it is enough to know that _one_ line in this +file matched, and we can skip on to the next file with 'nextfile'. Similarly, if we are only printing file names, we can print the file -name, and then skip to the next file with `nextfile'. Finally, each +name, and then skip to the next file with 'nextfile'. Finally, each line is printed, with a leading file name and colon if necessary: { @@ -16595,7 +16527,7 @@ line is printed, with a leading file name and colon if necessary: } } - The `END' rule takes care of producing the correct exit status. If + The 'END' rule takes care of producing the correct exit status. If there are no matches, the exit status is one; otherwise it is zero: END \ @@ -16603,7 +16535,7 @@ there are no matches, the exit status is one; otherwise it is zero: exit (total == 0) } - The `usage()' function prints a usage message in case of invalid + The 'usage()' function prints a usage message in case of invalid options, and then exits: function usage( e) @@ -16614,15 +16546,15 @@ options, and then exits: exit 1 } - The variable `e' is used so that the function fits nicely on the + The variable 'e' is used so that the function fits nicely on the printed page. - Just a note on programming style: you may have noticed that the `END' + Just a note on programming style: you may have noticed that the 'END' rule uses backslash continuation, with the open brace on a line by -itself. This is so that it more closely resembles the way functions -are written. Many of the examples in this major node use this style. -You can decide for yourself if you like writing your `BEGIN' and `END' -rules this way or not. +itself. This is so that it more closely resembles the way functions are +written. Many of the examples in this major node use this style. You +can decide for yourself if you like writing your 'BEGIN' and 'END' rules +this way or not. ---------- Footnotes ---------- @@ -16635,29 +16567,29 @@ File: gawk.info, Node: Id Program, Next: Split Program, Prev: Egrep Program, 11.2.3 Printing out User Information ------------------------------------ -The `id' utility lists a user's real and effective user ID numbers, -real and effective group ID numbers, and the user's group set, if any. -`id' only prints the effective user ID and group ID if they are -different from the real ones. If possible, `id' also supplies the -corresponding user and group names. The output might look like this: +The 'id' utility lists a user's real and effective user ID numbers, real +and effective group ID numbers, and the user's group set, if any. 'id' +only prints the effective user ID and group ID if they are different +from the real ones. If possible, 'id' also supplies the corresponding +user and group names. The output might look like this: $ id -| uid=1000(arnold) gid=1000(arnold) groups=1000(arnold),4(adm),7(lp),27(sudo) - This information is part of what is provided by `gawk''s `PROCINFO' -array (*note Built-in Variables::). However, the `id' utility provides + This information is part of what is provided by 'gawk''s 'PROCINFO' +array (*note Built-in Variables::). However, the 'id' utility provides a more palatable output than just individual numbers. - Here is a simple version of `id' written in `awk'. It uses the user + Here is a simple version of 'id' written in 'awk'. It uses the user database library functions (*note Passwd Functions::) and the group database library functions (*note Group Functions::): The program is fairly straightforward. All the work is done in the -`BEGIN' rule. The user and group ID numbers are obtained from -`PROCINFO'. The code is repetitive. The entry in the user database -for the real user ID number is split into parts at the `:'. The name is -the first field. Similar code is used for the effective user ID number -and the group numbers: +'BEGIN' rule. The user and group ID numbers are obtained from +'PROCINFO'. The code is repetitive. The entry in the user database for +the real user ID number is split into parts at the ':'. The name is the +first field. Similar code is used for the effective user ID number and +the group numbers: # id.awk --- implement id in awk # @@ -16718,23 +16650,22 @@ and the group numbers: printf("(%s)", a[1]) } - The test in the `for' loop is worth noting. Any supplementary -groups in the `PROCINFO' array have the indices `"group1"' through -`"groupN"' for some N, i.e., the total number of supplementary groups. -However, we don't know in advance how many of these groups there are. + The test in the 'for' loop is worth noting. Any supplementary groups +in the 'PROCINFO' array have the indices '"group1"' through '"groupN"' +for some N, i.e., the total number of supplementary groups. However, we +don't know in advance how many of these groups there are. This loop works by starting at one, concatenating the value with -`"group"', and then using `in' to see if that value is in the array -(*note Reference to Elements::). Eventually, `i' is incremented past +'"group"', and then using 'in' to see if that value is in the array +(*note Reference to Elements::). Eventually, 'i' is incremented past the last group in the array and the loop exits. - The loop is also correct if there are _no_ supplementary groups; -then the condition is false the first time it's tested, and the loop -body never executes. + The loop is also correct if there are _no_ supplementary groups; then +the condition is false the first time it's tested, and the loop body +never executes. - The `pr_first_field()' function simply isolates out some code that -is used repeatedly, making the whole program slightly shorter and -cleaner. + The 'pr_first_field()' function simply isolates out some code that is +used repeatedly, making the whole program slightly shorter and cleaner.  File: gawk.info, Node: Split Program, Next: Tee Program, Prev: Id Program, Up: Clones @@ -16742,29 +16673,29 @@ File: gawk.info, Node: Split Program, Next: Tee Program, Prev: Id Program, U 11.2.4 Splitting a Large File into Pieces ----------------------------------------- -The `split' program splits large text files into smaller pieces. Usage +The 'split' program splits large text files into smaller pieces. Usage is as follows:(1) - `split' [`-COUNT'] [FILE] [PREFIX] + 'split' ['-COUNT'] [FILE] [PREFIX] - By default, the output files are named `xaa', `xab', and so on. Each + By default, the output files are named 'xaa', 'xab', and so on. Each file has 1000 lines in it, with the likely exception of the last file. To change the number of lines in each file, supply a number on the -command line preceded with a minus; e.g., `-500' for files with 500 +command line preceded with a minus; e.g., '-500' for files with 500 lines in them instead of 1000. To change the name of the output files -to something like `myfileaa', `myfileab', and so on, supply an +to something like 'myfileaa', 'myfileab', and so on, supply an additional argument that specifies the file name prefix. - Here is a version of `split' in `awk'. It uses the `ord()' and -`chr()' functions presented in *note Ordinal Functions::. + Here is a version of 'split' in 'awk'. It uses the 'ord()' and +'chr()' functions presented in *note Ordinal Functions::. The program first sets its defaults, and then tests to make sure there are not too many arguments. It then looks at each argument in turn. The first argument could be a minus sign followed by a number. If it is, this happens to look like a negative number, so it is made -positive, and that is the count of lines. The data file name is -skipped over and the final argument is used as the prefix for the -output file names: +positive, and that is the count of lines. The data file name is skipped +over and the final argument is used as the prefix for the output file +names: # split.awk --- do split in awk # @@ -16795,13 +16726,13 @@ output file names: out = (outfile s1 s2) } - The next rule does most of the work. `tcount' (temporary count) -tracks how many lines have been printed to the output file so far. If -it is greater than `count', it is time to close the current file and -start a new one. `s1' and `s2' track the current suffixes for the file -name. If they are both `z', the file is just too big. Otherwise, `s1' -moves to the next letter in the alphabet and `s2' starts over again at -`a': + The next rule does most of the work. 'tcount' (temporary count) +tracks how many lines have been printed to the output file so far. If +it is greater than 'count', it is time to close the current file and +start a new one. 's1' and 's2' track the current suffixes for the file +name. If they are both 'z', the file is just too big. Otherwise, 's1' +moves to the next letter in the alphabet and 's2' starts over again at +'a': { if (++tcount > count) { @@ -16823,7 +16754,7 @@ moves to the next letter in the alphabet and `s2' starts over again at print > out } -The `usage()' function simply prints an error message and exits: +The 'usage()' function simply prints an error message and exits: function usage( e) { @@ -16832,16 +16763,16 @@ The `usage()' function simply prints an error message and exits: exit 1 } -The variable `e' is used so that the function fits nicely on the screen. +The variable 'e' is used so that the function fits nicely on the screen. - This program is a bit sloppy; it relies on `awk' to automatically -close the last file instead of doing it in an `END' rule. It also + This program is a bit sloppy; it relies on 'awk' to automatically +close the last file instead of doing it in an 'END' rule. It also assumes that letters are contiguous in the character set, which isn't true for EBCDIC systems. ---------- Footnotes ---------- - (1) This is the traditional usage. The POSIX usage is different, but + (1) This is the traditional usage. The POSIX usage is different, but not relevant for what the program aims to demonstrate.  @@ -16850,25 +16781,25 @@ File: gawk.info, Node: Tee Program, Next: Uniq Program, Prev: Split Program, 11.2.5 Duplicating Output into Multiple Files --------------------------------------------- -The `tee' program is known as a "pipe fitting." `tee' copies its +The 'tee' program is known as a "pipe fitting." 'tee' copies its standard input to its standard output and also duplicates it to the files named on the command line. Its usage is as follows: - `tee' [`-a'] FILE ... + 'tee' ['-a'] FILE ... - The `-a' option tells `tee' to append to the named files, instead of + The '-a' option tells 'tee' to append to the named files, instead of truncating them and starting over. - The `BEGIN' rule first makes a copy of all the command-line arguments -into an array named `copy'. `ARGV[0]' is not copied, since it is not -needed. `tee' cannot use `ARGV' directly, since `awk' attempts to -process each file name in `ARGV' as input data. + The 'BEGIN' rule first makes a copy of all the command-line arguments +into an array named 'copy'. 'ARGV[0]' is not copied, since it is not +needed. 'tee' cannot use 'ARGV' directly, since 'awk' attempts to +process each file name in 'ARGV' as input data. - If the first argument is `-a', then the flag variable `append' is -set to true, and both `ARGV[1]' and `copy[1]' are deleted. If `ARGC' is -less than two, then no file names were supplied and `tee' prints a -usage message and exits. Finally, `awk' is forced to read the standard -input by setting `ARGV[1]' to `"-"' and `ARGC' to two: + If the first argument is '-a', then the flag variable 'append' is set +to true, and both 'ARGV[1]' and 'copy[1]' are deleted. If 'ARGC' is +less than two, then no file names were supplied and 'tee' prints a usage +message and exits. Finally, 'awk' is forced to read the standard input +by setting 'ARGV[1]' to '"-"' and 'ARGC' to two: # tee.awk --- tee in awk # @@ -16918,13 +16849,13 @@ It is also possible to write the loop this way: else print > copy[i] -This is more concise but it is also less efficient. The `if' is tested -for each record and for each output file. By duplicating the loop -body, the `if' is only tested once for each input record. If there are -N input records and M output files, the first method only executes N -`if' statements, while the second executes N`*'M `if' statements. +This is more concise but it is also less efficient. The 'if' is tested +for each record and for each output file. By duplicating the loop body, +the 'if' is only tested once for each input record. If there are N +input records and M output files, the first method only executes N 'if' +statements, while the second executes N'*'M 'if' statements. - Finally, the `END' rule cleans up by closing all the output files: + Finally, the 'END' rule cleans up by closing all the output files: END \ { @@ -16938,64 +16869,64 @@ File: gawk.info, Node: Uniq Program, Next: Wc Program, Prev: Tee Program, Up 11.2.6 Printing Nonduplicated Lines of Text ------------------------------------------- -The `uniq' utility reads sorted lines of data on its standard input, -and by default removes duplicate lines. In other words, it only prints -unique lines--hence the name. `uniq' has a number of options. The +The 'uniq' utility reads sorted lines of data on its standard input, and +by default removes duplicate lines. In other words, it only prints +unique lines--hence the name. 'uniq' has a number of options. The usage is as follows: - `uniq' [`-udc' [`-N']] [`+N'] [INPUTFILE [OUTPUTFILE]] + 'uniq' ['-udc' ['-N']] ['+N'] [INPUTFILE [OUTPUTFILE]] - The options for `uniq' are: + The options for 'uniq' are: -`-d' +'-d' Print only repeated lines. -`-u' +'-u' Print only nonrepeated lines. -`-c' - Count lines. This option overrides `-d' and `-u'. Both repeated +'-c' + Count lines. This option overrides '-d' and '-u'. Both repeated and nonrepeated lines are counted. -`-N' +'-N' Skip N fields before comparing lines. The definition of fields is - similar to `awk''s default: nonwhitespace characters separated by + similar to 'awk''s default: nonwhitespace characters separated by runs of spaces and/or TABs. -`+N' +'+N' Skip N characters before comparing lines. Any fields specified - with `-N' are skipped first. + with '-N' are skipped first. -`INPUTFILE' - Data is read from the input file named on the command line, - instead of from the standard input. +'INPUTFILE' + Data is read from the input file named on the command line, instead + of from the standard input. -`OUTPUTFILE' +'OUTPUTFILE' The generated output is sent to the named output file, instead of to the standard output. - Normally `uniq' behaves as if both the `-d' and `-u' options are + Normally 'uniq' behaves as if both the '-d' and '-u' options are provided. - `uniq' uses the `getopt()' library function (*note Getopt Function::) -and the `join()' library function (*note Join Function::). + 'uniq' uses the 'getopt()' library function (*note Getopt Function::) +and the 'join()' library function (*note Join Function::). - The program begins with a `usage()' function and then a brief -outline of the options and their meanings in comments. The `BEGIN' -rule deals with the command-line arguments and options. It uses a trick -to get `getopt()' to handle options of the form `-25', treating such an -option as the option letter `2' with an argument of `5'. If indeed two -or more digits are supplied (`Optarg' looks like a number), `Optarg' is + The program begins with a 'usage()' function and then a brief outline +of the options and their meanings in comments. The 'BEGIN' rule deals +with the command-line arguments and options. It uses a trick to get +'getopt()' to handle options of the form '-25', treating such an option +as the option letter '2' with an argument of '5'. If indeed two or more +digits are supplied ('Optarg' looks like a number), 'Optarg' is concatenated with the option digit and then the result is added to zero to make it into a number. If there is only one digit in the option, -then `Optarg' is not needed. In this case, `Optind' must be decremented -so that `getopt()' processes it next time. This code is admittedly a +then 'Optarg' is not needed. In this case, 'Optind' must be decremented +so that 'getopt()' processes it next time. This code is admittedly a bit tricky. If no options are supplied, then the default is taken, to print both repeated and nonrepeated lines. The output file, if provided, is -assigned to `outputfile'. Early on, `outputfile' is initialized to the -standard output, `/dev/stdout': +assigned to 'outputfile'. Early on, 'outputfile' is initialized to the +standard output, '/dev/stdout': # uniq.awk --- do uniq in awk # @@ -17056,19 +16987,19 @@ standard output, `/dev/stdout': } } - The following function, `are_equal()', compares the current line, -`$0', to the previous line, `last'. It handles skipping fields and + The following function, 'are_equal()', compares the current line, +'$0', to the previous line, 'last'. It handles skipping fields and characters. If no field count and no character count are specified, -`are_equal()' simply returns one or zero depending upon the result of a -simple string comparison of `last' and `$0'. Otherwise, things get more +'are_equal()' simply returns one or zero depending upon the result of a +simple string comparison of 'last' and '$0'. Otherwise, things get more complicated. If fields have to be skipped, each line is broken into an -array using `split()' (*note String Functions::); the desired fields -are then joined back into a line using `join()'. The joined lines are -stored in `clast' and `cline'. If no fields are skipped, `clast' and -`cline' are set to `last' and `$0', respectively. Finally, if -characters are skipped, `substr()' is used to strip off the leading -`charcount' characters in `clast' and `cline'. The two strings are -then compared and `are_equal()' returns the result: +array using 'split()' (*note String Functions::); the desired fields are +then joined back into a line using 'join()'. The joined lines are +stored in 'clast' and 'cline'. If no fields are skipped, 'clast' and +'cline' are set to 'last' and '$0', respectively. Finally, if +characters are skipped, 'substr()' is used to strip off the leading +'charcount' characters in 'clast' and 'cline'. The two strings are then +compared and 'are_equal()' returns the result: function are_equal( n, m, clast, cline, alast, aline) { @@ -17093,23 +17024,23 @@ then compared and `are_equal()' returns the result: } The following two rules are the body of the program. The first one -is executed only for the very first line of data. It sets `last' equal -to `$0', so that subsequent lines of text have something to be compared +is executed only for the very first line of data. It sets 'last' equal +to '$0', so that subsequent lines of text have something to be compared to. - The second rule does the work. The variable `equal' is one or zero, -depending upon the results of `are_equal()''s comparison. If `uniq' is -counting repeated lines, and the lines are equal, then it increments -the `count' variable. Otherwise, it prints the line and resets `count', + The second rule does the work. The variable 'equal' is one or zero, +depending upon the results of 'are_equal()''s comparison. If 'uniq' is +counting repeated lines, and the lines are equal, then it increments the +'count' variable. Otherwise, it prints the line and resets 'count', since the two lines are not equal. - If `uniq' is not counting, and if the lines are equal, `count' is + If 'uniq' is not counting, and if the lines are equal, 'count' is incremented. Nothing is printed, since the point is to remove -duplicates. Otherwise, if `uniq' is counting repeated lines and more -than one line is seen, or if `uniq' is counting nonrepeated lines and -only one line is seen, then the line is printed, and `count' is reset. +duplicates. Otherwise, if 'uniq' is counting repeated lines and more +than one line is seen, or if 'uniq' is counting nonrepeated lines and +only one line is seen, then the line is printed, and 'count' is reset. - Finally, similar logic is used in the `END' rule to print the final + Finally, similar logic is used in the 'END' rule to print the final line of input data: NR == 1 { @@ -17157,44 +17088,44 @@ File: gawk.info, Node: Wc Program, Prev: Uniq Program, Up: Clones 11.2.7 Counting Things ---------------------- -The `wc' (word count) utility counts lines, words, and characters in -one or more input files. Its usage is as follows: +The 'wc' (word count) utility counts lines, words, and characters in one +or more input files. Its usage is as follows: - `wc' [`-lwc'] [FILES ...] + 'wc' ['-lwc'] [FILES ...] - If no files are specified on the command line, `wc' reads its -standard input. If there are multiple files, it also prints total + If no files are specified on the command line, 'wc' reads its +standard input. If there are multiple files, it also prints total counts for all the files. The options and their meanings are shown in the following list: -`-l' +'-l' Count only lines. -`-w' +'-w' Count only words. A "word" is a contiguous sequence of nonwhitespace characters, separated by spaces and/or TABs. - Luckily, this is the normal way `awk' separates fields in its - input data. + Luckily, this is the normal way 'awk' separates fields in its input + data. -`-c' +'-c' Count only characters. - Implementing `wc' in `awk' is particularly elegant, since `awk' does + Implementing 'wc' in 'awk' is particularly elegant, since 'awk' does a lot of the work for us; it splits lines into words (i.e., fields) and counts them, it counts lines (i.e., records), and it can easily tell us how long a line is. - This program uses the `getopt()' library function (*note Getopt + This program uses the 'getopt()' library function (*note Getopt Function::) and the file-transition functions (*note Filetrans Function::). This version has one notable difference from traditional versions of -`wc': it always prints the counts in the order lines, words, and -characters. Traditional versions note the order of the `-l', `-w', and -`-c' options on the command line, and print the counts in that order. +'wc': it always prints the counts in the order lines, words, and +characters. Traditional versions note the order of the '-l', '-w', and +'-c' options on the command line, and print the counts in that order. - The `BEGIN' rule does the argument processing. The variable -`print_total' is true if more than one file is named on the command + The 'BEGIN' rule does the argument processing. The variable +'print_total' is true if more than one file is named on the command line: # wc.awk --- count lines, words, characters @@ -17229,9 +17160,9 @@ line: print_total = (ARGC - i > 2) } - The `beginfile()' function is simple; it just resets the counts of + The 'beginfile()' function is simple; it just resets the counts of lines, words, and characters to zero, and saves the current file name in -`fname': +'fname': function beginfile(file) { @@ -17239,10 +17170,10 @@ lines, words, and characters to zero, and saves the current file name in fname = FILENAME } - The `endfile()' function adds the current file's numbers to the + The 'endfile()' function adds the current file's numbers to the running totals of lines, words, and characters. It then prints out -those numbers for the file that was just read. It relies on -`beginfile()' to reset the numbers for the following data file: +those numbers for the file that was just read. It relies on +'beginfile()' to reset the numbers for the following data file: function endfile(file) { @@ -17258,12 +17189,12 @@ those numbers for the file that was just read. It relies on printf "\t%s\n", fname } - There is one rule that is executed for each line. It adds the length -of the record, plus one, to `chars'.(1) Adding one plus the record + There is one rule that is executed for each line. It adds the length +of the record, plus one, to 'chars'.(1) Adding one plus the record length is needed because the newline character separating records (the -value of `RS') is not part of the record itself, and thus not included -in its length. Next, `lines' is incremented for each line read, and -`words' is incremented by the value of `NF', which is the number of +value of 'RS') is not part of the record itself, and thus not included +in its length. Next, 'lines' is incremented for each line read, and +'words' is incremented by the value of 'NF', which is the number of "words" on this line: # do per line @@ -17273,7 +17204,7 @@ in its length. Next, `lines' is incremented for each line read, and words += NF } - Finally, the `END' rule simply prints the totals for all the files: + Finally, the 'END' rule simply prints the totals for all the files: END { if (print_total) { @@ -17289,13 +17220,13 @@ in its length. Next, `lines' is incremented for each line read, and ---------- Footnotes ---------- - (1) Since `gawk' understands multibyte locales, this code counts + (1) Since 'gawk' understands multibyte locales, this code counts characters, not bytes.  File: gawk.info, Node: Miscellaneous Programs, Next: Programs Summary, Prev: Clones, Up: Sample Programs -11.3 A Grab Bag of `awk' Programs +11.3 A Grab Bag of 'awk' Programs ================================= This minor node is a large "grab bag" of miscellaneous programs. We @@ -17305,7 +17236,7 @@ hope you find them both interesting and enjoyable. * Dupword Program:: Finding duplicated words in a document. * Alarm Program:: An alarm clock. -* Translate Program:: A program similar to the `tr' utility. +* Translate Program:: A program similar to the 'tr' utility. * Labels Program:: Printing mailing labels. * Word Sorting:: A program to produce a word usage count. * History Sorting:: Eliminating duplicate entries from a history @@ -17313,7 +17244,7 @@ hope you find them both interesting and enjoyable. * Extract Program:: Pulling out programs from Texinfo source files. * Simple Sed:: A Simple Stream Editor. -* Igawk Program:: A wrapper for `awk' that includes +* Igawk Program:: A wrapper for 'awk' that includes files. * Anagram Program:: Finding anagrams from a dictionary. * Signature Program:: People do amazing things with too much time on @@ -17327,22 +17258,22 @@ File: gawk.info, Node: Dupword Program, Next: Alarm Program, Up: Miscellaneou A common error when writing large amounts of prose is to accidentally duplicate words. Typically you will see this in text as something like -"the the program does the following..." When the text is online, often +"the the program does the following..." When the text is online, often the duplicated words occur at the end of one line and the beginning of another, making them very difficult to spot. - This program, `dupword.awk', scans through a file one line at a time + This program, 'dupword.awk', scans through a file one line at a time and looks for adjacent occurrences of the same word. It also saves the -last word on a line (in the variable `prev') for comparison with the +last word on a line (in the variable 'prev') for comparison with the first word on the next line. - The first two statements make sure that the line is all lowercase, -so that, for example, "The" and "the" compare equal to each other. The + The first two statements make sure that the line is all lowercase, so +that, for example, "The" and "the" compare equal to each other. The next statement replaces nonalphanumeric and nonwhitespace characters with spaces, so that punctuation does not affect the comparison either. The characters are replaced with spaces so that formatting controls -don't create nonsense words (e.g., the Texinfo `@code{NF}' becomes -`codeNF' if punctuation is simply deleted). The record is then resplit +don't create nonsense words (e.g., the Texinfo '@code{NF}' becomes +'codeNF' if punctuation is simply deleted). The record is then resplit into fields, yielding just the actual words on the line, and ensuring that there are no empty fields. @@ -17373,30 +17304,30 @@ File: gawk.info, Node: Alarm Program, Next: Translate Program, Prev: Dupword 11.3.2 An Alarm Clock Program ----------------------------- - Nothing cures insomnia like a ringing alarm clock. -- Arnold - Robbins + Nothing cures insomnia like a ringing alarm clock. + -- _Arnold Robbins_ + Sleep is for web developers. + -- _Erik Quanstrom_ - Sleep is for web developers. -- Erik Quanstrom - - The following program is a simple "alarm clock" program. You give -it a time of day and an optional message. At the specified time, it -prints the message on the standard output. In addition, you can give it -the number of times to repeat the message as well as a delay between + The following program is a simple "alarm clock" program. You give it +a time of day and an optional message. At the specified time, it prints +the message on the standard output. In addition, you can give it the +number of times to repeat the message as well as a delay between repetitions. - This program uses the `getlocaltime()' function from *note + This program uses the 'getlocaltime()' function from *note Getlocaltime Function::. - All the work is done in the `BEGIN' rule. The first part is argument + All the work is done in the 'BEGIN' rule. The first part is argument checking and setting of defaults: the delay, the count, and the message to print. If the user supplied a message without the ASCII BEL -character (known as the "alert" character, `"\a"'), then it is added to +character (known as the "alert" character, '"\a"'), then it is added to the message. (On many systems, printing the ASCII BEL generates an -audible alert. Thus when the alarm goes off, the system calls attention +audible alert. Thus when the alarm goes off, the system calls attention to itself in case the user is not looking at the computer.) Just for a -change, this program uses a `switch' statement (*note Switch +change, this program uses a 'switch' statement (*note Switch Statement::), but the processing could be done with a series of -`if'-`else' statements instead. Here is the program: +'if'-'else' statements instead. Here is the program: # alarm.awk --- set an alarm # @@ -17445,10 +17376,9 @@ Statement::), but the processing could be done with a series of The next minor node of code turns the alarm time into hours and minutes, converts it (if necessary) to a 24-hour clock, and then turns -that time into a count of the seconds since midnight. Next it turns -the current time into a count of seconds since midnight. The -difference between the two is how long to wait before setting off the -alarm: +that time into a count of the seconds since midnight. Next it turns the +current time into a count of seconds since midnight. The difference +between the two is how long to wait before setting off the alarm: # split up alarm time split(ARGV[1], atime, ":") @@ -17478,12 +17408,12 @@ alarm: exit 1 } - Finally, the program uses the `system()' function (*note I/O -Functions::) to call the `sleep' utility. The `sleep' utility simply + Finally, the program uses the 'system()' function (*note I/O +Functions::) to call the 'sleep' utility. The 'sleep' utility simply pauses for the given number of seconds. If the exit status is not zero, -the program assumes that `sleep' was interrupted and exits. If `sleep' +the program assumes that 'sleep' was interrupted and exits. If 'sleep' exited with an OK status (zero), then the program prints the message in -a loop, again using `sleep' to delay for however many seconds are +a loop, again using 'sleep' to delay for however many seconds are necessary: # zzzzzz..... go away if interrupted @@ -17508,14 +17438,14 @@ File: gawk.info, Node: Translate Program, Next: Labels Program, Prev: Alarm P 11.3.3 Transliterating Characters --------------------------------- -The system `tr' utility transliterates characters. For example, it is +The system 'tr' utility transliterates characters. For example, it is often used to map uppercase letters into lowercase for further processing: GENERATE DATA | tr 'A-Z' 'a-z' | PROCESS DATA ... - `tr' requires two lists of characters.(1) When processing the -input, the first character in the first list is replaced with the first + 'tr' requires two lists of characters.(1) When processing the input, +the first character in the first list is replaced with the first character in the second list, the second character in the first list is replaced with the second character in the second list, and so on. If there are more characters in the "from" list than in the "to" list, the @@ -17523,38 +17453,38 @@ last character of the "to" list is used for the remaining characters in the "from" list. Once upon a time, a user proposed that a transliteration function -should be added to `gawk'. The following program was written to prove -that character transliteration could be done with a user-level -function. This program is not as complete as the system `tr' utility -but it does most of the job. - - The `translate' program demonstrates one of the few weaknesses of -standard `awk': dealing with individual characters is very painful, -requiring repeated use of the `substr()', `index()', and `gsub()' -built-in functions (*note String Functions::).(2) There are two -functions. The first, `stranslate()', takes three arguments: - -`from' +should be added to 'gawk'. The following program was written to prove +that character transliteration could be done with a user-level function. +This program is not as complete as the system 'tr' utility but it does +most of the job. + + The 'translate' program demonstrates one of the few weaknesses of +standard 'awk': dealing with individual characters is very painful, +requiring repeated use of the 'substr()', 'index()', and 'gsub()' +built-in functions (*note String Functions::).(2) There are two +functions. The first, 'stranslate()', takes three arguments: + +'from' A list of characters from which to translate. -`to' +'to' A list of characters to which to translate. -`target' +'target' The string on which to do the translation. - Associative arrays make the translation part fairly easy. `t_ar' + Associative arrays make the translation part fairly easy. 't_ar' holds the "to" characters, indexed by the "from" characters. Then a -simple loop goes through `from', one character at a time. For each -character in `from', if the character appears in `target', it is -replaced with the corresponding `to' character. +simple loop goes through 'from', one character at a time. For each +character in 'from', if the character appears in 'target', it is +replaced with the corresponding 'to' character. - The `translate()' function simply calls `stranslate()' using `$0' as -the target. The main program sets two global variables, `FROM' and -`TO', from the command line, and then changes `ARGV' so that `awk' -reads from the standard input. + The 'translate()' function simply calls 'stranslate()' using '$0' as +the target. The main program sets two global variables, 'FROM' and +'TO', from the command line, and then changes 'ARGV' so that 'awk' reads +from the standard input. - Finally, the processing rule simply calls `translate()' for each + Finally, the processing rule simply calls 'translate()' for each record: # translate.awk --- do tr-like stuff @@ -17605,27 +17535,27 @@ record: } While it is possible to do character transliteration in a user-level -function, it is not necessarily efficient, and we (the `gawk' authors) +function, it is not necessarily efficient, and we (the 'gawk' authors) started to consider adding a built-in function. However, shortly after writing this program, we learned that Brian Kernighan had added the -`toupper()' and `tolower()' functions to his `awk' (*note String +'toupper()' and 'tolower()' functions to his 'awk' (*note String Functions::). These functions handle the vast majority of the cases where character transliteration is necessary, and so we chose to simply -add those functions to `gawk' as well and then leave well enough alone. +add those functions to 'gawk' as well and then leave well enough alone. - An obvious improvement to this program would be to set up the `t_ar' -array only once, in a `BEGIN' rule. However, this assumes that the + An obvious improvement to this program would be to set up the 't_ar' +array only once, in a 'BEGIN' rule. However, this assumes that the "from" and "to" lists will never change throughout the lifetime of the program. ---------- Footnotes ---------- (1) On some older systems, including Solaris, the system version of -`tr' may require that the lists be written as range expressions -enclosed in square brackets (`[a-z]') and quoted, to prevent the shell -from attempting a file name expansion. This is not a feature. +'tr' may require that the lists be written as range expressions enclosed +in square brackets ('[a-z]') and quoted, to prevent the shell from +attempting a file name expansion. This is not a feature. - (2) This program was written before `gawk' acquired the ability to + (2) This program was written before 'gawk' acquired the ability to split each character in a string into separate array elements.  @@ -17640,25 +17570,25 @@ labels on it, two across and 10 down. The addresses are guaranteed to be no more than five lines of data. Each address is separated from the next by a blank line. - The basic idea is to read 20 labels worth of data. Each line of -each label is stored in the `line' array. The single rule takes care -of filling the `line' array and printing the page when 20 labels have -been read. + The basic idea is to read 20 labels worth of data. Each line of each +label is stored in the 'line' array. The single rule takes care of +filling the 'line' array and printing the page when 20 labels have been +read. - The `BEGIN' rule simply sets `RS' to the empty string, so that `awk' -splits records at blank lines (*note Records::). It sets `MAXLINES' to + The 'BEGIN' rule simply sets 'RS' to the empty string, so that 'awk' +splits records at blank lines (*note Records::). It sets 'MAXLINES' to 100, since 100 is the maximum number of lines on the page (20 * 5 = 100). - Most of the work is done in the `printpage()' function. The label -lines are stored sequentially in the `line' array. But they have to -print horizontally; `line[1]' next to `line[6]', `line[2]' next to -`line[7]', and so on. Two loops are used to accomplish this. The -outer loop, controlled by `i', steps through every 10 lines of data; -this is each row of labels. The inner loop, controlled by `j', goes -through the lines within the row. As `j' goes from 0 to 4, `i+j' is -the `j'-th line in the row, and `i+j+5' is the entry next to it. The -output ends up looking something like this: + Most of the work is done in the 'printpage()' function. The label +lines are stored sequentially in the 'line' array. But they have to +print horizontally; 'line[1]' next to 'line[6]', 'line[2]' next to +'line[7]', and so on. Two loops are used to accomplish this. The outer +loop, controlled by 'i', steps through every 10 lines of data; this is +each row of labels. The inner loop, controlled by 'j', goes through the +lines within the row. As 'j' goes from 0 to 4, 'i+j' is the 'j'-th line +in the row, and 'i+j+5' is the entry next to it. The output ends up +looking something like this: line 1 line 6 line 2 line 7 @@ -17667,7 +17597,7 @@ output ends up looking something like this: line 5 line 10 ... -The `printf' format string `%-41s' left-aligns the data and prints it +The 'printf' format string '%-41s' left-aligns the data and prints it within a fixed-width field. As a final note, an extra blank line is printed at lines 21 and 61, @@ -17676,7 +17606,7 @@ particular brand of labels in use when the program was written. You will also note that there are two blank lines at the top and two blank lines at the bottom. - The `END' rule arranges to flush the final page of labels; there may + The 'END' rule arranges to flush the final page of labels; there may not have been an even multiple of 20 labels in the data: # labels.awk --- print mailing labels @@ -17744,9 +17674,9 @@ File: gawk.info, Node: Word Sorting, Next: History Sorting, Prev: Labels Prog When working with large amounts of text, it can be interesting to know how often different words appear. For example, an author may overuse certain words, in which case he or she might wish to find synonyms to -substitute for words that appear too often. This node develops a -program for counting words and presenting the frequency information in -a useful format. +substitute for words that appear too often. This node develops a +program for counting words and presenting the frequency information in a +useful format. At first glance, a program like this would seem to do the job: @@ -17762,33 +17692,33 @@ a useful format. printf "%s\t%d\n", word, freq[word] } - The program relies on `awk''s default field splitting mechanism to + The program relies on 'awk''s default field splitting mechanism to break each line up into "words," and uses an associative array named -`freq', indexed by each word, to count the number of times the word -occurs. In the `END' rule, it prints the counts. +'freq', indexed by each word, to count the number of times the word +occurs. In the 'END' rule, it prints the counts. This program has several problems that prevent it from being useful on real text files: - * The `awk' language considers upper- and lowercase characters to be + * The 'awk' language considers upper- and lowercase characters to be distinct. Therefore, "bartender" and "Bartender" are not treated as the same word. This is undesirable, since in normal text, words are capitalized if they begin sentences, and a frequency analyzer should not be sensitive to capitalization. - * Words are detected using the `awk' convention that fields are + * Words are detected using the 'awk' convention that fields are separated just by whitespace. Other characters in the input - (except newlines) don't have any special meaning to `awk'. This + (except newlines) don't have any special meaning to 'awk'. This means that punctuation characters count as part of words. * The output does not come out in any useful order. You're more likely to be interested in which words occur most frequently or in having an alphabetized table of how frequently each word occurs. - The first problem can be solved by using `tolower()' to remove case -distinctions. The second problem can be solved by using `gsub()' to + The first problem can be solved by using 'tolower()' to remove case +distinctions. The second problem can be solved by using 'gsub()' to remove punctuation characters. Finally, we solve the third problem by -using the system `sort' utility to process the output of the `awk' +using the system 'sort' utility to process the output of the 'awk' script. Here is the new version of the program: # wordfreq.awk --- print list of word frequencies @@ -17806,30 +17736,29 @@ script. Here is the new version of the program: printf "%s\t%d\n", word, freq[word] } - The regexp `/[^[:alnum:]_[:blank:]]/' might have been written -`/[[:punct:]]/', but then underscores would also be removed, and we -want to keep them. + The regexp '/[^[:alnum:]_[:blank:]]/' might have been written +'/[[:punct:]]/', but then underscores would also be removed, and we want +to keep them. - Assuming we have saved this program in a file named `wordfreq.awk', -and that the data is in `file1', the following pipeline: + Assuming we have saved this program in a file named 'wordfreq.awk', +and that the data is in 'file1', the following pipeline: awk -f wordfreq.awk file1 | sort -k 2nr -produces a table of the words appearing in `file1' in order of +produces a table of the words appearing in 'file1' in order of decreasing frequency. - The `awk' program suitably massages the data and produces a word -frequency table, which is not ordered. The `awk' script's output is -then sorted by the `sort' utility and printed on the screen. + The 'awk' program suitably massages the data and produces a word +frequency table, which is not ordered. The 'awk' script's output is +then sorted by the 'sort' utility and printed on the screen. - The options given to `sort' specify a sort that uses the second -field of each input line (skipping one field), that the sort keys -should be treated as numeric quantities (otherwise `15' would come -before `5'), and that the sorting should be done in descending -(reverse) order. + The options given to 'sort' specify a sort that uses the second field +of each input line (skipping one field), that the sort keys should be +treated as numeric quantities (otherwise '15' would come before '5'), +and that the sorting should be done in descending (reverse) order. - The `sort' could even be done from within the program, by changing -the `END' action to: + The 'sort' could even be done from within the program, by changing +the 'END' action to: END { sort = "sort -k 2nr" @@ -17841,7 +17770,7 @@ the `END' action to: This way of sorting must be used on systems that do not have true pipes at the command-line (or batch-file) level. See the general operating system documentation for more information on how to use the -`sort' program. +'sort' program.  File: gawk.info, Node: History Sorting, Next: Extract Program, Prev: Word Sorting, Up: Miscellaneous Programs @@ -17849,24 +17778,24 @@ File: gawk.info, Node: History Sorting, Next: Extract Program, Prev: Word Sor 11.3.6 Removing Duplicates from Unsorted Text --------------------------------------------- -The `uniq' program (*note Uniq Program::), removes duplicate lines from +The 'uniq' program (*note Uniq Program::), removes duplicate lines from _sorted_ data. - Suppose, however, you need to remove duplicate lines from a data -file but that you want to preserve the order the lines are in. A good -example of this might be a shell history file. The history file keeps -a copy of all the commands you have entered, and it is not unusual to -repeat a command several times in a row. Occasionally you might want -to compact the history by removing duplicate entries. Yet it is -desirable to maintain the order of the original commands. - - This simple program does the job. It uses two arrays. The `data' -array is indexed by the text of each line. For each line, `data[$0]' -is incremented. If a particular line has not been seen before, then -`data[$0]' is zero. In this case, the text of the line is stored in -`lines[count]'. Each element of `lines' is a unique command, and the -indices of `lines' indicate the order in which those lines are -encountered. The `END' rule simply prints out the lines, in order: + Suppose, however, you need to remove duplicate lines from a data file +but that you want to preserve the order the lines are in. A good +example of this might be a shell history file. The history file keeps a +copy of all the commands you have entered, and it is not unusual to +repeat a command several times in a row. Occasionally you might want to +compact the history by removing duplicate entries. Yet it is desirable +to maintain the order of the original commands. + + This simple program does the job. It uses two arrays. The 'data' +array is indexed by the text of each line. For each line, 'data[$0]' is +incremented. If a particular line has not been seen before, then +'data[$0]' is zero. In this case, the text of the line is stored in +'lines[count]'. Each element of 'lines' is a unique command, and the +indices of 'lines' indicate the order in which those lines are +encountered. The 'END' rule simply prints out the lines, in order: # histsort.awk --- compact a shell history file # Thanks to Byron Rakitzis for the general idea @@ -17882,12 +17811,12 @@ encountered. The `END' rule simply prints out the lines, in order: } This program also provides a foundation for generating other useful -information. For example, using the following `print' statement in the -`END' rule indicates how often a particular command is used: +information. For example, using the following 'print' statement in the +'END' rule indicates how often a particular command is used: print data[lines[i]], lines[i] -This works because `data[$0]' is incremented each time a line is seen. +This works because 'data[$0]' is incremented each time a line is seen.  File: gawk.info, Node: Extract Program, Next: Simple Sed, Prev: History Sorting, Up: Miscellaneous Programs @@ -17896,51 +17825,51 @@ File: gawk.info, Node: Extract Program, Next: Simple Sed, Prev: History Sorti ---------------------------------------------------- The nodes *note Library Functions::, and *note Sample Programs::, are -the top level nodes for a large number of `awk' programs. If you want -to experiment with these programs, it is tedious to have to type them -in by hand. Here we present a program that can extract parts of a -Texinfo input file into separate files. +the top level nodes for a large number of 'awk' programs. If you want +to experiment with these programs, it is tedious to have to type them in +by hand. Here we present a program that can extract parts of a Texinfo +input file into separate files. -This Info file is written in Texinfo + This Info file is written in Texinfo (http://www.gnu.org/software/texinfo/), the GNU project's document formatting language. A single Texinfo source file can be used to produce both printed and online documentation. The Texinfo language is -described fully, starting with *note (Texinfo)Top:: -texinfo,Texinfo--The GNU Documentation Format. +described fully, starting with *note (Texinfo, texinfo,Texinfo---The GNU +Documentation Format)Top::. For our purposes, it is enough to know three things about Texinfo input files: - * The "at" symbol (`@') is special in Texinfo, much as the backslash - (`\') is in C or `awk'. Literal `@' symbols are represented in - Texinfo source files as `@@'. + * The "at" symbol ('@') is special in Texinfo, much as the backslash + ('\') is in C or 'awk'. Literal '@' symbols are represented in + Texinfo source files as '@@'. - * Comments start with either `@c' or `@comment'. The - file-extraction program works by using special comments that start - at the beginning of a line. + * Comments start with either '@c' or '@comment'. The file-extraction + program works by using special comments that start at the beginning + of a line. - * Lines containing `@group' and `@end group' commands bracket - example text that should not be split across a page boundary. + * Lines containing '@group' and '@end group' commands bracket example + text that should not be split across a page boundary. (Unfortunately, TeX isn't always smart enough to do things exactly right, so we have to give it some help.) - The following program, `extract.awk', reads through a Texinfo source + The following program, 'extract.awk', reads through a Texinfo source file and does two things, based on the special comments. Upon seeing -`@c system ...', it runs a command, by extracting the command text from -the control line and passing it on to the `system()' function (*note -I/O Functions::). Upon seeing `@c file FILENAME', each subsequent line -is sent to the file FILENAME, until `@c endfile' is encountered. The -rules in `extract.awk' match either `@c' or `@comment' by letting the -`omment' part be optional. Lines containing `@group' and `@end group' -are simply removed. `extract.awk' uses the `join()' library function -(*note Join Function::). +'@c system ...', it runs a command, by extracting the command text from +the control line and passing it on to the 'system()' function (*note I/O +Functions::). Upon seeing '@c file FILENAME', each subsequent line is +sent to the file FILENAME, until '@c endfile' is encountered. The rules +in 'extract.awk' match either '@c' or '@comment' by letting the 'omment' +part be optional. Lines containing '@group' and '@end group' are simply +removed. 'extract.awk' uses the 'join()' library function (*note Join +Function::). - The example programs in the online Texinfo source for `GAWK: -Effective AWK Programming' (`gawktexi.in') have all been bracketed -inside `file' and `endfile' lines. The `gawk' distribution uses a copy -of `extract.awk' to extract the sample programs and install many of -them in a standard directory where `gawk' can find them. The Texinfo -file looks something like this: + The example programs in the online Texinfo source for 'GAWK: +Effective AWK Programming' ('gawktexi.in') have all been bracketed +inside 'file' and 'endfile' lines. The 'gawk' distribution uses a copy +of 'extract.awk' to extract the sample programs and install many of them +in a standard directory where 'gawk' can find them. The Texinfo file +looks something like this: ... This program has a @code{BEGIN} rule, @@ -17961,11 +17890,11 @@ file looks something like this: @end example ... - `extract.awk' begins by setting `IGNORECASE' to one, so that mixed + 'extract.awk' begins by setting 'IGNORECASE' to one, so that mixed upper- and lowercase letters in the directives won't matter. - The first rule handles calling `system()', checking that a command is -given (`NF' is at least three) and also checking that the command exits + The first rule handles calling 'system()', checking that a command is +given ('NF' is at least three) and also checking that the command exits with a zero exit status, signifying OK: # extract.awk --- extract files and run programs @@ -17991,36 +17920,34 @@ with a zero exit status, signifying OK: } } -The variable `e' is used so that the rule fits nicely on the screen. +The variable 'e' is used so that the rule fits nicely on the screen. The second rule handles moving data into files. It verifies that a file name is given in the directive. If the file named is not the current file, then the current file is closed. Keeping the current file -open until a new file is encountered allows the use of the `>' +open until a new file is encountered allows the use of the '>' redirection for printing the contents, keeping open file management simple. - The `for' loop does the work. It reads lines using `getline' (*note + The 'for' loop does the work. It reads lines using 'getline' (*note Getline::). For an unexpected end of file, it calls the -`unexpected_eof()' function. If the line is an "endfile" line, then it -breaks out of the loop. If the line is an `@group' or `@end group' +'unexpected_eof()' function. If the line is an "endfile" line, then it +breaks out of the loop. If the line is an '@group' or '@end group' line, then it ignores it and goes on to the next line. Similarly, comments within examples are also ignored. Most of the work is in the following few lines. If the line has no -`@' symbols, the program can print it directly. Otherwise, each -leading `@' must be stripped off. To remove the `@' symbols, the line -is split into separate elements of the array `a', using the `split()' -function (*note String Functions::). The `@' symbol is used as the -separator character. Each element of `a' that is empty indicates two -successive `@' symbols in the original line. For each two empty -elements (`@@' in the original file), we have to add a single `@' -symbol back in. - - When the processing of the array is finished, `join()' is called -with the value of `SUBSEP' (*note Multidimensional::), to rejoin the -pieces back into a single line. That line is then printed to the -output file: +'@' symbols, the program can print it directly. Otherwise, each leading +'@' must be stripped off. To remove the '@' symbols, the line is split +into separate elements of the array 'a', using the 'split()' function +(*note String Functions::). The '@' symbol is used as the separator +character. Each element of 'a' that is empty indicates two successive +'@' symbols in the original line. For each two empty elements ('@@' in +the original file), we have to add a single '@' symbol back in. + + When the processing of the array is finished, 'join()' is called with +the value of 'SUBSEP' (*note Multidimensional::), to rejoin the pieces +back into a single line. That line is then printed to the output file: /^@c(omment)?[ \t]+file/ \ { @@ -18062,16 +17989,16 @@ output file: } } - An important thing to note is the use of the `>' redirection. -Output done with `>' only opens the file once; it stays open and -subsequent output is appended to the file (*note Redirection::). This -makes it easy to mix program text and explanatory prose for the same -sample source file (as has been done here!) without any hassle. The -file is only closed when a new data file name is encountered or at the -end of the input file. + An important thing to note is the use of the '>' redirection. Output +done with '>' only opens the file once; it stays open and subsequent +output is appended to the file (*note Redirection::). This makes it +easy to mix program text and explanatory prose for the same sample +source file (as has been done here!) without any hassle. The file is +only closed when a new data file name is encountered or at the end of +the input file. - Finally, the function `unexpected_eof()' prints an appropriate error -message and then exits. The `END' rule handles the final cleanup, + Finally, the function 'unexpected_eof()' prints an appropriate error +message and then exits. The 'END' rule handles the final cleanup, closing the open file: function unexpected_eof() @@ -18092,24 +18019,24 @@ File: gawk.info, Node: Simple Sed, Next: Igawk Program, Prev: Extract Program 11.3.8 A Simple Stream Editor ----------------------------- -The `sed' utility is a stream editor, a program that reads a stream of +The 'sed' utility is a stream editor, a program that reads a stream of data, makes changes to it, and passes it on. It is often used to make global changes to a large file or to a stream of data generated by a -pipeline of commands. While `sed' is a complicated program in its own +pipeline of commands. While 'sed' is a complicated program in its own right, its most common use is to perform global substitutions in the middle of a pipeline: command1 < orig.data | sed 's/old/new/g' | command2 > result - Here, `s/old/new/g' tells `sed' to look for the regexp `old' on each -input line and globally replace it with the text `new', i.e., all the -occurrences on a line. This is similar to `awk''s `gsub()' function + Here, 's/old/new/g' tells 'sed' to look for the regexp 'old' on each +input line and globally replace it with the text 'new', i.e., all the +occurrences on a line. This is similar to 'awk''s 'gsub()' function (*note String Functions::). - The following program, `awksed.awk', accepts at least two + The following program, 'awksed.awk', accepts at least two command-line arguments: the pattern to look for and the text to replace -it with. Any additional arguments are treated as data file names to -process. If none are provided, the standard input is used: +it with. Any additional arguments are treated as data file names to +process. If none are provided, the standard input is used: # awksed.awk --- do s/foo/bar/g using just print # Thanks to Michael Brennan for the idea @@ -18140,32 +18067,32 @@ process. If none are provided, the standard input is used: print } - The program relies on `gawk''s ability to have `RS' be a regexp, as -well as on the setting of `RT' to the actual text that terminates the + The program relies on 'gawk''s ability to have 'RS' be a regexp, as +well as on the setting of 'RT' to the actual text that terminates the record (*note Records::). - The idea is to have `RS' be the pattern to look for. `gawk' -automatically sets `$0' to the text between matches of the pattern. -This is text that we want to keep, unmodified. Then, by setting `ORS' -to the replacement text, a simple `print' statement outputs the text we + The idea is to have 'RS' be the pattern to look for. 'gawk' +automatically sets '$0' to the text between matches of the pattern. +This is text that we want to keep, unmodified. Then, by setting 'ORS' +to the replacement text, a simple 'print' statement outputs the text we want to keep, followed by the replacement text. There is one wrinkle to this scheme, which is what to do if the last -record doesn't end with text that matches `RS'. Using a `print' +record doesn't end with text that matches 'RS'. Using a 'print' statement unconditionally prints the replacement text, which is not -correct. However, if the file did not end in text that matches `RS', -`RT' is set to the null string. In this case, we can print `$0' using -`printf' (*note Printf::). - - The `BEGIN' rule handles the setup, checking for the right number of -arguments and calling `usage()' if there is a problem. Then it sets -`RS' and `ORS' from the command-line arguments and sets `ARGV[1]' and -`ARGV[2]' to the null string, so that they are not treated as file names +correct. However, if the file did not end in text that matches 'RS', +'RT' is set to the null string. In this case, we can print '$0' using +'printf' (*note Printf::). + + The 'BEGIN' rule handles the setup, checking for the right number of +arguments and calling 'usage()' if there is a problem. Then it sets +'RS' and 'ORS' from the command-line arguments and sets 'ARGV[1]' and +'ARGV[2]' to the null string, so that they are not treated as file names (*note ARGC and ARGV::). - The `usage()' function prints an error message and exits. Finally, + The 'usage()' function prints an error message and exits. Finally, the single rule handles the printing scheme outlined above, using -`print' or `printf' as appropriate, depending upon the value of `RT'. +'print' or 'printf' as appropriate, depending upon the value of 'RT'.  File: gawk.info, Node: Igawk Program, Next: Anagram Program, Prev: Simple Sed, Up: Miscellaneous Programs @@ -18173,18 +18100,18 @@ File: gawk.info, Node: Igawk Program, Next: Anagram Program, Prev: Simple Sed 11.3.9 An Easy Way to Use Library Functions ------------------------------------------- -In *note Include Files::, we saw how `gawk' provides a built-in -file-inclusion capability. However, this is a `gawk' extension. This +In *note Include Files::, we saw how 'gawk' provides a built-in +file-inclusion capability. However, this is a 'gawk' extension. This minor node provides the motivation for making file inclusion available -for standard `awk', and shows how to do it using a combination of shell -and `awk' programming. - - Using library functions in `awk' can be very beneficial. It -encourages code reuse and the writing of general functions. Programs are -smaller and therefore clearer. However, using library functions is -only easy when writing `awk' programs; it is painful when running them, -requiring multiple `-f' options. If `gawk' is unavailable, then so too -is the `AWKPATH' environment variable and the ability to put `awk' +for standard 'awk', and shows how to do it using a combination of shell +and 'awk' programming. + + Using library functions in 'awk' can be very beneficial. It +encourages code reuse and the writing of general functions. Programs +are smaller and therefore clearer. However, using library functions is +only easy when writing 'awk' programs; it is painful when running them, +requiring multiple '-f' options. If 'gawk' is unavailable, then so too +is the 'AWKPATH' environment variable and the ability to put 'awk' functions into a library directory (*note Options::). It would be nice to be able to write programs in the following manner: @@ -18200,93 +18127,93 @@ to be able to write programs in the following manner: ... } - The following program, `igawk.sh', provides this service. It -simulates `gawk''s searching of the `AWKPATH' variable and also allows -"nested" includes; i.e., a file that is included with `@include' can -contain further `@include' statements. `igawk' makes an effort to only -include files once, so that nested includes don't accidentally include -a library function twice. + The following program, 'igawk.sh', provides this service. It +simulates 'gawk''s searching of the 'AWKPATH' variable and also allows +"nested" includes; i.e., a file that is included with '@include' can +contain further '@include' statements. 'igawk' makes an effort to only +include files once, so that nested includes don't accidentally include a +library function twice. - `igawk' should behave just like `gawk' externally. This means it -should accept all of `gawk''s command-line arguments, including the -ability to have multiple source files specified via `-f', and the + 'igawk' should behave just like 'gawk' externally. This means it +should accept all of 'gawk''s command-line arguments, including the +ability to have multiple source files specified via '-f', and the ability to mix command-line and library source files. - The program is written using the POSIX Shell (`sh') command -language.(1) It works as follows: + The program is written using the POSIX Shell ('sh') command +language.(1) It works as follows: 1. Loop through the arguments, saving anything that doesn't represent - `awk' source code for later, when the expanded program is run. + 'awk' source code for later, when the expanded program is run. - 2. For any arguments that do represent `awk' text, put the arguments + 2. For any arguments that do represent 'awk' text, put the arguments into a shell variable that will be expanded. There are two cases: - a. Literal text, provided with `--source' or `--source='. This + a. Literal text, provided with '--source' or '--source='. This text is just appended directly. - b. Source file names, provided with `-f'. We use a neat trick - and append `@include FILENAME' to the shell variable's + b. Source file names, provided with '-f'. We use a neat trick + and append '@include FILENAME' to the shell variable's contents. Since the file-inclusion program works the way - `gawk' does, this gets the text of the file included into the + 'gawk' does, this gets the text of the file included into the program at the correct point. - 3. Run an `awk' program (naturally) over the shell variable's - contents to expand `@include' statements. The expanded program is - placed in a second shell variable. + 3. Run an 'awk' program (naturally) over the shell variable's contents + to expand '@include' statements. The expanded program is placed in + a second shell variable. - 4. Run the expanded program with `gawk' and any other original + 4. Run the expanded program with 'gawk' and any other original command-line arguments that the user supplied (such as the data file names). This program uses shell variables extensively: for storing -command-line arguments, the text of the `awk' program that will expand +command-line arguments, the text of the 'awk' program that will expand the user's program, for the user's original program, and for the expanded program. Doing so removes some potential problems that might arise were we to use temporary files instead, at the cost of making the script somewhat more complicated. The initial part of the program turns on shell tracing if the first -argument is `debug'. +argument is 'debug'. The next part loops through all the command-line arguments. There are several cases of interest: -`--' - This ends the arguments to `igawk'. Anything else should be - passed on to the user's `awk' program without being evaluated. +'--' + This ends the arguments to 'igawk'. Anything else should be passed + on to the user's 'awk' program without being evaluated. -`-W' - This indicates that the next option is specific to `gawk'. To make - argument processing easier, the `-W' is appended to the front of - the remaining arguments and the loop continues. (This is an `sh' +'-W' + This indicates that the next option is specific to 'gawk'. To make + argument processing easier, the '-W' is appended to the front of + the remaining arguments and the loop continues. (This is an 'sh' programming trick. Don't worry about it if you are not familiar - with `sh'.) + with 'sh'.) -`-v', `-F' - These are saved and passed on to `gawk'. +'-v', '-F' + These are saved and passed on to 'gawk'. -`-f', `--file', `--file=', `-Wfile=' - The file name is appended to the shell variable `program' with an - `@include' statement. The `expr' utility is used to remove the - leading option part of the argument (e.g., `--file='). (Typical - `sh' usage would be to use the `echo' and `sed' utilities to do - this work. Unfortunately, some versions of `echo' evaluate escape +'-f', '--file', '--file=', '-Wfile=' + The file name is appended to the shell variable 'program' with an + '@include' statement. The 'expr' utility is used to remove the + leading option part of the argument (e.g., '--file='). (Typical + 'sh' usage would be to use the 'echo' and 'sed' utilities to do + this work. Unfortunately, some versions of 'echo' evaluate escape sequences in their arguments, possibly mangling the program text. - Using `expr' avoids this problem.) + Using 'expr' avoids this problem.) -`--source', `--source=', `-Wsource=' - The source text is appended to `program'. +'--source', '--source=', '-Wsource=' + The source text is appended to 'program'. -`--version', `-Wversion' - `igawk' prints its version number, runs `gawk --version' to get - the `gawk' version information, and then exits. +'--version', '-Wversion' + 'igawk' prints its version number, runs 'gawk --version' to get the + 'gawk' version information, and then exits. - If none of the `-f', `--file', `-Wfile', `--source', or `-Wsource' + If none of the '-f', '--file', '-Wfile', '--source', or '-Wsource' arguments are supplied, then the first nonoption argument should be the -`awk' program. If there are no command-line arguments left, `igawk' +'awk' program. If there are no command-line arguments left, 'igawk' prints an error message and exits. Otherwise, the first argument is -appended to `program'. In any case, after the arguments have been -processed, `program' contains the complete text of the original `awk' +appended to 'program'. In any case, after the arguments have been +processed, 'program' contains the complete text of the original 'awk' program. The program is as follows: @@ -18367,27 +18294,27 @@ program. # At this point, `program' has the program. - The `awk' program to process `@include' directives is stored in the -shell variable `expand_prog'. Doing this keeps the shell script -readable. The `awk' program reads through the user's program, one line -at a time, using `getline' (*note Getline::). The input file names and -`@include' statements are managed using a stack. As each `@include' is + The 'awk' program to process '@include' directives is stored in the +shell variable 'expand_prog'. Doing this keeps the shell script +readable. The 'awk' program reads through the user's program, one line +at a time, using 'getline' (*note Getline::). The input file names and +'@include' statements are managed using a stack. As each '@include' is encountered, the current file name is "pushed" onto the stack and the -file named in the `@include' directive becomes the current file name. +file named in the '@include' directive becomes the current file name. As each file is finished, the stack is "popped," and the previous input file becomes the current input file again. The process is started by making the original file the first one on the stack. - The `pathto()' function does the work of finding the full path to a -file. It simulates `gawk''s behavior when searching the `AWKPATH' + The 'pathto()' function does the work of finding the full path to a +file. It simulates 'gawk''s behavior when searching the 'AWKPATH' environment variable (*note AWKPATH Variable::). If a file name has a -`/' in it, no path search is done. Similarly, if the file name is -`"-"', then that string is used as-is. Otherwise, the file name is -concatenated with the name of each directory in the path, and an -attempt is made to open the generated file name. The only way to test -if a file can be read in `awk' is to go ahead and try to read it with -`getline'; this is what `pathto()' does.(2) If the file can be read, it -is closed and the file name is returned: +'/' in it, no path search is done. Similarly, if the file name is +'"-"', then that string is used as-is. Otherwise, the file name is +concatenated with the name of each directory in the path, and an attempt +is made to open the generated file name. The only way to test if a file +can be read in 'awk' is to go ahead and try to read it with 'getline'; +this is what 'pathto()' does.(2) If the file can be read, it is closed +and the file name is returned: expand_prog=' @@ -18410,9 +18337,9 @@ is closed and the file name is returned: return "" } - The main program is contained inside one `BEGIN' rule. The first -thing it does is set up the `pathlist' array that `pathto()' uses. -After splitting the path on `:', null elements are replaced with `"."', + The main program is contained inside one 'BEGIN' rule. The first +thing it does is set up the 'pathlist' array that 'pathto()' uses. +After splitting the path on ':', null elements are replaced with '"."', which represents the current directory: BEGIN { @@ -18423,21 +18350,21 @@ which represents the current directory: pathlist[i] = "." } - The stack is initialized with `ARGV[1]', which will be -`"/dev/stdin"'. The main loop comes next. Input lines are read in -succession. Lines that do not start with `@include' are printed -verbatim. If the line does start with `@include', the file name is in -`$2'. `pathto()' is called to generate the full path. If it cannot, + The stack is initialized with 'ARGV[1]', which will be +'"/dev/stdin"'. The main loop comes next. Input lines are read in +succession. Lines that do not start with '@include' are printed +verbatim. If the line does start with '@include', the file name is in +'$2'. 'pathto()' is called to generate the full path. If it cannot, then the program prints an error message and continues. The next thing to check is if the file is included already. The -`processed' array is indexed by the full file name of each included -file and it tracks this information for us. If the file is seen again, -a warning message is printed. Otherwise, the new file name is pushed -onto the stack and processing continues. +'processed' array is indexed by the full file name of each included file +and it tracks this information for us. If the file is seen again, a +warning message is printed. Otherwise, the new file name is pushed onto +the stack and processing continues. - Finally, when `getline' encounters the end of the input file, the -file is closed and the stack is popped. When `stackptr' is less than + Finally, when 'getline' encounters the end of the input file, the +file is closed and the stack is popped. When 'stackptr' is less than zero, the program is done: stackptr = 0 @@ -18472,76 +18399,75 @@ zero, the program is done: EOF ) - The shell construct `COMMAND << MARKER' is called a "here document". + The shell construct 'COMMAND << MARKER' is called a "here document". Everything in the shell script up to the MARKER is fed to COMMAND as input. The shell processes the contents of the here document for variable and command substitution (and possibly other things as well, depending upon the shell). - The shell construct `$(...)' is called "command substitution". The + The shell construct '$(...)' is called "command substitution". The output of the command inside the parentheses is substituted into the command line. Because the result is used in a variable assignment, it is saved as a single string, even if the results contain whitespace. - The expanded program is saved in the variable `processed_program'. + The expanded program is saved in the variable 'processed_program'. It's done in these steps: - 1. Run `gawk' with the `@include'-processing program (the value of - the `expand_prog' shell variable) on standard input. + 1. Run 'gawk' with the '@include'-processing program (the value of the + 'expand_prog' shell variable) on standard input. 2. Standard input is the contents of the user's program, from the - shell variable `program'. Its contents are fed to `gawk' via a + shell variable 'program'. Its contents are fed to 'gawk' via a here document. 3. The results of this processing are saved in the shell variable - `processed_program' by using command substitution. + 'processed_program' by using command substitution. - The last step is to call `gawk' with the expanded program, along -with the original options and command-line arguments that the user -supplied. + The last step is to call 'gawk' with the expanded program, along with +the original options and command-line arguments that the user supplied. eval gawk $opts -- '"$processed_program"' '"$@"' - The `eval' command is a shell construct that reruns the shell's + The 'eval' command is a shell construct that reruns the shell's parsing process. This keeps things properly quoted. - This version of `igawk' represents the fifth version of this program. + This version of 'igawk' represents the fifth version of this program. There are four key simplifications that make the program work better: - * Using `@include' even for the files named with `-f' makes building - the initial collected `awk' program much simpler; all the - `@include' processing can be done once. + * Using '@include' even for the files named with '-f' makes building + the initial collected 'awk' program much simpler; all the + '@include' processing can be done once. - * Not trying to save the line read with `getline' in the `pathto()' - function when testing for the file's accessibility for use with - the main program simplifies things considerably. + * Not trying to save the line read with 'getline' in the 'pathto()' + function when testing for the file's accessibility for use with the + main program simplifies things considerably. - * Using a `getline' loop in the `BEGIN' rule does it all in one + * Using a 'getline' loop in the 'BEGIN' rule does it all in one place. It is not necessary to call out to a separate loop for - processing nested `@include' statements. + processing nested '@include' statements. - * Instead of saving the expanded program in a temporary file, - putting it in a shell variable avoids some potential security - problems. This has the disadvantage that the script relies upon - more features of the `sh' language, making it harder to follow for - those who aren't familiar with `sh'. + * Instead of saving the expanded program in a temporary file, putting + it in a shell variable avoids some potential security problems. + This has the disadvantage that the script relies upon more features + of the 'sh' language, making it harder to follow for those who + aren't familiar with 'sh'. Also, this program illustrates that it is often worthwhile to combine -`sh' and `awk' programming together. You can usually accomplish quite -a lot, without having to resort to low-level programming in C or C++, -and it is frequently easier to do certain kinds of string and argument -manipulation using the shell than it is in `awk'. +'sh' and 'awk' programming together. You can usually accomplish quite a +lot, without having to resort to low-level programming in C or C++, and +it is frequently easier to do certain kinds of string and argument +manipulation using the shell than it is in 'awk'. - Finally, `igawk' shows that it is not always necessary to add new + Finally, 'igawk' shows that it is not always necessary to add new features to a program; they can often be layered on top. ---------- Footnotes ---------- - (1) Fully explaining the `sh' language is beyond the scope of this -book. We provide some minimal explanations, but see a good shell + (1) Fully explaining the 'sh' language is beyond the scope of this +book. We provide some minimal explanations, but see a good shell programming book if you wish to understand things in more depth. - (2) On some very old versions of `awk', the test `getline junk < t' + (2) On some very old versions of 'awk', the test 'getline junk < t' can loop forever if the file exists but is empty. Caveat emptor.  @@ -18551,12 +18477,12 @@ File: gawk.info, Node: Anagram Program, Next: Signature Program, Prev: Igawk ------------------------------------------ An interesting programming challenge is to search for "anagrams" in a -word list (such as `/usr/share/dict/words' on many GNU/Linux systems). +word list (such as '/usr/share/dict/words' on many GNU/Linux systems). One word is an anagram of another if both words contain the same letters (for example, "babbling" and "blabbing"). An elegant algorithm is presented in Column 2, Problem C of Jon -Bentley's `Programming Pearls', second edition. The idea is to give +Bentley's 'Programming Pearls', second edition. The idea is to give words that are anagrams a common signature, sort all the words together by their signature, and then print them. Dr. Bentley observes that taking the letters in each word and sorting them produces that common @@ -18573,17 +18499,17 @@ order. /'s$/ { next } # Skip possessives - The program starts with a header, and then a rule to skip -possessives in the dictionary file. The next rule builds up the data -structure. The first dimension of the array is indexed by the -signature; the second dimension is the word itself: + The program starts with a header, and then a rule to skip possessives +in the dictionary file. The next rule builds up the data structure. +The first dimension of the array is indexed by the signature; the second +dimension is the word itself: { key = word2key($1) # Build signature data[key][$1] = $1 # Store word with signature } - The `word2key()' function creates the signature. It splits the word + The 'word2key()' function creates the signature. It splits the word apart into individual letters, sorts the letters, and then joins them back together: @@ -18600,8 +18526,8 @@ back together: return result } - Finally, the `END' rule traverses the array and prints out the -anagram lists. It sends the output to the system `sort' command, since + Finally, the 'END' rule traverses the array and prints out the +anagram lists. It sends the output to the system 'sort' command, since otherwise the anagrams would appear in arbitrary order: END { @@ -18642,7 +18568,7 @@ File: gawk.info, Node: Signature Program, Prev: Anagram Program, Up: Miscella The following program was written by Davide Brini and is published on his website (http://backreference.org/2011/02/03/obfuscated-awk/). It -serves as his signature in the Usenet group `comp.lang.awk'. He +serves as his signature in the Usenet group 'comp.lang.awk'. He supplies the following copyright terms: Copyright (C) 2008 Davide Brini @@ -18673,25 +18599,24 @@ File: gawk.info, Node: Programs Summary, Next: Programs Exercises, Prev: Misc continue on the theme that reading programs is an excellent way to learn Good Programming. - * Using `#!' to make `awk' programs directly runnable makes them - easier to use. Otherwise, invoke the program using `awk -f ...'. + * Using '#!' to make 'awk' programs directly runnable makes them + easier to use. Otherwise, invoke the program using 'awk -f ...'. - * Reimplementing standard POSIX programs in `awk' is a pleasant - exercise; `awk''s expressive power lets you write such programs in + * Reimplementing standard POSIX programs in 'awk' is a pleasant + exercise; 'awk''s expressive power lets you write such programs in relatively few lines of code, yet they are functionally complete and usable. - * One of standard `awk''s weaknesses is working with individual - characters. The ability to use `split()' with the empty string as + * One of standard 'awk''s weaknesses is working with individual + characters. The ability to use 'split()' with the empty string as the separator can considerably simplify such tasks. * The library functions from *note Library Functions::, proved their usefulness for a number of real (if small) programs. - * Besides reinventing POSIX wheels, other programs solved a - selection of interesting problems, such as finding duplicates - words in text, printing mailing labels, and finding anagrams. - + * Besides reinventing POSIX wheels, other programs solved a selection + of interesting problems, such as finding duplicates words in text, + printing mailing labels, and finding anagrams.  File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample Programs @@ -18699,44 +18624,44 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample 11.5 Exercises ============== - 1. Rewrite `cut.awk' (*note Cut Program::) using `split()' with `""' + 1. Rewrite 'cut.awk' (*note Cut Program::) using 'split()' with '""' as the seperator. - 2. In *note Egrep Program::, we mentioned that `egrep -i' could be - simulated in versions of `awk' without `IGNORECASE' by using - `tolower()' on the line and the pattern. In a footnote there, we + 2. In *note Egrep Program::, we mentioned that 'egrep -i' could be + simulated in versions of 'awk' without 'IGNORECASE' by using + 'tolower()' on the line and the pattern. In a footnote there, we also mentioned that this solution has a bug: the translated line is output, and not the original one. Fix this problem. - 3. The POSIX version of `id' takes options that control which - information is printed. Modify the `awk' version (*note Id + 3. The POSIX version of 'id' takes options that control which + information is printed. Modify the 'awk' version (*note Id Program::) to accept the same arguments and perform in the same way. - 4. The `split.awk' program (*note Split Program::) uses the `chr()' - and `ord()' functions to move through the letters of the alphabet. - Modify the program to instead use only the `awk' built-in - functions, such as `index()' and `substr()'. + 4. The 'split.awk' program (*note Split Program::) uses the 'chr()' + and 'ord()' functions to move through the letters of the alphabet. + Modify the program to instead use only the 'awk' built-in + functions, such as 'index()' and 'substr()'. - 5. The `split.awk' program (*note Split Program::) assumes that + 5. The 'split.awk' program (*note Split Program::) assumes that letters are contiguous in the character set, which isn't true for EBCDIC systems. Fix this problem. - 6. Why can't the `wc.awk' program (*note Wc Program::) just use the - value of `FNR' in `endfile()'? Hint: Examine the code in *note + 6. Why can't the 'wc.awk' program (*note Wc Program::) just use the + value of 'FNR' in 'endfile()'? Hint: Examine the code in *note Filetrans Function::. - 7. Manipulation of individual characters in the `translate' program - (*note Translate Program::) is painful using standard `awk' - functions. Given that `gawk' can split strings into individual - characters using `""' as the separator, how might you use this + 7. Manipulation of individual characters in the 'translate' program + (*note Translate Program::) is painful using standard 'awk' + functions. Given that 'gawk' can split strings into individual + characters using '""' as the separator, how might you use this feature to simplify the program? - 8. The `extract.awk' program (*note Extract Program::) was written - before `gawk' had the `gensub()' function. Use it to simplify the + 8. The 'extract.awk' program (*note Extract Program::) was written + before 'gawk' had the 'gensub()' function. Use it to simplify the code. - 9. Compare the performance of the `awksed.awk' program (*note Simple + 9. Compare the performance of the 'awksed.awk' program (*note Simple Sed::) with the more straightforward: BEGIN { @@ -18747,77 +18672,75 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample { gsub(pat, repl); print } - 10. What are the advantages and disadvantages of `awksed.awk' versus - the real `sed' utility? + 10. What are the advantages and disadvantages of 'awksed.awk' versus + the real 'sed' utility? - 11. In *note Igawk Program::, we mentioned that not trying to save the - line read with `getline' in the `pathto()' function when testing + 11. In *note Igawk Program::, we mentioned that not trying to save the + line read with 'getline' in the 'pathto()' function when testing for the file's accessibility for use with the main program simplifies things considerably. What problem does this engender though? - 12. As an additional example of the idea that it is not always + 12. As an additional example of the idea that it is not always necessary to add new features to a program, consider the idea of having two files in a directory in the search path: - `default.awk' - This file contains a set of default library functions, such - as `getopt()' and `assert()'. + 'default.awk' + This file contains a set of default library functions, such as + 'getopt()' and 'assert()'. - `site.awk' + 'site.awk' This file contains library functions that are specific to a site or installation; i.e., locally developed functions. - Having a separate file allows `default.awk' to change with - new `gawk' releases, without requiring the system - administrator to update it each time by adding the local - functions. + Having a separate file allows 'default.awk' to change with new + 'gawk' releases, without requiring the system administrator to + update it each time by adding the local functions. - One user suggested that `gawk' be modified to automatically read + One user suggested that 'gawk' be modified to automatically read these files upon startup. Instead, it would be very simple to - modify `igawk' to do this. Since `igawk' can process nested - `@include' directives, `default.awk' could simply contain - `@include' statements for the desired library functions. Make - this change. - - 13. Modify `anagram.awk' (*note Anagram Program::), to avoid the use - of the external `sort' utility. + modify 'igawk' to do this. Since 'igawk' can process nested + '@include' directives, 'default.awk' could simply contain + '@include' statements for the desired library functions. Make this + change. + 13. Modify 'anagram.awk' (*note Anagram Program::), to avoid the use + of the external 'sort' utility.  File: gawk.info, Node: Advanced Features, Next: Internationalization, Prev: Sample Programs, Up: Top -12 Advanced Features of `gawk' +12 Advanced Features of 'gawk' ****************************** Write documentation as if whoever reads it is a violent psychopath - who knows where you live. -- Steve English, as quoted by Peter - Langston + who knows where you live. + -- _Steve English, as quoted by Peter Langston_ - This major node discusses advanced features in `gawk'. It's a bit -of a "grab bag" of items that are otherwise unrelated to each other. -First, a command-line option allows `gawk' to recognize nondecimal -numbers in input data, not just in `awk' programs. Then, `gawk''s + This major node discusses advanced features in 'gawk'. It's a bit of +a "grab bag" of items that are otherwise unrelated to each other. +First, a command-line option allows 'gawk' to recognize nondecimal +numbers in input data, not just in 'awk' programs. Then, 'gawk''s special features for sorting arrays are presented. Next, two-way I/O, discussed briefly in earlier parts of this Info file, is described in full detail, along with the basics of TCP/IP networking. Finally, -`gawk' can "profile" an `awk' program, making it possible to tune it -for performance. +'gawk' can "profile" an 'awk' program, making it possible to tune it for +performance. A number of advanced features require separate major nodes of their own: * *note Internationalization::, discusses how to internationalize - your `awk' programs, so that they can speak multiple national + your 'awk' programs, so that they can speak multiple national languages. - * *note Debugger::, describes `gawk''s built-in command-line - debugger for debugging `awk' programs. + * *note Debugger::, describes 'gawk''s built-in command-line debugger + for debugging 'awk' programs. * *note Arbitrary Precision Arithmetic::, describes how you can use - `gawk' to perform arbitrary-precision arithmetic. + 'gawk' to perform arbitrary-precision arithmetic. * *note Dynamic Extensions::, discusses the ability to dynamically - add new built-in functions to `gawk'. + add new built-in functions to 'gawk'. * Menu: @@ -18825,8 +18748,8 @@ own: * Array Sorting:: Facilities for controlling array traversal and sorting arrays. * Two-way I/O:: Two-way communications with another process. -* TCP/IP Networking:: Using `gawk' for network programming. -* Profiling:: Profiling your `awk' programs. +* TCP/IP Networking:: Using 'gawk' for network programming. +* Profiling:: Profiling your 'awk' programs. * Advanced Features Summary:: Summary of advanced features.  @@ -18835,7 +18758,7 @@ File: gawk.info, Node: Nondecimal Data, Next: Array Sorting, Up: Advanced Fea 12.1 Allowing Nondecimal Input Data =================================== -If you run `gawk' with the `--non-decimal-data' option, you can have +If you run 'gawk' with the '--non-decimal-data' option, you can have nondecimal constants in your input data: $ echo 0123 123 0x123 | @@ -18843,16 +18766,16 @@ nondecimal constants in your input data: > $1, $2, $3 }' -| 83, 123, 291 - For this feature to work, write your program so that `gawk' treats + For this feature to work, write your program so that 'gawk' treats your data as numeric: $ echo 0123 123 0x123 | gawk '{ print $1, $2, $3 }' -| 0123 123 0x123 -The `print' statement treats its expressions as strings. Although the +The 'print' statement treats its expressions as strings. Although the fields can act as numbers when necessary, they are still strings, so -`print' does not try to treat them numerically. You need to add zero -to a field to force it to be treated as a number. For example: +'print' does not try to treat them numerically. You need to add zero to +a field to force it to be treated as a number. For example: $ echo 0123 123 0x123 | gawk --non-decimal-data ' > { print $1, $2, $3 @@ -18865,8 +18788,8 @@ because using this facility could lead to surprising results, the default is to leave it disabled. If you want it, you must explicitly request it. - CAUTION: _Use of this option is not recommended._ It can break old - programs very badly. Instead, use the `strtonum()' function to + CAUTION: _Use of this option is not recommended._ It can break old + programs very badly. Instead, use the 'strtonum()' function to convert your data (*note String Functions::). This makes your programs easier to write and easier to read, and leads to less surprising results. @@ -18877,10 +18800,10 @@ File: gawk.info, Node: Array Sorting, Next: Two-way I/O, Prev: Nondecimal Dat 12.2 Controlling Array Traversal and Array Sorting ================================================== -`gawk' lets you control the order in which a `for (i in array)' loop +'gawk' lets you control the order in which a 'for (i in array)' loop traverses an array. - In addition, two built-in functions, `asort()' and `asorti()', let + In addition, two built-in functions, 'asort()' and 'asorti()', let you sort arrays based on the array values and indices, respectively. These two functions also provide control over the sorting criteria used to order the elements during sorting. @@ -18888,7 +18811,7 @@ to order the elements during sorting. * Menu: * Controlling Array Traversal:: How to use PROCINFO["sorted_in"]. -* Array Sorting Functions:: How to use `asort()' and `asorti()'. +* Array Sorting Functions:: How to use 'asort()' and 'asorti()'.  File: gawk.info, Node: Controlling Array Traversal, Next: Array Sorting Functions, Up: Array Sorting @@ -18896,19 +18819,19 @@ File: gawk.info, Node: Controlling Array Traversal, Next: Array Sorting Functi 12.2.1 Controlling Array Traversal ---------------------------------- -By default, the order in which a `for (i in array)' loop scans an array +By default, the order in which a 'for (i in array)' loop scans an array is not defined; it is generally based upon the internal implementation -of arrays inside `awk'. +of arrays inside 'awk'. Often, though, it is desirable to be able to loop over the elements -in a particular order that you, the programmer, choose. `gawk' lets -you do this. +in a particular order that you, the programmer, choose. 'gawk' lets you +do this. *note Controlling Scanning::, describes how you can assign special, -pre-defined values to `PROCINFO["sorted_in"]' in order to control the -order in which `gawk' traverses an array during a `for' loop. +pre-defined values to 'PROCINFO["sorted_in"]' in order to control the +order in which 'gawk' traverses an array during a 'for' loop. - In addition, the value of `PROCINFO["sorted_in"]' can be a function + In addition, the value of 'PROCINFO["sorted_in"]' can be a function name. This lets you traverse an array based on any custom criterion. The array elements are ordered according to the return value of this function. The comparison function should be defined with at least four @@ -18926,14 +18849,14 @@ can be arrays if the array being traversed contains subarrays as values. (*Note Arrays of Arrays::, for more information about subarrays.) The three possible return values are interpreted as follows: -`comp_func(i1, v1, i2, v2) < 0' +'comp_func(i1, v1, i2, v2) < 0' Index I1 comes before index I2 during loop traversal. -`comp_func(i1, v1, i2, v2) == 0' - Indices I1 and I2 come together but the relative order with - respect to each other is undefined. +'comp_func(i1, v1, i2, v2) == 0' + Indices I1 and I2 come together but the relative order with respect + to each other is undefined. -`comp_func(i1, v1, i2, v2) > 0' +'comp_func(i1, v1, i2, v2) > 0' Index I1 comes after index I2 during loop traversal. Our first comparison function can be used to scan an array in @@ -18974,7 +18897,7 @@ traversal: return (v1 < v2) ? -1 : (v1 != v2) } - Here is a main program to demonstrate how `gawk' behaves using each + Here is a main program to demonstrate how 'gawk' behaves using each of the previous functions: BEGIN { @@ -19050,9 +18973,9 @@ specific field position and can be used for this purpose: } The first field in each entry of the password file is the user's -login name, and the fields are separated by colons. Each record -defines a subarray, with each field as an element in the subarray. -Running the program produces the following output: +login name, and the fields are separated by colons. Each record defines +a subarray, with each field as an element in the subarray. Running the +program produces the following output: $ gawk -v POS=1 -F: -f sort.awk /etc/passwd -| adm:x:3:4:adm:/var/adm:/sbin/nologin @@ -19079,10 +19002,10 @@ when comparing item values. The partial ordering of the equal elements may change during the next loop traversal, if other elements are added or removed from the array. One way to resolve ties when comparing elements with otherwise equal values is to include the indices in the -comparison rules. Note that doing this may make the loop traversal -less efficient, so consider it only if necessary. The following -comparison functions force a deterministic order, and are based on the -fact that the (string) indices of two elements are never equal: +comparison rules. Note that doing this may make the loop traversal less +efficient, so consider it only if necessary. The following comparison +functions force a deterministic order, and are based on the fact that +the (string) indices of two elements are never equal: function cmp_numeric(i1, v1, i2, v2) { @@ -19104,33 +19027,33 @@ such a function. When string comparisons are made during a sort, either for element values where one or both aren't numbers, or for element indices handled -as strings, the value of `IGNORECASE' (*note Built-in Variables::) +as strings, the value of 'IGNORECASE' (*note Built-in Variables::) controls whether the comparisons treat corresponding uppercase and lowercase letters as equivalent or distinct. Another point to keep in mind is that in the case of subarrays the element values can themselves be arrays; a production comparison -function should use the `isarray()' function (*note Type Functions::), +function should use the 'isarray()' function (*note Type Functions::), to check for this, and choose a defined sorting order for subarrays. - All sorting based on `PROCINFO["sorted_in"]' is disabled in POSIX -mode, since the `PROCINFO' array is not special in that case. + All sorting based on 'PROCINFO["sorted_in"]' is disabled in POSIX +mode, since the 'PROCINFO' array is not special in that case. - As a side note, sorting the array indices before traversing the -array has been reported to add 15% to 20% overhead to the execution -time of `awk' programs. For this reason, sorted array traversal is not -the default. + As a side note, sorting the array indices before traversing the array +has been reported to add 15% to 20% overhead to the execution time of +'awk' programs. For this reason, sorted array traversal is not the +default.  File: gawk.info, Node: Array Sorting Functions, Prev: Controlling Array Traversal, Up: Array Sorting -12.2.2 Sorting Array Values and Indices with `gawk' +12.2.2 Sorting Array Values and Indices with 'gawk' --------------------------------------------------- -In most `awk' implementations, sorting an array requires writing a -`sort()' function. While this can be educational for exploring +In most 'awk' implementations, sorting an array requires writing a +'sort()' function. While this can be educational for exploring different sorting algorithms, usually that's not the point of the -program. `gawk' provides the built-in `asort()' and `asorti()' +program. 'gawk' provides the built-in 'asort()' and 'asorti()' functions (*note String Functions::) for sorting arrays. For example: POPULATE THE ARRAY data @@ -19138,31 +19061,31 @@ functions (*note String Functions::) for sorting arrays. For example: for (i = 1; i <= n; i++) DO SOMETHING WITH data[i] - After the call to `asort()', the array `data' is indexed from 1 to -some number N, the total number of elements in `data'. (This count is -`asort()''s return value.) `data[1]' <= `data[2]' <= `data[3]', and so + After the call to 'asort()', the array 'data' is indexed from 1 to +some number N, the total number of elements in 'data'. (This count is +'asort()''s return value.) 'data[1]' <= 'data[2]' <= 'data[3]', and so on. The default comparison is based on the type of the elements (*note Typing and Comparison::). All numeric values come before all string values, which in turn come before all subarrays. - An important side effect of calling `asort()' is that _the array's -original indices are irrevocably lost_. As this isn't always -desirable, `asort()' accepts a second argument: + An important side effect of calling 'asort()' is that _the array's +original indices are irrevocably lost_. As this isn't always desirable, +'asort()' accepts a second argument: POPULATE THE ARRAY source n = asort(source, dest) for (i = 1; i <= n; i++) DO SOMETHING WITH dest[i] - In this case, `gawk' copies the `source' array into the `dest' array -and then sorts `dest', destroying its indices. However, the `source' + In this case, 'gawk' copies the 'source' array into the 'dest' array +and then sorts 'dest', destroying its indices. However, the 'source' array is not affected. Often, what's needed is to sort on the values of the _indices_ -instead of the values of the elements. To do that, use the `asorti()' +instead of the values of the elements. To do that, use the 'asorti()' function. The interface and behavior are identical to that of -`asort()', except that the index values are used for sorting, and -become the values of the result array: +'asort()', except that the index values are used for sorting, and become +the values of the result array: { source[$0] = some_func($0) } @@ -19177,15 +19100,15 @@ become the values of the result array: } } - So far, so good. Now it starts to get interesting. Both `asort()' -and `asorti()' accept a third string argument to control comparison of -array elements. When we introduced `asort()' and `asorti()' in *note + So far, so good. Now it starts to get interesting. Both 'asort()' +and 'asorti()' accept a third string argument to control comparison of +array elements. When we introduced 'asort()' and 'asorti()' in *note String Functions::, we ignored this third argument; however, now is the time to describe how this argument affects these two functions. Basically, the third argument specifies how the array is to be -sorted. There are two possibilities. As with `PROCINFO["sorted_in"]', -this argument may be one of the predefined names that `gawk' provides +sorted. There are two possibilities. As with 'PROCINFO["sorted_in"]', +this argument may be one of the predefined names that 'gawk' provides (*note Controlling Scanning::), or it may be the name of a user-defined function (*note Controlling Array Traversal::). @@ -19193,26 +19116,26 @@ function (*note Controlling Array Traversal::). chooses_, taking into account just the indices, just the values, or both. This is extremely powerful. - Once the array is sorted, `asort()' takes the _values_ in their -final order, and uses them to fill in the result array, whereas -`asorti()' takes the _indices_ in their final order, and uses them to -fill in the result array. + Once the array is sorted, 'asort()' takes the _values_ in their final +order, and uses them to fill in the result array, whereas 'asorti()' +takes the _indices_ in their final order, and uses them to fill in the +result array. NOTE: Copying array indices and elements isn't expensive in terms - of memory. Internally, `gawk' maintains "reference counts" to - data. For example, when `asort()' copies the first array to the + of memory. Internally, 'gawk' maintains "reference counts" to + data. For example, when 'asort()' copies the first array to the second one, there is only one copy of the original array elements' data, even though both arrays use the values. - Because `IGNORECASE' affects string comparisons, the value of -`IGNORECASE' also affects sorting for both `asort()' and `asorti()'. + Because 'IGNORECASE' affects string comparisons, the value of +'IGNORECASE' also affects sorting for both 'asort()' and 'asorti()'. Note also that the locale's sorting order does _not_ come into play; -comparisons are based on character values only.(1) Caveat Emptor. +comparisons are based on character values only.(1) Caveat Emptor. ---------- Footnotes ---------- (1) This is true because locale-based comparison occurs only when in -POSIX compatibility mode, and since `asort()' and `asorti()' are `gawk' +POSIX compatibility mode, and since 'asort()' and 'asorti()' are 'gawk' extensions, they are not available in that case.  @@ -19254,15 +19177,15 @@ temporary files: close(tempfile) system("rm " tempfile) -This works, but not elegantly. Among other things, it requires that -the program be run in a directory that cannot be shared among users; -for example, `/tmp' will not do, as another user might happen to be -using a temporary file with the same name. +This works, but not elegantly. Among other things, it requires that the +program be run in a directory that cannot be shared among users; for +example, '/tmp' will not do, as another user might happen to be using a +temporary file with the same name. - However, with `gawk', it is possible to open a _two-way_ pipe to + However, with 'gawk', it is possible to open a _two-way_ pipe to another process. The second process is termed a "coprocess", since it -runs in parallel with `gawk'. The two-way connection is created using -the `|&' operator (borrowed from the Korn shell, `ksh'):(1) +runs in parallel with 'gawk'. The two-way connection is created using +the '|&' operator (borrowed from the Korn shell, 'ksh'):(1) do { print DATA |& "subprogram" @@ -19270,43 +19193,42 @@ the `|&' operator (borrowed from the Korn shell, `ksh'):(1) } while (DATA LEFT TO PROCESS) close("subprogram") - The first time an I/O operation is executed using the `|&' operator, -`gawk' creates a two-way pipeline to a child process that runs the -other program. Output created with `print' or `printf' is written to -the program's standard input, and output from the program's standard -output can be read by the `gawk' program using `getline'. As is the -case with processes started by `|', the subprogram can be any program, -or pipeline of programs, that can be started by the shell. + The first time an I/O operation is executed using the '|&' operator, +'gawk' creates a two-way pipeline to a child process that runs the other +program. Output created with 'print' or 'printf' is written to the +program's standard input, and output from the program's standard output +can be read by the 'gawk' program using 'getline'. As is the case with +processes started by '|', the subprogram can be any program, or pipeline +of programs, that can be started by the shell. There are some cautionary items to be aware of: - * As the code inside `gawk' currently stands, the coprocess's - standard error goes to the same place that the parent `gawk''s - standard error goes. It is not possible to read the child's + * As the code inside 'gawk' currently stands, the coprocess's + standard error goes to the same place that the parent 'gawk''s + standard error goes. It is not possible to read the child's standard error separately. - * I/O buffering may be a problem. `gawk' automatically flushes all + * I/O buffering may be a problem. 'gawk' automatically flushes all output down the pipe to the coprocess. However, if the coprocess - does not flush its output, `gawk' may hang when doing a `getline' + does not flush its output, 'gawk' may hang when doing a 'getline' in order to read the coprocess's results. This could lead to a situation known as "deadlock", where each process is waiting for the other one to do something. It is possible to close just one end of the two-way pipe to a -coprocess, by supplying a second argument to the `close()' function of -either `"to"' or `"from"' (*note Close Files And Pipes::). These -strings tell `gawk' to close the end of the pipe that sends data to the +coprocess, by supplying a second argument to the 'close()' function of +either '"to"' or '"from"' (*note Close Files And Pipes::). These +strings tell 'gawk' to close the end of the pipe that sends data to the coprocess or the end that reads from it, respectively. - This is particularly necessary in order to use the system `sort' -utility as part of a coprocess; `sort' must read _all_ of its input -data before it can produce any output. The `sort' program does not -receive an end-of-file indication until `gawk' closes the write end of -the pipe. + This is particularly necessary in order to use the system 'sort' +utility as part of a coprocess; 'sort' must read _all_ of its input data +before it can produce any output. The 'sort' program does not receive +an end-of-file indication until 'gawk' closes the write end of the pipe. - When you have finished writing data to the `sort' utility, you can -close the `"to"' end of the pipe, and then start reading sorted data -via `getline'. For example: + When you have finished writing data to the 'sort' utility, you can +close the '"to"' end of the pipe, and then start reading sorted data via +'getline'. For example: BEGIN { command = "LC_ALL=C sort" @@ -19322,20 +19244,20 @@ via `getline'. For example: } This program writes the letters of the alphabet in reverse order, one -per line, down the two-way pipe to `sort'. It then closes the write -end of the pipe, so that `sort' receives an end-of-file indication. -This causes `sort' to sort the data and write the sorted data back to -the `gawk' program. Once all of the data has been read, `gawk' -terminates the coprocess and exits. - - As a side note, the assignment `LC_ALL=C' in the `sort' command -ensures traditional Unix (ASCII) sorting from `sort'. This is not +per line, down the two-way pipe to 'sort'. It then closes the write end +of the pipe, so that 'sort' receives an end-of-file indication. This +causes 'sort' to sort the data and write the sorted data back to the +'gawk' program. Once all of the data has been read, 'gawk' terminates +the coprocess and exits. + + As a side note, the assignment 'LC_ALL=C' in the 'sort' command +ensures traditional Unix (ASCII) sorting from 'sort'. This is not strictly necessary here, but it's good to know how to do this. - You may also use pseudo-ttys (ptys) for two-way communication -instead of pipes, if your system supports them. This is done on a -per-command basis, by setting a special element in the `PROCINFO' array -(*note Auto-set::), like so: + You may also use pseudo-ttys (ptys) for two-way communication instead +of pipes, if your system supports them. This is done on a per-command +basis, by setting a special element in the 'PROCINFO' array (*note +Auto-set::), like so: command = "sort -nr" # command, save in convenience variable PROCINFO[command, "pty"] = 1 # update PROCINFO @@ -19344,7 +19266,7 @@ per-command basis, by setting a special element in the `PROCINFO' array Using ptys usually avoids the buffer deadlock issues described earlier, at some loss in performance. If your system does not have ptys, or if -all the system's ptys are in use, `gawk' automatically falls back to +all the system's ptys are in use, 'gawk' automatically falls back to using regular pipes. ---------- Footnotes ---------- @@ -19355,14 +19277,14 @@ in Bash.  File: gawk.info, Node: TCP/IP Networking, Next: Profiling, Prev: Two-way I/O, Up: Advanced Features -12.4 Using `gawk' for Network Programming +12.4 Using 'gawk' for Network Programming ========================================= - `EMISTERED': - A host is a host from coast to coast, - and no-one can talk to host that's close, - unless the host that isn't close - is busy hung or dead. + 'EMISTERED': + A host is a host from coast to coast, + and no-one can talk to host that's close, + unless the host that isn't close + is busy hung or dead. In addition to being able to open a two-way pipeline to a coprocess on the same system (*note Two-way I/O::), it is possible to make a @@ -19370,45 +19292,44 @@ two-way connection to another process on another system across an IP network connection. You can think of this as just a _very long_ two-way pipeline to a -coprocess. The way `gawk' decides that you want to use TCP/IP +coprocess. The way 'gawk' decides that you want to use TCP/IP networking is by recognizing special file names that begin with one of -`/inet/', `/inet4/' or `/inet6'. +'/inet/', '/inet4/' or '/inet6'. The full syntax of the special file name is -`/NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT'. The -components are: +'/NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT'. The components +are: NET-TYPE - Specifies the kind of Internet connection to make. Use `/inet4/' - to force IPv4, and `/inet6/' to force IPv6. Plain `/inet/' (which + Specifies the kind of Internet connection to make. Use '/inet4/' + to force IPv4, and '/inet6/' to force IPv6. Plain '/inet/' (which used to be the only option) uses the system default, most likely IPv4. PROTOCOL - The protocol to use over IP. This must be either `tcp', or `udp', + The protocol to use over IP. This must be either 'tcp', or 'udp', for a TCP or UDP IP connection, respectively. The use of TCP is recommended for most applications. LOCAL-PORT - The local TCP or UDP port number to use. Use a port number of `0' - when you want the system to pick a port. This is what you should do - when writing a TCP or UDP client. You may also use a well-known - service name, such as `smtp' or `http', in which case `gawk' + The local TCP or UDP port number to use. Use a port number of '0' + when you want the system to pick a port. This is what you should + do when writing a TCP or UDP client. You may also use a well-known + service name, such as 'smtp' or 'http', in which case 'gawk' attempts to determine the predefined port number using the C - `getaddrinfo()' function. + 'getaddrinfo()' function. REMOTE-HOST The IP address or fully-qualified domain name of the Internet host to which you want to connect. REMOTE-PORT - The TCP or UDP port number to use on the given REMOTE-HOST. - Again, use `0' if you don't care, or else a well-known service - name. + The TCP or UDP port number to use on the given REMOTE-HOST. Again, + use '0' if you don't care, or else a well-known service name. NOTE: Failure in opening a two-way socket will result in a - non-fatal error being returned to the calling code. The value of - `ERRNO' indicates the error (*note Auto-set::). + non-fatal error being returned to the calling code. The value of + 'ERRNO' indicates the error (*note Auto-set::). Consider the following very simple example: @@ -19420,38 +19341,37 @@ REMOTE-PORT } This program reads the current date and time from the local system's -TCP `daytime' server. It then prints the results and closes the +TCP 'daytime' server. It then prints the results and closes the connection. - Because this topic is extensive, the use of `gawk' for TCP/IP -programming is documented separately. See *note (General -Introduction)Top:: gawkinet, TCP/IP Internetworking with `gawk', for a -much more complete introduction and discussion, as well as extensive -examples. + Because this topic is extensive, the use of 'gawk' for TCP/IP +programming is documented separately. See *note (General Introduction, +gawkinet, TCP/IP Internetworking with 'gawk')Top::, for a much more +complete introduction and discussion, as well as extensive examples.  File: gawk.info, Node: Profiling, Next: Advanced Features Summary, Prev: TCP/IP Networking, Up: Advanced Features -12.5 Profiling Your `awk' Programs +12.5 Profiling Your 'awk' Programs ================================== -You may produce execution traces of your `awk' programs. This is done -by passing the option `--profile' to `gawk'. When `gawk' has finished +You may produce execution traces of your 'awk' programs. This is done +by passing the option '--profile' to 'gawk'. When 'gawk' has finished running, it creates a profile of your program in a file named -`awkprof.out'. Because it is profiling, it also executes up to 45% -slower than `gawk' normally does. +'awkprof.out'. Because it is profiling, it also executes up to 45% +slower than 'gawk' normally does. - As shown in the following example, the `--profile' option can be -used to change the name of the file where `gawk' will write the profile: + As shown in the following example, the '--profile' option can be used +to change the name of the file where 'gawk' will write the profile: gawk --profile=myprog.prof -f myprog.awk data1 data2 -In the above example, `gawk' places the profile in `myprog.prof' -instead of in `awkprof.out'. +In the above example, 'gawk' places the profile in 'myprog.prof' instead +of in 'awkprof.out'. - Here is a sample session showing a simple `awk' program, its input -data, and the results from running `gawk' with the `--profile' option. -First, the `awk' program: + Here is a sample session showing a simple 'awk' program, its input +data, and the results from running 'gawk' with the '--profile' option. +First, the 'awk' program: BEGIN { print "First BEGIN rule" } @@ -19487,9 +19407,9 @@ First, the `awk' program: foo junk - Here is the `awkprof.out' that results from running the `gawk' -profiler on this program and data. (This example also illustrates that -`awk' programmers sometimes get up very early in the morning to work.) + Here is the 'awkprof.out' that results from running the 'gawk' +profiler on this program and data. (This example also illustrates that +'awk' programmers sometimes get up very early in the morning to work.) # gawk profile, created Thu Feb 27 05:16:21 2014 @@ -19541,62 +19461,61 @@ profiler on this program and data. (This example also illustrates that This example illustrates many of the basic features of profiling output. They are as follows: - * The program is printed in the order `BEGIN' rules, `BEGINFILE' - rules, pattern/action rules, `ENDFILE' rules, `END' rules and - functions, listed alphabetically. Multiple `BEGIN' and `END' - rules retain their separate identities, as do multiple `BEGINFILE' - and `ENDFILE' rules. + * The program is printed in the order 'BEGIN' rules, 'BEGINFILE' + rules, pattern/action rules, 'ENDFILE' rules, 'END' rules and + functions, listed alphabetically. Multiple 'BEGIN' and 'END' rules + retain their separate identities, as do multiple 'BEGINFILE' and + 'ENDFILE' rules. - * Pattern-action rules have two counts. The first count, to the - left of the rule, shows how many times the rule's pattern was - _tested_. The second count, to the right of the rule's opening - left brace in a comment, shows how many times the rule's action - was _executed_. The difference between the two indicates how many - times the rule's pattern evaluated to false. + * Pattern-action rules have two counts. The first count, to the left + of the rule, shows how many times the rule's pattern was _tested_. + The second count, to the right of the rule's opening left brace in + a comment, shows how many times the rule's action was _executed_. + The difference between the two indicates how many times the rule's + pattern evaluated to false. - * Similarly, the count for an `if'-`else' statement shows how many + * Similarly, the count for an 'if'-'else' statement shows how many times the condition was tested. To the right of the opening left - brace for the `if''s body is a count showing how many times the - condition was true. The count for the `else' indicates how many + brace for the 'if''s body is a count showing how many times the + condition was true. The count for the 'else' indicates how many times the test failed. - * The count for a loop header (such as `for' or `while') shows how - many times the loop test was executed. (Because of this, you - can't just look at the count on the first statement in a rule to + * The count for a loop header (such as 'for' or 'while') shows how + many times the loop test was executed. (Because of this, you can't + just look at the count on the first statement in a rule to determine how many times the rule was executed. If the first statement is a loop, the count is misleading.) - * For user-defined functions, the count next to the `function' + * For user-defined functions, the count next to the 'function' keyword indicates how many times the function was called. The - counts next to the statements in the body show how many times - those statements were executed. + counts next to the statements in the body show how many times those + statements were executed. - * The layout uses "K&R" style with TABs. Braces are used - everywhere, even when the body of an `if', `else', or loop is only - a single statement. + * The layout uses "K&R" style with TABs. Braces are used everywhere, + even when the body of an 'if', 'else', or loop is only a single + statement. * Parentheses are used only where needed, as indicated by the structure of the program and the precedence rules. For example, - `(3 + 5) * 4' means add three plus five, then multiply the total - by four. However, `3 + 5 * 4' has no parentheses, and means `3 + - (5 * 4)'. + '(3 + 5) * 4' means add three plus five, then multiply the total by + four. However, '3 + 5 * 4' has no parentheses, and means '3 + (5 * + 4)'. - * Parentheses are used around the arguments to `print' and `printf' - only when the `print' or `printf' statement is followed by a + * Parentheses are used around the arguments to 'print' and 'printf' + only when the 'print' or 'printf' statement is followed by a redirection. Similarly, if the target of a redirection isn't a scalar, it gets parenthesized. - * `gawk' supplies leading comments in front of the `BEGIN' and `END' - rules, the `BEGINFILE' and `ENDFILE' rules, the pattern/action + * 'gawk' supplies leading comments in front of the 'BEGIN' and 'END' + rules, the 'BEGINFILE' and 'ENDFILE' rules, the pattern/action rules, and the functions. - The profiled version of your program may not look exactly like what -you typed when you wrote it. This is because `gawk' creates the -profiled version by "pretty printing" its internal representation of -the program. The advantage to this is that `gawk' can produce a -standard representation. The disadvantage is that all source-code -comments are lost. Also, things such as: +you typed when you wrote it. This is because 'gawk' creates the +profiled version by "pretty printing" its internal representation of the +program. The advantage to this is that 'gawk' can produce a standard +representation. The disadvantage is that all source-code comments are +lost. Also, things such as: /foo/ @@ -19608,23 +19527,23 @@ come out as: which is correct, but possibly surprising. - Besides creating profiles when a program has completed, `gawk' can -produce a profile while it is running. This is useful if your `awk' + Besides creating profiles when a program has completed, 'gawk' can +produce a profile while it is running. This is useful if your 'awk' program goes into an infinite loop and you want to see what has been -executed. To use this feature, run `gawk' with the `--profile' option +executed. To use this feature, run 'gawk' with the '--profile' option in the background: $ gawk --profile -f myprog & [1] 13992 The shell prints a job number and process ID number; in this case, -13992. Use the `kill' command to send the `USR1' signal to `gawk': +13992. Use the 'kill' command to send the 'USR1' signal to 'gawk': $ kill -USR1 13992 As usual, the profiled version of the program is written to -`awkprof.out', or to a different file if one specified with the -`--profile' option. +'awkprof.out', or to a different file if one specified with the +'--profile' option. Along with the regular profile, as shown earlier, the profile file includes a trace of any active functions: @@ -19636,26 +19555,26 @@ includes a trace of any active functions: # 1. foo # -- main -- - You may send `gawk' the `USR1' signal as many times as you like. + You may send 'gawk' the 'USR1' signal as many times as you like. Each time, the profile and function call trace are appended to the output profile file. - If you use the `HUP' signal instead of the `USR1' signal, `gawk' + If you use the 'HUP' signal instead of the 'USR1' signal, 'gawk' produces the profile and the function call trace and then exits. - When `gawk' runs on MS-Windows systems, it uses the `INT' and `QUIT' -signals for producing the profile and, in the case of the `INT' signal, -`gawk' exits. This is because these systems don't support the `kill' + When 'gawk' runs on MS-Windows systems, it uses the 'INT' and 'QUIT' +signals for producing the profile and, in the case of the 'INT' signal, +'gawk' exits. This is because these systems don't support the 'kill' command, so the only signals you can deliver to a program are those -generated by the keyboard. The `INT' signal is generated by the -`Ctrl-' or `Ctrl-' key, while the `QUIT' signal is generated -by the `Ctrl-<\>' key. +generated by the keyboard. The 'INT' signal is generated by the +'Ctrl-' or 'Ctrl-' key, while the 'QUIT' signal is generated +by the 'Ctrl-<\>' key. - Finally, `gawk' also accepts another option, `--pretty-print'. When -called this way, `gawk' "pretty prints" the program into `awkprof.out', + Finally, 'gawk' also accepts another option, '--pretty-print'. When +called this way, 'gawk' "pretty prints" the program into 'awkprof.out', without any execution counts. - NOTE: Once upon a time, the `--pretty-print' option would also run + NOTE: Once upon a time, the '--pretty-print' option would also run your program. This is is no longer the case.  @@ -19664,46 +19583,45 @@ File: gawk.info, Node: Advanced Features Summary, Prev: Profiling, Up: Advanc 12.6 Summary ============ - * The `--non-decimal-data' option causes `gawk' to treat octal- and + * The '--non-decimal-data' option causes 'gawk' to treat octal- and hexadecimal-looking input data as octal and hexadecimal. This option should be used with caution or not at all; use of - `strtonum()' is preferable. + 'strtonum()' is preferable. - * You can take over complete control of sorting in `for (INDX in - ARRAY)' array traversal by setting `PROCINFO["sorted_in"]' to the + * You can take over complete control of sorting in 'for (INDX in + ARRAY)' array traversal by setting 'PROCINFO["sorted_in"]' to the name of a user-defined function that does the comparison of array elements based on index and value. * Similarly, you can supply the name of a user-defined comparison - function as the third argument to either `asort()' or `asorti()' - to control how those functions sort arrays. Or you may provide one - of the predefined control strings that work for - `PROCINFO["sorted_in"]'. - - * You can use the `|&' operator to create a two-way pipe to a - co-process. You read from the co-process with `getline' and write - to it with `print' or `printf'. Use `close()' to close off the + function as the third argument to either 'asort()' or 'asorti()' to + control how those functions sort arrays. Or you may provide one of + the predefined control strings that work for + 'PROCINFO["sorted_in"]'. + + * You can use the '|&' operator to create a two-way pipe to a + co-process. You read from the co-process with 'getline' and write + to it with 'print' or 'printf'. Use 'close()' to close off the co-process completely, or optionally, close off one side of the two-way communications. - * By using special "file names" with the `|&' operator, you can open + * By using special "file names" with the '|&' operator, you can open a TCP/IP (or UDP/IP) connection to remote hosts in the Internet. - `gawk' supports both IPv4 an IPv6. + 'gawk' supports both IPv4 an IPv6. - * You can generate statement count profiles of your program. This + * You can generate statement count profiles of your program. This can help you determine which parts of your program may be taking the most time and let you tune them more easily. Sending the - `USR1' signal while profiling causes `gawk' to dump the profile - and keep going, including a function call stack. + 'USR1' signal while profiling causes 'gawk' to dump the profile and + keep going, including a function call stack. - * You can also just "pretty print" the program. This currently also + * You can also just "pretty print" the program. This currently also runs the program, but that will change in the next major release. -  File: gawk.info, Node: Internationalization, Next: Debugger, Prev: Advanced Features, Up: Top -13 Internationalization with `gawk' +13 Internationalization with 'gawk' *********************************** Once upon a time, computer makers wrote software that worked only in @@ -19715,21 +19633,21 @@ became a common practice. For many years, the ability to provide internationalization was largely restricted to programs written in C and C++. This major node -describes the underlying library `gawk' uses for internationalization, -as well as how `gawk' makes internationalization features available at -the `awk' program level. Having internationalization available at the -`awk' level gives software developers additional flexibility--they are +describes the underlying library 'gawk' uses for internationalization, +as well as how 'gawk' makes internationalization features available at +the 'awk' program level. Having internationalization available at the +'awk' level gives software developers additional flexibility--they are no longer forced to write in C or C++ when internationalization is a requirement. * Menu: * I18N and L10N:: Internationalization and Localization. -* Explaining gettext:: How GNU `gettext' works. +* Explaining gettext:: How GNU 'gettext' works. * Programmer i18n:: Features for the programmer. * Translator i18n:: Features for the translator. * I18N Example:: A simple i18n example. -* Gawk I18N:: `gawk' is also internationalized. +* Gawk I18N:: 'gawk' is also internationalized. * I18N Summary:: Summary of I18N stuff.  @@ -19741,69 +19659,69 @@ File: gawk.info, Node: I18N and L10N, Next: Explaining gettext, Up: Internati "Internationalization" means writing (or modifying) a program once, in such a way that it can use multiple languages without requiring further source-code changes. "Localization" means providing the data necessary -for an internationalized program to work in a particular language. -Most typically, these terms refer to features such as the language used -for printing error messages, the language used to read responses, and -information related to how numerical and monetary values are printed -and read. +for an internationalized program to work in a particular language. Most +typically, these terms refer to features such as the language used for +printing error messages, the language used to read responses, and +information related to how numerical and monetary values are printed and +read.  File: gawk.info, Node: Explaining gettext, Next: Programmer i18n, Prev: I18N and L10N, Up: Internationalization -13.2 GNU `gettext' +13.2 GNU 'gettext' ================== -`gawk' uses GNU `gettext' to provide its internationalization features. -The facilities in GNU `gettext' focus on messages; strings printed by a -program, either directly or via formatting with `printf' or -`sprintf()'.(1) +'gawk' uses GNU 'gettext' to provide its internationalization features. +The facilities in GNU 'gettext' focus on messages; strings printed by a +program, either directly or via formatting with 'printf' or +'sprintf()'.(1) - When using GNU `gettext', each application has its own "text -domain". This is a unique name, such as `kpilot' or `gawk', that -identifies the application. A complete application may have multiple + When using GNU 'gettext', each application has its own "text domain". +This is a unique name, such as 'kpilot' or 'gawk', that identifies the +application. A complete application may have multiple components--programs written in C or C++, as well as scripts written in -`sh' or `awk'. All of the components use the same text domain. +'sh' or 'awk'. All of the components use the same text domain. To make the discussion concrete, assume we're writing an application -named `guide'. Internationalization consists of the following steps, -in this order: +named 'guide'. Internationalization consists of the following steps, in +this order: - 1. The programmer goes through the source for all of `guide''s + 1. The programmer goes through the source for all of 'guide''s components and marks each string that is a candidate for - translation. For example, `"`-F': option required"' is a good - candidate for translation. A table with strings of option names - is not (e.g., `gawk''s `--profile' option should remain the same, - no matter what the local language). + translation. For example, '"`-F': option required"' is a good + candidate for translation. A table with strings of option names is + not (e.g., 'gawk''s '--profile' option should remain the same, no + matter what the local language). - 2. The programmer indicates the application's text domain (`"guide"') - to the `gettext' library, by calling the `textdomain()' function. + 2. The programmer indicates the application's text domain ('"guide"') + to the 'gettext' library, by calling the 'textdomain()' function. 3. Messages from the application are extracted from the source code - and collected into a portable object template file (`guide.pot'), + and collected into a portable object template file ('guide.pot'), which lists the strings and their translations. The translations - are initially empty. The original (usually English) messages - serve as the key for lookup of the translations. + are initially empty. The original (usually English) messages serve + as the key for lookup of the translations. - 4. For each language with a translator, `guide.pot' is copied to a - portable object file (`.po') and translations are created and + 4. For each language with a translator, 'guide.pot' is copied to a + portable object file ('.po') and translations are created and shipped with the application. For example, there might be a - `fr.po' for a French translation. + 'fr.po' for a French translation. - 5. Each language's `.po' file is converted into a binary message - object (`.gmo') file. A message object file contains the original - messages and their translations in a binary format that allows - fast lookup of translations at runtime. + 5. Each language's '.po' file is converted into a binary message + object ('.gmo') file. A message object file contains the original + messages and their translations in a binary format that allows fast + lookup of translations at runtime. - 6. When `guide' is built and installed, the binary translation files + 6. When 'guide' is built and installed, the binary translation files are installed in a standard place. - 7. For testing and development, it is possible to tell `gettext' to - use `.gmo' files in a different directory than the standard one by - using the `bindtextdomain()' function. + 7. For testing and development, it is possible to tell 'gettext' to + use '.gmo' files in a different directory than the standard one by + using the 'bindtextdomain()' function. - 8. At runtime, `guide' looks up each string via a call to - `gettext()'. The returned string is the translated string if - available, or the original string if not. + 8. At runtime, 'guide' looks up each string via a call to 'gettext()'. + The returned string is the translated string if available, or the + original string if not. 9. If necessary, it is possible to access messages from a different text domain than the one belonging to the application, without @@ -19811,16 +19729,16 @@ in this order: forth. In C (or C++), the string marking and dynamic translation lookup are -accomplished by wrapping each string in a call to `gettext()': +accomplished by wrapping each string in a call to 'gettext()': printf("%s", gettext("Don't Panic!\n")); - The tools that extract messages from source code pull out all -strings enclosed in calls to `gettext()'. + The tools that extract messages from source code pull out all strings +enclosed in calls to 'gettext()'. - The GNU `gettext' developers, recognizing that typing `gettext(...)' + The GNU 'gettext' developers, recognizing that typing 'gettext(...)' over and over again is both painful and ugly to look at, use the macro -`_' (an underscore) to make things easier: +'_' (an underscore) to make things easier: /* In the standard header file: */ #define _(str) gettext(str) @@ -19832,125 +19750,125 @@ This reduces the typing overhead to just three extra characters per string and is considerably easier to read as well. There are locale "categories" for different types of locale-related -information. The defined locale categories that `gettext' knows about +information. The defined locale categories that 'gettext' knows about are: -`LC_MESSAGES' - Text messages. This is the default category for `gettext' +'LC_MESSAGES' + Text messages. This is the default category for 'gettext' operations, but it is possible to supply a different one explicitly, if necessary. (It is almost never necessary to supply a different category.) -`LC_COLLATE' +'LC_COLLATE' Text-collation information; i.e., how different characters and/or groups of characters sort in a given language. -`LC_CTYPE' - Character-type information (alphabetic, digit, upper- or - lowercase, and so on). This information is accessed via the POSIX - character classes in regular expressions, such as `/[[:alnum:]]/' - (*note Regexp Operators::). +'LC_CTYPE' + Character-type information (alphabetic, digit, upper- or lowercase, + and so on). This information is accessed via the POSIX character + classes in regular expressions, such as '/[[:alnum:]]/' (*note + Regexp Operators::). -`LC_MONETARY' +'LC_MONETARY' Monetary information, such as the currency symbol, and whether the symbol goes before or after a number. -`LC_NUMERIC' +'LC_NUMERIC' Numeric information, such as which characters to use for the decimal point and the thousands separator.(2) -`LC_RESPONSE' +'LC_RESPONSE' Response information, such as how "yes" and "no" appear in the local language, and possibly other information as well. -`LC_TIME' +'LC_TIME' Time- and date-related information, such as 12- or 24-hour clock, month printed before or after the day in a date, local month abbreviations, and so on. -`LC_ALL' - All of the above. (Not too useful in the context of `gettext'.) +'LC_ALL' + All of the above. (Not too useful in the context of 'gettext'.) ---------- Footnotes ---------- - (1) For some operating systems, the `gawk' port doesn't support GNU -`gettext'. Therefore, these features are not available if you are -using one of those operating systems. Sorry. + (1) For some operating systems, the 'gawk' port doesn't support GNU +'gettext'. Therefore, these features are not available if you are using +one of those operating systems. Sorry. - (2) Americans use a comma every three decimal places and a period -for the decimal point, while many Europeans do exactly the opposite: + (2) Americans use a comma every three decimal places and a period for +the decimal point, while many Europeans do exactly the opposite: 1,234.56 versus 1.234,56.  File: gawk.info, Node: Programmer i18n, Next: Translator i18n, Prev: Explaining gettext, Up: Internationalization -13.3 Internationalizing `awk' Programs +13.3 Internationalizing 'awk' Programs ====================================== -`gawk' provides the following variables and functions for +'gawk' provides the following variables and functions for internationalization: -`TEXTDOMAIN' +'TEXTDOMAIN' This variable indicates the application's text domain. For - compatibility with GNU `gettext', the default value is - `"messages"'. + compatibility with GNU 'gettext', the default value is + '"messages"'. -`_"your message here"' +'_"your message here"' String constants marked with a leading underscore are candidates for translation at runtime. String constants without a leading underscore are not translated. -``dcgettext(STRING' [`,' DOMAIN [`,' CATEGORY]]`)'' +'dcgettext(STRING [, DOMAIN [, CATEGORY]])' Return the translation of STRING in text domain DOMAIN for locale category CATEGORY. The default value for DOMAIN is the current - value of `TEXTDOMAIN'. The default value for CATEGORY is - `"LC_MESSAGES"'. + value of 'TEXTDOMAIN'. The default value for CATEGORY is + '"LC_MESSAGES"'. If you supply a value for CATEGORY, it must be a string equal to one of the known locale categories described in *note Explaining - gettext::. You must also supply a text domain. Use `TEXTDOMAIN' + gettext::. You must also supply a text domain. Use 'TEXTDOMAIN' if you want to use the current domain. - CAUTION: The order of arguments to the `awk' version of the - `dcgettext()' function is purposely different from the order - for the C version. The `awk' version's order was chosen to - be simple and to allow for reasonable `awk'-style default + CAUTION: The order of arguments to the 'awk' version of the + 'dcgettext()' function is purposely different from the order + for the C version. The 'awk' version's order was chosen to be + simple and to allow for reasonable 'awk'-style default arguments. -``dcngettext(STRING1, STRING2, NUMBER' [`,' DOMAIN [`,' CATEGORY]]`)'' +'dcngettext(STRING1, STRING2, NUMBER [, DOMAIN [, CATEGORY]])' Return the plural form used for NUMBER of the translation of STRING1 and STRING2 in text domain DOMAIN for locale category - CATEGORY. STRING1 is the English singular variant of a message, + CATEGORY. STRING1 is the English singular variant of a message, and STRING2 the English plural variant of the same message. The - default value for DOMAIN is the current value of `TEXTDOMAIN'. - The default value for CATEGORY is `"LC_MESSAGES"'. + default value for DOMAIN is the current value of 'TEXTDOMAIN'. The + default value for CATEGORY is '"LC_MESSAGES"'. - The same remarks about argument order as for the `dcgettext()' + The same remarks about argument order as for the 'dcgettext()' function apply. -``bindtextdomain(DIRECTORY' [`,' DOMAIN ]`)'' - Change the directory in which `gettext' looks for `.gmo' files, in +'bindtextdomain(DIRECTORY [, DOMAIN ])' + Change the directory in which 'gettext' looks for '.gmo' files, in case they will not or cannot be placed in the standard locations (e.g., during testing). Return the directory in which DOMAIN is "bound." - The default DOMAIN is the value of `TEXTDOMAIN'. If DIRECTORY is - the null string (`""'), then `bindtextdomain()' returns the - current binding for the given DOMAIN. + The default DOMAIN is the value of 'TEXTDOMAIN'. If DIRECTORY is + the null string ('""'), then 'bindtextdomain()' returns the current + binding for the given DOMAIN. - To use these facilities in your `awk' program, follow the steps + To use these facilities in your 'awk' program, follow the steps outlined in *note Explaining gettext::, like so: - 1. Set the variable `TEXTDOMAIN' to the text domain of your program. - This is best done in a `BEGIN' rule (*note BEGIN/END::), or it can - also be done via the `-v' command-line option (*note Options::): + 1. Set the variable 'TEXTDOMAIN' to the text domain of your program. + This is best done in a 'BEGIN' rule (*note BEGIN/END::), or it can + also be done via the '-v' command-line option (*note Options::): BEGIN { TEXTDOMAIN = "guide" ... } - 2. Mark all translatable strings with a leading underscore (`_') + 2. Mark all translatable strings with a leading underscore ('_') character. It _must_ be adjacent to the opening quote of the string. For example: @@ -19959,19 +19877,19 @@ outlined in *note Explaining gettext::, like so: printf(_"Number of users is %d\n", nusers) 3. If you are creating strings dynamically, you can still translate - them, using the `dcgettext()' built-in function: + them, using the 'dcgettext()' built-in function: message = nusers " users logged in" message = dcgettext(message, "adminprog") print message - Here, the call to `dcgettext()' supplies a different text domain - (`"adminprog"') in which to find the message, but it uses the - default `"LC_MESSAGES"' category. + Here, the call to 'dcgettext()' supplies a different text domain + ('"adminprog"') in which to find the message, but it uses the + default '"LC_MESSAGES"' category. - 4. During development, you might want to put the `.gmo' file in a + 4. During development, you might want to put the '.gmo' file in a private directory for testing. This is done with the - `bindtextdomain()' built-in function: + 'bindtextdomain()' built-in function: BEGIN { TEXTDOMAIN = "guide" # our text domain @@ -19984,30 +19902,29 @@ outlined in *note Explaining gettext::, like so: ... } - *Note I18N Example::, for an example program showing the steps to -create and use translations from `awk'. +create and use translations from 'awk'.  File: gawk.info, Node: Translator i18n, Next: I18N Example, Prev: Programmer i18n, Up: Internationalization -13.4 Translating `awk' Programs +13.4 Translating 'awk' Programs =============================== Once a program's translatable strings have been marked, they must be -extracted to create the initial `.pot' file. As part of translation, -it is often helpful to rearrange the order in which arguments to -`printf' are output. +extracted to create the initial '.pot' file. As part of translation, it +is often helpful to rearrange the order in which arguments to 'printf' +are output. - `gawk''s `--gen-pot' command-line option extracts the messages and -is discussed next. After that, `printf''s ability to rearrange the -order for `printf' arguments at runtime is covered. + 'gawk''s '--gen-pot' command-line option extracts the messages and is +discussed next. After that, 'printf''s ability to rearrange the order +for 'printf' arguments at runtime is covered. * Menu: * String Extraction:: Extracting marked strings. -* Printf Ordering:: Rearranging `printf' arguments. -* I18N Portability:: `awk'-level portability issues. +* Printf Ordering:: Rearranging 'printf' arguments. +* I18N Portability:: 'awk'-level portability issues.  File: gawk.info, Node: String Extraction, Next: Printf Ordering, Up: Translator i18n @@ -20015,33 +19932,33 @@ File: gawk.info, Node: String Extraction, Next: Printf Ordering, Up: Translat 13.4.1 Extracting Marked Strings -------------------------------- -Once your `awk' program is working, and all the strings have been -marked and you've set (and perhaps bound) the text domain, it is time -to produce translations. First, use the `--gen-pot' command-line -option to create the initial `.pot' file: +Once your 'awk' program is working, and all the strings have been marked +and you've set (and perhaps bound) the text domain, it is time to +produce translations. First, use the '--gen-pot' command-line option to +create the initial '.pot' file: $ gawk --gen-pot -f guide.awk > guide.pot - When run with `--gen-pot', `gawk' does not execute your program. -Instead, it parses it as usual and prints all marked strings to -standard output in the format of a GNU `gettext' Portable Object file. -Also included in the output are any constant strings that appear as the -first argument to `dcgettext()' or as the first and second argument to -`dcngettext()'.(1) *Note I18N Example::, for the full list of steps to -go through to create and test translations for `guide'. + When run with '--gen-pot', 'gawk' does not execute your program. +Instead, it parses it as usual and prints all marked strings to standard +output in the format of a GNU 'gettext' Portable Object file. Also +included in the output are any constant strings that appear as the first +argument to 'dcgettext()' or as the first and second argument to +'dcngettext()'.(1) *Note I18N Example::, for the full list of steps to +go through to create and test translations for 'guide'. ---------- Footnotes ---------- - (1) The `xgettext' utility that comes with GNU `gettext' can handle -`.awk' files. + (1) The 'xgettext' utility that comes with GNU 'gettext' can handle +'.awk' files.  File: gawk.info, Node: Printf Ordering, Next: I18N Portability, Prev: String Extraction, Up: Translator i18n -13.4.2 Rearranging `printf' Arguments +13.4.2 Rearranging 'printf' Arguments ------------------------------------- -Format strings for `printf' and `sprintf()' (*note Printf::) present a +Format strings for 'printf' and 'sprintf()' (*note Printf::) present a special problem for translation. Consider the following:(1) printf(_"String `%s' has %d characters\n", @@ -20051,21 +19968,21 @@ special problem for translation. Consider the following:(1) "%d Zeichen lang ist die Zeichenkette `%s'\n" - The problem should be obvious: the order of the format -specifications is different from the original! Even though `gettext()' -can return the translated string at runtime, it cannot change the -argument order in the call to `printf'. + The problem should be obvious: the order of the format specifications +is different from the original! Even though 'gettext()' can return the +translated string at runtime, it cannot change the argument order in the +call to 'printf'. - To solve this problem, `printf' format specifiers may have an + To solve this problem, 'printf' format specifiers may have an additional optional element, which we call a "positional specifier". For example: "%2$d Zeichen lang ist die Zeichenkette `%1$s'\n" Here, the positional specifier consists of an integer count, which -indicates which argument to use, and a `$'. Counts are one-based, and +indicates which argument to use, and a '$'. Counts are one-based, and the format string itself is _not_ included. Thus, in the following -example, `string' is the first argument and `length(string)' is the +example, 'string' is the first argument and 'length(string)' is the second: $ gawk 'BEGIN { @@ -20088,39 +20005,39 @@ precision capability: -| hello -| hello - NOTE: When using `*' with a positional specifier, the `*' comes - first, then the integer position, and then the `$'. This is + NOTE: When using '*' with a positional specifier, the '*' comes + first, then the integer position, and then the '$'. This is somewhat counterintuitive. - `gawk' does not allow you to mix regular format specifiers and those + 'gawk' does not allow you to mix regular format specifiers and those with positional specifiers in the same string: $ gawk 'BEGIN { printf "%d %3$s\n", 1, 2, "hi" }' - error--> gawk: cmd. line:1: fatal: must use `count$' on all formats or none + error-> gawk: cmd. line:1: fatal: must use `count$' on all formats or none - NOTE: There are some pathological cases that `gawk' may fail to + NOTE: There are some pathological cases that 'gawk' may fail to diagnose. In such cases, the output may not be what you expect. - It's still a bad idea to try mixing them, even if `gawk' doesn't + It's still a bad idea to try mixing them, even if 'gawk' doesn't detect it. - Although positional specifiers can be used directly in `awk' + Although positional specifiers can be used directly in 'awk' programs, their primary purpose is to help in producing correct translations of format strings into languages different from the one in which the program is first written. ---------- Footnotes ---------- - (1) This example is borrowed from the GNU `gettext' manual. + (1) This example is borrowed from the GNU 'gettext' manual.  File: gawk.info, Node: I18N Portability, Prev: Printf Ordering, Up: Translator i18n -13.4.3 `awk' Portability Issues +13.4.3 'awk' Portability Issues ------------------------------- -`gawk''s internationalization features were purposely chosen to have as -little impact as possible on the portability of `awk' programs that use -them to other versions of `awk'. Consider this program: +'gawk''s internationalization features were purposely chosen to have as +little impact as possible on the portability of 'awk' programs that use +them to other versions of 'awk'. Consider this program: BEGIN { TEXTDOMAIN = "guide" @@ -20129,19 +20046,19 @@ them to other versions of `awk'. Consider this program: print _"don't panic!" } -As written, it won't work on other versions of `awk'. However, it is +As written, it won't work on other versions of 'awk'. However, it is actually almost portable, requiring very little change: - * Assignments to `TEXTDOMAIN' won't have any effect, since - `TEXTDOMAIN' is not special in other `awk' implementations. + * Assignments to 'TEXTDOMAIN' won't have any effect, since + 'TEXTDOMAIN' is not special in other 'awk' implementations. - * Non-GNU versions of `awk' treat marked strings as the - concatenation of a variable named `_' with the string following - it.(1) Typically, the variable `_' has the null string (`""') as - its value, leaving the original string constant as the result. + * Non-GNU versions of 'awk' treat marked strings as the concatenation + of a variable named '_' with the string following it.(1) + Typically, the variable '_' has the null string ('""') as its + value, leaving the original string constant as the result. - * By defining "dummy" functions to replace `dcgettext()', - `dcngettext()' and `bindtextdomain()', the `awk' program can be + * By defining "dummy" functions to replace 'dcgettext()', + 'dcngettext()' and 'bindtextdomain()', the 'awk' program can be made to run, but all the messages are output in the original language. For example: @@ -20160,22 +20077,22 @@ actually almost portable, requiring very little change: return (number == 1 ? string1 : string2) } - * The use of positional specifications in `printf' or `sprintf()' is - _not_ portable. To support `gettext()' at the C level, many - systems' C versions of `sprintf()' do support positional + * The use of positional specifications in 'printf' or 'sprintf()' is + _not_ portable. To support 'gettext()' at the C level, many + systems' C versions of 'sprintf()' do support positional specifiers. But it works only if enough arguments are supplied in - the function call. Many versions of `awk' pass `printf' formats + the function call. Many versions of 'awk' pass 'printf' formats and arguments unchanged to the underlying C library version of - `sprintf()', but only one format and argument at a time. What + 'sprintf()', but only one format and argument at a time. What happens if a positional specification is used is anybody's guess. However, since the positional specifications are primarily for use - in _translated_ format strings, and since non-GNU `awk's never + in _translated_ format strings, and since non-GNU 'awk's never retrieve the translated string, this should not be a problem in practice. ---------- Footnotes ---------- - (1) This is good fodder for an "Obfuscated `awk'" contest. + (1) This is good fodder for an "Obfuscated 'awk'" contest.  File: gawk.info, Node: I18N Example, Next: Gawk I18N, Prev: Translator i18n, Up: Internationalization @@ -20184,7 +20101,7 @@ File: gawk.info, Node: I18N Example, Next: Gawk I18N, Prev: Translator i18n, ========================================== Now let's look at a step-by-step example of how to internationalize and -localize a simple `awk' program, using `guide.awk' as our original +localize a simple 'awk' program, using 'guide.awk' as our original source: BEGIN { @@ -20195,7 +20112,7 @@ source: print "Pardon me, Zaphod who?" } -Run `gawk --gen-pot' to create the `.pot' file: +Run 'gawk --gen-pot' to create the '.pot' file: $ gawk --gen-pot -f guide.awk > guide.pot @@ -20210,11 +20127,11 @@ This produces: msgstr "" This original portable object template file is saved and reused for -each language into which the application is translated. The `msgid' is -the original string and the `msgstr' is the translation. +each language into which the application is translated. The 'msgid' is +the original string and the 'msgstr' is the translation. - NOTE: Strings not marked with a leading underscore do not appear - in the `guide.pot' file. + NOTE: Strings not marked with a leading underscore do not appear in + the 'guide.pot' file. Next, the messages must be translated. Here is a translation to a hypothetical dialect of English, called "Mellow":(1) @@ -20233,17 +20150,17 @@ Following are the translations: msgstr "Like, the scoop is" The next step is to make the directory to hold the binary message -object file and then to create the `guide.mo' file. We pretend that -our file is to be used in the `en_US.UTF-8' locale. The directory -layout shown here is standard for GNU `gettext' on GNU/Linux systems. -Other versions of `gettext' may use a different layout: +object file and then to create the 'guide.mo' file. We pretend that our +file is to be used in the 'en_US.UTF-8' locale. The directory layout +shown here is standard for GNU 'gettext' on GNU/Linux systems. Other +versions of 'gettext' may use a different layout: $ mkdir en_US.UTF-8 en_US.UTF-8/LC_MESSAGES - The `msgfmt' utility does the conversion from human-readable `.po' -file to machine-readable `.mo' file. By default, `msgfmt' creates a -file named `messages'. This file must be renamed and placed in the -proper directory so that `gawk' can find it: + The 'msgfmt' utility does the conversion from human-readable '.po' +file to machine-readable '.mo' file. By default, 'msgfmt' creates a +file named 'messages'. This file must be renamed and placed in the +proper directory so that 'gawk' can find it: $ msgfmt guide-mellow.po $ mv messages en_US.UTF-8/LC_MESSAGES/guide.mo @@ -20255,9 +20172,9 @@ proper directory so that `gawk' can find it: -| Like, the scoop is 42 -| Pardon me, Zaphod who? - If the three replacement functions for `dcgettext()', `dcngettext()' -and `bindtextdomain()' (*note I18N Portability::) are in a file named -`libintl.awk', then we can run `guide.awk' unchanged as follows: + If the three replacement functions for 'dcgettext()', 'dcngettext()' +and 'bindtextdomain()' (*note I18N Portability::) are in a file named +'libintl.awk', then we can run 'guide.awk' unchanged as follows: $ gawk --posix -f guide.awk -f libintl.awk -| Don't Panic @@ -20266,21 +20183,21 @@ and `bindtextdomain()' (*note I18N Portability::) are in a file named ---------- Footnotes ---------- - (1) Perhaps it would be better if it were called "Hippy." Ah, well. + (1) Perhaps it would be better if it were called "Hippy." Ah, well.  File: gawk.info, Node: Gawk I18N, Next: I18N Summary, Prev: I18N Example, Up: Internationalization -13.6 `gawk' Can Speak Your Language +13.6 'gawk' Can Speak Your Language =================================== -`gawk' itself has been internationalized using the GNU `gettext' -package. (GNU `gettext' is described in complete detail in *note (GNU -`gettext' utilities)Top:: gettext, GNU gettext tools.) As of this -writing, the latest version of GNU `gettext' is version 0.19.1 +'gawk' itself has been internationalized using the GNU 'gettext' +package. (GNU 'gettext' is described in complete detail in *note (GNU +'gettext' utilities, gettext, GNU gettext tools)Top::.) As of this +writing, the latest version of GNU 'gettext' is version 0.19.1 (ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.1.tar.gz). - If a translation of `gawk''s messages exists, then `gawk' produces + If a translation of 'gawk''s messages exists, then 'gawk' produces usage messages, warnings, and fatal errors in the local language.  @@ -20294,47 +20211,46 @@ File: gawk.info, Node: I18N Summary, Prev: Gawk I18N, Up: Internationalizatio Localization means providing the data necessary for an internationalized program to work in a particular language. - * `gawk' uses GNU `gettext' to let you internationalize and localize - `awk' programs. A program's text domain identifies the program - for grouping all messages and other data together. + * 'gawk' uses GNU 'gettext' to let you internationalize and localize + 'awk' programs. A program's text domain identifies the program for + grouping all messages and other data together. * You mark a program's strings for translation by preceding them with - an underscore. Once that is done, the strings are extracted into a - `.pot' file. This file is copied for each language into a `.po' - file, and the `.po' files are compiled into `.gmo' files for use - at runtime. + an underscore. Once that is done, the strings are extracted into a + '.pot' file. This file is copied for each language into a '.po' + file, and the '.po' files are compiled into '.gmo' files for use at + runtime. - * You can use position specifications with `sprintf()' and `printf' + * You can use position specifications with 'sprintf()' and 'printf' to rearrange the placement of argument values in formatted strings - and output. This is useful for the translations of format control + and output. This is useful for the translations of format control strings. * The internationalization features have been designed so that they - can be easily worked around in a standard `awk'. - - * `gawk' itself has been internationalized and ships with a number - of translations for its messages. + can be easily worked around in a standard 'awk'. + * 'gawk' itself has been internationalized and ships with a number of + translations for its messages.  File: gawk.info, Node: Debugger, Next: Arbitrary Precision Arithmetic, Prev: Internationalization, Up: Top -14 Debugging `awk' Programs +14 Debugging 'awk' Programs *************************** It would be nice if computer programs worked perfectly the first time -they were run, but in real life, this rarely happens for programs of -any complexity. Thus, most programming languages have facilities -available for "debugging" programs, and now `awk' is no exception. +they were run, but in real life, this rarely happens for programs of any +complexity. Thus, most programming languages have facilities available +for "debugging" programs, and now 'awk' is no exception. - The `gawk' debugger is purposely modeled after the GNU Debugger -(GDB) (http://www.gnu.org/software/gdb/) command-line debugger. If you -are familiar with GDB, learning how to use `gawk' for debugging your -program is easy. + The 'gawk' debugger is purposely modeled after the GNU Debugger (GDB) +(http://www.gnu.org/software/gdb/) command-line debugger. If you are +familiar with GDB, learning how to use 'gawk' for debugging your program +is easy. * Menu: -* Debugging:: Introduction to `gawk' debugger. +* Debugging:: Introduction to 'gawk' debugger. * Sample Debugging Session:: Sample debugging session. * List of Debugger Commands:: Main debugger commands. * Readline Support:: Readline support. @@ -20344,11 +20260,11 @@ program is easy.  File: gawk.info, Node: Debugging, Next: Sample Debugging Session, Up: Debugger -14.1 Introduction to The `gawk' Debugger +14.1 Introduction to The 'gawk' Debugger ======================================== This minor node introduces debugging in general and begins the -discussion of debugging in `gawk'. +discussion of debugging in 'gawk'. * Menu: @@ -20363,7 +20279,7 @@ File: gawk.info, Node: Debugging Concepts, Next: Debugging Terms, Up: Debuggi --------------------------- (If you have used debuggers in other languages, you may want to skip -ahead to the next section on the specific features of the `awk' +ahead to the next section on the specific features of the 'awk' debugger.) Of course, a debugging program cannot remove bugs for you, since it @@ -20410,21 +20326,21 @@ defines terms used throughout the rest of this major node. Programs generally call functions during the course of their execution. One function can call another, or a function can call itself (recursion). You can view the chain of called functions - (main program calls A, which calls B, which calls C), as a stack - of executing functions: the currently running function is the - topmost one on the stack, and when it finishes (returns), the next - one down then becomes the active function. Such a stack is termed - a "call stack". + (main program calls A, which calls B, which calls C), as a stack of + executing functions: the currently running function is the topmost + one on the stack, and when it finishes (returns), the next one down + then becomes the active function. Such a stack is termed a "call + stack". For each function on the call stack, the system maintains a data area that contains the function's parameters, local variables, and - return value, as well as any other "bookkeeping" information - needed to manage the call stack. This data area is termed a - "stack frame". + return value, as well as any other "bookkeeping" information needed + to manage the call stack. This data area is termed a "stack + frame". - `gawk' also follows this model, and gives you access to the call - stack and to each stack frame. You can see the call stack, as well - as from where each function on the stack was invoked. Commands + 'gawk' also follows this model, and gives you access to the call + stack and to each stack frame. You can see the call stack, as well + as from where each function on the stack was invoked. Commands that print the call stack print information about each stack frame (as detailed later on). @@ -20439,14 +20355,14 @@ defines terms used throughout the rest of this major node. "Watchpoint" A watchpoint is similar to a breakpoint. The difference is that - breakpoints are oriented around the code: stop when a certain - point in the code is reached. A watchpoint, however, specifies - that program execution should stop when a _data value_ is changed. - This is useful, since sometimes it happens that a variable - receives an erroneous value, and it's hard to track down where - this happens just by looking at the code. By using a watchpoint, - you can stop whenever a variable is assigned to, and usually find - the errant code quite quickly. + breakpoints are oriented around the code: stop when a certain point + in the code is reached. A watchpoint, however, specifies that + program execution should stop when a _data value_ is changed. This + is useful, since sometimes it happens that a variable receives an + erroneous value, and it's hard to track down where this happens + just by looking at the code. By using a watchpoint, you can stop + whenever a variable is assigned to, and usually find the errant + code quite quickly.  File: gawk.info, Node: Awk Debugging, Prev: Debugging Terms, Up: Debugging @@ -20454,20 +20370,20 @@ File: gawk.info, Node: Awk Debugging, Prev: Debugging Terms, Up: Debugging 14.1.3 Awk Debugging -------------------- -Debugging an `awk' program has some specific aspects that are not -shared with other programming languages. +Debugging an 'awk' program has some specific aspects that are not shared +with other programming languages. - First of all, the fact that `awk' programs usually take input + First of all, the fact that 'awk' programs usually take input line-by-line from a file or files and operate on those lines using specific rules makes it especially useful to organize viewing the execution of the program in terms of these rules. As we will see, each -`awk' rule is treated almost like a function call, with its own -specific block of instructions. +'awk' rule is treated almost like a function call, with its own specific +block of instructions. - In addition, since `awk' is by design a very concise language, it is + In addition, since 'awk' is by design a very concise language, it is easy to lose sight of everything that is going on "inside" each line of -`awk' code. The debugger provides the opportunity to look at the -individual primitive instructions carried out by the higher-level `awk' +'awk' code. The debugger provides the opportunity to look at the +individual primitive instructions carried out by the higher-level 'awk' commands.  @@ -20476,9 +20392,9 @@ File: gawk.info, Node: Sample Debugging Session, Next: List of Debugger Comman 14.2 Sample Debugging Session ============================= -In order to illustrate the use of `gawk' as a debugger, let's look at a -sample debugging session. We will use the `awk' implementation of the -POSIX `uniq' command described earlier (*note Uniq Program::) as our +In order to illustrate the use of 'gawk' as a debugger, let's look at a +sample debugging session. We will use the 'awk' implementation of the +POSIX 'uniq' command described earlier (*note Uniq Program::) as our example. * Menu: @@ -20492,24 +20408,23 @@ File: gawk.info, Node: Debugger Invocation, Next: Finding The Bug, Up: Sample 14.2.1 How to Start the Debugger -------------------------------- -Starting the debugger is almost exactly like running `gawk', except you -have to pass an additional option `--debug' or the corresponding short -option `-D'. The file(s) containing the program and any supporting -code are given on the command line as arguments to one or more `-f' -options. (`gawk' is not designed to debug command-line programs, only -programs contained in files.) In our case, we invoke the debugger like -this: +Starting the debugger is almost exactly like running 'gawk', except you +have to pass an additional option '--debug' or the corresponding short +option '-D'. The file(s) containing the program and any supporting code +are given on the command line as arguments to one or more '-f' options. +('gawk' is not designed to debug command-line programs, only programs +contained in files.) In our case, we invoke the debugger like this: $ gawk -D -f getopt.awk -f join.awk -f uniq.awk inputfile -where both `getopt.awk' and `uniq.awk' are in `$AWKPATH'. (Experienced +where both 'getopt.awk' and 'uniq.awk' are in '$AWKPATH'. (Experienced users of GDB or similar debuggers should note that this syntax is -slightly different from what they are used to. With the `gawk' +slightly different from what they are used to. With the 'gawk' debugger, you give the arguments for running the program in the command -line to the debugger rather than as part of the `run' command at the +line to the debugger rather than as part of the 'run' command at the debugger prompt.) - Instead of immediately running the program on `inputfile', as `gawk' + Instead of immediately running the program on 'inputfile', as 'gawk' would ordinarily do, the debugger merely loads all the program source files, compiles them internally, and then gives us a prompt: @@ -20525,7 +20440,7 @@ File: gawk.info, Node: Finding The Bug, Prev: Debugger Invocation, Up: Sample ---------------------- Let's say that we are having a problem using (a faulty version of) -`uniq.awk' in the "field-skipping" mode, and it doesn't seem to be +'uniq.awk' in the "field-skipping" mode, and it doesn't seem to be catching lines which should be identical when skipping the first field, such as: @@ -20547,15 +20462,15 @@ we wrote: The first thing we usually want to do when trying to investigate a problem like this is to put a breakpoint in the program so that we can watch it at work and catch what it is doing wrong. A reasonable spot -for a breakpoint in `uniq.awk' is at the beginning of the function -`are_equal()', which compares the current line with the previous one. -To set the breakpoint, use the `b' (breakpoint) command: +for a breakpoint in 'uniq.awk' is at the beginning of the function +'are_equal()', which compares the current line with the previous one. +To set the breakpoint, use the 'b' (breakpoint) command: gawk> b are_equal -| Breakpoint 1 set at file `awklib/eg/prog/uniq.awk', line 64 The debugger tells us the file and line number where the breakpoint -is. Now type `r' or `run' and the program runs until it hits the +is. Now type 'r' or 'run' and the program runs until it hits the breakpoint for the first time: gawk> r @@ -20567,31 +20482,31 @@ breakpoint for the first time: gawk> Now we can look at what's going on inside our program. First of all, -let's see how we got to where we are. At the prompt, we type `bt' -(short for "backtrace"), and the debugger responds with a listing of -the current stack frames: +let's see how we got to where we are. At the prompt, we type 'bt' +(short for "backtrace"), and the debugger responds with a listing of the +current stack frames: gawk> bt -| #0 are_equal(n, m, clast, cline, alast, aline) at `awklib/eg/prog/uniq.awk':69 -| #1 in main() at `awklib/eg/prog/uniq.awk':89 - This tells us that `are_equal()' was called by the main program at -line 89 of `uniq.awk'. (This is not a big surprise, since this is the -only call to `are_equal()' in the program, but in more complex -programs, knowing who called a function and with what parameters can be -the key to finding the source of the problem.) + This tells us that 'are_equal()' was called by the main program at +line 89 of 'uniq.awk'. (This is not a big surprise, since this is the +only call to 'are_equal()' in the program, but in more complex programs, +knowing who called a function and with what parameters can be the key to +finding the source of the problem.) - Now that we're in `are_equal()', we can start looking at the values -of some variables. Let's say we type `p n' (`p' is short for "print"). -We would expect to see the value of `n', a parameter to `are_equal()'. + Now that we're in 'are_equal()', we can start looking at the values +of some variables. Let's say we type 'p n' ('p' is short for "print"). +We would expect to see the value of 'n', a parameter to 'are_equal()'. Actually, the debugger gives us: gawk> p n -| n = untyped variable -In this case, `n' is an uninitialized local variable, since the -function was called without arguments (*note Function Calls::). +In this case, 'n' is an uninitialized local variable, since the function +was called without arguments (*note Function Calls::). A more useful variable to display might be the current record: @@ -20599,14 +20514,14 @@ function was called without arguments (*note Function Calls::). -| $0 = string ("gawk is a wonderful program!") This might be a bit puzzling at first since this is the second line of -our test input above. Let's look at `NR': +our test input above. Let's look at 'NR': gawk> p NR -| NR = number (2) -So we can see that `are_equal()' was only called for the second record +So we can see that 'are_equal()' was only called for the second record of the file. Of course, this is because our program contains a rule for -`NR == 1': +'NR == 1': NR == 1 { last = $0 @@ -20619,19 +20534,19 @@ of the file. Of course, this is because our program contains a rule for -| last = string ("awk is a wonderful program!") Everything we have done so far has verified that the program has -worked as planned, up to and including the call to `are_equal()', so -the problem must be inside this function. To investigate further, we -must begin "stepping through" the lines of `are_equal()'. We start by -typing `n' (for "next"): +worked as planned, up to and including the call to 'are_equal()', so the +problem must be inside this function. To investigate further, we must +begin "stepping through" the lines of 'are_equal()'. We start by typing +'n' (for "next"): gawk> n -| 67 if (fcount > 0) { - This tells us that `gawk' is now ready to execute line 67, which + This tells us that 'gawk' is now ready to execute line 67, which decides whether to give the lines the special "field skipping" treatment -indicated by the `-f' command-line option. (Notice that we skipped -from where we were before at line 64 to here, since the condition in -line 64 `if (fcount == 0 && charcount == 0)' was false.) +indicated by the '-f' command-line option. (Notice that we skipped from +where we were before at line 64 to here, since the condition in line 64 +'if (fcount == 0 && charcount == 0)' was false.) Continuing to step, we now get to the splitting of the current and last records: @@ -20650,8 +20565,8 @@ split into, so we try to look: -| alast = array, 5 elements -| aline = array, 5 elements -(The `p' command can take more than one argument, similar to `awk''s -`print' statement.) +(The 'p' command can take more than one argument, similar to 'awk''s +'print' statement.) This is kind of disappointing, though. All we found out is that there are five elements in each of our arrays. Useful enough (we now @@ -20668,7 +20583,7 @@ Oops! gawk> p alast[1] -| alast["1"] = string ("awk") - This would be kind of slow for a 100-member array, though, so `gawk' + This would be kind of slow for a 100-member array, though, so 'gawk' provides a shortcut (reminiscent of another language not to be mentioned): @@ -20679,7 +20594,7 @@ mentioned): -| alast["4"] = string ("wonderful") -| alast["5"] = string ("program!") - It looks like we got this far OK. Let's take another step or two: + It looks like we got this far OK. Let's take another step or two: gawk> n -| 70 clast = join(alast, fcount, n) @@ -20717,7 +20632,7 @@ File: gawk.info, Node: List of Debugger Commands, Next: Readline Support, Pre 14.3 Main Debugger Commands =========================== -The `gawk' debugger command set can be divided into the following +The 'gawk' debugger command set can be divided into the following categories: * Breakpoint control @@ -20735,10 +20650,10 @@ categories: Each of these are discussed in the following subsections. In the following descriptions, commands which may be abbreviated show the abbreviation on a second description line. A debugger command name may -also be truncated if that partial name is unambiguous. The debugger has +also be truncated if that partial name is unambiguous. The debugger has the built-in capability to automatically repeat the previous command -just by hitting . This works for the commands `list', `next', -`nexti', `step', `stepi' and `continue' executed without any argument. +just by hitting . This works for the commands 'list', 'next', +'nexti', 'step', 'stepi' and 'continue' executed without any argument. * Menu: @@ -20761,89 +20676,89 @@ session is to get your breakpoints set up, since otherwise your program will just run as if it was not under the debugger. The commands for controlling breakpoints are: -`break' [[FILENAME`:']N | FUNCTION] [`"EXPRESSION"'] -`b' [[FILENAME`:']N | FUNCTION] [`"EXPRESSION"'] +'break' [[FILENAME':']N | FUNCTION] ['"EXPRESSION"'] +'b' [[FILENAME':']N | FUNCTION] ['"EXPRESSION"'] Without any argument, set a breakpoint at the next instruction to be executed in the selected stack frame. Arguments can be one of the following: - N + N Set a breakpoint at line number N in the current source file. - FILENAME`:'N + FILENAME':'N Set a breakpoint at line number N in source file FILENAME. - FUNCTION + FUNCTION Set a breakpoint at entry to (the first instruction of) function FUNCTION. - Each breakpoint is assigned a number which can be used to delete - it from the breakpoint list using the `delete' command. + Each breakpoint is assigned a number which can be used to delete it + from the breakpoint list using the 'delete' command. With a breakpoint, you may also supply a condition. This is an - `awk' expression (enclosed in double quotes) that the debugger - evaluates whenever the breakpoint is reached. If the condition is + 'awk' expression (enclosed in double quotes) that the debugger + evaluates whenever the breakpoint is reached. If the condition is true, then the debugger stops execution and prompts for a command. Otherwise, it continues executing the program. -`clear' [[FILENAME`:']N | FUNCTION] +'clear' [[FILENAME':']N | FUNCTION] Without any argument, delete any breakpoint at the next instruction - to be executed in the selected stack frame. If the program stops at - a breakpoint, this deletes that breakpoint so that the program + to be executed in the selected stack frame. If the program stops + at a breakpoint, this deletes that breakpoint so that the program does not stop at that location again. Arguments can be one of the following: - N + N Delete breakpoint(s) set at line number N in the current source file. - FILENAME`:'N + FILENAME':'N Delete breakpoint(s) set at line number N in source file FILENAME. - FUNCTION + FUNCTION Delete breakpoint(s) set at entry to function FUNCTION. -`condition' N `"EXPRESSION"' - Add a condition to existing breakpoint or watchpoint N. The - condition is an `awk' expression that the debugger evaluates - whenever the breakpoint or watchpoint is reached. If the condition +'condition' N '"EXPRESSION"' + Add a condition to existing breakpoint or watchpoint N. The + condition is an 'awk' expression that the debugger evaluates + whenever the breakpoint or watchpoint is reached. If the condition is true, then the debugger stops execution and prompts for a - command. Otherwise, the debugger continues executing the program. + command. Otherwise, the debugger continues executing the program. If the condition expression is not specified, any existing condition is removed; i.e., the breakpoint or watchpoint is made unconditional. -`delete' [N1 N2 ...] [N-M] -`d' [N1 N2 ...] [N-M] - Delete specified breakpoints or a range of breakpoints. Deletes +'delete' [N1 N2 ...] [N-M] +'d' [N1 N2 ...] [N-M] + Delete specified breakpoints or a range of breakpoints. Deletes all defined breakpoints if no argument is supplied. -`disable' [N1 N2 ... | N-M] - Disable specified breakpoints or a range of breakpoints. Without +'disable' [N1 N2 ... | N-M] + Disable specified breakpoints or a range of breakpoints. Without any argument, disables all breakpoints. -`enable' [`del' | `once'] [N1 N2 ...] [N-M] -`e' [`del' | `once'] [N1 N2 ...] [N-M] - Enable specified breakpoints or a range of breakpoints. Without - any argument, enables all breakpoints. Optionally, you can - specify how to enable the breakpoint: +'enable' ['del' | 'once'] [N1 N2 ...] [N-M] +'e' ['del' | 'once'] [N1 N2 ...] [N-M] + Enable specified breakpoints or a range of breakpoints. Without + any argument, enables all breakpoints. Optionally, you can specify + how to enable the breakpoint: - `del' + 'del' Enable the breakpoint(s) temporarily, then delete it when the program stops at the breakpoint. - `once' - Enable the breakpoint(s) temporarily, then disable it when - the program stops at the breakpoint. + 'once' + Enable the breakpoint(s) temporarily, then disable it when the + program stops at the breakpoint. -`ignore' N COUNT +'ignore' N COUNT Ignore breakpoint number N the next COUNT times it is hit. -`tbreak' [[FILENAME`:']N | FUNCTION] -`t' [[FILENAME`:']N | FUNCTION] +'tbreak' [[FILENAME':']N | FUNCTION] +'t' [[FILENAME':']N | FUNCTION] Set a temporary breakpoint (enabled for only one stop). The - arguments are the same as for `break'. + arguments are the same as for 'break'.  File: gawk.info, Node: Debugger Execution Control, Next: Viewing And Changing Data, Prev: Breakpoint Control, Up: List of Debugger Commands @@ -20855,19 +20770,19 @@ Now that your breakpoints are ready, you can start running the program and observing its behavior. There are more commands for controlling execution of the program than we saw in our earlier example: -`commands' [N] -`silent' +'commands' [N] +'silent' ... -`end' - Set a list of commands to be executed upon stopping at a - breakpoint or watchpoint. N is the breakpoint or watchpoint number. - Without a number, the last one set is used. The actual commands - follow, starting on the next line, and terminated by the `end' - command. If the command `silent' is in the list, the usual - messages about stopping at a breakpoint and the source line are - not printed. Any command in the list that resumes execution (e.g., - `continue') terminates the list (an implicit `end'), and - subsequent commands are ignored. For example: +'end' + Set a list of commands to be executed upon stopping at a breakpoint + or watchpoint. N is the breakpoint or watchpoint number. Without + a number, the last one set is used. The actual commands follow, + starting on the next line, and terminated by the 'end' command. If + the command 'silent' is in the list, the usual messages about + stopping at a breakpoint and the source line are not printed. Any + command in the list that resumes execution (e.g., 'continue') + terminates the list (an implicit 'end'), and subsequent commands + are ignored. For example: gawk> commands > silent @@ -20878,60 +20793,60 @@ execution of the program than we saw in our earlier example: > end gawk> -`continue' [COUNT] -`c' [COUNT] - Resume program execution. If continued from a breakpoint and COUNT +'continue' [COUNT] +'c' [COUNT] + Resume program execution. If continued from a breakpoint and COUNT is specified, ignores the breakpoint at that location the next COUNT times before stopping. -`finish' - Execute until the selected stack frame returns. Print the - returned value. +'finish' + Execute until the selected stack frame returns. Print the returned + value. -`next' [COUNT] -`n' [COUNT] +'next' [COUNT] +'n' [COUNT] Continue execution to the next source line, stepping over function calls. The argument COUNT controls how many times to repeat the - action, as in `step'. + action, as in 'step'. -`nexti' [COUNT] -`ni' [COUNT] +'nexti' [COUNT] +'ni' [COUNT] Execute one (or COUNT) instruction(s), stepping over function calls. -`return' [VALUE] - Cancel execution of a function call. If VALUE (either a string or a - number) is specified, it is used as the function's return value. +'return' [VALUE] + Cancel execution of a function call. If VALUE (either a string or + a number) is specified, it is used as the function's return value. If used in a frame other than the innermost one (the currently - executing function, i.e., frame number 0), discard all inner - frames in addition to the selected one, and the caller of that - frame becomes the innermost frame. + executing function, i.e., frame number 0), discard all inner frames + in addition to the selected one, and the caller of that frame + becomes the innermost frame. -`run' -`r' - Start/restart execution of the program. When restarting, the +'run' +'r' + Start/restart execution of the program. When restarting, the debugger retains the current breakpoints, watchpoints, command history, automatic display variables, and debugger options. -`step' [COUNT] -`s' [COUNT] - Continue execution until control reaches a different source line - in the current stack frame. `step' steps inside any function - called within the line. If the argument COUNT is supplied, steps - that many times before stopping, unless it encounters a breakpoint - or watchpoint. +'step' [COUNT] +'s' [COUNT] + Continue execution until control reaches a different source line in + the current stack frame. 'step' steps inside any function called + within the line. If the argument COUNT is supplied, steps that + many times before stopping, unless it encounters a breakpoint or + watchpoint. -`stepi' [COUNT] -`si' [COUNT] +'stepi' [COUNT] +'si' [COUNT] Execute one (or COUNT) instruction(s), stepping inside function calls. (For illustration of what is meant by an "instruction" in - `gawk', see the output shown under `dump' in *note Miscellaneous + 'gawk', see the output shown under 'dump' in *note Miscellaneous Debugger Commands::.) -`until' [[FILENAME`:']N | FUNCTION] -`u' [[FILENAME`:']N | FUNCTION] +'until' [[FILENAME':']N | FUNCTION] +'u' [[FILENAME':']N | FUNCTION] Without any argument, continue execution until a line past the - current line in current stack frame is reached. With an argument, + current line in current stack frame is reached. With an argument, continue execution until the specified location is reached, or the current stack frame returns. @@ -20941,11 +20856,11 @@ File: gawk.info, Node: Viewing And Changing Data, Next: Execution Stack, Prev 14.3.3 Viewing and Changing Data -------------------------------- -The commands for viewing and changing variables inside of `gawk' are: +The commands for viewing and changing variables inside of 'gawk' are: -`display' [VAR | `$'N] - Add variable VAR (or field `$N') to the display list. The value - of the variable or field is displayed each time the program stops. +'display' [VAR | '$'N] + Add variable VAR (or field '$N') to the display list. The value of + the variable or field is displayed each time the program stops. Each variable added to the list is identified by a unique number: gawk> display x @@ -20955,110 +20870,107 @@ The commands for viewing and changing variables inside of `gawk' are: current value. If the display variable refers to a function parameter, it is silently deleted from the list as soon as the execution reaches a context where no such variable of the given - name exists. Without argument, `display' displays the current + name exists. Without argument, 'display' displays the current values of items on the list. -`eval "AWK STATEMENTS"' - Evaluate AWK STATEMENTS in the context of the running program. - You can do anything that an `awk' program would do: assign values - to variables, call functions, and so on. +'eval "AWK STATEMENTS"' + Evaluate AWK STATEMENTS in the context of the running program. You + can do anything that an 'awk' program would do: assign values to + variables, call functions, and so on. -`eval' PARAM, ... +'eval' PARAM, ... AWK STATEMENTS -`end' - This form of `eval' is similar, but it allows you to define "local - variables" that exist in the context of the AWK STATEMENTS, - instead of using variables or function parameters defined by the - program. - -`print' VAR1[`,' VAR2 ...] -`p' VAR1[`,' VAR2 ...] - Print the value of a `gawk' variable or field. Fields must be +'end' + This form of 'eval' is similar, but it allows you to define "local + variables" that exist in the context of the AWK STATEMENTS, instead + of using variables or function parameters defined by the program. + +'print' VAR1[',' VAR2 ...] +'p' VAR1[',' VAR2 ...] + Print the value of a 'gawk' variable or field. Fields must be referenced by constants: gawk> print $3 This prints the third field in the input record (if the specified - field does not exist, it prints `Null field'). A variable can be - an array element, with the subscripts being constant values. To + field does not exist, it prints 'Null field'). A variable can be + an array element, with the subscripts being constant values. To print the contents of an array, prefix the name of the array with - the `@' symbol: + the '@' symbol: gawk> print @a This prints the indices and the corresponding values for all - elements in the array `a'. + elements in the array 'a'. -`printf' FORMAT [`,' ARG ...] - Print formatted text. The FORMAT may include escape sequences, - such as `\n' (*note Escape Sequences::). No newline is printed +'printf' FORMAT [',' ARG ...] + Print formatted text. The FORMAT may include escape sequences, + such as '\n' (*note Escape Sequences::). No newline is printed unless one is specified. -`set' VAR`='VALUE - Assign a constant (number or string) value to an `awk' variable or +'set' VAR'='VALUE + Assign a constant (number or string) value to an 'awk' variable or field. String values must be enclosed between double quotes - (`"'...`"'). + ('"'...'"'). - You can also set special `awk' variables, such as `FS', `NF', - `NR', etc. + You can also set special 'awk' variables, such as 'FS', 'NF', 'NR', + etc. -`watch' VAR | `$'N [`"EXPRESSION"'] -`w' VAR | `$'N [`"EXPRESSION"'] - Add variable VAR (or field `$N') to the watch list. The debugger +'watch' VAR | '$'N ['"EXPRESSION"'] +'w' VAR | '$'N ['"EXPRESSION"'] + Add variable VAR (or field '$N') to the watch list. The debugger then stops whenever the value of the variable or field changes. Each watched item is assigned a number which can be used to delete - it from the watch list using the `unwatch' command. + it from the watch list using the 'unwatch' command. With a watchpoint, you may also supply a condition. This is an - `awk' expression (enclosed in double quotes) that the debugger - evaluates whenever the watchpoint is reached. If the condition is + 'awk' expression (enclosed in double quotes) that the debugger + evaluates whenever the watchpoint is reached. If the condition is true, then the debugger stops execution and prompts for a command. - Otherwise, `gawk' continues executing the program. + Otherwise, 'gawk' continues executing the program. -`undisplay' [N] +'undisplay' [N] Remove item number N (or all items, if no argument) from the automatic display list. -`unwatch' [N] +'unwatch' [N] Remove item number N (or all items, if no argument) from the watch list. -  File: gawk.info, Node: Execution Stack, Next: Debugger Info, Prev: Viewing And Changing Data, Up: List of Debugger Commands 14.3.4 Dealing with the Stack ----------------------------- -Whenever you run a program which contains any function calls, `gawk' +Whenever you run a program which contains any function calls, 'gawk' maintains a stack of all of the function calls leading up to where the program is right now. You can see how you got to where you are, and also move around in the stack to see what the state of things was in the functions which called the one you are in. The commands for doing this are: -`backtrace' [COUNT] -`bt' [COUNT] +'backtrace' [COUNT] +'bt' [COUNT] Print a backtrace of all function calls (stack frames), or - innermost COUNT frames if COUNT > 0. Print the outermost COUNT - frames if COUNT < 0. The backtrace displays the name and - arguments to each function, the source file name, and the line - number. + innermost COUNT frames if COUNT > 0. Print the outermost COUNT + frames if COUNT < 0. The backtrace displays the name and arguments + to each function, the source file name, and the line number. -`down' [COUNT] +'down' [COUNT] Move COUNT (default 1) frames down the stack toward the innermost frame. Then select and print the frame. -`frame' [N] -`f' [N] +'frame' [N] +'f' [N] Select and print stack frame N. Frame 0 is the currently executing, or "innermost", frame (function call), frame 1 is the - frame that called the innermost one. The highest numbered frame is + frame that called the innermost one. The highest numbered frame is the one for the main program. The printed information consists of - the frame number, function and argument names, source file, and - the source line. + the frame number, function and argument names, source file, and the + source line. -`up' [COUNT] +'up' [COUNT] Move COUNT (default 1) frames up the stack toward the outermost frame. Then select and print the frame. @@ -21070,105 +20982,105 @@ File: gawk.info, Node: Debugger Info, Next: Miscellaneous Debugger Commands, Besides looking at the values of variables, there is often a need to get other sorts of information about the state of your program and of the -debugging environment itself. The `gawk' debugger has one command which -provides this information, appropriately called `info'. `info' is used +debugging environment itself. The 'gawk' debugger has one command which +provides this information, appropriately called 'info'. 'info' is used with one of a number of arguments that tell it exactly what you want to know: -`info' WHAT -`i' WHAT +'info' WHAT +'i' WHAT The value for WHAT should be one of the following: - `args' + 'args' Arguments of the selected frame. - `break' + 'break' List all currently set breakpoints. - `display' + 'display' List all items in the automatic display list. - `frame' + 'frame' Description of the selected stack frame. - `functions' + 'functions' List all function definitions including source file names and line numbers. - `locals' + 'locals' Local variables of the selected frame. - `source' - The name of the current source file. Each time the program + 'source' + The name of the current source file. Each time the program stops, the current source file is the file containing the current instruction. When the debugger first starts, the - current source file is the first file included via the `-f' - option. The `list FILENAME:LINENO' command can be used at any + current source file is the first file included via the '-f' + option. The 'list FILENAME:LINENO' command can be used at any time to change the current source. - `sources' + 'sources' List all program sources. - `variables' + 'variables' List all global variables. - `watch' + 'watch' List all items in the watch list. Additional commands give you control over the debugger, the ability to save the debugger's state, and the ability to run debugger commands from a file. The commands are: -`option' [NAME[`='VALUE]] -`o' [NAME[`='VALUE]] +'option' [NAME['='VALUE]] +'o' [NAME['='VALUE]] Without an argument, display the available debugger options and - their current values. `option NAME' shows the current value of the - named option. `option NAME=VALUE' assigns a new value to the named + their current values. 'option NAME' shows the current value of the + named option. 'option NAME=VALUE' assigns a new value to the named option. The available options are: - `history_size' + 'history_size' The maximum number of lines to keep in the history file - `./.gawk_history'. The default is 100. + './.gawk_history'. The default is 100. - `listsize' - The number of lines that `list' prints. The default is 15. + 'listsize' + The number of lines that 'list' prints. The default is 15. - `outfile' - Send `gawk' output to a file; debugger output still goes to - standard output. An empty string (`""') resets output to + 'outfile' + Send 'gawk' output to a file; debugger output still goes to + standard output. An empty string ('""') resets output to standard output. - `prompt' - The debugger prompt. The default is `gawk> '. + 'prompt' + The debugger prompt. The default is 'gawk> '. - `save_history' [`on' | `off'] - Save command history to file `./.gawk_history'. The default - is `on'. + 'save_history' ['on' | 'off'] + Save command history to file './.gawk_history'. The default + is 'on'. - `save_options' [`on' | `off'] - Save current options to file `./.gawkrc' upon exit. The - default is `on'. Options are read back in to the next - session upon startup. + 'save_options' ['on' | 'off'] + Save current options to file './.gawkrc' upon exit. The + default is 'on'. Options are read back in to the next session + upon startup. - `trace' [`on' | `off'] - Turn instruction tracing on or off. The default is `off'. + 'trace' ['on' | 'off'] + Turn instruction tracing on or off. The default is 'off'. -`save' FILENAME +'save' FILENAME Save the commands from the current session to the given file name, - so that they can be replayed using the `source' command. + so that they can be replayed using the 'source' command. -`source' FILENAME +'source' FILENAME Run command(s) from a file; an error in any command does not - terminate execution of subsequent commands. Comments (lines - starting with `#') are allowed in a command file. Empty lines are + terminate execution of subsequent commands. Comments (lines + starting with '#') are allowed in a command file. Empty lines are ignored; they do _not_ repeat the last command. You can't restart - the program by having more than one `run' command in the file. - Also, the list of commands may include additional `source' - commands; however, the `gawk' debugger will not source the same + the program by having more than one 'run' command in the file. + Also, the list of commands may include additional 'source' + commands; however, the 'gawk' debugger will not source the same file more than once in order to avoid infinite recursion. - In addition to, or instead of the `source' command, you can use - the `-D FILE' or `--debug=FILE' command-line options to execute + In addition to, or instead of the 'source' command, you can use the + '-D FILE' or '--debug=FILE' command-line options to execute commands from a file non-interactively (*note Options::).  @@ -21180,10 +21092,10 @@ File: gawk.info, Node: Miscellaneous Debugger Commands, Prev: Debugger Info, There are a few more commands which do not fit into the previous categories, as follows: -`dump' [FILENAME] +'dump' [FILENAME] Dump bytecode of the program to standard output or to the file named in FILENAME. This prints a representation of the internal - instructions which `gawk' executes to implement the `awk' commands + instructions which 'gawk' executes to implement the 'awk' commands in a program. This can be very enlightening, as the following partial dump of Davide Brini's obfuscated code (*note Signature Program::) demonstrates: @@ -21237,57 +21149,56 @@ categories, as follows: -| [ :0xfcc1a0] Op_after_endfile : gawk> -`help' -`h' - Print a list of all of the `gawk' debugger commands with a short - summary of their usage. `help COMMAND' prints the information +'help' +'h' + Print a list of all of the 'gawk' debugger commands with a short + summary of their usage. 'help COMMAND' prints the information about the command COMMAND. -`list' [`-' | `+' | N | FILENAME`:'N | N-M | FUNCTION] -`l' [`-' | `+' | N | FILENAME`:'N | N-M | FUNCTION] +'list' ['-' | '+' | N | FILENAME':'N | N-M | FUNCTION] +'l' ['-' | '+' | N | FILENAME':'N | N-M | FUNCTION] Print the specified lines (default 15) from the current source file - or the file named FILENAME. The possible arguments to `list' are + or the file named FILENAME. The possible arguments to 'list' are as follows: - `-' + '-' Print lines before the lines last printed. - `+' - Print lines after the lines last printed. `list' without any + '+' + Print lines after the lines last printed. 'list' without any argument does the same thing. - N + N Print lines centered around line number N. - N-M + N-M Print lines from N to M. - FILENAME`:'N + FILENAME':'N Print lines centered around line number N in source file - FILENAME. This command may change the current source file. + FILENAME. This command may change the current source file. - FUNCTION + FUNCTION Print lines centered around beginning of the function - FUNCTION. This command may change the current source file. + FUNCTION. This command may change the current source file. -`quit' -`q' +'quit' +'q' Exit the debugger. Debugging is great fun, but sometimes we all have to tend to other obligations in life, and sometimes we find the bug, and are free to go on to the next one! As we saw above, if you are running a program, the debugger warns you if you - accidentally type `q' or `quit', to make sure you really want to + accidentally type 'q' or 'quit', to make sure you really want to quit. -`trace' [`on' | `off'] +'trace' ['on' | 'off'] Turn on or off a continuous printing of instructions which are - about to be executed, along with printing the `awk' line which they - implement. The default is `off'. + about to be executed, along with printing the 'awk' line which they + implement. The default is 'off'. It is to be hoped that most of the "opcodes" in these instructions - are fairly self-explanatory, and using `stepi' and `nexti' while - `trace' is on will make them into familiar friends. - + are fairly self-explanatory, and using 'stepi' and 'nexti' while + 'trace' is on will make them into familiar friends.  File: gawk.info, Node: Readline Support, Next: Limitations, Prev: List of Debugger Commands, Up: Debugger @@ -21295,27 +21206,26 @@ File: gawk.info, Node: Readline Support, Next: Limitations, Prev: List of Deb 14.4 Readline Support ===================== -If `gawk' is compiled with the `readline' library +If 'gawk' is compiled with the 'readline' library (http://cnswww.cns.cwru.edu/php/chet/readline/readline.html), you can take advantage of that library's command completion and history -expansion features. The following types of completion are available: +expansion features. The following types of completion are available: Command completion Command names. Source file name completion - Source file names. Relevant commands are `break', `clear', `list', - `tbreak', and `until'. + Source file names. Relevant commands are 'break', 'clear', 'list', + 'tbreak', and 'until'. Argument completion - Non-numeric arguments to a command. Relevant commands are - `enable' and `info'. + Non-numeric arguments to a command. Relevant commands are 'enable' + and 'info'. Variable name completion Global variable names, and function arguments in the current - context if the program is running. Relevant commands are `display', - `print', `set', and `watch'. - + context if the program is running. Relevant commands are + 'display', 'print', 'set', and 'watch'.  File: gawk.info, Node: Limitations, Next: Debugging Summary, Prev: Readline Support, Up: Debugger @@ -21323,41 +21233,41 @@ File: gawk.info, Node: Limitations, Next: Debugging Summary, Prev: Readline S 14.5 Limitations and Future Plans ================================= -We hope you find the `gawk' debugger useful and enjoyable to work with, +We hope you find the 'gawk' debugger useful and enjoyable to work with, but as with any program, especially in its early releases, it still has some limitations. A few which are worth being aware of are: * At this point, the debugger does not give a detailed explanation of what you did wrong when you type in something it doesn't like. - Rather, it just responds `syntax error'. When you do figure out + Rather, it just responds 'syntax error'. When you do figure out what your mistake was, though, you'll feel like a real guru. * If you perused the dump of opcodes in *note Miscellaneous Debugger - Commands::, (or if you are already familiar with `gawk' internals), + Commands::, (or if you are already familiar with 'gawk' internals), you will realize that much of the internal manipulation of data in - `gawk', as in many interpreters, is done on a stack. `Op_push', - `Op_pop', etc., are the "bread and butter" of most `gawk' code. + 'gawk', as in many interpreters, is done on a stack. 'Op_push', + 'Op_pop', etc., are the "bread and butter" of most 'gawk' code. - Unfortunately, as of now, the `gawk' debugger does not allow you - to examine the stack's contents. That is, the intermediate - results of expression evaluation are on the stack, but cannot be - printed. Rather, only variables which are defined in the program - can be printed. Of course, a workaround for this is to use more - explicit variables at the debugging stage and then change back to - obscure, perhaps more optimal code later. + Unfortunately, as of now, the 'gawk' debugger does not allow you to + examine the stack's contents. That is, the intermediate results of + expression evaluation are on the stack, but cannot be printed. + Rather, only variables which are defined in the program can be + printed. Of course, a workaround for this is to use more explicit + variables at the debugging stage and then change back to obscure, + perhaps more optimal code later. * There is no way to look "inside" the process of compiling regular - expressions to see if you got it right. As an `awk' programmer, - you are expected to know what `/[^[:alnum:][:blank:]]/' means. + expressions to see if you got it right. As an 'awk' programmer, + you are expected to know what '/[^[:alnum:][:blank:]]/' means. - * The `gawk' debugger is designed to be used by running a program + * The 'gawk' debugger is designed to be used by running a program (with all its parameters) on the command line, as described in - *note Debugger Invocation::. There is no way (as of now) to - attach or "break in" to a running program. This seems reasonable - for a language which is used mainly for quickly executing, short + *note Debugger Invocation::. There is no way (as of now) to attach + or "break in" to a running program. This seems reasonable for a + language which is used mainly for quickly executing, short programs. - * The `gawk' debugger only accepts source supplied with the `-f' + * The 'gawk' debugger only accepts source supplied with the '-f' option. Look forward to a future release when these and other missing @@ -21371,52 +21281,51 @@ File: gawk.info, Node: Debugging Summary, Prev: Limitations, Up: Debugger ============ * Programs rarely work correctly the first time. Finding bugs is - "debugging" and a program that helps you find bugs is a - "debugger". `gawk' has a built-in debugger that works very - similarly to the GNU Debugger, GDB. + "debugging" and a program that helps you find bugs is a "debugger". + 'gawk' has a built-in debugger that works very similarly to the GNU + Debugger, GDB. * Debuggers let you step through your program one statement at a - time, examine and change variable and array values, and do a - number of other things that let understand what your program is - actually doing (as opposed to what it is supposed to do). + time, examine and change variable and array values, and do a number + of other things that let understand what your program is actually + doing (as opposed to what it is supposed to do). - * Like most debuggers, the `gawk' debugger works in terms of stack + * Like most debuggers, the 'gawk' debugger works in terms of stack frames, and lets you set both breakpoints (stop at a point in the code) and watchpoints (stop when a data value changes). * The debugger command set is fairly complete, providing control over - breakpoints, execution, viewing and changing data, working with - the stack, getting information, and other tasks. + breakpoints, execution, viewing and changing data, working with the + stack, getting information, and other tasks. - * If the `readline' library is available when `gawk' is compiled, it + * If the 'readline' library is available when 'gawk' is compiled, it is used by the debugger to provide command-line history and editing. -  File: gawk.info, Node: Arbitrary Precision Arithmetic, Next: Dynamic Extensions, Prev: Debugger, Up: Top -15 Arithmetic and Arbitrary Precision Arithmetic with `gawk' +15 Arithmetic and Arbitrary Precision Arithmetic with 'gawk' ************************************************************ -This major node introduces some basic concepts relating to how -computers do arithmetic and briefly lists the features in `gawk' for -performing arbitrary precision floating point computations. It then -proceeds to describe floating-point arithmetic, which is what `awk' -uses for all its computations, including a discussion of arbitrary -precision floating point arithmetic, which is a feature available only -in `gawk'. It continues on to present arbitrary precision integers, and -concludes with a description of some points where `gawk' and the POSIX -standard are not quite in agreement. +This major node introduces some basic concepts relating to how computers +do arithmetic and briefly lists the features in 'gawk' for performing +arbitrary precision floating point computations. It then proceeds to +describe floating-point arithmetic, which is what 'awk' uses for all its +computations, including a discussion of arbitrary precision floating +point arithmetic, which is a feature available only in 'gawk'. It +continues on to present arbitrary precision integers, and concludes with +a description of some points where 'gawk' and the POSIX standard are not +quite in agreement. * Menu: * Computer Arithmetic:: A quick intro to computer math. * Math Definitions:: Defining terms used. -* MPFR features:: The MPFR features in `gawk'. +* MPFR features:: The MPFR features in 'gawk'. * FP Math Caution:: Things to know. * Arbitrary Precision Integers:: Arbitrary Precision Integer Arithmetic with - `gawk'. + 'gawk'. * POSIX Floating Point Problems:: Standards Versus Existing Practice. * Floating point summary:: Summary of floating point discussion. @@ -21442,7 +21351,7 @@ that interest us are: Decimal arithmetic This is the kind of arithmetic you learned in elementary school, - using paper and pencil (and/or a calculator). In theory, numbers + using paper and pencil (and/or a calculator). In theory, numbers can have an arbitrary number of digits on either side (or both sides) of the decimal point, and the results of a computation are always exact. @@ -21452,7 +21361,7 @@ Decimal arithmetic these instructions. There are also libraries that do decimal arithmetic entirely in software. - Despite the fact that some users expect `gawk' to be performing + Despite the fact that some users expect 'gawk' to be performing decimal arithmetic,(1) it does not do so. Integer arithmetic @@ -21467,45 +21376,48 @@ Integer arithmetic to zero). In computer systems, integer arithmetic is exact, but the possible - range of values is limited. Integer arithmetic is generally - faster than floating point arithmetic. + range of values is limited. Integer arithmetic is generally faster + than floating point arithmetic. Floating point arithmetic Floating-point numbers represent what were called in school "real" numbers; i.e., those that have a fractional part, such as 3.1415927. The advantage to floating-point numbers is that they - can represent a much larger range of values than can integers. - The disadvantage is that there are numbers that they cannot - represent exactly. + can represent a much larger range of values than can integers. The + disadvantage is that there are numbers that they cannot represent + exactly. Modern systems support floating point arithmetic in hardware, with a limited range of values. There are software libraries that allow the use of arbitrary precision floating point calculations. - POSIX `awk' uses "double precision" floating-point numbers, which + POSIX 'awk' uses "double precision" floating-point numbers, which can hold more digits than "single precision" floating-point - numbers. `gawk' has facilities for performing arbitrary precision + numbers. 'gawk' has facilities for performing arbitrary precision floating point arithmetic, which we describe in more detail shortly. Computers work with integer and floating point values of different -ranges. Integer values are usually either 32 or 64 bits in size. Single -precision floating point values occupy 32 bits, whereas double precision -floating point values occupy 64 bits. Floating point values are always -signed. The possible ranges of values are shown in the following table. +ranges. Integer values are usually either 32 or 64 bits in size. +Single precision floating point values occupy 32 bits, whereas double +precision floating point values occupy 64 bits. Floating point values +are always signed. The possible ranges of values are shown in the +following table. Numeric representation Miniumum value Maximum value ---------------------------------------------------------------------------- +--------------------------------------------------------------------------- 32-bit signed integer -2,147,483,648 2,147,483,647 -32-bit unsigned integer 0 4,294,967,295 +32-bit unsigned 0 4,294,967,295 +integer 64-bit signed integer -9,223,372,036,854,775,8089,223,372,036,854,775,807 -64-bit unsigned integer 0 18,446,744,073,709,551,615 -Single precision `1.175494e-38' `3.402823e+38' -floating point -(approximate) -Double precision `2.225074e-308' `1.797693e+308' -floating point -(approximate) +64-bit unsigned 0 18,446,744,073,709,551,615 +integer +Single precision '1.175494e-38' '3.402823e+38' +floating point +(approximate) +Double precision '2.225074e-308' '1.797693e+308' +floating point +(approximate) ---------- Footnotes ---------- @@ -21517,7 +21429,7 @@ File: gawk.info, Node: Math Definitions, Next: MPFR features, Prev: Computer 15.2 Other Stuff To Know ======================== -The rest of this major node uses a number of terms. Here are some +The rest of this major node uses a number of terms. Here are some informal definitions that should help you work your way through the material here. @@ -21535,19 +21447,19 @@ material here. floating-point value store the exponent. "Inf" - A special value representing infinity. Operations involving another - number and infinity produce infinity. + A special value representing infinity. Operations involving + another number and infinity produce infinity. "NaN" - "Not A Number." A special value indicating a result that can't + "Not A Number." A special value indicating a result that can't happen in real math, but that can happen in floating-point computations. "Normalized" - How the significand (see later in this list) is usually stored. The - value is adjusted so that the first bit is one, and then that - leading one is assumed instead of physically stored. This - provides one extra bit of precision. + How the significand (see later in this list) is usually stored. + The value is adjusted so that the first bit is one, and then that + leading one is assumed instead of physically stored. This provides + one extra bit of precision. "Precision" The number of bits used to represent a floating-point number. The @@ -21564,9 +21476,9 @@ material here. are provided later. "Significand" - A floating point value consists the significand multiplied by 10 - to the power of the exponent. For example, in `1.2345e67', the - significand is `1.2345'. + A floating point value consists the significand multiplied by 10 to + the power of the exponent. For example, in '1.2345e67', the + significand is '1.2345'. "Stability" From the Wikipedia article on numerical stability @@ -21583,13 +21495,13 @@ and operations defined by the IEEE 754 standard. Three of the standard IEEE 754 types are 32-bit single precision, 64-bit double precision and 128-bit quadruple precision. The standard also specifies extended precision formats to allow greater precisions and larger exponent -ranges. (`awk' uses only the 64-bit double precision format.) +ranges. ('awk' uses only the 64-bit double precision format.) - *note table-ieee-formats:: lists the precision and exponent field -values for the basic IEEE 754 binary formats: + *note Table 15.1: table-ieee-formats. lists the precision and +exponent field values for the basic IEEE 754 binary formats: Name Total bits Precision emin emax ---------------------------------------------------------------------------- +--------------------------------------------------------------------------- Single 32 24 -126 +127 Double 64 53 -1022 +1023 Quadruple 128 113 -16382 +16383 @@ -21602,12 +21514,12 @@ Table 15.1: Basic IEEE Format Context Values  File: gawk.info, Node: MPFR features, Next: FP Math Caution, Prev: Math Definitions, Up: Arbitrary Precision Arithmetic -15.3 Arbitrary Precison Arithmetic Features In `gawk' +15.3 Arbitrary Precison Arithmetic Features In 'gawk' ===================================================== -By default, `gawk' uses the double precision floating point values +By default, 'gawk' uses the double precision floating point values supplied by the hardware of the system it runs on. However, if it was -compiled to do, `gawk' uses the GNU MPFR (http://www.mpfr.org) and GNU +compiled to do, 'gawk' uses the GNU MPFR (http://www.mpfr.org) and GNU MP (http://gmplib.org) (GMP) libraries for arbitrary precision arithmetic on numbers. You can see if MPFR support is available like so: @@ -21617,22 +21529,22 @@ so: -| Copyright (C) 1989, 1991-2014 Free Software Foundation. ... -(You may see different version numbers than what's shown here. That's +(You may see different version numbers than what's shown here. That's OK; what's important is to see that GNU MPFR and GNU MP are listed in the output.) - Additionally, there are a few elements available in the `PROCINFO' + Additionally, there are a few elements available in the 'PROCINFO' array to provide information about the MPFR and GMP libraries (*note Auto-set::). The MPFR library provides precise control over precisions and rounding modes, and gives correctly rounded, reproducible, platform-independent results. With either of the command-line options -`--bignum' or `-M', all floating-point arithmetic operators and numeric +'--bignum' or '-M', all floating-point arithmetic operators and numeric functions can yield results to any desired precision level supported by MPFR. - Two built-in variables, `PREC' and `ROUNDMODE', provide control over + Two built-in variables, 'PREC' and 'ROUNDMODE', provide control over the working precision and the rounding mode. The precision and the rounding mode are set globally for every operation to follow. *Note Auto-set::, for more information. @@ -21643,16 +21555,16 @@ File: gawk.info, Node: FP Math Caution, Next: Arbitrary Precision Integers, P 15.4 Floating Point Arithmetic: Caveat Emptor! ============================================== - Math class is tough! -- Late 1980's Barbie + Math class is tough! + -- _Late 1980's Barbie_ - This minor node provides a high level overview of the issues -involved when doing lots of floating-point arithmetic.(1) The -discussion applies to both hardware and arbitrary-precision -floating-point arithmetic. + This minor node provides a high level overview of the issues involved +when doing lots of floating-point arithmetic.(1) The discussion applies +to both hardware and arbitrary-precision floating-point arithmetic. - CAUTION: The material here is purposely general. If you need to do - serious computer arithmetic, you should do some research first, - and not rely just on what we tell you. + CAUTION: The material here is purposely general. If you need to do + serious computer arithmetic, you should do some research first, and + not rely just on what we tell you. * Menu: @@ -21667,7 +21579,7 @@ floating-point arithmetic. (1) There is a very nice paper on floating-point arithmetic (http://www.validlab.com/goldberg/paper.pdf) by David Goldberg, "What Every Computer Scientist Should Know About Floating-point Arithmetic," -`ACM Computing Surveys' *23*, 1 (1991-03), 5-48. This is worth reading +'ACM Computing Surveys' *23*, 1 (1991-03), 5-48. This is worth reading if you are interested in the details, but it does require a background in computer science. @@ -21681,7 +21593,7 @@ Binary floating-point representations and arithmetic are inexact. Simple values like 0.1 cannot be precisely represented using binary floating-point numbers, and the limited precision of floating-point numbers means that slight changes in the order of operations or the -precision of intermediate storage can change the result. To make +precision of intermediate storage can change the result. To make matters worse, with arbitrary precision floating-point, you can set the precision before starting a computation, but then you cannot be sure of the number of significant decimal places in the final result. @@ -21699,20 +21611,20 @@ File: gawk.info, Node: Inexact representation, Next: Comparing FP Values, Up: ................................................... So, before you start to write any code, you should think about what you -really want and what's really happening. Consider the two numbers in +really want and what's really happening. Consider the two numbers in the following example: x = 0.875 # 1/2 + 1/4 + 1/8 y = 0.425 - Unlike the number in `y', the number stored in `x' is exactly + Unlike the number in 'y', the number stored in 'x' is exactly representable in binary since it can be written as a finite sum of one -or more fractions whose denominators are all powers of two. When -`gawk' reads a floating-point number from program source, it -automatically rounds that number to whatever precision your machine -supports. If you try to print the numeric content of a variable using -an output format string of `"%.17g"', it may not produce the same -number as you assigned to it: +or more fractions whose denominators are all powers of two. When 'gawk' +reads a floating-point number from program source, it automatically +rounds that number to whatever precision your machine supports. If you +try to print the numeric content of a variable using an output format +string of '"%.17g"', it may not produce the same number as you assigned +to it: $ gawk 'BEGIN { x = 0.875; y = 0.425 > printf("%0.17g, %0.17g\n", x, y) }' @@ -21720,7 +21632,7 @@ number as you assigned to it: Often the error is so small you do not even notice it, and if you do, you can always specify how much precision you would like in your output. -Usually this is a format string like `"%.15g"', which when used in the +Usually this is a format string like '"%.15g"', which when used in the previous example, produces an output identical to the input.  @@ -21739,8 +21651,8 @@ work like you would expect: The general wisdom when comparing floating-point values is to see if they are within some small range of each other (called a "delta", or -"tolerance"). You have to decide how small a delta is important to -you. Code to do this looks something like this: +"tolerance"). You have to decide how small a delta is important to you. +Code to do this looks something like this: delta = 0.00001 # for example difference = abs(a) - abs(b) # subtract the two values @@ -21756,7 +21668,7 @@ File: gawk.info, Node: Errors accumulate, Prev: Comparing FP Values, Up: Inex .......................... The loss of accuracy during a single computation with floating-point -numbers usually isn't enough to worry about. However, if you compute a +numbers usually isn't enough to worry about. However, if you compute a value which is the result of a sequence of floating point operations, the error can accumulate and greatly affect the computation itself. Here is an attempt to compute the value of pi using one of its many @@ -21785,7 +21697,7 @@ zero: -| 3.224515243534819 -| 2.791117213058638 -| 0.000000000000000 - error--> gawk: pi.awk:6: fatal: division by zero attempted + error-> gawk: pi.awk:6: fatal: division by zero attempted Here is an additional example where the inaccuracies in internal representations yield an unexpected result: @@ -21803,14 +21715,14 @@ File: gawk.info, Node: Getting Accuracy, Next: Try To Round, Prev: Inexactnes 15.4.2 Getting The Accuracy You Need ------------------------------------ -Can arbitrary precision arithmetic give exact results? There are no -easy answers. The standard rules of algebra often do not apply when +Can arbitrary precision arithmetic give exact results? There are no +easy answers. The standard rules of algebra often do not apply when using floating-point arithmetic. Among other things, the distributive and associative laws do not hold completely, and order of operation may -be important for your computation. Rounding error, cumulative precision +be important for your computation. Rounding error, cumulative precision loss and underflow are often troublesome. - When `gawk' tests the expressions `0.1 + 12.2' and `12.3' for + When 'gawk' tests the expressions '0.1 + 12.2' and '12.3' for equality using the machine double precision arithmetic, it decides that they are not equal! (*Note Comparing FP Values::.) You can get the result you want by increasing the precision; 56 bits in this case does @@ -21821,18 +21733,18 @@ the job: If adding more bits is good, perhaps adding even more bits of precision is better? Here is what happens if we use an even larger -value of `PREC': +value of 'PREC': $ gawk -M -v PREC=201 'BEGIN { print (0.1 + 12.2 == 12.3) }' -| 0 - This is not a bug in `gawk' or in the MPFR library. It is easy to + This is not a bug in 'gawk' or in the MPFR library. It is easy to forget that the finite number of bits used to store the value is often just an approximation after proper rounding. The test for equality succeeds if and only if _all_ bits in the two operands are exactly the -same. Since this is not necessarily true after floating-point +same. Since this is not necessarily true after floating-point computations with a particular precision and effective rounding rule, a -straight test for equality may not work. Instead, compare the two +straight test for equality may not work. Instead, compare the two numbers to see if they are within the desirable delta of each other. In applications where 15 or fewer decimal places suffice, hardware @@ -21844,7 +21756,7 @@ precision can greatly enhance the stability and the accuracy of your computation in such cases. Repeated addition is not necessarily equivalent to multiplication in -floating-point arithmetic. In the example in *note Errors accumulate::: +floating-point arithmetic. In the example in *note Errors accumulate::: $ gawk 'BEGIN { > for (d = 1.1; d <= 1.5; d += 0.1) # loop five times (?) @@ -21854,7 +21766,7 @@ floating-point arithmetic. In the example in *note Errors accumulate::: -| 4 you may or may not succeed in getting the correct result by choosing an -arbitrarily large value for `PREC'. Reformulation of the problem at +arbitrarily large value for 'PREC'. Reformulation of the problem at hand is often the correct approach in such situations.  @@ -21890,24 +21802,24 @@ File: gawk.info, Node: Setting precision, Next: Setting the rounding mode, Pr 15.4.4 Setting The Precision ---------------------------- -`gawk' uses a global working precision; it does not keep track of the -precision or accuracy of individual numbers. Performing an arithmetic +'gawk' uses a global working precision; it does not keep track of the +precision or accuracy of individual numbers. Performing an arithmetic operation or calling a built-in function rounds the result to the -current working precision. The default working precision is 53 bits, -which you can modify using the built-in variable `PREC'. You can also -set the value to one of the predefined case-insensitive strings shown -in *note table-predefined-precision-strings::, to emulate an IEEE 754 -binary format. - -`PREC' IEEE 754 Binary Format ---------------------------------------------------- -`"half"' 16-bit half-precision. -`"single"' Basic 32-bit single precision. -`"double"' Basic 64-bit double precision. -`"quad"' Basic 128-bit quadruple precision. -`"oct"' 256-bit octuple precision. - -Table 15.2: Predefined Precision Strings For `PREC' +current working precision. The default working precision is 53 bits, +which you can modify using the built-in variable 'PREC'. You can also +set the value to one of the predefined case-insensitive strings shown in +*note Table 15.2: table-predefined-precision-strings, to emulate an IEEE +754 binary format. + +'PREC' IEEE 754 Binary Format +--------------------------------------------------- +'"half"' 16-bit half-precision. +'"single"' Basic 32-bit single precision. +'"double"' Basic 64-bit double precision. +'"quad"' Basic 128-bit quadruple precision. +'"oct"' 256-bit octuple precision. + +Table 15.2: Predefined Precision Strings For 'PREC' The following example illustrates the effects of changing precision on arithmetic operations: @@ -21917,19 +21829,19 @@ on arithmetic operations: -| 1e-400 -| 0 - CAUTION: Be wary of floating-point constants! When reading a - floating-point constant from program source code, `gawk' uses the - default precision (that of a C `double'), unless overridden by an - assignment to the special variable `PREC' on the command line, to - store it internally as a MPFR number. Changing the precision - using `PREC' in the program text does _not_ change the precision - of a constant. + CAUTION: Be wary of floating-point constants! When reading a + floating-point constant from program source code, 'gawk' uses the + default precision (that of a C 'double'), unless overridden by an + assignment to the special variable 'PREC' on the command line, to + store it internally as a MPFR number. Changing the precision using + 'PREC' in the program text does _not_ change the precision of a + constant. If you need to represent a floating-point constant at a higher - precision than the default and cannot use a command line - assignment to `PREC', you should either specify the constant as a - string, or as a rational number, whenever possible. The following - example illustrates the differences among various ways to print a + precision than the default and cannot use a command line assignment + to 'PREC', you should either specify the constant as a string, or + as a rational number, whenever possible. The following example + illustrates the differences among various ways to print a floating-point constant: $ gawk -M 'BEGIN { PREC = 113; printf("%0.25f\n", 0.1) }' @@ -21947,39 +21859,39 @@ File: gawk.info, Node: Setting the rounding mode, Prev: Setting precision, Up 15.4.5 Setting The Rounding Mode -------------------------------- -The `ROUNDMODE' variable provides program level control over the -rounding mode. The correspondence between `ROUNDMODE' and the IEEE -rounding modes is shown in *note table-gawk-rounding-modes::. +The 'ROUNDMODE' variable provides program level control over the +rounding mode. The correspondence between 'ROUNDMODE' and the IEEE +rounding modes is shown in *note Table 15.3: table-gawk-rounding-modes. -Rounding Mode IEEE Name `ROUNDMODE' ---------------------------------------------------------------------------- -Round to nearest, ties to even `roundTiesToEven' `"N"' or `"n"' -Round toward plus Infinity `roundTowardPositive' `"U"' or `"u"' -Round toward negative Infinity `roundTowardNegative' `"D"' or `"d"' -Round toward zero `roundTowardZero' `"Z"' or `"z"' -Round to nearest, ties away `roundTiesToAway' `"A"' or `"a"' -from zero +Rounding Mode IEEE Name 'ROUNDMODE' +--------------------------------------------------------------------------- +Round to nearest, ties to even 'roundTiesToEven' '"N"' or '"n"' +Round toward plus Infinity 'roundTowardPositive' '"U"' or '"u"' +Round toward negative Infinity 'roundTowardNegative' '"D"' or '"d"' +Round toward zero 'roundTowardZero' '"Z"' or '"z"' +Round to nearest, ties away 'roundTiesToAway' '"A"' or '"a"' +from zero -Table 15.3: `gawk' Rounding Modes +Table 15.3: 'gawk' Rounding Modes - `ROUNDMODE' has the default value `"N"', which selects the IEEE 754 -rounding mode `roundTiesToEven'. In *note Table 15.3: -table-gawk-rounding-modes, the value `"A"' selects `roundTiesToAway'. + 'ROUNDMODE' has the default value '"N"', which selects the IEEE 754 +rounding mode 'roundTiesToEven'. In *note Table 15.3: +table-gawk-rounding-modes, the value '"A"' selects 'roundTiesToAway'. This is only available if your version of the MPFR library supports it; -otherwise setting `ROUNDMODE' to `"A"' has no effect. +otherwise setting 'ROUNDMODE' to '"A"' has no effect. - The default mode `roundTiesToEven' is the most preferred, but the -least intuitive. This method does the obvious thing for most values, by + The default mode 'roundTiesToEven' is the most preferred, but the +least intuitive. This method does the obvious thing for most values, by rounding them up or down to the nearest digit. For example, rounding 1.132 to two digits yields 1.13, and rounding 1.157 yields 1.16. However, when it comes to rounding a value that is exactly halfway between, things do not work the way you probably learned in school. In -this case, the number is rounded to the nearest even digit. So -rounding 0.125 to two digits rounds down to 0.12, but rounding 0.6875 -to three digits rounds up to 0.688. You probably have already -encountered this rounding mode when using `printf' to format -floating-point numbers. For example: +this case, the number is rounded to the nearest even digit. So rounding +0.125 to two digits rounds down to 0.12, but rounding 0.6875 to three +digits rounds up to 0.688. You probably have already encountered this +rounding mode when using 'printf' to format floating-point numbers. For +example: BEGIN { x = -4.5 @@ -22001,48 +21913,49 @@ produces the following output when run on the author's system:(1) 3.5 => 4 4.5 => 4 - The theory behind `roundTiesToEven' is that it more or less evenly + The theory behind 'roundTiesToEven' is that it more or less evenly distributes upward and downward rounds of exact halves, which might -cause any accumulating round-off error to cancel itself out. This is the -default rounding mode for IEEE 754 computing functions and operators. +cause any accumulating round-off error to cancel itself out. This is +the default rounding mode for IEEE 754 computing functions and +operators. The other rounding modes are rarely used. Round toward positive -infinity (`roundTowardPositive') and round toward negative infinity -(`roundTowardNegative') are often used to implement interval -arithmetic, where you adjust the rounding mode to calculate upper and -lower bounds for the range of output. The `roundTowardZero' mode can be -used for converting floating-point numbers to integers. The rounding -mode `roundTiesToAway' rounds the result to the nearest number and -selects the number with the larger magnitude if a tie occurs. +infinity ('roundTowardPositive') and round toward negative infinity +('roundTowardNegative') are often used to implement interval arithmetic, +where you adjust the rounding mode to calculate upper and lower bounds +for the range of output. The 'roundTowardZero' mode can be used for +converting floating-point numbers to integers. The rounding mode +'roundTiesToAway' rounds the result to the nearest number and selects +the number with the larger magnitude if a tie occurs. Some numerical analysts will tell you that your choice of rounding -style has tremendous impact on the final outcome, and advise you to -wait until final output for any rounding. Instead, you can often avoid +style has tremendous impact on the final outcome, and advise you to wait +until final output for any rounding. Instead, you can often avoid round-off error problems by setting the precision initially to some value sufficiently larger than the final desired precision, so that the accumulation of round-off error does not influence the outcome. If you -suspect that results from your computation are sensitive to -accumulation of round-off error, look for a significant difference in -output when you change the rounding mode to be sure. +suspect that results from your computation are sensitive to accumulation +of round-off error, look for a significant difference in output when you +change the rounding mode to be sure. ---------- Footnotes ---------- - (1) It is possible for the output to be completely different if the -C library in your system does not use the IEEE 754 even-rounding rule -to round halfway cases for `printf'. + (1) It is possible for the output to be completely different if the C +library in your system does not use the IEEE 754 even-rounding rule to +round halfway cases for 'printf'.  File: gawk.info, Node: Arbitrary Precision Integers, Next: POSIX Floating Point Problems, Prev: FP Math Caution, Up: Arbitrary Precision Arithmetic -15.5 Arbitrary Precision Integer Arithmetic with `gawk' +15.5 Arbitrary Precision Integer Arithmetic with 'gawk' ======================================================= -When given one of the options `--bignum' or `-M', `gawk' performs all +When given one of the options '--bignum' or '-M', 'gawk' performs all integer arithmetic using GMP arbitrary precision integers. Any number that looks like an integer in a source or data file is stored as an -arbitrary precision integer. The size of the integer is limited only -by the available memory. For example, the following computes 5^4^3^2, -the result of which is beyond the limits of ordinary hardware +arbitrary precision integer. The size of the integer is limited only by +the available memory. For example, the following computes 5^4^3^2, the +result of which is beyond the limits of ordinary hardware double-precision floating point values: $ gawk -M 'BEGIN { @@ -22054,14 +21967,14 @@ double-precision floating point values: -| 62060698786608744707 ... 92256259918212890625 If instead you were to compute the same value using arbitrary -precision floating-point values, the precision needed for correct -output (using the formula `prec = 3.322 * dps'), would be 3.322 x -183231, or 608693. +precision floating-point values, the precision needed for correct output +(using the formula 'prec = 3.322 * dps'), would be 3.322 x 183231, or +608693. The result from an arithmetic operation with an integer and a -floating-point value is a floating-point value with a precision equal -to the working precision. The following program calculates the eighth -term in Sylvester's sequence(1) using a recurrence: +floating-point value is a floating-point value with a precision equal to +the working precision. The following program calculates the eighth term +in Sylvester's sequence(1) using a recurrence: $ gawk -M 'BEGIN { > s = 2.0 @@ -22072,14 +21985,13 @@ term in Sylvester's sequence(1) using a recurrence: -| 113423713055421845118910464 The output differs from the actual number, -113,423,713,055,421,844,361,000,443, because the default precision of -53 bits is not enough to represent the floating-point results exactly. -You can either increase the precision (100 bits is enough in this -case), or replace the floating-point constant `2.0' with an integer, to -perform all computations using integer arithmetic to get the correct -output. - - Sometimes `gawk' must implicitly convert an arbitrary precision +113,423,713,055,421,844,361,000,443, because the default precision of 53 +bits is not enough to represent the floating-point results exactly. You +can either increase the precision (100 bits is enough in this case), or +replace the floating-point constant '2.0' with an integer, to perform +all computations using integer arithmetic to get the correct output. + + Sometimes 'gawk' must implicitly convert an arbitrary precision integer into an arbitrary precision floating-point value. This is primarily because the MPFR library does not always provide the relevant interface to process arbitrary precision integers or mixed-mode numbers @@ -22096,18 +22008,18 @@ floating-point value to begin with: gawk -M 'BEGIN { n = 13.0; print n % 2.0 }' - Note that for the particular example above, it is likely best to -just use the following: + Note that for the particular example above, it is likely best to just +use the following: gawk -M 'BEGIN { n = 13; print n % 2 }' - When dividing two arbitrary precision integers with either `/' or -`%', the result is typically an arbitrary precision floating point -value (unless the denominator evenly divides into the numerator). In -order to do integer division or remainder with arbitrary precision -integers, use the built-in `div()' function (*note Numeric Functions::). + When dividing two arbitrary precision integers with either '/' or +'%', the result is typically an arbitrary precision floating point value +(unless the denominator evenly divides into the numerator). In order to +do integer division or remainder with arbitrary precision integers, use +the built-in 'div()' function (*note Numeric Functions::). - You can simulate the `div()' function in standard `awk' using this + You can simulate the 'div()' function in standard 'awk' using this user-defined function: # div --- do integer division @@ -22126,9 +22038,8 @@ user-defined function: ---------- Footnotes ---------- - (1) Weisstein, Eric W. `Sylvester's Sequence'. From MathWorld--A -Wolfram Web Resource -(`http://mathworld.wolfram.com/SylvestersSequence.html'). + (1) Weisstein, Eric W. 'Sylvester's Sequence'. From MathWorld--A +Wolfram Web Resource ().  File: gawk.info, Node: POSIX Floating Point Problems, Next: Floating point summary, Prev: Arbitrary Precision Integers, Up: Arbitrary Precision Arithmetic @@ -22136,18 +22047,18 @@ File: gawk.info, Node: POSIX Floating Point Problems, Next: Floating point sum 15.6 Standards Versus Existing Practice ======================================= -Historically, `awk' has converted any non-numeric looking string to the -numeric value zero, when required. Furthermore, the original -definition of the language and the original POSIX standards specified -that `awk' only understands decimal numbers (base 10), and not octal -(base 8) or hexadecimal numbers (base 16). +Historically, 'awk' has converted any non-numeric looking string to the +numeric value zero, when required. Furthermore, the original definition +of the language and the original POSIX standards specified that 'awk' +only understands decimal numbers (base 10), and not octal (base 8) or +hexadecimal numbers (base 16). Changes in the language of the 2001 and 2004 POSIX standards can be -interpreted to imply that `awk' should support additional features. +interpreted to imply that 'awk' should support additional features. These features are: * Interpretation of floating point data values specified in - hexadecimal notation (e.g., `0xDEADBEEF'). (Note: data values, + hexadecimal notation (e.g., '0xDEADBEEF'). (Note: data values, _not_ source code constants.) * Support for the special IEEE 754 floating point values "Not A @@ -22155,40 +22066,39 @@ These features are: ("-inf"). In particular, the format for these values is as specified by the ISO 1999 C standard, which ignores case and can allow implementation-dependent additional characters after the - `nan' and allow either `inf' or `infinity'. + 'nan' and allow either 'inf' or 'infinity'. The first problem is that both of these are clear changes to historical practice: - * The `gawk' maintainer feels that supporting hexadecimal floating + * The 'gawk' maintainer feels that supporting hexadecimal floating point values, in particular, is ugly, and was never intended by the original designers to be part of the language. - * Allowing completely alphabetic strings to have valid numeric - values is also a very severe departure from historical practice. + * Allowing completely alphabetic strings to have valid numeric values + is also a very severe departure from historical practice. - The second problem is that the `gawk' maintainer feels that this + The second problem is that the 'gawk' maintainer feels that this interpretation of the standard, which requires a certain amount of "language lawyering" to arrive at in the first place, was not even intended by the standard developers. In other words, "we see how you got where you are, but we don't think that that's where you want to be." Recognizing the above issues, but attempting to provide compatibility -with the earlier versions of the standard, the 2008 POSIX standard -added explicit wording to allow, but not require, that `awk' support +with the earlier versions of the standard, the 2008 POSIX standard added +explicit wording to allow, but not require, that 'awk' support hexadecimal floating point values and special values for "Not A Number" and infinity. - Although the `gawk' maintainer continues to feel that providing -those features is inadvisable, nevertheless, on systems that support -IEEE floating point, it seems reasonable to provide _some_ way to -support NaN and Infinity values. The solution implemented in `gawk' is -as follows: + Although the 'gawk' maintainer continues to feel that providing those +features is inadvisable, nevertheless, on systems that support IEEE +floating point, it seems reasonable to provide _some_ way to support NaN +and Infinity values. The solution implemented in 'gawk' is as follows: - * With the `--posix' command-line option, `gawk' becomes "hands - off." String values are passed directly to the system library's - `strtod()' function, and if it successfully returns a numeric - value, that is what's used.(1) By definition, the results are not + * With the '--posix' command-line option, 'gawk' becomes "hands off." + String values are passed directly to the system library's + 'strtod()' function, and if it successfully returns a numeric + value, that is what's used.(1) By definition, the results are not portable across different systems. They are also a little surprising: @@ -22197,12 +22107,12 @@ as follows: $ echo 0xDeadBeef | gawk --posix '{ print $1 + 0 }' -| 3735928559 - * Without `--posix', `gawk' interprets the four strings `+inf', - `-inf', `+nan', and `-nan' specially, producing the corresponding - special numeric values. The leading sign acts a signal to `gawk' + * Without '--posix', 'gawk' interprets the four strings '+inf', + '-inf', '+nan', and '-nan' specially, producing the corresponding + special numeric values. The leading sign acts a signal to 'gawk' (and the user) that the value is really numeric. Hexadecimal floating point is not supported (unless you also use - `--non-decimal-data', which is _not_ recommended). For example: + '--non-decimal-data', which is _not_ recommended). For example: $ echo nanny | gawk '{ print $1 + 0 }' -| 0 @@ -22211,8 +22121,8 @@ as follows: $ echo 0xDeadBeef | gawk '{ print $1 + 0 }' -| 0 - `gawk' ignores case in the four special values. Thus `+nan' and - `+NaN' are the same. + 'gawk' ignores case in the four special values. Thus '+nan' and + '+NaN' are the same. ---------- Footnotes ---------- @@ -22225,17 +22135,17 @@ File: gawk.info, Node: Floating point summary, Prev: POSIX Floating Point Prob ============ * Most computer arithmetic is done using either integers or - floating-point values. The default for `awk' is to use + floating-point values. The default for 'awk' is to use double-precision floating-point values. - * In the 1980's, Barbie mistakenly said "Math class is tough!" - While math isn't tough, floating-point arithmetic isn't the same - as pencil and paper math, and care must be taken: + * In the 1980's, Barbie mistakenly said "Math class is tough!" While + math isn't tough, floating-point arithmetic isn't the same as + pencil and paper math, and care must be taken: - Not all numbers can be represented exactly. - Comparing values should use a delta, instead of being done - directly with `==' and `!='. + directly with '==' and '!='. - Errors accumulate. @@ -22246,51 +22156,50 @@ File: gawk.info, Node: Floating point summary, Prev: POSIX Floating Point Prob * Often, increasing the accuracy and then rounding to the desired number of digits produces reasonable results. - * Use either `-M' or `--bignum' to enable MPFR arithmetic. Use - `PREC' to set the precision in bits, and `ROUNDMODE' to set the + * Use either '-M' or '--bignum' to enable MPFR arithmetic. Use + 'PREC' to set the precision in bits, and 'ROUNDMODE' to set the IEEE 754 rounding mode. - * With `-M' or `--bignum', `gawk' performs arbitrary precision + * With '-M' or '--bignum', 'gawk' performs arbitrary precision integer arithmetic using the GMP library. This is faster and more space efficient than using MPFR for the same calculations. * There are several "dark corners" with respect to floating-point - numbers where `gawk' disagrees with the POSIX standard. It pays - to be aware of them. - - * Overall, there is no need to be unduly suspicious about the - results from floating-point arithmetic. The lesson to remember is - that floating-point arithmetic is always more complex than - arithmetic using pencil and paper. In order to take advantage of - the power of computer floating-point, you need to know its - limitations and work within them. For most casual use of - floating-point arithmetic, you will often get the expected result - if you simply round the display of your final results to the - correct number of significant decimal digits. + numbers where 'gawk' disagrees with the POSIX standard. It pays to + be aware of them. + + * Overall, there is no need to be unduly suspicious about the results + from floating-point arithmetic. The lesson to remember is that + floating-point arithmetic is always more complex than arithmetic + using pencil and paper. In order to take advantage of the power of + computer floating-point, you need to know its limitations and work + within them. For most casual use of floating-point arithmetic, you + will often get the expected result if you simply round the display + of your final results to the correct number of significant decimal + digits. * As general advice, avoid presenting numerical data in a manner that implies better precision than is actually the case. -  File: gawk.info, Node: Dynamic Extensions, Next: Language History, Prev: Arbitrary Precision Arithmetic, Up: Top -16 Writing Extensions for `gawk' +16 Writing Extensions for 'gawk' ******************************** -It is possible to add new functions written in C or C++ to `gawk' using -dynamically loaded libraries. This facility is available on systems -that support the C `dlopen()' and `dlsym()' functions. This major node +It is possible to add new functions written in C or C++ to 'gawk' using +dynamically loaded libraries. This facility is available on systems +that support the C 'dlopen()' and 'dlsym()' functions. This major node describes how to create extensions using code written in C or C++. If you don't know anything about C programming, you can safely skip this major node, although you may wish to review the documentation on -the extensions that come with `gawk' (*note Extension Samples::), and -the information on the `gawkextlib' project (*note gawkextlib::). The -sample extensions are automatically built and installed when `gawk' is. +the extensions that come with 'gawk' (*note Extension Samples::), and +the information on the 'gawkextlib' project (*note gawkextlib::). The +sample extensions are automatically built and installed when 'gawk' is. - NOTE: When `--sandbox' is specified, extensions are disabled - (*note Options::). + NOTE: When '--sandbox' is specified, extensions are disabled (*note + Options::). * Menu: @@ -22298,11 +22207,11 @@ sample extensions are automatically built and installed when `gawk' is. * Plugin License:: A note about licensing. * Extension Mechanism Outline:: An outline of how it works. * Extension API Description:: A full description of the API. -* Finding Extensions:: How `gawk' finds compiled extensions. +* Finding Extensions:: How 'gawk' finds compiled extensions. * Extension Example:: Example C code for an extension. * Extension Samples:: The sample extensions that ship with - `gawk'. -* gawkextlib:: The `gawkextlib' project. + 'gawk'. +* gawkextlib:: The 'gawkextlib' project. * Extension summary:: Extension summary. * Extension Exercises:: Exercises. @@ -22313,23 +22222,23 @@ File: gawk.info, Node: Extension Intro, Next: Plugin License, Up: Dynamic Ext ================= An "extension" (sometimes called a "plug-in") is a piece of external -compiled code that `gawk' can load at runtime to provide additional -functionality, over and above the built-in capabilities described in -the rest of this Info file. +compiled code that 'gawk' can load at runtime to provide additional +functionality, over and above the built-in capabilities described in the +rest of this Info file. Extensions are useful because they allow you (of course) to extend -`gawk''s functionality. For example, they can provide access to system -calls (such as `chdir()' to change directory) and to other C library +'gawk''s functionality. For example, they can provide access to system +calls (such as 'chdir()' to change directory) and to other C library routines that could be of use. As with most software, "the sky is the limit;" if you can imagine something that you might want to do and can write in C or C++, you can write an extension to do it! Extensions are written in C or C++, using the "Application -Programming Interface" (API) defined for this purpose by the `gawk' +Programming Interface" (API) defined for this purpose by the 'gawk' developers. The rest of this major node explains the facilities that the API provides and how to use them, and presents a small sample extension. In addition, it documents the sample extensions included in -the `gawk' distribution, and describes the `gawkextlib' project. *Note +the 'gawk' distribution, and describes the 'gawkextlib' project. *Note Extension Design::, for a discussion of the extension mechanism goals and design. @@ -22340,13 +22249,13 @@ File: gawk.info, Node: Plugin License, Next: Extension Mechanism Outline, Pre ======================== Every dynamic extension should define the global symbol -`plugin_is_GPL_compatible' to assert that it has been licensed under a -GPL-compatible license. If this symbol does not exist, `gawk' emits a +'plugin_is_GPL_compatible' to assert that it has been licensed under a +GPL-compatible license. If this symbol does not exist, 'gawk' emits a fatal error and exits when it tries to load your extension. - The declared type of the symbol should be `int'. It does not need -to be in any allocated section, though. The code merely asserts that -the symbol exists in the global scope. Something like this is enough: + The declared type of the symbol should be 'int'. It does not need to +be in any allocated section, though. The code merely asserts that the +symbol exists in the global scope. Something like this is enough: int plugin_is_GPL_compatible; @@ -22356,44 +22265,45 @@ File: gawk.info, Node: Extension Mechanism Outline, Next: Extension API Descri 16.3 At A High Level How It Works ================================= -Communication between `gawk' and an extension is two-way. First, when -an extension is loaded, it is passed a pointer to a `struct' whose -fields are function pointers. This is shown in *note -figure-load-extension::. +Communication between 'gawk' and an extension is two-way. First, when +an extension is loaded, it is passed a pointer to a 'struct' whose +fields are function pointers. This is shown in *note Figure 16.1: +figure-load-extension. - API +[image src="api-figure1.txt" alt="Loading The Extension" text=" API Struct +---+ | | +---+ +---------------| | | +---+ dl_load(api_p, id); - | | | ___________________ + | | | ___________________ | +---+ | | +---------| | __________________ | | | +---+ || | | | | || | | +---+ || | | +---| | || - | | | +---+ \ || / - | | | \ / - v v v \/ + | | | +---+ \\ || / + | | | \\ / + v v v \\/ +-------+-+---+-+---+-+------------------+--------------------+ | |x| |x| |x| |OOOOOOOOOOOOOOOOOOOO| | |x| |x| |x| |OOOOOOOOOOOOOOOOOOOO| | |x| |x| |x| |OOOOOOOOOOOOOOOOOOOO| +-------+-+---+-+---+-+------------------+--------------------+ - gawk Main Program Address Space Extension + gawk Main Program Address Space Extension"] + Figure 16.1: Loading The Extension - The extension can call functions inside `gawk' through these -function pointers, at runtime, without needing (link-time) access to -`gawk''s symbols. One of these function pointers is to a function for -"registering" new built-in functions. This is shown in *note -figure-load-new-function::. + The extension can call functions inside 'gawk' through these function +pointers, at runtime, without needing (link-time) access to 'gawk''s +symbols. One of these function pointers is to a function for +"registering" new built-in functions. This is shown in *note Figure +16.2: figure-load-new-function. - register_ext_func({ "chdir", do_chdir, 1 }); +[image src="api-figure2.txt" alt="Loading The New Function" text=" register_ext_func({ \"chdir\", do_chdir, 1 }); +--------------------------------------------+ | | @@ -22404,17 +22314,19 @@ figure-load-new-function::. | |x| |x| |x| |OOOOOOOOOOOOOO|X|OOO| +-------+-+---+-+---+-+------------------+--------------+-+---+ - gawk Main Program Address Space Extension + gawk Main Program Address Space Extension"] + Figure 16.2: Loading The New Function In the other direction, the extension registers its new functions -with `gawk' by passing function pointers to the functions that provide -the new feature (`do_chdir()', for example). `gawk' associates the +with 'gawk' by passing function pointers to the functions that provide +the new feature ('do_chdir()', for example). 'gawk' associates the function pointer with a name and can then call it, using a defined -calling convention. This is shown in *note figure-call-new-function::. +calling convention. This is shown in *note Figure 16.3: +figure-call-new-function. - BEGIN { - chdir("/path") (*fnptr)(1); +[image src="api-figure3.txt" alt="Calling the new function" text=" BEGIN { + chdir(\"/path\") (*fnptr)(1); } +--------------------------------------------+ | | @@ -22425,32 +22337,33 @@ calling convention. This is shown in *note figure-call-new-function::. | |x| |x| |x| |OOOOOOOOOOOOOO|X|OOO| +-------+-+---+-+---+-+------------------+--------------+-+---+ - gawk Main Program Address Space Extension + gawk Main Program Address Space Extension"] + Figure 16.3: Calling The New Function - The `do_XXX()' function, in turn, then uses the function pointers in -the API `struct' to do its work, such as updating variables or arrays, -printing messages, setting `ERRNO', and so on. + The 'do_XXX()' function, in turn, then uses the function pointers in +the API 'struct' to do its work, such as updating variables or arrays, +printing messages, setting 'ERRNO', and so on. Convenience macros make calling through the function pointers look -like regular function calls so that extension code is quite readable -and understandable. +like regular function calls so that extension code is quite readable and +understandable. Although all of this sounds somewhat complicated, the result is that -extension code is quite straightforward to write and to read. You can -see this in the sample extensions `filefuncs.c' (*note Extension -Example::) and also the `testext.c' code for testing the APIs. +extension code is quite straightforward to write and to read. You can +see this in the sample extensions 'filefuncs.c' (*note Extension +Example::) and also the 'testext.c' code for testing the APIs. Some other bits and pieces: - * The API provides access to `gawk''s `do_XXX' values, reflecting - command line options, like `do_lint', `do_profiling' and so on + * The API provides access to 'gawk''s 'do_XXX' values, reflecting + command line options, like 'do_lint', 'do_profiling' and so on (*note Extension API Variables::). These are informational: an - extension cannot affect their values inside `gawk'. In addition, + extension cannot affect their values inside 'gawk'. In addition, attempting to assign to them produces a compile-time error. * The API also provides major and minor version numbers, so that an - extension can check if the `gawk' it is loaded with supports the + extension can check if the 'gawk' it is loaded with supports the facilities it was compiled with. (Version mismatches "shouldn't" happen, but we all know how _that_ goes.) *Note Extension Versioning::, for details. @@ -22461,10 +22374,10 @@ File: gawk.info, Node: Extension API Description, Next: Finding Extensions, P 16.4 API Description ==================== -C or C++ code for an extension must include the header file -`gawkapi.h', which declares the functions and defines the data types -used to communicate with `gawk'. This (rather large) minor node -describes the API in detail. +C or C++ code for an extension must include the header file 'gawkapi.h', +which declares the functions and defines the data types used to +communicate with 'gawk'. This (rather large) minor node describes the +API in detail. * Menu: @@ -22474,9 +22387,9 @@ describes the API in detail. * Memory Allocation Functions:: Functions for allocating memory. * Constructor Functions:: Functions for creating values. * Registration Functions:: Functions to register things with - `gawk'. + 'gawk'. * Printing Messages:: Functions for printing messages. -* Updating `ERRNO':: Functions for updating `ERRNO'. +* Updating 'ERRNO':: Functions for updating 'ERRNO'. * Accessing Parameters:: Functions for accessing parameters. * Symbol Table Access:: Functions for accessing global variables. @@ -22490,35 +22403,30 @@ File: gawk.info, Node: Extension API Functions Introduction, Next: General Dat 16.4.1 Introduction ------------------- -Access to facilities within `gawk' are made available by calling -through function pointers passed into your extension. +Access to facilities within 'gawk' are made available by calling through +function pointers passed into your extension. API function pointers are provided for the following kinds of operations: - * Registration functions. You may register: + * Registration functions. You may register: - extension functions, - - exit callbacks, - - a version string, - - input parsers, - - output wrappers, - - and two-way processors. All of these are discussed in detail, later in this major node. * Printing fatal, warning, and "lint" warning messages. - * Updating `ERRNO', or unsetting it. + * Updating 'ERRNO', or unsetting it. * Accessing parameters, including converting an undefined parameter into an array. - * Symbol table access: retrieving a global variable, creating one, - or changing one. + * Symbol table access: retrieving a global variable, creating one, or + changing one. * Allocating, reallocating, and releasing memory. @@ -22542,53 +22450,52 @@ operations: Some points about using the API: * The following types and/or macros and/or functions are referenced - in `gawkapi.h'. For correct use, you must therefore include the - corresponding standard header file _before_ including `gawkapi.h': + in 'gawkapi.h'. For correct use, you must therefore include the + corresponding standard header file _before_ including 'gawkapi.h': C Entity Header File - ------------------------------------------- - `EOF' `' - Values for `errno' `' - `FILE' `' - `NULL' `' - `memcpy()' `' - `memset()' `' - `size_t' `' - `struct stat' `' + ------------------------------------------- + 'EOF' '' + Values for 'errno' '' + 'FILE' '' + 'NULL' '' + 'memcpy()' '' + 'memset()' '' + 'size_t' '' + 'struct stat' '' Due to portability concerns, especially to systems that are not - fully standards-compliant, it is your responsibility to include - the correct files in the correct way. This requirement is - necessary in order to keep `gawkapi.h' clean, instead of becoming - a portability hodge-podge as can be seen in some parts of the - `gawk' source code. + fully standards-compliant, it is your responsibility to include the + correct files in the correct way. This requirement is necessary in + order to keep 'gawkapi.h' clean, instead of becoming a portability + hodge-podge as can be seen in some parts of the 'gawk' source code. - * The `gawkapi.h' file may be included more than once without ill + * The 'gawkapi.h' file may be included more than once without ill effect. Doing so, however, is poor coding practice. * Although the API only uses ISO C 90 features, there is an - exception; the "constructor" functions use the `inline' keyword. + exception; the "constructor" functions use the 'inline' keyword. If your compiler does not support this keyword, you should either - place `-Dinline=''' on your command line, or use the GNU Autotools - and include a `config.h' file in your extensions. + place '-Dinline=''' on your command line, or use the GNU Autotools + and include a 'config.h' file in your extensions. - * All pointers filled in by `gawk' are to memory managed by `gawk' + * All pointers filled in by 'gawk' are to memory managed by 'gawk' and should be treated by the extension as read-only. Memory for - _all_ strings passed into `gawk' from the extension _must_ come - from calling the API-provided function pointers `api_malloc()', - `api_calloc()' or `api_realloc()', and is managed by `gawk' from + _all_ strings passed into 'gawk' from the extension _must_ come + from calling the API-provided function pointers 'api_malloc()', + 'api_calloc()' or 'api_realloc()', and is managed by 'gawk' from then on. - * The API defines several simple `struct's that map values as seen - from `awk'. A value can be a `double', a string, or an array (as + * The API defines several simple 'struct's that map values as seen + from 'awk'. A value can be a 'double', a string, or an array (as in multidimensional arrays, or when creating a new array). String values maintain both pointer and length since embedded NUL characters are allowed. NOTE: By intent, strings are maintained using the current - multibyte encoding (as defined by `LC_XXX' environment + multibyte encoding (as defined by 'LC_XXX' environment variables) and not using wide characters. This matches how - `gawk' stores strings internally and also how characters are + 'gawk' stores strings internally and also how characters are likely to be input and output from files. * When retrieving a value (such as a parameter or that of a global @@ -22602,10 +22509,9 @@ operations: that is there, so that the extension can, e.g., print an error message (such as "scalar passed where array expected"). - While you may call the API functions by using the function pointers -directly, the interface is not so pretty. To make extension code look -more like regular code, the `gawkapi.h' header file defines several +directly, the interface is not so pretty. To make extension code look +more like regular code, the 'gawkapi.h' header file defines several macros that you should use in your code. This minor node presents the macros as if they were functions. @@ -22615,137 +22521,135 @@ File: gawk.info, Node: General Data Types, Next: Requesting Values, Prev: Ext 16.4.2 General Purpose Data Types --------------------------------- - I have a true love/hate relationship with unions. -- Arnold - Robbins + I have a true love/hate relationship with unions. + -- _Arnold Robbins_ That's the thing about unions: the compiler will arrange things so - they can accommodate both love and hate. -- Chet Ramey - - The extension API defines a number of simple types and structures -for general purpose use. Additional, more specialized, data structures -are introduced in subsequent minor nodes, together with the functions -that use them. - -`typedef void *awk_ext_id_t;' - A value of this type is received from `gawk' when an extension is - loaded. That value must then be passed back to `gawk' as the - first parameter of each API function. - -`#define awk_const ...' - This macro expands to `const' when compiling an extension, and to - nothing when compiling `gawk' itself. This makes certain fields - in the API data structures unwritable from extension code, while - allowing `gawk' to use them as it needs to. - -`typedef enum awk_bool {' -` awk_false = 0,' -` awk_true' -`} awk_bool_t;' + they can accommodate both love and hate. + -- _Chet Ramey_ + + The extension API defines a number of simple types and structures for +general purpose use. Additional, more specialized, data structures are +introduced in subsequent minor nodes, together with the functions that +use them. + +'typedef void *awk_ext_id_t;' + A value of this type is received from 'gawk' when an extension is + loaded. That value must then be passed back to 'gawk' as the first + parameter of each API function. + +'#define awk_const ...' + This macro expands to 'const' when compiling an extension, and to + nothing when compiling 'gawk' itself. This makes certain fields in + the API data structures unwritable from extension code, while + allowing 'gawk' to use them as it needs to. + +'typedef enum awk_bool {' +' awk_false = 0,' +' awk_true' +'} awk_bool_t;' A simple boolean type. -`typedef struct awk_string {' -` char *str; /* data */' -` size_t len; /* length thereof, in chars */' -`} awk_string_t;' - This represents a mutable string. `gawk' owns the memory pointed - to if it supplied the value. Otherwise, it takes ownership of the +'typedef struct awk_string {' +' char *str; /* data */' +' size_t len; /* length thereof, in chars */' +'} awk_string_t;' + This represents a mutable string. 'gawk' owns the memory pointed + to if it supplied the value. Otherwise, it takes ownership of the memory pointed to. *Such memory must come from calling the - API-provided function pointers `api_malloc()', `api_calloc()', or - `api_realloc()'!* + API-provided function pointers 'api_malloc()', 'api_calloc()', or + 'api_realloc()'!* As mentioned earlier, strings are maintained using the current multibyte encoding. -`typedef enum {' -` AWK_UNDEFINED,' -` AWK_NUMBER,' -` AWK_STRING,' -` AWK_ARRAY,' -` AWK_SCALAR, /* opaque access to a variable */' -` AWK_VALUE_COOKIE /* for updating a previously created value */' -`} awk_valtype_t;' - This `enum' indicates the type of a value. It is used in the - following `struct'. - -`typedef struct awk_value {' -` awk_valtype_t val_type;' -` union {' -` awk_string_t s;' -` double d;' -` awk_array_t a;' -` awk_scalar_t scl;' -` awk_value_cookie_t vc;' -` } u;' -`} awk_value_t;' - An "`awk' value." The `val_type' member indicates what kind of - value the `union' holds, and each member is of the appropriate +'typedef enum {' +' AWK_UNDEFINED,' +' AWK_NUMBER,' +' AWK_STRING,' +' AWK_ARRAY,' +' AWK_SCALAR, /* opaque access to a variable */' +' AWK_VALUE_COOKIE /* for updating a previously created value */' +'} awk_valtype_t;' + This 'enum' indicates the type of a value. It is used in the + following 'struct'. + +'typedef struct awk_value {' +' awk_valtype_t val_type;' +' union {' +' awk_string_t s;' +' double d;' +' awk_array_t a;' +' awk_scalar_t scl;' +' awk_value_cookie_t vc;' +' } u;' +'} awk_value_t;' + An "'awk' value." The 'val_type' member indicates what kind of + value the 'union' holds, and each member is of the appropriate type. -`#define str_value u.s' -`#define num_value u.d' -`#define array_cookie u.a' -`#define scalar_cookie u.scl' -`#define value_cookie u.vc' - These macros make accessing the fields of the `awk_value_t' more +'#define str_value u.s' +'#define num_value u.d' +'#define array_cookie u.a' +'#define scalar_cookie u.scl' +'#define value_cookie u.vc' + These macros make accessing the fields of the 'awk_value_t' more readable. -`typedef void *awk_scalar_t;' - Scalars can be represented as an opaque type. These values are - obtained from `gawk' and then passed back into it. This is +'typedef void *awk_scalar_t;' + Scalars can be represented as an opaque type. These values are + obtained from 'gawk' and then passed back into it. This is discussed in a general fashion below, and in more detail in *note Symbol table by cookie::. -`typedef void *awk_value_cookie_t;' +'typedef void *awk_value_cookie_t;' A "value cookie" is an opaque type representing a cached value. This is also discussed in a general fashion below, and in more detail in *note Cached values::. + Scalar values in 'awk' are either numbers or strings. The +'awk_value_t' struct represents values. The 'val_type' member indicates +what is in the 'union'. - Scalar values in `awk' are either numbers or strings. The -`awk_value_t' struct represents values. The `val_type' member -indicates what is in the `union'. - - Representing numbers is easy--the API uses a C `double'. Strings -require more work. Since `gawk' allows embedded NUL bytes in string -values, a string must be represented as a pair containing a -data-pointer and length. This is the `awk_string_t' type. + Representing numbers is easy--the API uses a C 'double'. Strings +require more work. Since 'gawk' allows embedded NUL bytes in string +values, a string must be represented as a pair containing a data-pointer +and length. This is the 'awk_string_t' type. Identifiers (i.e., the names of global variables) can be associated -with either scalar values or with arrays. In addition, `gawk' provides +with either scalar values or with arrays. In addition, 'gawk' provides true arrays of arrays, where any given array element can itself be an array. Discussion of arrays is delayed until *note Array Manipulation::. The various macros listed earlier make it easier to use the elements -of the `union' as if they were fields in a `struct'; this is a common -coding practice in C. Such code is easier to write and to read, -however it remains _your_ responsibility to make sure that the -`val_type' member correctly reflects the type of the value in the -`awk_value_t'. - - Conceptually, the first three members of the `union' (number, string, -and array) are all that is needed for working with `awk' values. +of the 'union' as if they were fields in a 'struct'; this is a common +coding practice in C. Such code is easier to write and to read, however +it remains _your_ responsibility to make sure that the 'val_type' member +correctly reflects the type of the value in the 'awk_value_t'. + + Conceptually, the first three members of the 'union' (number, string, +and array) are all that is needed for working with 'awk' values. However, since the API provides routines for accessing and changing the value of global scalar variables only by using the variable's name, -there is a performance penalty: `gawk' must find the variable each time -it is accessed and changed. This turns out to be a real issue, not -just a theoretical one. +there is a performance penalty: 'gawk' must find the variable each time +it is accessed and changed. This turns out to be a real issue, not just +a theoretical one. Thus, if you know that your extension will spend considerable time reading and/or changing the value of one or more scalar variables, you can obtain a "scalar cookie"(1) object for that variable, and then use the cookie for getting the variable's value or for changing the -variable's value. This is the `awk_scalar_t' type and `scalar_cookie' -macro. Given a scalar cookie, `gawk' can directly retrieve or modify +variable's value. This is the 'awk_scalar_t' type and 'scalar_cookie' +macro. Given a scalar cookie, 'gawk' can directly retrieve or modify the value, as required, without having to first find it. - The `awk_value_cookie_t' type and `value_cookie' macro are similar. + The 'awk_value_cookie_t' type and 'value_cookie' macro are similar. If you know that you wish to use the same numeric or string _value_ for -one or more variables, you can create the value once, retaining a -"value cookie" for it, and then pass in that value cookie whenever you -wish to set the value of a variable. This saves both storage space -within the running `gawk' process as well as the time needed to create -the value. +one or more variables, you can create the value once, retaining a "value +cookie" for it, and then pass in that value cookie whenever you wish to +set the value of a variable. This saves both storage space within the +running 'gawk' process as well as the time needed to create the value. ---------- Footnotes ---------- @@ -22761,30 +22665,29 @@ File: gawk.info, Node: Requesting Values, Next: Memory Allocation Functions, 16.4.3 Requesting Values ------------------------ -All of the functions that return values from `gawk' work in the same -way. You pass in an `awk_valtype_t' value to indicate what kind of +All of the functions that return values from 'gawk' work in the same +way. You pass in an 'awk_valtype_t' value to indicate what kind of value you expect. If the actual value matches what you requested, the -function returns true and fills in the `awk_value_t' result. -Otherwise, the function returns false, and the `val_type' member -indicates the type of the actual value. You may then print an error -message, or reissue the request for the actual value type, as -appropriate. This behavior is summarized in *note -table-value-types-returned::. +function returns true and fills in the 'awk_value_t' result. Otherwise, +the function returns false, and the 'val_type' member indicates the type +of the actual value. You may then print an error message, or reissue +the request for the actual value type, as appropriate. This behavior is +summarized in *note Table 16.1: table-value-types-returned. Type of Actual Value: --------------------------------------------------------------------------- - +-------------------------------------------------------------------------- String Number Array Undefined ------------------------------------------------------------------------------- +------------------------------------------------------------------------------ String String String false false - Number Number if can Number false false - be converted, - else false + Number Number if Number false false + can be + converted, + else false Type Array false false Array false Requested: Scalar Scalar Scalar false false Undefined String Number Array Undefined Value false false false false - Cookie + Cookie Table 16.1: API Value Types Returned @@ -22795,52 +22698,52 @@ File: gawk.info, Node: Memory Allocation Functions, Next: Constructor Function --------------------------------------------------------- The API provides a number of "memory allocation" functions for -allocating memory that can be passed to `gawk', as well as a number of +allocating memory that can be passed to 'gawk', as well as a number of convenience macros. -`void *gawk_malloc(size_t size);' - Call `gawk'-provided `api_malloc()' to allocate storage that may - be passed to `gawk'. +'void *gawk_malloc(size_t size);' + Call 'gawk'-provided 'api_malloc()' to allocate storage that may be + passed to 'gawk'. -`void *gawk_calloc(size_t nmemb, size_t size);' - Call `gawk'-provided `api_calloc()' to allocate storage that may - be passed to `gawk'. +'void *gawk_calloc(size_t nmemb, size_t size);' + Call 'gawk'-provided 'api_calloc()' to allocate storage that may be + passed to 'gawk'. -`void *gawk_realloc(void *ptr, size_t size);' - Call `gawk'-provided `api_realloc()' to allocate storage that may - be passed to `gawk'. +'void *gawk_realloc(void *ptr, size_t size);' + Call 'gawk'-provided 'api_realloc()' to allocate storage that may + be passed to 'gawk'. -`void gawk_free(void *ptr);' - Call `gawk'-provided `api_free()' to release storage that was - allocated with `gawk_malloc()', `gawk_calloc()' or - `gawk_realloc()'. +'void gawk_free(void *ptr);' + Call 'gawk'-provided 'api_free()' to release storage that was + allocated with 'gawk_malloc()', 'gawk_calloc()' or + 'gawk_realloc()'. The API has to provide these functions because it is possible for an -extension to be compiled and linked against a different version of the -C library than was used for the `gawk' executable.(1) If `gawk' were to -use its version of `free()' when the memory came from an unrelated -version of `malloc()', unexpected behavior would likely result. +extension to be compiled and linked against a different version of the C +library than was used for the 'gawk' executable.(1) If 'gawk' were to +use its version of 'free()' when the memory came from an unrelated +version of 'malloc()', unexpected behavior would likely result. Two convenience macros may be used for allocating storage from the -API-provided function pointers `api_malloc()' and `api_realloc()'. If -the allocation fails, they cause `gawk' to exit with a fatal error +API-provided function pointers 'api_malloc()' and 'api_realloc()'. If +the allocation fails, they cause 'gawk' to exit with a fatal error message. They should be used as if they were procedure calls that do not return a value. -`#define emalloc(pointer, type, size, message) ...' +'#define emalloc(pointer, type, size, message) ...' The arguments to this macro are as follows: - `pointer' + 'pointer' The pointer variable to point at the allocated storage. - `type' + 'type' The type of the pointer variable, used to create a cast for - the call to `api_malloc()'. + the call to 'api_malloc()'. - `size' + 'size' The total number of bytes to be allocated. - `message' + 'message' A message to be prefixed to the fatal error message. Typically this is the name of the function using the macro. @@ -22854,9 +22757,9 @@ not return a value. strcpy(message, greet); make_malloced_string(message, strlen(message), & result); -`#define erealloc(pointer, type, size, message) ...' - This is like `emalloc()', but it calls `api_realloc()', instead of - `api_malloc()'. The arguments are the same as for the `emalloc()' +'#define erealloc(pointer, type, size, message) ...' + This is like 'emalloc()', but it calls 'api_realloc()', instead of + 'api_malloc()'. The arguments are the same as for the 'emalloc()' macro. ---------- Footnotes ---------- @@ -22870,37 +22773,37 @@ File: gawk.info, Node: Constructor Functions, Next: Registration Functions, P 16.4.5 Constructor Functions ---------------------------- -The API provides a number of "constructor" functions for creating -string and numeric values, as well as a number of convenience macros. -This node presents them all as function prototypes, in the way that -extension code would use them. - -`static inline awk_value_t *' -`make_const_string(const char *string, size_t length, awk_value_t *result)' - This function creates a string value in the `awk_value_t' variable - pointed to by `result'. It expects `string' to be a C string - constant (or other string data), and automatically creates a - _copy_ of the data for storage in `result'. It returns `result'. - -`static inline awk_value_t *' -`make_malloced_string(const char *string, size_t length, awk_value_t *result)' - This function creates a string value in the `awk_value_t' variable - pointed to by `result'. It expects `string' to be a `char *' value +The API provides a number of "constructor" functions for creating string +and numeric values, as well as a number of convenience macros. This +node presents them all as function prototypes, in the way that extension +code would use them. + +'static inline awk_value_t *' +'make_const_string(const char *string, size_t length, awk_value_t *result)' + This function creates a string value in the 'awk_value_t' variable + pointed to by 'result'. It expects 'string' to be a C string + constant (or other string data), and automatically creates a _copy_ + of the data for storage in 'result'. It returns 'result'. + +'static inline awk_value_t *' +'make_malloced_string(const char *string, size_t length, awk_value_t *result)' + This function creates a string value in the 'awk_value_t' variable + pointed to by 'result'. It expects 'string' to be a 'char *' value pointing to data previously obtained from the api-provided - functions `api_malloc()', `api_calloc()' or `api_realloc()'. The - idea here is that the data is passed directly to `gawk', which - assumes responsibility for it. It returns `result'. + functions 'api_malloc()', 'api_calloc()' or 'api_realloc()'. The + idea here is that the data is passed directly to 'gawk', which + assumes responsibility for it. It returns 'result'. -`static inline awk_value_t *' -`make_null_string(awk_value_t *result)' +'static inline awk_value_t *' +'make_null_string(awk_value_t *result)' This specialized function creates a null string (the "undefined" - value) in the `awk_value_t' variable pointed to by `result'. It - returns `result'. + value) in the 'awk_value_t' variable pointed to by 'result'. It + returns 'result'. -`static inline awk_value_t *' -`make_number(double num, awk_value_t *result)' - This function simply creates a numeric value in the `awk_value_t' - variable pointed to by `result'. +'static inline awk_value_t *' +'make_number(double num, awk_value_t *result)' + This function simply creates a numeric value in the 'awk_value_t' + variable pointed to by 'result'.  File: gawk.info, Node: Registration Functions, Next: Printing Messages, Prev: Constructor Functions, Up: Extension API Description @@ -22909,7 +22812,7 @@ File: gawk.info, Node: Registration Functions, Next: Printing Messages, Prev: ----------------------------- This minor node describes the API functions for registering parts of -your extension with `gawk'. +your extension with 'gawk'. * Menu: @@ -22936,43 +22839,43 @@ Extension functions are described by the following record: The fields are: -`const char *name;' - The name of the new function. `awk' level code calls the function +'const char *name;' + The name of the new function. 'awk' level code calls the function by this name. This is a regular C string. - Function names must obey the rules for `awk' identifiers. That is, - they must begin with either a letter or an underscore, which may - be followed by any number of letters, digits, and underscores. - Letter case in function names is significant. + Function names must obey the rules for 'awk' identifiers. That is, + they must begin with either a letter or an underscore, which may be + followed by any number of letters, digits, and underscores. Letter + case in function names is significant. -`awk_value_t *(*function)(int num_actual_args, awk_value_t *result);' +'awk_value_t *(*function)(int num_actual_args, awk_value_t *result);' This is a pointer to the C function that provides the desired functionality. The function must fill in the result with either a - number or a string. `gawk' takes ownership of any string memory. + number or a string. 'gawk' takes ownership of any string memory. As mentioned earlier, string memory *must* come from the - api-provided functions `api_malloc()', `api_calloc()' or - `api_realloc()'. + api-provided functions 'api_malloc()', 'api_calloc()' or + 'api_realloc()'. - The `num_actual_args' argument tells the C function how many - actual parameters were passed from the calling `awk' code. + The 'num_actual_args' argument tells the C function how many actual + parameters were passed from the calling 'awk' code. - The function must return the value of `result'. This is for the - convenience of the calling code inside `gawk'. + The function must return the value of 'result'. This is for the + convenience of the calling code inside 'gawk'. -`size_t num_expected_args;' +'size_t num_expected_args;' This is the number of arguments the function expects to receive. Each extension function may decide what to do if the number of - arguments isn't what it expected. Following `awk' functions, it - is likely OK to ignore extra arguments. + arguments isn't what it expected. Following 'awk' functions, it is + likely OK to ignore extra arguments. Once you have a record representing your extension function, you -register it with `gawk' using this API function: +register it with 'gawk' using this API function: -`awk_bool_t add_ext_func(const char *namespace, const awk_ext_func_t *func);' +'awk_bool_t add_ext_func(const char *namespace, const awk_ext_func_t *func);' This function returns true upon success, false otherwise. The - `namespace' parameter is currently not used; you should pass in an - empty string (`""'). The `func' pointer is the address of a - `struct' representing your function, as just described. + 'namespace' parameter is currently not used; you should pass in an + empty string ('""'). The 'func' pointer is the address of a + 'struct' representing your function, as just described.  File: gawk.info, Node: Exit Callback Functions, Next: Extension Version String, Prev: Extension Functions, Up: Registration Functions @@ -22980,29 +22883,29 @@ File: gawk.info, Node: Exit Callback Functions, Next: Extension Version String 16.4.6.2 Registering An Exit Callback Function .............................................. -An "exit callback" function is a function that `gawk' calls before it +An "exit callback" function is a function that 'gawk' calls before it exits. Such functions are useful if you have general "cleanup" tasks that should be performed in your extension (such as closing data base connections or other resource deallocations). You can register such a -function with `gawk' using the following function. +function with 'gawk' using the following function. -`void awk_atexit(void (*funcp)(void *data, int exit_status),' -` void *arg0);' +'void awk_atexit(void (*funcp)(void *data, int exit_status),' +' void *arg0);' The parameters are: - `funcp' - A pointer to the function to be called before `gawk' exits. - The `data' parameter will be the original value of `arg0'. - The `exit_status' parameter is the exit status value that - `gawk' intends to pass to the `exit()' system call. + 'funcp' + A pointer to the function to be called before 'gawk' exits. + The 'data' parameter will be the original value of 'arg0'. + The 'exit_status' parameter is the exit status value that + 'gawk' intends to pass to the 'exit()' system call. - `arg0' - A pointer to private data which `gawk' saves in order to pass - to the function pointed to by `funcp'. + 'arg0' + A pointer to private data which 'gawk' saves in order to pass + to the function pointed to by 'funcp'. Exit callback functions are called in Last-In-First-Out (LIFO) order--that is, in the reverse order in which they are registered with -`gawk'. +'gawk'.  File: gawk.info, Node: Extension Version String, Next: Input Parsers, Prev: Exit Callback Functions, Up: Registration Functions @@ -23011,14 +22914,14 @@ File: gawk.info, Node: Extension Version String, Next: Input Parsers, Prev: E ................................................ You can register a version string which indicates the name and version -of your extension, with `gawk', as follows: +of your extension, with 'gawk', as follows: -`void register_ext_version(const char *version);' - Register the string pointed to by `version' with `gawk'. `gawk' - does _not_ copy the `version' string, so it should not be changed. +'void register_ext_version(const char *version);' + Register the string pointed to by 'version' with 'gawk'. 'gawk' + does _not_ copy the 'version' string, so it should not be changed. - `gawk' prints all registered extension version strings when it is -invoked with the `--version' option. + 'gawk' prints all registered extension version strings when it is +invoked with the '--version' option.  File: gawk.info, Node: Input Parsers, Next: Output Wrappers, Prev: Extension Version String, Up: Registration Functions @@ -23026,38 +22929,37 @@ File: gawk.info, Node: Input Parsers, Next: Output Wrappers, Prev: Extension 16.4.6.4 Customized Input Parsers ................................. -By default, `gawk' reads text files as its input. It uses the value of -`RS' to find the end of the record, and then uses `FS' (or -`FIELDWIDTHS' or `FPAT') to split it into fields (*note Reading -Files::). Additionally, it sets the value of `RT' (*note Built-in -Variables::). +By default, 'gawk' reads text files as its input. It uses the value of +'RS' to find the end of the record, and then uses 'FS' (or 'FIELDWIDTHS' +or 'FPAT') to split it into fields (*note Reading Files::). +Additionally, it sets the value of 'RT' (*note Built-in Variables::). If you want, you can provide your own custom input parser. An input -parser's job is to return a record to the `gawk' record processing -code, along with indicators for the value and length of the data to be -used for `RT', if any. +parser's job is to return a record to the 'gawk' record processing code, +along with indicators for the value and length of the data to be used +for 'RT', if any. To provide an input parser, you must first provide two functions (where XXX is a prefix name for your extension): -`awk_bool_t XXX_can_take_file(const awk_input_buf_t *iobuf)' - This function examines the information available in `iobuf' (which - we discuss shortly). Based on the information there, it decides - if the input parser should be used for this file. If so, it - should return true. Otherwise, it should return false. It should - not change any state (variable values, etc.) within `gawk'. - -`awk_bool_t XXX_take_control_of(awk_input_buf_t *iobuf)' - When `gawk' decides to hand control of the file over to the input - parser, it calls this function. This function in turn must fill - in certain fields in the `awk_input_buf_t' structure, and ensure - that certain conditions are true. It should then return true. If - an error of some kind occurs, it should not fill in any fields, - and should return false; then `gawk' will not use the input parser. +'awk_bool_t XXX_can_take_file(const awk_input_buf_t *iobuf)' + This function examines the information available in 'iobuf' (which + we discuss shortly). Based on the information there, it decides if + the input parser should be used for this file. If so, it should + return true. Otherwise, it should return false. It should not + change any state (variable values, etc.) within 'gawk'. + +'awk_bool_t XXX_take_control_of(awk_input_buf_t *iobuf)' + When 'gawk' decides to hand control of the file over to the input + parser, it calls this function. This function in turn must fill in + certain fields in the 'awk_input_buf_t' structure, and ensure that + certain conditions are true. It should then return true. If an + error of some kind occurs, it should not fill in any fields, and + should return false; then 'gawk' will not use the input parser. The details are presented shortly. Your extension should package these functions inside an -`awk_input_parser_t', which looks like this: +'awk_input_parser_t', which looks like this: typedef struct awk_input_parser { const char *name; /* name of parser */ @@ -23068,29 +22970,29 @@ used for `RT', if any. The fields are: -`const char *name;' - The name of the input parser. This is a regular C string. +'const char *name;' + The name of the input parser. This is a regular C string. -`awk_bool_t (*can_take_file)(const awk_input_buf_t *iobuf);' - A pointer to your `XXX_can_take_file()' function. +'awk_bool_t (*can_take_file)(const awk_input_buf_t *iobuf);' + A pointer to your 'XXX_can_take_file()' function. -`awk_bool_t (*take_control_of)(awk_input_buf_t *iobuf);' - A pointer to your `XXX_take_control_of()' function. +'awk_bool_t (*take_control_of)(awk_input_buf_t *iobuf);' + A pointer to your 'XXX_take_control_of()' function. -`awk_const struct input_parser *awk_const next;' - This is for use by `gawk'; therefore it is marked `awk_const' so +'awk_const struct input_parser *awk_const next;' + This is for use by 'gawk'; therefore it is marked 'awk_const' so that the extension cannot modify it. The steps are as follows: - 1. Create a `static awk_input_parser_t' variable and initialize it + 1. Create a 'static awk_input_parser_t' variable and initialize it appropriately. 2. When your extension is loaded, register your input parser with - `gawk' using the `register_input_parser()' API function (described + 'gawk' using the 'register_input_parser()' API function (described below). - An `awk_input_buf_t' looks like this: + An 'awk_input_buf_t' looks like this: typedef struct awk_input { const char *name; /* filename */ @@ -23105,143 +23007,143 @@ used for `RT', if any. } awk_input_buf_t; The fields can be divided into two categories: those for use -(initially, at least) by `XXX_can_take_file()', and those for use by -`XXX_take_control_of()'. The first group of fields and their uses are +(initially, at least) by 'XXX_can_take_file()', and those for use by +'XXX_take_control_of()'. The first group of fields and their uses are as follows: -`const char *name;' +'const char *name;' The name of the file. -`int fd;' - A file descriptor for the file. If `gawk' was able to open the - file, then `fd' will _not_ be equal to `INVALID_HANDLE'. +'int fd;' + A file descriptor for the file. If 'gawk' was able to open the + file, then 'fd' will _not_ be equal to 'INVALID_HANDLE'. Otherwise, it will. -`struct stat sbuf;' - If the file descriptor is valid, then `gawk' will have filled in - this structure via a call to the `fstat()' system call. +'struct stat sbuf;' + If the file descriptor is valid, then 'gawk' will have filled in + this structure via a call to the 'fstat()' system call. - The `XXX_can_take_file()' function should examine these fields and + The 'XXX_can_take_file()' function should examine these fields and decide if the input parser should be used for the file. The decision -can be made based upon `gawk' state (the value of a variable defined -previously by the extension and set by `awk' code), the name of the +can be made based upon 'gawk' state (the value of a variable defined +previously by the extension and set by 'awk' code), the name of the file, whether or not the file descriptor is valid, the information in -the `struct stat', or any combination of the above. +the 'struct stat', or any combination of the above. - Once `XXX_can_take_file()' has returned true, and `gawk' has decided -to use your input parser, it calls `XXX_take_control_of()'. That -function then fills one of either the `get_record' field or the -`read_func' field in the `awk_input_buf_t'. It must also ensure that -`fd' is _not_ set to `INVALID_HANDLE'. All of the fields that may be -filled by `XXX_take_control_of()' are as follows: + Once 'XXX_can_take_file()' has returned true, and 'gawk' has decided +to use your input parser, it calls 'XXX_take_control_of()'. That +function then fills one of either the 'get_record' field or the +'read_func' field in the 'awk_input_buf_t'. It must also ensure that +'fd' is _not_ set to 'INVALID_HANDLE'. All of the fields that may be +filled by 'XXX_take_control_of()' are as follows: -`void *opaque;' +'void *opaque;' This is used to hold any state information needed by the input - parser for this file. It is "opaque" to `gawk'. The input parser + parser for this file. It is "opaque" to 'gawk'. The input parser is not required to use this pointer. -`int (*get_record)(char **out,' -` struct awk_input *iobuf,' -` int *errcode,' -` char **rt_start,' -` size_t *rt_len);' +'int (*get_record)(char **out,' +' struct awk_input *iobuf,' +' int *errcode,' +' char **rt_start,' +' size_t *rt_len);' This function pointer should point to a function that creates the - input records. Said function is the core of the input parser. - Its behavior is described below. + input records. Said function is the core of the input parser. Its + behavior is described below. -`ssize_t (*read_func)();' +'ssize_t (*read_func)();' This function pointer should point to function that has the same - behavior as the standard POSIX `read()' system call. It is an - alternative to the `get_record' pointer. Its behavior is also + behavior as the standard POSIX 'read()' system call. It is an + alternative to the 'get_record' pointer. Its behavior is also described below. -`void (*close_func)(struct awk_input *iobuf);' +'void (*close_func)(struct awk_input *iobuf);' This function pointer should point to a function that does the - "tear down." It should release any resources allocated by - `XXX_take_control_of()'. It may also close the file. If it does - so, it should set the `fd' field to `INVALID_HANDLE'. + "tear down." It should release any resources allocated by + 'XXX_take_control_of()'. It may also close the file. If it does + so, it should set the 'fd' field to 'INVALID_HANDLE'. - If `fd' is still not `INVALID_HANDLE' after the call to this - function, `gawk' calls the regular `close()' system call. + If 'fd' is still not 'INVALID_HANDLE' after the call to this + function, 'gawk' calls the regular 'close()' system call. - Having a "tear down" function is optional. If your input parser - does not need it, do not set this field. Then, `gawk' calls the - regular `close()' system call on the file descriptor, so it should + Having a "tear down" function is optional. If your input parser + does not need it, do not set this field. Then, 'gawk' calls the + regular 'close()' system call on the file descriptor, so it should be valid. - The `XXX_get_record()' function does the work of creating input + The 'XXX_get_record()' function does the work of creating input records. The parameters are as follows: -`char **out' - This is a pointer to a `char *' variable which is set to point to - the record. `gawk' makes its own copy of the data, so the +'char **out' + This is a pointer to a 'char *' variable which is set to point to + the record. 'gawk' makes its own copy of the data, so the extension must manage this storage. -`struct awk_input *iobuf' - This is the `awk_input_buf_t' for the file. The fields should be - used for reading data (`fd') and for managing private state - (`opaque'), if any. +'struct awk_input *iobuf' + This is the 'awk_input_buf_t' for the file. The fields should be + used for reading data ('fd') and for managing private state + ('opaque'), if any. -`int *errcode' - If an error occurs, `*errcode' should be set to an appropriate - code from `'. +'int *errcode' + If an error occurs, '*errcode' should be set to an appropriate code + from ''. -`char **rt_start' -`size_t *rt_len' +'char **rt_start' +'size_t *rt_len' If the concept of a "record terminator" makes sense, then - `*rt_start' should be set to point to the data to be used for - `RT', and `*rt_len' should be set to the length of the data. - Otherwise, `*rt_len' should be set to zero. `gawk' makes its own - copy of this data, so the extension must manage the storage. + '*rt_start' should be set to point to the data to be used for 'RT', + and '*rt_len' should be set to the length of the data. Otherwise, + '*rt_len' should be set to zero. 'gawk' makes its own copy of this + data, so the extension must manage the storage. - The return value is the length of the buffer pointed to by `*out', -or `EOF' if end-of-file was reached or an error occurred. + The return value is the length of the buffer pointed to by '*out', or +'EOF' if end-of-file was reached or an error occurred. - It is guaranteed that `errcode' is a valid pointer, so there is no -need to test for a `NULL' value. `gawk' sets `*errcode' to zero, so + It is guaranteed that 'errcode' is a valid pointer, so there is no +need to test for a 'NULL' value. 'gawk' sets '*errcode' to zero, so there is no need to set it unless an error occurs. - If an error does occur, the function should return `EOF' and set -`*errcode' to a value greater than zero. In that case, if `*errcode' -does not equal zero, `gawk' automatically updates the `ERRNO' variable -based on the value of `*errcode'. (In general, setting `*errcode = + If an error does occur, the function should return 'EOF' and set +'*errcode' to a value greater than zero. In that case, if '*errcode' +does not equal zero, 'gawk' automatically updates the 'ERRNO' variable +based on the value of '*errcode'. (In general, setting '*errcode = errno' should do the right thing.) As an alternative to supplying a function that returns an input record, you may instead supply a function that simply reads bytes, and -let `gawk' parse the data into records. If you do so, the data should +let 'gawk' parse the data into records. If you do so, the data should be returned in the multibyte encoding of the current locale. Such a -function should follow the same behavior as the `read()' system call, -and you fill in the `read_func' pointer with its address in the -`awk_input_buf_t' structure. +function should follow the same behavior as the 'read()' system call, +and you fill in the 'read_func' pointer with its address in the +'awk_input_buf_t' structure. - By default, `gawk' sets the `read_func' pointer to point to the -`read()' system call. So your extension need not set this field + By default, 'gawk' sets the 'read_func' pointer to point to the +'read()' system call. So your extension need not set this field explicitly. NOTE: You must choose one method or the other: either a function that returns a record, or one that returns raw data. In - particular, if you supply a function to get a record, `gawk' will + particular, if you supply a function to get a record, 'gawk' will call it, and never call the raw read function. - `gawk' ships with a sample extension that reads directories, + 'gawk' ships with a sample extension that reads directories, returning records for each entry in the directory (*note Extension Sample Readdir::). You may wish to use that code as a guide for writing your own input parser. When writing an input parser, you should think about (and document) -how it is expected to interact with `awk' code. You may want it to -always be called, and take effect as appropriate (as the `readdir' -extension does). Or you may want it to take effect based upon the -value of an `awk' variable, as the XML extension from the `gawkextlib' -project does (*note gawkextlib::). In the latter case, code in a -`BEGINFILE' section can look at `FILENAME' and `ERRNO' to decide -whether or not to activate an input parser (*note BEGINFILE/ENDFILE::). +how it is expected to interact with 'awk' code. You may want it to +always be called, and take effect as appropriate (as the 'readdir' +extension does). Or you may want it to take effect based upon the value +of an 'awk' variable, as the XML extension from the 'gawkextlib' project +does (*note gawkextlib::). In the latter case, code in a 'BEGINFILE' +section can look at 'FILENAME' and 'ERRNO' to decide whether or not to +activate an input parser (*note BEGINFILE/ENDFILE::). You register your input parser with the following function: -`void register_input_parser(awk_input_parser_t *input_parser);' - Register the input parser pointed to by `input_parser' with `gawk'. +'void register_input_parser(awk_input_parser_t *input_parser);' + Register the input parser pointed to by 'input_parser' with 'gawk'.  File: gawk.info, Node: Output Wrappers, Next: Two-way processors, Prev: Input Parsers, Up: Registration Functions @@ -23250,8 +23152,8 @@ File: gawk.info, Node: Output Wrappers, Next: Two-way processors, Prev: Input ................................... An "output wrapper" is the mirror image of an input parser. It allows -an extension to take over the output to a file opened with the `>' or -`>>' I/O redirection operators (*note Redirection::). +an extension to take over the output to a file opened with the '>' or +'>>' I/O redirection operators (*note Redirection::). The output wrapper is very similar to the input parser structure: @@ -23264,28 +23166,27 @@ an extension to take over the output to a file opened with the `>' or The members are as follows: -`const char *name;' +'const char *name;' This is the name of the output wrapper. -`awk_bool_t (*can_take_file)(const awk_output_buf_t *outbuf);' +'awk_bool_t (*can_take_file)(const awk_output_buf_t *outbuf);' This points to a function that examines the information in the - `awk_output_buf_t' structure pointed to by `outbuf'. It should + 'awk_output_buf_t' structure pointed to by 'outbuf'. It should return true if the output wrapper wants to take over the file, and false otherwise. It should not change any state (variable values, - etc.) within `gawk'. + etc.) within 'gawk'. -`awk_bool_t (*take_control_of)(awk_output_buf_t *outbuf);' - The function pointed to by this field is called when `gawk' - decides to let the output wrapper take control of the file. It - should fill in appropriate members of the `awk_output_buf_t' - structure, as described below, and return true if successful, - false otherwise. +'awk_bool_t (*take_control_of)(awk_output_buf_t *outbuf);' + The function pointed to by this field is called when 'gawk' decides + to let the output wrapper take control of the file. It should fill + in appropriate members of the 'awk_output_buf_t' structure, as + described below, and return true if successful, false otherwise. -`awk_const struct output_wrapper *awk_const next;' - This is for use by `gawk'; therefore it is marked `awk_const' so +'awk_const struct output_wrapper *awk_const next;' + This is for use by 'gawk'; therefore it is marked 'awk_const' so that the extension cannot modify it. - The `awk_output_buf_t' structure looks like this: + The 'awk_output_buf_t' structure looks like this: typedef struct awk_output_buf { const char *name; /* name of output file */ @@ -23300,55 +23201,55 @@ an extension to take over the output to a file opened with the `>' or int (*gawk_fclose)(FILE *fp, void *opaque); } awk_output_buf_t; - Here too, your extension will define `XXX_can_take_file()' and -`XXX_take_control_of()' functions that examine and update data members -in the `awk_output_buf_t'. The data members are as follows: + Here too, your extension will define 'XXX_can_take_file()' and +'XXX_take_control_of()' functions that examine and update data members +in the 'awk_output_buf_t'. The data members are as follows: -`const char *name;' +'const char *name;' The name of the output file. -`const char *mode;' +'const char *mode;' The mode string (as would be used in the second argument to - `fopen()') with which the file was opened. + 'fopen()') with which the file was opened. -`FILE *fp;' - The `FILE' pointer from `'. `gawk' opens the file before +'FILE *fp;' + The 'FILE' pointer from ''. 'gawk' opens the file before attempting to find an output wrapper. -`awk_bool_t redirected;' - This field must be set to true by the `XXX_take_control_of()' +'awk_bool_t redirected;' + This field must be set to true by the 'XXX_take_control_of()' function. -`void *opaque;' - This pointer is opaque to `gawk'. The extension should use it to +'void *opaque;' + This pointer is opaque to 'gawk'. The extension should use it to store a pointer to any private data associated with the file. -`size_t (*gawk_fwrite)(const void *buf, size_t size, size_t count,' -` FILE *fp, void *opaque);' -`int (*gawk_fflush)(FILE *fp, void *opaque);' -`int (*gawk_ferror)(FILE *fp, void *opaque);' -`int (*gawk_fclose)(FILE *fp, void *opaque);' - These pointers should be set to point to functions that perform - the equivalent function as the `' functions do, if - appropriate. `gawk' uses these function pointers for all output. - `gawk' initializes the pointers to point to internal, "pass - through" functions that just call the regular `' +'size_t (*gawk_fwrite)(const void *buf, size_t size, size_t count,' +' FILE *fp, void *opaque);' +'int (*gawk_fflush)(FILE *fp, void *opaque);' +'int (*gawk_ferror)(FILE *fp, void *opaque);' +'int (*gawk_fclose)(FILE *fp, void *opaque);' + These pointers should be set to point to functions that perform the + equivalent function as the '' functions do, if + appropriate. 'gawk' uses these function pointers for all output. + 'gawk' initializes the pointers to point to internal, "pass + through" functions that just call the regular '' functions, so an extension only needs to redefine those functions that are appropriate for what it does. - The `XXX_can_take_file()' function should make a decision based upon -the `name' and `mode' fields, and any additional state (such as `awk' + The 'XXX_can_take_file()' function should make a decision based upon +the 'name' and 'mode' fields, and any additional state (such as 'awk' variable values) that is appropriate. - When `gawk' calls `XXX_take_control_of()', that function should fill -in the other fields, as appropriate, except for `fp', which it should + When 'gawk' calls 'XXX_take_control_of()', that function should fill +in the other fields, as appropriate, except for 'fp', which it should just use normally. You register your output wrapper with the following function: -`void register_output_wrapper(awk_output_wrapper_t *output_wrapper);' - Register the output wrapper pointed to by `output_wrapper' with - `gawk'. +'void register_output_wrapper(awk_output_wrapper_t *output_wrapper);' + Register the output wrapper pointed to by 'output_wrapper' with + 'gawk'.  File: gawk.info, Node: Two-way processors, Prev: Output Wrappers, Up: Registration Functions @@ -23357,8 +23258,8 @@ File: gawk.info, Node: Two-way processors, Prev: Output Wrappers, Up: Registr ...................................... A "two-way processor" combines an input parser and an output wrapper for -two-way I/O with the `|&' operator (*note Redirection::). It makes -identical use of the `awk_input_parser_t' and `awk_output_buf_t' +two-way I/O with the '|&' operator (*note Redirection::). It makes +identical use of the 'awk_input_parser_t' and 'awk_output_buf_t' structures as described earlier. A two-way processor is represented by the following structure: @@ -23374,110 +23275,110 @@ structures as described earlier. The fields are as follows: -`const char *name;' +'const char *name;' The name of the two-way processor. -`awk_bool_t (*can_take_two_way)(const char *name);' - This function returns true if it wants to take over two-way I/O - for this file name. It should not change any state (variable - values, etc.) within `gawk'. +'awk_bool_t (*can_take_two_way)(const char *name);' + This function returns true if it wants to take over two-way I/O for + this file name. It should not change any state (variable values, + etc.) within 'gawk'. -`awk_bool_t (*take_control_of)(const char *name,' -` awk_input_buf_t *inbuf,' -` awk_output_buf_t *outbuf);' - This function should fill in the `awk_input_buf_t' and - `awk_outut_buf_t' structures pointed to by `inbuf' and `outbuf', +'awk_bool_t (*take_control_of)(const char *name,' +' awk_input_buf_t *inbuf,' +' awk_output_buf_t *outbuf);' + This function should fill in the 'awk_input_buf_t' and + 'awk_outut_buf_t' structures pointed to by 'inbuf' and 'outbuf', respectively. These structures were described earlier. -`awk_const struct two_way_processor *awk_const next;' - This is for use by `gawk'; therefore it is marked `awk_const' so +'awk_const struct two_way_processor *awk_const next;' + This is for use by 'gawk'; therefore it is marked 'awk_const' so that the extension cannot modify it. - As with the input parser and output processor, you provide "yes I -can take this" and "take over for this" functions, -`XXX_can_take_two_way()' and `XXX_take_control_of()'. + As with the input parser and output processor, you provide "yes I can +take this" and "take over for this" functions, 'XXX_can_take_two_way()' +and 'XXX_take_control_of()'. You register your two-way processor with the following function: -`void register_two_way_processor(awk_two_way_processor_t *two_way_processor);' - Register the two-way processor pointed to by `two_way_processor' - with `gawk'. +'void register_two_way_processor(awk_two_way_processor_t *two_way_processor);' + Register the two-way processor pointed to by 'two_way_processor' + with 'gawk'.  -File: gawk.info, Node: Printing Messages, Next: Updating `ERRNO', Prev: Registration Functions, Up: Extension API Description +File: gawk.info, Node: Printing Messages, Next: Updating 'ERRNO', Prev: Registration Functions, Up: Extension API Description 16.4.7 Printing Messages ------------------------ You can print different kinds of warning messages from your extension, -as described below. Note that for these functions, you must pass in -the extension id received from `gawk' when the extension was loaded.(1) +as described below. Note that for these functions, you must pass in the +extension id received from 'gawk' when the extension was loaded.(1) -`void fatal(awk_ext_id_t id, const char *format, ...);' - Print a message and then cause `gawk' to exit immediately. +'void fatal(awk_ext_id_t id, const char *format, ...);' + Print a message and then cause 'gawk' to exit immediately. -`void warning(awk_ext_id_t id, const char *format, ...);' +'void warning(awk_ext_id_t id, const char *format, ...);' Print a warning message. -`void lintwarn(awk_ext_id_t id, const char *format, ...);' +'void lintwarn(awk_ext_id_t id, const char *format, ...);' Print a "lint warning." Normally this is the same as printing a - warning message, but if `gawk' was invoked with `--lint=fatal', + warning message, but if 'gawk' was invoked with '--lint=fatal', then lint warnings become fatal error messages. - All of these functions are otherwise like the C `printf()' family of -functions, where the `format' parameter is a string with literal + All of these functions are otherwise like the C 'printf()' family of +functions, where the 'format' parameter is a string with literal characters and formatting codes intermixed. ---------- Footnotes ---------- (1) Because the API uses only ISO C 90 features, it cannot make use -of the ISO C 99 variadic macro feature to hide that parameter. More's +of the ISO C 99 variadic macro feature to hide that parameter. More's the pity.  -File: gawk.info, Node: Updating `ERRNO', Next: Accessing Parameters, Prev: Printing Messages, Up: Extension API Description +File: gawk.info, Node: Updating 'ERRNO', Next: Accessing Parameters, Prev: Printing Messages, Up: Extension API Description -16.4.8 Updating `ERRNO' +16.4.8 Updating 'ERRNO' ----------------------- -The following functions allow you to update the `ERRNO' variable: +The following functions allow you to update the 'ERRNO' variable: -`void update_ERRNO_int(int errno_val);' - Set `ERRNO' to the string equivalent of the error code in - `errno_val'. The value should be one of the defined error codes in - `', and `gawk' turns it into a (possibly translated) - string using the C `strerror()' function. +'void update_ERRNO_int(int errno_val);' + Set 'ERRNO' to the string equivalent of the error code in + 'errno_val'. The value should be one of the defined error codes in + '', and 'gawk' turns it into a (possibly translated) + string using the C 'strerror()' function. -`void update_ERRNO_string(const char *string);' - Set `ERRNO' directly to the string value of `ERRNO'. `gawk' makes - a copy of the value of `string'. +'void update_ERRNO_string(const char *string);' + Set 'ERRNO' directly to the string value of 'ERRNO'. 'gawk' makes + a copy of the value of 'string'. -`void unset_ERRNO();' - Unset `ERRNO'. +'void unset_ERRNO();' + Unset 'ERRNO'.  -File: gawk.info, Node: Accessing Parameters, Next: Symbol Table Access, Prev: Updating `ERRNO', Up: Extension API Description +File: gawk.info, Node: Accessing Parameters, Next: Symbol Table Access, Prev: Updating 'ERRNO', Up: Extension API Description 16.4.9 Accessing and Updating Parameters ---------------------------------------- Two functions give you access to the arguments (parameters) passed to -your extension function. They are: - -`awk_bool_t get_argument(size_t count,' -` awk_valtype_t wanted,' -` awk_value_t *result);' - Fill in the `awk_value_t' structure pointed to by `result' with - the `count''th argument. Return true if the actual type matches - `wanted', false otherwise. In the latter case, `result->val_type' +your extension function. They are: + +'awk_bool_t get_argument(size_t count,' +' awk_valtype_t wanted,' +' awk_value_t *result);' + Fill in the 'awk_value_t' structure pointed to by 'result' with the + 'count''th argument. Return true if the actual type matches + 'wanted', false otherwise. In the latter case, 'result->val_type' indicates the actual type (*note Table 16.1: table-value-types-returned.). Counts are zero based--the first - argument is numbered zero, the second one, and so on. `wanted' + argument is numbered zero, the second one, and so on. 'wanted' indicates the type of value expected. -`awk_bool_t set_argument(size_t count, awk_array_t array);' +'awk_bool_t set_argument(size_t count, awk_array_t array);' Convert a parameter that was undefined into an array; this provides - call-by-reference for arrays. Return false if `count' is too big, + call-by-reference for arrays. Return false if 'count' is too big, or if the argument's type is not undefined. *Note Array Manipulation::, for more information on creating arrays. @@ -23493,7 +23394,7 @@ allows you to create and release cached values. * Menu: * Symbol table by name:: Accessing variables by name. -* Symbol table by cookie:: Accessing variables by ``cookie''. +* Symbol table by cookie:: Accessing variables by "cookie". * Cached values:: Creating and using cached values.  @@ -23503,38 +23404,38 @@ File: gawk.info, Node: Symbol table by name, Next: Symbol table by cookie, Up ............................................ The following routines provide the ability to access and update global -`awk'-level variables by name. In compiler terminology, identifiers of +'awk'-level variables by name. In compiler terminology, identifiers of different kinds are termed "symbols", thus the "sym" in the routines' names. The data structure which stores information about symbols is termed a "symbol table". -`awk_bool_t sym_lookup(const char *name,' -` awk_valtype_t wanted,' -` awk_value_t *result);' - Fill in the `awk_value_t' structure pointed to by `result' with - the value of the variable named by the string `name', which is a - regular C string. `wanted' indicates the type of value expected. - Return true if the actual type matches `wanted', false otherwise - In the latter case, `result->val_type' indicates the actual type +'awk_bool_t sym_lookup(const char *name,' +' awk_valtype_t wanted,' +' awk_value_t *result);' + Fill in the 'awk_value_t' structure pointed to by 'result' with the + value of the variable named by the string 'name', which is a + regular C string. 'wanted' indicates the type of value expected. + Return true if the actual type matches 'wanted', false otherwise In + the latter case, 'result->val_type' indicates the actual type (*note Table 16.1: table-value-types-returned.). -`awk_bool_t sym_update(const char *name, awk_value_t *value);' - Update the variable named by the string `name', which is a regular - C string. The variable is added to `gawk''s symbol table if it is +'awk_bool_t sym_update(const char *name, awk_value_t *value);' + Update the variable named by the string 'name', which is a regular + C string. The variable is added to 'gawk''s symbol table if it is not there. Return true if everything worked, false otherwise. Changing types (scalar to array or vice versa) of an existing variable is _not_ allowed, nor may this routine be used to update an array. This routine cannot be used to update any of the - predefined variables (such as `ARGC' or `NF'). + predefined variables (such as 'ARGC' or 'NF'). - An extension can look up the value of `gawk''s special variables. -However, with the exception of the `PROCINFO' array, an extension -cannot change any of those variables. + An extension can look up the value of 'gawk''s special variables. +However, with the exception of the 'PROCINFO' array, an extension cannot +change any of those variables. - NOTE: It is possible for the lookup of `PROCINFO' to fail. This - happens if the `awk' program being run does not reference - `PROCINFO'; in this case `gawk' doesn't bother to create the array + NOTE: It is possible for the lookup of 'PROCINFO' to fail. This + happens if the 'awk' program being run does not reference + 'PROCINFO'; in this case 'gawk' doesn't bother to create the array and populate it.  @@ -23544,28 +23445,28 @@ File: gawk.info, Node: Symbol table by cookie, Next: Cached values, Prev: Sym .............................................. A "scalar cookie" is an opaque handle that provides access to a global -variable or array. It is an optimization that avoids looking up -variables in `gawk''s symbol table every time access is needed. This +variable or array. It is an optimization that avoids looking up +variables in 'gawk''s symbol table every time access is needed. This was discussed earlier, in *note General Data Types::. The following functions let you work with scalar cookies. -`awk_bool_t sym_lookup_scalar(awk_scalar_t cookie,' -` awk_valtype_t wanted,' -` awk_value_t *result);' +'awk_bool_t sym_lookup_scalar(awk_scalar_t cookie,' +' awk_valtype_t wanted,' +' awk_value_t *result);' Retrieve the current value of a scalar cookie. Once you have - obtained a scalar_cookie using `sym_lookup()', you can use this + obtained a scalar_cookie using 'sym_lookup()', you can use this function to get its value more efficiently. Return false if the value cannot be retrieved. -`awk_bool_t sym_update_scalar(awk_scalar_t cookie, awk_value_t *value);' +'awk_bool_t sym_update_scalar(awk_scalar_t cookie, awk_value_t *value);' Update the value associated with a scalar cookie. Return false if - the new value is not of type `AWK_STRING' or `AWK_NUMBER'. Here + the new value is not of type 'AWK_STRING' or 'AWK_NUMBER'. Here too, the built-in variables may not be updated. It is not obvious at first glance how to work with scalar cookies or -what their raison d'e^tre really is. In theory, the `sym_lookup()' and -`sym_update()' routines are all you really need to work with variables. +what their raison d'e^tre really is. In theory, the 'sym_lookup()' and +'sym_update()' routines are all you really need to work with variables. For example, you might have code that looks up the value of a variable, evaluates a condition, and then possibly changes the value of the variable based on the result of that evaluation, like so: @@ -23586,13 +23487,13 @@ variable based on the result of that evaluation, like so: return make_number(0.0, result); } -This code looks (and is) simple and straightforward. So what's the +This code looks (and is) simple and straightforward. So what's the problem? - Consider what happens if `awk'-level code associated with your -extension calls the `magic()' function (implemented in C by -`do_magic()'), once per record, while processing hundreds of thousands -or millions of records. The `MAGIC_VAR' variable is looked up in the + Consider what happens if 'awk'-level code associated with your +extension calls the 'magic()' function (implemented in C by +'do_magic()'), once per record, while processing hundreds of thousands +or millions of records. The 'MAGIC_VAR' variable is looked up in the symbol table once or twice per function call! The symbol table lookup is really pure overhead; it is considerably @@ -23600,8 +23501,8 @@ more efficient to get a cookie that represents the variable, and use that to get the variable's value and update it as needed.(1) Thus, the way to use cookies is as follows. First, install your -extension's variable in `gawk''s symbol table using `sym_update()', as -usual. Then get a scalar cookie for the variable using `sym_lookup()': +extension's variable in 'gawk''s symbol table using 'sym_update()', as +usual. Then get a scalar cookie for the variable using 'sym_lookup()': static awk_scalar_t magic_var_cookie; /* cookie for MAGIC_VAR */ @@ -23622,7 +23523,7 @@ usual. Then get a scalar cookie for the variable using `sym_lookup()': } Next, use the routines in this section for retrieving and updating -the value through the cookie. Thus, `do_magic()' now becomes something +the value through the cookie. Thus, 'do_magic()' now becomes something like this: /* do_magic --- do something really great */ @@ -23648,7 +23549,7 @@ like this: ---------- Footnotes ---------- - (1) The difference is measurable and quite real. Trust us. + (1) The difference is measurable and quite real. Trust us.  File: gawk.info, Node: Cached values, Prev: Symbol table by cookie, Up: Symbol Table Access @@ -23658,31 +23559,31 @@ File: gawk.info, Node: Cached values, Prev: Symbol table by cookie, Up: Symbo The routines in this section allow you to create and release cached values. As with scalar cookies, in theory, cached values are not -necessary. You can create numbers and strings using the functions in -*note Constructor Functions::. You can then assign those values to -variables using `sym_update()' or `sym_update_scalar()', as you like. +necessary. You can create numbers and strings using the functions in +*note Constructor Functions::. You can then assign those values to +variables using 'sym_update()' or 'sym_update_scalar()', as you like. However, you can understand the point of cached values if you remember that _every_ string value's storage _must_ come from -`api_malloc()', `api_calloc()' or `api_realloc()'. If you have 20 +'api_malloc()', 'api_calloc()' or 'api_realloc()'. If you have 20 variables, all of which have the same string value, you must create 20 identical copies of the string.(1) It is clearly more efficient, if possible, to create a value once, -and then tell `gawk' to reuse the value for multiple variables. That is +and then tell 'gawk' to reuse the value for multiple variables. That is what the routines in this section let you do. The functions are as follows: -`awk_bool_t create_value(awk_value_t *value, awk_value_cookie_t *result);' - Create a cached string or numeric value from `value' for efficient - later assignment. Only values of type `AWK_NUMBER' and - `AWK_STRING' are allowed. Any other type is rejected. While - `AWK_UNDEFINED' could be allowed, doing so would result in - inferior performance. +'awk_bool_t create_value(awk_value_t *value, awk_value_cookie_t *result);' + Create a cached string or numeric value from 'value' for efficient + later assignment. Only values of type 'AWK_NUMBER' and + 'AWK_STRING' are allowed. Any other type is rejected. While + 'AWK_UNDEFINED' could be allowed, doing so would result in inferior + performance. -`awk_bool_t release_value(awk_value_cookie_t vc);' +'awk_bool_t release_value(awk_value_cookie_t vc);' Release the memory associated with a value cookie obtained from - `create_value()'. + 'create_value()'. You use value cookies in a fashion similar to the way you use scalar cookies. In the extension initialization routine, you create the value @@ -23725,27 +23626,27 @@ of variables: } Using value cookies in this way saves considerable storage, since all of -`VAR1' through `VAR100' share the same value. +'VAR1' through 'VAR100' share the same value. You might be wondering, "Is this sharing problematic? What happens -if `awk' code assigns a new value to `VAR1', are all the others be +if 'awk' code assigns a new value to 'VAR1', are all the others be changed too?" - That's a great question. The answer is that no, it's not a problem. -Internally, `gawk' uses "reference-counted strings". This means that -many variables can share the same string value, and `gawk' keeps track -of the usage. When a variable's value changes, `gawk' simply -decrements the reference count on the old value and updates the -variable to use the new value. + That's a great question. The answer is that no, it's not a problem. +Internally, 'gawk' uses "reference-counted strings". This means that +many variables can share the same string value, and 'gawk' keeps track +of the usage. When a variable's value changes, 'gawk' simply decrements +the reference count on the old value and updates the variable to use the +new value. Finally, as part of your cleanup action (*note Exit Callback Functions::) you should release any cached values that you created, -using `release_value()'. +using 'release_value()'. ---------- Footnotes ---------- (1) Numeric values are clearly less problematic, requiring only a C -`double' to store. +'double' to store.  File: gawk.info, Node: Array Manipulation, Next: Extension API Variables, Prev: Symbol Table Access, Up: Extension API Description @@ -23753,11 +23654,11 @@ File: gawk.info, Node: Array Manipulation, Next: Extension API Variables, Pre 16.4.11 Array Manipulation -------------------------- -The primary data structure(1) in `awk' is the associative array (*note -Arrays::). Extensions need to be able to manipulate `awk' arrays. The +The primary data structure(1) in 'awk' is the associative array (*note +Arrays::). Extensions need to be able to manipulate 'awk' arrays. The API provides a number of data structures for working with arrays, functions for working with individual elements, and functions for -working with arrays as a whole. This includes the ability to "flatten" +working with arrays as a whole. This includes the ability to "flatten" an array so that it is easy for C code to traverse every element in an array. The array data structures integrate nicely with the data structures for values to make it easy to both work with and create true @@ -23782,63 +23683,63 @@ File: gawk.info, Node: Array Data Types, Next: Array Functions, Up: Array Man The data types associated with arrays are listed below. -`typedef void *awk_array_t;' +'typedef void *awk_array_t;' If you request the value of an array variable, you get back an - `awk_array_t' value. This value is opaque(1) to the extension; it + 'awk_array_t' value. This value is opaque(1) to the extension; it uniquely identifies the array but can only be used by passing it - into API functions or receiving it from API functions. This is - very similar to way `FILE *' values are used with the `' + into API functions or receiving it from API functions. This is + very similar to way 'FILE *' values are used with the '' library routines. -`typedef struct awk_element {' -` /* convenience linked list pointer, not used by gawk */' -` struct awk_element *next;' -` enum {' -` AWK_ELEMENT_DEFAULT = 0, /* set by gawk */' -` AWK_ELEMENT_DELETE = 1 /* set by extension if should be deleted */' -` } flags;' -` awk_value_t index;' -` awk_value_t value;' -`} awk_element_t;' - The `awk_element_t' is a "flattened" array element. `awk' produces - an array of these inside the `awk_flat_array_t' (see the next - item). Individual elements may be marked for deletion. New +'typedef struct awk_element {' +' /* convenience linked list pointer, not used by gawk */' +' struct awk_element *next;' +' enum {' +' AWK_ELEMENT_DEFAULT = 0, /* set by gawk */' +' AWK_ELEMENT_DELETE = 1 /* set by extension if should be deleted */' +' } flags;' +' awk_value_t index;' +' awk_value_t value;' +'} awk_element_t;' + The 'awk_element_t' is a "flattened" array element. 'awk' produces + an array of these inside the 'awk_flat_array_t' (see the next + item). Individual elements may be marked for deletion. New elements must be added individually, one at a time, using the separate API for that purpose. The fields are as follows: - `struct awk_element *next;' + 'struct awk_element *next;' This pointer is for the convenience of extension writers. It allows an extension to create a linked list of new elements that can then be added to an array in a loop that traverses the list. - `enum { ... } flags;' - A set of flag values that convey information between `gawk' - and the extension. Currently there is only one: - `AWK_ELEMENT_DELETE'. Setting it causes `gawk' to delete the + 'enum { ... } flags;' + A set of flag values that convey information between 'gawk' + and the extension. Currently there is only one: + 'AWK_ELEMENT_DELETE'. Setting it causes 'gawk' to delete the element from the original array upon release of the flattened array. - `index' - `value' + 'index' + 'value' The index and value of the element, respectively. _All_ - memory pointed to by `index' and `value' belongs to `gawk'. - -`typedef struct awk_flat_array {' -` awk_const void *awk_const opaque1; /* private data for use by gawk */' -` awk_const void *awk_const opaque2; /* private data for use by gawk */' -` awk_const size_t count; /* how many elements */' -` awk_element_t elements[1]; /* will be extended */' -`} awk_flat_array_t;' - This is a flattened array. When an extension gets one of these - from `gawk', the `elements' array is of actual size `count'. The - `opaque1' and `opaque2' pointers are for use by `gawk'; therefore - they are marked `awk_const' so that the extension cannot modify + memory pointed to by 'index' and 'value' belongs to 'gawk'. + +'typedef struct awk_flat_array {' +' awk_const void *awk_const opaque1; /* private data for use by gawk */' +' awk_const void *awk_const opaque2; /* private data for use by gawk */' +' awk_const size_t count; /* how many elements */' +' awk_element_t elements[1]; /* will be extended */' +'} awk_flat_array_t;' + This is a flattened array. When an extension gets one of these + from 'gawk', the 'elements' array is of actual size 'count'. The + 'opaque1' and 'opaque2' pointers are for use by 'gawk'; therefore + they are marked 'awk_const' so that the extension cannot modify them. ---------- Footnotes ---------- - (1) It is also a "cookie," but the `gawk' developers did not wish to + (1) It is also a "cookie," but the 'gawk' developers did not wish to overuse this term.  @@ -23849,75 +23750,75 @@ File: gawk.info, Node: Array Functions, Next: Flattening Arrays, Prev: Array The following functions relate to individual array elements. -`awk_bool_t get_element_count(awk_array_t a_cookie, size_t *count);' - For the array represented by `a_cookie', return in `*count' the - number of elements it contains. A subarray counts as a single +'awk_bool_t get_element_count(awk_array_t a_cookie, size_t *count);' + For the array represented by 'a_cookie', return in '*count' the + number of elements it contains. A subarray counts as a single element. Return false if there is an error. -`awk_bool_t get_array_element(awk_array_t a_cookie,' -` const awk_value_t *const index,' -` awk_valtype_t wanted,' -` awk_value_t *result);' - For the array represented by `a_cookie', return in `*result' the - value of the element whose index is `index'. `wanted' specifies - the type of value you wish to retrieve. Return false if `wanted' - does not match the actual type or if `index' is not in the array +'awk_bool_t get_array_element(awk_array_t a_cookie,' +' const awk_value_t *const index,' +' awk_valtype_t wanted,' +' awk_value_t *result);' + For the array represented by 'a_cookie', return in '*result' the + value of the element whose index is 'index'. 'wanted' specifies + the type of value you wish to retrieve. Return false if 'wanted' + does not match the actual type or if 'index' is not in the array (*note Table 16.1: table-value-types-returned.). - The value for `index' can be numeric, in which case `gawk' - converts it to a string. Using non-integral values is possible, but + The value for 'index' can be numeric, in which case 'gawk' converts + it to a string. Using non-integral values is possible, but requires that you understand how such values are converted to strings (*note Conversion::); thus using integral values is safest. - As with _all_ strings passed into `gawk' from an extension, the - string value of `index' must come from the API-provided functions - `api_malloc()', `api_calloc()' or `api_realloc()' and `gawk' + As with _all_ strings passed into 'gawk' from an extension, the + string value of 'index' must come from the API-provided functions + 'api_malloc()', 'api_calloc()' or 'api_realloc()' and 'gawk' releases the storage. -`awk_bool_t set_array_element(awk_array_t a_cookie,' -` const awk_value_t *const index,' -` const awk_value_t *const value);' - In the array represented by `a_cookie', create or modify the - element whose index is given by `index'. The `ARGV' and `ENVIRON' - arrays may not be changed, although the `PROCINFO' array can be. +'awk_bool_t set_array_element(awk_array_t a_cookie,' +' const awk_value_t *const index,' +' const awk_value_t *const value);' + In the array represented by 'a_cookie', create or modify the + element whose index is given by 'index'. The 'ARGV' and 'ENVIRON' + arrays may not be changed, although the 'PROCINFO' array can be. -`awk_bool_t set_array_element_by_elem(awk_array_t a_cookie,' -` awk_element_t element);' - Like `set_array_element()', but take the `index' and `value' from - `element'. This is a convenience macro. +'awk_bool_t set_array_element_by_elem(awk_array_t a_cookie,' +' awk_element_t element);' + Like 'set_array_element()', but take the 'index' and 'value' from + 'element'. This is a convenience macro. -`awk_bool_t del_array_element(awk_array_t a_cookie,' -` const awk_value_t* const index);' +'awk_bool_t del_array_element(awk_array_t a_cookie,' +' const awk_value_t* const index);' Remove the element with the given index from the array represented - by `a_cookie'. Return true if the element was removed, or false - if the element did not exist in the array. + by 'a_cookie'. Return true if the element was removed, or false if + the element did not exist in the array. The following functions relate to arrays as a whole: -`awk_array_t create_array();' +'awk_array_t create_array();' Create a new array to which elements may be added. *Note Creating Arrays::, for a discussion of how to create a new array and add elements to it. -`awk_bool_t clear_array(awk_array_t a_cookie);' - Clear the array represented by `a_cookie'. Return false if there +'awk_bool_t clear_array(awk_array_t a_cookie);' + Clear the array represented by 'a_cookie'. Return false if there was some kind of problem, true otherwise. The array remains an - array, but after calling this function, it has no elements. This - is equivalent to using the `delete' statement (*note Delete::). + array, but after calling this function, it has no elements. This + is equivalent to using the 'delete' statement (*note Delete::). -`awk_bool_t flatten_array(awk_array_t a_cookie, awk_flat_array_t **data);' - For the array represented by `a_cookie', create an - `awk_flat_array_t' structure and fill it in. Set the pointer whose - address is passed as `data' to point to this structure. Return +'awk_bool_t flatten_array(awk_array_t a_cookie, awk_flat_array_t **data);' + For the array represented by 'a_cookie', create an + 'awk_flat_array_t' structure and fill it in. Set the pointer whose + address is passed as 'data' to point to this structure. Return true upon success, or false otherwise. *Note Flattening Arrays::, for a discussion of how to flatten an array and work with it. -`awk_bool_t release_flattened_array(awk_array_t a_cookie,' -` awk_flat_array_t *data);' +'awk_bool_t release_flattened_array(awk_array_t a_cookie,' +' awk_flat_array_t *data);' When done with a flattened array, release the storage using this - function. You must pass in both the original array cookie, and - the address of the created `awk_flat_array_t' structure. The - function returns true upon success, false otherwise. + function. You must pass in both the original array cookie, and the + address of the created 'awk_flat_array_t' structure. The function + returns true upon success, false otherwise.  File: gawk.info, Node: Flattening Arrays, Next: Creating Arrays, Prev: Array Functions, Up: Array Manipulation @@ -23927,10 +23828,10 @@ File: gawk.info, Node: Flattening Arrays, Next: Creating Arrays, Prev: Array To "flatten" an array is create a structure that represents the full array in a fashion that makes it easy for C code to traverse the entire -array. Test code in `extension/testext.c' does this, and also serves -as a nice example showing how to use the APIs. +array. Test code in 'extension/testext.c' does this, and also serves as +a nice example showing how to use the APIs. - First, the `gawk' script that drives the test extension: + First, the 'gawk' script that drives the test extension: @load "testext" BEGIN { @@ -23945,16 +23846,16 @@ as a nice example showing how to use the APIs. print "" } -This code creates an array with `split()' (*note String Functions::) -and then calls `dump_array_and_delete()'. That function looks up the -array whose name is passed as the first argument, and deletes the -element at the index passed in the second argument. The `awk' code -then prints the return value and checks if the element was indeed -deleted. Here is the C code that implements `dump_array_and_delete()'. -It has been edited slightly for presentation. +This code creates an array with 'split()' (*note String Functions::) and +then calls 'dump_array_and_delete()'. That function looks up the array +whose name is passed as the first argument, and deletes the element at +the index passed in the second argument. The 'awk' code then prints the +return value and checks if the element was indeed deleted. Here is the +C code that implements 'dump_array_and_delete()'. It has been edited +slightly for presentation. The first part declares variables, sets up the default return value -in `result', and checks that the function was called with the correct +in 'result', and checks that the function was called with the correct number of arguments: static awk_value_t * @@ -23975,9 +23876,9 @@ number of arguments: goto out; } - The function then proceeds in steps, as follows. First, retrieve the -name of the array, passed as the first argument. Then retrieve the -array itself. If either operation fails, print error messages and + The function then proceeds in steps, as follows. First, retrieve the +name of the array, passed as the first argument. Then retrieve the +array itself. If either operation fails, print error messages and return: /* get argument named array as flat array and print it */ @@ -23997,7 +23898,7 @@ return: } For testing purposes and to make sure that the C code sees the same -number of elements as the `awk' code, the second step is to get the +number of elements as the 'awk' code, the second step is to get the count of elements in the array and print it: if (! get_element_count(value2.array_cookie, & count)) { @@ -24009,7 +23910,7 @@ count of elements in the array and print it: (unsigned long) count); The third step is to actually flatten the array, and then to double -check that the count in the `awk_flat_array_t' is the same as the count +check that the count in the 'awk_flat_array_t' is the same as the count just retrieved: if (! flatten_array(value2.array_cookie, & flat_array)) { @@ -24027,7 +23928,7 @@ just retrieved: The fourth step is to retrieve the index of the element to be deleted, which was passed as the second argument. Remember that -argument counts passed to `get_argument()' are zero-based, thus the +argument counts passed to 'get_argument()' are zero-based, thus the second argument is numbered one: if (! get_argument(1, AWK_STRING, & value3)) { @@ -24035,11 +23936,11 @@ second argument is numbered one: goto out; } - The fifth step is where the "real work" is done. The function loops + The fifth step is where the "real work" is done. The function loops over every element in the array, printing the index and element values. -In addition, upon finding the element with the index that is supposed -to be deleted, the function sets the `AWK_ELEMENT_DELETE' bit in the -`flags' field of the element. When the array is released, `gawk' +In addition, upon finding the element with the index that is supposed to +be deleted, the function sets the 'AWK_ELEMENT_DELETE' bit in the +'flags' field of the element. When the array is released, 'gawk' traverses the flattened array, and deletes any elements which have this flag bit set: @@ -24060,11 +23961,11 @@ flag bit set: } } - The sixth step is to release the flattened array. This tells `gawk' + The sixth step is to release the flattened array. This tells 'gawk' that the extension is no longer using the array, and that it should -delete any elements marked for deletion. `gawk' also frees any storage -that was allocated, so you should not use the pointer (`flat_array' in -this code) once you have called `release_flattened_array()': +delete any elements marked for deletion. 'gawk' also frees any storage +that was allocated, so you should not use the pointer ('flat_array' in +this code) once you have called 'release_flattened_array()': if (! release_flattened_array(value2.array_cookie, flat_array)) { printf("dump_array_and_delete: could not release flattened array\n"); @@ -24099,30 +24000,30 @@ File: gawk.info, Node: Creating Arrays, Prev: Flattening Arrays, Up: Array Ma 16.4.11.4 How To Create and Populate Arrays ........................................... -Besides working with arrays created by `awk' code, you can create -arrays and populate them as you see fit, and then `awk' code can access -them and manipulate them. +Besides working with arrays created by 'awk' code, you can create arrays +and populate them as you see fit, and then 'awk' code can access them +and manipulate them. There are two important points about creating arrays from extension code: - 1. You must install a new array into `gawk''s symbol table - immediately upon creating it. Once you have done so, you can then - populate the array. + 1. You must install a new array into 'gawk''s symbol table immediately + upon creating it. Once you have done so, you can then populate the + array. Similarly, if installing a new array as a subarray of an existing array, you must add the new array to its parent before adding any elements to it. Thus, the correct way to build an array is to work "top down." - Create the array, and immediately install it in `gawk''s symbol - table using `sym_update()', or install it as an element in a - previously existing array using `set_array_element()'. We show + Create the array, and immediately install it in 'gawk''s symbol + table using 'sym_update()', or install it as an element in a + previously existing array using 'set_array_element()'. We show example code shortly. - 2. Due to gawk internals, after using `sym_update()' to install an - array into `gawk', you have to retrieve the array cookie from the - value passed in to `sym_update()' before doing anything else with + 2. Due to gawk internals, after using 'sym_update()' to install an + array into 'gawk', you have to retrieve the array cookie from the + value passed in to 'sym_update()' before doing anything else with it, like so: awk_value_t value; @@ -24138,13 +24039,13 @@ code: new_array = val.array_cookie; /* YOU MUST DO THIS */ If installing an array as a subarray, you must also retrieve the - value of the array cookie after the call to `set_element()'. + value of the array cookie after the call to 'set_element()'. The following C code is a simple test extension to create an array -with two regular elements and with a subarray. The leading `#include' +with two regular elements and with a subarray. The leading '#include' directives and boilerplate variable declarations are omitted for -brevity. The first step is to create a new array and then install it -in the symbol table: +brevity. The first step is to create a new array and then install it in +the symbol table: /* create_new_array --- create a named array */ @@ -24163,10 +24064,10 @@ in the symbol table: printf("create_new_array: sym_update(\"new_array\") failed!\n"); a_cookie = value.array_cookie; -Note how `a_cookie' is reset from the `array_cookie' field in the -`value' structure. +Note how 'a_cookie' is reset from the 'array_cookie' field in the +'value' structure. - The second step is to install two regular values into `new_array': + The second step is to install two regular values into 'new_array': (void) make_const_string("hello", 5, & index); (void) make_const_string("world", 5, & value); @@ -24229,7 +24130,7 @@ array: -| new_array["hello"] = world -| new_array["answer"] = 42 -(*Note Finding Extensions::, for more information on the `AWKLIBPATH' +(*Note Finding Extensions::, for more information on the 'AWKLIBPATH' environment variable.)  @@ -24240,14 +24141,14 @@ File: gawk.info, Node: Extension API Variables, Next: Extension API Boilerplat The API provides two sets of variables. The first provides information about the version of the API (both with which the extension was -compiled, and with which `gawk' was compiled). The second provides -information about how `gawk' was invoked. +compiled, and with which 'gawk' was compiled). The second provides +information about how 'gawk' was invoked. * Menu: * Extension Versioning:: API Version information. * Extension API Informational Variables:: Variables providing information about - `gawk''s invocation. + 'gawk''s invocation.  File: gawk.info, Node: Extension Versioning, Next: Extension API Informational Variables, Up: Extension API Variables @@ -24258,29 +24159,29 @@ File: gawk.info, Node: Extension Versioning, Next: Extension API Informational The API provides both a "major" and a "minor" version number. The API versions are available at compile time as constants: -`GAWK_API_MAJOR_VERSION' +'GAWK_API_MAJOR_VERSION' The major version of the API. -`GAWK_API_MINOR_VERSION' +'GAWK_API_MINOR_VERSION' The minor version of the API. The minor version increases when new functions are added to the API. -Such new functions are always added to the end of the API `struct'. +Such new functions are always added to the end of the API 'struct'. The major version increases (and the minor version is reset to zero) if any of the data types change size or member order, or if any of the existing functions change signature. It could happen that an extension may be compiled against one version -of the API but loaded by a version of `gawk' using a different version. -For this reason, the major and minor API versions of the running `gawk' -are included in the API `struct' as read-only constant integers: +of the API but loaded by a version of 'gawk' using a different version. +For this reason, the major and minor API versions of the running 'gawk' +are included in the API 'struct' as read-only constant integers: -`api->major_version' - The major version of the running `gawk'. +'api->major_version' + The major version of the running 'gawk'. -`api->minor_version' - The minor version of the running `gawk'. +'api->minor_version' + The minor version of the running 'gawk'. It is up to the extension to decide if there are API incompatibilities. Typically a check like this is enough: @@ -24294,8 +24195,8 @@ incompatibilities. Typically a check like this is enough: exit(1); } - Such code is included in the boilerplate `dl_load_func()' macro -provided in `gawkapi.h' (discussed later, in *note Extension API + Such code is included in the boilerplate 'dl_load_func()' macro +provided in 'gawkapi.h' (discussed later, in *note Extension API Boilerplate::).  @@ -24305,32 +24206,32 @@ File: gawk.info, Node: Extension API Informational Variables, Prev: Extension ................................. The API provides access to several variables that describe whether the -corresponding command-line options were enabled when `gawk' was -invoked. The variables are: +corresponding command-line options were enabled when 'gawk' was invoked. +The variables are: -`do_debug' - This variable is true if `gawk' was invoked with `--debug' option. +'do_debug' + This variable is true if 'gawk' was invoked with '--debug' option. -`do_lint' - This variable is true if `gawk' was invoked with `--lint' option +'do_lint' + This variable is true if 'gawk' was invoked with '--lint' option (*note Options::). -`do_mpfr' - This variable is true if `gawk' was invoked with `--bignum' option. +'do_mpfr' + This variable is true if 'gawk' was invoked with '--bignum' option. -`do_profile' - This variable is true if `gawk' was invoked with `--profile' +'do_profile' + This variable is true if 'gawk' was invoked with '--profile' option. -`do_sandbox' - This variable is true if `gawk' was invoked with `--sandbox' +'do_sandbox' + This variable is true if 'gawk' was invoked with '--sandbox' option. -`do_traditional' - This variable is true if `gawk' was invoked with `--traditional' +'do_traditional' + This variable is true if 'gawk' was invoked with '--traditional' option. - The value of `do_lint' can change if `awk' code modifies the `LINT' + The value of 'do_lint' can change if 'awk' code modifies the 'LINT' built-in variable (*note Built-in Variables::). The others should not change during execution. @@ -24341,11 +24242,11 @@ File: gawk.info, Node: Extension API Boilerplate, Prev: Extension API Variable ------------------------ As mentioned earlier (*note Extension Mechanism Outline::), the function -definitions as presented are really macros. To use these macros, your +definitions as presented are really macros. To use these macros, your extension must provide a small amount of boilerplate code (variables and functions) towards the top of your source file, using pre-defined names as described below. The boilerplate needed is also provided in comments -in the `gawkapi.h' header file: +in the 'gawkapi.h' header file: /* Boiler plate code: */ int plugin_is_GPL_compatible; @@ -24377,76 +24278,75 @@ in the `gawkapi.h' header file: These variables and functions are as follows: -`int plugin_is_GPL_compatible;' +'int plugin_is_GPL_compatible;' This asserts that the extension is compatible with the GNU GPL - (*note Copying::). If your extension does not have this, `gawk' + (*note Copying::). If your extension does not have this, 'gawk' will not load it (*note Plugin License::). -`static gawk_api_t *const api;' - This global `static' variable should be set to point to the - `gawk_api_t' pointer that `gawk' passes to your `dl_load()' +'static gawk_api_t *const api;' + This global 'static' variable should be set to point to the + 'gawk_api_t' pointer that 'gawk' passes to your 'dl_load()' function. This variable is used by all of the macros. -`static awk_ext_id_t ext_id;' - This global static variable should be set to the `awk_ext_id_t' - value that `gawk' passes to your `dl_load()' function. This +'static awk_ext_id_t ext_id;' + This global static variable should be set to the 'awk_ext_id_t' + value that 'gawk' passes to your 'dl_load()' function. This variable is used by all of the macros. -`static const char *ext_version = NULL; /* or ... = "some string" */' - This global `static' variable should be set either to `NULL', or - to point to a string giving the name and version of your extension. +'static const char *ext_version = NULL; /* or ... = "some string" */' + This global 'static' variable should be set either to 'NULL', or to + point to a string giving the name and version of your extension. -`static awk_ext_func_t func_table[] = { ... };' - This is an array of one or more `awk_ext_func_t' structures as +'static awk_ext_func_t func_table[] = { ... };' + This is an array of one or more 'awk_ext_func_t' structures as described earlier (*note Extension Functions::). It can then be - looped over for multiple calls to `add_ext_func()'. + looped over for multiple calls to 'add_ext_func()'. -`static awk_bool_t (*init_func)(void) = NULL;' -` OR' -`static awk_bool_t init_my_module(void) { ... }' -`static awk_bool_t (*init_func)(void) = init_my_module;' +'static awk_bool_t (*init_func)(void) = NULL;' +' OR' +'static awk_bool_t init_my_module(void) { ... }' +'static awk_bool_t (*init_func)(void) = init_my_module;' If you need to do some initialization work, you should define a function that does it (creates variables, opens files, etc.) and - then define the `init_func' pointer to point to your function. - The function should return `awk_false' upon failure, or `awk_true' - if everything goes well. + then define the 'init_func' pointer to point to your function. The + function should return 'awk_false' upon failure, or 'awk_true' if + everything goes well. If you don't need to do any initialization, define the pointer and - initialize it to `NULL'. + initialize it to 'NULL'. -`dl_load_func(func_table, some_name, "name_space_in_quotes")' - This macro expands to a `dl_load()' function that performs all the +'dl_load_func(func_table, some_name, "name_space_in_quotes")' + This macro expands to a 'dl_load()' function that performs all the necessary initializations. The point of the all the variables and arrays is to let the -`dl_load()' function (from the `dl_load_func()' macro) do all the -standard work. It does the following: +'dl_load()' function (from the 'dl_load_func()' macro) do all the +standard work. It does the following: - 1. Check the API versions. If the extension major version does not - match `gawk''s, or if the extension minor version is greater than - `gawk''s, it prints a fatal error message and exits. + 1. Check the API versions. If the extension major version does not + match 'gawk''s, or if the extension minor version is greater than + 'gawk''s, it prints a fatal error message and exits. - 2. Load the functions defined in `func_table'. If any of them fails + 2. Load the functions defined in 'func_table'. If any of them fails to load, it prints a warning message but continues on. - 3. If the `init_func' pointer is not `NULL', call the function it - points to. If it returns `awk_false', print a warning message. + 3. If the 'init_func' pointer is not 'NULL', call the function it + points to. If it returns 'awk_false', print a warning message. - 4. If `ext_version' is not `NULL', register the version string with - `gawk'. + 4. If 'ext_version' is not 'NULL', register the version string with + 'gawk'.  File: gawk.info, Node: Finding Extensions, Next: Extension Example, Prev: Extension API Description, Up: Dynamic Extensions -16.5 How `gawk' Finds Extensions +16.5 How 'gawk' Finds Extensions ================================ -Compiled extensions have to be installed in a directory where `gawk' -can find them. If `gawk' is configured and built in the default -fashion, the directory in which to find extensions is -`/usr/local/lib/gawk'. You can also specify a search path with a list -of directories to search for compiled extensions. *Note AWKLIBPATH -Variable::, for more information. +Compiled extensions have to be installed in a directory where 'gawk' can +find them. If 'gawk' is configured and built in the default fashion, +the directory in which to find extensions is '/usr/local/lib/gawk'. You +can also specify a search path with a list of directories to search for +compiled extensions. *Note AWKLIBPATH Variable::, for more information.  File: gawk.info, Node: Extension Example, Next: Extension Samples, Prev: Finding Extensions, Up: Dynamic Extensions @@ -24454,12 +24354,13 @@ File: gawk.info, Node: Extension Example, Next: Extension Samples, Prev: Find 16.6 Example: Some File Functions ================================= - No matter where you go, there you are. -- Buckaroo Bonzai + No matter where you go, there you are. + -- _Buckaroo Bonzai_ - Two useful functions that are not in `awk' are `chdir()' (so that an -`awk' program can change its directory) and `stat()' (so that an `awk' + Two useful functions that are not in 'awk' are 'chdir()' (so that an +'awk' program can change its directory) and 'stat()' (so that an 'awk' program can gather information about a file). This minor node -implements these functions for `gawk' in an extension. +implements these functions for 'gawk' in an extension. * Menu: @@ -24470,12 +24371,12 @@ implements these functions for `gawk' in an extension.  File: gawk.info, Node: Internal File Description, Next: Internal File Ops, Up: Extension Example -16.6.1 Using `chdir()' and `stat()' +16.6.1 Using 'chdir()' and 'stat()' ----------------------------------- -This minor node shows how to use the new functions at the `awk' level -once they've been integrated into the running `gawk' interpreter. -Using `chdir()' is very straightforward. It takes one argument, the new +This minor node shows how to use the new functions at the 'awk' level +once they've been integrated into the running 'gawk' interpreter. Using +'chdir()' is very straightforward. It takes one argument, the new directory to change to: @load "filefuncs" @@ -24489,12 +24390,12 @@ directory to change to: } ... - The return value is negative if the `chdir()' failed, and `ERRNO' + The return value is negative if the 'chdir()' failed, and 'ERRNO' (*note Built-in Variables::) is set to a string indicating the error. - Using `stat()' is a bit more complicated. The C `stat()' function + Using 'stat()' is a bit more complicated. The C 'stat()' function fills in a structure that has a fair amount of information. The right -way to model this in `awk' is to fill in an associative array with the +way to model this in 'awk' is to fill in an associative array with the appropriate information: file = "/home/arnold/.profile" @@ -24506,94 +24407,94 @@ appropriate information: } printf("size of %s is %d bytes\n", file, fdata["size"]) - The `stat()' function always clears the data array, even if the -`stat()' fails. It fills in the following elements: + The 'stat()' function always clears the data array, even if the +'stat()' fails. It fills in the following elements: -`"name"' - The name of the file that was `stat()''ed. +'"name"' + The name of the file that was 'stat()''ed. -`"dev"' -`"ino"' +'"dev"' +'"ino"' The file's device and inode numbers, respectively. -`"mode"' - The file's mode, as a numeric value. This includes both the file's +'"mode"' + The file's mode, as a numeric value. This includes both the file's type and its permissions. -`"nlink"' +'"nlink"' The number of hard links (directory entries) the file has. -`"uid"' -`"gid"' +'"uid"' +'"gid"' The numeric user and group ID numbers of the file's owner. -`"size"' +'"size"' The size in bytes of the file. -`"blocks"' - The number of disk blocks the file actually occupies. This may not +'"blocks"' + The number of disk blocks the file actually occupies. This may not be a function of the file's size if the file has holes. -`"atime"' -`"mtime"' -`"ctime"' +'"atime"' +'"mtime"' +'"ctime"' The file's last access, modification, and inode update times, respectively. These are numeric timestamps, suitable for - formatting with `strftime()' (*note Time Functions::). + formatting with 'strftime()' (*note Time Functions::). -`"pmode"' +'"pmode"' The file's "printable mode." This is a string representation of - the file's type and permissions, such as is produced by `ls - -l'--for example, `"drwxr-xr-x"'. + the file's type and permissions, such as is produced by 'ls + -l'--for example, '"drwxr-xr-x"'. -`"type"' - A printable string representation of the file's type. The value - is one of the following: +'"type"' + A printable string representation of the file's type. The value is + one of the following: - `"blockdev"' - `"chardev"' + '"blockdev"' + '"chardev"' The file is a block or character device ("special file"). - `"directory"' + '"directory"' The file is a directory. - `"fifo"' + '"fifo"' The file is a named-pipe (also known as a FIFO). - `"file"' + '"file"' The file is just a regular file. - `"socket"' - The file is an `AF_UNIX' ("Unix domain") socket in the + '"socket"' + The file is an 'AF_UNIX' ("Unix domain") socket in the filesystem. - `"symlink"' + '"symlink"' The file is a symbolic link. -`"devbsize"' - The size of a block for the element indexed by `"blocks"'. This - information is derived from either the `DEV_BSIZE' constant - defined in `' on most systems, or the `S_BLKSIZE' - constant in `' on BSD systems. For some other - systems, "a priori" knowledge is used to provide a value. Where no - value can be determined, it defaults to 512. +'"devbsize"' + The size of a block for the element indexed by '"blocks"'. This + information is derived from either the 'DEV_BSIZE' constant defined + in '' on most systems, or the 'S_BLKSIZE' constant in + '' on BSD systems. For some other systems, "a priori" + knowledge is used to provide a value. Where no value can be + determined, it defaults to 512. Several additional elements may be present depending upon the operating system and the type of the file. You can test for them in -your `awk' program by using the `in' operator (*note Reference to +your 'awk' program by using the 'in' operator (*note Reference to Elements::): -`"blksize"' - The preferred block size for I/O to the file. This field is not - present on all POSIX-like systems in the C `stat' structure. +'"blksize"' + The preferred block size for I/O to the file. This field is not + present on all POSIX-like systems in the C 'stat' structure. -`"linkval"' +'"linkval"' If the file is a symbolic link, this element is the name of the file the link points to (i.e., the value of the link). -`"rdev"' -`"major"' -`"minor"' +'"rdev"' +'"major"' +'"minor"' If the file is a block or character device file, then these values represent the numeric device number and the major and minor components of that number, respectively. @@ -24601,16 +24502,15 @@ Elements::):  File: gawk.info, Node: Internal File Ops, Next: Using Internal File Ops, Prev: Internal File Description, Up: Extension Example -16.6.2 C Code for `chdir()' and `stat()' +16.6.2 C Code for 'chdir()' and 'stat()' ---------------------------------------- Here is the C code for these extensions.(1) The file includes a number of standard header files, and then -includes the `gawkapi.h' header file which provides the API definitions. -Those are followed by the necessary variable declarations to make use -of the API macros and boilerplate code (*note Extension API -Boilerplate::). +includes the 'gawkapi.h' header file which provides the API definitions. +Those are followed by the necessary variable declarations to make use of +the API macros and boilerplate code (*note Extension API Boilerplate::). #ifdef HAVE_CONFIG_H #include @@ -24643,11 +24543,11 @@ Boilerplate::). int plugin_is_GPL_compatible; - By convention, for an `awk' function `foo()', the C function that -implements it is called `do_foo()'. The function should have two -arguments: the first is an `int' usually called `nargs', that -represents the number of actual arguments for the function. The second -is a pointer to an `awk_value_t', usually named `result'. + By convention, for an 'awk' function 'foo()', the C function that +implements it is called 'do_foo()'. The function should have two +arguments: the first is an 'int' usually called 'nargs', that represents +the number of actual arguments for the function. The second is a +pointer to an 'awk_value_t', usually named 'result'. /* do_chdir --- provide dynamically loaded chdir() builtin for gawk */ @@ -24664,12 +24564,12 @@ is a pointer to an `awk_value_t', usually named `result'. _("chdir: called with incorrect number of arguments, " "expecting 1")); - The `newdir' variable represents the new directory to change to, -retrieved with `get_argument()'. Note that the first argument is + The 'newdir' variable represents the new directory to change to, +retrieved with 'get_argument()'. Note that the first argument is numbered zero. If the argument is retrieved successfully, the function calls the -`chdir()' system call. If the `chdir()' fails, `ERRNO' is updated. +'chdir()' system call. If the 'chdir()' fails, 'ERRNO' is updated. if (get_argument(0, AWK_STRING, & newdir)) { ret = chdir(newdir.str_value.str); @@ -24677,14 +24577,14 @@ numbered zero. update_ERRNO_int(errno); } - Finally, the function returns the return value to the `awk' level: + Finally, the function returns the return value to the 'awk' level: return make_number(ret, result); } - The `stat()' extension is more involved. First comes a function -that turns a numeric mode into a printable representation (e.g., 644 -becomes `-rw-r--r--'). This is omitted here for brevity: + The 'stat()' extension is more involved. First comes a function that +turns a numeric mode into a printable representation (e.g., 644 becomes +'-rw-r--r--'). This is omitted here for brevity: /* format_mode --- turn a stat mode field into something readable */ @@ -24707,7 +24607,7 @@ omitted here for brevity: } Two helper functions simplify entering values in the array that will -contain the result of the `stat()': +contain the result of the 'stat()': /* array_set --- set an array element */ @@ -24733,9 +24633,9 @@ contain the result of the `stat()': } The following function does most of the work to fill in the -`awk_array_t' result array with values obtained from a valid `struct -stat'. It is done in a separate function to support the `stat()' -function for `gawk' and also to support the `fts()' extension which is +'awk_array_t' result array with values obtained from a valid 'struct +stat'. It is done in a separate function to support the 'stat()' +function for 'gawk' and also to support the 'fts()' extension which is included in the same file but whose code is not shown here (*note Extension Sample File Functions::). @@ -24774,7 +24674,7 @@ table to map file types to strings: int j, k; The destination array is cleared, and then code fills in various -elements based on values in the `struct stat': +elements based on values in the 'struct stat': /* empty out the array */ clear_array(array); @@ -24804,7 +24704,7 @@ elements based on values in the `struct stat': The latter part of the function makes selective additions to the destination array, depending upon the availability of certain members -and/or the type of the file. It then returns zero, for success: +and/or the type of the file. It then returns zero, for success: #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE array_set_numeric(array, "blksize", sbuf->st_blksize); @@ -24842,7 +24742,7 @@ and/or the type of the file. It then returns zero, for success: return 0; } - Finally, here is the `do_stat()' function. It starts with variable + Finally, here is the 'do_stat()' function. It starts with variable declarations and argument checking: /* do_stat --- provide a stat() function for gawk */ @@ -24867,14 +24767,14 @@ declarations and argument checking: return make_number(-1, result); } - The third argument to `stat()' was not discussed previously. This -argument is optional. If present, it causes `stat()' to use the `stat()' -system call instead of the `lstat()' system call. + The third argument to 'stat()' was not discussed previously. This +argument is optional. If present, it causes 'stat()' to use the +'stat()' system call instead of the 'lstat()' system call. - Then comes the actual work. First, the function gets the arguments. -Next, it gets the information for the file. The code use `lstat()' -(instead of `stat()') to get the file information, in case the file is -a symbolic link. If there's an error, it sets `ERRNO' and returns: + Then comes the actual work. First, the function gets the arguments. +Next, it gets the information for the file. The code use 'lstat()' +(instead of 'stat()') to get the file information, in case the file is a +symbolic link. If there's an error, it sets 'ERRNO' and returns: /* file is first arg, array to hold results is second */ if ( ! get_argument(0, AWK_STRING, & file_param) @@ -24900,8 +24800,8 @@ a symbolic link. If there's an error, it sets `ERRNO' and returns: return make_number(ret, result); } - The tedious work is done by `fill_stat_array()', shown earlier. -When done, return the result from `fill_stat_array()': + The tedious work is done by 'fill_stat_array()', shown earlier. When +done, return the result from 'fill_stat_array()': ret = fill_stat_array(name, array, & sbuf); @@ -24909,10 +24809,10 @@ When done, return the result from `fill_stat_array()': } Finally, it's necessary to provide the "glue" that loads the new -function(s) into `gawk'. +function(s) into 'gawk'. - The `filefuncs' extension also provides an `fts()' function, which -we omit here. For its sake there is an initialization function: + The 'filefuncs' extension also provides an 'fts()' function, which we +omit here. For its sake there is an initialization function: /* init_filefuncs --- initialization routine */ @@ -24922,8 +24822,8 @@ we omit here. For its sake there is an initialization function: ... } - We are almost done. We need an array of `awk_ext_func_t' structures -for loading each function into `gawk': + We are almost done. We need an array of 'awk_ext_func_t' structures +for loading each function into 'gawk': static awk_ext_func_t func_table[] = { { "chdir", do_chdir, 1 }, @@ -24933,9 +24833,9 @@ for loading each function into `gawk': #endif }; - Each extension must have a routine named `dl_load()' to load + Each extension must have a routine named 'dl_load()' to load everything that needs to be loaded. It is simplest to use the -`dl_load_func()' macro in `gawkapi.h': +'dl_load_func()' macro in 'gawkapi.h': /* define the dl_load() function using the boilerplate macro */ @@ -24946,7 +24846,7 @@ everything that needs to be loaded. It is simplest to use the ---------- Footnotes ---------- (1) This version is edited slightly for presentation. See -`extension/filefuncs.c' in the `gawk' distribution for the complete +'extension/filefuncs.c' in the 'gawk' distribution for the complete version.  @@ -24956,15 +24856,15 @@ File: gawk.info, Node: Using Internal File Ops, Prev: Internal File Ops, Up: --------------------------------- Now that the code is written, it must be possible to add it at runtime -to the running `gawk' interpreter. First, the code must be compiled. -Assuming that the functions are in a file named `filefuncs.c', and IDIR -is the location of the `gawkapi.h' header file, the following steps(1) +to the running 'gawk' interpreter. First, the code must be compiled. +Assuming that the functions are in a file named 'filefuncs.c', and IDIR +is the location of the 'gawkapi.h' header file, the following steps(1) create a GNU/Linux shared library: $ gcc -fPIC -shared -DHAVE_CONFIG_H -c -O -g -IIDIR filefuncs.c $ gcc -o filefuncs.so -shared filefuncs.o - Once the library exists, it is loaded by using the `@load' keyword. + Once the library exists, it is loaded by using the '@load' keyword. # file testff.awk @load "filefuncs" @@ -24993,7 +24893,7 @@ create a GNU/Linux shared library: print "JUNK modified:", strftime("%m %d %y %H:%M:%S", data["mtime"]) } - The `AWKLIBPATH' environment variable tells `gawk' where to find + The 'AWKLIBPATH' environment variable tells 'gawk' where to find extensions (*note Finding Extensions::). We set it to the current directory and run the program: @@ -25025,39 +24925,39 @@ directory and run the program: ---------- Footnotes ---------- (1) In practice, you would probably want to use the GNU -Autotools--Automake, Autoconf, Libtool, and `gettext'--to configure and -build your libraries. Instructions for doing so are beyond the scope of -this Info file. *Note gawkextlib::, for WWW links to the tools. +Autotools--Automake, Autoconf, Libtool, and 'gettext'--to configure and +build your libraries. Instructions for doing so are beyond the scope of +this Info file. *Note gawkextlib::, for WWW links to the tools.  File: gawk.info, Node: Extension Samples, Next: gawkextlib, Prev: Extension Example, Up: Dynamic Extensions -16.7 The Sample Extensions In The `gawk' Distribution +16.7 The Sample Extensions In The 'gawk' Distribution ===================================================== This minor node provides brief overviews of the sample extensions that -come in the `gawk' distribution. Some of them are intended for -production use, such the `filefuncs', `readdir' and `inplace' +come in the 'gawk' distribution. Some of them are intended for +production use, such the 'filefuncs', 'readdir' and 'inplace' extensions. Others mainly provide example code that shows how to use the extension API. * Menu: * Extension Sample File Functions:: The file functions sample. -* Extension Sample Fnmatch:: An interface to `fnmatch()'. -* Extension Sample Fork:: An interface to `fork()' and other +* Extension Sample Fnmatch:: An interface to 'fnmatch()'. +* Extension Sample Fork:: An interface to 'fork()' and other process functions. * Extension Sample Inplace:: Enabling in-place file editing. * Extension Sample Ord:: Character to value to character conversions. -* Extension Sample Readdir:: An interface to `readdir()'. +* Extension Sample Readdir:: An interface to 'readdir()'. * Extension Sample Revout:: Reversing output sample output wrapper. * Extension Sample Rev2way:: Reversing data sample two-way processor. * Extension Sample Read write array:: Serializing an array to a file. * Extension Sample Readfile:: Reading an entire file into a string. * Extension Sample API Tests:: Tests for the API. -* Extension Sample Time:: An interface to `gettimeofday()' - and `sleep()'. +* Extension Sample Time:: An interface to 'gettimeofday()' + and 'sleep()'.  File: gawk.info, Node: Extension Sample File Functions, Next: Extension Sample Fnmatch, Up: Extension Samples @@ -25065,69 +24965,67 @@ File: gawk.info, Node: Extension Sample File Functions, Next: Extension Sample 16.7.1 File Related Functions ----------------------------- -The `filefuncs' extension provides three different functions, as +The 'filefuncs' extension provides three different functions, as follows: The usage is: @load "filefuncs" This is how you load the extension. -`result = chdir("/some/directory")' - The `chdir()' function is a direct hook to the `chdir()' system - call to change the current directory. It returns zero upon - success or less than zero upon error. In the latter case it - updates `ERRNO'. +'result = chdir("/some/directory")' + The 'chdir()' function is a direct hook to the 'chdir()' system + call to change the current directory. It returns zero upon success + or less than zero upon error. In the latter case it updates + 'ERRNO'. -`result = stat("/some/path", statdata' [`, follow']`)' - The `stat()' function provides a hook into the `stat()' system +'result = stat("/some/path", statdata' [', follow']')' + The 'stat()' function provides a hook into the 'stat()' system call. It returns zero upon success or less than zero upon error. - In the latter case it updates `ERRNO'. + In the latter case it updates 'ERRNO'. - By default, it uses the `lstat()' system call. However, if passed - a third argument, it uses `stat()' instead. + By default, it uses the 'lstat()' system call. However, if passed + a third argument, it uses 'stat()' instead. - In all cases, it clears the `statdata' array. When the call is - successful, `stat()' fills the `statdata' array with information + In all cases, it clears the 'statdata' array. When the call is + successful, 'stat()' fills the 'statdata' array with information retrieved from the filesystem, as follows: - Subscript Field in `struct stat' File type - ------------------------------------------------------------ - `"name"' The file name All - `"dev"' `st_dev' All - `"ino"' `st_ino' All - `"mode"' `st_mode' All - `"nlink"' `st_nlink' All - `"uid"' `st_uid' All - `"gid"' `st_gid' All - `"size"' `st_size' All - `"atime"' `st_atime' All - `"mtime"' `st_mtime' All - `"ctime"' `st_ctime' All - `"rdev"' `st_rdev' Device files - `"major"' `st_major' Device files - `"minor"' `st_minor' Device files - `"blksize"'`st_blksize' All - `"pmode"' A human-readable version of the All - mode value, such as printed by - `ls'. For example, - `"-rwxr-xr-x"' - `"linkval"'The value of the symbolic link Symbolic - links - `"type"' The type of the file as a string. All - One of `"file"', `"blockdev"', - `"chardev"', `"directory"', - `"socket"', `"fifo"', `"symlink"', - `"door"', or `"unknown"'. Not - all systems support all file - types. - -`flags = or(FTS_PHYSICAL, ...)' -`result = fts(pathlist, flags, filedata)' - Walk the file trees provided in `pathlist' and fill in the - `filedata' array as described below. `flags' is the bitwise OR of + Subscript Field in 'struct stat' File type + ---------------------------------------------------------------- + '"name"' The file name All + '"dev"' 'st_dev' All + '"ino"' 'st_ino' All + '"mode"' 'st_mode' All + '"nlink"' 'st_nlink' All + '"uid"' 'st_uid' All + '"gid"' 'st_gid' All + '"size"' 'st_size' All + '"atime"' 'st_atime' All + '"mtime"' 'st_mtime' All + '"ctime"' 'st_ctime' All + '"rdev"' 'st_rdev' Device files + '"major"' 'st_major' Device files + '"minor"' 'st_minor' Device files + '"blksize"' 'st_blksize' All + '"pmode"' A human-readable version of the All + mode value, such as printed by + 'ls'. For example, '"-rwxr-xr-x"' + '"linkval"' The value of the symbolic link Symbolic + links + '"type"' The type of the file as a string. All + One of '"file"', '"blockdev"', + '"chardev"', '"directory"', + '"socket"', '"fifo"', '"symlink"', + '"door"', or '"unknown"'. Not all + systems support all file types. + +'flags = or(FTS_PHYSICAL, ...)' +'result = fts(pathlist, flags, filedata)' + Walk the file trees provided in 'pathlist' and fill in the + 'filedata' array as described below. 'flags' is the bitwise OR of several predefined constant values, also described below. Return zero if there were no errors, otherwise return -1. - The `fts()' function provides a hook to the C library `fts()' + The 'fts()' function provides a hook to the C library 'fts()' routines for traversing file hierarchies. Instead of returning data about one file at a time in a stream, it fills in a multidimensional array with data about each file and directory encountered in the @@ -25135,142 +25033,141 @@ requested hierarchies. The arguments are as follows: -`pathlist' +'pathlist' An array of file names. The element values are used; the index values are ignored. -`flags' +'flags' This should be the bitwise OR of one or more of the following - predefined constant flag values. At least one of `FTS_LOGICAL' or - `FTS_PHYSICAL' must be provided; otherwise `fts()' returns an - error value and sets `ERRNO'. The flags are: + predefined constant flag values. At least one of 'FTS_LOGICAL' or + 'FTS_PHYSICAL' must be provided; otherwise 'fts()' returns an error + value and sets 'ERRNO'. The flags are: - `FTS_LOGICAL' + 'FTS_LOGICAL' Do a "logical" file traversal, where the information returned for a symbolic link refers to the linked-to file, and not to the symbolic link itself. This flag is mutually exclusive - with `FTS_PHYSICAL'. + with 'FTS_PHYSICAL'. - `FTS_PHYSICAL' - Do a "physical" file traversal, where the information - returned for a symbolic link refers to the symbolic link - itself. This flag is mutually exclusive with `FTS_LOGICAL'. + 'FTS_PHYSICAL' + Do a "physical" file traversal, where the information returned + for a symbolic link refers to the symbolic link itself. This + flag is mutually exclusive with 'FTS_LOGICAL'. - `FTS_NOCHDIR' - As a performance optimization, the C library `fts()' routines - change directory as they traverse a file hierarchy. This - flag disables that optimization. + 'FTS_NOCHDIR' + As a performance optimization, the C library 'fts()' routines + change directory as they traverse a file hierarchy. This flag + disables that optimization. - `FTS_COMFOLLOW' - Immediately follow a symbolic link named in `pathlist', - whether or not `FTS_LOGICAL' is set. + 'FTS_COMFOLLOW' + Immediately follow a symbolic link named in 'pathlist', + whether or not 'FTS_LOGICAL' is set. - `FTS_SEEDOT' - By default, the `fts()' routines do not return entries for - `.' (dot) and `..' (dot-dot). This option causes entries for + 'FTS_SEEDOT' + By default, the 'fts()' routines do not return entries for '.' + (dot) and '..' (dot-dot). This option causes entries for dot-dot to also be included. (The extension always includes an entry for dot, see below.) - `FTS_XDEV' + 'FTS_XDEV' During a traversal, do not cross onto a different mounted filesystem. -`filedata' - The `filedata' array is first cleared. Then, `fts()' creates an - element in `filedata' for every element in `pathlist'. The index - is the name of the directory or file given in `pathlist'. The +'filedata' + The 'filedata' array is first cleared. Then, 'fts()' creates an + element in 'filedata' for every element in 'pathlist'. The index + is the name of the directory or file given in 'pathlist'. The element for this index is itself an array. There are two cases. - _The path is a file_ + _The path is a file_ In this case, the array contains two or three elements: - `"path"' - The full path to this file, starting from the "root" - that was given in the `pathlist' array. + '"path"' + The full path to this file, starting from the "root" that + was given in the 'pathlist' array. - `"stat"' + '"stat"' This element is itself an array, containing the same - information as provided by the `stat()' function - described earlier for its `statdata' argument. The - element may not be present if the `stat()' system call + information as provided by the 'stat()' function + described earlier for its 'statdata' argument. The + element may not be present if the 'stat()' system call for the file failed. - `"error"' + '"error"' If some kind of error was encountered, the array will - also contain an element named `"error"', which is a + also contain an element named '"error"', which is a string describing the error. - _The path is a directory_ - In this case, the array contains one element for each entry - in the directory. If an entry is a file, that element is as - for files, just described. If the entry is a directory, that + _The path is a directory_ + In this case, the array contains one element for each entry in + the directory. If an entry is a file, that element is as for + files, just described. If the entry is a directory, that element is (recursively), an array describing the - subdirectory. If `FTS_SEEDOT' was provided in the flags, - then there will also be an element named `".."'. This - element will be an array containing the data as provided by - `stat()'. + subdirectory. If 'FTS_SEEDOT' was provided in the flags, then + there will also be an element named '".."'. This element will + be an array containing the data as provided by 'stat()'. - In addition, there will be an element whose index is `"."'. + In addition, there will be an element whose index is '"."'. This element is an array containing the same two or three - elements as for a file: `"path"', `"stat"', and `"error"'. + elements as for a file: '"path"', '"stat"', and '"error"'. - The `fts()' function returns zero if there were no errors. -Otherwise it returns -1. + The 'fts()' function returns zero if there were no errors. Otherwise +it returns -1. - NOTE: The `fts()' extension does not exactly mimic the interface - of the C library `fts()' routines, choosing instead to provide an - interface that is based on associative arrays, which should be - more comfortable to use from an `awk' program. This includes the - lack of a comparison function, since `gawk' already provides - powerful array sorting facilities. While an `fts_read()'-like - interface could have been provided, this felt less natural than - simply creating a multidimensional array to represent the file - hierarchy and its information. + NOTE: The 'fts()' extension does not exactly mimic the interface of + the C library 'fts()' routines, choosing instead to provide an + interface that is based on associative arrays, which should be more + comfortable to use from an 'awk' program. This includes the lack + of a comparison function, since 'gawk' already provides powerful + array sorting facilities. While an 'fts_read()'-like interface + could have been provided, this felt less natural than simply + creating a multidimensional array to represent the file hierarchy + and its information. - See `test/fts.awk' in the `gawk' distribution for an example. + See 'test/fts.awk' in the 'gawk' distribution for an example.  File: gawk.info, Node: Extension Sample Fnmatch, Next: Extension Sample Fork, Prev: Extension Sample File Functions, Up: Extension Samples -16.7.2 Interface To `fnmatch()' +16.7.2 Interface To 'fnmatch()' ------------------------------- -This extension provides an interface to the C library `fnmatch()' +This extension provides an interface to the C library 'fnmatch()' function. The usage is: -`@load "fnmatch"' +'@load "fnmatch"' This is how you load the extension. -`result = fnmatch(pattern, string, flags)' - The return value is zero on success, `FNM_NOMATCH' if the string +'result = fnmatch(pattern, string, flags)' + The return value is zero on success, 'FNM_NOMATCH' if the string did not match the pattern, or a different non-zero value if an error occurred. - Besides the `fnmatch()' function, the `fnmatch' extension adds one -constant (`FNM_NOMATCH'), and an array of flag values named `FNM'. + Besides the 'fnmatch()' function, the 'fnmatch' extension adds one +constant ('FNM_NOMATCH'), and an array of flag values named 'FNM'. - The arguments to `fnmatch()' are: + The arguments to 'fnmatch()' are: -`pattern' +'pattern' The file name wildcard to match. -`string' +'string' The file name string. -`flag' +'flag' Either zero, or the bitwise OR of one or more of the flags in the - `FNM' array. + 'FNM' array. The flags are follows: -Array element Corresponding flag defined by `fnmatch()' --------------------------------------------------------------------------- -`FNM["CASEFOLD"]' `FNM_CASEFOLD' -`FNM["FILE_NAME"]' `FNM_FILE_NAME' -`FNM["LEADING_DIR"]'`FNM_LEADING_DIR' -`FNM["NOESCAPE"]' `FNM_NOESCAPE' -`FNM["PATHNAME"]' `FNM_PATHNAME' -`FNM["PERIOD"]' `FNM_PERIOD' +Array element Corresponding flag defined by 'fnmatch()' +-------------------------------------------------------------------------- +'FNM["CASEFOLD"]' 'FNM_CASEFOLD' +'FNM["FILE_NAME"]' 'FNM_FILE_NAME' +'FNM["LEADING_DIR"]''FNM_LEADING_DIR' +'FNM["NOESCAPE"]' 'FNM_NOESCAPE' +'FNM["PATHNAME"]' 'FNM_PATHNAME' +'FNM["PERIOD"]' 'FNM_PERIOD' Here is an example: @@ -25283,30 +25180,30 @@ Array element Corresponding flag defined by `fnmatch()'  File: gawk.info, Node: Extension Sample Fork, Next: Extension Sample Inplace, Prev: Extension Sample Fnmatch, Up: Extension Samples -16.7.3 Interface To `fork()', `wait()' and `waitpid()' +16.7.3 Interface To 'fork()', 'wait()' and 'waitpid()' ------------------------------------------------------ -The `fork' extension adds three functions, as follows. +The 'fork' extension adds three functions, as follows. -`@load "fork"' +'@load "fork"' This is how you load the extension. -`pid = fork()' - This function creates a new process. The return value is zero in +'pid = fork()' + This function creates a new process. The return value is zero in the child and the process-ID number of the child in the parent, or - -1 upon error. In the latter case, `ERRNO' indicates the problem. - In the child, `PROCINFO["pid"]' and `PROCINFO["ppid"]' are updated + -1 upon error. In the latter case, 'ERRNO' indicates the problem. + In the child, 'PROCINFO["pid"]' and 'PROCINFO["ppid"]' are updated to reflect the correct values. -`ret = waitpid(pid)' +'ret = waitpid(pid)' This function takes a numeric argument, which is the process-ID to - wait for. The return value is that of the `waitpid()' system call. + wait for. The return value is that of the 'waitpid()' system call. -`ret = wait()' +'ret = wait()' This function waits for the first child to die. The return value - is that of the `wait()' system call. + is that of the 'wait()' system call. - There is no corresponding `exec()' function. + There is no corresponding 'exec()' function. Here is an example: @@ -25323,9 +25220,9 @@ File: gawk.info, Node: Extension Sample Inplace, Next: Extension Sample Ord, 16.7.4 Enabling In-Place File Editing ------------------------------------- -The `inplace' extension emulates GNU `sed''s `-i' option which performs +The 'inplace' extension emulates GNU 'sed''s '-i' option which performs "in place" editing of each input file. It uses the bundled -`inplace.awk' include file to invoke the extension properly: +'inplace.awk' include file to invoke the extension properly: # inplace --- load and invoke the inplace extension. @@ -25344,9 +25241,9 @@ The `inplace' extension emulates GNU `sed''s `-i' option which performs For each regular file that is processed, the extension redirects standard output to a temporary file configured to have the same owner -and permissions as the original. After the file has been processed, -the extension restores standard output to its original destination. If -`INPLACE_SUFFIX' is not an empty string, the original file is linked to +and permissions as the original. After the file has been processed, the +extension restores standard output to its original destination. If +'INPLACE_SUFFIX' is not an empty string, the original file is linked to a backup file name created by appending that suffix. Finally, the temporary file is renamed to the original file name. @@ -25365,21 +25262,21 @@ processing immediately without damaging the original file.  File: gawk.info, Node: Extension Sample Ord, Next: Extension Sample Readdir, Prev: Extension Sample Inplace, Up: Extension Samples -16.7.5 Character and Numeric values: `ord()' and `chr()' +16.7.5 Character and Numeric values: 'ord()' and 'chr()' -------------------------------------------------------- -The `ordchr' extension adds two functions, named `ord()' and `chr()', -as follows. +The 'ordchr' extension adds two functions, named 'ord()' and 'chr()', as +follows. -`@load "ordchr"' +'@load "ordchr"' This is how you load the extension. -`number = ord(string)' - Return the numeric value of the first character in `string'. +'number = ord(string)' + Return the numeric value of the first character in 'string'. -`char = chr(number)' +'char = chr(number)' Return a string whose first character is that represented by - `number'. + 'number'. These functions are inspired by the Pascal language functions of the same name. Here is an example: @@ -25395,43 +25292,42 @@ File: gawk.info, Node: Extension Sample Readdir, Next: Extension Sample Revout 16.7.6 Reading Directories -------------------------- -The `readdir' extension adds an input parser for directories. The -usage is as follows: +The 'readdir' extension adds an input parser for directories. The usage +is as follows: @load "readdir" When this extension is in use, instead of skipping directories named -on the command line (or with `getline'), they are read, with each entry +on the command line (or with 'getline'), they are read, with each entry returned as a record. - The record consists of three fields. The first two are the inode + The record consists of three fields. The first two are the inode number and the file name, separated by a forward slash character. On -systems where the directory entry contains the file type, the record -has a third field (also separated by a slash) which is a single letter -indicating the type of the file. The letters are file types are shown -in *note table-readdir-file-types::. +systems where the directory entry contains the file type, the record has +a third field (also separated by a slash) which is a single letter +indicating the type of the file. The letters are file types are shown +in *note Table 16.2: table-readdir-file-types. Letter File Type --------------------------------------------------------------------------- -`b' Block device -`c' Character device -`d' Directory -`f' Regular file -`l' Symbolic link -`p' Named pipe (FIFO) -`s' Socket -`u' Anything else (unknown) - -Table 16.2: File Types Returned By `readdir()' +-------------------------------------------------------------------------- +'b' Block device +'c' Character device +'d' Directory +'f' Regular file +'l' Symbolic link +'p' Named pipe (FIFO) +'s' Socket +'u' Anything else (unknown) + +Table 16.2: File Types Returned By 'readdir()' On systems without the file type information, the third field is -always `u'. +always 'u'. NOTE: On GNU/Linux systems, there are filesystems that don't - support the `d_type' entry (see the readdir(3) manual page), and - so the file type is always `u'. You can use the `filefuncs' - extension to call `stat()' in order to get correct type - information. + support the 'd_type' entry (see the readdir(3) manual page), and so + the file type is always 'u'. You can use the 'filefuncs' extension + to call 'stat()' in order to get correct type information. Here is an example: @@ -25446,8 +25342,8 @@ File: gawk.info, Node: Extension Sample Revout, Next: Extension Sample Rev2way 16.7.7 Reversing Output ----------------------- -The `revoutput' extension adds a simple output wrapper that reverses -the characters in each output line. It's main purpose is to show how to +The 'revoutput' extension adds a simple output wrapper that reverses the +characters in each output line. It's main purpose is to show how to write an output wrapper, although it may be mildly amusing for the unwary. Here is an example: @@ -25458,7 +25354,7 @@ unwary. Here is an example: print "don't panic" > "/dev/stdout" } - The output from this program is: `cinap t'nod'. + The output from this program is: 'cinap t'nod'.  File: gawk.info, Node: Extension Sample Rev2way, Next: Extension Sample Read write array, Prev: Extension Sample Revout, Up: Extension Samples @@ -25466,11 +25362,11 @@ File: gawk.info, Node: Extension Sample Rev2way, Next: Extension Sample Read w 16.7.8 Two-Way I/O Example -------------------------- -The `revtwoway' extension adds a simple two-way processor that reverses -the characters in each line sent to it for reading back by the `awk' -program. It's main purpose is to show how to write a two-way -processor, although it may also be mildly amusing. The following -example shows how to use it: +The 'revtwoway' extension adds a simple two-way processor that reverses +the characters in each line sent to it for reading back by the 'awk' +program. It's main purpose is to show how to write a two-way processor, +although it may also be mildly amusing. The following example shows how +to use it: @load "revtwoway" @@ -25482,7 +25378,7 @@ example shows how to use it: close(cmd) } - The output from this program is: `cinap t'nod'. + The output from this program is: 'cinap t'nod'.  File: gawk.info, Node: Extension Sample Read write array, Next: Extension Sample Readfile, Prev: Extension Sample Rev2way, Up: Extension Samples @@ -25490,35 +25386,35 @@ File: gawk.info, Node: Extension Sample Read write array, Next: Extension Samp 16.7.9 Dumping and Restoring An Array ------------------------------------- -The `rwarray' extension adds two functions, named `writea()' and -`reada()', as follows: +The 'rwarray' extension adds two functions, named 'writea()' and +'reada()', as follows: -`ret = writea(file, array)' +'ret = writea(file, array)' This function takes a string argument, which is the name of the - file to which to dump the array, and the array itself as the - second argument. `writea()' understands arrays of arrays. It - returns one on success, or zero upon failure. + file to which to dump the array, and the array itself as the second + argument. 'writea()' understands arrays of arrays. It returns one + on success, or zero upon failure. -`ret = reada(file, array)' - `reada()' is the inverse of `writea()'; it reads the file named as +'ret = reada(file, array)' + 'reada()' is the inverse of 'writea()'; it reads the file named as its first argument, filling in the array named as the second - argument. It clears the array first. Here too, the return value + argument. It clears the array first. Here too, the return value is one on success and zero upon failure. - The array created by `reada()' is identical to that written by -`writea()' in the sense that the contents are the same. However, due to + The array created by 'reada()' is identical to that written by +'writea()' in the sense that the contents are the same. However, due to implementation issues, the array traversal order of the recreated array is likely to be different from that of the original array. As array -traversal order in `awk' is by default undefined, this is (technically) +traversal order in 'awk' is by default undefined, this is (technically) not a problem. If you need to guarantee a particular traversal order, -use the array sorting features in `gawk' to do so (*note Array +use the array sorting features in 'gawk' to do so (*note Array Sorting::). The file contains binary data. All integral values are written in -network byte order. However, double precision floating-point values -are written as native binary data. Thus, arrays containing only string -data can theoretically be dumped on systems with one byte order and -restored on systems with a different one, but this has not been tried. +network byte order. However, double precision floating-point values are +written as native binary data. Thus, arrays containing only string data +can theoretically be dumped on systems with one byte order and restored +on systems with a different one, but this has not been tried. Here is an example: @@ -25534,21 +25430,21 @@ File: gawk.info, Node: Extension Sample Readfile, Next: Extension Sample API T 16.7.10 Reading An Entire File ------------------------------ -The `readfile' extension adds a single function named `readfile()', and +The 'readfile' extension adds a single function named 'readfile()', and an input parser: -`@load "readfile"' +'@load "readfile"' This is how you load the extension. -`result = readfile("/some/path")' +'result = readfile("/some/path")' The argument is the name of the file to read. The return value is a string containing the entire contents of the requested file. - Upon error, the function returns the empty string and sets `ERRNO'. + Upon error, the function returns the empty string and sets 'ERRNO'. -`BEGIN { PROCINFO["readfile"] = 1 }' +'BEGIN { PROCINFO["readfile"] = 1 }' In addition, the extension adds an input parser that is activated - if `PROCINFO["readfile"]' exists. When activated, each input file - is returned in its entirety as `$0'. `RT' is set to the null + if 'PROCINFO["readfile"]' exists. When activated, each input file + is returned in its entirety as '$0'. 'RT' is set to the null string. Here is an example: @@ -25567,10 +25463,10 @@ File: gawk.info, Node: Extension Sample API Tests, Next: Extension Sample Time 16.7.11 API Tests ----------------- -The `testext' extension exercises parts of the extension API that are -not tested by the other samples. The `extension/testext.c' file -contains both the C code for the extension and `awk' test code inside C -comments that run the tests. The testing framework extracts the `awk' +The 'testext' extension exercises parts of the extension API that are +not tested by the other samples. The 'extension/testext.c' file +contains both the C code for the extension and 'awk' test code inside C +comments that run the tests. The testing framework extracts the 'awk' code and runs the tests. See the source file for more information.  @@ -25579,40 +25475,40 @@ File: gawk.info, Node: Extension Sample Time, Prev: Extension Sample API Tests 16.7.12 Extension Time Functions -------------------------------- -The `time' extension adds two functions, named `gettimeofday()' and -`sleep()', as follows: +The 'time' extension adds two functions, named 'gettimeofday()' and +'sleep()', as follows: -`@load "time"' +'@load "time"' This is how you load the extension. -`the_time = gettimeofday()' - Return the time in seconds that has elapsed since 1970-01-01 UTC - as a floating point value. If the time is unavailable on this - platform, return -1 and set `ERRNO'. The returned time should - have sub-second precision, but the actual precision may vary based - on the platform. If the standard C `gettimeofday()' system call - is available on this platform, then it simply returns the value. +'the_time = gettimeofday()' + Return the time in seconds that has elapsed since 1970-01-01 UTC as + a floating point value. If the time is unavailable on this + platform, return -1 and set 'ERRNO'. The returned time should have + sub-second precision, but the actual precision may vary based on + the platform. If the standard C 'gettimeofday()' system call is + available on this platform, then it simply returns the value. Otherwise, if on MS-Windows, it tries to use - `GetSystemTimeAsFileTime()'. + 'GetSystemTimeAsFileTime()'. -`result = sleep(SECONDS)' +'result = sleep(SECONDS)' Attempt to sleep for SECONDS seconds. If SECONDS is negative, or - the attempt to sleep fails, return -1 and set `ERRNO'. Otherwise, + the attempt to sleep fails, return -1 and set 'ERRNO'. Otherwise, return zero after sleeping for the indicated amount of time. Note that SECONDS may be a floating-point (non-integral) value. Implementation details: depending on platform availability, this - function tries to use `nanosleep()' or `select()' to implement the + function tries to use 'nanosleep()' or 'select()' to implement the delay.  File: gawk.info, Node: gawkextlib, Next: Extension summary, Prev: Extension Samples, Up: Dynamic Extensions -16.8 The `gawkextlib' Project +16.8 The 'gawkextlib' Project ============================= -The `gawkextlib' (http://sourceforge.net/projects/gawkextlib/) project -provides a number of `gawk' extensions, including one for processing -XML files. This is the evolution of the original `xgawk' (XML `gawk') +The 'gawkextlib' (http://sourceforge.net/projects/gawkextlib/) project +provides a number of 'gawk' extensions, including one for processing XML +files. This is the evolution of the original 'xgawk' (XML 'gawk') project. As of this writing, there are five extensions: @@ -25627,14 +25523,14 @@ project. * GD graphics library extension. * MPFR library extension. This provides access to a number of MPFR - functions which `gawk''s native MPFR support does not. + functions which 'gawk''s native MPFR support does not. - The `time' extension described earlier (*note Extension Sample + The 'time' extension described earlier (*note Extension Sample Time::) was originally from this project but has been moved in to the -main `gawk' distribution. +main 'gawk' distribution. - You can check out the code for the `gawkextlib' project using the -Git (http://git-scm.com) distributed source code control system. The + You can check out the code for the 'gawkextlib' project using the Git +(http://git-scm.com) distributed source code control system. The command is as follows: git clone git://git.code.sf.net/p/gawkextlib/code gawkextlib-code @@ -25645,18 +25541,18 @@ parser library installed in order to build and use the XML extension. In addition, you must have the GNU Autotools installed (Autoconf (http://www.gnu.org/software/autoconf), Automake (http://www.gnu.org/software/automake), Libtool -(http://www.gnu.org/software/libtool), and GNU `gettext' +(http://www.gnu.org/software/libtool), and GNU 'gettext' (http://www.gnu.org/software/gettext)). - The simple recipe for building and testing `gawkextlib' is as -follows. First, build and install `gawk': + The simple recipe for building and testing 'gawkextlib' is as +follows. First, build and install 'gawk': cd .../path/to/gawk/code ./configure --prefix=/tmp/newgawk Install in /tmp/newgawk for now make && make check Build and check that all is OK make install Install gawk - Next, build `gawkextlib' and test it: + Next, build 'gawkextlib' and test it: cd .../path/to/gawkextlib-code ./update-autotools Generate configure, etc. @@ -25665,13 +25561,13 @@ follows. First, build and install `gawk': make && make check Build and check that all is OK make install Install the extensions - If you have installed `gawk' in the standard way, then you will -likely not need the `--with-gawk' option when configuring `gawkextlib'. -You may also need to use the `sudo' utility to install both `gawk' and -`gawkextlib', depending upon how your system works. + If you have installed 'gawk' in the standard way, then you will +likely not need the '--with-gawk' option when configuring 'gawkextlib'. +You may also need to use the 'sudo' utility to install both 'gawk' and +'gawkextlib', depending upon how your system works. - If you write an extension that you wish to share with other `gawk' -users, please consider doing so through the `gawkextlib' project. See + If you write an extension that you wish to share with other 'gawk' +users, please consider doing so through the 'gawkextlib' project. See the project's web site for more information.  @@ -25680,40 +25576,40 @@ File: gawk.info, Node: Extension summary, Next: Extension Exercises, Prev: ga 16.9 Summary ============ - * You can write extensions (sometimes called plug-ins) for `gawk' in + * You can write extensions (sometimes called plug-ins) for 'gawk' in C or C++ using the Application Programming Interface (API) defined - by the `gawk' developers. + by the 'gawk' developers. * Extensions must have a license compatible with the GNU General - Public License (GPL), and they must assert that fact by declaring - a variable named `plugin_is_GPL_compatible'. + Public License (GPL), and they must assert that fact by declaring a + variable named 'plugin_is_GPL_compatible'. - * Communication between `gawk' and an extension is two-way. `gawk' - passes a `struct' to the extension which contains various data + * Communication between 'gawk' and an extension is two-way. 'gawk' + passes a 'struct' to the extension which contains various data fields and function pointers. The extension can then call into - `gawk' via the supplied function pointers to accomplish certain + 'gawk' via the supplied function pointers to accomplish certain tasks. * One of these tasks is to "register" the name and implementation of - a new `awk'-level function with `gawk'. The implementation takes + a new 'awk'-level function with 'gawk'. The implementation takes the form of a C function pointer with a defined signature. By - convention, implementation functions are named `do_XXXX()' for - some `awk'-level function `XXXX()'. + convention, implementation functions are named 'do_XXXX()' for some + 'awk'-level function 'XXXX()'. - * The API is defined in a header file named `gawkpi.h'. You must + * The API is defined in a header file named 'gawkpi.h'. You must include a number of standard header files _before_ including it in your source file. * API function pointers are provided for the following kinds of operations: - * Registration functions. You may register extension functions, + * Registration functions. You may register extension functions, exit callbacks, a version string, input parsers, output wrappers, and two-way processors. * Printing fatal, warning, and "lint" warning messages. - * Updating `ERRNO', or unsetting it. + * Updating 'ERRNO', or unsetting it. * Accessing parameters, including converting an undefined parameter into an array. @@ -25734,68 +25630,66 @@ File: gawk.info, Node: Extension summary, Next: Extension Exercises, Prev: ga elements * The API defines a number of standard data types for representing - `awk' values, array elements, and arrays. + 'awk' values, array elements, and arrays. * The API provide convenience functions for constructing values. It also provides memory management functions to ensure compatibility - between memory allocated by `gawk' and memory allocated by an + between memory allocated by 'gawk' and memory allocated by an extension. - * _All_ memory passed from `gawk' to an extension must be treated as + * _All_ memory passed from 'gawk' to an extension must be treated as read-only by the extension. - * _All_ memory passed from an extension to `gawk' must come from the - API's memory allocation functions. `gawk' takes responsibility for + * _All_ memory passed from an extension to 'gawk' must come from the + API's memory allocation functions. 'gawk' takes responsibility for the memory and will release it when appropriate. - * The API provides information about the running version of `gawk' so - that an extension can make sure it is compatible with the `gawk' + * The API provides information about the running version of 'gawk' so + that an extension can make sure it is compatible with the 'gawk' that loaded it. * It is easiest to start a new extension by copying the boilerplate - code described in this major node. Macros in the `gawkapi.h' make + code described in this major node. Macros in the 'gawkapi.h' make this easier to do. - * The `gawk' distribution includes a number of small but useful - sample extensions. The `gawkextlib' project includes several more, + * The 'gawk' distribution includes a number of small but useful + sample extensions. The 'gawkextlib' project includes several more, larger, extensions. If you wish to write an extension and - contribute it to the community of `gawk' users, the `gawkextlib' + contribute it to the community of 'gawk' users, the 'gawkextlib' project should be the place to do so. -  File: gawk.info, Node: Extension Exercises, Prev: Extension summary, Up: Dynamic Extensions 16.10 Exercises =============== - 1. Add functions to implement system calls such as `chown()', - `chmod()', and `umask()' to the file operations extension - presented in *note Internal File Ops::. - - 2. (Hard.) How would you provide namespaces in `gawk', so that the - names of functions in different extensions don't conflict with - each other? If you come up with a really good scheme, contact the - `gawk' maintainer to tell him about it. + 1. Add functions to implement system calls such as 'chown()', + 'chmod()', and 'umask()' to the file operations extension presented + in *note Internal File Ops::. - 3. Write a wrapper script that provides an interface similar to `sed - -i' for the "inplace" extension presented in *note Extension - Sample Inplace::. + 2. (Hard.) How would you provide namespaces in 'gawk', so that the + names of functions in different extensions don't conflict with each + other? If you come up with a really good scheme, contact the + 'gawk' maintainer to tell him about it. + 3. Write a wrapper script that provides an interface similar to 'sed + -i' for the "inplace" extension presented in *note Extension Sample + Inplace::.  File: gawk.info, Node: Language History, Next: Installation, Prev: Dynamic Extensions, Up: Top -Appendix A The Evolution of the `awk' Language +Appendix A The Evolution of the 'awk' Language ********************************************** -This Info file describes the GNU implementation of `awk', which follows -the POSIX specification. Many long-time `awk' users learned `awk' -programming with the original `awk' implementation in Version 7 Unix. -(This implementation was the basis for `awk' in Berkeley Unix, through +This Info file describes the GNU implementation of 'awk', which follows +the POSIX specification. Many long-time 'awk' users learned 'awk' +programming with the original 'awk' implementation in Version 7 Unix. +(This implementation was the basis for 'awk' in Berkeley Unix, through 4.3-Reno. Subsequent versions of Berkeley Unix, and some systems -derived from 4.4BSD-Lite, used various versions of `gawk' for their -`awk'.) This major node briefly describes the evolution of the `awk' +derived from 4.4BSD-Lite, used various versions of 'gawk' for their +'awk'.) This major node briefly describes the evolution of the 'awk' language, with cross-references to other parts of the Info file where you can find more information. @@ -25807,13 +25701,13 @@ you can find more information. and 4. * POSIX:: New features from the POSIX standard. * BTL:: New features from Brian Kernighan's version of - `awk'. -* POSIX/GNU:: The extensions in `gawk' not in POSIX - `awk'. -* Feature History:: The history of the features in `gawk'. + 'awk'. +* POSIX/GNU:: The extensions in 'gawk' not in POSIX + 'awk'. +* Feature History:: The history of the features in 'gawk'. * Common Extensions:: Common Extensions Summary. * Ranges and Locales:: How locales used to affect regexp ranges. -* Contributors:: The major contributors to `gawk'. +* Contributors:: The major contributors to 'gawk'. * History summary:: History summary.  @@ -25822,62 +25716,62 @@ File: gawk.info, Node: V7/SVR3.1, Next: SVR4, Up: Language History A.1 Major Changes Between V7 and SVR3.1 ======================================= -The `awk' language evolved considerably between the release of Version -7 Unix (1978) and the new version that was first made generally -available in System V Release 3.1 (1987). This minor node summarizes -the changes, with cross-references to further details: +The 'awk' language evolved considerably between the release of Version 7 +Unix (1978) and the new version that was first made generally available +in System V Release 3.1 (1987). This minor node summarizes the changes, +with cross-references to further details: - * The requirement for `;' to separate rules on a line (*note + * The requirement for ';' to separate rules on a line (*note Statements/Lines::). - * User-defined functions and the `return' statement (*note + * User-defined functions and the 'return' statement (*note User-defined::). - * The `delete' statement (*note Delete::). + * The 'delete' statement (*note Delete::). - * The `do'-`while' statement (*note Do Statement::). + * The 'do'-'while' statement (*note Do Statement::). - * The built-in functions `atan2()', `cos()', `sin()', `rand()', and - `srand()' (*note Numeric Functions::). + * The built-in functions 'atan2()', 'cos()', 'sin()', 'rand()', and + 'srand()' (*note Numeric Functions::). - * The built-in functions `gsub()', `sub()', and `match()' (*note + * The built-in functions 'gsub()', 'sub()', and 'match()' (*note String Functions::). - * The built-in functions `close()' and `system()' (*note I/O + * The built-in functions 'close()' and 'system()' (*note I/O Functions::). - * The `ARGC', `ARGV', `FNR', `RLENGTH', `RSTART', and `SUBSEP' + * The 'ARGC', 'ARGV', 'FNR', 'RLENGTH', 'RSTART', and 'SUBSEP' built-in variables (*note Built-in Variables::). - * Assignable `$0' (*note Changing Fields::). + * Assignable '$0' (*note Changing Fields::). - * The conditional expression using the ternary operator `?:' (*note + * The conditional expression using the ternary operator '?:' (*note Conditional Exp::). - * The expression `INDEX-VARIABLE in ARRAY' outside of `for' + * The expression 'INDEX-VARIABLE in ARRAY' outside of 'for' statements (*note Reference to Elements::). - * The exponentiation operator `^' (*note Arithmetic Ops::) and its - assignment operator form `^=' (*note Assignment Ops::). + * The exponentiation operator '^' (*note Arithmetic Ops::) and its + assignment operator form '^=' (*note Assignment Ops::). - * C-compatible operator precedence, which breaks some old `awk' + * C-compatible operator precedence, which breaks some old 'awk' programs (*note Precedence::). - * Regexps as the value of `FS' (*note Field Separators::) and as the - third argument to the `split()' function (*note String - Functions::), rather than using only the first character of `FS'. + * Regexps as the value of 'FS' (*note Field Separators::) and as the + third argument to the 'split()' function (*note String + Functions::), rather than using only the first character of 'FS'. - * Dynamic regexps as operands of the `~' and `!~' operators (*note + * Dynamic regexps as operands of the '~' and '!~' operators (*note Regexp Usage::). - * The escape sequences `\b', `\f', and `\r' (*note Escape + * The escape sequences '\b', '\f', and '\r' (*note Escape Sequences::). (Some vendors have updated their old versions of - `awk' to recognize `\b', `\f', and `\r', but this is not something + 'awk' to recognize '\b', '\f', and '\r', but this is not something you can rely on.) - * Redirection of input for the `getline' function (*note Getline::). + * Redirection of input for the 'getline' function (*note Getline::). - * Multiple `BEGIN' and `END' rules (*note BEGIN/END::). + * Multiple 'BEGIN' and 'END' rules (*note BEGIN/END::). * Multidimensional arrays (*note Multidimensional::). @@ -25887,36 +25781,36 @@ File: gawk.info, Node: SVR4, Next: POSIX, Prev: V7/SVR3.1, Up: Language Hist A.2 Changes Between SVR3.1 and SVR4 =================================== -The System V Release 4 (1989) version of Unix `awk' added these features -(some of which originated in `gawk'): +The System V Release 4 (1989) version of Unix 'awk' added these features +(some of which originated in 'gawk'): - * The `ENVIRON' array (*note Built-in Variables::). + * The 'ENVIRON' array (*note Built-in Variables::). - * Multiple `-f' options on the command line (*note Options::). + * Multiple '-f' options on the command line (*note Options::). - * The `-v' option for assigning variables before program execution + * The '-v' option for assigning variables before program execution begins (*note Options::). - * The `--' option for terminating command-line options. + * The '--' option for terminating command-line options. - * The `\a', `\v', and `\x' escape sequences (*note Escape + * The '\a', '\v', and '\x' escape sequences (*note Escape Sequences::). - * A defined return value for the `srand()' built-in function (*note + * A defined return value for the 'srand()' built-in function (*note Numeric Functions::). - * The `toupper()' and `tolower()' built-in string functions for case + * The 'toupper()' and 'tolower()' built-in string functions for case translation (*note String Functions::). - * A cleaner specification for the `%c' format-control letter in the - `printf' function (*note Control Letters::). + * A cleaner specification for the '%c' format-control letter in the + 'printf' function (*note Control Letters::). * The ability to dynamically pass the field width and precision - (`"%*.*d"') in the argument list of the `printf' function (*note + ('"%*.*d"') in the argument list of the 'printf' function (*note Control Letters::). - * The use of regexp constants, such as `/foo/', as expressions, where - they are equivalent to using the matching operator, as in `$0 ~ + * The use of regexp constants, such as '/foo/', as expressions, where + they are equivalent to using the matching operator, as in '$0 ~ /foo/' (*note Using Constant Regexps::). * Processing of escape sequences inside command-line variable @@ -25925,16 +25819,16 @@ The System V Release 4 (1989) version of Unix `awk' added these features  File: gawk.info, Node: POSIX, Next: BTL, Prev: SVR4, Up: Language History -A.3 Changes Between SVR4 and POSIX `awk' +A.3 Changes Between SVR4 and POSIX 'awk' ======================================== -The POSIX Command Language and Utilities standard for `awk' (1992) +The POSIX Command Language and Utilities standard for 'awk' (1992) introduced the following changes into the language: - * The use of `-W' for implementation-specific options (*note + * The use of '-W' for implementation-specific options (*note Options::). - * The use of `CONVFMT' for controlling the conversion of numbers to + * The use of 'CONVFMT' for controlling the conversion of numbers to strings (*note Conversion::). * The concept of a numeric string and tighter comparison rules to go @@ -25949,90 +25843,88 @@ introduced the following changes into the language: In 2012, a number of extensions that had been commonly available for many years were finally added to POSIX. They are: - * The `fflush()' built-in function for flushing buffered output + * The 'fflush()' built-in function for flushing buffered output (*note I/O Functions::). - * The `nextfile' statement (*note Nextfile Statement::). + * The 'nextfile' statement (*note Nextfile Statement::). - * The ability to delete all of an array at once with `delete ARRAY' + * The ability to delete all of an array at once with 'delete ARRAY' (*note Delete::). - *Note Common Extensions::, for a list of common extensions not permitted by the POSIX standard. The 2008 POSIX standard can be found online at -`http://www.opengroup.org/onlinepubs/9699919799/'. +.  File: gawk.info, Node: BTL, Next: POSIX/GNU, Prev: POSIX, Up: Language History -A.4 Extensions in Brian Kernighan's `awk' +A.4 Extensions in Brian Kernighan's 'awk' ========================================= Brian Kernighan has made his version available via his home page (*note Other Versions::). This minor node describes common extensions that originally appeared -in his version of `awk'. +in his version of 'awk'. - * The `**' and `**=' operators (*note Arithmetic Ops:: and *note + * The '**' and '**=' operators (*note Arithmetic Ops:: and *note Assignment Ops::). - * The use of `func' as an abbreviation for `function' (*note + * The use of 'func' as an abbreviation for 'function' (*note Definition Syntax::). - * The `fflush()' built-in function for flushing buffered output + * The 'fflush()' built-in function for flushing buffered output (*note I/O Functions::). - *Note Common Extensions::, for a full list of the extensions -available in his `awk'. +available in his 'awk'.  File: gawk.info, Node: POSIX/GNU, Next: Feature History, Prev: BTL, Up: Language History -A.5 Extensions in `gawk' Not in POSIX `awk' +A.5 Extensions in 'gawk' Not in POSIX 'awk' =========================================== -The GNU implementation, `gawk', adds a large number of features. They -can all be disabled with either the `--traditional' or `--posix' options +The GNU implementation, 'gawk', adds a large number of features. They +can all be disabled with either the '--traditional' or '--posix' options (*note Options::). - A number of features have come and gone over the years. This minor -node summarizes the additional features over POSIX `awk' that are in -the current version of `gawk'. + A number of features have come and gone over the years. This minor +node summarizes the additional features over POSIX 'awk' that are in the +current version of 'gawk'. * Additional built-in variables: - - The `ARGIND' `BINMODE', `ERRNO', `FIELDWIDTHS', `FPAT', - `IGNORECASE', `LINT', `PROCINFO', `RT', and `TEXTDOMAIN' + - The 'ARGIND' 'BINMODE', 'ERRNO', 'FIELDWIDTHS', 'FPAT', + 'IGNORECASE', 'LINT', 'PROCINFO', 'RT', and 'TEXTDOMAIN' variables (*note Built-in Variables::). * Special files in I/O redirections: - - The `/dev/stdin', `/dev/stdout', `/dev/stderr' and - `/dev/fd/N' special file names (*note Special Files::). + - The '/dev/stdin', '/dev/stdout', '/dev/stderr' and '/dev/fd/N' + special file names (*note Special Files::). - - The `/inet', `/inet4', and `/inet6' special files for TCP/IP - networking using `|&' to specify which version of the IP + - The '/inet', '/inet4', and '/inet6' special files for TCP/IP + networking using '|&' to specify which version of the IP protocol to use. (*note TCP/IP Networking::). * Changes and/or additions to the language: - - The `\x' escape sequence (*note Escape Sequences::). + - The '\x' escape sequence (*note Escape Sequences::). - Full support for both POSIX and GNU regexps (*note Regexp::). - - The ability for `FS' and for the third argument to `split()' + - The ability for 'FS' and for the third argument to 'split()' to be null strings (*note Single Character Fields::). - - The ability for `RS' to be a regexp (*note Records::). + - The ability for 'RS' to be a regexp (*note Records::). - - The ability to use octal and hexadecimal constants in `awk' + - The ability to use octal and hexadecimal constants in 'awk' program source code (*note Nondecimal-numbers::). - - The `|&' operator for two-way I/O to a coprocess (*note + - The '|&' operator for two-way I/O to a coprocess (*note Two-way I/O::). - Indirect function calls (*note Indirect Calls::). @@ -26042,83 +25934,83 @@ the current version of `gawk'. * New keywords: - - The `BEGINFILE' and `ENDFILE' special patterns. (*note + - The 'BEGINFILE' and 'ENDFILE' special patterns. (*note BEGINFILE/ENDFILE::). - - The ability to delete all of an array at once with `delete + - The ability to delete all of an array at once with 'delete ARRAY' (*note Delete::). - - The `nextfile' statement (*note Nextfile Statement::). + - The 'nextfile' statement (*note Nextfile Statement::). - - The `switch' statement (*note Switch Statement::). + - The 'switch' statement (*note Switch Statement::). - * Changes to standard `awk' functions: + * Changes to standard 'awk' functions: - - The optional second argument to `close()' that allows closing + - The optional second argument to 'close()' that allows closing one end of a two-way pipe to a coprocess (*note Two-way I/O::). - - POSIX compliance for `gsub()' and `sub()'. + - POSIX compliance for 'gsub()' and 'sub()'. - - The `length()' function accepts an array argument and returns + - The 'length()' function accepts an array argument and returns the number of elements in the array (*note String Functions::). - - The optional third argument to the `match()' function for + - The optional third argument to the 'match()' function for capturing text-matching subexpressions within a regexp (*note String Functions::). - - Positional specifiers in `printf' formats for making + - Positional specifiers in 'printf' formats for making translations easier (*note Printf Ordering::). - - The `split()' function's additional optional fourth argument + - The 'split()' function's additional optional fourth argument which is an array to hold the text of the field separators. (*note String Functions::). - * Additional functions only in `gawk': + * Additional functions only in 'gawk': - - The `and()', `compl()', `lshift()', `or()', `rshift()', and - `xor()' functions for bit manipulation (*note Bitwise + - The 'and()', 'compl()', 'lshift()', 'or()', 'rshift()', and + 'xor()' functions for bit manipulation (*note Bitwise Functions::). - - The `asort()' and `asorti()' functions for sorting arrays + - The 'asort()' and 'asorti()' functions for sorting arrays (*note Array Sorting::). - - The `bindtextdomain()', `dcgettext()' and `dcngettext()' + - The 'bindtextdomain()', 'dcgettext()' and 'dcngettext()' functions for internationalization (*note Programmer i18n::). - - The `fflush()' function from Brian Kernighan's version of - `awk' (*note I/O Functions::). + - The 'fflush()' function from Brian Kernighan's version of + 'awk' (*note I/O Functions::). - - The `gensub()', `patsplit()', and `strtonum()' functions for + - The 'gensub()', 'patsplit()', and 'strtonum()' functions for more powerful text manipulation (*note String Functions::). - - The `mktime()', `systime()', and `strftime()' functions for + - The 'mktime()', 'systime()', and 'strftime()' functions for working with timestamps (*note Time Functions::). * Changes and/or additions in the command-line options: - - The `AWKPATH' environment variable for specifying a path - search for the `-f' command-line option (*note Options::). - - - The `AWKLIBPATH' environment variable for specifying a path - search for the `-l' command-line option (*note Options::). - - - The `-b', `-c', `-C', `-d', `-D', `-e', `-E', `-g', `-h', - `-i', `-l', `-L', `-M', `-n', `-N', `-o', `-O', `-p', `-P', - `-r', `-S', `-t', and `-V' short options. Also, the ability - to use GNU-style long-named options that start with `--' and - the `--assign', `--bignum', `--characters-as-bytes', - `--copyright', `--debug', `--dump-variables', `--execle', - `--field-separator', `--file', `--gen-pot', `--help', - `--include', `--lint', `--lint-old', `--load', - `--non-decimal-data', `--optimize', `--posix', - `--pretty-print', `--profile', `--re-interval', `--sandbox', - `--source', `--traditional', `--use-lc-numeric', and - `--version' long options (*note Options::). + - The 'AWKPATH' environment variable for specifying a path + search for the '-f' command-line option (*note Options::). + + - The 'AWKLIBPATH' environment variable for specifying a path + search for the '-l' command-line option (*note Options::). + + - The '-b', '-c', '-C', '-d', '-D', '-e', '-E', '-g', '-h', + '-i', '-l', '-L', '-M', '-n', '-N', '-o', '-O', '-p', '-P', + '-r', '-S', '-t', and '-V' short options. Also, the ability + to use GNU-style long-named options that start with '--' and + the '--assign', '--bignum', '--characters-as-bytes', + '--copyright', '--debug', '--dump-variables', '--execle', + '--field-separator', '--file', '--gen-pot', '--help', + '--include', '--lint', '--lint-old', '--load', + '--non-decimal-data', '--optimize', '--posix', + '--pretty-print', '--profile', '--re-interval', '--sandbox', + '--source', '--traditional', '--use-lc-numeric', and + '--version' long options (*note Options::). * Support for the following obsolete systems was removed from the - code and the documentation for `gawk' version 4.0: + code and the documentation for 'gawk' version 4.0: - Amiga @@ -26144,216 +26036,213 @@ the current version of `gawk'. - GCC for VAX and Alpha has not been tested for a while. - * Support for the following obsolete systems was removed from the - code and the documentation for `gawk' version 4.1: + code and the documentation for 'gawk' version 4.1: - Ultrix -  File: gawk.info, Node: Feature History, Next: Common Extensions, Prev: POSIX/GNU, Up: Language History -A.6 History of `gawk' Features +A.6 History of 'gawk' Features ============================== -This minor node describes the features in `gawk' over and above those -in POSIX `awk', in the order they were added to `gawk'. +This minor node describes the features in 'gawk' over and above those in +POSIX 'awk', in the order they were added to 'gawk'. - Version 2.10 of `gawk' introduced the following features: + Version 2.10 of 'gawk' introduced the following features: - * The `AWKPATH' environment variable for specifying a path search for - the `-f' command-line option (*note Options::). + * The 'AWKPATH' environment variable for specifying a path search for + the '-f' command-line option (*note Options::). - * The `IGNORECASE' variable and its effects (*note + * The 'IGNORECASE' variable and its effects (*note Case-sensitivity::). - * The `/dev/stdin', `/dev/stdout', `/dev/stderr' and `/dev/fd/N' + * The '/dev/stdin', '/dev/stdout', '/dev/stderr' and '/dev/fd/N' special file names (*note Special Files::). - Version 2.13 of `gawk' introduced the following features: + Version 2.13 of 'gawk' introduced the following features: - * The `FIELDWIDTHS' variable and its effects (*note Constant Size::). + * The 'FIELDWIDTHS' variable and its effects (*note Constant Size::). - * The `systime()' and `strftime()' built-in functions for obtaining + * The 'systime()' and 'strftime()' built-in functions for obtaining and printing timestamps (*note Time Functions::). * Additional command-line options (*note Options::): - - The `-W lint' option to provide error and portability checking + - The '-W lint' option to provide error and portability checking for both the source code and at runtime. - - The `-W compat' option to turn off the GNU extensions. + - The '-W compat' option to turn off the GNU extensions. - - The `-W posix' option for full POSIX compliance. + - The '-W posix' option for full POSIX compliance. - Version 2.14 of `gawk' introduced the following feature: + Version 2.14 of 'gawk' introduced the following feature: - * The `next file' statement for skipping to the next data file - (*note Nextfile Statement::). + * The 'next file' statement for skipping to the next data file (*note + Nextfile Statement::). - Version 2.15 of `gawk' introduced the following features: + Version 2.15 of 'gawk' introduced the following features: * New variables (*note Built-in Variables::): - - `ARGIND', which tracks the movement of `FILENAME' through - `ARGV'. + - 'ARGIND', which tracks the movement of 'FILENAME' through + 'ARGV'. - - `ERRNO', which contains the system error message when - `getline' returns -1 or `close()' fails. + - 'ERRNO', which contains the system error message when + 'getline' returns -1 or 'close()' fails. - * The `/dev/pid', `/dev/ppid', `/dev/pgrpid', and `/dev/user' - special file names. These have since been removed. + * The '/dev/pid', '/dev/ppid', '/dev/pgrpid', and '/dev/user' special + file names. These have since been removed. - * The ability to delete all of an array at once with `delete ARRAY' + * The ability to delete all of an array at once with 'delete ARRAY' (*note Delete::). * Command line option changes (*note Options::): - The ability to use GNU-style long-named options that start - with `--'. + with '--'. - - The `--source' option for mixing command-line and library-file + - The '--source' option for mixing command-line and library-file source code. - Version 3.0 of `gawk' introduced the following features: + Version 3.0 of 'gawk' introduced the following features: * New or changed variables: - - `IGNORECASE' changed, now applying to string comparison as + - 'IGNORECASE' changed, now applying to string comparison as well as regexp operations (*note Case-sensitivity::). - - `RT', which contains the input text that matched `RS' (*note + - 'RT', which contains the input text that matched 'RS' (*note Records::). * Full support for both POSIX and GNU regexps (*note Regexp::). - * The `gensub()' function for more powerful text manipulation (*note + * The 'gensub()' function for more powerful text manipulation (*note String Functions::). - * The `strftime()' function acquired a default time format, allowing + * The 'strftime()' function acquired a default time format, allowing it to be called with no arguments (*note Time Functions::). - * The ability for `FS' and for the third argument to `split()' to be + * The ability for 'FS' and for the third argument to 'split()' to be null strings (*note Single Character Fields::). - * The ability for `RS' to be a regexp (*note Records::). + * The ability for 'RS' to be a regexp (*note Records::). - * The `next file' statement became `nextfile' (*note Nextfile + * The 'next file' statement became 'nextfile' (*note Nextfile Statement::). - * The `fflush()' function from Brian Kernighan's `awk' (then at Bell + * The 'fflush()' function from Brian Kernighan's 'awk' (then at Bell Laboratories; *note I/O Functions::). * New command line options: - - The `--lint-old' option to warn about constructs that are not - available in the original Version 7 Unix version of `awk' + - The '--lint-old' option to warn about constructs that are not + available in the original Version 7 Unix version of 'awk' (*note V7/SVR3.1::). - - The `-m' option from Brian Kernighan's `awk'. (He was still + - The '-m' option from Brian Kernighan's 'awk'. (He was still at Bell Laboratories at the time.) This was later removed - from both his `awk' and from `gawk'. + from both his 'awk' and from 'gawk'. - - The `--re-interval' option to provide interval expressions in + - The '--re-interval' option to provide interval expressions in regexps (*note Regexp Operators::). - - The `--traditional' option was added as a better name for - `--compat' (*note Options::). + - The '--traditional' option was added as a better name for + '--compat' (*note Options::). - * The use of GNU Autoconf to control the configuration process - (*note Quick Installation::). + * The use of GNU Autoconf to control the configuration process (*note + Quick Installation::). * Amiga support. This has since been removed. - - Version 3.1 of `gawk' introduced the following features: + Version 3.1 of 'gawk' introduced the following features: * New variables (*note Built-in Variables::): - - `BINMODE', for non-POSIX systems, which allows binary I/O for + - 'BINMODE', for non-POSIX systems, which allows binary I/O for input and/or output files (*note PC Using::). - - `LINT', which dynamically controls lint warnings. + - 'LINT', which dynamically controls lint warnings. - - `PROCINFO', an array for providing process-related + - 'PROCINFO', an array for providing process-related information. - - `TEXTDOMAIN', for setting an application's + - 'TEXTDOMAIN', for setting an application's internationalization text domain (*note Internationalization::). - * The ability to use octal and hexadecimal constants in `awk' - program source code (*note Nondecimal-numbers::). + * The ability to use octal and hexadecimal constants in 'awk' program + source code (*note Nondecimal-numbers::). - * The `|&' operator for two-way I/O to a coprocess (*note Two-way + * The '|&' operator for two-way I/O to a coprocess (*note Two-way I/O::). - * The `/inet' special files for TCP/IP networking using `|&' (*note + * The '/inet' special files for TCP/IP networking using '|&' (*note TCP/IP Networking::). - * The optional second argument to `close()' that allows closing one + * The optional second argument to 'close()' that allows closing one end of a two-way pipe to a coprocess (*note Two-way I/O::). - * The optional third argument to the `match()' function for - capturing text-matching subexpressions within a regexp (*note - String Functions::). + * The optional third argument to the 'match()' function for capturing + text-matching subexpressions within a regexp (*note String + Functions::). - * Positional specifiers in `printf' formats for making translations + * Positional specifiers in 'printf' formats for making translations easier (*note Printf Ordering::). * A number of new built-in functions: - - The `asort()' and `asorti()' functions for sorting arrays + - The 'asort()' and 'asorti()' functions for sorting arrays (*note Array Sorting::). - - The `bindtextdomain()', `dcgettext()' and `dcngettext()' + - The 'bindtextdomain()', 'dcgettext()' and 'dcngettext()' functions for internationalization (*note Programmer i18n::). - - The `extension()' function and the ability to add new - built-in functions dynamically (*note Dynamic Extensions::). + - The 'extension()' function and the ability to add new built-in + functions dynamically (*note Dynamic Extensions::). - - The `mktime()' function for creating timestamps (*note Time + - The 'mktime()' function for creating timestamps (*note Time Functions::). - - The `and()', `or()', `xor()', `compl()', `lshift()', - `rshift()', and `strtonum()' functions (*note Bitwise + - The 'and()', 'or()', 'xor()', 'compl()', 'lshift()', + 'rshift()', and 'strtonum()' functions (*note Bitwise Functions::). - * The support for `next file' as two words was removed completely + * The support for 'next file' as two words was removed completely (*note Nextfile Statement::). * Additional command-line options (*note Options::): - - The `--dump-variables' option to print a list of all global + - The '--dump-variables' option to print a list of all global variables. - - The `--exec' option, for use in CGI scripts. + - The '--exec' option, for use in CGI scripts. - - The `--gen-po' command-line option and the use of a leading + - The '--gen-po' command-line option and the use of a leading underscore to mark strings that should be translated (*note String Extraction::). - - The `--non-decimal-data' option to allow non-decimal input + - The '--non-decimal-data' option to allow non-decimal input data (*note Nondecimal Data::). - - The `--profile' option and `pgawk', the profiling version of - `gawk', for producing execution profiles of `awk' programs + - The '--profile' option and 'pgawk', the profiling version of + 'gawk', for producing execution profiles of 'awk' programs (*note Profiling::). - - The `--use-lc-numeric' option to force `gawk' to use the + - The '--use-lc-numeric' option to force 'gawk' to use the locale's decimal point for parsing input data (*note Conversion::). * The use of GNU Automake to help in standardizing the configuration process (*note Quick Installation::). - * The use of GNU `gettext' for `gawk''s own message output (*note + * The use of GNU 'gettext' for 'gawk''s own message output (*note Gawk I18N::). - * BeOS support. This was later removed. + * BeOS support. This was later removed. - * Tandem support. This was later removed. + * Tandem support. This was later removed. * The Atari port became officially unsupported and was later removed entirely. @@ -26361,119 +26250,119 @@ in POSIX `awk', in the order they were added to `gawk'. * The source code changed to use ISO C standard-style function definitions. - * POSIX compliance for `sub()' and `gsub()' (*note Gory Details::). + * POSIX compliance for 'sub()' and 'gsub()' (*note Gory Details::). - * The `length()' function was extended to accept an array argument + * The 'length()' function was extended to accept an array argument and return the number of elements in the array (*note String Functions::). - * The `strftime()' function acquired a third argument to enable + * The 'strftime()' function acquired a third argument to enable printing times as UTC (*note Time Functions::). - Version 4.0 of `gawk' introduced the following features: + Version 4.0 of 'gawk' introduced the following features: * Variable additions: - - `FPAT', which allows you to specify a regexp that matches the + - 'FPAT', which allows you to specify a regexp that matches the fields, instead of matching the field separator (*note Splitting By Content::). - - If `PROCINFO["sorted_in"]' exists, `for(iggy in foo)' loops + - If 'PROCINFO["sorted_in"]' exists, 'for(iggy in foo)' loops sort the indices before looping over them. The value of this element provides control over how the indices are sorted before the loop traversal starts (*note Controlling Scanning::). - - `PROCINFO["strftime"]', which holds the default format for - `strftime()' (*note Time Functions::). + - 'PROCINFO["strftime"]', which holds the default format for + 'strftime()' (*note Time Functions::). - * The special files `/dev/pid', `/dev/ppid', `/dev/pgrpid' and - `/dev/user' were removed. + * The special files '/dev/pid', '/dev/ppid', '/dev/pgrpid' and + '/dev/user' were removed. - * Support for IPv6 was added via the `/inet6' special file. - `/inet4' forces IPv4 and `/inet' chooses the system default, which - is probably IPv4 (*note TCP/IP Networking::). + * Support for IPv6 was added via the '/inet6' special file. '/inet4' + forces IPv4 and '/inet' chooses the system default, which is + probably IPv4 (*note TCP/IP Networking::). - * The use of `\s' and `\S' escape sequences in regular expressions + * The use of '\s' and '\S' escape sequences in regular expressions (*note GNU Regexp Operators::). * Interval expressions became part of default regular expressions (*note Regexp Operators::). - * POSIX character classes work even with `--traditional' (*note + * POSIX character classes work even with '--traditional' (*note Regexp Operators::). - * `break' and `continue' became invalid outside a loop, even with - `--traditional' (*note Break Statement::, and also see *note + * 'break' and 'continue' became invalid outside a loop, even with + '--traditional' (*note Break Statement::, and also see *note Continue Statement::). - * `fflush()', `nextfile', and `delete ARRAY' are allowed if - `--posix' or `--traditional', since they are all now part of POSIX. + * 'fflush()', 'nextfile', and 'delete ARRAY' are allowed if '--posix' + or '--traditional', since they are all now part of POSIX. - * An optional third argument to `asort()' and `asorti()', specifying + * An optional third argument to 'asort()' and 'asorti()', specifying how to sort (*note String Functions::). - * The behavior of `fflush()' changed to match Brian Kernighan's `awk' - and for POSIX; now both `fflush()' and `fflush("")' flush all open + * The behavior of 'fflush()' changed to match Brian Kernighan's 'awk' + and for POSIX; now both 'fflush()' and 'fflush("")' flush all open output redirections (*note I/O Functions::). - * The `isarray()' function which distinguishes if an item is an array + * The 'isarray()' function which distinguishes if an item is an array or not, to make it possible to traverse arrays of arrays (*note Type Functions::). - * The `patsplit()' function which gives the same capability as - `FPAT', for splitting (*note String Functions::). + * The 'patsplit()' function which gives the same capability as + 'FPAT', for splitting (*note String Functions::). - * An optional fourth argument to the `split()' function, which is an + * An optional fourth argument to the 'split()' function, which is an array to hold the values of the separators (*note String Functions::). * Arrays of arrays (*note Arrays of Arrays::). - * The `BEGINFILE' and `ENDFILE' special patterns (*note + * The 'BEGINFILE' and 'ENDFILE' special patterns (*note BEGINFILE/ENDFILE::). * Indirect function calls (*note Indirect Calls::). - * `switch' / `case' are enabled by default (*note Switch + * 'switch' / 'case' are enabled by default (*note Switch Statement::). * Command line option changes (*note Options::): - - The `-b' and `--characters-as-bytes' options which prevent - `gawk' from treating input as a multibyte string. + - The '-b' and '--characters-as-bytes' options which prevent + 'gawk' from treating input as a multibyte string. - - The redundant `--compat', `--copyleft', and `--usage' long + - The redundant '--compat', '--copyleft', and '--usage' long options were removed. - - The `--gen-po' option was finally renamed to the correct - `--gen-pot'. + - The '--gen-po' option was finally renamed to the correct + '--gen-pot'. - - The `--sandbox' option which disables certain features. + - The '--sandbox' option which disables certain features. - - All long options acquired corresponding short options, for - use in `#!' scripts. + - All long options acquired corresponding short options, for use + in '#!' scripts. * Directories named on the command line now produce a warning, not a - fatal error, unless `--posix' or `--traditional' are used (*note + fatal error, unless '--posix' or '--traditional' are used (*note Command line directories::). - * The `gawk' internals were rewritten, bringing the `dgawk' debugger + * The 'gawk' internals were rewritten, bringing the 'dgawk' debugger and possibly improved performance (*note Debugger::). * Per the GNU Coding Standards, dynamic extensions must now define a - global symbol indicating that they are GPL-compatible (*note - Plugin License::). + global symbol indicating that they are GPL-compatible (*note Plugin + License::). - * In POSIX mode, string comparisons use `strcoll()' / `wcscoll()' + * In POSIX mode, string comparisons use 'strcoll()' / 'wcscoll()' (*note POSIX String Comparison::). * The option for raw sockets was removed, since it was never implemented (*note TCP/IP Networking::). - * Ranges of the form `[d-h]' are treated as if they were in the C + * Ranges of the form '[d-h]' are treated as if they were in the C locale, no matter what kind of regexp is being used, and even if - `--posix' (*note Ranges and Locales::). + '--posix' (*note Ranges and Locales::). * Support was removed for the following systems: @@ -26499,72 +26388,71 @@ in POSIX `awk', in the order they were added to `gawk'. - Prestandard VAX C compiler for VAX/VMS - Version 4.1 of `gawk' introduced the following features: + Version 4.1 of 'gawk' introduced the following features: - * Three new arrays: `SYMTAB', `FUNCTAB', and - `PROCINFO["identifiers"]' (*note Auto-set::). + * Three new arrays: 'SYMTAB', 'FUNCTAB', and + 'PROCINFO["identifiers"]' (*note Auto-set::). - * The three executables `gawk', `pgawk', and `dgawk', were merged - into one, named just `gawk'. As a result the command line options + * The three executables 'gawk', 'pgawk', and 'dgawk', were merged + into one, named just 'gawk'. As a result the command line options changed. * Command line option changes (*note Options::): - - The `-D' option invokes the debugger. + - The '-D' option invokes the debugger. - - The `-i' and `--include' options load `awk' library files. + - The '-i' and '--include' options load 'awk' library files. - - The `-l' and `--load' options load compiled dynamic + - The '-l' and '--load' options load compiled dynamic extensions. - - The `-M' and `--bignum' options enable MPFR. + - The '-M' and '--bignum' options enable MPFR. - - The `-o' only does pretty-printing. + - The '-o' only does pretty-printing. - - The `-p' option is used for profiling. + - The '-p' option is used for profiling. - - The `-R' option was removed. + - The '-R' option was removed. - * Support for high precision arithmetic with MPFR. (*note Arbitrary + * Support for high precision arithmetic with MPFR. (*note Arbitrary Precision Arithmetic::). - * The `and()', `or()' and `xor()' functions changed to allow any + * The 'and()', 'or()' and 'xor()' functions changed to allow any number of arguments, with a minimum of two (*note Bitwise Functions::). * The dynamic extension interface was completely redone (*note Dynamic Extensions::). -  File: gawk.info, Node: Common Extensions, Next: Ranges and Locales, Prev: Feature History, Up: Language History A.7 Common Extensions Summary ============================= -This minor node summarizes the common extensions supported by `gawk', -Brian Kernighan's `awk', and `mawk', the three most widely-used freely -available versions of `awk' (*note Other Versions::). +This minor node summarizes the common extensions supported by 'gawk', +Brian Kernighan's 'awk', and 'mawk', the three most widely-used freely +available versions of 'awk' (*note Other Versions::). Feature BWK Awk Mawk GNU Awk --------------------------------------------------------- -`\x' Escape sequence X X X -`FS' as null string X X X -`/dev/stdin' special file X X X -`/dev/stdout' special file X X X -`/dev/stderr' special file X X X -`delete' without subscript X X X -`fflush()' function X X X -`length()' of an array X X X -`nextfile' statement X X X -`**' and `**=' operators X X -`func' keyword X X -`BINMODE' variable X X -`RS' as regexp X X +-------------------------------------------------------- +'\x' Escape sequence X X X +'FS' as null string X X X +'/dev/stdin' special file X X X +'/dev/stdout' special file X X X +'/dev/stderr' special file X X X +'delete' without subscript X X X +'fflush()' function X X X +'length()' of an array X X X +'nextfile' statement X X X +'**' and '**=' operators X X +'func' keyword X X +'BINMODE' variable X X +'RS' as regexp X X Time related functions X X - (Technically speaking, as of late 2012, `fflush()', `delete ARRAY', -and `nextfile' are no longer extensions, since they have been added to + (Technically speaking, as of late 2012, 'fflush()', 'delete ARRAY', +and 'nextfile' are no longer extensions, since they have been added to POSIX.)  @@ -26573,24 +26461,24 @@ File: gawk.info, Node: Ranges and Locales, Next: Contributors, Prev: Common E A.8 Regexp Ranges and Locales: A Long Sad Story =============================================== -This minor node describes the confusing history of ranges within -regular expressions and their interactions with locales, and how this -affected different versions of `gawk'. +This minor node describes the confusing history of ranges within regular +expressions and their interactions with locales, and how this affected +different versions of 'gawk'. The original Unix tools that worked with regular expressions defined -character ranges (such as `[a-z]') to match any character between the +character ranges (such as '[a-z]') to match any character between the first character in the range and the last character in the range, -inclusive. Ordering was based on the numeric value of each character -in the machine's native character set. Thus, on ASCII-based systems, -`[a-z]' matched all the lowercase letters, and only the lowercase -letters, since the numeric values for the letters from `a' through `z' -were contiguous. (On an EBCDIC system, the range `[a-z]' includes +inclusive. Ordering was based on the numeric value of each character in +the machine's native character set. Thus, on ASCII-based systems, +'[a-z]' matched all the lowercase letters, and only the lowercase +letters, since the numeric values for the letters from 'a' through 'z' +were contiguous. (On an EBCDIC system, the range '[a-z]' includes additional, non-alphabetic characters as well.) Almost all introductory Unix literature explained range expressions as working in this fashion, and in particular, would teach that the -"correct" way to match lowercase letters was with `[a-z]', and that -`[A-Z]' was the "correct" way to match uppercase letters. And indeed, +"correct" way to match lowercase letters was with '[a-z]', and that +'[A-Z]' was the "correct" way to match uppercase letters. And indeed, this was true.(1) The 1992 POSIX standard introduced the idea of locales (*note @@ -26601,63 +26489,63 @@ different kinds of characters besides the traditional ones in the ASCII character set. However, the standard _changed_ the interpretation of range -expressions. In the `"C"' and `"POSIX"' locales, a range expression -like `[a-dx-z]' is still equivalent to `[abcdxyz]', as in ASCII. But +expressions. In the '"C"' and '"POSIX"' locales, a range expression +like '[a-dx-z]' is still equivalent to '[abcdxyz]', as in ASCII. But outside those locales, the ordering was defined to be based on "collation order". - In many locales, `A' and `a' are both less than `B'. In other -words, these locales sort characters in dictionary order, and -`[a-dx-z]' is typically not equivalent to `[abcdxyz]'; instead it might -be equivalent to `[ABCXYabcdxyz]', for example. + In many locales, 'A' and 'a' are both less than 'B'. In other words, +these locales sort characters in dictionary order, and '[a-dx-z]' is +typically not equivalent to '[abcdxyz]'; instead it might be equivalent +to '[ABCXYabcdxyz]', for example. This point needs to be emphasized: Much literature teaches that you -should use `[a-z]' to match a lowercase character. But on systems with +should use '[a-z]' to match a lowercase character. But on systems with non-ASCII locales, this also matched all of the uppercase characters -except `A' or `Z'! This was a continuous cause of confusion, even well +except 'A' or 'Z'! This was a continuous cause of confusion, even well into the twenty-first century. - To demonstrate these issues, the following example uses the `sub()' + To demonstrate these issues, the following example uses the 'sub()' function, which does text replacement (*note String Functions::). Here, the intent is to remove trailing uppercase characters: $ echo something1234abc | gawk-3.1.8 '{ sub("[A-Z]*$", ""); print }' -| something1234a -This output is unexpected, since the `bc' at the end of -`something1234abc' should not normally match `[A-Z]*'. This result is +This output is unexpected, since the 'bc' at the end of +'something1234abc' should not normally match '[A-Z]*'. This result is due to the locale setting (and thus you may not see it on your system). - Similar considerations apply to other ranges. For example, `["-/]' + Similar considerations apply to other ranges. For example, '["-/]' is perfectly valid in ASCII, but is not valid in many Unicode locales, -such as `en_US.UTF-8'. +such as 'en_US.UTF-8'. - Early versions of `gawk' used regexp matching code that was not + Early versions of 'gawk' used regexp matching code that was not locale aware, so ranges had their traditional interpretation. - When `gawk' switched to using locale-aware regexp matchers, the -problems began; especially as both GNU/Linux and commercial Unix -vendors started implementing non-ASCII locales, _and making them the -default_. Perhaps the most frequently asked question became something -like "why does `[A-Z]' match lowercase letters?!?" + When 'gawk' switched to using locale-aware regexp matchers, the +problems began; especially as both GNU/Linux and commercial Unix vendors +started implementing non-ASCII locales, _and making them the default_. +Perhaps the most frequently asked question became something like "why +does '[A-Z]' match lowercase letters?!?" This situation existed for close to 10 years, if not more, and the -`gawk' maintainer grew weary of trying to explain that `gawk' was being -nicely standards-compliant, and that the issue was in the user's -locale. During the development of version 4.0, he modified `gawk' to -always treat ranges in the original, pre-POSIX fashion, unless -`--posix' was used (*note Options::).(2) +'gawk' maintainer grew weary of trying to explain that 'gawk' was being +nicely standards-compliant, and that the issue was in the user's locale. +During the development of version 4.0, he modified 'gawk' to always +treat ranges in the original, pre-POSIX fashion, unless '--posix' was +used (*note Options::).(2) - Fortunately, shortly before the final release of `gawk' 4.0, the + Fortunately, shortly before the final release of 'gawk' 4.0, the maintainer learned that the 2008 standard had changed the definition of -ranges, such that outside the `"C"' and `"POSIX"' locales, the meaning +ranges, such that outside the '"C"' and '"POSIX"' locales, the meaning of range expressions was _undefined_.(3) By using this lovely technical term, the standard gives license to implementors to implement ranges in whatever way they choose. The -`gawk' maintainer chose to apply the pre-POSIX meaning in all cases: -the default regexp matching; with `--traditional' and with `--posix'; -in all cases, `gawk' remains POSIX compliant. +'gawk' maintainer chose to apply the pre-POSIX meaning in all cases: the +default regexp matching; with '--traditional' and with '--posix'; in all +cases, 'gawk' remains POSIX compliant. ---------- Footnotes ---------- @@ -26676,17 +26564,18 @@ and its rationale  File: gawk.info, Node: Contributors, Next: History summary, Prev: Ranges and Locales, Up: Language History -A.9 Major Contributors to `gawk' +A.9 Major Contributors to 'gawk' ================================ - Always give credit where credit is due. -- Anonymous + Always give credit where credit is due. + -- _Anonymous_ - This minor node names the major contributors to `gawk' and/or this + This minor node names the major contributors to 'gawk' and/or this Info file, in approximate chronological order: * Dr. Alfred V. Aho, Dr. Peter J. Weinberger, and Dr. Brian W. Kernighan, all of Bell Laboratories, designed and implemented Unix - `awk', from which `gawk' gets the majority of its feature set. + 'awk', from which 'gawk' gets the majority of its feature set. * Paul Rubin did the initial design and implementation in 1986, and wrote the first draft (around 40 pages) of this Info file. @@ -26697,14 +26586,14 @@ Info file, in approximate chronological order: to around 90 pages. * Richard Stallman helped finish the implementation and the initial - draft of this Info file. He is also the founder of the FSF and - the GNU project. + draft of this Info file. He is also the founder of the FSF and the + GNU project. * John Woods contributed parts of the code (mostly fixes) in the - initial version of `gawk'. + initial version of 'gawk'. - * In 1988, David Trueman took over primary maintenance of `gawk', - making it compatible with "new" `awk', and greatly improving its + * In 1988, David Trueman took over primary maintenance of 'gawk', + making it compatible with "new" 'awk', and greatly improving its performance. * Conrad Kwok, Scott Garfinkle, and Kent Williams did the initial @@ -26712,7 +26601,7 @@ Info file, in approximate chronological order: * Pat Rankin provided the VMS port and its documentation. - * Hal Peterson provided help in porting `gawk' to Cray systems. + * Hal Peterson provided help in porting 'gawk' to Cray systems. (This is no longer supported.) * Kai Uwe Rommel provided the initial port to OS/2 and its @@ -26720,8 +26609,8 @@ Info file, in approximate chronological order: * Michal Jaegermann provided the port to Atari systems and its documentation. (This port is no longer supported.) He continues - to provide portability checking, and has done a lot of work to - make sure `gawk' works on non-32-bit systems. + to provide portability checking, and has done a lot of work to make + sure 'gawk' works on non-32-bit systems. * Fred Fish provided the port to Amiga systems and its documentation. (With Fred's sad passing, this is no longer supported.) @@ -26739,18 +26628,18 @@ Info file, in approximate chronological order: instrumental in keeping the documentation up to date for the various PC platforms. - * Christos Zoulas provided the `extension()' built-in function for - dynamically adding new modules. (This was obsoleted at `gawk' + * Christos Zoulas provided the 'extension()' built-in function for + dynamically adding new modules. (This was obsoleted at 'gawk' 4.1.) * Ju"rgen Kahrs contributed the initial version of the TCP/IP networking code and documentation, and motivated the inclusion of - the `|&' operator. + the '|&' operator. * Stephen Davies provided the initial port to Tandem systems and its documentation. (However, this is no longer supported.) He was also instrumental in the initial work to integrate the byte-code - internals into the `gawk' code base. + internals into the 'gawk' code base. * Matthew Woehlke provided improvements for Tandem's POSIX-compliant systems. @@ -26758,19 +26647,19 @@ Info file, in approximate chronological order: * Martin Brown provided the port to BeOS and its documentation. (This is no longer supported.) - * Arno Peters did the initial work to convert `gawk' to use GNU - Automake and GNU `gettext'. + * Arno Peters did the initial work to convert 'gawk' to use GNU + Automake and GNU 'gettext'. - * Alan J. Broder provided the initial version of the `asort()' + * Alan J. Broder provided the initial version of the 'asort()' function as well as the code for the optional third argument to the - `match()' function. + 'match()' function. - * Andreas Buening updated the `gawk' port for OS/2. + * Andreas Buening updated the 'gawk' port for OS/2. * Isamu Hasegawa, of IBM in Japan, contributed support for multibyte characters. - * Michael Benzinger contributed the initial code for `switch' + * Michael Benzinger contributed the initial code for 'switch' statements. * Patrick T.J. McPhee contributed the code for dynamic loading in @@ -26778,12 +26667,12 @@ Info file, in approximate chronological order: * Anders Wallin helped keep the VMS port going for several years. - * Assaf Gordon contributed the code to implement the `--sandbox' + * Assaf Gordon contributed the code to implement the '--sandbox' option. * John Haque made the following contributions: - - The modifications to convert `gawk' into a byte-code + - The modifications to convert 'gawk' into a byte-code interpreter, including the debugger. - The addition of true arrays of arrays. @@ -26793,7 +26682,7 @@ Info file, in approximate chronological order: - The initial text of *note Arbitrary Precision Arithmetic::. - - The work to merge the three versions of `gawk' into one, for + - The work to merge the three versions of 'gawk' into one, for the 4.1 release. - Improved array internals for arrays indexed by integers. @@ -26806,15 +26695,15 @@ Info file, in approximate chronological order: * Efraim Yawitz contributed the original text for *note Debugger::. - * The development of the extension API first released with `gawk' - 4.1 was driven primarily by Arnold Robbins and Andrew Schorr, with + * The development of the extension API first released with 'gawk' 4.1 + was driven primarily by Arnold Robbins and Andrew Schorr, with notable contributions from the rest of the development team. * Antonio Giovanni Colombo rewrote a number of examples in the early chapters that were severely dated, for which I am incredibly grateful. - * Arnold Robbins has been working on `gawk' since 1988, at first + * Arnold Robbins has been working on 'gawk' since 1988, at first helping David Trueman, and as the primary maintainer since around 1994. @@ -26824,62 +26713,61 @@ File: gawk.info, Node: History summary, Prev: Contributors, Up: Language Hist A.10 Summary ============ - * The `awk' language has evolved over time. The first release was + * The 'awk' language has evolved over time. The first release was with V7 Unix circa 1978. In 1987 for System V Release 3.1, major additions, including user-defined functions, were made to the language. Additional changes were made for System V Release 4, in 1989. Since then, further minor changes happen under the auspices of the POSIX standard. - * Brian Kernighan's `awk' provides a small number of extensions that - are implemented in common with other versions of `awk'. + * Brian Kernighan's 'awk' provides a small number of extensions that + are implemented in common with other versions of 'awk'. - * `gawk' provides a large number of extensions over POSIX `awk'. - They can be disabled with either the `--traditional' or `--posix' + * 'gawk' provides a large number of extensions over POSIX 'awk'. + They can be disabled with either the '--traditional' or '--posix' options. - * The interaction of POSIX locales and regexp matching in `gawk' has - been confusing over the years. Today, `gawk' implements Rational - Range Interpretation, where ranges of the form `[a-z]' match - _only_ the characters numerically between `a' through `z' in the - machine's native character set. Usually this is ASCII but it can - be EBCDIC on IBM S/390 systems. + * The interaction of POSIX locales and regexp matching in 'gawk' has + been confusing over the years. Today, 'gawk' implements Rational + Range Interpretation, where ranges of the form '[a-z]' match _only_ + the characters numerically between 'a' through 'z' in the machine's + native character set. Usually this is ASCII but it can be EBCDIC + on IBM S/390 systems. - * Many people have contributed to `gawk' development over the years. + * Many people have contributed to 'gawk' development over the years. We hope that the list provided in this major node is complete and gives the appropriate credit where credit is due. -  File: gawk.info, Node: Installation, Next: Notes, Prev: Language History, Up: Top -Appendix B Installing `gawk' +Appendix B Installing 'gawk' **************************** -This appendix provides instructions for installing `gawk' on the -various platforms that are supported by the developers. The primary -developer supports GNU/Linux (and Unix), whereas the other ports are -contributed. *Note Bugs::, for the electronic mail addresses of the -people who did the respective ports. +This appendix provides instructions for installing 'gawk' on the various +platforms that are supported by the developers. The primary developer +supports GNU/Linux (and Unix), whereas the other ports are contributed. +*Note Bugs::, for the electronic mail addresses of the people who did +the respective ports. * Menu: -* Gawk Distribution:: What is in the `gawk' distribution. -* Unix Installation:: Installing `gawk' under various +* Gawk Distribution:: What is in the 'gawk' distribution. +* Unix Installation:: Installing 'gawk' under various versions of Unix. * Non-Unix Installation:: Installation on Other Operating Systems. * Bugs:: Reporting Problems and Bugs. -* Other Versions:: Other freely available `awk' +* Other Versions:: Other freely available 'awk' implementations. * Installation summary:: Summary of installation.  File: gawk.info, Node: Gawk Distribution, Next: Unix Installation, Up: Installation -B.1 The `gawk' Distribution +B.1 The 'gawk' Distribution =========================== -This minor node describes how to get the `gawk' distribution, how to +This minor node describes how to get the 'gawk' distribution, how to extract it, and then what is in the various files and subdirectories. * Menu: @@ -26891,16 +26779,16 @@ extract it, and then what is in the various files and subdirectories.  File: gawk.info, Node: Getting, Next: Extracting, Up: Gawk Distribution -B.1.1 Getting the `gawk' Distribution +B.1.1 Getting the 'gawk' Distribution ------------------------------------- There are two ways to get GNU software: * Copy it from someone else who already has it. - * Retrieve `gawk' from the Internet host `ftp.gnu.org', in the - directory `/gnu/gawk'. Both anonymous `ftp' and `http' access are - supported. If you have the `wget' program, you can use a command + * Retrieve 'gawk' from the Internet host 'ftp.gnu.org', in the + directory '/gnu/gawk'. Both anonymous 'ftp' and 'http' access are + supported. If you have the 'wget' program, you can use a command like the following: wget http://ftp.gnu.org/gnu/gawk/gawk-4.1.1.tar.gz @@ -26917,285 +26805,283 @@ File: gawk.info, Node: Extracting, Next: Distribution contents, Prev: Getting B.1.2 Extracting the Distribution --------------------------------- -`gawk' is distributed as several `tar' files compressed with different -compression programs: `gzip', `bzip2', and `xz'. For simplicity, the +'gawk' is distributed as several 'tar' files compressed with different +compression programs: 'gzip', 'bzip2', and 'xz'. For simplicity, the rest of these instructions assume you are using the one compressed with -the GNU Zip program, `gzip'. +the GNU Zip program, 'gzip'. - Once you have the distribution (for example, `gawk-4.1.1.tar.gz'), -use `gzip' to expand the file and then use `tar' to extract it. You -can use the following pipeline to produce the `gawk' distribution: + Once you have the distribution (for example, 'gawk-4.1.1.tar.gz'), +use 'gzip' to expand the file and then use 'tar' to extract it. You can +use the following pipeline to produce the 'gawk' distribution: gzip -d -c gawk-4.1.1.tar.gz | tar -xvpf - - On a system with GNU `tar', you can let `tar' do the decompression + On a system with GNU 'tar', you can let 'tar' do the decompression for you: tar -xvpzf gawk-4.1.1.tar.gz -Extracting the archive creates a directory named `gawk-4.1.1' in the +Extracting the archive creates a directory named 'gawk-4.1.1' in the current directory. - The distribution file name is of the form `gawk-V.R.P.tar.gz'. The -V represents the major version of `gawk', the R represents the current -release of version V, and the P represents a "patch level", meaning -that minor bugs have been fixed in the release. The current patch -level is 1, but when retrieving distributions, you should get the -version with the highest version, release, and patch level. (Note, -however, that patch levels greater than or equal to 70 denote "beta" or -nonproduction software; you might not want to retrieve such a version -unless you don't mind experimenting.) If you are not on a Unix or -GNU/Linux system, you need to make other arrangements for getting and -extracting the `gawk' distribution. You should consult a local expert. + The distribution file name is of the form 'gawk-V.R.P.tar.gz'. The V +represents the major version of 'gawk', the R represents the current +release of version V, and the P represents a "patch level", meaning that +minor bugs have been fixed in the release. The current patch level is +1, but when retrieving distributions, you should get the version with +the highest version, release, and patch level. (Note, however, that +patch levels greater than or equal to 70 denote "beta" or nonproduction +software; you might not want to retrieve such a version unless you don't +mind experimenting.) If you are not on a Unix or GNU/Linux system, you +need to make other arrangements for getting and extracting the 'gawk' +distribution. You should consult a local expert.  File: gawk.info, Node: Distribution contents, Prev: Extracting, Up: Gawk Distribution -B.1.3 Contents of the `gawk' Distribution +B.1.3 Contents of the 'gawk' Distribution ----------------------------------------- -The `gawk' distribution has a number of C source files, documentation +The 'gawk' distribution has a number of C source files, documentation files, subdirectories, and files related to the configuration process (*note Unix Installation::), as well as several subdirectories related to different non-Unix operating systems: -Various `.c', `.y', and `.h' files - The actual `gawk' source code. +Various '.c', '.y', and '.h' files + The actual 'gawk' source code. -`ABOUT-NLS' - Information about GNU `gettext' and translations. +'ABOUT-NLS' + Information about GNU 'gettext' and translations. -`AUTHORS' - A file with some information about the authorship of `gawk'. It +'AUTHORS' + A file with some information about the authorship of 'gawk'. It exists only to satisfy the pedants at the Free Software Foundation. -`README' -`README_d/README.*' - Descriptive files: `README' for `gawk' under Unix and the rest for +'README' +'README_d/README.*' + Descriptive files: 'README' for 'gawk' under Unix and the rest for the various hardware and software combinations. -`INSTALL' +'INSTALL' A file providing an overview of the configuration and installation process. -`ChangeLog' +'ChangeLog' A detailed list of source code changes as bugs are fixed or improvements made. -`ChangeLog.0' +'ChangeLog.0' An older list of source code changes. -`NEWS' - A list of changes to `gawk' since the last release or patch. +'NEWS' + A list of changes to 'gawk' since the last release or patch. -`NEWS.0' - An older list of changes to `gawk'. +'NEWS.0' + An older list of changes to 'gawk'. -`COPYING' +'COPYING' The GNU General Public License. -`POSIX.STD' - A description of behaviors in the POSIX standard for `awk' which - are left undefined, or where `gawk' may not comply fully, as well +'POSIX.STD' + A description of behaviors in the POSIX standard for 'awk' which + are left undefined, or where 'gawk' may not comply fully, as well as a list of things that the POSIX standard should describe but does not. -`doc/awkforai.txt' +'doc/awkforai.txt' Pointers to the original draft of a short article describing why - `gawk' is a good language for Artificial Intelligence (AI) + 'gawk' is a good language for Artificial Intelligence (AI) programming. -`doc/bc_notes' - A brief description of `gawk''s "byte code" internals. - -`doc/README.card' -`doc/ad.block' -`doc/awkcard.in' -`doc/cardfonts' -`doc/colors' -`doc/macros' -`doc/no.colors' -`doc/setter.outline' - The `troff' source for a five-color `awk' reference card. A - modern version of `troff' such as GNU `troff' (`groff') is needed - to produce the color version. See the file `README.card' for - instructions if you have an older `troff'. - -`doc/gawk.1' - The `troff' source for a manual page describing `gawk'. This is +'doc/bc_notes' + A brief description of 'gawk''s "byte code" internals. + +'doc/README.card' +'doc/ad.block' +'doc/awkcard.in' +'doc/cardfonts' +'doc/colors' +'doc/macros' +'doc/no.colors' +'doc/setter.outline' + The 'troff' source for a five-color 'awk' reference card. A modern + version of 'troff' such as GNU 'troff' ('groff') is needed to + produce the color version. See the file 'README.card' for + instructions if you have an older 'troff'. + +'doc/gawk.1' + The 'troff' source for a manual page describing 'gawk'. This is distributed for the convenience of Unix users. -`doc/gawktexi.in' -`doc/sidebar.awk' - The Texinfo source file for this Info file. It should be - processed by `doc/sidebar.awk' before processing with `texi2dvi' - or `texi2pdf' to produce a printed document, and with `makeinfo' - to produce an Info or HTML file. The `Makefile' takes care of - this processing and produces printable output via `texi2dvi' or - `texi2pdf'. +'doc/gawktexi.in' +'doc/sidebar.awk' + The Texinfo source file for this Info file. It should be processed + by 'doc/sidebar.awk' before processing with 'texi2dvi' or + 'texi2pdf' to produce a printed document, and with 'makeinfo' to + produce an Info or HTML file. The 'Makefile' takes care of this + processing and produces printable output via 'texi2dvi' or + 'texi2pdf'. -`doc/gawk.texi' - The file produced after processing `gawktexi.in' with - `sidebar.awk'. +'doc/gawk.texi' + The file produced after processing 'gawktexi.in' with + 'sidebar.awk'. -`doc/gawk.info' +'doc/gawk.info' The generated Info file for this Info file. -`doc/gawkinet.texi' - The Texinfo source file for *note (General Introduction)Top:: - gawkinet, TCP/IP Internetworking with `gawk'. It should be - processed with TeX (via `texi2dvi' or `texi2pdf') to produce a - printed document and with `makeinfo' to produce an Info or HTML - file. +'doc/gawkinet.texi' + The Texinfo source file for *note (General Introduction, gawkinet, + TCP/IP Internetworking with 'gawk')Top::. It should be processed + with TeX (via 'texi2dvi' or 'texi2pdf') to produce a printed + document and with 'makeinfo' to produce an Info or HTML file. -`doc/gawkinet.info' - The generated Info file for `TCP/IP Internetworking with `gawk''. +'doc/gawkinet.info' + The generated Info file for 'TCP/IP Internetworking with 'gawk''. -`doc/igawk.1' - The `troff' source for a manual page describing the `igawk' - program presented in *note Igawk Program::. (Since `gawk' can do - its own `@include' processing, neither `igawk' nor `igawk.1' are +'doc/igawk.1' + The 'troff' source for a manual page describing the 'igawk' program + presented in *note Igawk Program::. (Since 'gawk' can do its own + '@include' processing, neither 'igawk' nor 'igawk.1' are installed.) -`doc/Makefile.in' +'doc/Makefile.in' The input file used during the configuration process to generate - the actual `Makefile' for creating the documentation. + the actual 'Makefile' for creating the documentation. -`Makefile.am' -`*/Makefile.am' +'Makefile.am' +'*/Makefile.am' Files used by the GNU Automake software for generating the - `Makefile.in' files used by Autoconf and `configure'. - -`Makefile.in' -`aclocal.m4' -`bisonfix.awk' -`config.guess' -`configh.in' -`configure.ac' -`configure' -`custom.h' -`depcomp' -`install-sh' -`missing_d/*' -`mkinstalldirs' -`m4/*' + 'Makefile.in' files used by Autoconf and 'configure'. + +'Makefile.in' +'aclocal.m4' +'bisonfix.awk' +'config.guess' +'configh.in' +'configure.ac' +'configure' +'custom.h' +'depcomp' +'install-sh' +'missing_d/*' +'mkinstalldirs' +'m4/*' These files and subdirectories are used when configuring and - compiling `gawk' for various Unix systems. Most of them are - explained in *note Unix Installation::. The rest are there to + compiling 'gawk' for various Unix systems. Most of them are + explained in *note Unix Installation::. The rest are there to support the main infrastructure. -`po/*' - The `po' library contains message translations. +'po/*' + The 'po' library contains message translations. -`awklib/extract.awk' -`awklib/Makefile.am' -`awklib/Makefile.in' -`awklib/eg/*' - The `awklib' directory contains a copy of `extract.awk' (*note +'awklib/extract.awk' +'awklib/Makefile.am' +'awklib/Makefile.in' +'awklib/eg/*' + The 'awklib' directory contains a copy of 'extract.awk' (*note Extract Program::), which can be used to extract the sample - programs from the Texinfo source file for this Info file. It also - contains a `Makefile.in' file, which `configure' uses to generate - a `Makefile'. `Makefile.am' is used by GNU Automake to create - `Makefile.in'. The library functions from *note Library - Functions::, are included as ready-to-use files in the `gawk' + programs from the Texinfo source file for this Info file. It also + contains a 'Makefile.in' file, which 'configure' uses to generate a + 'Makefile'. 'Makefile.am' is used by GNU Automake to create + 'Makefile.in'. The library functions from *note Library + Functions::, are included as ready-to-use files in the 'gawk' distribution. They are installed as part of the installation process. The rest of the programs in this Info file are available - in appropriate subdirectories of `awklib/eg'. + in appropriate subdirectories of 'awklib/eg'. -`extension/*' +'extension/*' The source code, manual pages, and infrastructure files for the - sample extensions included with `gawk'. *Note Dynamic + sample extensions included with 'gawk'. *Note Dynamic Extensions::, for more information. -`posix/*' - Files needed for building `gawk' on POSIX-compliant systems. +'posix/*' + Files needed for building 'gawk' on POSIX-compliant systems. -`pc/*' - Files needed for building `gawk' under MS-Windows and OS/2 (*note +'pc/*' + Files needed for building 'gawk' under MS-Windows and OS/2 (*note PC Installation::, for details). -`vms/*' - Files needed for building `gawk' under Vax/VMS and OpenVMS (*note +'vms/*' + Files needed for building 'gawk' under Vax/VMS and OpenVMS (*note VMS Installation::, for details). -`test/*' - A test suite for `gawk'. You can use `make check' from the - top-level `gawk' directory to run your version of `gawk' against - the test suite. If `gawk' successfully passes `make check', then +'test/*' + A test suite for 'gawk'. You can use 'make check' from the + top-level 'gawk' directory to run your version of 'gawk' against + the test suite. If 'gawk' successfully passes 'make check', then you can be confident of a successful port.  File: gawk.info, Node: Unix Installation, Next: Non-Unix Installation, Prev: Gawk Distribution, Up: Installation -B.2 Compiling and Installing `gawk' on Unix-like Systems +B.2 Compiling and Installing 'gawk' on Unix-like Systems ======================================================== -Usually, you can compile and install `gawk' by typing only two -commands. However, if you use an unusual system, you may need to -configure `gawk' for your system yourself. +Usually, you can compile and install 'gawk' by typing only two commands. +However, if you use an unusual system, you may need to configure 'gawk' +for your system yourself. * Menu: -* Quick Installation:: Compiling `gawk' under Unix. +* Quick Installation:: Compiling 'gawk' under Unix. * Additional Configuration Options:: Other compile-time options. * Configuration Philosophy:: How it's all supposed to work.  File: gawk.info, Node: Quick Installation, Next: Additional Configuration Options, Up: Unix Installation -B.2.1 Compiling `gawk' for Unix-like Systems +B.2.1 Compiling 'gawk' for Unix-like Systems -------------------------------------------- The normal installation steps should work on all modern commercial Unix-derived systems, GNU/Linux, BSD-based systems, and the Cygwin environment for MS-Windows. - After you have extracted the `gawk' distribution, `cd' to -`gawk-4.1.1'. Like most GNU software, `gawk' is configured -automatically for your system by running the `configure' program. This + After you have extracted the 'gawk' distribution, 'cd' to +'gawk-4.1.1'. Like most GNU software, 'gawk' is configured +automatically for your system by running the 'configure' program. This program is a Bourne shell script that is generated automatically using GNU Autoconf. (The Autoconf software is described fully starting with -*note (Autoconf)Top:: autoconf,Autoconf--Generating Automatic -Configuration Scripts.) +*note (Autoconf, autoconf,Autoconf---Generating Automatic Configuration +Scripts)Top::.) - To configure `gawk', simply run `configure': + To configure 'gawk', simply run 'configure': sh ./configure - This produces a `Makefile' and `config.h' tailored to your system. -The `config.h' file describes various facts about your system. You -might want to edit the `Makefile' to change the `CFLAGS' variable, -which controls the command-line options that are passed to the C -compiler (such as optimization levels or compiling for debugging). + This produces a 'Makefile' and 'config.h' tailored to your system. +The 'config.h' file describes various facts about your system. You +might want to edit the 'Makefile' to change the 'CFLAGS' variable, which +controls the command-line options that are passed to the C compiler +(such as optimization levels or compiling for debugging). - Alternatively, you can add your own values for most `make' variables -on the command line, such as `CC' and `CFLAGS', when running -`configure': + Alternatively, you can add your own values for most 'make' variables +on the command line, such as 'CC' and 'CFLAGS', when running +'configure': CC=cc CFLAGS=-g sh ./configure -See the file `INSTALL' in the `gawk' distribution for all the details. +See the file 'INSTALL' in the 'gawk' distribution for all the details. - After you have run `configure' and possibly edited the `Makefile', + After you have run 'configure' and possibly edited the 'Makefile', type: make -Shortly thereafter, you should have an executable version of `gawk'. -That's all there is to it! To verify that `gawk' is working properly, -run `make check'. All of the tests should succeed. If these steps do -not work, or if any of the tests fail, check the files in the -`README_d' directory to see if you've found a known problem. If the -failure is not described there, please send in a bug report (*note -Bugs::). - - Of course, once you've built `gawk', it is likely that you will wish -to install it. To do so, you need to run the command `make install', -as a user with the appropriate permissions. How to do this varies by -system, but on many systems you can use the `sudo' command to do so. -The command then becomes `sudo make install'. It is likely that you +Shortly thereafter, you should have an executable version of 'gawk'. +That's all there is to it! To verify that 'gawk' is working properly, +run 'make check'. All of the tests should succeed. If these steps do +not work, or if any of the tests fail, check the files in the 'README_d' +directory to see if you've found a known problem. If the failure is not +described there, please send in a bug report (*note Bugs::). + + Of course, once you've built 'gawk', it is likely that you will wish +to install it. To do so, you need to run the command 'make install', as +a user with the appropriate permissions. How to do this varies by +system, but on many systems you can use the 'sudo' command to do so. +The command then becomes 'sudo make install'. It is likely that you will be asked for your password, and you will have to have been set up -previously as a user who is allowed to run the `sudo' command. +previously as a user who is allowed to run the 'sudo' command.  File: gawk.info, Node: Additional Configuration Options, Next: Configuration Philosophy, Prev: Quick Installation, Up: Unix Installation @@ -27203,41 +27089,41 @@ File: gawk.info, Node: Additional Configuration Options, Next: Configuration P B.2.2 Additional Configuration Options -------------------------------------- -There are several additional options you may use on the `configure' -command line when compiling `gawk' from scratch, including: +There are several additional options you may use on the 'configure' +command line when compiling 'gawk' from scratch, including: -`--disable-extensions' +'--disable-extensions' Disable configuring and building the sample extensions in the - `extension' directory. This is useful for cross-compiling. The + 'extension' directory. This is useful for cross-compiling. The default action is to dynamically check if the extensions can be configured and compiled. -`--disable-lint' - Disable all lint checking within `gawk'. The `--lint' and - `--lint-old' options (*note Options::) are accepted, but silently - do nothing. Similarly, setting the `LINT' variable (*note - User-modified::) has no effect on the running `awk' program. +'--disable-lint' + Disable all lint checking within 'gawk'. The '--lint' and + '--lint-old' options (*note Options::) are accepted, but silently + do nothing. Similarly, setting the 'LINT' variable (*note + User-modified::) has no effect on the running 'awk' program. When used with GCC's automatic dead-code-elimination, this option - cuts almost 200K bytes off the size of the `gawk' executable on + cuts almost 200K bytes off the size of the 'gawk' executable on GNU/Linux x86 systems. Results on other systems and with other - compilers are likely to vary. Using this option may bring you - some slight performance improvement. + compilers are likely to vary. Using this option may bring you some + slight performance improvement. - Using this option will cause some of the tests in the test suite - to fail. This option may be removed at a later date. + Using this option will cause some of the tests in the test suite to + fail. This option may be removed at a later date. -`--disable-nls' +'--disable-nls' Disable all message-translation facilities. This is usually not desirable, but it may bring you some slight performance improvement. -`--with-whiny-user-strftime' - Force use of the included version of the C `strftime()' function +'--with-whiny-user-strftime' + Force use of the included version of the C 'strftime()' function for deficient systems. - Use the command `./configure --help' to see the full list of options -that `configure' supplies. + Use the command './configure --help' to see the full list of options +that 'configure' supplies.  File: gawk.info, Node: Configuration Philosophy, Prev: Additional Configuration Options, Up: Unix Installation @@ -27248,42 +27134,42 @@ B.2.3 The Configuration Process This minor node is of interest only if you know something about using the C language and Unix-like operating systems. - The source code for `gawk' generally attempts to adhere to formal -standards wherever possible. This means that `gawk' uses library + The source code for 'gawk' generally attempts to adhere to formal +standards wherever possible. This means that 'gawk' uses library routines that are specified by the ISO C standard and by the POSIX -operating system interface standard. The `gawk' source code requires +operating system interface standard. The 'gawk' source code requires using an ISO C compiler (the 1990 standard). Many Unix systems do not support all of either the ISO or the POSIX -standards. The `missing_d' subdirectory in the `gawk' distribution -contains replacement versions of those functions that are most likely -to be missing. +standards. The 'missing_d' subdirectory in the 'gawk' distribution +contains replacement versions of those functions that are most likely to +be missing. - The `config.h' file that `configure' creates contains definitions + The 'config.h' file that 'configure' creates contains definitions that describe features of the particular operating system where you are -attempting to compile `gawk'. The three things described by this file +attempting to compile 'gawk'. The three things described by this file are: what header files are available, so that they can be correctly -included, what (supposedly) standard functions are actually available -in your C libraries, and various miscellaneous facts about your -operating system. For example, there may not be an `st_blksize' -element in the `stat' structure. In this case, -`HAVE_STRUCT_STAT_ST_BLKSIZE' is undefined. +included, what (supposedly) standard functions are actually available in +your C libraries, and various miscellaneous facts about your operating +system. For example, there may not be an 'st_blksize' element in the +'stat' structure. In this case, 'HAVE_STRUCT_STAT_ST_BLKSIZE' is +undefined. - It is possible for your C compiler to lie to `configure'. It may do + It is possible for your C compiler to lie to 'configure'. It may do so by not exiting with an error when a library function is not -available. To get around this, edit the file `custom.h'. Use an -`#ifdef' that is appropriate for your system, and either `#define' any -constants that `configure' should have defined but didn't, or `#undef' -any constants that `configure' defined and should not have. `custom.h' -is automatically included by `config.h'. +available. To get around this, edit the file 'custom.h'. Use an +'#ifdef' that is appropriate for your system, and either '#define' any +constants that 'configure' should have defined but didn't, or '#undef' +any constants that 'configure' defined and should not have. 'custom.h' +is automatically included by 'config.h'. - It is also possible that the `configure' program generated by + It is also possible that the 'configure' program generated by Autoconf will not work on your system in some other fashion. If you do -have a problem, the file `configure.ac' is the input for Autoconf. You +have a problem, the file 'configure.ac' is the input for Autoconf. You may be able to change this file and generate a new version of -`configure' that works on your system (*note Bugs::, for information on -how to report problems in configuring `gawk'). The same mechanism may -be used to send in updates to `configure.ac' and/or `custom.h'. +'configure' that works on your system (*note Bugs::, for information on +how to report problems in configuring 'gawk'). The same mechanism may +be used to send in updates to 'configure.ac' and/or 'custom.h'.  File: gawk.info, Node: Non-Unix Installation, Next: Bugs, Prev: Unix Installation, Up: Installation @@ -27291,14 +27177,14 @@ File: gawk.info, Node: Non-Unix Installation, Next: Bugs, Prev: Unix Installa B.3 Installation on Other Operating Systems =========================================== -This minor node describes how to install `gawk' on various non-Unix +This minor node describes how to install 'gawk' on various non-Unix systems. * Menu: -* PC Installation:: Installing and Compiling `gawk' on +* PC Installation:: Installing and Compiling 'gawk' on MS-DOS and OS/2. -* VMS Installation:: Installing `gawk' on VMS. +* VMS Installation:: Installing 'gawk' on VMS.  File: gawk.info, Node: PC Installation, Next: VMS Installation, Up: Non-Unix Installation @@ -27306,29 +27192,29 @@ File: gawk.info, Node: PC Installation, Next: VMS Installation, Up: Non-Unix B.3.1 Installation on PC Operating Systems ------------------------------------------ -This minor node covers installation and usage of `gawk' on x86 machines -running MS-DOS, any version of MS-Windows, or OS/2. In this minor -node, the term "Windows32" refers to any of Microsoft +This minor node covers installation and usage of 'gawk' on x86 machines +running MS-DOS, any version of MS-Windows, or OS/2. In this minor node, +the term "Windows32" refers to any of Microsoft Windows-95/98/ME/NT/2000/XP/Vista/7/8. The limitations of MS-DOS (and MS-DOS shells under the other -operating systems) has meant that various "DOS extenders" are often -used with programs such as `gawk'. The varying capabilities of -Microsoft Windows 3.1 and Windows32 can add to the confusion. For an -overview of the considerations, please refer to `README_d/README.pc' in -the distribution. +operating systems) has meant that various "DOS extenders" are often used +with programs such as 'gawk'. The varying capabilities of Microsoft +Windows 3.1 and Windows32 can add to the confusion. For an overview of +the considerations, please refer to 'README_d/README.pc' in the +distribution. * Menu: * PC Binary Installation:: Installing a prepared distribution. -* PC Compiling:: Compiling `gawk' for MS-DOS, +* PC Compiling:: Compiling 'gawk' for MS-DOS, Windows32, and OS/2. -* PC Testing:: Testing `gawk' on PC systems. -* PC Using:: Running `gawk' on MS-DOS, Windows32 +* PC Testing:: Testing 'gawk' on PC systems. +* PC Using:: Running 'gawk' on MS-DOS, Windows32 and OS/2. -* Cygwin:: Building and running `gawk' for +* Cygwin:: Building and running 'gawk' for Cygwin. -* MSYS:: Using `gawk' In The MSYS Environment. +* MSYS:: Using 'gawk' In The MSYS Environment.  File: gawk.info, Node: PC Binary Installation, Next: PC Compiling, Up: PC Installation @@ -27337,30 +27223,30 @@ B.3.1.1 Installing a Prepared Distribution for PC Systems ......................................................... If you have received a binary distribution prepared by the MS-DOS -maintainers, then `gawk' and the necessary support files appear under -the `gnu' directory, with executables in `gnu/bin', libraries in -`gnu/lib/awk', and manual pages under `gnu/man'. This is designed for -easy installation to a `/gnu' directory on your drive--however, the -files can be installed anywhere provided `AWKPATH' is set properly. -Regardless of the installation directory, the first line of `igawk.cmd' -and `igawk.bat' (in `gnu/bin') may need to be edited. +maintainers, then 'gawk' and the necessary support files appear under +the 'gnu' directory, with executables in 'gnu/bin', libraries in +'gnu/lib/awk', and manual pages under 'gnu/man'. This is designed for +easy installation to a '/gnu' directory on your drive--however, the +files can be installed anywhere provided 'AWKPATH' is set properly. +Regardless of the installation directory, the first line of 'igawk.cmd' +and 'igawk.bat' (in 'gnu/bin') may need to be edited. The binary distribution contains a separate file describing the -contents. In particular, it may include more than one version of the -`gawk' executable. - - OS/2 (32 bit, EMX) binary distributions are prepared for the `/usr' -directory of your preferred drive. Set `UNIXROOT' to your installation -drive (e.g., `e:') if you want to install `gawk' onto another drive -than the hardcoded default `c:'. Executables appear in `/usr/bin', -libraries under `/usr/share/awk', manual pages under `/usr/man', -Texinfo documentation under `/usr/info', and NLS files under -`/usr/share/locale'. Note that the files can be installed anywhere -provided `AWKPATH' is set properly. - - If you already have a file `/usr/info/dir' from another package _do -not overwrite it!_ Instead enter the following commands at your prompt -(replace `x:' by your installation drive): +contents. In particular, it may include more than one version of the +'gawk' executable. + + OS/2 (32 bit, EMX) binary distributions are prepared for the '/usr' +directory of your preferred drive. Set 'UNIXROOT' to your installation +drive (e.g., 'e:') if you want to install 'gawk' onto another drive than +the hardcoded default 'c:'. Executables appear in '/usr/bin', libraries +under '/usr/share/awk', manual pages under '/usr/man', Texinfo +documentation under '/usr/info', and NLS files under +'/usr/share/locale'. Note that the files can be installed anywhere +provided 'AWKPATH' is set properly. + + If you already have a file '/usr/info/dir' from another package _do +not overwrite it!_ Instead enter the following commands at your prompt +(replace 'x:' by your installation drive): install-info --info-dir=x:/usr/info x:/usr/info/gawk.info install-info --info-dir=x:/usr/info x:/usr/info/gawkinet.info @@ -27371,40 +27257,40 @@ additional or more detailed installation instructions.  File: gawk.info, Node: PC Compiling, Next: PC Testing, Prev: PC Binary Installation, Up: PC Installation -B.3.1.2 Compiling `gawk' for PC Operating Systems +B.3.1.2 Compiling 'gawk' for PC Operating Systems ................................................. -`gawk' can be compiled for MS-DOS, Windows32, and OS/2 using the GNU +'gawk' can be compiled for MS-DOS, Windows32, and OS/2 using the GNU development tools from DJ Delorie (DJGPP: MS-DOS only), MinGW (Windows32) or Eberhard Mattes (EMX: MS-DOS, Windows32 and OS/2). The -file `README_d/README.pc' in the `gawk' distribution contains -additional notes, and `pc/Makefile' contains important information on -compilation options. - -To build `gawk' for MS-DOS and Windows32, copy the files in the `pc' -directory (_except_ for `ChangeLog') to the directory with the rest of -the `gawk' sources, then invoke `make' with the appropriate target name -as an argument to build `gawk'. The `Makefile' copied from the `pc' -directory contains a configuration section with comments and may need -to be edited in order to work with your `make' utility. - - The `Makefile' supports a number of targets for building various +file 'README_d/README.pc' in the 'gawk' distribution contains additional +notes, and 'pc/Makefile' contains important information on compilation +options. + + To build 'gawk' for MS-DOS and Windows32, copy the files in the 'pc' +directory (_except_ for 'ChangeLog') to the directory with the rest of +the 'gawk' sources, then invoke 'make' with the appropriate target name +as an argument to build 'gawk'. The 'Makefile' copied from the 'pc' +directory contains a configuration section with comments and may need to +be edited in order to work with your 'make' utility. + + The 'Makefile' supports a number of targets for building various MS-DOS and Windows32 versions. A list of targets is printed if the -`make' command is given without a target. As an example, to build -`gawk' using the DJGPP tools, enter `make djgpp'. (The DJGPP tools +'make' command is given without a target. As an example, to build +'gawk' using the DJGPP tools, enter 'make djgpp'. (The DJGPP tools needed for the build may be found at -`ftp://ftp.delorie.com/pub/djgpp/current/v2gnu/'.) To build a native -MS-Windows binary of `gawk', type `make mingw32'. +.) To build a native +MS-Windows binary of 'gawk', type 'make mingw32'. - The 32 bit EMX version of `gawk' works "out of the box" under OS/2. + The 32 bit EMX version of 'gawk' works "out of the box" under OS/2. However, it is highly recommended to use GCC 2.95.3 for the compilation. -In principle, it is possible to compile `gawk' the following way: +In principle, it is possible to compile 'gawk' the following way: $ ./configure $ make This is not recommended, though. To get an OMF executable you should -use the following commands at your `sh' prompt: +use the following commands at your 'sh' prompt: $ CFLAGS="-O2 -Zomf -Zmt" $ export CFLAGS @@ -27423,7 +27309,7 @@ other set of (self-consistent) environment variables and compiler flags. $ LIBS="-lgcc" $ export LIBS - You can also get an `a.out' executable if you prefer: + You can also get an 'a.out' executable if you prefer: $ CFLAGS="-O2 -Zmt" $ export CFLAGS @@ -27433,15 +27319,15 @@ other set of (self-consistent) environment variables and compiler flags. $ ./configure --prefix=c:/usr $ make - NOTE: Compilation of `a.out' executables also works with GCC 3.2. + NOTE: Compilation of 'a.out' executables also works with GCC 3.2. Versions later than GCC 3.2 have not been tested successfully. - `make install' works as expected with the EMX build. + 'make install' works as expected with the EMX build. - NOTE: Ancient OS/2 ports of GNU `make' are not able to handle the + NOTE: Ancient OS/2 ports of GNU 'make' are not able to handle the Makefiles of this package. If you encounter any problems with - `make', try GNU Make 3.79.1 or later versions. You should find - the latest version on `ftp://hobbes.nmsu.edu/pub/os2/'.(1) + 'make', try GNU Make 3.79.1 or later versions. You should find the + latest version on .(1) ---------- Footnotes ---------- @@ -27451,99 +27337,99 @@ not find a package for GNU Make.  File: gawk.info, Node: PC Testing, Next: PC Using, Prev: PC Compiling, Up: PC Installation -B.3.1.3 Testing `gawk' on PC Operating Systems +B.3.1.3 Testing 'gawk' on PC Operating Systems .............................................. -Using `make' to run the standard tests and to install `gawk' requires -additional Unix-like tools, including `sh', `sed', and `cp'. In order -to run the tests, the `test/*.ok' files may need to be converted so -that they have the usual MS-DOS-style end-of-line markers. -Alternatively, run `make check CMP="diff -a"' to use GNU `diff' in text -mode instead of `cmp' to compare the resulting files. +Using 'make' to run the standard tests and to install 'gawk' requires +additional Unix-like tools, including 'sh', 'sed', and 'cp'. In order +to run the tests, the 'test/*.ok' files may need to be converted so that +they have the usual MS-DOS-style end-of-line markers. Alternatively, +run 'make check CMP="diff -a"' to use GNU 'diff' in text mode instead of +'cmp' to compare the resulting files. Most of the tests work properly with Stewartson's shell along with the companion utilities or appropriate GNU utilities. However, some -editing of `test/Makefile' is required. It is recommended that you copy -the file `pc/Makefile.tst' over the file `test/Makefile' as a -replacement. Details can be found in `README_d/README.pc' and in the -file `pc/Makefile.tst'. - - On OS/2 the `pid' test fails because `spawnl()' is used instead of -`fork()'/`execl()' to start child processes. Also the `mbfw1' and -`mbprintf1' tests fail because the needed multibyte functionality is -not available. +editing of 'test/Makefile' is required. It is recommended that you copy +the file 'pc/Makefile.tst' over the file 'test/Makefile' as a +replacement. Details can be found in 'README_d/README.pc' and in the +file 'pc/Makefile.tst'. + + On OS/2 the 'pid' test fails because 'spawnl()' is used instead of +'fork()'/'execl()' to start child processes. Also the 'mbfw1' and +'mbprintf1' tests fail because the needed multibyte functionality is not +available.  File: gawk.info, Node: PC Using, Next: Cygwin, Prev: PC Testing, Up: PC Installation -B.3.1.4 Using `gawk' on PC Operating Systems +B.3.1.4 Using 'gawk' on PC Operating Systems ............................................ Under MS-DOS and MS-Windows, the Cygwin and MinGW environments support -both the `|&' operator and TCP/IP networking (*note TCP/IP -Networking::). EMX (OS/2 only) supports at least the `|&' operator. +both the '|&' operator and TCP/IP networking (*note TCP/IP +Networking::). EMX (OS/2 only) supports at least the '|&' operator. - The MS-DOS and MS-Windows versions of `gawk' search for program -files as described in *note AWKPATH Variable::. However, semicolons -(rather than colons) separate elements in the `AWKPATH' variable. If -`AWKPATH' is not set or is empty, then the default search path for -MS-Windows and MS-DOS versions is `.;c:/lib/awk;c:/gnu/lib/awk'. + The MS-DOS and MS-Windows versions of 'gawk' search for program files +as described in *note AWKPATH Variable::. However, semicolons (rather +than colons) separate elements in the 'AWKPATH' variable. If 'AWKPATH' +is not set or is empty, then the default search path for MS-Windows and +MS-DOS versions is '.;c:/lib/awk;c:/gnu/lib/awk'. The search path for OS/2 (32 bit, EMX) is determined by the prefix -directory (most likely `/usr' or `c:/usr') that has been specified as -an option of the `configure' script as is the case for the Unix -versions. If `c:/usr' is the prefix directory then the default search -path contains `.' and `c:/usr/share/awk'. Additionally, to support -binary distributions of `gawk' for OS/2 systems whose drive `c:' might -not support long file names or might not exist at all, there is a -special environment variable. If `UNIXROOT' specifies a drive then -this specific drive is also searched for program files. E.g., if -`UNIXROOT' is set to `e:' the complete default search path is -`.;c:/usr/share/awk;e:/usr/share/awk'. - - An `sh'-like shell (as opposed to `command.com' under MS-DOS or -`cmd.exe' under MS-Windows or OS/2) may be useful for `awk' programming. +directory (most likely '/usr' or 'c:/usr') that has been specified as an +option of the 'configure' script as is the case for the Unix versions. +If 'c:/usr' is the prefix directory then the default search path +contains '.' and 'c:/usr/share/awk'. Additionally, to support binary +distributions of 'gawk' for OS/2 systems whose drive 'c:' might not +support long file names or might not exist at all, there is a special +environment variable. If 'UNIXROOT' specifies a drive then this +specific drive is also searched for program files. E.g., if 'UNIXROOT' +is set to 'e:' the complete default search path is +'.;c:/usr/share/awk;e:/usr/share/awk'. + + An 'sh'-like shell (as opposed to 'command.com' under MS-DOS or +'cmd.exe' under MS-Windows or OS/2) may be useful for 'awk' programming. The DJGPP collection of tools includes an MS-DOS port of Bash, and -several shells are available for OS/2, including `ksh'. +several shells are available for OS/2, including 'ksh'. - Under MS-Windows, OS/2 and MS-DOS, `gawk' (and many other text -programs) silently translate end-of-line `\r\n' to `\n' on input and -`\n' to `\r\n' on output. A special `BINMODE' variable (c.e.) allows + Under MS-Windows, OS/2 and MS-DOS, 'gawk' (and many other text +programs) silently translate end-of-line '\r\n' to '\n' on input and +'\n' to '\r\n' on output. A special 'BINMODE' variable (c.e.) allows control over these translations and is interpreted as follows: - * If `BINMODE' is `"r"', or one, then binary mode is set on read + * If 'BINMODE' is '"r"', or one, then binary mode is set on read (i.e., no translations on reads). - * If `BINMODE' is `"w"', or two, then binary mode is set on write + * If 'BINMODE' is '"w"', or two, then binary mode is set on write (i.e., no translations on writes). - * If `BINMODE' is `"rw"' or `"wr"' or three, binary mode is set for + * If 'BINMODE' is '"rw"' or '"wr"' or three, binary mode is set for both read and write. - * `BINMODE=NON-NULL-STRING' is the same as `BINMODE=3' (i.e., no - translations on reads or writes). However, `gawk' issues a warning - message if the string is not one of `"rw"' or `"wr"'. + * 'BINMODE=NON-NULL-STRING' is the same as 'BINMODE=3' (i.e., no + translations on reads or writes). However, 'gawk' issues a warning + message if the string is not one of '"rw"' or '"wr"'. The modes for standard input and standard output are set one time only -(after the command line is read, but before processing any of the `awk' -program). Setting `BINMODE' for standard input or standard output is -accomplished by using an appropriate `-v BINMODE=N' option on the -command line. `BINMODE' is set at the time a file or pipe is opened -and cannot be changed mid-stream. - - The name `BINMODE' was chosen to match `mawk' (*note Other -Versions::). `mawk' and `gawk' handle `BINMODE' similarly; however, -`mawk' adds a `-W BINMODE=N' option and an environment variable that -can set `BINMODE', `RS', and `ORS'. The files `binmode[1-3].awk' -(under `gnu/lib/awk' in some of the prepared binary distributions) have -been chosen to match `mawk''s `-W BINMODE=N' option. These can be -changed or discarded; in particular, the setting of `RS' giving the -fewest "surprises" is open to debate. `mawk' uses `RS = "\r\n"' if -binary mode is set on read, which is appropriate for files with the -MS-DOS-style end-of-line. +(after the command line is read, but before processing any of the 'awk' +program). Setting 'BINMODE' for standard input or standard output is +accomplished by using an appropriate '-v BINMODE=N' option on the +command line. 'BINMODE' is set at the time a file or pipe is opened and +cannot be changed mid-stream. + + The name 'BINMODE' was chosen to match 'mawk' (*note Other +Versions::). 'mawk' and 'gawk' handle 'BINMODE' similarly; however, +'mawk' adds a '-W BINMODE=N' option and an environment variable that can +set 'BINMODE', 'RS', and 'ORS'. The files 'binmode[1-3].awk' (under +'gnu/lib/awk' in some of the prepared binary distributions) have been +chosen to match 'mawk''s '-W BINMODE=N' option. These can be changed or +discarded; in particular, the setting of 'RS' giving the fewest +"surprises" is open to debate. 'mawk' uses 'RS = "\r\n"' if binary mode +is set on read, which is appropriate for files with the MS-DOS-style +end-of-line. To illustrate, the following examples set binary mode on writes for -standard output and other files, and set `ORS' as the "usual" +standard output and other files, and set 'ORS' as the "usual" MS-DOS-style end-of-line: gawk -v BINMODE=2 -v ORS="\r\n" ... @@ -27552,8 +27438,8 @@ or: gawk -v BINMODE=w -f binmode2.awk ... -These give the same result as the `-W BINMODE=2' option in `mawk'. The -following changes the record separator to `"\r\n"' and sets binary mode +These give the same result as the '-W BINMODE=2' option in 'mawk'. The +following changes the record separator to '"\r\n"' and sets binary mode on reads, but does not affect the mode on standard input: gawk -v RS="\r\n" --source "BEGIN { BINMODE = 1 }" ... @@ -27562,73 +27448,73 @@ or: gawk -f binmode1.awk ... -With proper quoting, in the first example the setting of `RS' can be -moved into the `BEGIN' rule. +With proper quoting, in the first example the setting of 'RS' can be +moved into the 'BEGIN' rule.  File: gawk.info, Node: Cygwin, Next: MSYS, Prev: PC Using, Up: PC Installation -B.3.1.5 Using `gawk' In The Cygwin Environment +B.3.1.5 Using 'gawk' In The Cygwin Environment .............................................. -`gawk' can be built and used "out of the box" under MS-Windows if you +'gawk' can be built and used "out of the box" under MS-Windows if you are using the Cygwin environment (http://www.cygwin.com). This -environment provides an excellent simulation of GNU/Linux, using the -GNU tools, such as Bash, the GNU Compiler Collection (GCC), GNU Make, -and other GNU programs. Compilation and installation for Cygwin is the -same as for a Unix system: +environment provides an excellent simulation of GNU/Linux, using the GNU +tools, such as Bash, the GNU Compiler Collection (GCC), GNU Make, and +other GNU programs. Compilation and installation for Cygwin is the same +as for a Unix system: tar -xvpzf gawk-4.1.1.tar.gz cd gawk-4.1.1 ./configure make - When compared to GNU/Linux on the same system, the `configure' step + When compared to GNU/Linux on the same system, the 'configure' step on Cygwin takes considerably longer. However, it does finish, and then -the `make' proceeds as usual. +the 'make' proceeds as usual.  File: gawk.info, Node: MSYS, Prev: Cygwin, Up: PC Installation -B.3.1.6 Using `gawk' In The MSYS Environment +B.3.1.6 Using 'gawk' In The MSYS Environment ............................................ -In the MSYS environment under MS-Windows, `gawk' automatically uses -binary mode for reading and writing files. Thus there is no need to -use the `BINMODE' variable. +In the MSYS environment under MS-Windows, 'gawk' automatically uses +binary mode for reading and writing files. Thus there is no need to use +the 'BINMODE' variable. This can cause problems with other Unix-like components that have -been ported to MS-Windows that expect `gawk' to do automatic -translation of `"\r\n"', since it won't. Caveat Emptor! +been ported to MS-Windows that expect 'gawk' to do automatic translation +of '"\r\n"', since it won't. Caveat Emptor!  File: gawk.info, Node: VMS Installation, Prev: PC Installation, Up: Non-Unix Installation -B.3.2 How to Compile and Install `gawk' on Vax/VMS and OpenVMS +B.3.2 How to Compile and Install 'gawk' on Vax/VMS and OpenVMS -------------------------------------------------------------- -This node describes how to compile and install `gawk' under VMS. The +This node describes how to compile and install 'gawk' under VMS. The older designation "VMS" is used throughout to refer to OpenVMS. * Menu: -* VMS Compilation:: How to compile `gawk' under VMS. -* VMS Dynamic Extensions:: Compiling `gawk' dynamic extensions on +* VMS Compilation:: How to compile 'gawk' under VMS. +* VMS Dynamic Extensions:: Compiling 'gawk' dynamic extensions on VMS. -* VMS Installation Details:: How to install `gawk' under VMS. -* VMS Running:: How to run `gawk' under VMS. +* VMS Installation Details:: How to install 'gawk' under VMS. +* VMS Running:: How to run 'gawk' under VMS. * VMS GNV:: The VMS GNV Project. * VMS Old Gawk:: An old version comes with some VMS systems.  File: gawk.info, Node: VMS Compilation, Next: VMS Dynamic Extensions, Up: VMS Installation -B.3.2.1 Compiling `gawk' on VMS +B.3.2.1 Compiling 'gawk' on VMS ............................... -To compile `gawk' under VMS, there is a `DCL' command procedure that -issues all the necessary `CC' and `LINK' commands. There is also a -`Makefile' for use with the `MMS' and `MMK' utilities. From the source +To compile 'gawk' under VMS, there is a 'DCL' command procedure that +issues all the necessary 'CC' and 'LINK' commands. There is also a +'Makefile' for use with the 'MMS' and 'MMK' utilities. From the source directory, use either: $ @[.vms]vmsbuild.com @@ -27641,19 +27527,19 @@ or: $ MMK/DESCRIPTION=[.vms]descrip.mms gawk - `MMK' is an open source, free, near-clone of `MMS' and can better -handle ODS-5 volumes with upper- and lowercase file names. `MMK' is -available from `https://github.com/endlesssoftware/mmk'. + 'MMK' is an open source, free, near-clone of 'MMS' and can better +handle ODS-5 volumes with upper- and lowercase file names. 'MMK' is +available from . With ODS-5 volumes and extended parsing enabled, the case of the target parameter may need to be exact. - `gawk' has been tested under VAX/VMS 7.3 and Alpha/VMS 7.3-1 using + 'gawk' has been tested under VAX/VMS 7.3 and Alpha/VMS 7.3-1 using Compaq C V6.4, and Alpha/VMS 7.3, Alpha/VMS 7.3-2, and IA64/VMS 8.3. The most recent builds used HP C V7.3 on Alpha VMS 8.3 and both Alpha and IA64 VMS 8.4 used HP C 7.3.(1) - *Note VMS GNV::, for information on building `gawk' as a PCSI kit + *Note VMS GNV::, for information on building 'gawk' as a PCSI kit that is compatible with the GNV product. ---------- Footnotes ---------- @@ -27663,7 +27549,7 @@ that is compatible with the GNV product.  File: gawk.info, Node: VMS Dynamic Extensions, Next: VMS Installation Details, Prev: VMS Compilation, Up: VMS Installation -B.3.2.2 Compiling `gawk' Dynamic Extensions on VMS +B.3.2.2 Compiling 'gawk' Dynamic Extensions on VMS .................................................. The extensions that have been ported to VMS can be built using one of @@ -27675,15 +27561,14 @@ or: $ MMK/DESCRIPTION=[.vms]descrip.mms extensions - `gawk' uses `AWKLIBPATH' as either an environment variable or a + 'gawk' uses 'AWKLIBPATH' as either an environment variable or a logical name to find the dynamic extensions. - Dynamic extensions need to be compiled with the same compiler -options for floating point, pointer size, and symbol name handling as -were used to compile `gawk' itself. Alpha and Itanium should use IEEE -floating point. The pointer size is 32 bits, and the symbol name -handling should be exact case with CRC shortening for symbols longer -than 32 bits. + Dynamic extensions need to be compiled with the same compiler options +for floating point, pointer size, and symbol name handling as were used +to compile 'gawk' itself. Alpha and Itanium should use IEEE floating +point. The pointer size is 32 bits, and the symbol name handling should +be exact case with CRC shortening for symbols longer than 32 bits. For Alpha and Itanium: @@ -27712,70 +27597,69 @@ header file is included.  File: gawk.info, Node: VMS Installation Details, Next: VMS Running, Prev: VMS Dynamic Extensions, Up: VMS Installation -B.3.2.3 Installing `gawk' on VMS +B.3.2.3 Installing 'gawk' on VMS ................................ -To use `gawk', all you need is a "foreign" command, which is a `DCL' -symbol whose value begins with a dollar sign. For example: +To use 'gawk', all you need is a "foreign" command, which is a 'DCL' +symbol whose value begins with a dollar sign. For example: $ GAWK :== $disk1:[gnubin]gawk -Substitute the actual location of `gawk.exe' for `$disk1:[gnubin]'. The -symbol should be placed in the `login.com' of any user who wants to run -`gawk', so that it is defined every time the user logs on. -Alternatively, the symbol may be placed in the system-wide -`sylogin.com' procedure, which allows all users to run `gawk'. +Substitute the actual location of 'gawk.exe' for '$disk1:[gnubin]'. The +symbol should be placed in the 'login.com' of any user who wants to run +'gawk', so that it is defined every time the user logs on. +Alternatively, the symbol may be placed in the system-wide 'sylogin.com' +procedure, which allows all users to run 'gawk'. - If your `gawk' was installed by a PCSI kit into the `GNV$GNU:' -directory tree, the program will be known as -`GNV$GNU:[bin]gnv$gawk.exe' and the help file will be -`GNV$GNU:[vms_help]gawk.hlp'. + If your 'gawk' was installed by a PCSI kit into the 'GNV$GNU:' +directory tree, the program will be known as 'GNV$GNU:[bin]gnv$gawk.exe' +and the help file will be 'GNV$GNU:[vms_help]gawk.hlp'. - The PCSI kit also installs a `GNV$GNU:[vms_bin]gawk_verb.cld' file -which can be used to add `gawk' and `awk' as DCL commands. + The PCSI kit also installs a 'GNV$GNU:[vms_bin]gawk_verb.cld' file +which can be used to add 'gawk' and 'awk' as DCL commands. For just the current process you can use: $ set command gnv$gnu:[vms_bin]gawk_verb.cld - Or the system manager can use `GNV$GNU:[vms_bin]gawk_verb.cld' to -add the `gawk' and `awk' to the system wide `DCLTABLES'. + Or the system manager can use 'GNV$GNU:[vms_bin]gawk_verb.cld' to add +the 'gawk' and 'awk' to the system wide 'DCLTABLES'. - The DCL syntax is documented in the `gawk.hlp' file. + The DCL syntax is documented in the 'gawk.hlp' file. - Optionally, the `gawk.hlp' entry can be loaded into a VMS help + Optionally, the 'gawk.hlp' entry can be loaded into a VMS help library: $ LIBRARY/HELP sys$help:helplib [.vms]gawk.hlp -(You may want to substitute a site-specific help library rather than -the standard VMS library `HELPLIB'.) After loading the help text, the +(You may want to substitute a site-specific help library rather than the +standard VMS library 'HELPLIB'.) After loading the help text, the command: $ HELP GAWK -provides information about both the `gawk' implementation and the `awk' +provides information about both the 'gawk' implementation and the 'awk' programming language. - The logical name `AWK_LIBRARY' can designate a default location for -`awk' program files. For the `-f' option, if the specified file name -has no device or directory path information in it, `gawk' looks in the + The logical name 'AWK_LIBRARY' can designate a default location for +'awk' program files. For the '-f' option, if the specified file name +has no device or directory path information in it, 'gawk' looks in the current directory first, then in the directory specified by the -translation of `AWK_LIBRARY' if the file is not found. If, after -searching in both directories, the file still is not found, `gawk' -appends the suffix `.awk' to the file name and retries the file search. -If `AWK_LIBRARY' has no definition, a default value of `SYS$LIBRARY:' -is used for it. +translation of 'AWK_LIBRARY' if the file is not found. If, after +searching in both directories, the file still is not found, 'gawk' +appends the suffix '.awk' to the file name and retries the file search. +If 'AWK_LIBRARY' has no definition, a default value of 'SYS$LIBRARY:' is +used for it.  File: gawk.info, Node: VMS Running, Next: VMS GNV, Prev: VMS Installation Details, Up: VMS Installation -B.3.2.4 Running `gawk' on VMS +B.3.2.4 Running 'gawk' on VMS ............................. Command-line parsing and quoting conventions are significantly different on VMS, so examples in this Info file or from other sources often need -minor changes. They _are_ minor though, and all `awk' programs should +minor changes. They _are_ minor though, and all 'awk' programs should run correctly. Here are a couple of trivial tests: @@ -27786,51 +27670,50 @@ run correctly. Note that uppercase and mixed-case text must be quoted. - The VMS port of `gawk' includes a `DCL'-style interface in addition + The VMS port of 'gawk' includes a 'DCL'-style interface in addition to the original shell-style interface (see the help entry for details). One side effect of dual command-line parsing is that if there is only a single parameter (as in the quoted string program above), the command -becomes ambiguous. To work around this, the normally optional `--' -flag is required to force Unix-style parsing rather than `DCL' parsing. -If any other dash-type options (or multiple parameters such as data -files to process) are present, there is no ambiguity and `--' can be -omitted. +becomes ambiguous. To work around this, the normally optional '--' flag +is required to force Unix-style parsing rather than 'DCL' parsing. If +any other dash-type options (or multiple parameters such as data files +to process) are present, there is no ambiguity and '--' can be omitted. - The `exit' value is a Unix-style value and is encoded to a VMS exit + The 'exit' value is a Unix-style value and is encoded to a VMS exit status value when the program exits. - The VMS severity bits will be set based on the `exit' value. A -failure is indicated by 1 and VMS sets the `ERROR' status. A fatal -error is indicated by 2 and VMS will set the `FATAL' status. All other -values will have the `SUCCESS' status. The exit value is encoded to -comply with VMS coding standards and will have the `C_FACILITY_NO' of -`0x350000' with the constant `0xA000' added to the number shifted over + The VMS severity bits will be set based on the 'exit' value. A +failure is indicated by 1 and VMS sets the 'ERROR' status. A fatal +error is indicated by 2 and VMS will set the 'FATAL' status. All other +values will have the 'SUCCESS' status. The exit value is encoded to +comply with VMS coding standards and will have the 'C_FACILITY_NO' of +'0x350000' with the constant '0xA000' added to the number shifted over by 3 bits to make room for the severity codes. - To extract the actual `gawk' exit code from the VMS status use: + To extract the actual 'gawk' exit code from the VMS status use: unix_status = (vms_status .and. &x7f8) / 8 -A C program that uses `exec()' to call `gawk' will get the original +A C program that uses 'exec()' to call 'gawk' will get the original Unix-style exit value. - Older versions of `gawk' treated a Unix exit code 0 as 1, a failure + Older versions of 'gawk' treated a Unix exit code 0 as 1, a failure as 2, a fatal error as 4, and passed all the other numbers through. This violated the VMS exit status coding requirements. - VAX/VMS floating point uses unbiased rounding. *Note Round + VAX/VMS floating point uses unbiased rounding. *Note Round Function::. - VMS reports time values in GMT unless one of the `SYS$TIMEZONE_RULE' -or `TZ' logical names is set. Older versions of VMS, such as VAX/VMS + VMS reports time values in GMT unless one of the 'SYS$TIMEZONE_RULE' +or 'TZ' logical names is set. Older versions of VMS, such as VAX/VMS 7.3 do not set these logical names. - The default search path, when looking for `awk' program files -specified by the `-f' option, is `"SYS$DISK:[],AWK_LIBRARY:"'. The -logical name `AWKPATH' can be used to override this default. The format -of `AWKPATH' is a comma-separated list of directory specifications. + The default search path, when looking for 'awk' program files +specified by the '-f' option, is '"SYS$DISK:[],AWK_LIBRARY:"'. The +logical name 'AWKPATH' can be used to override this default. The format +of 'AWKPATH' is a comma-separated list of directory specifications. When defining it, the value should be quoted so that it retains a single -translation and not a multitranslation `RMS' searchlist. +translation and not a multitranslation 'RMS' searchlist.  File: gawk.info, Node: VMS GNV, Next: VMS Old Gawk, Prev: VMS Running, Up: VMS Installation @@ -27839,29 +27722,28 @@ B.3.2.5 The VMS GNV Project ........................... The VMS GNV package provides a build environment similar to POSIX with -ports of a collection of open source tools. The `gawk' found in the GNV +ports of a collection of open source tools. The 'gawk' found in the GNV base kit is an older port. Currently the GNV project is being -reorganized to supply individual PCSI packages for each component. See -`https://sourceforge.net/p/gnv/wiki/InstallingGNVPackages/'. +reorganized to supply individual PCSI packages for each component. See . - The normal build procedure for `gawk' produces a program that is + The normal build procedure for 'gawk' produces a program that is suitable for use with GNV. - The `vms/gawk_build_steps.txt' in the source documents the procedure + The 'vms/gawk_build_steps.txt' in the source documents the procedure for building a VMS PCSI kit that is compatible with GNV.  File: gawk.info, Node: VMS Old Gawk, Prev: VMS GNV, Up: VMS Installation -B.3.2.6 Some VMS Systems Have An Old Version of `gawk' +B.3.2.6 Some VMS Systems Have An Old Version of 'gawk' ...................................................... -Some versions of VMS have an old version of `gawk'. To access it, +Some versions of VMS have an old version of 'gawk'. To access it, define a symbol, as follows: $ gawk :== $sys$common:[syshlp.examples.tcpip.snmp]gawk.exe - This is apparently version 2.15.6, which is extremely old. We + This is apparently version 2.15.6, which is extremely old. We recommend compiling and using the current version.  @@ -27870,12 +27752,12 @@ File: gawk.info, Node: Bugs, Next: Other Versions, Prev: Non-Unix Installatio B.4 Reporting Problems and Bugs =============================== - There is nothing more dangerous than a bored archeologist. -- The - Hitchhiker's Guide to the Galaxy + There is nothing more dangerous than a bored archeologist. + -- _The Hitchhiker's Guide to the Galaxy_ - If you have problems with `gawk' or think that you have found a bug, -please report it to the developers; we cannot promise to do anything -but we might well want to fix it. + If you have problems with 'gawk' or think that you have found a bug, +please report it to the developers; we cannot promise to do anything but +we might well want to fix it. Before reporting a bug, make sure you have actually found a real bug. Carefully reread the documentation and see if it really says you can do @@ -27884,30 +27766,30 @@ to do something or not, report that too; it's a bug in the documentation! Before reporting a bug or trying to fix it yourself, try to isolate -it to the smallest possible `awk' program and input data file that +it to the smallest possible 'awk' program and input data file that reproduces the problem. Then send us the program and data file, some idea of what kind of Unix system you're using, the compiler you used to -compile `gawk', and the exact results `gawk' gave you. Also say what +compile 'gawk', and the exact results 'gawk' gave you. Also say what you expected to occur; this helps us decide whether the problem is really in the documentation. - Please include the version number of `gawk' you are using. You can -get this information with the command `gawk --version'. + Please include the version number of 'gawk' you are using. You can +get this information with the command 'gawk --version'. Once you have a precise problem, send email to . - The `gawk' maintainers subscribe to this address and thus they will + The 'gawk' maintainers subscribe to this address and thus they will receive your bug report. If necessary, the primary maintainer can be reached directly at . The bug reporting address is preferred since the email list is archived at the GNU Project. _All -email should be in English. This is the only language understood in +email should be in English. This is the only language understood in common by all the maintainers._ - CAUTION: Do _not_ try to report bugs in `gawk' by posting to the - Usenet/Internet newsgroup `comp.lang.awk'. While the `gawk' + CAUTION: Do _not_ try to report bugs in 'gawk' by posting to the + Usenet/Internet newsgroup 'comp.lang.awk'. While the 'gawk' developers do occasionally read this newsgroup, there is no - guarantee that we will see your posting. The steps described - above are the official recognized ways for reporting bugs. Really. + guarantee that we will see your posting. The steps described above + are the official recognized ways for reporting bugs. Really. NOTE: Many distributions of GNU/Linux and the various BSD-based operating systems have their own bug reporting systems. If you @@ -27916,30 +27798,34 @@ common by all the maintainers._ This is for two reasons. First, while some distributions forward bug reports "upstream" to the GNU mailing list, many don't, so - there is a good chance that the `gawk' maintainer won't even see + there is a good chance that the 'gawk' maintainer won't even see the bug report! Second, mail to the GNU list is archived, and having everything at the GNU project keeps things self-contained and not dependant on other web sites. Non-bug suggestions are always welcome as well. If you have -questions about things that are unclear in the documentation or are -just obscure features, ask me; I will try to help you out, although I -may not have the time to fix the problem. You can send me electronic -mail at the Internet address noted previously. +questions about things that are unclear in the documentation or are just +obscure features, ask me; I will try to help you out, although I may not +have the time to fix the problem. You can send me electronic mail at +the Internet address noted previously. - If you find bugs in one of the non-Unix ports of `gawk', please send + If you find bugs in one of the non-Unix ports of 'gawk', please send an electronic mail message to the person who maintains that port. They -are named in the following list, as well as in the `README' file in the -`gawk' distribution. Information in the `README' file should be +are named in the following list, as well as in the 'README' file in the +'gawk' distribution. Information in the 'README' file should be considered authoritative if it conflicts with this Info file. - The people maintaining the non-Unix ports of `gawk' are as follows: + The people maintaining the non-Unix ports of 'gawk' are as follows: MS-DOS with DJGPP Scott Deifik, . + MS-Windows with MinGW Eli Zaretskii, . + OS/2 Andreas Buening, . + VMS Pat Rankin, , and John Malmberg, . + z/OS (OS/390) Dave Pitts, . If your bug is also reproducible under Unix, please send a copy of @@ -27948,107 +27834,107 @@ your report to the email list as well.  File: gawk.info, Node: Other Versions, Next: Installation summary, Prev: Bugs, Up: Installation -B.5 Other Freely Available `awk' Implementations +B.5 Other Freely Available 'awk' Implementations ================================================ It's kind of fun to put comments like this in your awk code. - `// Do C++ comments work? answer: yes! of course' -- Michael - Brennan + '// Do C++ comments work? answer: yes! of course' + -- _Michael Brennan_ - There are a number of other freely available `awk' implementations. + There are a number of other freely available 'awk' implementations. This minor node briefly describes where to get them: -Unix `awk' - Brian Kernighan, one of the original designers of Unix `awk', has - made his implementation of `awk' freely available. You can +Unix 'awk' + Brian Kernighan, one of the original designers of Unix 'awk', has + made his implementation of 'awk' freely available. You can retrieve this version via the World Wide Web from his home page (http://www.cs.princeton.edu/~bwk). It is available in several archive formats: - Shell archive - `http://www.cs.princeton.edu/~bwk/btl.mirror/awk.shar' + Shell archive + - Compressed `tar' file - `http://www.cs.princeton.edu/~bwk/btl.mirror/awk.tar.gz' + Compressed 'tar' file + - Zip file - `http://www.cs.princeton.edu/~bwk/btl.mirror/awk.zip' + Zip file + You can also retrieve it from Git Hub: git clone git://github.com/onetrueawk/awk bwkawk The above command creates a copy of the Git - (http://www.git-scm.com) repository in a directory named `bwkawk'. - If you leave that argument off the `git' command line, the - repository copy is created in a directory named `awk'. + (http://www.git-scm.com) repository in a directory named 'bwkawk'. + If you leave that argument off the 'git' command line, the + repository copy is created in a directory named 'awk'. This version requires an ISO C (1990 standard) compiler; the C compiler from GCC (the GNU Compiler Collection) works quite nicely. - *Note Common Extensions::, for a list of extensions in this `awk' - that are not in POSIX `awk'. + *Note Common Extensions::, for a list of extensions in this 'awk' + that are not in POSIX 'awk'. -`mawk' - Michael Brennan wrote an independent implementation of `awk', - called `mawk'. It is available under the GPL (*note Copying::), - just as `gawk' is. +'mawk' + Michael Brennan wrote an independent implementation of 'awk', + called 'mawk'. It is available under the GPL (*note Copying::), + just as 'gawk' is. - The original distribution site for the `mawk' source code no - longer has it. A copy is available at - `http://www.skeeve.com/gawk/mawk1.3.3.tar.gz'. + The original distribution site for the 'mawk' source code no longer + has it. A copy is available at + . - In 2009, Thomas Dickey took on `mawk' maintenance. Basic + In 2009, Thomas Dickey took on 'mawk' maintenance. Basic information is available on the project's web page (http://www.invisible-island.net/mawk). The download URL is - `http://invisible-island.net/datafiles/release/mawk.tar.gz'. + . - Once you have it, `gunzip' may be used to decompress this file. - Installation is similar to `gawk''s (*note Unix Installation::). + Once you have it, 'gunzip' may be used to decompress this file. + Installation is similar to 'gawk''s (*note Unix Installation::). - *Note Common Extensions::, for a list of extensions in `mawk' that - are not in POSIX `awk'. + *Note Common Extensions::, for a list of extensions in 'mawk' that + are not in POSIX 'awk'. -`awka' - Written by Andrew Sumner, `awka' translates `awk' programs into C, +'awka' + Written by Andrew Sumner, 'awka' translates 'awk' programs into C, compiles them, and links them with a library of functions that - provides the core `awk' functionality. It also has a number of + provides the core 'awk' functionality. It also has a number of extensions. - The `awk' translator is released under the GPL, and the library is + The 'awk' translator is released under the GPL, and the library is under the LGPL. - To get `awka', go to `http://sourceforge.net/projects/awka'. + To get 'awka', go to . The project seems to be frozen; no new code changes have been made since approximately 2003. -`pawk' +'pawk' Nelson H.F. Beebe at the University of Utah has modified Brian - Kernighan's `awk' to provide timing and profiling information. It - is different from `gawk' with the `--profile' option. (*note + Kernighan's 'awk' to provide timing and profiling information. It + is different from 'gawk' with the '--profile' option. (*note Profiling::), in that it uses CPU-based profiling, not line-count profiling. You may find it at either - `ftp://ftp.math.utah.edu/pub/pawk/pawk-20030606.tar.gz' or - `http://www.math.utah.edu/pub/pawk/pawk-20030606.tar.gz'. + or + . Busybox Awk Busybox is a GPL-licensed program providing small versions of many - applications within a single executable. It is aimed at embedded - systems. It includes a full implementation of POSIX `awk'. When - building it, be careful not to do `make install' as it will - overwrite copies of other applications in your `/usr/local/bin'. + applications within a single executable. It is aimed at embedded + systems. It includes a full implementation of POSIX 'awk'. When + building it, be careful not to do 'make install' as it will + overwrite copies of other applications in your '/usr/local/bin'. For more information, see the project's home page (http://busybox.net). -The OpenSolaris POSIX `awk' - The versions of `awk' in `/usr/xpg4/bin' and `/usr/xpg6/bin' on +The OpenSolaris POSIX 'awk' + The versions of 'awk' in '/usr/xpg4/bin' and '/usr/xpg6/bin' on Solaris are more-or-less POSIX-compliant. They are based on the - `awk' from Mortice Kern Systems for PCs. This author was able to + 'awk' from Mortice Kern Systems for PCs. This author was able to make this code compile and work under GNU/Linux with 1-2 hours of - work. Making it more generally portable (using GNU Autoconf - and/or Automake) would take more work, and this has not been done, - at least to our knowledge. + work. Making it more generally portable (using GNU Autoconf and/or + Automake) would take more work, and this has not been done, at + least to our knowledge. The source code used to be available from the OpenSolaris web site. However, that project was ended and the web site shut down. @@ -28056,34 +27942,34 @@ The OpenSolaris POSIX `awk' (http://wiki.illumos.org/display/illumos/illumos+Home) makes this implementation available. You can view the files one at a time from - `https://github.com/joyent/illumos-joyent/blob/master/usr/src/cmd/awk_xpg4'. + . -`jawk' - This is an interpreter for `awk' written in Java. It claims to be +'jawk' + This is an interpreter for 'awk' written in Java. It claims to be a full interpreter, although because it uses Java facilities for I/O and for regexp matching, the language it supports is different - from POSIX `awk'. More information is available on the project's + from POSIX 'awk'. More information is available on the project's home page (http://jawk.sourceforge.net). Libmawk - This is an embeddable `awk' interpreter derived from `mawk'. For - more information see `http://repo.hu/projects/libmawk/'. + This is an embeddable 'awk' interpreter derived from 'mawk'. For + more information see . -`pawk' - This is a Python module that claims to bring `awk'-like features - to Python. See `https://github.com/alecthomas/pawk' for more - information. (This is not related to Nelson Beebe's modified - version of Brian Kernighan's `awk', described earlier.) +'pawk' + This is a Python module that claims to bring 'awk'-like features to + Python. See for more + information. (This is not related to Nelson Beebe's modified + version of Brian Kernighan's 'awk', described earlier.) QSE Awk - This is an embeddable `awk' interpreter. For more information see - `http://code.google.com/p/qse/' and `http://awk.info/?tools/qse'. + This is an embeddable 'awk' interpreter. For more information see + and . -`QTawk' - This is an independent implementation of `awk' distributed under - the GPL. It has a large number of extensions over standard `awk' +'QTawk' + This is an independent implementation of 'awk' distributed under + the GPL. It has a large number of extensions over standard 'awk' and may not be 100% syntactically compatible with it. See - `http://www.quiktrim.org/QTawk.html' for more information, + for more information, including the manual and a download link. The project may also be frozen; no new code changes have been made @@ -28094,34 +27980,32 @@ Other Versions (http://en.wikipedia.org/wiki/Awk_language#Versions_and_implementations), for information on additional versions. -  File: gawk.info, Node: Installation summary, Prev: Other Versions, Up: Installation B.6 Summary =========== - * The `gawk' distribution is available from GNU project's main - distribution site, `ftp.gnu.org'. The canonical build recipe is: + * The 'gawk' distribution is available from GNU project's main + distribution site, 'ftp.gnu.org'. The canonical build recipe is: wget http://ftp.gnu.org/gnu/gawk/gawk-4.1.1.tar.gz tar -xvpzf gawk-4.1.1.tar.gz cd gawk-4.1.1 ./configure && make && make check - * `gawk' may be built on non-POSIX systems as well. The currently + * 'gawk' may be built on non-POSIX systems as well. The currently supported systems are MS-Windows using DJGPP, MSYS, MinGW and - Cygwin, OS/2 using EMX, and both Vax/VMS and OpenVMS. - Instructions for each system are included in this major node. + Cygwin, OS/2 using EMX, and both Vax/VMS and OpenVMS. Instructions + for each system are included in this major node. * Bug reports should be sent via email to . Bug reports should be in English, and should include the version of - `gawk', how it was compiled, and a short program and data file + 'gawk', how it was compiled, and a short program and data file which demonstrate the problem. - * There are a number of other freely available `awk' - implementations. Many are POSIX compliant; others are less so. - + * There are a number of other freely available 'awk' implementations. + Many are POSIX compliant; others are less so.  File: gawk.info, Node: Notes, Next: Basic Concepts, Prev: Installation, Up: Top @@ -28130,14 +28014,14 @@ Appendix C Implementation Notes ******************************* This appendix contains information mainly of interest to implementers -and maintainers of `gawk'. Everything in it applies specifically to -`gawk' and not to other implementations. +and maintainers of 'gawk'. Everything in it applies specifically to +'gawk' and not to other implementations. * Menu: -* Compatibility Mode:: How to disable certain `gawk' +* Compatibility Mode:: How to disable certain 'gawk' extensions. -* Additions:: Making Additions To `gawk'. +* Additions:: Making Additions To 'gawk'. * Future Extensions:: New features that may be implemented one day. * Implementation Limitations:: Some limitations of the implementation. * Extension Design:: Design notes about the extension API. @@ -28150,43 +28034,43 @@ File: gawk.info, Node: Compatibility Mode, Next: Additions, Up: Notes C.1 Downward Compatibility and Debugging ======================================== -*Note POSIX/GNU::, for a summary of the GNU extensions to the `awk' +*Note POSIX/GNU::, for a summary of the GNU extensions to the 'awk' language and program. All of these features can be turned off by -invoking `gawk' with the `--traditional' option or with the `--posix' +invoking 'gawk' with the '--traditional' option or with the '--posix' option. - If `gawk' is compiled for debugging with `-DDEBUG', then there is -one more option available on the command line: + If 'gawk' is compiled for debugging with '-DDEBUG', then there is one +more option available on the command line: -`-Y' -`--parsedebug' +'-Y' +'--parsedebug' Print out the parse stack information as the program is being parsed. - This option is intended only for serious `gawk' developers and not + This option is intended only for serious 'gawk' developers and not for the casual user. It probably has not even been compiled into your -version of `gawk', since it slows down execution. +version of 'gawk', since it slows down execution.  File: gawk.info, Node: Additions, Next: Future Extensions, Prev: Compatibility Mode, Up: Notes -C.2 Making Additions to `gawk' +C.2 Making Additions to 'gawk' ============================== -If you find that you want to enhance `gawk' in a significant fashion, +If you find that you want to enhance 'gawk' in a significant fashion, you are perfectly free to do so. That is the point of having free software; the source code is available and you are free to change it as you want (*note Copying::). - This minor node discusses the ways you might want to change `gawk' -as well as any considerations you should bear in mind. + This minor node discusses the ways you might want to change 'gawk' as +well as any considerations you should bear in mind. * Menu: * Accessing The Source:: Accessing the Git repository. * Adding Code:: Adding code to the main body of - `gawk'. -* New Ports:: Porting `gawk' to a new operating + 'gawk'. +* New Ports:: Porting 'gawk' to a new operating system. * Derived Files:: Why derived files are kept in the Git repository. @@ -28194,34 +28078,34 @@ as well as any considerations you should bear in mind.  File: gawk.info, Node: Accessing The Source, Next: Adding Code, Up: Additions -C.2.1 Accessing The `gawk' Git Repository +C.2.1 Accessing The 'gawk' Git Repository ----------------------------------------- -As `gawk' is Free Software, the source code is always available. *note -Gawk Distribution::, describes how to get and build the formal, -released versions of `gawk'. +As 'gawk' is Free Software, the source code is always available. *note +Gawk Distribution::, describes how to get and build the formal, released +versions of 'gawk'. - However, if you want to modify `gawk' and contribute back your + However, if you want to modify 'gawk' and contribute back your changes, you will probably wish to work with the development version. -To do so, you will need to access the `gawk' source code repository. +To do so, you will need to access the 'gawk' source code repository. The code is maintained using the Git distributed version control system (http://git-scm.com/). You will need to install it if your system doesn't have it. Once you have done so, use the command: git clone git://git.savannah.gnu.org/gawk.git -This clones the `gawk' repository. If you are behind a firewall that +This clones the 'gawk' repository. If you are behind a firewall that does not allow you to use the Git native protocol, you can still access the repository using: git clone http://git.savannah.gnu.org/r/gawk.git - Once you have made changes, you can use `git diff' to produce a -patch, and send that to the `gawk' maintainer; see *note Bugs::, for -how to do that. + Once you have made changes, you can use 'git diff' to produce a +patch, and send that to the 'gawk' maintainer; see *note Bugs::, for how +to do that. Once upon a time there was Git-CVS gateway for use by people who -could not install Git. However, this gateway no longer works, so you +could not install Git. However, this gateway no longer works, so you may have better luck using a more modern version control system like Bazaar, that has a Git plug-in for working with Git repositories. @@ -28231,217 +28115,217 @@ File: gawk.info, Node: Adding Code, Next: New Ports, Prev: Accessing The Sour C.2.2 Adding New Features ------------------------- -You are free to add any new features you like to `gawk'. However, if -you want your changes to be incorporated into the `gawk' distribution, +You are free to add any new features you like to 'gawk'. However, if +you want your changes to be incorporated into the 'gawk' distribution, there are several steps that you need to take in order to make it possible to include them: - 1. Before building the new feature into `gawk' itself, consider - writing it as an extension module (*note Dynamic Extensions::). - If that's not possible, continue with the rest of the steps in - this list. + 1. Before building the new feature into 'gawk' itself, consider + writing it as an extension module (*note Dynamic Extensions::). If + that's not possible, continue with the rest of the steps in this + list. 2. Be prepared to sign the appropriate paperwork. In order for the - FSF to distribute your changes, you must either place those - changes in the public domain and submit a signed statement to that - effect, or assign the copyright in your changes to the FSF. Both - of these actions are easy to do and _many_ people have done so - already. If you have questions, please contact me (*note Bugs::), - or . + FSF to distribute your changes, you must either place those changes + in the public domain and submit a signed statement to that effect, + or assign the copyright in your changes to the FSF. Both of these + actions are easy to do and _many_ people have done so already. If + you have questions, please contact me (*note Bugs::), or + . 3. Get the latest version. It is much easier for me to integrate - changes if they are relative to the most recent distributed - version of `gawk', or better yet, relative to the latest code in - the Git repository. If your version of `gawk' is very old, I may - not be able to integrate your changes at all. (*Note Getting::, - for information on getting the latest version of `gawk'.) - - 4. See *note (Version)Top:: standards, GNU Coding Standards. This - document describes how GNU software should be written. If you + changes if they are relative to the most recent distributed version + of 'gawk', or better yet, relative to the latest code in the Git + repository. If your version of 'gawk' is very old, I may not be + able to integrate your changes at all. (*Note Getting::, for + information on getting the latest version of 'gawk'.) + + 4. See *note (Version, standards, GNU Coding Standards)Top::. This + document describes how GNU software should be written. If you haven't read it, please do so, preferably _before_ starting to - modify `gawk'. (The `GNU Coding Standards' are available from the + modify 'gawk'. (The 'GNU Coding Standards' are available from the GNU Project's web site (http://www.gnu.org/prep/standards_toc.html). Texinfo, Info, and DVI versions are also available.) - 5. Use the `gawk' coding style. The C code for `gawk' follows the - instructions in the `GNU Coding Standards', with minor exceptions. + 5. Use the 'gawk' coding style. The C code for 'gawk' follows the + instructions in the 'GNU Coding Standards', with minor exceptions. The code is formatted using the traditional "K&R" style, particularly as regards to the placement of braces and the use of - TABs. In brief, the coding rules for `gawk' are as follows: + TABs. In brief, the coding rules for 'gawk' are as follows: * Use ANSI/ISO style (prototype) function headers when defining functions. * Put the name of the function at the beginning of its own line. - * Put the return type of the function, even if it is `int', on + * Put the return type of the function, even if it is 'int', on the line above the line with the name and arguments of the function. * Put spaces around parentheses used in control structures - (`if', `while', `for', `do', `switch', and `return'). + ('if', 'while', 'for', 'do', 'switch', and 'return'). * Do not put spaces in front of parentheses used in function calls. - * Put spaces around all C operators and after commas in - function calls. + * Put spaces around all C operators and after commas in function + calls. * Do not use the comma operator to produce multiple side - effects, except in `for' loop initialization and increment + effects, except in 'for' loop initialization and increment parts, and in macro bodies. * Use real TABs for indenting, not spaces. * Use the "K&R" brace layout style. - * Use comparisons against `NULL' and `'\0'' in the conditions of - `if', `while', and `for' statements, as well as in the `case's - of `switch' statements, instead of just the plain pointer or + * Use comparisons against 'NULL' and ''\0'' in the conditions of + 'if', 'while', and 'for' statements, as well as in the 'case's + of 'switch' statements, instead of just the plain pointer or character value. - * Use `true' and `false' for `bool' values, the `NULL' symbolic - constant for pointer values, and the character constant - `'\0'' where appropriate, instead of `1' and `0'. + * Use 'true' and 'false' for 'bool' values, the 'NULL' symbolic + constant for pointer values, and the character constant ''\0'' + where appropriate, instead of '1' and '0'. * Provide one-line descriptive comments for each function. - * Do not use the `alloca()' function for allocating memory off + * Do not use the 'alloca()' function for allocating memory off the stack. Its use causes more portability trouble than is worth the minor benefit of not having to free the storage. - Instead, use `malloc()' and `free()'. + Instead, use 'malloc()' and 'free()'. - * Do not use comparisons of the form `! strcmp(a, b)' or - similar. As Henry Spencer once said, "`strcmp()' is not a - boolean!" Instead, use `strcmp(a, b) == 0'. + * Do not use comparisons of the form '! strcmp(a, b)' or + similar. As Henry Spencer once said, "'strcmp()' is not a + boolean!" Instead, use 'strcmp(a, b) == 0'. * If adding new bit flag values, use explicit hexadecimal - constants (`0x001', `0x002', `0x004', and son on) instead of - shifting one left by successive amounts (`(1<<0)', `(1<<1)', + constants ('0x001', '0x002', '0x004', and son on) instead of + shifting one left by successive amounts ('(1<<0)', '(1<<1)', and so on). NOTE: If I have to reformat your code to follow the coding - style used in `gawk', I may not bother to integrate your + style used in 'gawk', I may not bother to integrate your changes at all. 6. Update the documentation. Along with your new code, please supply new sections and/or chapters for this Info file. If at all possible, please use real Texinfo, instead of just supplying unformatted ASCII text (although even that is better than no - documentation at all). Conventions to be followed in `GAWK: - Effective AWK Programming' are provided after the `@bye' at the - end of the Texinfo source file. If possible, please update the - `man' page as well. + documentation at all). Conventions to be followed in 'GAWK: + Effective AWK Programming' are provided after the '@bye' at the end + of the Texinfo source file. If possible, please update the 'man' + page as well. You will also have to sign paperwork for your documentation changes. - 7. Submit changes as unified diffs. Use `diff -u -r -N' to compare - the original `gawk' source tree with your version. I recommend - using the GNU version of `diff', or best of all, `git diff' or - `git format-patch'. Send the output produced by `diff' to me when - you submit your changes. (*Note Bugs::, for the electronic mail + 7. Submit changes as unified diffs. Use 'diff -u -r -N' to compare + the original 'gawk' source tree with your version. I recommend + using the GNU version of 'diff', or best of all, 'git diff' or 'git + format-patch'. Send the output produced by 'diff' to me when you + submit your changes. (*Note Bugs::, for the electronic mail information.) Using this format makes it easy for me to apply your changes to the - master version of the `gawk' source code (using `patch'). If I + master version of the 'gawk' source code (using 'patch'). If I have to apply the changes manually, using a text editor, I may not do so, particularly if there are lots of changes. - 8. Include an entry for the `ChangeLog' file with your submission. - This helps further minimize the amount of work I have to do, - making it easier for me to accept patches. It is simplest if you - just make this part of your diff. + 8. Include an entry for the 'ChangeLog' file with your submission. + This helps further minimize the amount of work I have to do, making + it easier for me to accept patches. It is simplest if you just + make this part of your diff. Although this sounds like a lot of work, please remember that while -you may write the new code, I have to maintain it and support it. If it +you may write the new code, I have to maintain it and support it. If it isn't possible for me to do that with a minimum of extra work, then I probably will not.  File: gawk.info, Node: New Ports, Next: Derived Files, Prev: Adding Code, Up: Additions -C.2.3 Porting `gawk' to a New Operating System +C.2.3 Porting 'gawk' to a New Operating System ---------------------------------------------- -If you want to port `gawk' to a new operating system, there are several +If you want to port 'gawk' to a new operating system, there are several steps: 1. Follow the guidelines in *note Adding Code::, concerning coding style, submission of diffs, and so on. 2. Be prepared to sign the appropriate paperwork. In order for the - FSF to distribute your code, you must either place your code in - the public domain and submit a signed statement to that effect, or - assign the copyright in your code to the FSF. Both of these - actions are easy to do and _many_ people have done so already. If - you have questions, please contact me, or . + FSF to distribute your code, you must either place your code in the + public domain and submit a signed statement to that effect, or + assign the copyright in your code to the FSF. Both of these actions + are easy to do and _many_ people have done so already. If you have + questions, please contact me, or . 3. When doing a port, bear in mind that your code must coexist - peacefully with the rest of `gawk' and the other ports. Avoid - gratuitous changes to the system-independent parts of the code. If - at all possible, avoid sprinkling `#ifdef's just for your port + peacefully with the rest of 'gawk' and the other ports. Avoid + gratuitous changes to the system-independent parts of the code. If + at all possible, avoid sprinkling '#ifdef's just for your port throughout the code. If the changes needed for a particular system affect too much of the code, I probably will not accept them. In such a case, you - can, of course, distribute your changes on your own, as long as - you comply with the GPL (*note Copying::). + can, of course, distribute your changes on your own, as long as you + comply with the GPL (*note Copying::). - 4. A number of the files that come with `gawk' are maintained by other + 4. A number of the files that come with 'gawk' are maintained by other people. Thus, you should not change them unless it is for a very - good reason; i.e., changes are not out of the question, but - changes to these files are scrutinized extra carefully. The files - are `dfa.c', `dfa.h', `getopt.c', `getopt.h', `getopt1.c', - `getopt_int.h', `gettext.h', `regcomp.c', `regex.c', `regex.h', - `regex_internal.c', `regex_internal.h', and `regexec.c'. + good reason; i.e., changes are not out of the question, but changes + to these files are scrutinized extra carefully. The files are + 'dfa.c', 'dfa.h', 'getopt.c', 'getopt.h', 'getopt1.c', + 'getopt_int.h', 'gettext.h', 'regcomp.c', 'regex.c', 'regex.h', + 'regex_internal.c', 'regex_internal.h', and 'regexec.c'. 5. A number of other files are provided by the GNU Autotools - (Autoconf, Automake, and GNU `gettext'). You should not change - them either, unless it is for a very good reason. The files are - `ABOUT-NLS', `config.guess', `config.rpath', `config.sub', - `depcomp', `INSTALL', `install-sh', `missing', `mkinstalldirs', - `xalloc.h', and `ylwrap'. + (Autoconf, Automake, and GNU 'gettext'). You should not change + them either, unless it is for a very good reason. The files are + 'ABOUT-NLS', 'config.guess', 'config.rpath', 'config.sub', + 'depcomp', 'INSTALL', 'install-sh', 'missing', 'mkinstalldirs', + 'xalloc.h', and 'ylwrap'. 6. Be willing to continue to maintain the port. Non-Unix operating - systems are supported by volunteers who maintain the code needed - to compile and run `gawk' on their systems. If noone volunteers to + systems are supported by volunteers who maintain the code needed to + compile and run 'gawk' on their systems. If noone volunteers to maintain a port, it becomes unsupported and it may be necessary to remove it from the distribution. - 7. Supply an appropriate `gawkmisc.???' file. Each port has its own - `gawkmisc.???' that implements certain operating system specific - functions. This is cleaner than a plethora of `#ifdef's scattered - throughout the code. The `gawkmisc.c' in the main source - directory includes the appropriate `gawkmisc.???' file from each + 7. Supply an appropriate 'gawkmisc.???' file. Each port has its own + 'gawkmisc.???' that implements certain operating system specific + functions. This is cleaner than a plethora of '#ifdef's scattered + throughout the code. The 'gawkmisc.c' in the main source directory + includes the appropriate 'gawkmisc.???' file from each subdirectory. Be sure to update it as well. - Each port's `gawkmisc.???' file has a suffix reminiscent of the + Each port's 'gawkmisc.???' file has a suffix reminiscent of the machine or operating system for the port--for example, - `pc/gawkmisc.pc' and `vms/gawkmisc.vms'. The use of separate - suffixes, instead of plain `gawkmisc.c', makes it possible to move + 'pc/gawkmisc.pc' and 'vms/gawkmisc.vms'. The use of separate + suffixes, instead of plain 'gawkmisc.c', makes it possible to move files from a port's subdirectory into the main subdirectory, - without accidentally destroying the real `gawkmisc.c' file. + without accidentally destroying the real 'gawkmisc.c' file. (Currently, this is only an issue for the PC operating system ports.) - 8. Supply a `Makefile' as well as any other C source and header files - that are necessary for your operating system. All your code - should be in a separate subdirectory, with a name that is the same - as, or reminiscent of, either your operating system or the - computer system. If possible, try to structure things so that it - is not necessary to move files out of the subdirectory into the - main source directory. If that is not possible, then be sure to - avoid using names for your files that duplicate the names of files - in the main source directory. + 8. Supply a 'Makefile' as well as any other C source and header files + that are necessary for your operating system. All your code should + be in a separate subdirectory, with a name that is the same as, or + reminiscent of, either your operating system or the computer + system. If possible, try to structure things so that it is not + necessary to move files out of the subdirectory into the main + source directory. If that is not possible, then be sure to avoid + using names for your files that duplicate the names of files in the + main source directory. - 9. Update the documentation. Please write a section (or sections) - for this Info file describing the installation and compilation - steps needed to compile and/or install `gawk' for your system. + 9. Update the documentation. Please write a section (or sections) for + this Info file describing the installation and compilation steps + needed to compile and/or install 'gawk' for your system. Following these steps makes it much easier to integrate your changes -into `gawk' and have them coexist happily with other operating systems' +into 'gawk' and have them coexist happily with other operating systems' code that is already there. In the code that you supply and maintain, feel free to use a coding @@ -28453,17 +28337,17 @@ File: gawk.info, Node: Derived Files, Prev: New Ports, Up: Additions C.2.4 Why Generated Files Are Kept In Git ----------------------------------------- -If you look at the `gawk' source in the Git repository, you will notice +If you look at the 'gawk' source in the Git repository, you will notice that it includes files that are automatically generated by GNU -infrastructure tools, such as `Makefile.in' from Automake and even -`configure' from Autoconf. +infrastructure tools, such as 'Makefile.in' from Automake and even +'configure' from Autoconf. This is different from many Free Software projects that do not store -the derived files, because that keeps the repository less cluttered, -and it is easier to see the substantive changes when comparing versions -and trying to understand what changed between commits. +the derived files, because that keeps the repository less cluttered, and +it is easier to see the substantive changes when comparing versions and +trying to understand what changed between commits. - However, there are two reasons why the `gawk' maintainer likes to + However, there are two reasons why the 'gawk' maintainer likes to have everything in the repository. First, because it is then easy to reproduce any given version @@ -28471,30 +28355,30 @@ completely, without relying upon the availability of (older, likely obsolete, and maybe even impossible to find) other tools. As an extreme example, if you ever even think about trying to -compile, oh, say, the V7 `awk', you will discover that not only do you -have to bootstrap the V7 `yacc' to do so, but you also need the V7 -`lex'. And the latter is pretty much impossible to bring up on a -modern GNU/Linux system.(1) - - (Or, let's say `gawk' 1.2 required `bison' whatever-it-was in 1989 -and that there was no `awkgram.c' file in the repository. Is there a -guarantee that we could find that `bison' version? Or that _it_ would +compile, oh, say, the V7 'awk', you will discover that not only do you +have to bootstrap the V7 'yacc' to do so, but you also need the V7 +'lex'. And the latter is pretty much impossible to bring up on a modern +GNU/Linux system.(1) + + (Or, let's say 'gawk' 1.2 required 'bison' whatever-it-was in 1989 +and that there was no 'awkgram.c' file in the repository. Is there a +guarantee that we could find that 'bison' version? Or that _it_ would build?) - If the repository has all the generated files, then it's easy to -just check them out and build. (Or _easier_, depending upon how far -back we go.) + If the repository has all the generated files, then it's easy to just +check them out and build. (Or _easier_, depending upon how far back we +go.) And that brings us to the second (and stronger) reason why all the files really need to be in Git. It boils down to who do you cater -to--the `gawk' developer(s), or the user who just wants to check out a +to--the 'gawk' developer(s), or the user who just wants to check out a version and try it out? - The `gawk' maintainer wants it to be possible for any interested -`awk' user in the world to just clone the repository, check out the -branch of interest and build it. Without their having to have the -correct version(s) of the autotools.(2) That is the point of the -`bootstrap.sh' file. It touches the various other files in the right + The 'gawk' maintainer wants it to be possible for any interested +'awk' user in the world to just clone the repository, check out the +branch of interest and build it. Without their having to have the +correct version(s) of the autotools.(2) That is the point of the +'bootstrap.sh' file. It touches the various other files in the right order such that # The canonical incantation for building GNU software: @@ -28502,17 +28386,17 @@ order such that will _just work_. - This is extremely important for the `master' and `gawk-X.Y-stable' + This is extremely important for the 'master' and 'gawk-X.Y-stable' branches. - Further, the `gawk' maintainer would argue that it's also important -for the `gawk' developers. When he tried to check out the `xgawk' -branch(3) to build it, he couldn't. (No `ltmain.sh' file, and he had no + Further, the 'gawk' maintainer would argue that it's also important +for the 'gawk' developers. When he tried to check out the 'xgawk' +branch(3) to build it, he couldn't. (No 'ltmain.sh' file, and he had no idea how to create it, and that was not the only problem.) He felt _extremely_ frustrated. With respect to that branch, the maintainer is no different than Jane User who wants to try to build -`gawk-4.1-stable' or `master' from the repository. +'gawk-4.1-stable' or 'master' from the repository. Thus, the maintainer thinks that it's not just important, but critical, that for any given branch, the above incantation _just works_. @@ -28525,17 +28409,17 @@ critical, that for any given branch, the above incantation _just works_. A. It's the maintainer's job to merge them and he will deal with it. - B. He is really good at `git diff x y > /tmp/diff1 ; gvim + B. He is really good at 'git diff x y > /tmp/diff1 ; gvim /tmp/diff1' to remove the diffs that aren't of interest in order to review code. 2. It would certainly help if everyone used the same versions of the GNU tools as he does, which in general are the latest released - versions of Automake, Autoconf, `bison', and GNU `gettext'. + versions of Automake, Autoconf, 'bison', and GNU 'gettext'. - Installing from source is quite easy. It's how the maintainer - worked for years (and still works). He had `/usr/local/bin' at - the front of his `PATH' and just did: + Installing from source is quite easy. It's how the maintainer + worked for years (and still works). He had '/usr/local/bin' at the + front of his 'PATH' and just did: wget http://ftp.gnu.org/gnu/PACKAGE/PACKAGE-X.Y.Z.tar.gz tar -xpzvf PACKAGE-X.Y.Z.tar.gz @@ -28543,23 +28427,22 @@ critical, that for any given branch, the above incantation _just works_. ./configure && make && make check make install # as root - Most of the above was originally written by the maintainer to other -`gawk' developers. It raised the objection from one of the developers +'gawk' developers. It raised the objection from one of the developers "... that anybody pulling down the source from Git is not an end user." - However, this is not true. There are "power `awk' users" who can -build `gawk' (using the magic incantation shown previously) but who -can't program in C. Thus, the major branches should be kept buildable + However, this is not true. There are "power 'awk' users" who can +build 'gawk' (using the magic incantation shown previously) but who +can't program in C. Thus, the major branches should be kept buildable all the time. - It was then suggested that there be a `cron' job to create nightly + It was then suggested that there be a 'cron' job to create nightly tarballs of "the source." Here, the problem is that there are source -trees, corresponding to the various branches! So, nightly tarballs -aren't the answer, especially as the repository can go for weeks -without significant change being introduced. +trees, corresponding to the various branches! So, nightly tarballs +aren't the answer, especially as the repository can go for weeks without +significant change being introduced. - Fortunately, the Git server can meet this need. For any given branch + Fortunately, the Git server can meet this need. For any given branch named BRANCHNAME, use: wget http://git.savannah.gnu.org/cgit/gawk.git/snapshot/gawk-BRANCHNAME.tar.gz @@ -28568,18 +28451,18 @@ to retrieve a snapshot of the given branch. ---------- Footnotes ---------- - (1) We tried. It was painful. + (1) We tried. It was painful. (2) There is one GNU program that is (in our opinion) severely -difficult to bootstrap from the Git repository. For example, on the +difficult to bootstrap from the Git repository. For example, on the author's old (but still working) PowerPC Macintosh with Mac OS X 10.5, it was necessary to bootstrap a ton of software, starting with Git itself, in order to try to work with the latest code. It's not pleasant, and especially on older systems, it's a big waste of time. - Starting with the latest tarball was no picnic either. The -maintainers had dropped `.gz' and `.bz2' files and only distribute -`.tar.xz' files. It was necessary to bootstrap `xz' first! + Starting with the latest tarball was no picnic either. The +maintainers had dropped '.gz' and '.bz2' files and only distribute +'.tar.xz' files. It was necessary to bootstrap 'xz' first! (3) A branch (since removed) created by one of the other developers that did not include the generated files. @@ -28591,15 +28474,16 @@ C.3 Probable Future Extensions ============================== AWK is a language similar to PERL, only considerably more elegant. - -- Arnold Robbins + -- _Arnold Robbins_ - Hey! -- Larry Wall + Hey! + -- _Larry Wall_ - The `TODO' file in the `master' branch of the `gawk' Git repository + The 'TODO' file in the 'master' branch of the 'gawk' Git repository lists possible future enhancements. Some of these relate to the source -code, and others to possible new features. Please see that file for -the list. *Note Additions::, if you are interested in tackling any of -the projects listed there. +code, and others to possible new features. Please see that file for the +list. *Note Additions::, if you are interested in tackling any of the +projects listed there.  File: gawk.info, Node: Implementation Limitations, Next: Extension Design, Prev: Future Extensions, Up: Notes @@ -28607,30 +28491,31 @@ File: gawk.info, Node: Implementation Limitations, Next: Extension Design, Pr C.4 Some Limitations of the Implementation ========================================== -This following table describes limits of `gawk' on a Unix-like system -(although it is variable even then). Other systems may have different +This following table describes limits of 'gawk' on a Unix-like system +(although it is variable even then). Other systems may have different limits. Item Limit --------------------------------------------------------------------------- +-------------------------------------------------------------------------- Characters in a character 2^(number of bits per byte) -class -Length of input record `MAX_INT' +class +Length of input record 'MAX_INT' Length of output record Unlimited Length of source line Unlimited -Number of fields in a record `MAX_LONG' +Number of fields in a 'MAX_LONG' +record Number of file redirections Unlimited -Number of input records in `MAX_LONG' -one file -Number of input records `MAX_LONG' -total +Number of input records in 'MAX_LONG' +one file +Number of input records 'MAX_LONG' +total Number of pipe redirections min(number of processes per user, number of open files) Numeric values Double-precision floating point (if not using MPFR) -Size of a field `MAX_INT' -Size of a literal string `MAX_INT' -Size of a printf string `MAX_INT' +Size of a field 'MAX_INT' +Size of a literal string 'MAX_INT' +Size of a printf string 'MAX_INT'  File: gawk.info, Node: Extension Design, Next: Old Extension Mechanism, Prev: Implementation Limitations, Up: Notes @@ -28641,15 +28526,15 @@ C.5 Extension API Design This minor node documents the design of the extension API, including a discussion of some of the history and problems that needed to be solved. - The first version of extensions for `gawk' was developed in the -mid-1990s and released with `gawk' 3.1 in the late 1990s. The basic + The first version of extensions for 'gawk' was developed in the +mid-1990s and released with 'gawk' 3.1 in the late 1990s. The basic mechanisms and design remained unchanged for close to 15 years, until 2012. - The old extension mechanism used data types and functions from -`gawk' itself, with a "clever hack" to install extension functions. + The old extension mechanism used data types and functions from 'gawk' +itself, with a "clever hack" to install extension functions. - `gawk' included some sample extensions, of which a few were really + 'gawk' included some sample extensions, of which a few were really useful. However, it was clear from the outset that the extension mechanism was bolted onto the side and was not really well thought out. @@ -28668,33 +28553,33 @@ C.5.1 Problems With The Old Mechanism The old extension mechanism had several problems: - * It depended heavily upon `gawk' internals. Any time the `NODE' + * It depended heavily upon 'gawk' internals. Any time the 'NODE' structure(1) changed, an extension would have to be recompiled. Furthermore, to really write extensions required understanding - something about `gawk''s internal functions. There was some + something about 'gawk''s internal functions. There was some documentation in this Info file, but it was quite minimal. - * Being able to call into `gawk' from an extension required linker - facilities that are common on Unix-derived systems but that did - not work on MS-Windows systems; users wanting extensions on - MS-Windows had to statically link them into `gawk', even though - MS-Windows supports dynamic loading of shared objects. + * Being able to call into 'gawk' from an extension required linker + facilities that are common on Unix-derived systems but that did not + work on MS-Windows systems; users wanting extensions on MS-Windows + had to statically link them into 'gawk', even though MS-Windows + supports dynamic loading of shared objects. - * The API would change occasionally as `gawk' changed; no + * The API would change occasionally as 'gawk' changed; no compatibility between versions was ever offered or planned for. - Despite the drawbacks, the `xgawk' project developers forked `gawk' -and developed several significant extensions. They also enhanced -`gawk''s facilities relating to file inclusion and shared object access. + Despite the drawbacks, the 'xgawk' project developers forked 'gawk' +and developed several significant extensions. They also enhanced +'gawk''s facilities relating to file inclusion and shared object access. A new API was desired for a long time, but only in 2012 did the -`gawk' maintainer and the `xgawk' developers finally start working on -it together. More information about the `xgawk' project is provided in +'gawk' maintainer and the 'xgawk' developers finally start working on it +together. More information about the 'xgawk' project is provided in *note gawkextlib::. ---------- Footnotes ---------- - (1) A critical central data structure inside `gawk'. + (1) A critical central data structure inside 'gawk'.  File: gawk.info, Node: Extension New Mechanism Goals, Next: Extension Other Design Decisions, Prev: Old Extension Problems, Up: Extension Design @@ -28704,21 +28589,21 @@ C.5.2 Goals For A New Mechanism Some goals for the new API were: - * The API should be independent of `gawk' internals. Changes in - `gawk' internals should not be visible to the writer of an + * The API should be independent of 'gawk' internals. Changes in + 'gawk' internals should not be visible to the writer of an extension function. - * The API should provide _binary_ compatibility across `gawk' + * The API should provide _binary_ compatibility across 'gawk' releases as long as the API itself does not change. * The API should enable extensions written in C or C++ to have - roughly the same "appearance" to `awk'-level code as `awk' - functions do. This means that extensions should have: + roughly the same "appearance" to 'awk'-level code as 'awk' + functions do. This means that extensions should have: - The ability to access function parameters. - - The ability to turn an undefined parameter into an array - (call by reference). + - The ability to turn an undefined parameter into an array (call + by reference). - The ability to create, access and update global variables. @@ -28726,20 +28611,20 @@ Some goals for the new API were: flattening") in order to loop over all the element in an easy fashion for C code. - - The ability to create arrays (including `gawk''s true arrays + - The ability to create arrays (including 'gawk''s true arrays of arrays). Some additional important goals were: * The API should use only features in ISO C 90, so that extensions - can be written using the widest range of C and C++ compilers. The - header should include the appropriate `#ifdef __cplusplus' and - `extern "C"' magic so that a C++ compiler could be used. (If - using C++, the runtime system has to be smart enough to call any - constructors and destructors, as `gawk' is a C program. As of this + can be written using the widest range of C and C++ compilers. The + header should include the appropriate '#ifdef __cplusplus' and + 'extern "C"' magic so that a C++ compiler could be used. (If using + C++, the runtime system has to be smart enough to call any + constructors and destructors, as 'gawk' is a C program. As of this writing, this has not been tested.) - * The API mechanism should not require access to `gawk''s symbols(1) + * The API mechanism should not require access to 'gawk''s symbols(1) by the compile-time or dynamic linker, in order to enable creation of extensions that also work on MS-Windows. @@ -28747,29 +28632,29 @@ Some goals for the new API were: that should be available to extensions, which were also subsequently provided: - * Extensions should have the ability to hook into `gawk''s I/O - redirection mechanism. In particular, the `xgawk' developers + * Extensions should have the ability to hook into 'gawk''s I/O + redirection mechanism. In particular, the 'xgawk' developers provided a so-called "open hook" to take over reading records. During development, this was generalized to allow extensions to hook into input processing, output processing, and two-way I/O. * An extension should be able to provide a "call back" function to - perform cleanup actions when `gawk' exits. + perform cleanup actions when 'gawk' exits. * An extension should be able to provide a version string so that - `gawk''s `--version' option can provide information about + 'gawk''s '--version' option can provide information about extensions as well. - The requirement to avoid access to `gawk''s symbols is, at first + The requirement to avoid access to 'gawk''s symbols is, at first glance, a difficult one to meet. One design, apparently used by Perl and Ruby and maybe others, would -be to make the mainline `gawk' code into a library, with the `gawk' -utility a small C `main()' function linked against the library. +be to make the mainline 'gawk' code into a library, with the 'gawk' +utility a small C 'main()' function linked against the library. This seemed like the tail wagging the dog, complicating build and -installation and making a simple copy of the `gawk' executable from one -system to another (or one place to another on the same system!) into a +installation and making a simple copy of the 'gawk' executable from one +system to another (or one place to another on the same system!) into a chancy operation. Pat Rankin suggested the solution that was adopted. *Note Extension @@ -28778,7 +28663,7 @@ Mechanism Outline::, for the details. ---------- Footnotes ---------- (1) The "symbols" are the variables and functions defined inside -`gawk'. Access to these symbols by code external to `gawk' loaded +'gawk'. Access to these symbols by code external to 'gawk' loaded dynamically at runtime is problematic on MS-Windows.  @@ -28788,40 +28673,40 @@ C.5.3 Other Design Decisions ---------------------------- As an arbitrary design decision, extensions can read the values of -built-in variables and arrays (such as `ARGV' and `FS'), but cannot -change them, with the exception of `PROCINFO'. +built-in variables and arrays (such as 'ARGV' and 'FS'), but cannot +change them, with the exception of 'PROCINFO'. The reason for this is to prevent an extension function from -affecting the flow of an `awk' program outside its control. While a -real `awk' function can do what it likes, that is at the discretion of +affecting the flow of an 'awk' program outside its control. While a +real 'awk' function can do what it likes, that is at the discretion of the programmer. An extension function should provide a service or make -a C API available for use within `awk', and not mess with `FS' or -`ARGC' and `ARGV'. +a C API available for use within 'awk', and not mess with 'FS' or 'ARGC' +and 'ARGV'. - In addition, it becomes easy to start down a slippery slope. How -much access to `gawk' facilities do extensions need? Do they need -`getline'? What about calling `gsub()' or compiling regular -expressions? What about calling into `awk' functions? (_That_ would be + In addition, it becomes easy to start down a slippery slope. How +much access to 'gawk' facilities do extensions need? Do they need +'getline'? What about calling 'gsub()' or compiling regular +expressions? What about calling into 'awk' functions? (_That_ would be messy.) - In order to avoid these issues, the `gawk' developers chose to start + In order to avoid these issues, the 'gawk' developers chose to start with the simplest, most basic features that are still truly useful. - Another decision is that although `gawk' provides nice things like + Another decision is that although 'gawk' provides nice things like MPFR, and arrays indexed internally by integers, these features are not being brought out to the API in order to keep things simple and close to -traditional `awk' semantics. (In fact, arrays indexed internally by +traditional 'awk' semantics. (In fact, arrays indexed internally by integers are so transparent that they aren't even documented!) - Additionally, all functions in the API check that their pointer -input parameters are not `NULL'. If they are, they return an error. -(It is a good idea for extension code to verify that pointers received -from `gawk' are not `NULL'. Such a thing should not happen, but the -`gawk' developers are only human, and they have been known to -occasionally make mistakes.) + Additionally, all functions in the API check that their pointer input +parameters are not 'NULL'. If they are, they return an error. (It is a +good idea for extension code to verify that pointers received from +'gawk' are not 'NULL'. Such a thing should not happen, but the 'gawk' +developers are only human, and they have been known to occasionally make +mistakes.) - With time, the API will undoubtedly evolve; the `gawk' developers -expect this to be driven by user needs. For now, the current API seems + With time, the API will undoubtedly evolve; the 'gawk' developers +expect this to be driven by user needs. For now, the current API seems to provide a minimal yet powerful set of features for creating extensions. @@ -28833,12 +28718,12 @@ C.5.4 Room For Future Growth The API can later be expanded, in two ways: - * `gawk' passes an "extension id" into the extension when it first + * 'gawk' passes an "extension id" into the extension when it first loads the extension. The extension then passes this id back to - `gawk' with each function call. This mechanism allows `gawk' to + 'gawk' with each function call. This mechanism allows 'gawk' to identify the extension calling into it, should it need to know. - * Similarly, the extension passes a "name space" into `gawk' when it + * Similarly, the extension passes a "name space" into 'gawk' when it registers each extension function. This accommodates a possible future mechanism for grouping extension functions and possibly avoiding name conflicts. @@ -28853,34 +28738,34 @@ C.6 Compatibility For Old Extensions ==================================== *note Dynamic Extensions::, describes the supported API and mechanisms -for writing extensions for `gawk'. This API was introduced in version -4.1. However, for many years `gawk' provided an extension mechanism -that required knowledge of `gawk' internals and that was not as well +for writing extensions for 'gawk'. This API was introduced in version +4.1. However, for many years 'gawk' provided an extension mechanism +that required knowledge of 'gawk' internals and that was not as well designed. - In order to provide a transition period, `gawk' version 4.1 -continues to support the original extension mechanism. This will be -true for the life of exactly one major release. This support will be -withdrawn, and removed from the source code, at the next major release. + In order to provide a transition period, 'gawk' version 4.1 continues +to support the original extension mechanism. This will be true for the +life of exactly one major release. This support will be withdrawn, and +removed from the source code, at the next major release. Briefly, original-style extensions should be compiled by including -the `awk.h' header file in the extension source code. Additionally, you -must define the identifier `GAWK' when building (use `-DGAWK' with -Unix-style compilers). Otherwise, the definitions in `gawkapi.h' will -cause conflicts with those in `awk.h' and your extension will not +the 'awk.h' header file in the extension source code. Additionally, you +must define the identifier 'GAWK' when building (use '-DGAWK' with +Unix-style compilers). Otherwise, the definitions in 'gawkapi.h' will +cause conflicts with those in 'awk.h' and your extension will not compile. Just as in previous versions, you load an old-style extension with -the `extension()' built-in function (which is not otherwise documented). +the 'extension()' built-in function (which is not otherwise documented). This function in turn finds and loads the shared object file containing -the extension and calls its `dl_load()' C routine. +the extension and calls its 'dl_load()' C routine. Because original-style and new-style extensions use different -initialization routines (`dl_load()' versus `dlload()'), they may safely -be installed in the same directory (to be found by `AWKLIBPATH') -without conflict. +initialization routines ('dl_load()' versus 'dlload()'), they may safely +be installed in the same directory (to be found by 'AWKLIBPATH') without +conflict. - The `gawk' development team strongly recommends that you convert any + The 'gawk' development team strongly recommends that you convert any old extensions that you may have to use the new API described in *note Dynamic Extensions::. @@ -28890,30 +28775,28 @@ File: gawk.info, Node: Notes summary, Prev: Old Extension Mechanism, Up: Note C.7 Summary =========== - * `gawk''s extensions can be disabled with either the - `--traditional' option or with the `--posix' option. The - `--parsedebug' option is available if `gawk' is compiled with - `-DDEBUG'. + * 'gawk''s extensions can be disabled with either the '--traditional' + option or with the '--posix' option. The '--parsedebug' option is + available if 'gawk' is compiled with '-DDEBUG'. - * The source code for `gawk' is maintained in a publicly accessable - Git repository. Anyone may check it out and view the source. + * The source code for 'gawk' is maintained in a publicly accessable + Git repository. Anyone may check it out and view the source. - * Contributions to `gawk' are welcome. Following the steps outlined + * Contributions to 'gawk' are welcome. Following the steps outlined in this major node will make it easier to integrate your - contributions into the code base. This applies both to new - feature contributions and to ports to additional operating systems. + contributions into the code base. This applies both to new feature + contributions and to ports to additional operating systems. - * `gawk' has some limits--generally those that are imposed by the + * 'gawk' has some limits--generally those that are imposed by the machine architecture. * The extension API design was intended to solve a number of problems with the previous extension mechanism, enable features needed by - the `xgawk' project, and provide binary compatibility going + the 'xgawk' project, and provide binary compatibility going forward. * The previous extension mechanism is still supported in version 4.1 - of `gawk', but it _will_ be removed in the next major release. - + of 'gawk', but it _will_ be removed in the next major release.  File: gawk.info, Node: Basic Concepts, Next: Glossary, Prev: Notes, Up: Top @@ -28923,7 +28806,7 @@ Appendix D Basic Programming Concepts This major node attempts to define some of the basic concepts and terms that are used throughout the rest of this Info file. As this Info file -is specifically about `awk', and not about computer programming in +is specifically about 'awk', and not about computer programming in general, the coverage here is by necessity fairly cursory and simplistic. (If you need more background, there are many other introductory texts that you should refer to instead.) @@ -28940,39 +28823,41 @@ D.1 What a Program Does ======================= At the most basic level, the job of a program is to process some input -data and produce results. See *note figure-general-flow::. +data and produce results. See *note Figure D.1: figure-general-flow. - _______ -+------+ / \ +---------+ +[image src="general-program.txt" alt="General program flow" text=" _______ ++------+ / \\ +---------+ | Data | -----> < Program > -----> | Results | -+------+ \_______/ +---------+ ++------+ \\_______/ +---------+"] + Figure D.1: General Program Flow - The "program" in the figure can be either a compiled program(1) -(such as `ls'), or it may be "interpreted". In the latter case, a -machine-executable program such as `awk' reads your program, and then + The "program" in the figure can be either a compiled program(1) (such +as 'ls'), or it may be "interpreted". In the latter case, a +machine-executable program such as 'awk' reads your program, and then uses the instructions in your program to process the data. When you write a program, it usually consists of the following, very -basic set of steps, as shown in *note figure-process-flow::: +basic set of steps, as shown in *note Figure D.2: figure-process-flow.: - ______ -+----------------+ / More \ No +----------+ +[image src="process-flow.txt" alt="Basic Program Stages" text=" ______ ++----------------+ / More \\ No +----------+ | Initialization | -------> < Data > -------> | Clean Up | -+----------------+ ^ \ ? / +----------+ ++----------------+ ^ \\ ? / +----------+ | +--+-+ | | Yes | | | V | +---------+ +-----+ Process | - +---------+ + +---------+"] + Figure D.2: Basic Program Steps Initialization These are the things you do before actually starting to process - data, such as checking arguments, initializing any data you need - to work with, and so on. This step corresponds to `awk''s `BEGIN' + data, such as checking arguments, initializing any data you need to + work with, and so on. This step corresponds to 'awk''s 'BEGIN' rule (*note BEGIN/END::). If you were baking a cake, this might consist of laying out all the @@ -28985,7 +28870,7 @@ Processing In most programming languages, you have to manually manage the reading of data, checking to see if there is more each time you - read a chunk. `awk''s pattern-action paradigm (*note Getting + read a chunk. 'awk''s pattern-action paradigm (*note Getting Started::) handles the mechanics of this for you. In baking a cake, the processing corresponds to the actual labor: @@ -28994,7 +28879,7 @@ Processing Clean Up Once you've processed all the data, you may have things you need to - do before exiting. This step corresponds to `awk''s `END' rule + do before exiting. This step corresponds to 'awk''s 'END' rule (*note BEGIN/END::). After the cake comes out of the oven, you still have to wrap it in @@ -29002,9 +28887,9 @@ Clean Up mixing bowls and utensils. An "algorithm" is a detailed set of instructions necessary to -accomplish a task, or process data. It is much the same as a recipe -for baking a cake. Programs implement algorithms. Often, it is up to -you to design the algorithm and implement it, simultaneously. +accomplish a task, or process data. It is much the same as a recipe for +baking a cake. Programs implement algorithms. Often, it is up to you +to design the algorithm and implement it, simultaneously. The "logical chunks" we talked about previously are called "records", similar to the records a company keeps on employees, a school keeps for @@ -29018,12 +28903,12 @@ results, not too surprisingly, is termed "output". They are often referred to together as "input/output," and even more often, as "I/O" for short. (You will also see "input" and "output" used as verbs.) - `awk' manages the reading of data for you, as well as the breaking -it up into records and fields. Your program's job is to tell `awk' -what to do with the data. You do this by describing "patterns" in the -data to look for, and "actions" to execute when those patterns are -seen. This "data-driven" nature of `awk' programs usually makes them -both easier to write and easier to read. + 'awk' manages the reading of data for you, as well as the breaking it +up into records and fields. Your program's job is to tell 'awk' what to +do with the data. You do this by describing "patterns" in the data to +look for, and "actions" to execute when those patterns are seen. This +"data-driven" nature of 'awk' programs usually makes them both easier to +write and easier to read. ---------- Footnotes ---------- @@ -29039,18 +28924,18 @@ D.2 Data Values in a Computer In a program, you keep track of information and values in things called "variables". A variable is just a name for a given value, such as -`first_name', `last_name', `address', and so on. `awk' has several +'first_name', 'last_name', 'address', and so on. 'awk' has several predefined variables, and it has special names to refer to the current input record and the fields of the record. You may also group multiple associated values under one name, as an array. - Data, particularly in `awk', consists of either numeric values, such + Data, particularly in 'awk', consists of either numeric values, such as 42 or 3.1415927, or string values. String values are essentially anything that's not a number, such as a name. Strings are sometimes referred to as "character data", since they store the individual -characters that comprise them. Individual variables, as well as -numeric and string variables, are referred to as "scalar" values. -Groups of values, such as arrays, are not scalars. +characters that comprise them. Individual variables, as well as numeric +and string variables, are referred to as "scalar" values. Groups of +values, such as arrays, are not scalars. *note Computer Arithmetic::, provided a basic introduction to numeric types (integer and floating-point) and how they are used in a computer. @@ -29060,41 +28945,41 @@ presented. While you are probably used to the idea of a number without a value (i.e., zero), it takes a bit more getting used to the idea of zero-length character data. Nevertheless, such a thing exists. It is -called the "null string". The null string is character data that has -no value. In other words, it is empty. It is written in `awk' programs -like this: `""'. +called the "null string". The null string is character data that has no +value. In other words, it is empty. It is written in 'awk' programs +like this: '""'. Humans are used to working in decimal; i.e., base 10. In base 10, numbers go from 0 to 9, and then "roll over" into the next column. -(Remember grade school? 42 = 4 x 10 + 2.) +(Remember grade school? 42 = 4 x 10 + 2.) There are other number bases though. Computers commonly use base 2 or "binary", base 8 or "octal", and base 16 or "hexadecimal". In binary, each column represents two times the value in the column to its -right. Each column may contain either a 0 or a 1. Thus, binary 1010 +right. Each column may contain either a 0 or a 1. Thus, binary 1010 represents (1 x 8) + (0 x 4) + (1 x 2) + (0 x 1), or decimal 10. Octal and hexadecimal are discussed more in *note Nondecimal-numbers::. At the very lowest level, computers store values as groups of binary digits, or "bits". Modern computers group bits into groups of eight, -called "bytes". Advanced applications sometimes have to manipulate -bits directly, and `gawk' provides functions for doing so. +called "bytes". Advanced applications sometimes have to manipulate bits +directly, and 'gawk' provides functions for doing so. Programs are written in programming languages. Hundreds, if not thousands, of programming languages exist. One of the most popular is the C programming language. The C language had a very strong influence -on the design of the `awk' language. +on the design of the 'awk' language. - There have been several versions of C. The first is often referred -to as "K&R" C, after the initials of Brian Kernighan and Dennis Ritchie, -the authors of the first book on C. (Dennis Ritchie created the -language, and Brian Kernighan was one of the creators of `awk'.) + There have been several versions of C. The first is often referred to +as "K&R" C, after the initials of Brian Kernighan and Dennis Ritchie, +the authors of the first book on C. (Dennis Ritchie created the +language, and Brian Kernighan was one of the creators of 'awk'.) In the mid-1980s, an effort began to produce an international -standard for C. This work culminated in 1989, with the production of -the ANSI standard for C. This standard became an ISO standard in 1990. -In 1999, a revised ISO C standard was approved and released. Where it -makes sense, POSIX `awk' is compatible with 1999 ISO C. +standard for C. This work culminated in 1989, with the production of the +ANSI standard for C. This standard became an ISO standard in 1990. In +1999, a revised ISO C standard was approved and released. Where it +makes sense, POSIX 'awk' is compatible with 1999 ISO C.  File: gawk.info, Node: Glossary, Next: Copying, Prev: Basic Concepts, Up: Top @@ -29103,42 +28988,42 @@ Glossary ******** Action - A series of `awk' statements attached to a rule. If the rule's - pattern matches an input record, `awk' executes the rule's action. + A series of 'awk' statements attached to a rule. If the rule's + pattern matches an input record, 'awk' executes the rule's action. Actions are always enclosed in braces. (*Note Action Overview::.) -Amazing `awk' Assembler +Amazing 'awk' Assembler Henry Spencer at the University of Toronto wrote a retargetable - assembler completely as `sed' and `awk' scripts. It is thousands + assembler completely as 'sed' and 'awk' scripts. It is thousands of lines long, including machine descriptions for several eight-bit microcomputers. It is a good example of a program that would have been better written in another language. You can get it from - `http://awk.info/?awk100/aaa'. + . Ada A programming language originally defined by the U.S. Department of - Defense for embedded programming. It was designed to enforce good + Defense for embedded programming. It was designed to enforce good Software Engineering practices. -Amazingly Workable Formatter (`awf') +Amazingly Workable Formatter ('awf') Henry Spencer at the University of Toronto wrote a formatter that - accepts a large subset of the `nroff -ms' and `nroff -man' - formatting commands, using `awk' and `sh'. It is available from - `http://awk.info/?tools/awf'. + accepts a large subset of the 'nroff -ms' and 'nroff -man' + formatting commands, using 'awk' and 'sh'. It is available from + . Anchor - The regexp metacharacters `^' and `$', which force the match to - the beginning or end of the string, respectively. + The regexp metacharacters '^' and '$', which force the match to the + beginning or end of the string, respectively. ANSI The American National Standards Institute. This organization - produces many standards, among them the standards for the C and - C++ programming languages. These standards often become - international standards as well. See also "ISO." + produces many standards, among them the standards for the C and C++ + programming languages. These standards often become international + standards as well. See also "ISO." Array A grouping of multiple values under the same name. Most languages - just provide sequential arrays. `awk' provides associative arrays. + just provide sequential arrays. 'awk' provides associative arrays. Assertion A statement in a program that a condition is true at this point in @@ -29146,7 +29031,7 @@ Assertion to behave. Assignment - An `awk' expression that changes the value of some `awk' variable + An 'awk' expression that changes the value of some 'awk' variable or data object. An object that you can assign to is called an "lvalue". The assigned values are called "rvalues". *Note Assignment Ops::. @@ -29155,29 +29040,29 @@ Associative Array Arrays in which the indices may be numbers or strings, not just sequential integers in a fixed range. -`awk' Language - The language in which `awk' programs are written. +'awk' Language + The language in which 'awk' programs are written. -`awk' Program - An `awk' program consists of a series of "patterns" and "actions", +'awk' Program + An 'awk' program consists of a series of "patterns" and "actions", collectively known as "rules". For each input record given to the - program, the program's rules are all processed in turn. `awk' + program, the program's rules are all processed in turn. 'awk' programs may also contain function definitions. -`awk' Script - Another name for an `awk' program. +'awk' Script + Another name for an 'awk' program. Bash The GNU version of the standard shell (the Bourne-Again SHell). See also "Bourne Shell." Bit - Short for "Binary Digit." All values in computer memory - ultimately reduce to binary digits: values that are either zero or - one. Groups of bits may be interpreted differently--as integers, + Short for "Binary Digit." All values in computer memory ultimately + reduce to binary digits: values that are either zero or one. + Groups of bits may be interpreted differently--as integers, floating-point numbers, character data, addresses of other memory - objects, or other data. `awk' lets you work with floating-point - numbers and strings. `gawk' lets you manipulate bit values with + objects, or other data. 'awk' lets you work with floating-point + numbers and strings. 'gawk' lets you manipulate bit values with the built-in functions described in *note Bitwise Functions::. Computers are often defined by how many bits they use to represent @@ -29186,53 +29071,53 @@ Bit essentially disappeared. Boolean Expression - Named after the English mathematician Boole. See also "Logical + Named after the English mathematician Boole. See also "Logical Expression." Bourne Shell - The standard shell (`/bin/sh') on Unix and Unix-like systems, + The standard shell ('/bin/sh') on Unix and Unix-like systems, originally written by Steven R. Bourne at Bell Laboratories. Many - shells (Bash, `ksh', `pdksh', `zsh') are generally upwardly + shells (Bash, 'ksh', 'pdksh', 'zsh') are generally upwardly compatible with the Bourne shell. Built-in Function - The `awk' language provides built-in functions that perform various + The 'awk' language provides built-in functions that perform various numerical, I/O-related, and string computations. Examples are - `sqrt()' (for the square root of a number) and `substr()' (for a - substring of a string). `gawk' provides functions for timestamp + 'sqrt()' (for the square root of a number) and 'substr()' (for a + substring of a string). 'gawk' provides functions for timestamp management, bit manipulation, array sorting, type checking, and runtime string translation. (*Note Built-in::.) Built-in Variable - `ARGC', `ARGV', `CONVFMT', `ENVIRON', `FILENAME', `FNR', `FS', - `NF', `NR', `OFMT', `OFS', `ORS', `RLENGTH', `RSTART', `RS', and - `SUBSEP' are the variables that have special meaning to `awk'. In - addition, `ARGIND', `BINMODE', `ERRNO', `FIELDWIDTHS', `FPAT', - `IGNORECASE', `LINT', `PROCINFO', `RT', and `TEXTDOMAIN' are the - variables that have special meaning to `gawk'. Changing some of - them affects `awk''s running environment. (*Note Built-in + 'ARGC', 'ARGV', 'CONVFMT', 'ENVIRON', 'FILENAME', 'FNR', 'FS', + 'NF', 'NR', 'OFMT', 'OFS', 'ORS', 'RLENGTH', 'RSTART', 'RS', and + 'SUBSEP' are the variables that have special meaning to 'awk'. In + addition, 'ARGIND', 'BINMODE', 'ERRNO', 'FIELDWIDTHS', 'FPAT', + 'IGNORECASE', 'LINT', 'PROCINFO', 'RT', and 'TEXTDOMAIN' are the + variables that have special meaning to 'gawk'. Changing some of + them affects 'awk''s running environment. (*Note Built-in Variables::.) Braces - The characters `{' and `}'. Braces are used in `awk' for + The characters '{' and '}'. Braces are used in 'awk' for delimiting actions, compound statements, and function bodies. C The system programming language that most GNU software is written - in. The `awk' programming language has C-like syntax, and this - Info file points out similarities between `awk' and C when + in. The 'awk' programming language has C-like syntax, and this + Info file points out similarities between 'awk' and C when appropriate. - In general, `gawk' attempts to be as similar to the 1990 version - of ISO C as makes sense. + In general, 'gawk' attempts to be as similar to the 1990 version of + ISO C as makes sense. C++ A popular object-oriented programming language derived from C. Character Set The set of numeric codes used by a computer system to represent the - characters (letters, numbers, punctuation, etc.) of a particular - country or place. The most common character set in use today is + characters (letters, numbers, punctuation, etc.) of a particular + country or place. The most common character set in use today is ASCII (American Standard Code for Information Interchange). Many European countries use an extension of ASCII known as ISO-8859-1 (ISO Latin-1). The Unicode character set (http://www.unicode.org) @@ -29240,14 +29125,14 @@ Character Set used on GNU/Linux systems. CHEM - A preprocessor for `pic' that reads descriptions of molecules and - produces `pic' input for drawing them. It was written in `awk' by + A preprocessor for 'pic' that reads descriptions of molecules and + produces 'pic' input for drawing them. It was written in 'awk' by Brian Kernighan and Jon Bentley, and is available from - `http://netlib.sandia.gov/netlib/typesetting/chem.gz'. + . Cookie A peculiar goodie, token, saying or remembrance produced by or - presented to a program. (With thanks to Professor Doug McIlroy.) + presented to a program. (With thanks to Professor Doug McIlroy.) Coprocess A subordinate program with which two-way communications is @@ -29259,25 +29144,25 @@ Compiler directly by the computer. See also "Interpreter." Compound Statement - A series of `awk' statements, enclosed in curly braces. Compound + A series of 'awk' statements, enclosed in curly braces. Compound statements may be nested. (*Note Statements::.) Concatenation Concatenating two strings means sticking them together, one after - another, producing a new string. For example, the string `foo' - concatenated with the string `bar' gives the string `foobar'. + another, producing a new string. For example, the string 'foo' + concatenated with the string 'bar' gives the string 'foobar'. (*Note Concatenation::.) Conditional Expression - An expression using the `?:' ternary operator, such as `EXPR1 ? + An expression using the '?:' ternary operator, such as 'EXPR1 ? EXPR2 : EXPR3'. The expression EXPR1 is evaluated; if the result is true, the value of the whole expression is the value of EXPR2; otherwise the value is EXPR3. In either case, only one of EXPR2 - and EXPR3 is evaluated. (*Note Conditional Exp::.) + and EXPR3 is evaluated. (*Note Conditional Exp::.) Comparison Expression - A relation that is either true or false, such as `a < b'. - Comparison expressions are used in `if', `while', `do', and `for' + A relation that is either true or false, such as 'a < b'. + Comparison expressions are used in 'if', 'while', 'do', and 'for' statements, and in patterns to select which input records to process. (*Note Typing and Comparison::.) @@ -29287,45 +29172,43 @@ Curly Braces Dark Corner An area in the language where specifications often were (or still are) not clear, leading to unexpected or undesirable behavior. - Such areas are marked in this Info file with "(d.c.)" in the text + Such areas are marked in this Info file with "(d.c.)" in the text and are indexed under the heading "dark corner." Data Driven - A description of `awk' programs, where you specify the data you - are interested in processing, and what to do when that data is - seen. + A description of 'awk' programs, where you specify the data you are + interested in processing, and what to do when that data is seen. Data Objects - These are numbers and strings of characters. Numbers are - converted into strings and vice versa, as needed. (*Note - Conversion::.) + These are numbers and strings of characters. Numbers are converted + into strings and vice versa, as needed. (*Note Conversion::.) Deadlock The situation in which two communicating processes are each waiting for the other to perform an action. Debugger - A program used to help developers remove "bugs" from (de-bug) - their programs. + A program used to help developers remove "bugs" from (de-bug) their + programs. Double Precision An internal representation of numbers that can have fractional parts. Double precision numbers keep track of more digits than do - single precision numbers, but operations on them are sometimes - more expensive. This is the way `awk' stores numeric values. It - is the C type `double'. + single precision numbers, but operations on them are sometimes more + expensive. This is the way 'awk' stores numeric values. It is the + C type 'double'. Dynamic Regular Expression A dynamic regular expression is a regular expression written as an ordinary expression. It could be a string constant, such as - `"foo"', but it may also be an expression whose value can vary. + '"foo"', but it may also be an expression whose value can vary. (*Note Computed Regexps::.) Environment - A collection of strings, of the form `NAME=VAL', that each program - has available to it. Users generally place values into the + A collection of strings, of the form 'NAME=VAL', that each program + has available to it. Users generally place values into the environment in order to provide information to various programs. - Typical examples are the environment variables `HOME' and `PATH'. + Typical examples are the environment variables 'HOME' and 'PATH'. Empty String See "Null String." @@ -29336,30 +29219,30 @@ Epoch with library functions available for converting these values into standard date and time formats. - The epoch on Unix and POSIX systems is 1970-01-01 00:00:00 UTC. - See also "GMT" and "UTC." + The epoch on Unix and POSIX systems is 1970-01-01 00:00:00 UTC. See + also "GMT" and "UTC." Escape Sequences A special sequence of characters used for describing nonprinting - characters, such as `\n' for newline or `\033' for the ASCII ESC - (Escape) character. (*Note Escape Sequences::.) + characters, such as '\n' for newline or '\033' for the ASCII ESC + (Escape) character. (*Note Escape Sequences::.) Extension An additional feature or change to a programming language or utility not defined by that language's or utility's standard. - `gawk' has (too) many extensions over POSIX `awk'. + 'gawk' has (too) many extensions over POSIX 'awk'. FDL See "Free Documentation License." Field - When `awk' reads an input record, it splits the record into pieces + When 'awk' reads an input record, it splits the record into pieces separated by whitespace (or by a separator regexp that you can - change by setting the built-in variable `FS'). Such pieces are + change by setting the built-in variable 'FS'). Such pieces are called fields. If the pieces are of fixed length, you can use the - built-in variable `FIELDWIDTHS' to describe their lengths. If you + built-in variable 'FIELDWIDTHS' to describe their lengths. If you wish to specify the contents of fields instead of the field - separator, you can use the built-in variable `FPAT' to do so. + separator, you can use the built-in variable 'FPAT' to do so. (*Note Field Separators::, *note Constant Size::, and *note Splitting By Content::.) @@ -29369,24 +29252,24 @@ Flag Floating-Point Number Often referred to in mathematical terms as a "rational" or real - number, this is just a number that can have a fractional part. - See also "Double Precision" and "Single Precision." + number, this is just a number that can have a fractional part. See + also "Double Precision" and "Single Precision." Format - Format strings control the appearance of output in the - `strftime()' and `sprintf()' functions, and in the `printf' - statement as well. Also, data conversions from numbers to strings - are controlled by the format strings contained in the built-in - variables `CONVFMT' and `OFMT'. (*Note Control Letters::.) + Format strings control the appearance of output in the 'strftime()' + and 'sprintf()' functions, and in the 'printf' statement as well. + Also, data conversions from numbers to strings are controlled by + the format strings contained in the built-in variables 'CONVFMT' + and 'OFMT'. (*Note Control Letters::.) Free Documentation License This document describes the terms under which this Info file is - published and may be copied. (*Note GNU Free Documentation + published and may be copied. (*Note GNU Free Documentation License::.) Function A specialized group of statements used to encapsulate general or - program-specific tasks. `awk' has a number of built-in functions, + program-specific tasks. 'awk' has a number of built-in functions, and also allows you to define your own. (*Note Functions::.) FSF @@ -29398,15 +29281,15 @@ Free Software Foundation Richard M. Stallman, the author of the original Emacs editor. GNU Emacs is the most widely used version of Emacs today. -`gawk' - The GNU implementation of `awk'. +'gawk' + The GNU implementation of 'awk'. General Public License - This document describes the terms under which `gawk' and its source - code may be distributed. (*Note Copying::.) + This document describes the terms under which 'gawk' and its source + code may be distributed. (*Note Copying::.) GMT - "Greenwich Mean Time." This is the old term for UTC. It is the + "Greenwich Mean Time." This is the old term for UTC. It is the time of day used internally for Unix and POSIX systems. See also "Epoch" and "UTC." @@ -29418,21 +29301,20 @@ GNU GNU/Linux A variant of the GNU system using the Linux kernel, instead of the Free Software Foundation's Hurd kernel. The Linux kernel is a - stable, efficient, full-featured clone of Unix that has been - ported to a variety of architectures. It is most popular on - PC-class systems, but runs well on a variety of other systems too. - The Linux kernel source code is available under the terms of the - GNU General Public License, which is perhaps its most important - aspect. + stable, efficient, full-featured clone of Unix that has been ported + to a variety of architectures. It is most popular on PC-class + systems, but runs well on a variety of other systems too. The + Linux kernel source code is available under the terms of the GNU + General Public License, which is perhaps its most important aspect. GPL See "General Public License." Hexadecimal - Base 16 notation, where the digits are `0'-`9' and `A'-`F', with - `A' representing 10, `B' representing 11, and so on, up to `F' for - 15. Hexadecimal numbers are written in C using a leading `0x', to - indicate their base. Thus, `0x12' is 18 ((1 x 16) + 2). *Note + Base 16 notation, where the digits are '0'-'9' and 'A'-'F', with + 'A' representing 10, 'B' representing 11, and so on, up to 'F' for + 15. Hexadecimal numbers are written in C using a leading '0x', to + indicate their base. Thus, '0x12' is 18 ((1 x 16) + 2). *Note Nondecimal-numbers::. I/O @@ -29440,9 +29322,8 @@ I/O out of a running program. Input Record - A single chunk of data that is read in by `awk'. Usually, an - `awk' input record consists of one line of text. (*Note - Records::.) + A single chunk of data that is read in by 'awk'. Usually, an 'awk' + input record consists of one line of text. (*Note Records::.) Integer A whole number, i.e., a number that does not have a fractional @@ -29454,23 +29335,23 @@ Internationalization Interpreter A program that reads human-readable source code directly, and uses - the instructions in it to process data and produce results. `awk' + the instructions in it to process data and produce results. 'awk' is typically (but not always) implemented as an interpreter. See also "Compiler." Interval Expression A component of a regular expression that lets you specify repeated matches of some part of the regexp. Interval expressions were not - originally available in `awk' programs. + originally available in 'awk' programs. ISO The International Organization for Standardization. This organization produces international standards for many things, including programming languages, such as C and C++. In the computer arena, important standards like those for C, C++, and - POSIX become both American national and ISO international - standards simultaneously. This Info file refers to Standard C as - "ISO C" throughout. See the ISO website + POSIX become both American national and ISO international standards + simultaneously. This Info file refers to Standard C as "ISO C" + throughout. See the ISO website (http://www.iso.org/iso/home/about.htm) for more information about the name of the organization and its language-independent three-letter acronym. @@ -29478,19 +29359,19 @@ ISO Java A modern programming language originally developed by Sun Microsystems (now Oracle) supporting Object-Oriented programming. - Although usually implemented by compiling to the instructions for - a standard virtual machine (the JVM), the language can be compiled - to native code. + Although usually implemented by compiling to the instructions for a + standard virtual machine (the JVM), the language can be compiled to + native code. Keyword - In the `awk' language, a keyword is a word that has special + In the 'awk' language, a keyword is a word that has special meaning. Keywords are reserved and may not be used as variable names. - `gawk''s keywords are: `BEGIN', `BEGINFILE', `END', `ENDFILE', - `break', `case', `continue', `default' `delete', `do...while', - `else', `exit', `for...in', `for', `function', `func', `if', - `next', `nextfile', `switch', and `while'. + 'gawk''s keywords are: 'BEGIN', 'BEGINFILE', 'END', 'ENDFILE', + 'break', 'case', 'continue', 'default' 'delete', 'do...while', + 'else', 'exit', 'for...in', 'for', 'function', 'func', 'if', + 'next', 'nextfile', 'switch', and 'while'. Lesser General Public License This document describes the terms under which binary library @@ -29509,14 +29390,14 @@ Localization Logical Expression An expression using the operators for logic, AND, OR, and NOT, - written `&&', `||', and `!' in `awk'. Often called Boolean + written '&&', '||', and '!' in 'awk'. Often called Boolean expressions, after the mathematician who pioneered this kind of mathematical logic. Lvalue An expression that can appear on the left side of an assignment operator. In most languages, lvalues can be variables or array - elements. In `awk', a field designator can also be used as an + elements. In 'awk', a field designator can also be used as an lvalue. Matching @@ -29534,42 +29415,42 @@ No-op Null String A string with no characters in it. It is represented explicitly in - `awk' programs by placing two double quote characters next to each - other (`""'). It can appear in input data by having two successive + 'awk' programs by placing two double quote characters next to each + other ('""'). It can appear in input data by having two successive occurrences of the field separator appear next to each other. Number - A numeric-valued data object. Modern `awk' implementations use + A numeric-valued data object. Modern 'awk' implementations use double precision floating-point to represent numbers. Ancient - `awk' implementations used single precision floating-point. + 'awk' implementations used single precision floating-point. Octal - Base-eight notation, where the digits are `0'-`7'. Octal numbers - are written in C using a leading `0', to indicate their base. - Thus, `013' is 11 ((1 x 8) + 3). *Note Nondecimal-numbers::. + Base-eight notation, where the digits are '0'-'7'. Octal numbers + are written in C using a leading '0', to indicate their base. + Thus, '013' is 11 ((1 x 8) + 3). *Note Nondecimal-numbers::. Pattern - Patterns tell `awk' which input records are interesting to which + Patterns tell 'awk' which input records are interesting to which rules. A pattern is an arbitrary conditional expression against which input is tested. If the condition is satisfied, the pattern is said to "match" the input record. A typical pattern might compare - the input record against a regular expression. (*Note Pattern + the input record against a regular expression. (*Note Pattern Overview::.) PEBKAC An acronym describing what is possibly the most frequent source of - computer usage problems. (Problem Exists Between Keyboard And + computer usage problems. (Problem Exists Between Keyboard And Chair.) POSIX The name for a series of standards that specify a Portable Operating System interface. The "IX" denotes the Unix heritage of - these standards. The main standard of interest for `awk' users is - `IEEE Standard for Information Technology, Standard 1003.1-2008'. + these standards. The main standard of interest for 'awk' users is + 'IEEE Standard for Information Technology, Standard 1003.1-2008'. The 2008 POSIX standard can be found online at - `http://www.opengroup.org/onlinepubs/9699919799/'. + . Precedence The order in which operations are performed when operators are used @@ -29577,14 +29458,14 @@ Precedence Private Variables and/or functions that are meant for use exclusively by - library functions and not for the main `awk' program. Special care + library functions and not for the main 'awk' program. Special care must be taken when naming such variables and functions. (*Note Library Names::.) Range (of input lines) A sequence of consecutive lines from the input file(s). A pattern - can specify ranges of input lines for `awk' to process or it can - specify single lines. (*Note Pattern Overview::.) + can specify ranges of input lines for 'awk' to process or it can + specify single lines. (*Note Pattern Overview::.) Recursion When a function calls itself, either directly or indirectly. If @@ -29593,43 +29474,43 @@ Recursion Redirection Redirection means performing input from something other than the - standard input stream, or performing output to something other - than the standard output stream. + standard input stream, or performing output to something other than + the standard output stream. - You can redirect input to the `getline' statement using the `<', - `|', and `|&' operators. You can redirect the output of the - `print' and `printf' statements to a file or a system command, - using the `>', `>>', `|', and `|&' operators. (*Note Getline::, + You can redirect input to the 'getline' statement using the '<', + '|', and '|&' operators. You can redirect the output of the + 'print' and 'printf' statements to a file or a system command, + using the '>', '>>', '|', and '|&' operators. (*Note Getline::, and *note Redirection::.) Regexp See "Regular Expression." Regular Expression - A regular expression ("regexp" for short) is a pattern that - denotes a set of strings, possibly an infinite set. For example, - the regular expression `R.*xp' matches any string starting with - the letter `R' and ending with the letters `xp'. In `awk', - regular expressions are used in patterns and in conditional - expressions. Regular expressions may contain escape sequences. - (*Note Regexp::.) + A regular expression ("regexp" for short) is a pattern that denotes + a set of strings, possibly an infinite set. For example, the + regular expression 'R.*xp' matches any string starting with the + letter 'R' and ending with the letters 'xp'. In 'awk', regular + expressions are used in patterns and in conditional expressions. + Regular expressions may contain escape sequences. (*Note + Regexp::.) Regular Expression Constant A regular expression constant is a regular expression written - within slashes, such as `/foo/'. This regular expression is chosen - when you write the `awk' program and cannot be changed during its - execution. (*Note Regexp Usage::.) + within slashes, such as '/foo/'. This regular expression is chosen + when you write the 'awk' program and cannot be changed during its + execution. (*Note Regexp Usage::.) Rule - A segment of an `awk' program that specifies how to process single + A segment of an 'awk' program that specifies how to process single input records. A rule consists of a "pattern" and an "action". - `awk' reads an input record; then, for each rule, if the input - record satisfies the rule's pattern, `awk' executes the rule's + 'awk' reads an input record; then, for each rule, if the input + record satisfies the rule's pattern, 'awk' executes the rule's action. Otherwise, the rule does nothing for that input record. Rvalue A value that can appear on the right side of an assignment - operator. In `awk', essentially every expression has a value. + operator. In 'awk', essentially every expression has a value. These values are rvalues. Scalar @@ -29637,15 +29518,15 @@ Scalar scalars; arrays and functions are not. Search Path - In `gawk', a list of directories to search for `awk' program - source files. In the shell, a list of directories to search for + In 'gawk', a list of directories to search for 'awk' program source + files. In the shell, a list of directories to search for executable programs. Seed The initial value, or starting point, for a sequence of random numbers. -`sed' +'sed' See "Stream Editor." Shell @@ -29654,7 +29535,7 @@ Shell batch files, or shell scripts. Short-Circuit - The nature of the `awk' logical operators `&&' and `||'. If the + The nature of the 'awk' logical operators '&&' and '||'. If the value of the entire expression is determinable from evaluating just the lefthand side of these operators, the righthand side is not evaluated. (*Note Boolean Ops::.) @@ -29667,19 +29548,19 @@ Side Effect Single Precision An internal representation of numbers that can have fractional - parts. Single precision numbers keep track of fewer digits than - do double precision numbers, but operations on them are sometimes - less expensive in terms of CPU time. This is the type used by - some ancient versions of `awk' to store numeric values. It is the - C type `float'. + parts. Single precision numbers keep track of fewer digits than do + double precision numbers, but operations on them are sometimes less + expensive in terms of CPU time. This is the type used by some + ancient versions of 'awk' to store numeric values. It is the C + type 'float'. Space The character generated by hitting the space bar on the keyboard. Special File - A file name interpreted internally by `gawk', instead of being + A file name interpreted internally by 'gawk', instead of being handed directly to the underlying operating system--for example, - `/dev/stderr'. (*Note Special Files::.) + '/dev/stderr'. (*Note Special Files::.) Stream Editor A program that reads records from an input stream and processes @@ -29689,13 +29570,13 @@ Stream Editor programs which require input from the user. String - A datum consisting of a sequence of characters, such as `I am a + A datum consisting of a sequence of characters, such as 'I am a string'. Constant strings are written with double quotes in the - `awk' language and may contain escape sequences. (*Note Escape + 'awk' language and may contain escape sequences. (*Note Escape Sequences::.) Tab - The character generated by hitting the `TAB' key on the keyboard. + The character generated by hitting the 'TAB' key on the keyboard. It usually expands to up to eight spaces upon output. Text Domain @@ -29704,15 +29585,15 @@ Text Domain Timestamp A value in the "seconds since the epoch" format used by Unix and - POSIX systems. Used for the `gawk' functions `mktime()', - `strftime()', and `systime()'. See also "Epoch," "GMT," and "UTC." + POSIX systems. Used for the 'gawk' functions 'mktime()', + 'strftime()', and 'systime()'. See also "Epoch," "GMT," and "UTC." Unix A computer operating system originally developed in the early 1970's at AT&T Bell Laboratories. It initially became popular in universities around the world and later moved into commercial environments as a software development system and network server - system. There are many commercial versions of Unix, as well as + system. There are many commercial versions of Unix, as well as several work-alike systems whose source code is freely available (such as GNU/Linux, NetBSD (http://www.netbsd.org), FreeBSD (http://www.freebsd.org), and OpenBSD (http://www.openbsd.org)). @@ -29720,12 +29601,12 @@ Unix UTC The accepted abbreviation for "Universal Coordinated Time." This is standard time in Greenwich, England, which is used as a - reference time for day and date calculations. See also "Epoch" - and "GMT." + reference time for day and date calculations. See also "Epoch" and + "GMT." Whitespace - A sequence of space, TAB, or newline characters occurring inside - an input record or a string. + A sequence of space, TAB, or newline characters occurring inside an + input record or a string.  File: gawk.info, Node: Copying, Next: GNU Free Documentation License, Prev: Glossary, Up: Top @@ -29734,7 +29615,8 @@ GNU General Public License ************************** Version 3, 29 June 2007 - Copyright (C) 2007 Free Software Foundation, Inc. `http://fsf.org/' + + Copyright (C) 2007 Free Software Foundation, Inc. Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. @@ -29748,11 +29630,11 @@ and other kinds of works. The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to -share and change all versions of a program--to make sure it remains -free software for all its users. We, the Free Software Foundation, use -the GNU General Public License for most of our software; it applies -also to any other work released this way by its authors. You can apply -it to your programs, too. +share and change all versions of a program--to make sure it remains free +software for all its users. We, the Free Software Foundation, use the +GNU General Public License for most of our software; it applies also to +any other work released this way by its authors. You can apply it to +your programs, too. When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you @@ -29762,9 +29644,9 @@ want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things. To protect your rights, we need to prevent others from denying you -these rights or asking you to surrender the rights. Therefore, you -have certain responsibilities if you distribute copies of the software, -or if you modify it: responsibilities to respect the freedom of others. +these rights or asking you to surrender the rights. Therefore, you have +certain responsibilities if you distribute copies of the software, or if +you modify it: responsibilities to respect the freedom of others. For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same @@ -29783,16 +29665,15 @@ changed, so that their problems will not be attributed erroneously to authors of previous versions. Some devices are designed to deny users access to install or run -modified versions of the software inside them, although the -manufacturer can do so. This is fundamentally incompatible with the -aim of protecting users' freedom to change the software. The -systematic pattern of such abuse occurs in the area of products for -individuals to use, which is precisely where it is most unacceptable. -Therefore, we have designed this version of the GPL to prohibit the -practice for those products. If such problems arise substantially in -other domains, we stand ready to extend this provision to those domains -in future versions of the GPL, as needed to protect the freedom of -users. +modified versions of the software inside them, although the manufacturer +can do so. This is fundamentally incompatible with the aim of +protecting users' freedom to change the software. The systematic +pattern of such abuse occurs in the area of products for individuals to +use, which is precisely where it is most unacceptable. Therefore, we +have designed this version of the GPL to prohibit the practice for those +products. If such problems arise substantially in other domains, we +stand ready to extend this provision to those domains in future versions +of the GPL, as needed to protect the freedom of users. Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and use of @@ -29829,8 +29710,8 @@ TERMS AND CONDITIONS To "propagate" a work means to do anything with it that, without permission, would make you directly or secondarily liable for - infringement under applicable copyright law, except executing it - on a computer or modifying a private copy. Propagation includes + infringement under applicable copyright law, except executing it on + a computer or modifying a private copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as well. @@ -29844,8 +29725,8 @@ TERMS AND CONDITIONS to the extent that it includes a convenient and prominently visible feature that (1) displays an appropriate copyright notice, and (2) tells the user that there is no warranty for the work (except to - the extent that warranties are provided), that licensees may - convey the work under this License, and how to view a copy of this + the extent that warranties are provided), that licensees may convey + the work under this License, and how to view a copy of this License. If the interface presents a list of user commands or options, such as a menu, a prominent item in the list meets this criterion. @@ -29853,8 +29734,8 @@ TERMS AND CONDITIONS 1. Source Code. The "source code" for a work means the preferred form of the work - for making modifications to it. "Object code" means any - non-source form of a work. + for making modifications to it. "Object code" means any non-source + form of a work. A "Standard Interface" means an interface that either is an official standard defined by a recognized standards body, or, in @@ -29865,10 +29746,10 @@ TERMS AND CONDITIONS The "System Libraries" of an executable work include anything, other than the work as a whole, that (a) is included in the normal form of packaging a Major Component, but which is not part of that - Major Component, and (b) serves only to enable use of the work - with that Major Component, or to implement a Standard Interface - for which an implementation is available to the public in source - code form. A "Major Component", in this context, means a major + Major Component, and (b) serves only to enable use of the work with + that Major Component, or to implement a Standard Interface for + which an implementation is available to the public in source code + form. A "Major Component", in this context, means a major essential component (kernel, window system, and so on) of the specific operating system (if any) on which the executable work runs, or a compiler used to produce the work, or an object code @@ -29876,15 +29757,15 @@ TERMS AND CONDITIONS The "Corresponding Source" for a work in object code form means all the source code needed to generate, install, and (for an executable - work) run the object code and to modify the work, including - scripts to control those activities. However, it does not include - the work's System Libraries, or general-purpose tools or generally + work) run the object code and to modify the work, including scripts + to control those activities. However, it does not include the + work's System Libraries, or general-purpose tools or generally available free programs which are used unmodified in performing those activities but which are not part of the work. For example, - Corresponding Source includes interface definition files - associated with source files for the work, and the source code for - shared libraries and dynamically linked subprograms that the work - is specifically designed to require, such as by intimate data + Corresponding Source includes interface definition files associated + with source files for the work, and the source code for shared + libraries and dynamically linked subprograms that the work is + specifically designed to require, such as by intimate data communication or control flow between those subprograms and other parts of the work. @@ -29901,22 +29782,22 @@ TERMS AND CONDITIONS copyright on the Program, and are irrevocable provided the stated conditions are met. This License explicitly affirms your unlimited permission to run the unmodified Program. The output from running - a covered work is covered by this License only if the output, - given its content, constitutes a covered work. This License - acknowledges your rights of fair use or other equivalent, as - provided by copyright law. + a covered work is covered by this License only if the output, given + its content, constitutes a covered work. This License acknowledges + your rights of fair use or other equivalent, as provided by + copyright law. You may make, run and propagate covered works that you do not convey, without conditions so long as your license otherwise remains in force. You may convey covered works to others for the - sole purpose of having them make modifications exclusively for - you, or provide you with facilities for running those works, - provided that you comply with the terms of this License in - conveying all material for which you do not control copyright. - Those thus making or running the covered works for you must do so - exclusively on your behalf, under your direction and control, on - terms that prohibit them from making any copies of your - copyrighted material outside their relationship with you. + sole purpose of having them make modifications exclusively for you, + or provide you with facilities for running those works, provided + that you comply with the terms of this License in conveying all + material for which you do not control copyright. Those thus making + or running the covered works for you must do so exclusively on your + behalf, under your direction and control, on terms that prohibit + them from making any copies of your copyrighted material outside + their relationship with you. Conveying under any other circumstances is permitted solely under the conditions stated below. Sublicensing is not allowed; section @@ -29933,8 +29814,8 @@ TERMS AND CONDITIONS When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License - with respect to the covered work, and you disclaim any intention - to limit operation or modification of the work as a means of + with respect to the covered work, and you disclaim any intention to + limit operation or modification of the work as a means of enforcing, against the work's users, your or third parties' legal rights to forbid circumvention of technological measures. @@ -30004,8 +29885,8 @@ TERMS AND CONDITIONS b. Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by a - written offer, valid for at least three years and valid for - as long as you offer spare parts or customer support for that + written offer, valid for at least three years and valid for as + long as you offer spare parts or customer support for that product model, to give anyone who possesses the object code either (1) a copy of the Corresponding Source for all the software in the product that is covered by this License, on a @@ -30015,32 +29896,31 @@ TERMS AND CONDITIONS to copy the Corresponding Source from a network server at no charge. - c. Convey individual copies of the object code with a copy of - the written offer to provide the Corresponding Source. This + c. Convey individual copies of the object code with a copy of the + written offer to provide the Corresponding Source. This alternative is allowed only occasionally and noncommercially, and only if you received the object code with such an offer, in accord with subsection 6b. d. Convey the object code by offering access from a designated - place (gratis or for a charge), and offer equivalent access - to the Corresponding Source in the same way through the same + place (gratis or for a charge), and offer equivalent access to + the Corresponding Source in the same way through the same place at no further charge. You need not require recipients to copy the Corresponding Source along with the object code. If the place to copy the object code is a network server, the - Corresponding Source may be on a different server (operated - by you or a third party) that supports equivalent copying - facilities, provided you maintain clear directions next to - the object code saying where to find the Corresponding Source. + Corresponding Source may be on a different server (operated by + you or a third party) that supports equivalent copying + facilities, provided you maintain clear directions next to the + object code saying where to find the Corresponding Source. Regardless of what server hosts the Corresponding Source, you - remain obligated to ensure that it is available for as long - as needed to satisfy these requirements. + remain obligated to ensure that it is available for as long as + needed to satisfy these requirements. e. Convey the object code using peer-to-peer transmission, provided you inform other peers where the object code and Corresponding Source of the work are being offered to the general public at no charge under subsection 6d. - A separable portion of the object code, whose source code is excluded from the Corresponding Source as a System Library, need not be included in conveying the object code work. @@ -30048,8 +29928,8 @@ TERMS AND CONDITIONS A "User Product" is either (1) a "consumer product", which means any tangible personal property which is normally used for personal, family, or household purposes, or (2) anything designed or sold for - incorporation into a dwelling. In determining whether a product - is a consumer product, doubtful cases shall be resolved in favor of + incorporation into a dwelling. In determining whether a product is + a consumer product, doubtful cases shall be resolved in favor of coverage. For a particular product received by a particular user, "normally used" refers to a typical or common use of that class of product, regardless of the status of the particular user or of the @@ -30080,11 +29960,11 @@ TERMS AND CONDITIONS The requirement to provide Installation Information does not include a requirement to continue to provide support service, - warranty, or updates for a work that has been modified or - installed by the recipient, or for the User Product in which it - has been modified or installed. Access to a network may be denied - when the modification itself materially and adversely affects the - operation of the network or violates the rules and protocols for + warranty, or updates for a work that has been modified or installed + by the recipient, or for the User Product in which it has been + modified or installed. Access to a network may be denied when the + modification itself materially and adversely affects the operation + of the network or violates the rules and protocols for communication across the network. Corresponding Source conveyed, and Installation Information @@ -30114,8 +29994,8 @@ TERMS AND CONDITIONS Notwithstanding any other provision of this License, for material you add to a covered work, you may (if authorized by the copyright - holders of that material) supplement the terms of this License - with terms: + holders of that material) supplement the terms of this License with + terms: a. Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License; or @@ -30125,9 +30005,8 @@ TERMS AND CONDITIONS Legal Notices displayed by works containing it; or c. Prohibiting misrepresentation of the origin of that material, - or requiring that modified versions of such material be - marked in reasonable ways as different from the original - version; or + or requiring that modified versions of such material be marked + in reasonable ways as different from the original version; or d. Limiting the use for publicity purposes of names of licensors or authors of the material; or @@ -30146,11 +30025,10 @@ TERMS AND CONDITIONS you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document - contains a further restriction but permits relicensing or - conveying under this License, you may add to a covered work - material governed by the terms of that license document, provided - that the further restriction does not survive such relicensing or - conveying. + contains a further restriction but permits relicensing or conveying + under this License, you may add to a covered work material governed + by the terms of that license document, provided that the further + restriction does not survive such relicensing or conveying. If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the @@ -30166,13 +30044,13 @@ TERMS AND CONDITIONS You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights - under this License (including any patent licenses granted under - the third paragraph of section 11). + under this License (including any patent licenses granted under the + third paragraph of section 11). However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) - provisionally, unless and until the copyright holder explicitly - and finally terminates your license, and (b) permanently, if the + provisionally, unless and until the copyright holder explicitly and + finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. @@ -30184,10 +30062,10 @@ TERMS AND CONDITIONS after your receipt of the notice. Termination of your rights under this section does not terminate - the licenses of parties who have received copies or rights from - you under this License. If your rights have been terminated and - not permanently reinstated, you do not qualify to receive new - licenses for the same material under section 10. + the licenses of parties who have received copies or rights from you + under this License. If your rights have been terminated and not + permanently reinstated, you do not qualify to receive new licenses + for the same material under section 10. 9. Acceptance Not Required for Having Copies. @@ -30201,7 +30079,7 @@ TERMS AND CONDITIONS by modifying or propagating a covered work, you indicate your acceptance of this License to do so. - 10. Automatic Licensing of Downstream Recipients. + 10. Automatic Licensing of Downstream Recipients. Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and @@ -30215,21 +30093,21 @@ TERMS AND CONDITIONS covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party's predecessor in interest had or - could give under the previous paragraph, plus a right to - possession of the Corresponding Source of the work from the - predecessor in interest, if the predecessor has it or can get it - with reasonable efforts. + could give under the previous paragraph, plus a right to possession + of the Corresponding Source of the work from the predecessor in + interest, if the predecessor has it or can get it with reasonable + efforts. You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you - may not impose a license fee, royalty, or other charge for - exercise of rights granted under this License, and you may not - initiate litigation (including a cross-claim or counterclaim in a - lawsuit) alleging that any patent claim is infringed by making, - using, selling, offering for sale, or importing the Program or any - portion of it. + may not impose a license fee, royalty, or other charge for exercise + of rights granted under this License, and you may not initiate + litigation (including a cross-claim or counterclaim in a lawsuit) + alleging that any patent claim is infringed by making, using, + selling, offering for sale, or importing the Program or any portion + of it. - 11. Patents. + 11. Patents. A "contributor" is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. @@ -30249,15 +30127,15 @@ TERMS AND CONDITIONS Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and - otherwise run, modify and propagate the contents of its - contributor version. + otherwise run, modify and propagate the contents of its contributor + version. In the following three paragraphs, a "patent license" is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a - patent or covenant not to sue for patent infringement). To - "grant" such a patent license to a party means to make such an - agreement or commitment not to enforce a patent against the party. + patent or covenant not to sue for patent infringement). To "grant" + such a patent license to a party means to make such an agreement or + commitment not to enforce a patent against the party. If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available @@ -30287,36 +30165,35 @@ TERMS AND CONDITIONS conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third - party that is in the business of distributing software, under - which you make payment to the third party based on the extent of - your activity of conveying the work, and under which the third - party grants, to any of the parties who would receive the covered - work from you, a discriminatory patent license (a) in connection - with copies of the covered work conveyed by you (or copies made - from those copies), or (b) primarily for and in connection with - specific products or compilations that contain the covered work, - unless you entered into that arrangement, or that patent license - was granted, prior to 28 March 2007. + party that is in the business of distributing software, under which + you make payment to the third party based on the extent of your + activity of conveying the work, and under which the third party + grants, to any of the parties who would receive the covered work + from you, a discriminatory patent license (a) in connection with + copies of the covered work conveyed by you (or copies made from + those copies), or (b) primarily for and in connection with specific + products or compilations that contain the covered work, unless you + entered into that arrangement, or that patent license was granted, + prior to 28 March 2007. Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law. - 12. No Surrender of Others' Freedom. + 12. No Surrender of Others' Freedom. - If conditions are imposed on you (whether by court order, - agreement or otherwise) that contradict the conditions of this - License, they do not excuse you from the conditions of this - License. If you cannot convey a covered work so as to satisfy - simultaneously your obligations under this License and any other - pertinent obligations, then as a consequence you may not convey it - at all. For example, if you agree to terms that obligate you to - collect a royalty for further conveying from those to whom you - convey the Program, the only way you could satisfy both those - terms and this License would be to refrain entirely from conveying - the Program. + If conditions are imposed on you (whether by court order, agreement + or otherwise) that contradict the conditions of this License, they + do not excuse you from the conditions of this License. If you + cannot convey a covered work so as to satisfy simultaneously your + obligations under this License and any other pertinent obligations, + then as a consequence you may not convey it at all. For example, + if you agree to terms that obligate you to collect a royalty for + further conveying from those to whom you convey the Program, the + only way you could satisfy both those terms and this License would + be to refrain entirely from conveying the Program. - 13. Use with the GNU Affero General Public License. + 13. Use with the GNU Affero General Public License. Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed @@ -30327,22 +30204,21 @@ TERMS AND CONDITIONS General Public License, section 13, concerning interaction through a network will apply to the combination as such. - 14. Revised Versions of this License. + 14. Revised Versions of this License. The Free Software Foundation may publish revised and/or new - versions of the GNU General Public License from time to time. - Such new versions will be similar in spirit to the present - version, but may differ in detail to address new problems or - concerns. + versions of the GNU General Public License from time to time. Such + new versions will be similar in spirit to the present version, but + may differ in detail to address new problems or concerns. Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License "or any later version" applies to it, you have the option of following the terms and conditions either of - that numbered version or of any later version published by the - Free Software Foundation. If the Program does not specify a - version number of the GNU General Public License, you may choose - any version ever published by the Free Software Foundation. + that numbered version or of any later version published by the Free + Software Foundation. If the Program does not specify a version + number of the GNU General Public License, you may choose any + version ever published by the Free Software Foundation. If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that @@ -30354,24 +30230,24 @@ TERMS AND CONDITIONS author or copyright holder as a result of your choosing to follow a later version. - 15. Disclaimer of Warranty. + 15. Disclaimer of Warranty. THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY - APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE + APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF - MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE + MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. - 16. Limitation of Liability. + 16. Limitation of Liability. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES - AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU - FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR + AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR + DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD @@ -30379,7 +30255,7 @@ TERMS AND CONDITIONS PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. - 17. Interpretation of Sections 15 and 16. + 17. Interpretation of Sections 15 and 16. If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, @@ -30388,7 +30264,6 @@ TERMS AND CONDITIONS connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee. - END OF TERMS AND CONDITIONS =========================== @@ -30419,7 +30294,7 @@ state the exclusion of warranty; and each file should have at least the General Public License for more details. You should have received a copy of the GNU General Public License - along with this program. If not, see `http://www.gnu.org/licenses/'. + along with this program. If not, see . Also add information on how to contact you by electronic and paper mail. @@ -30428,11 +30303,11 @@ mail. notice like this when it starts in an interactive mode: PROGRAM Copyright (C) YEAR NAME OF AUTHOR - This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This program comes with ABSOLUTELY NO WARRANTY; for details type 'show w'. This is free software, and you are welcome to redistribute it - under certain conditions; type `show c' for details. + under certain conditions; type 'show c' for details. - The hypothetical commands `show w' and `show c' should show the + The hypothetical commands 'show w' and 'show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an "about box". @@ -30440,14 +30315,14 @@ use an "about box". You should also get your employer (if you work as a programmer) or school, if any, to sign a "copyright disclaimer" for the program, if necessary. For more information on this, and how to apply and follow -the GNU GPL, see `http://www.gnu.org/licenses/'. +the GNU GPL, see . The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, -please read `http://www.gnu.org/philosophy/why-not-lgpl.html'. +please read .  File: gawk.info, Node: GNU Free Documentation License, Next: Index, Prev: Copying, Up: Top @@ -30456,8 +30331,9 @@ GNU Free Documentation License ****************************** Version 1.3, 3 November 2008 + Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. - `http://fsf.org/' + Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. @@ -30482,21 +30358,21 @@ GNU Free Documentation License free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless - of subject matter or whether it is published as a printed book. - We recommend this License principally for works whose purpose is + of subject matter or whether it is published as a printed book. We + recommend this License principally for works whose purpose is instruction or reference. 1. APPLICABILITY AND DEFINITIONS This License applies to any manual or other work, in any medium, - that contains a notice placed by the copyright holder saying it - can be distributed under the terms of this License. Such a notice + that contains a notice placed by the copyright holder saying it can + be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The "Document", below, refers to any such manual or work. Any member - of the public is a licensee, and is addressed as "you". You - accept the license if you copy, modify or distribute the work in a - way requiring permission under copyright law. + of the public is a licensee, and is addressed as "you". You accept + the license if you copy, modify or distribute the work in a way + requiring permission under copyright law. A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with @@ -30514,12 +30390,12 @@ GNU Free Documentation License regarding them. The "Invariant Sections" are certain Secondary Sections whose - titles are designated, as being those of Invariant Sections, in - the notice that says that the Document is released under this - License. If a section does not fit the above definition of - Secondary then it is not allowed to be designated as Invariant. - The Document may contain zero Invariant Sections. If the Document - does not identify any Invariant Sections then there are none. + titles are designated, as being those of Invariant Sections, in the + notice that says that the Document is released under this License. + If a section does not fit the above definition of Secondary then it + is not allowed to be designated as Invariant. The Document may + contain zero Invariant Sections. If the Document does not identify + any Invariant Sections then there are none. The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice @@ -30530,27 +30406,27 @@ GNU Free Documentation License A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document - straightforwardly with generic text editors or (for images - composed of pixels) generic paint programs or (for drawings) some - widely available drawing editor, and that is suitable for input to - text formatters or for automatic translation to a variety of - formats suitable for input to text formatters. A copy made in an - otherwise Transparent file format whose markup, or absence of - markup, has been arranged to thwart or discourage subsequent - modification by readers is not Transparent. An image format is - not Transparent if used for any substantial amount of text. A - copy that is not "Transparent" is called "Opaque". + straightforwardly with generic text editors or (for images composed + of pixels) generic paint programs or (for drawings) some widely + available drawing editor, and that is suitable for input to text + formatters or for automatic translation to a variety of formats + suitable for input to text formatters. A copy made in an otherwise + Transparent file format whose markup, or absence of markup, has + been arranged to thwart or discourage subsequent modification by + readers is not Transparent. An image format is not Transparent if + used for any substantial amount of text. A copy that is not + "Transparent" is called "Opaque". Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, - SGML or XML using a publicly available DTD, and - standard-conforming simple HTML, PostScript or PDF designed for - human modification. Examples of transparent image formats include - PNG, XCF and JPG. Opaque formats include proprietary formats that - can be read and edited only by proprietary word processors, SGML or - XML for which the DTD and/or processing tools are not generally - available, and the machine-generated HTML, PostScript or PDF - produced by some word processors for output purposes only. + SGML or XML using a publicly available DTD, and standard-conforming + simple HTML, PostScript or PDF designed for human modification. + Examples of transparent image formats include PNG, XCF and JPG. + Opaque formats include proprietary formats that can be read and + edited only by proprietary word processors, SGML or XML for which + the DTD and/or processing tools are not generally available, and + the machine-generated HTML, PostScript or PDF produced by some word + processors for output purposes only. The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the @@ -30588,8 +30464,8 @@ GNU Free Documentation License may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you - distribute a large enough number of copies you must also follow - the conditions in section 3. + distribute a large enough number of copies you must also follow the + conditions in section 3. You may also lend copies, under the same conditions stated above, and you may publicly display copies. @@ -30603,12 +30479,11 @@ GNU Free Documentation License these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The - front cover must present the full title with all words of the - title equally prominent and visible. You may add other material - on the covers in addition. Copying with changes limited to the - covers, as long as they preserve the title of the Document and - satisfy these conditions, can be treated as verbatim copying in - other respects. + front cover must present the full title with all words of the title + equally prominent and visible. You may add other material on the + covers in addition. Copying with changes limited to the covers, as + long as they preserve the title of the Document and satisfy these + conditions, can be treated as verbatim copying in other respects. If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit @@ -30616,40 +30491,39 @@ GNU Free Documentation License adjacent pages. If you publish or distribute Opaque copies of the Document - numbering more than 100, you must either include a - machine-readable Transparent copy along with each Opaque copy, or - state in or with each Opaque copy a computer-network location from - which the general network-using public has access to download - using public-standard network protocols a complete Transparent - copy of the Document, free of added material. If you use the - latter option, you must take reasonably prudent steps, when you - begin distribution of Opaque copies in quantity, to ensure that - this Transparent copy will remain thus accessible at the stated - location until at least one year after the last time you - distribute an Opaque copy (directly or through your agents or - retailers) of that edition to the public. + numbering more than 100, you must either include a machine-readable + Transparent copy along with each Opaque copy, or state in or with + each Opaque copy a computer-network location from which the general + network-using public has access to download using public-standard + network protocols a complete Transparent copy of the Document, free + of added material. If you use the latter option, you must take + reasonably prudent steps, when you begin distribution of Opaque + copies in quantity, to ensure that this Transparent copy will + remain thus accessible at the stated location until at least one + year after the last time you distribute an Opaque copy (directly or + through your agents or retailers) of that edition to the public. It is requested, but not required, that you contact the authors of - the Document well before redistributing any large number of - copies, to give them a chance to provide you with an updated - version of the Document. + the Document well before redistributing any large number of copies, + to give them a chance to provide you with an updated version of the + Document. 4. MODIFICATIONS You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you - release the Modified Version under precisely this License, with - the Modified Version filling the role of the Document, thus - licensing distribution and modification of the Modified Version to - whoever possesses a copy of it. In addition, you must do these - things in the Modified Version: + release the Modified Version under precisely this License, with the + Modified Version filling the role of the Document, thus licensing + distribution and modification of the Modified Version to whoever + possesses a copy of it. In addition, you must do these things in + the Modified Version: A. Use in the Title Page (and on the covers, if any) a title - distinct from that of the Document, and from those of - previous versions (which should, if there were any, be listed - in the History section of the Document). You may use the - same title as a previous version if the original publisher of - that version gives permission. + distinct from that of the Document, and from those of previous + versions (which should, if there were any, be listed in the + History section of the Document). You may use the same title + as a previous version if the original publisher of that + version gives permission. B. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in @@ -30679,31 +30553,30 @@ GNU Free Documentation License I. Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new - authors, and publisher of the Modified Version as given on - the Title Page. If there is no section Entitled "History" in - the Document, create one stating the title, year, authors, - and publisher of the Document as given on its Title Page, - then add an item describing the Modified Version as stated in - the previous sentence. + authors, and publisher of the Modified Version as given on the + Title Page. If there is no section Entitled "History" in the + Document, create one stating the title, year, authors, and + publisher of the Document as given on its Title Page, then add + an item describing the Modified Version as stated in the + previous sentence. J. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for - previous versions it was based on. These may be placed in - the "History" section. You may omit a network location for a - work that was published at least four years before the - Document itself, or if the original publisher of the version - it refers to gives permission. + previous versions it was based on. These may be placed in the + "History" section. You may omit a network location for a work + that was published at least four years before the Document + itself, or if the original publisher of the version it refers + to gives permission. K. For any section Entitled "Acknowledgements" or "Dedications", - Preserve the Title of the section, and preserve in the - section all the substance and tone of each of the contributor + Preserve the Title of the section, and preserve in the section + all the substance and tone of each of the contributor acknowledgements and/or dedications given therein. - L. Preserve all the Invariant Sections of the Document, - unaltered in their text and in their titles. Section numbers - or the equivalent are not considered part of the section - titles. + L. Preserve all the Invariant Sections of the Document, unaltered + in their text and in their titles. Section numbers or the + equivalent are not considered part of the section titles. M. Delete any section Entitled "Endorsements". Such a section may not be included in the Modified Version. @@ -30716,11 +30589,11 @@ GNU Free Documentation License If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no - material copied from the Document, you may at your option - designate some or all of these sections as invariant. To do this, - add their titles to the list of Invariant Sections in the Modified - Version's license notice. These titles must be distinct from any - other section titles. + material copied from the Document, you may at your option designate + some or all of these sections as invariant. To do this, add their + titles to the list of Invariant Sections in the Modified Version's + license notice. These titles must be distinct from any other + section titles. You may add a section Entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various @@ -30729,15 +30602,15 @@ GNU Free Documentation License definition of a standard. You may add a passage of up to five words as a Front-Cover Text, - and a passage of up to 25 words as a Back-Cover Text, to the end - of the list of Cover Texts in the Modified Version. Only one - passage of Front-Cover Text and one of Back-Cover Text may be - added by (or through arrangements made by) any one entity. If the - Document already includes a cover text for the same cover, - previously added by you or by arrangement made by the same entity - you are acting on behalf of, you may not add another; but you may - replace the old one, on explicit permission from the previous - publisher that added the old one. + and a passage of up to 25 words as a Back-Cover Text, to the end of + the list of Cover Texts in the Modified Version. Only one passage + of Front-Cover Text and one of Back-Cover Text may be added by (or + through arrangements made by) any one entity. If the Document + already includes a cover text for the same cover, previously added + by you or by arrangement made by the same entity you are acting on + behalf of, you may not add another; but you may replace the old + one, on explicit permission from the previous publisher that added + the old one. The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to @@ -30747,8 +30620,8 @@ GNU Free Documentation License You may combine the Document with other documents released under this License, under the terms defined in section 4 above for - modified versions, provided that you include in the combination - all of the Invariant Sections of all of the original documents, + modified versions, provided that you include in the combination all + of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers. @@ -30775,20 +30648,20 @@ GNU Free Documentation License documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the - rules of this License for verbatim copying of each of the - documents in all other respects. + rules of this License for verbatim copying of each of the documents + in all other respects. You may extract a single document from such a collection, and distribute it individually under this License, provided you insert - a copy of this License into the extracted document, and follow - this License in all other respects regarding verbatim copying of - that document. + a copy of this License into the extracted document, and follow this + License in all other respects regarding verbatim copying of that + document. 7. AGGREGATION WITH INDEPENDENT WORKS A compilation of the Document or its derivatives with other - separate and independent documents or works, in or on a volume of - a storage or distribution medium, is called an "aggregate" if the + separate and independent documents or works, in or on a volume of a + storage or distribution medium, is called an "aggregate" if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this @@ -30833,8 +30706,8 @@ GNU Free Documentation License However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) - provisionally, unless and until the copyright holder explicitly - and finally terminates your license, and (b) permanently, if the + provisionally, unless and until the copyright holder explicitly and + finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. @@ -30846,33 +30719,33 @@ GNU Free Documentation License after your receipt of the notice. Termination of your rights under this section does not terminate - the licenses of parties who have received copies or rights from - you under this License. If your rights have been terminated and - not permanently reinstated, receipt of a copy of some or all of - the same material does not give you any rights to use it. + the licenses of parties who have received copies or rights from you + under this License. If your rights have been terminated and not + permanently reinstated, receipt of a copy of some or all of the + same material does not give you any rights to use it. - 10. FUTURE REVISIONS OF THIS LICENSE + 10. FUTURE REVISIONS OF THIS LICENSE The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See - `http://www.gnu.org/copyleft/'. + . Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been - published (not as a draft) by the Free Software Foundation. If - the Document does not specify a version number of this License, - you may choose any version ever published (not as a draft) by the - Free Software Foundation. If the Document specifies that a proxy - can decide which future versions of this License can be used, that + published (not as a draft) by the Free Software Foundation. If the + Document does not specify a version number of this License, you may + choose any version ever published (not as a draft) by the Free + Software Foundation. If the Document specifies that a proxy can + decide which future versions of this License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Document. - 11. RELICENSING + 11. RELICENSING "Massive Multiauthor Collaboration Site" (or "MMC Site") means any World Wide Web server that publishes copyrightable works and also @@ -30902,7 +30775,6 @@ GNU Free Documentation License site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing. - ADDENDUM: How to use this License for your documents ==================================================== @@ -30919,7 +30791,7 @@ notices just after the title page: Free Documentation License''. If you have Invariant Sections, Front-Cover Texts and Back-Cover -Texts, replace the "with...Texts." line with this: +Texts, replace the "with...Texts." line with this: with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts @@ -30930,9 +30802,9 @@ combination of the three, merge those two alternatives to suit the situation. If your document contains nontrivial examples of program code, we -recommend releasing these examples in parallel under your choice of -free software license, such as the GNU General Public License, to -permit their use in free software. +recommend releasing these examples in parallel under your choice of free +software license, such as the GNU General Public License, to permit +their use in free software.  File: gawk.info, Node: Index, Prev: GNU Free Documentation License, Up: Top @@ -30943,313 +30815,354 @@ Index [index] * Menu: -* ! (exclamation point), ! operator: Boolean Ops. (line 67) -* ! (exclamation point), ! operator <1>: Egrep Program. (line 175) -* ! (exclamation point), ! operator <2>: Ranges. (line 48) -* ! (exclamation point), ! operator: Precedence. (line 52) -* ! (exclamation point), != operator <1>: Precedence. (line 65) -* ! (exclamation point), != operator: Comparison Operators. +* '!' (exclamation point), '!' operator: Boolean Ops. (line 67) +* '!' (exclamation point), '!' operator <1>: Precedence. (line 51) +* '!' (exclamation point), '!' operator <2>: Ranges. (line 47) +* '!' (exclamation point), '!' operator <3>: Egrep Program. (line 174) +* '!' (exclamation point), '!=' operator: Comparison Operators. (line 11) -* ! (exclamation point), !~ operator <1>: Expression Patterns. - (line 24) -* ! (exclamation point), !~ operator <2>: Precedence. (line 80) -* ! (exclamation point), !~ operator <3>: Comparison Operators. +* '!' (exclamation point), '!=' operator <1>: Precedence. (line 64) +* '!' (exclamation point), '!~' operator: Regexp Usage. (line 19) +* '!' (exclamation point), '!~' operator <1>: Case-sensitivity. + (line 26) +* '!' (exclamation point), '!~' operator <2>: Computed Regexps. + (line 6) +* '!' (exclamation point), '!~' operator <3>: Regexp Constants. + (line 6) +* '!' (exclamation point), '!~' operator <4>: Comparison Operators. (line 11) -* ! (exclamation point), !~ operator <4>: Regexp Constants. (line 6) -* ! (exclamation point), !~ operator <5>: Computed Regexps. (line 6) -* ! (exclamation point), !~ operator <6>: Case-sensitivity. (line 26) -* ! (exclamation point), !~ operator: Regexp Usage. (line 19) -* " (double quote) in shell commands: Read Terminal. (line 25) -* " (double quote), in regexp constants: Computed Regexps. (line 29) -* " (double quote), in shell commands: Quoting. (line 54) -* # (number sign), #! (executable scripts): Executable Scripts. +* '!' (exclamation point), '!~' operator <5>: Comparison Operators. + (line 98) +* '!' (exclamation point), '!~' operator <6>: Precedence. (line 79) +* '!' (exclamation point), '!~' operator <7>: Expression Patterns. + (line 24) +* '"' (double quote) in shell commands: Read Terminal. (line 25) +* '"' (double quote), in regexp constants: Computed Regexps. (line 29) +* '"' (double quote), in shell commands: Quoting. (line 54) +* '#' (number sign), '#!' (executable scripts): Executable Scripts. (line 6) -* # (number sign), commenting: Comments. (line 6) -* $ (dollar sign), $ field operator <1>: Precedence. (line 43) -* $ (dollar sign), $ field operator: Fields. (line 19) -* $ (dollar sign), incrementing fields and arrays: Increment Ops. +* '#' (number sign), commenting: Comments. (line 6) +* '$' (dollar sign), '$' field operator: Fields. (line 19) +* '$' (dollar sign), '$' field operator <1>: Precedence. (line 42) +* '$' (dollar sign), incrementing fields and arrays: Increment Ops. (line 30) -* $ (dollar sign), regexp operator: Regexp Operators. (line 35) -* % (percent sign), % operator: Precedence. (line 55) -* % (percent sign), %= operator <1>: Precedence. (line 95) -* % (percent sign), %= operator: Assignment Ops. (line 130) -* & (ampersand), && operator <1>: Precedence. (line 86) -* & (ampersand), && operator: Boolean Ops. (line 57) -* & (ampersand), gsub()/gensub()/sub() functions and: Gory Details. +* '$' (dollar sign), regexp operator: Regexp Operators. (line 35) +* '%' (percent sign), '%' operator: Precedence. (line 54) +* '%' (percent sign), '%=' operator: Assignment Ops. (line 129) +* '%' (percent sign), '%=' operator <1>: Precedence. (line 94) +* '&' (ampersand), '&&' operator: Boolean Ops. (line 57) +* '&' (ampersand), '&&' operator <1>: Precedence. (line 85) +* '&' (ampersand), 'gsub()'/'gensub()'/'sub()' functions and: Gory Details. (line 6) -* ' (single quote): One-shot. (line 15) -* ' (single quote) in gawk command lines: Long. (line 33) -* ' (single quote), in shell commands: Quoting. (line 48) -* ' (single quote), vs. apostrophe: Comments. (line 27) -* ' (single quote), with double quotes: Quoting. (line 70) -* () (parentheses), in a profile: Profiling. (line 146) -* () (parentheses), regexp operator: Regexp Operators. (line 80) -* * (asterisk), * operator, as multiplication operator: Precedence. - (line 55) -* * (asterisk), * operator, as regexp operator: Regexp Operators. +* ''' (single quote): One-shot. (line 15) +* ''' (single quote) in 'gawk' command lines: Long. (line 33) +* ''' (single quote), in shell commands: Quoting. (line 48) +* ''' (single quote), vs. apostrophe: Comments. (line 27) +* ''' (single quote), with double quotes: Quoting. (line 70) +* '()' (parentheses), in a profile: Profiling. (line 146) +* '()' (parentheses), regexp operator: Regexp Operators. (line 80) +* '*' (asterisk), '*' operator, as multiplication operator: Precedence. + (line 54) +* '*' (asterisk), '*' operator, as regexp operator: Regexp Operators. (line 88) -* * (asterisk), * operator, null strings, matching: Gory Details. +* '*' (asterisk), '*' operator, null strings, matching: Gory Details. (line 164) -* * (asterisk), ** operator <1>: Precedence. (line 49) -* * (asterisk), ** operator: Arithmetic Ops. (line 81) -* * (asterisk), **= operator <1>: Precedence. (line 95) -* * (asterisk), **= operator: Assignment Ops. (line 130) -* * (asterisk), *= operator <1>: Precedence. (line 95) -* * (asterisk), *= operator: Assignment Ops. (line 130) -* + (plus sign), + operator: Precedence. (line 52) -* + (plus sign), ++ operator <1>: Precedence. (line 46) -* + (plus sign), ++ operator: Increment Ops. (line 11) -* + (plus sign), += operator <1>: Precedence. (line 95) -* + (plus sign), += operator: Assignment Ops. (line 82) -* + (plus sign), regexp operator: Regexp Operators. (line 103) -* , (comma), in range patterns: Ranges. (line 6) -* - (hyphen), - operator: Precedence. (line 52) -* - (hyphen), -- operator <1>: Precedence. (line 46) -* - (hyphen), -- operator: Increment Ops. (line 48) -* - (hyphen), -= operator <1>: Precedence. (line 95) -* - (hyphen), -= operator: Assignment Ops. (line 130) -* - (hyphen), filenames beginning with: Options. (line 59) -* - (hyphen), in bracket expressions: Bracket Expressions. (line 17) -* --assign option: Options. (line 32) -* --bignum option: Options. (line 205) -* --characters-as-bytes option: Options. (line 68) -* --copyright option: Options. (line 88) -* --debug option: Options. (line 108) -* --disable-extensions configuration option: Additional Configuration Options. +* '*' (asterisk), '**' operator: Arithmetic Ops. (line 81) +* '*' (asterisk), '**' operator <1>: Precedence. (line 48) +* '*' (asterisk), '**=' operator: Assignment Ops. (line 129) +* '*' (asterisk), '**=' operator <1>: Precedence. (line 94) +* '*' (asterisk), '*=' operator: Assignment Ops. (line 129) +* '*' (asterisk), '*=' operator <1>: Precedence. (line 94) +* '+' (plus sign), '+' operator: Precedence. (line 51) +* '+' (plus sign), '+' operator <1>: Precedence. (line 57) +* '+' (plus sign), '++' operator: Increment Ops. (line 11) +* '+' (plus sign), '++' operator <1>: Increment Ops. (line 40) +* '+' (plus sign), '++' operator <2>: Precedence. (line 45) +* '+' (plus sign), '+=' operator: Assignment Ops. (line 81) +* '+' (plus sign), '+=' operator <1>: Precedence. (line 94) +* '+' (plus sign), regexp operator: Regexp Operators. (line 103) +* ',' (comma), in range patterns: Ranges. (line 6) +* '-' (hyphen), '-' operator: Precedence. (line 51) +* '-' (hyphen), '-' operator <1>: Precedence. (line 57) +* '-' (hyphen), '--' operator: Increment Ops. (line 48) +* '-' (hyphen), '--' operator <1>: Precedence. (line 45) +* '-' (hyphen), '-=' operator: Assignment Ops. (line 129) +* '-' (hyphen), '-=' operator <1>: Precedence. (line 94) +* '-' (hyphen), filenames beginning with: Options. (line 60) +* '-' (hyphen), in bracket expressions: Bracket Expressions. (line 17) +* '--assign' option: Options. (line 32) +* '--bignum' option: Options. (line 203) +* '--characters-as-bytes' option: Options. (line 69) +* '--copyright' option: Options. (line 89) +* '--debug' option: Options. (line 108) +* '--disable-extensions' configuration option: Additional Configuration Options. (line 9) -* --disable-lint configuration option: Additional Configuration Options. +* '--disable-lint' configuration option: Additional Configuration Options. (line 15) -* --disable-nls configuration option: Additional Configuration Options. +* '--disable-nls' configuration option: Additional Configuration Options. (line 30) -* --dump-variables option: Options. (line 93) -* --dump-variables option, using for library functions: Library Names. +* '--dump-variables' option: Options. (line 94) +* '--dump-variables' option, using for library functions: Library Names. (line 45) -* --exec option: Options. (line 125) -* --field-separator option: Options. (line 21) -* --file option: Options. (line 25) -* --gen-pot option <1>: String Extraction. (line 6) -* --gen-pot option: Options. (line 147) -* --help option: Options. (line 154) -* --include option: Options. (line 159) -* --lint option <1>: Options. (line 185) -* --lint option: Command Line. (line 20) -* --lint-old option: Options. (line 293) -* --load option: Options. (line 173) -* --non-decimal-data option <1>: Nondecimal Data. (line 6) -* --non-decimal-data option: Options. (line 211) -* --non-decimal-data option, strtonum() function and: Nondecimal Data. +* '--exec' option: Options. (line 125) +* '--field-separator' option: Options. (line 21) +* '--file' option: Options. (line 25) +* '--gen-pot' option: Options. (line 147) +* '--gen-pot' option <1>: String Extraction. (line 6) +* '--gen-pot' option <2>: String Extraction. (line 6) +* '--help' option: Options. (line 154) +* '--include' option: Options. (line 159) +* '--lint' option: Command Line. (line 20) +* '--lint' option <1>: Options. (line 184) +* '--lint-old' option: Options. (line 290) +* '--load' option: Options. (line 172) +* '--non-decimal-data' option: Options. (line 209) +* '--non-decimal-data' option <1>: Nondecimal Data. (line 6) +* '--non-decimal-data' option, 'strtonum()' function and: Nondecimal Data. (line 36) -* --optimize option: Options. (line 235) -* --posix option: Options. (line 252) -* --posix option, --traditional option and: Options. (line 271) -* --pretty-print option: Options. (line 224) -* --profile option <1>: Profiling. (line 12) -* --profile option: Options. (line 240) -* --re-interval option: Options. (line 277) -* --sandbox option: Options. (line 284) -* --sandbox option, disabling system() function: I/O Functions. - (line 97) -* --sandbox option, input redirection with getline: Getline. (line 19) -* --sandbox option, output redirection with print, printf: Redirection. +* '--optimize' option: Options. (line 233) +* '--posix' option: Options. (line 250) +* '--posix' option, '--traditional' option and: Options. (line 268) +* '--pretty-print' option: Options. (line 222) +* '--profile' option: Options. (line 238) +* '--profile' option <1>: Profiling. (line 12) +* '--re-interval' option: Options. (line 274) +* '--sandbox' option: Options. (line 281) +* '--sandbox' option, disabling 'system()' function: I/O Functions. + (line 98) +* '--sandbox' option, input redirection with 'getline': Getline. + (line 19) +* '--sandbox' option, output redirection with 'print', 'printf': Redirection. (line 6) -* --source option: Options. (line 117) -* --traditional option: Options. (line 81) -* --traditional option, --posix option and: Options. (line 271) -* --use-lc-numeric option: Options. (line 219) -* --version option: Options. (line 298) -* --with-whiny-user-strftime configuration option: Additional Configuration Options. +* '--source' option: Options. (line 117) +* '--source' option <1>: Options. (line 331) +* '--traditional' option: Options. (line 82) +* '--traditional' option, '--posix' option and: Options. (line 268) +* '--use-lc-numeric' option: Options. (line 217) +* '--version' option: Options. (line 295) +* '--with-whiny-user-strftime' configuration option: Additional Configuration Options. (line 35) -* -b option: Options. (line 68) -* -C option: Options. (line 88) -* -c option: Options. (line 81) -* -D option: Options. (line 108) -* -d option: Options. (line 93) -* -E option: Options. (line 125) -* -e option: Options. (line 117) -* -f option: Options. (line 25) -* -F option: Options. (line 21) -* -f option: Long. (line 12) -* -F option, -Ft sets FS to TAB: Options. (line 306) -* -F option, command line: Command Line Field Separator. +* '-b' option: Options. (line 69) +* '-c' option: Options. (line 82) +* '-C' option: Options. (line 89) +* '-d' option: Options. (line 94) +* '-D' option: Options. (line 108) +* '-e' option: Options. (line 117) +* '-E' option: Options. (line 125) +* '-f' option: Long. (line 12) +* '-F' option: Options. (line 21) +* '-f' option <1>: Options. (line 25) +* '-F' option, '-Ft' sets 'FS' to TAB: Options. (line 303) +* '-F' option, command line: Command Line Field Separator. (line 6) -* -f option, multiple uses: Options. (line 311) -* -g option: Options. (line 147) -* -h option: Options. (line 154) -* -i option: Options. (line 159) -* -L option: Options. (line 293) -* -l option: Options. (line 173) -* -M option: Options. (line 205) -* -N option: Options. (line 219) -* -n option: Options. (line 211) -* -O option: Options. (line 235) -* -o option: Options. (line 224) -* -P option: Options. (line 252) -* -p option: Options. (line 240) -* -r option: Options. (line 277) -* -S option: Options. (line 284) -* -v option: Assignment Options. (line 12) -* -V option: Options. (line 298) -* -v option: Options. (line 32) -* -W option: Options. (line 46) -* . (period), regexp operator: Regexp Operators. (line 44) -* .gmo files: Explaining gettext. (line 42) -* .gmo files, specifying directory of <1>: Programmer i18n. (line 47) -* .gmo files, specifying directory of: Explaining gettext. (line 54) -* .mo files, converting from .po: I18N Example. (line 63) -* .po files <1>: Translator i18n. (line 6) -* .po files: Explaining gettext. (line 37) -* .po files, converting to .mo: I18N Example. (line 63) -* .pot files: Explaining gettext. (line 31) -* / (forward slash) to enclose regular expressions: Regexp. (line 10) -* / (forward slash), / operator: Precedence. (line 55) -* / (forward slash), /= operator <1>: Precedence. (line 95) -* / (forward slash), /= operator: Assignment Ops. (line 130) -* / (forward slash), /= operator, vs. /=.../ regexp constant: Assignment Ops. - (line 148) -* / (forward slash), patterns and: Expression Patterns. (line 24) -* /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) -* /dev/... special files: Special FD. (line 46) -* /dev/fd/N special files (gawk): Special FD. (line 46) -* /inet/... special files (gawk): TCP/IP Networking. (line 6) -* /inet4/... special files (gawk): TCP/IP Networking. (line 6) -* /inet6/... special files (gawk): TCP/IP Networking. (line 6) -* ; (semicolon), AWKPATH variable and: PC Using. (line 10) -* ; (semicolon), separating statements in actions <1>: Statements. - (line 10) -* ; (semicolon), separating statements in actions <2>: Action Overview. +* '-f' option, multiple uses: Options. (line 308) +* '-g' option: Options. (line 147) +* '-h' option: Options. (line 154) +* '-i' option: Options. (line 159) +* '-l' option: Options. (line 172) +* '-l' option <1>: Options. (line 184) +* '-L' option: Options. (line 290) +* '-M' option: Options. (line 203) +* '-n' option: Options. (line 209) +* '-N' option: Options. (line 217) +* '-o' option: Options. (line 222) +* '-O' option: Options. (line 233) +* '-p' option: Options. (line 238) +* '-P' option: Options. (line 250) +* '-r' option: Options. (line 274) +* '-S' option: Options. (line 281) +* '-v' option: Options. (line 32) +* '-V' option: Options. (line 295) +* '-v' option <1>: Assignment Options. (line 12) +* '-W' option: Options. (line 47) +* '.' (period), regexp operator: Regexp Operators. (line 44) +* '.gmo' files: Explaining gettext. (line 42) +* '.gmo' files, specifying directory of: Explaining gettext. (line 54) +* '.gmo' files, specifying directory of <1>: Programmer i18n. (line 47) +* '.mo' files, converting from '.po': I18N Example. (line 63) +* '.po' files: Explaining gettext. (line 37) +* '.po' files <1>: Translator i18n. (line 6) +* '.po' files, converting to '.mo': I18N Example. (line 63) +* '.pot' files: Explaining gettext. (line 31) +* '/' (forward slash) to enclose regular expressions: Regexp. (line 10) +* '/' (forward slash), '/' operator: Precedence. (line 54) +* '/' (forward slash), '/=' operator: Assignment Ops. (line 129) +* '/' (forward slash), '/=' operator <1>: Precedence. (line 94) +* '/' (forward slash), '/=' operator, vs. '/=.../' regexp constant: Assignment Ops. + (line 149) +* '/' (forward slash), patterns and: Expression Patterns. (line 24) +* '/=' operator vs. '/=.../' regexp constant: Assignment Ops. (line 149) +* '/dev/...' special files: Special FD. (line 46) +* '/dev/fd/N' special files ('gawk'): Special FD. (line 46) +* '/inet/...' special files ('gawk'): TCP/IP Networking. (line 6) +* '/inet4/...' special files ('gawk'): TCP/IP Networking. (line 6) +* '/inet6/...' special files ('gawk'): TCP/IP Networking. (line 6) +* ';' (semicolon), 'AWKPATH' variable and: PC Using. (line 10) +* ';' (semicolon), separating statements in actions: Statements/Lines. + (line 90) +* ';' (semicolon), separating statements in actions <1>: Action Overview. (line 19) -* ; (semicolon), separating statements in actions: Statements/Lines. - (line 91) -* < (left angle bracket), < operator <1>: Precedence. (line 65) -* < (left angle bracket), < operator: Comparison Operators. +* ';' (semicolon), separating statements in actions <2>: Statements. + (line 10) +* '<' (left angle bracket), '<' operator: Comparison Operators. (line 11) -* < (left angle bracket), < operator (I/O): Getline/File. (line 6) -* < (left angle bracket), <= operator <1>: Precedence. (line 65) -* < (left angle bracket), <= operator: Comparison Operators. +* '<' (left angle bracket), '<' operator <1>: Precedence. (line 64) +* '<' (left angle bracket), '<' operator (I/O): Getline/File. (line 6) +* '<' (left angle bracket), '<=' operator: Comparison Operators. (line 11) -* = (equals sign), = operator: Assignment Ops. (line 6) -* = (equals sign), == operator <1>: Precedence. (line 65) -* = (equals sign), == operator: Comparison Operators. +* '<' (left angle bracket), '<=' operator <1>: Precedence. (line 64) +* '=' (equals sign), '=' operator: Assignment Ops. (line 6) +* '=' (equals sign), '==' operator: Comparison Operators. (line 11) -* > (right angle bracket), > operator <1>: Precedence. (line 65) -* > (right angle bracket), > operator: Comparison Operators. +* '=' (equals sign), '==' operator <1>: Precedence. (line 64) +* '>' (right angle bracket), '>' operator: Comparison Operators. (line 11) -* > (right angle bracket), > operator (I/O): Redirection. (line 22) -* > (right angle bracket), >= operator <1>: Precedence. (line 65) -* > (right angle bracket), >= operator: Comparison Operators. +* '>' (right angle bracket), '>' operator <1>: Precedence. (line 64) +* '>' (right angle bracket), '>' operator (I/O): Redirection. (line 22) +* '>' (right angle bracket), '>=' operator: Comparison Operators. (line 11) -* > (right angle bracket), >> operator (I/O) <1>: Precedence. (line 65) -* > (right angle bracket), >> operator (I/O): Redirection. (line 50) -* ? (question mark), ?: operator: Precedence. (line 92) -* ? (question mark), regexp operator <1>: GNU Regexp Operators. - (line 59) -* ? (question mark), regexp operator: Regexp Operators. (line 112) -* [] (square brackets), regexp operator: Regexp Operators. (line 56) -* \ (backslash): Comments. (line 50) -* \ (backslash) in shell commands: Read Terminal. (line 25) -* \ (backslash), \" escape sequence: Escape Sequences. (line 76) -* \ (backslash), \' operator (gawk): GNU Regexp Operators. - (line 56) -* \ (backslash), \/ escape sequence: Escape Sequences. (line 69) -* \ (backslash), \< operator (gawk): GNU Regexp Operators. - (line 30) -* \ (backslash), \> operator (gawk): GNU Regexp Operators. - (line 34) -* \ (backslash), \` operator (gawk): GNU Regexp Operators. - (line 54) -* \ (backslash), \a escape sequence: Escape Sequences. (line 34) -* \ (backslash), \b escape sequence: Escape Sequences. (line 38) -* \ (backslash), \B operator (gawk): GNU Regexp Operators. - (line 43) -* \ (backslash), \f escape sequence: Escape Sequences. (line 41) -* \ (backslash), \n escape sequence: Escape Sequences. (line 44) -* \ (backslash), \NNN escape sequence: Escape Sequences. (line 56) -* \ (backslash), \r escape sequence: Escape Sequences. (line 47) -* \ (backslash), \S operator (gawk): GNU Regexp Operators. - (line 17) -* \ (backslash), \s operator (gawk): GNU Regexp Operators. - (line 13) -* \ (backslash), \t escape sequence: Escape Sequences. (line 50) -* \ (backslash), \v escape sequence: Escape Sequences. (line 53) -* \ (backslash), \W operator (gawk): GNU Regexp Operators. - (line 26) -* \ (backslash), \w operator (gawk): GNU Regexp Operators. - (line 21) -* \ (backslash), \x escape sequence: Escape Sequences. (line 61) -* \ (backslash), \y operator (gawk): GNU Regexp Operators. - (line 38) -* \ (backslash), as field separator: Command Line Field Separator. +* '>' (right angle bracket), '>=' operator <1>: Precedence. (line 64) +* '>' (right angle bracket), '>>' operator (I/O): Redirection. + (line 50) +* '>' (right angle bracket), '>>' operator (I/O) <1>: Precedence. + (line 64) +* '?' (question mark), '?:' operator: Precedence. (line 91) +* '?' (question mark), regexp operator: Regexp Operators. (line 112) +* '?' (question mark), regexp operator <1>: GNU Regexp Operators. + (line 62) +* '[]' (square brackets), regexp operator: Regexp Operators. (line 56) +* '\' (backslash): Comments. (line 50) +* '\' (backslash) in shell commands: Read Terminal. (line 25) +* '\' (backslash), as field separator: Command Line Field Separator. (line 27) -* \ (backslash), continuing lines and <1>: Egrep Program. (line 223) -* \ (backslash), continuing lines and: Statements/Lines. (line 19) -* \ (backslash), continuing lines and, comments and: Statements/Lines. - (line 76) -* \ (backslash), continuing lines and, in csh: Statements/Lines. - (line 44) -* \ (backslash), gsub()/gensub()/sub() functions and: Gory Details. +* '\' (backslash), continuing lines and: Statements/Lines. (line 19) +* '\' (backslash), continuing lines and <1>: Egrep Program. (line 222) +* '\' (backslash), continuing lines and, comments and: Statements/Lines. + (line 75) +* '\' (backslash), continuing lines and, in 'csh': Statements/Lines. + (line 43) +* '\' (backslash), 'gsub()'/'gensub()'/'sub()' functions and: Gory Details. (line 6) -* \ (backslash), in bracket expressions: Bracket Expressions. (line 17) -* \ (backslash), in escape sequences: Escape Sequences. (line 6) -* \ (backslash), in escape sequences, POSIX and: Escape Sequences. - (line 112) -* \ (backslash), in regexp constants: Computed Regexps. (line 29) -* \ (backslash), in shell commands: Quoting. (line 48) -* \ (backslash), regexp operator: Regexp Operators. (line 18) -* ^ (caret), ^ operator: Precedence. (line 49) -* ^ (caret), ^= operator <1>: Precedence. (line 95) -* ^ (caret), ^= operator: Assignment Ops. (line 130) -* ^ (caret), in bracket expressions: Bracket Expressions. (line 17) -* ^ (caret), in FS: Regexp Field Splitting. +* '\' (backslash), in bracket expressions: Bracket Expressions. + (line 17) +* '\' (backslash), in escape sequences: Escape Sequences. (line 6) +* '\' (backslash), in escape sequences <1>: Escape Sequences. (line 93) +* '\' (backslash), in escape sequences, POSIX and: Escape Sequences. + (line 111) +* '\' (backslash), in regexp constants: Computed Regexps. (line 29) +* '\' (backslash), in shell commands: Quoting. (line 48) +* '\' (backslash), regexp operator: Regexp Operators. (line 18) +* '\' (backslash), '\"' escape sequence: Escape Sequences. (line 76) +* '\' (backslash), '\'' operator ('gawk'): GNU Regexp Operators. (line 59) -* ^ (caret), regexp operator <1>: GNU Regexp Operators. +* '\' (backslash), '\/' escape sequence: Escape Sequences. (line 69) +* '\' (backslash), '\<' operator ('gawk'): GNU Regexp Operators. + (line 33) +* '\' (backslash), '\>' operator ('gawk'): GNU Regexp Operators. + (line 37) +* '\' (backslash), '\a' escape sequence: Escape Sequences. (line 34) +* '\' (backslash), '\b' escape sequence: Escape Sequences. (line 38) +* '\' (backslash), '\B' operator ('gawk'): GNU Regexp Operators. + (line 46) +* '\' (backslash), '\f' escape sequence: Escape Sequences. (line 41) +* '\' (backslash), '\n' escape sequence: Escape Sequences. (line 44) +* '\' (backslash), '\'NNN escape sequence: Escape Sequences. (line 56) +* '\' (backslash), '\r' escape sequence: Escape Sequences. (line 47) +* '\' (backslash), '\s' operator ('gawk'): GNU Regexp Operators. + (line 13) +* '\' (backslash), '\S' operator ('gawk'): GNU Regexp Operators. + (line 17) +* '\' (backslash), '\t' escape sequence: Escape Sequences. (line 50) +* '\' (backslash), '\v' escape sequence: Escape Sequences. (line 53) +* '\' (backslash), '\w' operator ('gawk'): GNU Regexp Operators. + (line 22) +* '\' (backslash), '\W' operator ('gawk'): GNU Regexp Operators. + (line 28) +* '\' (backslash), '\x' escape sequence: Escape Sequences. (line 61) +* '\' (backslash), '\y' operator ('gawk'): GNU Regexp Operators. + (line 41) +* '\' (backslash), '\`' operator ('gawk'): GNU Regexp Operators. + (line 57) +* '^' (caret), in bracket expressions: Bracket Expressions. (line 17) +* '^' (caret), in 'FS': Regexp Field Splitting. (line 59) -* ^ (caret), regexp operator: Regexp Operators. (line 22) -* _ (underscore), C macro: Explaining gettext. (line 71) -* _ (underscore), in names of private variables: Library Names. +* '^' (caret), regexp operator: Regexp Operators. (line 22) +* '^' (caret), regexp operator <1>: GNU Regexp Operators. + (line 62) +* '^' (caret), '^' operator: Precedence. (line 48) +* '^' (caret), '^=' operator: Assignment Ops. (line 129) +* '^' (caret), '^=' operator <1>: Precedence. (line 94) +* '_' (underscore), C macro: Explaining gettext. (line 71) +* '_' (underscore), in names of private variables: Library Names. (line 29) -* _ (underscore), translatable string: Programmer i18n. (line 69) -* _gr_init() user-defined function: Group Functions. (line 83) -* _ord_init() user-defined function: Ordinal Functions. (line 16) -* _pw_init() user-defined function: Passwd Functions. (line 105) +* '_' (underscore), translatable string: Programmer i18n. (line 69) +* '_gr_init()' user-defined function: Group Functions. (line 83) +* '_ord_init()' user-defined function: Ordinal Functions. (line 16) +* '_pw_init()' user-defined function: Passwd Functions. (line 105) +* '{}' (braces): Profiling. (line 142) +* '{}' (braces), actions and: Action Overview. (line 19) +* '{}' (braces), statements, grouping: Statements. (line 10) +* '|' (vertical bar): Regexp Operators. (line 70) +* '|' (vertical bar), '|' operator (I/O): Getline/Pipe. (line 10) +* '|' (vertical bar), '|' operator (I/O) <1>: Redirection. (line 57) +* '|' (vertical bar), '|' operator (I/O) <2>: Precedence. (line 64) +* '|' (vertical bar), '|&' operator (I/O): Getline/Coprocess. (line 6) +* '|' (vertical bar), '|&' operator (I/O) <1>: Redirection. (line 102) +* '|' (vertical bar), '|&' operator (I/O) <2>: Precedence. (line 64) +* '|' (vertical bar), '|&' operator (I/O) <3>: Two-way I/O. (line 44) +* '|' (vertical bar), '|&' operator (I/O), pipes, closing: Close Files And Pipes. + (line 119) +* '|' (vertical bar), '||' operator: Boolean Ops. (line 57) +* '|' (vertical bar), '||' operator <1>: Precedence. (line 88) +* '~' (tilde), '~' operator: Regexp Usage. (line 19) +* '~' (tilde), '~' operator <1>: Case-sensitivity. (line 26) +* '~' (tilde), '~' operator <2>: Computed Regexps. (line 6) +* '~' (tilde), '~' operator <3>: Regexp Constants. (line 6) +* '~' (tilde), '~' operator <4>: Comparison Operators. + (line 11) +* '~' (tilde), '~' operator <5>: Comparison Operators. + (line 98) +* '~' (tilde), '~' operator <6>: Precedence. (line 79) +* '~' (tilde), '~' operator <7>: Expression Patterns. (line 24) * accessing fields: Fields. (line 6) * accessing global variables from extensions: Symbol Table Access. (line 6) -* account information <1>: Group Functions. (line 6) * account information: Passwd Functions. (line 16) +* account information <1>: Group Functions. (line 6) * actions: Action Overview. (line 6) * actions, control statements in: Statements. (line 6) * actions, default: Very Simple. (line 34) * actions, empty: Very Simple. (line 39) * Ada programming language: Glossary. (line 19) -* adding, features to gawk: Adding Code. (line 6) +* adding, features to 'gawk': Adding Code. (line 6) * adding, fields: Changing Fields. (line 53) * advanced features, fixed-width data: Constant Size. (line 10) -* advanced features, gawk: Advanced Features. (line 6) +* advanced features, 'gawk': Advanced Features. (line 6) * advanced features, network programming: TCP/IP Networking. (line 6) * advanced features, nondecimal input data: Nondecimal Data. (line 6) * advanced features, processes, communicating with: Two-way I/O. (line 23) * advanced features, specifying field content: Splitting By Content. (line 10) -* Aho, Alfred <1>: Contributors. (line 11) * Aho, Alfred: History. (line 17) +* Aho, Alfred <1>: Contributors. (line 12) * alarm clock example program: Alarm Program. (line 11) -* alarm.awk program: Alarm Program. (line 31) -* algorithms: Basic High Level. (line 68) +* 'alarm.awk' program: Alarm Program. (line 31) +* algorithms: Basic High Level. (line 57) * allocating memory for extensions: Memory Allocation Functions. (line 6) * Alpha (DEC): Manual History. (line 28) -* amazing awk assembler (aaa): Glossary. (line 11) -* amazingly workable formatter (awf): Glossary. (line 24) -* ambiguity, syntactic: /= operator vs. /=.../ regexp constant: Assignment Ops. - (line 148) -* ampersand (&), && operator <1>: Precedence. (line 86) -* ampersand (&), && operator: Boolean Ops. (line 57) -* ampersand (&), gsub()/gensub()/sub() functions and: Gory Details. +* amazing 'awk' assembler ('aaa'): Glossary. (line 11) +* amazingly workable formatter ('awf'): Glossary. (line 24) +* ambiguity, syntactic: '/=' operator vs. '/=.../' regexp constant: Assignment Ops. + (line 149) +* ampersand ('&'), '&&' operator: Boolean Ops. (line 57) +* ampersand ('&'), '&&' operator <1>: Precedence. (line 85) +* ampersand ('&'), 'gsub()'/'gensub()'/'sub()' functions and: Gory Details. (line 6) -* anagram.awk program: Anagram Program. (line 22) +* 'anagram.awk' program: Anagram Program. (line 22) * anagrams, finding: Anagram Program. (line 6) -* and: Bitwise Functions. (line 39) +* 'and': Bitwise Functions. (line 39) * AND bitwise operation: Bitwise Functions. (line 6) * and Boolean-logic operator: Boolean Ops. (line 6) * ANSI: Glossary. (line 34) @@ -31262,21 +31175,22 @@ Index * arbitrary precision integers: Arbitrary Precision Integers. (line 6) * archeologists: Bugs. (line 6) -* arctangent: Numeric Functions. (line 11) -* ARGC/ARGV variables: Auto-set. (line 15) -* ARGC/ARGV variables, command-line arguments: Other Arguments. +* arctangent: Numeric Functions. (line 10) +* 'ARGC'/'ARGV' variables: Auto-set. (line 15) +* 'ARGC'/'ARGV' variables, command-line arguments: Other Arguments. (line 12) -* ARGC/ARGV variables, how to use: ARGC and ARGV. (line 6) -* ARGC/ARGV variables, portability and: Executable Scripts. (line 42) -* ARGIND variable: Auto-set. (line 44) -* ARGIND variable, command-line arguments: Other Arguments. (line 12) -* arguments, command-line <1>: ARGC and ARGV. (line 6) -* arguments, command-line <2>: Auto-set. (line 15) +* 'ARGC'/'ARGV' variables, how to use: ARGC and ARGV. (line 6) +* 'ARGC'/'ARGV' variables, portability and: Executable Scripts. + (line 42) +* 'ARGIND' variable: Auto-set. (line 44) +* 'ARGIND' variable, command-line arguments: Other Arguments. (line 12) * arguments, command-line: Other Arguments. (line 6) -* arguments, command-line, invoking awk: Command Line. (line 6) +* arguments, command-line <1>: Auto-set. (line 15) +* arguments, command-line <2>: ARGC and ARGV. (line 6) +* arguments, command-line, invoking 'awk': Command Line. (line 6) * arguments, in function calls: Function Calls. (line 18) * arguments, processing: Getopt Function. (line 6) -* ARGV array, indexing into: Other Arguments. (line 12) +* 'ARGV' array, indexing into: Other Arguments. (line 12) * arithmetic operators: Arithmetic Ops. (line 6) * array manipulation in extensions: Array Manipulation. (line 6) * array members: Reference to Elements. @@ -31287,21 +31201,21 @@ Index * arrays: Arrays. (line 6) * arrays of arrays: Arrays of Arrays. (line 6) * arrays, an example of using: Array Example. (line 6) -* arrays, and IGNORECASE variable: Array Intro. (line 92) +* arrays, and 'IGNORECASE' variable: Array Intro. (line 91) * arrays, as parameters to functions: Pass By Value/Reference. - (line 47) -* arrays, associative: Array Intro. (line 50) + (line 46) +* arrays, associative: Array Intro. (line 48) * arrays, associative, library functions and: Library Names. (line 57) * arrays, deleting entire contents: Delete. (line 39) * arrays, elements that don't exist: Reference to Elements. (line 23) * arrays, elements, assigning values: Assigning Elements. (line 6) * arrays, elements, deleting: Delete. (line 6) -* arrays, elements, order of access by in operator: Scanning an Array. +* arrays, elements, order of access by 'in' operator: Scanning an Array. (line 48) * arrays, elements, retrieving number of: String Functions. (line 42) -* arrays, for statement and: Scanning an Array. (line 20) -* arrays, indexing: Array Intro. (line 50) +* arrays, 'for' statement and: Scanning an Array. (line 20) +* arrays, indexing: Array Intro. (line 48) * arrays, merging into strings: Join Function. (line 6) * arrays, multidimensional: Multidimensional. (line 10) * arrays, multidimensional, scanning: Multiscanning. (line 11) @@ -31313,208 +31227,217 @@ Index * arrays, scanning: Scanning an Array. (line 6) * arrays, sorting: Array Sorting Functions. (line 6) -* arrays, sorting, and IGNORECASE variable: Array Sorting Functions. +* arrays, sorting, and 'IGNORECASE' variable: Array Sorting Functions. (line 83) -* arrays, sparse: Array Intro. (line 71) +* arrays, sparse: Array Intro. (line 70) * arrays, subscripts, uninitialized variables as: Uninitialized Subscripts. (line 6) * arrays, unassigned elements: Reference to Elements. (line 18) -* artificial intelligence, gawk and: Distribution contents. +* artificial intelligence, 'gawk' and: Distribution contents. (line 52) -* ASCII <1>: Glossary. (line 133) * ASCII: Ordinal Functions. (line 45) -* asort <1>: Array Sorting Functions. +* ASCII <1>: Glossary. (line 133) +* 'asort': String Functions. (line 42) +* 'asort' <1>: Array Sorting Functions. (line 6) -* asort: String Functions. (line 42) -* asort() function (gawk), arrays, sorting: Array Sorting Functions. +* 'asort()' function ('gawk'), arrays, sorting: Array Sorting Functions. (line 6) -* asorti <1>: Array Sorting Functions. +* 'asorti': String Functions. (line 42) +* 'asorti' <1>: Array Sorting Functions. (line 6) -* asorti: String Functions. (line 42) -* asorti() function (gawk), arrays, sorting: Array Sorting Functions. +* 'asorti()' function ('gawk'), arrays, sorting: Array Sorting Functions. (line 6) -* assert() function (C library): Assert Function. (line 6) -* assert() user-defined function: Assert Function. (line 28) +* 'assert()' function (C library): Assert Function. (line 6) +* 'assert()' user-defined function: Assert Function. (line 28) * assertions: Assert Function. (line 6) * assign values to variables, in debugger: Viewing And Changing Data. - (line 59) + (line 58) * assignment operators: Assignment Ops. (line 6) -* assignment operators, evaluation order: Assignment Ops. (line 111) -* assignment operators, lvalues/rvalues: Assignment Ops. (line 32) +* assignment operators, evaluation order: Assignment Ops. (line 110) +* assignment operators, lvalues/rvalues: Assignment Ops. (line 31) * assignments as filenames: Ignoring Assigns. (line 6) -* associative arrays: Array Intro. (line 50) -* asterisk (*), * operator, as multiplication operator: Precedence. - (line 55) -* asterisk (*), * operator, as regexp operator: Regexp Operators. +* associative arrays: Array Intro. (line 48) +* asterisk ('*'), '*' operator, as multiplication operator: Precedence. + (line 54) +* asterisk ('*'), '*' operator, as regexp operator: Regexp Operators. (line 88) -* asterisk (*), * operator, null strings, matching: Gory Details. +* asterisk ('*'), '*' operator, null strings, matching: Gory Details. (line 164) -* asterisk (*), ** operator <1>: Precedence. (line 49) -* asterisk (*), ** operator: Arithmetic Ops. (line 81) -* asterisk (*), **= operator <1>: Precedence. (line 95) -* asterisk (*), **= operator: Assignment Ops. (line 130) -* asterisk (*), *= operator <1>: Precedence. (line 95) -* asterisk (*), *= operator: Assignment Ops. (line 130) -* atan2: Numeric Functions. (line 11) +* asterisk ('*'), '**' operator: Arithmetic Ops. (line 81) +* asterisk ('*'), '**' operator <1>: Precedence. (line 48) +* asterisk ('*'), '**=' operator: Assignment Ops. (line 129) +* asterisk ('*'), '**=' operator <1>: Precedence. (line 94) +* asterisk ('*'), '*=' operator: Assignment Ops. (line 129) +* asterisk ('*'), '*=' operator <1>: Precedence. (line 94) +* 'atan2': Numeric Functions. (line 10) * automatic displays, in debugger: Debugger Info. (line 24) -* awf (amazingly workable formatter) program: Glossary. (line 24) -* awk debugging, enabling: Options. (line 108) -* awk language, POSIX version: Assignment Ops. (line 137) -* awk profiling, enabling: Options. (line 240) -* awk programs <1>: Two Rules. (line 6) -* awk programs <2>: Executable Scripts. (line 6) -* awk programs: Getting Started. (line 12) -* awk programs, complex: When. (line 29) -* awk programs, documenting <1>: Library Names. (line 6) -* awk programs, documenting: Comments. (line 6) -* awk programs, examples of: Sample Programs. (line 6) -* awk programs, execution of: Next Statement. (line 16) -* awk programs, internationalizing <1>: Programmer i18n. (line 6) -* awk programs, internationalizing: I18N Functions. (line 6) -* awk programs, lengthy: Long. (line 6) -* awk programs, lengthy, assertions: Assert Function. (line 6) -* awk programs, location of: Options. (line 25) -* awk programs, one-line examples: Very Simple. (line 45) -* awk programs, profiling: Profiling. (line 6) -* awk programs, running <1>: Long. (line 6) -* awk programs, running: Running gawk. (line 6) -* awk programs, running, from shell scripts: One-shot. (line 22) -* awk programs, running, without input files: Read Terminal. (line 17) -* awk programs, shell variables in: Using Shell Variables. +* 'awf' (amazingly workable formatter) program: Glossary. (line 24) +* 'awk' debugging, enabling: Options. (line 108) +* 'awk' language, POSIX version: Assignment Ops. (line 138) +* 'awk' profiling, enabling: Options. (line 238) +* 'awk' programs: Getting Started. (line 12) +* 'awk' programs <1>: Executable Scripts. (line 6) +* 'awk' programs <2>: Two Rules. (line 6) +* 'awk' programs, complex: When. (line 29) +* 'awk' programs, documenting: Comments. (line 6) +* 'awk' programs, documenting <1>: Library Names. (line 6) +* 'awk' programs, examples of: Sample Programs. (line 6) +* 'awk' programs, execution of: Next Statement. (line 16) +* 'awk' programs, internationalizing: I18N Functions. (line 6) +* 'awk' programs, internationalizing <1>: Programmer i18n. (line 6) +* 'awk' programs, lengthy: Long. (line 6) +* 'awk' programs, lengthy, assertions: Assert Function. (line 6) +* 'awk' programs, location of: Options. (line 25) +* 'awk' programs, location of <1>: Options. (line 125) +* 'awk' programs, location of <2>: Options. (line 159) +* 'awk' programs, one-line examples: Very Simple. (line 45) +* 'awk' programs, profiling: Profiling. (line 6) +* 'awk' programs, running: Running gawk. (line 6) +* 'awk' programs, running <1>: Long. (line 6) +* 'awk' programs, running, from shell scripts: One-shot. (line 22) +* 'awk' programs, running, without input files: Read Terminal. + (line 17) +* 'awk' programs, shell variables in: Using Shell Variables. (line 6) -* awk, function of: Getting Started. (line 6) -* awk, gawk and <1>: This Manual. (line 14) -* awk, gawk and: Preface. (line 23) -* awk, history of: History. (line 17) -* awk, implementation issues, pipes: Redirection. (line 135) -* awk, implementations: Other Versions. (line 6) -* awk, implementations, limits: Getline Notes. (line 14) -* awk, invoking: Command Line. (line 6) -* awk, new vs. old: Names. (line 6) -* awk, new vs. old, OFMT variable: Strings And Numbers. (line 57) -* awk, POSIX and: Preface. (line 23) -* awk, POSIX and, See Also POSIX awk: Preface. (line 23) -* awk, regexp constants and: Comparison Operators. - (line 102) -* awk, See Also gawk: Preface. (line 36) -* awk, terms describing: This Manual. (line 6) -* awk, uses for <1>: When. (line 6) -* awk, uses for <2>: Getting Started. (line 12) -* awk, uses for: Preface. (line 23) -* awk, versions of <1>: V7/SVR3.1. (line 6) -* awk, versions of: Names. (line 10) -* awk, versions of, changes between SVR3.1 and SVR4: SVR4. (line 6) -* awk, versions of, changes between SVR4 and POSIX awk: POSIX. +* 'awk', function of: Getting Started. (line 6) +* 'awk', 'gawk' and: Preface. (line 23) +* 'awk', 'gawk' and <1>: This Manual. (line 14) +* 'awk', history of: History. (line 17) +* 'awk', implementation issues, pipes: Redirection. (line 134) +* 'awk', implementations: Other Versions. (line 6) +* 'awk', implementations, limits: Getline Notes. (line 14) +* 'awk', invoking: Command Line. (line 6) +* 'awk', new vs. old: Names. (line 6) +* 'awk', new vs. old, 'OFMT' variable: Strings And Numbers. (line 56) +* 'awk', POSIX and: Preface. (line 23) +* 'awk', POSIX and, See Also POSIX 'awk': Preface. (line 23) +* 'awk', regexp constants and: Comparison Operators. + (line 103) +* 'awk', See Also 'gawk': Preface. (line 36) +* 'awk', terms describing: This Manual. (line 6) +* 'awk', uses for: Preface. (line 23) +* 'awk', uses for <1>: Getting Started. (line 12) +* 'awk', uses for <2>: When. (line 6) +* 'awk', versions of: Names. (line 10) +* 'awk', versions of <1>: V7/SVR3.1. (line 6) +* 'awk', versions of, changes between SVR3.1 and SVR4: SVR4. (line 6) +* 'awk', versions of, changes between SVR4 and POSIX 'awk': POSIX. (line 6) -* awk, versions of, changes between V7 and SVR3.1: V7/SVR3.1. (line 6) -* awk, versions of, See Also Brian Kernighan's awk <1>: Other Versions. +* 'awk', versions of, changes between V7 and SVR3.1: V7/SVR3.1. + (line 6) +* 'awk', versions of, See Also Brian Kernighan's 'awk': BTL. (line 6) +* 'awk', versions of, See Also Brian Kernighan's 'awk' <1>: Other Versions. (line 13) -* awk, versions of, See Also Brian Kernighan's awk: BTL. (line 6) -* awka compiler for awk: Other Versions. (line 64) -* AWKLIBPATH environment variable: AWKLIBPATH Variable. (line 6) -* AWKPATH environment variable <1>: PC Using. (line 10) -* AWKPATH environment variable: AWKPATH Variable. (line 6) -* awkprof.out file: Profiling. (line 6) -* awksed.awk program: Simple Sed. (line 25) -* awkvars.out file: Options. (line 93) -* b debugger command (alias for break): Breakpoint Control. (line 11) -* backslash (\): Comments. (line 50) -* backslash (\) in shell commands: Read Terminal. (line 25) -* backslash (\), \" escape sequence: Escape Sequences. (line 76) -* backslash (\), \' operator (gawk): GNU Regexp Operators. - (line 56) -* backslash (\), \/ escape sequence: Escape Sequences. (line 69) -* backslash (\), \< operator (gawk): GNU Regexp Operators. - (line 30) -* backslash (\), \> operator (gawk): GNU Regexp Operators. - (line 34) -* backslash (\), \` operator (gawk): GNU Regexp Operators. - (line 54) -* backslash (\), \a escape sequence: Escape Sequences. (line 34) -* backslash (\), \b escape sequence: Escape Sequences. (line 38) -* backslash (\), \B operator (gawk): GNU Regexp Operators. +* 'awka' compiler for 'awk': Other Versions. (line 64) +* 'AWKLIBPATH' environment variable: AWKLIBPATH Variable. (line 6) +* 'AWKPATH' environment variable: AWKPATH Variable. (line 6) +* 'AWKPATH' environment variable <1>: PC Using. (line 10) +* 'awkprof.out' file: Profiling. (line 6) +* 'awksed.awk' program: Simple Sed. (line 25) +* 'awkvars.out' file: Options. (line 94) +* 'b' debugger command (alias for 'break'): Breakpoint Control. + (line 11) +* backslash ('\'): Comments. (line 50) +* backslash ('\') in shell commands: Read Terminal. (line 25) +* backslash ('\'), as field separator: Command Line Field Separator. + (line 27) +* backslash ('\'), continuing lines and: Statements/Lines. (line 19) +* backslash ('\'), continuing lines and <1>: Egrep Program. (line 222) +* backslash ('\'), continuing lines and, comments and: Statements/Lines. + (line 75) +* backslash ('\'), continuing lines and, in 'csh': Statements/Lines. (line 43) -* backslash (\), \f escape sequence: Escape Sequences. (line 41) -* backslash (\), \n escape sequence: Escape Sequences. (line 44) -* backslash (\), \NNN escape sequence: Escape Sequences. (line 56) -* backslash (\), \r escape sequence: Escape Sequences. (line 47) -* backslash (\), \S operator (gawk): GNU Regexp Operators. +* backslash ('\'), 'gsub()'/'gensub()'/'sub()' functions and: Gory Details. + (line 6) +* backslash ('\'), in bracket expressions: Bracket Expressions. (line 17) -* backslash (\), \s operator (gawk): GNU Regexp Operators. +* backslash ('\'), in escape sequences: Escape Sequences. (line 6) +* backslash ('\'), in escape sequences <1>: Escape Sequences. (line 93) +* backslash ('\'), in escape sequences, POSIX and: Escape Sequences. + (line 111) +* backslash ('\'), in regexp constants: Computed Regexps. (line 29) +* backslash ('\'), in shell commands: Quoting. (line 48) +* backslash ('\'), regexp operator: Regexp Operators. (line 18) +* backslash ('\'), '\"' escape sequence: Escape Sequences. (line 76) +* backslash ('\'), '\'' operator ('gawk'): GNU Regexp Operators. + (line 59) +* backslash ('\'), '\/' escape sequence: Escape Sequences. (line 69) +* backslash ('\'), '\<' operator ('gawk'): GNU Regexp Operators. + (line 33) +* backslash ('\'), '\>' operator ('gawk'): GNU Regexp Operators. + (line 37) +* backslash ('\'), '\a' escape sequence: Escape Sequences. (line 34) +* backslash ('\'), '\b' escape sequence: Escape Sequences. (line 38) +* backslash ('\'), '\B' operator ('gawk'): GNU Regexp Operators. + (line 46) +* backslash ('\'), '\f' escape sequence: Escape Sequences. (line 41) +* backslash ('\'), '\n' escape sequence: Escape Sequences. (line 44) +* backslash ('\'), '\'NNN escape sequence: Escape Sequences. (line 56) +* backslash ('\'), '\r' escape sequence: Escape Sequences. (line 47) +* backslash ('\'), '\s' operator ('gawk'): GNU Regexp Operators. (line 13) -* backslash (\), \t escape sequence: Escape Sequences. (line 50) -* backslash (\), \v escape sequence: Escape Sequences. (line 53) -* backslash (\), \W operator (gawk): GNU Regexp Operators. - (line 26) -* backslash (\), \w operator (gawk): GNU Regexp Operators. - (line 21) -* backslash (\), \x escape sequence: Escape Sequences. (line 61) -* backslash (\), \y operator (gawk): GNU Regexp Operators. - (line 38) -* backslash (\), as field separator: Command Line Field Separator. - (line 27) -* backslash (\), continuing lines and <1>: Egrep Program. (line 223) -* backslash (\), continuing lines and: Statements/Lines. (line 19) -* backslash (\), continuing lines and, comments and: Statements/Lines. - (line 76) -* backslash (\), continuing lines and, in csh: Statements/Lines. - (line 44) -* backslash (\), gsub()/gensub()/sub() functions and: Gory Details. - (line 6) -* backslash (\), in bracket expressions: Bracket Expressions. (line 17) -* backslash (\), in escape sequences: Escape Sequences. (line 6) -* backslash (\), in escape sequences, POSIX and: Escape Sequences. - (line 112) -* backslash (\), in regexp constants: Computed Regexps. (line 29) -* backslash (\), in shell commands: Quoting. (line 48) -* backslash (\), regexp operator: Regexp Operators. (line 18) -* backtrace debugger command: Execution Stack. (line 13) -* Beebe, Nelson H.F. <1>: Other Versions. (line 78) +* backslash ('\'), '\S' operator ('gawk'): GNU Regexp Operators. + (line 17) +* backslash ('\'), '\t' escape sequence: Escape Sequences. (line 50) +* backslash ('\'), '\v' escape sequence: Escape Sequences. (line 53) +* backslash ('\'), '\w' operator ('gawk'): GNU Regexp Operators. + (line 22) +* backslash ('\'), '\W' operator ('gawk'): GNU Regexp Operators. + (line 28) +* backslash ('\'), '\x' escape sequence: Escape Sequences. (line 61) +* backslash ('\'), '\y' operator ('gawk'): GNU Regexp Operators. + (line 41) +* backslash ('\'), '\`' operator ('gawk'): GNU Regexp Operators. + (line 57) +* 'backtrace' debugger command: Execution Stack. (line 13) * Beebe, Nelson H.F.: Acknowledgments. (line 60) -* BEGIN pattern <1>: Using BEGIN/END. (line 6) -* BEGIN pattern <2>: BEGIN/END. (line 6) -* BEGIN pattern: Field Separators. (line 45) -* BEGIN pattern, and profiling: Profiling. (line 62) -* BEGIN pattern, assert() user-defined function and: Assert Function. +* Beebe, Nelson H.F. <1>: Other Versions. (line 78) +* 'BEGIN' pattern: Field Separators. (line 44) +* 'BEGIN' pattern <1>: BEGIN/END. (line 6) +* 'BEGIN' pattern <2>: Using BEGIN/END. (line 6) +* 'BEGIN' pattern, and profiling: Profiling. (line 62) +* 'BEGIN' pattern, 'assert()' user-defined function and: Assert Function. (line 83) -* BEGIN pattern, Boolean patterns and: Expression Patterns. (line 70) -* BEGIN pattern, exit statement and: Exit Statement. (line 12) -* BEGIN pattern, getline and: Getline Notes. (line 19) -* BEGIN pattern, headings, adding: Print Examples. (line 43) -* BEGIN pattern, next/nextfile statements and <1>: Next Statement. +* 'BEGIN' pattern, Boolean patterns and: Expression Patterns. (line 70) +* 'BEGIN' pattern, 'exit' statement and: Exit Statement. (line 12) +* 'BEGIN' pattern, 'getline' and: Getline Notes. (line 19) +* 'BEGIN' pattern, headings, adding: Print Examples. (line 42) +* 'BEGIN' pattern, 'next'/'nextfile' statements and: I/O And BEGIN/END. + (line 36) +* 'BEGIN' pattern, 'next'/'nextfile' statements and <1>: Next Statement. (line 45) -* BEGIN pattern, next/nextfile statements and: I/O And BEGIN/END. - (line 37) -* BEGIN pattern, OFS/ORS variables, assigning values to: Output Separators. +* 'BEGIN' pattern, 'OFS'/'ORS' variables, assigning values to: Output Separators. (line 20) -* BEGIN pattern, operators and: Using BEGIN/END. (line 17) -* BEGIN pattern, print statement and: I/O And BEGIN/END. (line 16) -* BEGIN pattern, pwcat program: Passwd Functions. (line 143) -* BEGIN pattern, running awk programs and: Cut Program. (line 68) -* BEGIN pattern, TEXTDOMAIN variable and: Programmer i18n. (line 60) -* BEGINFILE pattern: BEGINFILE/ENDFILE. (line 6) -* BEGINFILE pattern, Boolean patterns and: Expression Patterns. +* 'BEGIN' pattern, operators and: Using BEGIN/END. (line 17) +* 'BEGIN' pattern, 'print' statement and: I/O And BEGIN/END. (line 15) +* 'BEGIN' pattern, 'pwcat' program: Passwd Functions. (line 143) +* 'BEGIN' pattern, running 'awk' programs and: Cut Program. (line 68) +* 'BEGIN' pattern, 'TEXTDOMAIN' variable and: Programmer i18n. + (line 60) +* 'BEGINFILE' pattern: BEGINFILE/ENDFILE. (line 6) +* 'BEGINFILE' pattern, Boolean patterns and: Expression Patterns. (line 70) -* beginfile() user-defined function: Filetrans Function. (line 62) +* 'beginfile()' user-defined function: Filetrans Function. (line 62) * Bentley, Jon: Glossary. (line 143) -* Benzinger, Michael: Contributors. (line 97) -* Berry, Karl <1>: Ranges and Locales. (line 74) +* Benzinger, Michael: Contributors. (line 98) * Berry, Karl: Acknowledgments. (line 33) +* Berry, Karl <1>: Ranges and Locales. (line 74) * binary input/output: User-modified. (line 15) -* bindtextdomain <1>: Programmer i18n. (line 47) -* bindtextdomain: I18N Functions. (line 12) -* bindtextdomain() function (C library): Explaining gettext. (line 50) -* bindtextdomain() function (gawk), portability and: I18N Portability. +* 'bindtextdomain': I18N Functions. (line 11) +* 'bindtextdomain' <1>: Programmer i18n. (line 47) +* 'bindtextdomain()' function (C library): Explaining gettext. + (line 50) +* 'bindtextdomain()' function ('gawk'), portability and: I18N Portability. (line 33) -* BINMODE variable <1>: PC Using. (line 33) -* BINMODE variable: User-modified. (line 15) +* 'BINMODE' variable: User-modified. (line 15) +* 'BINMODE' variable <1>: PC Using. (line 33) * bit-manipulation functions: Bitwise Functions. (line 6) -* bits2str() user-defined function: Bitwise Functions. (line 70) +* 'bits2str()' user-defined function: Bitwise Functions. (line 71) * bitwise AND: Bitwise Functions. (line 39) * bitwise complement: Bitwise Functions. (line 43) * bitwise OR: Bitwise Functions. (line 49) -* bitwise XOR: Bitwise Functions. (line 55) +* bitwise XOR: Bitwise Functions. (line 56) * bitwise, complement: Bitwise Functions. (line 25) * bitwise, operations: Bitwise Functions. (line 6) * bitwise, shift: Bitwise Functions. (line 32) @@ -31524,25 +31447,25 @@ Index * Boolean expressions, as patterns: Expression Patterns. (line 39) * Boolean operators, See Boolean expressions: Boolean Ops. (line 6) * Bourne shell, quoting rules for: Quoting. (line 18) -* braces ({}): Profiling. (line 142) -* braces ({}), actions and: Action Overview. (line 19) -* braces ({}), statements, grouping: Statements. (line 10) -* bracket expressions <1>: Bracket Expressions. (line 6) +* braces ('{}'): Profiling. (line 142) +* braces ('{}'), actions and: Action Overview. (line 19) +* braces ('{}'), statements, grouping: Statements. (line 10) * bracket expressions: Regexp Operators. (line 56) +* bracket expressions <1>: Bracket Expressions. (line 6) * bracket expressions, character classes: Bracket Expressions. (line 30) * bracket expressions, collating elements: Bracket Expressions. - (line 77) + (line 76) * bracket expressions, collating symbols: Bracket Expressions. - (line 84) + (line 83) * bracket expressions, complemented: Regexp Operators. (line 64) * bracket expressions, equivalence classes: Bracket Expressions. - (line 90) -* bracket expressions, non-ASCII: Bracket Expressions. (line 77) + (line 89) +* bracket expressions, non-ASCII: Bracket Expressions. (line 76) * bracket expressions, range expressions: Bracket Expressions. (line 6) -* break debugger command: Breakpoint Control. (line 11) -* break statement: Break Statement. (line 6) +* 'break' debugger command: Breakpoint Control. (line 11) +* 'break' statement: Break Statement. (line 6) * breakpoint: Debugging Terms. (line 33) * breakpoint at location, how to delete: Breakpoint Control. (line 36) * breakpoint commands: Debugger Execution Control. @@ -31551,188 +31474,192 @@ Index * breakpoint, delete by number: Breakpoint Control. (line 64) * breakpoint, how to disable or enable: Breakpoint Control. (line 69) * breakpoint, setting: Breakpoint Control. (line 11) -* Brennan, Michael <1>: Other Versions. (line 6) -* Brennan, Michael <2>: Two-way I/O. (line 6) -* Brennan, Michael <3>: Simple Sed. (line 25) -* Brennan, Michael <4>: Delete. (line 56) * Brennan, Michael: Foreword. (line 83) -* Brian Kernighan's awk <1>: I/O Functions. (line 43) -* Brian Kernighan's awk <2>: Gory Details. (line 15) -* Brian Kernighan's awk <3>: String Functions. (line 490) -* Brian Kernighan's awk <4>: Delete. (line 48) -* Brian Kernighan's awk <5>: Nextfile Statement. (line 47) -* Brian Kernighan's awk <6>: Continue Statement. (line 43) -* Brian Kernighan's awk <7>: Break Statement. (line 51) -* Brian Kernighan's awk <8>: I/O And BEGIN/END. (line 16) -* Brian Kernighan's awk <9>: Concatenation. (line 36) -* Brian Kernighan's awk <10>: Getline/Pipe. (line 62) -* Brian Kernighan's awk <11>: Regexp Field Splitting. +* Brennan, Michael <1>: Delete. (line 56) +* Brennan, Michael <2>: Simple Sed. (line 25) +* Brennan, Michael <3>: Two-way I/O. (line 6) +* Brennan, Michael <4>: Other Versions. (line 6) +* Brennan, Michael <5>: Other Versions. (line 44) +* Brian Kernighan's 'awk': Preface. (line 15) +* Brian Kernighan's 'awk' <1>: When. (line 21) +* Brian Kernighan's 'awk' <2>: Escape Sequences. (line 115) +* Brian Kernighan's 'awk' <3>: GNU Regexp Operators. + (line 86) +* Brian Kernighan's 'awk' <4>: Regexp Field Splitting. (line 67) -* Brian Kernighan's awk <12>: GNU Regexp Operators. - (line 83) -* Brian Kernighan's awk <13>: Escape Sequences. (line 116) -* Brian Kernighan's awk <14>: When. (line 21) -* Brian Kernighan's awk: Preface. (line 15) -* Brian Kernighan's awk, extensions: BTL. (line 6) -* Brian Kernighan's awk, source code: Other Versions. (line 13) +* Brian Kernighan's 'awk' <5>: Getline/Pipe. (line 62) +* Brian Kernighan's 'awk' <6>: Concatenation. (line 36) +* Brian Kernighan's 'awk' <7>: I/O And BEGIN/END. (line 15) +* Brian Kernighan's 'awk' <8>: Break Statement. (line 51) +* Brian Kernighan's 'awk' <9>: Continue Statement. (line 43) +* Brian Kernighan's 'awk' <10>: Nextfile Statement. (line 46) +* Brian Kernighan's 'awk' <11>: Delete. (line 48) +* Brian Kernighan's 'awk' <12>: String Functions. (line 489) +* Brian Kernighan's 'awk' <13>: Gory Details. (line 15) +* Brian Kernighan's 'awk' <14>: I/O Functions. (line 43) +* Brian Kernighan's 'awk', extensions: BTL. (line 6) +* Brian Kernighan's 'awk', source code: Other Versions. (line 13) * Brini, Davide: Signature Program. (line 6) * Brink, Jeroen: DOS Quoting. (line 10) -* Broder, Alan J.: Contributors. (line 88) -* Brown, Martin: Contributors. (line 82) -* BSD-based operating systems: Glossary. (line 611) -* bt debugger command (alias for backtrace): Execution Stack. (line 13) -* Buening, Andreas <1>: Bugs. (line 71) -* Buening, Andreas <2>: Contributors. (line 92) +* Broder, Alan J.: Contributors. (line 89) +* Brown, Martin: Contributors. (line 83) +* BSD-based operating systems: Glossary. (line 607) +* 'bt' debugger command (alias for 'backtrace'): Execution Stack. + (line 13) * Buening, Andreas: Acknowledgments. (line 60) +* Buening, Andreas <1>: Contributors. (line 93) +* Buening, Andreas <2>: Bugs. (line 71) +* buffering, input/output: I/O Functions. (line 139) * buffering, input/output <1>: Two-way I/O. (line 70) -* buffering, input/output: I/O Functions. (line 140) -* buffering, interactive vs. noninteractive: I/O Functions. (line 109) +* buffering, interactive vs. noninteractive: I/O Functions. (line 108) * buffers, flushing: I/O Functions. (line 32) +* buffers, flushing <1>: I/O Functions. (line 139) * buffers, operators for: GNU Regexp Operators. - (line 48) -* bug reports, email address, bug-gawk@gnu.org: Bugs. (line 30) -* bug-gawk@gnu.org bug reporting address: Bugs. (line 30) + (line 51) +* bug reports, email address, 'bug-gawk@gnu.org': Bugs. (line 30) +* 'bug-gawk@gnu.org' bug reporting address: Bugs. (line 30) * built-in functions: Functions. (line 6) * built-in functions, evaluation order: Calling Built-in. (line 30) * built-in variables: Built-in Variables. (line 6) -* built-in variables, -v option, setting with: Options. (line 40) +* built-in variables, '-v' option, setting with: Options. (line 41) * built-in variables, conveying information: Auto-set. (line 6) * built-in variables, user-modifiable: User-modified. (line 6) * Busybox Awk: Other Versions. (line 88) * call by reference: Pass By Value/Reference. - (line 47) + (line 46) * call by value: Pass By Value/Reference. - (line 18) + (line 17) * call stack, display in debugger: Execution Stack. (line 13) -* caret (^), ^ operator: Precedence. (line 49) -* caret (^), ^= operator <1>: Precedence. (line 95) -* caret (^), ^= operator: Assignment Ops. (line 130) -* caret (^), in bracket expressions: Bracket Expressions. (line 17) -* caret (^), regexp operator <1>: GNU Regexp Operators. - (line 59) -* caret (^), regexp operator: Regexp Operators. (line 22) -* case keyword: Switch Statement. (line 6) +* caret ('^'), in bracket expressions: Bracket Expressions. (line 17) +* caret ('^'), regexp operator: Regexp Operators. (line 22) +* caret ('^'), regexp operator <1>: GNU Regexp Operators. + (line 62) +* caret ('^'), '^' operator: Precedence. (line 48) +* caret ('^'), '^=' operator: Assignment Ops. (line 129) +* caret ('^'), '^=' operator <1>: Precedence. (line 94) +* 'case' keyword: Switch Statement. (line 6) * case sensitivity, and regexps: User-modified. (line 76) * case sensitivity, and string comparisons: User-modified. (line 76) -* case sensitivity, array indices and: Array Intro. (line 92) -* case sensitivity, converting case: String Functions. (line 520) +* case sensitivity, array indices and: Array Intro. (line 91) +* case sensitivity, converting case: String Functions. (line 519) * case sensitivity, example programs: Library Functions. (line 53) -* case sensitivity, gawk: Case-sensitivity. (line 26) +* case sensitivity, 'gawk': Case-sensitivity. (line 26) * case sensitivity, regexps and: Case-sensitivity. (line 6) -* CGI, awk scripts for: Options. (line 125) +* CGI, 'awk' scripts for: Options. (line 125) * character classes, See bracket expressions: Regexp Operators. (line 56) * character lists in regular expression: Bracket Expressions. (line 6) * character lists, See bracket expressions: Regexp Operators. (line 56) -* character sets (machine character encodings) <1>: Glossary. (line 133) * character sets (machine character encodings): Ordinal Functions. (line 45) +* character sets (machine character encodings) <1>: Glossary. (line 133) * character sets, See Also bracket expressions: Regexp Operators. (line 56) * characters, counting: Wc Program. (line 6) * characters, transliterating: Translate Program. (line 6) * characters, values of as numbers: Ordinal Functions. (line 6) * Chassell, Robert J.: Acknowledgments. (line 33) -* chdir() extension function: Extension Sample File Functions. +* 'chdir()' extension function: Extension Sample File Functions. (line 12) -* chem utility: Glossary. (line 143) -* chr() extension function: Extension Sample Ord. +* 'chem' utility: Glossary. (line 143) +* 'chr()' extension function: Extension Sample Ord. (line 15) -* chr() user-defined function: Ordinal Functions. (line 16) -* clear debugger command: Breakpoint Control. (line 36) +* 'chr()' user-defined function: Ordinal Functions. (line 16) +* 'clear' debugger command: Breakpoint Control. (line 36) * Cliff random numbers: Cliff Random Function. (line 6) -* cliff_rand() user-defined function: Cliff Random Function. +* 'cliff_rand()' user-defined function: Cliff Random Function. (line 12) -* close <1>: I/O Functions. (line 10) -* close: Close Files And Pipes. +* 'close': Close Files And Pipes. (line 18) +* 'close' <1>: I/O Functions. (line 10) * close file or coprocess: I/O Functions. (line 10) -* close() function, portability: Close Files And Pipes. +* 'close()' function, portability: Close Files And Pipes. (line 81) -* close() function, return value: Close Files And Pipes. +* 'close()' function, return value: Close Files And Pipes. (line 131) -* close() function, two-way pipes and: Two-way I/O. (line 77) -* Close, Diane <1>: Contributors. (line 20) +* 'close()' function, two-way pipes and: Two-way I/O. (line 77) * Close, Diane: Manual History. (line 41) +* Close, Diane <1>: Contributors. (line 21) * Collado, Manuel: Acknowledgments. (line 60) -* collating elements: Bracket Expressions. (line 77) -* collating symbols: Bracket Expressions. (line 84) -* Colombo, Antonio <1>: Contributors. (line 137) +* collating elements: Bracket Expressions. (line 76) +* collating symbols: Bracket Expressions. (line 83) * Colombo, Antonio: Acknowledgments. (line 60) -* columns, aligning: Print Examples. (line 70) +* Colombo, Antonio <1>: Contributors. (line 138) +* columns, aligning: Print Examples. (line 69) * columns, cutting: Cut Program. (line 6) -* comma (,), in range patterns: Ranges. (line 6) +* comma (','), in range patterns: Ranges. (line 6) * command completion, in debugger: Readline Support. (line 6) -* command line, arguments <1>: ARGC and ARGV. (line 6) -* command line, arguments <2>: Auto-set. (line 15) * command line, arguments: Other Arguments. (line 6) +* command line, arguments <1>: Auto-set. (line 15) +* command line, arguments <2>: ARGC and ARGV. (line 6) * command line, directories on: Command line directories. (line 6) * command line, formats: Running gawk. (line 12) -* command line, FS on, setting: Command Line Field Separator. +* command line, 'FS' on, setting: Command Line Field Separator. (line 6) -* command line, invoking awk from: Command Line. (line 6) -* command line, option -f: Long. (line 12) +* command line, invoking 'awk' from: Command Line. (line 6) +* command line, option '-f': Long. (line 12) * command line, options: Options. (line 6) -* command line, options, end of: Options. (line 54) +* command line, options, end of: Options. (line 55) * command line, variables, assigning on: Assignment Options. (line 6) * command-line options, processing: Getopt Function. (line 6) * command-line options, string extraction: String Extraction. (line 6) -* commands debugger command: Debugger Execution Control. +* 'commands' debugger command: Debugger Execution Control. (line 10) * commands to execute at breakpoint: Debugger Execution Control. (line 10) * commenting: Comments. (line 6) -* commenting, backslash continuation and: Statements/Lines. (line 76) -* common extensions, ** operator: Arithmetic Ops. (line 30) -* common extensions, **= operator: Assignment Ops. (line 137) -* common extensions, /dev/stderr special file: Special FD. (line 46) -* common extensions, /dev/stdin special file: Special FD. (line 46) -* common extensions, /dev/stdout special file: Special FD. (line 46) -* common extensions, \x escape sequence: Escape Sequences. (line 61) -* common extensions, BINMODE variable: PC Using. (line 33) -* common extensions, delete to delete entire arrays: Delete. (line 39) -* common extensions, func keyword: Definition Syntax. (line 89) -* common extensions, length() applied to an array: String Functions. +* commenting, backslash continuation and: Statements/Lines. (line 75) +* common extensions, '**' operator: Arithmetic Ops. (line 30) +* common extensions, '**=' operator: Assignment Ops. (line 138) +* common extensions, '/dev/stderr' special file: Special FD. (line 46) +* common extensions, '/dev/stdin' special file: Special FD. (line 46) +* common extensions, '/dev/stdout' special file: Special FD. (line 46) +* common extensions, 'BINMODE' variable: PC Using. (line 33) +* common extensions, 'delete' to delete entire arrays: Delete. + (line 39) +* common extensions, 'func' keyword: Definition Syntax. (line 89) +* common extensions, 'length()' applied to an array: String Functions. (line 197) -* common extensions, RS as a regexp: gawk split records. (line 6) +* common extensions, 'RS' as a regexp: gawk split records. (line 6) * common extensions, single character fields: Single Character Fields. (line 6) -* comp.lang.awk newsgroup: Bugs. (line 39) +* common extensions, '\x' escape sequence: Escape Sequences. (line 61) +* 'comp.lang.awk' newsgroup: Bugs. (line 39) * comparison expressions: Typing and Comparison. (line 9) * comparison expressions, as patterns: Expression Patterns. (line 14) * comparison expressions, string vs. regexp: Comparison Operators. - (line 78) -* compatibility mode (gawk), extensions: POSIX/GNU. (line 6) -* compatibility mode (gawk), file names: Special Caveats. (line 9) -* compatibility mode (gawk), hexadecimal numbers: Nondecimal-numbers. - (line 60) -* compatibility mode (gawk), octal numbers: Nondecimal-numbers. - (line 60) -* compatibility mode (gawk), specifying: Options. (line 81) + (line 79) +* compatibility mode ('gawk'), extensions: POSIX/GNU. (line 6) +* compatibility mode ('gawk'), file names: Special Caveats. (line 9) +* compatibility mode ('gawk'), hexadecimal numbers: Nondecimal-numbers. + (line 59) +* compatibility mode ('gawk'), octal numbers: Nondecimal-numbers. + (line 59) +* compatibility mode ('gawk'), specifying: Options. (line 82) +* compiled programs: Basic High Level. (line 13) * compiled programs <1>: Glossary. (line 157) -* compiled programs: Basic High Level. (line 15) -* compiling gawk for Cygwin: Cygwin. (line 6) -* compiling gawk for MS-DOS and MS-Windows: PC Compiling. (line 13) -* compiling gawk for VMS: VMS Compilation. (line 6) -* compiling gawk with EMX for OS/2: PC Compiling. (line 28) -* compl: Bitwise Functions. (line 43) +* compiling 'gawk' for Cygwin: Cygwin. (line 6) +* compiling 'gawk' for MS-DOS and MS-Windows: PC Compiling. (line 13) +* compiling 'gawk' for VMS: VMS Compilation. (line 6) +* compiling 'gawk' with EMX for OS/2: PC Compiling. (line 28) +* 'compl': Bitwise Functions. (line 43) * complement, bitwise: Bitwise Functions. (line 25) * compound statements, control statements and: Statements. (line 10) -* concatenating: Concatenation. (line 8) -* condition debugger command: Breakpoint Control. (line 54) +* concatenating: Concatenation. (line 9) +* 'condition' debugger command: Breakpoint Control. (line 54) * conditional expressions: Conditional Exp. (line 6) -* configuration option, --disable-extensions: Additional Configuration Options. +* configuration option, '--disable-extensions': Additional Configuration Options. (line 9) -* configuration option, --disable-lint: Additional Configuration Options. +* configuration option, '--disable-lint': Additional Configuration Options. (line 15) -* configuration option, --disable-nls: Additional Configuration Options. +* configuration option, '--disable-nls': Additional Configuration Options. (line 30) -* configuration option, --with-whiny-user-strftime: Additional Configuration Options. +* configuration option, '--with-whiny-user-strftime': Additional Configuration Options. (line 35) -* configuration options, gawk: Additional Configuration Options. +* configuration options, 'gawk': Additional Configuration Options. (line 6) * constant regexps: Regexp Usage. (line 57) * constants, nondecimal: Nondecimal Data. (line 6) @@ -31740,208 +31667,213 @@ Index * constants, types of: Constants. (line 6) * continue program, in debugger: Debugger Execution Control. (line 33) -* continue statement: Continue Statement. (line 6) +* 'continue' statement: Continue Statement. (line 6) * control statements: Statements. (line 6) * controlling array scanning order: Controlling Scanning. (line 14) -* convert string to lower case: String Functions. (line 521) -* convert string to number: String Functions. (line 388) -* convert string to upper case: String Functions. (line 527) +* convert string to lower case: String Functions. (line 520) +* convert string to number: String Functions. (line 387) +* convert string to upper case: String Functions. (line 526) * converting integer array subscripts: Numeric Array Subscripts. (line 31) -* converting, dates to timestamps: Time Functions. (line 76) -* converting, numbers to strings <1>: Bitwise Functions. (line 109) +* converting, dates to timestamps: Time Functions. (line 75) * converting, numbers to strings: Strings And Numbers. (line 6) -* converting, strings to numbers <1>: Bitwise Functions. (line 109) +* converting, numbers to strings <1>: Bitwise Functions. (line 110) * converting, strings to numbers: Strings And Numbers. (line 6) -* CONVFMT variable <1>: User-modified. (line 30) -* CONVFMT variable: Strings And Numbers. (line 29) -* CONVFMT variable, and array subscripts: Numeric Array Subscripts. +* converting, strings to numbers <1>: Bitwise Functions. (line 110) +* 'CONVFMT' variable: Strings And Numbers. (line 29) +* 'CONVFMT' variable <1>: User-modified. (line 30) +* 'CONVFMT' variable, and array subscripts: Numeric Array Subscripts. (line 6) * cookie: Glossary. (line 149) -* coprocesses <1>: Two-way I/O. (line 44) * coprocesses: Redirection. (line 102) +* coprocesses <1>: Two-way I/O. (line 44) * coprocesses, closing: Close Files And Pipes. (line 6) -* coprocesses, getline from: Getline/Coprocess. (line 6) -* cos: Numeric Functions. (line 15) -* cosine: Numeric Functions. (line 15) +* coprocesses, 'getline' from: Getline/Coprocess. (line 6) +* 'cos': Numeric Functions. (line 14) +* cosine: Numeric Functions. (line 14) * counting: Wc Program. (line 6) -* csh utility: Statements/Lines. (line 44) -* csh utility, POSIXLY_CORRECT environment variable: Options. (line 353) -* csh utility, |& operator, comparison with: Two-way I/O. (line 44) -* ctime() user-defined function: Function Example. (line 73) +* 'csh' utility: Statements/Lines. (line 43) +* 'csh' utility, 'POSIXLY_CORRECT' environment variable: Options. + (line 350) +* 'csh' utility, '|&' operator, comparison with: Two-way I/O. (line 44) +* 'ctime()' user-defined function: Function Example. (line 73) * currency symbols, localization: Explaining gettext. (line 104) -* current system time: Time Functions. (line 66) -* custom.h file: Configuration Philosophy. +* current system time: Time Functions. (line 65) +* 'custom.h' file: Configuration Philosophy. (line 30) * customized input parser: Input Parsers. (line 6) * customized output wrapper: Output Wrappers. (line 6) * customized two-way processor: Two-way processors. (line 6) -* cut utility: Cut Program. (line 6) -* cut.awk program: Cut Program. (line 45) -* d debugger command (alias for delete): Breakpoint Control. (line 64) +* 'cut' utility: Cut Program. (line 6) +* 'cut' utility <1>: Cut Program. (line 6) +* 'cut.awk' program: Cut Program. (line 45) +* 'd' debugger command (alias for 'delete'): Breakpoint Control. + (line 64) * d.c., See dark corner: Conventions. (line 38) -* dark corner <1>: Glossary. (line 188) * dark corner: Conventions. (line 38) -* dark corner, "0" is actually true: Truth Values. (line 24) -* dark corner, /= operator vs. /=.../ regexp constant: Assignment Ops. - (line 148) -* dark corner, ^, in FS: Regexp Field Splitting. - (line 59) +* dark corner <1>: Glossary. (line 188) +* dark corner, '"0"' is actually true: Truth Values. (line 24) +* dark corner, '/=' operator vs. '/=.../' regexp constant: Assignment Ops. + (line 149) * dark corner, array subscripts: Uninitialized Subscripts. (line 43) -* dark corner, break statement: Break Statement. (line 51) -* dark corner, close() function: Close Files And Pipes. +* dark corner, 'break' statement: Break Statement. (line 51) +* dark corner, 'close()' function: Close Files And Pipes. (line 131) * dark corner, command-line arguments: Assignment Options. (line 43) -* dark corner, continue statement: Continue Statement. (line 43) -* dark corner, CONVFMT variable: Strings And Numbers. (line 40) +* dark corner, 'continue' statement: Continue Statement. (line 43) +* dark corner, 'CONVFMT' variable: Strings And Numbers. (line 39) * dark corner, escape sequences: Other Arguments. (line 31) * dark corner, escape sequences, for metacharacters: Escape Sequences. - (line 134) -* dark corner, exit statement: Exit Statement. (line 30) + (line 133) +* dark corner, 'exit' statement: Exit Statement. (line 30) * dark corner, field separators: Field Splitting Summary. - (line 46) -* dark corner, FILENAME variable <1>: Auto-set. (line 98) -* dark corner, FILENAME variable: Getline Notes. (line 19) -* dark corner, FNR/NR variables: Auto-set. (line 309) + (line 45) +* dark corner, 'FILENAME' variable: Getline Notes. (line 19) +* dark corner, 'FILENAME' variable <1>: Auto-set. (line 98) +* dark corner, 'FNR'/'NR' variables: Auto-set. (line 309) * dark corner, format-control characters: Control Letters. (line 18) -* dark corner, FS as null string: Single Character Fields. +* dark corner, format-control characters <1>: Control Letters. + (line 93) +* dark corner, 'FS' as null string: Single Character Fields. (line 20) -* dark corner, input files: awk split records. (line 110) -* dark corner, invoking awk: Command Line. (line 16) -* dark corner, length() function: String Functions. (line 183) +* dark corner, input files: awk split records. (line 109) +* dark corner, invoking 'awk': Command Line. (line 16) +* dark corner, 'length()' function: String Functions. (line 183) * dark corner, locale's decimal point character: Locale influences conversions. (line 17) * dark corner, multiline records: Multiple Line. (line 35) -* dark corner, NF variable, decrementing: Changing Fields. (line 107) -* dark corner, OFMT variable: OFMT. (line 27) +* dark corner, 'NF' variable, decrementing: Changing Fields. (line 107) +* dark corner, 'OFMT' variable: OFMT. (line 27) * dark corner, regexp constants: Using Constant Regexps. (line 6) -* dark corner, regexp constants, /= operator and: Assignment Ops. - (line 148) +* dark corner, regexp constants, '/=' operator and: Assignment Ops. + (line 149) * dark corner, regexp constants, as arguments to user-defined functions: Using Constant Regexps. (line 43) -* dark corner, split() function: String Functions. (line 359) -* dark corner, strings, storing: gawk split records. (line 83) -* dark corner, value of ARGV[0]: Auto-set. (line 39) +* dark corner, 'split()' function: String Functions. (line 358) +* dark corner, strings, storing: gawk split records. (line 82) +* dark corner, value of 'ARGV[0]': Auto-set. (line 39) +* dark corner, '^', in 'FS': Regexp Field Splitting. + (line 59) * data, fixed-width: Constant Size. (line 10) -* data-driven languages: Basic High Level. (line 85) +* data-driven languages: Basic High Level. (line 74) * database, group, reading: Group Functions. (line 6) * database, users, reading: Passwd Functions. (line 6) -* date utility, GNU: Time Functions. (line 17) -* date utility, POSIX: Time Functions. (line 254) -* dates, converting to timestamps: Time Functions. (line 76) +* 'date' utility, GNU: Time Functions. (line 17) +* 'date' utility, POSIX: Time Functions. (line 252) +* dates, converting to timestamps: Time Functions. (line 75) * dates, information related to, localization: Explaining gettext. (line 116) -* Davies, Stephen <1>: Contributors. (line 74) * Davies, Stephen: Acknowledgments. (line 60) -* dcgettext <1>: Programmer i18n. (line 19) -* dcgettext: I18N Functions. (line 22) -* dcgettext() function (gawk), portability and: I18N Portability. +* Davies, Stephen <1>: Contributors. (line 75) +* 'dcgettext': I18N Functions. (line 21) +* 'dcgettext' <1>: Programmer i18n. (line 19) +* 'dcgettext()' function ('gawk'), portability and: I18N Portability. (line 33) -* dcngettext <1>: Programmer i18n. (line 36) -* dcngettext: I18N Functions. (line 28) -* dcngettext() function (gawk), portability and: I18N Portability. +* 'dcngettext': I18N Functions. (line 27) +* 'dcngettext' <1>: Programmer i18n. (line 36) +* 'dcngettext()' function ('gawk'), portability and: I18N Portability. (line 33) * deadlocks: Two-way I/O. (line 70) -* debugger commands, b (break): Breakpoint Control. (line 11) -* debugger commands, backtrace: Execution Stack. (line 13) -* debugger commands, break: Breakpoint Control. (line 11) -* debugger commands, bt (backtrace): Execution Stack. (line 13) -* debugger commands, c (continue): Debugger Execution Control. +* debugger commands, 'b' ('break'): Breakpoint Control. (line 11) +* debugger commands, 'backtrace': Execution Stack. (line 13) +* debugger commands, 'break': Breakpoint Control. (line 11) +* debugger commands, 'bt' ('backtrace'): Execution Stack. (line 13) +* debugger commands, 'c' ('continue'): Debugger Execution Control. (line 33) -* debugger commands, clear: Breakpoint Control. (line 36) -* debugger commands, commands: Debugger Execution Control. +* debugger commands, 'clear': Breakpoint Control. (line 36) +* debugger commands, 'commands': Debugger Execution Control. (line 10) -* debugger commands, condition: Breakpoint Control. (line 54) -* debugger commands, continue: Debugger Execution Control. +* debugger commands, 'condition': Breakpoint Control. (line 54) +* debugger commands, 'continue': Debugger Execution Control. (line 33) -* debugger commands, d (delete): Breakpoint Control. (line 64) -* debugger commands, delete: Breakpoint Control. (line 64) -* debugger commands, disable: Breakpoint Control. (line 69) -* debugger commands, display: Viewing And Changing Data. +* debugger commands, 'd' ('delete'): Breakpoint Control. (line 64) +* debugger commands, 'delete': Breakpoint Control. (line 64) +* debugger commands, 'disable': Breakpoint Control. (line 69) +* debugger commands, 'display': Viewing And Changing Data. (line 8) -* debugger commands, down: Execution Stack. (line 21) -* debugger commands, dump: Miscellaneous Debugger Commands. +* debugger commands, 'down': Execution Stack. (line 20) +* debugger commands, 'dump': Miscellaneous Debugger Commands. (line 9) -* debugger commands, e (enable): Breakpoint Control. (line 73) -* debugger commands, enable: Breakpoint Control. (line 73) -* debugger commands, end: Debugger Execution Control. +* debugger commands, 'e' ('enable'): Breakpoint Control. (line 73) +* debugger commands, 'enable': Breakpoint Control. (line 73) +* debugger commands, 'end': Debugger Execution Control. (line 10) -* debugger commands, eval: Viewing And Changing Data. +* debugger commands, 'eval': Viewing And Changing Data. (line 23) -* debugger commands, f (frame): Execution Stack. (line 25) -* debugger commands, finish: Debugger Execution Control. +* debugger commands, 'f' ('frame'): Execution Stack. (line 24) +* debugger commands, 'finish': Debugger Execution Control. (line 39) -* debugger commands, frame: Execution Stack. (line 25) -* debugger commands, h (help): Miscellaneous Debugger Commands. +* debugger commands, 'frame': Execution Stack. (line 24) +* debugger commands, 'h' ('help'): Miscellaneous Debugger Commands. (line 66) -* debugger commands, help: Miscellaneous Debugger Commands. +* debugger commands, 'help': Miscellaneous Debugger Commands. (line 66) -* debugger commands, i (info): Debugger Info. (line 13) -* debugger commands, ignore: Breakpoint Control. (line 87) -* debugger commands, info: Debugger Info. (line 13) -* debugger commands, l (list): Miscellaneous Debugger Commands. +* debugger commands, 'i' ('info'): Debugger Info. (line 13) +* debugger commands, 'ignore': Breakpoint Control. (line 87) +* debugger commands, 'info': Debugger Info. (line 13) +* debugger commands, 'l' ('list'): Miscellaneous Debugger Commands. (line 72) -* debugger commands, list: Miscellaneous Debugger Commands. +* debugger commands, 'list': Miscellaneous Debugger Commands. (line 72) -* debugger commands, n (next): Debugger Execution Control. +* debugger commands, 'n' ('next'): Debugger Execution Control. (line 43) -* debugger commands, next: Debugger Execution Control. +* debugger commands, 'next': Debugger Execution Control. (line 43) -* debugger commands, nexti: Debugger Execution Control. +* debugger commands, 'nexti': Debugger Execution Control. (line 49) -* debugger commands, ni (nexti): Debugger Execution Control. +* debugger commands, 'ni' ('nexti'): Debugger Execution Control. (line 49) -* debugger commands, o (option): Debugger Info. (line 57) -* debugger commands, option: Debugger Info. (line 57) -* debugger commands, p (print): Viewing And Changing Data. - (line 36) -* debugger commands, print: Viewing And Changing Data. - (line 36) -* debugger commands, printf: Viewing And Changing Data. - (line 54) -* debugger commands, q (quit): Miscellaneous Debugger Commands. +* debugger commands, 'o' ('option'): Debugger Info. (line 57) +* debugger commands, 'option': Debugger Info. (line 57) +* debugger commands, 'p' ('print'): Viewing And Changing Data. + (line 35) +* debugger commands, 'print': Viewing And Changing Data. + (line 35) +* debugger commands, 'printf': Viewing And Changing Data. + (line 53) +* debugger commands, 'q' ('quit'): Miscellaneous Debugger Commands. (line 99) -* debugger commands, quit: Miscellaneous Debugger Commands. +* debugger commands, 'quit': Miscellaneous Debugger Commands. (line 99) -* debugger commands, r (run): Debugger Execution Control. +* debugger commands, 'r' ('run'): Debugger Execution Control. (line 62) -* debugger commands, return: Debugger Execution Control. +* debugger commands, 'return': Debugger Execution Control. (line 54) -* debugger commands, run: Debugger Execution Control. +* debugger commands, 'run': Debugger Execution Control. (line 62) -* debugger commands, s (step): Debugger Execution Control. +* debugger commands, 's' ('step'): Debugger Execution Control. (line 68) -* debugger commands, set: Viewing And Changing Data. - (line 59) -* debugger commands, si (stepi): Debugger Execution Control. +* debugger commands, 'set': Viewing And Changing Data. + (line 58) +* debugger commands, 'si' ('stepi'): Debugger Execution Control. (line 76) -* debugger commands, silent: Debugger Execution Control. +* debugger commands, 'silent': Debugger Execution Control. (line 10) -* debugger commands, step: Debugger Execution Control. +* debugger commands, 'step': Debugger Execution Control. (line 68) -* debugger commands, stepi: Debugger Execution Control. +* debugger commands, 'stepi': Debugger Execution Control. (line 76) -* debugger commands, t (tbreak): Breakpoint Control. (line 90) -* debugger commands, tbreak: Breakpoint Control. (line 90) -* debugger commands, trace: Miscellaneous Debugger Commands. +* debugger commands, 't' ('tbreak'): Breakpoint Control. (line 90) +* debugger commands, 'tbreak': Breakpoint Control. (line 90) +* debugger commands, 'trace': Miscellaneous Debugger Commands. (line 108) -* debugger commands, u (until): Debugger Execution Control. +* debugger commands, 'u' ('until'): Debugger Execution Control. (line 83) -* debugger commands, undisplay: Viewing And Changing Data. - (line 80) -* debugger commands, until: Debugger Execution Control. +* debugger commands, 'undisplay': Viewing And Changing Data. + (line 79) +* debugger commands, 'until': Debugger Execution Control. (line 83) -* debugger commands, unwatch: Viewing And Changing Data. - (line 84) -* debugger commands, up: Execution Stack. (line 34) -* debugger commands, w (watch): Viewing And Changing Data. - (line 67) -* debugger commands, watch: Viewing And Changing Data. - (line 67) +* debugger commands, 'unwatch': Viewing And Changing Data. + (line 83) +* debugger commands, 'up': Execution Stack. (line 33) +* debugger commands, 'w' ('watch'): Viewing And Changing Data. + (line 66) +* debugger commands, 'watch': Viewing And Changing Data. + (line 66) * debugger default list amount: Debugger Info. (line 69) * debugger history file: Debugger Info. (line 80) * debugger history size: Debugger Info. (line 65) @@ -31949,97 +31881,109 @@ Index * debugger prompt: Debugger Info. (line 77) * debugger, how to start: Debugger Invocation. (line 6) * debugger, read commands from a file: Debugger Info. (line 96) -* debugging awk programs: Debugger. (line 6) -* debugging gawk, bug reports: Bugs. (line 9) -* decimal point character, locale specific: Options. (line 268) +* debugging 'awk' programs: Debugger. (line 6) +* debugging 'gawk', bug reports: Bugs. (line 9) +* decimal point character, locale specific: Options. (line 265) * decrement operators: Increment Ops. (line 35) -* default keyword: Switch Statement. (line 6) -* Deifik, Scott <1>: Bugs. (line 71) -* Deifik, Scott <2>: Contributors. (line 53) +* 'default' keyword: Switch Statement. (line 6) * Deifik, Scott: Acknowledgments. (line 60) -* delete ARRAY: Delete. (line 39) +* Deifik, Scott <1>: Contributors. (line 54) +* Deifik, Scott <2>: Bugs. (line 71) +* 'delete' ARRAY: Delete. (line 39) * delete breakpoint at location: Breakpoint Control. (line 36) * delete breakpoint by number: Breakpoint Control. (line 64) -* delete debugger command: Breakpoint Control. (line 64) -* delete statement: Delete. (line 6) +* 'delete' debugger command: Breakpoint Control. (line 64) +* 'delete' statement: Delete. (line 6) * delete watchpoint: Viewing And Changing Data. - (line 84) + (line 83) * deleting elements in arrays: Delete. (line 6) * deleting entire arrays: Delete. (line 39) * Demaille, Akim: Acknowledgments. (line 60) * describe call stack frame, in debugger: Debugger Info. (line 27) -* differences between gawk and awk: String Functions. (line 197) -* differences in awk and gawk, ARGC/ARGV variables: ARGC and ARGV. +* differences between 'gawk' and 'awk': String Functions. (line 197) +* differences in 'awk' and 'gawk', 'ARGC'/'ARGV' variables: ARGC and ARGV. (line 88) -* differences in awk and gawk, ARGIND variable: Auto-set. (line 44) -* differences in awk and gawk, array elements, deleting: Delete. +* differences in 'awk' and 'gawk', 'ARGIND' variable: Auto-set. + (line 44) +* differences in 'awk' and 'gawk', array elements, deleting: Delete. (line 39) -* differences in awk and gawk, AWKLIBPATH environment variable: AWKLIBPATH Variable. +* differences in 'awk' and 'gawk', 'AWKLIBPATH' environment variable: AWKLIBPATH Variable. (line 6) -* differences in awk and gawk, AWKPATH environment variable: AWKPATH Variable. +* differences in 'awk' and 'gawk', 'AWKPATH' environment variable: AWKPATH Variable. (line 6) -* differences in awk and gawk, BEGIN/END patterns: I/O And BEGIN/END. - (line 16) -* differences in awk and gawk, BEGINFILE/ENDFILE patterns: BEGINFILE/ENDFILE. +* differences in 'awk' and 'gawk', 'BEGIN'/'END' patterns: I/O And BEGIN/END. + (line 15) +* differences in 'awk' and 'gawk', 'BEGINFILE'/'ENDFILE' patterns: BEGINFILE/ENDFILE. (line 6) -* differences in awk and gawk, BINMODE variable <1>: PC Using. - (line 33) -* differences in awk and gawk, BINMODE variable: User-modified. +* differences in 'awk' and 'gawk', 'BINMODE' variable: User-modified. (line 15) -* differences in awk and gawk, close() function: Close Files And Pipes. +* differences in 'awk' and 'gawk', 'BINMODE' variable <1>: PC Using. + (line 33) +* differences in 'awk' and 'gawk', 'close()' function: Close Files And Pipes. (line 81) -* differences in awk and gawk, command line directories: Command line directories. +* differences in 'awk' and 'gawk', 'close()' function <1>: Close Files And Pipes. + (line 131) +* differences in 'awk' and 'gawk', command line directories: Command line directories. (line 6) -* differences in awk and gawk, ERRNO variable: Auto-set. (line 82) -* differences in awk and gawk, error messages: Special FD. (line 16) -* differences in awk and gawk, FIELDWIDTHS variable: User-modified. +* differences in 'awk' and 'gawk', 'ERRNO' variable: Auto-set. + (line 82) +* differences in 'awk' and 'gawk', error messages: Special FD. + (line 16) +* differences in 'awk' and 'gawk', 'FIELDWIDTHS' variable: User-modified. (line 37) -* differences in awk and gawk, FPAT variable: User-modified. (line 43) -* differences in awk and gawk, FUNCTAB variable: Auto-set. (line 123) -* differences in awk and gawk, function arguments (gawk): Calling Built-in. +* differences in 'awk' and 'gawk', 'FPAT' variable: User-modified. + (line 43) +* differences in 'awk' and 'gawk', 'FUNCTAB' variable: Auto-set. + (line 123) +* differences in 'awk' and 'gawk', function arguments ('gawk'): Calling Built-in. (line 16) -* differences in awk and gawk, getline command: Getline. (line 19) -* differences in awk and gawk, IGNORECASE variable: User-modified. +* differences in 'awk' and 'gawk', 'getline' command: Getline. + (line 19) +* differences in 'awk' and 'gawk', 'IGNORECASE' variable: User-modified. (line 76) -* differences in awk and gawk, implementation limitations <1>: Redirection. - (line 135) -* differences in awk and gawk, implementation limitations: Getline Notes. +* differences in 'awk' and 'gawk', implementation limitations: Getline Notes. (line 14) -* differences in awk and gawk, indirect function calls: Indirect Calls. +* differences in 'awk' and 'gawk', implementation limitations <1>: Redirection. + (line 134) +* differences in 'awk' and 'gawk', indirect function calls: Indirect Calls. (line 6) -* differences in awk and gawk, input/output operators <1>: Redirection. - (line 102) -* differences in awk and gawk, input/output operators: Getline/Coprocess. +* differences in 'awk' and 'gawk', input/output operators: Getline/Coprocess. (line 6) -* differences in awk and gawk, line continuations: Conditional Exp. +* differences in 'awk' and 'gawk', input/output operators <1>: Redirection. + (line 102) +* differences in 'awk' and 'gawk', line continuations: Conditional Exp. (line 34) -* differences in awk and gawk, LINT variable: User-modified. (line 88) -* differences in awk and gawk, match() function: String Functions. +* differences in 'awk' and 'gawk', 'LINT' variable: User-modified. + (line 88) +* differences in 'awk' and 'gawk', 'match()' function: String Functions. (line 260) -* differences in awk and gawk, print/printf statements: Format Modifiers. +* differences in 'awk' and 'gawk', 'print'/'printf' statements: Format Modifiers. (line 13) -* differences in awk and gawk, PROCINFO array: Auto-set. (line 136) -* differences in awk and gawk, read timeouts: Read Timeout. (line 6) -* differences in awk and gawk, record separators: awk split records. - (line 124) -* differences in awk and gawk, regexp constants: Using Constant Regexps. +* differences in 'awk' and 'gawk', 'PROCINFO' array: Auto-set. + (line 136) +* differences in 'awk' and 'gawk', read timeouts: Read Timeout. + (line 6) +* differences in 'awk' and 'gawk', record separators: awk split records. + (line 123) +* differences in 'awk' and 'gawk', regexp constants: Using Constant Regexps. (line 43) -* differences in awk and gawk, regular expressions: Case-sensitivity. +* differences in 'awk' and 'gawk', regular expressions: Case-sensitivity. (line 26) -* differences in awk and gawk, RS/RT variables: gawk split records. +* differences in 'awk' and 'gawk', 'RS'/'RT' variables: gawk split records. (line 58) -* differences in awk and gawk, RT variable: Auto-set. (line 265) -* differences in awk and gawk, single-character fields: Single Character Fields. +* differences in 'awk' and 'gawk', 'RT' variable: Auto-set. (line 265) +* differences in 'awk' and 'gawk', single-character fields: Single Character Fields. (line 6) -* differences in awk and gawk, split() function: String Functions. - (line 347) -* differences in awk and gawk, strings: Scalar Constants. (line 20) -* differences in awk and gawk, strings, storing: gawk split records. - (line 77) -* differences in awk and gawk, SYMTAB variable: Auto-set. (line 269) -* differences in awk and gawk, TEXTDOMAIN variable: User-modified. +* differences in 'awk' and 'gawk', 'split()' function: String Functions. + (line 346) +* differences in 'awk' and 'gawk', strings: Scalar Constants. (line 20) +* differences in 'awk' and 'gawk', strings, storing: gawk split records. + (line 76) +* differences in 'awk' and 'gawk', 'SYMTAB' variable: Auto-set. + (line 269) +* differences in 'awk' and 'gawk', 'TEXTDOMAIN' variable: User-modified. (line 152) -* differences in awk and gawk, trunc-mod operation: Arithmetic Ops. +* differences in 'awk' and 'gawk', trunc-mod operation: Arithmetic Ops. (line 66) * directories, command line: Command line directories. (line 6) @@ -32048,104 +31992,108 @@ Index (line 6) * directories, searching for source files: AWKPATH Variable. (line 6) * disable breakpoint: Breakpoint Control. (line 69) -* disable debugger command: Breakpoint Control. (line 69) -* display debugger command: Viewing And Changing Data. +* 'disable' debugger command: Breakpoint Control. (line 69) +* 'display' debugger command: Viewing And Changing Data. (line 8) * display debugger options: Debugger Info. (line 57) -* div: Numeric Functions. (line 18) +* 'div': Numeric Functions. (line 17) +* div: Numeric Functions. (line 17) * division: Arithmetic Ops. (line 44) -* do-while statement: Do Statement. (line 6) -* do-while statement, use of regexps in: Regexp Usage. (line 19) -* documentation, of awk programs: Library Names. (line 6) +* 'do'-'while' statement: Do Statement. (line 6) +* 'do'-'while' statement, use of regexps in: Regexp Usage. (line 19) +* documentation, of 'awk' programs: Library Names. (line 6) * documentation, online: Manual History. (line 11) * documents, searching: Dupword Program. (line 6) -* dollar sign ($), $ field operator <1>: Precedence. (line 43) -* dollar sign ($), $ field operator: Fields. (line 19) -* dollar sign ($), incrementing fields and arrays: Increment Ops. +* dollar sign ('$'), '$' field operator: Fields. (line 19) +* dollar sign ('$'), '$' field operator <1>: Precedence. (line 42) +* dollar sign ('$'), incrementing fields and arrays: Increment Ops. (line 30) -* dollar sign ($), regexp operator: Regexp Operators. (line 35) -* double quote (") in shell commands: Read Terminal. (line 25) -* double quote ("), in regexp constants: Computed Regexps. (line 29) -* double quote ("), in shell commands: Quoting. (line 54) -* down debugger command: Execution Stack. (line 21) +* dollar sign ('$'), regexp operator: Regexp Operators. (line 35) +* double quote ('"') in shell commands: Read Terminal. (line 25) +* double quote ('"'), in regexp constants: Computed Regexps. (line 29) +* double quote ('"'), in shell commands: Quoting. (line 54) +* 'down' debugger command: Execution Stack. (line 20) * Drepper, Ulrich: Acknowledgments. (line 52) -* dump all variables of a program: Options. (line 93) -* dump debugger command: Miscellaneous Debugger Commands. +* dump all variables of a program: Options. (line 94) +* 'dump' debugger command: Miscellaneous Debugger Commands. (line 9) -* dupword.awk program: Dupword Program. (line 31) -* dynamic profiling: Profiling. (line 179) +* 'dupword.awk' program: Dupword Program. (line 31) +* dynamic profiling: Profiling. (line 178) * dynamically loaded extensions: Dynamic Extensions. (line 6) -* e debugger command (alias for enable): Breakpoint Control. (line 73) +* 'e' debugger command (alias for 'enable'): Breakpoint Control. + (line 73) * EBCDIC: Ordinal Functions. (line 45) -* effective group ID of gawk user: Auto-set. (line 141) -* effective user ID of gawk user: Auto-set. (line 145) -* egrep utility <1>: Egrep Program. (line 6) -* egrep utility: Bracket Expressions. (line 24) -* egrep.awk program: Egrep Program. (line 54) +* effective group ID of 'gawk' user: Auto-set. (line 141) +* effective user ID of 'gawk' user: Auto-set. (line 145) +* 'egrep' utility: Bracket Expressions. (line 24) +* 'egrep' utility <1>: Egrep Program. (line 6) +* 'egrep.awk' program: Egrep Program. (line 53) * elements in arrays, assigning values: Assigning Elements. (line 6) * elements in arrays, deleting: Delete. (line 6) -* elements in arrays, order of access by in operator: Scanning an Array. +* elements in arrays, order of access by 'in' operator: Scanning an Array. (line 48) * elements in arrays, scanning: Scanning an Array. (line 6) * elements of arrays: Reference to Elements. (line 6) -* email address for bug reports, bug-gawk@gnu.org: Bugs. (line 30) -* EMISTERED: TCP/IP Networking. (line 6) +* email address for bug reports, 'bug-gawk@gnu.org': Bugs. (line 30) +* 'EMISTERED': TCP/IP Networking. (line 6) * empty array elements: Reference to Elements. (line 18) * empty pattern: Empty. (line 6) -* empty strings: awk split records. (line 114) +* empty strings: awk split records. (line 113) * empty strings, See null strings: Regexp Field Splitting. (line 43) * enable breakpoint: Breakpoint Control. (line 73) -* enable debugger command: Breakpoint Control. (line 73) -* end debugger command: Debugger Execution Control. +* 'enable' debugger command: Breakpoint Control. (line 73) +* 'end' debugger command: Debugger Execution Control. (line 10) -* END pattern <1>: Using BEGIN/END. (line 6) -* END pattern: BEGIN/END. (line 6) -* END pattern, and profiling: Profiling. (line 62) -* END pattern, assert() user-defined function and: Assert Function. +* 'END' pattern: BEGIN/END. (line 6) +* 'END' pattern <1>: Using BEGIN/END. (line 6) +* 'END' pattern, and profiling: Profiling. (line 62) +* 'END' pattern, 'assert()' user-defined function and: Assert Function. (line 75) -* END pattern, backslash continuation and: Egrep Program. (line 223) -* END pattern, Boolean patterns and: Expression Patterns. (line 70) -* END pattern, exit statement and: Exit Statement. (line 12) -* END pattern, next/nextfile statements and <1>: Next Statement. +* 'END' pattern, backslash continuation and: Egrep Program. (line 222) +* 'END' pattern, Boolean patterns and: Expression Patterns. (line 70) +* 'END' pattern, 'exit' statement and: Exit Statement. (line 12) +* 'END' pattern, 'next'/'nextfile' statements and: I/O And BEGIN/END. + (line 36) +* 'END' pattern, 'next'/'nextfile' statements and <1>: Next Statement. (line 45) -* END pattern, next/nextfile statements and: I/O And BEGIN/END. - (line 37) -* END pattern, operators and: Using BEGIN/END. (line 17) -* END pattern, print statement and: I/O And BEGIN/END. (line 16) -* ENDFILE pattern: BEGINFILE/ENDFILE. (line 6) -* ENDFILE pattern, Boolean patterns and: Expression Patterns. (line 70) -* endfile() user-defined function: Filetrans Function. (line 62) -* endgrent() function (C library): Group Functions. (line 213) -* endgrent() user-defined function: Group Functions. (line 216) -* endpwent() function (C library): Passwd Functions. (line 210) -* endpwent() user-defined function: Passwd Functions. (line 213) +* 'END' pattern, operators and: Using BEGIN/END. (line 17) +* 'END' pattern, 'print' statement and: I/O And BEGIN/END. (line 15) +* 'ENDFILE' pattern: BEGINFILE/ENDFILE. (line 6) +* 'ENDFILE' pattern, Boolean patterns and: Expression Patterns. + (line 70) +* 'endfile()' user-defined function: Filetrans Function. (line 62) +* 'endgrent()' function (C library): Group Functions. (line 213) +* 'endgrent()' user-defined function: Group Functions. (line 216) +* 'endpwent()' function (C library): Passwd Functions. (line 210) +* 'endpwent()' user-defined function: Passwd Functions. (line 213) * English, Steve: Advanced Features. (line 6) -* ENVIRON array: Auto-set. (line 60) -* environment variables used by gawk: Environment Variables. +* 'ENVIRON' array: Auto-set. (line 59) +* environment variables used by 'gawk': Environment Variables. (line 6) -* environment variables, in ENVIRON array: Auto-set. (line 60) -* epoch, definition of: Glossary. (line 234) -* equals sign (=), = operator: Assignment Ops. (line 6) -* equals sign (=), == operator <1>: Precedence. (line 65) -* equals sign (=), == operator: Comparison Operators. +* environment variables, in 'ENVIRON' array: Auto-set. (line 59) +* epoch, definition of: Glossary. (line 232) +* equals sign ('='), '=' operator: Assignment Ops. (line 6) +* equals sign ('='), '==' operator: Comparison Operators. (line 11) +* equals sign ('='), '==' operator <1>: Precedence. (line 64) * EREs (Extended Regular Expressions): Bracket Expressions. (line 24) -* ERRNO variable <1>: TCP/IP Networking. (line 54) -* ERRNO variable: Auto-set. (line 82) -* ERRNO variable, with BEGINFILE pattern: BEGINFILE/ENDFILE. (line 26) -* ERRNO variable, with close() function: Close Files And Pipes. +* 'ERRNO' variable: Auto-set. (line 82) +* 'ERRNO' variable <1>: TCP/IP Networking. (line 53) +* 'ERRNO' variable, with 'BEGINFILE' pattern: BEGINFILE/ENDFILE. + (line 26) +* 'ERRNO' variable, with 'close()' function: Close Files And Pipes. (line 139) -* ERRNO variable, with getline command: Getline. (line 19) +* 'ERRNO' variable, with 'getline' command: Getline. (line 19) * error handling: Special FD. (line 16) -* error handling, ERRNO variable and: Auto-set. (line 82) +* error handling, 'ERRNO' variable and: Auto-set. (line 82) * error output: Special FD. (line 6) -* escape processing, gsub()/gensub()/sub() functions: Gory Details. +* escape processing, 'gsub()'/'gensub()'/'sub()' functions: Gory Details. (line 6) * escape sequences, in strings: Escape Sequences. (line 6) -* eval debugger command: Viewing And Changing Data. +* 'eval' debugger command: Viewing And Changing Data. (line 23) * evaluate expressions, in debugger: Viewing And Changing Data. (line 23) @@ -32153,30 +32101,35 @@ Index * evaluation order, concatenation: Concatenation. (line 41) * evaluation order, functions: Calling Built-in. (line 30) * examining fields: Fields. (line 6) -* exclamation point (!), ! operator <1>: Egrep Program. (line 175) -* exclamation point (!), ! operator <2>: Precedence. (line 52) -* exclamation point (!), ! operator: Boolean Ops. (line 67) -* exclamation point (!), != operator <1>: Precedence. (line 65) -* exclamation point (!), != operator: Comparison Operators. +* exclamation point ('!'), '!' operator: Boolean Ops. (line 67) +* exclamation point ('!'), '!' operator <1>: Precedence. (line 51) +* exclamation point ('!'), '!' operator <2>: Egrep Program. (line 174) +* exclamation point ('!'), '!=' operator: Comparison Operators. (line 11) -* exclamation point (!), !~ operator <1>: Expression Patterns. - (line 24) -* exclamation point (!), !~ operator <2>: Precedence. (line 80) -* exclamation point (!), !~ operator <3>: Comparison Operators. +* exclamation point ('!'), '!=' operator <1>: Precedence. (line 64) +* exclamation point ('!'), '!~' operator: Regexp Usage. (line 19) +* exclamation point ('!'), '!~' operator <1>: Case-sensitivity. + (line 26) +* exclamation point ('!'), '!~' operator <2>: Computed Regexps. + (line 6) +* exclamation point ('!'), '!~' operator <3>: Regexp Constants. + (line 6) +* exclamation point ('!'), '!~' operator <4>: Comparison Operators. (line 11) -* exclamation point (!), !~ operator <4>: Regexp Constants. (line 6) -* exclamation point (!), !~ operator <5>: Computed Regexps. (line 6) -* exclamation point (!), !~ operator <6>: Case-sensitivity. (line 26) -* exclamation point (!), !~ operator: Regexp Usage. (line 19) -* exit statement: Exit Statement. (line 6) -* exit status, of gawk: Exit Status. (line 6) -* exit status, of VMS: VMS Running. (line 29) +* exclamation point ('!'), '!~' operator <5>: Comparison Operators. + (line 98) +* exclamation point ('!'), '!~' operator <6>: Precedence. (line 79) +* exclamation point ('!'), '!~' operator <7>: Expression Patterns. + (line 24) +* 'exit' statement: Exit Statement. (line 6) +* exit status, of 'gawk': Exit Status. (line 6) +* exit status, of VMS: VMS Running. (line 28) * exit the debugger: Miscellaneous Debugger Commands. (line 99) -* exp: Numeric Functions. (line 33) -* expand utility: Very Simple. (line 69) +* 'exp': Numeric Functions. (line 32) +* 'expand' utility: Very Simple. (line 69) * Expat XML parser library: gawkextlib. (line 35) -* exponent: Numeric Functions. (line 33) +* exponent: Numeric Functions. (line 32) * expressions: Expressions. (line 6) * expressions, as patterns: Expression Patterns. (line 6) * expressions, assignment: Assignment Ops. (line 6) @@ -32199,99 +32152,105 @@ Index * extension registration: Registration Functions. (line 6) * extension search path: Finding Extensions. (line 6) -* extensions distributed with gawk: Extension Samples. (line 6) +* extensions distributed with 'gawk': Extension Samples. (line 6) * extensions, allocating memory: Memory Allocation Functions. (line 6) -* extensions, Brian Kernighan's awk <1>: Common Extensions. (line 6) -* extensions, Brian Kernighan's awk: BTL. (line 6) -* extensions, common, ** operator: Arithmetic Ops. (line 30) -* extensions, common, **= operator: Assignment Ops. (line 137) -* extensions, common, /dev/stderr special file: Special FD. (line 46) -* extensions, common, /dev/stdin special file: Special FD. (line 46) -* extensions, common, /dev/stdout special file: Special FD. (line 46) -* extensions, common, \x escape sequence: Escape Sequences. (line 61) -* extensions, common, BINMODE variable: PC Using. (line 33) -* extensions, common, delete to delete entire arrays: Delete. (line 39) -* extensions, common, fflush() function: I/O Functions. (line 43) -* extensions, common, func keyword: Definition Syntax. (line 89) -* extensions, common, length() applied to an array: String Functions. +* extensions, Brian Kernighan's 'awk': BTL. (line 6) +* extensions, Brian Kernighan's 'awk' <1>: Common Extensions. (line 6) +* extensions, common, '**' operator: Arithmetic Ops. (line 30) +* extensions, common, '**=' operator: Assignment Ops. (line 138) +* extensions, common, '/dev/stderr' special file: Special FD. (line 46) +* extensions, common, '/dev/stdin' special file: Special FD. (line 46) +* extensions, common, '/dev/stdout' special file: Special FD. (line 46) +* extensions, common, 'BINMODE' variable: PC Using. (line 33) +* extensions, common, 'delete' to delete entire arrays: Delete. + (line 39) +* extensions, common, 'fflush()' function: I/O Functions. (line 43) +* extensions, common, 'func' keyword: Definition Syntax. (line 89) +* extensions, common, 'length()' applied to an array: String Functions. (line 197) -* extensions, common, RS as a regexp: gawk split records. (line 6) +* extensions, common, 'RS' as a regexp: gawk split records. (line 6) * extensions, common, single character fields: Single Character Fields. (line 6) -* extensions, in gawk, not in POSIX awk: POSIX/GNU. (line 6) -* extensions, mawk: Common Extensions. (line 6) +* extensions, common, '\x' escape sequence: Escape Sequences. (line 61) +* extensions, in 'gawk', not in POSIX 'awk': POSIX/GNU. (line 6) +* extensions, 'mawk': Common Extensions. (line 6) * extensions, where to find: gawkextlib. (line 6) -* extract.awk program: Extract Program. (line 79) +* 'extract.awk' program: Extract Program. (line 79) * extraction, of marked strings (internationalization): String Extraction. (line 6) -* f debugger command (alias for frame): Execution Stack. (line 25) +* 'f' debugger command (alias for 'frame'): Execution Stack. (line 24) * false, logical: Truth Values. (line 6) * FDL (Free Documentation License): GNU Free Documentation License. - (line 7) -* features, adding to gawk: Adding Code. (line 6) + (line 8) +* features, adding to 'gawk': Adding Code. (line 6) * features, deprecated: Obsolete. (line 6) * features, undocumented: Undocumented. (line 6) -* Fenlason, Jay <1>: Contributors. (line 18) * Fenlason, Jay: History. (line 30) -* fflush: I/O Functions. (line 28) +* Fenlason, Jay <1>: Contributors. (line 19) +* 'fflush': I/O Functions. (line 28) * field numbers: Nonconstant Fields. (line 6) -* field operator $: Fields. (line 19) +* field operator '$': Fields. (line 19) * field operators, dollar sign as: Fields. (line 19) * field separator, in multiline records: Multiple Line. (line 41) * field separator, on command line: Command Line Field Separator. (line 6) * field separator, POSIX and: Field Splitting Summary. - (line 40) -* field separators <1>: User-modified. (line 50) + (line 39) * field separators: Field Separators. (line 15) -* field separators, choice of: Field Separators. (line 51) -* field separators, FIELDWIDTHS variable and: User-modified. (line 37) -* field separators, FPAT variable and: User-modified. (line 43) +* field separators <1>: User-modified. (line 50) +* field separators <2>: User-modified. (line 113) +* field separators, choice of: Field Separators. (line 50) +* field separators, 'FIELDWIDTHS' variable and: User-modified. + (line 37) +* field separators, 'FPAT' variable and: User-modified. (line 43) * field separators, POSIX and: Fields. (line 6) +* field separators, regular expressions as: Field Separators. (line 50) * field separators, regular expressions as <1>: Regexp Field Splitting. (line 6) -* field separators, regular expressions as: Field Separators. (line 51) -* field separators, See Also OFS: Changing Fields. (line 64) +* field separators, See Also 'OFS': Changing Fields. (line 64) * field separators, spaces as: Cut Program. (line 109) -* fields <1>: Basic High Level. (line 73) -* fields <2>: Fields. (line 6) * fields: Reading Files. (line 14) +* fields <1>: Fields. (line 6) +* fields <2>: Basic High Level. (line 62) * fields, adding: Changing Fields. (line 53) * fields, changing contents of: Changing Fields. (line 6) * fields, cutting: Cut Program. (line 6) * fields, examining: Fields. (line 6) * fields, number of: Fields. (line 33) * fields, numbers: Nonconstant Fields. (line 6) -* fields, printing: Print Examples. (line 21) +* fields, printing: Print Examples. (line 20) * fields, separating: Field Separators. (line 15) +* fields, separating <1>: Field Separators. (line 15) * fields, single-character: Single Character Fields. (line 6) -* FIELDWIDTHS variable <1>: User-modified. (line 37) -* FIELDWIDTHS variable: Constant Size. (line 23) +* 'FIELDWIDTHS' variable: Constant Size. (line 23) +* 'FIELDWIDTHS' variable <1>: User-modified. (line 37) * file descriptors: Special FD. (line 6) -* file names, distinguishing: Auto-set. (line 56) +* file names, distinguishing: Auto-set. (line 55) * file names, in compatibility mode: Special Caveats. (line 9) -* file names, standard streams in gawk: Special FD. (line 46) -* FILENAME variable <1>: Auto-set. (line 98) -* FILENAME variable: Reading Files. (line 6) -* FILENAME variable, getline, setting with: Getline Notes. (line 19) +* file names, standard streams in 'gawk': Special FD. (line 46) +* 'FILENAME' variable: Reading Files. (line 6) +* 'FILENAME' variable <1>: Auto-set. (line 98) +* 'FILENAME' variable, 'getline', setting with: Getline Notes. + (line 19) * filenames, assignments as: Ignoring Assigns. (line 6) -* files, .gmo: Explaining gettext. (line 42) -* files, .gmo, specifying directory of <1>: Programmer i18n. (line 47) -* files, .gmo, specifying directory of: Explaining gettext. (line 54) -* files, .mo, converting from .po: I18N Example. (line 63) -* files, .po <1>: Translator i18n. (line 6) -* files, .po: Explaining gettext. (line 37) -* files, .po, converting to .mo: I18N Example. (line 63) -* files, .pot: Explaining gettext. (line 31) -* files, /dev/... special files: Special FD. (line 46) -* files, /inet/... (gawk): TCP/IP Networking. (line 6) -* files, /inet4/... (gawk): TCP/IP Networking. (line 6) -* files, /inet6/... (gawk): TCP/IP Networking. (line 6) -* files, awk programs in: Long. (line 6) -* files, awkprof.out: Profiling. (line 6) -* files, awkvars.out: Options. (line 93) +* files, '.gmo': Explaining gettext. (line 42) +* files, '.gmo', specifying directory of: Explaining gettext. (line 54) +* files, '.gmo', specifying directory of <1>: Programmer i18n. + (line 47) +* files, '.mo', converting from '.po': I18N Example. (line 63) +* files, '.po': Explaining gettext. (line 37) +* files, '.po' <1>: Translator i18n. (line 6) +* files, '.po', converting to '.mo': I18N Example. (line 63) +* files, '.pot': Explaining gettext. (line 31) +* files, '/dev/...' special files: Special FD. (line 46) +* files, '/inet/...' ('gawk'): TCP/IP Networking. (line 6) +* files, '/inet4/...' ('gawk'): TCP/IP Networking. (line 6) +* files, '/inet6/...' ('gawk'): TCP/IP Networking. (line 6) +* files, 'awk' programs in: Long. (line 6) +* files, 'awkprof.out': Profiling. (line 6) +* files, 'awkvars.out': Options. (line 94) * files, closing: I/O Functions. (line 10) * files, descriptors, See file descriptors: Special FD. (line 6) * files, group: Group Functions. (line 6) @@ -32304,22 +32263,22 @@ Index * files, message object: Explaining gettext. (line 42) * files, message object, converting from portable object files: I18N Example. (line 63) -* files, message object, specifying directory of <1>: Programmer i18n. - (line 47) * files, message object, specifying directory of: Explaining gettext. (line 54) +* files, message object, specifying directory of <1>: Programmer i18n. + (line 47) * files, multiple passes over: Other Arguments. (line 49) * files, multiple, duplicating output into: Tee Program. (line 6) * files, output, See output files: Close Files And Pipes. (line 6) * files, password: Passwd Functions. (line 16) -* files, portable object <1>: Translator i18n. (line 6) * files, portable object: Explaining gettext. (line 37) +* files, portable object <1>: Translator i18n. (line 6) * files, portable object template: Explaining gettext. (line 31) * files, portable object, converting to message object files: I18N Example. (line 63) * files, portable object, generating: Options. (line 147) -* files, processing, ARGIND variable and: Auto-set. (line 51) +* files, processing, 'ARGIND' variable and: Auto-set. (line 50) * files, reading: Rewind Function. (line 6) * files, reading, multiline records: Multiple Line. (line 6) * files, searching for regular expressions: Egrep Program. (line 6) @@ -32329,79 +32288,81 @@ Index * files, Texinfo, extracting programs from: Extract Program. (line 6) * find substring in string: String Functions. (line 155) * finding extensions: Finding Extensions. (line 6) -* finish debugger command: Debugger Execution Control. +* 'finish' debugger command: Debugger Execution Control. (line 39) -* Fish, Fred: Contributors. (line 50) +* Fish, Fred: Contributors. (line 51) * fixed-width data: Constant Size. (line 10) -* flag variables <1>: Tee Program. (line 20) * flag variables: Boolean Ops. (line 67) +* flag variables <1>: Tee Program. (line 20) * floating-point, numbers, arbitrary precision: Arbitrary Precision Arithmetic. (line 6) -* floating-point, VAX/VMS: VMS Running. (line 51) +* floating-point, VAX/VMS: VMS Running. (line 50) * flush buffered output: I/O Functions. (line 28) -* fnmatch() extension function: Extension Sample Fnmatch. +* 'fnmatch()' extension function: Extension Sample Fnmatch. (line 12) -* FNR variable <1>: Auto-set. (line 107) -* FNR variable: Records. (line 6) -* FNR variable, changing: Auto-set. (line 309) -* for statement: For Statement. (line 6) -* for statement, looping over arrays: Scanning an Array. (line 20) -* fork() extension function: Extension Sample Fork. +* 'FNR' variable: Records. (line 6) +* 'FNR' variable <1>: Auto-set. (line 108) +* 'FNR' variable, changing: Auto-set. (line 309) +* 'for' statement: For Statement. (line 6) +* 'for' statement, looping over arrays: Scanning an Array. (line 20) +* 'fork()' extension function: Extension Sample Fork. (line 11) * format specifiers: Basic Printf. (line 15) * format specifiers, mixing regular with positional specifiers: Printf Ordering. (line 57) -* format specifiers, printf statement: Control Letters. (line 6) -* format specifiers, strftime() function (gawk): Time Functions. - (line 89) +* format specifiers, 'printf' statement: Control Letters. (line 6) +* format specifiers, 'strftime()' function ('gawk'): Time Functions. + (line 88) * format time string: Time Functions. (line 48) * formats, numeric output: OFMT. (line 6) * formatting output: Printf. (line 6) -* formatting strings: String Functions. (line 381) -* forward slash (/) to enclose regular expressions: Regexp. (line 10) -* forward slash (/), / operator: Precedence. (line 55) -* forward slash (/), /= operator <1>: Precedence. (line 95) -* forward slash (/), /= operator: Assignment Ops. (line 130) -* forward slash (/), /= operator, vs. /=.../ regexp constant: Assignment Ops. - (line 148) -* forward slash (/), patterns and: Expression Patterns. (line 24) -* FPAT variable <1>: User-modified. (line 43) -* FPAT variable: Splitting By Content. +* formatting strings: String Functions. (line 380) +* forward slash ('/') to enclose regular expressions: Regexp. (line 10) +* forward slash ('/'), '/' operator: Precedence. (line 54) +* forward slash ('/'), '/=' operator: Assignment Ops. (line 129) +* forward slash ('/'), '/=' operator <1>: Precedence. (line 94) +* forward slash ('/'), '/=' operator, vs. '/=.../' regexp constant: Assignment Ops. + (line 149) +* forward slash ('/'), patterns and: Expression Patterns. (line 24) +* 'FPAT' variable: Splitting By Content. (line 27) -* frame debugger command: Execution Stack. (line 25) +* 'FPAT' variable <1>: User-modified. (line 43) +* 'frame' debugger command: Execution Stack. (line 24) * Free Documentation License (FDL): GNU Free Documentation License. - (line 7) -* Free Software Foundation (FSF) <1>: Glossary. (line 296) -* Free Software Foundation (FSF) <2>: Getting. (line 10) + (line 8) * Free Software Foundation (FSF): Manual History. (line 6) -* FreeBSD: Glossary. (line 611) -* FS variable <1>: User-modified. (line 50) -* FS variable: Field Separators. (line 15) -* FS variable, --field-separator option and: Options. (line 21) -* FS variable, as null string: Single Character Fields. +* Free Software Foundation (FSF) <1>: Getting. (line 10) +* Free Software Foundation (FSF) <2>: Glossary. (line 294) +* Free Software Foundation (FSF) <3>: Glossary. (line 312) +* FreeBSD: Glossary. (line 607) +* 'FS' variable: Field Separators. (line 15) +* 'FS' variable <1>: User-modified. (line 50) +* 'FS' variable, '--field-separator' option and: Options. (line 21) +* 'FS' variable, as null string: Single Character Fields. (line 20) -* FS variable, as TAB character: Options. (line 264) -* FS variable, changing value of: Field Separators. (line 35) -* FS variable, running awk programs and: Cut Program. (line 68) -* FS variable, setting from command line: Command Line Field Separator. +* 'FS' variable, as TAB character: Options. (line 262) +* 'FS' variable, changing value of: Field Separators. (line 34) +* 'FS' variable, running 'awk' programs and: Cut Program. (line 68) +* 'FS' variable, setting from command line: Command Line Field Separator. (line 6) -* FS, containing ^: Regexp Field Splitting. +* 'FS', containing '^': Regexp Field Splitting. (line 59) -* FS, in multiline records: Multiple Line. (line 41) -* FSF (Free Software Foundation) <1>: Glossary. (line 296) -* FSF (Free Software Foundation) <2>: Getting. (line 10) +* 'FS', in multiline records: Multiple Line. (line 41) * FSF (Free Software Foundation): Manual History. (line 6) -* fts() extension function: Extension Sample File Functions. - (line 61) -* FUNCTAB array: Auto-set. (line 123) +* FSF (Free Software Foundation) <1>: Getting. (line 10) +* FSF (Free Software Foundation) <2>: Glossary. (line 294) +* FSF (Free Software Foundation) <3>: Glossary. (line 312) +* 'fts()' extension function: Extension Sample File Functions. + (line 59) +* 'FUNCTAB' array: Auto-set. (line 123) * function calls: Function Calls. (line 6) * function calls, indirect: Indirect Calls. (line 6) * function definition example: Function Example. (line 6) * function pointers: Indirect Calls. (line 6) * functions, arrays as parameters to: Pass By Value/Reference. - (line 47) -* functions, built-in <1>: Functions. (line 6) + (line 46) * functions, built-in: Function Calls. (line 10) +* functions, built-in <1>: Functions. (line 6) * functions, built-in, evaluation order: Calling Built-in. (line 30) * functions, defining: Definition Syntax. (line 6) * functions, library: Library Functions. (line 6) @@ -32426,265 +32387,276 @@ Index * functions, library, rounding numbers: Round Function. (line 6) * functions, library, user database, reading: Passwd Functions. (line 6) -* functions, names of <1>: Definition Syntax. (line 20) * functions, names of: Arrays. (line 18) +* functions, names of <1>: Definition Syntax. (line 20) * functions, recursive: Definition Syntax. (line 79) * functions, string-translation: I18N Functions. (line 6) * functions, undefined: Pass By Value/Reference. - (line 71) + (line 70) * functions, user-defined: User-defined. (line 6) * functions, user-defined, calling: Function Caveats. (line 6) * functions, user-defined, counts, in a profile: Profiling. (line 137) * functions, user-defined, library of: Library Functions. (line 6) -* functions, user-defined, next/nextfile statements and <1>: Nextfile Statement. - (line 47) -* functions, user-defined, next/nextfile statements and: Next Statement. +* functions, user-defined, 'next'/'nextfile' statements and: Next Statement. (line 45) +* functions, user-defined, 'next'/'nextfile' statements and <1>: Nextfile Statement. + (line 46) * G-d: Acknowledgments. (line 82) -* Garfinkle, Scott: Contributors. (line 34) -* gawk program, dynamic profiling: Profiling. (line 179) -* gawk version: Auto-set. (line 207) -* gawk, ARGIND variable in: Other Arguments. (line 12) -* gawk, awk and <1>: This Manual. (line 14) -* gawk, awk and: Preface. (line 23) -* gawk, bitwise operations in: Bitwise Functions. (line 39) -* gawk, break statement in: Break Statement. (line 51) -* gawk, built-in variables and: Built-in Variables. (line 14) -* gawk, character classes and: Bracket Expressions. (line 98) -* gawk, coding style in: Adding Code. (line 39) -* gawk, command-line options, and regular expressions: GNU Regexp Operators. - (line 70) -* gawk, comparison operators and: Comparison Operators. - (line 50) -* gawk, configuring: Configuration Philosophy. +* Garfinkle, Scott: Contributors. (line 35) +* 'gawk' program, dynamic profiling: Profiling. (line 178) +* 'gawk' version: Auto-set. (line 207) +* 'gawk', 'ARGIND' variable in: Other Arguments. (line 12) +* 'gawk', 'awk' and: Preface. (line 23) +* 'gawk', 'awk' and <1>: This Manual. (line 14) +* 'gawk', bitwise operations in: Bitwise Functions. (line 39) +* 'gawk', 'break' statement in: Break Statement. (line 51) +* 'gawk', built-in variables and: Built-in Variables. (line 14) +* 'gawk', character classes and: Bracket Expressions. (line 97) +* 'gawk', coding style in: Adding Code. (line 39) +* 'gawk', command-line options, and regular expressions: GNU Regexp Operators. + (line 73) +* 'gawk', comparison operators and: Comparison Operators. + (line 51) +* 'gawk', configuring: Configuration Philosophy. (line 6) -* gawk, configuring, options: Additional Configuration Options. +* 'gawk', configuring, options: Additional Configuration Options. (line 6) -* gawk, continue statement in: Continue Statement. (line 43) -* gawk, distribution: Distribution contents. +* 'gawk', 'continue' statement in: Continue Statement. (line 43) +* 'gawk', distribution: Distribution contents. (line 6) -* gawk, ERRNO variable in <1>: TCP/IP Networking. (line 54) -* gawk, ERRNO variable in <2>: Auto-set. (line 82) -* gawk, ERRNO variable in <3>: BEGINFILE/ENDFILE. (line 26) -* gawk, ERRNO variable in <4>: Close Files And Pipes. +* 'gawk', 'ERRNO' variable in: Getline. (line 19) +* 'gawk', 'ERRNO' variable in <1>: Close Files And Pipes. (line 139) -* gawk, ERRNO variable in: Getline. (line 19) -* gawk, escape sequences: Escape Sequences. (line 124) -* gawk, extensions, disabling: Options. (line 252) -* gawk, features, adding: Adding Code. (line 6) -* gawk, features, advanced: Advanced Features. (line 6) -* gawk, field separators and: User-modified. (line 71) -* gawk, FIELDWIDTHS variable in <1>: User-modified. (line 37) -* gawk, FIELDWIDTHS variable in: Constant Size. (line 23) -* gawk, file names in: Special Files. (line 6) -* gawk, format-control characters: Control Letters. (line 18) -* gawk, FPAT variable in <1>: User-modified. (line 43) -* gawk, FPAT variable in: Splitting By Content. +* 'gawk', 'ERRNO' variable in <2>: BEGINFILE/ENDFILE. (line 26) +* 'gawk', 'ERRNO' variable in <3>: Auto-set. (line 82) +* 'gawk', 'ERRNO' variable in <4>: TCP/IP Networking. (line 53) +* 'gawk', escape sequences: Escape Sequences. (line 123) +* 'gawk', extensions, disabling: Options. (line 250) +* 'gawk', features, adding: Adding Code. (line 6) +* 'gawk', features, advanced: Advanced Features. (line 6) +* 'gawk', field separators and: User-modified. (line 71) +* 'gawk', 'FIELDWIDTHS' variable in: Constant Size. (line 23) +* 'gawk', 'FIELDWIDTHS' variable in <1>: User-modified. (line 37) +* 'gawk', file names in: Special Files. (line 6) +* 'gawk', format-control characters: Control Letters. (line 18) +* 'gawk', format-control characters <1>: Control Letters. (line 93) +* 'gawk', 'FPAT' variable in: Splitting By Content. (line 27) -* gawk, FUNCTAB array in: Auto-set. (line 123) -* gawk, function arguments and: Calling Built-in. (line 16) -* gawk, hexadecimal numbers and: Nondecimal-numbers. (line 42) -* gawk, IGNORECASE variable in <1>: Array Sorting Functions. +* 'gawk', 'FPAT' variable in <1>: User-modified. (line 43) +* 'gawk', 'FUNCTAB' array in: Auto-set. (line 123) +* 'gawk', function arguments and: Calling Built-in. (line 16) +* 'gawk', hexadecimal numbers and: Nondecimal-numbers. (line 41) +* 'gawk', 'IGNORECASE' variable in: Case-sensitivity. (line 26) +* 'gawk', 'IGNORECASE' variable in <1>: User-modified. (line 76) +* 'gawk', 'IGNORECASE' variable in <2>: Array Intro. (line 91) +* 'gawk', 'IGNORECASE' variable in <3>: String Functions. (line 58) +* 'gawk', 'IGNORECASE' variable in <4>: Array Sorting Functions. (line 83) -* gawk, IGNORECASE variable in <2>: String Functions. (line 58) -* gawk, IGNORECASE variable in <3>: Array Intro. (line 92) -* gawk, IGNORECASE variable in <4>: User-modified. (line 76) -* gawk, IGNORECASE variable in: Case-sensitivity. (line 26) -* gawk, implementation issues: Notes. (line 6) -* gawk, implementation issues, debugging: Compatibility Mode. (line 6) -* gawk, implementation issues, downward compatibility: Compatibility Mode. +* 'gawk', implementation issues: Notes. (line 6) +* 'gawk', implementation issues, debugging: Compatibility Mode. + (line 6) +* 'gawk', implementation issues, downward compatibility: Compatibility Mode. (line 6) -* gawk, implementation issues, limits: Getline Notes. (line 14) -* gawk, implementation issues, pipes: Redirection. (line 135) -* gawk, installing: Installation. (line 6) -* gawk, internationalization and, See internationalization: Internationalization. +* 'gawk', implementation issues, limits: Getline Notes. (line 14) +* 'gawk', implementation issues, pipes: Redirection. (line 134) +* 'gawk', installing: Installation. (line 6) +* 'gawk', internationalization and, See internationalization: Internationalization. (line 13) -* gawk, interpreter, adding code to: Using Internal File Ops. +* 'gawk', interpreter, adding code to: Using Internal File Ops. (line 6) -* gawk, interval expressions and: Regexp Operators. (line 140) -* gawk, line continuation in: Conditional Exp. (line 34) -* gawk, LINT variable in: User-modified. (line 88) -* gawk, list of contributors to: Contributors. (line 6) -* gawk, MS-DOS version of: PC Using. (line 10) -* gawk, MS-Windows version of: PC Using. (line 10) -* gawk, newlines in: Statements/Lines. (line 12) -* gawk, octal numbers and: Nondecimal-numbers. (line 42) -* gawk, OS/2 version of: PC Using. (line 16) -* gawk, PROCINFO array in <1>: Two-way I/O. (line 117) -* gawk, PROCINFO array in <2>: Time Functions. (line 47) -* gawk, PROCINFO array in: Auto-set. (line 136) -* gawk, regexp constants and: Using Constant Regexps. +* 'gawk', interval expressions and: Regexp Operators. (line 140) +* 'gawk', line continuation in: Conditional Exp. (line 34) +* 'gawk', 'LINT' variable in: User-modified. (line 88) +* 'gawk', list of contributors to: Contributors. (line 6) +* 'gawk', MS-DOS version of: PC Using. (line 10) +* 'gawk', MS-Windows version of: PC Using. (line 10) +* 'gawk', newlines in: Statements/Lines. (line 12) +* 'gawk', octal numbers and: Nondecimal-numbers. (line 41) +* 'gawk', OS/2 version of: PC Using. (line 16) +* 'gawk', 'PROCINFO' array in: Auto-set. (line 136) +* 'gawk', 'PROCINFO' array in <1>: Auto-set. (line 242) +* 'gawk', 'PROCINFO' array in <2>: Time Functions. (line 47) +* 'gawk', 'PROCINFO' array in <3>: Two-way I/O. (line 116) +* 'gawk', regexp constants and: Using Constant Regexps. (line 28) -* gawk, regular expressions, case sensitivity: Case-sensitivity. +* 'gawk', regular expressions, case sensitivity: Case-sensitivity. (line 26) -* gawk, regular expressions, operators: GNU Regexp Operators. +* 'gawk', regular expressions, operators: GNU Regexp Operators. (line 6) -* gawk, regular expressions, precedence: Regexp Operators. (line 162) -* gawk, RT variable in <1>: Auto-set. (line 265) -* gawk, RT variable in <2>: Multiple Line. (line 129) -* gawk, RT variable in: awk split records. (line 124) -* gawk, See Also awk: Preface. (line 36) -* gawk, source code, obtaining: Getting. (line 6) -* gawk, splitting fields and: Constant Size. (line 88) -* gawk, string-translation functions: I18N Functions. (line 6) -* gawk, SYMTAB array in: Auto-set. (line 269) -* gawk, TEXTDOMAIN variable in: User-modified. (line 152) -* gawk, timestamps: Time Functions. (line 6) -* gawk, uses for: Preface. (line 36) -* gawk, versions of, information about, printing: Options. (line 298) -* gawk, VMS version of: VMS Installation. (line 6) -* gawk, word-boundary operator: GNU Regexp Operators. - (line 63) -* gawkextlib: gawkextlib. (line 6) -* gawkextlib project: gawkextlib. (line 6) -* General Public License (GPL): Glossary. (line 305) +* 'gawk', regular expressions, precedence: Regexp Operators. (line 162) +* 'gawk', 'RT' variable in: awk split records. (line 123) +* 'gawk', 'RT' variable in <1>: Multiple Line. (line 129) +* 'gawk', 'RT' variable in <2>: Auto-set. (line 265) +* 'gawk', See Also 'awk': Preface. (line 36) +* 'gawk', source code, obtaining: Getting. (line 6) +* 'gawk', splitting fields and: Constant Size. (line 87) +* 'gawk', string-translation functions: I18N Functions. (line 6) +* 'gawk', 'SYMTAB' array in: Auto-set. (line 269) +* 'gawk', 'TEXTDOMAIN' variable in: User-modified. (line 152) +* 'gawk', timestamps: Time Functions. (line 6) +* 'gawk', uses for: Preface. (line 36) +* 'gawk', versions of, information about, printing: Options. (line 295) +* 'gawk', VMS version of: VMS Installation. (line 6) +* 'gawk', word-boundary operator: GNU Regexp Operators. + (line 66) +* 'gawkextlib': gawkextlib. (line 6) +* 'gawkextlib' project: gawkextlib. (line 6) +* General Public License (GPL): Glossary. (line 303) * General Public License, See GPL: Manual History. (line 11) * generate time values: Time Functions. (line 25) -* gensub <1>: String Functions. (line 89) -* gensub: Using Constant Regexps. +* 'gensub': Using Constant Regexps. (line 43) -* gensub() function (gawk), escape processing: Gory Details. (line 6) -* getaddrinfo() function (C library): TCP/IP Networking. (line 38) -* getgrent() function (C library): Group Functions. (line 6) -* getgrent() user-defined function: Group Functions. (line 6) -* getgrgid() function (C library): Group Functions. (line 184) -* getgrgid() user-defined function: Group Functions. (line 187) -* getgrnam() function (C library): Group Functions. (line 173) -* getgrnam() user-defined function: Group Functions. (line 178) -* getgruser() function (C library): Group Functions. (line 193) -* getgruser() function, user-defined: Group Functions. (line 196) -* getline command: Reading Files. (line 20) -* getline command, _gr_init() user-defined function: Group Functions. - (line 83) -* getline command, _pw_init() function: Passwd Functions. (line 154) -* getline command, coprocesses, using from <1>: Close Files And Pipes. +* 'gensub' <1>: String Functions. (line 89) +* 'gensub()' function ('gawk'), escape processing: Gory Details. + (line 6) +* 'getaddrinfo()' function (C library): TCP/IP Networking. (line 38) +* 'getgrent()' function (C library): Group Functions. (line 6) +* 'getgrent()' function (C library) <1>: Group Functions. (line 202) +* 'getgrent()' user-defined function: Group Functions. (line 6) +* 'getgrent()' user-defined function <1>: Group Functions. (line 205) +* 'getgrgid()' function (C library): Group Functions. (line 184) +* 'getgrgid()' user-defined function: Group Functions. (line 187) +* 'getgrnam()' function (C library): Group Functions. (line 173) +* 'getgrnam()' user-defined function: Group Functions. (line 178) +* 'getgruser()' function (C library): Group Functions. (line 193) +* 'getgruser()' function, user-defined: Group Functions. (line 196) +* 'getline' command: Reading Files. (line 20) +* 'getline' command, coprocesses, using from: Getline/Coprocess. (line 6) -* getline command, coprocesses, using from: Getline/Coprocess. +* 'getline' command, coprocesses, using from <1>: Close Files And Pipes. (line 6) -* getline command, deadlock and: Two-way I/O. (line 70) -* getline command, explicit input with: Getline. (line 6) -* getline command, FILENAME variable and: Getline Notes. (line 19) -* getline command, return values: Getline. (line 19) -* getline command, variants: Getline Summary. (line 6) -* getline from a file: Getline/File. (line 6) -* getline into a variable: Getline/Variable. (line 6) -* getline statement, BEGINFILE/ENDFILE patterns and: BEGINFILE/ENDFILE. +* 'getline' command, deadlock and: Two-way I/O. (line 70) +* 'getline' command, explicit input with: Getline. (line 6) +* 'getline' command, 'FILENAME' variable and: Getline Notes. (line 19) +* 'getline' command, return values: Getline. (line 19) +* 'getline' command, variants: Getline Summary. (line 6) +* 'getline' command, '_gr_init()' user-defined function: Group Functions. + (line 83) +* 'getline' command, '_pw_init()' function: Passwd Functions. (line 154) +* 'getline' from a file: Getline/File. (line 6) +* 'getline' into a variable: Getline/Variable. (line 6) +* 'getline' statement, 'BEGINFILE'/'ENDFILE' patterns and: BEGINFILE/ENDFILE. (line 54) -* getlocaltime() user-defined function: Getlocaltime Function. +* 'getlocaltime()' user-defined function: Getlocaltime Function. (line 16) -* getopt() function (C library): Getopt Function. (line 15) -* getopt() user-defined function: Getopt Function. (line 108) -* getpwent() function (C library): Passwd Functions. (line 16) -* getpwent() user-defined function: Passwd Functions. (line 16) -* getpwnam() function (C library): Passwd Functions. (line 177) -* getpwnam() user-defined function: Passwd Functions. (line 182) -* getpwuid() function (C library): Passwd Functions. (line 188) -* getpwuid() user-defined function: Passwd Functions. (line 192) -* gettext library: Explaining gettext. (line 6) -* gettext library, locale categories: Explaining gettext. (line 81) -* gettext() function (C library): Explaining gettext. (line 63) -* gettimeofday() extension function: Extension Sample Time. +* 'getopt()' function (C library): Getopt Function. (line 15) +* 'getopt()' user-defined function: Getopt Function. (line 108) +* 'getopt()' user-defined function <1>: Getopt Function. (line 134) +* 'getpwent()' function (C library): Passwd Functions. (line 16) +* 'getpwent()' function (C library) <1>: Passwd Functions. (line 198) +* 'getpwent()' user-defined function: Passwd Functions. (line 16) +* 'getpwent()' user-defined function <1>: Passwd Functions. (line 202) +* 'getpwnam()' function (C library): Passwd Functions. (line 177) +* 'getpwnam()' user-defined function: Passwd Functions. (line 182) +* 'getpwuid()' function (C library): Passwd Functions. (line 188) +* 'getpwuid()' user-defined function: Passwd Functions. (line 192) +* 'gettext' library: Explaining gettext. (line 6) +* 'gettext' library, locale categories: Explaining gettext. (line 81) +* 'gettext()' function (C library): Explaining gettext. (line 63) +* 'gettimeofday()' extension function: Extension Sample Time. (line 12) -* git utility <1>: Adding Code. (line 112) -* git utility <2>: Accessing The Source. +* 'git' utility: gawkextlib. (line 29) +* 'git' utility <1>: Other Versions. (line 29) +* 'git' utility <2>: Accessing The Source. (line 10) -* git utility <3>: Other Versions. (line 29) -* git utility: gawkextlib. (line 29) -* Git, use of for gawk source code: Derived Files. (line 6) +* 'git' utility <3>: Adding Code. (line 112) +* Git, use of for 'gawk' source code: Derived Files. (line 6) * GNITS mailing list: Acknowledgments. (line 52) -* GNU awk, See gawk: Preface. (line 53) +* GNU 'awk', See 'gawk': Preface. (line 53) * GNU Free Documentation License: GNU Free Documentation License. - (line 7) -* GNU General Public License: Glossary. (line 305) -* GNU Lesser General Public License: Glossary. (line 396) -* GNU long options <1>: Options. (line 6) + (line 8) +* GNU General Public License: Glossary. (line 303) +* GNU Lesser General Public License: Glossary. (line 392) * GNU long options: Command Line. (line 13) +* GNU long options <1>: Options. (line 6) * GNU long options, printing list of: Options. (line 154) -* GNU Project <1>: Glossary. (line 314) * GNU Project: Manual History. (line 11) -* GNU/Linux <1>: Glossary. (line 611) -* GNU/Linux <2>: I18N Example. (line 55) +* GNU Project <1>: Glossary. (line 312) * GNU/Linux: Manual History. (line 28) -* Gordon, Assaf: Contributors. (line 105) -* GPL (General Public License) <1>: Glossary. (line 305) +* GNU/Linux <1>: I18N Example. (line 55) +* GNU/Linux <2>: Glossary. (line 607) +* Gordon, Assaf: Contributors. (line 106) * GPL (General Public License): Manual History. (line 11) -* GPL (General Public License), printing: Options. (line 88) -* grcat program: Group Functions. (line 16) -* Grigera, Juan: Contributors. (line 57) +* GPL (General Public License) <1>: Glossary. (line 303) +* GPL (General Public License), printing: Options. (line 89) +* 'grcat' program: Group Functions. (line 16) +* Grigera, Juan: Contributors. (line 58) * group database, reading: Group Functions. (line 6) * group file: Group Functions. (line 6) -* group ID of gawk user: Auto-set. (line 180) +* group ID of 'gawk' user: Auto-set. (line 180) * groups, information about: Group Functions. (line 6) -* gsub <1>: String Functions. (line 139) -* gsub: Using Constant Regexps. +* 'gsub': Using Constant Regexps. (line 43) -* gsub() function, arguments of: String Functions. (line 460) -* gsub() function, escape processing: Gory Details. (line 6) -* h debugger command (alias for help): Miscellaneous Debugger Commands. +* 'gsub' <1>: String Functions. (line 139) +* 'gsub()' function, arguments of: String Functions. (line 459) +* 'gsub()' function, escape processing: Gory Details. (line 6) +* 'h' debugger command (alias for 'help'): Miscellaneous Debugger Commands. (line 66) -* Hankerson, Darrel <1>: Contributors. (line 60) * Hankerson, Darrel: Acknowledgments. (line 60) -* Haque, John: Contributors. (line 108) +* Hankerson, Darrel <1>: Contributors. (line 61) +* Haque, John: Contributors. (line 109) * Hartholz, Elaine: Acknowledgments. (line 38) * Hartholz, Marshall: Acknowledgments. (line 38) -* Hasegawa, Isamu: Contributors. (line 94) -* help debugger command: Miscellaneous Debugger Commands. +* Hasegawa, Isamu: Contributors. (line 95) +* 'help' debugger command: Miscellaneous Debugger Commands. (line 66) * hexadecimal numbers: Nondecimal-numbers. (line 6) -* hexadecimal values, enabling interpretation of: Options. (line 211) +* hexadecimal values, enabling interpretation of: Options. (line 209) * history expansion, in debugger: Readline Support. (line 6) -* histsort.awk program: History Sorting. (line 25) +* 'histsort.awk' program: History Sorting. (line 25) * Hughes, Phil: Acknowledgments. (line 43) -* HUP signal, for dynamic profiling: Profiling. (line 211) -* hyphen (-), - operator: Precedence. (line 52) -* hyphen (-), -- operator <1>: Precedence. (line 46) -* hyphen (-), -- operator: Increment Ops. (line 48) -* hyphen (-), -= operator <1>: Precedence. (line 95) -* hyphen (-), -= operator: Assignment Ops. (line 130) -* hyphen (-), filenames beginning with: Options. (line 59) -* hyphen (-), in bracket expressions: Bracket Expressions. (line 17) -* i debugger command (alias for info): Debugger Info. (line 13) -* id utility: Id Program. (line 6) -* id.awk program: Id Program. (line 30) -* if statement: If Statement. (line 6) -* if statement, actions, changing: Ranges. (line 25) -* if statement, use of regexps in: Regexp Usage. (line 19) -* igawk.sh program: Igawk Program. (line 124) +* 'HUP' signal, for dynamic profiling: Profiling. (line 210) +* hyphen ('-'), '-' operator: Precedence. (line 51) +* hyphen ('-'), '-' operator <1>: Precedence. (line 57) +* hyphen ('-'), '--' operator: Increment Ops. (line 48) +* hyphen ('-'), '--' operator <1>: Precedence. (line 45) +* hyphen ('-'), '-=' operator: Assignment Ops. (line 129) +* hyphen ('-'), '-=' operator <1>: Precedence. (line 94) +* hyphen ('-'), filenames beginning with: Options. (line 60) +* hyphen ('-'), in bracket expressions: Bracket Expressions. (line 17) +* 'i' debugger command (alias for 'info'): Debugger Info. (line 13) +* 'id' utility: Id Program. (line 6) +* 'id.awk' program: Id Program. (line 30) +* 'if' statement: If Statement. (line 6) +* 'if' statement, actions, changing: Ranges. (line 25) +* 'if' statement, use of regexps in: Regexp Usage. (line 19) +* 'igawk.sh' program: Igawk Program. (line 124) * ignore breakpoint: Breakpoint Control. (line 87) -* ignore debugger command: Breakpoint Control. (line 87) -* IGNORECASE variable: User-modified. (line 76) -* IGNORECASE variable, and array indices: Array Intro. (line 92) -* IGNORECASE variable, and array sorting functions: Array Sorting Functions. +* 'ignore' debugger command: Breakpoint Control. (line 87) +* 'IGNORECASE' variable: User-modified. (line 76) +* 'IGNORECASE' variable, and array indices: Array Intro. (line 91) +* 'IGNORECASE' variable, and array sorting functions: Array Sorting Functions. (line 83) -* IGNORECASE variable, in example programs: Library Functions. +* 'IGNORECASE' variable, in example programs: Library Functions. (line 53) -* IGNORECASE variable, with ~ and !~ operators: Case-sensitivity. +* 'IGNORECASE' variable, with '~' and '!~' operators: Case-sensitivity. (line 26) * Illumos: Other Versions. (line 105) -* Illumos, POSIX-compliant awk: Other Versions. (line 105) -* implementation issues, gawk: Notes. (line 6) -* implementation issues, gawk, debugging: Compatibility Mode. (line 6) -* implementation issues, gawk, limits <1>: Redirection. (line 135) -* implementation issues, gawk, limits: Getline Notes. (line 14) -* in operator <1>: For Statement. (line 75) -* in operator <2>: Precedence. (line 83) -* in operator: Comparison Operators. +* Illumos, POSIX-compliant 'awk': Other Versions. (line 105) +* implementation issues, 'gawk': Notes. (line 6) +* implementation issues, 'gawk', debugging: Compatibility Mode. + (line 6) +* implementation issues, 'gawk', limits: Getline Notes. (line 14) +* implementation issues, 'gawk', limits <1>: Redirection. (line 134) +* 'in' operator: Comparison Operators. (line 11) -* in operator, index existence in multidimensional arrays: Multidimensional. - (line 43) -* in operator, order of array access: Scanning an Array. (line 48) -* in operator, testing if array element exists: Reference to Elements. +* 'in' operator <1>: Precedence. (line 82) +* 'in' operator <2>: For Statement. (line 75) +* 'in' operator, index existence in multidimensional arrays: Multidimensional. + (line 41) +* 'in' operator, order of array access: Scanning an Array. (line 48) +* 'in' operator, testing if array element exists: Reference to Elements. (line 37) -* in operator, use in loops: Scanning an Array. (line 17) +* 'in' operator, use in loops: Scanning an Array. (line 17) * increment operators: Increment Ops. (line 6) -* index: String Functions. (line 155) -* indexing arrays: Array Intro. (line 50) +* 'index': String Functions. (line 155) +* indexing arrays: Array Intro. (line 48) * indirect function calls: Indirect Calls. (line 6) * infinite precision: Arbitrary Precision Arithmetic. (line 6) -* info debugger command: Debugger Info. (line 13) -* initialization, automatic: More Complex. (line 38) -* inplace extension: Extension Sample Inplace. +* 'info' debugger command: Debugger Info. (line 13) +* initialization, automatic: More Complex. (line 39) +* 'inplace' extension: Extension Sample Inplace. (line 6) * input files: Reading Files. (line 6) * input files, closing: Close Files And Pipes. @@ -32692,9 +32664,10 @@ Index * input files, counting elements in: Wc Program. (line 6) * input files, examples: Sample Data Files. (line 6) * input files, reading: Reading Files. (line 6) -* input files, running awk without: Read Terminal. (line 6) +* input files, running 'awk' without: Read Terminal. (line 6) +* input files, running 'awk' without <1>: Read Terminal. (line 17) * input files, variable assignments and: Other Arguments. (line 19) -* input pipeline: Getline/Pipe. (line 9) +* input pipeline: Getline/Pipe. (line 10) * input record, length of: String Functions. (line 174) * input redirection: Getline/File. (line 6) * input, data, nondecimal: Nondecimal Data. (line 6) @@ -32702,32 +32675,32 @@ Index * input, files, See input files: Multiple Line. (line 6) * input, multiline records: Multiple Line. (line 6) * input, splitting into records: Records. (line 6) -* input, standard <1>: Special FD. (line 6) * input, standard: Read Terminal. (line 6) +* input, standard <1>: Special FD. (line 6) * input/output functions: I/O Functions. (line 6) * input/output, binary: User-modified. (line 15) -* input/output, from BEGIN and END: I/O And BEGIN/END. (line 6) +* input/output, from 'BEGIN' and 'END': I/O And BEGIN/END. (line 6) * input/output, two-way: Two-way I/O. (line 44) * insomnia, cure for: Alarm Program. (line 6) * installation, VMS: VMS Installation. (line 6) -* installing gawk: Installation. (line 6) +* installing 'gawk': Installation. (line 6) * instruction tracing, in debugger: Debugger Info. (line 89) -* int: Numeric Functions. (line 38) -* INT signal (MS-Windows): Profiling. (line 214) +* 'int': Numeric Functions. (line 37) +* 'INT' signal (MS-Windows): Profiling. (line 213) * integer array indices: Numeric Array Subscripts. (line 31) * integers, arbitrary precision: Arbitrary Precision Integers. (line 6) * integers, unsigned: Computer Arithmetic. (line 41) -* interacting with other programs: I/O Functions. (line 75) -* internationalization <1>: I18N and L10N. (line 6) +* interacting with other programs: I/O Functions. (line 76) * internationalization: I18N Functions. (line 6) +* internationalization <1>: I18N and L10N. (line 6) +* internationalization, localization: User-modified. (line 152) * internationalization, localization <1>: Internationalization. (line 13) -* internationalization, localization: User-modified. (line 152) * internationalization, localization, character classes: Bracket Expressions. - (line 98) -* internationalization, localization, gawk and: Internationalization. + (line 97) +* internationalization, localization, 'gawk' and: Internationalization. (line 13) * internationalization, localization, locale categories: Explaining gettext. (line 81) @@ -32736,100 +32709,100 @@ Index * internationalization, localization, portability and: I18N Portability. (line 6) * internationalizing a program: Explaining gettext. (line 6) -* interpreted programs <1>: Glossary. (line 356) -* interpreted programs: Basic High Level. (line 15) +* interpreted programs: Basic High Level. (line 13) +* interpreted programs <1>: Glossary. (line 352) * interval expressions, regexp operator: Regexp Operators. (line 117) -* inventory-shipped file: Sample Data Files. (line 32) -* invoke shell command: I/O Functions. (line 75) -* isarray: Type Functions. (line 11) -* ISO: Glossary. (line 367) +* 'inventory-shipped' file: Sample Data Files. (line 32) +* invoke shell command: I/O Functions. (line 76) +* 'isarray': Type Functions. (line 11) +* ISO: Glossary. (line 363) * ISO 8859-1: Glossary. (line 133) * ISO Latin-1: Glossary. (line 133) * Jacobs, Andrew: Passwd Functions. (line 90) -* Jaegermann, Michal <1>: Contributors. (line 45) * Jaegermann, Michal: Acknowledgments. (line 60) -* Java implementation of awk: Other Versions. (line 113) -* Java programming language: Glossary. (line 379) -* jawk: Other Versions. (line 113) +* Jaegermann, Michal <1>: Contributors. (line 46) +* Java implementation of 'awk': Other Versions. (line 113) +* Java programming language: Glossary. (line 375) +* 'jawk': Other Versions. (line 113) * Jedi knights: Undocumented. (line 6) * Johansen, Chris: Signature Program. (line 25) -* join() user-defined function: Join Function. (line 18) -* Kahrs, Ju"rgen <1>: Contributors. (line 70) +* 'join()' user-defined function: Join Function. (line 18) * Kahrs, Ju"rgen: Acknowledgments. (line 60) +* Kahrs, Ju"rgen <1>: Contributors. (line 71) * Kasal, Stepan: Acknowledgments. (line 60) * Kenobi, Obi-Wan: Undocumented. (line 6) -* Kernighan, Brian <1>: Glossary. (line 143) -* Kernighan, Brian <2>: Basic Data Typing. (line 54) -* Kernighan, Brian <3>: Other Versions. (line 13) -* Kernighan, Brian <4>: Contributors. (line 11) -* Kernighan, Brian <5>: BTL. (line 6) -* Kernighan, Brian <6>: Library Functions. (line 12) -* Kernighan, Brian <7>: Concatenation. (line 6) -* Kernighan, Brian <8>: Getline/Pipe. (line 6) -* Kernighan, Brian <9>: Acknowledgments. (line 76) -* Kernighan, Brian <10>: Conventions. (line 34) * Kernighan, Brian: History. (line 17) -* kill command, dynamic profiling: Profiling. (line 188) +* Kernighan, Brian <1>: Conventions. (line 34) +* Kernighan, Brian <2>: Acknowledgments. (line 76) +* Kernighan, Brian <3>: Getline/Pipe. (line 6) +* Kernighan, Brian <4>: Concatenation. (line 6) +* Kernighan, Brian <5>: Library Functions. (line 12) +* Kernighan, Brian <6>: BTL. (line 6) +* Kernighan, Brian <7>: Contributors. (line 12) +* Kernighan, Brian <8>: Other Versions. (line 13) +* Kernighan, Brian <9>: Basic Data Typing. (line 54) +* Kernighan, Brian <10>: Glossary. (line 143) +* 'kill' command, dynamic profiling: Profiling. (line 187) * Knights, jedi: Undocumented. (line 6) -* Kwok, Conrad: Contributors. (line 34) -* l debugger command (alias for list): Miscellaneous Debugger Commands. +* Kwok, Conrad: Contributors. (line 35) +* 'l' debugger command (alias for 'list'): Miscellaneous Debugger Commands. (line 72) -* labels.awk program: Labels Program. (line 51) +* 'labels.awk' program: Labels Program. (line 51) * Langston, Peter: Advanced Features. (line 6) -* languages, data-driven: Basic High Level. (line 85) -* LC_ALL locale category: Explaining gettext. (line 121) -* LC_COLLATE locale category: Explaining gettext. (line 94) -* LC_CTYPE locale category: Explaining gettext. (line 98) -* LC_MESSAGES locale category: Explaining gettext. (line 88) -* LC_MESSAGES locale category, bindtextdomain() function (gawk): Programmer i18n. +* languages, data-driven: Basic High Level. (line 74) +* 'LC_ALL' locale category: Explaining gettext. (line 121) +* 'LC_COLLATE' locale category: Explaining gettext. (line 94) +* 'LC_CTYPE' locale category: Explaining gettext. (line 98) +* 'LC_MESSAGES' locale category: Explaining gettext. (line 88) +* 'LC_MESSAGES' locale category, 'bindtextdomain()' function ('gawk'): Programmer i18n. (line 88) -* LC_MONETARY locale category: Explaining gettext. (line 104) -* LC_NUMERIC locale category: Explaining gettext. (line 108) -* LC_RESPONSE locale category: Explaining gettext. (line 112) -* LC_TIME locale category: Explaining gettext. (line 116) -* left angle bracket (<), < operator <1>: Precedence. (line 65) -* left angle bracket (<), < operator: Comparison Operators. +* 'LC_MONETARY' locale category: Explaining gettext. (line 104) +* 'LC_NUMERIC' locale category: Explaining gettext. (line 108) +* 'LC_RESPONSE' locale category: Explaining gettext. (line 112) +* 'LC_TIME' locale category: Explaining gettext. (line 116) +* left angle bracket ('<'), '<' operator: Comparison Operators. (line 11) -* left angle bracket (<), < operator (I/O): Getline/File. (line 6) -* left angle bracket (<), <= operator <1>: Precedence. (line 65) -* left angle bracket (<), <= operator: Comparison Operators. +* left angle bracket ('<'), '<' operator <1>: Precedence. (line 64) +* left angle bracket ('<'), '<' operator (I/O): Getline/File. (line 6) +* left angle bracket ('<'), '<=' operator: Comparison Operators. (line 11) +* left angle bracket ('<'), '<=' operator <1>: Precedence. (line 64) * left shift: Bitwise Functions. (line 46) * left shift, bitwise: Bitwise Functions. (line 32) * leftmost longest match: Multiple Line. (line 26) -* length: String Functions. (line 167) +* 'length': String Functions. (line 167) * length of input record: String Functions. (line 174) * length of string: String Functions. (line 167) -* Lesser General Public License (LGPL): Glossary. (line 396) -* LGPL (Lesser General Public License): Glossary. (line 396) +* Lesser General Public License (LGPL): Glossary. (line 392) +* LGPL (Lesser General Public License): Glossary. (line 392) * libmawk: Other Versions. (line 121) -* libraries of awk functions: Library Functions. (line 6) -* libraries of awk functions, assertions: Assert Function. (line 6) -* libraries of awk functions, associative arrays and: Library Names. +* libraries of 'awk' functions: Library Functions. (line 6) +* libraries of 'awk' functions, assertions: Assert Function. (line 6) +* libraries of 'awk' functions, associative arrays and: Library Names. (line 57) -* libraries of awk functions, character values as numbers: Ordinal Functions. +* libraries of 'awk' functions, character values as numbers: Ordinal Functions. (line 6) -* libraries of awk functions, command-line options: Getopt Function. +* libraries of 'awk' functions, command-line options: Getopt Function. (line 6) -* libraries of awk functions, example program for using: Igawk Program. +* libraries of 'awk' functions, example program for using: Igawk Program. (line 6) -* libraries of awk functions, group database, reading: Group Functions. +* libraries of 'awk' functions, group database, reading: Group Functions. (line 6) -* libraries of awk functions, managing, data files: Data File Management. +* libraries of 'awk' functions, managing, data files: Data File Management. (line 6) -* libraries of awk functions, managing, time: Getlocaltime Function. +* libraries of 'awk' functions, managing, time: Getlocaltime Function. (line 6) -* libraries of awk functions, merging arrays into strings: Join Function. +* libraries of 'awk' functions, merging arrays into strings: Join Function. (line 6) -* libraries of awk functions, rounding numbers: Round Function. +* libraries of 'awk' functions, rounding numbers: Round Function. (line 6) -* libraries of awk functions, user database, reading: Passwd Functions. +* libraries of 'awk' functions, user database, reading: Passwd Functions. (line 6) * line breaks: Statements/Lines. (line 6) * line continuations: Boolean Ops. (line 62) -* line continuations, gawk: Conditional Exp. (line 34) -* line continuations, in print statement: Print Examples. (line 76) -* line continuations, with C shell: More Complex. (line 30) +* line continuations, 'gawk': Conditional Exp. (line 34) +* line continuations, in 'print' statement: Print Examples. (line 75) +* line continuations, with C shell: More Complex. (line 31) * lines, blank, printing: Print. (line 22) * lines, counting: Wc Program. (line 6) * lines, duplicate, removing: History Sorting. (line 6) @@ -32840,172 +32813,175 @@ Index * lint checking, array subscripts: Uninitialized Subscripts. (line 43) * lint checking, empty programs: Command Line. (line 16) -* lint checking, issuing warnings: Options. (line 185) -* lint checking, POSIXLY_CORRECT environment variable: Options. - (line 338) +* lint checking, issuing warnings: Options. (line 184) +* lint checking, 'POSIXLY_CORRECT' environment variable: Options. + (line 335) * lint checking, undefined functions: Pass By Value/Reference. - (line 88) -* LINT variable: User-modified. (line 88) -* Linux <1>: Glossary. (line 611) -* Linux <2>: I18N Example. (line 55) + (line 87) +* 'LINT' variable: User-modified. (line 88) * Linux: Manual History. (line 28) +* Linux <1>: I18N Example. (line 55) +* Linux <2>: Glossary. (line 607) * list all global variables, in debugger: Debugger Info. (line 48) -* list debugger command: Miscellaneous Debugger Commands. +* 'list' debugger command: Miscellaneous Debugger Commands. (line 72) * list function definitions, in debugger: Debugger Info. (line 30) -* loading, extensions: Options. (line 173) +* loading, extensions: Options. (line 172) * local variables, in a function: Variable Scope. (line 6) * locale categories: Explaining gettext. (line 81) -* locale decimal point character: Options. (line 268) +* locale decimal point character: Options. (line 265) * locale, definition of: Locales. (line 6) * localization: I18N and L10N. (line 6) * localization, See internationalization, localization: I18N and L10N. (line 6) -* log: Numeric Functions. (line 45) +* 'log': Numeric Functions. (line 44) * log files, timestamps in: Time Functions. (line 6) -* logarithm: Numeric Functions. (line 45) +* logarithm: Numeric Functions. (line 44) * logical false/true: Truth Values. (line 6) * logical operators, See Boolean expressions: Boolean Ops. (line 6) * login information: Passwd Functions. (line 16) * long options: Command Line. (line 13) * loops: While Statement. (line 6) -* loops, break statement and: Break Statement. (line 6) -* loops, continue statements and: For Statement. (line 64) +* loops, 'break' statement and: Break Statement. (line 6) +* loops, 'continue' statements and: For Statement. (line 64) * loops, count for header, in a profile: Profiling. (line 131) -* loops, do-while: Do Statement. (line 6) +* loops, 'do'-'while': Do Statement. (line 6) * loops, exiting: Break Statement. (line 6) -* loops, for, array scanning: Scanning an Array. (line 6) -* loops, for, iterative: For Statement. (line 6) -* loops, See Also while statement: While Statement. (line 6) -* loops, while: While Statement. (line 6) -* ls utility: More Complex. (line 15) -* lshift: Bitwise Functions. (line 46) -* lvalues/rvalues: Assignment Ops. (line 32) -* mail-list file: Sample Data Files. (line 6) +* loops, 'for', array scanning: Scanning an Array. (line 6) +* loops, 'for', iterative: For Statement. (line 6) +* loops, See Also 'while' statement: While Statement. (line 6) +* loops, 'while': While Statement. (line 6) +* 'ls' utility: More Complex. (line 15) +* 'lshift': Bitwise Functions. (line 46) +* lvalues/rvalues: Assignment Ops. (line 31) +* 'mail-list' file: Sample Data Files. (line 6) * mailing labels, printing: Labels Program. (line 6) * mailing list, GNITS: Acknowledgments. (line 52) -* Malmberg, John <1>: Bugs. (line 71) * Malmberg, John: Acknowledgments. (line 60) +* Malmberg, John <1>: Bugs. (line 71) * mark parity: Ordinal Functions. (line 45) * marked string extraction (internationalization): String Extraction. (line 6) * marked strings, extracting: String Extraction. (line 6) * Marx, Groucho: Increment Ops. (line 60) -* match: String Functions. (line 207) +* 'match': String Functions. (line 207) * match regexp in string: String Functions. (line 207) -* match() function, RSTART/RLENGTH variables: String Functions. +* 'match()' function, 'RSTART'/'RLENGTH' variables: String Functions. (line 224) * matching, expressions, See comparison expressions: Typing and Comparison. (line 9) * matching, leftmost longest: Multiple Line. (line 26) * matching, null strings: Gory Details. (line 164) -* mawk utility <1>: Other Versions. (line 44) -* mawk utility <2>: Nextfile Statement. (line 47) -* mawk utility <3>: Concatenation. (line 36) -* mawk utility <4>: Getline/Pipe. (line 62) -* mawk utility: Escape Sequences. (line 124) +* 'mawk' utility: Escape Sequences. (line 123) +* 'mawk' utility <1>: Getline/Pipe. (line 62) +* 'mawk' utility <2>: Concatenation. (line 36) +* 'mawk' utility <3>: Nextfile Statement. (line 46) +* 'mawk' utility <4>: Other Versions. (line 44) * maximum precision supported by MPFR library: Auto-set. (line 221) * McIlroy, Doug: Glossary. (line 149) -* McPhee, Patrick: Contributors. (line 100) +* McPhee, Patrick: Contributors. (line 101) * message object files: Explaining gettext. (line 42) * message object files, converting from portable object files: I18N Example. (line 63) -* message object files, specifying directory of <1>: Programmer i18n. - (line 47) * message object files, specifying directory of: Explaining gettext. (line 54) +* message object files, specifying directory of <1>: Programmer i18n. + (line 47) * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) -* metacharacters, escape sequences for: Escape Sequences. (line 130) +* metacharacters, escape sequences for: Escape Sequences. (line 129) * minimum precision supported by MPFR library: Auto-set. (line 224) -* mktime: Time Functions. (line 25) +* 'mktime': Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) * monetary information, localization: Explaining gettext. (line 104) * Moore, Duncan: Getline Notes. (line 40) -* msgfmt utility: I18N Example. (line 63) +* 'msgfmt' utility: I18N Example. (line 63) * multiple precision: Arbitrary Precision Arithmetic. (line 6) * multiple-line records: Multiple Line. (line 6) -* n debugger command (alias for next): Debugger Execution Control. +* 'n' debugger command (alias for 'next'): Debugger Execution Control. (line 43) -* names, arrays/variables <1>: Library Names. (line 6) * names, arrays/variables: Arrays. (line 18) -* names, functions <1>: Library Names. (line 6) +* names, arrays/variables <1>: Library Names. (line 6) * names, functions: Definition Syntax. (line 20) -* namespace issues <1>: Library Names. (line 6) +* names, functions <1>: Library Names. (line 6) * namespace issues: Arrays. (line 18) +* namespace issues <1>: Library Names. (line 6) * namespace issues, functions: Definition Syntax. (line 20) -* nawk utility: Names. (line 10) -* NetBSD: Glossary. (line 611) +* 'nawk' utility: Names. (line 10) +* NetBSD: Glossary. (line 607) * networks, programming: TCP/IP Networking. (line 6) * networks, support for: Special Network. (line 6) -* newlines <1>: Boolean Ops. (line 67) -* newlines <2>: Options. (line 258) * newlines: Statements/Lines. (line 6) +* newlines <1>: Options. (line 256) +* newlines <2>: Boolean Ops. (line 67) * newlines, as field separators: Default Field Splitting. (line 6) * newlines, as record separators: awk split records. (line 12) * newlines, in dynamic regexps: Computed Regexps. (line 59) * newlines, in regexp constants: Computed Regexps. (line 69) -* newlines, printing: Print Examples. (line 12) -* newlines, separating statements in actions <1>: Statements. (line 10) +* newlines, printing: Print Examples. (line 11) * newlines, separating statements in actions: Action Overview. (line 19) -* next debugger command: Debugger Execution Control. +* newlines, separating statements in actions <1>: Statements. (line 10) +* 'next' debugger command: Debugger Execution Control. (line 43) -* next file statement: Feature History. (line 169) -* next statement <1>: Next Statement. (line 6) -* next statement: Boolean Ops. (line 85) -* next statement, BEGIN/END patterns and: I/O And BEGIN/END. (line 37) -* next statement, BEGINFILE/ENDFILE patterns and: BEGINFILE/ENDFILE. +* 'next file' statement: Feature History. (line 168) +* 'next' statement: Boolean Ops. (line 85) +* 'next' statement <1>: Next Statement. (line 6) +* 'next' statement, 'BEGIN'/'END' patterns and: I/O And BEGIN/END. + (line 36) +* 'next' statement, 'BEGINFILE'/'ENDFILE' patterns and: BEGINFILE/ENDFILE. (line 49) -* next statement, user-defined functions and: Next Statement. (line 45) -* nextfile statement: Nextfile Statement. (line 6) -* nextfile statement, BEGIN/END patterns and: I/O And BEGIN/END. - (line 37) -* nextfile statement, BEGINFILE/ENDFILE patterns and: BEGINFILE/ENDFILE. +* 'next' statement, user-defined functions and: Next Statement. + (line 45) +* 'nextfile' statement: Nextfile Statement. (line 6) +* 'nextfile' statement, 'BEGIN'/'END' patterns and: I/O And BEGIN/END. + (line 36) +* 'nextfile' statement, 'BEGINFILE'/'ENDFILE' patterns and: BEGINFILE/ENDFILE. (line 26) -* nextfile statement, user-defined functions and: Nextfile Statement. - (line 47) -* nexti debugger command: Debugger Execution Control. +* 'nextfile' statement, user-defined functions and: Nextfile Statement. + (line 46) +* 'nexti' debugger command: Debugger Execution Control. (line 49) -* NF variable <1>: Auto-set. (line 112) -* NF variable: Fields. (line 33) -* NF variable, decrementing: Changing Fields. (line 107) -* ni debugger command (alias for nexti): Debugger Execution Control. +* 'NF' variable: Fields. (line 33) +* 'NF' variable <1>: Auto-set. (line 113) +* 'NF' variable, decrementing: Changing Fields. (line 107) +* 'ni' debugger command (alias for 'nexti'): Debugger Execution Control. (line 49) -* noassign.awk program: Ignoring Assigns. (line 15) +* 'noassign.awk' program: Ignoring Assigns. (line 15) * non-existent array elements: Reference to Elements. (line 23) * not Boolean-logic operator: Boolean Ops. (line 6) -* NR variable <1>: Auto-set. (line 131) -* NR variable: Records. (line 6) -* NR variable, changing: Auto-set. (line 309) -* null strings <1>: Basic Data Typing. (line 26) -* null strings <2>: Truth Values. (line 6) -* null strings <3>: Regexp Field Splitting. +* 'NR' variable: Records. (line 6) +* 'NR' variable <1>: Auto-set. (line 131) +* 'NR' variable, changing: Auto-set. (line 309) +* null strings: awk split records. (line 113) +* null strings <1>: Regexp Field Splitting. (line 43) -* null strings: awk split records. (line 114) -* null strings in gawk arguments, quoting and: Quoting. (line 79) +* null strings <2>: Truth Values. (line 6) +* null strings <3>: Basic Data Typing. (line 26) +* null strings in 'gawk' arguments, quoting and: Quoting. (line 79) * null strings, and deleting array elements: Delete. (line 27) * null strings, as array subscripts: Uninitialized Subscripts. (line 43) * null strings, converting numbers to strings: Strings And Numbers. (line 21) * null strings, matching: Gory Details. (line 164) -* number as string of bits: Bitwise Functions. (line 109) +* number as string of bits: Bitwise Functions. (line 110) * number of array elements: String Functions. (line 197) -* number sign (#), #! (executable scripts): Executable Scripts. +* number sign ('#'), '#!' (executable scripts): Executable Scripts. (line 6) -* number sign (#), commenting: Comments. (line 6) +* number sign ('#'), commenting: Comments. (line 6) * numbers, as array subscripts: Numeric Array Subscripts. (line 6) * numbers, as values of characters: Ordinal Functions. (line 6) * numbers, Cliff random: Cliff Random Function. (line 6) -* numbers, converting <1>: Bitwise Functions. (line 109) * numbers, converting: Strings And Numbers. (line 6) +* numbers, converting <1>: Bitwise Functions. (line 110) * numbers, converting, to strings: User-modified. (line 30) +* numbers, converting, to strings <1>: User-modified. (line 105) * numbers, hexadecimal: Nondecimal-numbers. (line 6) * numbers, octal: Nondecimal-numbers. (line 6) * numbers, rounding: Round Function. (line 6) @@ -33013,93 +32989,99 @@ Index * numeric functions: Numeric Functions. (line 6) * numeric, output format: OFMT. (line 6) * numeric, strings: Variable Typing. (line 6) -* o debugger command (alias for option): Debugger Info. (line 57) -* oawk utility: Names. (line 10) +* 'o' debugger command (alias for 'option'): Debugger Info. (line 57) +* 'oawk' utility: Names. (line 10) * obsolete features: Obsolete. (line 6) * octal numbers: Nondecimal-numbers. (line 6) -* octal values, enabling interpretation of: Options. (line 211) -* OFMT variable <1>: User-modified. (line 105) -* OFMT variable <2>: Strings And Numbers. (line 57) -* OFMT variable: OFMT. (line 15) -* OFMT variable, POSIX awk and: OFMT. (line 27) -* OFS variable <1>: User-modified. (line 114) -* OFS variable <2>: Output Separators. (line 6) -* OFS variable: Changing Fields. (line 64) -* OpenBSD: Glossary. (line 611) +* octal values, enabling interpretation of: Options. (line 209) +* 'OFMT' variable: OFMT. (line 15) +* 'OFMT' variable <1>: Strings And Numbers. (line 56) +* 'OFMT' variable <2>: User-modified. (line 105) +* 'OFMT' variable, POSIX 'awk' and: OFMT. (line 27) +* 'OFS' variable: Changing Fields. (line 64) +* 'OFS' variable <1>: Output Separators. (line 6) +* 'OFS' variable <2>: User-modified. (line 113) +* OpenBSD: Glossary. (line 607) * OpenSolaris: Other Versions. (line 96) * operating systems, BSD-based: Manual History. (line 28) -* operating systems, PC, gawk on: PC Using. (line 6) -* operating systems, PC, gawk on, installing: PC Installation. +* operating systems, PC, 'gawk' on: PC Using. (line 6) +* operating systems, PC, 'gawk' on, installing: PC Installation. (line 6) -* operating systems, porting gawk to: New Ports. (line 6) +* operating systems, porting 'gawk' to: New Ports. (line 6) * operating systems, See Also GNU/Linux, PC operating systems, Unix: Installation. (line 6) * operations, bitwise: Bitwise Functions. (line 6) * operators, arithmetic: Arithmetic Ops. (line 6) * operators, assignment: Assignment Ops. (line 6) -* operators, assignment, evaluation order: Assignment Ops. (line 111) +* operators, assignment <1>: Assignment Ops. (line 31) +* operators, assignment, evaluation order: Assignment Ops. (line 110) * operators, Boolean, See Boolean expressions: Boolean Ops. (line 6) * operators, decrement/increment: Increment Ops. (line 6) * operators, GNU-specific: GNU Regexp Operators. (line 6) -* operators, input/output <1>: Precedence. (line 65) -* operators, input/output <2>: Redirection. (line 22) -* operators, input/output <3>: Getline/Coprocess. (line 6) -* operators, input/output <4>: Getline/Pipe. (line 9) * operators, input/output: Getline/File. (line 6) +* operators, input/output <1>: Getline/Pipe. (line 10) +* operators, input/output <2>: Getline/Coprocess. (line 6) +* operators, input/output <3>: Redirection. (line 22) +* operators, input/output <4>: Redirection. (line 102) +* operators, input/output <5>: Precedence. (line 64) +* operators, input/output <6>: Precedence. (line 64) +* operators, input/output <7>: Precedence. (line 64) * operators, logical, See Boolean expressions: Boolean Ops. (line 6) -* operators, precedence <1>: Precedence. (line 6) * operators, precedence: Increment Ops. (line 60) +* operators, precedence <1>: Precedence. (line 6) * operators, relational, See operators, comparison: Typing and Comparison. (line 9) * operators, short-circuit: Boolean Ops. (line 57) -* operators, string: Concatenation. (line 8) +* operators, string: Concatenation. (line 9) * operators, string-matching: Regexp Usage. (line 19) * operators, string-matching, for buffers: GNU Regexp Operators. - (line 48) -* operators, word-boundary (gawk): GNU Regexp Operators. - (line 63) -* option debugger command: Debugger Info. (line 57) + (line 51) +* operators, word-boundary ('gawk'): GNU Regexp Operators. + (line 66) +* 'option' debugger command: Debugger Info. (line 57) * options, command-line: Options. (line 6) -* options, command-line, end of: Options. (line 54) -* options, command-line, invoking awk: Command Line. (line 6) +* options, command-line, end of: Options. (line 55) +* options, command-line, invoking 'awk': Command Line. (line 6) * options, command-line, processing: Getopt Function. (line 6) * options, deprecated: Obsolete. (line 6) -* options, long <1>: Options. (line 6) * options, long: Command Line. (line 13) +* options, long <1>: Options. (line 6) * options, printing list of: Options. (line 154) -* or: Bitwise Functions. (line 49) +* 'or': Bitwise Functions. (line 49) * OR bitwise operation: Bitwise Functions. (line 6) * or Boolean-logic operator: Boolean Ops. (line 6) -* ord() extension function: Extension Sample Ord. +* 'ord()' extension function: Extension Sample Ord. (line 12) -* ord() user-defined function: Ordinal Functions. (line 16) +* 'ord()' user-defined function: Ordinal Functions. (line 16) * order of evaluation, concatenation: Concatenation. (line 41) -* ORS variable <1>: User-modified. (line 119) -* ORS variable: Output Separators. (line 20) -* output field separator, See OFS variable: Changing Fields. (line 64) -* output record separator, See ORS variable: Output Separators. +* 'ORS' variable: Output Separators. (line 20) +* 'ORS' variable <1>: User-modified. (line 119) +* output field separator, See 'OFS' variable: Changing Fields. + (line 64) +* output record separator, See 'ORS' variable: Output Separators. (line 20) * output redirection: Redirection. (line 6) * output wrapper: Output Wrappers. (line 6) * output, buffering: I/O Functions. (line 32) +* output, buffering <1>: I/O Functions. (line 139) * output, duplicating into files: Tee Program. (line 6) * output, files, closing: Close Files And Pipes. (line 6) -* output, format specifier, OFMT: OFMT. (line 15) +* output, format specifier, 'OFMT': OFMT. (line 15) * output, formatted: Printf. (line 6) * output, pipes: Redirection. (line 57) * output, printing, See printing: Printing. (line 6) * output, records: Output Separators. (line 20) * output, standard: Special FD. (line 6) -* p debugger command (alias for print): Viewing And Changing Data. - (line 36) -* Papadopoulos, Panos: Contributors. (line 128) -* parent process ID of gawk process: Auto-set. (line 189) -* parentheses (), in a profile: Profiling. (line 146) -* parentheses (), regexp operator: Regexp Operators. (line 80) +* 'p' debugger command (alias for 'print'): Viewing And Changing Data. + (line 35) +* Papadopoulos, Panos: Contributors. (line 129) +* parent process ID of 'gawk' process: Auto-set. (line 189) +* parentheses '()', in a profile: Profiling. (line 146) +* parentheses '()', regexp operator: Regexp Operators. (line 80) * password file: Passwd Functions. (line 16) -* patsplit: String Functions. (line 294) +* 'patsplit': String Functions. (line 294) * patterns: Patterns and Actions. (line 6) * patterns, comparison expressions as: Expression Patterns. (line 14) @@ -33110,147 +33092,160 @@ Index * patterns, ranges in: Ranges. (line 6) * patterns, regexp constants as: Expression Patterns. (line 34) * patterns, types of: Pattern Overview. (line 15) -* pawk (profiling version of Brian Kernighan's awk): Other Versions. +* 'pawk' (profiling version of Brian Kernighan's 'awk'): Other Versions. (line 78) -* pawk, awk-like facilities for Python: Other Versions. (line 125) -* PC operating systems, gawk on: PC Using. (line 6) -* PC operating systems, gawk on, installing: PC Installation. (line 6) -* percent sign (%), % operator: Precedence. (line 55) -* percent sign (%), %= operator <1>: Precedence. (line 95) -* percent sign (%), %= operator: Assignment Ops. (line 130) -* period (.), regexp operator: Regexp Operators. (line 44) +* 'pawk', 'awk'-like facilities for Python: Other Versions. (line 125) +* PC operating systems, 'gawk' on: PC Using. (line 6) +* PC operating systems, 'gawk' on, installing: PC Installation. + (line 6) +* percent sign ('%'), '%' operator: Precedence. (line 54) +* percent sign ('%'), '%=' operator: Assignment Ops. (line 129) +* percent sign ('%'), '%=' operator <1>: Precedence. (line 94) +* period ('.'), regexp operator: Regexp Operators. (line 44) * Perl: Future Extensions. (line 6) -* Peters, Arno: Contributors. (line 85) -* Peterson, Hal: Contributors. (line 39) +* Peters, Arno: Contributors. (line 86) +* Peterson, Hal: Contributors. (line 40) * pipe, closing: Close Files And Pipes. (line 6) -* pipe, input: Getline/Pipe. (line 9) +* pipe, input: Getline/Pipe. (line 10) * pipe, output: Redirection. (line 57) -* Pitts, Dave <1>: Bugs. (line 71) * Pitts, Dave: Acknowledgments. (line 60) +* Pitts, Dave <1>: Bugs. (line 71) * Plauger, P.J.: Library Functions. (line 12) * plug-in: Extension Intro. (line 6) -* plus sign (+), + operator: Precedence. (line 52) -* plus sign (+), ++ operator <1>: Precedence. (line 46) -* plus sign (+), ++ operator: Increment Ops. (line 11) -* plus sign (+), += operator <1>: Precedence. (line 95) -* plus sign (+), += operator: Assignment Ops. (line 82) -* plus sign (+), regexp operator: Regexp Operators. (line 103) +* plus sign ('+'), '+' operator: Precedence. (line 51) +* plus sign ('+'), '+' operator <1>: Precedence. (line 57) +* plus sign ('+'), '++' operator: Increment Ops. (line 11) +* plus sign ('+'), '++' operator <1>: Increment Ops. (line 40) +* plus sign ('+'), '++' operator <2>: Precedence. (line 45) +* plus sign ('+'), '+=' operator: Assignment Ops. (line 81) +* plus sign ('+'), '+=' operator <1>: Precedence. (line 94) +* plus sign ('+'), regexp operator: Regexp Operators. (line 103) * pointers to functions: Indirect Calls. (line 6) -* portability: Escape Sequences. (line 94) -* portability, #! (executable scripts): Executable Scripts. (line 33) -* portability, ** operator and: Arithmetic Ops. (line 81) -* portability, **= operator and: Assignment Ops. (line 143) -* portability, ARGV variable: Executable Scripts. (line 42) +* portability: Escape Sequences. (line 93) +* portability, '#!' (executable scripts): Executable Scripts. (line 33) +* portability, '**' operator and: Arithmetic Ops. (line 81) +* portability, '**=' operator and: Assignment Ops. (line 144) +* portability, 'ARGV' variable: Executable Scripts. (line 42) * portability, backslash continuation and: Statements/Lines. (line 30) * portability, backslash in escape sequences: Escape Sequences. - (line 112) -* portability, close() function and: Close Files And Pipes. + (line 111) +* portability, 'close()' function and: Close Files And Pipes. (line 81) * portability, data files as single record: gawk split records. (line 65) * portability, deleting array elements: Delete. (line 56) * portability, example programs: Library Functions. (line 42) -* portability, functions, defining: Definition Syntax. (line 105) -* portability, gawk: New Ports. (line 6) -* portability, gettext library and: Explaining gettext. (line 11) +* portability, functions, defining: Definition Syntax. (line 104) +* portability, 'gawk': New Ports. (line 6) +* portability, 'gettext' library and: Explaining gettext. (line 11) * portability, internationalization and: I18N Portability. (line 6) -* portability, length() function: String Functions. (line 176) -* portability, new awk vs. old awk: Strings And Numbers. (line 57) -* portability, next statement in user-defined functions: Pass By Value/Reference. - (line 91) -* portability, NF variable, decrementing: Changing Fields. (line 115) +* portability, 'length()' function: String Functions. (line 176) +* portability, new 'awk' vs. old 'awk': Strings And Numbers. (line 56) +* portability, 'next' statement in user-defined functions: Pass By Value/Reference. + (line 90) +* portability, 'NF' variable, decrementing: Changing Fields. (line 115) * portability, operators: Increment Ops. (line 60) -* portability, operators, not in POSIX awk: Precedence. (line 98) -* portability, POSIXLY_CORRECT environment variable: Options. (line 358) -* portability, substr() function: String Functions. (line 510) -* portable object files <1>: Translator i18n. (line 6) +* portability, operators, not in POSIX 'awk': Precedence. (line 97) +* portability, 'POSIXLY_CORRECT' environment variable: Options. + (line 355) +* portability, 'substr()' function: String Functions. (line 509) * portable object files: Explaining gettext. (line 37) +* portable object files <1>: Translator i18n. (line 6) * portable object files, converting to message object files: I18N Example. (line 63) * portable object files, generating: Options. (line 147) * portable object template files: Explaining gettext. (line 31) -* porting gawk: New Ports. (line 6) -* positional specifiers, printf statement <1>: Printf Ordering. +* porting 'gawk': New Ports. (line 6) +* positional specifiers, 'printf' statement: Format Modifiers. + (line 13) +* positional specifiers, 'printf' statement <1>: Printf Ordering. (line 6) -* positional specifiers, printf statement: Format Modifiers. (line 13) -* positional specifiers, printf statement, mixing with regular formats: Printf Ordering. +* positional specifiers, 'printf' statement, mixing with regular formats: Printf Ordering. (line 57) -* POSIX awk <1>: Assignment Ops. (line 137) -* POSIX awk: This Manual. (line 14) -* POSIX awk, ** operator and: Precedence. (line 98) -* POSIX awk, **= operator and: Assignment Ops. (line 143) -* POSIX awk, < operator and: Getline/File. (line 26) -* POSIX awk, arithmetic operators and: Arithmetic Ops. (line 30) -* POSIX awk, backslashes in string constants: Escape Sequences. - (line 112) -* POSIX awk, BEGIN/END patterns: I/O And BEGIN/END. (line 16) -* POSIX awk, bracket expressions and: Bracket Expressions. (line 24) -* POSIX awk, bracket expressions and, character classes: Bracket Expressions. +* POSIX 'awk': This Manual. (line 14) +* POSIX 'awk' <1>: Assignment Ops. (line 138) +* POSIX 'awk', '**' operator and: Precedence. (line 97) +* POSIX 'awk', '**=' operator and: Assignment Ops. (line 144) +* POSIX 'awk', '<' operator and: Getline/File. (line 26) +* POSIX 'awk', arithmetic operators and: Arithmetic Ops. (line 30) +* POSIX 'awk', backslashes in string constants: Escape Sequences. + (line 111) +* POSIX 'awk', 'BEGIN'/'END' patterns: I/O And BEGIN/END. (line 15) +* POSIX 'awk', bracket expressions and: Bracket Expressions. (line 24) +* POSIX 'awk', bracket expressions and, character classes: Bracket Expressions. (line 30) -* POSIX awk, break statement and: Break Statement. (line 51) -* POSIX awk, changes in awk versions: POSIX. (line 6) -* POSIX awk, continue statement and: Continue Statement. (line 43) -* POSIX awk, CONVFMT variable and: User-modified. (line 30) -* POSIX awk, date utility and: Time Functions. (line 254) -* POSIX awk, field separators and <1>: Field Splitting Summary. - (line 40) -* POSIX awk, field separators and: Fields. (line 6) -* POSIX awk, FS variable and: User-modified. (line 60) -* POSIX awk, function keyword in: Definition Syntax. (line 89) -* POSIX awk, functions and, gsub()/sub(): Gory Details. (line 54) -* POSIX awk, functions and, length(): String Functions. (line 176) -* POSIX awk, GNU long options and: Options. (line 15) -* POSIX awk, interval expressions in: Regexp Operators. (line 136) -* POSIX awk, next/nextfile statements and: Next Statement. (line 45) -* POSIX awk, numeric strings and: Variable Typing. (line 6) -* POSIX awk, OFMT variable and <1>: Strings And Numbers. (line 57) -* POSIX awk, OFMT variable and: OFMT. (line 27) -* POSIX awk, period (.), using: Regexp Operators. (line 51) -* POSIX awk, printf format strings and: Format Modifiers. (line 159) -* POSIX awk, regular expressions and: Regexp Operators. (line 162) -* POSIX awk, timestamps and: Time Functions. (line 6) -* POSIX awk, | I/O operator and: Getline/Pipe. (line 55) -* POSIX mode: Options. (line 252) -* POSIX, awk and: Preface. (line 23) -* POSIX, gawk extensions not included in: POSIX/GNU. (line 6) -* POSIX, programs, implementing in awk: Clones. (line 6) -* POSIXLY_CORRECT environment variable: Options. (line 338) -* PREC variable: User-modified. (line 124) -* precedence <1>: Precedence. (line 6) +* POSIX 'awk', bracket expressions and, character classes <1>: Bracket Expressions. + (line 97) +* POSIX 'awk', 'break' statement and: Break Statement. (line 51) +* POSIX 'awk', changes in 'awk' versions: POSIX. (line 6) +* POSIX 'awk', 'continue' statement and: Continue Statement. (line 43) +* POSIX 'awk', 'CONVFMT' variable and: User-modified. (line 30) +* POSIX 'awk', 'date' utility and: Time Functions. (line 252) +* POSIX 'awk', field separators and: Fields. (line 6) +* POSIX 'awk', field separators and <1>: Field Splitting Summary. + (line 39) +* POSIX 'awk', 'FS' variable and: User-modified. (line 60) +* POSIX 'awk', 'function' keyword in: Definition Syntax. (line 89) +* POSIX 'awk', functions and, 'gsub()'/'sub()': Gory Details. (line 54) +* POSIX 'awk', functions and, 'length()': String Functions. (line 176) +* POSIX 'awk', GNU long options and: Options. (line 15) +* POSIX 'awk', interval expressions in: Regexp Operators. (line 136) +* POSIX 'awk', 'next'/'nextfile' statements and: Next Statement. + (line 45) +* POSIX 'awk', numeric strings and: Variable Typing. (line 6) +* POSIX 'awk', 'OFMT' variable and: OFMT. (line 27) +* POSIX 'awk', 'OFMT' variable and <1>: Strings And Numbers. (line 56) +* POSIX 'awk', period ('.'), using: Regexp Operators. (line 51) +* POSIX 'awk', 'printf' format strings and: Format Modifiers. (line 158) +* POSIX 'awk', regular expressions and: Regexp Operators. (line 162) +* POSIX 'awk', timestamps and: Time Functions. (line 6) +* POSIX 'awk', '|' I/O operator and: Getline/Pipe. (line 56) +* POSIX mode: Options. (line 250) +* POSIX mode <1>: Options. (line 335) +* POSIX, 'awk' and: Preface. (line 23) +* POSIX, 'gawk' extensions not included in: POSIX/GNU. (line 6) +* POSIX, programs, implementing in 'awk': Clones. (line 6) +* 'POSIXLY_CORRECT' environment variable: Options. (line 335) +* 'PREC' variable: User-modified. (line 124) * precedence: Increment Ops. (line 60) +* precedence <1>: Precedence. (line 6) * precedence, regexp operators: Regexp Operators. (line 157) -* print debugger command: Viewing And Changing Data. - (line 36) -* print statement: Printing. (line 16) -* print statement, BEGIN/END patterns and: I/O And BEGIN/END. (line 16) -* print statement, commas, omitting: Print Examples. (line 31) -* print statement, I/O operators in: Precedence. (line 71) -* print statement, line continuations and: Print Examples. (line 76) -* print statement, OFMT variable and: User-modified. (line 114) -* print statement, See Also redirection, of output: Redirection. +* 'print' debugger command: Viewing And Changing Data. + (line 35) +* 'print' statement: Printing. (line 16) +* 'print' statement, 'BEGIN'/'END' patterns and: I/O And BEGIN/END. + (line 15) +* 'print' statement, commas, omitting: Print Examples. (line 30) +* 'print' statement, I/O operators in: Precedence. (line 70) +* 'print' statement, line continuations and: Print Examples. (line 75) +* 'print' statement, 'OFMT' variable and: User-modified. (line 113) +* 'print' statement, See Also redirection, of output: Redirection. (line 17) -* print statement, sprintf() function and: Round Function. (line 6) +* 'print' statement, 'sprintf()' function and: Round Function. + (line 6) * print variables, in debugger: Viewing And Changing Data. - (line 36) -* printf debugger command: Viewing And Changing Data. - (line 54) -* printf statement <1>: Printf. (line 6) -* printf statement: Printing. (line 16) -* printf statement, columns, aligning: Print Examples. (line 70) -* printf statement, format-control characters: Control Letters. + (line 35) +* 'printf' debugger command: Viewing And Changing Data. + (line 53) +* 'printf' statement: Printing. (line 16) +* 'printf' statement <1>: Printf. (line 6) +* 'printf' statement, columns, aligning: Print Examples. (line 69) +* 'printf' statement, format-control characters: Control Letters. (line 6) -* printf statement, I/O operators in: Precedence. (line 71) -* printf statement, modifiers: Format Modifiers. (line 6) -* printf statement, positional specifiers <1>: Printf Ordering. +* 'printf' statement, I/O operators in: Precedence. (line 70) +* 'printf' statement, modifiers: Format Modifiers. (line 6) +* 'printf' statement, positional specifiers: Format Modifiers. + (line 13) +* 'printf' statement, positional specifiers <1>: Printf Ordering. (line 6) -* printf statement, positional specifiers: Format Modifiers. (line 13) -* printf statement, positional specifiers, mixing with regular formats: Printf Ordering. +* 'printf' statement, positional specifiers, mixing with regular formats: Printf Ordering. (line 57) -* printf statement, See Also redirection, of output: Redirection. +* 'printf' statement, See Also redirection, of output: Redirection. (line 17) -* printf statement, sprintf() function and: Round Function. (line 6) -* printf statement, syntax of: Basic Printf. (line 6) +* 'printf' statement, 'sprintf()' function and: Round Function. + (line 6) +* 'printf' statement, syntax of: Basic Printf. (line 6) * printing: Printing. (line 6) * printing messages from extensions: Printing Messages. (line 6) * printing, list of options: Options. (line 154) @@ -33258,284 +33253,295 @@ Index * printing, unduplicated lines of text: Uniq Program. (line 6) * printing, user information: Id Program. (line 6) * private variables: Library Names. (line 11) -* process group idIDof gawk process: Auto-set. (line 183) -* process ID of gawk process: Auto-set. (line 186) +* process group idIDof 'gawk' process: Auto-set. (line 183) +* process ID of 'gawk' process: Auto-set. (line 186) * processes, two-way communications with: Two-way I/O. (line 23) * processing data: Basic High Level. (line 6) -* PROCINFO array <1>: Passwd Functions. (line 6) -* PROCINFO array <2>: Time Functions. (line 47) -* PROCINFO array: Auto-set. (line 136) -* PROCINFO array, and communications via ptys: Two-way I/O. (line 117) -* PROCINFO array, and group membership: Group Functions. (line 6) -* PROCINFO array, and user and group ID numbers: Id Program. (line 15) -* PROCINFO array, testing the field splitting: Passwd Functions. +* 'PROCINFO' array: Auto-set. (line 136) +* 'PROCINFO' array <1>: Time Functions. (line 47) +* 'PROCINFO' array <2>: Passwd Functions. (line 6) +* 'PROCINFO' array, and communications via ptys: Two-way I/O. (line 116) +* 'PROCINFO' array, and group membership: Group Functions. (line 6) +* 'PROCINFO' array, and user and group ID numbers: Id Program. + (line 15) +* 'PROCINFO' array, testing the field splitting: Passwd Functions. (line 161) -* PROCINFO array, uses: Auto-set. (line 242) -* PROCINFO, values of sorted_in: Controlling Scanning. +* 'PROCINFO' array, uses: Auto-set. (line 242) +* 'PROCINFO', values of 'sorted_in': Controlling Scanning. (line 26) -* profiling awk programs: Profiling. (line 6) -* profiling awk programs, dynamically: Profiling. (line 179) +* profiling 'awk' programs: Profiling. (line 6) +* profiling 'awk' programs, dynamically: Profiling. (line 178) * program identifiers: Auto-set. (line 154) * program, definition of: Getting Started. (line 21) * programmers, attractiveness of: Two-way I/O. (line 6) -* programming conventions, --non-decimal-data option: Nondecimal Data. +* programming conventions, '--non-decimal-data' option: Nondecimal Data. (line 36) -* programming conventions, ARGC/ARGV variables: Auto-set. (line 35) -* programming conventions, exit statement: Exit Statement. (line 38) +* programming conventions, 'ARGC'/'ARGV' variables: Auto-set. (line 35) +* programming conventions, 'exit' statement: Exit Statement. (line 38) * programming conventions, function parameters: Return Statement. - (line 45) + (line 44) * programming conventions, functions, calling: Calling Built-in. (line 10) * programming conventions, functions, writing: Definition Syntax. (line 61) -* programming conventions, gawk extensions: Internal File Ops. - (line 45) +* programming conventions, 'gawk' extensions: Internal File Ops. + (line 44) * programming conventions, private variable names: Library Names. (line 23) * programming language, recipe for: History. (line 6) * programming languages, Ada: Glossary. (line 19) * programming languages, data-driven vs. procedural: Getting Started. (line 12) -* programming languages, Java: Glossary. (line 379) -* programming, basic steps: Basic High Level. (line 20) +* programming languages, Java: Glossary. (line 375) +* programming, basic steps: Basic High Level. (line 18) * programming, concepts: Basic Concepts. (line 6) -* pwcat program: Passwd Functions. (line 23) -* q debugger command (alias for quit): Miscellaneous Debugger Commands. +* programming, concepts <1>: Basic Concepts. (line 6) +* 'pwcat' program: Passwd Functions. (line 23) +* 'q' debugger command (alias for 'quit'): Miscellaneous Debugger Commands. (line 99) * QSE Awk: Other Versions. (line 131) * Quanstrom, Erik: Alarm Program. (line 8) -* question mark (?), ?: operator: Precedence. (line 92) -* question mark (?), regexp operator <1>: GNU Regexp Operators. - (line 59) -* question mark (?), regexp operator: Regexp Operators. (line 112) +* question mark ('?'), '?:' operator: Precedence. (line 91) +* question mark ('?'), regexp operator: Regexp Operators. (line 112) +* question mark ('?'), regexp operator <1>: GNU Regexp Operators. + (line 62) * QuikTrim Awk: Other Versions. (line 135) -* quit debugger command: Miscellaneous Debugger Commands. +* 'quit' debugger command: Miscellaneous Debugger Commands. (line 99) -* QUIT signal (MS-Windows): Profiling. (line 214) -* quoting in gawk command lines: Long. (line 26) -* quoting in gawk command lines, tricks for: Quoting. (line 88) +* 'QUIT' signal (MS-Windows): Profiling. (line 213) +* quoting in 'gawk' command lines: Long. (line 26) +* quoting in 'gawk' command lines, tricks for: Quoting. (line 88) * quoting, for small awk programs: Comments. (line 27) -* r debugger command (alias for run): Debugger Execution Control. +* 'r' debugger command (alias for 'run'): Debugger Execution Control. (line 62) * Rakitzis, Byron: History Sorting. (line 25) -* Ramey, Chet <1>: General Data Types. (line 6) * Ramey, Chet: Acknowledgments. (line 60) -* rand: Numeric Functions. (line 49) +* Ramey, Chet <1>: General Data Types. (line 6) +* 'rand': Numeric Functions. (line 48) * random numbers, Cliff: Cliff Random Function. (line 6) -* random numbers, rand()/srand() functions: Numeric Functions. - (line 49) -* random numbers, seed of: Numeric Functions. (line 79) +* random numbers, 'rand()'/'srand()' functions: Numeric Functions. + (line 48) +* random numbers, seed of: Numeric Functions. (line 78) * range expressions (regexps): Bracket Expressions. (line 6) * range patterns: Ranges. (line 6) -* range patterns, line continuation and: Ranges. (line 65) -* Rankin, Pat <1>: Bugs. (line 71) -* Rankin, Pat <2>: Contributors. (line 37) -* Rankin, Pat <3>: Assignment Ops. (line 100) +* range patterns, line continuation and: Ranges. (line 64) * Rankin, Pat: Acknowledgments. (line 60) -* reada() extension function: Extension Sample Read write array. +* Rankin, Pat <1>: Assignment Ops. (line 99) +* Rankin, Pat <2>: Contributors. (line 38) +* Rankin, Pat <3>: Bugs. (line 71) +* 'reada()' extension function: Extension Sample Read write array. (line 15) * readable data files, checking: File Checking. (line 6) -* readable.awk program: File Checking. (line 11) -* readdir extension: Extension Sample Readdir. +* 'readable.awk' program: File Checking. (line 11) +* 'readdir' extension: Extension Sample Readdir. (line 9) -* readfile() extension function: Extension Sample Readfile. +* 'readfile()' extension function: Extension Sample Readfile. (line 12) -* readfile() user-defined function: Readfile Function. (line 30) +* 'readfile()' user-defined function: Readfile Function. (line 30) * reading input files: Reading Files. (line 6) * recipe for a programming language: History. (line 6) -* record separators <1>: User-modified. (line 133) * record separators: awk split records. (line 6) +* record separators <1>: User-modified. (line 133) * record separators, changing: awk split records. (line 85) * record separators, regular expressions as: awk split records. - (line 124) + (line 123) * record separators, with multiline records: Multiple Line. (line 10) -* records <1>: Basic High Level. (line 73) * records: Reading Files. (line 14) +* records <1>: Basic High Level. (line 62) * records, multiline: Multiple Line. (line 6) * records, printing: Print. (line 22) * records, splitting input into: Records. (line 6) -* records, terminating: awk split records. (line 124) -* records, treating files as: gawk split records. (line 92) +* records, terminating: awk split records. (line 123) +* records, treating files as: gawk split records. (line 91) * recursive functions: Definition Syntax. (line 79) -* redirect gawk output, in debugger: Debugger Info. (line 72) +* redirect 'gawk' output, in debugger: Debugger Info. (line 72) * redirection of input: Getline/File. (line 6) * redirection of output: Redirection. (line 6) * reference counting, sorting arrays: Array Sorting Functions. (line 77) * regexp: Regexp. (line 6) -* regexp constants <1>: Comparison Operators. - (line 102) -* regexp constants <2>: Regexp Constants. (line 6) * regexp constants: Regexp Usage. (line 57) -* regexp constants, /=.../, /= operator and: Assignment Ops. (line 148) +* regexp constants <1>: Regexp Constants. (line 6) +* regexp constants <2>: Comparison Operators. + (line 103) +* regexp constants, '/=.../', '/=' operator and: Assignment Ops. + (line 149) * regexp constants, as patterns: Expression Patterns. (line 34) -* regexp constants, in gawk: Using Constant Regexps. +* regexp constants, in 'gawk': Using Constant Regexps. (line 28) * regexp constants, slashes vs. quotes: Computed Regexps. (line 29) * regexp constants, vs. string constants: Computed Regexps. (line 39) * register extension: Registration Functions. (line 6) * regular expressions: Regexp. (line 6) -* regular expressions as field separators: Field Separators. (line 51) +* regular expressions as field separators: Field Separators. (line 50) * regular expressions, anchors in: Regexp Operators. (line 22) * regular expressions, as field separators: Regexp Field Splitting. (line 6) -* regular expressions, as patterns <1>: Regexp Patterns. (line 6) * regular expressions, as patterns: Regexp Usage. (line 6) +* regular expressions, as patterns <1>: Regexp Patterns. (line 6) * regular expressions, as record separators: awk split records. - (line 124) -* regular expressions, case sensitivity <1>: User-modified. (line 76) + (line 123) * regular expressions, case sensitivity: Case-sensitivity. (line 6) +* regular expressions, case sensitivity <1>: User-modified. (line 76) * regular expressions, computed: Computed Regexps. (line 6) * regular expressions, constants, See regexp constants: Regexp Usage. (line 57) * regular expressions, dynamic: Computed Regexps. (line 6) * regular expressions, dynamic, with embedded newlines: Computed Regexps. (line 59) -* regular expressions, gawk, command-line options: GNU Regexp Operators. - (line 70) -* regular expressions, interval expressions and: Options. (line 277) +* regular expressions, 'gawk', command-line options: GNU Regexp Operators. + (line 73) +* regular expressions, interval expressions and: Options. (line 274) * regular expressions, leftmost longest match: Leftmost Longest. (line 6) -* regular expressions, operators <1>: Regexp Operators. (line 6) * regular expressions, operators: Regexp Usage. (line 19) +* regular expressions, operators <1>: Regexp Operators. (line 6) * regular expressions, operators, for buffers: GNU Regexp Operators. - (line 48) + (line 51) * regular expressions, operators, for words: GNU Regexp Operators. (line 6) -* regular expressions, operators, gawk: GNU Regexp Operators. +* regular expressions, operators, 'gawk': GNU Regexp Operators. (line 6) * regular expressions, operators, precedence of: Regexp Operators. (line 157) * regular expressions, searching for: Egrep Program. (line 6) * relational operators, See comparison operators: Typing and Comparison. (line 9) -* replace in string: String Functions. (line 406) -* return debugger command: Debugger Execution Control. +* replace in string: String Functions. (line 405) +* 'return' debugger command: Debugger Execution Control. (line 54) -* return statement, user-defined functions: Return Statement. (line 6) -* return value, close() function: Close Files And Pipes. +* 'return' statement, user-defined functions: Return Statement. + (line 6) +* return value, 'close()' function: Close Files And Pipes. (line 131) -* rev() user-defined function: Function Example. (line 53) -* revoutput extension: Extension Sample Revout. +* 'rev()' user-defined function: Function Example. (line 53) +* 'revoutput' extension: Extension Sample Revout. (line 11) -* revtwoway extension: Extension Sample Rev2way. +* 'revtwoway' extension: Extension Sample Rev2way. (line 12) -* rewind() user-defined function: Rewind Function. (line 16) -* right angle bracket (>), > operator <1>: Precedence. (line 65) -* right angle bracket (>), > operator: Comparison Operators. +* 'rewind()' user-defined function: Rewind Function. (line 16) +* right angle bracket ('>'), '>' operator: Comparison Operators. (line 11) -* right angle bracket (>), > operator (I/O): Redirection. (line 22) -* right angle bracket (>), >= operator <1>: Precedence. (line 65) -* right angle bracket (>), >= operator: Comparison Operators. +* right angle bracket ('>'), '>' operator <1>: Precedence. (line 64) +* right angle bracket ('>'), '>' operator (I/O): Redirection. (line 22) +* right angle bracket ('>'), '>=' operator: Comparison Operators. (line 11) -* right angle bracket (>), >> operator (I/O) <1>: Precedence. (line 65) -* right angle bracket (>), >> operator (I/O): Redirection. (line 50) -* right shift: Bitwise Functions. (line 52) +* right angle bracket ('>'), '>=' operator <1>: Precedence. (line 64) +* right angle bracket ('>'), '>>' operator (I/O): Redirection. + (line 50) +* right angle bracket ('>'), '>>' operator (I/O) <1>: Precedence. + (line 64) +* right shift: Bitwise Functions. (line 53) * right shift, bitwise: Bitwise Functions. (line 32) * Ritchie, Dennis: Basic Data Typing. (line 54) -* RLENGTH variable: Auto-set. (line 252) -* RLENGTH variable, match() function and: String Functions. (line 224) -* Robbins, Arnold <1>: Future Extensions. (line 6) -* Robbins, Arnold <2>: Bugs. (line 32) -* Robbins, Arnold <3>: Contributors. (line 141) -* Robbins, Arnold <4>: General Data Types. (line 6) -* Robbins, Arnold <5>: Alarm Program. (line 6) -* Robbins, Arnold <6>: Passwd Functions. (line 90) -* Robbins, Arnold <7>: Getline/Pipe. (line 39) +* 'RLENGTH' variable: Auto-set. (line 252) +* 'RLENGTH' variable, 'match()' function and: String Functions. + (line 224) * Robbins, Arnold: Command Line Field Separator. (line 73) -* Robbins, Bill: Getline/Pipe. (line 39) +* Robbins, Arnold <1>: Getline/Pipe. (line 40) +* Robbins, Arnold <2>: Passwd Functions. (line 90) +* Robbins, Arnold <3>: Alarm Program. (line 6) +* Robbins, Arnold <4>: General Data Types. (line 6) +* Robbins, Arnold <5>: Contributors. (line 142) +* Robbins, Arnold <6>: Bugs. (line 32) +* Robbins, Arnold <7>: Future Extensions. (line 6) +* Robbins, Bill: Getline/Pipe. (line 40) * Robbins, Harry: Acknowledgments. (line 82) * Robbins, Jean: Acknowledgments. (line 82) -* Robbins, Miriam <1>: Passwd Functions. (line 90) -* Robbins, Miriam <2>: Getline/Pipe. (line 39) * Robbins, Miriam: Acknowledgments. (line 82) -* Rommel, Kai Uwe: Contributors. (line 42) -* round to nearest integer: Numeric Functions. (line 38) -* round() user-defined function: Round Function. (line 16) +* Robbins, Miriam <1>: Getline/Pipe. (line 40) +* Robbins, Miriam <2>: Passwd Functions. (line 90) +* Rommel, Kai Uwe: Contributors. (line 43) +* round to nearest integer: Numeric Functions. (line 37) +* 'round()' user-defined function: Round Function. (line 16) * rounding numbers: Round Function. (line 6) -* ROUNDMODE variable: User-modified. (line 128) -* RS variable <1>: User-modified. (line 133) -* RS variable: awk split records. (line 12) -* RS variable, multiline records and: Multiple Line. (line 17) -* rshift: Bitwise Functions. (line 52) -* RSTART variable: Auto-set. (line 258) -* RSTART variable, match() function and: String Functions. (line 224) -* RT variable <1>: Auto-set. (line 265) -* RT variable <2>: Multiple Line. (line 129) -* RT variable: awk split records. (line 124) -* Rubin, Paul <1>: Contributors. (line 15) +* 'ROUNDMODE' variable: User-modified. (line 128) +* 'RS' variable: awk split records. (line 12) +* 'RS' variable <1>: User-modified. (line 133) +* 'RS' variable, multiline records and: Multiple Line. (line 17) +* 'rshift': Bitwise Functions. (line 53) +* 'RSTART' variable: Auto-set. (line 258) +* 'RSTART' variable, 'match()' function and: String Functions. + (line 224) +* 'RT' variable: awk split records. (line 123) +* 'RT' variable <1>: Multiple Line. (line 129) +* 'RT' variable <2>: Auto-set. (line 265) * Rubin, Paul: History. (line 30) +* Rubin, Paul <1>: Contributors. (line 16) * rule, definition of: Getting Started. (line 21) -* run debugger command: Debugger Execution Control. +* 'run' debugger command: Debugger Execution Control. (line 62) -* rvalues/lvalues: Assignment Ops. (line 32) -* s debugger command (alias for step): Debugger Execution Control. +* rvalues/lvalues: Assignment Ops. (line 31) +* 's' debugger command (alias for 'step'): Debugger Execution Control. (line 68) * sample debugging session: Sample Debugging Session. (line 6) -* sandbox mode: Options. (line 284) +* sandbox mode: Options. (line 281) * save debugger options: Debugger Info. (line 84) * scalar or array: Type Functions. (line 11) * scalar values: Basic Data Typing. (line 13) * scanning arrays: Scanning an Array. (line 6) * scanning multidimensional arrays: Multiscanning. (line 11) -* Schorr, Andrew <1>: Contributors. (line 133) -* Schorr, Andrew <2>: Auto-set. (line 292) * Schorr, Andrew: Acknowledgments. (line 60) +* Schorr, Andrew <1>: Auto-set. (line 292) +* Schorr, Andrew <2>: Contributors. (line 134) * Schreiber, Bert: Acknowledgments. (line 38) * Schreiber, Rita: Acknowledgments. (line 38) * search and replace in strings: String Functions. (line 89) * search in string: String Functions. (line 155) -* search paths <1>: VMS Running. (line 58) -* search paths <2>: PC Using. (line 10) * search paths: Programs Exercises. (line 63) +* search paths <1>: PC Using. (line 10) +* search paths <2>: VMS Running. (line 57) * search paths, for loadable extensions: AWKLIBPATH Variable. (line 6) -* search paths, for source files <1>: VMS Running. (line 58) -* search paths, for source files <2>: PC Using. (line 10) -* search paths, for source files <3>: Programs Exercises. (line 63) * search paths, for source files: AWKPATH Variable. (line 6) +* search paths, for source files <1>: Programs Exercises. (line 63) +* search paths, for source files <2>: PC Using. (line 10) +* search paths, for source files <3>: VMS Running. (line 57) * searching, files for regular expressions: Egrep Program. (line 6) * searching, for words: Dupword Program. (line 6) -* sed utility <1>: Glossary. (line 11) -* sed utility <2>: Simple Sed. (line 6) -* sed utility: Field Splitting Summary. - (line 46) -* seeding random number generator: Numeric Functions. (line 79) -* semicolon (;), AWKPATH variable and: PC Using. (line 10) -* semicolon (;), separating statements in actions <1>: Statements. - (line 10) -* semicolon (;), separating statements in actions <2>: Action Overview. +* 'sed' utility: Field Splitting Summary. + (line 45) +* 'sed' utility <1>: Simple Sed. (line 6) +* 'sed' utility <2>: Glossary. (line 11) +* seeding random number generator: Numeric Functions. (line 78) +* semicolon (';'), 'AWKPATH' variable and: PC Using. (line 10) +* semicolon (';'), separating statements in actions: Statements/Lines. + (line 90) +* semicolon (';'), separating statements in actions <1>: Action Overview. (line 19) -* semicolon (;), separating statements in actions: Statements/Lines. - (line 91) +* semicolon (';'), separating statements in actions <2>: Statements. + (line 10) * separators, field: User-modified. (line 50) -* separators, field, FIELDWIDTHS variable and: User-modified. (line 37) -* separators, field, FPAT variable and: User-modified. (line 43) +* separators, field <1>: User-modified. (line 113) +* separators, field, 'FIELDWIDTHS' variable and: User-modified. + (line 37) +* separators, field, 'FPAT' variable and: User-modified. (line 43) * separators, field, POSIX and: Fields. (line 6) -* separators, for records <1>: User-modified. (line 133) * separators, for records: awk split records. (line 6) +* separators, for records <1>: awk split records. (line 85) +* separators, for records <2>: User-modified. (line 133) * separators, for records, regular expressions as: awk split records. - (line 124) + (line 123) * separators, for statements in actions: Action Overview. (line 19) * separators, subscript: User-modified. (line 146) * set breakpoint: Breakpoint Control. (line 11) -* set debugger command: Viewing And Changing Data. - (line 59) -* set directory of message catalogs: I18N Functions. (line 12) +* 'set' debugger command: Viewing And Changing Data. + (line 58) +* set directory of message catalogs: I18N Functions. (line 11) * set watchpoint: Viewing And Changing Data. - (line 67) + (line 66) * shadowing of variable values: Definition Syntax. (line 67) * shell quoting, double quote: Read Terminal. (line 25) * shell quoting, rules for: Quoting. (line 6) -* shells, piping commands into: Redirection. (line 142) +* shells, piping commands into: Redirection. (line 141) * shells, quoting: Using Shell Variables. (line 12) * shells, quoting, rules for: Quoting. (line 18) * shells, scripts: One-shot. (line 22) -* shells, sea: Undocumented. (line 8) +* shells, sea: Undocumented. (line 9) * shells, variables: Using Shell Variables. (line 6) * shift, bitwise: Bitwise Functions. (line 32) @@ -33547,160 +33553,162 @@ Index * show name of current source file, in debugger: Debugger Info. (line 37) * show watchpoints: Debugger Info. (line 51) -* si debugger command (alias for stepi): Debugger Execution Control. +* 'si' debugger command (alias for 'stepi'): Debugger Execution Control. (line 76) -* side effects <1>: Increment Ops. (line 11) * side effects: Concatenation. (line 41) +* side effects <1>: Increment Ops. (line 11) +* side effects <2>: Increment Ops. (line 75) * side effects, array indexing: Reference to Elements. (line 42) -* side effects, asort() function: Array Sorting Functions. +* side effects, 'asort()' function: Array Sorting Functions. (line 24) -* side effects, assignment expressions: Assignment Ops. (line 23) +* side effects, assignment expressions: Assignment Ops. (line 22) * side effects, Boolean operators: Boolean Ops. (line 30) * side effects, conditional expressions: Conditional Exp. (line 22) * side effects, decrement/increment operators: Increment Ops. (line 11) -* side effects, FILENAME variable: Getline Notes. (line 19) +* side effects, 'FILENAME' variable: Getline Notes. (line 19) * side effects, function calls: Function Calls. (line 57) * side effects, statements: Action Overview. (line 32) * sidebar, A Constant's Base Does Not Affect Its Value: Nondecimal-numbers. - (line 64) + (line 63) * sidebar, Backslash Before Regular Characters: Escape Sequences. - (line 110) -* sidebar, Changing FS Does Not Affect the Fields: Field Splitting Summary. - (line 38) -* sidebar, Changing NR and FNR: Auto-set. (line 307) -* sidebar, Controlling Output Buffering with system(): I/O Functions. - (line 138) + (line 109) +* sidebar, Changing 'FS' Does Not Affect the Fields: Field Splitting Summary. + (line 37) +* sidebar, Changing 'NR' and 'FNR': Auto-set. (line 307) +* sidebar, Controlling Output Buffering with 'system()': I/O Functions. + (line 137) * sidebar, Escape Sequences for Metacharacters: Escape Sequences. - (line 128) -* sidebar, FS and IGNORECASE: Field Splitting Summary. - (line 64) + (line 127) +* sidebar, 'FS' and 'IGNORECASE': Field Splitting Summary. + (line 63) * sidebar, Interactive Versus Noninteractive Buffering: I/O Functions. - (line 107) + (line 106) * sidebar, Matching the Null String: Gory Details. (line 162) * sidebar, Operator Evaluation Order: Increment Ops. (line 58) -* sidebar, Piping into sh: Redirection. (line 140) -* sidebar, Portability Issues with #!: Executable Scripts. (line 31) -* sidebar, Pre-POSIX awk Used OFMT For String Conversion: Strings And Numbers. - (line 55) +* sidebar, Piping into 'sh': Redirection. (line 139) +* sidebar, Portability Issues with '#!': Executable Scripts. (line 31) +* sidebar, Pre-POSIX 'awk' Used 'OFMT' For String Conversion: Strings And Numbers. + (line 54) * sidebar, Recipe For A Programming Language: History. (line 6) -* sidebar, RS = "\0" Is Not Portable: gawk split records. (line 63) -* sidebar, So Why Does gawk have BEGINFILE and ENDFILE?: Filetrans Function. +* sidebar, 'RS = "\0"' Is Not Portable: gawk split records. (line 63) +* sidebar, So Why Does 'gawk' have 'BEGINFILE' and 'ENDFILE'?: Filetrans Function. (line 83) -* sidebar, Syntactic Ambiguities Between /= and Regular Expressions: Assignment Ops. - (line 146) -* sidebar, Understanding $0: Changing Fields. (line 134) -* sidebar, Using \n in Bracket Expressions of Dynamic Regexps: Computed Regexps. - (line 57) -* sidebar, Using close()'s Return Value: Close Files And Pipes. +* sidebar, Syntactic Ambiguities Between '/=' and Regular Expressions: Assignment Ops. + (line 147) +* sidebar, Understanding '$0': Changing Fields. (line 134) +* sidebar, Using 'close()''s Return Value: Close Files And Pipes. (line 129) -* SIGHUP signal, for dynamic profiling: Profiling. (line 211) -* SIGINT signal (MS-Windows): Profiling. (line 214) -* signals, HUP/SIGHUP, for profiling: Profiling. (line 211) -* signals, INT/SIGINT (MS-Windows): Profiling. (line 214) -* signals, QUIT/SIGQUIT (MS-Windows): Profiling. (line 214) -* signals, USR1/SIGUSR1, for profiling: Profiling. (line 188) +* sidebar, Using '\n' in Bracket Expressions of Dynamic Regexps: Computed Regexps. + (line 57) +* 'SIGHUP' signal, for dynamic profiling: Profiling. (line 210) +* 'SIGINT' signal (MS-Windows): Profiling. (line 213) +* signals, 'HUP'/'SIGHUP', for profiling: Profiling. (line 210) +* signals, 'INT'/'SIGINT' (MS-Windows): Profiling. (line 213) +* signals, 'QUIT'/'SIGQUIT' (MS-Windows): Profiling. (line 213) +* signals, 'USR1'/'SIGUSR1', for profiling: Profiling. (line 187) * signature program: Signature Program. (line 6) -* SIGQUIT signal (MS-Windows): Profiling. (line 214) -* SIGUSR1 signal, for dynamic profiling: Profiling. (line 188) -* silent debugger command: Debugger Execution Control. +* 'SIGQUIT' signal (MS-Windows): Profiling. (line 213) +* 'SIGUSR1' signal, for dynamic profiling: Profiling. (line 187) +* 'silent' debugger command: Debugger Execution Control. (line 10) -* sin: Numeric Functions. (line 90) -* sine: Numeric Functions. (line 90) -* single quote ('): One-shot. (line 15) -* single quote (') in gawk command lines: Long. (line 33) -* single quote ('), in shell commands: Quoting. (line 48) -* single quote ('), vs. apostrophe: Comments. (line 27) -* single quote ('), with double quotes: Quoting. (line 70) +* 'sin': Numeric Functions. (line 89) +* sine: Numeric Functions. (line 89) +* single quote ('''): One-shot. (line 15) +* single quote (''') in 'gawk' command lines: Long. (line 33) +* single quote ('''), in shell commands: Quoting. (line 48) +* single quote ('''), vs. apostrophe: Comments. (line 27) +* single quote ('''), with double quotes: Quoting. (line 70) * single-character fields: Single Character Fields. (line 6) * single-step execution, in the debugger: Debugger Execution Control. (line 43) * Skywalker, Luke: Undocumented. (line 6) -* sleep utility: Alarm Program. (line 111) -* sleep() extension function: Extension Sample Time. +* 'sleep' utility: Alarm Program. (line 110) +* 'sleep()' extension function: Extension Sample Time. (line 22) -* Solaris, POSIX-compliant awk: Other Versions. (line 96) +* Solaris, POSIX-compliant 'awk': Other Versions. (line 96) * sort array: String Functions. (line 42) * sort array indices: String Functions. (line 42) * sort function, arrays, sorting: Array Sorting Functions. (line 6) -* sort utility: Word Sorting. (line 50) -* sort utility, coprocesses and: Two-way I/O. (line 83) +* 'sort' utility: Word Sorting. (line 50) +* 'sort' utility, coprocesses and: Two-way I/O. (line 83) * sorting characters in different languages: Explaining gettext. (line 94) -* source code, awka: Other Versions. (line 64) -* source code, Brian Kernighan's awk: Other Versions. (line 13) +* source code, 'awka': Other Versions. (line 64) +* source code, Brian Kernighan's 'awk': Other Versions. (line 13) * source code, Busybox Awk: Other Versions. (line 88) -* source code, gawk: Gawk Distribution. (line 6) -* source code, Illumos awk: Other Versions. (line 105) -* source code, jawk: Other Versions. (line 113) +* source code, 'gawk': Gawk Distribution. (line 6) +* source code, Illumos 'awk': Other Versions. (line 105) +* source code, 'jawk': Other Versions. (line 113) * source code, libmawk: Other Versions. (line 121) -* source code, mawk: Other Versions. (line 44) +* source code, 'mawk': Other Versions. (line 44) * source code, mixing: Options. (line 117) -* source code, pawk: Other Versions. (line 78) -* source code, pawk (Python version): Other Versions. (line 125) +* source code, 'pawk': Other Versions. (line 78) +* source code, 'pawk' (Python version): Other Versions. (line 125) * source code, QSE Awk: Other Versions. (line 131) * source code, QuikTrim Awk: Other Versions. (line 135) -* source code, Solaris awk: Other Versions. (line 96) +* source code, Solaris 'awk': Other Versions. (line 96) * source files, search path for: Programs Exercises. (line 63) -* sparse arrays: Array Intro. (line 71) +* sparse arrays: Array Intro. (line 70) * Spencer, Henry: Glossary. (line 11) -* split: String Functions. (line 313) +* 'split': String Functions. (line 313) * split string into array: String Functions. (line 294) -* split utility: Split Program. (line 6) -* split() function, array elements, deleting: Delete. (line 61) -* split.awk program: Split Program. (line 30) -* sprintf <1>: String Functions. (line 381) -* sprintf: OFMT. (line 15) -* sprintf() function, OFMT variable and: User-modified. (line 114) -* sprintf() function, print/printf statements and: Round Function. +* 'split' utility: Split Program. (line 6) +* 'split()' function, array elements, deleting: Delete. (line 61) +* 'split.awk' program: Split Program. (line 30) +* 'sprintf': OFMT. (line 15) +* 'sprintf' <1>: String Functions. (line 380) +* 'sprintf()' function, 'OFMT' variable and: User-modified. (line 113) +* 'sprintf()' function, 'print'/'printf' statements and: Round Function. (line 6) -* sqrt: Numeric Functions. (line 93) -* square brackets ([]), regexp operator: Regexp Operators. (line 56) -* square root: Numeric Functions. (line 93) -* srand: Numeric Functions. (line 97) +* 'sqrt': Numeric Functions. (line 92) +* square brackets ('[]'), regexp operator: Regexp Operators. (line 56) +* square root: Numeric Functions. (line 92) +* 'srand': Numeric Functions. (line 96) * stack frame: Debugging Terms. (line 10) -* Stallman, Richard <1>: Glossary. (line 296) -* Stallman, Richard <2>: Contributors. (line 23) -* Stallman, Richard <3>: Acknowledgments. (line 18) * Stallman, Richard: Manual History. (line 6) +* Stallman, Richard <1>: Acknowledgments. (line 18) +* Stallman, Richard <2>: Contributors. (line 24) +* Stallman, Richard <3>: Glossary. (line 294) * standard error: Special FD. (line 6) -* standard input <1>: Special FD. (line 6) * standard input: Read Terminal. (line 6) +* standard input <1>: Special FD. (line 6) * standard output: Special FD. (line 6) * starting the debugger: Debugger Invocation. (line 6) -* stat() extension function: Extension Sample File Functions. +* 'stat()' extension function: Extension Sample File Functions. (line 18) * statements, compound, control statements and: Statements. (line 10) * statements, control, in actions: Statements. (line 6) -* statements, multiple: Statements/Lines. (line 91) -* step debugger command: Debugger Execution Control. +* statements, multiple: Statements/Lines. (line 90) +* 'step' debugger command: Debugger Execution Control. (line 68) -* stepi debugger command: Debugger Execution Control. +* 'stepi' debugger command: Debugger Execution Control. (line 76) * stop automatic display, in debugger: Viewing And Changing Data. - (line 80) -* stream editors <1>: Simple Sed. (line 6) + (line 79) * stream editors: Field Splitting Summary. - (line 46) -* strftime: Time Functions. (line 48) + (line 45) +* stream editors <1>: Simple Sed. (line 6) +* 'strftime': Time Functions. (line 48) * string constants: Scalar Constants. (line 15) * string constants, vs. regexp constants: Computed Regexps. (line 39) * string extraction (internationalization): String Extraction. (line 6) * string length: String Functions. (line 167) -* string operators: Concatenation. (line 8) +* string operators: Concatenation. (line 9) * string, regular expression match: String Functions. (line 207) * string-manipulation functions: String Functions. (line 6) * string-matching operators: Regexp Usage. (line 19) * string-translation functions: I18N Functions. (line 6) -* strings splitting, example: String Functions. (line 333) -* strings, converting <1>: Bitwise Functions. (line 109) +* strings splitting, example: String Functions. (line 332) * strings, converting: Strings And Numbers. (line 6) -* strings, converting letter case: String Functions. (line 520) +* strings, converting <1>: Bitwise Functions. (line 110) +* strings, converting letter case: String Functions. (line 519) * strings, converting, numbers to: User-modified. (line 30) -* strings, empty, See null strings: awk split records. (line 114) +* strings, converting, numbers to <1>: User-modified. (line 105) +* strings, empty, See null strings: awk split records. (line 113) * strings, extracting: String Extraction. (line 6) * strings, for localization: Programmer i18n. (line 14) * strings, length limitations: Scalar Constants. (line 20) @@ -33708,14 +33716,14 @@ Index * strings, null: Regexp Field Splitting. (line 43) * strings, numeric: Variable Typing. (line 6) -* strtonum: String Functions. (line 388) -* strtonum() function (gawk), --non-decimal-data option and: Nondecimal Data. +* 'strtonum': String Functions. (line 387) +* 'strtonum()' function ('gawk'), '--non-decimal-data' option and: Nondecimal Data. (line 36) -* sub <1>: String Functions. (line 406) -* sub: Using Constant Regexps. +* 'sub': Using Constant Regexps. (line 43) -* sub() function, arguments of: String Functions. (line 460) -* sub() function, escape processing: Gory Details. (line 6) +* 'sub' <1>: String Functions. (line 405) +* 'sub()' function, arguments of: String Functions. (line 459) +* 'sub()' function, escape processing: Gory Details. (line 6) * subscript separators: User-modified. (line 146) * subscripts in arrays, multidimensional: Multidimensional. (line 10) * subscripts in arrays, multidimensional, scanning: Multiscanning. @@ -33724,57 +33732,61 @@ Index (line 6) * subscripts in arrays, uninitialized variables as: Uninitialized Subscripts. (line 6) -* SUBSEP variable: User-modified. (line 146) -* SUBSEP variable, and multidimensional arrays: Multidimensional. +* 'SUBSEP' variable: User-modified. (line 146) +* 'SUBSEP' variable, and multidimensional arrays: Multidimensional. (line 16) * substitute in string: String Functions. (line 89) -* substr: String Functions. (line 479) -* substring: String Functions. (line 479) +* 'substr': String Functions. (line 478) +* substring: String Functions. (line 478) * Sumner, Andrew: Other Versions. (line 64) -* supplementary groups of gawk process: Auto-set. (line 237) -* switch statement: Switch Statement. (line 6) -* SYMTAB array: Auto-set. (line 269) -* syntactic ambiguity: /= operator vs. /=.../ regexp constant: Assignment Ops. - (line 148) -* system: I/O Functions. (line 75) -* systime: Time Functions. (line 66) -* t debugger command (alias for tbreak): Breakpoint Control. (line 90) -* tbreak debugger command: Breakpoint Control. (line 90) +* supplementary groups of 'gawk' process: Auto-set. (line 237) +* 'switch' statement: Switch Statement. (line 6) +* 'SYMTAB' array: Auto-set. (line 269) +* syntactic ambiguity: '/=' operator vs. '/=.../' regexp constant: Assignment Ops. + (line 149) +* 'system': I/O Functions. (line 76) +* 'systime': Time Functions. (line 65) +* 't' debugger command (alias for 'tbreak'): Breakpoint Control. + (line 90) +* 'tbreak' debugger command: Breakpoint Control. (line 90) * Tcl: Library Names. (line 57) * TCP/IP: TCP/IP Networking. (line 6) * TCP/IP, support for: Special Network. (line 6) -* tee utility: Tee Program. (line 6) -* tee.awk program: Tee Program. (line 26) +* 'tee' utility: Tee Program. (line 6) +* 'tee.awk' program: Tee Program. (line 26) * temporary breakpoint: Breakpoint Control. (line 90) -* terminating records: awk split records. (line 124) -* testbits.awk program: Bitwise Functions. (line 70) -* testext extension: Extension Sample API Tests. +* terminating records: awk split records. (line 123) +* 'testbits.awk' program: Bitwise Functions. (line 71) +* 'testext' extension: Extension Sample API Tests. (line 6) -* Texinfo <1>: Adding Code. (line 100) -* Texinfo <2>: Distribution contents. - (line 77) -* Texinfo <3>: Extract Program. (line 12) -* Texinfo <4>: Dupword Program. (line 17) -* Texinfo <5>: Library Functions. (line 33) * Texinfo: Conventions. (line 6) +* Texinfo <1>: Library Functions. (line 33) +* Texinfo <2>: Dupword Program. (line 17) +* Texinfo <3>: Extract Program. (line 12) +* Texinfo <4>: Distribution contents. + (line 77) +* Texinfo <5>: Adding Code. (line 100) * Texinfo, chapter beginnings in files: Regexp Operators. (line 22) * Texinfo, extracting programs from source files: Extract Program. (line 6) * text, printing: Print. (line 22) * text, printing, unduplicated lines of: Uniq Program. (line 6) -* TEXTDOMAIN variable <1>: Programmer i18n. (line 9) -* TEXTDOMAIN variable: User-modified. (line 152) -* TEXTDOMAIN variable, BEGIN pattern and: Programmer i18n. (line 60) -* TEXTDOMAIN variable, portability and: I18N Portability. (line 20) -* textdomain() function (C library): Explaining gettext. (line 28) -* tilde (~), ~ operator <1>: Expression Patterns. (line 24) -* tilde (~), ~ operator <2>: Precedence. (line 80) -* tilde (~), ~ operator <3>: Comparison Operators. +* 'TEXTDOMAIN' variable: User-modified. (line 152) +* 'TEXTDOMAIN' variable <1>: Programmer i18n. (line 9) +* 'TEXTDOMAIN' variable, 'BEGIN' pattern and: Programmer i18n. + (line 60) +* 'TEXTDOMAIN' variable, portability and: I18N Portability. (line 20) +* 'textdomain()' function (C library): Explaining gettext. (line 28) +* tilde ('~'), '~' operator: Regexp Usage. (line 19) +* tilde ('~'), '~' operator <1>: Case-sensitivity. (line 26) +* tilde ('~'), '~' operator <2>: Computed Regexps. (line 6) +* tilde ('~'), '~' operator <3>: Regexp Constants. (line 6) +* tilde ('~'), '~' operator <4>: Comparison Operators. (line 11) -* tilde (~), ~ operator <4>: Regexp Constants. (line 6) -* tilde (~), ~ operator <5>: Computed Regexps. (line 6) -* tilde (~), ~ operator <6>: Case-sensitivity. (line 26) -* tilde (~), ~ operator: Regexp Usage. (line 19) +* tilde ('~'), '~' operator <5>: Comparison Operators. + (line 98) +* tilde ('~'), '~' operator <6>: Precedence. (line 79) +* tilde ('~'), '~' operator <7>: Expression Patterns. (line 24) * time functions: Time Functions. (line 6) * time, alarm clock example program: Alarm Program. (line 11) * time, localization and: Explaining gettext. (line 116) @@ -33783,92 +33795,95 @@ Index * time, retrieving: Time Functions. (line 17) * timeout, reading input: Read Timeout. (line 6) * timestamps: Time Functions. (line 6) -* timestamps, converting dates to: Time Functions. (line 76) +* timestamps <1>: Time Functions. (line 65) +* timestamps, converting dates to: Time Functions. (line 75) * timestamps, formatted: Getlocaltime Function. (line 6) -* tolower: String Functions. (line 521) -* toupper: String Functions. (line 527) -* tr utility: Translate Program. (line 6) -* trace debugger command: Miscellaneous Debugger Commands. +* 'tolower': String Functions. (line 520) +* 'toupper': String Functions. (line 526) +* 'tr' utility: Translate Program. (line 6) +* 'trace' debugger command: Miscellaneous Debugger Commands. (line 108) * traceback, display in debugger: Execution Stack. (line 13) -* translate string: I18N Functions. (line 22) -* translate.awk program: Translate Program. (line 55) -* treating files, as single records: gawk split records. (line 92) -* troubleshooting, --non-decimal-data option: Options. (line 211) -* troubleshooting, == operator: Comparison Operators. - (line 37) -* troubleshooting, awk uses FS not IFS: Field Separators. (line 30) +* translate string: I18N Functions. (line 21) +* 'translate.awk' program: Translate Program. (line 55) +* treating files, as single records: gawk split records. (line 91) +* troubleshooting, '--non-decimal-data' option: Options. (line 209) +* troubleshooting, '==' operator: Comparison Operators. + (line 38) +* troubleshooting, 'awk' uses 'FS' not 'IFS': Field Separators. + (line 29) * troubleshooting, backslash before nonspecial character: Escape Sequences. - (line 112) + (line 111) * troubleshooting, division: Arithmetic Ops. (line 44) * troubleshooting, fatal errors, field widths, specifying: Constant Size. (line 23) -* troubleshooting, fatal errors, printf format strings: Format Modifiers. - (line 159) -* troubleshooting, fflush() function: I/O Functions. (line 63) +* troubleshooting, fatal errors, 'printf' format strings: Format Modifiers. + (line 158) +* troubleshooting, 'fflush()' function: I/O Functions. (line 64) * troubleshooting, function call syntax: Function Calls. (line 30) -* troubleshooting, gawk: Compatibility Mode. (line 6) -* troubleshooting, gawk, bug reports: Bugs. (line 9) -* troubleshooting, gawk, fatal errors, function arguments: Calling Built-in. +* troubleshooting, 'gawk': Compatibility Mode. (line 6) +* troubleshooting, 'gawk', bug reports: Bugs. (line 9) +* troubleshooting, 'gawk', fatal errors, function arguments: Calling Built-in. (line 16) -* troubleshooting, getline function: File Checking. (line 25) -* troubleshooting, gsub()/sub() functions: String Functions. (line 470) -* troubleshooting, match() function: String Functions. (line 289) -* troubleshooting, print statement, omitting commas: Print Examples. - (line 31) +* troubleshooting, 'getline' function: File Checking. (line 25) +* troubleshooting, 'gsub()'/'sub()' functions: String Functions. + (line 469) +* troubleshooting, 'match()' function: String Functions. (line 289) +* troubleshooting, 'print' statement, omitting commas: Print Examples. + (line 30) * troubleshooting, printing: Redirection. (line 118) * troubleshooting, quotes with file names: Special FD. (line 68) * troubleshooting, readable data files: File Checking. (line 6) * troubleshooting, regexp constants vs. string constants: Computed Regexps. (line 39) -* troubleshooting, string concatenation: Concatenation. (line 26) -* troubleshooting, substr() function: String Functions. (line 497) -* troubleshooting, system() function: I/O Functions. (line 97) +* troubleshooting, string concatenation: Concatenation. (line 27) +* troubleshooting, 'substr()' function: String Functions. (line 496) +* troubleshooting, 'system()' function: I/O Functions. (line 98) * troubleshooting, typographical errors, global variables: Options. - (line 98) + (line 99) * true, logical: Truth Values. (line 6) -* Trueman, David <1>: Contributors. (line 30) -* Trueman, David <2>: Acknowledgments. (line 47) * Trueman, David: History. (line 30) +* Trueman, David <1>: Acknowledgments. (line 47) +* Trueman, David <2>: Contributors. (line 31) * trunc-mod operation: Arithmetic Ops. (line 66) * truth values: Truth Values. (line 6) * type conversion: Strings And Numbers. (line 21) -* u debugger command (alias for until): Debugger Execution Control. +* 'u' debugger command (alias for 'until'): Debugger Execution Control. (line 83) * unassigned array elements: Reference to Elements. (line 18) * undefined functions: Pass By Value/Reference. - (line 71) -* underscore (_), C macro: Explaining gettext. (line 71) -* underscore (_), in names of private variables: Library Names. + (line 70) +* underscore ('_'), C macro: Explaining gettext. (line 71) +* underscore ('_'), in names of private variables: Library Names. (line 29) -* underscore (_), translatable string: Programmer i18n. (line 69) -* undisplay debugger command: Viewing And Changing Data. - (line 80) +* underscore ('_'), translatable string: Programmer i18n. (line 69) +* 'undisplay' debugger command: Viewing And Changing Data. + (line 79) * undocumented features: Undocumented. (line 6) -* Unicode <1>: Glossary. (line 133) -* Unicode <2>: Ranges and Locales. (line 61) * Unicode: Ordinal Functions. (line 45) +* Unicode <1>: Ranges and Locales. (line 61) +* Unicode <2>: Glossary. (line 133) * uninitialized variables, as array subscripts: Uninitialized Subscripts. (line 6) -* uniq utility: Uniq Program. (line 6) -* uniq.awk program: Uniq Program. (line 65) -* Unix: Glossary. (line 611) -* Unix awk, backslashes in escape sequences: Escape Sequences. - (line 124) -* Unix awk, close() function and: Close Files And Pipes. +* 'uniq' utility: Uniq Program. (line 6) +* 'uniq.awk' program: Uniq Program. (line 65) +* Unix: Glossary. (line 607) +* Unix 'awk', backslashes in escape sequences: Escape Sequences. + (line 123) +* Unix 'awk', 'close()' function and: Close Files And Pipes. (line 131) -* Unix awk, password files, field separators and: Command Line Field Separator. +* Unix 'awk', password files, field separators and: Command Line Field Separator. (line 64) -* Unix, awk scripts and: Executable Scripts. (line 6) -* UNIXROOT variable, on OS/2 systems: PC Using. (line 16) +* Unix, 'awk' scripts and: Executable Scripts. (line 6) +* 'UNIXROOT' variable, on OS/2 systems: PC Using. (line 16) * unsigned integers: Computer Arithmetic. (line 41) -* until debugger command: Debugger Execution Control. +* 'until' debugger command: Debugger Execution Control. (line 83) -* unwatch debugger command: Viewing And Changing Data. - (line 84) -* up debugger command: Execution Stack. (line 34) +* 'unwatch' debugger command: Viewing And Changing Data. + (line 83) +* 'up' debugger command: Execution Stack. (line 33) * user database, reading: Passwd Functions. (line 6) * user-defined functions: User-defined. (line 6) * user-defined, functions, counts, in a profile: Profiling. (line 137) @@ -33876,677 +33891,654 @@ Index * user-modifiable variables: User-modified. (line 6) * users, information about, printing: Id Program. (line 6) * users, information about, retrieving: Passwd Functions. (line 16) -* USR1 signal, for dynamic profiling: Profiling. (line 188) +* 'USR1' signal, for dynamic profiling: Profiling. (line 187) * values, numeric: Basic Data Typing. (line 13) * values, string: Basic Data Typing. (line 13) * variable assignments and input files: Other Arguments. (line 19) * variable typing: Typing and Comparison. (line 9) -* variables <1>: Basic Data Typing. (line 6) * variables: Other Features. (line 6) +* variables <1>: Basic Data Typing. (line 6) * variables, assigning on command line: Assignment Options. (line 6) -* variables, built-in <1>: Built-in Variables. (line 6) * variables, built-in: Using Variables. (line 20) -* variables, built-in, -v option, setting with: Options. (line 40) +* variables, built-in <1>: Built-in Variables. (line 6) +* variables, built-in, '-v' option, setting with: Options. (line 41) * variables, built-in, conveying information: Auto-set. (line 6) * variables, flag: Boolean Ops. (line 67) -* variables, getline command into, using <1>: Getline/Variable/Coprocess. +* variables, 'getline' command into, using: Getline/Variable. (line 6) +* variables, 'getline' command into, using <1>: Getline/Variable/File. (line 6) -* variables, getline command into, using <2>: Getline/Variable/Pipe. +* variables, 'getline' command into, using <2>: Getline/Variable/Pipe. (line 6) -* variables, getline command into, using <3>: Getline/Variable/File. +* variables, 'getline' command into, using <3>: Getline/Variable/Coprocess. (line 6) -* variables, getline command into, using: Getline/Variable. (line 6) * variables, global, for library functions: Library Names. (line 11) -* variables, global, printing list of: Options. (line 93) +* variables, global, printing list of: Options. (line 94) * variables, initializing: Using Variables. (line 20) * variables, local to a function: Variable Scope. (line 6) * variables, names of: Arrays. (line 18) * variables, private: Library Names. (line 11) * variables, setting: Options. (line 32) * variables, shadowing: Definition Syntax. (line 67) -* variables, types of: Assignment Ops. (line 40) +* variables, types of: Assignment Ops. (line 39) * variables, types of, comparison expressions and: Typing and Comparison. (line 9) * variables, uninitialized, as array subscripts: Uninitialized Subscripts. (line 6) * variables, user-defined: Variables. (line 6) -* version of gawk: Auto-set. (line 207) -* version of gawk extension API: Auto-set. (line 232) +* version of 'gawk': Auto-set. (line 207) +* version of 'gawk' extension API: Auto-set. (line 232) * version of GNU MP library: Auto-set. (line 218) * version of GNU MPFR library: Auto-set. (line 214) -* vertical bar (|): Regexp Operators. (line 70) -* vertical bar (|), | operator (I/O) <1>: Precedence. (line 65) -* vertical bar (|), | operator (I/O): Getline/Pipe. (line 9) -* vertical bar (|), |& operator (I/O) <1>: Two-way I/O. (line 44) -* vertical bar (|), |& operator (I/O) <2>: Precedence. (line 65) -* vertical bar (|), |& operator (I/O): Getline/Coprocess. (line 6) -* vertical bar (|), || operator <1>: Precedence. (line 89) -* vertical bar (|), || operator: Boolean Ops. (line 57) +* vertical bar ('|'): Regexp Operators. (line 70) +* vertical bar ('|'), '|' operator (I/O): Getline/Pipe. (line 10) +* vertical bar ('|'), '|' operator (I/O) <1>: Precedence. (line 64) +* vertical bar ('|'), '|&' operator (I/O): Getline/Coprocess. (line 6) +* vertical bar ('|'), '|&' operator (I/O) <1>: Precedence. (line 64) +* vertical bar ('|'), '|&' operator (I/O) <2>: Two-way I/O. (line 44) +* vertical bar ('|'), '||' operator: Boolean Ops. (line 57) +* vertical bar ('|'), '||' operator <1>: Precedence. (line 88) * Vinschen, Corinna: Acknowledgments. (line 60) -* w debugger command (alias for watch): Viewing And Changing Data. - (line 67) -* w utility: Constant Size. (line 23) -* wait() extension function: Extension Sample Fork. +* 'w' debugger command (alias for 'watch'): Viewing And Changing Data. + (line 66) +* 'w' utility: Constant Size. (line 23) +* 'wait()' extension function: Extension Sample Fork. (line 22) -* waitpid() extension function: Extension Sample Fork. +* 'waitpid()' extension function: Extension Sample Fork. (line 18) -* walk_array() user-defined function: Walking Arrays. (line 14) -* Wall, Larry <1>: Future Extensions. (line 6) +* 'walk_array()' user-defined function: Walking Arrays. (line 14) * Wall, Larry: Array Intro. (line 6) -* Wallin, Anders: Contributors. (line 103) -* warnings, issuing: Options. (line 185) -* watch debugger command: Viewing And Changing Data. - (line 67) +* Wall, Larry <1>: Future Extensions. (line 6) +* Wallin, Anders: Contributors. (line 104) +* warnings, issuing: Options. (line 184) +* 'watch' debugger command: Viewing And Changing Data. + (line 66) * watchpoint: Debugging Terms. (line 42) -* wc utility: Wc Program. (line 6) -* wc.awk program: Wc Program. (line 46) -* Weinberger, Peter <1>: Contributors. (line 11) +* 'wc' utility: Wc Program. (line 6) +* 'wc.awk' program: Wc Program. (line 46) * Weinberger, Peter: History. (line 17) -* while statement: While Statement. (line 6) -* while statement, use of regexps in: Regexp Usage. (line 19) +* Weinberger, Peter <1>: Contributors. (line 12) +* 'while' statement: While Statement. (line 6) +* 'while' statement, use of regexps in: Regexp Usage. (line 19) * whitespace, as field separators: Default Field Splitting. (line 6) * whitespace, functions, calling: Calling Built-in. (line 10) -* whitespace, newlines as: Options. (line 258) -* Williams, Kent: Contributors. (line 34) -* Woehlke, Matthew: Contributors. (line 79) -* Woods, John: Contributors. (line 27) +* whitespace, newlines as: Options. (line 256) +* Williams, Kent: Contributors. (line 35) +* Woehlke, Matthew: Contributors. (line 80) +* Woods, John: Contributors. (line 28) * word boundaries, matching: GNU Regexp Operators. - (line 38) + (line 41) * word, regexp definition of: GNU Regexp Operators. (line 6) -* word-boundary operator (gawk): GNU Regexp Operators. - (line 63) -* wordfreq.awk program: Word Sorting. (line 56) +* word-boundary operator ('gawk'): GNU Regexp Operators. + (line 66) +* 'wordfreq.awk' program: Word Sorting. (line 56) * words, counting: Wc Program. (line 6) * words, duplicate, searching for: Dupword Program. (line 6) * words, usage counts, generating: Word Sorting. (line 6) -* writea() extension function: Extension Sample Read write array. +* 'writea()' extension function: Extension Sample Read write array. (line 9) -* xgettext utility: String Extraction. (line 13) -* xor: Bitwise Functions. (line 55) +* 'xgettext' utility: String Extraction. (line 13) +* 'xor': Bitwise Functions. (line 56) * XOR bitwise operation: Bitwise Functions. (line 6) -* Yawitz, Efraim: Contributors. (line 131) -* Zaretskii, Eli <1>: Bugs. (line 71) -* Zaretskii, Eli <2>: Contributors. (line 55) +* Yawitz, Efraim: Contributors. (line 132) * Zaretskii, Eli: Acknowledgments. (line 60) -* zerofile.awk program: Empty Files. (line 21) -* Zoulas, Christos: Contributors. (line 66) -* {} (braces): Profiling. (line 142) -* {} (braces), actions and: Action Overview. (line 19) -* {} (braces), statements, grouping: Statements. (line 10) -* | (vertical bar): Regexp Operators. (line 70) -* | (vertical bar), | operator (I/O) <1>: Precedence. (line 65) -* | (vertical bar), | operator (I/O) <2>: Redirection. (line 57) -* | (vertical bar), | operator (I/O): Getline/Pipe. (line 9) -* | (vertical bar), |& operator (I/O) <1>: Two-way I/O. (line 44) -* | (vertical bar), |& operator (I/O) <2>: Precedence. (line 65) -* | (vertical bar), |& operator (I/O) <3>: Redirection. (line 102) -* | (vertical bar), |& operator (I/O): Getline/Coprocess. (line 6) -* | (vertical bar), |& operator (I/O), pipes, closing: Close Files And Pipes. - (line 119) -* | (vertical bar), || operator <1>: Precedence. (line 89) -* | (vertical bar), || operator: Boolean Ops. (line 57) -* ~ (tilde), ~ operator <1>: Expression Patterns. (line 24) -* ~ (tilde), ~ operator <2>: Precedence. (line 80) -* ~ (tilde), ~ operator <3>: Comparison Operators. - (line 11) -* ~ (tilde), ~ operator <4>: Regexp Constants. (line 6) -* ~ (tilde), ~ operator <5>: Computed Regexps. (line 6) -* ~ (tilde), ~ operator <6>: Case-sensitivity. (line 26) -* ~ (tilde), ~ operator: Regexp Usage. (line 19) +* Zaretskii, Eli <1>: Contributors. (line 56) +* Zaretskii, Eli <2>: Bugs. (line 71) +* 'zerofile.awk' program: Empty Files. (line 20) +* Zoulas, Christos: Contributors. (line 67)  Tag Table: -Node: Top1204 -Node: Foreword41858 -Node: Preface46203 -Ref: Preface-Footnote-149350 -Ref: Preface-Footnote-249457 -Node: History49689 -Node: Names52063 -Ref: Names-Footnote-153527 -Node: This Manual53600 -Ref: This Manual-Footnote-159379 -Node: Conventions59479 -Node: Manual History61635 -Ref: Manual History-Footnote-165074 -Ref: Manual History-Footnote-265115 -Node: How To Contribute65189 -Node: Acknowledgments66428 -Node: Getting Started70724 -Node: Running gawk73158 -Node: One-shot74348 -Node: Read Terminal75573 -Ref: Read Terminal-Footnote-177223 -Ref: Read Terminal-Footnote-277499 -Node: Long77670 -Node: Executable Scripts79046 -Ref: Executable Scripts-Footnote-180879 -Ref: Executable Scripts-Footnote-280981 -Node: Comments81528 -Node: Quoting84001 -Node: DOS Quoting89317 -Node: Sample Data Files89992 -Node: Very Simple92507 -Node: Two Rules97145 -Node: More Complex99039 -Ref: More Complex-Footnote-1101971 -Node: Statements/Lines102056 -Ref: Statements/Lines-Footnote-1106512 -Node: Other Features106777 -Node: When107705 -Node: Intro Summary109875 -Node: Invoking Gawk110641 -Node: Command Line112156 -Node: Options112947 -Ref: Options-Footnote-1128647 -Node: Other Arguments128672 -Node: Naming Standard Input131334 -Node: Environment Variables132428 -Node: AWKPATH Variable132986 -Ref: AWKPATH Variable-Footnote-1135858 -Ref: AWKPATH Variable-Footnote-2135903 -Node: AWKLIBPATH Variable136163 -Node: Other Environment Variables136922 -Node: Exit Status140372 -Node: Include Files141047 -Node: Loading Shared Libraries144625 -Node: Obsolete146009 -Node: Undocumented146706 -Node: Invoking Summary146973 -Node: Regexp148553 -Node: Regexp Usage150003 -Node: Escape Sequences152036 -Node: Regexp Operators157703 -Ref: Regexp Operators-Footnote-1165183 -Ref: Regexp Operators-Footnote-2165330 -Node: Bracket Expressions165428 -Ref: table-char-classes167318 -Node: GNU Regexp Operators170258 -Node: Case-sensitivity173981 -Ref: Case-sensitivity-Footnote-1176873 -Ref: Case-sensitivity-Footnote-2177108 -Node: Leftmost Longest177216 -Node: Computed Regexps178417 -Node: Regexp Summary181789 -Node: Reading Files183260 -Node: Records185352 -Node: awk split records186095 -Node: gawk split records190953 -Ref: gawk split records-Footnote-1195474 -Node: Fields195511 -Ref: Fields-Footnote-1198475 -Node: Nonconstant Fields198561 -Ref: Nonconstant Fields-Footnote-1200791 -Node: Changing Fields200993 -Node: Field Separators206947 -Node: Default Field Splitting209649 -Node: Regexp Field Splitting210766 -Node: Single Character Fields214107 -Node: Command Line Field Separator215166 -Node: Full Line Fields218508 -Ref: Full Line Fields-Footnote-1219016 -Node: Field Splitting Summary219062 -Ref: Field Splitting Summary-Footnote-1222161 -Node: Constant Size222262 -Node: Splitting By Content226869 -Ref: Splitting By Content-Footnote-1230619 -Node: Multiple Line230659 -Ref: Multiple Line-Footnote-1236515 -Node: Getline236694 -Node: Plain Getline238910 -Node: Getline/Variable241005 -Node: Getline/File242152 -Node: Getline/Variable/File243536 -Ref: Getline/Variable/File-Footnote-1245135 -Node: Getline/Pipe245222 -Node: Getline/Variable/Pipe247921 -Node: Getline/Coprocess249028 -Node: Getline/Variable/Coprocess250280 -Node: Getline Notes251017 -Node: Getline Summary253821 -Ref: table-getline-variants254229 -Node: Read Timeout255141 -Ref: Read Timeout-Footnote-1258968 -Node: Command line directories259026 -Node: Input Summary259930 -Node: Input Exercises263067 -Node: Printing263800 -Node: Print265522 -Node: Print Examples266863 -Node: Output Separators269642 -Node: OFMT271658 -Node: Printf273016 -Node: Basic Printf273922 -Node: Control Letters275461 -Node: Format Modifiers279452 -Node: Printf Examples285479 -Node: Redirection287943 -Node: Special Files294915 -Node: Special FD295446 -Ref: Special FD-Footnote-1299070 -Node: Special Network299144 -Node: Special Caveats299994 -Node: Close Files And Pipes300790 -Ref: Close Files And Pipes-Footnote-1307951 -Ref: Close Files And Pipes-Footnote-2308099 -Node: Output Summary308249 -Node: Output exercises309246 -Node: Expressions309926 -Node: Values311111 -Node: Constants311787 -Node: Scalar Constants312467 -Ref: Scalar Constants-Footnote-1313326 -Node: Nondecimal-numbers313576 -Node: Regexp Constants316576 -Node: Using Constant Regexps317051 -Node: Variables320121 -Node: Using Variables320776 -Node: Assignment Options322500 -Node: Conversion324375 -Node: Strings And Numbers324899 -Ref: Strings And Numbers-Footnote-1327961 -Node: Locale influences conversions328070 -Ref: table-locale-affects330787 -Node: All Operators331375 -Node: Arithmetic Ops332005 -Node: Concatenation334510 -Ref: Concatenation-Footnote-1337306 -Node: Assignment Ops337426 -Ref: table-assign-ops342409 -Node: Increment Ops343726 -Node: Truth Values and Conditions347164 -Node: Truth Values348247 -Node: Typing and Comparison349296 -Node: Variable Typing350089 -Ref: Variable Typing-Footnote-1353989 -Node: Comparison Operators354111 -Ref: table-relational-ops354521 -Node: POSIX String Comparison358071 -Ref: POSIX String Comparison-Footnote-1359155 -Node: Boolean Ops359293 -Ref: Boolean Ops-Footnote-1363363 -Node: Conditional Exp363454 -Node: Function Calls365181 -Node: Precedence369061 -Node: Locales372730 -Node: Expressions Summary374361 -Node: Patterns and Actions376902 -Node: Pattern Overview378018 -Node: Regexp Patterns379695 -Node: Expression Patterns380238 -Node: Ranges384019 -Node: BEGIN/END387125 -Node: Using BEGIN/END387887 -Ref: Using BEGIN/END-Footnote-1390623 -Node: I/O And BEGIN/END390729 -Node: BEGINFILE/ENDFILE393014 -Node: Empty395945 -Node: Using Shell Variables396262 -Node: Action Overview398545 -Node: Statements400872 -Node: If Statement402720 -Node: While Statement404218 -Node: Do Statement406262 -Node: For Statement407418 -Node: Switch Statement410570 -Node: Break Statement412673 -Node: Continue Statement414728 -Node: Next Statement416521 -Node: Nextfile Statement418911 -Node: Exit Statement421566 -Node: Built-in Variables423970 -Node: User-modified425097 -Ref: User-modified-Footnote-1432786 -Node: Auto-set432848 -Ref: Auto-set-Footnote-1445767 -Ref: Auto-set-Footnote-2445972 -Node: ARGC and ARGV446028 -Node: Pattern Action Summary449882 -Node: Arrays452105 -Node: Array Basics453654 -Node: Array Intro454480 -Ref: figure-array-elements456453 -Node: Reference to Elements458860 -Node: Assigning Elements461133 -Node: Array Example461624 -Node: Scanning an Array463356 -Node: Controlling Scanning466371 -Ref: Controlling Scanning-Footnote-1471544 -Node: Delete471860 -Ref: Delete-Footnote-1474625 -Node: Numeric Array Subscripts474682 -Node: Uninitialized Subscripts476865 -Node: Multidimensional478490 -Node: Multiscanning481583 -Node: Arrays of Arrays483172 -Node: Arrays Summary487835 -Node: Functions489940 -Node: Built-in490813 -Node: Calling Built-in491891 -Node: Numeric Functions493879 -Ref: Numeric Functions-Footnote-1498515 -Ref: Numeric Functions-Footnote-2498872 -Ref: Numeric Functions-Footnote-3498920 -Node: String Functions499189 -Ref: String Functions-Footnote-1522200 -Ref: String Functions-Footnote-2522329 -Ref: String Functions-Footnote-3522577 -Node: Gory Details522664 -Ref: table-sub-escapes524333 -Ref: table-sub-posix-92525687 -Ref: table-sub-proposed527038 -Ref: table-posix-sub528392 -Ref: table-gensub-escapes529937 -Ref: Gory Details-Footnote-1531113 -Ref: Gory Details-Footnote-2531164 -Node: I/O Functions531315 -Ref: I/O Functions-Footnote-1538438 -Node: Time Functions538585 -Ref: Time Functions-Footnote-1549049 -Ref: Time Functions-Footnote-2549117 -Ref: Time Functions-Footnote-3549275 -Ref: Time Functions-Footnote-4549386 -Ref: Time Functions-Footnote-5549498 -Ref: Time Functions-Footnote-6549725 -Node: Bitwise Functions549991 -Ref: table-bitwise-ops550553 -Ref: Bitwise Functions-Footnote-1554798 -Node: Type Functions554982 -Node: I18N Functions556124 -Node: User-defined557769 -Node: Definition Syntax558573 -Ref: Definition Syntax-Footnote-1563752 -Node: Function Example563821 -Ref: Function Example-Footnote-1566465 -Node: Function Caveats566487 -Node: Calling A Function567005 -Node: Variable Scope567960 -Node: Pass By Value/Reference570948 -Node: Return Statement574456 -Node: Dynamic Typing577440 -Node: Indirect Calls578369 -Node: Functions Summary588082 -Node: Library Functions590621 -Ref: Library Functions-Footnote-1594239 -Ref: Library Functions-Footnote-2594382 -Node: Library Names594553 -Ref: Library Names-Footnote-1598026 -Ref: Library Names-Footnote-2598246 -Node: General Functions598332 -Node: Strtonum Function599360 -Node: Assert Function602140 -Node: Round Function605466 -Node: Cliff Random Function607007 -Node: Ordinal Functions608023 -Ref: Ordinal Functions-Footnote-1611100 -Ref: Ordinal Functions-Footnote-2611352 -Node: Join Function611563 -Ref: Join Function-Footnote-1613334 -Node: Getlocaltime Function613534 -Node: Readfile Function617270 -Node: Data File Management619109 -Node: Filetrans Function619741 -Node: Rewind Function623810 -Node: File Checking625368 -Ref: File Checking-Footnote-1626500 -Node: Empty Files626701 -Node: Ignoring Assigns628680 -Node: Getopt Function630234 -Ref: Getopt Function-Footnote-1641537 -Node: Passwd Functions641740 -Ref: Passwd Functions-Footnote-1650719 -Node: Group Functions650807 -Ref: Group Functions-Footnote-1658748 -Node: Walking Arrays658961 -Node: Library Functions Summary660564 -Node: Library exercises661952 -Node: Sample Programs663232 -Node: Running Examples664002 -Node: Clones664730 -Node: Cut Program665954 -Node: Egrep Program675822 -Ref: Egrep Program-Footnote-1683793 -Node: Id Program683903 -Node: Split Program687567 -Ref: Split Program-Footnote-1691105 -Node: Tee Program691233 -Node: Uniq Program694040 -Node: Wc Program701470 -Ref: Wc Program-Footnote-1705735 -Node: Miscellaneous Programs705827 -Node: Dupword Program707040 -Node: Alarm Program709071 -Node: Translate Program713885 -Ref: Translate Program-Footnote-1718276 -Ref: Translate Program-Footnote-2718546 -Node: Labels Program718680 -Ref: Labels Program-Footnote-1722051 -Node: Word Sorting722135 -Node: History Sorting726178 -Node: Extract Program728014 -Node: Simple Sed735550 -Node: Igawk Program738612 -Ref: Igawk Program-Footnote-1752923 -Ref: Igawk Program-Footnote-2753124 -Node: Anagram Program753262 -Node: Signature Program756330 -Node: Programs Summary757577 -Node: Programs Exercises758792 -Node: Advanced Features762443 -Node: Nondecimal Data764391 -Node: Array Sorting765968 -Node: Controlling Array Traversal766665 -Node: Array Sorting Functions774945 -Ref: Array Sorting Functions-Footnote-1778852 -Node: Two-way I/O779046 -Ref: Two-way I/O-Footnote-1784562 -Node: TCP/IP Networking784644 -Node: Profiling787488 -Node: Advanced Features Summary795039 -Node: Internationalization796903 -Node: I18N and L10N798383 -Node: Explaining gettext799069 -Ref: Explaining gettext-Footnote-1804209 -Ref: Explaining gettext-Footnote-2804393 -Node: Programmer i18n804558 -Node: Translator i18n808783 -Node: String Extraction809577 -Ref: String Extraction-Footnote-1810538 -Node: Printf Ordering810624 -Ref: Printf Ordering-Footnote-1813406 -Node: I18N Portability813470 -Ref: I18N Portability-Footnote-1815919 -Node: I18N Example815982 -Ref: I18N Example-Footnote-1818704 -Node: Gawk I18N818776 -Node: I18N Summary819414 -Node: Debugger820753 -Node: Debugging821775 -Node: Debugging Concepts822216 -Node: Debugging Terms824072 -Node: Awk Debugging826669 -Node: Sample Debugging Session827561 -Node: Debugger Invocation828081 -Node: Finding The Bug829414 -Node: List of Debugger Commands835896 -Node: Breakpoint Control837228 -Node: Debugger Execution Control840892 -Node: Viewing And Changing Data844252 -Node: Execution Stack847610 -Node: Debugger Info849123 -Node: Miscellaneous Debugger Commands853117 -Node: Readline Support858301 -Node: Limitations859193 -Node: Debugging Summary861467 -Node: Arbitrary Precision Arithmetic862631 -Node: Computer Arithmetic863960 -Ref: Computer Arithmetic-Footnote-1868347 -Node: Math Definitions868404 -Ref: table-ieee-formats871288 -Node: MPFR features871792 -Node: FP Math Caution873434 -Ref: FP Math Caution-Footnote-1874475 -Node: Inexactness of computations874844 -Node: Inexact representation875792 -Node: Comparing FP Values877147 -Node: Errors accumulate878111 -Node: Getting Accuracy879544 -Node: Try To Round882203 -Node: Setting precision883102 -Ref: table-predefined-precision-strings883784 -Node: Setting the rounding mode885577 -Ref: table-gawk-rounding-modes885941 -Ref: Setting the rounding mode-Footnote-1889395 -Node: Arbitrary Precision Integers889574 -Ref: Arbitrary Precision Integers-Footnote-1893369 -Node: POSIX Floating Point Problems893518 -Ref: POSIX Floating Point Problems-Footnote-1897394 -Node: Floating point summary897432 -Node: Dynamic Extensions899649 -Node: Extension Intro901201 -Node: Plugin License902466 -Node: Extension Mechanism Outline903151 -Ref: figure-load-extension903575 -Ref: figure-load-new-function905060 -Ref: figure-call-new-function906062 -Node: Extension API Description908046 -Node: Extension API Functions Introduction909496 -Node: General Data Types914361 -Ref: General Data Types-Footnote-1920054 -Node: Requesting Values920353 -Ref: table-value-types-returned921090 -Node: Memory Allocation Functions922048 -Ref: Memory Allocation Functions-Footnote-1924795 -Node: Constructor Functions924891 -Node: Registration Functions926649 -Node: Extension Functions927334 -Node: Exit Callback Functions929636 -Node: Extension Version String930885 -Node: Input Parsers931535 -Node: Output Wrappers941349 -Node: Two-way processors945865 -Node: Printing Messages948069 -Ref: Printing Messages-Footnote-1949146 -Node: Updating `ERRNO'949298 -Node: Accessing Parameters950037 -Node: Symbol Table Access951267 -Node: Symbol table by name951781 -Node: Symbol table by cookie953757 -Ref: Symbol table by cookie-Footnote-1957890 -Node: Cached values957953 -Ref: Cached values-Footnote-1961457 -Node: Array Manipulation961548 -Ref: Array Manipulation-Footnote-1962646 -Node: Array Data Types962685 -Ref: Array Data Types-Footnote-1965388 -Node: Array Functions965480 -Node: Flattening Arrays969354 -Node: Creating Arrays976206 -Node: Extension API Variables980937 -Node: Extension Versioning981573 -Node: Extension API Informational Variables983474 -Node: Extension API Boilerplate984560 -Node: Finding Extensions988364 -Node: Extension Example988924 -Node: Internal File Description989654 -Node: Internal File Ops993745 -Ref: Internal File Ops-Footnote-11005177 -Node: Using Internal File Ops1005317 -Ref: Using Internal File Ops-Footnote-11007664 -Node: Extension Samples1007932 -Node: Extension Sample File Functions1009456 -Node: Extension Sample Fnmatch1017024 -Node: Extension Sample Fork1018506 -Node: Extension Sample Inplace1019719 -Node: Extension Sample Ord1021394 -Node: Extension Sample Readdir1022230 -Ref: table-readdir-file-types1023086 -Node: Extension Sample Revout1023885 -Node: Extension Sample Rev2way1024476 -Node: Extension Sample Read write array1025217 -Node: Extension Sample Readfile1027096 -Node: Extension Sample API Tests1028196 -Node: Extension Sample Time1028721 -Node: gawkextlib1030036 -Node: Extension summary1032849 -Node: Extension Exercises1036542 -Node: Language History1037264 -Node: V7/SVR3.11038907 -Node: SVR41041227 -Node: POSIX1042669 -Node: BTL1044055 -Node: POSIX/GNU1044789 -Node: Feature History1050532 -Node: Common Extensions1063662 -Node: Ranges and Locales1064974 -Ref: Ranges and Locales-Footnote-11069591 -Ref: Ranges and Locales-Footnote-21069618 -Ref: Ranges and Locales-Footnote-31069852 -Node: Contributors1070073 -Node: History summary1075498 -Node: Installation1076867 -Node: Gawk Distribution1077818 -Node: Getting1078302 -Node: Extracting1079126 -Node: Distribution contents1080768 -Node: Unix Installation1086538 -Node: Quick Installation1087155 -Node: Additional Configuration Options1089597 -Node: Configuration Philosophy1091335 -Node: Non-Unix Installation1093686 -Node: PC Installation1094144 -Node: PC Binary Installation1095455 -Node: PC Compiling1097303 -Ref: PC Compiling-Footnote-11100302 -Node: PC Testing1100407 -Node: PC Using1101583 -Node: Cygwin1105741 -Node: MSYS1106550 -Node: VMS Installation1107064 -Node: VMS Compilation1107860 -Ref: VMS Compilation-Footnote-11109082 -Node: VMS Dynamic Extensions1109140 -Node: VMS Installation Details1110513 -Node: VMS Running1112765 -Node: VMS GNV1115599 -Node: VMS Old Gawk1116322 -Node: Bugs1116792 -Node: Other Versions1120796 -Node: Installation summary1127051 -Node: Notes1128107 -Node: Compatibility Mode1128972 -Node: Additions1129754 -Node: Accessing The Source1130679 -Node: Adding Code1132115 -Node: New Ports1138293 -Node: Derived Files1142774 -Ref: Derived Files-Footnote-11147855 -Ref: Derived Files-Footnote-21147889 -Ref: Derived Files-Footnote-31148485 -Node: Future Extensions1148599 -Node: Implementation Limitations1149205 -Node: Extension Design1150453 -Node: Old Extension Problems1151607 -Ref: Old Extension Problems-Footnote-11153124 -Node: Extension New Mechanism Goals1153181 -Ref: Extension New Mechanism Goals-Footnote-11156541 -Node: Extension Other Design Decisions1156730 -Node: Extension Future Growth1158836 -Node: Old Extension Mechanism1159672 -Node: Notes summary1161434 -Node: Basic Concepts1162620 -Node: Basic High Level1163301 -Ref: figure-general-flow1163573 -Ref: figure-process-flow1164172 -Ref: Basic High Level-Footnote-11167401 -Node: Basic Data Typing1167586 -Node: Glossary1170914 -Node: Copying1196066 -Node: GNU Free Documentation License1233622 -Node: Index1258758 +Node: Top1200 +Node: Foreword41842 +Node: Preface46186 +Ref: Preface-Footnote-149331 +Ref: Preface-Footnote-249438 +Node: History49671 +Node: Names52046 +Ref: Names-Footnote-153512 +Node: This Manual53585 +Ref: This Manual-Footnote-159367 +Node: Conventions59467 +Node: Manual History61640 +Ref: Manual History-Footnote-165081 +Ref: Manual History-Footnote-265122 +Node: How To Contribute65196 +Node: Acknowledgments66435 +Node: Getting Started70730 +Node: Running gawk73164 +Node: One-shot74354 +Node: Read Terminal75578 +Ref: Read Terminal-Footnote-177228 +Ref: Read Terminal-Footnote-277504 +Node: Long77675 +Node: Executable Scripts79051 +Ref: Executable Scripts-Footnote-180886 +Ref: Executable Scripts-Footnote-280988 +Node: Comments81537 +Node: Quoting84011 +Node: DOS Quoting89327 +Node: Sample Data Files90002 +Node: Very Simple92517 +Node: Two Rules97156 +Node: More Complex99050 +Ref: More Complex-Footnote-1101985 +Node: Statements/Lines102070 +Ref: Statements/Lines-Footnote-1106530 +Node: Other Features106795 +Node: When107724 +Node: Intro Summary109894 +Node: Invoking Gawk110660 +Node: Command Line112175 +Node: Options112966 +Ref: Options-Footnote-1128650 +Node: Other Arguments128675 +Node: Naming Standard Input131335 +Node: Environment Variables132429 +Node: AWKPATH Variable132987 +Ref: AWKPATH Variable-Footnote-1135859 +Ref: AWKPATH Variable-Footnote-2135904 +Node: AWKLIBPATH Variable136165 +Node: Other Environment Variables136924 +Node: Exit Status140380 +Node: Include Files141055 +Node: Loading Shared Libraries144639 +Node: Obsolete146024 +Node: Undocumented146721 +Node: Invoking Summary147017 +Node: Regexp148593 +Node: Regexp Usage150043 +Node: Escape Sequences152076 +Node: Regexp Operators157742 +Ref: Regexp Operators-Footnote-1165228 +Ref: Regexp Operators-Footnote-2165375 +Node: Bracket Expressions165473 +Ref: table-char-classes167371 +Node: GNU Regexp Operators170315 +Node: Case-sensitivity174045 +Ref: Case-sensitivity-Footnote-1176939 +Ref: Case-sensitivity-Footnote-2177174 +Node: Leftmost Longest177282 +Node: Computed Regexps178484 +Node: Regexp Summary181854 +Node: Reading Files183324 +Node: Records185417 +Node: awk split records186160 +Node: gawk split records191021 +Ref: gawk split records-Footnote-1195546 +Node: Fields195583 +Ref: Fields-Footnote-1198548 +Node: Nonconstant Fields198634 +Ref: Nonconstant Fields-Footnote-1200863 +Node: Changing Fields201066 +Node: Field Separators207019 +Node: Default Field Splitting209716 +Node: Regexp Field Splitting210834 +Node: Single Character Fields214176 +Node: Command Line Field Separator215236 +Node: Full Line Fields218579 +Ref: Full Line Fields-Footnote-1219087 +Node: Field Splitting Summary219133 +Ref: Field Splitting Summary-Footnote-1222231 +Node: Constant Size222332 +Node: Splitting By Content226939 +Ref: Splitting By Content-Footnote-1230696 +Node: Multiple Line230736 +Ref: Multiple Line-Footnote-1236594 +Node: Getline236773 +Node: Plain Getline238987 +Node: Getline/Variable241081 +Node: Getline/File242228 +Node: Getline/Variable/File243613 +Ref: Getline/Variable/File-Footnote-1245213 +Node: Getline/Pipe245301 +Node: Getline/Variable/Pipe248026 +Node: Getline/Coprocess249134 +Node: Getline/Variable/Coprocess250387 +Node: Getline Notes251125 +Node: Getline Summary253930 +Ref: table-getline-variants254348 +Node: Read Timeout255179 +Ref: Read Timeout-Footnote-1259010 +Node: Command line directories259068 +Node: Input Summary259972 +Node: Input Exercises262928 +Node: Printing263660 +Node: Print265382 +Node: Print Examples266723 +Node: Output Separators269503 +Node: OFMT271519 +Node: Printf272878 +Node: Basic Printf273784 +Node: Control Letters275324 +Node: Format Modifiers279318 +Node: Printf Examples285354 +Node: Redirection287818 +Node: Special Files294794 +Node: Special FD295325 +Ref: Special FD-Footnote-1298951 +Node: Special Network299025 +Node: Special Caveats299873 +Node: Close Files And Pipes300669 +Ref: Close Files And Pipes-Footnote-1307832 +Ref: Close Files And Pipes-Footnote-2307980 +Node: Output Summary308131 +Node: Output exercises309128 +Node: Expressions309807 +Node: Values310991 +Node: Constants311668 +Node: Scalar Constants312348 +Ref: Scalar Constants-Footnote-1313209 +Node: Nondecimal-numbers313459 +Node: Regexp Constants316462 +Node: Using Constant Regexps316937 +Node: Variables320007 +Node: Using Variables320662 +Node: Assignment Options322387 +Node: Conversion324261 +Node: Strings And Numbers324785 +Ref: Strings And Numbers-Footnote-1327845 +Node: Locale influences conversions327954 +Ref: table-locale-affects330683 +Node: All Operators331297 +Node: Arithmetic Ops331927 +Node: Concatenation334433 +Ref: Concatenation-Footnote-1337256 +Node: Assignment Ops337376 +Ref: table-assign-ops342372 +Node: Increment Ops343685 +Node: Truth Values and Conditions347150 +Node: Truth Values348224 +Node: Typing and Comparison349272 +Node: Variable Typing350077 +Ref: Variable Typing-Footnote-1353933 +Node: Comparison Operators354055 +Ref: table-relational-ops354474 +Node: POSIX String Comparison358043 +Ref: POSIX String Comparison-Footnote-1359128 +Node: Boolean Ops359266 +Ref: Boolean Ops-Footnote-1363340 +Node: Conditional Exp363432 +Node: Function Calls365157 +Node: Precedence369037 +Node: Locales372705 +Node: Expressions Summary374336 +Node: Patterns and Actions376879 +Node: Pattern Overview377995 +Node: Regexp Patterns379670 +Node: Expression Patterns380212 +Node: Ranges383994 +Node: BEGIN/END387101 +Node: Using BEGIN/END387863 +Ref: Using BEGIN/END-Footnote-1390600 +Node: I/O And BEGIN/END390706 +Node: BEGINFILE/ENDFILE392992 +Node: Empty395924 +Node: Using Shell Variables396241 +Node: Action Overview398525 +Node: Statements400851 +Node: If Statement402699 +Node: While Statement404197 +Node: Do Statement406241 +Node: For Statement407397 +Node: Switch Statement410550 +Node: Break Statement412657 +Node: Continue Statement414711 +Node: Next Statement416504 +Node: Nextfile Statement418896 +Node: Exit Statement421554 +Node: Built-in Variables423952 +Node: User-modified425079 +Ref: User-modified-Footnote-1432758 +Node: Auto-set432820 +Ref: Auto-set-Footnote-1445763 +Ref: Auto-set-Footnote-2445969 +Node: ARGC and ARGV446025 +Node: Pattern Action Summary449880 +Node: Arrays452106 +Node: Array Basics453655 +Node: Array Intro454481 +Ref: figure-array-elements456492 +Node: Reference to Elements458977 +Node: Assigning Elements461250 +Node: Array Example461741 +Node: Scanning an Array463473 +Node: Controlling Scanning466489 +Ref: Controlling Scanning-Footnote-1471667 +Node: Delete471983 +Ref: Delete-Footnote-1474752 +Node: Numeric Array Subscripts474809 +Node: Uninitialized Subscripts476991 +Node: Multidimensional478618 +Node: Multiscanning481709 +Node: Arrays of Arrays483300 +Node: Arrays Summary487977 +Node: Functions490083 +Node: Built-in490955 +Node: Calling Built-in492033 +Node: Numeric Functions494021 +Ref: Numeric Functions-Footnote-1498657 +Ref: Numeric Functions-Footnote-2499014 +Ref: Numeric Functions-Footnote-3499062 +Node: String Functions499331 +Ref: String Functions-Footnote-1522348 +Ref: String Functions-Footnote-2522477 +Ref: String Functions-Footnote-3522725 +Node: Gory Details522812 +Ref: table-sub-escapes524490 +Ref: table-sub-posix-92525846 +Ref: table-sub-proposed527201 +Ref: table-posix-sub528556 +Ref: table-gensub-escapes530105 +Ref: Gory Details-Footnote-1531270 +Ref: Gory Details-Footnote-2531321 +Node: I/O Functions531472 +Ref: I/O Functions-Footnote-1538590 +Node: Time Functions538738 +Ref: Time Functions-Footnote-1549199 +Ref: Time Functions-Footnote-2549267 +Ref: Time Functions-Footnote-3549425 +Ref: Time Functions-Footnote-4549536 +Ref: Time Functions-Footnote-5549648 +Ref: Time Functions-Footnote-6549875 +Node: Bitwise Functions550141 +Ref: table-bitwise-ops550734 +Ref: Bitwise Functions-Footnote-1554966 +Node: Type Functions555152 +Node: I18N Functions556298 +Node: User-defined557946 +Node: Definition Syntax558750 +Ref: Definition Syntax-Footnote-1563931 +Node: Function Example564000 +Ref: Function Example-Footnote-1566644 +Node: Function Caveats566666 +Node: Calling A Function567184 +Node: Variable Scope568139 +Node: Pass By Value/Reference571127 +Node: Return Statement574636 +Node: Dynamic Typing577620 +Node: Indirect Calls578550 +Node: Functions Summary588271 +Node: Library Functions590809 +Ref: Library Functions-Footnote-1594428 +Ref: Library Functions-Footnote-2594571 +Node: Library Names594742 +Ref: Library Names-Footnote-1598218 +Ref: Library Names-Footnote-2598438 +Node: General Functions598524 +Node: Strtonum Function599552 +Node: Assert Function602333 +Node: Round Function605661 +Node: Cliff Random Function607202 +Node: Ordinal Functions608218 +Ref: Ordinal Functions-Footnote-1611295 +Ref: Ordinal Functions-Footnote-2611547 +Node: Join Function611757 +Ref: Join Function-Footnote-1613528 +Node: Getlocaltime Function613728 +Node: Readfile Function617464 +Node: Data File Management619305 +Node: Filetrans Function619937 +Node: Rewind Function624006 +Node: File Checking625564 +Ref: File Checking-Footnote-1626697 +Node: Empty Files626898 +Node: Ignoring Assigns628877 +Node: Getopt Function630431 +Ref: Getopt Function-Footnote-1641740 +Node: Passwd Functions641943 +Ref: Passwd Functions-Footnote-1650923 +Node: Group Functions651011 +Ref: Group Functions-Footnote-1658954 +Node: Walking Arrays659169 +Node: Library Functions Summary660774 +Node: Library exercises662166 +Node: Sample Programs663445 +Node: Running Examples664215 +Node: Clones664943 +Node: Cut Program666167 +Node: Egrep Program676036 +Ref: Egrep Program-Footnote-1684017 +Node: Id Program684127 +Node: Split Program687794 +Ref: Split Program-Footnote-1691337 +Node: Tee Program691466 +Node: Uniq Program694274 +Node: Wc Program701711 +Ref: Wc Program-Footnote-1705981 +Node: Miscellaneous Programs706073 +Node: Dupword Program707286 +Node: Alarm Program709316 +Node: Translate Program714179 +Ref: Translate Program-Footnote-1718572 +Ref: Translate Program-Footnote-2718842 +Node: Labels Program718976 +Ref: Labels Program-Footnote-1722347 +Node: Word Sorting722431 +Node: History Sorting726476 +Node: Extract Program728312 +Node: Simple Sed735855 +Node: Igawk Program738921 +Ref: Igawk Program-Footnote-1753237 +Ref: Igawk Program-Footnote-2753439 +Node: Anagram Program753577 +Node: Signature Program756646 +Node: Programs Summary757893 +Node: Programs Exercises759107 +Node: Advanced Features762755 +Node: Nondecimal Data764710 +Node: Array Sorting766288 +Node: Controlling Array Traversal766985 +Node: Array Sorting Functions775267 +Ref: Array Sorting Functions-Footnote-1779176 +Node: Two-way I/O779370 +Ref: Two-way I/O-Footnote-1784888 +Node: TCP/IP Networking784970 +Node: Profiling787828 +Node: Advanced Features Summary795378 +Node: Internationalization797245 +Node: I18N and L10N798725 +Node: Explaining gettext799412 +Ref: Explaining gettext-Footnote-1804550 +Ref: Explaining gettext-Footnote-2804735 +Node: Programmer i18n804900 +Node: Translator i18n809104 +Node: String Extraction809898 +Ref: String Extraction-Footnote-1810861 +Node: Printf Ordering810947 +Ref: Printf Ordering-Footnote-1813729 +Node: I18N Portability813793 +Ref: I18N Portability-Footnote-1816242 +Node: I18N Example816305 +Ref: I18N Example-Footnote-1819028 +Node: Gawk I18N819101 +Node: I18N Summary819740 +Node: Debugger821080 +Node: Debugging822102 +Node: Debugging Concepts822543 +Node: Debugging Terms824399 +Node: Awk Debugging826999 +Node: Sample Debugging Session827891 +Node: Debugger Invocation828411 +Node: Finding The Bug829744 +Node: List of Debugger Commands836225 +Node: Breakpoint Control837558 +Node: Debugger Execution Control841238 +Node: Viewing And Changing Data844607 +Node: Execution Stack847964 +Node: Debugger Info849474 +Node: Miscellaneous Debugger Commands853494 +Node: Readline Support858686 +Node: Limitations859580 +Node: Debugging Summary861853 +Node: Arbitrary Precision Arithmetic863015 +Node: Computer Arithmetic864345 +Ref: Computer Arithmetic-Footnote-1868604 +Node: Math Definitions868661 +Ref: table-ieee-formats871560 +Node: MPFR features872063 +Node: FP Math Caution873706 +Ref: FP Math Caution-Footnote-1874773 +Node: Inexactness of computations875142 +Node: Inexact representation876091 +Node: Comparing FP Values877448 +Node: Errors accumulate878412 +Node: Getting Accuracy879845 +Node: Try To Round882511 +Node: Setting precision883410 +Ref: table-predefined-precision-strings884105 +Node: Setting the rounding mode885899 +Ref: table-gawk-rounding-modes886273 +Ref: Setting the rounding mode-Footnote-1889683 +Node: Arbitrary Precision Integers889862 +Ref: Arbitrary Precision Integers-Footnote-1893658 +Node: POSIX Floating Point Problems893807 +Ref: POSIX Floating Point Problems-Footnote-1897686 +Node: Floating point summary897724 +Node: Dynamic Extensions899945 +Node: Extension Intro901498 +Node: Plugin License902764 +Node: Extension Mechanism Outline903449 +Ref: figure-load-extension903884 +Ref: figure-load-new-function905454 +Ref: figure-call-new-function906542 +Node: Extension API Description908602 +Node: Extension API Functions Introduction910052 +Node: General Data Types914908 +Ref: General Data Types-Footnote-1920654 +Node: Requesting Values920953 +Ref: table-value-types-returned921702 +Node: Memory Allocation Functions922586 +Ref: Memory Allocation Functions-Footnote-1925339 +Node: Constructor Functions925435 +Node: Registration Functions927199 +Node: Extension Functions927884 +Node: Exit Callback Functions930189 +Node: Extension Version String931440 +Node: Input Parsers932090 +Node: Output Wrappers941914 +Node: Two-way processors946429 +Node: Printing Messages948634 +Ref: Printing Messages-Footnote-1949711 +Node: Updating 'ERRNO'949864 +Node: Accessing Parameters950604 +Node: Symbol Table Access951836 +Node: Symbol table by name952348 +Node: Symbol table by cookie954325 +Ref: Symbol table by cookie-Footnote-1958462 +Node: Cached values958526 +Ref: Cached values-Footnote-1962035 +Node: Array Manipulation962126 +Ref: Array Manipulation-Footnote-1963225 +Node: Array Data Types963264 +Ref: Array Data Types-Footnote-1965971 +Node: Array Functions966063 +Node: Flattening Arrays969942 +Node: Creating Arrays976801 +Node: Extension API Variables981533 +Node: Extension Versioning982169 +Node: Extension API Informational Variables984070 +Node: Extension API Boilerplate985155 +Node: Finding Extensions988964 +Node: Extension Example989524 +Node: Internal File Description990279 +Node: Internal File Ops994383 +Ref: Internal File Ops-Footnote-11005826 +Node: Using Internal File Ops1005966 +Ref: Using Internal File Ops-Footnote-11008313 +Node: Extension Samples1008583 +Node: Extension Sample File Functions1010108 +Node: Extension Sample Fnmatch1017619 +Node: Extension Sample Fork1019100 +Node: Extension Sample Inplace1020316 +Node: Extension Sample Ord1021991 +Node: Extension Sample Readdir1022827 +Ref: table-readdir-file-types1023695 +Node: Extension Sample Revout1024488 +Node: Extension Sample Rev2way1025079 +Node: Extension Sample Read write array1025820 +Node: Extension Sample Readfile1027701 +Node: Extension Sample API Tests1028801 +Node: Extension Sample Time1029327 +Node: gawkextlib1030642 +Node: Extension summary1033455 +Node: Extension Exercises1037151 +Node: Language History1037872 +Node: V7/SVR3.11039515 +Node: SVR41041835 +Node: POSIX1043277 +Node: BTL1044662 +Node: POSIX/GNU1045395 +Node: Feature History1051138 +Node: Common Extensions1064269 +Node: Ranges and Locales1065580 +Ref: Ranges and Locales-Footnote-11070194 +Ref: Ranges and Locales-Footnote-21070221 +Ref: Ranges and Locales-Footnote-31070455 +Node: Contributors1070676 +Node: History summary1076129 +Node: Installation1077499 +Node: Gawk Distribution1078449 +Node: Getting1078933 +Node: Extracting1079757 +Node: Distribution contents1081400 +Node: Unix Installation1087169 +Node: Quick Installation1087785 +Node: Additional Configuration Options1090230 +Node: Configuration Philosophy1091969 +Node: Non-Unix Installation1094321 +Node: PC Installation1094779 +Node: PC Binary Installation1096090 +Node: PC Compiling1097942 +Ref: PC Compiling-Footnote-11100944 +Node: PC Testing1101049 +Node: PC Using1102229 +Node: Cygwin1106386 +Node: MSYS1107195 +Node: VMS Installation1107709 +Node: VMS Compilation1108504 +Ref: VMS Compilation-Footnote-11109727 +Node: VMS Dynamic Extensions1109785 +Node: VMS Installation Details1111158 +Node: VMS Running1113412 +Node: VMS GNV1116248 +Node: VMS Old Gawk1116971 +Node: Bugs1117442 +Node: Other Versions1121556 +Node: Installation summary1127846 +Node: Notes1128901 +Node: Compatibility Mode1129766 +Node: Additions1130548 +Node: Accessing The Source1131473 +Node: Adding Code1132910 +Node: New Ports1139092 +Node: Derived Files1143579 +Ref: Derived Files-Footnote-11148668 +Ref: Derived Files-Footnote-21148703 +Ref: Derived Files-Footnote-31149301 +Node: Future Extensions1149415 +Node: Implementation Limitations1150071 +Node: Extension Design1151254 +Node: Old Extension Problems1152408 +Ref: Old Extension Problems-Footnote-11153926 +Node: Extension New Mechanism Goals1153983 +Ref: Extension New Mechanism Goals-Footnote-11157347 +Node: Extension Other Design Decisions1157536 +Node: Extension Future Growth1159647 +Node: Old Extension Mechanism1160483 +Node: Notes summary1162246 +Node: Basic Concepts1163428 +Node: Basic High Level1164109 +Ref: figure-general-flow1164391 +Ref: figure-process-flow1165076 +Ref: Basic High Level-Footnote-11168377 +Node: Basic Data Typing1168562 +Node: Glossary1171890 +Node: Copying1197041 +Node: GNU Free Documentation License1234579 +Node: Index1259696  End Tag Table -- cgit v1.2.3 From dc03ae8d25acc19f27f015ab568e07f7d24fe2f6 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 11 Sep 2014 19:42:21 +0300 Subject: Restore gawk.info, still using C makeinfo. --- doc/gawk.info | 24232 +++++++++++++++++++++++++------------------------------- 1 file changed, 10602 insertions(+), 13630 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 65ae1509..2b8c0e0b 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -1,10 +1,19 @@ -This is gawk.info, produced by makeinfo version 5.1 from gawk.texi. +This is gawk.info, produced by makeinfo version 4.13 from gawk.texi. -Copyright (C) 1989, 1991, 1992, 1993, 1996-2005, 2007, 2009-2014 +INFO-DIR-SECTION Text creation and manipulation +START-INFO-DIR-ENTRY +* Gawk: (gawk). A text scanning and processing language. +END-INFO-DIR-ENTRY +INFO-DIR-SECTION Individual utilities +START-INFO-DIR-ENTRY +* awk: (gawk)Invoking gawk. Text scanning and processing. +END-INFO-DIR-ENTRY + + Copyright (C) 1989, 1991, 1992, 1993, 1996-2005, 2007, 2009-2014 Free Software Foundation, Inc. - This is Edition 4.1 of 'GAWK: Effective AWK Programming: A User's + This is Edition 4.1 of `GAWK: Effective AWK Programming: A User's Guide for GNU Awk', for the 4.1.1 (or later) version of the GNU implementation of AWK. @@ -12,21 +21,12 @@ implementation of AWK. under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being "GNU General Public License", with the -Front-Cover Texts being "A GNU Manual", and with the Back-Cover Texts as -in (a) below. A copy of the license is included in the section entitled -"GNU Free Documentation License". +Front-Cover Texts being "A GNU Manual", and with the Back-Cover Texts +as in (a) below. A copy of the license is included in the section +entitled "GNU Free Documentation License". a. The FSF's Back-Cover Text is: "You have the freedom to copy and modify this GNU manual." -INFO-DIR-SECTION Text creation and manipulation -START-INFO-DIR-ENTRY -* Gawk: (gawk). A text scanning and processing language. -END-INFO-DIR-ENTRY - -INFO-DIR-SECTION Individual utilities -START-INFO-DIR-ENTRY -* awk: (gawk)Invoking gawk. Text scanning and processing. -END-INFO-DIR-ENTRY  File: gawk.info, Node: Top, Next: Foreword, Up: (dir) @@ -34,14 +34,14 @@ File: gawk.info, Node: Top, Next: Foreword, Up: (dir) General Introduction ******************** -This file documents 'awk', a program that you can use to select +This file documents `awk', a program that you can use to select particular records in a file and perform operations upon them. Copyright (C) 1989, 1991, 1992, 1993, 1996-2005, 2007, 2009-2014 Free Software Foundation, Inc. - This is Edition 4.1 of 'GAWK: Effective AWK Programming: A User's + This is Edition 4.1 of `GAWK: Effective AWK Programming: A User's Guide for GNU Awk', for the 4.1.1 (or later) version of the GNU implementation of AWK. @@ -49,9 +49,9 @@ implementation of AWK. under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being "GNU General Public License", with the -Front-Cover Texts being "A GNU Manual", and with the Back-Cover Texts as -in (a) below. A copy of the license is included in the section entitled -"GNU Free Documentation License". +Front-Cover Texts being "A GNU Manual", and with the Back-Cover Texts +as in (a) below. A copy of the license is included in the section +entitled "GNU Free Documentation License". a. The FSF's Back-Cover Text is: "You have the freedom to copy and modify this GNU manual." @@ -63,14 +63,14 @@ in (a) below. A copy of the license is included in the section entitled * Preface:: What this Info file is about; brief history and acknowledgments. * Getting Started:: A basic introduction to using - 'awk'. How to run an 'awk' + `awk'. How to run an `awk' program. Command-line syntax. -* Invoking Gawk:: How to run 'gawk'. +* Invoking Gawk:: How to run `gawk'. * Regexp:: All about matching things using regular expressions. * Reading Files:: How to read files and manipulate fields. -* Printing:: How to print using 'awk'. Describes - the 'print' and 'printf' +* Printing:: How to print using `awk'. Describes + the `print' and `printf' statements. Also describes redirection of output. * Expressions:: Expressions are the basic building blocks @@ -79,36 +79,36 @@ in (a) below. A copy of the license is included in the section entitled * Arrays:: The description and use of arrays. Also includes array-oriented control statements. * Functions:: Built-in and user-defined functions. -* Library Functions:: A Library of 'awk' Functions. -* Sample Programs:: Many 'awk' programs with complete +* Library Functions:: A Library of `awk' Functions. +* Sample Programs:: Many `awk' programs with complete explanations. * Advanced Features:: Stuff for advanced users, specific to - 'gawk'. -* Internationalization:: Getting 'gawk' to speak your + `gawk'. +* Internationalization:: Getting `gawk' to speak your language. -* Debugger:: The 'gawk' debugger. +* Debugger:: The `gawk' debugger. * Arbitrary Precision Arithmetic:: Arbitrary precision arithmetic with - 'gawk'. + `gawk'. * Dynamic Extensions:: Adding new built-in functions to - 'gawk'. -* Language History:: The evolution of the 'awk' + `gawk'. +* Language History:: The evolution of the `awk' language. -* Installation:: Installing 'gawk' under various +* Installation:: Installing `gawk' under various operating systems. -* Notes:: Notes about adding things to 'gawk' +* Notes:: Notes about adding things to `gawk' and possible future work. * Basic Concepts:: A very quick introduction to programming concepts. * Glossary:: An explanation of some unfamiliar terms. * Copying:: Your right to copy and distribute - 'gawk'. + `gawk'. * GNU Free Documentation License:: The license for this Info file. * Index:: Concept and Variable Index. -* History:: The history of 'gawk' and - 'awk'. +* History:: The history of `gawk' and + `awk'. * Names:: What name to use to find - 'awk'. + `awk'. * This Manual:: Using this Info file. Includes sample input files that you can use. * Conventions:: Typographical Conventions. @@ -116,23 +116,23 @@ in (a) below. A copy of the license is included in the section entitled this Info file. * How To Contribute:: Helping to save the world. * Acknowledgments:: Acknowledgments. -* Running gawk:: How to run 'gawk' programs; +* Running gawk:: How to run `gawk' programs; includes command-line syntax. * One-shot:: Running a short throwaway - 'awk' program. + `awk' program. * Read Terminal:: Using no input files (input from the keyboard instead). -* Long:: Putting permanent 'awk' +* Long:: Putting permanent `awk' programs in files. -* Executable Scripts:: Making self-contained 'awk' +* Executable Scripts:: Making self-contained `awk' programs. -* Comments:: Adding documentation to 'gawk' +* Comments:: Adding documentation to `gawk' programs. * Quoting:: More discussion of shell quoting issues. * DOS Quoting:: Quoting in Windows Batch Files. * Sample Data Files:: Sample data files for use in the - 'awk' programs illustrated in + `awk' programs illustrated in this Info file. * Very Simple:: A very simple example. * Two Rules:: A less simple one-line example using @@ -140,11 +140,11 @@ in (a) below. A copy of the license is included in the section entitled * More Complex:: A more complex example. * Statements/Lines:: Subdividing or combining statements into lines. -* Other Features:: Other Features of 'awk'. -* When:: When to use 'gawk' and when to +* Other Features:: Other Features of `awk'. +* When:: When to use `gawk' and when to use other things. * Intro Summary:: Summary of the introduction. -* Command Line:: How to run 'awk'. +* Command Line:: How to run `awk'. * Options:: Command-line options and their meanings. * Other Arguments:: Input file names and variable @@ -152,13 +152,13 @@ in (a) below. A copy of the license is included in the section entitled * Naming Standard Input:: How to specify standard input with other files. * Environment Variables:: The environment variables - 'gawk' uses. + `gawk' uses. * AWKPATH Variable:: Searching directories for - 'awk' programs. + `awk' programs. * AWKLIBPATH Variable:: Searching directories for - 'awk' shared libraries. + `awk' shared libraries. * Other Environment Variables:: The environment variables. -* Exit Status:: 'gawk''s exit status. +* Exit Status:: `gawk''s exit status. * Include Files:: Including other files into your program. * Loading Shared Libraries:: Loading shared libraries into your @@ -169,13 +169,7 @@ in (a) below. A copy of the license is included in the section entitled * Regexp Usage:: How to Use Regular Expressions. * Escape Sequences:: How to write nonprinting characters. * Regexp Operators:: Regular Expression Operators. -<<<<<<< HEAD -* Bracket Expressions:: What can go between '[...]'. -* GNU Regexp Operators:: Operators specific to GNU software. -* Case-sensitivity:: How to do case-insensitive matching. -======= * Bracket Expressions:: What can go between `[...]'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Leftmost Longest:: How much text matches. * Computed Regexps:: Using Dynamic Regexps. * GNU Regexp Operators:: Operators specific to GNU software. @@ -183,9 +177,9 @@ in (a) below. A copy of the license is included in the section entitled * Regexp Summary:: Regular expressions summary. * Records:: Controlling how data is split into records. -* awk split records:: How standard 'awk' splits +* awk split records:: How standard `awk' splits records. -* gawk split records:: How 'gawk' splits records. +* gawk split records:: How `gawk' splits records. * Fields:: An introduction to fields. * Nonconstant Fields:: Nonconstant Field Numbers. * Changing Fields:: Changing the Contents of a Field. @@ -195,13 +189,8 @@ in (a) below. A copy of the license is included in the section entitled * Regexp Field Splitting:: Using regexps as the field separator. * Single Character Fields:: Making each character a separate field. -<<<<<<< HEAD -* Command Line Field Separator:: Setting 'FS' from the - command-line. -======= * Command Line Field Separator:: Setting `FS' from the command line. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Full Line Fields:: Making the full line be a single field. * Field Splitting Summary:: Some final points and a summary table. @@ -209,44 +198,44 @@ in (a) below. A copy of the license is included in the section entitled * Splitting By Content:: Defining Fields By Content * Multiple Line:: Reading multiline records. * Getline:: Reading files under explicit program - control using the 'getline' + control using the `getline' function. -* Plain Getline:: Using 'getline' with no +* Plain Getline:: Using `getline' with no arguments. -* Getline/Variable:: Using 'getline' into a variable. -* Getline/File:: Using 'getline' from a file. -* Getline/Variable/File:: Using 'getline' into a variable +* Getline/Variable:: Using `getline' into a variable. +* Getline/File:: Using `getline' from a file. +* Getline/Variable/File:: Using `getline' into a variable from a file. -* Getline/Pipe:: Using 'getline' from a pipe. -* Getline/Variable/Pipe:: Using 'getline' into a variable +* Getline/Pipe:: Using `getline' from a pipe. +* Getline/Variable/Pipe:: Using `getline' into a variable from a pipe. -* Getline/Coprocess:: Using 'getline' from a coprocess. -* Getline/Variable/Coprocess:: Using 'getline' into a variable +* Getline/Coprocess:: Using `getline' from a coprocess. +* Getline/Variable/Coprocess:: Using `getline' into a variable from a coprocess. * Getline Notes:: Important things to know about - 'getline'. -* Getline Summary:: Summary of 'getline' Variants. + `getline'. +* Getline Summary:: Summary of `getline' Variants. * Read Timeout:: Reading input with a timeout. * Command-line directories:: What happens if you put a directory on the command line. * Input Summary:: Input summary. * Input Exercises:: Exercises. -* Print:: The 'print' statement. -* Print Examples:: Simple examples of 'print' +* Print:: The `print' statement. +* Print Examples:: Simple examples of `print' statements. * Output Separators:: The output separators and how to change them. * OFMT:: Controlling Numeric Output With - 'print'. -* Printf:: The 'printf' statement. -* Basic Printf:: Syntax of the 'printf' statement. + `print'. +* Printf:: The `printf' statement. +* Basic Printf:: Syntax of the `printf' statement. * Control Letters:: Format-control letters. * Format Modifiers:: Format-specification modifiers. * Printf Examples:: Several examples. * Redirection:: How to redirect output to multiple files and pipes. * Special Files:: File name interpretation in - 'gawk'. 'gawk' allows + `gawk'. `gawk' allows access to inherited file descriptors. * Special FD:: Special files for I/O. * Special Network:: Special files for network @@ -271,30 +260,30 @@ in (a) below. A copy of the license is included in the section entitled This is an advanced method of input. * Conversion:: The conversion of strings to numbers and vice versa. -* Strings And Numbers:: How 'awk' Converts Between +* Strings And Numbers:: How `awk' Converts Between Strings And Numbers. * Locale influences conversions:: How the locale may affect conversions. -* All Operators:: 'gawk''s operators. -* Arithmetic Ops:: Arithmetic operations ('+', - '-', etc.) +* All Operators:: `gawk''s operators. +* Arithmetic Ops:: Arithmetic operations (`+', + `-', etc.) * Concatenation:: Concatenating strings. * Assignment Ops:: Changing the value of a variable or a field. * Increment Ops:: Incrementing the numeric value of a variable. * Truth Values and Conditions:: Testing for true and false. -* Truth Values:: What is "true" and what is - "false". +* Truth Values:: What is ``true'' and what is + ``false''. * Typing and Comparison:: How variables acquire types and how this affects comparison of numbers and - strings with '<', etc. + strings with `<', etc. * Variable Typing:: String type versus numeric type. * Comparison Operators:: The comparison operators. * POSIX String Comparison:: String comparison with POSIX rules. * Boolean Ops:: Combining comparison expressions using - boolean operators '||' ("or"), - '&&' ("and") and '!' - ("not"). + boolean operators `||' (``or''), + `&&' (``and'') and `!' + (``not''). * Conditional Exp:: Conditional expressions select between two subexpressions under control of a third subexpression. @@ -317,12 +306,12 @@ in (a) below. A copy of the license is included in the section entitled * Empty:: The empty pattern, which matches every record. * Using Shell Variables:: How to use shell variables with - 'awk'. + `awk'. * Action Overview:: What goes into an action. * Statements:: Describes the various control statements in detail. * If Statement:: Conditionally execute some - 'awk' statements. + `awk' statements. * While Statement:: Loop until some condition is satisfied. * Do Statement:: Do specified action while looping @@ -340,14 +329,14 @@ in (a) below. A copy of the license is included in the section entitled * Next Statement:: Stop processing the current input record. * Nextfile Statement:: Stop processing the current file. -* Exit Statement:: Stop execution of 'awk'. +* Exit Statement:: Stop execution of `awk'. * Built-in Variables:: Summarizes the built-in variables. * User-modified:: Built-in variables that you change to - control 'awk'. -* Auto-set:: Built-in variables where 'awk' + control `awk'. +* Auto-set:: Built-in variables where `awk' gives you information. -* ARGC and ARGV:: Ways to use 'ARGC' and - 'ARGV'. +* ARGC and ARGV:: Ways to use `ARGC' and + `ARGV'. * Pattern Action Summary:: Patterns and Actions summary. * Array Basics:: The basics of arrays. * Array Intro:: Introduction to Arrays @@ -355,35 +344,35 @@ in (a) below. A copy of the license is included in the section entitled array. * Assigning Elements:: How to change an element of an array. * Array Example:: Basic Example of an Array -* Scanning an Array:: A variation of the 'for' +* Scanning an Array:: A variation of the `for' statement. It loops through the indices of an array's existing elements. * Controlling Scanning:: Controlling the order in which arrays are scanned. -* Delete:: The 'delete' statement removes an +* Delete:: The `delete' statement removes an element from an array. * Numeric Array Subscripts:: How to use numbers as subscripts in - 'awk'. + `awk'. * Uninitialized Subscripts:: Using Uninitialized variables as subscripts. * Multidimensional:: Emulating multidimensional arrays in - 'awk'. + `awk'. * Multiscanning:: Scanning multidimensional arrays. * Arrays of Arrays:: True multidimensional arrays. * Arrays Summary:: Summary of arrays. * Built-in:: Summarizes the built-in functions. * Calling Built-in:: How to call built-in functions. * Numeric Functions:: Functions that work with numbers, - including 'int()', 'sin()' - and 'rand()'. + including `int()', `sin()' + and `rand()'. * String Functions:: Functions for string manipulation, - such as 'split()', 'match()' - and 'sprintf()'. + such as `split()', `match()' + and `sprintf()'. * Gory Details:: More than you want to know about - '\' and '&' with - 'sub()', 'gsub()', and - 'gensub()'. + `\' and `&' with + `sub()', `gsub()', and + `gensub()'. * I/O Functions:: Functions for files and shell commands. * Time Functions:: Functions for dealing with timestamps. @@ -411,11 +400,11 @@ in (a) below. A copy of the license is included in the section entitled variables in library functions. * General Functions:: Functions that are of general use. * Strtonum Function:: A replacement for the built-in - 'strtonum()' function. + `strtonum()' function. * Assert Function:: A function for assertions in - 'awk' programs. + `awk' programs. * Round Function:: A function for rounding if - 'sprintf()' does not do it + `sprintf()' does not do it correctly. * Cliff Random Function:: The Cliff Random Number Generator. * Ordinal Functions:: Functions for using characters as @@ -445,19 +434,19 @@ in (a) below. A copy of the license is included in the section entitled * Library Exercises:: Exercises. * Running Examples:: How to run these examples. * Clones:: Clones of common utilities. -* Cut Program:: The 'cut' utility. -* Egrep Program:: The 'egrep' utility. -* Id Program:: The 'id' utility. -* Split Program:: The 'split' utility. -* Tee Program:: The 'tee' utility. -* Uniq Program:: The 'uniq' utility. -* Wc Program:: The 'wc' utility. -* Miscellaneous Programs:: Some interesting 'awk' +* Cut Program:: The `cut' utility. +* Egrep Program:: The `egrep' utility. +* Id Program:: The `id' utility. +* Split Program:: The `split' utility. +* Tee Program:: The `tee' utility. +* Uniq Program:: The `uniq' utility. +* Wc Program:: The `wc' utility. +* Miscellaneous Programs:: Some interesting `awk' programs. * Dupword Program:: Finding duplicated words in a document. * Alarm Program:: An alarm clock. -* Translate Program:: A program similar to the 'tr' +* Translate Program:: A program similar to the `tr' utility. * Labels Program:: Printing mailing labels. * Word Sorting:: A program to produce a word usage @@ -467,7 +456,7 @@ in (a) below. A copy of the license is included in the section entitled * Extract Program:: Pulling out programs from Texinfo source files. * Simple Sed:: A Simple Stream Editor. -* Igawk Program:: A wrapper for 'awk' that +* Igawk Program:: A wrapper for `awk' that includes files. * Anagram Program:: Finding anagrams from a dictionary. * Signature Program:: People do amazing things with too much @@ -478,27 +467,27 @@ in (a) below. A copy of the license is included in the section entitled * Array Sorting:: Facilities for controlling array traversal and sorting arrays. * Controlling Array Traversal:: How to use PROCINFO["sorted_in"]. -* Array Sorting Functions:: How to use 'asort()' and - 'asorti()'. +* Array Sorting Functions:: How to use `asort()' and + `asorti()'. * Two-way I/O:: Two-way communications with another process. -* TCP/IP Networking:: Using 'gawk' for network +* TCP/IP Networking:: Using `gawk' for network programming. -* Profiling:: Profiling your 'awk' programs. +* Profiling:: Profiling your `awk' programs. * Advanced Features Summary:: Summary of advanced features. * I18N and L10N:: Internationalization and Localization. -* Explaining gettext:: How GNU 'gettext' works. +* Explaining gettext:: How GNU `gettext' works. * Programmer i18n:: Features for the programmer. * Translator i18n:: Features for the translator. * String Extraction:: Extracting marked strings. -* Printf Ordering:: Rearranging 'printf' arguments. -* I18N Portability:: 'awk'-level portability +* Printf Ordering:: Rearranging `printf' arguments. +* I18N Portability:: `awk'-level portability issues. * I18N Example:: A simple i18n example. -* Gawk I18N:: 'gawk' is also +* Gawk I18N:: `gawk' is also internationalized. * I18N Summary:: Summary of I18N stuff. -* Debugging:: Introduction to 'gawk' +* Debugging:: Introduction to `gawk' debugger. * Debugging Concepts:: Debugging in General. * Debugging Terms:: Additional Debugging Concepts. @@ -519,7 +508,7 @@ in (a) below. A copy of the license is included in the section entitled * Debugging Summary:: Debugging summary. * Computer Arithmetic:: A quick intro to computer math. * Math Definitions:: Defining terms used. -* MPFR features:: The MPFR features in 'gawk'. +* MPFR features:: The MPFR features in `gawk'. * FP Math Caution:: Things to know. * Inexactness of computations:: Floating point math is not exact. * Inexact representation:: Numbers are not exactly represented. @@ -530,7 +519,7 @@ in (a) below. A copy of the license is included in the section entitled * Setting precision:: How to set the precision. * Setting the rounding mode:: How to set the rounding mode. * Arbitrary Precision Integers:: Arbitrary Precision Integer Arithmetic - with 'gawk'. + with `gawk'. * POSIX Floating Point Problems:: Standards Versus Existing Practice. * Floating point summary:: Summary of floating point discussion. * Extension Intro:: What is an extension. @@ -543,7 +532,7 @@ in (a) below. A copy of the license is included in the section entitled * Memory Allocation Functions:: Functions for allocating memory. * Constructor Functions:: Functions for creating values. * Registration Functions:: Functions to register things with - 'gawk'. + `gawk'. * Extension Functions:: Registering extension functions. * Exit Callback Functions:: Registering an exit callback. * Extension Version String:: Registering a version string. @@ -551,12 +540,12 @@ in (a) below. A copy of the license is included in the section entitled * Output Wrappers:: Registering an output wrapper. * Two-way processors:: Registering a two-way processor. * Printing Messages:: Functions for printing messages. -* Updating 'ERRNO':: Functions for updating 'ERRNO'. +* Updating `ERRNO':: Functions for updating `ERRNO'. * Accessing Parameters:: Functions for accessing parameters. * Symbol Table Access:: Functions for accessing global variables. * Symbol table by name:: Accessing variables by name. -* Symbol table by cookie:: Accessing variables by "cookie". +* Symbol table by cookie:: Accessing variables by ``cookie''. * Cached values:: Creating and using cached values. * Array Manipulation:: Functions for working with arrays. * Array Data Types:: Data types for working with arrays. @@ -566,24 +555,24 @@ in (a) below. A copy of the license is included in the section entitled * Extension API Variables:: Variables provided by the API. * Extension Versioning:: API Version information. * Extension API Informational Variables:: Variables providing information about - 'gawk''s invocation. + `gawk''s invocation. * Extension API Boilerplate:: Boilerplate code for using the API. -* Finding Extensions:: How 'gawk' finds compiled +* Finding Extensions:: How `gawk' finds compiled extensions. * Extension Example:: Example C code for an extension. * Internal File Description:: What the new functions will do. * Internal File Ops:: The code for internal file operations. * Using Internal File Ops:: How to use an external extension. * Extension Samples:: The sample extensions that ship with - 'gawk'. + `gawk'. * Extension Sample File Functions:: The file functions sample. -* Extension Sample Fnmatch:: An interface to 'fnmatch()'. -* Extension Sample Fork:: An interface to 'fork()' and +* Extension Sample Fnmatch:: An interface to `fnmatch()'. +* Extension Sample Fork:: An interface to `fork()' and other process functions. * Extension Sample Inplace:: Enabling in-place file editing. * Extension Sample Ord:: Character to value to character conversions. -* Extension Sample Readdir:: An interface to 'readdir()'. +* Extension Sample Readdir:: An interface to `readdir()'. * Extension Sample Revout:: Reversing output sample output wrapper. * Extension Sample Rev2way:: Reversing data sample two-way @@ -591,9 +580,9 @@ in (a) below. A copy of the license is included in the section entitled * Extension Sample Read write array:: Serializing an array to a file. * Extension Sample Readfile:: Reading an entire file into a string. * Extension Sample API Tests:: Tests for the API. -* Extension Sample Time:: An interface to 'gettimeofday()' - and 'sleep()'. -* gawkextlib:: The 'gawkextlib' project. +* Extension Sample Time:: An interface to `gettimeofday()' + and `sleep()'. +* gawkextlib:: The `gawkextlib' project. * Extension summary:: Extension summary. * Extension Exercises:: Exercises. * V7/SVR3.1:: The major changes between V7 and @@ -602,63 +591,63 @@ in (a) below. A copy of the license is included in the section entitled Releases 3.1 and 4. * POSIX:: New features from the POSIX standard. * BTL:: New features from Brian Kernighan's - version of 'awk'. -* POSIX/GNU:: The extensions in 'gawk' not - in POSIX 'awk'. + version of `awk'. +* POSIX/GNU:: The extensions in `gawk' not + in POSIX `awk'. * Feature History:: The history of the features in - 'gawk'. + `gawk'. * Common Extensions:: Common Extensions Summary. * Ranges and Locales:: How locales used to affect regexp ranges. * Contributors:: The major contributors to - 'gawk'. + `gawk'. * History summary:: History summary. -* Gawk Distribution:: What is in the 'gawk' +* Gawk Distribution:: What is in the `gawk' distribution. * Getting:: How to get the distribution. * Extracting:: How to extract the distribution. * Distribution contents:: What is in the distribution. -* Unix Installation:: Installing 'gawk' under +* Unix Installation:: Installing `gawk' under various versions of Unix. -* Quick Installation:: Compiling 'gawk' under Unix. +* Quick Installation:: Compiling `gawk' under Unix. * Additional Configuration Options:: Other compile-time options. * Configuration Philosophy:: How it's all supposed to work. * Non-Unix Installation:: Installation on Other Operating Systems. * PC Installation:: Installing and Compiling - 'gawk' on MS-DOS and OS/2. + `gawk' on MS-DOS and OS/2. * PC Binary Installation:: Installing a prepared distribution. -* PC Compiling:: Compiling 'gawk' for MS-DOS, +* PC Compiling:: Compiling `gawk' for MS-DOS, Windows32, and OS/2. -* PC Testing:: Testing 'gawk' on PC systems. -* PC Using:: Running 'gawk' on MS-DOS, +* PC Testing:: Testing `gawk' on PC systems. +* PC Using:: Running `gawk' on MS-DOS, Windows32 and OS/2. -* Cygwin:: Building and running 'gawk' +* Cygwin:: Building and running `gawk' for Cygwin. -* MSYS:: Using 'gawk' In The MSYS +* MSYS:: Using `gawk' In The MSYS Environment. -* VMS Installation:: Installing 'gawk' on VMS. -* VMS Compilation:: How to compile 'gawk' under +* VMS Installation:: Installing `gawk' on VMS. +* VMS Compilation:: How to compile `gawk' under VMS. -* VMS Dynamic Extensions:: Compiling 'gawk' dynamic +* VMS Dynamic Extensions:: Compiling `gawk' dynamic extensions on VMS. -* VMS Installation Details:: How to install 'gawk' under +* VMS Installation Details:: How to install `gawk' under VMS. -* VMS Running:: How to run 'gawk' under VMS. +* VMS Running:: How to run `gawk' under VMS. * VMS GNV:: The VMS GNV Project. * VMS Old Gawk:: An old version comes with some VMS systems. * Bugs:: Reporting Problems and Bugs. -* Other Versions:: Other freely available 'awk' +* Other Versions:: Other freely available `awk' implementations. * Installation summary:: Summary of installation. -* Compatibility Mode:: How to disable certain 'gawk' +* Compatibility Mode:: How to disable certain `gawk' extensions. -* Additions:: Making Additions To 'gawk'. +* Additions:: Making Additions To `gawk'. * Accessing The Source:: Accessing the Git repository. * Adding Code:: Adding code to the main body of - 'gawk'. -* New Ports:: Porting 'gawk' to a new + `gawk'. +* New Ports:: Porting `gawk' to a new operating system. * Derived Files:: Why derived files are kept in the Git repository. @@ -676,8 +665,8 @@ in (a) below. A copy of the license is included in the section entitled * Basic High Level:: The high level view. * Basic Data Typing:: A very quick intro to data types. - To my parents, for their love, and for the wonderful example they set -for me. + To my parents, for their love, and for the wonderful example they +set for me. To my wife Miriam, for making me complete. Thank you for building your life together with me. @@ -691,85 +680,85 @@ File: gawk.info, Node: Foreword, Next: Preface, Prev: Top, Up: Top Foreword ******** -Arnold Robbins and I are good friends. We were introduced in 1990 by -circumstances--and our favorite programming language, AWK. The -circumstances started a couple of years earlier. I was working at a new +Arnold Robbins and I are good friends. We were introduced in 1990 by +circumstances--and our favorite programming language, AWK. The +circumstances started a couple of years earlier. I was working at a new job and noticed an unplugged Unix computer sitting in the corner. No -one knew how to use it, and neither did I. However, a couple of days -later it was running, and I was 'root' and the one-and-only user. That +one knew how to use it, and neither did I. However, a couple of days +later it was running, and I was `root' and the one-and-only user. That day, I began the transition from statistician to Unix programmer. On one of many trips to the library or bookstore in search of books on Unix, I found the gray AWK book, a.k.a. Aho, Kernighan and -Weinberger, 'The AWK Programming Language', Addison-Wesley, 1988. AWK's -simple programming paradigm--find a pattern in the input and then +Weinberger, `The AWK Programming Language', Addison-Wesley, 1988. +AWK's simple programming paradigm--find a pattern in the input and then perform an action--often reduced complex or tedious data manipulations to few lines of code. I was excited to try my hand at programming in AWK. - Alas, the 'awk' on my computer was a limited version of the language -described in the AWK book. I discovered that my computer had "old -'awk'" and the AWK book described "new 'awk'." I learned that this was -typical; the old version refused to step aside or relinquish its name. -If a system had a new 'awk', it was invariably called 'nawk', and few -systems had it. The best way to get a new 'awk' was to 'ftp' the source -code for 'gawk' from 'prep.ai.mit.edu'. 'gawk' was a version of new -'awk' written by David Trueman and Arnold, and available under the GNU -General Public License. - - (Incidentally, it's no longer difficult to find a new 'awk'. 'gawk' + Alas, the `awk' on my computer was a limited version of the +language described in the AWK book. I discovered that my computer had +"old `awk'" and the AWK book described "new `awk'." I learned that +this was typical; the old version refused to step aside or relinquish +its name. If a system had a new `awk', it was invariably called +`nawk', and few systems had it. The best way to get a new `awk' was to +`ftp' the source code for `gawk' from `prep.ai.mit.edu'. `gawk' was a +version of new `awk' written by David Trueman and Arnold, and available +under the GNU General Public License. + + (Incidentally, it's no longer difficult to find a new `awk'. `gawk' ships with GNU/Linux, and you can download binaries or source code for -almost any system; my wife uses 'gawk' on her VMS box.) +almost any system; my wife uses `gawk' on her VMS box.) My Unix system started out unplugged from the wall; it certainly was -not plugged into a network. So, oblivious to the existence of 'gawk' -and the Unix community in general, and desiring a new 'awk', I wrote my -own, called 'mawk'. Before I was finished I knew about 'gawk', but it -was too late to stop, so I eventually posted to a 'comp.sources' +not plugged into a network. So, oblivious to the existence of `gawk' +and the Unix community in general, and desiring a new `awk', I wrote my +own, called `mawk'. Before I was finished I knew about `gawk', but it +was too late to stop, so I eventually posted to a `comp.sources' newsgroup. A few days after my posting, I got a friendly email from Arnold -introducing himself. He suggested we share design and algorithms and -attached a draft of the POSIX standard so that I could update 'mawk' to +introducing himself. He suggested we share design and algorithms and +attached a draft of the POSIX standard so that I could update `mawk' to support language extensions added after publication of the AWK book. Frankly, if our roles had been reversed, I would not have been so -open and we probably would have never met. I'm glad we did meet. He is -an AWK expert's AWK expert and a genuinely nice person. Arnold +open and we probably would have never met. I'm glad we did meet. He +is an AWK expert's AWK expert and a genuinely nice person. Arnold contributes significant amounts of his expertise and time to the Free Software Foundation. - This book is the 'gawk' reference manual, but at its core it is a -book about AWK programming that will appeal to a wide audience. It is a -definitive reference to the AWK language as defined by the 1987 Bell + This book is the `gawk' reference manual, but at its core it is a +book about AWK programming that will appeal to a wide audience. It is +a definitive reference to the AWK language as defined by the 1987 Bell Laboratories release and codified in the 1992 POSIX Utilities standard. On the other hand, the novice AWK programmer can study a wealth of practical programs that emphasize the power of AWK's basic idioms: data driven control-flow, pattern matching with regular expressions, and associative arrays. Those looking for something new can try out -'gawk''s interface to network protocols via special '/inet' files. +`gawk''s interface to network protocols via special `/inet' files. - The programs in this book make clear that an AWK program is typically -much smaller and faster to develop than a counterpart written in C. -Consequently, there is often a payoff to prototype an algorithm or -design in AWK to get it running quickly and expose problems early. + The programs in this book make clear that an AWK program is +typically much smaller and faster to develop than a counterpart written +in C. Consequently, there is often a payoff to prototype an algorithm +or design in AWK to get it running quickly and expose problems early. Often, the interpreted performance is adequate and the AWK prototype becomes the product. - The new 'pgawk' (profiling 'gawk'), produces program execution + The new `pgawk' (profiling `gawk'), produces program execution counts. I recently experimented with an algorithm that for n lines of input, exhibited ~ C n^2 performance, while theory predicted ~ C n log n -behavior. A few minutes poring over the 'awkprof.out' profile -pinpointed the problem to a single line of code. 'pgawk' is a welcome +behavior. A few minutes poring over the `awkprof.out' profile +pinpointed the problem to a single line of code. `pgawk' is a welcome addition to my programmer's toolbox. Arnold has distilled over a decade of experience writing and using -AWK programs, and developing 'gawk', into this book. If you use AWK or +AWK programs, and developing `gawk', into this book. If you use AWK or want to learn how, then read this book. Michael Brennan - Author of 'mawk' + Author of `mawk' March, 2001  @@ -781,29 +770,19 @@ Preface Several kinds of tasks occur repeatedly when working with text files. You might want to extract certain lines and discard the rest. Or you may need to make changes wherever certain patterns appear, but leave the -<<<<<<< HEAD -rest of the file alone. Writing single-use programs for these tasks in -languages such as C, C++, or Java is time-consuming and inconvenient. -Such jobs are often easier with 'awk'. The 'awk' utility interprets a -special-purpose programming language that makes it easy to handle simple -data-reformatting jobs. - - The GNU implementation of 'awk' is called 'gawk'; if you invoke it -======= rest of the file alone. Such jobs are often easy with `awk'. The `awk' utility interprets a special-purpose programming language that makes it easy to handle simple data-reformatting jobs. The GNU implementation of `awk' is called `gawk'; if you invoke it ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac with the proper options or environment variables (*note Options::), it -is fully compatible with the POSIX(1) specification of the 'awk' -language and with the Unix version of 'awk' maintained by Brian -Kernighan. This means that all properly written 'awk' programs should -work with 'gawk'. Thus, we usually don't distinguish between 'gawk' and -other 'awk' implementations. +is fully compatible with the POSIX(1) specification of the `awk' +language and with the Unix version of `awk' maintained by Brian +Kernighan. This means that all properly written `awk' programs should +work with `gawk'. Thus, we usually don't distinguish between `gawk' +and other `awk' implementations. - Using 'awk' allows you to: + Using `awk' allows you to: * Manage small, personal databases @@ -816,7 +795,7 @@ other 'awk' implementations. * Experiment with algorithms that you can adapt later to other computer languages - In addition, 'gawk' provides facilities that make it easy to: + In addition, `gawk' provides facilities that make it easy to: * Extract bits and pieces of data for processing @@ -824,39 +803,30 @@ other 'awk' implementations. * Perform simple network communications - * Profile and debug 'awk' programs. + * Profile and debug `awk' programs. * Extend the language with functions written in C or C++. - This Info file teaches you about the 'awk' language and how you can + This Info file teaches you about the `awk' language and how you can use it effectively. You should already be familiar with basic system -commands, such as 'cat' and 'ls',(2) as well as basic shell facilities, +commands, such as `cat' and `ls',(2) as well as basic shell facilities, such as input/output (I/O) redirection and pipes. - Implementations of the 'awk' language are available for many + Implementations of the `awk' language are available for many different computing environments. This Info file, while describing the -<<<<<<< HEAD -'awk' language in general, also describes the particular implementation -of 'awk' called 'gawk' (which stands for "GNU 'awk'"). 'gawk' runs on a -broad range of Unix systems, ranging from Intel(R)-architecture PC-based -computers up through large-scale systems. 'gawk' has also been ported -to Mac OS X, Microsoft Windows (all versions) and OS/2 PCs, and OpenVMS. -(Some other, obsolete systems to which 'gawk' was once ported are no -======= `awk' language in general, also describes the particular implementation of `awk' called `gawk' (which stands for "GNU `awk'"). `gawk' runs on a broad range of Unix systems, ranging from Intel-architecture PC-based computers up through large-scale systems. `gawk' has also been ported to Mac OS X, Microsoft Windows (all versions) and OS/2 PCs, and OpenVMS. (Some other, obsolete systems to which `gawk' was once ported are no ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac longer supported and the code for those systems has been removed.) * Menu: -* History:: The history of 'gawk' and - 'awk'. -* Names:: What name to use to find 'awk'. +* History:: The history of `gawk' and + `awk'. +* Names:: What name to use to find `awk'. * This Manual:: Using this Info file. Includes sample input files that you can use. * Conventions:: Typographical Conventions. @@ -867,77 +837,65 @@ longer supported and the code for those systems has been removed.) ---------- Footnotes ---------- -<<<<<<< HEAD - (1) The 2008 POSIX standard is accessable online at . -======= (1) The 2008 POSIX standard is accessible online at `http://www.opengroup.org/onlinepubs/9699919799/'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (2) These commands are available on POSIX-compliant systems, as well -as on traditional Unix-based systems. If you are using some other +as on traditional Unix-based systems. If you are using some other operating system, you still need to be familiar with the ideas of I/O redirection and pipes.  File: gawk.info, Node: History, Next: Names, Up: Preface -History of 'awk' and 'gawk' +History of `awk' and `gawk' =========================== Recipe For A Programming Language - 1 part 'egrep' 1 part 'snobol' - 2 parts 'ed' 3 parts C + 1 part `egrep' 1 part `snobol' + 2 parts `ed' 3 parts C - Blend all parts well using 'lex' and 'yacc'. Document minimally and + Blend all parts well using `lex' and `yacc'. Document minimally and release. - After eight years, add another part 'egrep' and two more parts C. + After eight years, add another part `egrep' and two more parts C. Document very well and release. - The name 'awk' comes from the initials of its designers: Alfred V. +The name `awk' comes from the initials of its designers: Alfred V. Aho, Peter J. Weinberger and Brian W. Kernighan. The original version -of 'awk' was written in 1977 at AT&T Bell Laboratories. In 1985, a new +of `awk' was written in 1977 at AT&T Bell Laboratories. In 1985, a new version made the programming language more powerful, introducing user-defined functions, multiple input streams, and computed regular expressions. This new version became widely available with Unix System V Release 3.1 (1987). The version in System V Release 4 (1989) added some new features and cleaned up the behavior in some of the "dark -corners" of the language. The specification for 'awk' in the POSIX +corners" of the language. The specification for `awk' in the POSIX Command Language and Utilities standard further clarified the language. -Both the 'gawk' designers and the original Bell Laboratories 'awk' +Both the `gawk' designers and the original Bell Laboratories `awk' designers provided feedback for the POSIX specification. - Paul Rubin wrote the GNU implementation, 'gawk', in 1986. Jay + Paul Rubin wrote the GNU implementation, `gawk', in 1986. Jay Fenlason completed it, with advice from Richard Stallman. John Woods -<<<<<<< HEAD -contributed parts of the code as well. In 1988 and 1989, David Trueman, -with help from me, thoroughly reworked 'gawk' for compatibility with the -newer 'awk'. Circa 1994, I became the primary maintainer. Current -development focuses on bug fixes, performance improvements, standards -compliance, and occasionally, new features. -======= contributed parts of the code as well. In 1988 and 1989, David Trueman, with help from me, thoroughly reworked `gawk' for compatibility with the newer `awk'. Circa 1994, I became the primary maintainer. Current development focuses on bug fixes, performance improvements, standards compliance and, occasionally, new features. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac In May of 1997, Ju"rgen Kahrs felt the need for network access from -'awk', and with a little help from me, set about adding features to do -this for 'gawk'. At that time, he also wrote the bulk of 'TCP/IP -Internetworking with 'gawk'' (a separate document, available as part of -the 'gawk' distribution). His code finally became part of the main -'gawk' distribution with 'gawk' version 3.1. - - John Haque rewrote the 'gawk' internals, in the process providing an -'awk'-level debugger. This version became available as 'gawk' version +`awk', and with a little help from me, set about adding features to do +this for `gawk'. At that time, he also wrote the bulk of `TCP/IP +Internetworking with `gawk'' (a separate document, available as part of +the `gawk' distribution). His code finally became part of the main +`gawk' distribution with `gawk' version 3.1. + + John Haque rewrote the `gawk' internals, in the process providing an +`awk'-level debugger. This version became available as `gawk' version 4.0, in 2011. - *Note Contributors::, for a complete list of those who made important -contributions to 'gawk'. + *Note Contributors::, for a complete list of those who made +important contributions to `gawk'.  File: gawk.info, Node: Names, Next: This Manual, Prev: History, Up: Preface @@ -945,27 +903,8 @@ File: gawk.info, Node: Names, Next: This Manual, Prev: History, Up: Preface A Rose by Any Other Name ======================== -The 'awk' language has evolved over the years. Full details are +The `awk' language has evolved over the years. Full details are provided in *note Language History::. The language described in this -<<<<<<< HEAD -Info file is often referred to as "new 'awk'" ('nawk'). - - For some time after new 'awk' was introduced, there were systems with -multiple versions of 'awk'. Some systems had an 'awk' utility that -implemented the original version of the 'awk' language and a 'nawk' -utility for the new version. Others had an 'oawk' version for the "old -'awk'" language and plain 'awk' for the new one. Still others only had -one version, which is usually the new one. - - Today, only Solaris systems still use an old 'awk' for the default -'awk' utility. (A more modern 'awk' lives in '/usr/xpg6/bin' on these -systems.) All other modern systems use some version of new 'awk'.(1) - - It is likely that you already have some version of new 'awk' on your -system, which is what you should use when running your programs. (Of -course, if you're reading this Info file, chances are good that you have -'gawk'!) -======= Info file is often referred to as "new `awk'". By analogy, the original version of `awk' is referred to as "old `awk'." @@ -979,22 +918,17 @@ one, you will see something like this if you try the test program: In this case, you should find a version of new `awk', or just install `gawk'! ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Throughout this Info file, whenever we refer to a language feature -that should be available in any complete implementation of POSIX 'awk', -we simply use the term 'awk'. When referring to a feature that is -specific to the GNU implementation, we use the term 'gawk'. +that should be available in any complete implementation of POSIX `awk', +we simply use the term `awk'. When referring to a feature that is +specific to the GNU implementation, we use the term `gawk'. ---------- Footnotes ---------- -<<<<<<< HEAD - (1) Many of these systems use 'gawk' for their 'awk' implementation! -======= (1) Only Solaris systems still use an old `awk' for the default `awk' utility. A more modern `awk' lives in `/usr/xpg6/bin' on these systems. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: This Manual, Next: Conventions, Prev: Names, Up: Preface @@ -1002,138 +936,138 @@ File: gawk.info, Node: This Manual, Next: Conventions, Prev: Names, Up: Pref Using This Book =============== -The term 'awk' refers to a particular program as well as to the language -you use to tell this program what to do. When we need to be careful, we -call the language "the 'awk' language," and the program "the 'awk' -utility." This Info file explains both how to write programs in the -'awk' language and how to run the 'awk' utility. The term "'awk' -program" refers to a program written by you in the 'awk' programming -language. +The term `awk' refers to a particular program as well as to the +language you use to tell this program what to do. When we need to be +careful, we call the language "the `awk' language," and the program +"the `awk' utility." This Info file explains both how to write +programs in the `awk' language and how to run the `awk' utility. The +term "`awk' program" refers to a program written by you in the `awk' +programming language. - Primarily, this Info file explains the features of 'awk' as defined -in the POSIX standard. It does so in the context of the 'gawk' + Primarily, this Info file explains the features of `awk' as defined +in the POSIX standard. It does so in the context of the `gawk' implementation. While doing so, it also attempts to describe important -differences between 'gawk' and other 'awk' implementations.(1) Finally, -any 'gawk' features that are not in the POSIX standard for 'awk' are +differences between `gawk' and other `awk' implementations.(1) Finally, +any `gawk' features that are not in the POSIX standard for `awk' are noted. There are sidebars scattered throughout the Info file. They add a -more complete explanation of points that are relevant, but not likely to -be of interest on first reading. All appear in the index, under the +more complete explanation of points that are relevant, but not likely +to be of interest on first reading. All appear in the index, under the heading "sidebar." - Most of the time, the examples use complete 'awk' programs. Some of -the more advanced sections show only the part of the 'awk' program that + Most of the time, the examples use complete `awk' programs. Some of +the more advanced sections show only the part of the `awk' program that illustrates the concept currently being described. While this Info file is aimed principally at people who have not been -exposed to 'awk', there is a lot of information here that even the 'awk' +exposed to `awk', there is a lot of information here that even the `awk' expert should find useful. In particular, the description of POSIX -'awk' and the example programs in *note Library Functions::, and in +`awk' and the example programs in *note Library Functions::, and in *note Sample Programs::, should be of interest. This Info file is split into several parts, as follows: - Part I describes the 'awk' language and 'gawk' program in detail. It -starts with the basics, and continues through all of the features of -'awk'. It contains the following chapters: + Part I describes the `awk' language and `gawk' program in detail. +It starts with the basics, and continues through all of the features of +`awk'. It contains the following chapters: *note Getting Started::, provides the essentials you need to know to -begin using 'awk'. +begin using `awk'. - *note Invoking Gawk::, describes how to run 'gawk', the meaning of -its command-line options, and how it finds 'awk' program source files. + *note Invoking Gawk::, describes how to run `gawk', the meaning of +its command-line options, and how it finds `awk' program source files. *note Regexp::, introduces regular expressions in general, and in -particular the flavors supported by POSIX 'awk' and 'gawk'. +particular the flavors supported by POSIX `awk' and `gawk'. - *note Reading Files::, describes how 'awk' reads your data. It -introduces the concepts of records and fields, as well as the 'getline' + *note Reading Files::, describes how `awk' reads your data. It +introduces the concepts of records and fields, as well as the `getline' command. I/O redirection is first described here. Network I/O is also briefly introduced here. - *note Printing::, describes how 'awk' programs can produce output -with 'print' and 'printf'. + *note Printing::, describes how `awk' programs can produce output +with `print' and `printf'. *note Expressions::, describes expressions, which are the basic building blocks for getting most things done in a program. *note Patterns and Actions::, describes how to write patterns for matching records, actions for doing something when a record is matched, -and the built-in variables 'awk' and 'gawk' use. +and the built-in variables `awk' and `gawk' use. - *note Arrays::, covers 'awk''s one-and-only data structure: + *note Arrays::, covers `awk''s one-and-only data structure: associative arrays. Deleting array elements and whole arrays is also -described, as well as sorting arrays in 'gawk'. It also describes how -'gawk' provides arrays of arrays. +described, as well as sorting arrays in `gawk'. It also describes how +`gawk' provides arrays of arrays. - *note Functions::, describes the built-in functions 'awk' and 'gawk' + *note Functions::, describes the built-in functions `awk' and `gawk' provide, as well as how to define your own functions. - Part II shows how to use 'awk' and 'gawk' for problem solving. There -is lots of code here for you to read and learn from. It contains the -following chapters: + Part II shows how to use `awk' and `gawk' for problem solving. +There is lots of code here for you to read and learn from. It contains +the following chapters: - *note Library Functions::, which provides a number of functions meant -to be used from main 'awk' programs. + *note Library Functions::, which provides a number of functions +meant to be used from main `awk' programs. - *note Sample Programs::, which provides many sample 'awk' programs. + *note Sample Programs::, which provides many sample `awk' programs. - Reading these two chapters allows you to see 'awk' solving real + Reading these two chapters allows you to see `awk' solving real problems. - Part III focuses on features specific to 'gawk'. It contains the + Part III focuses on features specific to `gawk'. It contains the following chapters: - *note Advanced Features::, describes a number of 'gawk'-specific -advanced features. Of particular note are the abilities to have two-way -communications with another process, perform TCP/IP networking, and -profile your 'awk' programs. + *note Advanced Features::, describes a number of `gawk'-specific +advanced features. Of particular note are the abilities to have +two-way communications with another process, perform TCP/IP networking, +and profile your `awk' programs. - *note Internationalization::, describes special features in 'gawk' + *note Internationalization::, describes special features in `gawk' for translating program messages into different languages at runtime. - *note Debugger::, describes the 'awk' debugger. + *note Debugger::, describes the `awk' debugger. - *note Arbitrary Precision Arithmetic::, describes advanced arithmetic -facilities provided by 'gawk'. + *note Arbitrary Precision Arithmetic::, describes advanced +arithmetic facilities provided by `gawk'. *note Dynamic Extensions::, describes how to add new variables and -functions to 'gawk' by writing extensions in C or C++. +functions to `gawk' by writing extensions in C or C++. Part IV provides the appendices, the Glossary, and two licenses that -cover the 'gawk' source code and this Info file, respectively. It +cover the `gawk' source code and this Info file, respectively. It contains the following appendices: - *note Language History::, describes how the 'awk' language has + *note Language History::, describes how the `awk' language has evolved since its first release to present. It also describes how -'gawk' has acquired features over time. +`gawk' has acquired features over time. - *note Installation::, describes how to get 'gawk', how to compile it + *note Installation::, describes how to get `gawk', how to compile it on POSIX-compatible systems, and how to compile and use it on different -non-POSIX systems. It also describes how to report bugs in 'gawk' and -where to get other freely available 'awk' implementations. +non-POSIX systems. It also describes how to report bugs in `gawk' and +where to get other freely available `awk' implementations. - *note Notes::, describes how to disable 'gawk''s extensions, as well -as how to contribute new code to 'gawk', and some possible future -directions for 'gawk' development. + *note Notes::, describes how to disable `gawk''s extensions, as well +as how to contribute new code to `gawk', and some possible future +directions for `gawk' development. *note Basic Concepts::, provides some very cursory background material for those who are completely unfamiliar with computer programming. - The *note Glossary::, defines most, if not all, the significant terms -used throughout the Info file. If you find terms that you aren't + The *note Glossary::, defines most, if not all, the significant +terms used throughout the Info file. If you find terms that you aren't familiar with, try looking them up here. *note Copying::, and *note GNU Free Documentation License::, present -the licenses that cover the 'gawk' source code and this Info file, +the licenses that cover the `gawk' source code and this Info file, respectively. ---------- Footnotes ---------- (1) All such differences appear in the index under the entry -"differences in 'awk' and 'gawk'." +"differences in `awk' and `gawk'."  File: gawk.info, Node: Conventions, Next: Manual History, Prev: This Manual, Up: Preface @@ -1142,37 +1076,28 @@ Typographical Conventions ========================= This Info file is written in Texinfo -(http://www.gnu.org/software/texinfo/), the GNU documentation formatting -language. A single Texinfo source file is used to produce both the -printed and online versions of the documentation. This minor node -briefly documents the typographical conventions used in Texinfo. - -<<<<<<< HEAD - Examples you would type at the command-line are preceded by the -common shell primary and secondary prompts, '$' and '>'. Input that you -type is shown 'like this'. Output from the command is preceded by the -glyph "-|". This typically represents the command's standard output. -Error messages, and other output on the command's standard error, are -preceded by the glyph "error->". For example: -======= +(http://www.gnu.org/software/texinfo/), the GNU documentation +formatting language. A single Texinfo source file is used to produce +both the printed and online versions of the documentation. This minor +node briefly documents the typographical conventions used in Texinfo. + Examples you would type at the command line are preceded by the common shell primary and secondary prompts, `$' and `>'. Input that you type is shown `like this'. Output from the command is preceded by the glyph "-|". This typically represents the command's standard output. Error messages, and other output on the command's standard error, are preceded by the glyph "error-->". For example: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac $ echo hi on stdout -| hi on stdout $ echo hello on stderr 1>&2 - error-> hello on stderr + error--> hello on stderr - Characters that you type at the keyboard look 'like this'. In + Characters that you type at the keyboard look `like this'. In particular, there are special characters called "control characters." -These are characters that you type by holding down both the 'CONTROL' -key and another key, at the same time. For example, a 'Ctrl-d' is typed -by first pressing and holding the 'CONTROL' key, next pressing the 'd' +These are characters that you type by holding down both the `CONTROL' +key and another key, at the same time. For example, a `Ctrl-d' is typed +by first pressing and holding the `CONTROL' key, next pressing the `d' key and finally releasing both keys. For the sake of brevity, throughout this Info file, we refer to @@ -1183,20 +1108,20 @@ Dark Corners ------------ Dark corners are basically fractal -- no matter how much you - illuminate, there's always a smaller but darker one. - -- _Brian Kernighan_ + illuminate, there's always a smaller but darker one. -- Brian + Kernighan - Until the POSIX standard (and 'GAWK: Effective AWK Programming'), -many features of 'awk' were either poorly documented or not documented -at all. Descriptions of such features (often called "dark corners") are -noted in this Info file with "(d.c.)". They also appear in the index -under the heading "dark corner." + Until the POSIX standard (and `GAWK: Effective AWK Programming'), +many features of `awk' were either poorly documented or not documented +at all. Descriptions of such features (often called "dark corners") +are noted in this Info file with "(d.c.)". They also appear in the +index under the heading "dark corner." As noted by the opening quote, though, any coverage of dark corners is, by definition, incomplete. - Extensions to the standard 'awk' language that are supported by more -than one 'awk' implementation are marked "(c.e.)," and listed in the + Extensions to the standard `awk' language that are supported by more +than one `awk' implementation are marked "(c.e.)," and listed in the index under "common extensions" and "extensions, common."  @@ -1206,8 +1131,8 @@ The GNU Project and This Book ============================= The Free Software Foundation (FSF) is a nonprofit organization dedicated -to the production and distribution of freely distributable software. It -was founded by Richard M. Stallman, the author of the original Emacs +to the production and distribution of freely distributable software. +It was founded by Richard M. Stallman, the author of the original Emacs editor. GNU Emacs is the most widely used version of Emacs today. The GNU(1) Project is an ongoing effort on the part of the Free @@ -1216,61 +1141,47 @@ POSIX-compliant computing environment. The FSF uses the "GNU General Public License" (GPL) to ensure that their software's source code is always available to the end user. A copy of the GPL is included for your reference (*note Copying::). The GPL applies to the C language -source code for 'gawk'. To find out more about the FSF and the GNU +source code for `gawk'. To find out more about the FSF and the GNU Project online, see the GNU Project's home page (http://www.gnu.org). This Info file may also be read from their web site (http://www.gnu.org/software/gawk/manual/). A shell, an editor (Emacs), highly portable optimizing C, C++, and -Objective-C compilers, a symbolic debugger and dozens of large and small -utilities (such as 'gawk'), have all been completed and are freely -available. The GNU operating system kernel (the HURD), has been +Objective-C compilers, a symbolic debugger and dozens of large and +small utilities (such as `gawk'), have all been completed and are +freely available. The GNU operating system kernel (the HURD), has been released but remains in an early stage of development. Until the GNU operating system is more fully developed, you should consider using GNU/Linux, a freely distributable, Unix-like operating -<<<<<<< HEAD -system for Intel(R), Power Architecture, Sun SPARC, IBM S/390, and other -systems.(2) Many GNU/Linux distributions are available for download -from the Internet. - - (There are numerous other freely available, Unix-like operating -systems based on the Berkeley Software Distribution, and some of them -use recent versions of 'gawk' for their versions of 'awk'. NetBSD -(http://www.netbsd.org), FreeBSD (http://www.freebsd.org), and OpenBSD -(http://www.openbsd.org) are three of the most popular ones, but there -are others.) - -======= system for Intel, Power Architecture, Sun SPARC, IBM S/390, and other systems.(2) Many GNU/Linux distributions are available for download from the Internet. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac The Info file itself has gone through a number of previous editions. -Paul Rubin wrote the very first draft of 'The GAWK Manual'; it was +Paul Rubin wrote the very first draft of `The GAWK Manual'; it was around 40 pages in size. Diane Close and Richard Stallman improved it, yielding a version that was around 90 pages long and barely described -the original, "old" version of 'awk'. +the original, "old" version of `awk'. I started working with that version in the fall of 1988. As work on it progressed, the FSF published several preliminary versions (numbered -0.X). In 1996, Edition 1.0 was released with 'gawk' 3.0.0. The FSF -published the first two editions under the title 'The GNU Awk User's +0.X). In 1996, Edition 1.0 was released with `gawk' 3.0.0. The FSF +published the first two editions under the title `The GNU Awk User's Guide'. This edition maintains the basic structure of the previous editions. For FSF edition 4.0, the content has been thoroughly reviewed and -updated. All references to 'gawk' versions prior to 4.0 have been +updated. All references to `gawk' versions prior to 4.0 have been removed. Of significant note for this edition was *note Debugger::. - For FSF edition 4.1, the content has been reorganized into parts, and -the major new additions are *note Arbitrary Precision Arithmetic::, and -*note Dynamic Extensions::. + For FSF edition 4.1, the content has been reorganized into parts, +and the major new additions are *note Arbitrary Precision Arithmetic::, +and *note Dynamic Extensions::. This Info file will undoubtedly continue to evolve. An electronic -version comes with the 'gawk' distribution from the FSF. If you find an -error in this Info file, please report it! *Note Bugs::, for +version comes with the `gawk' distribution from the FSF. If you find +an error in this Info file, please report it! *Note Bugs::, for information on submitting problem reports electronically. ---------- Footnotes ---------- @@ -1285,26 +1196,26 @@ File: gawk.info, Node: How To Contribute, Next: Acknowledgments, Prev: Manual How to Contribute ================= -As the maintainer of GNU 'awk', I once thought that I would be able to -manage a collection of publicly available 'awk' programs and I even +As the maintainer of GNU `awk', I once thought that I would be able to +manage a collection of publicly available `awk' programs and I even solicited contributions. Making things available on the Internet helps -keep the 'gawk' distribution down to manageable size. +keep the `gawk' distribution down to manageable size. The initial collection of material, such as it is, is still available -at . In the hopes of doing -something more broad, I acquired the 'awk.info' domain. +at `ftp://ftp.freefriends.org/arnold/Awkstuff'. In the hopes of doing +something more broad, I acquired the `awk.info' domain. However, I found that I could not dedicate enough time to managing contributed code: the archive did not grow and the domain went unused for several years. Late in 2008, a volunteer took on the task of setting up an -'awk'-related web site----and did a very nice job. +`awk'-related web site--`http://awk.info'--and did a very nice job. - If you have written an interesting 'awk' program, or have written a -'gawk' extension that you would like to share with the rest of the -world, please see for how to contribute it -to the web site. + If you have written an interesting `awk' program, or have written a +`gawk' extension that you would like to share with the rest of the +world, please see `http://awk.info/?contribute' for how to contribute +it to the web site. As of this writing, this website is in search of a maintainer; please contact me if you are interested. @@ -1315,15 +1226,15 @@ File: gawk.info, Node: Acknowledgments, Prev: How To Contribute, Up: Preface Acknowledgments =============== -The initial draft of 'The GAWK Manual' had the following +The initial draft of `The GAWK Manual' had the following acknowledgments: Many people need to be thanked for their assistance in producing this manual. Jay Fenlason contributed many ideas and sample programs. Richard Mlynarik and Robert Chassell gave helpful - comments on drafts of this manual. The paper 'A Supplemental - Document for 'awk'' by John W. Pierce of the Chemistry Department - at UC San Diego, pinpointed several issues relevant both to 'awk' + comments on drafts of this manual. The paper `A Supplemental + Document for `awk'' by John W. Pierce of the Chemistry Department + at UC San Diego, pinpointed several issues relevant both to `awk' implementation and to this manual, that would otherwise have escaped us. @@ -1344,21 +1255,21 @@ acknowledgements: Robert J. Chassell provided much valuable advice on the use of Texinfo. He also deserves special thanks for convincing me _not_ - to title this Info file 'How To Gawk Politely'. Karl Berry helped + to title this Info file `How To Gawk Politely'. Karl Berry helped significantly with the TeX part of Texinfo. I would like to thank Marshall and Elaine Hartholz of Seattle and Dr. Bert and Rita Schreiber of Detroit for large amounts of quiet vacation time in their homes, which allowed me to make significant - progress on this Info file and on 'gawk' itself. + progress on this Info file and on `gawk' itself. Phil Hughes of SSC contributed in a very important way by loaning me his laptop GNU/Linux system, not once, but twice, which allowed me to do a lot of work while away from home. David Trueman deserves special credit; he has done a yeoman job of - evolving 'gawk' so that it performs well and without bugs. - Although he is no longer involved with 'gawk', working with him on + evolving `gawk' so that it performs well and without bugs. + Although he is no longer involved with `gawk', working with him on this project was a significant pleasure. The intrepid members of the GNITS mailing list, and most notably @@ -1367,25 +1278,21 @@ acknowledgements: Chuck Toporek, Mary Sheehan, and Claire Cloutier of O'Reilly & Associates contributed significant editorial help for this Info - file for the 3.1 release of 'gawk'. + file for the 3.1 release of `gawk'. Dr. Nelson Beebe, Andreas Buening, Dr. Manuel Collado, Antonio Colombo, Stephen Davies, Scott Deifik, Akim Demaille, Darrel Hankerson, Michal Jaegermann, Ju"rgen Kahrs, Stepan Kasal, John Malmberg, Dave Pitts, Chet Ramey, Pat Rankin, Andrew Schorr, Corinna Vinschen, and Eli -Zaretskii (in alphabetical order) make up the current 'gawk' "crack -portability team." Without their hard work and help, 'gawk' would not -be nearly the fine program it is today. It has been and continues to be -a pleasure working with this team of fine people. +Zaretskii (in alphabetical order) make up the current `gawk' "crack +portability team." Without their hard work and help, `gawk' would not +be nearly the fine program it is today. It has been and continues to +be a pleasure working with this team of fine people. - Notable code and documentation contributions were made by a number of -people. *Note Contributors::, for the full list. + Notable code and documentation contributions were made by a number +of people. *Note Contributors::, for the full list. -<<<<<<< HEAD - Thanks to Patrice Dumas for the new 'makeinfo' program. Thanks to -======= Thanks to Patrice Dumas for the new `makeinfo' program. Thanks to ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Karl Berry who continues to work to keep the Texinfo markup language sane. @@ -1394,9 +1301,9 @@ reviewers for the 2015 edition of this Info file. Their feedback helped improve the final work. I would like to thank Brian Kernighan for invaluable assistance -during the testing and debugging of 'gawk', and for ongoing help and +during the testing and debugging of `gawk', and for ongoing help and advice in clarifying numerous points about the language. We could not -have done nearly as good a job on either 'gawk' or its documentation +have done nearly as good a job on either `gawk' or its documentation without his help. Brian is in a class by himself as a programmer and technical author. @@ -1407,34 +1314,34 @@ humbling... I must thank my wonderful wife, Miriam, for her patience through the many versions of this project, for her proofreading, and for sharing me -with the computer. I would like to thank my parents for their love, and -for the grace with which they raised and educated me. Finally, I also -must acknowledge my gratitude to G-d, for the many opportunities He has -sent my way, as well as for the gifts He has given me with which to take -advantage of those opportunities. +with the computer. I would like to thank my parents for their love, +and for the grace with which they raised and educated me. Finally, I +also must acknowledge my gratitude to G-d, for the many opportunities +He has sent my way, as well as for the gifts He has given me with which +to take advantage of those opportunities.  File: gawk.info, Node: Getting Started, Next: Invoking Gawk, Prev: Preface, Up: Top -1 Getting Started with 'awk' +1 Getting Started with `awk' **************************** -The basic function of 'awk' is to search files for lines (or other units -of text) that contain certain patterns. When a line matches one of the -patterns, 'awk' performs specified actions on that line. 'awk' keeps -processing input lines in this way until it reaches the end of the input -files. +The basic function of `awk' is to search files for lines (or other +units of text) that contain certain patterns. When a line matches one +of the patterns, `awk' performs specified actions on that line. `awk' +keeps processing input lines in this way until it reaches the end of +the input files. - Programs in 'awk' are different from programs in most other -languages, because 'awk' programs are "data-driven"; that is, you + Programs in `awk' are different from programs in most other +languages, because `awk' programs are "data-driven"; that is, you describe the data you want to work with and then what to do when you find it. Most other languages are "procedural"; you have to describe, in great detail, every step the program is to take. When working with procedural languages, it is usually much harder to clearly describe the -data your program will process. For this reason, 'awk' programs are +data your program will process. For this reason, `awk' programs are often refreshingly easy to read and write. - When you run 'awk', you specify an 'awk' "program" that tells 'awk' + When you run `awk', you specify an `awk' "program" that tells `awk' what to do. The program consists of a series of "rules". (It may also contain "function definitions", an advanced feature that we will ignore for now. *Note User-defined::.) Each rule specifies one pattern to @@ -1442,8 +1349,8 @@ search for and one action to perform upon finding the pattern. Syntactically, a rule consists of a pattern followed by an action. The action is enclosed in braces to separate it from the pattern. -Newlines usually separate rules. Therefore, an 'awk' program looks like -this: +Newlines usually separate rules. Therefore, an `awk' program looks +like this: PATTERN { ACTION } PATTERN { ACTION } @@ -1451,9 +1358,9 @@ this: * Menu: -* Running gawk:: How to run 'gawk' programs; includes +* Running gawk:: How to run `gawk' programs; includes command-line syntax. -* Sample Data Files:: Sample data files for use in the 'awk' +* Sample Data Files:: Sample data files for use in the `awk' programs illustrated in this Info file. * Very Simple:: A very simple example. * Two Rules:: A less simple one-line example using two @@ -1461,19 +1368,19 @@ this: * More Complex:: A more complex example. * Statements/Lines:: Subdividing or combining statements into lines. -* Other Features:: Other Features of 'awk'. -* When:: When to use 'gawk' and when to use +* Other Features:: Other Features of `awk'. +* When:: When to use `gawk' and when to use other things. * Intro Summary:: Summary of the introduction.  File: gawk.info, Node: Running gawk, Next: Sample Data Files, Up: Getting Started -1.1 How to Run 'awk' Programs +1.1 How to Run `awk' Programs ============================= -There are several ways to run an 'awk' program. If the program is -short, it is easiest to include it in the command that runs 'awk', like +There are several ways to run an `awk' program. If the program is +short, it is easiest to include it in the command that runs `awk', like this: awk 'PROGRAM' INPUT-FILE1 INPUT-FILE2 ... @@ -1488,42 +1395,42 @@ variations of each. * Menu: -* One-shot:: Running a short throwaway 'awk' +* One-shot:: Running a short throwaway `awk' program. * Read Terminal:: Using no input files (input from the keyboard instead). -* Long:: Putting permanent 'awk' programs in +* Long:: Putting permanent `awk' programs in files. -* Executable Scripts:: Making self-contained 'awk' programs. -* Comments:: Adding documentation to 'gawk' +* Executable Scripts:: Making self-contained `awk' programs. +* Comments:: Adding documentation to `gawk' programs. * Quoting:: More discussion of shell quoting issues.  File: gawk.info, Node: One-shot, Next: Read Terminal, Up: Running gawk -1.1.1 One-Shot Throwaway 'awk' Programs +1.1.1 One-Shot Throwaway `awk' Programs --------------------------------------- -Once you are familiar with 'awk', you will often type in simple programs -the moment you want to use them. Then you can write the program as the -first argument of the 'awk' command, like this: +Once you are familiar with `awk', you will often type in simple +programs the moment you want to use them. Then you can write the +program as the first argument of the `awk' command, like this: awk 'PROGRAM' INPUT-FILE1 INPUT-FILE2 ... -where PROGRAM consists of a series of PATTERNS and ACTIONS, as described -earlier. +where PROGRAM consists of a series of PATTERNS and ACTIONS, as +described earlier. - This command format instructs the "shell", or command interpreter, to -start 'awk' and use the PROGRAM to process records in the input file(s). -There are single quotes around PROGRAM so the shell won't interpret any -'awk' characters as special shell characters. The quotes also cause the -shell to treat all of PROGRAM as a single argument for 'awk', and allow -PROGRAM to be more than one line long. + This command format instructs the "shell", or command interpreter, +to start `awk' and use the PROGRAM to process records in the input +file(s). There are single quotes around PROGRAM so the shell won't +interpret any `awk' characters as special shell characters. The quotes +also cause the shell to treat all of PROGRAM as a single argument for +`awk', and allow PROGRAM to be more than one line long. - This format is also useful for running short or medium-sized 'awk' + This format is also useful for running short or medium-sized `awk' programs from shell scripts, because it avoids the need for a separate -file for the 'awk' program. A self-contained shell script is more +file for the `awk' program. A self-contained shell script is more reliable because there are no other files to misplace. *note Very Simple::, presents several short, self-contained programs. @@ -1531,40 +1438,28 @@ reliable because there are no other files to misplace.  File: gawk.info, Node: Read Terminal, Next: Long, Prev: One-shot, Up: Running gawk -1.1.2 Running 'awk' Without Input Files +1.1.2 Running `awk' Without Input Files --------------------------------------- -You can also run 'awk' without any input files. If you type the +You can also run `awk' without any input files. If you type the following command line: awk 'PROGRAM' -'awk' applies the PROGRAM to the "standard input", which usually means +`awk' applies the PROGRAM to the "standard input", which usually means whatever you type on the keyboard. This continues until you indicate -end-of-file by typing 'Ctrl-d'. (On other operating systems, the +end-of-file by typing `Ctrl-d'. (On other operating systems, the end-of-file character may be different. For example, on OS/2, it is -'Ctrl-z'.) +`Ctrl-z'.) As an example, the following program prints a friendly piece of -<<<<<<< HEAD -advice (from Douglas Adams's 'The Hitchhiker's Guide to the Galaxy'), to -keep you from worrying about the complexities of computer programming(1) -('BEGIN' is a feature we haven't discussed yet): -======= advice (from Douglas Adams's `The Hitchhiker's Guide to the Galaxy'), to keep you from worrying about the complexities of computer programming: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac $ awk "BEGIN { print "Don\47t Panic!" }" -| Don't Panic! -<<<<<<< HEAD - This program does not read any input. The '\' before each of the -inner double quotes is necessary because of the shell's quoting -rules--in particular because it mixes both single quotes and double -quotes.(2) -======= `awk' executes statements associated with `BEGIN' before reading any input. If there are no other statements in your program, as is the case here, `awk' just stops, instead of trying to read input it doesn't @@ -1577,11 +1472,10 @@ tricks. interactively, to disable the C shell-style command history, which treats `!' as a special character. We recommend putting this command into your personal startup file. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - This next simple 'awk' program emulates the 'cat' utility; it copies -whatever you type on the keyboard to its standard output (why this works -is explained shortly). + This next simple `awk' program emulates the `cat' utility; it copies +whatever you type on the keyboard to its standard output (why this +works is explained shortly). $ awk '{ print }' Now is the time for all good men @@ -1594,45 +1488,25 @@ is explained shortly). -| What, me worry? Ctrl-d -<<<<<<< HEAD - ---------- Footnotes ---------- - - (1) If you use Bash as your shell, you should execute the command -'set +H' before running this program interactively, to disable the C -shell-style command history, which treats '!' as a special character. -We recommend putting this command into your personal startup file. - - (2) Although we generally recommend the use of single quotes around -the program text, double quotes are needed here in order to put the -single quote into the message. - -======= ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Long, Next: Executable Scripts, Prev: Read Terminal, Up: Running gawk 1.1.3 Running Long Programs --------------------------- -Sometimes your 'awk' programs can be very long. In this case, it is +Sometimes your `awk' programs can be very long. In this case, it is more convenient to put the program into a separate file. In order to -tell 'awk' to use that file for its program, you type: +tell `awk' to use that file for its program, you type: awk -f SOURCE-FILE INPUT-FILE1 INPUT-FILE2 ... -<<<<<<< HEAD - The '-f' instructs the 'awk' utility to get the 'awk' program from -the file SOURCE-FILE. Any file name can be used for SOURCE-FILE. For -example, you could put the program: -======= The `-f' instructs the `awk' utility to get the `awk' program from the file SOURCE-FILE (*note Options::). Any file name can be used for SOURCE-FILE. For example, you could put the program: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac BEGIN { print "Don't Panic!" } -into the file 'advice'. Then this command: +into the file `advice'. Then this command: awk -f advice @@ -1640,57 +1514,49 @@ does the same thing as this one: awk "BEGIN { print \"Don't Panic!\" }" -This was explained earlier (*note Read Terminal::). Note that you don't -usually need single quotes around the file name that you specify with -'-f', because most file names don't contain any of the shell's special -characters. Notice that in 'advice', the 'awk' program did not have -single quotes around it. The quotes are only needed for programs that -are provided on the 'awk' command line. +This was explained earlier (*note Read Terminal::). Note that you +don't usually need single quotes around the file name that you specify +with `-f', because most file names don't contain any of the shell's +special characters. Notice that in `advice', the `awk' program did not +have single quotes around it. The quotes are only needed for programs +that are provided on the `awk' command line. - If you want to clearly identify your 'awk' program files as such, you -can add the extension '.awk' to the file name. This doesn't affect the -execution of the 'awk' program but it does make "housekeeping" easier. + If you want to clearly identify your `awk' program files as such, +you can add the extension `.awk' to the file name. This doesn't affect +the execution of the `awk' program but it does make "housekeeping" +easier.  File: gawk.info, Node: Executable Scripts, Next: Comments, Prev: Long, Up: Running gawk -1.1.4 Executable 'awk' Programs +1.1.4 Executable `awk' Programs ------------------------------- -Once you have learned 'awk', you may want to write self-contained 'awk' -scripts, using the '#!' script mechanism. You can do this on many -systems.(1) For example, you could update the file 'advice' to look +Once you have learned `awk', you may want to write self-contained `awk' +scripts, using the `#!' script mechanism. You can do this on many +systems.(1) For example, you could update the file `advice' to look like this: #! /bin/awk -f BEGIN { print "Don't Panic!" } -<<<<<<< HEAD -After making this file executable (with the 'chmod' utility), simply -type 'advice' at the shell and the system arranges to run 'awk'(2) as if -you had typed 'awk -f advice': -======= After making this file executable (with the `chmod' utility), simply type `advice' at the shell and the system arranges to run `awk' as if you had typed `awk -f advice': ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac $ chmod +x advice $ advice -| Don't Panic! (We assume you have the current directory in your shell's search path -variable [typically '$PATH']. If not, you may need to type './advice' +variable [typically `$PATH']. If not, you may need to type `./advice' at the shell.) - Self-contained 'awk' scripts are useful when you want to write a + Self-contained `awk' scripts are useful when you want to write a program that users can invoke without their having to know that the -program is written in 'awk'. +program is written in `awk'. -<<<<<<< HEAD - Portability Issues with '#!' -======= Understanding `#!' `awk' is an "interpreted" language. This means that the `awk' @@ -1709,44 +1575,31 @@ executed program. The first argument in the list is the full file name of the `awk' program. The rest of the argument list contains either options to `awk', or data files, or both. Note that on many systems `awk' may be found in `/usr/bin' instead of in `/bin'. Caveat Emptor. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Some systems limit the length of the interpreter name to 32 characters. Often, this can be dealt with by using a symbolic link. - You should not put more than one argument on the '#!' line after the -path to 'awk'. It does not work. The operating system treats the rest -of the line as a single argument and passes it to 'awk'. Doing this -leads to confusing behavior--most likely a usage diagnostic of some sort -from 'awk'. + You should not put more than one argument on the `#!' line after the +path to `awk'. It does not work. The operating system treats the rest +of the line as a single argument and passes it to `awk'. Doing this +leads to confusing behavior--most likely a usage diagnostic of some +sort from `awk'. - Finally, the value of 'ARGV[0]' (*note Built-in Variables::) varies -depending upon your operating system. Some systems put 'awk' there, -some put the full pathname of 'awk' (such as '/bin/awk'), and some put -the name of your script ('advice'). (d.c.) Don't rely on the value of -'ARGV[0]' to provide your script name. + Finally, the value of `ARGV[0]' (*note Built-in Variables::) varies +depending upon your operating system. Some systems put `awk' there, +some put the full pathname of `awk' (such as `/bin/awk'), and some put +the name of your script (`advice'). (d.c.) Don't rely on the value of +`ARGV[0]' to provide your script name. ---------- Footnotes ---------- - (1) The '#!' mechanism works on GNU/Linux systems, BSD-based systems + (1) The `#!' mechanism works on GNU/Linux systems, BSD-based systems and commercial Unix systems. -<<<<<<< HEAD - (2) The line beginning with '#!' lists the full file name of an -interpreter to run and an optional initial command-line argument to pass -to that interpreter. The operating system then runs the interpreter -with the given argument and the full argument list of the executed -program. The first argument in the list is the full file name of the -'awk' program. The rest of the argument list contains either options to -'awk', or data files, or both. Note that on many systems 'awk' may be -found in '/usr/bin' instead of in '/bin'. Caveat Emptor. - -======= ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Comments, Next: Quoting, Prev: Executable Scripts, Up: Running gawk -1.1.5 Comments in 'awk' Programs +1.1.5 Comments in `awk' Programs -------------------------------- A "comment" is some text that is included in a program for the sake of @@ -1755,28 +1608,28 @@ Comments can explain what the program does and how it works. Nearly all programming languages have provisions for comments, as programs are typically hard to understand without them. - In the 'awk' language, a comment starts with the sharp sign character -('#') and continues to the end of the line. The '#' does not have to be -the first character on the line. The 'awk' language ignores the rest of -a line following a sharp sign. For example, we could have put the -following into 'advice': + In the `awk' language, a comment starts with the sharp sign +character (`#') and continues to the end of the line. The `#' does not +have to be the first character on the line. The `awk' language ignores +the rest of a line following a sharp sign. For example, we could have +put the following into `advice': # This program prints a nice friendly message. It helps # keep novice users from being afraid of the computer. BEGIN { print "Don't Panic!" } - You can put comment lines into keyboard-composed throwaway 'awk' + You can put comment lines into keyboard-composed throwaway `awk' programs, but this usually isn't very useful; the purpose of a comment is to help you or another person understand the program when reading it at a later time. - CAUTION: As mentioned in *note One-shot::, you can enclose small to - medium programs in single quotes, in order to keep your shell + CAUTION: As mentioned in *note One-shot::, you can enclose small + to medium programs in single quotes, in order to keep your shell scripts self-contained. When doing so, _don't_ put an apostrophe (i.e., a single quote) into a comment (or anywhere else in your - program). The shell interprets the quote as the closing quote for - the entire program. As a result, usually the shell prints a - message about mismatched quotes, and if 'awk' actually runs, it + program). The shell interprets the quote as the closing quote for + the entire program. As a result, usually the shell prints a + message about mismatched quotes, and if `awk' actually runs, it will probably print strange messages about syntax errors. For example, look at the following: @@ -1786,14 +1639,14 @@ at a later time. The shell sees that the first two quotes match, and that a new quoted object begins at the end of the command line. It therefore prompts with the secondary prompt, waiting for more input. With - Unix 'awk', closing the quoted string produces this result: + Unix `awk', closing the quoted string produces this result: $ awk '{ print "hello" } # let's be cute' > ' - error-> awk: can't open file be - error-> source line number 1 + error--> awk: can't open file be + error--> source line number 1 - Putting a backslash before the single quote in 'let's' wouldn't + Putting a backslash before the single quote in `let's' wouldn't help, since backslashes are not special inside single quotes. The next node describes the shell's quoting rules. @@ -1807,11 +1660,11 @@ File: gawk.info, Node: Quoting, Prev: Comments, Up: Running gawk * DOS Quoting:: Quoting in Windows Batch Files. -For short to medium length 'awk' programs, it is most convenient to -enter the program on the 'awk' command line. This is best done by -enclosing the entire program in single quotes. This is true whether you -are entering the program interactively at the shell prompt, or writing -it as part of a larger shell script: + For short to medium length `awk' programs, it is most convenient to +enter the program on the `awk' command line. This is best done by +enclosing the entire program in single quotes. This is true whether +you are entering the program interactively at the shell prompt, or +writing it as part of a larger shell script: awk 'PROGRAM TEXT' INPUT-FILE1 INPUT-FILE2 ... @@ -1824,16 +1677,16 @@ Shell). If you use the C shell, you're on your own. throughout this Info file, which is that of the "null", or empty, string. - The null string is character data that has no value. In other words, -it is empty. It is written in 'awk' programs like this: '""'. In the -shell, it can be written using single or double quotes: '""' or ''''. -While the null string has no characters in it, it does exist. Consider -this command: + The null string is character data that has no value. In other +words, it is empty. It is written in `awk' programs like this: `""'. +In the shell, it can be written using single or double quotes: `""' or +`'''. While the null string has no characters in it, it does exist. +Consider this command: $ echo "" -Here, the 'echo' utility receives a single argument, even though that -argument has no characters in it. In the rest of this Info file, we use +Here, the `echo' utility receives a single argument, even though that +argument has no characters in it. In the rest of this Info file, we use the terms "null string" and "empty string" interchangeably. Now, on to the quoting rules. @@ -1841,28 +1694,28 @@ the quoting rules. with other quoted items. The shell turns everything into one argument for the command. - * Preceding any single character with a backslash ('\') quotes that + * Preceding any single character with a backslash (`\') quotes that character. The shell removes the backslash and passes the quoted character on to the command. * Single quotes protect everything between the opening and closing quotes. The shell does no interpretation of the quoted text, - passing it on verbatim to the command. It is _impossible_ to embed - a single quote inside single-quoted text. Refer back to *note - Comments::, for an example of what happens if you try. + passing it on verbatim to the command. It is _impossible_ to + embed a single quote inside single-quoted text. Refer back to + *note Comments::, for an example of what happens if you try. * Double quotes protect most things between the opening and closing quotes. The shell does at least variable and command substitution on the quoted text. Different shells may do additional kinds of processing on double-quoted text. - Since certain characters within double-quoted text are processed by - the shell, they must be "escaped" within the text. Of note are the - characters '$', '`', '\', and '"', all of which must be preceded by - a backslash within double-quoted text if they are to be passed on - literally to the program. (The leading backslash is stripped - first.) Thus, the example seen in *note Read Terminal::, is - applicable: + Since certain characters within double-quoted text are processed + by the shell, they must be "escaped" within the text. Of note are + the characters `$', ``', `\', and `"', all of which must be + preceded by a backslash within double-quoted text if they are to + be passed on literally to the program. (The leading backslash is + stripped first.) Thus, the example seen in *note Read Terminal::, + is applicable: $ awk "BEGIN { print \"Don't Panic!\" }" -| Don't Panic! @@ -1870,15 +1723,9 @@ the quoting rules. Note that the single quote is not special within double quotes. * Null strings are removed when they occur as part of a non-null -<<<<<<< HEAD - command-line argument, while explicit non-null objects are kept. - For example, to specify that the field separator 'FS' should be set - to the null string, use: -======= command-line argument, while explicit null objects are kept. For example, to specify that the field separator `FS' should be set to the null string, use: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac awk -F "" 'PROGRAM' FILES # correct @@ -1886,8 +1733,8 @@ the quoting rules. awk -F"" 'PROGRAM' FILES # wrong! - In the second case, 'awk' will attempt to use the text of the - program as the value of 'FS', and the first file name as the text + In the second case, `awk' will attempt to use the text of the + program as the value of `FS', and the first file name as the text of the program! This results in syntax errors at best, and confusing behavior at worst. @@ -1908,17 +1755,17 @@ and the third are single-quoted, the second is double-quoted. Judge for yourself which of these two is the more readable. Another option is to use double quotes, escaping the embedded, -'awk'-level double quotes: +`awk'-level double quotes: $ awk "BEGIN { print \"Here is a single quote <'>\" }" -| Here is a single quote <'> This option is also painful, because double quotes, backslashes, and -dollar signs are very common in more advanced 'awk' programs. +dollar signs are very common in more advanced `awk' programs. - A third option is to use the octal escape sequence equivalents (*note -Escape Sequences::) for the single- and double-quote characters, like -so: + A third option is to use the octal escape sequence equivalents +(*note Escape Sequences::) for the single- and double-quote characters, +like so: $ awk 'BEGIN { print "Here is a single quote <\47>" }' -| Here is a single quote <'> @@ -1934,7 +1781,7 @@ this: $ awk -v sq="'" 'BEGIN { print "Here is a single quote <" sq ">" }' -| Here is a single quote <'> - If you really need both single and double quotes in your 'awk' + If you really need both single and double quotes in your `awk' program, it is probably best to move it into a separate file, where the shell won't be part of the picture, and you can say what you mean. @@ -1963,25 +1810,18 @@ File: gawk.info, Node: Sample Data Files, Next: Very Simple, Prev: Running ga =============================== Many of the examples in this Info file take their input from two sample -data files. The first, 'mail-list', represents a list of peoples' names +data files. The first, `mail-list', represents a list of peoples' names together with their email addresses and information about those people. -The second data file, called 'inventory-shipped', contains information +The second data file, called `inventory-shipped', contains information about monthly shipments. In both files, each line is considered to be one "record". - In the data file 'mail-list', each record contains the name of a + In the data file `mail-list', each record contains the name of a person, his/her phone number, his/her email-address, and a code for -<<<<<<< HEAD -their relationship with the author of the list. An 'A' in the last -column means that the person is an acquaintance. An 'F' in the last -column means that the person is a friend. An 'R' means that the person -is a relative: -======= their relationship with the author of the list. The columns are aligned using spaces. An `A' in the last column means that the person is an acquaintance. An `F' in the last column means that the person is a friend. An `R' means that the person is a relative: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Amelia 555-5553 amelia.zodiacusque@gmail.com F Anthony 555-3412 anthony.asserturo@hotmail.com A @@ -1995,7 +1835,7 @@ a friend. An `R' means that the person is a relative: Samuel 555-3430 samuel.lanceolis@shu.edu A Jean-Paul 555-2127 jeanpaul.campanorum@nyu.edu R - The data file 'inventory-shipped' represents information about + The data file `inventory-shipped' represents information about shipments during the year. Each record contains the month, the number of green crates shipped, the number of red boxes shipped, the number of orange bags shipped, and the number of blue packages shipped, @@ -2021,8 +1861,8 @@ the data for the two years. Mar 24 75 70 495 Apr 21 70 74 514 - The sample files are included in the 'gawk' distribution, in the -directory 'awklib/eg/data'. + The sample files are included in the `gawk' distribution, in the +directory `awklib/eg/data'.  File: gawk.info, Node: Very Simple, Next: Two Rules, Prev: Sample Data Files, Up: Getting Started @@ -2030,23 +1870,23 @@ File: gawk.info, Node: Very Simple, Next: Two Rules, Prev: Sample Data Files, 1.3 Some Simple Examples ======================== -The following command runs a simple 'awk' program that searches the -input file 'mail-list' for the character string 'li' (a grouping of +The following command runs a simple `awk' program that searches the +input file `mail-list' for the character string `li' (a grouping of characters is usually called a "string"; the term "string" is based on similar usage in English, such as "a string of pearls," or "a string of cars in a train"): awk '/li/ { print $0 }' mail-list -When lines containing 'li' are found, they are printed because 'print $0' -means print the current line. (Just 'print' by itself means the same -thing, so we could have written that instead.) +When lines containing `li' are found, they are printed because +`print $0' means print the current line. (Just `print' by itself means +the same thing, so we could have written that instead.) - You will notice that slashes ('/') surround the string 'li' in the -'awk' program. The slashes indicate that 'li' is the pattern to search + You will notice that slashes (`/') surround the string `li' in the +`awk' program. The slashes indicate that `li' is the pattern to search for. This type of pattern is called a "regular expression", which is covered in more detail later (*note Regexp::). The pattern is allowed -to match parts of words. There are single quotes around the 'awk' +to match parts of words. There are single quotes around the `awk' program so that the shell won't interpret any of it as special shell characters. @@ -2058,26 +1898,26 @@ characters. -| Julie 555-6699 julie.perscrutabor@skeeve.com F -| Samuel 555-3430 samuel.lanceolis@shu.edu A - In an 'awk' rule, either the pattern or the action can be omitted, + In an `awk' rule, either the pattern or the action can be omitted, but not both. If the pattern is omitted, then the action is performed -for _every_ input line. If the action is omitted, the default action is -to print all lines that match the pattern. +for _every_ input line. If the action is omitted, the default action +is to print all lines that match the pattern. - Thus, we could leave out the action (the 'print' statement and the -braces) in the previous example and the result would be the same: 'awk' -prints all lines matching the pattern 'li'. By comparison, omitting the -'print' statement but retaining the braces makes an empty action that -does nothing (i.e., no lines are printed). + Thus, we could leave out the action (the `print' statement and the +braces) in the previous example and the result would be the same: `awk' +prints all lines matching the pattern `li'. By comparison, omitting +the `print' statement but retaining the braces makes an empty action +that does nothing (i.e., no lines are printed). - Many practical 'awk' programs are just a line or two. Following is a + Many practical `awk' programs are just a line or two. Following is a collection of useful, short programs to get you started. Some of these -programs contain constructs that haven't been covered yet. (The +programs contain constructs that haven't been covered yet. (The description of the program will give you a good idea of what is going -on, but please read the rest of the Info file to become an 'awk' -expert!) Most of the examples use a data file named 'data'. This is +on, but please read the rest of the Info file to become an `awk' +expert!) Most of the examples use a data file named `data'. This is just a placeholder; if you use these programs yourself, substitute your -own file names for 'data'. For future reference, note that there is -often more than one way to do things in 'awk'. At some point, you may +own file names for `data'. For future reference, note that there is +often more than one way to do things in `awk'. At some point, you may want to look back at these examples and see if you can come up with different ways to do the same things shown here: @@ -2085,12 +1925,9 @@ different ways to do the same things shown here: awk 'length($0) > 80' data - The sole rule has a relational expression as its pattern and it has - no action--so it uses the default action, printing the record. + The sole rule has a relational expression as its pattern and it + has no action--so it uses the default action, printing the record. -<<<<<<< HEAD - * Print the length of the longest line in 'data': -======= * Print the length of the longest input line: awk '{ if (length($0) > max) max = length($0) } @@ -2100,21 +1937,14 @@ different ways to do the same things shown here: read; it's the other side of the coin to `BEGIN'. * Print the length of the longest line in `data': ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac expand data | awk '{ if (x < length($0)) x = length($0) } END { print "maximum line length is " x }' -<<<<<<< HEAD - The input is processed by the 'expand' utility to change TABs into - spaces, so the widths compared are actually the right-margin - columns. -======= This example differs slightly from the previous one: The input is processed by the `expand' utility to change TABs into spaces, so the widths compared are actually the right-margin columns, as opposed to the number of input characters on each line. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Print every line that has at least one field: @@ -2151,7 +1981,7 @@ different ways to do the same things shown here: awk 'NR % 2 == 0' data - If you use the expression 'NR % 2 == 1' instead, the program would + If you use the expression `NR % 2 == 1' instead, the program would print the odd-numbered lines.  @@ -2160,31 +1990,31 @@ File: gawk.info, Node: Two Rules, Next: More Complex, Prev: Very Simple, Up: 1.4 An Example with Two Rules ============================= -The 'awk' utility reads the input files one line at a time. For each -line, 'awk' tries the patterns of each of the rules. If several +The `awk' utility reads the input files one line at a time. For each +line, `awk' tries the patterns of each of the rules. If several patterns match, then several actions execute in the order in which they -appear in the 'awk' program. If no patterns match, then no actions run. +appear in the `awk' program. If no patterns match, then no actions run. - After processing all the rules that match the line (and perhaps there -are none), 'awk' reads the next line. (However, *note Next Statement::, -and also *note Nextfile Statement::). This continues until the program -reaches the end of the file. For example, the following 'awk' program -contains two rules: + After processing all the rules that match the line (and perhaps +there are none), `awk' reads the next line. (However, *note Next +Statement::, and also *note Nextfile Statement::). This continues +until the program reaches the end of the file. For example, the +following `awk' program contains two rules: /12/ { print $0 } /21/ { print $0 } -The first rule has the string '12' as the pattern and 'print $0' as the -action. The second rule has the string '21' as the pattern and also has -'print $0' as the action. Each rule's action is enclosed in its own -pair of braces. +The first rule has the string `12' as the pattern and `print $0' as the +action. The second rule has the string `21' as the pattern and also +has `print $0' as the action. Each rule's action is enclosed in its +own pair of braces. - This program prints every line that contains the string '12' _or_ the -string '21'. If a line contains both strings, it is printed twice, once -by each rule. + This program prints every line that contains the string `12' _or_ +the string `21'. If a line contains both strings, it is printed twice, +once by each rule. This is what happens if we run this program on our two sample data -files, 'mail-list' and 'inventory-shipped': +files, `mail-list' and `inventory-shipped': $ awk '/12/ { print $0 } > /21/ { print $0 }' mail-list inventory-shipped @@ -2196,7 +2026,7 @@ files, 'mail-list' and 'inventory-shipped': -| Jan 21 36 64 620 -| Apr 21 70 74 514 -Note how the line beginning with 'Jean-Paul' in 'mail-list' was printed +Note how the line beginning with `Jean-Paul' in `mail-list' was printed twice, once for each rule.  @@ -2206,7 +2036,7 @@ File: gawk.info, Node: More Complex, Next: Statements/Lines, Prev: Two Rules, ========================== Now that we've mastered some simple tasks, let's look at what typical -'awk' programs do. This example shows how 'awk' can be used to +`awk' programs do. This example shows how `awk' can be used to summarize, select, and rearrange the output of another utility. It uses features that haven't been covered yet, so don't worry if you don't understand all the details: @@ -2216,9 +2046,9 @@ understand all the details: This command prints the total number of bytes in all the files in the current directory that were last modified in November (of any year). -The 'ls -l' part of this example is a system command that gives you a +The `ls -l' part of this example is a system command that gives you a listing of the files in a directory, including each file's size and the -date the file was last modified. Its output looks like this: +date the file was last modified. Its output looks like this: -rw-r--r-- 1 arnold user 1933 Nov 7 13:05 Makefile -rw-r--r-- 1 arnold user 10809 Nov 7 13:03 awk.h @@ -2230,51 +2060,51 @@ date the file was last modified. Its output looks like this: -rw-r--r-- 1 arnold user 7989 Nov 7 13:03 awk4.c The first field contains read-write permissions, the second field -contains the number of links to the file, and the third field identifies -the owner of the file. The fourth field identifies the group of the -file. The fifth field contains the size of the file in bytes. The -sixth, seventh, and eighth fields contain the month, day, and time, +contains the number of links to the file, and the third field +identifies the owner of the file. The fourth field identifies the group +of the file. The fifth field contains the size of the file in bytes. +The sixth, seventh, and eighth fields contain the month, day, and time, respectively, that the file was last modified. Finally, the ninth field contains the file name.(1) - The '$6 == "Nov"' in our 'awk' program is an expression that tests -whether the sixth field of the output from 'ls -l' matches the string -'Nov'. Each time a line has the string 'Nov' for its sixth field, 'awk' -performs the action 'sum += $5'. This adds the fifth field (the file's -size) to the variable 'sum'. As a result, when 'awk' has finished -reading all the input lines, 'sum' is the total of the sizes of the -files whose lines matched the pattern. (This works because 'awk' -variables are automatically initialized to zero.) + The `$6 == "Nov"' in our `awk' program is an expression that tests +whether the sixth field of the output from `ls -l' matches the string +`Nov'. Each time a line has the string `Nov' for its sixth field, +`awk' performs the action `sum += $5'. This adds the fifth field (the +file's size) to the variable `sum'. As a result, when `awk' has +finished reading all the input lines, `sum' is the total of the sizes +of the files whose lines matched the pattern. (This works because +`awk' variables are automatically initialized to zero.) - After the last line of output from 'ls' has been processed, the 'END' -rule executes and prints the value of 'sum'. In this example, the value -of 'sum' is 80600. + After the last line of output from `ls' has been processed, the +`END' rule executes and prints the value of `sum'. In this example, +the value of `sum' is 80600. - These more advanced 'awk' techniques are covered in later sections + These more advanced `awk' techniques are covered in later sections (*note Action Overview::). Before you can move on to more advanced -'awk' programming, you have to know how 'awk' interprets your input and -displays your output. By manipulating fields and using 'print' +`awk' programming, you have to know how `awk' interprets your input and +displays your output. By manipulating fields and using `print' statements, you can produce some very useful and impressive-looking reports. ---------- Footnotes ---------- - (1) The 'LC_ALL=C' is needed to produce this traditional-style output -from 'ls'. + (1) The `LC_ALL=C' is needed to produce this traditional-style +output from `ls'.  File: gawk.info, Node: Statements/Lines, Next: Other Features, Prev: More Complex, Up: Getting Started -1.6 'awk' Statements Versus Lines +1.6 `awk' Statements Versus Lines ================================= -Most often, each line in an 'awk' program is a separate statement or +Most often, each line in an `awk' program is a separate statement or separate rule, like this: awk '/12/ { print $0 } /21/ { print $0 }' mail-list inventory-shipped - However, 'gawk' ignores newlines after any of the following symbols + However, `gawk' ignores newlines after any of the following symbols and keywords: , { ? : || && do else @@ -2283,7 +2113,7 @@ A newline at any other point is considered the end of the statement.(1) If you would like to split a single statement into two lines at a point where a newline would terminate it, you can "continue" it by -ending the first line with a backslash character ('\'). The backslash +ending the first line with a backslash character (`\'). The backslash must be the final character on the line in order to be recognized as a continuation character. A backslash is allowed anywhere in the statement, even in the middle of a string or regular expression. For @@ -2293,26 +2123,27 @@ example: on the next line/ { print $1 }' We have generally not used backslash continuation in our sample -programs. 'gawk' places no limit on the length of a line, so backslash +programs. `gawk' places no limit on the length of a line, so backslash continuation is never strictly necessary; it just makes programs more readable. For this same reason, as well as for clarity, we have kept most statements short in the programs presented throughout the Info -file. Backslash continuation is most useful when your 'awk' program is -in a separate source file instead of entered from the command line. You -should also note that many 'awk' implementations are more particular -about where you may use backslash continuation. For example, they may -not allow you to split a string constant using backslash continuation. -Thus, for maximum portability of your 'awk' programs, it is best not to -split your lines in the middle of a regular expression or a string. +file. Backslash continuation is most useful when your `awk' program is +in a separate source file instead of entered from the command line. +You should also note that many `awk' implementations are more +particular about where you may use backslash continuation. For example, +they may not allow you to split a string constant using backslash +continuation. Thus, for maximum portability of your `awk' programs, it +is best not to split your lines in the middle of a regular expression +or a string. CAUTION: _Backslash continuation does not work as described with - the C shell._ It works for 'awk' programs in files and for + the C shell._ It works for `awk' programs in files and for one-shot programs, _provided_ you are using a POSIX-compliant shell, such as the Unix Bourne shell or Bash. But the C shell - behaves differently! There, you must use two backslashes in a row, - followed by a newline. Note also that when using the C shell, - _every_ newline in your 'awk' program must be escaped with a - backslash. To illustrate: + behaves differently! There, you must use two backslashes in a + row, followed by a newline. Note also that when using the C + shell, _every_ newline in your `awk' program must be escaped with + a backslash. To illustrate: % awk 'BEGIN { \ ? print \\ @@ -2320,8 +2151,8 @@ split your lines in the middle of a regular expression or a string. ? }' -| hello, world - Here, the '%' and '?' are the C shell's primary and secondary - prompts, analogous to the standard shell's '$' and '>'. + Here, the `%' and `?' are the C shell's primary and secondary + prompts, analogous to the standard shell's `$' and `>'. Compare the previous example to how it is done with a POSIX-compliant shell: @@ -2332,120 +2163,97 @@ split your lines in the middle of a regular expression or a string. > }' -| hello, world - 'awk' is a line-oriented language. Each rule's action has to begin + `awk' is a line-oriented language. Each rule's action has to begin on the same line as the pattern. To have the pattern and action on -separate lines, you _must_ use backslash continuation; there is no other -option. +separate lines, you _must_ use backslash continuation; there is no +other option. Another thing to keep in mind is that backslash continuation and -comments do not mix. As soon as 'awk' sees the '#' that starts a -comment, it ignores _everything_ on the rest of the line. For example: +comments do not mix. As soon as `awk' sees the `#' that starts a +comment, it ignores _everything_ on the rest of the line. For example: $ gawk 'BEGIN { print "dont panic" # a friendly \ > BEGIN rule > }' - error-> gawk: cmd. line:2: BEGIN rule - error-> gawk: cmd. line:2: ^ syntax error + error--> gawk: cmd. line:2: BEGIN rule + error--> gawk: cmd. line:2: ^ syntax error In this case, it looks like the backslash would continue the comment -onto the next line. However, the backslash-newline combination is never -even noticed because it is "hidden" inside the comment. Thus, the -'BEGIN' is noted as a syntax error. +onto the next line. However, the backslash-newline combination is never +even noticed because it is "hidden" inside the comment. Thus, the +`BEGIN' is noted as a syntax error. - When 'awk' statements within one rule are short, you might want to -put more than one of them on a line. This is accomplished by separating -the statements with a semicolon (';'). This also applies to the rules -themselves. Thus, the program shown at the start of this minor node -could also be written this way: + When `awk' statements within one rule are short, you might want to +put more than one of them on a line. This is accomplished by +separating the statements with a semicolon (`;'). This also applies to +the rules themselves. Thus, the program shown at the start of this +minor node could also be written this way: /12/ { print $0 } ; /21/ { print $0 } NOTE: The requirement that states that rules on the same line must - be separated with a semicolon was not in the original 'awk' + be separated with a semicolon was not in the original `awk' language; it was added for consistency with the treatment of statements within an action. ---------- Footnotes ---------- - (1) The '?' and ':' referred to here is the three-operand conditional -expression described in *note Conditional Exp::. Splitting lines after -'?' and ':' is a minor 'gawk' extension; if '--posix' is specified -(*note Options::), then this extension is disabled. + (1) The `?' and `:' referred to here is the three-operand +conditional expression described in *note Conditional Exp::. Splitting +lines after `?' and `:' is a minor `gawk' extension; if `--posix' is +specified (*note Options::), then this extension is disabled.  File: gawk.info, Node: Other Features, Next: When, Prev: Statements/Lines, Up: Getting Started -1.7 Other Features of 'awk' +1.7 Other Features of `awk' =========================== -The 'awk' language provides a number of predefined, or "built-in", -variables that your programs can use to get information from 'awk'. +The `awk' language provides a number of predefined, or "built-in", +variables that your programs can use to get information from `awk'. There are other variables your program can set as well to control how -'awk' processes your data. +`awk' processes your data. - In addition, 'awk' provides a number of built-in functions for doing -common computational and string-related operations. 'gawk' provides + In addition, `awk' provides a number of built-in functions for doing +common computational and string-related operations. `gawk' provides built-in functions for working with timestamps, performing bit manipulation, for runtime string translation (internationalization), determining the type of a variable, and array sorting. -<<<<<<< HEAD - As we develop our presentation of the 'awk' language, we introduce -most of the variables and many of the functions. They are described -systematically in *note Built-in Variables::, and *note Built-in::. -======= As we develop our presentation of the `awk' language, we introduce most of the variables and many of the functions. They are described systematically in *note Built-in Variables::, and in *note Built-in::. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: When, Next: Intro Summary, Prev: Other Features, Up: Getting Started -1.8 When to Use 'awk' +1.8 When to Use `awk' ===================== -Now that you've seen some of what 'awk' can do, you might wonder how -'awk' could be useful for you. By using utility programs, advanced +Now that you've seen some of what `awk' can do, you might wonder how +`awk' could be useful for you. By using utility programs, advanced patterns, field separators, arithmetic statements, and other selection -criteria, you can produce much more complex output. The 'awk' language +criteria, you can produce much more complex output. The `awk' language is very useful for producing reports from large amounts of raw data, such as summarizing information from the output of other utility -programs like 'ls'. (*Note More Complex::.) +programs like `ls'. (*Note More Complex::.) - Programs written with 'awk' are usually much smaller than they would -be in other languages. This makes 'awk' programs easy to compose and -use. Often, 'awk' programs can be quickly composed at your keyboard, -used once, and thrown away. Because 'awk' programs are interpreted, you + Programs written with `awk' are usually much smaller than they would +be in other languages. This makes `awk' programs easy to compose and +use. Often, `awk' programs can be quickly composed at your keyboard, +used once, and thrown away. Because `awk' programs are interpreted, you can avoid the (usually lengthy) compilation part of the typical edit-compile-test-debug cycle of software development. - Complex programs have been written in 'awk', including a complete + Complex programs have been written in `awk', including a complete retargetable assembler for eight-bit microprocessors (*note Glossary::, for more information), and a microcode assembler for a special-purpose -<<<<<<< HEAD -Prolog computer. While the original 'awk''s capabilities were strained -by tasks of such complexity, modern versions are more capable. Even -Brian Kernighan's version of 'awk' has fewer predefined limits, and -those that it has are much larger than they used to be. -======= Prolog computer. While the original `awk''s capabilities were strained by tasks of such complexity, modern versions are more capable. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - If you find yourself writing 'awk' scripts of more than, say, a few + If you find yourself writing `awk' scripts of more than, say, a few hundred lines, you might consider using a different programming language. The shell is good at string and pattern matching; in -<<<<<<< HEAD -addition, it allows powerful use of the system utilities. More -conventional languages, such as C, C++, and Java, offer better -facilities for system programming and for managing the complexity of -large programs. Python offers a nice balance between high-level ease of -programming and access to system facilities. Programs in these -languages may require more lines of source code than the equivalent -'awk' programs, but they are easier to maintain and usually run more -efficiently. -======= addition, it allows powerful use of the system utilities. Python offers a nice balance between high-level ease of programming and access to system facilities.(1) @@ -2453,7 +2261,6 @@ to system facilities.(1) ---------- Footnotes ---------- (1) Other popular scripting languages include Ruby and Perl. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Intro Summary, Prev: When, Up: Getting Started @@ -2461,58 +2268,53 @@ File: gawk.info, Node: Intro Summary, Prev: When, Up: Getting Started 1.9 Summary =========== - * Programs in 'awk' consist of PATTERN-ACTION pairs. + * Programs in `awk' consist of PATTERN-ACTION pairs. -<<<<<<< HEAD - * Use either 'awk 'PROGRAM' FILES' or 'awk -f PROGRAM-FILE FILES' to - run 'awk'. -======= * An ACTION without a PATTERN always runs. The default ACTION for a pattern without one is `{ print $0 }'. * Use either `awk 'PROGRAM' FILES' or `awk -f PROGRAM-FILE FILES' to run `awk'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - * You may use the special '#!' header line to create 'awk' programs + * You may use the special `#!' header line to create `awk' programs that are directly executable. - * Comments in 'awk' programs start with '#' and continue to the end + * Comments in `awk' programs start with `#' and continue to the end of the same line. - * Be aware of quoting issues when writing 'awk' programs as part of a - larger shell script (or MS-Windows batch file). + * Be aware of quoting issues when writing `awk' programs as part of + a larger shell script (or MS-Windows batch file). * You may use backslash continuation to continue a source line. Lines are automatically continued after a comma, open brace, - question mark, colon, '||', '&&', 'do' and 'else'. + question mark, colon, `||', `&&', `do' and `else'.  File: gawk.info, Node: Invoking Gawk, Next: Regexp, Prev: Getting Started, Up: Top -2 Running 'awk' and 'gawk' +2 Running `awk' and `gawk' ************************** -This major node covers how to run 'awk', both POSIX-standard and -'gawk'-specific command-line options, and what 'awk' and 'gawk' do with -non-option arguments. It then proceeds to cover how 'gawk' searches for -source files, reading standard input along with other files, 'gawk''s -environment variables, 'gawk''s exit status, using include files, and -obsolete and undocumented options and/or features. +This major node covers how to run `awk', both POSIX-standard and +`gawk'-specific command-line options, and what `awk' and `gawk' do with +non-option arguments. It then proceeds to cover how `gawk' searches +for source files, reading standard input along with other files, +`gawk''s environment variables, `gawk''s exit status, using include +files, and obsolete and undocumented options and/or features. - Many of the options and features described here are discussed in more -detail later in the Info file; feel free to skip over things in this -major node that don't interest you right now. + Many of the options and features described here are discussed in +more detail later in the Info file; feel free to skip over things in +this major node that don't interest you right now. * Menu: -* Command Line:: How to run 'awk'. +* Command Line:: How to run `awk'. * Options:: Command-line options and their meanings. * Other Arguments:: Input file names and variable assignments. * Naming Standard Input:: How to specify standard input with other files. -* Environment Variables:: The environment variables 'gawk' uses. -* Exit Status:: 'gawk''s exit status. +* Environment Variables:: The environment variables `gawk' uses. +* Exit Status:: `gawk''s exit status. * Include Files:: Including other files into your program. * Loading Shared Libraries:: Loading shared libraries into your program. * Obsolete:: Obsolete Options and/or features. @@ -2522,26 +2324,26 @@ major node that don't interest you right now.  File: gawk.info, Node: Command Line, Next: Options, Up: Invoking Gawk -2.1 Invoking 'awk' +2.1 Invoking `awk' ================== -There are two ways to run 'awk'--with an explicit program or with one or -more program files. Here are templates for both of them; items enclosed -in [...] in these templates are optional: +There are two ways to run `awk'--with an explicit program or with one +or more program files. Here are templates for both of them; items +enclosed in [...] in these templates are optional: - 'awk' [OPTIONS] '-f' PROGFILE ['--'] FILE ... - 'awk' [OPTIONS] ['--'] ''PROGRAM'' FILE ... + `awk' [OPTIONS] `-f' PROGFILE [`--'] FILE ... + `awk' [OPTIONS] [`--'] `'PROGRAM'' FILE ... - Besides traditional one-letter POSIX-style options, 'gawk' also + Besides traditional one-letter POSIX-style options, `gawk' also supports GNU long options. - It is possible to invoke 'awk' with an empty program: + It is possible to invoke `awk' with an empty program: awk '' datafile1 datafile2 -Doing so makes little sense, though; 'awk' exits silently when given an -empty program. (d.c.) If '--lint' has been specified on the command -line, 'gawk' issues a warning that the program is empty. +Doing so makes little sense, though; `awk' exits silently when given an +empty program. (d.c.) If `--lint' has been specified on the command +line, `gawk' issues a warning that the program is empty.  File: gawk.info, Node: Options, Next: Other Arguments, Prev: Command Line, Up: Invoking Gawk @@ -2553,183 +2355,151 @@ Options begin with a dash and consist of a single character. GNU-style long options consist of two dashes and a keyword. The keyword can be abbreviated, as long as the abbreviation allows the option to be uniquely identified. If the option takes an argument, then the keyword -is either immediately followed by an equals sign ('=') and the +is either immediately followed by an equals sign (`=') and the argument's value, or the keyword and the argument's value are separated by whitespace. If a particular option with a value is given more than once, it is the last value that counts. - Each long option for 'gawk' has a corresponding POSIX-style short + Each long option for `gawk' has a corresponding POSIX-style short option. The long and short options are interchangeable in all contexts. The following list describes options mandated by the POSIX standard: -'-F FS' -'--field-separator FS' - Set the 'FS' variable to FS (*note Field Separators::). +`-F FS' +`--field-separator FS' + Set the `FS' variable to FS (*note Field Separators::). -'-f SOURCE-FILE' -'--file SOURCE-FILE' - Read 'awk' program source from SOURCE-FILE instead of in the first +`-f SOURCE-FILE' +`--file SOURCE-FILE' + Read `awk' program source from SOURCE-FILE instead of in the first non-option argument. This option may be given multiple times; the - 'awk' program consists of the concatenation of the contents of each - specified SOURCE-FILE. + `awk' program consists of the concatenation of the contents of + each specified SOURCE-FILE. -'-v VAR=VAL' -'--assign VAR=VAL' +`-v VAR=VAL' +`--assign VAR=VAL' Set the variable VAR to the value VAL _before_ execution of the program begins. Such variable values are available inside the - 'BEGIN' rule (*note Other Arguments::). + `BEGIN' rule (*note Other Arguments::). - The '-v' option can only set one variable, but it can be used more - than once, setting another variable each time, like this: 'awk -v foo=1 - -v bar=2 ...'. + The `-v' option can only set one variable, but it can be used more + than once, setting another variable each time, like this: `awk + -v foo=1 -v bar=2 ...'. - CAUTION: Using '-v' to set the values of the built-in - variables may lead to surprising results. 'awk' will reset + CAUTION: Using `-v' to set the values of the built-in + variables may lead to surprising results. `awk' will reset the values of those variables as it needs to, possibly ignoring any predefined value you may have given. -'-W GAWK-OPT' +`-W GAWK-OPT' Provide an implementation-specific option. This is the POSIX convention for providing implementation-specific options. These options also have corresponding GNU-style long options. Note that the long options may be abbreviated, as long as the abbreviations - remain unique. The full list of 'gawk'-specific options is + remain unique. The full list of `gawk'-specific options is provided next. -'--' +`--' Signal the end of the command-line options. The following - arguments are not treated as options even if they begin with '-'. - This interpretation of '--' follows the POSIX argument parsing + arguments are not treated as options even if they begin with `-'. + This interpretation of `--' follows the POSIX argument parsing conventions. - This is useful if you have file names that start with '-', or in - shell scripts, if you have file names that will be specified by the - user that could start with '-'. It is also useful for passing - options on to the 'awk' program; see *note Getopt Function::. + This is useful if you have file names that start with `-', or in + shell scripts, if you have file names that will be specified by + the user that could start with `-'. It is also useful for passing + options on to the `awk' program; see *note Getopt Function::. - The following list describes 'gawk'-specific options: + The following list describes `gawk'-specific options: -'-b' -'--characters-as-bytes' - Cause 'gawk' to treat all input data as single-byte characters. In - addition, all output written with 'print' or 'printf' are treated - as single-byte characters. +`-b' +`--characters-as-bytes' + Cause `gawk' to treat all input data as single-byte characters. + In addition, all output written with `print' or `printf' are + treated as single-byte characters. - Normally, 'gawk' follows the POSIX standard and attempts to process + Normally, `gawk' follows the POSIX standard and attempts to process its input data according to the current locale (*note Locales::). This can often involve converting multibyte characters into wide characters (internally), and can lead to problems or confusion if - the input data does not contain valid multibyte characters. This - option is an easy way to tell 'gawk': "hands off my data!". + the input data does not contain valid multibyte characters. This + option is an easy way to tell `gawk': "hands off my data!". -'-c' -'--traditional' +`-c' +`--traditional' Specify "compatibility mode", in which the GNU extensions to the -<<<<<<< HEAD - 'awk' language are disabled, so that 'gawk' behaves just like Brian - Kernighan's version 'awk'. *Note POSIX/GNU::, which summarizes the - extensions. Also see *note Compatibility Mode::. -======= `awk' language are disabled, so that `gawk' behaves just like BWK `awk'. *Note POSIX/GNU::, which summarizes the extensions. Also see *note Compatibility Mode::. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac -'-C' -'--copyright' +`-C' +`--copyright' Print the short version of the General Public License and then exit. -'-d'[FILE] -'--dump-variables'['='FILE] +`-d'[FILE] +`--dump-variables'[`='FILE] Print a sorted list of global variables, their types, and final values to FILE. If no FILE is provided, print this list to the - file named 'awkvars.out' in the current directory. No space is - allowed between the '-d' and FILE, if FILE is supplied. + file named `awkvars.out' in the current directory. No space is + allowed between the `-d' and FILE, if FILE is supplied. Having a list of all global variables is a good way to look for typographical errors in your programs. You would also use this - option if you have a large program with a lot of functions, and you - want to be sure that your functions don't inadvertently use global - variables that you meant to be local. (This is a particularly easy - mistake to make with simple variable names like 'i', 'j', etc.) - -'-D'[FILE] -'--debug'['='FILE] - Enable debugging of 'awk' programs (*note Debugging::). By + option if you have a large program with a lot of functions, and + you want to be sure that your functions don't inadvertently use + global variables that you meant to be local. (This is a + particularly easy mistake to make with simple variable names like + `i', `j', etc.) + +`-D'[FILE] +`--debug'[`='FILE] + Enable debugging of `awk' programs (*note Debugging::). By default, the debugger reads commands interactively from the keyboard. The optional FILE argument allows you to specify a file with a list of commands for the debugger to execute - non-interactively. No space is allowed between the '-D' and FILE, + non-interactively. No space is allowed between the `-D' and FILE, if FILE is supplied. -'-e' PROGRAM-TEXT -'--source' PROGRAM-TEXT +`-e' PROGRAM-TEXT +`--source' PROGRAM-TEXT Provide program source code in the PROGRAM-TEXT. This option allows you to mix source code in files with source code that you enter on the command line. This is particularly useful when you have library functions that you want to use from your command-line programs (*note AWKPATH Variable::). -'-E' FILE -'--exec' FILE - Similar to '-f', read 'awk' program text from FILE. There are two - differences from '-f': +`-E' FILE +`--exec' FILE + Similar to `-f', read `awk' program text from FILE. There are two + differences from `-f': - * This option terminates option processing; anything else on the - command line is passed on directly to the 'awk' program. + * This option terminates option processing; anything else on + the command line is passed on directly to the `awk' program. - * Command-line variable assignments of the form 'VAR=VALUE' are + * Command-line variable assignments of the form `VAR=VALUE' are disallowed. This option is particularly necessary for World Wide Web CGI -<<<<<<< HEAD - applications that pass arguments through the URL; using this option - prevents a malicious (or other) user from passing in options, - assignments, or 'awk' source code (via '--source') to the CGI - application. This option should be used with '#!' scripts (*note -======= applications that pass arguments through the URL; using this option prevents a malicious (or other) user from passing in options, assignments, or `awk' source code (via `-e') to the CGI application. This option should be used with `#!' scripts (*note ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Executable Scripts::), like so: #! /usr/local/bin/gawk -E AWK PROGRAM HERE ... -'-g' -'--gen-pot' - Analyze the source program and generate a GNU 'gettext' Portable +`-g' +`--gen-pot' + Analyze the source program and generate a GNU `gettext' Portable Object Template file on standard output for all string constants that have been marked for translation. *Note Internationalization::, for information about this option. -'-h' -'--help' +`-h' +`--help' Print a "usage" message summarizing the short and long style -<<<<<<< HEAD - options that 'gawk' accepts and then exit. - -'-i' SOURCE-FILE -'--include' SOURCE-FILE - Read 'awk' source library from SOURCE-FILE. This option is - completely equivalent to using the '@include' directive inside your - program. This option is very similar to the '-f' option, but there - are two important differences. First, when '-i' is used, the - program source is not loaded if it has been previously loaded, - whereas with '-f', 'gawk' always loads the file. Second, because - this option is intended to be used with code libraries, 'gawk' does - not recognize such files as constituting main program input. Thus, - after processing an '-i' argument, 'gawk' still expects to find the - main source code via the '-f' option or on the command-line. - -'-l' EXT -'--load' EXT - Load a dynamic extension named EXT. Extensions are stored as -======= options that `gawk' accepts and then exit. `-i' SOURCE-FILE @@ -2749,181 +2519,158 @@ The following list describes options mandated by the POSIX standard: `-l' EXT `--load' EXT Load a dynamic extension named EXT. Extensions are stored as ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac system shared libraries. This option searches for the library - using the 'AWKLIBPATH' environment variable. The correct library + using the `AWKLIBPATH' environment variable. The correct library suffix for your platform will be supplied by default, so it need not be specified in the extension name. The extension - initialization routine should be named 'dl_load()'. An alternative - is to use the '@load' keyword inside the program to load a shared - library. This feature is described in detail in *note Dynamic - Extensions::. + initialization routine should be named `dl_load()'. An + alternative is to use the `@load' keyword inside the program to + load a shared library. This feature is described in detail in + *note Dynamic Extensions::. -'-L'[VALUE] -'--lint'['='VALUE] +`-L'[VALUE] +`--lint'[`='VALUE] Warn about constructs that are dubious or nonportable to other -<<<<<<< HEAD - 'awk' implementations. No space is allowed between the '-D' and - VALUE, if VALUE is supplied. Some warnings are issued when 'gawk' -======= `awk' implementations. No space is allowed between the `-L' and VALUE, if VALUE is supplied. Some warnings are issued when `gawk' ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac first reads your program. Others are issued at runtime, as your - program executes. With an optional argument of 'fatal', lint + program executes. With an optional argument of `fatal', lint warnings become fatal errors. This may be drastic, but its use - will certainly encourage the development of cleaner 'awk' programs. - With an optional argument of 'invalid', only warnings about things - that are actually invalid are issued. (This is not fully + will certainly encourage the development of cleaner `awk' programs. + With an optional argument of `invalid', only warnings about things + that are actually invalid are issued. (This is not fully implemented yet.) - Some warnings are only printed once, even if the dubious constructs - they warn about occur multiple times in your 'awk' program. Thus, - when eliminating problems pointed out by '--lint', you should take - care to search for all occurrences of each inappropriate construct. - As 'awk' programs are usually short, doing so is not burdensome. - -'-M' -'--bignum' - Force arbitrary precision arithmetic on numbers. This option has - no effect if 'gawk' is not compiled to use the GNU MPFR and MP + Some warnings are only printed once, even if the dubious + constructs they warn about occur multiple times in your `awk' + program. Thus, when eliminating problems pointed out by `--lint', + you should take care to search for all occurrences of each + inappropriate construct. As `awk' programs are usually short, + doing so is not burdensome. + +`-M' +`--bignum' + Force arbitrary precision arithmetic on numbers. This option has + no effect if `gawk' is not compiled to use the GNU MPFR and MP libraries (*note Arbitrary Precision Arithmetic::). -'-n' -'--non-decimal-data' +`-n' +`--non-decimal-data' Enable automatic interpretation of octal and hexadecimal values in input data (*note Nondecimal Data::). CAUTION: This option can severely break old programs. Use with care. -'-N' -'--use-lc-numeric' +`-N' +`--use-lc-numeric' Force the use of the locale's decimal point character when parsing numeric input data (*note Locales::). -'-o'[FILE] -'--pretty-print'['='FILE] - Enable pretty-printing of 'awk' programs. By default, output - program is created in a file named 'awkprof.out' (*note +`-o'[FILE] +`--pretty-print'[`='FILE] + Enable pretty-printing of `awk' programs. By default, output + program is created in a file named `awkprof.out' (*note Profiling::). The optional FILE argument allows you to specify a different file name for the output. No space is allowed between - the '-o' and FILE, if FILE is supplied. + the `-o' and FILE, if FILE is supplied. NOTE: In the past, this option would also execute your program. This is no longer the case. -'-O' -'--optimize' +`-O' +`--optimize' Enable some optimizations on the internal representation of the program. At the moment this includes just simple constant folding. -'-p'[FILE] -'--profile'['='FILE] - Enable profiling of 'awk' programs (*note Profiling::). By - default, profiles are created in a file named 'awkprof.out'. The +`-p'[FILE] +`--profile'[`='FILE] + Enable profiling of `awk' programs (*note Profiling::). By + default, profiles are created in a file named `awkprof.out'. The optional FILE argument allows you to specify a different file name - for the profile file. No space is allowed between the '-p' and + for the profile file. No space is allowed between the `-p' and FILE, if FILE is supplied. The profile contains execution counts for each statement in the program in the left margin, and function call counts for each function. -'-P' -'--posix' - Operate in strict POSIX mode. This disables all 'gawk' extensions - (just like '--traditional') and disables all extensions not allowed - by POSIX. *Note Common Extensions::, for a summary of the - extensions in 'gawk' that are disabled by this option. Also, the +`-P' +`--posix' + Operate in strict POSIX mode. This disables all `gawk' extensions + (just like `--traditional') and disables all extensions not + allowed by POSIX. *Note Common Extensions::, for a summary of the + extensions in `gawk' that are disabled by this option. Also, the following additional restrictions apply: - * Newlines do not act as whitespace to separate fields when 'FS' - is equal to a single space (*note Fields::). + * Newlines do not act as whitespace to separate fields when + `FS' is equal to a single space (*note Fields::). - * Newlines are not allowed after '?' or ':' (*note Conditional + * Newlines are not allowed after `?' or `:' (*note Conditional Exp::). -<<<<<<< HEAD - * Specifying '-Ft' on the command-line does not set the value of - 'FS' to be a single TAB character (*note Field Separators::). -======= * Specifying `-Ft' on the command line does not set the value of `FS' to be a single TAB character (*note Field Separators::). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * The locale's decimal point character is used for parsing input data (*note Locales::). - If you supply both '--traditional' and '--posix' on the command - line, '--posix' takes precedence. 'gawk' issues a warning if both + If you supply both `--traditional' and `--posix' on the command + line, `--posix' takes precedence. `gawk' issues a warning if both options are supplied. -'-r' -'--re-interval' +`-r' +`--re-interval' Allow interval expressions (*note Regexp Operators::) in regexps. - This is now 'gawk''s default behavior. Nevertheless, this option - remains both for backward compatibility, and for use in combination - with '--traditional'. - -'-S' -'--sandbox' - Disable the 'system()' function, input redirections with 'getline', - output redirections with 'print' and 'printf', and dynamic - extensions. This is particularly useful when you want to run 'awk' - scripts from questionable sources and need to make sure the scripts - can't access your system (other than the specified input data - file). - -'-t' -'--lint-old' + This is now `gawk''s default behavior. Nevertheless, this option + remains both for backward compatibility, and for use in + combination with `--traditional'. + +`-S' +`--sandbox' + Disable the `system()' function, input redirections with `getline', + output redirections with `print' and `printf', and dynamic + extensions. This is particularly useful when you want to run + `awk' scripts from questionable sources and need to make sure the + scripts can't access your system (other than the specified input + data file). + +`-t' +`--lint-old' Warn about constructs that are not available in the original - version of 'awk' from Version 7 Unix (*note V7/SVR3.1::). + version of `awk' from Version 7 Unix (*note V7/SVR3.1::). -'-V' -'--version' - Print version information for this particular copy of 'gawk'. This - allows you to determine if your copy of 'gawk' is up to date with - respect to whatever the Free Software Foundation is currently +`-V' +`--version' + Print version information for this particular copy of `gawk'. + This allows you to determine if your copy of `gawk' is up to date + with respect to whatever the Free Software Foundation is currently distributing. It is also useful for bug reports (*note Bugs::). As long as program text has been supplied, any other options are flagged as invalid with a warning message but are otherwise ignored. In compatibility mode, as a special case, if the value of FS supplied -to the '-F' option is 't', then 'FS' is set to the TAB character -('"\t"'). This is true only for '--traditional' and not for '--posix' +to the `-F' option is `t', then `FS' is set to the TAB character +(`"\t"'). This is true only for `--traditional' and not for `--posix' (*note Field Separators::). - The '-f' option may be used more than once on the command line. If -it is, 'awk' reads its program source from all of the named files, as if -they had been concatenated together into one big file. This is useful -for creating libraries of 'awk' functions. These functions can be -written once and then retrieved from a standard place, instead of having -to be included into each individual program. (As mentioned in *note -Definition Syntax::, function names must be unique.) - - With standard 'awk', library functions can still be used, even if the -program is entered at the keyboard, by specifying '-f /dev/tty'. After -typing your program, type 'Ctrl-d' (the end-of-file character) to -terminate it. (You may also use '-f -' to read program source from the + The `-f' option may be used more than once on the command line. If +it is, `awk' reads its program source from all of the named files, as +if they had been concatenated together into one big file. This is +useful for creating libraries of `awk' functions. These functions can +be written once and then retrieved from a standard place, instead of +having to be included into each individual program. (As mentioned in +*note Definition Syntax::, function names must be unique.) + + With standard `awk', library functions can still be used, even if +the program is entered at the keyboard, by specifying `-f /dev/tty'. +After typing your program, type `Ctrl-d' (the end-of-file character) to +terminate it. (You may also use `-f -' to read program source from the standard input but then you will not be able to also use the standard input as a source of data.) -<<<<<<< HEAD - Because it is clumsy using the standard 'awk' mechanisms to mix -source file and command-line 'awk' programs, 'gawk' provides the -'--source' option. This does not require you to pre-empt the standard -input for your source code; it allows you to easily mix command-line and -library source code (*note AWKPATH Variable::). As with '-f', the -'--source' and '--include' options may also be used multiple times on -the command line. - - If no '-f' or '--source' option is specified, then 'gawk' uses the -first non-option command-line argument as the text of the program source -code. -======= Because it is clumsy using the standard `awk' mechanisms to mix source file and command-line `awk' programs, `gawk' provides the `-e' option. This does not require you to pre-empt the standard input for @@ -2933,30 +2680,29 @@ options may also be used multiple times on the command line. If no `-f' or `-e' option is specified, then `gawk' uses the first non-option command-line argument as the text of the program source code. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - If the environment variable 'POSIXLY_CORRECT' exists, then 'gawk' -behaves in strict POSIX mode, exactly as if you had supplied '--posix'. + If the environment variable `POSIXLY_CORRECT' exists, then `gawk' +behaves in strict POSIX mode, exactly as if you had supplied `--posix'. Many GNU programs look for this environment variable to suppress -extensions that conflict with POSIX, but 'gawk' behaves differently: it +extensions that conflict with POSIX, but `gawk' behaves differently: it suppresses all extensions, even those that do not conflict with POSIX, -and behaves in strict POSIX mode. If '--lint' is supplied on the -command line and 'gawk' turns on POSIX mode because of -'POSIXLY_CORRECT', then it issues a warning message indicating that +and behaves in strict POSIX mode. If `--lint' is supplied on the +command line and `gawk' turns on POSIX mode because of +`POSIXLY_CORRECT', then it issues a warning message indicating that POSIX mode is in effect. You would typically set this variable in your -shell's startup file. For a Bourne-compatible shell (such as Bash), you -would add these lines to the '.profile' file in your home directory: +shell's startup file. For a Bourne-compatible shell (such as Bash), +you would add these lines to the `.profile' file in your home directory: POSIXLY_CORRECT=true export POSIXLY_CORRECT For a C shell-compatible shell,(1) you would add this line to the -'.login' file in your home directory: +`.login' file in your home directory: setenv POSIXLY_CORRECT true - Having 'POSIXLY_CORRECT' set is not recommended for daily use, but it -is good for testing the portability of your programs to other + Having `POSIXLY_CORRECT' set is not recommended for daily use, but +it is good for testing the portability of your programs to other environments. ---------- Footnotes ---------- @@ -2970,57 +2716,57 @@ File: gawk.info, Node: Other Arguments, Next: Naming Standard Input, Prev: Op ================================ Any additional arguments on the command line are normally treated as -input files to be processed in the order specified. However, an -argument that has the form 'VAR=VALUE', assigns the value VALUE to the +input files to be processed in the order specified. However, an +argument that has the form `VAR=VALUE', assigns the value VALUE to the variable VAR--it does not specify a file at all. (See *note Assignment Options::.) - All these arguments are made available to your 'awk' program in the -'ARGV' array (*note Built-in Variables::). Command-line options and the -program text (if present) are omitted from 'ARGV'. All other arguments, -including variable assignments, are included. As each element of 'ARGV' -is processed, 'gawk' sets the variable 'ARGIND' to the index in 'ARGV' -of the current element. + All these arguments are made available to your `awk' program in the +`ARGV' array (*note Built-in Variables::). Command-line options and +the program text (if present) are omitted from `ARGV'. All other +arguments, including variable assignments, are included. As each +element of `ARGV' is processed, `gawk' sets the variable `ARGIND' to +the index in `ARGV' of the current element. Changing `ARGC' and `ARGV' in your `awk' program lets you control how `awk' processes the input files; this is described in more detail in *note ARGC and ARGV::. The distinction between file name arguments and variable-assignment -arguments is made when 'awk' is about to open the next input file. At +arguments is made when `awk' is about to open the next input file. At that point in execution, it checks the file name to see whether it is -really a variable assignment; if so, 'awk' sets the variable instead of +really a variable assignment; if so, `awk' sets the variable instead of reading a file. Therefore, the variables actually receive the given values after all previously specified files have been read. In particular, the values of -variables assigned in this fashion are _not_ available inside a 'BEGIN' -rule (*note BEGIN/END::), because such rules are run before 'awk' begins -scanning the argument list. +variables assigned in this fashion are _not_ available inside a `BEGIN' +rule (*note BEGIN/END::), because such rules are run before `awk' +begins scanning the argument list. The variable values given on the command line are processed for escape sequences (*note Escape Sequences::). (d.c.) - In some very early implementations of 'awk', when a variable + In some very early implementations of `awk', when a variable assignment occurred before any file names, the assignment would happen -_before_ the 'BEGIN' rule was executed. 'awk''s behavior was thus +_before_ the `BEGIN' rule was executed. `awk''s behavior was thus inconsistent; some command-line assignments were available inside the -'BEGIN' rule, while others were not. Unfortunately, some applications -came to depend upon this "feature." When 'awk' was changed to be more -consistent, the '-v' option was added to accommodate applications that +`BEGIN' rule, while others were not. Unfortunately, some applications +came to depend upon this "feature." When `awk' was changed to be more +consistent, the `-v' option was added to accommodate applications that depended upon the old behavior. The variable assignment feature is most useful for assigning to -variables such as 'RS', 'OFS', and 'ORS', which control input and output -formats, before scanning the data files. It is also useful for +variables such as `RS', `OFS', and `ORS', which control input and +output formats, before scanning the data files. It is also useful for controlling state if multiple passes are needed over a data file. For example: awk 'pass == 1 { PASS 1 STUFF } pass == 2 { PASS 2 STUFF }' pass=1 mydata pass=2 mydata - Given the variable assignment feature, the '-F' option for setting -the value of 'FS' is not strictly necessary. It remains for historical + Given the variable assignment feature, the `-F' option for setting +the value of `FS' is not strictly necessary. It remains for historical compatibility.  @@ -3033,140 +2779,121 @@ Often, you may wish to read standard input together with other files. For example, you may wish to read one file, read standard input coming from a pipe, and then read another file. - The way to name the standard input, with all versions of 'awk', is to -use a single, standalone minus sign or dash, '-'. For example: + The way to name the standard input, with all versions of `awk', is +to use a single, standalone minus sign or dash, `-'. For example: SOME_COMMAND | awk -f myprog.awk file1 - file2 -Here, 'awk' first reads 'file1', then it reads the output of -SOME_COMMAND, and finally it reads 'file2'. +Here, `awk' first reads `file1', then it reads the output of +SOME_COMMAND, and finally it reads `file2'. - You may also use '"-"' to name standard input when reading files with -'getline' (*note Getline/File::). + You may also use `"-"' to name standard input when reading files +with `getline' (*note Getline/File::). -<<<<<<< HEAD - In addition, 'gawk' allows you to specify the special file name -'/dev/stdin', both on the command line and with 'getline'. Some other -versions of 'awk' also support this, but it is not standard. (Some -operating systems provide a '/dev/stdin' file in the file system; -however, 'gawk' always processes this file name itself.) -======= In addition, `gawk' allows you to specify the special file name `/dev/stdin', both on the command line and with `getline'. Some other versions of `awk' also support this, but it is not standard. (Some operating systems provide a `/dev/stdin' file in the filesystem; however, `gawk' always processes this file name itself.) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Environment Variables, Next: Exit Status, Prev: Naming Standard Input, Up: Invoking Gawk -2.5 The Environment Variables 'gawk' Uses +2.5 The Environment Variables `gawk' Uses ========================================= -A number of environment variables influence how 'gawk' behaves. +A number of environment variables influence how `gawk' behaves. * Menu: -* AWKPATH Variable:: Searching directories for 'awk' +* AWKPATH Variable:: Searching directories for `awk' programs. -* AWKLIBPATH Variable:: Searching directories for 'awk' shared +* AWKLIBPATH Variable:: Searching directories for `awk' shared libraries. * Other Environment Variables:: The environment variables.  File: gawk.info, Node: AWKPATH Variable, Next: AWKLIBPATH Variable, Up: Environment Variables -2.5.1 The 'AWKPATH' Environment Variable +2.5.1 The `AWKPATH' Environment Variable ---------------------------------------- -<<<<<<< HEAD -The previous minor node described how 'awk' program files can be named -on the command-line with the '-f' option. In most 'awk' -======= The previous minor node described how `awk' program files can be named on the command line with the `-f' option. In most `awk' ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac implementations, you must supply a precise path name for each program -file, unless the file is in the current directory. But in 'gawk', if -the file name supplied to the '-f' or '-i' options does not contain a -directory separator '/', then 'gawk' searches a list of directories +file, unless the file is in the current directory. But in `gawk', if +the file name supplied to the `-f' or `-i' options does not contain a +directory separator `/', then `gawk' searches a list of directories (called the "search path"), one by one, looking for a file with the specified name. - The search path is a string consisting of directory names separated -by colons(1). 'gawk' gets its search path from the 'AWKPATH' -environment variable. If that variable does not exist, 'gawk' uses a -default path, '.:/usr/local/share/awk'.(2) +The search path is a string consisting of directory names separated by +colons(1). `gawk' gets its search path from the `AWKPATH' environment +variable. If that variable does not exist, `gawk' uses a default path, +`.:/usr/local/share/awk'.(2) The search path feature is particularly helpful for building -libraries of useful 'awk' functions. The library files can be placed in -a standard directory in the default path and then specified on the +libraries of useful `awk' functions. The library files can be placed +in a standard directory in the default path and then specified on the command line with a short file name. Otherwise, the full file name would have to be typed for each file. -<<<<<<< HEAD - By using the '-i' option, or the '--source' and '-f' options, your -command-line 'awk' programs can use facilities in 'awk' library files -(*note Library Functions::). Path searching is not done if 'gawk' is in -compatibility mode. This is true for both '--traditional' and -'--posix'. *Note Options::. -======= By using the `-i' option, or the `-e' and `-f' options, your command-line `awk' programs can use facilities in `awk' library files (*note Library Functions::). Path searching is not done if `gawk' is in compatibility mode. This is true for both `--traditional' and `--posix'. *Note Options::. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - If the source code is not found after the initial search, the path is -searched again after adding the default '.awk' suffix to the file name. + If the source code is not found after the initial search, the path +is searched again after adding the default `.awk' suffix to the file +name. NOTE: To include the current directory in the path, either place - '.' explicitly in the path or write a null entry in the path. (A - null entry is indicated by starting or ending the path with a colon - or by placing two colons next to each other ['::'].) This path - search mechanism is similar to the shell's. (See 'The Bourne-Again - SHell manual'. (http://www.gnu.org/software/bash/manual/)) - - However, 'gawk' always looks in the current directory _before_ - searching 'AWKPATH', so there is no real reason to include the + `.' explicitly in the path or write a null entry in the path. (A + null entry is indicated by starting or ending the path with a + colon or by placing two colons next to each other [`::'].) This + path search mechanism is similar to the shell's. (See `The + Bourne-Again SHell manual'. + (http://www.gnu.org/software/bash/manual/)) + + However, `gawk' always looks in the current directory _before_ + searching `AWKPATH', so there is no real reason to include the current directory in the search path. - If 'AWKPATH' is not defined in the environment, 'gawk' places its -default search path into 'ENVIRON["AWKPATH"]'. This makes it easy to -determine the actual search path that 'gawk' used from within an 'awk' + If `AWKPATH' is not defined in the environment, `gawk' places its +default search path into `ENVIRON["AWKPATH"]'. This makes it easy to +determine the actual search path that `gawk' used from within an `awk' program. - While you can change 'ENVIRON["AWKPATH"]' within your 'awk' program, -this has no effect on the running program's behavior. This makes sense: -the 'AWKPATH' environment variable is used to find the program source -files. Once your program is running, all the files have been found, and -'gawk' no longer needs to use 'AWKPATH'. + While you can change `ENVIRON["AWKPATH"]' within your `awk' program, +this has no effect on the running program's behavior. This makes +sense: the `AWKPATH' environment variable is used to find the program +source files. Once your program is running, all the files have been +found, and `gawk' no longer needs to use `AWKPATH'. ---------- Footnotes ---------- (1) Semicolons on MS-Windows and MS-DOS. - (2) Your version of 'gawk' may use a different directory; it will -depend upon how 'gawk' was built and installed. The actual directory is -the value of '$(datadir)' generated when 'gawk' was configured. You + (2) Your version of `gawk' may use a different directory; it will +depend upon how `gawk' was built and installed. The actual directory is +the value of `$(datadir)' generated when `gawk' was configured. You probably don't need to worry about this, though.  File: gawk.info, Node: AWKLIBPATH Variable, Next: Other Environment Variables, Prev: AWKPATH Variable, Up: Environment Variables -2.5.2 The 'AWKLIBPATH' Environment Variable +2.5.2 The `AWKLIBPATH' Environment Variable ------------------------------------------- -The 'AWKLIBPATH' environment variable is similar to the 'AWKPATH' +The `AWKLIBPATH' environment variable is similar to the `AWKPATH' variable, but it is used to search for loadable extensions (stored as -system shared libraries) specified with the '-l' option rather than for -source files. If the extension is not found, the path is searched again -after adding the appropriate shared library suffix for the platform. -For example, on GNU/Linux systems, the suffix '.so' is used. The search -path specified is also used for extensions loaded via the '@load' -keyword (*note Loading Shared Libraries::). +system shared libraries) specified with the `-l' option rather than for +source files. If the extension is not found, the path is searched +again after adding the appropriate shared library suffix for the +platform. For example, on GNU/Linux systems, the suffix `.so' is used. +The search path specified is also used for extensions loaded via the +`@load' keyword (*note Loading Shared Libraries::).  File: gawk.info, Node: Other Environment Variables, Prev: AWKLIBPATH Variable, Up: Environment Variables @@ -3174,50 +2901,29 @@ File: gawk.info, Node: Other Environment Variables, Prev: AWKLIBPATH Variable, 2.5.3 Other Environment Variables --------------------------------- -A number of other environment variables affect 'gawk''s behavior, but -they are more specialized. Those in the following list are meant to be +A number of other environment variables affect `gawk''s behavior, but +they are more specialized. Those in the following list are meant to be used by regular users. -<<<<<<< HEAD -'POSIXLY_CORRECT' - Causes 'gawk' to switch POSIX compatibility mode, disabling all -======= `POSIXLY_CORRECT' Causes `gawk' to switch to POSIX compatibility mode, disabling all ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac traditional and GNU extensions. *Note Options::. -'GAWK_SOCK_RETRIES' - Controls the number of times 'gawk' attempts to retry a two-way +`GAWK_SOCK_RETRIES' + Controls the number of times `gawk' attempts to retry a two-way TCP/IP (socket) connection before giving up. *Note TCP/IP Networking::. -'GAWK_MSEC_SLEEP' - Specifies the interval between connection retries, in milliseconds. - On systems that do not support the 'usleep()' system call, the - value is rounded up to an integral number of seconds. +`GAWK_MSEC_SLEEP' + Specifies the interval between connection retries, in + milliseconds. On systems that do not support the `usleep()' system + call, the value is rounded up to an integral number of seconds. -'GAWK_READ_TIMEOUT' - Specifies the time, in milliseconds, for 'gawk' to wait for input +`GAWK_READ_TIMEOUT' + Specifies the time, in milliseconds, for `gawk' to wait for input before returning with an error. *Note Read Timeout::. The environment variables in the following list are meant for use by -<<<<<<< HEAD -the 'gawk' developers for testing and tuning. They are subject to -change. The variables are: - -'AWKBUFSIZE' - This variable only affects 'gawk' on POSIX-compliant systems. With - a value of 'exact', 'gawk' uses the size of each input file as the - size of the memory buffer to allocate for I/O. Otherwise, the value - should be a number, and 'gawk' uses that number as the size of the - buffer to allocate. (When this variable is not set, 'gawk' uses - the smaller of the file's size and the "default" blocksize, which - is usually the file systems I/O blocksize.) - -'AWK_HASH' - If this variable exists with a value of 'gst', 'gawk' switches to -======= the `gawk' developers for testing and tuning. They are subject to change. The variables are: @@ -3232,64 +2938,63 @@ change. The variables are: `AWK_HASH' If this variable exists with a value of `gst', `gawk' switches to ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac using the hash function from GNU Smalltalk for managing arrays. This function may be marginally faster than the standard function. -'AWKREADFUNC' - If this variable exists, 'gawk' switches to reading source files - one line at a time, instead of reading in blocks. This exists for +`AWKREADFUNC' + If this variable exists, `gawk' switches to reading source files + one line at a time, instead of reading in blocks. This exists for debugging problems on filesystems on non-POSIX operating systems where I/O is performed in records, not in blocks. -'GAWK_MSG_SRC' - If this variable exists, 'gawk' includes the source file name and - line number from which warning and/or fatal messages are generated. - Its purpose is to help isolate the source of a message, since there - can be multiple places which produce the same warning or error - message. - -'GAWK_NO_DFA' - If this variable exists, 'gawk' does not use the DFA regexp matcher - for "does it match" kinds of tests. This can cause 'gawk' to be - slower. Its purpose is to help isolate differences between the two - regexp matchers that 'gawk' uses internally. (There aren't +`GAWK_MSG_SRC' + If this variable exists, `gawk' includes the source file name and + line number from which warning and/or fatal messages are + generated. Its purpose is to help isolate the source of a + message, since there can be multiple places which produce the same + warning or error message. + +`GAWK_NO_DFA' + If this variable exists, `gawk' does not use the DFA regexp matcher + for "does it match" kinds of tests. This can cause `gawk' to be + slower. Its purpose is to help isolate differences between the two + regexp matchers that `gawk' uses internally. (There aren't supposed to be differences, but occasionally theory and practice don't coordinate with each other.) -'GAWK_STACKSIZE' - This specifies the amount by which 'gawk' should grow its internal +`GAWK_STACKSIZE' + This specifies the amount by which `gawk' should grow its internal evaluation stack, when needed. -'INT_CHAIN_MAX' - The average number of items 'gawk' will maintain on a hash chain +`INT_CHAIN_MAX' + The average number of items `gawk' will maintain on a hash chain for managing arrays indexed by integers. -'STR_CHAIN_MAX' - The average number of items 'gawk' will maintain on a hash chain +`STR_CHAIN_MAX' + The average number of items `gawk' will maintain on a hash chain for managing arrays indexed by strings. -'TIDYMEM' - If this variable exists, 'gawk' uses the 'mtrace()' library calls +`TIDYMEM' + If this variable exists, `gawk' uses the `mtrace()' library calls from GNU LIBC to help track down possible memory leaks.  File: gawk.info, Node: Exit Status, Next: Include Files, Prev: Environment Variables, Up: Invoking Gawk -2.6 'gawk''s Exit Status +2.6 `gawk''s Exit Status ======================== -If the 'exit' statement is used with a value (*note Exit Statement::), -then 'gawk' exits with the numeric value given to it. +If the `exit' statement is used with a value (*note Exit Statement::), +then `gawk' exits with the numeric value given to it. - Otherwise, if there were no problems during execution, 'gawk' exits -with the value of the C constant 'EXIT_SUCCESS'. This is usually zero. + Otherwise, if there were no problems during execution, `gawk' exits +with the value of the C constant `EXIT_SUCCESS'. This is usually zero. - If an error occurs, 'gawk' exits with the value of the C constant -'EXIT_FAILURE'. This is usually one. + If an error occurs, `gawk' exits with the value of the C constant +`EXIT_FAILURE'. This is usually one. - If 'gawk' exits because of a fatal error, the exit status is 2. On -non-POSIX systems, this value may be mapped to 'EXIT_FAILURE'. + If `gawk' exits because of a fatal error, the exit status is 2. On +non-POSIX systems, this value may be mapped to `EXIT_FAILURE'.  File: gawk.info, Node: Include Files, Next: Loading Shared Libraries, Prev: Exit Status, Up: Invoking Gawk @@ -3297,63 +3002,63 @@ File: gawk.info, Node: Include Files, Next: Loading Shared Libraries, Prev: E 2.7 Including Other Files Into Your Program =========================================== -This minor node describes a feature that is specific to 'gawk'. +This minor node describes a feature that is specific to `gawk'. - The '@include' keyword can be used to read external 'awk' source -files. This gives you the ability to split large 'awk' source files + The `@include' keyword can be used to read external `awk' source +files. This gives you the ability to split large `awk' source files into smaller, more manageable pieces, and also lets you reuse common -'awk' code from various 'awk' scripts. In other words, you can group -together 'awk' functions, used to carry out specific tasks, into -external files. These files can be used just like function libraries, -using the '@include' keyword in conjunction with the 'AWKPATH' -environment variable. Note that source files may also be included using -the '-i' option. +`awk' code from various `awk' scripts. In other words, you can group +together `awk' functions, used to carry out specific tasks, into +external files. These files can be used just like function libraries, +using the `@include' keyword in conjunction with the `AWKPATH' +environment variable. Note that source files may also be included +using the `-i' option. - Let's see an example. We'll start with two (trivial) 'awk' scripts, -namely 'test1' and 'test2'. Here is the 'test1' script: + Let's see an example. We'll start with two (trivial) `awk' scripts, +namely `test1' and `test2'. Here is the `test1' script: BEGIN { print "This is script test1." } -and here is 'test2': +and here is `test2': @include "test1" BEGIN { print "This is script test2." } - Running 'gawk' with 'test2' produces the following result: + Running `gawk' with `test2' produces the following result: $ gawk -f test2 -| This is file test1. -| This is file test2. - 'gawk' runs the 'test2' script which includes 'test1' using the -'@include' keyword. So, to include external 'awk' source files you just -use '@include' followed by the name of the file to be included, enclosed -in double quotes. + `gawk' runs the `test2' script which includes `test1' using the +`@include' keyword. So, to include external `awk' source files you just +use `@include' followed by the name of the file to be included, +enclosed in double quotes. NOTE: Keep in mind that this is a language construct and the file name cannot be a string variable, but rather just a literal string constant in double quotes. The files to be included may be nested; e.g., given a third script, -namely 'test3': +namely `test3': @include "test2" BEGIN { print "This is script test3." } -Running 'gawk' with the 'test3' script produces the following results: +Running `gawk' with the `test3' script produces the following results: $ gawk -f test3 -| This is file test1. -| This is file test2. -| This is file test3. - The file name can, of course, be a pathname. For example: + The file name can, of course, be a pathname. For example: @include "../io_funcs" @@ -3361,31 +3066,32 @@ or: @include "/usr/awklib/network" -are valid. The 'AWKPATH' environment variable can be of great value -when using '@include'. The same rules for the use of the 'AWKPATH' +are valid. The `AWKPATH' environment variable can be of great value +when using `@include'. The same rules for the use of the `AWKPATH' variable in command-line file searches (*note AWKPATH Variable::) apply -to '@include' also. +to `@include' also. - This is very helpful in constructing 'gawk' function libraries. If -you have a large script with useful, general purpose 'awk' functions, + This is very helpful in constructing `gawk' function libraries. If +you have a large script with useful, general purpose `awk' functions, you can break it down into library files and put those files in a -special directory. You can then include those "libraries," using either -the full pathnames of the files, or by setting the 'AWKPATH' environment -variable accordingly and then using '@include' with just the file part -of the full pathname. Of course you can have more than one directory to -keep library files; the more complex the working environment is, the -more directories you may need to organize the files to be included. - - Given the ability to specify multiple '-f' options, the '@include' -mechanism is not strictly necessary. However, the '@include' keyword -can help you in constructing self-contained 'gawk' programs, thus +special directory. You can then include those "libraries," using +either the full pathnames of the files, or by setting the `AWKPATH' +environment variable accordingly and then using `@include' with just +the file part of the full pathname. Of course you can have more than +one directory to keep library files; the more complex the working +environment is, the more directories you may need to organize the files +to be included. + + Given the ability to specify multiple `-f' options, the `@include' +mechanism is not strictly necessary. However, the `@include' keyword +can help you in constructing self-contained `gawk' programs, thus reducing the need for writing complex and tedious command lines. In -particular, '@include' is very useful for writing CGI scripts to be run +particular, `@include' is very useful for writing CGI scripts to be run from web pages. As mentioned in *note AWKPATH Variable::, the current directory is -always searched first for source files, before searching in 'AWKPATH', -and this also applies to files named with '@include'. +always searched first for source files, before searching in `AWKPATH', +and this also applies to files named with `@include'.  File: gawk.info, Node: Loading Shared Libraries, Next: Obsolete, Prev: Include Files, Up: Invoking Gawk @@ -3393,19 +3099,19 @@ File: gawk.info, Node: Loading Shared Libraries, Next: Obsolete, Prev: Includ 2.8 Loading Dynamic Extensions Into Your Program ================================================ -This minor node describes a feature that is specific to 'gawk'. +This minor node describes a feature that is specific to `gawk'. - The '@load' keyword can be used to read external 'awk' extensions + The `@load' keyword can be used to read external `awk' extensions (stored as system shared libraries). This allows you to link in -compiled code that may offer superior performance and/or give you access -to extended capabilities not supported by the 'awk' language. The -'AWKLIBPATH' variable is used to search for the extension. Using -'@load' is completely equivalent to using the '-l' command-line option. +compiled code that may offer superior performance and/or give you +access to extended capabilities not supported by the `awk' language. +The `AWKLIBPATH' variable is used to search for the extension. Using +`@load' is completely equivalent to using the `-l' command-line option. - If the extension is not initially found in 'AWKLIBPATH', another + If the extension is not initially found in `AWKLIBPATH', another search is conducted after appending the platform's default shared -library suffix to the file name. For example, on GNU/Linux systems, the -suffix '.so' is used. +library suffix to the file name. For example, on GNU/Linux systems, +the suffix `.so' is used. $ gawk '@load "ordchr"; BEGIN {print chr(65)}' -| A @@ -3415,12 +3121,12 @@ This is equivalent to the following example: $ gawk -lordchr 'BEGIN {print chr(65)}' -| A -For command-line usage, the '-l' option is more convenient, but '@load' -is useful for embedding inside an 'awk' source file that requires access -to an extension. +For command-line usage, the `-l' option is more convenient, but `@load' +is useful for embedding inside an `awk' source file that requires +access to an extension. *note Dynamic Extensions::, describes how to write extensions (in C -or C++) that can be loaded with either '@load' or the '-l' option. +or C++) that can be loaded with either `@load' or the `-l' option.  File: gawk.info, Node: Obsolete, Next: Undocumented, Prev: Loading Shared Libraries, Up: Invoking Gawk @@ -3429,14 +3135,14 @@ File: gawk.info, Node: Obsolete, Next: Undocumented, Prev: Loading Shared Lib ==================================== This minor node describes features and/or command-line options from -previous releases of 'gawk' that are either not available in the current -version or that are still supported but deprecated (meaning that they -will _not_ be in the next release). +previous releases of `gawk' that are either not available in the +current version or that are still supported but deprecated (meaning that +they will _not_ be in the next release). - The process-related special files '/dev/pid', '/dev/ppid', -'/dev/pgrpid', and '/dev/user' were deprecated in 'gawk' 3.1, but still + The process-related special files `/dev/pid', `/dev/ppid', +`/dev/pgrpid', and `/dev/user' were deprecated in `gawk' 3.1, but still worked. As of version 4.0, they are no longer interpreted specially by -'gawk'. (Use 'PROCINFO' instead; see *note Auto-set::.) +`gawk'. (Use `PROCINFO' instead; see *note Auto-set::.)  File: gawk.info, Node: Undocumented, Next: Invoking Summary, Prev: Obsolete, Up: Invoking Gawk @@ -3444,8 +3150,7 @@ File: gawk.info, Node: Undocumented, Next: Invoking Summary, Prev: Obsolete, 2.10 Undocumented Options and Features ====================================== - Use the Source, Luke! - -- _Obi-Wan_ + Use the Source, Luke! -- Obi-Wan This minor node intentionally left blank. @@ -3455,46 +3160,41 @@ File: gawk.info, Node: Invoking Summary, Prev: Undocumented, Up: Invoking Gaw 2.11 Summary ============ - * Use either 'awk 'PROGRAM' FILES' or 'awk -f PROGRAM-FILE FILES' to - run 'awk'. + * Use either `awk 'PROGRAM' FILES' or `awk -f PROGRAM-FILE FILES' to + run `awk'. -<<<<<<< HEAD - * The three standard 'awk' options are '-f', '-F' and '-v'. 'gawk' - supplies these and many others, as well as corresponding GNU-style - long options. -======= * The three standard options for all versions of `awk' are `-f', `-F' and `-v'. `gawk' supplies these and many others, as well as corresponding GNU-style long options. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Non-option command-line arguments are usually treated as file - names, unless they have the form 'VAR=VALUE', in which case they + names, unless they have the form `VAR=VALUE', in which case they are taken as variable assignments to be performed at that point in processing the input. * All non-option command-line arguments, excluding the program text, - are placed in the 'ARGV' array. Adjusting 'ARGC' and 'ARGV' - affects how 'awk' processes input. + are placed in the `ARGV' array. Adjusting `ARGC' and `ARGV' + affects how `awk' processes input. - * You can use a single minus sign ('-') to refer to standard input on - the command line. + * You can use a single minus sign (`-') to refer to standard input + on the command line. - * 'gawk' pays attention to a number of environment variables. - 'AWKPATH', 'AWKLIBPATH', and 'POSIXLY_CORRECT' are the most + * `gawk' pays attention to a number of environment variables. + `AWKPATH', `AWKLIBPATH', and `POSIXLY_CORRECT' are the most important ones. - * 'gawk''s exit status conveys information to the program that - invoked it. Use the 'exit' statement from within an 'awk' program + * `gawk''s exit status conveys information to the program that + invoked it. Use the `exit' statement from within an `awk' program to set the exit status. - * 'gawk' allows you to include other 'awk' source files into your - program using the '@include' statement and/or the '-i' and '-f' + * `gawk' allows you to include other `awk' source files into your + program using the `@include' statement and/or the `-i' and `-f' command-line options. - * 'gawk' allows you to load additional functions written in C or C++ - using the '@load' statement and/or the '-l' option. (This advanced - feature is described later on in *note Dynamic Extensions::.) + * `gawk' allows you to load additional functions written in C or C++ + using the `@load' statement and/or the `-l' option. (This + advanced feature is described later on in *note Dynamic + Extensions::.)  File: gawk.info, Node: Regexp, Next: Reading Files, Prev: Invoking Gawk, Up: Top @@ -3504,37 +3204,23 @@ File: gawk.info, Node: Regexp, Next: Reading Files, Prev: Invoking Gawk, Up: A "regular expression", or "regexp", is a way of describing a set of strings. Because regular expressions are such a fundamental part of -'awk' programming, their format and use deserve a separate major node. +`awk' programming, their format and use deserve a separate major node. - A regular expression enclosed in slashes ('/') is an 'awk' pattern + A regular expression enclosed in slashes (`/') is an `awk' pattern that matches every input record whose text belongs to that set. The simplest regular expression is a sequence of letters, numbers, or both. -<<<<<<< HEAD -Such a regexp matches any string that contains that sequence. Thus, the -regexp 'foo' matches any string containing 'foo'. Therefore, the -pattern '/foo/' matches any input record containing the three characters -'foo' _anywhere_ in the record. Other kinds of regexps let you specify -more complicated classes of strings. -======= Such a regexp matches any string that contains that sequence. Thus, the regexp `foo' matches any string containing `foo'. Therefore, the pattern `/foo/' matches any input record containing the three adjacent characters `foo' _anywhere_ in the record. Other kinds of regexps let you specify more complicated classes of strings. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Menu: * Regexp Usage:: How to Use Regular Expressions. * Escape Sequences:: How to write nonprinting characters. * Regexp Operators:: Regular Expression Operators. -<<<<<<< HEAD -* Bracket Expressions:: What can go between '[...]'. -* GNU Regexp Operators:: Operators specific to GNU software. -* Case-sensitivity:: How to do case-insensitive matching. -======= * Bracket Expressions:: What can go between `[...]'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Leftmost Longest:: How much text matches. * Computed Regexps:: Using Dynamic Regexps. * GNU Regexp Operators:: Operators specific to GNU software. @@ -3549,10 +3235,10 @@ File: gawk.info, Node: Regexp Usage, Next: Escape Sequences, Up: Regexp A regular expression can be used as a pattern by enclosing it in slashes. Then the regular expression is tested against the entire text -of each record. (Normally, it only needs to match some part of the text -in order to succeed.) For example, the following prints the second -field of each record where the string 'li' appears anywhere in the -record: +of each record. (Normally, it only needs to match some part of the +text in order to succeed.) For example, the following prints the +second field of each record where the string `li' appears anywhere in +the record: $ awk '/li/ { print $2 }' mail-list -| 555-5553 @@ -3562,16 +3248,16 @@ record: Regular expressions can also be used in matching expressions. These expressions allow you to specify the string to match against; it need -not be the entire current input record. The two operators '~' and '!~' +not be the entire current input record. The two operators `~' and `!~' perform regular expression comparisons. Expressions using these -operators can be used as patterns, or in 'if', 'while', 'for', and 'do' +operators can be used as patterns, or in `if', `while', `for', and `do' statements. (*Note Statements::.) For example: EXP ~ /REGEXP/ is true if the expression EXP (taken as a string) matches REGEXP. The following example matches, or selects, all input records with the -uppercase letter 'J' somewhere in the first field: +uppercase letter `J' somewhere in the first field: $ awk '$1 ~ /J/' inventory-shipped -| Jan 13 25 15 115 @@ -3583,13 +3269,13 @@ uppercase letter 'J' somewhere in the first field: awk '{ if ($1 ~ /J/) print }' inventory-shipped - This next example is true if the expression EXP (taken as a character -string) does _not_ match REGEXP: + This next example is true if the expression EXP (taken as a +character string) does _not_ match REGEXP: EXP !~ /REGEXP/ The following example matches, or selects, all input records whose -first field _does not_ contain the uppercase letter 'J': +first field _does not_ contain the uppercase letter `J': $ awk '$1 !~ /J/' inventory-shipped -| Feb 15 32 24 226 @@ -3598,9 +3284,9 @@ first field _does not_ contain the uppercase letter 'J': -| May 16 34 29 208 ... - When a regexp is enclosed in slashes, such as '/foo/', we call it a -"regexp constant", much like '5.27' is a numeric constant and '"foo"' is -a string constant. + When a regexp is enclosed in slashes, such as `/foo/', we call it a +"regexp constant", much like `5.27' is a numeric constant and `"foo"' +is a string constant.  File: gawk.info, Node: Escape Sequences, Next: Regexp Operators, Prev: Regexp Usage, Up: Regexp @@ -3609,69 +3295,62 @@ File: gawk.info, Node: Escape Sequences, Next: Regexp Operators, Prev: Regexp ==================== Some characters cannot be included literally in string constants -('"foo"') or regexp constants ('/foo/'). Instead, they should be +(`"foo"') or regexp constants (`/foo/'). Instead, they should be represented with "escape sequences", which are character sequences -beginning with a backslash ('\'). One use of an escape sequence is to +beginning with a backslash (`\'). One use of an escape sequence is to include a double-quote character in a string constant. Because a plain -double quote ends the string, you must use '\"' to represent an actual +double quote ends the string, you must use `\"' to represent an actual double-quote character as a part of the string. For example: $ awk 'BEGIN { print "He said \"hi!\" to her." }' -| He said "hi!" to her. - The backslash character itself is another character that cannot be -included normally; you must write '\\' to put one backslash in the + The backslash character itself is another character that cannot be +included normally; you must write `\\' to put one backslash in the string or regexp. Thus, the string whose contents are the two -characters '"' and '\' must be written '"\"\\"'. +characters `"' and `\' must be written `"\"\\"'. Other escape sequences represent unprintable characters such as TAB or newline. While there is nothing to stop you from entering most unprintable characters directly in a string constant or regexp constant, they may look ugly. - The following table lists all the escape sequences used in 'awk' and -what they represent. Unless noted otherwise, all these escape sequences + The following table lists all the escape sequences used in `awk' and +what they represent. Unless noted otherwise, all these escape sequences apply to both string constants and regexp constants: -'\\' - A literal backslash, '\'. +`\\' + A literal backslash, `\'. -'\a' - The "alert" character, 'Ctrl-g', ASCII code 7 (BEL). (This often +`\a' + The "alert" character, `Ctrl-g', ASCII code 7 (BEL). (This often makes some sort of audible noise.) -'\b' - Backspace, 'Ctrl-h', ASCII code 8 (BS). +`\b' + Backspace, `Ctrl-h', ASCII code 8 (BS). -'\f' - Formfeed, 'Ctrl-l', ASCII code 12 (FF). +`\f' + Formfeed, `Ctrl-l', ASCII code 12 (FF). -'\n' - Newline, 'Ctrl-j', ASCII code 10 (LF). +`\n' + Newline, `Ctrl-j', ASCII code 10 (LF). -'\r' - Carriage return, 'Ctrl-m', ASCII code 13 (CR). +`\r' + Carriage return, `Ctrl-m', ASCII code 13 (CR). -'\t' - Horizontal TAB, 'Ctrl-i', ASCII code 9 (HT). +`\t' + Horizontal TAB, `Ctrl-i', ASCII code 9 (HT). -'\v' - Vertical tab, 'Ctrl-k', ASCII code 11 (VT). +`\v' + Vertical tab, `Ctrl-k', ASCII code 11 (VT). -'\NNN' - The octal value NNN, where NNN stands for 1 to 3 digits between '0' - and '7'. For example, the code for the ASCII ESC (escape) - character is '\033'. +`\NNN' + The octal value NNN, where NNN stands for 1 to 3 digits between + `0' and `7'. For example, the code for the ASCII ESC (escape) + character is `\033'. -'\xHH...' +`\xHH...' The hexadecimal value HH, where HH stands for a sequence of -<<<<<<< HEAD - hexadecimal digits ('0'-'9', and either 'A'-'F' or 'a'-'f'). Like - the same construct in ISO C, the escape sequence continues until - the first nonhexadecimal digit is seen. (c.e.) However, using - more than two hexadecimal digits produces undefined results. (The - '\x' escape sequence is not allowed in POSIX 'awk'.) -======= hexadecimal digits (`0'-`9', and either `A'-`F' or `a'-`f'). A maximum of two digts are allowed after the `\x'. Any further hexadecimal digits are treated as simple letters or numbers. @@ -3683,23 +3362,10 @@ apply to both string constants and regexp constants: value until a non-hexadecimal digit or the end of the string was encountered. However, using more than two hexadecimal digits produces ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac -'\/' +`\/' A literal slash (necessary for regexp constants only). This sequence is used when you want to write a regexp constant that -<<<<<<< HEAD - contains a slash. Because the regexp is delimited by slashes, you - need to escape the slash that is part of the pattern, in order to - tell 'awk' to keep processing the rest of the regexp. - -'\"' - A literal double quote (necessary for string constants only). This - sequence is used when you want to write a string constant that - contains a double quote. Because the string is delimited by double - quotes, you need to escape the quote that is part of the string, in - order to tell 'awk' to keep processing the rest of the string. -======= contains a slash (such as `/.*:\/home\/[[:alnum:]]+:.*/'; the `[[:alnum:]]' notation is discussed shortly, in *note Bracket Expressions::). Because the regexp is delimited by slashes, you @@ -3713,28 +3379,27 @@ apply to both string constants and regexp constants: Because the string is delimited by double quotes, you need to escape any quote that is part of the string, in order to tell `awk' to keep processing the rest of the string. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - In 'gawk', a number of additional two-character sequences that begin + In `gawk', a number of additional two-character sequences that begin with a backslash have special meaning in regexps. *Note GNU Regexp Operators::. In a regexp, a backslash before any character that is not in the -previous list and not listed in *note GNU Regexp Operators::, means that -the next character should be taken literally, even if it would normally -be a regexp operator. For example, '/a\+b/' matches the three -characters 'a+b'. +previous list and not listed in *note GNU Regexp Operators::, means +that the next character should be taken literally, even if it would +normally be a regexp operator. For example, `/a\+b/' matches the three +characters `a+b'. - For complete portability, do not use a backslash before any character -not shown in the previous list. + For complete portability, do not use a backslash before any +character not shown in the previous list. To summarize: * The escape sequences in the table above are always processed first, - for both string constants and regexp constants. This happens very - early, as soon as 'awk' reads your program. + for both string constants and regexp constants. This happens very + early, as soon as `awk' reads your program. - * 'gawk' processes both regexp constants and dynamic regexps (*note + * `gawk' processes both regexp constants and dynamic regexps (*note Computed Regexps::), for the special operators listed in *note GNU Regexp Operators::. @@ -3744,42 +3409,33 @@ not shown in the previous list. Backslash Before Regular Characters If you place a backslash in a string constant before something that -is not one of the characters previously listed, POSIX 'awk' purposely +is not one of the characters previously listed, POSIX `awk' purposely leaves what happens as undefined. There are two choices: Strip the backslash out -<<<<<<< HEAD - This is what Brian Kernighan's 'awk' and 'gawk' both do. For - example, '"a\qc"' is the same as '"aqc"'. (Because this is such an - easy bug both to introduce and to miss, 'gawk' warns you about it.) - Consider 'FS = "[ \t]+\|[ \t]+"' to use vertical bars surrounded by - whitespace as the field separator. There should be two backslashes - in the string: 'FS = "[ \t]+\\|[ \t]+"'.) -======= This is what BWK `awk' and `gawk' both do. For example, `"a\qc"' is the same as `"aqc"'. (Because this is such an easy bug both to introduce and to miss, `gawk' warns you about it.) Consider `FS = "[ \t]+\|[ \t]+"' to use vertical bars surrounded by whitespace as the field separator. There should be two backslashes in the string: `FS = "[ \t]+\\|[ \t]+"'.) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Leave the backslash alone - Some other 'awk' implementations do this. In such implementations, - typing '"a\qc"' is the same as typing '"a\\qc"'. + Some other `awk' implementations do this. In such + implementations, typing `"a\qc"' is the same as typing `"a\\qc"'. Escape Sequences for Metacharacters Suppose you use an octal or hexadecimal escape to represent a regexp -metacharacter. (See *note Regexp Operators::.) Does 'awk' treat the +metacharacter. (See *note Regexp Operators::.) Does `awk' treat the character as a literal character or as a regexp operator? - Historically, such characters were taken literally. (d.c.) However, -the POSIX standard indicates that they should be treated as real -metacharacters, which is what 'gawk' does. In compatibility mode (*note -Options::), 'gawk' treats the characters represented by octal and -hexadecimal escape sequences literally when used in regexp constants. -Thus, '/a\52b/' is equivalent to '/a\*b/'. + Historically, such characters were taken literally. (d.c.) +However, the POSIX standard indicates that they should be treated as +real metacharacters, which is what `gawk' does. In compatibility mode +(*note Options::), `gawk' treats the characters represented by octal +and hexadecimal escape sequences literally when used in regexp +constants. Thus, `/a\52b/' is equivalent to `/a\*b/'.  File: gawk.info, Node: Regexp Operators, Next: Bracket Expressions, Prev: Escape Sequences, Up: Regexp @@ -3791,117 +3447,88 @@ You can combine regular expressions with special characters, called "regular expression operators" or "metacharacters", to increase the power and versatility of regular expressions. - The escape sequences described in *note Escape Sequences::, are valid -inside a regexp. They are introduced by a '\' and are recognized and -converted into corresponding real characters as the very first step in -processing regexps. + The escape sequences described in *note Escape Sequences::, are +valid inside a regexp. They are introduced by a `\' and are recognized +and converted into corresponding real characters as the very first step +in processing regexps. Here is a list of metacharacters. All characters that are not escape sequences and that are not listed in the table stand for themselves: -'\' +`\' This is used to suppress the special meaning of a character when - matching. For example, '\$' matches the character '$'. + matching. For example, `\$' matches the character `$'. -'^' - This matches the beginning of a string. For example, '^@chapter' - matches '@chapter' at the beginning of a string and can be used to - identify chapter beginnings in Texinfo source files. The '^' is +`^' + This matches the beginning of a string. For example, `^@chapter' + matches `@chapter' at the beginning of a string and can be used to + identify chapter beginnings in Texinfo source files. The `^' is known as an "anchor", because it anchors the pattern to match only at the beginning of the string. - It is important to realize that '^' does not match the beginning of - a line (the point right after a '\n' newline character) embedded in - a string. The condition is not true in the following example: + It is important to realize that `^' does not match the beginning of + a line (the point right after a `\n' newline character) embedded + in a string. The condition is not true in the following example: if ("line1\nLINE 2" ~ /^L/) ... -'$' - This is similar to '^', but it matches only at the end of a string. - For example, 'p$' matches a record that ends with a 'p'. The '$' +`$' + This is similar to `^', but it matches only at the end of a string. + For example, `p$' matches a record that ends with a `p'. The `$' is an anchor and does not match the end of a line (the point right - before a '\n' newline character) embedded in a string. The + before a `\n' newline character) embedded in a string. The condition in the following example is not true: if ("line1\nLINE 2" ~ /1$/) ... -'.' (period) +`.' (period) This matches any single character, _including_ the newline - character. For example, '.P' matches any single character followed - by a 'P' in a string. Using concatenation, we can make a regular - expression such as 'U.A', which matches any three-character - sequence that begins with 'U' and ends with 'A'. + character. For example, `.P' matches any single character + followed by a `P' in a string. Using concatenation, we can make a + regular expression such as `U.A', which matches any + three-character sequence that begins with `U' and ends with `A'. - In strict POSIX mode (*note Options::), '.' does not match the NUL + In strict POSIX mode (*note Options::), `.' does not match the NUL character, which is a character with all bits equal to zero. - Otherwise, NUL is just another character. Other versions of 'awk' + Otherwise, NUL is just another character. Other versions of `awk' may not be able to match the NUL character. -'['...']' - This is called a "bracket expression".(1) It matches any _one_ of +`['...`]' + This is called a "bracket expression".(1) It matches any _one_ of the characters that are enclosed in the square brackets. For - example, '[MVX]' matches any one of the characters 'M', 'V', or 'X' - in a string. A full discussion of what can be inside the square - brackets of a bracket expression is given in *note Bracket + example, `[MVX]' matches any one of the characters `M', `V', or + `X' in a string. A full discussion of what can be inside the + square brackets of a bracket expression is given in *note Bracket Expressions::. -'[^'...']' +`[^'...`]' This is a "complemented bracket expression". The first character - after the '[' _must_ be a '^'. It matches any characters _except_ - those in the square brackets. For example, '[^awk]' matches any - character that is not an 'a', 'w', or 'k'. + after the `[' _must_ be a `^'. It matches any characters _except_ + those in the square brackets. For example, `[^awk]' matches any + character that is not an `a', `w', or `k'. -'|' +`|' This is the "alternation operator" and it is used to specify -<<<<<<< HEAD - alternatives. The '|' has the lowest precedence of all the regular - expression operators. For example, '^P|[[:digit:]]' matches any - string that matches either '^P' or '[[:digit:]]'. This means it - matches any string that starts with 'P' or contains a digit. -======= alternatives. The `|' has the lowest precedence of all the regular expression operators. For example, `^P|[aeiouy]' matches any string that matches either `^P' or `[aeiouy]'. This means it matches any string that starts with `P' or contains (anywhere within it) a lowercase English vowel. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac The alternation applies to the largest possible regexps on either side. -'('...')' +`('...`)' Parentheses are used for grouping in regular expressions, as in arithmetic. They can be used to concatenate regular expressions - containing the alternation operator, '|'. For example, - '@(samp|code)\{[^}]+\}' matches both '@code{foo}' and '@samp{bar}'. - (These are Texinfo formatting control sequences. The '+' is + containing the alternation operator, `|'. For example, + `@(samp|code)\{[^}]+\}' matches both `@code{foo}' and `@samp{bar}'. + (These are Texinfo formatting control sequences. The `+' is explained further on in this list.) -'*' +`*' This symbol means that the preceding regular expression should be repeated as many times as necessary to find a match. For example, -<<<<<<< HEAD - 'ph*' applies the '*' symbol to the preceding 'h' and looks for - matches of one 'p' followed by any number of 'h's. This also - matches just 'p' if no 'h's are present. - - The '*' repeats the _smallest_ possible preceding expression. (Use - parentheses if you want to repeat a larger expression.) It finds - as many repetitions as possible. For example, 'awk '/\(c[ad][ad]*r - x\)/ { print }' sample' prints every record in 'sample' containing - a string of the form '(car x)', '(cdr x)', '(cadr x)', and so on. - Notice the escaping of the parentheses by preceding them with - backslashes. - -'+' - This symbol is similar to '*', except that the preceding expression - must be matched at least once. This means that 'wh+y' would match - 'why' and 'whhy', but not 'wy', whereas 'wh*y' would match all - three. The following is a simpler way of writing the last '*' - example: - - awk '/\(c[ad]+r x\)/ { print }' sample -======= `ph*' applies the `*' symbol to the preceding `h' and looks for matches of one `p' followed by any number of `h's. This also matches just `p' if no `h's are present. @@ -3920,16 +3547,15 @@ sequences and that are not listed in the table stand for themselves: expression must be matched at least once. This means that `wh+y' would match `why' and `whhy', but not `wy', whereas `wh*y' would match all three. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac -'?' - This symbol is similar to '*', except that the preceding expression - can be matched either once or not at all. For example, 'fe?d' - matches 'fed' and 'fd', but nothing else. +`?' + This symbol is similar to `*', except that the preceding + expression can be matched either once or not at all. For example, + `fe?d' matches `fed' and `fd', but nothing else. -'{'N'}' -'{'N',}' -'{'N','M'}' +`{'N`}' +`{'N`,}' +`{'N`,'M`}' One or two numbers inside braces denote an "interval expression". If there is one number in the braces, the preceding regexp is repeated N times. If there are two numbers separated by a comma, @@ -3937,53 +3563,54 @@ sequences and that are not listed in the table stand for themselves: number followed by a comma, then the preceding regexp is repeated at least N times: - 'wh{3}y' - Matches 'whhhy', but not 'why' or 'whhhhy'. + `wh{3}y' + Matches `whhhy', but not `why' or `whhhhy'. - 'wh{3,5}y' - Matches 'whhhy', 'whhhhy', or 'whhhhhy', only. + `wh{3,5}y' + Matches `whhhy', `whhhhy', or `whhhhhy', only. - 'wh{2,}y' - Matches 'whhy' or 'whhhy', and so on. + `wh{2,}y' + Matches `whhy' or `whhhy', and so on. - Interval expressions were not traditionally available in 'awk'. - They were added as part of the POSIX standard to make 'awk' and - 'egrep' consistent with each other. + Interval expressions were not traditionally available in `awk'. + They were added as part of the POSIX standard to make `awk' and + `egrep' consistent with each other. - Initially, because old programs may use '{' and '}' in regexp - constants, 'gawk' did _not_ match interval expressions in regexps. + Initially, because old programs may use `{' and `}' in regexp + constants, `gawk' did _not_ match interval expressions in regexps. - However, beginning with version 4.0, 'gawk' does match interval + However, beginning with version 4.0, `gawk' does match interval expressions by default. This is because compatibility with POSIX - has become more important to most 'gawk' users than compatibility + has become more important to most `gawk' users than compatibility with old programs. - For programs that use '{' and '}' in regexp constants, it is good + For programs that use `{' and `}' in regexp constants, it is good practice to always escape them with a backslash. Then the regexp constants are valid and work the way you want them to, using any - version of 'awk'.(2) + version of `awk'.(2) - Finally, when '{' and '}' appear in regexp constants in a way that - cannot be interpreted as an interval expression (such as '/q{a}/'), - then they stand for themselves. + Finally, when `{' and `}' appear in regexp constants in a way that + cannot be interpreted as an interval expression (such as + `/q{a}/'), then they stand for themselves. - In regular expressions, the '*', '+', and '?' operators, as well as -the braces '{' and '}', have the highest precedence, followed by -concatenation, and finally by '|'. As in arithmetic, parentheses can + In regular expressions, the `*', `+', and `?' operators, as well as +the braces `{' and `}', have the highest precedence, followed by +concatenation, and finally by `|'. As in arithmetic, parentheses can change how operators are grouped. - In POSIX 'awk' and 'gawk', the '*', '+', and '?' operators stand for + In POSIX `awk' and `gawk', the `*', `+', and `?' operators stand for themselves when there is nothing in the regexp that precedes them. For -example, '/+/' matches a literal plus sign. However, many other -versions of 'awk' treat such a usage as a syntax error. +example, `/+/' matches a literal plus sign. However, many other +versions of `awk' treat such a usage as a syntax error. - If 'gawk' is in compatibility mode (*note Options::), interval + If `gawk' is in compatibility mode (*note Options::), interval expressions are not available in regular expressions. ---------- Footnotes ---------- - (1) In other literature, you may see a bracket expression referred to -as either a "character set", a "character class", or a "character list". + (1) In other literature, you may see a bracket expression referred +to as either a "character set", a "character class", or a "character +list". (2) Use two backslashes if you're using a string constant with a regexp operator or function. @@ -4000,98 +3627,95 @@ those listed between the opening and closing square brackets. Within a bracket expression, a "range expression" consists of two characters separated by a hyphen. It matches any single character that sorts between the two characters, based upon the system's native -character set. For example, '[0-9]' is equivalent to '[0123456789]'. +character set. For example, `[0-9]' is equivalent to `[0123456789]'. (See *note Ranges and Locales::, for an explanation of how the POSIX -standard and 'gawk' have changed over time. This is mainly of +standard and `gawk' have changed over time. This is mainly of historical interest.) - To include one of the characters '\', ']', '-', or '^' in a bracket -expression, put a '\' in front of it. For example: + To include one of the characters `\', `]', `-', or `^' in a bracket +expression, put a `\' in front of it. For example: [d\]] -<<<<<<< HEAD -matches either 'd' or ']'. -======= matches either `d' or `]'. Additionally, if you place `]' right after the opening `[', the closing bracket is treated as one of the characters to be matched. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - This treatment of '\' in bracket expressions is compatible with other -'awk' implementations and is also mandated by POSIX. The regular -expressions in 'awk' are a superset of the POSIX specification for + This treatment of `\' in bracket expressions is compatible with +other `awk' implementations and is also mandated by POSIX. The regular +expressions in `awk' are a superset of the POSIX specification for Extended Regular Expressions (EREs). POSIX EREs are based on the -regular expressions accepted by the traditional 'egrep' utility. +regular expressions accepted by the traditional `egrep' utility. "Character classes" are a feature introduced in the POSIX standard. A character class is a special notation for describing lists of -characters that have a specific attribute, but the actual characters can -vary from country to country and/or from character set to character set. -For example, the notion of what is an alphabetic character differs -between the United States and France. +characters that have a specific attribute, but the actual characters +can vary from country to country and/or from character set to character +set. For example, the notion of what is an alphabetic character +differs between the United States and France. A character class is only valid in a regexp _inside_ the brackets of -a bracket expression. Character classes consist of '[:', a keyword -denoting the class, and ':]'. *note Table 3.1: table-char-classes. -lists the character classes defined by the POSIX standard. +a bracket expression. Character classes consist of `[:', a keyword +denoting the class, and `:]'. *note table-char-classes:: lists the +character classes defined by the POSIX standard. Class Meaning --------------------------------------------------------------------------- -'[:alnum:]' Alphanumeric characters. -'[:alpha:]' Alphabetic characters. -'[:blank:]' Space and TAB characters. -'[:cntrl:]' Control characters. -'[:digit:]' Numeric characters. -'[:graph:]' Characters that are both printable and visible. (A space - is printable but not visible, whereas an 'a' is both.) -'[:lower:]' Lowercase alphabetic characters. -'[:print:]' Printable characters (characters that are not control +-------------------------------------------------------------------------- +`[:alnum:]' Alphanumeric characters. +`[:alpha:]' Alphabetic characters. +`[:blank:]' Space and TAB characters. +`[:cntrl:]' Control characters. +`[:digit:]' Numeric characters. +`[:graph:]' Characters that are both printable and visible. (A space is + printable but not visible, whereas an `a' is both.) +`[:lower:]' Lowercase alphabetic characters. +`[:print:]' Printable characters (characters that are not control characters). -'[:punct:]' Punctuation characters (characters that are not letters, +`[:punct:]' Punctuation characters (characters that are not letters, digits, control characters, or space characters). -'[:space:]' Space characters (such as space, TAB, and formfeed, to name +`[:space:]' Space characters (such as space, TAB, and formfeed, to name a few). -'[:upper:]' Uppercase alphabetic characters. -'[:xdigit:]'Characters that are hexadecimal digits. +`[:upper:]' Uppercase alphabetic characters. +`[:xdigit:]'Characters that are hexadecimal digits. Table 3.1: POSIX Character Classes For example, before the POSIX standard, you had to write -'/[A-Za-z0-9]/' to match alphanumeric characters. If your character set -had other alphabetic characters in it, this would not match them. With -the POSIX character classes, you can write '/[[:alnum:]]/' to match the -alphabetic and numeric characters in your character set. +`/[A-Za-z0-9]/' to match alphanumeric characters. If your character +set had other alphabetic characters in it, this would not match them. +With the POSIX character classes, you can write `/[[:alnum:]]/' to +match the alphabetic and numeric characters in your character set. Some utilities that match regular expressions provide a non-standard -'[:ascii:]' character class; 'awk' does not. However, you can simulate -such a construct using '[\x00-\x7F]'. This matches all values +`[:ascii:]' character class; `awk' does not. However, you can simulate +such a construct using `[\x00-\x7F]'. This matches all values numerically between zero and 127, which is the defined range of the -ASCII character set. Use a complemented character list ('[^\x00-\x7F]') -to match any single-byte characters that are not in the ASCII range. +ASCII character set. Use a complemented character list +(`[^\x00-\x7F]') to match any single-byte characters that are not in +the ASCII range. Two additional special sequences can appear in bracket expressions. These apply to non-ASCII character sets, which can have single symbols (called "collating elements") that are represented with more than one -character. They can also have several characters that are equivalent -for "collating", or sorting, purposes. (For example, in French, a plain -"e" and a grave-accented "e`" are equivalent.) These sequences are: +character. They can also have several characters that are equivalent for +"collating", or sorting, purposes. (For example, in French, a plain "e" +and a grave-accented "e`" are equivalent.) These sequences are: Collating symbols - Multicharacter collating elements enclosed between '[.' and '.]'. - For example, if 'ch' is a collating element, then '[[.ch.]]' is a - regexp that matches this collating element, whereas '[ch]' is a - regexp that matches either 'c' or 'h'. + Multicharacter collating elements enclosed between `[.' and `.]'. + For example, if `ch' is a collating element, then `[[.ch.]]' is a + regexp that matches this collating element, whereas `[ch]' is a + regexp that matches either `c' or `h'. Equivalence classes - Locale-specific names for a list of characters that are equal. The - name is enclosed between '[=' and '=]'. For example, the name 'e' - might be used to represent all of "e," "e`," and "e'." In this - case, '[[=e=]]' is a regexp that matches any of 'e', 'e'', or 'e`'. + Locale-specific names for a list of characters that are equal. The + name is enclosed between `[=' and `=]'. For example, the name `e' + might be used to represent all of "e," "e`," and "e'." In this + case, `[[=e=]]' is a regexp that matches any of `e', `e'', or `e`'. These features are very valuable in non-English-speaking locales. - CAUTION: The library functions that 'gawk' uses for regular + CAUTION: The library functions that `gawk' uses for regular expression matching currently recognize only POSIX character classes; they do not recognize collating symbols or equivalence classes. @@ -4208,99 +3832,86 @@ often in practice, but it's worth noting for future reference.  File: gawk.info, Node: GNU Regexp Operators, Next: Case-sensitivity, Prev: Computed Regexps, Up: Regexp -<<<<<<< HEAD -3.5 'gawk'-Specific Regexp Operators -======= 3.7 `gawk'-Specific Regexp Operators ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac ==================================== GNU software that deals with regular expressions provides a number of additional regexp operators. These operators are described in this -minor node and are specific to 'gawk'; they are not available in other -'awk' implementations. Most of the additional operators deal with word +minor node and are specific to `gawk'; they are not available in other +`awk' implementations. Most of the additional operators deal with word matching. For our purposes, a "word" is a sequence of one or more -letters, digits, or underscores ('_'): +letters, digits, or underscores (`_'): -'\s' +`\s' Matches any whitespace character. Think of it as shorthand for - '[[:space:]]'. + `[[:space:]]'. -'\S' +`\S' Matches any character that is not whitespace. Think of it as - shorthand for '[^[:space:]]'. + shorthand for `[^[:space:]]'. -'\w' +`\w' Matches any word-constituent character--that is, it matches any - letter, digit, or underscore. Think of it as shorthand for - '[[:alnum:]_]'. + letter, digit, or underscore. Think of it as shorthand for + `[[:alnum:]_]'. -'\W' - Matches any character that is not word-constituent. Think of it as - shorthand for '[^[:alnum:]_]'. +`\W' + Matches any character that is not word-constituent. Think of it + as shorthand for `[^[:alnum:]_]'. -'\<' +`\<' Matches the empty string at the beginning of a word. For example, - '/\' +`\>' Matches the empty string at the end of a word. For example, - '/stow\>/' matches 'stow' but not 'stowaway'. + `/stow\>/' matches `stow' but not `stowaway'. -'\y' +`\y' Matches the empty string at either the beginning or the end of a - word (i.e., the word boundar*y*). For example, '\yballs?\y' - matches either 'ball' or 'balls', as a separate word. + word (i.e., the word boundar*y*). For example, `\yballs?\y' + matches either `ball' or `balls', as a separate word. -'\B' +`\B' Matches the empty string that occurs between two word-constituent - characters. For example, '/\Brat\B/' matches 'crate' but it does - not match 'dirty rat'. '\B' is essentially the opposite of '\y'. + characters. For example, `/\Brat\B/' matches `crate' but it does + not match `dirty rat'. `\B' is essentially the opposite of `\y'. There are two other operators that work on buffers. In Emacs, a -"buffer" is, naturally, an Emacs buffer. For other programs, 'gawk''s +"buffer" is, naturally, an Emacs buffer. For other programs, `gawk''s regexp library routines consider the entire string to match as the buffer. The operators are: -'\`' +`\`' Matches the empty string at the beginning of a buffer (string). -'\'' +`\'' Matches the empty string at the end of a buffer (string). - Because '^' and '$' always work in terms of the beginning and end of -strings, these operators don't add any new capabilities for 'awk'. They -are provided for compatibility with other GNU software. + Because `^' and `$' always work in terms of the beginning and end of +strings, these operators don't add any new capabilities for `awk'. +They are provided for compatibility with other GNU software. - In other GNU software, the word-boundary operator is '\b'. However, -that conflicts with the 'awk' language's definition of '\b' as -backspace, so 'gawk' uses a different letter. An alternative method + In other GNU software, the word-boundary operator is `\b'. However, +that conflicts with the `awk' language's definition of `\b' as +backspace, so `gawk' uses a different letter. An alternative method would have been to require two backslashes in the GNU operators, but -this was deemed too confusing. The current method of using '\y' for the -GNU '\b' appears to be the lesser of two evils. +this was deemed too confusing. The current method of using `\y' for the +GNU `\b' appears to be the lesser of two evils. - The various command-line options (*note Options::) control how 'gawk' -interprets characters in regexps: + The various command-line options (*note Options::) control how +`gawk' interprets characters in regexps: No options - In the default case, 'gawk' provides all the facilities of POSIX + In the default case, `gawk' provides all the facilities of POSIX regexps and the GNU regexp operators described in *note Regexp Operators::. -'--posix' +`--posix' Only POSIX regexps are supported; the GNU operators are not special - (e.g., '\w' matches a literal 'w'). Interval expressions are + (e.g., `\w' matches a literal `w'). Interval expressions are allowed. -<<<<<<< HEAD -'--traditional' - Traditional Unix 'awk' regexps are matched. The GNU operators are - not special, and interval expressions are not available. The POSIX - character classes ('[[:alnum:]]', etc.) are supported, as Brian - Kernighan's 'awk' does support them. Characters described by octal - and hexadecimal escape sequences are treated literally, even if - they represent regexp metacharacters. -======= `--traditional' Traditional Unix `awk' regexps are matched. The GNU operators are not special, and interval expressions are not available. The @@ -4308,10 +3919,9 @@ No options BWK `awk' does support them. Characters described by octal and hexadecimal escape sequences are treated literally, even if they represent regexp metacharacters. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac -'--re-interval' - Allow interval expressions in regexps, if '--traditional' has been +`--re-interval' + Allow interval expressions in regexps, if `--traditional' has been provided. Otherwise, interval expressions are available by default. @@ -4323,32 +3933,32 @@ File: gawk.info, Node: Case-sensitivity, Next: Regexp Summary, Prev: GNU Rege Case is normally significant in regular expressions, both when matching ordinary characters (i.e., not metacharacters) and inside bracket -expressions. Thus, a 'w' in a regular expression matches only a -lowercase 'w' and not an uppercase 'W'. +expressions. Thus, a `w' in a regular expression matches only a +lowercase `w' and not an uppercase `W'. The simplest way to do a case-independent match is to use a bracket -expression--for example, '[Ww]'. However, this can be cumbersome if you -need to use it often, and it can make the regular expressions harder to -read. There are two alternatives that you might prefer. +expression--for example, `[Ww]'. However, this can be cumbersome if +you need to use it often, and it can make the regular expressions harder +to read. There are two alternatives that you might prefer. One way to perform a case-insensitive match at a particular point in the program is to convert the data to a single case, using the -'tolower()' or 'toupper()' built-in string functions (which we haven't +`tolower()' or `toupper()' built-in string functions (which we haven't discussed yet; *note String Functions::). For example: tolower($1) ~ /foo/ { ... } converts the first field to lowercase before matching against it. This -works in any POSIX-compliant 'awk'. +works in any POSIX-compliant `awk'. - Another method, specific to 'gawk', is to set the variable -'IGNORECASE' to a nonzero value (*note Built-in Variables::). When -'IGNORECASE' is not zero, _all_ regexp and string operations ignore + Another method, specific to `gawk', is to set the variable +`IGNORECASE' to a nonzero value (*note Built-in Variables::). When +`IGNORECASE' is not zero, _all_ regexp and string operations ignore case. - Changing the value of 'IGNORECASE' dynamically controls the + Changing the value of `IGNORECASE' dynamically controls the case-sensitivity of the program as it runs. Case is significant by -default because 'IGNORECASE' (like most variables) is initialized to +default because `IGNORECASE' (like most variables) is initialized to zero: x = "aB" @@ -4357,165 +3967,52 @@ zero: IGNORECASE = 1 if (x ~ /ab/) ... # now it will succeed - In general, you cannot use 'IGNORECASE' to make certain rules + In general, you cannot use `IGNORECASE' to make certain rules case-insensitive and other rules case-sensitive, because there is no -straightforward way to set 'IGNORECASE' just for the pattern of a -particular rule.(1) To do this, use either bracket expressions or -'tolower()'. However, one thing you can do with 'IGNORECASE' only is +straightforward way to set `IGNORECASE' just for the pattern of a +particular rule.(1) To do this, use either bracket expressions or +`tolower()'. However, one thing you can do with `IGNORECASE' only is dynamically turn case-sensitivity on or off for all the rules at once. - 'IGNORECASE' can be set on the command line or in a 'BEGIN' rule + `IGNORECASE' can be set on the command line or in a `BEGIN' rule (*note Other Arguments::; also *note Using BEGIN/END::). Setting -'IGNORECASE' from the command line is a way to make a program +`IGNORECASE' from the command line is a way to make a program case-insensitive without having to edit it. In multibyte locales, the equivalences between upper- and lowercase -characters are tested based on the wide-character values of the locale's -character set. Otherwise, the characters are tested based on the -ISO-8859-1 (ISO Latin-1) character set. This character set is a +characters are tested based on the wide-character values of the +locale's character set. Otherwise, the characters are tested based on +the ISO-8859-1 (ISO Latin-1) character set. This character set is a superset of the traditional 128 ASCII characters, which also provides a number of characters suitable for use with European languages.(2) - The value of 'IGNORECASE' has no effect if 'gawk' is in compatibility -mode (*note Options::). Case is always significant in compatibility -mode. + The value of `IGNORECASE' has no effect if `gawk' is in +compatibility mode (*note Options::). Case is always significant in +compatibility mode. ---------- Footnotes ---------- (1) Experienced C and C++ programmers will note that it is possible, -using something like 'IGNORECASE = 1 && /foObAr/ { ... }' and -'IGNORECASE = 0 || /foobar/ { ... }'. However, this is somewhat obscure -and we don't recommend it. - - (2) If you don't understand this, don't worry about it; it just means -that 'gawk' does the right thing. - - -<<<<<<< HEAD -File: gawk.info, Node: Leftmost Longest, Next: Computed Regexps, Prev: Case-sensitivity, Up: Regexp - -3.7 How Much Text Matches? -========================== - -Consider the following: - - echo aaaabcd | awk '{ sub(/a+/, ""); print }' - - This example uses the 'sub()' function (which we haven't discussed -yet; *note String Functions::) to make a change to the input record. -Here, the regexp '/a+/' indicates "one or more 'a' characters," and the -replacement text is ''. - - The input contains four 'a' characters. 'awk' (and POSIX) regular -expressions always match the leftmost, _longest_ sequence of input -characters that can match. Thus, all four 'a' characters are replaced -with '' in this example: - - $ echo aaaabcd | awk '{ sub(/a+/, ""); print }' - -| bcd - - For simple match/no-match tests, this is not so important. But when -doing text matching and substitutions with the 'match()', 'sub()', -'gsub()', and 'gensub()' functions, it is very important. *Note String -Functions::, for more information on these functions. Understanding -this principle is also important for regexp-based record and field -splitting (*note Records::, and also *note Field Separators::). - - -File: gawk.info, Node: Computed Regexps, Next: Regexp Summary, Prev: Leftmost Longest, Up: Regexp - -3.8 Using Dynamic Regexps -========================= - -The righthand side of a '~' or '!~' operator need not be a regexp -constant (i.e., a string of characters between slashes). It may be any -expression. The expression is evaluated and converted to a string if -necessary; the contents of the string are then used as the regexp. A -regexp computed in this way is called a "dynamic regexp" or a "computed -regexp": - - BEGIN { digits_regexp = "[[:digit:]]+" } - $0 ~ digits_regexp { print } - -This sets 'digits_regexp' to a regexp that describes one or more digits, -and tests whether the input record matches this regexp. - - NOTE: When using the '~' and '!~' operators, there is a difference - between a regexp constant enclosed in slashes and a string constant - enclosed in double quotes. If you are going to use a string - constant, you have to understand that the string is, in essence, - scanned _twice_: the first time when 'awk' reads your program, and - the second time when it goes to match the string on the lefthand - side of the operator with the pattern on the right. This is true - of any string-valued expression (such as 'digits_regexp', shown - previously), not just string constants. - - What difference does it make if the string is scanned twice? The -answer has to do with escape sequences, and particularly with -backslashes. To get a backslash into a regular expression inside a -string, you have to type two backslashes. - - For example, '/\*/' is a regexp constant for a literal '*'. Only one -backslash is needed. To do the same thing with a string, you have to -type '"\\*"'. The first backslash escapes the second one so that the -string actually contains the two characters '\' and '*'. - - Given that you can use both regexp and string constants to describe -regular expressions, which should you use? The answer is "regexp -constants," for several reasons: - - * String constants are more complicated to write and more difficult - to read. Using regexp constants makes your programs less - error-prone. Not understanding the difference between the two - kinds of constants is a common source of errors. - - * It is more efficient to use regexp constants. 'awk' can note that - you have supplied a regexp and store it internally in a form that - makes pattern matching more efficient. When using a string - constant, 'awk' must first convert the string into this internal - form and then perform the pattern matching. - - * Using regexp constants is better form; it shows clearly that you - intend a regexp match. - - Using '\n' in Bracket Expressions of Dynamic Regexps - - Some versions of 'awk' do not allow the newline character to be used -inside a bracket expression for a dynamic regexp: - - $ awk '$0 ~ "[ \t\n]"' - error-> awk: newline in character class [ - error-> ]... - error-> source line number 1 - error-> context is - error-> >>> <<< - - But a newline in a regexp constant works with no problem: +using something like `IGNORECASE = 1 && /foObAr/ { ... }' and +`IGNORECASE = 0 || /foobar/ { ... }'. However, this is somewhat +obscure and we don't recommend it. - $ awk '$0 ~ /[ \t\n]/' - here is a sample line - -| here is a sample line - Ctrl-d - - 'gawk' does not have this problem, and it isn't likely to occur often -in practice, but it's worth noting for future reference. + (2) If you don't understand this, don't worry about it; it just +means that `gawk' does the right thing.  -File: gawk.info, Node: Regexp Summary, Prev: Computed Regexps, Up: Regexp -======= File: gawk.info, Node: Regexp Summary, Prev: Case-sensitivity, Up: Regexp ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac 3.9 Summary =========== * Regular expressions describe sets of strings to be matched. In - 'awk', regular expression constants are written enclosed between - slashes: '/'...'/'. + `awk', regular expression constants are written enclosed between + slashes: `/'...`/'. * Regexp constants may be used standalone in patterns and in conditional expressions, or as part of matching expressions using - the '~' and '!~' operators. + the `~' and `!~' operators. * Escape sequences let you represent non-printable characters and also let you represent regexp metacharacters as literal characters @@ -4528,9 +4025,9 @@ File: gawk.info, Node: Regexp Summary, Prev: Case-sensitivity, Up: Regexp Within bracket expressions, POSIX character classes let you specify certain groups of characters in a locale-independent fashion. - * 'gawk''s 'IGNORECASE' variable lets you control the case - sensitivity of regexp matching. In other 'awk' versions, use - 'tolower()' or 'toupper()'. + * `gawk''s `IGNORECASE' variable lets you control the case + sensitivity of regexp matching. In other `awk' versions, use + `tolower()' or `toupper()'. * Regular expressions match the leftmost longest text in the string being matched. This matters for cases where you need to know the @@ -4540,19 +4037,20 @@ File: gawk.info, Node: Regexp Summary, Prev: Case-sensitivity, Up: Regexp * Matching expressions may use dynamic regexps, that is, string values treated as regular expressions. +  File: gawk.info, Node: Reading Files, Next: Printing, Prev: Regexp, Up: Top 4 Reading Input Files ********************* -In the typical 'awk' program, 'awk' reads all input either from the -standard input (by default, this is the keyboard, but often it is a pipe -from another command) or from files whose names you specify on the 'awk' -command line. If you specify input files, 'awk' reads them in order, -processing all the data from one before going on to the next. The name -of the current input file can be found in the built-in variable -'FILENAME' (*note Built-in Variables::). +In the typical `awk' program, `awk' reads all input either from the +standard input (by default, this is the keyboard, but often it is a +pipe from another command) or from files whose names you specify on the +`awk' command line. If you specify input files, `awk' reads them in +order, processing all the data from one before going on to the next. +The name of the current input file can be found in the built-in variable +`FILENAME' (*note Built-in Variables::). The input is read in units called "records", and is processed by the rules of your program one record at a time. By default, each record is @@ -4560,10 +4058,10 @@ one line. Each record is automatically split into chunks called "fields". This makes it more convenient for programs to work on the parts of a record. - On rare occasions, you may need to use the 'getline' command. The -'getline' command is valuable, both because it can do explicit input -from any number of files, and because the files used with it do not have -to be named on the 'awk' command line (*note Getline::). + On rare occasions, you may need to use the `getline' command. The +`getline' command is valuable, both because it can do explicit input +from any number of files, and because the files used with it do not +have to be named on the `awk' command line (*note Getline::). * Menu: @@ -4576,7 +4074,7 @@ to be named on the 'awk' command line (*note Getline::). * Splitting By Content:: Defining Fields By Content * Multiple Line:: Reading multiline records. * Getline:: Reading files under explicit program control - using the 'getline' function. + using the `getline' function. * Read Timeout:: Reading input with a timeout. * Command-line directories:: What happens if you put a directory on the command line. @@ -4589,15 +4087,6 @@ File: gawk.info, Node: Records, Next: Fields, Up: Reading Files 4.1 How Input Is Split into Records =================================== -<<<<<<< HEAD -The 'awk' utility divides the input for your 'awk' program into records -and fields. 'awk' keeps track of the number of records that have been -read so far from the current input file. This value is stored in a -built-in variable called 'FNR'. It is reset to zero when a new file is -started. Another built-in variable, 'NR', records the total number of -input records read so far from all data files. It starts at zero, but -is never automatically reset to zero. -======= `awk' divides the input for your program into records and fields. It keeps track of the number of records that have been read so far from the current input file. This value is stored in a built-in variable @@ -4605,45 +4094,44 @@ called `FNR' which is reset to zero when a new file is started. Another built-in variable, `NR', records the total number of input records read so far from all data files. It starts at zero, but is never automatically reset to zero. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Menu: -* awk split records:: How standard 'awk' splits records. -* gawk split records:: How 'gawk' splits records. +* awk split records:: How standard `awk' splits records. +* gawk split records:: How `gawk' splits records.  File: gawk.info, Node: awk split records, Next: gawk split records, Up: Records -4.1.1 Record Splitting With Standard 'awk' +4.1.1 Record Splitting With Standard `awk' ------------------------------------------ Records are separated by a character called the "record separator". By default, the record separator is the newline character. This is why records are, by default, single lines. A different character can be -used for the record separator by assigning the character to the built-in -variable 'RS'. +used for the record separator by assigning the character to the +built-in variable `RS'. - Like any other variable, the value of 'RS' can be changed in the -'awk' program with the assignment operator, '=' (*note Assignment + Like any other variable, the value of `RS' can be changed in the +`awk' program with the assignment operator, `=' (*note Assignment Ops::). The new record-separator character should be enclosed in -quotation marks, which indicate a string constant. Often the right time -to do this is at the beginning of execution, before any input is +quotation marks, which indicate a string constant. Often the right +time to do this is at the beginning of execution, before any input is processed, so that the very first record is read with the proper -separator. To do this, use the special 'BEGIN' pattern (*note +separator. To do this, use the special `BEGIN' pattern (*note BEGIN/END::). For example: awk 'BEGIN { RS = "u" } { print $0 }' mail-list -changes the value of 'RS' to 'u', before reading any input. This is a -string whose first character is the letter "u;" as a result, records are -separated by the letter "u." Then the input file is read, and the -second rule in the 'awk' program (the action with no pattern) prints -each record. Because each 'print' statement adds a newline at the end -of its output, this 'awk' program copies the input with each 'u' changed -to a newline. Here are the results of running the program on -'mail-list': +changes the value of `RS' to `u', before reading any input. This is a +string whose first character is the letter "u;" as a result, records +are separated by the letter "u." Then the input file is read, and the +second rule in the `awk' program (the action with no pattern) prints +each record. Because each `print' statement adds a newline at the end +of its output, this `awk' program copies the input with each `u' +changed to a newline. Here are the results of running the program on +`mail-list': $ awk 'BEGIN { RS = "u" } > { print $0 }' mail-list @@ -4686,84 +4174,85 @@ to a newline. Here are the results of running the program on -| R -| -Note that the entry for the name 'Bill' is not split. In the original +Note that the entry for the name `Bill' is not split. In the original data file (*note Sample Data Files::), the line looks like this: Bill 555-1675 bill.drowning@hotmail.com A -It contains no 'u' so there is no reason to split the record, unlike the -others which have one or more occurrences of the 'u'. In fact, this -record is treated as part of the previous record; the newline separating -them in the output is the original newline in the data file, not the one -added by 'awk' when it printed the record! +It contains no `u' so there is no reason to split the record, unlike +the others which have one or more occurrences of the `u'. In fact, +this record is treated as part of the previous record; the newline +separating them in the output is the original newline in the data file, +not the one added by `awk' when it printed the record! Another way to change the record separator is on the command line, using the variable-assignment feature (*note Other Arguments::): awk '{ print $0 }' RS="u" mail-list -This sets 'RS' to 'u' before processing 'mail-list'. +This sets `RS' to `u' before processing `mail-list'. - Using an alphabetic character such as 'u' for the record separator is -highly likely to produce strange results. Using an unusual character -such as '/' is more likely to produce correct behavior in the majority -of cases, but there are no guarantees. The moral is: Know Your Data. + Using an alphabetic character such as `u' for the record separator +is highly likely to produce strange results. Using an unusual +character such as `/' is more likely to produce correct behavior in the +majority of cases, but there are no guarantees. The moral is: Know Your +Data. - There is one unusual case, that occurs when 'gawk' is being fully + There is one unusual case, that occurs when `gawk' is being fully POSIX-compliant (*note Options::). Then, the following (extreme) -pipeline prints a surprising '1': +pipeline prints a surprising `1': $ echo | gawk --posix 'BEGIN { RS = "a" } ; { print NF }' -| 1 There is one field, consisting of a newline. The value of the -built-in variable 'NF' is the number of fields in the current record. -(In the normal case, 'gawk' treats the newline as whitespace, printing -'0' as the result. Most other versions of 'awk' also act this way.) +built-in variable `NF' is the number of fields in the current record. +(In the normal case, `gawk' treats the newline as whitespace, printing +`0' as the result. Most other versions of `awk' also act this way.) Reaching the end of an input file terminates the current input record, even if the last character in the file is not the character in -'RS'. (d.c.) +`RS'. (d.c.) - The empty string '""' (a string without any characters) has a special -meaning as the value of 'RS'. It means that records are separated by -one or more blank lines and nothing else. *Note Multiple Line::, for -more details. + The empty string `""' (a string without any characters) has a +special meaning as the value of `RS'. It means that records are +separated by one or more blank lines and nothing else. *Note Multiple +Line::, for more details. - If you change the value of 'RS' in the middle of an 'awk' run, the + If you change the value of `RS' in the middle of an `awk' run, the new value is used to delimit subsequent records, but the record currently being processed, as well as records already processed, are not affected. - After the end of the record has been determined, 'gawk' sets the -variable 'RT' to the text in the input that matched 'RS'. + After the end of the record has been determined, `gawk' sets the +variable `RT' to the text in the input that matched `RS'.  File: gawk.info, Node: gawk split records, Prev: awk split records, Up: Records -4.1.2 Record Splitting With 'gawk' +4.1.2 Record Splitting With `gawk' ---------------------------------- -When using 'gawk', the value of 'RS' is not limited to a one-character -string. It can be any regular expression (*note Regexp::). (c.e.) In +When using `gawk', the value of `RS' is not limited to a one-character +string. It can be any regular expression (*note Regexp::). (c.e.) In general, each record ends at the next string that matches the regular expression; the next record starts at the end of the matching string. -This general rule is actually at work in the usual case, where 'RS' +This general rule is actually at work in the usual case, where `RS' contains just a newline: a record ends at the beginning of the next matching string (the next newline in the input), and the following record starts just after the end of this string (at the first character -of the following line). The newline, because it matches 'RS', is not +of the following line). The newline, because it matches `RS', is not part of either record. - When 'RS' is a single character, 'RT' contains the same single -character. However, when 'RS' is a regular expression, 'RT' contains + When `RS' is a single character, `RT' contains the same single +character. However, when `RS' is a regular expression, `RT' contains the actual input text that matched the regular expression. - If the input file ended without any text that matches 'RS', 'gawk' -sets 'RT' to the null string. + If the input file ended without any text that matches `RS', `gawk' +sets `RT' to the null string. The following example illustrates both of these features. It sets -'RS' equal to a regular expression that matches either a newline or a +`RS' equal to a regular expression that matches either a newline or a series of one or more uppercase letters with optional leading and/or trailing whitespace: @@ -4775,31 +4264,6 @@ trailing whitespace: -| Record = record 3 and RT = [ -| ] -<<<<<<< HEAD -The final line of output has an extra blank line. This is because the -value of 'RT' is a newline, and the 'print' statement supplies its own -terminating newline. *Note Simple Sed::, for a more useful example of -'RS' as a regexp and 'RT'. - - If you set 'RS' to a regular expression that allows optional trailing -text, such as 'RS = "abc(XYZ)?"' it is possible, due to implementation -constraints, that 'gawk' may match the leading part of the regular -expression, but not the trailing part, particularly if the input text -that could match the trailing part is fairly long. 'gawk' attempts to -avoid this problem, but currently, there's no guarantee that this will -never happen. - - NOTE: Remember that in 'awk', the '^' and '$' anchor metacharacters - match the beginning and end of a _string_, and not the beginning - and end of a _line_. As a result, something like 'RS = - "^[[:upper:]]"' can only match at the beginning of a file. This is - because 'gawk' views the input file as one long string that happens - to contain newline characters in it. It is thus best to avoid - anchor characters in the value of 'RS'. - - The use of 'RS' as a regular expression and the 'RT' variable are -'gawk' extensions; they are not available in compatibility mode (*note -======= The square brackets delineate the contents of `RT', letting you see the leading and trailing whitespace. The final value of `RT' `RT' is a newline. *Note Simple Sed::, for a more useful example of `RS' as a @@ -4823,40 +4287,40 @@ that this will never happen. The use of `RS' as a regular expression and the `RT' variable are `gawk' extensions; they are not available in compatibility mode (*note ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Options::). In compatibility mode, only the first character of the -value of 'RS' is used to determine the end of the record. +value of `RS' is used to determine the end of the record. - 'RS = "\0"' Is Not Portable + `RS = "\0"' Is Not Portable There are times when you might want to treat an entire data file as a -single record. The only way to make this happen is to give 'RS' a value -that you know doesn't occur in the input file. This is hard to do in a -general way, such that a program always works for arbitrary input files. +single record. The only way to make this happen is to give `RS' a +value that you know doesn't occur in the input file. This is hard to +do in a general way, such that a program always works for arbitrary +input files. You might think that for text files, the NUL character, which consists of a character with all bits equal to zero, is a good value to -use for 'RS' in this case: +use for `RS' in this case: BEGIN { RS = "\0" } # whole file becomes one record? - 'gawk' in fact accepts this, and uses the NUL character for the + `gawk' in fact accepts this, and uses the NUL character for the record separator. This works for certain special files, such as -'/proc/environ' on GNU/Linux systems, where the NUL character is in fact -the record separator. However, this usage is _not_ portable to most -other 'awk' implementations. +`/proc/environ' on GNU/Linux systems, where the NUL character is in +fact the record separator. However, this usage is _not_ portable to +most other `awk' implementations. - Almost all other 'awk' implementations(1) store strings internally as -C-style strings. C strings use the NUL character as the string -terminator. In effect, this means that 'RS = "\0"' is the same as 'RS = -""'. (d.c.) + Almost all other `awk' implementations(1) store strings internally +as C-style strings. C strings use the NUL character as the string +terminator. In effect, this means that `RS = "\0"' is the same as `RS += ""'. (d.c.) - It happens that recent versions of 'mawk' can use the NUL character -as a record separator. However, this is a special case: 'mawk' does not + It happens that recent versions of `mawk' can use the NUL character +as a record separator. However, this is a special case: `mawk' does not allow embedded NUL characters in strings. *Note Readfile Function::, for an interesting, portable way to read -whole files. If you are using 'gawk', see *note Extension Sample +whole files. If you are using `gawk', see *note Extension Sample Readfile::, for another option. ---------- Footnotes ---------- @@ -4869,55 +4333,56 @@ File: gawk.info, Node: Fields, Next: Nonconstant Fields, Prev: Records, Up: 4.2 Examining Fields ==================== -When 'awk' reads an input record, the record is automatically "parsed" -or separated by the 'awk' utility into chunks called "fields". By +When `awk' reads an input record, the record is automatically "parsed" +or separated by the `awk' utility into chunks called "fields". By default, fields are separated by "whitespace", like words in a line. -Whitespace in 'awk' means any string of one or more spaces, TABs, or +Whitespace in `awk' means any string of one or more spaces, TABs, or newlines;(1) other characters, such as formfeed, vertical tab, etc., that are considered whitespace by other languages, are _not_ considered -whitespace by 'awk'. +whitespace by `awk'. The purpose of fields is to make it more convenient for you to refer to these pieces of the record. You don't have to use them--you can -operate on the whole record if you want--but fields are what make simple -'awk' programs so powerful. +operate on the whole record if you want--but fields are what make +simple `awk' programs so powerful. - You use a dollar-sign ('$') to refer to a field in an 'awk' program, -followed by the number of the field you want. Thus, '$1' refers to the -first field, '$2' to the second, and so on. (Unlike the Unix shells, -the field numbers are not limited to single digits. '$127' is the one + You use a dollar-sign (`$') to refer to a field in an `awk' program, +followed by the number of the field you want. Thus, `$1' refers to the +first field, `$2' to the second, and so on. (Unlike the Unix shells, +the field numbers are not limited to single digits. `$127' is the one hundred twenty-seventh field in the record.) For example, suppose the following is a line of input: This seems like a pretty nice example. -Here the first field, or '$1', is 'This', the second field, or '$2', is -'seems', and so on. Note that the last field, '$7', is 'example.'. -Because there is no space between the 'e' and the '.', the period is +Here the first field, or `$1', is `This', the second field, or `$2', is +`seems', and so on. Note that the last field, `$7', is `example.'. +Because there is no space between the `e' and the `.', the period is considered part of the seventh field. - 'NF' is a built-in variable whose value is the number of fields in -the current record. 'awk' automatically updates the value of 'NF' each + `NF' is a built-in variable whose value is the number of fields in +the current record. `awk' automatically updates the value of `NF' each time it reads a record. No matter how many fields there are, the last -field in a record can be represented by '$NF'. So, '$NF' is the same as -'$7', which is 'example.'. If you try to reference a field beyond the -last one (such as '$8' when the record has only seven fields), you get -the empty string. (If used in a numeric operation, you get zero.) +field in a record can be represented by `$NF'. So, `$NF' is the same +as `$7', which is `example.'. If you try to reference a field beyond +the last one (such as `$8' when the record has only seven fields), you +get the empty string. (If used in a numeric operation, you get zero.) - The use of '$0', which looks like a reference to the "zero-th" field, -is a special case: it represents the whole input record. Use it when -you are not interested in specific fields. Here are some more examples: + The use of `$0', which looks like a reference to the "zero-th" +field, is a special case: it represents the whole input record. Use it +when you are not interested in specific fields. Here are some more +examples: $ awk '$1 ~ /li/ { print $0 }' mail-list -| Amelia 555-5553 amelia.zodiacusque@gmail.com F -| Julie 555-6699 julie.perscrutabor@skeeve.com F -This example prints each record in the file 'mail-list' whose first -field contains the string 'li'. The operator '~' is called a "matching +This example prints each record in the file `mail-list' whose first +field contains the string `li'. The operator `~' is called a "matching operator" (*note Regexp Usage::); it tests whether a string (here, the -field '$1') matches a given regular expression. +field `$1') matches a given regular expression. - By contrast, the following example looks for 'li' in _the entire + By contrast, the following example looks for `li' in _the entire record_ and prints the first field and the last field for each matching input record: @@ -4929,7 +4394,7 @@ input record: ---------- Footnotes ---------- - (1) In POSIX 'awk', newlines are not considered whitespace for + (1) In POSIX `awk', newlines are not considered whitespace for separating fields.  @@ -4938,14 +4403,15 @@ File: gawk.info, Node: Nonconstant Fields, Next: Changing Fields, Prev: Field 4.3 Nonconstant Field Numbers ============================= -A field number need not be a constant. Any expression in the 'awk' -language can be used after a '$' to refer to a field. The value of the -expression specifies the field number. If the value is a string, rather -than a number, it is converted to a number. Consider this example: +A field number need not be a constant. Any expression in the `awk' +language can be used after a `$' to refer to a field. The value of the +expression specifies the field number. If the value is a string, +rather than a number, it is converted to a number. Consider this +example: awk '{ print $NR }' -Recall that 'NR' is the number of records read so far: one in the first +Recall that `NR' is the number of records read so far: one in the first record, two in the second, etc. So this example prints the first field of the first record, the second field of the second record, and so on. For the twentieth record, field number 20 is printed; most likely, the @@ -4954,33 +4420,33 @@ another example of using expressions as field numbers: awk '{ print $(2*2) }' mail-list - 'awk' evaluates the expression '(2*2)' and uses its value as the -number of the field to print. The '*' sign represents multiplication, -so the expression '2*2' evaluates to four. The parentheses are used so -that the multiplication is done before the '$' operation; they are + `awk' evaluates the expression `(2*2)' and uses its value as the +number of the field to print. The `*' sign represents multiplication, +so the expression `2*2' evaluates to four. The parentheses are used so +that the multiplication is done before the `$' operation; they are necessary whenever there is a binary operator(1) in the field-number expression. This example, then, prints the type of relationship (the -fourth field) for every line of the file 'mail-list'. (All of the 'awk' -operators are listed, in order of decreasing precedence, in *note +fourth field) for every line of the file `mail-list'. (All of the +`awk' operators are listed, in order of decreasing precedence, in *note Precedence::.) If the field number you compute is zero, you get the entire record. -Thus, '$(2-2)' has the same value as '$0'. Negative field numbers are +Thus, `$(2-2)' has the same value as `$0'. Negative field numbers are not allowed; trying to reference one usually terminates the program. (The POSIX standard does not define what happens when you reference a -negative field number. 'gawk' notices this and terminates your program. -Other 'awk' implementations may behave differently.) +negative field number. `gawk' notices this and terminates your +program. Other `awk' implementations may behave differently.) - As mentioned in *note Fields::, 'awk' stores the current record's -number of fields in the built-in variable 'NF' (also *note Built-in -Variables::). The expression '$NF' is not a special feature--it is the -direct consequence of evaluating 'NF' and using its value as a field + As mentioned in *note Fields::, `awk' stores the current record's +number of fields in the built-in variable `NF' (also *note Built-in +Variables::). The expression `$NF' is not a special feature--it is the +direct consequence of evaluating `NF' and using its value as a field number. ---------- Footnotes ---------- - (1) A "binary operator", such as '*' for multiplication, is one that -takes two operands. The distinction is required, since 'awk' also has + (1) A "binary operator", such as `*' for multiplication, is one that +takes two operands. The distinction is required, since `awk' also has unary (one-operand) and ternary (three-operand) operators.  @@ -4989,9 +4455,9 @@ File: gawk.info, Node: Changing Fields, Next: Field Separators, Prev: Noncons 4.4 Changing the Contents of a Field ==================================== -The contents of a field, as seen by 'awk', can be changed within an -'awk' program; this changes what 'awk' perceives as the current input -record. (The actual input is untouched; 'awk' _never_ modifies the +The contents of a field, as seen by `awk', can be changed within an +`awk' program; this changes what `awk' perceives as the current input +record. (The actual input is untouched; `awk' _never_ modifies the input file.) Consider the following example and its output: $ awk '{ nboxes = $3 ; $3 = $3 - 10 @@ -5002,21 +4468,21 @@ input file.) Consider the following example and its output: ... The program first saves the original value of field three in the -variable 'nboxes'. The '-' sign represents subtraction, so this program -reassigns field three, '$3', as the original value of field three minus -ten: '$3 - 10'. (*Note Arithmetic Ops::.) Then it prints the original -and new values for field three. (Someone in the warehouse made a -consistent mistake while inventorying the red boxes.) +variable `nboxes'. The `-' sign represents subtraction, so this +program reassigns field three, `$3', as the original value of field +three minus ten: `$3 - 10'. (*Note Arithmetic Ops::.) Then it prints +the original and new values for field three. (Someone in the warehouse +made a consistent mistake while inventorying the red boxes.) - For this to work, the text in '$3' must make sense as a number; the + For this to work, the text in `$3' must make sense as a number; the string of characters must be converted to a number for the computer to do arithmetic on it. The number resulting from the subtraction is converted back to a string of characters that then becomes field three. *Note Conversion::. - When the value of a field is changed (as perceived by 'awk'), the + When the value of a field is changed (as perceived by `awk'), the text of the input record is recalculated to contain the new field where -the old one was. In other words, '$0' changes to reflect the altered +the old one was. In other words, `$0' changes to reflect the altered field. Thus, this program prints a copy of the input file, with 10 subtracted from the second field of each line: @@ -5026,8 +4492,8 @@ subtracted from the second field of each line: -| Mar 5 24 34 228 ... - It is also possible to also assign contents to fields that are out of -range. For example: + It is also possible to also assign contents to fields that are out +of range. For example: $ awk '{ $6 = ($5 + $4 + $3 + $2) > print $6 }' inventory-shipped @@ -5036,26 +4502,26 @@ range. For example: -| 301 ... -We've just created '$6', whose value is the sum of fields '$2', '$3', -'$4', and '$5'. The '+' sign represents addition. For the file -'inventory-shipped', '$6' represents the total number of parcels shipped -for a particular month. +We've just created `$6', whose value is the sum of fields `$2', `$3', +`$4', and `$5'. The `+' sign represents addition. For the file +`inventory-shipped', `$6' represents the total number of parcels +shipped for a particular month. - Creating a new field changes 'awk''s internal copy of the current -input record, which is the value of '$0'. Thus, if you do 'print $0' + Creating a new field changes `awk''s internal copy of the current +input record, which is the value of `$0'. Thus, if you do `print $0' after adding a field, the record printed includes the new field, with the appropriate number of field separators between it and the previously existing fields. - This recomputation affects and is affected by 'NF' (the number of -fields; *note Fields::). For example, the value of 'NF' is set to the -number of the highest field you create. The exact format of '$0' is + This recomputation affects and is affected by `NF' (the number of +fields; *note Fields::). For example, the value of `NF' is set to the +number of the highest field you create. The exact format of `$0' is also affected by a feature that has not been discussed yet: the "output -field separator", 'OFS', used to separate the fields (*note Output +field separator", `OFS', used to separate the fields (*note Output Separators::). Note, however, that merely _referencing_ an out-of-range field does -_not_ change the value of either '$0' or 'NF'. Referencing an +_not_ change the value of either `$0' or `NF'. Referencing an out-of-range field only produces an empty string. For example: if ($(NF+1) != "") @@ -5063,13 +4529,13 @@ out-of-range field only produces an empty string. For example: else print "everything is normal" -should print 'everything is normal', because 'NF+1' is certain to be out -of range. (*Note If Statement::, for more information about 'awk''s -'if-else' statements. *Note Typing and Comparison::, for more -information about the '!=' operator.) +should print `everything is normal', because `NF+1' is certain to be +out of range. (*Note If Statement::, for more information about +`awk''s `if-else' statements. *Note Typing and Comparison::, for more +information about the `!=' operator.) It is important to note that making an assignment to an existing -field changes the value of '$0' but does not change the value of 'NF', +field changes the value of `$0' but does not change the value of `NF', even when you assign the empty string to a field. For example: $ echo a b c d | awk '{ OFS = ":"; $2 = "" @@ -5078,7 +4544,7 @@ even when you assign the empty string to a field. For example: -| 4 The field is still there; it just has an empty value, delimited by the -two colons between 'a' and 'c'. This example shows what happens if you +two colons between `a' and `c'. This example shows what happens if you create a new field: $ echo a b c d | awk '{ OFS = ":"; $2 = ""; $6 = "new" @@ -5086,51 +4552,51 @@ create a new field: -| a::c:d::new -| 6 -The intervening field, '$5', is created with an empty value (indicated -by the second pair of adjacent colons), and 'NF' is updated with the +The intervening field, `$5', is created with an empty value (indicated +by the second pair of adjacent colons), and `NF' is updated with the value six. - Decrementing 'NF' throws away the values of the fields after the new -value of 'NF' and recomputes '$0'. (d.c.) Here is an example: + Decrementing `NF' throws away the values of the fields after the new +value of `NF' and recomputes `$0'. (d.c.) Here is an example: $ echo a b c d e f | awk '{ print "NF =", NF; > NF = 3; print $0 }' -| NF = 6 -| a b c - CAUTION: Some versions of 'awk' don't rebuild '$0' when 'NF' is - decremented. Caveat emptor. + CAUTION: Some versions of `awk' don't rebuild `$0' when `NF' is + decremented. Caveat emptor. - Finally, there are times when it is convenient to force 'awk' to + Finally, there are times when it is convenient to force `awk' to rebuild the entire record, using the current value of the fields and -'OFS'. To do this, use the seemingly innocuous assignment: +`OFS'. To do this, use the seemingly innocuous assignment: $1 = $1 # force record to be reconstituted print $0 # or whatever else with $0 -This forces 'awk' to rebuild the record. It does help to add a comment, -as we've shown here. +This forces `awk' to rebuild the record. It does help to add a +comment, as we've shown here. - There is a flip side to the relationship between '$0' and the fields. -Any assignment to '$0' causes the record to be reparsed into fields -using the _current_ value of 'FS'. This also applies to any built-in -function that updates '$0', such as 'sub()' and 'gsub()' (*note String -Functions::). + There is a flip side to the relationship between `$0' and the +fields. Any assignment to `$0' causes the record to be reparsed into +fields using the _current_ value of `FS'. This also applies to any +built-in function that updates `$0', such as `sub()' and `gsub()' +(*note String Functions::). - Understanding '$0' + Understanding `$0' - It is important to remember that '$0' is the _full_ record, exactly + It is important to remember that `$0' is the _full_ record, exactly as it was read from the input. This includes any leading or trailing -whitespace, and the exact whitespace (or other characters) that separate -the fields. +whitespace, and the exact whitespace (or other characters) that +separate the fields. - It is a not-uncommon error to try to change the field separators in a -record simply by setting 'FS' and 'OFS', and then expecting a plain -'print' or 'print $0' to print the modified record. + It is a not-uncommon error to try to change the field separators in +a record simply by setting `FS' and `OFS', and then expecting a plain +`print' or `print $0' to print the modified record. But this does not work, since nothing was done to change the record itself. Instead, you must force the record to be rebuilt, typically -with a statement such as '$1 = $1', as described earlier. +with a statement such as `$1 = $1', as described earlier.  File: gawk.info, Node: Field Separators, Next: Constant Size, Prev: Changing Fields, Up: Reading Files @@ -5143,40 +4609,37 @@ File: gawk.info, Node: Field Separators, Next: Constant Size, Prev: Changing * Default Field Splitting:: How fields are normally separated. * Regexp Field Splitting:: Using regexps as the field separator. * Single Character Fields:: Making each character a separate field. -<<<<<<< HEAD -* Command Line Field Separator:: Setting 'FS' from the command-line. -======= * Command Line Field Separator:: Setting `FS' from the command line. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Full Line Fields:: Making the full line be a single field. * Field Splitting Summary:: Some final points and a summary table. -The "field separator", which is either a single character or a regular -expression, controls the way 'awk' splits an input record into fields. -'awk' scans the input record for character sequences that match the -separator; the fields themselves are the text between the matches. + The "field separator", which is either a single character or a +regular expression, controls the way `awk' splits an input record into +fields. `awk' scans the input record for character sequences that +match the separator; the fields themselves are the text between the +matches. In the examples that follow, we use the bullet symbol (*) to -represent spaces in the output. If the field separator is 'oo', then +represent spaces in the output. If the field separator is `oo', then the following line: moo goo gai pan -is split into three fields: 'm', '*g', and '*gai*pan'. Note the leading -spaces in the values of the second and third fields. +is split into three fields: `m', `*g', and `*gai*pan'. Note the +leading spaces in the values of the second and third fields. - The field separator is represented by the built-in variable 'FS'. -Shell programmers take note: 'awk' does _not_ use the name 'IFS' that is -used by the POSIX-compliant shells (such as the Unix Bourne shell, 'sh', -or Bash). + The field separator is represented by the built-in variable `FS'. +Shell programmers take note: `awk' does _not_ use the name `IFS' that +is used by the POSIX-compliant shells (such as the Unix Bourne shell, +`sh', or Bash). - The value of 'FS' can be changed in the 'awk' program with the -assignment operator, '=' (*note Assignment Ops::). Often the right time -to do this is at the beginning of execution before any input has been -processed, so that the very first record is read with the proper -separator. To do this, use the special 'BEGIN' pattern (*note -BEGIN/END::). For example, here we set the value of 'FS' to the string -'","': + The value of `FS' can be changed in the `awk' program with the +assignment operator, `=' (*note Assignment Ops::). Often the right +time to do this is at the beginning of execution before any input has +been processed, so that the very first record is read with the proper +separator. To do this, use the special `BEGIN' pattern (*note +BEGIN/END::). For example, here we set the value of `FS' to the string +`","': awk 'BEGIN { FS = "," } ; { print $2 }' @@ -5184,7 +4647,7 @@ Given the input line: John Q. Smith, 29 Oak St., Walamazoo, MI 42139 -this 'awk' program extracts and prints the string '*29*Oak*St.'. +this `awk' program extracts and prints the string `*29*Oak*St.'. Sometimes the input data contains separator characters that don't separate fields the way you thought they would. For instance, the @@ -5193,12 +4656,12 @@ attached, such as: John Q. Smith, LXIX, 29 Oak St., Walamazoo, MI 42139 -The same program would extract '*LXIX', instead of '*29*Oak*St.'. If +The same program would extract `*LXIX', instead of `*29*Oak*St.'. If you were expecting the program to print the address, you would be surprised. The moral is to choose your data layout and separator -characters carefully to prevent such problems. (If the data is not in a -form that is easy to process, perhaps you can massage it first with a -separate 'awk' program.) +characters carefully to prevent such problems. (If the data is not in +a form that is easy to process, perhaps you can massage it first with a +separate `awk' program.)  File: gawk.info, Node: Default Field Splitting, Next: Regexp Field Splitting, Up: Field Separators @@ -5206,16 +4669,17 @@ File: gawk.info, Node: Default Field Splitting, Next: Regexp Field Splitting, 4.5.1 Whitespace Normally Separates Fields ------------------------------------------ -Fields are normally separated by whitespace sequences (spaces, TABs, and -newlines), not by single spaces. Two spaces in a row do not delimit an -empty field. The default value of the field separator 'FS' is a string -containing a single space, '" "'. If 'awk' interpreted this value in -the usual way, each space character would separate fields, so two spaces -in a row would make an empty field between them. The reason this does -not happen is that a single space as the value of 'FS' is a special -case--it is taken to specify the default manner of delimiting fields. - - If 'FS' is any other single character, such as '","', then each +Fields are normally separated by whitespace sequences (spaces, TABs, +and newlines), not by single spaces. Two spaces in a row do not +delimit an empty field. The default value of the field separator `FS' +is a string containing a single space, `" "'. If `awk' interpreted +this value in the usual way, each space character would separate +fields, so two spaces in a row would make an empty field between them. +The reason this does not happen is that a single space as the value of +`FS' is a special case--it is taken to specify the default manner of +delimiting fields. + + If `FS' is any other single character, such as `","', then each occurrence of that character separates two fields. Two consecutive occurrences delimit an empty field. If the character occurs at the beginning or the end of the line, that too delimits an empty field. The @@ -5229,35 +4693,36 @@ File: gawk.info, Node: Regexp Field Splitting, Next: Single Character Fields, -------------------------------------------------- The previous node discussed the use of single characters or simple -strings as the value of 'FS'. More generally, the value of 'FS' may be -a string containing any regular expression. In this case, each match in -the record for the regular expression separates fields. For example, -the assignment: +strings as the value of `FS'. More generally, the value of `FS' may be +a string containing any regular expression. In this case, each match +in the record for the regular expression separates fields. For +example, the assignment: FS = ", \t" makes every area of an input line that consists of a comma followed by a -space and a TAB into a field separator. ('\t' is an "escape sequence" +space and a TAB into a field separator. (`\t' is an "escape sequence" that stands for a TAB; *note Escape Sequences::, for the complete list of similar escape sequences.) For a less trivial example of a regular expression, try using single -spaces to separate fields the way single commas are used. 'FS' can be -set to '"[ ]"' (left bracket, space, right bracket). This regular +spaces to separate fields the way single commas are used. `FS' can be +set to `"[ ]"' (left bracket, space, right bracket). This regular expression matches a single space and nothing else (*note Regexp::). - There is an important difference between the two cases of 'FS = " "' -(a single space) and 'FS = "[ \t\n]+"' (a regular expression matching -one or more spaces, TABs, or newlines). For both values of 'FS', fields -are separated by "runs" (multiple adjacent occurrences) of spaces, TABs, -and/or newlines. However, when the value of 'FS' is '" "', 'awk' first -strips leading and trailing whitespace from the record and then decides -where the fields are. For example, the following pipeline prints 'b': + There is an important difference between the two cases of `FS = " "' +(a single space) and `FS = "[ \t\n]+"' (a regular expression matching +one or more spaces, TABs, or newlines). For both values of `FS', +fields are separated by "runs" (multiple adjacent occurrences) of +spaces, TABs, and/or newlines. However, when the value of `FS' is +`" "', `awk' first strips leading and trailing whitespace from the +record and then decides where the fields are. For example, the +following pipeline prints `b': $ echo ' a b c d ' | awk '{ print $2 }' -| b -However, this pipeline prints 'a' (note the extra spaces around each +However, this pipeline prints `a' (note the extra spaces around each letter): $ echo ' a b c d ' | awk 'BEGIN { FS = "[ \t\n]+" } @@ -5266,36 +4731,30 @@ letter): In this case, the first field is null, or empty. - The stripping of leading and trailing whitespace also comes into play -whenever '$0' is recomputed. For instance, study this pipeline: + The stripping of leading and trailing whitespace also comes into +play whenever `$0' is recomputed. For instance, study this pipeline: $ echo ' a b c d' | awk '{ print; $2 = $2; print }' -| a b c d -| a b c d -The first 'print' statement prints the record as it was read, with -leading whitespace intact. The assignment to '$2' rebuilds '$0' by -concatenating '$1' through '$NF' together, separated by the value of -'OFS'. Because the leading whitespace was ignored when finding '$1', it -is not part of the new '$0'. Finally, the last 'print' statement prints -the new '$0'. +The first `print' statement prints the record as it was read, with +leading whitespace intact. The assignment to `$2' rebuilds `$0' by +concatenating `$1' through `$NF' together, separated by the value of +`OFS'. Because the leading whitespace was ignored when finding `$1', +it is not part of the new `$0'. Finally, the last `print' statement +prints the new `$0'. There is an additional subtlety to be aware of when using regular expressions for field splitting. It is not well-specified in the POSIX -standard, or anywhere else, what '^' means when splitting fields. Does -the '^' match only at the beginning of the entire record? Or is each -field separator a new string? It turns out that different 'awk' +standard, or anywhere else, what `^' means when splitting fields. Does +the `^' match only at the beginning of the entire record? Or is each +field separator a new string? It turns out that different `awk' versions answer this question differently, and you should not rely on any specific behavior in your programs. (d.c.) -<<<<<<< HEAD - As a point of information, Brian Kernighan's 'awk' allows '^' to -match only at the beginning of the record. 'gawk' also works this way. -For example: -======= As a point of information, BWK `awk' allows `^' to match only at the beginning of the record. `gawk' also works this way. For example: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac $ echo 'xxAA xxBxx C' | > gawk -F '(^x+)|( +)' '{ for (i = 1; i <= NF; i++) @@ -5312,8 +4771,8 @@ File: gawk.info, Node: Single Character Fields, Next: Command Line Field Separ -------------------------------------------- There are times when you may want to examine each character of a record -separately. This can be done in 'gawk' by simply assigning the null -string ('""') to 'FS'. (c.e.) In this case, each individual character +separately. This can be done in `gawk' by simply assigning the null +string (`""') to `FS'. (c.e.) In this case, each individual character in the record becomes a separate field. For example: $ echo a b | gawk 'BEGIN { FS = "" } @@ -5325,67 +4784,59 @@ in the record becomes a separate field. For example: -| Field 2 is -| Field 3 is b - Traditionally, the behavior of 'FS' equal to '""' was not defined. -In this case, most versions of Unix 'awk' simply treat the entire record + Traditionally, the behavior of `FS' equal to `""' was not defined. +In this case, most versions of Unix `awk' simply treat the entire record as only having one field. (d.c.) In compatibility mode (*note -Options::), if 'FS' is the null string, then 'gawk' also behaves this +Options::), if `FS' is the null string, then `gawk' also behaves this way.  File: gawk.info, Node: Command Line Field Separator, Next: Full Line Fields, Prev: Single Character Fields, Up: Field Separators -4.5.4 Setting 'FS' from the Command Line +4.5.4 Setting `FS' from the Command Line ---------------------------------------- -'FS' can be set on the command line. Use the '-F' option to do so. For -example: +`FS' can be set on the command line. Use the `-F' option to do so. +For example: awk -F, 'PROGRAM' INPUT-FILES -sets 'FS' to the ',' character. Notice that the option uses an -uppercase 'F' instead of a lowercase 'f'. The latter option ('-f') -specifies a file containing an 'awk' program. Case is significant in -command-line options: the '-F' and '-f' options have nothing to do with -each other. You can use both options at the same time to set the 'FS' -variable _and_ get an 'awk' program from a file. +sets `FS' to the `,' character. Notice that the option uses an +uppercase `F' instead of a lowercase `f'. The latter option (`-f') +specifies a file containing an `awk' program. Case is significant in +command-line options: the `-F' and `-f' options have nothing to do with +each other. You can use both options at the same time to set the `FS' +variable _and_ get an `awk' program from a file. - The value used for the argument to '-F' is processed in exactly the -same way as assignments to the built-in variable 'FS'. Any special + The value used for the argument to `-F' is processed in exactly the +same way as assignments to the built-in variable `FS'. Any special characters in the field separator must be escaped appropriately. For -example, to use a '\' as the field separator on the command line, you +example, to use a `\' as the field separator on the command line, you would have to type: # same as FS = "\\" awk -F\\\\ '...' files ... -Because '\' is used for quoting in the shell, 'awk' sees '-F\\'. Then -'awk' processes the '\\' for escape characters (*note Escape -Sequences::), finally yielding a single '\' to use for the field +Because `\' is used for quoting in the shell, `awk' sees `-F\\'. Then +`awk' processes the `\\' for escape characters (*note Escape +Sequences::), finally yielding a single `\' to use for the field separator. As a special case, in compatibility mode (*note Options::), if the -<<<<<<< HEAD -argument to '-F' is 't', then 'FS' is set to the TAB character. If you -type '-F\t' at the shell, without any quotes, the '\' gets deleted, so -'awk' figures that you really want your fields to be separated with TABs -and not 't's. Use '-v FS="t"' or '-F"[t]"' on the command line if you -really do want to separate your fields with 't's. -======= argument to `-F' is `t', then `FS' is set to the TAB character. If you type `-F\t' at the shell, without any quotes, the `\' gets deleted, so `awk' figures that you really want your fields to be separated with TABs and not `t's. Use `-v FS="t"' or `-F"[t]"' on the command line if you really do want to separate your fields with `t's. Use `-F '\t'' when not in compatibility mode to specify that TABs separate fields. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - As an example, let's use an 'awk' program file called 'edu.awk' that -contains the pattern '/edu/' and the action 'print $1': + As an example, let's use an `awk' program file called `edu.awk' that +contains the pattern `/edu/' and the action `print $1': /edu/ { print $1 } - Let's also set 'FS' to be the '-' character and run the program on -the file 'mail-list'. The following command prints a list of the names + Let's also set `FS' to be the `-' character and run the program on +the file `mail-list'. The following command prints a list of the names of the people that work at or attend a university, and the first three digits of their phone numbers: @@ -5399,19 +4850,19 @@ looked like this: Jean-Paul 555-2127 jeanpaul.campanorum@nyu.edu R - The '-' as part of the person's name was used as the field separator, -instead of the '-' in the phone number that was originally intended. -This demonstrates why you have to be careful in choosing your field and -record separators. + The `-' as part of the person's name was used as the field +separator, instead of the `-' in the phone number that was originally +intended. This demonstrates why you have to be careful in choosing +your field and record separators. Perhaps the most common use of a single character as the field -separator occurs when processing the Unix system password file. On many -Unix systems, each user has a separate entry in the system password -file, one line per user. The information in these lines is separated by -colons. The first field is the user's login name and the second is the -user's encrypted or shadow password. (A shadow password is indicated by -the presence of a single 'x' in the second field.) A password file -entry might look like this: +separator occurs when processing the Unix system password file. On +many Unix systems, each user has a separate entry in the system +password file, one line per user. The information in these lines is +separated by colons. The first field is the user's login name and the +second is the user's encrypted or shadow password. (A shadow password +is indicated by the presence of a single `x' in the second field.) A +password file entry might look like this: arnold:x:2076:10:Arnold Robbins:/home/arnold:/bin/bash @@ -5427,12 +4878,12 @@ File: gawk.info, Node: Full Line Fields, Next: Field Splitting Summary, Prev: -------------------------------------------- Occasionally, it's useful to treat the whole input line as a single -field. This can be done easily and portably simply by setting 'FS' to -'"\n"' (a newline).(1) +field. This can be done easily and portably simply by setting `FS' to +`"\n"' (a newline).(1) awk -F'\n' 'PROGRAM' FILES ... -When you do this, '$1' is the same as '$0'. +When you do this, `$1' is the same as `$0'. ---------- Footnotes ---------- @@ -5445,50 +4896,51 @@ File: gawk.info, Node: Field Splitting Summary, Prev: Full Line Fields, Up: F ----------------------------- It is important to remember that when you assign a string constant as -the value of 'FS', it undergoes normal 'awk' string processing. For -example, with Unix 'awk' and 'gawk', the assignment 'FS = "\.."' assigns -the character string '".."' to 'FS' (the backslash is stripped). This -creates a regexp meaning "fields are separated by occurrences of any two -characters." If instead you want fields to be separated by a literal -period followed by any single character, use 'FS = "\\.."'. +the value of `FS', it undergoes normal `awk' string processing. For +example, with Unix `awk' and `gawk', the assignment `FS = "\.."' +assigns the character string `".."' to `FS' (the backslash is +stripped). This creates a regexp meaning "fields are separated by +occurrences of any two characters." If instead you want fields to be +separated by a literal period followed by any single character, use `FS += "\\.."'. The following table summarizes how fields are split, based on the -value of 'FS' ('==' means "is equal to"): +value of `FS' (`==' means "is equal to"): -'FS == " "' +`FS == " "' Fields are separated by runs of whitespace. Leading and trailing whitespace are ignored. This is the default. -'FS == ANY OTHER SINGLE CHARACTER' +`FS == ANY OTHER SINGLE CHARACTER' Fields are separated by each occurrence of the character. Multiple successive occurrences delimit empty fields, as do leading and trailing occurrences. The character can even be a regexp metacharacter; it does not need to be escaped. -'FS == REGEXP' +`FS == REGEXP' Fields are separated by occurrences of characters that match REGEXP. Leading and trailing matches of REGEXP delimit empty fields. -'FS == ""' +`FS == ""' Each individual character in the record becomes a separate field. - (This is a 'gawk' extension; it is not specified by the POSIX + (This is a `gawk' extension; it is not specified by the POSIX standard.) - Changing 'FS' Does Not Affect the Fields + Changing `FS' Does Not Affect the Fields - According to the POSIX standard, 'awk' is supposed to behave as if -each record is split into fields at the time it is read. In particular, -this means that if you change the value of 'FS' after a record is read, -the value of the fields (i.e., how they were split) should reflect the -old value of 'FS', not the new one. + According to the POSIX standard, `awk' is supposed to behave as if +each record is split into fields at the time it is read. In +particular, this means that if you change the value of `FS' after a +record is read, the value of the fields (i.e., how they were split) +should reflect the old value of `FS', not the new one. - However, many older implementations of 'awk' do not work this way. + However, many older implementations of `awk' do not work this way. Instead, they defer splitting the fields until a field is actually -referenced. The fields are split using the _current_ value of 'FS'! -(d.c.) This behavior can be difficult to diagnose. The following +referenced. The fields are split using the _current_ value of `FS'! +(d.c.) This behavior can be difficult to diagnose. The following example illustrates the difference between the two methods. (The -'sed'(1) command prints just the first line of '/etc/passwd'.) +`sed'(1) command prints just the first line of `/etc/passwd'.) sed 1q /etc/passwd | awk '{ FS = ":" ; print $1 }' @@ -5496,21 +4948,16 @@ which usually prints: root -<<<<<<< HEAD -on an incorrect implementation of 'awk', while 'gawk' prints something -like: -======= on an incorrect implementation of `awk', while `gawk' prints the full first line of the file, something like: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac root:nSijPlPhZZwgE:0:0:Root:/: - 'FS' and 'IGNORECASE' + `FS' and `IGNORECASE' - The 'IGNORECASE' variable (*note User-modified::) affects field -splitting _only_ when the value of 'FS' is a regexp. It has no effect -when 'FS' is a single character, even if that character is a letter. + The `IGNORECASE' variable (*note User-modified::) affects field +splitting _only_ when the value of `FS' is a regexp. It has no effect +when `FS' is a single character, even if that character is a letter. Thus, in the following code: FS = "c" @@ -5518,14 +4965,14 @@ Thus, in the following code: $0 = "aCa" print $1 -The output is 'aCa'. If you really want to split fields on an +The output is `aCa'. If you really want to split fields on an alphabetic character while ignoring case, use a regexp that will do it -for you. E.g., 'FS = "[c]"'. In this case, 'IGNORECASE' will take +for you. E.g., `FS = "[c]"'. In this case, `IGNORECASE' will take effect. ---------- Footnotes ---------- - (1) The 'sed' utility is a "stream editor." Its behavior is also + (1) The `sed' utility is a "stream editor." Its behavior is also defined by the POSIX standard.  @@ -5534,31 +4981,32 @@ File: gawk.info, Node: Constant Size, Next: Splitting By Content, Prev: Field 4.6 Reading Fixed-Width Data ============================ - NOTE: This minor node discusses an advanced feature of 'gawk'. If - you are a novice 'awk' user, you might want to skip it on the first - reading. + NOTE: This minor node discusses an advanced feature of `gawk'. If + you are a novice `awk' user, you might want to skip it on the + first reading. - 'gawk' provides a facility for dealing with fixed-width fields with -no distinctive field separator. For example, data of this nature arises -in the input for old Fortran programs where numbers are run together, or -in the output of programs that did not anticipate the use of their -output as input for other programs. + `gawk' provides a facility for dealing with fixed-width fields with +no distinctive field separator. For example, data of this nature +arises in the input for old Fortran programs where numbers are run +together, or in the output of programs that did not anticipate the use +of their output as input for other programs. An example of the latter is a table where all the columns are lined up by the use of a variable number of spaces and _empty fields are just -spaces_. Clearly, 'awk''s normal field splitting based on 'FS' does not -work well in this case. Although a portable 'awk' program can use a -series of 'substr()' calls on '$0' (*note String Functions::), this is -awkward and inefficient for a large number of fields. - - The splitting of an input record into fixed-width fields is specified -by assigning a string containing space-separated numbers to the built-in -variable 'FIELDWIDTHS'. Each number specifies the width of the field, -_including_ columns between fields. If you want to ignore the columns -between fields, you can specify the width as a separate field that is -subsequently ignored. It is a fatal error to supply a field width that -is not a positive number. The following data is the output of the Unix -'w' utility. It is useful to illustrate the use of 'FIELDWIDTHS': +spaces_. Clearly, `awk''s normal field splitting based on `FS' does +not work well in this case. Although a portable `awk' program can use +a series of `substr()' calls on `$0' (*note String Functions::), this +is awkward and inefficient for a large number of fields. + + The splitting of an input record into fixed-width fields is +specified by assigning a string containing space-separated numbers to +the built-in variable `FIELDWIDTHS'. Each number specifies the width +of the field, _including_ columns between fields. If you want to +ignore the columns between fields, you can specify the width as a +separate field that is subsequently ignored. It is a fatal error to +supply a field width that is not a positive number. The following data +is the output of the Unix `w' utility. It is useful to illustrate the +use of `FIELDWIDTHS': 10:06pm up 21 days, 14:04, 23 users User tty login idle JCPU PCPU what @@ -5575,7 +5023,7 @@ is not a positive number. The following data is the output of the Unix to number of seconds, and prints out the first two fields and the calculated idle time: - NOTE: This program uses a number of 'awk' features that haven't + NOTE: This program uses a number of `awk' features that haven't been introduced yet. BEGIN { FIELDWIDTHS = "9 6 10 6 7 7 35" } @@ -5611,16 +5059,16 @@ United States, voters mark their choices by punching holes in computer cards. These cards are then processed to count the votes for any particular candidate or on any particular issue. Because a voter may choose not to vote on some issue, any column on the card may be empty. -An 'awk' program for processing such data could use the 'FIELDWIDTHS' -feature to simplify reading the data. (Of course, getting 'gawk' to run -on a system with card readers is another story!) +An `awk' program for processing such data could use the `FIELDWIDTHS' +feature to simplify reading the data. (Of course, getting `gawk' to +run on a system with card readers is another story!) - Assigning a value to 'FS' causes 'gawk' to use 'FS' for field -splitting again. Use 'FS = FS' to make this happen, without having to -know the current value of 'FS'. In order to tell which kind of field -splitting is in effect, use 'PROCINFO["FS"]' (*note Auto-set::). The -value is '"FS"' if regular field splitting is being used, or it is -'"FIELDWIDTHS"' if fixed-width field splitting is being used: + Assigning a value to `FS' causes `gawk' to use `FS' for field +splitting again. Use `FS = FS' to make this happen, without having to +know the current value of `FS'. In order to tell which kind of field +splitting is in effect, use `PROCINFO["FS"]' (*note Auto-set::). The +value is `"FS"' if regular field splitting is being used, or it is +`"FIELDWIDTHS"' if fixed-width field splitting is being used: if (PROCINFO["FS"] == "FS") REGULAR FIELD SPLITTING ... @@ -5630,7 +5078,7 @@ value is '"FS"' if regular field splitting is being used, or it is CONTENT-BASED FIELD SPLITTING ... (see next minor node) This information is useful when writing a function that needs to -temporarily change 'FS' or 'FIELDWIDTHS', read some records, and then +temporarily change `FS' or `FIELDWIDTHS', read some records, and then restore the original settings (*note Passwd Functions::, for an example of such a function). @@ -5640,36 +5088,36 @@ File: gawk.info, Node: Splitting By Content, Next: Multiple Line, Prev: Const 4.7 Defining Fields By Content ============================== - NOTE: This minor node discusses an advanced feature of 'gawk'. If - you are a novice 'awk' user, you might want to skip it on the first - reading. + NOTE: This minor node discusses an advanced feature of `gawk'. If + you are a novice `awk' user, you might want to skip it on the + first reading. - Normally, when using 'FS', 'gawk' defines the fields as the parts of -the record that occur in between each field separator. In other words, -'FS' defines what a field _is not_, instead of what a field _is_. + Normally, when using `FS', `gawk' defines the fields as the parts of +the record that occur in between each field separator. In other words, +`FS' defines what a field _is not_, instead of what a field _is_. However, there are times when you really want to define the fields by what they are, and not by what they are not. The most notorious such case is so-called "comma separated value" -(CSV) data. Many spreadsheet programs, for example, can export their +(CSV) data. Many spreadsheet programs, for example, can export their data into text files, where each record is terminated with a newline, -and fields are separated by commas. If only commas separated the data, -there wouldn't be an issue. The problem comes when one of the fields -contains an _embedded_ comma. While there is no formal standard +and fields are separated by commas. If only commas separated the data, +there wouldn't be an issue. The problem comes when one of the fields +contains an _embedded_ comma. While there is no formal standard specification for CSV data(1), in such cases, most programs embed the -field in double quotes. So we might have data like this: +field in double quotes. So we might have data like this: Robbins,Arnold,"1234 A Pretty Street, NE",MyTown,MyState,12345-6789,USA - The 'FPAT' variable offers a solution for cases like this. The value -of 'FPAT' should be a string that provides a regular expression. This -regular expression describes the contents of each field. + The `FPAT' variable offers a solution for cases like this. The +value of `FPAT' should be a string that provides a regular expression. +This regular expression describes the contents of each field. In the case of CSV data as presented above, each field is either -"anything that is not a comma," or "a double quote, anything that is not -a double quote, and a closing double quote." If written as a regular -expression constant (*note Regexp::), we would have -'/([^,]+)|("[^"]+")/'. Writing this as a string requires us to escape +"anything that is not a comma," or "a double quote, anything that is +not a double quote, and a closing double quote." If written as a +regular expression constant (*note Regexp::), we would have +`/([^,]+)|("[^"]+")/'. Writing this as a string requires us to escape the double quotes, leading to: FPAT = "([^,]+)|(\"[^\"]+\")" @@ -5699,7 +5147,7 @@ the double quotes, leading to: $6 = <12345-6789> $7 = - Note the embedded comma in the value of '$3'. + Note the embedded comma in the value of `$3'. A straightforward improvement when processing CSV data of this sort would be to remove the quotes when they occur, with something like this: @@ -5709,33 +5157,28 @@ would be to remove the quotes when they occur, with something like this: $i = substr($i, 2, len - 2) # Get text within the two quotes } - As with 'FS', the 'IGNORECASE' variable (*note User-modified::) -affects field splitting with 'FPAT'. + As with `FS', the `IGNORECASE' variable (*note User-modified::) +affects field splitting with `FPAT'. -<<<<<<< HEAD - Similar to 'FIELDWIDTHS', the value of 'PROCINFO["FS"]' will be -'"FPAT"' if content-based field splitting is being used. -======= Assigning a value to `FPAT' overrides field splitting with `FS' and with `FIELDWIDTHS'. Similar to `FIELDWIDTHS', the value of `PROCINFO["FS"]' will be `"FPAT"' if content-based field splitting is being used. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - NOTE: Some programs export CSV data that contains embedded newlines - between the double quotes. 'gawk' provides no way to deal with - this. Since there is no formal specification for CSV data, there - isn't much more to be done; the 'FPAT' mechanism provides an - elegant solution for the majority of cases, and the 'gawk' - developers are satisfied with that. + NOTE: Some programs export CSV data that contains embedded + newlines between the double quotes. `gawk' provides no way to + deal with this. Since there is no formal specification for CSV + data, there isn't much more to be done; the `FPAT' mechanism + provides an elegant solution for the majority of cases, and the + `gawk' developers are satisfied with that. - As written, the regexp used for 'FPAT' requires that each field have -a least one character. A straightforward modification (changing changed -the first '+' to '*') allows fields to be empty: + As written, the regexp used for `FPAT' requires that each field have +a least one character. A straightforward modification (changing +changed the first `+' to `*') allows fields to be empty: FPAT = "([^,]*)|(\"[^\"]+\")" - Finally, the 'patsplit()' function makes the same functionality + Finally, the `patsplit()' function makes the same functionality available for splitting regular strings (*note String Functions::). To recap, `gawk' provides three independent methods to split input @@ -5754,27 +5197,27 @@ File: gawk.info, Node: Multiple Line, Next: Getline, Prev: Splitting By Conte ========================= In some databases, a single line cannot conveniently hold all the -information in one entry. In such cases, you can use multiline records. -The first step in doing this is to choose your data format. +information in one entry. In such cases, you can use multiline +records. The first step in doing this is to choose your data format. One technique is to use an unusual character or string to separate records. For example, you could use the formfeed character (written -'\f' in 'awk', as in C) to separate them, making each record a page of -the file. To do this, just set the variable 'RS' to '"\f"' (a string +`\f' in `awk', as in C) to separate them, making each record a page of +the file. To do this, just set the variable `RS' to `"\f"' (a string containing the formfeed character). Any other character could equally well be used, as long as it won't be part of the data in a record. Another technique is to have blank lines separate records. By a -special dispensation, an empty string as the value of 'RS' indicates -that records are separated by one or more blank lines. When 'RS' is set +special dispensation, an empty string as the value of `RS' indicates +that records are separated by one or more blank lines. When `RS' is set to the empty string, each record always ends at the first blank line encountered. The next record doesn't start until the first nonblank line that follows. No matter how many blank lines appear in a row, they -all act as one record separator. (Blank lines must be completely empty; -lines that contain only whitespace do not count.) +all act as one record separator. (Blank lines must be completely +empty; lines that contain only whitespace do not count.) - You can achieve the same effect as 'RS = ""' by assigning the string -'"\n\n+"' to 'RS'. This regexp matches the newline at the end of the + You can achieve the same effect as `RS = ""' by assigning the string +`"\n\n+"' to `RS'. This regexp matches the newline at the end of the record and one or more blank lines after the record. In addition, a regular expression always matches the longest possible sequence when there is a choice (*note Leftmost Longest::). So the next record @@ -5782,37 +5225,37 @@ doesn't start until the first nonblank line that follows--no matter how many blank lines appear in a row, they are considered one record separator. - However, there is an important difference between 'RS = ""' and 'RS = -"\n\n+"'. In the first case, leading newlines in the input data file -are ignored, and if a file ends without extra blank lines after the last -record, the final newline is removed from the record. In the second -case, this special processing is not done. (d.c.) + However, there is an important difference between `RS = ""' and `RS += "\n\n+"'. In the first case, leading newlines in the input data file +are ignored, and if a file ends without extra blank lines after the +last record, the final newline is removed from the record. In the +second case, this special processing is not done. (d.c.) Now that the input is separated into records, the second step is to separate the fields in the record. One way to do this is to divide each of the lines into fields in the normal manner. This happens by default -as the result of a special feature. When 'RS' is set to the empty -string, _and_ 'FS' is set to a single character, the newline character +as the result of a special feature. When `RS' is set to the empty +string, _and_ `FS' is set to a single character, the newline character _always_ acts as a field separator. This is in addition to whatever -field separations result from 'FS'.(1) +field separations result from `FS'.(1) The original motivation for this special exception was probably to -provide useful behavior in the default case (i.e., 'FS' is equal to -'" "'). This feature can be a problem if you really don't want the -newline character to separate fields, because there is no way to prevent -it. However, you can work around this by using the 'split()' function -to break up the record manually (*note String Functions::). If you have -a single character field separator, you can work around the special -feature in a different way, by making 'FS' into a regexp for that single -character. For example, if the field separator is a percent character, -instead of 'FS = "%"', use 'FS = "[%]"'. +provide useful behavior in the default case (i.e., `FS' is equal to +`" "'). This feature can be a problem if you really don't want the +newline character to separate fields, because there is no way to +prevent it. However, you can work around this by using the `split()' +function to break up the record manually (*note String Functions::). +If you have a single character field separator, you can work around the +special feature in a different way, by making `FS' into a regexp for +that single character. For example, if the field separator is a +percent character, instead of `FS = "%"', use `FS = "[%]"'. Another way to separate fields is to put each field on a separate -line: to do this, just set the variable 'FS' to the string '"\n"'. -(This single character separator matches a single newline.) A practical -example of a data file organized this way might be a mailing list, where -each entry is separated by blank lines. Consider a mailing list in a -file named 'addresses', which looks like this: +line: to do this, just set the variable `FS' to the string `"\n"'. +(This single character separator matches a single newline.) A +practical example of a data file organized this way might be a mailing +list, where each entry is separated by blank lines. Consider a mailing +list in a file named `addresses', which looks like this: Jane Doe 123 Main Street @@ -5853,65 +5296,48 @@ A simple program to process this file is as follows: *Note Labels Program::, for a more realistic program that deals with address lists. The following table summarizes how records are split, -based on the value of 'RS'. ('==' means "is equal to.") +based on the value of `RS'. (`==' means "is equal to.") -'RS == "\n"' - Records are separated by the newline character ('\n'). In effect, +`RS == "\n"' + Records are separated by the newline character (`\n'). In effect, every line in the data file is a separate record, including blank lines. This is the default. -'RS == ANY SINGLE CHARACTER' +`RS == ANY SINGLE CHARACTER' Records are separated by each occurrence of the character. Multiple successive occurrences delimit empty records. -'RS == ""' - Records are separated by runs of blank lines. When 'FS' is a +`RS == ""' + Records are separated by runs of blank lines. When `FS' is a single character, then the newline character always serves as a - field separator, in addition to whatever value 'FS' may have. + field separator, in addition to whatever value `FS' may have. Leading and trailing newlines in a file are ignored. -'RS == REGEXP' +`RS == REGEXP' Records are separated by occurrences of characters that match REGEXP. Leading and trailing matches of REGEXP delimit empty - records. (This is a 'gawk' extension; it is not specified by the + records. (This is a `gawk' extension; it is not specified by the POSIX standard.) - In all cases, 'gawk' sets 'RT' to the input text that matched the -value specified by 'RS'. But if the input file ended without any text -that matches 'RS', then 'gawk' sets 'RT' to the null string. + In all cases, `gawk' sets `RT' to the input text that matched the +value specified by `RS'. But if the input file ended without any text +that matches `RS', then `gawk' sets `RT' to the null string. ---------- Footnotes ---------- - (1) When 'FS' is the null string ('""') or a regexp, this special -feature of 'RS' does not apply. It does apply to the default field -separator of a single space: 'FS = " "'. + (1) When `FS' is the null string (`""') or a regexp, this special +feature of `RS' does not apply. It does apply to the default field +separator of a single space: `FS = " "'.  File: gawk.info, Node: Getline, Next: Read Timeout, Prev: Multiple Line, Up: Reading Files -4.9 Explicit Input with 'getline' +4.9 Explicit Input with `getline' ================================= -So far we have been getting our input data from 'awk''s main input +So far we have been getting our input data from `awk''s main input stream--either the standard input (usually your keyboard, sometimes the output from another program) or from the files specified on the command -<<<<<<< HEAD -line. The 'awk' language has a special built-in command called -'getline' that can be used to read input under your explicit control. - - The 'getline' command is used in several different ways and should -_not_ be used by beginners. The examples that follow the explanation of -the 'getline' command include material that has not been covered yet. -Therefore, come back and study the 'getline' command _after_ you have -reviewed the rest of this Info file and have a good knowledge of how -'awk' works. - - The 'getline' command returns one if it finds a record and zero if it -encounters the end of the file. If there is some error in getting a -record, such as a file that cannot be opened, then 'getline' returns -1. -In this case, 'gawk' sets the variable 'ERRNO' to a string describing -the error that occurred. -======= line. The `awk' language has a special built-in command called `getline' that can be used to read input under your explicit control. @@ -5927,41 +5353,40 @@ encounters the end of the file. If there is some error in getting a record, such as a file that cannot be opened, then `getline' returns -1. In this case, `gawk' sets the variable `ERRNO' to a string describing the error that occurred. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac In the following examples, COMMAND stands for a string value that represents a shell command. - NOTE: When '--sandbox' is specified (*note Options::), reading + NOTE: When `--sandbox' is specified (*note Options::), reading lines from files, pipes and coprocesses is disabled. * Menu: -* Plain Getline:: Using 'getline' with no arguments. -* Getline/Variable:: Using 'getline' into a variable. -* Getline/File:: Using 'getline' from a file. -* Getline/Variable/File:: Using 'getline' into a variable from a +* Plain Getline:: Using `getline' with no arguments. +* Getline/Variable:: Using `getline' into a variable. +* Getline/File:: Using `getline' from a file. +* Getline/Variable/File:: Using `getline' into a variable from a file. -* Getline/Pipe:: Using 'getline' from a pipe. -* Getline/Variable/Pipe:: Using 'getline' into a variable from a +* Getline/Pipe:: Using `getline' from a pipe. +* Getline/Variable/Pipe:: Using `getline' into a variable from a pipe. -* Getline/Coprocess:: Using 'getline' from a coprocess. -* Getline/Variable/Coprocess:: Using 'getline' into a variable from a +* Getline/Coprocess:: Using `getline' from a coprocess. +* Getline/Variable/Coprocess:: Using `getline' into a variable from a coprocess. -* Getline Notes:: Important things to know about 'getline'. -* Getline Summary:: Summary of 'getline' Variants. +* Getline Notes:: Important things to know about `getline'. +* Getline Summary:: Summary of `getline' Variants.  File: gawk.info, Node: Plain Getline, Next: Getline/Variable, Up: Getline -4.9.1 Using 'getline' with No Arguments +4.9.1 Using `getline' with No Arguments --------------------------------------- -The 'getline' command can be used without arguments to read input from -the current input file. All it does in this case is read the next input -record and split it up into fields. This is useful if you've finished -processing the current record, but want to do some special processing on -the next record _right now_. For example: +The `getline' command can be used without arguments to read input from +the current input file. All it does in this case is read the next +input record and split it up into fields. This is useful if you've +finished processing the current record, but want to do some special +processing on the next record _right now_. For example: # Remove text between /* and */, inclusive { @@ -5995,14 +5420,6 @@ the next record _right now_. For example: print $0 } -<<<<<<< HEAD - This 'awk' program deletes C-style comments ('/* ... */') from the -input. By replacing the 'print $0' with other statements, you could -perform more complicated processing on the decommented input, such as -searching for matches of a regular expression. (This program has a -subtle problem--it does not work if one comment ends and another begins -on the same line.) -======= This `awk' program deletes C-style comments (`/* ... */') from the input. It uses a number of features we haven't covered yet, including string concatenation (*note Concatenation::) and the `index()' and @@ -6012,14 +5429,13 @@ complicated processing on the decommented input, such as searching for matches of a regular expression. (This program has a subtle problem--it does not work if one comment ends and another begins on the same line.) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - This form of the 'getline' command sets 'NF', 'NR', 'FNR', 'RT', and -the value of '$0'. + This form of the `getline' command sets `NF', `NR', `FNR', `RT', and +the value of `$0'. - NOTE: The new value of '$0' is used to test the patterns of any - subsequent rules. The original value of '$0' that triggered the - rule that executed 'getline' is lost. By contrast, the 'next' + NOTE: The new value of `$0' is used to test the patterns of any + subsequent rules. The original value of `$0' that triggered the + rule that executed `getline' is lost. By contrast, the `next' statement reads a new record but immediately begins processing it normally, starting with the first rule in the program. *Note Next Statement::. @@ -6027,15 +5443,15 @@ the value of '$0'.  File: gawk.info, Node: Getline/Variable, Next: Getline/File, Prev: Plain Getline, Up: Getline -4.9.2 Using 'getline' into a Variable +4.9.2 Using `getline' into a Variable ------------------------------------- -You can use 'getline VAR' to read the next record from 'awk''s input +You can use `getline VAR' to read the next record from `awk''s input into the variable VAR. No other processing is done. For example, suppose the next line is a comment or a special string, and you want to -read it without triggering any rules. This form of 'getline' allows you -to read that line and store it in a variable so that the main -read-a-line-and-check-each-rule loop of 'awk' never sees it. The +read it without triggering any rules. This form of `getline' allows +you to read that line and store it in a variable so that the main +read-a-line-and-check-each-rule loop of `awk' never sees it. The following example swaps every two lines of input: { @@ -6060,23 +5476,23 @@ and produces these results: phore free - The 'getline' command used in this way sets only the variables 'NR', -'FNR' and 'RT' (and of course, VAR). The record is not split into -fields, so the values of the fields (including '$0') and the value of -'NF' do not change. + The `getline' command used in this way sets only the variables `NR', +`FNR' and `RT' (and of course, VAR). The record is not split into +fields, so the values of the fields (including `$0') and the value of +`NF' do not change.  File: gawk.info, Node: Getline/File, Next: Getline/Variable/File, Prev: Getline/Variable, Up: Getline -4.9.3 Using 'getline' from a File +4.9.3 Using `getline' from a File --------------------------------- -Use 'getline < FILE' to read the next record from FILE. Here FILE is a -string-valued expression that specifies the file name. '< FILE' is -called a "redirection" because it directs input to come from a different -place. For example, the following program reads its input record from -the file 'secondary.input' when it encounters a first field with a value -equal to 10 in the current input file: +Use `getline < FILE' to read the next record from FILE. Here FILE is a +string-valued expression that specifies the file name. `< FILE' is +called a "redirection" because it directs input to come from a +different place. For example, the following program reads its input +record from the file `secondary.input' when it encounters a first field +with a value equal to 10 in the current input file: { if ($1 == 10) { @@ -6086,33 +5502,33 @@ equal to 10 in the current input file: print } - Because the main input stream is not used, the values of 'NR' and -'FNR' are not changed. However, the record it reads is split into -fields in the normal manner, so the values of '$0' and the other fields -are changed, resulting in a new value of 'NF'. 'RT' is also set. + Because the main input stream is not used, the values of `NR' and +`FNR' are not changed. However, the record it reads is split into +fields in the normal manner, so the values of `$0' and the other fields +are changed, resulting in a new value of `NF'. `RT' is also set. - According to POSIX, 'getline < EXPRESSION' is ambiguous if EXPRESSION -contains unparenthesized operators other than '$'; for example, 'getline -< dir "/" file' is ambiguous because the concatenation operator (not -discussed yet; *note Concatenation::) is not parenthesized. You should -write it as 'getline < (dir "/" file)' if you want your program to be -portable to all 'awk' implementations. + According to POSIX, `getline < EXPRESSION' is ambiguous if +EXPRESSION contains unparenthesized operators other than `$'; for +example, `getline < dir "/" file' is ambiguous because the +concatenation operator (not discussed yet; *note Concatenation::) is +not parenthesized. You should write it as `getline < (dir "/" file)' if +you want your program to be portable to all `awk' implementations.  File: gawk.info, Node: Getline/Variable/File, Next: Getline/Pipe, Prev: Getline/File, Up: Getline -4.9.4 Using 'getline' into a Variable from a File +4.9.4 Using `getline' into a Variable from a File ------------------------------------------------- -Use 'getline VAR < FILE' to read input from the file FILE, and put it in -the variable VAR. As above, FILE is a string-valued expression that +Use `getline VAR < FILE' to read input from the file FILE, and put it +in the variable VAR. As above, FILE is a string-valued expression that specifies the file from which to read. - In this version of 'getline', none of the built-in variables are + In this version of `getline', none of the built-in variables are changed and the record is not split into fields. The only variable -changed is VAR.(1) For example, the following program copies all the +changed is VAR.(1) For example, the following program copies all the input files to the output, except for records that say -'@include FILENAME'. Such a record is replaced by the contents of the +`@include FILENAME'. Such a record is replaced by the contents of the file FILENAME: { @@ -6126,38 +5542,37 @@ file FILENAME: Note here how the name of the extra input file is not built into the program; it is taken directly from the data, specifically from the -second field on the '@include' line. +second field on the `@include' line. - The 'close()' function is called to ensure that if two identical -'@include' lines appear in the input, the entire specified file is + The `close()' function is called to ensure that if two identical +`@include' lines appear in the input, the entire specified file is included twice. *Note Close Files And Pipes::. One deficiency of this program is that it does not process nested -'@include' statements (i.e., '@include' statements in included files) +`@include' statements (i.e., `@include' statements in included files) the way a true macro preprocessor would. *Note Igawk Program::, for a -program that does handle nested '@include' statements. +program that does handle nested `@include' statements. ---------- Footnotes ---------- - (1) This is not quite true. 'RT' could be changed if 'RS' is a + (1) This is not quite true. `RT' could be changed if `RS' is a regular expression.  File: gawk.info, Node: Getline/Pipe, Next: Getline/Variable/Pipe, Prev: Getline/Variable/File, Up: Getline -4.9.5 Using 'getline' from a Pipe +4.9.5 Using `getline' from a Pipe --------------------------------- Omniscience has much to recommend it. Failing that, attention to - details would be useful. - -- _Brian Kernighan_ + details would be useful. -- Brian Kernighan - The output of a command can also be piped into 'getline', using -'COMMAND | getline'. In this case, the string COMMAND is run as a shell -command and its output is piped into 'awk' to be used as input. This -form of 'getline' reads one record at a time from the pipe. For + The output of a command can also be piped into `getline', using +`COMMAND | getline'. In this case, the string COMMAND is run as a +shell command and its output is piped into `awk' to be used as input. +This form of `getline' reads one record at a time from the pipe. For example, the following program copies its input to its output, except -for lines that begin with '@execute', which are replaced by the output +for lines that begin with `@execute', which are replaced by the output produced by running the rest of the line as a shell command: { @@ -6170,8 +5585,8 @@ produced by running the rest of the line as a shell command: print } -The 'close()' function is called to ensure that if two identical -'@execute' lines appear in the input, the command is run for each one. +The `close()' function is called to ensure that if two identical +`@execute' lines appear in the input, the command is run for each one. *Note Close Files And Pipes::. Given the input: foo @@ -6190,29 +5605,10 @@ the program might produce: bill ttyp1 Jul 13 14:23 (murphy:0) bletch -Notice that this program ran the command 'who' and printed the previous +Notice that this program ran the command `who' and printed the previous result. (If you try this program yourself, you will of course get different results, depending upon who is logged in on your system.) -<<<<<<< HEAD - This variation of 'getline' splits the record into fields, sets the -value of 'NF', and recomputes the value of '$0'. The values of 'NR' and -'FNR' are not changed. 'RT' is set. - - According to POSIX, 'EXPRESSION | getline' is ambiguous if EXPRESSION -contains unparenthesized operators other than '$'--for example, '"echo " -"date" | getline' is ambiguous because the concatenation operator is not -parenthesized. You should write it as '("echo " "date") | getline' if -you want your program to be portable to all 'awk' implementations. - - NOTE: Unfortunately, 'gawk' has not been consistent in its - treatment of a construct like '"echo " "date" | getline'. Most - versions, including the current version, treat it at as '("echo " - "date") | getline'. (This how Brian Kernighan's 'awk' behaves.) - Some versions changed and treated it as '"echo " ("date" | - getline)'. (This is how 'mawk' behaves.) In short, _always_ use - explicit parentheses, and then you won't have to worry. -======= This variation of `getline' splits the record into fields, sets the value of `NF', and recomputes the value of `$0'. The values of `NR' and `FNR' are not changed. `RT' is set. @@ -6231,18 +5627,17 @@ all `awk' implementations. changed and treated it as `"echo " ("date" | getline)'. (This is how `mawk' behaves.) In short, _always_ use explicit parentheses, and then you won't have to worry. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Getline/Variable/Pipe, Next: Getline/Coprocess, Prev: Getline/Pipe, Up: Getline -4.9.6 Using 'getline' into a Variable from a Pipe +4.9.6 Using `getline' into a Variable from a Pipe ------------------------------------------------- -When you use 'COMMAND | getline VAR', the output of COMMAND is sent -through a pipe to 'getline' and into the variable VAR. For example, the +When you use `COMMAND | getline VAR', the output of COMMAND is sent +through a pipe to `getline' and into the variable VAR. For example, the following program reads the current date and time into the variable -'current_time', using the 'date' utility, and then prints it: +`current_time', using the `date' utility, and then prints it: BEGIN { "date" | getline current_time @@ -6250,108 +5645,108 @@ following program reads the current date and time into the variable print "Report printed on " current_time } - In this version of 'getline', none of the built-in variables are + In this version of `getline', none of the built-in variables are changed and the record is not split into fields. - According to POSIX, 'EXPRESSION | getline VAR' is ambiguous if -EXPRESSION contains unparenthesized operators other than '$'; for -example, '"echo " "date" | getline VAR' is ambiguous because the -concatenation operator is not parenthesized. You should write it as '("echo " -"date") | getline VAR' if you want your program to be portable to other -'awk' implementations. + According to POSIX, `EXPRESSION | getline VAR' is ambiguous if +EXPRESSION contains unparenthesized operators other than `$'; for +example, `"echo " "date" | getline VAR' is ambiguous because the +concatenation operator is not parenthesized. You should write it as +`("echo " "date") | getline VAR' if you want your program to be +portable to other `awk' implementations.  File: gawk.info, Node: Getline/Coprocess, Next: Getline/Variable/Coprocess, Prev: Getline/Variable/Pipe, Up: Getline -4.9.7 Using 'getline' from a Coprocess +4.9.7 Using `getline' from a Coprocess -------------------------------------- -Input into 'getline' from a pipe is a one-way operation. The command -that is started with 'COMMAND | getline' only sends data _to_ your 'awk' -program. +Input into `getline' from a pipe is a one-way operation. The command +that is started with `COMMAND | getline' only sends data _to_ your +`awk' program. On occasion, you might want to send data to another program for -processing and then read the results back. 'gawk' allows you to start a -"coprocess", with which two-way communications are possible. This is -done with the '|&' operator. Typically, you write data to the coprocess -first and then read results back, as shown in the following: +processing and then read the results back. `gawk' allows you to start +a "coprocess", with which two-way communications are possible. This is +done with the `|&' operator. Typically, you write data to the +coprocess first and then read results back, as shown in the following: print "SOME QUERY" |& "db_server" "db_server" |& getline -which sends a query to 'db_server' and then reads the results. +which sends a query to `db_server' and then reads the results. - The values of 'NR' and 'FNR' are not changed, because the main input + The values of `NR' and `FNR' are not changed, because the main input stream is not used. However, the record is split into fields in the -normal manner, thus changing the values of '$0', of the other fields, -and of 'NF' and 'RT'. +normal manner, thus changing the values of `$0', of the other fields, +and of `NF' and `RT'. - Coprocesses are an advanced feature. They are discussed here only -because this is the minor node on 'getline'. *Note Two-way I/O::, where -coprocesses are discussed in more detail. + Coprocesses are an advanced feature. They are discussed here only +because this is the minor node on `getline'. *Note Two-way I/O::, +where coprocesses are discussed in more detail.  File: gawk.info, Node: Getline/Variable/Coprocess, Next: Getline Notes, Prev: Getline/Coprocess, Up: Getline -4.9.8 Using 'getline' into a Variable from a Coprocess +4.9.8 Using `getline' into a Variable from a Coprocess ------------------------------------------------------ -When you use 'COMMAND |& getline VAR', the output from the coprocess -COMMAND is sent through a two-way pipe to 'getline' and into the +When you use `COMMAND |& getline VAR', the output from the coprocess +COMMAND is sent through a two-way pipe to `getline' and into the variable VAR. - In this version of 'getline', none of the built-in variables are + In this version of `getline', none of the built-in variables are changed and the record is not split into fields. The only variable -changed is VAR. However, 'RT' is set. +changed is VAR. However, `RT' is set. - Coprocesses are an advanced feature. They are discussed here only -because this is the minor node on 'getline'. *Note Two-way I/O::, where -coprocesses are discussed in more detail. + Coprocesses are an advanced feature. They are discussed here only +because this is the minor node on `getline'. *Note Two-way I/O::, +where coprocesses are discussed in more detail.  File: gawk.info, Node: Getline Notes, Next: Getline Summary, Prev: Getline/Variable/Coprocess, Up: Getline -4.9.9 Points to Remember About 'getline' +4.9.9 Points to Remember About `getline' ---------------------------------------- -Here are some miscellaneous points about 'getline' that you should bear +Here are some miscellaneous points about `getline' that you should bear in mind: - * When 'getline' changes the value of '$0' and 'NF', 'awk' does _not_ - automatically jump to the start of the program and start testing - the new record against every pattern. However, the new record is - tested against any subsequent rules. - - * Some very old 'awk' implementations limit the number of pipelines - that an 'awk' program may have open to just one. In 'gawk', there - is no such limit. You can open as many pipelines (and coprocesses) - as the underlying operating system permits. - - * An interesting side effect occurs if you use 'getline' without a - redirection inside a 'BEGIN' rule. Because an unredirected - 'getline' reads from the command-line data files, the first - 'getline' command causes 'awk' to set the value of 'FILENAME'. - Normally, 'FILENAME' does not have a value inside 'BEGIN' rules, + * When `getline' changes the value of `$0' and `NF', `awk' does + _not_ automatically jump to the start of the program and start + testing the new record against every pattern. However, the new + record is tested against any subsequent rules. + + * Some very old `awk' implementations limit the number of pipelines + that an `awk' program may have open to just one. In `gawk', there + is no such limit. You can open as many pipelines (and + coprocesses) as the underlying operating system permits. + + * An interesting side effect occurs if you use `getline' without a + redirection inside a `BEGIN' rule. Because an unredirected + `getline' reads from the command-line data files, the first + `getline' command causes `awk' to set the value of `FILENAME'. + Normally, `FILENAME' does not have a value inside `BEGIN' rules, because you have not yet started to process the command-line data files. (d.c.) (*Note BEGIN/END::, also *note Auto-set::.) - * Using 'FILENAME' with 'getline' ('getline < FILENAME') is likely to - be a source for confusion. 'awk' opens a separate input stream + * Using `FILENAME' with `getline' (`getline < FILENAME') is likely + to be a source for confusion. `awk' opens a separate input stream from the current input file. However, by not using a variable, - '$0' and 'NR' are still updated. If you're doing this, it's + `$0' and `NR' are still updated. If you're doing this, it's probably by accident, and you should reconsider what it is you're trying to accomplish. - * *note Getline Summary::, presents a table summarizing the 'getline' - variants and which variables they can affect. It is worth noting - that those variants which do not use redirection can cause - 'FILENAME' to be updated if they cause 'awk' to start reading a new - input file. + * *note Getline Summary::, presents a table summarizing the + `getline' variants and which variables they can affect. It is + worth noting that those variants which do not use redirection can + cause `FILENAME' to be updated if they cause `awk' to start + reading a new input file. * If the variable being assigned is an expression with side effects, - different versions of 'awk' behave differently upon encountering + different versions of `awk' behave differently upon encountering end-of-file. Some versions don't evaluate the expression; many - versions (including 'gawk') do. Here is an example, due to Duncan + versions (including `gawk') do. Here is an example, due to Duncan Moore: BEGIN { @@ -6360,42 +5755,41 @@ in mind: print c } - Here, the side effect is the '++c'. Is 'c' incremented if end of - file is encountered, before the element in 'a' is assigned? + Here, the side effect is the `++c'. Is `c' incremented if end of + file is encountered, before the element in `a' is assigned? - 'gawk' treats 'getline' like a function call, and evaluates the - expression 'a[++c]' before attempting to read from 'f'. However, - some versions of 'awk' only evaluate the expression once they know + `gawk' treats `getline' like a function call, and evaluates the + expression `a[++c]' before attempting to read from `f'. However, + some versions of `awk' only evaluate the expression once they know that there is a string value to be assigned. Caveat Emptor.  File: gawk.info, Node: Getline Summary, Prev: Getline Notes, Up: Getline -4.9.10 Summary of 'getline' Variants +4.9.10 Summary of `getline' Variants ------------------------------------ -*note Table 4.1: table-getline-variants. summarizes the eight variants -of 'getline', listing which built-in variables are set by each one, and -whether the variant is standard or a 'gawk' extension. Note: for each -variant, 'gawk' sets the 'RT' built-in variable. +*note table-getline-variants:: summarizes the eight variants of +`getline', listing which built-in variables are set by each one, and +whether the variant is standard or a `gawk' extension. Note: for each +variant, `gawk' sets the `RT' built-in variable. Variant Effect Standard / Extension -------------------------------------------------------------------------- -'getline' Sets '$0', 'NF', 'FNR', Standard - 'NR', and 'RT' -'getline' VAR Sets VAR, 'FNR', 'NR', Standard - and 'RT' -'getline <' FILE Sets '$0', 'NF', and 'RT' Standard -'getline VAR < FILE' Sets VAR and 'RT' Standard -COMMAND '| getline' Sets '$0', 'NF', and 'RT' Standard -COMMAND '| getline' Sets VAR and 'RT' Standard -VAR -COMMAND '|& getline' Sets '$0', 'NF', and 'RT' Extension -COMMAND '|& getline' Sets VAR and 'RT' Extension -VAR - -Table 4.1: 'getline' Variants and What They Set +------------------------------------------------------------------------- +`getline' Sets `$0', `NF', `FNR', Standard + `NR', and `RT' +`getline' VAR Sets VAR, `FNR', `NR', and Standard + `RT' +`getline <' FILE Sets `$0', `NF', and `RT' Standard +`getline VAR < FILE' Sets VAR and `RT' Standard +COMMAND `| getline' Sets `$0', `NF', and `RT' Standard +COMMAND `| getline' VAR Sets VAR and `RT' Standard +COMMAND `|& getline' Sets `$0', `NF', and `RT' Extension +COMMAND `|& getline' Sets VAR and `RT' Extension +VAR + +Table 4.1: `getline' Variants and What They Set  File: gawk.info, Node: Read Timeout, Next: Command-line directories, Prev: Getline, Up: Reading Files @@ -6403,16 +5797,16 @@ File: gawk.info, Node: Read Timeout, Next: Command-line directories, Prev: Ge 4.10 Reading Input With A Timeout ================================= -This minor node describes a feature that is specific to 'gawk'. +This minor node describes a feature that is specific to `gawk'. You may specify a timeout in milliseconds for reading input from the keyboard, a pipe, or two-way communication, including TCP/IP sockets. -This can be done on a per input, command or connection basis, by setting -a special element in the 'PROCINFO' (*note Auto-set::) array: +This can be done on a per input, command or connection basis, by +setting a special element in the `PROCINFO' (*note Auto-set::) array: PROCINFO["input_name", "READ_TIMEOUT"] = TIMEOUT IN MILLISECONDS - When set, this causes 'gawk' to time out and return failure if no + When set, this causes `gawk' to time out and return failure if no data is available to read within the specified timeout period. For example, a TCP client can decide to give up on receiving any response from the server after a certain amount of time: @@ -6431,8 +5825,8 @@ for more than five seconds: while ((getline < "/dev/stdin") > 0) print $0 - 'gawk' terminates the read operation if input does not arrive after -waiting for the timeout period, returns failure and sets the 'ERRNO' + `gawk' terminates the read operation if input does not arrive after +waiting for the timeout period, returns failure and sets the `ERRNO' variable to an appropriate string value. A negative or zero value for the timeout is the same as specifying no timeout at all. @@ -6448,10 +5842,10 @@ patterns, like so: In this case, failure to respond within five seconds results in the following error message: - error-> gawk: cmd. line:2: (FILENAME=- FNR=1) fatal: error reading input file `-': Connection timed out + error--> gawk: cmd. line:2: (FILENAME=- FNR=1) fatal: error reading input file `-': Connection timed out The timeout can be set or changed at any time, and will take effect -on the next attempt to read from the input device. In the following +on the next attempt to read from the input device. In the following example, we start with a timeout value of one second, and progressively reduce it by one-tenth of a second until we wait indefinitely for the input to arrive: @@ -6463,28 +5857,29 @@ input to arrive: } NOTE: You should not assume that the read operation will block - exactly after the tenth record has been printed. It is possible - that 'gawk' will read and buffer more than one record's worth of - data the first time. Because of this, changing the value of + exactly after the tenth record has been printed. It is possible + that `gawk' will read and buffer more than one record's worth of + data the first time. Because of this, changing the value of timeout like in the above example is not very useful. - If the 'PROCINFO' element is not present and the environment variable -'GAWK_READ_TIMEOUT' exists, 'gawk' uses its value to initialize the -timeout value. The exclusive use of the environment variable to specify -timeout has the disadvantage of not being able to control it on a per -command or connection basis. + If the `PROCINFO' element is not present and the environment +variable `GAWK_READ_TIMEOUT' exists, `gawk' uses its value to +initialize the timeout value. The exclusive use of the environment +variable to specify timeout has the disadvantage of not being able to +control it on a per command or connection basis. - 'gawk' considers a timeout event to be an error even though the + `gawk' considers a timeout event to be an error even though the attempt to read from the underlying device may succeed in a later -attempt. This is a limitation, and it also means that you cannot use +attempt. This is a limitation, and it also means that you cannot use this to multiplex input from two or more sources. Assigning a timeout value prevents read operations from blocking -indefinitely. But bear in mind that there are other ways 'gawk' can +indefinitely. But bear in mind that there are other ways `gawk' can stall waiting for an input device to be ready. A network client can -sometimes take a long time to establish a connection before it can start -reading any data, or the attempt to open a FIFO special file for reading -can block indefinitely until some other process opens it for writing. +sometimes take a long time to establish a connection before it can +start reading any data, or the attempt to open a FIFO special file for +reading can block indefinitely until some other process opens it for +writing. ---------- Footnotes ---------- @@ -6496,22 +5891,22 @@ File: gawk.info, Node: Command-line directories, Next: Input Summary, Prev: R 4.11 Directories On The Command Line ==================================== -According to the POSIX standard, files named on the 'awk' command line +According to the POSIX standard, files named on the `awk' command line must be text files; it is a fatal error if they are not. Most versions -of 'awk' treat a directory on the command line as a fatal error. +of `awk' treat a directory on the command line as a fatal error. - By default, 'gawk' produces a warning for a directory on the command + By default, `gawk' produces a warning for a directory on the command line, but otherwise ignores it. This makes it easier to use shell -wildcards with your 'awk' program: +wildcards with your `awk' program: $ gawk -f whizprog.awk * Directories could kill this progam - If either of the '--posix' or '--traditional' options is given, then -'gawk' reverts to treating a directory on the command line as a fatal + If either of the `--posix' or `--traditional' options is given, then +`gawk' reverts to treating a directory on the command line as a fatal error. *Note Extension Sample Readdir::, for a way to treat directories as -usable data from an 'awk' program. +usable data from an `awk' program.  File: gawk.info, Node: Input Summary, Next: Input Exercises, Prev: Command-line directories, Up: Reading Files @@ -6519,66 +5914,68 @@ File: gawk.info, Node: Input Summary, Next: Input Exercises, Prev: Command-li 4.12 Summary ============ - * Input is split into records based on the value of 'RS'. The + * Input is split into records based on the value of `RS'. The possibilities are as follows: - Value of 'RS' Records are split on 'awk' / 'gawk' - --------------------------------------------------------------------------- - Any single That character 'awk' - character - The empty string Runs of two or more 'awk' - ('""') newlines - A regexp Text that matches the 'gawk' - regexp + Value of `RS' Records are split on `awk' / `gawk' + ---------------------------------------------------------------------- + Any single That character `awk' + character + The empty string Runs of two or more `awk' + (`""') newlines + A regexp Text that matches the `gawk' + regexp - * 'gawk' sets 'RT' to the text matched by 'RS'. + * `gawk' sets `RT' to the text matched by `RS'. - * After splitting the input into records, 'awk' further splits the - record into individual fields, named '$1', '$2' and so on. '$0' is - the whole record, and 'NF' indicates how many fields there are. + * After splitting the input into records, `awk' further splits the + record into individual fields, named `$1', `$2' and so on. `$0' is + the whole record, and `NF' indicates how many fields there are. The default way to split fields is between whitespace characters. - * Fields may be referenced using a variable, as in '$NF'. Fields may - also be assigned values, which causes the value of '$0' to be - recomputed when it is later referenced. Assigning to a field with - a number greater than 'NF' creates the field and rebuilds the - record, using 'OFS' to separate the fields. Incrementing 'NF' does - the same thing. Decrementing 'NF' throws away fields and rebuilds - the record. + * Fields may be referenced using a variable, as in `$NF'. Fields + may also be assigned values, which causes the value of `$0' to be + recomputed when it is later referenced. Assigning to a field with + a number greater than `NF' creates the field and rebuilds the + record, using `OFS' to separate the fields. Incrementing `NF' + does the same thing. Decrementing `NF' throws away fields and + rebuilds the record. * Field splitting is more complicated than record splitting. - Field separator value Fields are split ... 'awk' / - 'gawk' - --------------------------------------------------------------------------- - 'FS == " "' On runs of whitespace 'awk' - 'FS == ANY SINGLE On that character 'awk' - CHARACTER' - 'FS == REGEXP' On text matching the regexp 'awk' - 'FS == ""' Each individual character 'gawk' - is a separate field - 'FIELDWIDTHS == LIST OF Based on character position 'gawk' - COLUMNS' - 'FPAT == REGEXP' On text around text 'gawk' - matching the regexp - - Using 'FS = "\n"' causes the entire record to be a single field + Field separator value Fields are split ... `awk' / + `gawk' + ---------------------------------------------------------------------- + `FS == " "' On runs of whitespace `awk' + `FS == ANY SINGLE On that character `awk' + CHARACTER' + `FS == REGEXP' On text matching the `awk' + regexp + `FS == ""' Each individual character `gawk' + is a separate field + `FIELDWIDTHS == LIST OF Based on character `gawk' + COLUMNS' position + `FPAT == REGEXP' On text around text `gawk' + matching the regexp + + Using `FS = "\n"' causes the entire record to be a single field (assuming that newlines separate records). - * 'FS' may be set from the command line using the '-F' option. This + * `FS' may be set from the command line using the `-F' option. This can also be done using command-line variable assignment. - * 'PROCINFO["FS"]' can be used to see how fields are being split. + * `PROCINFO["FS"]' can be used to see how fields are being split. - * Use 'getline' in its various forms to read additional records, from - the default input stream, from a file, or from a pipe or + * Use `getline' in its various forms to read additional records, + from the default input stream, from a file, or from a pipe or co-process. - * Use 'PROCINFO[FILE, "READ_TIMEOUT"]' to cause reads to timeout for + * Use `PROCINFO[FILE, "READ_TIMEOUT"]' to cause reads to timeout for FILE. - * Directories on the command line are fatal for standard 'awk'; - 'gawk' ignores them if not in POSIX mode. + * Directories on the command line are fatal for standard `awk'; + `gawk' ignores them if not in POSIX mode. +  File: gawk.info, Node: Input Exercises, Prev: Input Summary, Up: Reading Files @@ -6586,25 +5983,18 @@ File: gawk.info, Node: Input Exercises, Prev: Input Summary, Up: Reading File 4.13 Exercises ============== - 1. Using the 'FIELDWIDTHS' variable (*note Constant Size::), write a + 1. Using the `FIELDWIDTHS' variable (*note Constant Size::), write a program to read election data, where each record represents one voter's votes. Come up with a way to define which columns are associated with each ballot item, and print the total votes, including abstentions, for each item. 2. *note Plain Getline::, presented a program to remove C-style -<<<<<<< HEAD - comments ('/* ... */') from the input. That program does not work - if one comment ends on one line and another one starts later on the - same line. Write a program that does handle multiple comments on - the line. -======= comments (`/* ... */') from the input. That program does not work if one comment ends on one line and another one starts later on the same line. That can be fixed by making one simple change. What is it? ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Printing, Next: Expressions, Prev: Reading Files, Up: Top @@ -6613,31 +6003,31 @@ File: gawk.info, Node: Printing, Next: Expressions, Prev: Reading Files, Up: ***************** One of the most common programming actions is to "print", or output, -some or all of the input. Use the 'print' statement for simple output, -and the 'printf' statement for fancier formatting. The 'print' +some or all of the input. Use the `print' statement for simple output, +and the `printf' statement for fancier formatting. The `print' statement is not limited when computing _which_ values to print. However, with two exceptions, you cannot specify _how_ to print them--how many columns, whether to use exponential notation or not, and so on. (For the exceptions, *note Output Separators::, and *note -OFMT::.) For printing with specifications, you need the 'printf' +OFMT::.) For printing with specifications, you need the `printf' statement (*note Printf::). - Besides basic and formatted printing, this major node also covers I/O -redirections to files and pipes, introduces the special file names that -'gawk' processes internally, and discusses the 'close()' built-in + Besides basic and formatted printing, this major node also covers +I/O redirections to files and pipes, introduces the special file names +that `gawk' processes internally, and discusses the `close()' built-in function. * Menu: -* Print:: The 'print' statement. -* Print Examples:: Simple examples of 'print' statements. +* Print:: The `print' statement. +* Print Examples:: Simple examples of `print' statements. * Output Separators:: The output separators and how to change them. -* OFMT:: Controlling Numeric Output With 'print'. -* Printf:: The 'printf' statement. +* OFMT:: Controlling Numeric Output With `print'. +* Printf:: The `printf' statement. * Redirection:: How to redirect output to multiple files and pipes. -* Special Files:: File name interpretation in 'gawk'. - 'gawk' allows access to inherited file +* Special Files:: File name interpretation in `gawk'. + `gawk' allows access to inherited file descriptors. * Close Files And Pipes:: Closing Input and Output Files and Pipes. * Output Summary:: Output summary. @@ -6646,10 +6036,10 @@ function.  File: gawk.info, Node: Print, Next: Print Examples, Up: Printing -5.1 The 'print' Statement +5.1 The `print' Statement ========================= -The 'print' statement is used for producing output with simple, +The `print' statement is used for producing output with simple, standardized formatting. You specify only the strings or numbers to print, in a list separated by commas. They are output, separated by single spaces, followed by a newline. The statement looks like this: @@ -6657,21 +6047,21 @@ single spaces, followed by a newline. The statement looks like this: print ITEM1, ITEM2, ... The entire list of items may be optionally enclosed in parentheses. The -parentheses are necessary if any of the item expressions uses the '>' +parentheses are necessary if any of the item expressions uses the `>' relational operator; otherwise it could be confused with an output redirection (*note Redirection::). The items to print can be constant strings or numbers, fields of the -current record (such as '$1'), variables, or any 'awk' expression. +current record (such as `$1'), variables, or any `awk' expression. Numeric values are converted to strings and then printed. - The simple statement 'print' with no items is equivalent to 'print + The simple statement `print' with no items is equivalent to `print $0': it prints the entire current record. To print a blank line, use -'print ""', where '""' is the empty string. To print a fixed piece of -text, use a string constant, such as '"Don't Panic"', as one item. If +`print ""', where `""' is the empty string. To print a fixed piece of +text, use a string constant, such as `"Don't Panic"', as one item. If you forget to use the double-quote characters, your text is taken as an -'awk' expression, and you will probably get an error. Keep in mind that -a space is printed between any two items. +`awk' expression, and you will probably get an error. Keep in mind +that a space is printed between any two items. Note that the `print' statement is a statement and not an expression--you can't use it the pattern part of a pattern-action @@ -6680,24 +6070,25 @@ statement, for example.  File: gawk.info, Node: Print Examples, Next: Output Separators, Prev: Print, Up: Printing -5.2 'print' Statement Examples +5.2 `print' Statement Examples ============================== -Each 'print' statement makes at least one line of output. However, it -isn't limited to only one line. If an item value is a string containing -a newline, the newline is output along with the rest of the string. A -single 'print' statement can make any number of lines this way. +Each `print' statement makes at least one line of output. However, it +isn't limited to only one line. If an item value is a string +containing a newline, the newline is output along with the rest of the +string. A single `print' statement can make any number of lines this +way. The following is an example of printing a string that contains -embedded newlines (the '\n' is an escape sequence, used to represent the -newline character; *note Escape Sequences::): +embedded newlines (the `\n' is an escape sequence, used to represent +the newline character; *note Escape Sequences::): $ awk 'BEGIN { print "line one\nline two\nline three" }' -| line one -| line two -| line three - The next example, which is run on the 'inventory-shipped' file, + The next example, which is run on the `inventory-shipped' file, prints the first two fields of each input record, with a space between them: @@ -6707,10 +6098,10 @@ them: -| Mar 15 ... - A common mistake in using the 'print' statement is to omit the comma + A common mistake in using the `print' statement is to omit the comma between two items. This often has the effect of making the items run together in the output, with no space. The reason for this is that -juxtaposing two string expressions in 'awk' means to concatenate them. +juxtaposing two string expressions in `awk' means to concatenate them. Here is the same program, without the comma: $ awk '{ print $1 $2 }' inventory-shipped @@ -6719,11 +6110,11 @@ Here is the same program, without the comma: -| Mar15 ... - To someone unfamiliar with the 'inventory-shipped' file, neither + To someone unfamiliar with the `inventory-shipped' file, neither example's output makes much sense. A heading line at the beginning would make it clearer. Let's add some headings to our table of months -('$1') and green crates shipped ('$2'). We do this using a 'BEGIN' rule -(*note BEGIN/END::) so that the headings are only printed once: +(`$1') and green crates shipped (`$2'). We do this using a `BEGIN' +rule (*note BEGIN/END::) so that the headings are only printed once: awk 'BEGIN { print "Month Crates" print "----- ------" } @@ -6738,8 +6129,8 @@ When run, the program prints the following: Mar 15 ... -The only problem, however, is that the headings and the table data don't -line up! We can fix this by printing some spaces between the two +The only problem, however, is that the headings and the table data +don't line up! We can fix this by printing some spaces between the two fields: awk 'BEGIN { print "Month Crates" @@ -6748,11 +6139,11 @@ fields: Lining up columns this way can get pretty complicated when there are many columns to fix. Counting spaces for two or three columns is -simple, but any more than this can take up a lot of time. This is why -the 'printf' statement was created (*note Printf::); one of its +simple, but any more than this can take up a lot of time. This is why +the `printf' statement was created (*note Printf::); one of its specialties is lining up columns of data. - NOTE: You can continue either a 'print' or 'printf' statement + NOTE: You can continue either a `print' or `printf' statement simply by putting a newline after any comma (*note Statements/Lines::). @@ -6762,28 +6153,28 @@ File: gawk.info, Node: Output Separators, Next: OFMT, Prev: Print Examples, 5.3 Output Separators ===================== -As mentioned previously, a 'print' statement contains a list of items -separated by commas. In the output, the items are normally separated by -single spaces. However, this doesn't need to be the case; a single +As mentioned previously, a `print' statement contains a list of items +separated by commas. In the output, the items are normally separated +by single spaces. However, this doesn't need to be the case; a single space is simply the default. Any string of characters may be used as -the "output field separator" by setting the built-in variable 'OFS'. -The initial value of this variable is the string '" "'--that is, a +the "output field separator" by setting the built-in variable `OFS'. +The initial value of this variable is the string `" "'--that is, a single space. - The output from an entire 'print' statement is called an "output -record". Each 'print' statement outputs one output record, and then -outputs a string called the "output record separator" (or 'ORS'). The -initial value of 'ORS' is the string '"\n"'; i.e., a newline character. -Thus, each 'print' statement normally makes a separate line. + The output from an entire `print' statement is called an "output +record". Each `print' statement outputs one output record, and then +outputs a string called the "output record separator" (or `ORS'). The +initial value of `ORS' is the string `"\n"'; i.e., a newline character. +Thus, each `print' statement normally makes a separate line. In order to change how output fields and records are separated, -assign new values to the variables 'OFS' and 'ORS'. The usual place to -do this is in the 'BEGIN' rule (*note BEGIN/END::), so that it happens +assign new values to the variables `OFS' and `ORS'. The usual place to +do this is in the `BEGIN' rule (*note BEGIN/END::), so that it happens before any input is processed. It can also be done with assignments on -the command line, before the names of the input files, or using the '-v' -command-line option (*note Options::). The following example prints the -first and second fields of each input record, separated by a semicolon, -with a blank line added after each newline: +the command line, before the names of the input files, or using the +`-v' command-line option (*note Options::). The following example +prints the first and second fields of each input record, separated by a +semicolon, with a blank line added after each newline: $ awk 'BEGIN { OFS = ";"; ORS = "\n\n" } > { print $1, $2 }' mail-list @@ -6810,56 +6201,57 @@ with a blank line added after each newline: -| Jean-Paul;555-2127 -| - If the value of 'ORS' does not contain a newline, the program's + If the value of `ORS' does not contain a newline, the program's output runs together on a single line.  File: gawk.info, Node: OFMT, Next: Printf, Prev: Output Separators, Up: Printing -5.4 Controlling Numeric Output with 'print' +5.4 Controlling Numeric Output with `print' =========================================== -When printing numeric values with the 'print' statement, 'awk' -internally converts the number to a string of characters and prints that -string. 'awk' uses the 'sprintf()' function to do this conversion +When printing numeric values with the `print' statement, `awk' +internally converts the number to a string of characters and prints +that string. `awk' uses the `sprintf()' function to do this conversion (*note String Functions::). For now, it suffices to say that the -'sprintf()' function accepts a "format specification" that tells it how -to format numbers (or strings), and that there are a number of different -ways in which numbers can be formatted. The different format +`sprintf()' function accepts a "format specification" that tells it how +to format numbers (or strings), and that there are a number of +different ways in which numbers can be formatted. The different format specifications are discussed more fully in *note Control Letters::. - The built-in variable 'OFMT' contains the default format -specification that 'print' uses with 'sprintf()' when it wants to -convert a number to a string for printing. The default value of 'OFMT' -is '"%.6g"'. The way 'print' prints numbers can be changed by supplying -different format specifications as the value of 'OFMT', as shown in the -following example: + The built-in variable `OFMT' contains the default format +specification that `print' uses with `sprintf()' when it wants to +convert a number to a string for printing. The default value of `OFMT' +is `"%.6g"'. The way `print' prints numbers can be changed by +supplying different format specifications as the value of `OFMT', as +shown in the following example: $ awk 'BEGIN { > OFMT = "%.0f" # print numbers as integers (rounds) > print 17.23, 17.54 }' -| 17 18 -According to the POSIX standard, 'awk''s behavior is undefined if 'OFMT' -contains anything but a floating-point conversion specification. (d.c.) +According to the POSIX standard, `awk''s behavior is undefined if +`OFMT' contains anything but a floating-point conversion specification. +(d.c.)  File: gawk.info, Node: Printf, Next: Redirection, Prev: OFMT, Up: Printing -5.5 Using 'printf' Statements for Fancier Printing +5.5 Using `printf' Statements for Fancier Printing ================================================== -For more precise control over the output format than what is provided by -'print', use 'printf'. With 'printf' you can specify the width to use -for each item, as well as various formatting choices for numbers (such -as what output base to use, whether to print an exponent, whether to -print a sign, and how many digits to print after the decimal point). +For more precise control over the output format than what is provided +by `print', use `printf'. With `printf' you can specify the width to +use for each item, as well as various formatting choices for numbers +(such as what output base to use, whether to print an exponent, whether +to print a sign, and how many digits to print after the decimal point). You do this by supplying a string, called the "format string", that controls how and where to print the other arguments. * Menu: -* Basic Printf:: Syntax of the 'printf' statement. +* Basic Printf:: Syntax of the `printf' statement. * Control Letters:: Format-control letters. * Format Modifiers:: Format-specification modifiers. * Printf Examples:: Several examples. @@ -6867,34 +6259,34 @@ controls how and where to print the other arguments.  File: gawk.info, Node: Basic Printf, Next: Control Letters, Up: Printf -5.5.1 Introduction to the 'printf' Statement +5.5.1 Introduction to the `printf' Statement -------------------------------------------- -A simple 'printf' statement looks like this: +A simple `printf' statement looks like this: printf FORMAT, ITEM1, ITEM2, ... The entire list of arguments may optionally be enclosed in parentheses. -The parentheses are necessary if any of the item expressions use the '>' +The parentheses are necessary if any of the item expressions use the `>' relational operator; otherwise, it can be confused with an output redirection (*note Redirection::). - The difference between 'printf' and 'print' is the FORMAT argument. -This is an expression whose value is taken as a string; it specifies how -to output each of the other arguments. It is called the "format + The difference between `printf' and `print' is the FORMAT argument. +This is an expression whose value is taken as a string; it specifies +how to output each of the other arguments. It is called the "format string". The format string is very similar to that in the ISO C library -function 'printf()'. Most of FORMAT is text to output verbatim. +function `printf()'. Most of FORMAT is text to output verbatim. Scattered among this text are "format specifiers"--one per item. Each format specifier says to output the next item in the argument list at that place in the format. - The 'printf' statement does not automatically append a newline to its -output. It outputs only what the format string specifies. So if a + The `printf' statement does not automatically append a newline to +its output. It outputs only what the format string specifies. So if a newline is needed, you must include one in the format string. The -output separator variables 'OFS' and 'ORS' have no effect on 'printf' -statements. For example: +output separator variables `OFS' and `ORS' have no effect on `printf' +statements. For example: $ awk 'BEGIN { > ORS = "\nOUCH!\n"; OFS = "+" @@ -6903,7 +6295,7 @@ statements. For example: > }' -| Dont Panic! -Here, neither the '+' nor the 'OUCH' appear in the output message. +Here, neither the `+' nor the `OUCH' appear in the output message.  File: gawk.info, Node: Control Letters, Next: Format Modifiers, Prev: Basic Printf, Up: Printf @@ -6911,120 +6303,120 @@ File: gawk.info, Node: Control Letters, Next: Format Modifiers, Prev: Basic P 5.5.2 Format-Control Letters ---------------------------- -A format specifier starts with the character '%' and ends with a -"format-control letter"--it tells the 'printf' statement how to output +A format specifier starts with the character `%' and ends with a +"format-control letter"--it tells the `printf' statement how to output one item. The format-control letter specifies what _kind_ of value to print. The rest of the format specifier is made up of optional "modifiers" that control _how_ to print the value, such as the field width. Here is a list of the format-control letters: -'%c' - Print a number as an ASCII character; thus, 'printf "%c", 65' - outputs the letter 'A'. The output for a string value is the first +`%c' + Print a number as an ASCII character; thus, `printf "%c", 65' + outputs the letter `A'. The output for a string value is the first character of the string. NOTE: The POSIX standard says the first character of a string - is printed. In locales with multibyte characters, 'gawk' + is printed. In locales with multibyte characters, `gawk' attempts to convert the leading bytes of the string into a valid wide character and then to print the multibyte encoding of that character. Similarly, when printing a numeric value, - 'gawk' allows the value to be within the numeric range of + `gawk' allows the value to be within the numeric range of values that can be held in a wide character. If the - conversion to multibyte encoding fails, 'gawk' uses the low + conversion to multibyte encoding fails, `gawk' uses the low eight bits of the value as the character to print. - Other 'awk' versions generally restrict themselves to printing + Other `awk' versions generally restrict themselves to printing the first byte of a string or to numeric values within the range of a single byte (0-255). -'%d', '%i' +`%d', `%i' Print a decimal integer. The two control letters are equivalent. - (The '%i' specification is for compatibility with ISO C.) + (The `%i' specification is for compatibility with ISO C.) -'%e', '%E' +`%e', `%E' Print a number in scientific (exponential) notation; for example: printf "%4.3e\n", 1950 - prints '1.950e+03', with a total of four significant figures, three - of which follow the decimal point. (The '4.3' represents two - modifiers, discussed in the next node.) '%E' uses 'E' instead of - 'e' in the output. + prints `1.950e+03', with a total of four significant figures, + three of which follow the decimal point. (The `4.3' represents + two modifiers, discussed in the next node.) `%E' uses `E' instead + of `e' in the output. -'%f' +`%f' Print a number in floating-point notation. For example: printf "%4.3f", 1950 - prints '1950.000', with a total of four significant figures, three - of which follow the decimal point. (The '4.3' represents two + prints `1950.000', with a total of four significant figures, three + of which follow the decimal point. (The `4.3' represents two modifiers, discussed in the next node.) On systems supporting IEEE 754 floating point format, values - representing negative infinity are formatted as '-inf' or - '-infinity', and positive infinity as 'inf' and 'infinity'. The - special "not a number" value formats as '-nan' or 'nan' (*note Math - Definitions::). + representing negative infinity are formatted as `-inf' or + `-infinity', and positive infinity as `inf' and `infinity'. The + special "not a number" value formats as `-nan' or `nan' (*note + Math Definitions::). -'%F' - Like '%f' but the infinity and "not a number" values are spelled +`%F' + Like `%f' but the infinity and "not a number" values are spelled using uppercase letters. - The '%F' format is a POSIX extension to ISO C; not all systems - support it. On those that don't, 'gawk' uses '%f' instead. + The `%F' format is a POSIX extension to ISO C; not all systems + support it. On those that don't, `gawk' uses `%f' instead. -'%g', '%G' +`%g', `%G' Print a number in either scientific notation or in floating-point - notation, whichever uses fewer characters; if the result is printed - in scientific notation, '%G' uses 'E' instead of 'e'. + notation, whichever uses fewer characters; if the result is + printed in scientific notation, `%G' uses `E' instead of `e'. -'%o' +`%o' Print an unsigned octal integer (*note Nondecimal-numbers::). -'%s' +`%s' Print a string. -'%u' +`%u' Print an unsigned decimal integer. (This format is of marginal - use, because all numbers in 'awk' are floating-point; it is + use, because all numbers in `awk' are floating-point; it is provided primarily for compatibility with C.) -'%x', '%X' - Print an unsigned hexadecimal integer; '%X' uses the letters 'A' - through 'F' instead of 'a' through 'f' (*note +`%x', `%X' + Print an unsigned hexadecimal integer; `%X' uses the letters `A' + through `F' instead of `a' through `f' (*note Nondecimal-numbers::). -'%%' - Print a single '%'. This does not consume an argument and it +`%%' + Print a single `%'. This does not consume an argument and it ignores any modifiers. - NOTE: When using the integer format-control letters for values that - are outside the range of the widest C integer type, 'gawk' switches - to the '%g' format specifier. If '--lint' is provided on the - command line (*note Options::), 'gawk' warns about this. Other - versions of 'awk' may print invalid values or do something else - entirely. (d.c.) + NOTE: When using the integer format-control letters for values + that are outside the range of the widest C integer type, `gawk' + switches to the `%g' format specifier. If `--lint' is provided on + the command line (*note Options::), `gawk' warns about this. + Other versions of `awk' may print invalid values or do something + else entirely. (d.c.)  File: gawk.info, Node: Format Modifiers, Next: Printf Examples, Prev: Control Letters, Up: Printf -5.5.3 Modifiers for 'printf' Formats +5.5.3 Modifiers for `printf' Formats ------------------------------------ -A format specification can also include "modifiers" that can control how -much of the item's value is printed, as well as how much space it gets. -The modifiers come between the '%' and the format-control letter. We -will use the bullet symbol "*" in the following examples to represent -spaces in the output. Here are the possible modifiers, in the order in +A format specification can also include "modifiers" that can control +how much of the item's value is printed, as well as how much space it +gets. The modifiers come between the `%' and the format-control letter. +We will use the bullet symbol "*" in the following examples to represent +spaces in the output. Here are the possible modifiers, in the order in which they may appear: -'N$' - An integer constant followed by a '$' is a "positional specifier". +`N$' + An integer constant followed by a `$' is a "positional specifier". Normally, format specifications are applied to arguments in the - order given in the format string. With a positional specifier, the - format specification is applied to a specific argument, instead of - what would be the next argument in the list. Positional specifiers - begin counting with one. Thus: + order given in the format string. With a positional specifier, + the format specification is applied to a specific argument, + instead of what would be the next argument in the list. + Positional specifiers begin counting with one. Thus: printf "%s %s\n", "don't", "panic" printf "%2$s %1$s\n", "panic", "don't" @@ -7032,12 +6424,12 @@ which they may appear: prints the famous friendly message twice. At first glance, this feature doesn't seem to be of much use. It - is in fact a 'gawk' extension, intended for use in translating + is in fact a `gawk' extension, intended for use in translating messages at runtime. *Note Printf Ordering::, which describes how and why to use positional specifiers. For now, we will not use them. -'-' +`-' The minus sign, used before the width modifier (see later on in this list), says to left-justify the argument within its specified width. Normally, the argument is printed right-justified in the @@ -7045,35 +6437,35 @@ which they may appear: printf "%-4s", "foo" - prints 'foo*'. + prints `foo*'. -'SPACE' +`SPACE' For numeric conversions, prefix positive values with a space and negative values with a minus sign. -'+' - The plus sign, used before the width modifier (see later on in this - list), says to always supply a sign for numeric conversions, even - if the data to format is positive. The '+' overrides the space - modifier. - -'#' - Use an "alternate form" for certain control letters. For '%o', - supply a leading zero. For '%x' and '%X', supply a leading '0x' or - '0X' for a nonzero result. For '%e', '%E', '%f', and '%F', the - result always contains a decimal point. For '%g' and '%G', +`+' + The plus sign, used before the width modifier (see later on in + this list), says to always supply a sign for numeric conversions, + even if the data to format is positive. The `+' overrides the + space modifier. + +`#' + Use an "alternate form" for certain control letters. For `%o', + supply a leading zero. For `%x' and `%X', supply a leading `0x' + or `0X' for a nonzero result. For `%e', `%E', `%f', and `%F', the + result always contains a decimal point. For `%g' and `%G', trailing zeros are not removed from the result. -'0' - A leading '0' (zero) acts as a flag that indicates that output +`0' + A leading `0' (zero) acts as a flag that indicates that output should be padded with zeros instead of spaces. This applies only to the numeric output formats. This flag only has an effect when the field width is wider than the value to print. -''' +`'' A single quote or apostrophe character is a POSIX extension to ISO - C. It indicates that the integer part of a floating point value, or - the entire part of an integer decimal value, should have a + C. It indicates that the integer part of a floating point value, + or the entire part of an integer decimal value, should have a thousands-separator character in it. This only works in locales that support such characters. For example: @@ -7087,20 +6479,20 @@ which they may appear: For more information about locales and internationalization issues, see *note Locales::. - NOTE: The ''' flag is a nice feature, but its use complicates + NOTE: The `'' flag is a nice feature, but its use complicates things: it becomes difficult to use it in command-line programs. For information on appropriate quoting tricks, see *note Quoting::. -'WIDTH' +`WIDTH' This is a number specifying the desired minimum width of a field. - Inserting any number between the '%' sign and the format-control + Inserting any number between the `%' sign and the format-control character forces the field to expand to this width. The default way to do this is to pad with spaces on the left. For example: printf "%4s", "foo" - prints '*foo'. + prints `*foo'. The value of WIDTH is a minimum width, not a maximum. If the item value requires more than WIDTH characters, it can be as wide as @@ -7108,26 +6500,26 @@ which they may appear: printf "%4s", "foobar" - prints 'foobar'. + prints `foobar'. Preceding the WIDTH with a minus sign causes the output to be padded with spaces on the right, instead of on the left. -'.PREC' - A period followed by an integer constant specifies the precision to - use when printing. The meaning of the precision varies by control - letter: +`.PREC' + A period followed by an integer constant specifies the precision + to use when printing. The meaning of the precision varies by + control letter: - '%d', '%i', '%o', '%u', '%x', '%X' + `%d', `%i', `%o', `%u', `%x', `%X' Minimum number of digits to print. - '%e', '%E', '%f', '%F' + `%e', `%E', `%f', `%F' Number of digits to the right of the decimal point. - '%g', '%G' + `%g', `%G' Maximum number of significant digits. - '%s' + `%s' Maximum number of characters from the string that should print. @@ -7135,12 +6527,12 @@ which they may appear: printf "%.4s", "foobar" - prints 'foob'. + prints `foob'. - The C library 'printf''s dynamic WIDTH and PREC capability (for -example, '"%*.*s"') is supported. Instead of supplying explicit WIDTH -and/or PREC values in the format string, they are passed in the argument -list. For example: + The C library `printf''s dynamic WIDTH and PREC capability (for +example, `"%*.*s"') is supported. Instead of supplying explicit WIDTH +and/or PREC values in the format string, they are passed in the +argument list. For example: w = 5 p = 3 @@ -7152,9 +6544,10 @@ is exactly equivalent to: s = "abcdefg" printf "%5.3s\n", s -Both programs output '**abc'. Earlier versions of 'awk' did not support -this capability. If you must use such a version, you may simulate this -feature by using concatenation to build up the format string, like so: +Both programs output `**abc'. Earlier versions of `awk' did not +support this capability. If you must use such a version, you may +simulate this feature by using concatenation to build up the format +string, like so: w = 5 p = 3 @@ -7163,27 +6556,28 @@ feature by using concatenation to build up the format string, like so: This is not particularly easy to read but it does work. - C programmers may be used to supplying additional modifiers ('h', -'j', 'l', 'L', 't', and 'z') in 'printf' format strings. These are not -valid in 'awk'. Most 'awk' implementations silently ignore them. If -'--lint' is provided on the command line (*note Options::), 'gawk' warns -about their use. If '--posix' is supplied, their use is a fatal error. + C programmers may be used to supplying additional modifiers (`h', +`j', `l', `L', `t', and `z') in `printf' format strings. These are not +valid in `awk'. Most `awk' implementations silently ignore them. If +`--lint' is provided on the command line (*note Options::), `gawk' +warns about their use. If `--posix' is supplied, their use is a fatal +error.  File: gawk.info, Node: Printf Examples, Prev: Format Modifiers, Up: Printf -5.5.4 Examples Using 'printf' +5.5.4 Examples Using `printf' ----------------------------- -The following simple example shows how to use 'printf' to make an +The following simple example shows how to use `printf' to make an aligned table: awk '{ printf "%-10s %s\n", $1, $2 }' mail-list -This command prints the names of the people ('$1') in the file -'mail-list' as a string of 10 characters that are left-justified. It -also prints the phone numbers ('$2') next on the line. This produces an -aligned two-column table of names and phone numbers, as shown here: +This command prints the names of the people (`$1') in the file +`mail-list' as a string of 10 characters that are left-justified. It +also prints the phone numbers (`$2') next on the line. This produces +an aligned two-column table of names and phone numbers, as shown here: $ awk '{ printf "%-10s %s\n", $1, $2 }' mail-list -| Amelia 555-5553 @@ -7200,7 +6594,7 @@ aligned two-column table of names and phone numbers, as shown here: In this case, the phone numbers had to be printed as strings because the numbers are separated by a dash. Printing the phone numbers as -numbers would have produced just the first three digits: '555'. This +numbers would have produced just the first three digits: `555'. This would have been pretty confusing. It wasn't necessary to specify a width for the phone numbers because @@ -7208,24 +6602,24 @@ they are last on their lines. They don't need to have spaces after them. The table could be made to look even nicer by adding headings to the -tops of the columns. This is done using a 'BEGIN' rule (*note -BEGIN/END::) so that the headers are only printed once, at the beginning -of the 'awk' program: +tops of the columns. This is done using a `BEGIN' rule (*note +BEGIN/END::) so that the headers are only printed once, at the +beginning of the `awk' program: awk 'BEGIN { print "Name Number" print "---- ------" } { printf "%-10s %s\n", $1, $2 }' mail-list - The above example mixes 'print' and 'printf' statements in the same -program. Using just 'printf' statements can produce the same results: + The above example mixes `print' and `printf' statements in the same +program. Using just `printf' statements can produce the same results: awk 'BEGIN { printf "%-10s %s\n", "Name", "Number" printf "%-10s %s\n", "----", "------" } { printf "%-10s %s\n", $1, $2 }' mail-list -Printing each column heading with the same format specification used for -the column elements ensures that the headings are aligned just like the -columns. +Printing each column heading with the same format specification used +for the column elements ensures that the headings are aligned just like +the columns. The fact that the same format specification is used three times can be emphasized by storing it in a variable, like this: @@ -7238,39 +6632,39 @@ be emphasized by storing it in a variable, like this:  File: gawk.info, Node: Redirection, Next: Special Files, Prev: Printf, Up: Printing -5.6 Redirecting Output of 'print' and 'printf' +5.6 Redirecting Output of `print' and `printf' ============================================== -So far, the output from 'print' and 'printf' has gone to the standard -output, usually the screen. Both 'print' and 'printf' can also send +So far, the output from `print' and `printf' has gone to the standard +output, usually the screen. Both `print' and `printf' can also send their output to other places. This is called "redirection". - NOTE: When '--sandbox' is specified (*note Options::), redirecting + NOTE: When `--sandbox' is specified (*note Options::), redirecting output to files and pipes is disabled. - A redirection appears after the 'print' or 'printf' statement. -Redirections in 'awk' are written just like redirections in shell -commands, except that they are written inside the 'awk' program. + A redirection appears after the `print' or `printf' statement. +Redirections in `awk' are written just like redirections in shell +commands, except that they are written inside the `awk' program. There are four forms of output redirection: output to a file, output appended to a file, output through a pipe to another command, and output -to a coprocess. We show them all for the 'print' statement, but they -work identically for 'printf': +to a coprocess. We show them all for the `print' statement, but they +work identically for `printf': -'print ITEMS > OUTPUT-FILE' +`print ITEMS > OUTPUT-FILE' This redirection prints the items into the output file named - OUTPUT-FILE. The file name OUTPUT-FILE can be any expression. Its - value is changed to a string and then used as a file name (*note - Expressions::). + OUTPUT-FILE. The file name OUTPUT-FILE can be any expression. + Its value is changed to a string and then used as a file name + (*note Expressions::). When this type of redirection is used, the OUTPUT-FILE is erased - before the first output is written to it. Subsequent writes to the - same OUTPUT-FILE do not erase OUTPUT-FILE, but append to it. (This - is different from how you use redirections in shell scripts.) If - OUTPUT-FILE does not exist, it is created. For example, here is - how an 'awk' program can write a list of peoples' names to one file - named 'name-list', and a list of phone numbers to another file - named 'phone-list': + before the first output is written to it. Subsequent writes to + the same OUTPUT-FILE do not erase OUTPUT-FILE, but append to it. + (This is different from how you use redirections in shell scripts.) + If OUTPUT-FILE does not exist, it is created. For example, here + is how an `awk' program can write a list of peoples' names to one + file named `name-list', and a list of phone numbers to another file + named `phone-list': $ awk '{ print $2 > "phone-list" > print $1 > "name-list" }' mail-list @@ -7285,20 +6679,20 @@ work identically for 'printf': Each output file contains one name or number per line. -'print ITEMS >> OUTPUT-FILE' +`print ITEMS >> OUTPUT-FILE' This redirection prints the items into the pre-existing output file - named OUTPUT-FILE. The difference between this and the single-'>' + named OUTPUT-FILE. The difference between this and the single-`>' redirection is that the old contents (if any) of OUTPUT-FILE are - not erased. Instead, the 'awk' output is appended to the file. If - OUTPUT-FILE does not exist, then it is created. + not erased. Instead, the `awk' output is appended to the file. + If OUTPUT-FILE does not exist, then it is created. -'print ITEMS | COMMAND' +`print ITEMS | COMMAND' It is possible to send output to another program through a pipe - instead of into a file. This redirection opens a pipe to COMMAND, - and writes the values of ITEMS through this pipe to another process - created to execute COMMAND. + instead of into a file. This redirection opens a pipe to + COMMAND, and writes the values of ITEMS through this pipe to + another process created to execute COMMAND. - The redirection argument COMMAND is actually an 'awk' expression. + The redirection argument COMMAND is actually an `awk' expression. Its value is converted to a string whose contents give the shell command to be run. For example, the following produces two files, one unsorted list of peoples' names, and one list sorted in reverse @@ -7309,11 +6703,11 @@ work identically for 'printf': print $1 | command }' mail-list The unsorted list is written with an ordinary redirection, while - the sorted list is written by piping through the 'sort' utility. + the sorted list is written by piping through the `sort' utility. The next example uses redirection to mail a message to the mailing - list 'bug-system'. This might be useful when trouble is - encountered in an 'awk' script run periodically for system + list `bug-system'. This might be useful when trouble is + encountered in an `awk' script run periodically for system maintenance: report = "mail bug-system" @@ -7323,38 +6717,38 @@ work identically for 'printf': close(report) The message is built using string concatenation and saved in the - variable 'm'. It's then sent down the pipeline to the 'mail' + variable `m'. It's then sent down the pipeline to the `mail' program. (The parentheses group the items to concatenate--see *note Concatenation::.) - The 'close()' function is called here because it's a good idea to + The `close()' function is called here because it's a good idea to close the pipe as soon as all the intended output has been sent to it. *Note Close Files And Pipes::, for more information. This example also illustrates the use of a variable to represent a FILE or COMMAND--it is not necessary to always use a string constant. Using a variable is generally a good idea, because (if - you mean to refer to that same file or command) 'awk' requires that - the string value be written identically every time. + you mean to refer to that same file or command) `awk' requires + that the string value be written identically every time. -'print ITEMS |& COMMAND' +`print ITEMS |& COMMAND' This redirection prints the items to the input of COMMAND. The - difference between this and the single-'|' redirection is that the - output from COMMAND can be read with 'getline'. Thus COMMAND is a + difference between this and the single-`|' redirection is that the + output from COMMAND can be read with `getline'. Thus COMMAND is a "coprocess", which works together with, but subsidiary to, the - 'awk' program. + `awk' program. - This feature is a 'gawk' extension, and is not available in POSIX - 'awk'. *Note Getline/Coprocess::, for a brief discussion. *Note + This feature is a `gawk' extension, and is not available in POSIX + `awk'. *Note Getline/Coprocess::, for a brief discussion. *Note Two-way I/O::, for a more complete discussion. - Redirecting output using '>', '>>', '|', or '|&' asks the system to + Redirecting output using `>', `>>', `|', or `|&' asks the system to open a file, pipe, or coprocess only if the particular FILE or COMMAND -you specify has not already been written to by your program or if it has -been closed since it was last written to. +you specify has not already been written to by your program or if it +has been closed since it was last written to. - It is a common error to use '>' redirection for the first 'print' to -a file, and then to use '>>' for subsequent output: + It is a common error to use `>' redirection for the first `print' to +a file, and then to use `>>' for subsequent output: # clear the file print "Don't panic" > "guide.txt" @@ -7363,46 +6757,42 @@ a file, and then to use '>>' for subsequent output: print "Avoid improbability generators" >> "guide.txt" This is indeed how redirections must be used from the shell. But in -'awk', it isn't necessary. In this kind of case, a program should use -'>' for all the 'print' statements, since the output file is only opened -once. (It happens that if you mix '>' and '>>' that output is produced -in the expected order. However, mixing the operators for the same file -is definitely poor style, and is confusing to readers of your program.) - - Many older 'awk' implementations limit the number of pipelines that -an 'awk' program may have open to just one! In 'gawk', there is no such -limit. 'gawk' allows a program to open as many pipelines as the +`awk', it isn't necessary. In this kind of case, a program should use +`>' for all the `print' statements, since the output file is only +opened once. (It happens that if you mix `>' and `>>' that output is +produced in the expected order. However, mixing the operators for the +same file is definitely poor style, and is confusing to readers of your +program.) + + Many older `awk' implementations limit the number of pipelines that +an `awk' program may have open to just one! In `gawk', there is no +such limit. `gawk' allows a program to open as many pipelines as the underlying operating system permits. - Piping into 'sh' + Piping into `sh' A particularly powerful way to use redirection is to build command -lines and pipe them into the shell, 'sh'. For example, suppose you have -a list of files brought over from a system where all the file names are -stored in uppercase, and you wish to rename them to have names in all -lowercase. The following program is both simple and efficient: +lines and pipe them into the shell, `sh'. For example, suppose you +have a list of files brought over from a system where all the file names +are stored in uppercase, and you wish to rename them to have names in +all lowercase. The following program is both simple and efficient: { printf("mv %s %s\n", $0, tolower($0)) | "sh" } END { close("sh") } - The 'tolower()' function returns its argument string with all + The `tolower()' function returns its argument string with all uppercase characters converted to lowercase (*note String Functions::). -The program builds up a list of command lines, using the 'mv' utility to -rename the files. It then sends the list to the shell for execution. +The program builds up a list of command lines, using the `mv' utility +to rename the files. It then sends the list to the shell for execution.  File: gawk.info, Node: Special Files, Next: Close Files And Pipes, Prev: Redirection, Up: Printing -<<<<<<< HEAD -5.7 Special File Name in 'gawk' -=============================== -======= 5.7 Special File Names in `gawk' ================================ ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac -'gawk' provides a number of special file names that it interprets +`gawk' provides a number of special file names that it interprets internally. These file names provide access to standard file descriptors and TCP/IP networking. @@ -7422,68 +6812,61 @@ Running programs conventionally have three input and output streams already available to them for reading and writing. These are known as the "standard input", "standard output", and "standard error output". These streams are, by default, connected to your keyboard and screen, -but they are often redirected with the shell, via the '<', '<<', '>', -'>>', '>&', and '|' operators. Standard error is typically used for +but they are often redirected with the shell, via the `<', `<<', `>', +`>>', `>&', and `|' operators. Standard error is typically used for writing error messages; the reason there are two separate streams, standard output and standard error, is so that they can be redirected separately. - In other implementations of 'awk', the only way to write an error -message to standard error in an 'awk' program is as follows: + In other implementations of `awk', the only way to write an error +message to standard error in an `awk' program is as follows: print "Serious error detected!" | "cat 1>&2" This works by opening a pipeline to a shell command that can access the -<<<<<<< HEAD -standard error stream that it inherits from the 'awk' process. This is -far from elegant, and it is also inefficient, because it requires a -separate process. So people writing 'awk' programs often don't do this. -Instead, they send the error messages to the screen, like this: -======= standard error stream that it inherits from the `awk' process. This is far from elegant, and it also requires a separate process. So people writing `awk' programs often don't do this. Instead, they send the error messages to the screen, like this: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac print "Serious error detected!" > "/dev/tty" -('/dev/tty' is a special file supplied by the operating system that is -connected to your keyboard and screen. It represents the "terminal,"(1) +(`/dev/tty' is a special file supplied by the operating system that is +connected to your keyboard and screen. It represents the "terminal,"(1) which on modern systems is a keyboard and screen, not a serial console.) This usually has the same effect but not always: although the standard error stream is usually the screen, it can be redirected; when that -happens, writing to the screen is not correct. In fact, if 'awk' is run -from a background job, it may not have a terminal at all. Then opening -'/dev/tty' fails. +happens, writing to the screen is not correct. In fact, if `awk' is +run from a background job, it may not have a terminal at all. Then +opening `/dev/tty' fails. - 'gawk' provides special file names for accessing the three standard -streams. (c.e.) It also provides syntax for accessing any other + `gawk' provides special file names for accessing the three standard +streams. (c.e.) It also provides syntax for accessing any other inherited open files. If the file name matches one of these special -names when 'gawk' redirects input or output, then it directly uses the -stream that the file name stands for. These special file names work for -all operating systems that 'gawk' has been ported to, not just those -that are POSIX-compliant: +names when `gawk' redirects input or output, then it directly uses the +stream that the file name stands for. These special file names work +for all operating systems that `gawk' has been ported to, not just +those that are POSIX-compliant: -'/dev/stdin' +`/dev/stdin' The standard input (file descriptor 0). -'/dev/stdout' +`/dev/stdout' The standard output (file descriptor 1). -'/dev/stderr' +`/dev/stderr' The standard error output (file descriptor 2). -'/dev/fd/N' +`/dev/fd/N' The file associated with file descriptor N. Such a file must be - opened by the program initiating the 'awk' execution (typically the - shell). Unless special pains are taken in the shell from which - 'gawk' is invoked, only descriptors 0, 1, and 2 are available. + opened by the program initiating the `awk' execution (typically + the shell). Unless special pains are taken in the shell from which + `gawk' is invoked, only descriptors 0, 1, and 2 are available. - The file names '/dev/stdin', '/dev/stdout', and '/dev/stderr' are -aliases for '/dev/fd/0', '/dev/fd/1', and '/dev/fd/2', respectively. + The file names `/dev/stdin', `/dev/stdout', and `/dev/stderr' are +aliases for `/dev/fd/0', `/dev/fd/1', and `/dev/fd/2', respectively. However, they are more self-explanatory. The proper way to write an -error message in a 'gawk' program is to use '/dev/stderr', like this: +error message in a `gawk' program is to use `/dev/stderr', like this: print "Serious error detected!" > "/dev/stderr" @@ -7491,16 +6874,16 @@ error message in a 'gawk' program is to use '/dev/stderr', like this: redirection, the value must be a string. It is a common error to omit the quotes, which leads to confusing results. - Finally, using the 'close()' function on a file name of the form -'"/dev/fd/N"', for file descriptor numbers above two, does actually + Finally, using the `close()' function on a file name of the form +`"/dev/fd/N"', for file descriptor numbers above two, does actually close the given file descriptor. - The '/dev/stdin', '/dev/stdout', and '/dev/stderr' special files are -also recognized internally by several other versions of 'awk'. + The `/dev/stdin', `/dev/stdout', and `/dev/stderr' special files are +also recognized internally by several other versions of `awk'. ---------- Footnotes ---------- - (1) The "tty" in '/dev/tty' stands for "Teletype," a serial terminal. + (1) The "tty" in `/dev/tty' stands for "Teletype," a serial terminal.  File: gawk.info, Node: Special Network, Next: Special Caveats, Prev: Special FD, Up: Special Files @@ -7508,15 +6891,16 @@ File: gawk.info, Node: Special Network, Next: Special Caveats, Prev: Special 5.7.2 Special Files for Network Communications ---------------------------------------------- -'gawk' programs can open a two-way TCP/IP connection, acting as either a -client or a server. This is done using a special file name of the form: +`gawk' programs can open a two-way TCP/IP connection, acting as either +a client or a server. This is done using a special file name of the +form: - /NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT + `/NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT' - The NET-TYPE is one of 'inet', 'inet4' or 'inet6'. The PROTOCOL is -one of 'tcp' or 'udp', and the other fields represent the other + The NET-TYPE is one of `inet', `inet4' or `inet6'. The PROTOCOL is +one of `tcp' or `udp', and the other fields represent the other essential pieces of information for making a networking connection. -These file names are used with the '|&' operator for communicating with +These file names are used with the `|&' operator for communicating with a coprocess (*note Two-way I/O::). This is an advanced feature, mentioned here only for completeness. Full discussion is delayed until *note TCP/IP Networking::. @@ -7528,14 +6912,14 @@ File: gawk.info, Node: Special Caveats, Prev: Special Network, Up: Special Fi ------------------------------- Here is a list of things to bear in mind when using the special file -names that 'gawk' provides: +names that `gawk' provides: - * Recognition of these special file names is disabled if 'gawk' is in + * Recognition of these special file names is disabled if `gawk' is in compatibility mode (*note Options::). - * 'gawk' _always_ interprets these special file names. For example, - using '/dev/fd/4' for output actually writes on file descriptor 4, - and not on a new file descriptor that is 'dup()''ed from file + * `gawk' _always_ interprets these special file names. For example, + using `/dev/fd/4' for output actually writes on file descriptor 4, + and not on a new file descriptor that is `dup()''ed from file descriptor 4. Most of the time this does not matter; however, it is important to _not_ close any of the files related to file descriptors 0, 1, and 2. Doing so results in unpredictable @@ -7547,21 +6931,21 @@ File: gawk.info, Node: Close Files And Pipes, Next: Output Summary, Prev: Spe 5.8 Closing Input and Output Redirections ========================================= -If the same file name or the same shell command is used with 'getline' -more than once during the execution of an 'awk' program (*note +If the same file name or the same shell command is used with `getline' +more than once during the execution of an `awk' program (*note Getline::), the file is opened (or the command is executed) the first time only. At that time, the first record of input is read from that file or command. The next time the same file or command is used with -'getline', another record is read from it, and so on. +`getline', another record is read from it, and so on. - Similarly, when a file or pipe is opened for output, 'awk' remembers + Similarly, when a file or pipe is opened for output, `awk' remembers the file name or command associated with it, and subsequent writes to the same file or command are appended to the previous writes. The file -or pipe stays open until 'awk' exits. +or pipe stays open until `awk' exits. This implies that special steps are necessary in order to read the same file again from the beginning, or to rerun a shell command (rather -than reading more output from the same command). The 'close()' function +than reading more output from the same command). The `close()' function makes these things possible: close(FILENAME) @@ -7572,7 +6956,7 @@ or: The argument FILENAME or COMMAND can be any expression. Its value must _exactly_ match the string that was used to open the file or start -the command (spaces and other "irrelevant" characters included). For +the command (spaces and other "irrelevant" characters included). For example, if you open a pipe with this: "sort -r names" | getline foo @@ -7581,28 +6965,28 @@ then you must close it with this: close("sort -r names") - Once this function call is executed, the next 'getline' from that -file or command, or the next 'print' or 'printf' to that file or -command, reopens the file or reruns the command. Because the expression -that you use to close a file or pipeline must exactly match the -expression used to open the file or run the command, it is good practice -to use a variable to store the file name or command. The previous -example becomes the following: + Once this function call is executed, the next `getline' from that +file or command, or the next `print' or `printf' to that file or +command, reopens the file or reruns the command. Because the +expression that you use to close a file or pipeline must exactly match +the expression used to open the file or run the command, it is good +practice to use a variable to store the file name or command. The +previous example becomes the following: sortcom = "sort -r names" sortcom | getline foo ... close(sortcom) -This helps avoid hard-to-find typographical errors in your 'awk' +This helps avoid hard-to-find typographical errors in your `awk' programs. Here are some of the reasons for closing an output file: - * To write a file and read it back later on in the same 'awk' + * To write a file and read it back later on in the same `awk' program. Close the file after writing it, then begin reading it - with 'getline'. + with `getline'. - * To write numerous files, successively, in the same 'awk' program. - If the files aren't closed, eventually 'awk' may exceed a system + * To write numerous files, successively, in the same `awk' program. + If the files aren't closed, eventually `awk' may exceed a system limit on the number of open files in one process. It is best to close each one when the program has finished writing it. @@ -7610,25 +6994,25 @@ programs. Here are some of the reasons for closing an output file: pipe, the command reading the pipe normally continues to try to read input as long as the pipe is open. Often this means the command cannot really do its work until the pipe is closed. For - example, if output is redirected to the 'mail' program, the message - is not actually sent until the pipe is closed. + example, if output is redirected to the `mail' program, the + message is not actually sent until the pipe is closed. * To run the same program a second time, with the same arguments. This is not the same thing as giving more input to the first run! - For example, suppose a program pipes output to the 'mail' program. + For example, suppose a program pipes output to the `mail' program. If it outputs several lines redirected to this pipe without closing it, they make a single message of several lines. By contrast, if the program closes the pipe after each line of output, then each line makes a separate message. - If you use more files than the system allows you to have open, 'gawk' -attempts to multiplex the available open files among your data files. -'gawk''s ability to do this depends upon the facilities of your + If you use more files than the system allows you to have open, +`gawk' attempts to multiplex the available open files among your data +files. `gawk''s ability to do this depends upon the facilities of your operating system, so it may not always work. It is therefore both good -practice and good portability advice to always use 'close()' on your +practice and good portability advice to always use `close()' on your files when you are done with them. In fact, if you are using a lot of -pipes, it is essential that you close commands when done. For example, +pipes, it is essential that you close commands when done. For example, consider something like this: { @@ -7641,62 +7025,62 @@ consider something like this: } This example creates a new pipeline based on data in _each_ record. -Without the call to 'close()' indicated in the comment, 'awk' creates +Without the call to `close()' indicated in the comment, `awk' creates child processes to run the commands, until it eventually runs out of file descriptors for more pipelines. Even though each command has finished (as indicated by the -end-of-file return status from 'getline'), the child process is not -terminated;(1) more importantly, the file descriptor for the pipe is not -closed and released until 'close()' is called or 'awk' exits. +end-of-file return status from `getline'), the child process is not +terminated;(1) more importantly, the file descriptor for the pipe is +not closed and released until `close()' is called or `awk' exits. - 'close()' silently does nothing if given an argument that does not + `close()' silently does nothing if given an argument that does not represent a file, pipe or coprocess that was opened with a redirection. -In such a case, it returns a negative value, indicating an error. In -addition, 'gawk' sets 'ERRNO' to a string indicating the error. +In such a case, it returns a negative value, indicating an error. In +addition, `gawk' sets `ERRNO' to a string indicating the error. - Note also that 'close(FILENAME)' has no "magic" effects on the + Note also that `close(FILENAME)' has no "magic" effects on the implicit loop that reads through the files named on the command line. It is, more likely, a close of a file that was never opened with a -redirection, so 'awk' silently does nothing. +redirection, so `awk' silently does nothing. - When using the '|&' operator to communicate with a coprocess, it is + When using the `|&' operator to communicate with a coprocess, it is occasionally useful to be able to close one end of the two-way pipe without closing the other. This is done by supplying a second argument -to 'close()'. As in any other call to 'close()', the first argument is +to `close()'. As in any other call to `close()', the first argument is the name of the command or special file used to start the coprocess. -The second argument should be a string, with either of the values '"to"' -or '"from"'. Case does not matter. As this is an advanced feature, a -more complete discussion is delayed until *note Two-way I/O::, which -discusses it in more detail and gives an example. +The second argument should be a string, with either of the values +`"to"' or `"from"'. Case does not matter. As this is an advanced +feature, a more complete discussion is delayed until *note Two-way +I/O::, which discusses it in more detail and gives an example. - Using 'close()''s Return Value + Using `close()''s Return Value - In many older versions of Unix 'awk', the 'close()' function is + In many older versions of Unix `awk', the `close()' function is actually a statement. It is a syntax error to try and use the return -value from 'close()': (d.c.) +value from `close()': (d.c.) command = "..." command | getline info retval = close(command) # syntax error in many Unix awks - 'gawk' treats 'close()' as a function. The return value is -1 if the -argument names something that was never opened with a redirection, or if -there is a system problem closing the file or process. In these cases, -'gawk' sets the built-in variable 'ERRNO' to a string describing the -problem. + `gawk' treats `close()' as a function. The return value is -1 if +the argument names something that was never opened with a redirection, +or if there is a system problem closing the file or process. In these +cases, `gawk' sets the built-in variable `ERRNO' to a string describing +the problem. - In 'gawk', when closing a pipe or coprocess (input or output), the -return value is the exit status of the command.(2) Otherwise, it is the -return value from the system's 'close()' or 'fclose()' C functions when + In `gawk', when closing a pipe or coprocess (input or output), the +return value is the exit status of the command.(2) Otherwise, it is the +return value from the system's `close()' or `fclose()' C functions when closing input or output files, respectively. This value is zero if the close succeeds, or -1 if it fails. - The POSIX standard is very vague; it says that 'close()' returns zero -on success and nonzero otherwise. In general, different implementations -vary in what they report when closing pipes; thus the return value -cannot be used portably. (d.c.) In POSIX mode (*note Options::), -'gawk' just returns zero when closing a pipe. + The POSIX standard is very vague; it says that `close()' returns +zero on success and nonzero otherwise. In general, different +implementations vary in what they report when closing pipes; thus the +return value cannot be used portably. (d.c.) In POSIX mode (*note +Options::), `gawk' just returns zero when closing a pipe. ---------- Footnotes ---------- @@ -7704,8 +7088,8 @@ cannot be used portably. (d.c.) In POSIX mode (*note Options::), is called a "zombie," and cleaning up after it is referred to as "reaping." - (2) This is a full 16-bit value as returned by the 'wait()' system -call. See the system manual pages for information on how to decode this + (2) This is a full 16-bit value as returned by the `wait()' system +call. See the system manual pages for information on how to decode this value.  @@ -7714,25 +7098,26 @@ File: gawk.info, Node: Output Summary, Next: Output Exercises, Prev: Close Fi 5.9 Summary =========== - * The 'print' statement prints comma-separated expressions. Each - expression is separated by the value of 'OFS' and terminated by the - value of 'ORS'. 'OFMT' provides the conversion format for numeric - values for the 'print' statement. + * The `print' statement prints comma-separated expressions. Each + expression is separated by the value of `OFS' and terminated by + the value of `ORS'. `OFMT' provides the conversion format for + numeric values for the `print' statement. - * The 'printf' statement provides finer-grained control over output, + * The `printf' statement provides finer-grained control over output, with format control letters for different data types and various flags that modify the behavior of the format control letters. - * Output from both 'print' and 'printf' may be redirected to files, + * Output from both `print' and `printf' may be redirected to files, pipes, and co-processes. - * 'gawk' provides special file names for access to standard input, + * `gawk' provides special file names for access to standard input, output and error, and for network communications. - * Use 'close()' to close open file, pipe and co-process redirections. + * Use `close()' to close open file, pipe and co-process redirections. For co-processes, it is possible to close only one direction of the communications. +  File: gawk.info, Node: Output Exercises, Prev: Output Summary, Up: Printing @@ -7745,10 +7130,10 @@ File: gawk.info, Node: Output Exercises, Prev: Output Summary, Up: Printing print "----- ------" } { print $1, " ", $2 }' inventory-shipped - from *note Output Separators::, by using a new value of 'OFS'. + from *note Output Separators::, by using a new value of `OFS'. - 2. Use the 'printf' statement to line up the headings and table data - for the 'inventory-shipped' example that was covered in *note + 2. Use the `printf' statement to line up the headings and table data + for the `inventory-shipped' example that was covered in *note Print::. 3. What happens if you forget the double quotes when redirecting @@ -7756,27 +7141,29 @@ File: gawk.info, Node: Output Exercises, Prev: Output Summary, Up: Printing BEGIN { print "Serious error detected!" > /dev/stderr } +  File: gawk.info, Node: Expressions, Next: Patterns and Actions, Prev: Printing, Up: Top 6 Expressions ************* -Expressions are the basic building blocks of 'awk' patterns and actions. -An expression evaluates to a value that you can print, test, or pass to -a function. Additionally, an expression can assign a new value to a -variable or a field by using an assignment operator. +Expressions are the basic building blocks of `awk' patterns and +actions. An expression evaluates to a value that you can print, test, +or pass to a function. Additionally, an expression can assign a new +value to a variable or a field by using an assignment operator. An expression can serve as a pattern or action statement on its own. Most other kinds of statements contain one or more expressions that specify the data on which to operate. As in other languages, -expressions in 'awk' include variables, array references, constants, and -function calls, as well as combinations of these with various operators. +expressions in `awk' include variables, array references, constants, +and function calls, as well as combinations of these with various +operators. * Menu: * Values:: Constants, Variables, and Regular Expressions. -* All Operators:: 'gawk''s operators. +* All Operators:: `gawk''s operators. * Truth Values and Conditions:: Testing for true and false. * Function Calls:: A function call is an expression. * Precedence:: How various operators nest. @@ -7790,7 +7177,7 @@ File: gawk.info, Node: Values, Next: All Operators, Up: Expressions ======================================== Expressions are built up from values and the operations performed upon -them. This minor node describes the elementary objects which provide +them. This minor node describes the elementary objects which provide the values used in expressions. * Menu: @@ -7812,8 +7199,8 @@ same value. There are three types of constants: numeric, string, and regular expression. Each is used in the appropriate context when you need a data value -that isn't going to change. Numeric constants can have different forms, -but are stored identically internally. +that isn't going to change. Numeric constants can have different +forms, but are stored identically internally. * Menu: @@ -7829,7 +7216,7 @@ File: gawk.info, Node: Scalar Constants, Next: Nondecimal-numbers, Up: Consta A "numeric constant" stands for a number. This number can be an integer, a decimal fraction, or a number in scientific (exponential) -notation.(1) Here are some examples of numeric constants that all have +notation.(1) Here are some examples of numeric constants that all have the same value: 105 @@ -7841,10 +7228,11 @@ double-quotation marks. For example: "parrot" -represents the string whose contents are 'parrot'. Strings in 'gawk' -can be of any length, and they can contain any of the possible eight-bit -ASCII characters including ASCII NUL (character code zero). Other 'awk' -implementations may have difficulty with some character codes. +represents the string whose contents are `parrot'. Strings in `gawk' +can be of any length, and they can contain any of the possible +eight-bit ASCII characters including ASCII NUL (character code zero). +Other `awk' implementations may have difficulty with some character +codes. ---------- Footnotes ---------- @@ -7859,29 +7247,30 @@ File: gawk.info, Node: Nondecimal-numbers, Next: Regexp Constants, Prev: Scal 6.1.1.2 Octal and Hexadecimal Numbers ..................................... -In 'awk', all numbers are in decimal; i.e., base 10. Many other +In `awk', all numbers are in decimal; i.e., base 10. Many other programming languages allow you to specify numbers in other bases, often octal (base 8) and hexadecimal (base 16). In octal, the numbers go 0, -1, 2, 3, 4, 5, 6, 7, 10, 11, 12, etc. Just as '11', in decimal, is 1 -times 10 plus 1, so '11', in octal, is 1 times 8, plus 1. This equals 9 -in decimal. In hexadecimal, there are 16 digits. Since the everyday -decimal number system only has ten digits ('0'-'9'), the letters 'a' -through 'f' are used to represent the rest. (Case in the letters is -usually irrelevant; hexadecimal 'a' and 'A' have the same value.) Thus, -'11', in hexadecimal, is 1 times 16 plus 1, which equals 17 in decimal. - - Just by looking at plain '11', you can't tell what base it's in. So, -in C, C++, and other languages derived from C, there is a special -notation to signify the base. Octal numbers start with a leading '0', -and hexadecimal numbers start with a leading '0x' or '0X': - -'11' +1, 2, 3, 4, 5, 6, 7, 10, 11, 12, etc. Just as `11', in decimal, is 1 +times 10 plus 1, so `11', in octal, is 1 times 8, plus 1. This equals 9 +in decimal. In hexadecimal, there are 16 digits. Since the everyday +decimal number system only has ten digits (`0'-`9'), the letters `a' +through `f' are used to represent the rest. (Case in the letters is +usually irrelevant; hexadecimal `a' and `A' have the same value.) +Thus, `11', in hexadecimal, is 1 times 16 plus 1, which equals 17 in +decimal. + + Just by looking at plain `11', you can't tell what base it's in. +So, in C, C++, and other languages derived from C, there is a special +notation to signify the base. Octal numbers start with a leading `0', +and hexadecimal numbers start with a leading `0x' or `0X': + +`11' Decimal value 11. -'011' +`011' Octal 11, decimal value 9. -'0x11' +`0x11' Hexadecimal 11, decimal value 17. This example shows the difference: @@ -7889,39 +7278,39 @@ and hexadecimal numbers start with a leading '0x' or '0X': $ gawk 'BEGIN { printf "%d, %d, %d\n", 011, 11, 0x11 }' -| 9, 11, 17 - Being able to use octal and hexadecimal constants in your programs is -most useful when working with data that cannot be represented -conveniently as characters or as regular numbers, such as binary data of -various sorts. + Being able to use octal and hexadecimal constants in your programs +is most useful when working with data that cannot be represented +conveniently as characters or as regular numbers, such as binary data +of various sorts. - 'gawk' allows the use of octal and hexadecimal constants in your + `gawk' allows the use of octal and hexadecimal constants in your program text. However, such numbers in the input data are not treated differently; doing so by default would break old programs. (If you -really need to do this, use the '--non-decimal-data' command-line +really need to do this, use the `--non-decimal-data' command-line option; *note Nondecimal Data::.) If you have octal or hexadecimal -data, you can use the 'strtonum()' function (*note String Functions::) +data, you can use the `strtonum()' function (*note String Functions::) to convert the data into a number. Most of the time, you will want to use octal or hexadecimal constants when working with the built-in bit manipulation functions; see *note Bitwise Functions::, for more information. - Unlike some early C implementations, '8' and '9' are not valid in -octal constants; e.g., 'gawk' treats '018' as decimal 18: + Unlike some early C implementations, `8' and `9' are not valid in +octal constants; e.g., `gawk' treats `018' as decimal 18: $ gawk 'BEGIN { print "021 is", 021 ; print 018 }' -| 021 is 17 -| 18 - Octal and hexadecimal source code constants are a 'gawk' extension. -If 'gawk' is in compatibility mode (*note Options::), they are not + Octal and hexadecimal source code constants are a `gawk' extension. +If `gawk' is in compatibility mode (*note Options::), they are not available. A Constant's Base Does Not Affect Its Value Once a numeric constant has been converted internally into a number, -'gawk' no longer remembers what the original form of the constant was; -the internal value is always used. This has particular consequences for -conversion of numbers to strings: +`gawk' no longer remembers what the original form of the constant was; +the internal value is always used. This has particular consequences +for conversion of numbers to strings: $ gawk 'BEGIN { printf "0x11 is <%s>\n", 0x11 }' -| 0x11 is <17> @@ -7933,18 +7322,11 @@ File: gawk.info, Node: Regexp Constants, Prev: Nondecimal-numbers, Up: Consta .................................... A regexp constant is a regular expression description enclosed in -<<<<<<< HEAD -slashes, such as '/^beginning and end$/'. Most regexps used in 'awk' -programs are constant, but the '~' and '!~' matching operators can also -match computed or dynamic regexps (which are just ordinary strings or -variables that contain a regexp). -======= slashes, such as `/^beginning and end$/'. Most regexps used in `awk' programs are constant, but the `~' and `!~' matching operators can also match computed or dynamic regexps (which are typically just ordinary strings or variables that contain a regexp, but could be a more complex expression). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Using Constant Regexps, Next: Variables, Prev: Constants, Up: Values @@ -7952,11 +7334,11 @@ File: gawk.info, Node: Using Constant Regexps, Next: Variables, Prev: Constan 6.1.2 Using Regular Expression Constants ---------------------------------------- -When used on the righthand side of the '~' or '!~' operators, a regexp +When used on the righthand side of the `~' or `!~' operators, a regexp constant merely stands for the regexp that is to be matched. However, -regexp constants (such as '/foo/') may be used like simple expressions. +regexp constants (such as `/foo/') may be used like simple expressions. When a regexp constant appears by itself, it has the same meaning as if -it appeared in a pattern, i.e., '($0 ~ /foo/)' (d.c.) *Note Expression +it appeared in a pattern, i.e., `($0 ~ /foo/)' (d.c.) *Note Expression Patterns::. This means that the following two code segments: if ($0 ~ /barfly/ || $0 ~ /camelot/) @@ -7968,33 +7350,33 @@ and: print "found" are exactly equivalent. One rather bizarre consequence of this rule is -that the following Boolean expression is valid, but does not do what the -user probably intended: +that the following Boolean expression is valid, but does not do what +the user probably intended: # Note that /foo/ is on the left of the ~ if (/foo/ ~ $1) print "found foo" -This code is "obviously" testing '$1' for a match against the regexp -'/foo/'. But in fact, the expression '/foo/ ~ $1' really means '($0 ~ +This code is "obviously" testing `$1' for a match against the regexp +`/foo/'. But in fact, the expression `/foo/ ~ $1' really means `($0 ~ /foo/) ~ $1'. In other words, first match the input record against the -regexp '/foo/'. The result is either zero or one, depending upon the +regexp `/foo/'. The result is either zero or one, depending upon the success or failure of the match. That result is then matched against the first field in the record. Because it is unlikely that you would -ever really want to make this kind of test, 'gawk' issues a warning when -it sees this construct in a program. Another consequence of this rule -is that the assignment statement: +ever really want to make this kind of test, `gawk' issues a warning +when it sees this construct in a program. Another consequence of this +rule is that the assignment statement: matches = /foo/ -assigns either zero or one to the variable 'matches', depending upon the -contents of the current input record. +assigns either zero or one to the variable `matches', depending upon +the contents of the current input record. Constant regular expressions are also used as the first argument for -the 'gensub()', 'sub()', and 'gsub()' functions, as the second argument -of the 'match()' function, and as the third argument of the 'split()' -and 'patsplit()' functions (*note String Functions::). Modern -implementations of 'awk', including 'gawk', allow the third argument of -'split()' to be a regexp constant, but some older implementations do +the `gensub()', `sub()', and `gsub()' functions, as the second argument +of the `match()' function, and as the third argument of the `split()' +and `patsplit()' functions (*note String Functions::). Modern +implementations of `awk', including `gawk', allow the third argument of +`split()' to be a regexp constant, but some older implementations do not. (d.c.) This can lead to confusion when attempting to use regexp constants as arguments to user-defined functions (*note User-defined::). For example: @@ -8016,21 +7398,12 @@ For example: } In this example, the programmer wants to pass a regexp constant to -<<<<<<< HEAD -the user-defined function 'mysub', which in turn passes it on to either -'sub()' or 'gsub()'. However, what really happens is that the 'pat' -parameter is either one or zero, depending upon whether or not '$0' -matches '/hi/'. 'gawk' issues a warning when it sees a regexp constant -used as a parameter to a user-defined function, since passing a truth -value in this way is probably not what was intended. -======= the user-defined function `mysub()', which in turn passes it on to either `sub()' or `gsub()'. However, what really happens is that the `pat' parameter is either one or zero, depending upon whether or not `$0' matches `/hi/'. `gawk' issues a warning when it sees a regexp constant used as a parameter to a user-defined function, since passing a truth value in this way is probably not what was intended. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Variables, Next: Conversion, Prev: Using Constant Regexps, Up: Values @@ -8041,7 +7414,7 @@ File: gawk.info, Node: Variables, Next: Conversion, Prev: Using Constant Rege Variables are ways of storing values at one point in your program for use later in another part of your program. They can be manipulated entirely within the program text, and they can also be assigned values -on the 'awk' command line. +on the `awk' command line. * Menu: @@ -8057,33 +7430,33 @@ File: gawk.info, Node: Using Variables, Next: Assignment Options, Up: Variabl .................................... Variables let you give names to values and refer to them later. -Variables have already been used in many of the examples. The name of a -variable must be a sequence of letters, digits, or underscores, and it -may not begin with a digit. Case is significant in variable names; 'a' -and 'A' are distinct variables. +Variables have already been used in many of the examples. The name of +a variable must be a sequence of letters, digits, or underscores, and +it may not begin with a digit. Case is significant in variable names; +`a' and `A' are distinct variables. A variable name is a valid expression by itself; it represents the variable's current value. Variables are given new values with "assignment operators", "increment operators", and "decrement -operators". *Note Assignment Ops::. In addition, the 'sub()' and -'gsub()' functions can change a variable's value, and the 'match()', -'patsplit()' and 'split()' functions can change the contents of their -array parameters. *Note String Functions::. +operators". *Note Assignment Ops::. In addition, the `sub()' and +`gsub()' functions can change a variable's value, and the `match()', +`patsplit()' and `split()' functions can change the contents of their +array parameters. *Note String Functions::. - A few variables have special built-in meanings, such as 'FS' (the -field separator), and 'NF' (the number of fields in the current input + A few variables have special built-in meanings, such as `FS' (the +field separator), and `NF' (the number of fields in the current input record). *Note Built-in Variables::, for a list of the built-in variables. These built-in variables can be used and assigned just like all other variables, but their values are also used or changed -automatically by 'awk'. All built-in variables' names are entirely +automatically by `awk'. All built-in variables' names are entirely uppercase. - Variables in 'awk' can be assigned either numeric or string values. + Variables in `awk' can be assigned either numeric or string values. The kind of value a variable holds can change over the life of a program. By default, variables are initialized to the empty string, which is zero if converted to a number. There is no need to explicitly -"initialize" a variable in 'awk', which is what you would do in C and in -most other traditional languages. +"initialize" a variable in `awk', which is what you would do in C and +in most other traditional languages.  File: gawk.info, Node: Assignment Options, Prev: Using Variables, Up: Variables @@ -8091,34 +7464,34 @@ File: gawk.info, Node: Assignment Options, Prev: Using Variables, Up: Variabl 6.1.3.2 Assigning Variables on the Command Line ............................................... -Any 'awk' variable can be set by including a "variable assignment" among -the arguments on the command line when 'awk' is invoked (*note Other -Arguments::). Such an assignment has the following form: +Any `awk' variable can be set by including a "variable assignment" +among the arguments on the command line when `awk' is invoked (*note +Other Arguments::). Such an assignment has the following form: VARIABLE=TEXT -With it, a variable is set either at the beginning of the 'awk' run or -in between input files. When the assignment is preceded with the '-v' +With it, a variable is set either at the beginning of the `awk' run or +in between input files. When the assignment is preceded with the `-v' option, as in the following: -v VARIABLE=TEXT -the variable is set at the very beginning, even before the 'BEGIN' rules -execute. The '-v' option and its assignment must precede all the file -name arguments, as well as the program text. (*Note Options::, for more -information about the '-v' option.) Otherwise, the variable assignment -is performed at a time determined by its position among the input file -arguments--after the processing of the preceding input file argument. -For example: +the variable is set at the very beginning, even before the `BEGIN' +rules execute. The `-v' option and its assignment must precede all the +file name arguments, as well as the program text. (*Note Options::, +for more information about the `-v' option.) Otherwise, the variable +assignment is performed at a time determined by its position among the +input file arguments--after the processing of the preceding input file +argument. For example: awk '{ print $n }' n=4 inventory-shipped n=2 mail-list -prints the value of field number 'n' for all input records. Before the -first file is read, the command line sets the variable 'n' equal to +prints the value of field number `n' for all input records. Before the +first file is read, the command line sets the variable `n' equal to four. This causes the fourth field to be printed in lines from -'inventory-shipped'. After the first file has finished, but before the -second file is started, 'n' is set to two, so that the second field is -printed in lines from 'mail-list': +`inventory-shipped'. After the first file has finished, but before the +second file is started, `n' is set to two, so that the second field is +printed in lines from `mail-list': $ awk '{ print $n }' n=4 inventory-shipped n=2 mail-list -| 15 @@ -8129,7 +7502,7 @@ printed in lines from 'mail-list': ... Command-line arguments are made available for explicit examination by -the 'awk' program in the 'ARGV' array (*note ARGC and ARGV::). 'awk' +the `awk' program in the `ARGV' array (*note ARGC and ARGV::). `awk' processes the values of command-line assignments for escape sequences (*note Escape Sequences::). (d.c.) @@ -8141,23 +7514,23 @@ File: gawk.info, Node: Conversion, Prev: Variables, Up: Values Number to string and string to number conversion are generally straightforward. There can be subtleties to be aware of; this minor -node discusses this important facet of 'awk'. +node discusses this important facet of `awk'. * Menu: -* Strings And Numbers:: How 'awk' Converts Between Strings And +* Strings And Numbers:: How `awk' Converts Between Strings And Numbers. * Locale influences conversions:: How the locale may affect conversions.  File: gawk.info, Node: Strings And Numbers, Next: Locale influences conversions, Up: Conversion -6.1.4.1 How 'awk' Converts Between Strings And Numbers +6.1.4.1 How `awk' Converts Between Strings And Numbers ...................................................... Strings are converted to numbers and numbers are converted to strings, -if the context of the 'awk' program demands it. For example, if the -value of either 'foo' or 'bar' in the expression 'foo + bar' happens to +if the context of the `awk' program demands it. For example, if the +value of either `foo' or `bar' in the expression `foo + bar' happens to be a string, it is converted to a number before the addition is performed. If numeric values appear in string concatenation, they are converted to strings. Consider the following: @@ -8165,59 +7538,60 @@ converted to strings. Consider the following: two = 2; three = 3 print (two three) + 4 -This prints the (numeric) value 27. The numeric values of the variables -'two' and 'three' are converted to strings and concatenated together. -The resulting string is converted back to the number 23, to which 4 is -then added. +This prints the (numeric) value 27. The numeric values of the +variables `two' and `three' are converted to strings and concatenated +together. The resulting string is converted back to the number 23, to +which 4 is then added. If, for some reason, you need to force a number to be converted to a -string, concatenate that number with the empty string, '""'. To force a -string to be converted to a number, add zero to that string. A string -is converted to a number by interpreting any numeric prefix of the -string as numerals: '"2.5"' converts to 2.5, '"1e3"' converts to 1000, -and '"25fix"' has a numeric value of 25. Strings that can't be +string, concatenate that number with the empty string, `""'. To force +a string to be converted to a number, add zero to that string. A +string is converted to a number by interpreting any numeric prefix of +the string as numerals: `"2.5"' converts to 2.5, `"1e3"' converts to +1000, and `"25fix"' has a numeric value of 25. Strings that can't be interpreted as valid numbers convert to zero. The exact manner in which numbers are converted into strings is -controlled by the 'awk' built-in variable 'CONVFMT' (*note Built-in -Variables::). Numbers are converted using the 'sprintf()' function with -'CONVFMT' as the format specifier (*note String Functions::). +controlled by the `awk' built-in variable `CONVFMT' (*note Built-in +Variables::). Numbers are converted using the `sprintf()' function +with `CONVFMT' as the format specifier (*note String Functions::). - 'CONVFMT''s default value is '"%.6g"', which creates a value with at + `CONVFMT''s default value is `"%.6g"', which creates a value with at most six significant digits. For some applications, you might want to -change it to specify more precision. On most modern machines, 17 digits -is usually enough to capture a floating-point number's value exactly.(1) +change it to specify more precision. On most modern machines, 17 +digits is usually enough to capture a floating-point number's value +exactly.(1) - Strange results can occur if you set 'CONVFMT' to a string that -doesn't tell 'sprintf()' how to format floating-point numbers in a -useful way. For example, if you forget the '%' in the format, 'awk' + Strange results can occur if you set `CONVFMT' to a string that +doesn't tell `sprintf()' how to format floating-point numbers in a +useful way. For example, if you forget the `%' in the format, `awk' converts all numbers to the same constant string. As a special case, if a number is an integer, then the result of converting it to a string is _always_ an integer, no matter what the -value of 'CONVFMT' may be. Given the following code fragment: +value of `CONVFMT' may be. Given the following code fragment: CONVFMT = "%2.2f" a = 12 b = a "" -'b' has the value '"12"', not '"12.00"'. (d.c.) +`b' has the value `"12"', not `"12.00"'. (d.c.) - Pre-POSIX 'awk' Used 'OFMT' For String Conversion + Pre-POSIX `awk' Used `OFMT' For String Conversion - Prior to the POSIX standard, 'awk' used the value of 'OFMT' for -converting numbers to strings. 'OFMT' specifies the output format to -use when printing numbers with 'print'. 'CONVFMT' was introduced in + Prior to the POSIX standard, `awk' used the value of `OFMT' for +converting numbers to strings. `OFMT' specifies the output format to +use when printing numbers with `print'. `CONVFMT' was introduced in order to separate the semantics of conversion from the semantics of -printing. Both 'CONVFMT' and 'OFMT' have the same default value: -'"%.6g"'. In the vast majority of cases, old 'awk' programs do not +printing. Both `CONVFMT' and `OFMT' have the same default value: +`"%.6g"'. In the vast majority of cases, old `awk' programs do not change their behavior. *Note Print::, for more information on the -'print' statement. +`print' statement. ---------- Footnotes ---------- - (1) Pathological cases can require up to 752 digits (!), but we doubt -that you need to worry about this. + (1) Pathological cases can require up to 752 digits (!), but we +doubt that you need to worry about this.  File: gawk.info, Node: Locale influences conversions, Prev: Strings And Numbers, Up: Conversion @@ -8226,22 +7600,22 @@ File: gawk.info, Node: Locale influences conversions, Prev: Strings And Number ........................................ Where you are can matter when it comes to converting between numbers and -strings. The local character set and language--the "locale"--can affect -numeric formats. In particular, for 'awk' programs, it affects the -decimal point character and the thousands-separator character. The -'"C"' locale, and most English-language locales, use the period -character ('.') as the decimal point and don't have a thousands -separator. However, many (if not most) European and non-English locales -use the comma (',') as the decimal point character. European locales -often use either a space or a period as the thousands separator, if they -have one. - - The POSIX standard says that 'awk' always uses the period as the -decimal point when reading the 'awk' program source code, and for +strings. The local character set and language--the "locale"--can +affect numeric formats. In particular, for `awk' programs, it affects +the decimal point character and the thousands-separator character. The +`"C"' locale, and most English-language locales, use the period +character (`.') as the decimal point and don't have a thousands +separator. However, many (if not most) European and non-English +locales use the comma (`,') as the decimal point character. European +locales often use either a space or a period as the thousands +separator, if they have one. + + The POSIX standard says that `awk' always uses the period as the +decimal point when reading the `awk' program source code, and for command-line variable assignments (*note Other Arguments::). However, -when interpreting input data, for 'print' and 'printf' output, and for +when interpreting input data, for `print' and `printf' output, and for number to string conversion, the local decimal point character is used. -(d.c.) In all cases, numbers in source code and in input data cannot +(d.c.) In all cases, numbers in source code and in input data cannot have a thousands separator. Here are some examples indicating the difference in behavior, on a GNU/Linux system: @@ -8255,38 +7629,37 @@ difference in behavior, on a GNU/Linux system: $ echo 4,321 | LC_ALL=en_DK.utf-8 gawk '{ print $1 + 1 }' -| 5,321 -The 'en_DK.utf-8' locale is for English in Denmark, where the comma acts -as the decimal point separator. In the normal '"C"' locale, 'gawk' -treats '4,321' as '4', while in the Danish locale, it's treated as the +The `en_DK.utf-8' locale is for English in Denmark, where the comma +acts as the decimal point separator. In the normal `"C"' locale, `gawk' +treats `4,321' as `4', while in the Danish locale, it's treated as the full number, 4.321. - Some earlier versions of 'gawk' fully complied with this aspect of + Some earlier versions of `gawk' fully complied with this aspect of the standard. However, many users in non-English locales complained about this behavior, since their data used a period as the decimal point, so the default behavior was restored to use a period as the -decimal point character. You can use the '--use-lc-numeric' option -(*note Options::) to force 'gawk' to use the locale's decimal point -character. ('gawk' also uses the locale's decimal point character when -in POSIX mode, either via '--posix', or the 'POSIXLY_CORRECT' +decimal point character. You can use the `--use-lc-numeric' option +(*note Options::) to force `gawk' to use the locale's decimal point +character. (`gawk' also uses the locale's decimal point character when +in POSIX mode, either via `--posix', or the `POSIXLY_CORRECT' environment variable, as shown previously.) - *note Table 6.1: table-locale-affects. describes the cases in which -the locale's decimal point character is used and when a period is used. + *note table-locale-affects:: describes the cases in which the +locale's decimal point character is used and when a period is used. Some of these features have not been described yet. -Feature Default '--posix' or - '--use-lc-numeric' ------------------------------------------------------------- -'%'g' Use locale Use locale -'%g' Use period Use locale +Feature Default `--posix' or `--use-lc-numeric' +------------------------------------------------------------ +`%'g' Use locale Use locale +`%g' Use period Use locale Input Use period Use locale -'strtonum()'Use period Use locale +`strtonum()'Use period Use locale Table 6.1: Locale Decimal Point versus A Period Finally, modern day formal standards and IEEE standard floating point representation can have an unusual but important effect on the way -'gawk' converts some special string values to numbers. The details are +`gawk' converts some special string values to numbers. The details are presented in *note POSIX Floating Point Problems::.  @@ -8300,7 +7673,7 @@ provided by constants and variables. * Menu: -* Arithmetic Ops:: Arithmetic operations ('+', '-', +* Arithmetic Ops:: Arithmetic operations (`+', `-', etc.) * Concatenation:: Concatenating strings. * Assignment Ops:: Changing the value of a variable or a field. @@ -8312,11 +7685,11 @@ File: gawk.info, Node: Arithmetic Ops, Next: Concatenation, Up: All Operators 6.2.1 Arithmetic Operators -------------------------- -The 'awk' language uses the common arithmetic operators when evaluating -expressions. All of these arithmetic operators follow normal precedence -rules and work as you would expect them to. +The `awk' language uses the common arithmetic operators when evaluating +expressions. All of these arithmetic operators follow normal +precedence rules and work as you would expect them to. - The following example uses a file named 'grades', which contains a + The following example uses a file named `grades', which contains a list of student names as well as three test scores per student (it's a small class): @@ -8324,7 +7697,7 @@ small class): Sandy 84 72 93 Chris 72 92 89 -This program takes the file 'grades' and prints the average of the +This program takes the file `grades' and prints the average of the scores: $ awk '{ sum = $2 + $3 + $4 ; avg = sum / 3 @@ -8333,62 +7706,62 @@ scores: -| Sandy 83 -| Chris 84.3333 - The following list provides the arithmetic operators in 'awk', in + The following list provides the arithmetic operators in `awk', in order from the highest precedence to the lowest: -'X ^ Y' -'X ** Y' - Exponentiation; X raised to the Y power. '2 ^ 3' has the value - eight; the character sequence '**' is equivalent to '^'. (c.e.) +`X ^ Y' +`X ** Y' + Exponentiation; X raised to the Y power. `2 ^ 3' has the value + eight; the character sequence `**' is equivalent to `^'. (c.e.) -'- X' +`- X' Negation. -'+ X' +`+ X' Unary plus; the expression is converted to a number. -'X * Y' +`X * Y' Multiplication. -'X / Y' - Division; because all numbers in 'awk' are floating-point numbers, - the result is _not_ rounded to an integer--'3 / 4' has the value - 0.75. (It is a common mistake, especially for C programmers, to - forget that _all_ numbers in 'awk' are floating-point, and that - division of integer-looking constants produces a real number, not - an integer.) +`X / Y' + Division; because all numbers in `awk' are floating-point + numbers, the result is _not_ rounded to an integer--`3 / 4' has + the value 0.75. (It is a common mistake, especially for C + programmers, to forget that _all_ numbers in `awk' are + floating-point, and that division of integer-looking constants + produces a real number, not an integer.) -'X % Y' +`X % Y' Remainder; further discussion is provided in the text, just after this list. -'X + Y' +`X + Y' Addition. -'X - Y' +`X - Y' Subtraction. Unary plus and minus have the same precedence, the multiplication operators all have the same precedence, and addition and subtraction have the same precedence. - When computing the remainder of 'X % Y', the quotient is rounded -toward zero to an integer and multiplied by Y. This result is + When computing the remainder of `X % Y', the quotient is rounded +toward zero to an integer and multiplied by Y. This result is subtracted from X; this operation is sometimes known as "trunc-mod." The following relation always holds: b * int(a / b) + (a % b) == a One possibly undesirable effect of this definition of remainder is -that 'X % Y' is negative if X is negative. Thus: +that `X % Y' is negative if X is negative. Thus: -17 % 8 = -1 - In other 'awk' implementations, the signedness of the remainder may + In other `awk' implementations, the signedness of the remainder may be machine-dependent. - NOTE: The POSIX standard only specifies the use of '^' for - exponentiation. For maximum portability, do not use the '**' + NOTE: The POSIX standard only specifies the use of `^' for + exponentiation. For maximum portability, do not use the `**' operator.  @@ -8397,8 +7770,7 @@ File: gawk.info, Node: Concatenation, Next: Assignment Ops, Prev: Arithmetic 6.2.2 String Concatenation -------------------------- - It seemed like a good idea at the time. - -- _Brian Kernighan_ + It seemed like a good idea at the time. -- Brian Kernighan There is only one string operation: concatenation. It does not have a specific operator to represent it. Instead, concatenation is @@ -8410,8 +7782,8 @@ For example: -| Field number one: Anthony ... - Without the space in the string constant after the ':', the line runs -together. For example: + Without the space in the string constant after the `:', the line +runs together. For example: $ awk '{ print "Field number one:" $1 }' mail-list -| Field number one:Amelia @@ -8420,32 +7792,34 @@ together. For example: Because string concatenation does not have an explicit operator, it is often necessary to insure that it happens at the right time by using -parentheses to enclose the items to concatenate. For example, you might -expect that the following code fragment concatenates 'file' and 'name': +parentheses to enclose the items to concatenate. For example, you +might expect that the following code fragment concatenates `file' and +`name': file = "file" name = "name" print "something meaningful" > file name -This produces a syntax error with some versions of Unix 'awk'.(1) It is +This produces a syntax error with some versions of Unix `awk'.(1) It is necessary to use the following: print "something meaningful" > (file name) Parentheses should be used around concatenation in all but the most -common contexts, such as on the righthand side of '='. Be careful about -the kinds of expressions used in string concatenation. In particular, -the order of evaluation of expressions used for concatenation is -undefined in the 'awk' language. Consider this example: +common contexts, such as on the righthand side of `='. Be careful +about the kinds of expressions used in string concatenation. In +particular, the order of evaluation of expressions used for +concatenation is undefined in the `awk' language. Consider this +example: BEGIN { a = "don't" print (a " " (a = "panic")) } -It is not defined whether the second assignment to 'a' happens before or -after the value of 'a' is retrieved for producing the concatenated -value. The result could be either 'don't panic', or 'panic panic'. +It is not defined whether the second assignment to `a' happens before +or after the value of `a' is retrieved for producing the concatenated +value. The result could be either `don't panic', or `panic panic'. The precedence of concatenation, when mixed with other operators, is often counter-intuitive. Consider this example: @@ -8455,16 +7829,16 @@ often counter-intuitive. Consider this example: This "obviously" is concatenating -12, a space, and -24. But where did the space disappear to? The answer lies in the combination of -operator precedences and 'awk''s automatic conversion rules. To get the -desired result, write the program this way: +operator precedences and `awk''s automatic conversion rules. To get +the desired result, write the program this way: $ awk 'BEGIN { print -12 " " (-24) }' -| -12 -24 - This forces 'awk' to treat the '-' on the '-24' as unary. Otherwise, -it's parsed as follows: + This forces `awk' to treat the `-' on the `-24' as unary. +Otherwise, it's parsed as follows: - -12 ('" "' - 24) + -12 (`" "' - 24) => -12 (0 - 24) => -12 (-24) => -12-24 @@ -8475,13 +7849,8 @@ you'll get. ---------- Footnotes ---------- -<<<<<<< HEAD - (1) It happens that Brian Kernighan's 'awk', 'gawk' and 'mawk' all -"get it right," but you should not rely on this. -======= (1) It happens that BWK `awk', `gawk' and `mawk' all "get it right," but you should not rely on this. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Assignment Ops, Next: Increment Ops, Prev: Concatenation, Up: All Operators @@ -8489,23 +7858,24 @@ File: gawk.info, Node: Assignment Ops, Next: Increment Ops, Prev: Concatenati 6.2.3 Assignment Expressions ---------------------------- -An "assignment" is an expression that stores a (usually different) value -into a variable. For example, let's assign the value one to the -variable 'z': +An "assignment" is an expression that stores a (usually different) +value into a variable. For example, let's assign the value one to the +variable `z': z = 1 - After this expression is executed, the variable 'z' has the value -one. Whatever old value 'z' had before the assignment is forgotten. + After this expression is executed, the variable `z' has the value +one. Whatever old value `z' had before the assignment is forgotten. - Assignments can also store string values. For example, the following -stores the value '"this food is good"' in the variable 'message': + Assignments can also store string values. For example, the +following stores the value `"this food is good"' in the variable +`message': thing = "food" predicate = "good" message = "this " thing " is " predicate -This also illustrates string concatenation. The '=' sign is called an +This also illustrates string concatenation. The `=' sign is called an "assignment operator". It is the simplest assignment operator because the value of the righthand operand is stored unchanged. Most operators (addition, concatenation, and so on) have no effect except to compute a @@ -8520,11 +7890,11 @@ array element (*note Arrays::). These are all called "lvalues", which means they can appear on the lefthand side of an assignment operator. The righthand operand may be any expression; it produces the new value that the assignment stores in the specified variable, field, or array -element. (Such values are called "rvalues".) +element. (Such values are called "rvalues".) It is important to note that variables do _not_ have permanent types. A variable's type is simply the type of whatever value was last assigned -to it. In the following program fragment, the variable 'foo' has a +to it. In the following program fragment, the variable `foo' has a numeric value at first, and a string value later on: foo = 1 @@ -8532,43 +7902,43 @@ numeric value at first, and a string value later on: foo = "bar" print foo -When the second assignment gives 'foo' a string value, the fact that it +When the second assignment gives `foo' a string value, the fact that it previously had a numeric value is forgotten. String values that do not begin with a digit have a numeric value of -zero. After executing the following code, the value of 'foo' is five: +zero. After executing the following code, the value of `foo' is five: foo = "a string" foo = foo + 5 NOTE: Using a variable as a number and then later as a string can be confusing and is poor programming style. The previous two - examples illustrate how 'awk' works, _not_ how you should write + examples illustrate how `awk' works, _not_ how you should write your programs! An assignment is an expression, so it has a value--the same value -that is assigned. Thus, 'z = 1' is an expression with the value one. +that is assigned. Thus, `z = 1' is an expression with the value one. One consequence of this is that you can write multiple assignments together, such as: x = y = z = 5 -This example stores the value five in all three variables ('x', 'y', and -'z'). It does so because the value of 'z = 5', which is five, is stored -into 'y' and then the value of 'y = z = 5', which is five, is stored -into 'x'. +This example stores the value five in all three variables (`x', `y', +and `z'). It does so because the value of `z = 5', which is five, is +stored into `y' and then the value of `y = z = 5', which is five, is +stored into `x'. Assignments may be used anywhere an expression is called for. For -example, it is valid to write 'x != (y = 1)' to set 'y' to one, and then -test whether 'x' equals one. But this style tends to make programs hard -to read; such nesting of assignments should be avoided, except perhaps -in a one-shot program. +example, it is valid to write `x != (y = 1)' to set `y' to one, and +then test whether `x' equals one. But this style tends to make +programs hard to read; such nesting of assignments should be avoided, +except perhaps in a one-shot program. - Aside from '=', there are several other assignment operators that do + Aside from `=', there are several other assignment operators that do arithmetic with the old value of the variable. For example, the -operator '+=' computes a new value by adding the righthand value to the +operator `+=' computes a new value by adding the righthand value to the old value of the variable. Thus, the following assignment adds five to -the value of 'foo': +the value of `foo': foo += 5 @@ -8578,9 +7948,9 @@ This is equivalent to the following: Use whichever makes the meaning of your program clearer. - There are situations where using '+=' (or any assignment operator) is -_not_ the same as simply repeating the lefthand operand in the righthand -expression. For example: + There are situations where using `+=' (or any assignment operator) +is _not_ the same as simply repeating the lefthand operand in the +righthand expression. For example: # Thanks to Pat Rankin for this example BEGIN { @@ -8593,10 +7963,10 @@ expression. For example: print x, bar[x] } -The indices of 'bar' are practically guaranteed to be different, because -'rand()' returns different values each time it is called. (Arrays and -the 'rand()' function haven't been covered yet. *Note Arrays::, and see -*note Numeric Functions::, for more information). This example +The indices of `bar' are practically guaranteed to be different, because +`rand()' returns different values each time it is called. (Arrays and +the `rand()' function haven't been covered yet. *Note Arrays::, and +see *note Numeric Functions::, for more information). This example illustrates an important fact about assignment operators: the lefthand expression is only evaluated _once_. @@ -8606,53 +7976,46 @@ first, the lefthand or the righthand. Consider this example: i = 1 a[i += 2] = i + 1 -The value of 'a[3]' could be either two or four. +The value of `a[3]' could be either two or four. - *note Table 6.2: table-assign-ops. lists the arithmetic assignment -operators. In each case, the righthand operand is an expression whose -value is converted to a number. + *note table-assign-ops:: lists the arithmetic assignment operators. +In each case, the righthand operand is an expression whose value is +converted to a number. Operator Effect --------------------------------------------------------------------------- -LVALUE '+=' Add INCREMENT to the value of LVALUE. -INCREMENT -LVALUE '-=' Subtract DECREMENT from the value of LVALUE. -DECREMENT -LVALUE '*=' Multiply the value of LVALUE by COEFFICIENT. -COEFFICIENT -LVALUE '/=' DIVISOR Divide the value of LVALUE by DIVISOR. -LVALUE '%=' MODULUS Set LVALUE to its remainder by MODULUS. -LVALUE '^=' POWER -LVALUE '**=' POWER Raise LVALUE to the power POWER. (c.e.) +-------------------------------------------------------------------------- +LVALUE `+=' INCREMENT Add INCREMENT to the value of LVALUE. +LVALUE `-=' DECREMENT Subtract DECREMENT from the value of LVALUE. +LVALUE `*=' Multiply the value of LVALUE by COEFFICIENT. +COEFFICIENT +LVALUE `/=' DIVISOR Divide the value of LVALUE by DIVISOR. +LVALUE `%=' MODULUS Set LVALUE to its remainder by MODULUS. +LVALUE `^=' POWER +LVALUE `**=' POWER Raise LVALUE to the power POWER. (c.e.) Table 6.2: Arithmetic Assignment Operators - NOTE: Only the '^=' operator is specified by POSIX. For maximum - portability, do not use the '**=' operator. + NOTE: Only the `^=' operator is specified by POSIX. For maximum + portability, do not use the `**=' operator. - Syntactic Ambiguities Between '/=' and Regular Expressions + Syntactic Ambiguities Between `/=' and Regular Expressions - There is a syntactic ambiguity between the '/=' assignment operator -and regexp constants whose first character is an '='. (d.c.) This is -most notable in some commercial 'awk' versions. For example: + There is a syntactic ambiguity between the `/=' assignment operator +and regexp constants whose first character is an `='. (d.c.) This is +most notable in some commercial `awk' versions. For example: $ awk /==/ /dev/null - error-> awk: syntax error at source line 1 - error-> context is - error-> >>> /= <<< - error-> awk: bailing out at source line 1 + error--> awk: syntax error at source line 1 + error--> context is + error--> >>> /= <<< + error--> awk: bailing out at source line 1 A workaround is: awk '/[=]=/' /dev/null -<<<<<<< HEAD - 'gawk' does not have this problem; Brian Kernighan's 'awk' and 'mawk' -also do not (*note Other Versions::). -======= `gawk' does not have this problem; BWK `awk' and `mawk' also do not (*note Other Versions::). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Increment Ops, Prev: Assignment Ops, Up: All Operators @@ -8661,62 +8024,61 @@ File: gawk.info, Node: Increment Ops, Prev: Assignment Ops, Up: All Operators --------------------------------------- "Increment" and "decrement operators" increase or decrease the value of -a variable by one. An assignment operator can do the same thing, so the -increment operators add no power to the 'awk' language; however, they -are convenient abbreviations for very common operations. +a variable by one. An assignment operator can do the same thing, so +the increment operators add no power to the `awk' language; however, +they are convenient abbreviations for very common operations. - The operator used for adding one is written '++'. It can be used to + The operator used for adding one is written `++'. It can be used to increment a variable either before or after taking its value. To -"pre-increment" a variable 'v', write '++v'. This adds one to the value -of 'v'--that new value is also the value of the expression. (The -assignment expression 'v += 1' is completely equivalent.) Writing the -'++' after the variable specifies "post-increment". This increments the -variable value just the same; the difference is that the value of the -increment expression itself is the variable's _old_ value. Thus, if -'foo' has the value four, then the expression 'foo++' has the value -four, but it changes the value of 'foo' to five. In other words, the -operator returns the old value of the variable, but with the side effect -of incrementing it. - - The post-increment 'foo++' is nearly the same as writing '(foo += 1) -- 1'. It is not perfectly equivalent because all numbers in 'awk' are -floating-point--in floating-point, 'foo + 1 - 1' does not necessarily -equal 'foo'. But the difference is minute as long as you stick to +"pre-increment" a variable `v', write `++v'. This adds one to the +value of `v'--that new value is also the value of the expression. (The +assignment expression `v += 1' is completely equivalent.) Writing the +`++' after the variable specifies "post-increment". This increments +the variable value just the same; the difference is that the value of +the increment expression itself is the variable's _old_ value. Thus, +if `foo' has the value four, then the expression `foo++' has the value +four, but it changes the value of `foo' to five. In other words, the +operator returns the old value of the variable, but with the side +effect of incrementing it. + + The post-increment `foo++' is nearly the same as writing `(foo += 1) +- 1'. It is not perfectly equivalent because all numbers in `awk' are +floating-point--in floating-point, `foo + 1 - 1' does not necessarily +equal `foo'. But the difference is minute as long as you stick to numbers that are fairly small (less than 10e12). Fields and array elements are incremented just like variables. (Use -'$(i++)' when you want to do a field reference and a variable increment +`$(i++)' when you want to do a field reference and a variable increment at the same time. The parentheses are necessary because of the -precedence of the field reference operator '$'.) +precedence of the field reference operator `$'.) - The decrement operator '--' works just like '++', except that it -subtracts one instead of adding it. As with '++', it can be used before -the lvalue to pre-decrement or after it to post-decrement. Following is -a summary of increment and decrement expressions: + The decrement operator `--' works just like `++', except that it +subtracts one instead of adding it. As with `++', it can be used before +the lvalue to pre-decrement or after it to post-decrement. Following +is a summary of increment and decrement expressions: -'++LVALUE' +`++LVALUE' Increment LVALUE, returning the new value as the value of the expression. -'LVALUE++' +`LVALUE++' Increment LVALUE, returning the _old_ value of LVALUE as the value of the expression. -'--LVALUE' +`--LVALUE' Decrement LVALUE, returning the new value as the value of the - expression. (This expression is like '++LVALUE', but instead of + expression. (This expression is like `++LVALUE', but instead of adding, it subtracts.) -'LVALUE--' +`LVALUE--' Decrement LVALUE, returning the _old_ value of LVALUE as the value - of the expression. (This expression is like 'LVALUE++', but + of the expression. (This expression is like `LVALUE++', but instead of adding, it subtracts.) Operator Evaluation Order Doctor, doctor! It hurts when I do this! - So don't do that! - -- _Groucho Marx_ + So don't do that! -- Groucho Marx What happens for something like the following? @@ -8730,10 +8092,10 @@ Or something even stranger? print b In other words, when do the various side effects prescribed by the -postfix operators ('b++') take effect? When side effects happen is +postfix operators (`b++') take effect? When side effects happen is "implementation defined". In other words, it is up to the particular -version of 'awk'. The result for the first example may be 12 or 13, and -for the second, it may be 22 or 23. +version of `awk'. The result for the first example may be 12 or 13, +and for the second, it may be 22 or 23. In short, doing things like this is not recommended and definitely not anything that you can rely upon for portability. You should avoid @@ -8746,19 +8108,19 @@ File: gawk.info, Node: Truth Values and Conditions, Next: Function Calls, Pre =============================== In certain contexts, expression values also serve as "truth values;" -i.e., they determine what should happen next as the program runs. This -minor node describes how 'awk' defines "true" and "false" and how values -are compared. +i.e., they determine what should happen next as the program runs. This +minor node describes how `awk' defines "true" and "false" and how +values are compared. * Menu: -* Truth Values:: What is "true" and what is "false". +* Truth Values:: What is ``true'' and what is ``false''. * Typing and Comparison:: How variables acquire types and how this affects comparison of numbers and strings with - '<', etc. + `<', etc. * Boolean Ops:: Combining comparison expressions using boolean - operators '||' ("or"), '&&' - ("and") and '!' ("not"). + operators `||' (``or''), `&&' + (``and'') and `!' (``not''). * Conditional Exp:: Conditional expressions select between two subexpressions under control of a third subexpression. @@ -8766,17 +8128,17 @@ are compared.  File: gawk.info, Node: Truth Values, Next: Typing and Comparison, Up: Truth Values and Conditions -6.3.1 True and False in 'awk' +6.3.1 True and False in `awk' ----------------------------- Many programming languages have a special representation for the concepts of "true" and "false." Such languages usually use the special -constants 'true' and 'false', or perhaps their uppercase equivalents. -However, 'awk' is different. It borrows a very simple concept of true -and false from C. In 'awk', any nonzero numeric value _or_ any nonempty -string value is true. Any other value (zero or the null string, '""') -is false. The following program prints 'A strange truth value' three -times: +constants `true' and `false', or perhaps their uppercase equivalents. +However, `awk' is different. It borrows a very simple concept of true +and false from C. In `awk', any nonzero numeric value _or_ any +nonempty string value is true. Any other value (zero or the null +string, `""') is false. The following program prints `A strange truth +value' three times: BEGIN { if (3.1415927) @@ -8788,7 +8150,7 @@ times: } There is a surprising consequence of the "nonzero or non-null" rule: -the string constant '"0"' is actually true, because it is non-null. +the string constant `"0"' is actually true, because it is non-null. (d.c.)  @@ -8797,13 +8159,13 @@ File: gawk.info, Node: Typing and Comparison, Next: Boolean Ops, Prev: Truth 6.3.2 Variable Typing and Comparison Expressions ------------------------------------------------ - The Guide is definitive. Reality is frequently inaccurate. - -- _The Hitchhiker's Guide to the Galaxy_ + The Guide is definitive. Reality is frequently inaccurate. -- The + Hitchhiker's Guide to the Galaxy - Unlike other programming languages, 'awk' variables do not have a -fixed type. Instead, they can be either a number or a string, depending + Unlike other programming languages, `awk' variables do not have a +fixed type. Instead, they can be either a number or a string, depending upon the value that is assigned to them. We look now at how variables -are typed, and how 'awk' compares variables. +are typed, and how `awk' compares variables. * Menu: @@ -8817,24 +8179,11 @@ File: gawk.info, Node: Variable Typing, Next: Comparison Operators, Up: Typin 6.3.2.1 String Type Versus Numeric Type ....................................... -<<<<<<< HEAD -The 1992 POSIX standard introduced the concept of a "numeric string", -which is simply a string that looks like a number--for example, '" +2"'. -This concept is used for determining the type of a variable. The type -of the variable is important because the types of two variables -determine how they are compared. - - The various versions of the POSIX standard did not get the rules -quite right for several editions. Fortunately, as of at least the 2008 -standard (and possibly earlier), the standard has been fixed, and -variable typing follows these rules:(1) -======= The POSIX standard introduced the concept of a "numeric string", which is simply a string that looks like a number--for example, `" +2"'. This concept is used for determining the type of a variable. The type of the variable is important because the types of two variables determine how they are compared. Variable typing follows these rules: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * A numeric constant or the result of a numeric operation has the NUMERIC attribute. @@ -8842,17 +8191,17 @@ determine how they are compared. Variable typing follows these rules: * A string constant or the result of a string operation has the STRING attribute. - * Fields, 'getline' input, 'FILENAME', 'ARGV' elements, 'ENVIRON' - elements, and the elements of an array created by 'patsplit()', - 'split()' and 'match()' that are numeric strings have the STRNUM + * Fields, `getline' input, `FILENAME', `ARGV' elements, `ENVIRON' + elements, and the elements of an array created by `patsplit()', + `split()' and `match()' that are numeric strings have the STRNUM attribute. Otherwise, they have the STRING attribute. Uninitialized variables also have the STRNUM attribute. * Attributes propagate across assignments but are not changed by any use. - The last rule is particularly important. In the following program, -'a' has numeric type, even though it is later used in a string + The last rule is particularly important. In the following program, +`a' has numeric type, even though it is later used in a string operation: BEGIN { @@ -8862,35 +8211,26 @@ operation: } When two operands are compared, either string comparison or numeric -comparison may be used. This depends upon the attributes of the +comparison may be used. This depends upon the attributes of the operands, according to the following symmetric matrix: - +------------------------------- + +--------------------------------------------- | STRING NUMERIC STRNUM - -----+------------------------------- + -------+--------------------------------------------- | STRING | string string string | NUMERIC | string numeric numeric | STRNUM | string numeric numeric - -----+------------------------------- - -<<<<<<< HEAD - The basic idea is that user input that looks numeric--and _only_ user -input--should be treated as numeric, even though it is actually made of -characters and is therefore also a string. Thus, for example, the -string constant '" +3.14"', when it appears in program source code, is a -string--even though it looks numeric--and is _never_ treated as number -for comparison purposes. -======= + -------+--------------------------------------------- + The basic idea is that user input that looks numeric--and _only_ user input--should be treated as numeric, even though it is actually made of characters and is therefore also a string. Thus, for example, the string constant `" +3.14"', when it appears in program source code, is a string--even though it looks numeric--and is _never_ treated as a number for comparison purposes. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac In short, when one operand is a "pure" string, such as a string constant, then a string comparison is performed. Otherwise, a numeric @@ -8899,10 +8239,10 @@ comparison is performed. This point bears additional emphasis: All user input is made of characters, and so is first and foremost of STRING type; input strings that look numeric are additionally given the STRNUM attribute. Thus, -the six-character input string ' +3.14' receives the STRNUM attribute. -In contrast, the eight characters '" +3.14"' appearing in program text -comprise a string constant. The following examples print '1' when the -comparison between the two different constants is true, '0' otherwise: +the six-character input string ` +3.14' receives the STRNUM attribute. +In contrast, the eight characters `" +3.14"' appearing in program text +comprise a string constant. The following examples print `1' when the +comparison between the two different constants is true, `0' otherwise: $ echo ' +3.14' | gawk '{ print $0 == " +3.14" }' True -| 1 @@ -8921,14 +8261,6 @@ comparison between the two different constants is true, '0' otherwise: $ echo ' +3.14' | gawk '{ print $1 == 3.14 }' True -| 1 -<<<<<<< HEAD - ---------- Footnotes ---------- - - (1) 'gawk' has followed these rules for many years, and it is -gratifying that the POSIX standard is also now correct. - -======= ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Comparison Operators, Next: POSIX String Comparison, Prev: Variable Typing, Up: Typing and Comparison @@ -8937,38 +8269,37 @@ File: gawk.info, Node: Comparison Operators, Next: POSIX String Comparison, P "Comparison expressions" compare strings or numbers for relationships such as equality. They are written using "relational operators", which -are a superset of those in C. *note Table 6.3: table-relational-ops. -describes them. +are a superset of those in C. *note table-relational-ops:: describes +them. Expression Result --------------------------------------------------------------------------- -X '<' Y True if X is less than Y. -X '<=' Y True if X is less than or equal to Y. -X '>' Y True if X is greater than Y. -X '>=' Y True if X is greater than or equal to Y. -X '==' Y True if X is equal to Y. -X '!=' Y True if X is not equal to Y. -X '~' Y True if the string X matches the regexp denoted by - Y. -X '!~' Y True if the string X does not match the regexp +-------------------------------------------------------------------------- +X `<' Y True if X is less than Y. +X `<=' Y True if X is less than or equal to Y. +X `>' Y True if X is greater than Y. +X `>=' Y True if X is greater than or equal to Y. +X `==' Y True if X is equal to Y. +X `!=' Y True if X is not equal to Y. +X `~' Y True if the string X matches the regexp denoted by Y. +X `!~' Y True if the string X does not match the regexp denoted by Y. -SUBSCRIPT 'in' True if the array ARRAY has an element with the +SUBSCRIPT `in' True if the array ARRAY has an element with the ARRAY subscript SUBSCRIPT. Table 6.3: Relational Operators Comparison expressions have the value one if true and zero if false. When comparing operands of mixed types, numeric operands are converted -to strings using the value of 'CONVFMT' (*note Conversion::). +to strings using the value of `CONVFMT' (*note Conversion::). Strings are compared by comparing the first character of each, then -the second character of each, and so on. Thus, '"10"' is less than -'"9"'. If there are two strings where one is a prefix of the other, the -shorter string is less than the longer one. Thus, '"abc"' is less than -'"abcd"'. +the second character of each, and so on. Thus, `"10"' is less than +`"9"'. If there are two strings where one is a prefix of the other, +the shorter string is less than the longer one. Thus, `"abc"' is less +than `"abcd"'. - It is very easy to accidentally mistype the '==' operator and leave -off one of the '=' characters. The result is still valid 'awk' code, + It is very easy to accidentally mistype the `==' operator and leave +off one of the `=' characters. The result is still valid `awk' code, but the program does not do what is intended: if (a = b) # oops! should be a == b @@ -8976,31 +8307,31 @@ but the program does not do what is intended: else ... -Unless 'b' happens to be zero or the null string, the 'if' part of the +Unless `b' happens to be zero or the null string, the `if' part of the test always succeeds. Because the operators are so similar, this kind of error is very difficult to spot when scanning the source code. The following table of expressions illustrates the kind of comparison -'gawk' performs, as well as what the result of the comparison is: +`gawk' performs, as well as what the result of the comparison is: -'1.5 <= 2.0' +`1.5 <= 2.0' numeric comparison (true) -'"abc" >= "xyz"' +`"abc" >= "xyz"' string comparison (false) -'1.5 != " +2"' +`1.5 != " +2"' string comparison (true) -'"1e2" < "3"' +`"1e2" < "3"' string comparison (true) -'a = 2; b = "2"' -'a == b' +`a = 2; b = "2"' +`a == b' string comparison (true) -'a = 2; b = " +2"' -'a == b' +`a = 2; b = " +2"' +`a == b' string comparison (false) In this example: @@ -9008,38 +8339,38 @@ of error is very difficult to spot when scanning the source code. $ echo 1e2 3 | awk '{ print ($1 < $2) ? "true" : "false" }' -| false -the result is 'false' because both '$1' and '$2' are user input. They -are numeric strings--therefore both have the STRNUM attribute, dictating -a numeric comparison. The purpose of the comparison rules and the use -of numeric strings is to attempt to produce the behavior that is "least -surprising," while still "doing the right thing." +the result is `false' because both `$1' and `$2' are user input. They +are numeric strings--therefore both have the STRNUM attribute, +dictating a numeric comparison. The purpose of the comparison rules +and the use of numeric strings is to attempt to produce the behavior +that is "least surprising," while still "doing the right thing." String comparisons and regular expression comparisons are very different. For example: x == "foo" -has the value one, or is true if the variable 'x' is precisely 'foo'. +has the value one, or is true if the variable `x' is precisely `foo'. By contrast: x ~ /foo/ -has the value one if 'x' contains 'foo', such as '"Oh, what a fool am +has the value one if `x' contains `foo', such as `"Oh, what a fool am I!"'. - The righthand operand of the '~' and '!~' operators may be either a -regexp constant ('/'...'/') or an ordinary expression. In the latter + The righthand operand of the `~' and `!~' operators may be either a +regexp constant (`/'...`/') or an ordinary expression. In the latter case, the value of the expression as a string is used as a dynamic regexp (*note Regexp Usage::; also *note Computed Regexps::). - In modern implementations of 'awk', a constant regular expression in -slashes by itself is also an expression. The regexp '/REGEXP/' is an + In modern implementations of `awk', a constant regular expression in +slashes by itself is also an expression. The regexp `/REGEXP/' is an abbreviation for the following comparison expression: $0 ~ /REGEXP/ - One special place where '/foo/' is _not_ an abbreviation for '$0 ~ -/foo/' is when it is the righthand operand of '~' or '!~'. *Note Using + One special place where `/foo/' is _not_ an abbreviation for `$0 ~ +/foo/' is when it is the righthand operand of `~' or `!~'. *Note Using Constant Regexps::, where this is discussed in more detail.  @@ -9048,15 +8379,15 @@ File: gawk.info, Node: POSIX String Comparison, Prev: Comparison Operators, U 6.3.2.3 String Comparison With POSIX Rules .......................................... -The POSIX standard says that string comparison is performed based on the -locale's "collating order". This is the order in which characters sort, -as defined by the locale (for more discussion, *note Ranges and +The POSIX standard says that string comparison is performed based on +the locale's "collating order". This is the order in which characters +sort, as defined by the locale (for more discussion, *note Ranges and Locales::). This order is usually very different from the results obtained when doing straight character-by-character comparison.(1) Because this behavior differs considerably from existing practice, -'gawk' only implements it when in POSIX mode (*note Options::). Here is -an example to illustrate the difference, in an 'en_US.UTF-8' locale: +`gawk' only implements it when in POSIX mode (*note Options::). Here +is an example to illustrate the difference, in an `en_US.UTF-8' locale: $ gawk 'BEGIN { printf("ABC < abc = %s\n", > ("ABC" < "abc" ? "TRUE" : "FALSE")) }' @@ -9067,8 +8398,8 @@ an example to illustrate the difference, in an 'en_US.UTF-8' locale: ---------- Footnotes ---------- - (1) Technically, string comparison is supposed to behave the same way -as if the strings are compared with the C 'strcoll()' function. + (1) Technically, string comparison is supposed to behave the same +way as if the strings are compared with the C `strcoll()' function.  File: gawk.info, Node: Boolean Ops, Next: Conditional Exp, Prev: Typing and Comparison, Up: Truth Values and Conditions @@ -9077,39 +8408,39 @@ File: gawk.info, Node: Boolean Ops, Next: Conditional Exp, Prev: Typing and C ------------------------- A "Boolean expression" is a combination of comparison expressions or -matching expressions, using the Boolean operators "or" ('||'), "and" -('&&'), and "not" ('!'), along with parentheses to control nesting. The -truth value of the Boolean expression is computed by combining the truth -values of the component expressions. Boolean expressions are also -referred to as "logical expressions". The terms are equivalent. +matching expressions, using the Boolean operators "or" (`||'), "and" +(`&&'), and "not" (`!'), along with parentheses to control nesting. +The truth value of the Boolean expression is computed by combining the +truth values of the component expressions. Boolean expressions are +also referred to as "logical expressions". The terms are equivalent. Boolean expressions can be used wherever comparison and matching -expressions can be used. They can be used in 'if', 'while', 'do', and -'for' statements (*note Statements::). They have numeric values (one if -true, zero if false) that come into play if the result of the Boolean -expression is stored in a variable or used in arithmetic. +expressions can be used. They can be used in `if', `while', `do', and +`for' statements (*note Statements::). They have numeric values (one +if true, zero if false) that come into play if the result of the +Boolean expression is stored in a variable or used in arithmetic. - In addition, every Boolean expression is also a valid pattern, so you -can use one as a pattern to control the execution of rules. The Boolean -operators are: + In addition, every Boolean expression is also a valid pattern, so +you can use one as a pattern to control the execution of rules. The +Boolean operators are: -'BOOLEAN1 && BOOLEAN2' +`BOOLEAN1 && BOOLEAN2' True if both BOOLEAN1 and BOOLEAN2 are true. For example, the following statement prints the current input record if it contains - both 'edu' and 'li': + both `edu' and `li': if ($0 ~ /edu/ && $0 ~ /li/) print The subexpression BOOLEAN2 is evaluated only if BOOLEAN1 is true. This can make a difference when BOOLEAN2 contains expressions that - have side effects. In the case of '$0 ~ /foo/ && ($2 == bar++)', - the variable 'bar' is not incremented if there is no substring - 'foo' in the record. + have side effects. In the case of `$0 ~ /foo/ && ($2 == bar++)', + the variable `bar' is not incremented if there is no substring + `foo' in the record. -'BOOLEAN1 || BOOLEAN2' - True if at least one of BOOLEAN1 or BOOLEAN2 is true. For example, - the following statement prints all records in the input that - contain _either_ 'edu' or 'li' or both: +`BOOLEAN1 || BOOLEAN2' + True if at least one of BOOLEAN1 or BOOLEAN2 is true. For + example, the following statement prints all records in the input + that contain _either_ `edu' or `li' or both: if ($0 ~ /edu/ || $0 ~ /li/) print @@ -9117,36 +8448,30 @@ operators are: This can make a difference when BOOLEAN2 contains expressions that have side effects. -'! BOOLEAN' +`! BOOLEAN' True if BOOLEAN is false. For example, the following program - prints 'no home!' in the unusual event that the 'HOME' environment + prints `no home!' in the unusual event that the `HOME' environment variable is not defined: BEGIN { if (! ("HOME" in ENVIRON)) print "no home!" } - (The 'in' operator is described in *note Reference to Elements::.) + (The `in' operator is described in *note Reference to Elements::.) - The '&&' and '||' operators are called "short-circuit" operators + The `&&' and `||' operators are called "short-circuit" operators because of the way they work. Evaluation of the full expression is "short-circuited" if the result can be determined part way through its evaluation. -<<<<<<< HEAD - Statements that use '&&' or '||' can be continued simply by putting a -newline after them. But you cannot put a newline in front of either of -these operators without using backslash continuation (*note -======= Statements that end with `&&' or `||' can be continued simply by putting a newline after them. But you cannot put a newline in front of either of these operators without using backslash continuation (*note ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Statements/Lines::). - The actual value of an expression using the '!' operator is either + The actual value of an expression using the `!' operator is either one or zero, depending upon the truth value of the expression it is -applied to. The '!' operator is often useful for changing the sense of -a flag variable from false to true and back again. For example, the +applied to. The `!' operator is often useful for changing the sense of +a flag variable from false to true and back again. For example, the following program is one way to print lines in between special bracketing lines: @@ -9154,17 +8479,13 @@ bracketing lines: interested { print } $1 == "END" { interested = ! interested; next } -The variable 'interested', as with all 'awk' variables, starts out +The variable `interested', as with all `awk' variables, starts out initialized to zero, which is also false. When a line is seen whose -first field is 'START', the value of 'interested' is toggled to true, -using '!'. The next rule prints lines as long as 'interested' is true. -When a line is seen whose first field is 'END', 'interested' is toggled +first field is `START', the value of `interested' is toggled to true, +using `!'. The next rule prints lines as long as `interested' is true. +When a line is seen whose first field is `END', `interested' is toggled back to false.(1) -<<<<<<< HEAD - NOTE: The 'next' statement is discussed in *note Next Statement::. - 'next' tells 'awk' to skip the rest of the rules, get the next -======= Most commonly, the `!' operator is used in the conditions of `if' and `while' statements, where it often makes more sense to phrase the logic in the negative: @@ -9175,14 +8496,13 @@ logic in the negative: NOTE: The `next' statement is discussed in *note Next Statement::. `next' tells `awk' to skip the rest of the rules, get the next ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac record, and start processing the rules over again at the top. The - reason it's there is to avoid printing the bracketing 'START' and - 'END' lines. + reason it's there is to avoid printing the bracketing `START' and + `END' lines. ---------- Footnotes ---------- - (1) This program has a bug; it prints lines starting with 'END'. How + (1) This program has a bug; it prints lines starting with `END'. How would you fix it?  @@ -9193,36 +8513,36 @@ File: gawk.info, Node: Conditional Exp, Prev: Boolean Ops, Up: Truth Values a A "conditional expression" is a special kind of expression that has three operands. It allows you to use one expression's value to select -one of two other expressions. The conditional expression is the same as -in the C language, as shown here: +one of two other expressions. The conditional expression is the same +as in the C language, as shown here: SELECTOR ? IF-TRUE-EXP : IF-FALSE-EXP -There are three subexpressions. The first, SELECTOR, is always computed -first. If it is "true" (not zero or not null), then IF-TRUE-EXP is -computed next and its value becomes the value of the whole expression. -Otherwise, IF-FALSE-EXP is computed next and its value becomes the value -of the whole expression. For example, the following expression produces -the absolute value of 'x': +There are three subexpressions. The first, SELECTOR, is always +computed first. If it is "true" (not zero or not null), then +IF-TRUE-EXP is computed next and its value becomes the value of the +whole expression. Otherwise, IF-FALSE-EXP is computed next and its +value becomes the value of the whole expression. For example, the +following expression produces the absolute value of `x': x >= 0 ? x : -x Each time the conditional expression is computed, only one of IF-TRUE-EXP and IF-FALSE-EXP is used; the other is ignored. This is important when the expressions have side effects. For example, this -conditional expression examines element 'i' of either array 'a' or array -'b', and increments 'i': +conditional expression examines element `i' of either array `a' or +array `b', and increments `i': x == y ? a[i++] : b[i++] -This is guaranteed to increment 'i' exactly once, because each time only -one of the two increment expressions is executed and the other is not. -*Note Arrays::, for more information about arrays. +This is guaranteed to increment `i' exactly once, because each time +only one of the two increment expressions is executed and the other is +not. *Note Arrays::, for more information about arrays. - As a minor 'gawk' extension, a statement that uses '?:' can be + As a minor `gawk' extension, a statement that uses `?:' can be continued simply by putting a newline after either character. However, putting a newline in front of either character does not work without -using backslash continuation (*note Statements/Lines::). If '--posix' +using backslash continuation (*note Statements/Lines::). If `--posix' is specified (*note Options::), this extension is disabled.  @@ -9233,22 +8553,22 @@ File: gawk.info, Node: Function Calls, Next: Precedence, Prev: Truth Values a A "function" is a name for a particular calculation. This enables you to ask for it by name at any point in the program. For example, the -function 'sqrt()' computes the square root of a number. +function `sqrt()' computes the square root of a number. A fixed set of functions are "built-in", which means they are -available in every 'awk' program. The 'sqrt()' function is one of +available in every `awk' program. The `sqrt()' function is one of these. *Note Built-in::, for a list of built-in functions and their descriptions. In addition, you can define functions for use in your program. *Note User-defined::, for instructions on how to do this. -Finally, 'gawk' lets you write functions in C or C++ that may be called +Finally, `gawk' lets you write functions in C or C++ that may be called from your program: see *note Dynamic Extensions::. - The way to use a function is with a "function call" expression, which -consists of the function name followed immediately by a list of + The way to use a function is with a "function call" expression, +which consists of the function name followed immediately by a list of "arguments" in parentheses. The arguments are expressions that provide the raw materials for the function's calculations. When there is more than one argument, they are separated by commas. If there are no -arguments, just write '()' after the function name. The following +arguments, just write `()' after the function name. The following examples show function calls with and without arguments: sqrt(x^2 + y^2) one argument @@ -9256,16 +8576,16 @@ examples show function calls with and without arguments: rand() no arguments CAUTION: Do not put any space between the function name and the - open-parenthesis! A user-defined function name looks just like the - name of a variable--a space would make the expression look like - concatenation of a variable with an expression inside parentheses. - With built-in functions, space before the parenthesis is harmless, - but it is best not to get into the habit of using space to avoid - mistakes with user-defined functions. + open-parenthesis! A user-defined function name looks just like + the name of a variable--a space would make the expression look + like concatenation of a variable with an expression inside + parentheses. With built-in functions, space before the + parenthesis is harmless, but it is best not to get into the habit + of using space to avoid mistakes with user-defined functions. - Each function expects a particular number of arguments. For example, -the 'sqrt()' function must be called with a single argument, the number -of which to take the square root: + Each function expects a particular number of arguments. For +example, the `sqrt()' function must be called with a single argument, +the number of which to take the square root: sqrt(ARGUMENT) @@ -9273,19 +8593,19 @@ of which to take the square root: If those arguments are not supplied, the functions use a reasonable default value. *Note Built-in::, for full details. If arguments are omitted in calls to user-defined functions, then those arguments are -treated as local variables. Such local variables act like the empty +treated as local variables. Such local variables act like the empty string if referenced where a string value is required, and like zero if referenced where a numeric value is required (*note User-defined::). - As an advanced feature, 'gawk' provides indirect function calls, + As an advanced feature, `gawk' provides indirect function calls, which is a way to choose the function to call at runtime, instead of -when you write the source code to your program. We defer discussion of +when you write the source code to your program. We defer discussion of this feature until later; see *note Indirect Calls::. Like every other expression, the function call has a value, often called the "return value", which is computed by the function based on the arguments you give it. In this example, the return value of -'sqrt(ARGUMENT)' is the square root of ARGUMENT. The following program +`sqrt(ARGUMENT)' is the square root of ARGUMENT. The following program reads numbers, one number per line, and prints the square root of each one: @@ -9299,9 +8619,9 @@ one: Ctrl-d A function can also have side effects, such as assigning values to -certain variables or doing I/O. This program shows how the 'match()' -function (*note String Functions::) changes the variables 'RSTART' and -'RLENGTH': +certain variables or doing I/O. This program shows how the `match()' +function (*note String Functions::) changes the variables `RSTART' and +`RLENGTH': { if (match($1, $2)) @@ -9327,9 +8647,9 @@ File: gawk.info, Node: Precedence, Next: Locales, Prev: Function Calls, Up: ============================================ "Operator precedence" determines how operators are grouped when -different operators appear close by in one expression. For example, '*' -has higher precedence than '+'; thus, 'a + b * c' means to multiply 'b' -and 'c', and then add 'a' to the product (i.e., 'a + (b * c)'). +different operators appear close by in one expression. For example, +`*' has higher precedence than `+'; thus, `a + b * c' means to multiply +`b' and `c', and then add `a' to the product (i.e., `a + (b * c)'). The normal precedence of the operators can be overruled by using parentheses. Think of the precedence rules as saying where the @@ -9342,83 +8662,84 @@ help prevent any such mistakes. When operators of equal precedence are used together, the leftmost operator groups first, except for the assignment, conditional, and -exponentiation operators, which group in the opposite order. Thus, 'a - -b + c' groups as '(a - b) + c' and 'a = b = c' groups as 'a = (b = c)'. +exponentiation operators, which group in the opposite order. Thus, `a +- b + c' groups as `(a - b) + c' and `a = b = c' groups as `a = (b = +c)'. Normally the precedence of prefix unary operators does not matter, -because there is only one way to interpret them: innermost first. Thus, -'$++i' means '$(++i)' and '++$x' means '++($x)'. However, when another -operator follows the operand, then the precedence of the unary operators -can matter. '$x^2' means '($x)^2', but '-x^2' means '-(x^2)', because -'-' has lower precedence than '^', whereas '$' has higher precedence. -Also, operators cannot be combined in a way that violates the precedence -rules; for example, '$$0++--' is not a valid expression because the -first '$' has higher precedence than the '++'; to avoid the problem the -expression can be rewritten as '$($0++)--'. - - This table presents 'awk''s operators, in order of highest to lowest +because there is only one way to interpret them: innermost first. +Thus, `$++i' means `$(++i)' and `++$x' means `++($x)'. However, when +another operator follows the operand, then the precedence of the unary +operators can matter. `$x^2' means `($x)^2', but `-x^2' means +`-(x^2)', because `-' has lower precedence than `^', whereas `$' has +higher precedence. Also, operators cannot be combined in a way that +violates the precedence rules; for example, `$$0++--' is not a valid +expression because the first `$' has higher precedence than the `++'; +to avoid the problem the expression can be rewritten as `$($0++)--'. + + This table presents `awk''s operators, in order of highest to lowest precedence: -'('...')' +`('...`)' Grouping. -'$' +`$' Field reference. -'++ --' +`++ --' Increment, decrement. -'^ **' +`^ **' Exponentiation. These operators group right-to-left. -'+ - !' +`+ - !' Unary plus, minus, logical "not." -'* / %' +`* / %' Multiplication, division, remainder. -'+ -' +`+ -' Addition, subtraction. String Concatenation There is no special symbol for concatenation. The operands are simply written side by side (*note Concatenation::). -'< <= == != > >= >> | |&' +`< <= == != > >= >> | |&' Relational and redirection. The relational operators and the redirections have the same precedence level. Characters such as - '>' serve both as relationals and as redirections; the context + `>' serve both as relationals and as redirections; the context distinguishes between the two meanings. - Note that the I/O redirection operators in 'print' and 'printf' + Note that the I/O redirection operators in `print' and `printf' statements belong to the statement level, not to expressions. The redirection does not produce an expression that could be the operand of another operator. As a result, it does not make sense to use a redirection operator near another operator of lower precedence without parentheses. Such combinations (for example, - 'print foo > a ? b : c'), result in syntax errors. The correct way - to write this statement is 'print foo > (a ? b : c)'. + `print foo > a ? b : c'), result in syntax errors. The correct + way to write this statement is `print foo > (a ? b : c)'. -'~ !~' +`~ !~' Matching, nonmatching. -'in' +`in' Array membership. -'&&' +`&&' Logical "and". -'||' +`||' Logical "or". -'?:' +`?:' Conditional. This operator groups right-to-left. -'= += -= *= /= %= ^= **=' +`= += -= *= /= %= ^= **=' Assignment. These operators group right-to-left. - NOTE: The '|&', '**', and '**=' operators are not specified by - POSIX. For maximum portability, do not use them. + NOTE: The `|&', `**', and `**=' operators are not specified by + POSIX. For maximum portability, do not use them.  File: gawk.info, Node: Locales, Next: Expressions Summary, Prev: Precedence, Up: Expressions @@ -9426,34 +8747,34 @@ File: gawk.info, Node: Locales, Next: Expressions Summary, Prev: Precedence, 6.6 Where You Are Makes A Difference ==================================== -Modern systems support the notion of "locales": a way to tell the system -about the local character set and language. The ISO C standard defines -a default '"C"' locale, which is an environment that is typical of what -many C programmers are used to. +Modern systems support the notion of "locales": a way to tell the +system about the local character set and language. The ISO C standard +defines a default `"C"' locale, which is an environment that is typical +of what many C programmers are used to. Once upon a time, the locale setting used to affect regexp matching (*note Ranges and Locales::), but this is no longer true. - Locales can affect record splitting. For the normal case of 'RS = + Locales can affect record splitting. For the normal case of `RS = "\n"', the locale is largely irrelevant. For other single-character -record separators, setting 'LC_ALL=C' in the environment will give you -much better performance when reading records. Otherwise, 'gawk' has to +record separators, setting `LC_ALL=C' in the environment will give you +much better performance when reading records. Otherwise, `gawk' has to make several function calls, _per input character_, to find the record terminator. Locales can affect how dates and times are formatted (*note Time Functions::). For example, a common way to abbreviate the date September 4, 2015 in the United States is "9/4/15." In many countries -in Europe, however, it is abbreviated "4.9.15." Thus, the '%x' -specification in a '"US"' locale might produce '9/4/15', while in a -'"EUROPE"' locale, it might produce '4.9.15'. +in Europe, however, it is abbreviated "4.9.15." Thus, the `%x' +specification in a `"US"' locale might produce `9/4/15', while in a +`"EUROPE"' locale, it might produce `4.9.15'. According to POSIX, string comparison is also affected by locales (similar to regular expressions). The details are presented in *note POSIX String Comparison::. Finally, the locale affects the value of the decimal point character -used when 'gawk' parses input data. This is discussed in detail in +used when `gawk' parses input data. This is discussed in detail in *note Conversion::.  @@ -9466,34 +8787,34 @@ File: gawk.info, Node: Expressions Summary, Prev: Locales, Up: Expressions They are built from constants, variables, function calls and combinations of the various kinds of values with operators. - * 'awk' supplies three kinds of constants: numeric, string, and - regexp. 'gawk' lets you specify numeric constants in octal and + * `awk' supplies three kinds of constants: numeric, string, and + regexp. `gawk' lets you specify numeric constants in octal and hexadecimal (bases 8 and 16) in addition to decimal (base 10). In - certain contexts, a standalone regexp constant such as '/foo/' has - the same meaning as '$0 ~ /foo/'. + certain contexts, a standalone regexp constant such as `/foo/' has + the same meaning as `$0 ~ /foo/'. - * Variables hold values between uses in computations. A number of - built-in variables provide information to your 'awk' program, and a - number of others let you control how 'awk' behaves. + * Variables hold values between uses in computations. A number of + built-in variables provide information to your `awk' program, and + a number of others let you control how `awk' behaves. * Numbers are automatically converted to strings, and strings to - numbers, as needed by 'awk'. Numeric values are converted as if - they were formatted with 'sprintf()' using the format in 'CONVFMT'. + numbers, as needed by `awk'. Numeric values are converted as if + they were formatted with `sprintf()' using the format in `CONVFMT'. Locales can influence the conversions. - * 'awk' provides the usual arithmetic operators (addition, - subtraction, multiplication, division, modulus), and unary plus and - minus. It also provides comparison operators, boolean operators, - and regexp matching operators. String concatenation is + * `awk' provides the usual arithmetic operators (addition, + subtraction, multiplication, division, modulus), and unary plus + and minus. It also provides comparison operators, boolean + operators, and regexp matching operators. String concatenation is accomplished by placing two expressions next to each other; there - is no explicit operator. The three-operand '?:' operator provides + is no explicit operator. The three-operand `?:' operator provides an "if-else" test within expressions. * Assignment operators provide convenient shorthands for common arithmetic operations. - * In 'awk', a value is considered to be true if it is non-zero _or_ - non-null. Otherwise, the value is false. + * In `awk', a value is considered to be true if it is non-zero _or_ + non-null. Otherwise, the value is false. * A value's type is set upon each assignment and may change over its lifetime. The type determines how it behaves in comparisons @@ -9501,37 +8822,38 @@ File: gawk.info, Node: Expressions Summary, Prev: Locales, Up: Expressions * Function calls return a value which may be used as part of a larger expression. Expressions used to pass parameter values are fully - evaluated before the function is called. 'awk' provides built-in - and user-defined functions; this is described later on in this Info - file. + evaluated before the function is called. `awk' provides built-in + and user-defined functions; this is described later on in this + Info file. * Operator precedence specifies the order in which operations are - performed, unless explicitly overridden by parentheses. 'awk''s + performed, unless explicitly overridden by parentheses. `awk''s operator precedence is compatible with that of C. - * Locales can affect the format of data as output by an 'awk' + * Locales can affect the format of data as output by an `awk' program, and occasionally the format for data read as input. +  File: gawk.info, Node: Patterns and Actions, Next: Arrays, Prev: Expressions, Up: Top 7 Patterns, Actions, and Variables ********************************** -As you have already seen, each 'awk' statement consists of a pattern +As you have already seen, each `awk' statement consists of a pattern with an associated action. This major node describes how you build patterns and actions, what kinds of things you can do within actions, -and 'awk''s built-in variables. +and `awk''s built-in variables. The pattern-action rules and the statements available for use within -actions form the core of 'awk' programming. In a sense, everything +actions form the core of `awk' programming. In a sense, everything covered up to here has been the foundation that programs are built on top of. Now it's time to start building something useful. * Menu: * Pattern Overview:: What goes into a pattern. -* Using Shell Variables:: How to use shell variables with 'awk'. +* Using Shell Variables:: How to use shell variables with `awk'. * Action Overview:: What goes into an action. * Statements:: Describes the various control statements in detail. @@ -9553,34 +8875,34 @@ File: gawk.info, Node: Pattern Overview, Next: Using Shell Variables, Up: Pat * BEGINFILE/ENDFILE:: Two special patterns for advanced control. * Empty:: The empty pattern, which matches every record. -Patterns in 'awk' control the execution of rules--a rule is executed + Patterns in `awk' control the execution of rules--a rule is executed when its pattern matches the current input record. The following is a -summary of the types of 'awk' patterns: +summary of the types of `awk' patterns: -'/REGULAR EXPRESSION/' - A regular expression. It matches when the text of the input record +`/REGULAR EXPRESSION/' + A regular expression. It matches when the text of the input record fits the regular expression. (*Note Regexp::.) -'EXPRESSION' +`EXPRESSION' A single expression. It matches when its value is nonzero (if a number) or non-null (if a string). (*Note Expression Patterns::.) -'BEGPAT, ENDPAT' +`BEGPAT, ENDPAT' A pair of patterns separated by a comma, specifying a range of records. The range includes both the initial record that matches BEGPAT and the final record that matches ENDPAT. (*Note Ranges::.) -'BEGIN' -'END' +`BEGIN' +`END' Special patterns for you to supply startup or cleanup actions for - your 'awk' program. (*Note BEGIN/END::.) + your `awk' program. (*Note BEGIN/END::.) -'BEGINFILE' -'ENDFILE' +`BEGINFILE' +`ENDFILE' Special patterns for you to supply startup or cleanup actions to be done on a per-file basis. (*Note BEGINFILE/ENDFILE::.) -'EMPTY' +`EMPTY' The empty pattern matches every input record. (*Note Empty::.)  @@ -9591,7 +8913,7 @@ File: gawk.info, Node: Regexp Patterns, Next: Expression Patterns, Up: Patter Regular expressions are one of the first kinds of patterns presented in this book. This kind of pattern is simply a regexp constant in the -pattern part of a rule. Its meaning is '$0 ~ /PATTERN/'. The pattern +pattern part of a rule. Its meaning is `$0 ~ /PATTERN/'. The pattern matches when the input record matches the regexp. For example: /foo|bar|baz/ { buzzwords++ } @@ -9603,49 +8925,49 @@ File: gawk.info, Node: Expression Patterns, Next: Ranges, Prev: Regexp Patter 7.1.2 Expressions as Patterns ----------------------------- -Any 'awk' expression is valid as an 'awk' pattern. The pattern matches +Any `awk' expression is valid as an `awk' pattern. The pattern matches if the expression's value is nonzero (if a number) or non-null (if a string). The expression is reevaluated each time the rule is tested -against a new input record. If the expression uses fields such as '$1', -the value depends directly on the new input record's text; otherwise, it -depends on only what has happened so far in the execution of the 'awk' -program. +against a new input record. If the expression uses fields such as +`$1', the value depends directly on the new input record's text; +otherwise, it depends on only what has happened so far in the execution +of the `awk' program. Comparison expressions, using the comparison operators described in *note Typing and Comparison::, are a very common kind of pattern. Regexp matching and nonmatching are also very common expressions. The -left operand of the '~' and '!~' operators is a string. The right +left operand of the `~' and `!~' operators is a string. The right operand is either a constant regular expression enclosed in slashes -('/REGEXP/'), or any expression whose string value is used as a dynamic +(`/REGEXP/'), or any expression whose string value is used as a dynamic regular expression (*note Computed Regexps::). The following example prints the second field of each input record whose first field is -precisely 'li': +precisely `li': $ awk '$1 == "li" { print $2 }' mail-list (There is no output, because there is no person with the exact name -'li'.) Contrast this with the following regular expression match, which -accepts any record with a first field that contains 'li': +`li'.) Contrast this with the following regular expression match, which +accepts any record with a first field that contains `li': $ awk '$1 ~ /li/ { print $2 }' mail-list -| 555-5553 -| 555-6699 A regexp constant as a pattern is also a special case of an -expression pattern. The expression '/li/' has the value one if 'li' -appears in the current input record. Thus, as a pattern, '/li/' matches -any record containing 'li'. +expression pattern. The expression `/li/' has the value one if `li' +appears in the current input record. Thus, as a pattern, `/li/' matches +any record containing `li'. Boolean expressions are also commonly used as patterns. Whether the pattern matches an input record depends on whether its subexpressions match. For example, the following command prints all the records in -'mail-list' that contain both 'edu' and 'li': +`mail-list' that contain both `edu' and `li': $ awk '/edu/ && /li/' mail-list -| Samuel 555-3430 samuel.lanceolis@shu.edu A - The following command prints all records in 'mail-list' that contain -_either_ 'edu' or 'li' (or both, of course): + The following command prints all records in `mail-list' that contain +_either_ `edu' or `li' (or both, of course): $ awk '/edu/ || /li/' mail-list -| Amelia 555-5553 amelia.zodiacusque@gmail.com F @@ -9655,8 +8977,8 @@ _either_ 'edu' or 'li' (or both, of course): -| Samuel 555-3430 samuel.lanceolis@shu.edu A -| Jean-Paul 555-2127 jeanpaul.campanorum@nyu.edu R - The following command prints all records in 'mail-list' that do _not_ -contain the string 'li': + The following command prints all records in `mail-list' that do +_not_ contain the string `li': $ awk '! /li/' mail-list -| Anthony 555-3412 anthony.asserturo@hotmail.com A @@ -9667,12 +8989,12 @@ contain the string 'li': -| Martin 555-6480 martin.codicibus@hotmail.com A -| Jean-Paul 555-2127 jeanpaul.campanorum@nyu.edu R - The subexpressions of a Boolean operator in a pattern can be constant -regular expressions, comparisons, or any other 'awk' expressions. Range -patterns are not expressions, so they cannot appear inside Boolean -patterns. Likewise, the special patterns 'BEGIN', 'END', 'BEGINFILE' -and 'ENDFILE', which never match any input record, are not expressions -and cannot appear inside Boolean patterns. + The subexpressions of a Boolean operator in a pattern can be +constant regular expressions, comparisons, or any other `awk' +expressions. Range patterns are not expressions, so they cannot appear +inside Boolean patterns. Likewise, the special patterns `BEGIN', `END', +`BEGINFILE' and `ENDFILE', which never match any input record, are not +expressions and cannot appear inside Boolean patterns. The precedence of the different operators which can appear in patterns is described in *note Precedence::. @@ -9684,78 +9006,80 @@ File: gawk.info, Node: Ranges, Next: BEGIN/END, Prev: Expression Patterns, U -------------------------------------------- A "range pattern" is made of two patterns separated by a comma, in the -form 'BEGPAT, ENDPAT'. It is used to match ranges of consecutive input +form `BEGPAT, ENDPAT'. It is used to match ranges of consecutive input records. The first pattern, BEGPAT, controls where the range begins, while ENDPAT controls where the pattern ends. For example, the following: awk '$1 == "on", $1 == "off"' myfile -prints every record in 'myfile' between 'on'/'off' pairs, inclusive. +prints every record in `myfile' between `on'/`off' pairs, inclusive. A range pattern starts out by matching BEGPAT against every input record. When a record matches BEGPAT, the range pattern is "turned on" -and the range pattern matches this record as well. As long as the range -pattern stays turned on, it automatically matches every input record -read. The range pattern also matches ENDPAT against every input record; -when this succeeds, the range pattern is "turned off" again for the -following record. Then the range pattern goes back to checking BEGPAT -against each record. +and the range pattern matches this record as well. As long as the +range pattern stays turned on, it automatically matches every input +record read. The range pattern also matches ENDPAT against every input +record; when this succeeds, the range pattern is "turned off" again for +the following record. Then the range pattern goes back to checking +BEGPAT against each record. The record that turns on the range pattern and the one that turns it -off both match the range pattern. If you don't want to operate on these -records, you can write 'if' statements in the rule's action to +off both match the range pattern. If you don't want to operate on +these records, you can write `if' statements in the rule's action to distinguish them from the records you are interested in. It is possible for a pattern to be turned on and off by the same -record. If the record satisfies both conditions, then the action is +record. If the record satisfies both conditions, then the action is executed for just that record. For example, suppose there is text -between two identical markers (e.g., the '%' symbol), each on its own +between two identical markers (e.g., the `%' symbol), each on its own line, that should be ignored. A first attempt would be to combine a -range pattern that describes the delimited text with the 'next' +range pattern that describes the delimited text with the `next' statement (not discussed yet, *note Next Statement::). This causes -'awk' to skip any further processing of the current record and start -over again with the next input record. Such a program looks like this: +`awk' to skip any further processing of the current record and start +over again with the next input record. Such a program looks like this: /^%$/,/^%$/ { next } { print } This program fails because the range pattern is both turned on and -turned off by the first line, which just has a '%' on it. To accomplish -this task, write the program in the following manner, using a flag: +turned off by the first line, which just has a `%' on it. To +accomplish this task, write the program in the following manner, using +a flag: /^%$/ { skip = ! skip; next } skip == 1 { next } # skip lines with `skip' set - In a range pattern, the comma (',') has the lowest precedence of all -the operators (i.e., it is evaluated last). Thus, the following program -attempts to combine a range pattern with another, simpler test: + In a range pattern, the comma (`,') has the lowest precedence of all +the operators (i.e., it is evaluated last). Thus, the following +program attempts to combine a range pattern with another, simpler test: echo Yes | awk '/1/,/2/ || /Yes/' - The intent of this program is '(/1/,/2/) || /Yes/'. However, 'awk' -interprets this as '/1/, (/2/ || /Yes/)'. This cannot be changed or + The intent of this program is `(/1/,/2/) || /Yes/'. However, `awk' +interprets this as `/1/, (/2/ || /Yes/)'. This cannot be changed or worked around; range patterns do not combine with other patterns: $ echo Yes | gawk '(/1/,/2/) || /Yes/' - error-> gawk: cmd. line:1: (/1/,/2/) || /Yes/ - error-> gawk: cmd. line:1: ^ syntax error + error--> gawk: cmd. line:1: (/1/,/2/) || /Yes/ + error--> gawk: cmd. line:1: ^ syntax error - As a minor point of interest, although it is poor style, POSIX allows -you to put a newline after the comma in a range pattern. (d.c.) + As a minor point of interest, although it is poor style, POSIX +allows you to put a newline after the comma in a range pattern. +(d.c.)  File: gawk.info, Node: BEGIN/END, Next: BEGINFILE/ENDFILE, Prev: Ranges, Up: Pattern Overview -7.1.4 The 'BEGIN' and 'END' Special Patterns +7.1.4 The `BEGIN' and `END' Special Patterns -------------------------------------------- All the patterns described so far are for matching input records. The -'BEGIN' and 'END' special patterns are different. They supply startup -and cleanup actions for 'awk' programs. 'BEGIN' and 'END' rules must +`BEGIN' and `END' special patterns are different. They supply startup +and cleanup actions for `awk' programs. `BEGIN' and `END' rules must have actions; there is no default action for these rules because there -is no current record when they run. 'BEGIN' and 'END' rules are often -referred to as "'BEGIN' and 'END' blocks" by long-time 'awk' +is no current record when they run. `BEGIN' and `END' rules are often +referred to as "`BEGIN' and `END' blocks" by long-time `awk' programmers. * Menu: @@ -9769,8 +9093,8 @@ File: gawk.info, Node: Using BEGIN/END, Next: I/O And BEGIN/END, Up: BEGIN/EN 7.1.4.1 Startup and Cleanup Actions ................................... -A 'BEGIN' rule is executed once only, before the first input record is -read. Likewise, an 'END' rule is executed once only, after all the +A `BEGIN' rule is executed once only, before the first input record is +read. Likewise, an `END' rule is executed once only, after all the input is read. For example: $ awk ' @@ -9781,116 +9105,109 @@ input is read. For example: -| "li" appears in 4 records. This program finds the number of records in the input file -'mail-list' that contain the string 'li'. The 'BEGIN' rule prints a -title for the report. There is no need to use the 'BEGIN' rule to -initialize the counter 'n' to zero, since 'awk' does this automatically -(*note Variables::). The second rule increments the variable 'n' every -time a record containing the pattern 'li' is read. The 'END' rule -prints the value of 'n' at the end of the run. - - The special patterns 'BEGIN' and 'END' cannot be used in ranges or +`mail-list' that contain the string `li'. The `BEGIN' rule prints a +title for the report. There is no need to use the `BEGIN' rule to +initialize the counter `n' to zero, since `awk' does this automatically +(*note Variables::). The second rule increments the variable `n' every +time a record containing the pattern `li' is read. The `END' rule +prints the value of `n' at the end of the run. + + The special patterns `BEGIN' and `END' cannot be used in ranges or with Boolean operators (indeed, they cannot be used with any operators). -An 'awk' program may have multiple 'BEGIN' and/or 'END' rules. They are -executed in the order in which they appear: all the 'BEGIN' rules at -startup and all the 'END' rules at termination. 'BEGIN' and 'END' rules -may be intermixed with other rules. This feature was added in the 1987 -version of 'awk' and is included in the POSIX standard. The original -(1978) version of 'awk' required the 'BEGIN' rule to be placed at the -beginning of the program, the 'END' rule to be placed at the end, and -only allowed one of each. This is no longer required, but it is a good -idea to follow this template in terms of program organization and -readability. - - Multiple 'BEGIN' and 'END' rules are useful for writing library -functions, because each library file can have its own 'BEGIN' and/or -'END' rule to do its own initialization and/or cleanup. The order in -which library functions are named on the command line controls the order -in which their 'BEGIN' and 'END' rules are executed. Therefore, you -have to be careful when writing such rules in library files so that the -order in which they are executed doesn't matter. *Note Options::, for -more information on using library functions. *Note Library Functions::, -for a number of useful library functions. - - If an 'awk' program has only 'BEGIN' rules and no other rules, then -the program exits after the 'BEGIN' rule is run.(1) However, if an -'END' rule exists, then the input is read, even if there are no other -rules in the program. This is necessary in case the 'END' rule checks -the 'FNR' and 'NR' variables. +An `awk' program may have multiple `BEGIN' and/or `END' rules. They +are executed in the order in which they appear: all the `BEGIN' rules +at startup and all the `END' rules at termination. `BEGIN' and `END' +rules may be intermixed with other rules. This feature was added in +the 1987 version of `awk' and is included in the POSIX standard. The +original (1978) version of `awk' required the `BEGIN' rule to be placed +at the beginning of the program, the `END' rule to be placed at the +end, and only allowed one of each. This is no longer required, but it +is a good idea to follow this template in terms of program organization +and readability. + + Multiple `BEGIN' and `END' rules are useful for writing library +functions, because each library file can have its own `BEGIN' and/or +`END' rule to do its own initialization and/or cleanup. The order in +which library functions are named on the command line controls the +order in which their `BEGIN' and `END' rules are executed. Therefore, +you have to be careful when writing such rules in library files so that +the order in which they are executed doesn't matter. *Note Options::, +for more information on using library functions. *Note Library +Functions::, for a number of useful library functions. + + If an `awk' program has only `BEGIN' rules and no other rules, then +the program exits after the `BEGIN' rule is run.(1) However, if an +`END' rule exists, then the input is read, even if there are no other +rules in the program. This is necessary in case the `END' rule checks +the `FNR' and `NR' variables. ---------- Footnotes ---------- - (1) The original version of 'awk' kept reading and ignoring input + (1) The original version of `awk' kept reading and ignoring input until the end of the file was seen.  File: gawk.info, Node: I/O And BEGIN/END, Prev: Using BEGIN/END, Up: BEGIN/END -7.1.4.2 Input/Output from 'BEGIN' and 'END' Rules +7.1.4.2 Input/Output from `BEGIN' and `END' Rules ................................................. There are several (sometimes subtle) points to be aware of when doing -I/O from a 'BEGIN' or 'END' rule. The first has to do with the value of -'$0' in a 'BEGIN' rule. Because 'BEGIN' rules are executed before any -input is read, there simply is no input record, and therefore no fields, -when executing 'BEGIN' rules. References to '$0' and the fields yield a -null string or zero, depending upon the context. One way to give '$0' a -real value is to execute a 'getline' command without a variable (*note -Getline::). Another way is simply to assign a value to '$0'. +I/O from a `BEGIN' or `END' rule. The first has to do with the value +of `$0' in a `BEGIN' rule. Because `BEGIN' rules are executed before +any input is read, there simply is no input record, and therefore no +fields, when executing `BEGIN' rules. References to `$0' and the fields +yield a null string or zero, depending upon the context. One way to +give `$0' a real value is to execute a `getline' command without a +variable (*note Getline::). Another way is simply to assign a value to +`$0'. The second point is similar to the first but from the other -direction. Traditionally, due largely to implementation issues, '$0' -and 'NF' were _undefined_ inside an 'END' rule. The POSIX standard -specifies that 'NF' is available in an 'END' rule. It contains the +direction. Traditionally, due largely to implementation issues, `$0' +and `NF' were _undefined_ inside an `END' rule. The POSIX standard +specifies that `NF' is available in an `END' rule. It contains the number of fields from the last input record. Most probably due to an -<<<<<<< HEAD -oversight, the standard does not say that '$0' is also preserved, -although logically one would think that it should be. In fact, 'gawk' -does preserve the value of '$0' for use in 'END' rules. Be aware, -however, that Brian Kernighan's 'awk', and possibly other -implementations, do not. -======= oversight, the standard does not say that `$0' is also preserved, although logically one would think that it should be. In fact, `gawk' does preserve the value of `$0' for use in `END' rules. Be aware, however, that BWK `awk', and possibly other implementations, do not. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - - The third point follows from the first two. The meaning of 'print' -inside a 'BEGIN' or 'END' rule is the same as always: 'print $0'. If -'$0' is the null string, then this prints an empty record. Many long -time 'awk' programmers use an unadorned 'print' in 'BEGIN' and 'END' -rules, to mean 'print ""', relying on '$0' being null. Although one -might generally get away with this in 'BEGIN' rules, it is a very bad -idea in 'END' rules, at least in 'gawk'. It is also poor style, since + + The third point follows from the first two. The meaning of `print' +inside a `BEGIN' or `END' rule is the same as always: `print $0'. If +`$0' is the null string, then this prints an empty record. Many long +time `awk' programmers use an unadorned `print' in `BEGIN' and `END' +rules, to mean `print ""', relying on `$0' being null. Although one +might generally get away with this in `BEGIN' rules, it is a very bad +idea in `END' rules, at least in `gawk'. It is also poor style, since if an empty line is needed in the output, the program should print one explicitly. - Finally, the 'next' and 'nextfile' statements are not allowed in a -'BEGIN' rule, because the implicit + Finally, the `next' and `nextfile' statements are not allowed in a +`BEGIN' rule, because the implicit read-a-record-and-match-against-the-rules loop has not started yet. -Similarly, those statements are not valid in an 'END' rule, since all +Similarly, those statements are not valid in an `END' rule, since all the input has been read. (*Note Next Statement::, and see *note Nextfile Statement::.)  File: gawk.info, Node: BEGINFILE/ENDFILE, Next: Empty, Prev: BEGIN/END, Up: Pattern Overview -7.1.5 The 'BEGINFILE' and 'ENDFILE' Special Patterns +7.1.5 The `BEGINFILE' and `ENDFILE' Special Patterns ---------------------------------------------------- -This minor node describes a 'gawk'-specific feature. +This minor node describes a `gawk'-specific feature. - Two special kinds of rule, 'BEGINFILE' and 'ENDFILE', give you -"hooks" into 'gawk''s command-line file processing loop. As with the -'BEGIN' and 'END' rules (*note BEGIN/END::), all 'BEGINFILE' rules in a -program are merged, in the order they are read by 'gawk', and all -'ENDFILE' rules are merged as well. + Two special kinds of rule, `BEGINFILE' and `ENDFILE', give you +"hooks" into `gawk''s command-line file processing loop. As with the +`BEGIN' and `END' rules (*note BEGIN/END::), all `BEGINFILE' rules in a +program are merged, in the order they are read by `gawk', and all +`ENDFILE' rules are merged as well. - The body of the 'BEGINFILE' rules is executed just before 'gawk' -reads the first record from a file. 'FILENAME' is set to the name of -the current file, and 'FNR' is set to zero. + The body of the `BEGINFILE' rules is executed just before `gawk' +reads the first record from a file. `FILENAME' is set to the name of +the current file, and `FNR' is set to zero. - The 'BEGINFILE' rule provides you the opportunity to accomplish two + The `BEGINFILE' rule provides you the opportunity to accomplish two tasks that would otherwise be difficult or impossible to perform: * You can test if the file is readable. Normally, it is a fatal @@ -9898,40 +9215,40 @@ tasks that would otherwise be difficult or impossible to perform: reading. However, you can bypass the fatal error and move on to the next file on the command line. - You do this by checking if the 'ERRNO' variable is not the empty - string; if so, then 'gawk' was not able to open the file. In this - case, your program can execute the 'nextfile' statement (*note - Nextfile Statement::). This causes 'gawk' to skip the file - entirely. Otherwise, 'gawk' exits with the usual fatal error. + You do this by checking if the `ERRNO' variable is not the empty + string; if so, then `gawk' was not able to open the file. In this + case, your program can execute the `nextfile' statement (*note + Nextfile Statement::). This causes `gawk' to skip the file + entirely. Otherwise, `gawk' exits with the usual fatal error. * If you have written extensions that modify the record handling (by inserting an "input parser," *note Input Parsers::), you can invoke - them at this point, before 'gawk' has started processing the file. + them at this point, before `gawk' has started processing the file. (This is a _very_ advanced feature, currently used only by the - 'gawkextlib' project (http://gawkextlib.sourceforge.net).) + `gawkextlib' project (http://gawkextlib.sourceforge.net).) - The 'ENDFILE' rule is called when 'gawk' has finished processing the + The `ENDFILE' rule is called when `gawk' has finished processing the last record in an input file. For the last input file, it will be -called before any 'END' rules. The 'ENDFILE' rule is executed even for +called before any `END' rules. The `ENDFILE' rule is executed even for empty input files. Normally, when an error occurs when reading input in the normal input -processing loop, the error is fatal. However, if an 'ENDFILE' rule is -present, the error becomes non-fatal, and instead 'ERRNO' is set. This +processing loop, the error is fatal. However, if an `ENDFILE' rule is +present, the error becomes non-fatal, and instead `ERRNO' is set. This makes it possible to catch and process I/O errors at the level of the -'awk' program. +`awk' program. - The 'next' statement (*note Next Statement::) is not allowed inside -either a 'BEGINFILE' or and 'ENDFILE' rule. The 'nextfile' statement -(*note Nextfile Statement::) is allowed only inside a 'BEGINFILE' rule, -but not inside an 'ENDFILE' rule. + The `next' statement (*note Next Statement::) is not allowed inside +either a `BEGINFILE' or and `ENDFILE' rule. The `nextfile' statement +(*note Nextfile Statement::) is allowed only inside a `BEGINFILE' rule, +but not inside an `ENDFILE' rule. - The 'getline' statement (*note Getline::) is restricted inside both -'BEGINFILE' and 'ENDFILE': only redirected forms of 'getline' are + The `getline' statement (*note Getline::) is restricted inside both +`BEGINFILE' and `ENDFILE': only redirected forms of `getline' are allowed. - 'BEGINFILE' and 'ENDFILE' are 'gawk' extensions. In most other 'awk' -implementations, or if 'gawk' is in compatibility mode (*note + `BEGINFILE' and `ENDFILE' are `gawk' extensions. In most other +`awk' implementations, or if `gawk' is in compatibility mode (*note Options::), they are not special.  @@ -9953,10 +9270,10 @@ File: gawk.info, Node: Using Shell Variables, Next: Action Overview, Prev: Pa 7.2 Using Shell Variables in Programs ===================================== -'awk' programs are often used as components in larger programs written +`awk' programs are often used as components in larger programs written in shell. For example, it is very common to use a shell variable to -hold a pattern that the 'awk' program searches for. There are two ways -to get the value of the shell variable into the body of the 'awk' +hold a pattern that the `awk' program searches for. There are two ways +to get the value of the shell variable into the body of the `awk' program. The most common method is to use shell quoting to substitute the @@ -9968,35 +9285,35 @@ consider the following program: awk "/$pattern/ "'{ nmatches++ } END { print nmatches, "found" }' /path/to/data -The 'awk' program consists of two pieces of quoted text that are +The `awk' program consists of two pieces of quoted text that are concatenated together to form the program. The first part is -double-quoted, which allows substitution of the 'pattern' shell variable -inside the quotes. The second part is single-quoted. +double-quoted, which allows substitution of the `pattern' shell +variable inside the quotes. The second part is single-quoted. Variable substitution via quoting works, but can be potentially messy. It requires a good understanding of the shell's quoting rules (*note Quoting::), and it's often difficult to correctly match up the quotes when reading the program. - A better method is to use 'awk''s variable assignment feature (*note -Assignment Options::) to assign the shell variable's value to an 'awk' -variable. Then use dynamic regexps to match the pattern (*note Computed -Regexps::). The following shows how to redo the previous example using -this technique: + A better method is to use `awk''s variable assignment feature (*note +Assignment Options::) to assign the shell variable's value to an `awk' +variable. Then use dynamic regexps to match the pattern (*note +Computed Regexps::). The following shows how to redo the previous +example using this technique: printf "Enter search pattern: " read pattern awk -v pat="$pattern" '$0 ~ pat { nmatches++ } END { print nmatches, "found" }' /path/to/data -Now, the 'awk' program is just one single-quoted string. The assignment -'-v pat="$pattern"' still requires double quotes, in case there is -whitespace in the value of '$pattern'. The 'awk' variable 'pat' could -be named 'pattern' too, but that would be more confusing. Using a -variable also provides more flexibility, since the variable can be used -anywhere inside the program--for printing, as an array subscript, or for -any other use--without requiring the quoting tricks at every point in -the program. +Now, the `awk' program is just one single-quoted string. The +assignment `-v pat="$pattern"' still requires double quotes, in case +there is whitespace in the value of `$pattern'. The `awk' variable +`pat' could be named `pattern' too, but that would be more confusing. +Using a variable also provides more flexibility, since the variable can +be used anywhere inside the program--for printing, as an array +subscript, or for any other use--without requiring the quoting tricks +at every point in the program.  File: gawk.info, Node: Action Overview, Next: Statements, Prev: Using Shell Variables, Up: Patterns and Actions @@ -10004,55 +9321,55 @@ File: gawk.info, Node: Action Overview, Next: Statements, Prev: Using Shell V 7.3 Actions =========== -An 'awk' program or script consists of a series of rules and function +An `awk' program or script consists of a series of rules and function definitions interspersed. (Functions are described later. *Note User-defined::.) A rule contains a pattern and an action, either of which (but not both) may be omitted. The purpose of the "action" is to -tell 'awk' what to do once a match for the pattern is found. Thus, in -outline, an 'awk' program generally looks like this: +tell `awk' what to do once a match for the pattern is found. Thus, in +outline, an `awk' program generally looks like this: - [PATTERN] '{ ACTION }' - PATTERN ['{ ACTION }'] + [PATTERN] `{ ACTION }' + PATTERN [`{ ACTION }'] ... - 'function NAME(ARGS) { ... }' + `function NAME(ARGS) { ... }' ... - An action consists of one or more 'awk' "statements", enclosed in -braces ('{...}'). Each statement specifies one thing to do. The + An action consists of one or more `awk' "statements", enclosed in +braces (`{...}'). Each statement specifies one thing to do. The statements are separated by newlines or semicolons. The braces around an action must be used even if the action contains only one statement, -or if it contains no statements at all. However, if you omit the action -entirely, omit the braces as well. An omitted action is equivalent to -'{ print $0 }': +or if it contains no statements at all. However, if you omit the +action entirely, omit the braces as well. An omitted action is +equivalent to `{ print $0 }': - /foo/ { } match 'foo', do nothing -- empty action - /foo/ match 'foo', print the record -- omitted action + /foo/ { } match `foo', do nothing -- empty action + /foo/ match `foo', print the record -- omitted action - The following types of statements are supported in 'awk': + The following types of statements are supported in `awk': Expressions - Call functions or assign values to variables (*note Expressions::). - Executing this kind of statement simply computes the value of the - expression. This is useful when the expression has side effects - (*note Assignment Ops::). + Call functions or assign values to variables (*note + Expressions::). Executing this kind of statement simply computes + the value of the expression. This is useful when the expression + has side effects (*note Assignment Ops::). Control statements - Specify the control flow of 'awk' programs. The 'awk' language - gives you C-like constructs ('if', 'for', 'while', and 'do') as + Specify the control flow of `awk' programs. The `awk' language + gives you C-like constructs (`if', `for', `while', and `do') as well as a few special ones (*note Statements::). Compound statements Enclose one or more statements in braces. A compound statement is used in order to put several statements together in the body of an - 'if', 'while', 'do', or 'for' statement. + `if', `while', `do', or `for' statement. Input statements - Use the 'getline' command (*note Getline::). Also supplied in - 'awk' are the 'next' statement (*note Next Statement::), and the - 'nextfile' statement (*note Nextfile Statement::). + Use the `getline' command (*note Getline::). Also supplied in + `awk' are the `next' statement (*note Next Statement::), and the + `nextfile' statement (*note Nextfile Statement::). Output statements - Such as 'print' and 'printf'. *Note Printing::. + Such as `print' and `printf'. *Note Printing::. Deletion statements For deleting array elements. *Note Delete::. @@ -10063,13 +9380,13 @@ File: gawk.info, Node: Statements, Next: Built-in Variables, Prev: Action Ove 7.4 Control Statements in Actions ================================= -"Control statements", such as 'if', 'while', and so on, control the flow -of execution in 'awk' programs. Most of 'awk''s control statements are -patterned after similar statements in C. +"Control statements", such as `if', `while', and so on, control the +flow of execution in `awk' programs. Most of `awk''s control +statements are patterned after similar statements in C. - All the control statements start with special keywords, such as 'if' -and 'while', to distinguish them from simple expressions. Many control -statements contain other statements. For example, the 'if' statement + All the control statements start with special keywords, such as `if' +and `while', to distinguish them from simple expressions. Many control +statements contain other statements. For example, the `if' statement contains another statement that may or may not be executed. The contained statement is called the "body". To include more than one statement in the body, group them into a single "compound statement" @@ -10077,7 +9394,7 @@ with braces, separating them with newlines or semicolons. * Menu: -* If Statement:: Conditionally execute some 'awk' +* If Statement:: Conditionally execute some `awk' statements. * While Statement:: Loop until some condition is satisfied. * Do Statement:: Do specified action while looping until some @@ -10091,55 +9408,56 @@ with braces, separating them with newlines or semicolons. loop. * Next Statement:: Stop processing the current input record. * Nextfile Statement:: Stop processing the current file. -* Exit Statement:: Stop execution of 'awk'. +* Exit Statement:: Stop execution of `awk'.  File: gawk.info, Node: If Statement, Next: While Statement, Up: Statements -7.4.1 The 'if'-'else' Statement +7.4.1 The `if'-`else' Statement ------------------------------- -The 'if'-'else' statement is 'awk''s decision-making statement. It +The `if'-`else' statement is `awk''s decision-making statement. It looks like this: - 'if (CONDITION) THEN-BODY' ['else ELSE-BODY'] + `if (CONDITION) THEN-BODY' [`else ELSE-BODY'] The CONDITION is an expression that controls what the rest of the statement does. If the CONDITION is true, THEN-BODY is executed; -otherwise, ELSE-BODY is executed. The 'else' part of the statement is -optional. The condition is considered false if its value is zero or the -null string; otherwise, the condition is true. Refer to the following: +otherwise, ELSE-BODY is executed. The `else' part of the statement is +optional. The condition is considered false if its value is zero or +the null string; otherwise, the condition is true. Refer to the +following: if (x % 2 == 0) print "x is even" else print "x is odd" - In this example, if the expression 'x % 2 == 0' is true (that is, if -the value of 'x' is evenly divisible by two), then the first 'print' -statement is executed; otherwise, the second 'print' statement is -executed. If the 'else' keyword appears on the same line as THEN-BODY + In this example, if the expression `x % 2 == 0' is true (that is, if +the value of `x' is evenly divisible by two), then the first `print' +statement is executed; otherwise, the second `print' statement is +executed. If the `else' keyword appears on the same line as THEN-BODY and THEN-BODY is not a compound statement (i.e., not surrounded by -braces), then a semicolon must separate THEN-BODY from the 'else'. To +braces), then a semicolon must separate THEN-BODY from the `else'. To illustrate this, the previous example can be rewritten as: if (x % 2 == 0) print "x is even"; else print "x is odd" -If the ';' is left out, 'awk' can't interpret the statement and it +If the `;' is left out, `awk' can't interpret the statement and it produces a syntax error. Don't actually write programs this way, -because a human reader might fail to see the 'else' if it is not the +because a human reader might fail to see the `else' if it is not the first thing on its line.  File: gawk.info, Node: While Statement, Next: Do Statement, Prev: If Statement, Up: Statements -7.4.2 The 'while' Statement +7.4.2 The `while' Statement --------------------------- -In programming, a "loop" is a part of a program that can be executed two -or more times in succession. The 'while' statement is the simplest -looping statement in 'awk'. It repeatedly executes a statement as long +In programming, a "loop" is a part of a program that can be executed +two or more times in succession. The `while' statement is the simplest +looping statement in `awk'. It repeatedly executes a statement as long as a condition is true. For example: while (CONDITION) @@ -10147,13 +9465,13 @@ as a condition is true. For example: BODY is a statement called the "body" of the loop, and CONDITION is an expression that controls how long the loop keeps running. The first -thing the 'while' statement does is test the CONDITION. If the +thing the `while' statement does is test the CONDITION. If the CONDITION is true, it executes the statement BODY. (The CONDITION is true when the value is not zero and not a null string.) After BODY has been executed, CONDITION is tested again, and if it is still true, BODY is executed again. This process repeats until the CONDITION is no longer true. If the CONDITION is initially false, the body of the loop -is never executed and 'awk' continues with the statement following the +is never executed and `awk' continues with the statement following the loop. This example prints the first three fields of each record, one per line: @@ -10167,27 +9485,27 @@ per line: The body of this loop is a compound statement enclosed in braces, containing two statements. The loop works in the following manner: -first, the value of 'i' is set to one. Then, the 'while' statement -tests whether 'i' is less than or equal to three. This is true when 'i' -equals one, so the 'i'-th field is printed. Then the 'i++' increments -the value of 'i' and the loop repeats. The loop terminates when 'i' -reaches four. +first, the value of `i' is set to one. Then, the `while' statement +tests whether `i' is less than or equal to three. This is true when +`i' equals one, so the `i'-th field is printed. Then the `i++' +increments the value of `i' and the loop repeats. The loop terminates +when `i' reaches four. - A newline is not required between the condition and the body; however -using one makes the program clearer unless the body is a compound -statement or else is very simple. The newline after the open-brace that -begins the compound statement is not required either, but the program is -harder to read without it. + A newline is not required between the condition and the body; +however using one makes the program clearer unless the body is a +compound statement or else is very simple. The newline after the +open-brace that begins the compound statement is not required either, +but the program is harder to read without it.  File: gawk.info, Node: Do Statement, Next: For Statement, Prev: While Statement, Up: Statements -7.4.3 The 'do'-'while' Statement +7.4.3 The `do'-`while' Statement -------------------------------- -The 'do' loop is a variation of the 'while' looping statement. The 'do' -loop executes the BODY once and then repeats the BODY as long as the -CONDITION is true. It looks like this: +The `do' loop is a variation of the `while' looping statement. The +`do' loop executes the BODY once and then repeats the BODY as long as +the CONDITION is true. It looks like this: do BODY @@ -10195,13 +9513,13 @@ CONDITION is true. It looks like this: Even if the CONDITION is false at the start, the BODY is executed at least once (and only once, unless executing BODY makes CONDITION true). -Contrast this with the corresponding 'while' statement: +Contrast this with the corresponding `while' statement: while (CONDITION) BODY -This statement does not execute BODY even once if the CONDITION is false -to begin with. The following is an example of a 'do' statement: +This statement does not execute BODY even once if the CONDITION is +false to begin with. The following is an example of a `do' statement: { i = 1 @@ -10212,26 +9530,26 @@ to begin with. The following is an example of a 'do' statement: } This program prints each input record 10 times. However, it isn't a -very realistic example, since in this case an ordinary 'while' would do +very realistic example, since in this case an ordinary `while' would do just as well. This situation reflects actual experience; only -occasionally is there a real use for a 'do' statement. +occasionally is there a real use for a `do' statement.  File: gawk.info, Node: For Statement, Next: Switch Statement, Prev: Do Statement, Up: Statements -7.4.4 The 'for' Statement +7.4.4 The `for' Statement ------------------------- -The 'for' statement makes it more convenient to count iterations of a -loop. The general form of the 'for' statement looks like this: +The `for' statement makes it more convenient to count iterations of a +loop. The general form of the `for' statement looks like this: for (INITIALIZATION; CONDITION; INCREMENT) BODY -The INITIALIZATION, CONDITION, and INCREMENT parts are arbitrary 'awk' -expressions, and BODY stands for any 'awk' statement. +The INITIALIZATION, CONDITION, and INCREMENT parts are arbitrary `awk' +expressions, and BODY stands for any `awk' statement. - The 'for' statement starts by executing INITIALIZATION. Then, as + The `for' statement starts by executing INITIALIZATION. Then, as long as the CONDITION is true, it repeatedly executes BODY and then INCREMENT. Typically, INITIALIZATION sets a variable to either zero or one, INCREMENT adds one to it, and CONDITION compares it against the @@ -10245,33 +9563,34 @@ desired number of iterations. For example: This prints the first three fields of each input record, with one field per line. - It isn't possible to set more than one variable in the INITIALIZATION -part without using a multiple assignment statement such as 'x = y = 0'. -This makes sense only if all the initial values are equal. (But it is -possible to initialize additional variables by writing their assignments -as separate statements preceding the 'for' loop.) + It isn't possible to set more than one variable in the +INITIALIZATION part without using a multiple assignment statement such +as `x = y = 0'. This makes sense only if all the initial values are +equal. (But it is possible to initialize additional variables by +writing their assignments as separate statements preceding the `for' +loop.) - The same is true of the INCREMENT part. Incrementing additional + The same is true of the INCREMENT part. Incrementing additional variables requires separate statements at the end of the loop. The C -compound expression, using C's comma operator, is useful in this context -but it is not supported in 'awk'. +compound expression, using C's comma operator, is useful in this +context but it is not supported in `awk'. Most often, INCREMENT is an increment expression, as in the previous -example. But this is not required; it can be any expression whatsoever. -For example, the following statement prints all the powers of two -between 1 and 100: +example. But this is not required; it can be any expression +whatsoever. For example, the following statement prints all the powers +of two between 1 and 100: for (i = 1; i <= 100; i *= 2) print i If there is nothing to be done, any of the three expressions in the -parentheses following the 'for' keyword may be omitted. Thus, 'for (; x > 0;)' -is equivalent to 'while (x > 0)'. If the CONDITION is omitted, it is -treated as true, effectively yielding an "infinite loop" (i.e., a loop -that never terminates). +parentheses following the `for' keyword may be omitted. Thus, +`for (; x > 0;)' is equivalent to `while (x > 0)'. If the CONDITION is +omitted, it is treated as true, effectively yielding an "infinite loop" +(i.e., a loop that never terminates). - In most cases, a 'for' loop is an abbreviation for a 'while' loop, as -shown here: + In most cases, a `for' loop is an abbreviation for a `while' loop, +as shown here: INITIALIZATION while (CONDITION) { @@ -10279,46 +9598,46 @@ shown here: INCREMENT } -The only exception is when the 'continue' statement (*note Continue -Statement::) is used inside the loop. Changing a 'for' statement to a -'while' statement in this way can change the effect of the 'continue' +The only exception is when the `continue' statement (*note Continue +Statement::) is used inside the loop. Changing a `for' statement to a +`while' statement in this way can change the effect of the `continue' statement inside the loop. - The 'awk' language has a 'for' statement in addition to a 'while' -statement because a 'for' loop is often both less work to type and more + The `awk' language has a `for' statement in addition to a `while' +statement because a `for' loop is often both less work to type and more natural to think of. Counting the number of iterations is very common -in loops. It can be easier to think of this counting as part of looping -rather than as something to do inside the loop. +in loops. It can be easier to think of this counting as part of +looping rather than as something to do inside the loop. - There is an alternate version of the 'for' loop, for iterating over + There is an alternate version of the `for' loop, for iterating over all the indices of an array: for (i in array) DO SOMETHING WITH array[i] *Note Scanning an Array::, for more information on this version of the -'for' loop. +`for' loop.  File: gawk.info, Node: Switch Statement, Next: Break Statement, Prev: For Statement, Up: Statements -7.4.5 The 'switch' Statement +7.4.5 The `switch' Statement ---------------------------- -This minor node describes a 'gawk'-specific feature. If 'gawk' is in +This minor node describes a `gawk'-specific feature. If `gawk' is in compatibility mode (*note Options::), it is not available. - The 'switch' statement allows the evaluation of an expression and the -execution of statements based on a 'case' match. Case statements are -checked for a match in the order they are defined. If no suitable -'case' is found, the 'default' section is executed, if supplied. + The `switch' statement allows the evaluation of an expression and +the execution of statements based on a `case' match. Case statements +are checked for a match in the order they are defined. If no suitable +`case' is found, the `default' section is executed, if supplied. - Each 'case' contains a single constant, be it numeric, string, or -regexp. The 'switch' expression is evaluated, and then each 'case''s -constant is compared against the result in turn. The type of constant + Each `case' contains a single constant, be it numeric, string, or +regexp. The `switch' expression is evaluated, and then each `case''s +constant is compared against the result in turn. The type of constant determines the comparison: numeric or string do the usual comparisons. A regexp constant does a regular expression match against the string -value of the original expression. The general form of the 'switch' +value of the original expression. The general form of the `switch' statement looks like this: switch (EXPRESSION) { @@ -10328,10 +9647,10 @@ statement looks like this: DEFAULT-BODY } - Control flow in the 'switch' statement works as it does in C. Once a -match to a given case is made, the case statement bodies execute until a -'break', 'continue', 'next', 'nextfile' or 'exit' is encountered, or the -end of the 'switch' statement itself. For example: + Control flow in the `switch' statement works as it does in C. Once a +match to a given case is made, the case statement bodies execute until +a `break', `continue', `next', `nextfile' or `exit' is encountered, or +the end of the `switch' statement itself. For example: while ((c = getopt(ARGC, ARGV, "aksx")) != -1) { switch (c) { @@ -10357,32 +9676,22 @@ end of the 'switch' statement itself. For example: } } -<<<<<<< HEAD - Note that if none of the statements specified above halt execution of -a matched 'case' statement, execution falls through to the next 'case' -until execution halts. In the above example, for any case value -starting with '2' followed by one or more digits, the 'print' statement -is executed and then falls through into the 'default' section, executing -its 'print' statement. In turn, the -1 case will also be executed since -the 'default' does not halt execution. -======= Note that if none of the statements specified above halt execution of a matched `case' statement, execution falls through to the next `case' until execution halts. In the above example, the `case' for `"?"' falls through to the `default' case, which is to call a function named `usage()'. (The `getopt()' function being called here is described in *note Getopt Function::.) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Break Statement, Next: Continue Statement, Prev: Switch Statement, Up: Statements -7.4.6 The 'break' Statement +7.4.6 The `break' Statement --------------------------- -The 'break' statement jumps out of the innermost 'for', 'while', or 'do' -loop that encloses it. The following example finds the smallest divisor -of any integer, and also identifies prime numbers: +The `break' statement jumps out of the innermost `for', `while', or +`do' loop that encloses it. The following example finds the smallest +divisor of any integer, and also identifies prime numbers: # find smallest divisor of num { @@ -10397,15 +9706,15 @@ of any integer, and also identifies prime numbers: printf "%d is prime\n", num } - When the remainder is zero in the first 'if' statement, 'awk' -immediately "breaks out" of the containing 'for' loop. This means that -'awk' proceeds immediately to the statement following the loop and -continues processing. (This is very different from the 'exit' -statement, which stops the entire 'awk' program. *Note Exit + When the remainder is zero in the first `if' statement, `awk' +immediately "breaks out" of the containing `for' loop. This means that +`awk' proceeds immediately to the statement following the loop and +continues processing. (This is very different from the `exit' +statement, which stops the entire `awk' program. *Note Exit Statement::.) - The following program illustrates how the CONDITION of a 'for' or -'while' statement could be replaced with a 'break' inside an 'if': + The following program illustrates how the CONDITION of a `for' or +`while' statement could be replaced with a `break' inside an `if': # find smallest divisor of num { @@ -10422,39 +9731,30 @@ Statement::.) } } - The 'break' statement is also used to break out of the 'switch' + The `break' statement is also used to break out of the `switch' statement. This is discussed in *note Switch Statement::. -<<<<<<< HEAD - The 'break' statement has no meaning when used outside the body of a -loop or 'switch'. However, although it was never documented, historical -implementations of 'awk' treated the 'break' statement outside of a loop -as if it were a 'next' statement (*note Next Statement::). (d.c.) -Recent versions of Brian Kernighan's 'awk' no longer allow this usage, -nor does 'gawk'. -======= The `break' statement has no meaning when used outside the body of a loop or `switch'. However, although it was never documented, historical implementations of `awk' treated the `break' statement outside of a loop as if it were a `next' statement (*note Next Statement::). (d.c.) Recent versions of BWK `awk' no longer allow this usage, nor does `gawk'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Continue Statement, Next: Next Statement, Prev: Break Statement, Up: Statements -7.4.7 The 'continue' Statement +7.4.7 The `continue' Statement ------------------------------ -Similar to 'break', the 'continue' statement is used only inside 'for', -'while', and 'do' loops. It skips over the rest of the loop body, +Similar to `break', the `continue' statement is used only inside `for', +`while', and `do' loops. It skips over the rest of the loop body, causing the next cycle around the loop to begin immediately. Contrast -this with 'break', which jumps out of the loop altogether. +this with `break', which jumps out of the loop altogether. - The 'continue' statement in a 'for' loop directs 'awk' to skip the + The `continue' statement in a `for' loop directs `awk' to skip the rest of the body of the loop and resume execution with the -increment-expression of the 'for' statement. The following program +increment-expression of the `for' statement. The following program illustrates this fact: BEGIN { @@ -10467,9 +9767,9 @@ illustrates this fact: } This program prints all the numbers from 0 to 20--except for 5, for -which the 'printf' is skipped. Because the increment 'x++' is not -skipped, 'x' does not remain stuck at 5. Contrast the 'for' loop from -the previous example with the following 'while' loop: +which the `printf' is skipped. Because the increment `x++' is not +skipped, `x' does not remain stuck at 5. Contrast the `for' loop from +the previous example with the following `while' loop: BEGIN { x = 0 @@ -10482,17 +9782,6 @@ the previous example with the following 'while' loop: print "" } -<<<<<<< HEAD -This program loops forever once 'x' reaches 5. - - The 'continue' statement has no special meaning with respect to the -'switch' statement, nor does it have any meaning when used outside the -body of a loop. Historical versions of 'awk' treated a 'continue' -statement outside a loop the same way they treated a 'break' statement -outside a loop: as if it were a 'next' statement (*note Next -Statement::). (d.c.) Recent versions of Brian Kernighan's 'awk' no -longer work this way, nor does 'gawk'. -======= This program loops forever once `x' reaches 5, since the increment (`x++') is never reached. @@ -10503,33 +9792,32 @@ statement outside a loop the same way they treated a `break' statement outside a loop: as if it were a `next' statement (*note Next Statement::). (d.c.) Recent versions of BWK `awk' no longer work this way, nor does `gawk'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Next Statement, Next: Nextfile Statement, Prev: Continue Statement, Up: Statements -7.4.8 The 'next' Statement +7.4.8 The `next' Statement -------------------------- -The 'next' statement forces 'awk' to immediately stop processing the -current record and go on to the next record. This means that no further -rules are executed for the current record, and the rest of the current -rule's action isn't executed. +The `next' statement forces `awk' to immediately stop processing the +current record and go on to the next record. This means that no +further rules are executed for the current record, and the rest of the +current rule's action isn't executed. - Contrast this with the effect of the 'getline' function (*note -Getline::). That also causes 'awk' to read the next record immediately, -but it does not alter the flow of control in any way (i.e., the rest of -the current action executes with a new input record). + Contrast this with the effect of the `getline' function (*note +Getline::). That also causes `awk' to read the next record +immediately, but it does not alter the flow of control in any way +(i.e., the rest of the current action executes with a new input record). - At the highest level, 'awk' program execution is a loop that reads an -input record and then tests each rule's pattern against it. If you -think of this loop as a 'for' statement whose body contains the rules, -then the 'next' statement is analogous to a 'continue' statement. It + At the highest level, `awk' program execution is a loop that reads +an input record and then tests each rule's pattern against it. If you +think of this loop as a `for' statement whose body contains the rules, +then the `next' statement is analogous to a `continue' statement. It skips to the end of the body of this implicit loop and executes the increment (which reads another record). - For example, suppose an 'awk' program works only on records with four -fields, and it shouldn't fail when given bad input. To avoid + For example, suppose an `awk' program works only on records with +four fields, and it shouldn't fail when given bad input. To avoid complicating the rest of the program, write a "weed out" rule near the beginning, in the following manner: @@ -10539,143 +9827,120 @@ beginning, in the following manner: next } -Because of the 'next' statement, the program's subsequent rules won't +Because of the `next' statement, the program's subsequent rules won't see the bad record. The error message is redirected to the standard error output stream, as error messages should be. For more detail see *note Special Files::. - If the 'next' statement causes the end of the input to be reached, -then the code in any 'END' rules is executed. *Note BEGIN/END::. + If the `next' statement causes the end of the input to be reached, +then the code in any `END' rules is executed. *Note BEGIN/END::. - The 'next' statement is not allowed inside 'BEGINFILE' and 'ENDFILE' -rules. *Note BEGINFILE/ENDFILE::. + The `next' statement is not allowed inside `BEGINFILE' and `ENDFILE' +rules. *Note BEGINFILE/ENDFILE::. According to the POSIX standard, the behavior is undefined if the -'next' statement is used in a 'BEGIN' or 'END' rule. 'gawk' treats it -as a syntax error. Although POSIX permits it, most other 'awk' -implementations don't allow the 'next' statement inside function bodies -(*note User-defined::). Just as with any other 'next' statement, a -'next' statement inside a function body reads the next record and starts -processing it with the first rule in the program. +`next' statement is used in a `BEGIN' or `END' rule. `gawk' treats it +as a syntax error. Although POSIX permits it, most other `awk' +implementations don't allow the `next' statement inside function bodies +(*note User-defined::). Just as with any other `next' statement, a +`next' statement inside a function body reads the next record and +starts processing it with the first rule in the program.  File: gawk.info, Node: Nextfile Statement, Next: Exit Statement, Prev: Next Statement, Up: Statements -7.4.9 The 'nextfile' Statement +7.4.9 The `nextfile' Statement ------------------------------ -The 'nextfile' statement is similar to the 'next' statement. However, -instead of abandoning processing of the current record, the 'nextfile' -statement instructs 'awk' to stop processing the current data file. +The `nextfile' statement is similar to the `next' statement. However, +instead of abandoning processing of the current record, the `nextfile' +statement instructs `awk' to stop processing the current data file. - Upon execution of the 'nextfile' statement, 'FILENAME' is updated to -the name of the next data file listed on the command line, 'FNR' is + Upon execution of the `nextfile' statement, `FILENAME' is updated to +the name of the next data file listed on the command line, `FNR' is reset to one, and processing starts over with the first rule in the -<<<<<<< HEAD -program. If the 'nextfile' statement causes the end of the input to be -reached, then the code in any 'END' rules is executed. An exception to -this is when 'nextfile' is invoked during execution of any statement in -an 'END' rule; In this case, it causes the program to stop immediately. -======= program. If the `nextfile' statement causes the end of the input to be reached, then the code in any `END' rules is executed. An exception to this is when `nextfile' is invoked during execution of any statement in an `END' rule; in this case, it causes the program to stop immediately. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac *Note BEGIN/END::. - The 'nextfile' statement is useful when there are many data files to + The `nextfile' statement is useful when there are many data files to process but it isn't necessary to process every record in every file. -Without 'nextfile', in order to move on to the next data file, a program -would have to continue scanning the unwanted records. The 'nextfile' +Without `nextfile', in order to move on to the next data file, a program +would have to continue scanning the unwanted records. The `nextfile' statement accomplishes this much more efficiently. -<<<<<<< HEAD - In 'gawk', execution of 'nextfile' causes additional things to -happen: any 'ENDFILE' rules are executed except in the case as mentioned -below, 'ARGIND' is incremented, and any 'BEGINFILE' rules are executed. -('ARGIND' hasn't been introduced yet. *Note Built-in Variables::.) -======= In `gawk', execution of `nextfile' causes additional things to happen: any `ENDFILE' rules are executed if `gawk' is not currently in an `END' or `BEGINFILE' rule, `ARGIND' is incremented, and any `BEGINFILE' rules are executed. (`ARGIND' hasn't been introduced yet. *Note Built-in Variables::.) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - With 'gawk', 'nextfile' is useful inside a 'BEGINFILE' rule to skip -over a file that would otherwise cause 'gawk' to exit with a fatal -error. In this case, 'ENDFILE' rules are not executed. *Note + With `gawk', `nextfile' is useful inside a `BEGINFILE' rule to skip +over a file that would otherwise cause `gawk' to exit with a fatal +error. In this case, `ENDFILE' rules are not executed. *Note BEGINFILE/ENDFILE::. - While one might think that 'close(FILENAME)' would accomplish the -same as 'nextfile', this isn't true. 'close()' is reserved for closing + While one might think that `close(FILENAME)' would accomplish the +same as `nextfile', this isn't true. `close()' is reserved for closing files, pipes, and coprocesses that are opened with redirections. It is -not related to the main processing that 'awk' does with the files listed -in 'ARGV'. +not related to the main processing that `awk' does with the files +listed in `ARGV'. - NOTE: For many years, 'nextfile' was a 'gawk' extension. As of + NOTE: For many years, `nextfile' was a `gawk' extension. As of September, 2012, it was accepted for inclusion into the POSIX standard. See the Austin Group website (http://austingroupbugs.net/view.php?id=607). -<<<<<<< HEAD - The current version of the Brian Kernighan's 'awk', and 'mawk' (*note -Other Versions::) also support 'nextfile'. However, they don't allow -the 'nextfile' statement inside function bodies (*note User-defined::). -'gawk' does; a 'nextfile' inside a function body reads the next record -and starts processing it with the first rule in the program, just as any -other 'nextfile' statement. -======= The current version of BWK `awk', and `mawk' (*note Other Versions::) also support `nextfile'. However, they don't allow the `nextfile' statement inside function bodies (*note User-defined::). `gawk' does; a `nextfile' inside a function body reads the next record and starts processing it with the first rule in the program, just as any other `nextfile' statement. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Exit Statement, Prev: Nextfile Statement, Up: Statements -7.4.10 The 'exit' Statement +7.4.10 The `exit' Statement --------------------------- -The 'exit' statement causes 'awk' to immediately stop executing the +The `exit' statement causes `awk' to immediately stop executing the current rule and to stop processing input; any remaining input is -ignored. The 'exit' statement is written as follows: - - 'exit' [RETURN CODE] - - When an 'exit' statement is executed from a 'BEGIN' rule, the program -stops processing everything immediately. No input records are read. -However, if an 'END' rule is present, as part of executing the 'exit' -statement, the 'END' rule is executed (*note BEGIN/END::). If 'exit' is -used in the body of an 'END' rule, it causes the program to stop -immediately. - - An 'exit' statement that is not part of a 'BEGIN' or 'END' rule stops -the execution of any further automatic rules for the current record, -skips reading any remaining input records, and executes the 'END' rule -if there is one. Any 'ENDFILE' rules are also skipped; they are not -executed. - - In such a case, if you don't want the 'END' rule to do its job, set a -variable to nonzero before the 'exit' statement and check that variable -in the 'END' rule. *Note Assert Function::, for an example that does -this. - - If an argument is supplied to 'exit', its value is used as the exit -status code for the 'awk' process. If no argument is supplied, 'exit' -causes 'awk' to return a "success" status. In the case where an -argument is supplied to a first 'exit' statement, and then 'exit' is -called a second time from an 'END' rule with no argument, 'awk' uses the -previously supplied exit value. (d.c.) *Note Exit Status::, for more -information. +ignored. The `exit' statement is written as follows: + + `exit' [RETURN CODE] + + When an `exit' statement is executed from a `BEGIN' rule, the +program stops processing everything immediately. No input records are +read. However, if an `END' rule is present, as part of executing the +`exit' statement, the `END' rule is executed (*note BEGIN/END::). If +`exit' is used in the body of an `END' rule, it causes the program to +stop immediately. + + An `exit' statement that is not part of a `BEGIN' or `END' rule +stops the execution of any further automatic rules for the current +record, skips reading any remaining input records, and executes the +`END' rule if there is one. Any `ENDFILE' rules are also skipped; they +are not executed. + + In such a case, if you don't want the `END' rule to do its job, set +a variable to nonzero before the `exit' statement and check that +variable in the `END' rule. *Note Assert Function::, for an example +that does this. + + If an argument is supplied to `exit', its value is used as the exit +status code for the `awk' process. If no argument is supplied, `exit' +causes `awk' to return a "success" status. In the case where an +argument is supplied to a first `exit' statement, and then `exit' is +called a second time from an `END' rule with no argument, `awk' uses +the previously supplied exit value. (d.c.) *Note Exit Status::, for +more information. For example, suppose an error condition occurs that is difficult or impossible to handle. Conventionally, programs report this by exiting -with a nonzero status. An 'awk' program can do this using an 'exit' +with a nonzero status. An `awk' program can do this using an `exit' statement with a nonzero argument, as shown in the following example: BEGIN { @@ -10688,8 +9953,9 @@ statement with a nonzero argument, as shown in the following example: } NOTE: For full portability, exit values should be between zero and - 126, inclusive. Negative values, and values of 127 or greater, may - not produce consistent results across different operating systems. + 126, inclusive. Negative values, and values of 127 or greater, + may not produce consistent results across different operating + systems.  File: gawk.info, Node: Built-in Variables, Next: Pattern Action Summary, Prev: Statements, Up: Patterns and Actions @@ -10697,159 +9963,160 @@ File: gawk.info, Node: Built-in Variables, Next: Pattern Action Summary, Prev 7.5 Built-in Variables ====================== -Most 'awk' variables are available to use for your own purposes; they +Most `awk' variables are available to use for your own purposes; they never change unless your program assigns values to them, and they never affect anything unless your program examines them. However, a few -variables in 'awk' have special built-in meanings. 'awk' examines some -of these automatically, so that they enable you to tell 'awk' how to do -certain things. Others are set automatically by 'awk', so that they -carry information from the internal workings of 'awk' to your program. +variables in `awk' have special built-in meanings. `awk' examines some +of these automatically, so that they enable you to tell `awk' how to do +certain things. Others are set automatically by `awk', so that they +carry information from the internal workings of `awk' to your program. - This minor node documents all of 'gawk''s built-in variables, most of -which are also documented in the major nodes describing their areas of -activity. + This minor node documents all of `gawk''s built-in variables, most +of which are also documented in the major nodes describing their areas +of activity. * Menu: * User-modified:: Built-in variables that you change to control - 'awk'. -* Auto-set:: Built-in variables where 'awk' gives + `awk'. +* Auto-set:: Built-in variables where `awk' gives you information. -* ARGC and ARGV:: Ways to use 'ARGC' and 'ARGV'. +* ARGC and ARGV:: Ways to use `ARGC' and `ARGV'.  File: gawk.info, Node: User-modified, Next: Auto-set, Up: Built-in Variables -7.5.1 Built-in Variables That Control 'awk' +7.5.1 Built-in Variables That Control `awk' ------------------------------------------- The following is an alphabetical list of variables that you can change -to control how 'awk' does certain things. +to control how `awk' does certain things. - The variables that are specific to 'gawk' are marked with a pound -sign ('#'). These variables are 'gawk' extensions. In other 'awk' -implementations or if 'gawk' is in compatibility mode (*note Options::), -they are not special. (Any exceptions are noted in the description of -each variable.) + The variables that are specific to `gawk' are marked with a pound +sign (`#'). These variables are `gawk' extensions. In other `awk' +implementations or if `gawk' is in compatibility mode (*note +Options::), they are not special. (Any exceptions are noted in the +description of each variable.) -'BINMODE #' +`BINMODE #' On non-POSIX systems, this variable specifies use of binary mode - for all I/O. Numeric values of one, two, or three specify that + for all I/O. Numeric values of one, two, or three specify that input files, output files, or all files, respectively, should use - binary I/O. A numeric value less than zero is treated as zero, and - a numeric value greater than three is treated as three. - Alternatively, string values of '"r"' or '"w"' specify that input - files and output files, respectively, should use binary I/O. A - string value of '"rw"' or '"wr"' indicates that all files should - use binary I/O. Any other string value is treated the same as - '"rw"', but causes 'gawk' to generate a warning message. 'BINMODE' - is described in more detail in *note PC Using::. 'mawk' *note - Other Versions::), also supports this variable, but only using - numeric values. - -'CONVFMT' + binary I/O. A numeric value less than zero is treated as zero, + and a numeric value greater than three is treated as three. + Alternatively, string values of `"r"' or `"w"' specify that input + files and output files, respectively, should use binary I/O. A + string value of `"rw"' or `"wr"' indicates that all files should + use binary I/O. Any other string value is treated the same as + `"rw"', but causes `gawk' to generate a warning message. + `BINMODE' is described in more detail in *note PC Using::. `mawk' + *note Other Versions::), also supports this variable, but only + using numeric values. + +``CONVFMT'' This string controls conversion of numbers to strings (*note Conversion::). It works by being passed, in effect, as the first - argument to the 'sprintf()' function (*note String Functions::). - Its default value is '"%.6g"'. 'CONVFMT' was introduced by the + argument to the `sprintf()' function (*note String Functions::). + Its default value is `"%.6g"'. `CONVFMT' was introduced by the POSIX standard. -'FIELDWIDTHS #' - A space-separated list of columns that tells 'gawk' how to split +`FIELDWIDTHS #' + A space-separated list of columns that tells `gawk' how to split input with fixed columnar boundaries. Assigning a value to - 'FIELDWIDTHS' overrides the use of 'FS' and 'FPAT' for field + `FIELDWIDTHS' overrides the use of `FS' and `FPAT' for field splitting. *Note Constant Size::, for more information. -'FPAT #' - A regular expression (as a string) that tells 'gawk' to create the +`FPAT #' + A regular expression (as a string) that tells `gawk' to create the fields based on text that matches the regular expression. - Assigning a value to 'FPAT' overrides the use of 'FS' and - 'FIELDWIDTHS' for field splitting. *Note Splitting By Content::, + Assigning a value to `FPAT' overrides the use of `FS' and + `FIELDWIDTHS' for field splitting. *Note Splitting By Content::, for more information. -'FS' - The input field separator (*note Field Separators::). The value is - a single-character string or a multicharacter regular expression - that matches the separations between fields in an input record. If - the value is the null string ('""'), then each character in the - record becomes a separate field. (This behavior is a 'gawk' - extension. POSIX 'awk' does not specify the behavior when 'FS' is - the null string. Nonetheless, some other versions of 'awk' also - treat '""' specially.) - - The default value is '" "', a string consisting of a single space. +`FS' + The input field separator (*note Field Separators::). The value + is a single-character string or a multicharacter regular + expression that matches the separations between fields in an input + record. If the value is the null string (`""'), then each + character in the record becomes a separate field. (This behavior + is a `gawk' extension. POSIX `awk' does not specify the behavior + when `FS' is the null string. Nonetheless, some other versions of + `awk' also treat `""' specially.) + + The default value is `" "', a string consisting of a single space. As a special exception, this value means that any sequence of spaces, TABs, and/or newlines is a single separator.(1) It also causes spaces, TABs, and newlines at the beginning and end of a record to be ignored. - You can set the value of 'FS' on the command line using the '-F' + You can set the value of `FS' on the command line using the `-F' option: awk -F, 'PROGRAM' INPUT-FILES - If 'gawk' is using 'FIELDWIDTHS' or 'FPAT' for field splitting, - assigning a value to 'FS' causes 'gawk' to return to the normal, - 'FS'-based field splitting. An easy way to do this is to simply - say 'FS = FS', perhaps with an explanatory comment. + If `gawk' is using `FIELDWIDTHS' or `FPAT' for field splitting, + assigning a value to `FS' causes `gawk' to return to the normal, + `FS'-based field splitting. An easy way to do this is to simply + say `FS = FS', perhaps with an explanatory comment. -'IGNORECASE #' - If 'IGNORECASE' is nonzero or non-null, then all string comparisons +`IGNORECASE #' + If `IGNORECASE' is nonzero or non-null, then all string comparisons and all regular expression matching are case independent. Thus, - regexp matching with '~' and '!~', as well as the 'gensub()', - 'gsub()', 'index()', 'match()', 'patsplit()', 'split()', and - 'sub()' functions, record termination with 'RS', and field - splitting with 'FS' and 'FPAT', all ignore case when doing their - particular regexp operations. However, the value of 'IGNORECASE' + regexp matching with `~' and `!~', as well as the `gensub()', + `gsub()', `index()', `match()', `patsplit()', `split()', and + `sub()' functions, record termination with `RS', and field + splitting with `FS' and `FPAT', all ignore case when doing their + particular regexp operations. However, the value of `IGNORECASE' does _not_ affect array subscripting and it does not affect field splitting when using a single-character field separator. *Note Case-sensitivity::. -'LINT #' - When this variable is true (nonzero or non-null), 'gawk' behaves as - if the '--lint' command-line option is in effect (*note Options::). - With a value of '"fatal"', lint warnings become fatal errors. With - a value of '"invalid"', only warnings about things that are - actually invalid are issued. (This is not fully implemented yet.) - Any other true value prints nonfatal warnings. Assigning a false - value to 'LINT' turns off the lint warnings. - - This variable is a 'gawk' extension. It is not special in other - 'awk' implementations. Unlike the other special variables, - changing 'LINT' does affect the production of lint warnings, even - if 'gawk' is in compatibility mode. Much as the '--lint' and - '--traditional' options independently control different aspects of - 'gawk''s behavior, the control of lint warnings during program - execution is independent of the flavor of 'awk' being executed. - -'OFMT' +`LINT #' + When this variable is true (nonzero or non-null), `gawk' behaves + as if the `--lint' command-line option is in effect (*note + Options::). With a value of `"fatal"', lint warnings become fatal + errors. With a value of `"invalid"', only warnings about things + that are actually invalid are issued. (This is not fully + implemented yet.) Any other true value prints nonfatal warnings. + Assigning a false value to `LINT' turns off the lint warnings. + + This variable is a `gawk' extension. It is not special in other + `awk' implementations. Unlike the other special variables, + changing `LINT' does affect the production of lint warnings, even + if `gawk' is in compatibility mode. Much as the `--lint' and + `--traditional' options independently control different aspects of + `gawk''s behavior, the control of lint warnings during program + execution is independent of the flavor of `awk' being executed. + +`OFMT' Controls conversion of numbers to strings (*note Conversion::) for - printing with the 'print' statement. It works by being passed as - the first argument to the 'sprintf()' function (*note String - Functions::). Its default value is '"%.6g"'. Earlier versions of - 'awk' also used 'OFMT' to specify the format for converting numbers - to strings in general expressions; this is now done by 'CONVFMT'. - -'OFS' - This is the output field separator (*note Output Separators::). It - is output between the fields printed by a 'print' statement. Its - default value is '" "', a string consisting of a single space. - -'ORS' + printing with the `print' statement. It works by being passed as + the first argument to the `sprintf()' function (*note String + Functions::). Its default value is `"%.6g"'. Earlier versions of + `awk' also used `OFMT' to specify the format for converting + numbers to strings in general expressions; this is now done by + `CONVFMT'. + +`OFS' + This is the output field separator (*note Output Separators::). + It is output between the fields printed by a `print' statement. + Its default value is `" "', a string consisting of a single space. + +`ORS' The output record separator. It is output at the end of every - 'print' statement. Its default value is '"\n"', the newline + `print' statement. Its default value is `"\n"', the newline character. (*Note Output Separators::.) -'PREC #' +`PREC #' The working precision of arbitrary precision floating-point numbers, 53 bits by default (*note Setting precision::). -'ROUNDMODE #' +`ROUNDMODE #' The rounding mode to use for arbitrary precision arithmetic on - numbers, by default '"N"' ('roundTiesToEven' in the IEEE 754 + numbers, by default `"N"' (`roundTiesToEven' in the IEEE 754 standard; *note Setting the rounding mode::). -'RS' +``RS'' The input record separator. Its default value is a string containing a single newline character, which means that an input record consists of a single line of text. It can also be the null @@ -10857,28 +10124,28 @@ each variable.) If it is a regexp, records are separated by matches of the regexp in the input text. (*Note Records::.) - The ability for 'RS' to be a regular expression is a 'gawk' - extension. In most other 'awk' implementations, or if 'gawk' is in - compatibility mode (*note Options::), just the first character of - 'RS''s value is used. + The ability for `RS' to be a regular expression is a `gawk' + extension. In most other `awk' implementations, or if `gawk' is + in compatibility mode (*note Options::), just the first character + of `RS''s value is used. -'SUBSEP' - The subscript separator. It has the default value of '"\034"' and +``SUBSEP'' + The subscript separator. It has the default value of `"\034"' and is used to separate the parts of the indices of a multidimensional - array. Thus, the expression 'foo["A", "B"]' really accesses - 'foo["A\034B"]' (*note Multidimensional::). + array. Thus, the expression `foo["A", "B"]' really accesses + `foo["A\034B"]' (*note Multidimensional::). -'TEXTDOMAIN #' - Used for internationalization of programs at the 'awk' level. It +`TEXTDOMAIN #' + Used for internationalization of programs at the `awk' level. It sets the default text domain for specially marked string constants - in the source text, as well as for the 'dcgettext()', - 'dcngettext()' and 'bindtextdomain()' functions (*note - Internationalization::). The default value of 'TEXTDOMAIN' is - '"messages"'. + in the source text, as well as for the `dcgettext()', + `dcngettext()' and `bindtextdomain()' functions (*note + Internationalization::). The default value of `TEXTDOMAIN' is + `"messages"'. ---------- Footnotes ---------- - (1) In POSIX 'awk', newline does not count as whitespace. + (1) In POSIX `awk', newline does not count as whitespace.  File: gawk.info, Node: Auto-set, Next: ARGC and ARGV, Prev: User-modified, Up: Built-in Variables @@ -10886,20 +10153,20 @@ File: gawk.info, Node: Auto-set, Next: ARGC and ARGV, Prev: User-modified, U 7.5.2 Built-in Variables That Convey Information ------------------------------------------------ -The following is an alphabetical list of variables that 'awk' sets +The following is an alphabetical list of variables that `awk' sets automatically on certain occasions in order to provide information to your program. - The variables that are specific to 'gawk' are marked with a pound -sign ('#'). These variables are 'gawk' extensions. In other 'awk' -implementations or if 'gawk' is in compatibility mode (*note Options::), -they are not special. + The variables that are specific to `gawk' are marked with a pound +sign (`#'). These variables are `gawk' extensions. In other `awk' +implementations or if `gawk' is in compatibility mode (*note +Options::), they are not special. -'ARGC', 'ARGV' - The command-line arguments available to 'awk' programs are stored - in an array called 'ARGV'. 'ARGC' is the number of command-line - arguments present. *Note Other Arguments::. Unlike most 'awk' - arrays, 'ARGV' is indexed from 0 to 'ARGC' - 1. In the following +`ARGC', `ARGV' + The command-line arguments available to `awk' programs are stored + in an array called `ARGV'. `ARGC' is the number of command-line + arguments present. *Note Other Arguments::. Unlike most `awk' + arrays, `ARGV' is indexed from 0 to `ARGC' - 1. In the following example: $ awk 'BEGIN { @@ -10910,255 +10177,250 @@ they are not special. -| inventory-shipped -| mail-list - 'ARGV[0]' contains 'awk', 'ARGV[1]' contains 'inventory-shipped', - and 'ARGV[2]' contains 'mail-list'. The value of 'ARGC' is three, - one more than the index of the last element in 'ARGV', because the + `ARGV[0]' contains `awk', `ARGV[1]' contains `inventory-shipped', + and `ARGV[2]' contains `mail-list'. The value of `ARGC' is three, + one more than the index of the last element in `ARGV', because the elements are numbered from zero. - The names 'ARGC' and 'ARGV', as well as the convention of indexing - the array from 0 to 'ARGC' - 1, are derived from the C language's + The names `ARGC' and `ARGV', as well as the convention of indexing + the array from 0 to `ARGC' - 1, are derived from the C language's method of accessing command-line arguments. - The value of 'ARGV[0]' can vary from system to system. Also, you - should note that the program text is _not_ included in 'ARGV', nor - are any of 'awk''s command-line options. *Note ARGC and ARGV::, - for information about how 'awk' uses these variables. (d.c.) + The value of `ARGV[0]' can vary from system to system. Also, you + should note that the program text is _not_ included in `ARGV', nor + are any of `awk''s command-line options. *Note ARGC and ARGV::, + for information about how `awk' uses these variables. (d.c.) -'ARGIND #' - The index in 'ARGV' of the current file being processed. Every - time 'gawk' opens a new data file for processing, it sets 'ARGIND' - to the index in 'ARGV' of the file name. When 'gawk' is processing - the input files, 'FILENAME == ARGV[ARGIND]' is always true. +`ARGIND #' + The index in `ARGV' of the current file being processed. Every + time `gawk' opens a new data file for processing, it sets `ARGIND' + to the index in `ARGV' of the file name. When `gawk' is + processing the input files, `FILENAME == ARGV[ARGIND]' is always + true. This variable is useful in file processing; it allows you to tell how far along you are in the list of data files as well as to distinguish between successive instances of the same file name on the command line. - While you can change the value of 'ARGIND' within your 'awk' - program, 'gawk' automatically sets it to a new value when the next + While you can change the value of `ARGIND' within your `awk' + program, `gawk' automatically sets it to a new value when the next file is opened. -'ENVIRON' - An associative array containing the values of the environment. The - array indices are the environment variable names; the elements are - the values of the particular environment variables. For example, - 'ENVIRON["HOME"]' might be '/home/arnold'. +`ENVIRON' + An associative array containing the values of the environment. + The array indices are the environment variable names; the elements + are the values of the particular environment variables. For + example, `ENVIRON["HOME"]' might be `/home/arnold'. - For POSIX 'awk', changing this array does not affect the - environment passed on to any programs that 'awk' may spawn via - redirection or the 'system()' function. + For POSIX `awk', changing this array does not affect the + environment passed on to any programs that `awk' may spawn via + redirection or the `system()' function. However, beginning with version 4.2, if not in POSIX compatibility - mode, 'gawk' does update its own environment when 'ENVIRON' is + mode, `gawk' does update its own environment when `ENVIRON' is changed, thus changing the environment seen by programs that it creates. You should therefore be especially careful if you modify - 'ENVIRON["PATH"]"', which is the search path for finding executable - programs. + `ENVIRON["PATH"]"', which is the search path for finding + executable programs. - Some operating systems may not have environment variables. On such - systems, the 'ENVIRON' array is empty (except for 'ENVIRON["AWKPATH"]' - and 'ENVIRON["AWKLIBPATH"]'; *note AWKPATH Variable::, and *note - AWKLIBPATH Variable::). + Some operating systems may not have environment variables. On + such systems, the `ENVIRON' array is empty (except for + `ENVIRON["AWKPATH"]' and `ENVIRON["AWKLIBPATH"]'; *note AWKPATH + Variable::, and *note AWKLIBPATH Variable::). -'ERRNO #' - If a system error occurs during a redirection for 'getline', during - a read for 'getline', or during a 'close()' operation, then 'ERRNO' - contains a string describing the error. +`ERRNO #' + If a system error occurs during a redirection for `getline', during + a read for `getline', or during a `close()' operation, then + `ERRNO' contains a string describing the error. - In addition, 'gawk' clears 'ERRNO' before opening each command-line - input file. This enables checking if the file is readable inside a - 'BEGINFILE' pattern (*note BEGINFILE/ENDFILE::). + In addition, `gawk' clears `ERRNO' before opening each + command-line input file. This enables checking if the file is + readable inside a `BEGINFILE' pattern (*note BEGINFILE/ENDFILE::). - Otherwise, 'ERRNO' works similarly to the C variable 'errno'. - Except for the case just mentioned, 'gawk' _never_ clears it (sets - it to zero or '""'). Thus, you should only expect its value to be + Otherwise, `ERRNO' works similarly to the C variable `errno'. + Except for the case just mentioned, `gawk' _never_ clears it (sets + it to zero or `""'). Thus, you should only expect its value to be meaningful when an I/O operation returns a failure value, such as - 'getline' returning -1. You are, of course, free to clear it + `getline' returning -1. You are, of course, free to clear it yourself before doing an I/O operation. -'FILENAME' +`FILENAME' The name of the current input file. When no data files are listed - on the command line, 'awk' reads from the standard input and - 'FILENAME' is set to '"-"'. 'FILENAME' changes each time a new - file is read (*note Reading Files::). Inside a 'BEGIN' rule, the - value of 'FILENAME' is '""', since there are no input files being - processed yet.(1) (d.c.) Note, though, that using 'getline' - (*note Getline::) inside a 'BEGIN' rule can give 'FILENAME' a - value. - -'FNR' - The current record number in the current file. 'FNR' is + on the command line, `awk' reads from the standard input and + `FILENAME' is set to `"-"'. `FILENAME' changes each time a new + file is read (*note Reading Files::). Inside a `BEGIN' rule, the + value of `FILENAME' is `""', since there are no input files being + processed yet.(1) (d.c.) Note, though, that using `getline' (*note + Getline::) inside a `BEGIN' rule can give `FILENAME' a value. + +`FNR' + The current record number in the current file. `FNR' is incremented each time a new record is read (*note Records::). It is reinitialized to zero each time a new input file is started. -'NF' - The number of fields in the current input record. 'NF' is set each - time a new record is read, when a new field is created or when '$0' - changes (*note Fields::). +`NF' + The number of fields in the current input record. `NF' is set + each time a new record is read, when a new field is created or + when `$0' changes (*note Fields::). Unlike most of the variables described in this node, assigning a - value to 'NF' has the potential to affect 'awk''s internal - workings. In particular, assignments to 'NF' can be used to create - or remove fields from the current record. *Note Changing Fields::. + value to `NF' has the potential to affect `awk''s internal + workings. In particular, assignments to `NF' can be used to + create or remove fields from the current record. *Note Changing + Fields::. -'FUNCTAB #' +`FUNCTAB #' An array whose indices and corresponding values are the names of all the built-in, user-defined and extension functions in the program. - NOTE: Attempting to use the 'delete' statement with the - 'FUNCTAB' array causes a fatal error. Any attempt to assign - to an element of 'FUNCTAB' also causes a fatal error. + NOTE: Attempting to use the `delete' statement with the + `FUNCTAB' array causes a fatal error. Any attempt to assign + to an element of `FUNCTAB' also causes a fatal error. -'NR' - The number of input records 'awk' has processed since the beginning - of the program's execution (*note Records::). 'NR' is incremented - each time a new record is read. +`NR' + The number of input records `awk' has processed since the + beginning of the program's execution (*note Records::). `NR' is + incremented each time a new record is read. -'PROCINFO #' +`PROCINFO #' The elements of this array provide access to information about the - running 'awk' program. The following elements (listed + running `awk' program. The following elements (listed alphabetically) are guaranteed to be available: - 'PROCINFO["egid"]' - The value of the 'getegid()' system call. + `PROCINFO["egid"]' + The value of the `getegid()' system call. - 'PROCINFO["euid"]' - The value of the 'geteuid()' system call. + `PROCINFO["euid"]' + The value of the `geteuid()' system call. - 'PROCINFO["FS"]' - This is '"FS"' if field splitting with 'FS' is in effect, - '"FIELDWIDTHS"' if field splitting with 'FIELDWIDTHS' is in - effect, or '"FPAT"' if field matching with 'FPAT' is in + `PROCINFO["FS"]' + This is `"FS"' if field splitting with `FS' is in effect, + `"FIELDWIDTHS"' if field splitting with `FIELDWIDTHS' is in + effect, or `"FPAT"' if field matching with `FPAT' is in effect. - 'PROCINFO["identifiers"]' + `PROCINFO["identifiers"]' A subarray, indexed by the names of all identifiers used in the text of the AWK program. For each identifier, the value of the element is one of the following: - '"array"' + `"array"' The identifier is an array. -<<<<<<< HEAD - '"extension"' - The identifier is an extension function loaded via - '@load'. -======= `"builtin"' The identifier is a built-in function. `"extension"' The identifier is an extension function loaded via `@load' or `-l'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - '"scalar"' + `"scalar"' The identifier is a scalar. - '"untyped"' + `"untyped"' The identifier is untyped (could be used as a scalar or - array, 'gawk' doesn't know yet). + array, `gawk' doesn't know yet). - '"user"' + `"user"' The identifier is a user-defined function. - The values indicate what 'gawk' knows about the identifiers + The values indicate what `gawk' knows about the identifiers after it has finished parsing the program; they are _not_ updated while the program runs. - 'PROCINFO["gid"]' - The value of the 'getgid()' system call. + `PROCINFO["gid"]' + The value of the `getgid()' system call. - 'PROCINFO["pgrpid"]' + `PROCINFO["pgrpid"]' The process group ID of the current process. - 'PROCINFO["pid"]' + `PROCINFO["pid"]' The process ID of the current process. - 'PROCINFO["ppid"]' + `PROCINFO["ppid"]' The parent process ID of the current process. - 'PROCINFO["sorted_in"]' - If this element exists in 'PROCINFO', its value controls the - order in which array indices will be processed by 'for (INDEX - in ARRAY)' loops. Since this is an advanced feature, we defer - the full description until later; see *note Scanning an + `PROCINFO["sorted_in"]' + If this element exists in `PROCINFO', its value controls the + order in which array indices will be processed by `for (INDEX + in ARRAY)' loops. Since this is an advanced feature, we + defer the full description until later; see *note Scanning an Array::. - 'PROCINFO["strftime"]' - The default time format string for 'strftime()'. Assigning a + `PROCINFO["strftime"]' + The default time format string for `strftime()'. Assigning a new value to this element changes the default. *Note Time Functions::. - 'PROCINFO["uid"]' - The value of the 'getuid()' system call. + `PROCINFO["uid"]' + The value of the `getuid()' system call. - 'PROCINFO["version"]' - The version of 'gawk'. + `PROCINFO["version"]' + The version of `gawk'. The following additional elements in the array are available to provide information about the MPFR and GMP libraries if your - version of 'gawk' supports arbitrary precision numbers (*note + version of `gawk' supports arbitrary precision numbers (*note Arbitrary Precision Arithmetic::): - 'PROCINFO["mpfr_version"]' + `PROCINFO["mpfr_version"]' The version of the GNU MPFR library. - 'PROCINFO["gmp_version"]' + `PROCINFO["gmp_version"]' The version of the GNU MP library. - 'PROCINFO["prec_max"]' + `PROCINFO["prec_max"]' The maximum precision supported by MPFR. - 'PROCINFO["prec_min"]' + `PROCINFO["prec_min"]' The minimum precision required by MPFR. The following additional elements in the array are available to - provide information about the version of the extension API, if your - version of 'gawk' supports dynamic loading of extension functions - (*note Dynamic Extensions::): + provide information about the version of the extension API, if + your version of `gawk' supports dynamic loading of extension + functions (*note Dynamic Extensions::): - 'PROCINFO["api_major"]' + `PROCINFO["api_major"]' The major version of the extension API. - 'PROCINFO["api_minor"]' + `PROCINFO["api_minor"]' The minor version of the extension API. - On some systems, there may be elements in the array, '"group1"' - through '"groupN"' for some N. N is the number of supplementary - groups that the process has. Use the 'in' operator to test for + On some systems, there may be elements in the array, `"group1"' + through `"groupN"' for some N. N is the number of supplementary + groups that the process has. Use the `in' operator to test for these elements (*note Reference to Elements::). - The 'PROCINFO' array has the following additional uses: + The `PROCINFO' array has the following additional uses: * It may be used to cause coprocesses to communicate over pseudo-ttys instead of through two-way pipes; this is discussed further in *note Two-way I/O::. - * It may be used to provide a timeout when reading from any open - input file, pipe, or coprocess. *Note Read Timeout::, for - more information. + * It may be used to provide a timeout when reading from any + open input file, pipe, or coprocess. *Note Read Timeout::, + for more information. -'RLENGTH' - The length of the substring matched by the 'match()' function - (*note String Functions::). 'RLENGTH' is set by invoking the - 'match()' function. Its value is the length of the matched string, - or -1 if no match is found. +`RLENGTH' + The length of the substring matched by the `match()' function + (*note String Functions::). `RLENGTH' is set by invoking the + `match()' function. Its value is the length of the matched + string, or -1 if no match is found. -'RSTART' +`RSTART' The start-index in characters of the substring that is matched by - the 'match()' function (*note String Functions::). 'RSTART' is set - by invoking the 'match()' function. Its value is the position of - the string where the matched substring starts, or zero if no match - was found. + the `match()' function (*note String Functions::). `RSTART' is + set by invoking the `match()' function. Its value is the position + of the string where the matched substring starts, or zero if no + match was found. -'RT #' - The input text that matched the text denoted by 'RS', the record +`RT #' + The input text that matched the text denoted by `RS', the record separator. It is set every time a record is read. -'SYMTAB #' +`SYMTAB #' An array whose indices are the names of all currently defined global variables and arrays in the program. The array may be used for indirect access to read or write the value of a variable: @@ -11167,23 +10429,23 @@ they are not special. SYMTAB["foo"] = 4 print foo # prints 4 - The 'isarray()' function (*note Type Functions::) may be used to - test if an element in 'SYMTAB' is an array. Also, you may not use - the 'delete' statement with the 'SYMTAB' array. + The `isarray()' function (*note Type Functions::) may be used to + test if an element in `SYMTAB' is an array. Also, you may not use + the `delete' statement with the `SYMTAB' array. - You may use an index for 'SYMTAB' that is not a predefined + You may use an index for `SYMTAB' that is not a predefined identifier: SYMTAB["xxx"] = 5 print SYMTAB["xxx"] - This works as expected: in this case 'SYMTAB' acts just like a + This works as expected: in this case `SYMTAB' acts just like a regular array. The only difference is that you can't then delete - 'SYMTAB["xxx"]'. + `SYMTAB["xxx"]'. - The 'SYMTAB' array is more interesting than it looks. Andrew - Schorr points out that it effectively gives 'awk' data pointers. - Consider his example: + The `SYMTAB' array is more interesting than it looks. Andrew Schorr + points out that it effectively gives `awk' data pointers. Consider + his example: # Indirect multiply of any variable by amount, return result @@ -11193,12 +10455,12 @@ they are not special. } NOTE: In order to avoid severe time-travel paradoxes,(2) - neither 'FUNCTAB' nor 'SYMTAB' are available as elements - within the 'SYMTAB' array. + neither `FUNCTAB' nor `SYMTAB' are available as elements + within the `SYMTAB' array. - Changing 'NR' and 'FNR' + Changing `NR' and `FNR' - 'awk' increments 'NR' and 'FNR' each time it reads a record, instead + `awk' increments `NR' and `FNR' each time it reads a record, instead of setting them to the absolute value of the number of records read. This means that a program can change these variables and their new values are incremented for each record. (d.c.) The following example @@ -11214,14 +10476,14 @@ shows this: -| 18 -| 19 -Before 'FNR' was added to the 'awk' language (*note V7/SVR3.1::), many -'awk' programs used this feature to track the number of records in a -file by resetting 'NR' to zero when 'FILENAME' changed. +Before `FNR' was added to the `awk' language (*note V7/SVR3.1::), many +`awk' programs used this feature to track the number of records in a +file by resetting `NR' to zero when `FILENAME' changed. ---------- Footnotes ---------- - (1) Some early implementations of Unix 'awk' initialized 'FILENAME' -to '"-"', even if there were data files to be processed. This behavior + (1) Some early implementations of Unix `awk' initialized `FILENAME' +to `"-"', even if there were data files to be processed. This behavior was incorrect and should not be relied upon in your programs. (2) Not to mention difficult implementation issues. @@ -11229,11 +10491,11 @@ was incorrect and should not be relied upon in your programs.  File: gawk.info, Node: ARGC and ARGV, Prev: Auto-set, Up: Built-in Variables -7.5.3 Using 'ARGC' and 'ARGV' +7.5.3 Using `ARGC' and `ARGV' ----------------------------- *note Auto-set::, presented the following program describing the -information contained in 'ARGC' and 'ARGV': +information contained in `ARGC' and `ARGV': $ awk 'BEGIN { > for (i = 0; i < ARGC; i++) @@ -11243,14 +10505,14 @@ information contained in 'ARGC' and 'ARGV': -| inventory-shipped -| mail-list -In this example, 'ARGV[0]' contains 'awk', 'ARGV[1]' contains -'inventory-shipped', and 'ARGV[2]' contains 'mail-list'. Notice that -the 'awk' program is not entered in 'ARGV'. The other command-line +In this example, `ARGV[0]' contains `awk', `ARGV[1]' contains +`inventory-shipped', and `ARGV[2]' contains `mail-list'. Notice that +the `awk' program is not entered in `ARGV'. The other command-line options, with their arguments, are also not entered. This includes -variable assignments done with the '-v' option (*note Options::). +variable assignments done with the `-v' option (*note Options::). Normal variable assignments on the command line _are_ treated as -arguments and do show up in the 'ARGV' array. Given the following -program in a file named 'showargs.awk': +arguments and do show up in the `ARGV' array. Given the following +program in a file named `showargs.awk': BEGIN { printf "A=%d, B=%d\n", A, B @@ -11268,31 +10530,27 @@ Running it produces the following: -| ARGV[2] = /dev/null -| A=1, B=2 - A program can alter 'ARGC' and the elements of 'ARGV'. Each time -'awk' reaches the end of an input file, it uses the next element of -'ARGV' as the name of the next input file. By storing a different -string there, a program can change which files are read. Use '"-"' to + A program can alter `ARGC' and the elements of `ARGV'. Each time +`awk' reaches the end of an input file, it uses the next element of +`ARGV' as the name of the next input file. By storing a different +string there, a program can change which files are read. Use `"-"' to represent the standard input. Storing additional elements and -incrementing 'ARGC' causes additional files to be read. +incrementing `ARGC' causes additional files to be read. - If the value of 'ARGC' is decreased, that eliminates input files from -the end of the list. By recording the old value of 'ARGC' elsewhere, a -program can treat the eliminated arguments as something other than file -names. + If the value of `ARGC' is decreased, that eliminates input files +from the end of the list. By recording the old value of `ARGC' +elsewhere, a program can treat the eliminated arguments as something +other than file names. To eliminate a file from the middle of the list, store the null -string ('""') into 'ARGV' in place of the file's name. As a special -feature, 'awk' ignores file names that have been replaced with the null -string. Another option is to use the 'delete' statement to remove -elements from 'ARGV' (*note Delete::). +string (`""') into `ARGV' in place of the file's name. As a special +feature, `awk' ignores file names that have been replaced with the null +string. Another option is to use the `delete' statement to remove +elements from `ARGV' (*note Delete::). - All of these actions are typically done in the 'BEGIN' rule, before + All of these actions are typically done in the `BEGIN' rule, before actual processing of the input begins. *Note Split Program::, and see *note Tee Program::, for examples of each way of removing elements from -<<<<<<< HEAD -'ARGV'. The following fragment processes 'ARGV' in order to examine, -and then remove, command-line options: -======= `ARGV'. To actually get options into an `awk' program, end the `awk' options @@ -11303,7 +10561,6 @@ manner: The following fragment processes `ARGV' in order to examine, and then remove, the above command-line options: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac BEGIN { for (i = 1; i < ARGC; i++) { @@ -11321,21 +10578,6 @@ then remove, the above command-line options: } } -<<<<<<< HEAD - To actually get the options into the 'awk' program, end the 'awk' -options with '--' and then supply the 'awk' program's options, in the -following manner: - - awk -f myprog -- -v -q file1 file2 ... - - This is not necessary in 'gawk'. Unless '--posix' has been -specified, 'gawk' silently puts any unrecognized options into 'ARGV' for -the 'awk' program to deal with. As soon as it sees an unknown option, -'gawk' stops looking for other options that it might otherwise -recognize. The previous example with 'gawk' would be: - - gawk -f myprog -q -v file1 file2 ... -======= Ending the `awk' options with `--' isn't necessary in `gawk'. Unless `--posix' has been specified, `gawk' silently puts any unrecognized options into `ARGV' for the `awk' program to deal with. As soon as it @@ -11344,11 +10586,10 @@ might otherwise recognize. The previous command line with `gawk' would be: gawk -f myprog.awk -q -v file1 file2 ... ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac -Because '-q' is not a valid 'gawk' option, it and the following '-v' are -passed on to the 'awk' program. (*Note Getopt Function::, for an 'awk' -library function that parses command-line options.) +Because `-q' is not a valid `gawk' option, it and the following `-v' +are passed on to the `awk' program. (*Note Getopt Function::, for an +`awk' library function that parses command-line options.)  File: gawk.info, Node: Pattern Action Summary, Prev: Built-in Variables, Up: Patterns and Actions @@ -11356,81 +10597,82 @@ File: gawk.info, Node: Pattern Action Summary, Prev: Built-in Variables, Up: 7.6 Summary =========== - * Pattern-action pairs make up the basic elements of an 'awk' + * Pattern-action pairs make up the basic elements of an `awk' program. Patterns are either normal expressions, range - expressions, regexp constants, one of the special keywords 'BEGIN', - 'END', 'BEGINFILE', 'ENDFILE', or empty. The action executes if - the current record matches the pattern. Empty (missing) patterns - match all records. - - * I/O from 'BEGIN' and 'END' rules have certain constraints. This is - also true, only more so, for 'BEGINFILE' and 'ENDFILE' rules. The - latter two give you "hooks" into 'gawk''s file processing, allowing - you to recover from a file that otherwise would cause a fatal error - (such as a file that cannot be opened). - - * Shell variables can be used in 'awk' programs by careful use of - shell quoting. It is easier to pass a shell variable into 'awk' by - using the '-v' option and an 'awk' variable. - - * Actions consist of statements enclosed in curly braces. Statements + expressions, regexp constants, one of the special keywords + `BEGIN', `END', `BEGINFILE', `ENDFILE', or empty. The action + executes if the current record matches the pattern. Empty + (missing) patterns match all records. + + * I/O from `BEGIN' and `END' rules have certain constraints. This + is also true, only more so, for `BEGINFILE' and `ENDFILE' rules. + The latter two give you "hooks" into `gawk''s file processing, + allowing you to recover from a file that otherwise would cause a + fatal error (such as a file that cannot be opened). + + * Shell variables can be used in `awk' programs by careful use of + shell quoting. It is easier to pass a shell variable into `awk' + by using the `-v' option and an `awk' variable. + + * Actions consist of statements enclosed in curly braces. Statements are built up from expressions, control statements, compound statements, input and output statements, and deletion statements. - * The control statements in 'awk' are 'if'-'else', 'while', 'for', - and 'do'-'while'. 'gawk' adds the 'switch' statement. There are - two flavors of 'for' statement: one for for performing general + * The control statements in `awk' are `if'-`else', `while', `for', + and `do'-`while'. `gawk' adds the `switch' statement. There are + two flavors of `for' statement: one for for performing general looping, and the other iterating through an array. - * 'break' and 'continue' let you exit early or start the next - iteration of a loop (or get out of a 'switch'). + * `break' and `continue' let you exit early or start the next + iteration of a loop (or get out of a `switch'). - * 'next' and 'nextfile' let you read the next record and start over + * `next' and `nextfile' let you read the next record and start over at the top of your program, or skip to the next input file and start over, respectively. - * The 'exit' statement terminates your program. When executed from - an action (or function body) it transfers control to the 'END' - statements. From an 'END' statement body, it exits immediately. - You may pass an optional numeric value to be used at 'awk''s exit + * The `exit' statement terminates your program. When executed from + an action (or function body) it transfers control to the `END' + statements. From an `END' statement body, it exits immediately. + You may pass an optional numeric value to be used at `awk''s exit status. - * Some built-in variables provide control over 'awk', mainly for I/O. - Other variables convey information from 'awk' to your program. + * Some built-in variables provide control over `awk', mainly for I/O. + Other variables convey information from `awk' to your program. +  File: gawk.info, Node: Arrays, Next: Functions, Prev: Patterns and Actions, Up: Top -8 Arrays in 'awk' +8 Arrays in `awk' ***************** An "array" is a table of values called "elements". The elements of an array are distinguished by their "indices". Indices may be either numbers or strings. - This major node describes how arrays work in 'awk', how to use array + This major node describes how arrays work in `awk', how to use array elements, how to scan through every element in an array, and how to -remove array elements. It also describes how 'awk' simulates +remove array elements. It also describes how `awk' simulates multidimensional arrays, as well as some of the less obvious points -about array usage. The major node moves on to discuss 'gawk''s facility -for sorting arrays, and ends with a brief description of 'gawk''s +about array usage. The major node moves on to discuss `gawk''s facility +for sorting arrays, and ends with a brief description of `gawk''s ability to support true arrays of arrays. - 'awk' maintains a single set of names that may be used for naming + `awk' maintains a single set of names that may be used for naming variables, arrays, and functions (*note User-defined::). Thus, you -cannot have a variable and an array with the same name in the same 'awk' -program. +cannot have a variable and an array with the same name in the same +`awk' program. * Menu: * Array Basics:: The basics of arrays. -* Delete:: The 'delete' statement removes an element +* Delete:: The `delete' statement removes an element from an array. * Numeric Array Subscripts:: How to use numbers as subscripts in - 'awk'. + `awk'. * Uninitialized Subscripts:: Using Uninitialized variables as subscripts. * Multidimensional:: Emulating multidimensional arrays in - 'awk'. + `awk'. * Arrays of Arrays:: True multidimensional arrays. * Arrays Summary:: Summary of arrays. @@ -11440,8 +10682,8 @@ File: gawk.info, Node: Array Basics, Next: Delete, Up: Arrays 8.1 The Basics of Arrays ======================== -This minor node presents the basics: working with elements in arrays one -at a time, and traversing all of the elements in an array. +This minor node presents the basics: working with elements in arrays +one at a time, and traversing all of the elements in an array. * Menu: @@ -11449,7 +10691,7 @@ at a time, and traversing all of the elements in an array. * Reference to Elements:: How to examine one element of an array. * Assigning Elements:: How to change an element of an array. * Array Example:: Basic Example of an Array -* Scanning an Array:: A variation of the 'for' statement. It +* Scanning an Array:: A variation of the `for' statement. It loops through the indices of an array's existing elements. * Controlling Scanning:: Controlling the order in which arrays are @@ -11461,20 +10703,20 @@ File: gawk.info, Node: Array Intro, Next: Reference to Elements, Up: Array Ba 8.1.1 Introduction to Arrays ---------------------------- - Doing linear scans over an associative array is like trying to club - someone to death with a loaded Uzi. - -- _Larry Wall_ + Doing linear scans over an associative array is like trying to + club someone to death with a loaded Uzi. -- Larry Wall - The 'awk' language provides one-dimensional arrays for storing groups -of related strings or numbers. Every 'awk' array must have a name. -Array names have the same syntax as variable names; any valid variable -name would also be a valid array name. But one name cannot be used in -both ways (as an array and as a variable) in the same 'awk' program. + The `awk' language provides one-dimensional arrays for storing +groups of related strings or numbers. Every `awk' array must have a +name. Array names have the same syntax as variable names; any valid +variable name would also be a valid array name. But one name cannot be +used in both ways (as an array and as a variable) in the same `awk' +program. - Arrays in 'awk' superficially resemble arrays in other programming -languages, but there are fundamental differences. In 'awk', it isn't + Arrays in `awk' superficially resemble arrays in other programming +languages, but there are fundamental differences. In `awk', it isn't necessary to specify the size of an array before starting to use it. -Additionally, any number or string in 'awk', not just consecutive +Additionally, any number or string in `awk', not just consecutive integers, may be used as an array index. In most other languages, arrays must be "declared" before use, @@ -11484,29 +10726,28 @@ of memory to be allocated for that many elements. Usually, an index in the array must be a positive integer. For example, the index zero specifies the first element in the array, which is actually stored at the beginning of the block of memory. Index one specifies the second -element, which is stored in memory right after the first element, and so -on. It is impossible to add more elements to the array, because it has -room only for as many elements as given in the declaration. (Some -languages allow arbitrary starting and ending indices--e.g., '15 .. +element, which is stored in memory right after the first element, and +so on. It is impossible to add more elements to the array, because it +has room only for as many elements as given in the declaration. (Some +languages allow arbitrary starting and ending indices--e.g., `15 .. 27'--but the size of the array is still fixed when the array is declared.) A contiguous array of four elements might look like the following -example, conceptually, if the element values are 8, '"foo"', '""', and -30 as shown in *note Figure 8.1: figure-array-elements.: +example, conceptually, if the element values are 8, `"foo"', `""', and +30 as shown in *note figure-array-elements::: -[image src="array-elements.txt" alt="Basic Program Stages" text="+---------+---------+--------+---------+ -| 8 | \"foo\" | \"\" | 30 | @r{Value} +---------+---------+--------+---------+ - 0 1 2 3 @r{Index}"] - +| 8 | "foo" | "" | 30 | @r{Value} ++---------+---------+--------+---------+ + 0 1 2 3 @r{Index} Figure 8.1: A Contiguous Array Only the values are stored; the indices are implicit from the order of -the values. Here, 8 is the value at index zero, because 8 appears in -the position with zero elements before it. +the values. Here, 8 is the value at index zero, because 8 appears in the +position with zero elements before it. - Arrays in 'awk' are different--they are "associative". This means + Arrays in `awk' are different--they are "associative". This means that each array is a collection of pairs: an index and its corresponding array element value: @@ -11518,9 +10759,9 @@ array element value: The pairs are shown in jumbled order because their order is irrelevant.(1) - One advantage of associative arrays is that new pairs can be added at -any time. For example, suppose a tenth element is added to the array -whose value is '"number ten"'. The result is: + One advantage of associative arrays is that new pairs can be added +at any time. For example, suppose a tenth element is added to the array +whose value is `"number ten"'. The result is: Index 10 Value "number ten" Index 3 Value 30 @@ -11545,24 +10786,18 @@ from English to French: Here we decided to translate the number one in both spelled-out and numeric form--thus illustrating that a single array can have both numbers and strings as indices. (In fact, array subscripts are always -<<<<<<< HEAD -strings; this is discussed in more detail in *note Numeric Array -Subscripts::.) Here, the number '1' isn't double-quoted, since 'awk' -automatically converts it to a string. -======= strings. There are some subtleties to how numbers work when used as array subscripts; this is discussed in more detail in *note Numeric Array Subscripts::.) Here, the number `1' isn't double-quoted, since `awk' automatically converts it to a string. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - The value of 'IGNORECASE' has no effect upon array subscripting. The -identical string value used to store an array element must be used to -retrieve it. When 'awk' creates an array (e.g., with the 'split()' + The value of `IGNORECASE' has no effect upon array subscripting. +The identical string value used to store an array element must be used +to retrieve it. When `awk' creates an array (e.g., with the `split()' built-in function), that array's indices are consecutive integers starting at one. (*Note String Functions::.) - 'awk''s arrays are efficient--the time to access an element is + `awk''s arrays are efficient--the time to access an element is independent of the number of elements in the array. ---------- Footnotes ---------- @@ -11585,33 +10820,28 @@ Here, ARRAY is the name of an array. The expression INDEX-EXPRESSION is the index of the desired element of the array. The value of the array reference is the current value of that array -element. For example, 'foo[4.3]' is an expression for the element of -array 'foo' at index '4.3'. +element. For example, `foo[4.3]' is an expression for the element of +array `foo' at index `4.3'. A reference to an array element that has no recorded value yields a -value of '""', the null string. This includes elements that have not +value of `""', the null string. This includes elements that have not been assigned any value as well as elements that have been deleted (*note Delete::). - NOTE: A reference to an element that does not exist _automatically_ - creates that array element, with the null string as its value. (In - some cases, this is unfortunate, because it might waste memory - inside 'awk'.) + NOTE: A reference to an element that does not exist + _automatically_ creates that array element, with the null string + as its value. (In some cases, this is unfortunate, because it + might waste memory inside `awk'.) - Novice 'awk' programmers often make the mistake of checking if an + Novice `awk' programmers often make the mistake of checking if an element exists by checking if the value is empty: # Check if "foo" exists in a: Incorrect! if (a["foo"] != "") ... -<<<<<<< HEAD - This is incorrect, since this will _create_ 'a["foo"]' if it didn't - exist before! -======= This is incorrect for two reasons. First, it _creates_ `a["foo"]' if it didn't exist before! Second, it is valid (if a bit unusual) to set an array element equal to the empty string. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac To determine whether an element exists in an array at a certain index, use the following expression: @@ -11620,24 +10850,18 @@ index, use the following expression: This expression tests whether the particular index INDX exists, without the side effect of creating that element if it is not present. The -<<<<<<< HEAD -expression has the value one (true) if 'ARRAY[INDX]' exists and zero -(false) if it does not exist. For example, this statement tests whether -the array 'frequencies' contains the index '2': -======= expression has the value one (true) if `ARRAY[INDX]' exists and zero (false) if it does not exist. (We use INDX here, since `index' is the name of a built-in function.) For example, this statement tests whether the array `frequencies' contains the index `2': ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac if (2 in frequencies) print "Subscript 2 is present." - Note that this is _not_ a test of whether the array 'frequencies' + Note that this is _not_ a test of whether the array `frequencies' contains an element whose _value_ is two. There is no way to do that except to scan all the elements. Also, this _does not_ create -'frequencies[2]', while the following (incorrect) alternative does: +`frequencies[2]', while the following (incorrect) alternative does: if (frequencies[2] != "") print "Subscript 2 is present." @@ -11648,7 +10872,7 @@ File: gawk.info, Node: Assigning Elements, Next: Array Example, Prev: Referen 8.1.3 Assigning Array Elements ------------------------------ -Array elements can be assigned values just like 'awk' variables: +Array elements can be assigned values just like `awk' variables: ARRAY[INDEX-EXPRESSION] = VALUE @@ -11666,8 +10890,8 @@ The following program takes a list of lines, each beginning with a line number, and prints them out in order of line number. The line numbers are not in order when they are first read--instead they are scrambled. This program sorts the lines by making an array using the line numbers -as subscripts. The program then prints out the lines in sorted order of -their numbers. It is a very simple program and gets confused upon +as subscripts. The program then prints out the lines in sorted order +of their numbers. It is a very simple program and gets confused upon encountering repeated numbers, gaps, or lines that don't begin with a number: @@ -11682,11 +10906,11 @@ number: print arr[x] } - The first rule keeps track of the largest line number seen so far; it -also stores each line into the array 'arr', at an index that is the + The first rule keeps track of the largest line number seen so far; +it also stores each line into the array `arr', at an index that is the line's number. The second rule runs after all the input has been read, -to print out all the lines. When this program is run with the following -input: +to print out all the lines. When this program is run with the +following input: 5 I am the Five man 2 Who are you? The new number two! @@ -11704,7 +10928,7 @@ Its output is: If a line number is repeated, the last line with a given number overrides the others. Gaps in the line numbers can be handled with an -easy improvement to the program's 'END' rule, as follows: +easy improvement to the program's `END' rule, as follows: END { for (x = 1; x <= max; x++) @@ -11720,11 +10944,11 @@ File: gawk.info, Node: Scanning an Array, Next: Controlling Scanning, Prev: A In programs that use arrays, it is often necessary to use a loop that executes once for each element of an array. In other languages, where -arrays are contiguous and indices are limited to positive integers, this -is easy: all the valid indices can be found by counting from the lowest -index up to the highest. This technique won't do the job in 'awk', -because any number or string can be an array index. So 'awk' has a -special kind of 'for' statement for scanning an array: +arrays are contiguous and indices are limited to positive integers, +this is easy: all the valid indices can be found by counting from the +lowest index up to the highest. This technique won't do the job in +`awk', because any number or string can be an array index. So `awk' +has a special kind of `for' statement for scanning an array: for (VAR in ARRAY) BODY @@ -11732,14 +10956,14 @@ special kind of 'for' statement for scanning an array: This loop executes BODY once for each index in ARRAY that the program has previously used, with the variable VAR set to that index. - The following program uses this form of the 'for' statement. The + The following program uses this form of the `for' statement. The first rule scans the input records and notes which words appear (at -least once) in the input, by storing a one into the array 'used' with -the word as index. The second rule scans the elements of 'used' to find -all the distinct words that appear in the input. It prints each word -that is more than 10 characters long and also prints the number of such -words. *Note String Functions::, for more information on the built-in -function 'length()'. +least once) in the input, by storing a one into the array `used' with +the word as index. The second rule scans the elements of `used' to +find all the distinct words that appear in the input. It prints each +word that is more than 10 characters long and also prints the number of +such words. *Note String Functions::, for more information on the +built-in function `length()'. # Record a 1 for each word that is used at least once { @@ -11762,15 +10986,15 @@ function 'length()'. The order in which elements of the array are accessed by this statement is determined by the internal arrangement of the array -elements within 'awk' and in standard 'awk' cannot be controlled or +elements within `awk' and in standard `awk' cannot be controlled or changed. This can lead to problems if new elements are added to ARRAY -by statements in the loop body; it is not predictable whether the 'for' +by statements in the loop body; it is not predictable whether the `for' loop will reach them. Similarly, changing VAR inside the loop may produce strange results. It is best to avoid such things. - As a point of information, 'gawk' sets up the list of elements to be + As a point of information, `gawk' sets up the list of elements to be iterated over before the loop starts, and does not change it. But not -all 'awk' versions do so. Consider this program, named 'loopcheck.awk': +all `awk' versions do so. Consider this program, named `loopcheck.awk': BEGIN { a["here"] = "here" @@ -11784,7 +11008,7 @@ all 'awk' versions do so. Consider this program, named 'loopcheck.awk': } } - Here is what happens when run with 'gawk': + Here is what happens when run with `gawk': $ gawk -f loopcheck.awk -| here @@ -11792,11 +11016,7 @@ all 'awk' versions do so. Consider this program, named 'loopcheck.awk': -| a -| is -<<<<<<< HEAD - Contrast this to Brian Kernighan's 'awk': -======= Contrast this to BWK `awk': ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac $ nawk -f loopcheck.awk -| loop @@ -11808,87 +11028,87 @@ all 'awk' versions do so. Consider this program, named 'loopcheck.awk':  File: gawk.info, Node: Controlling Scanning, Prev: Scanning an Array, Up: Array Basics -8.1.6 Using Predefined Array Scanning Orders With 'gawk' +8.1.6 Using Predefined Array Scanning Orders With `gawk' -------------------------------------------------------- -This node describes a feature that is specific to 'gawk'. +This node describes a feature that is specific to `gawk'. - By default, when a 'for' loop traverses an array, the order is -undefined, meaning that the 'awk' implementation determines the order in -which the array is traversed. This order is usually based on the + By default, when a `for' loop traverses an array, the order is +undefined, meaning that the `awk' implementation determines the order +in which the array is traversed. This order is usually based on the internal implementation of arrays and will vary from one version of -'awk' to the next. +`awk' to the next. - Often, though, you may wish to do something simple, such as "traverse -the array by comparing the indices in ascending order," or "traverse the -array by comparing the values in descending order." 'gawk' provides two -mechanisms which give you this control. + Often, though, you may wish to do something simple, such as +"traverse the array by comparing the indices in ascending order," or +"traverse the array by comparing the values in descending order." +`gawk' provides two mechanisms which give you this control. - * Set 'PROCINFO["sorted_in"]' to one of a set of predefined values. + * Set `PROCINFO["sorted_in"]' to one of a set of predefined values. We describe this now. - * Set 'PROCINFO["sorted_in"]' to the name of a user-defined function - to use for comparison of array elements. This advanced feature is + * Set `PROCINFO["sorted_in"]' to the name of a user-defined function + to use for comparison of array elements. This advanced feature is described later, in *note Array Sorting::. - The following special values for 'PROCINFO["sorted_in"]' are + The following special values for `PROCINFO["sorted_in"]' are available: -'"@unsorted"' +`"@unsorted"' Array elements are processed in arbitrary order, which is the - default 'awk' behavior. + default `awk' behavior. -'"@ind_str_asc"' +`"@ind_str_asc"' Order by indices in ascending order compared as strings; this is the most basic sort. (Internally, array indices are always - strings, so with 'a[2*5] = 1' the index is '"10"' rather than + strings, so with `a[2*5] = 1' the index is `"10"' rather than numeric 10.) -'"@ind_num_asc"' - Order by indices in ascending order but force them to be treated as - numbers in the process. Any index with a non-numeric value will - end up positioned as if it were zero. +`"@ind_num_asc"' + Order by indices in ascending order but force them to be treated + as numbers in the process. Any index with a non-numeric value + will end up positioned as if it were zero. -'"@val_type_asc"' +`"@val_type_asc"' Order by element values in ascending order (rather than by indices). Ordering is by the type assigned to the element (*note Typing and Comparison::). All numeric values come before all - string values, which in turn come before all subarrays. (Subarrays - have not been described yet; *note Arrays of Arrays::.) + string values, which in turn come before all subarrays. + (Subarrays have not been described yet; *note Arrays of Arrays::.) -'"@val_str_asc"' +`"@val_str_asc"' Order by element values in ascending order (rather than by indices). Scalar values are compared as strings. Subarrays, if present, come out last. -'"@val_num_asc"' +`"@val_num_asc"' Order by element values in ascending order (rather than by indices). Scalar values are compared as numbers. Subarrays, if present, come out last. When numeric values are equal, the string values are used to provide an ordering: this guarantees consistent - results across different versions of the C 'qsort()' function,(1) - which 'gawk' uses internally to perform the sorting. + results across different versions of the C `qsort()' function,(1) + which `gawk' uses internally to perform the sorting. -'"@ind_str_desc"' +`"@ind_str_desc"' String indices ordered from high to low. -'"@ind_num_desc"' +`"@ind_num_desc"' Numeric indices ordered from high to low. -'"@val_type_desc"' +`"@val_type_desc"' Element values, based on type, ordered from high to low. Subarrays, if present, come out first. -'"@val_str_desc"' +`"@val_str_desc"' Element values, treated as strings, ordered from high to low. Subarrays, if present, come out first. -'"@val_num_desc"' +`"@val_num_desc"' Element values, treated as numbers, ordered from high to low. Subarrays, if present, come out first. - The array traversal order is determined before the 'for' loop starts -to run. Changing 'PROCINFO["sorted_in"]' in the loop body does not + The array traversal order is determined before the `for' loop starts +to run. Changing `PROCINFO["sorted_in"]' in the loop body does not affect the loop. For example: $ gawk 'BEGIN { @@ -11918,10 +11138,10 @@ relative to each other is determined by their index strings. Here are some additional things to bear in mind about sorted array traversal. - * The value of 'PROCINFO["sorted_in"]' is global. That is, it - affects all array traversal 'for' loops. If you need to change it - within your own code, you should see if it's defined and save and - restore the value: + * The value of `PROCINFO["sorted_in"]' is global. That is, it affects + all array traversal `for' loops. If you need to change it within + your own code, you should see if it's defined and save and restore + the value: ... if ("sorted_in" in PROCINFO) { @@ -11933,98 +11153,92 @@ traversal. PROCINFO["sorted_in"] = save_sorted * As mentioned, the default array traversal order is represented by - '"@unsorted"'. You can also get the default behavior by assigning - the null string to 'PROCINFO["sorted_in"]' or by just deleting the - '"sorted_in"' element from the 'PROCINFO' array with the 'delete' - statement. (The 'delete' statement hasn't been described yet; + `"@unsorted"'. You can also get the default behavior by assigning + the null string to `PROCINFO["sorted_in"]' or by just deleting the + `"sorted_in"' element from the `PROCINFO' array with the `delete' + statement. (The `delete' statement hasn't been described yet; *note Delete::.) - In addition, 'gawk' provides built-in functions for sorting arrays; + In addition, `gawk' provides built-in functions for sorting arrays; see *note Array Sorting Functions::. ---------- Footnotes ---------- - (1) When two elements compare as equal, the C 'qsort()' function does -not guarantee that they will maintain their original relative order -after sorting. Using the string value to provide a unique ordering when -the numeric values are equal ensures that 'gawk' behaves consistently -across different environments. + (1) When two elements compare as equal, the C `qsort()' function +does not guarantee that they will maintain their original relative +order after sorting. Using the string value to provide a unique +ordering when the numeric values are equal ensures that `gawk' behaves +consistently across different environments.  File: gawk.info, Node: Delete, Next: Numeric Array Subscripts, Prev: Array Basics, Up: Arrays -8.2 The 'delete' Statement +8.2 The `delete' Statement ========================== -To remove an individual element of an array, use the 'delete' statement: +To remove an individual element of an array, use the `delete' statement: delete ARRAY[INDEX-EXPRESSION] Once an array element has been deleted, any value the element once -had is no longer available. It is as if the element had never been +had is no longer available. It is as if the element had never been referred to or been given a value. The following is an example of deleting elements in an array: for (i in frequencies) delete frequencies[i] -This example removes all the elements from the array 'frequencies'. -Once an element is deleted, a subsequent 'for' statement to scan the -array does not report that element and the 'in' operator to check for +This example removes all the elements from the array `frequencies'. +Once an element is deleted, a subsequent `for' statement to scan the +array does not report that element and the `in' operator to check for the presence of that element returns zero (i.e., false): delete foo[4] if (4 in foo) print "This will never be printed" - It is important to note that deleting an element is _not_ the same as -assigning it a null value (the empty string, '""'). For example: + It is important to note that deleting an element is _not_ the same +as assigning it a null value (the empty string, `""'). For example: foo[4] = "" if (4 in foo) print "This is printed, even though foo[4] is empty" It is not an error to delete an element that does not exist. -However, if '--lint' is provided on the command line (*note Options::), -'gawk' issues a warning message when an element that is not in the array -is deleted. +However, if `--lint' is provided on the command line (*note Options::), +`gawk' issues a warning message when an element that is not in the +array is deleted. All the elements of an array may be deleted with a single statement -by leaving off the subscript in the 'delete' statement, as follows: +by leaving off the subscript in the `delete' statement, as follows: delete ARRAY - Using this version of the 'delete' statement is about three times -more efficient than the equivalent loop that deletes each element one at -a time. + Using this version of the `delete' statement is about three times +more efficient than the equivalent loop that deletes each element one +at a time. - NOTE: For many years, using 'delete' without a subscript was a - 'gawk' extension. As of September, 2012, it was accepted for - inclusion into the POSIX standard. See the Austin Group website + NOTE: For many years, using `delete' without a subscript was a + `gawk' extension. As of September, 2012, it was accepted for + inclusion into the POSIX standard. See the Austin Group website (http://austingroupbugs.net/view.php?id=544). This form of the -<<<<<<< HEAD - 'delete' statement is also supported by Brian Kernighan's 'awk' and - 'mawk', as well as by a number of other implementations (*note - Other Versions::). -======= `delete' statement is also supported by BWK `awk' and `mawk', as well as by a number of other implementations (*note Other Versions::). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac The following statement provides a portable but nonobvious way to clear out an array:(1) split("", array) - The 'split()' function (*note String Functions::) clears out the -target array first. This call asks it to split apart the null string. + The `split()' function (*note String Functions::) clears out the +target array first. This call asks it to split apart the null string. Because there is no data to split out, the function simply clears the array and then returns. CAUTION: Deleting an array does not change its type; you cannot delete an array and then use the array's name as a scalar (i.e., a - regular variable). For example, the following does not work: + regular variable). For example, the following does not work: a[1] = 3 delete a @@ -12041,11 +11255,11 @@ File: gawk.info, Node: Numeric Array Subscripts, Next: Uninitialized Subscript ===================================== An important aspect to remember about arrays is that _array subscripts -are always strings_. When a numeric value is used as a subscript, it is -converted to a string value before being used for subscripting (*note -Conversion::). This means that the value of the built-in variable -'CONVFMT' can affect how your program accesses elements of an array. -For example: +are always strings_. When a numeric value is used as a subscript, it +is converted to a string value before being used for subscripting +(*note Conversion::). This means that the value of the built-in +variable `CONVFMT' can affect how your program accesses elements of an +array. For example: xyz = 12.153 data[xyz] = 1 @@ -12055,20 +11269,20 @@ For example: else printf "%s is not in data\n", xyz -This prints '12.15 is not in data'. The first statement gives 'xyz' a -numeric value. Assigning to 'data[xyz]' subscripts 'data' with the -string value '"12.153"' (using the default conversion value of -'CONVFMT', '"%.6g"'). Thus, the array element 'data["12.153"]' is +This prints `12.15 is not in data'. The first statement gives `xyz' a +numeric value. Assigning to `data[xyz]' subscripts `data' with the +string value `"12.153"' (using the default conversion value of +`CONVFMT', `"%.6g"'). Thus, the array element `data["12.153"]' is assigned the value one. The program then changes the value of -'CONVFMT'. The test '(xyz in data)' generates a new string value from -'xyz'--this time '"12.15"'--because the value of 'CONVFMT' only allows -two significant digits. This test fails, since '"12.15"' is different -from '"12.153"'. +`CONVFMT'. The test `(xyz in data)' generates a new string value from +`xyz'--this time `"12.15"'--because the value of `CONVFMT' only allows +two significant digits. This test fails, since `"12.15"' is different +from `"12.153"'. According to the rules for conversions (*note Conversion::), integer values are always converted to strings as integers, no matter what the -value of 'CONVFMT' may happen to be. So the usual case of the following -works: +value of `CONVFMT' may happen to be. So the usual case of the +following works: for (i = 1; i <= maxsub; i++) do something with array[i] @@ -12076,14 +11290,14 @@ works: The "integer values always convert to strings as integers" rule has an additional consequence for array indexing. Octal and hexadecimal constants (*note Nondecimal-numbers::) are converted internally into -numbers, and their original form is forgotten. This means, for example, -that 'array[17]', 'array[021]', and 'array[0x11]' all refer to the same -element! +numbers, and their original form is forgotten. This means, for +example, that `array[17]', `array[021]', and `array[0x11]' all refer to +the same element! - As with many things in 'awk', the majority of the time things work as -one would expect them to. But it is useful to have a precise knowledge -of the actual rules since they can sometimes have a subtle effect on -your programs. + As with many things in `awk', the majority of the time things work +as one would expect them to. But it is useful to have a precise +knowledge of the actual rules since they can sometimes have a subtle +effect on your programs.  File: gawk.info, Node: Uninitialized Subscripts, Next: Multidimensional, Prev: Numeric Array Subscripts, Up: Arrays @@ -12109,13 +11323,13 @@ might look like this: the output! Upon first glance, we would think that this program should have -worked. The variable 'lines' is uninitialized, and uninitialized -variables have the numeric value zero. So, 'awk' should have printed -the value of 'l[0]'. +worked. The variable `lines' is uninitialized, and uninitialized +variables have the numeric value zero. So, `awk' should have printed +the value of `l[0]'. - The issue here is that subscripts for 'awk' arrays are _always_ -strings. Uninitialized variables, when used as strings, have the value -'""', not zero. Thus, 'line 1' ends up stored in 'l[""]'. The + The issue here is that subscripts for `awk' arrays are _always_ +strings. Uninitialized variables, when used as strings, have the value +`""', not zero. Thus, `line 1' ends up stored in `l[""]'. The following version of the program works correctly: { l[lines++] = $0 } @@ -12124,14 +11338,14 @@ following version of the program works correctly: print l[i] } - Here, the '++' forces 'lines' to be numeric, thus making the "old -value" numeric zero. This is then converted to '"0"' as the array + Here, the `++' forces `lines' to be numeric, thus making the "old +value" numeric zero. This is then converted to `"0"' as the array subscript. - Even though it is somewhat unusual, the null string ('""') is a valid -array subscript. (d.c.) 'gawk' warns about the use of the null string -as a subscript if '--lint' is provided on the command line (*note -Options::). + Even though it is somewhat unusual, the null string (`""') is a +valid array subscript. (d.c.) `gawk' warns about the use of the null +string as a subscript if `--lint' is provided on the command line +(*note Options::).  File: gawk.info, Node: Multidimensional, Next: Arrays of Arrays, Prev: Uninitialized Subscripts, Up: Arrays @@ -12143,39 +11357,41 @@ File: gawk.info, Node: Multidimensional, Next: Arrays of Arrays, Prev: Uninit * Multiscanning:: Scanning multidimensional arrays. -A multidimensional array is an array in which an element is identified -by a sequence of indices instead of a single index. For example, a -two-dimensional array requires two indices. The usual way (in most -languages, including 'awk') to refer to an element of a two-dimensional -array named 'grid' is with 'grid[X,Y]'. + A multidimensional array is an array in which an element is +identified by a sequence of indices instead of a single index. For +example, a two-dimensional array requires two indices. The usual way +(in most languages, including `awk') to refer to an element of a +two-dimensional array named `grid' is with `grid[X,Y]'. - Multidimensional arrays are supported in 'awk' through concatenation -of indices into one string. 'awk' converts the indices into strings + Multidimensional arrays are supported in `awk' through concatenation +of indices into one string. `awk' converts the indices into strings (*note Conversion::) and concatenates them together, with a separator -between them. This creates a single string that describes the values of -the separate indices. The combined string is used as a single index +between them. This creates a single string that describes the values +of the separate indices. The combined string is used as a single index into an ordinary, one-dimensional array. The separator used is the -value of the built-in variable 'SUBSEP'. - - For example, suppose we evaluate the expression 'foo[5,12] = "value"' -when the value of 'SUBSEP' is '"@"'. The numbers 5 and 12 are converted -to strings and concatenated with an '@' between them, yielding '"5@12"'; -thus, the array element 'foo["5@12"]' is set to '"value"'. - - Once the element's value is stored, 'awk' has no record of whether it -was stored with a single index or a sequence of indices. The two -expressions 'foo[5,12]' and 'foo[5 SUBSEP 12]' are always equivalent. - - The default value of 'SUBSEP' is the string '"\034"', which contains -a nonprinting character that is unlikely to appear in an 'awk' program -or in most input data. The usefulness of choosing an unlikely character -comes from the fact that index values that contain a string matching -'SUBSEP' can lead to combined strings that are ambiguous. Suppose that -'SUBSEP' is '"@"'; then 'foo["a@b", "c"]' and 'foo["a", "b@c"]' are -indistinguishable because both are actually stored as 'foo["a@b@c"]'. +value of the built-in variable `SUBSEP'. + + For example, suppose we evaluate the expression `foo[5,12] = "value"' +when the value of `SUBSEP' is `"@"'. The numbers 5 and 12 are +converted to strings and concatenated with an `@' between them, +yielding `"5@12"'; thus, the array element `foo["5@12"]' is set to +`"value"'. + + Once the element's value is stored, `awk' has no record of whether +it was stored with a single index or a sequence of indices. The two +expressions `foo[5,12]' and `foo[5 SUBSEP 12]' are always equivalent. + + The default value of `SUBSEP' is the string `"\034"', which contains +a nonprinting character that is unlikely to appear in an `awk' program +or in most input data. The usefulness of choosing an unlikely +character comes from the fact that index values that contain a string +matching `SUBSEP' can lead to combined strings that are ambiguous. +Suppose that `SUBSEP' is `"@"'; then `foo["a@b", "c"]' and +`foo["a", "b@c"]' are indistinguishable because both are actually +stored as `foo["a@b@c"]'. To test whether a particular index sequence exists in a -multidimensional array, use the same operator ('in') that is used for +multidimensional array, use the same operator (`in') that is used for single dimensional arrays. Write the whole sequence of indices in parentheses, separated by commas, as the left operand: @@ -12224,38 +11440,38 @@ File: gawk.info, Node: Multiscanning, Up: Multidimensional 8.5.1 Scanning Multidimensional Arrays -------------------------------------- -There is no special 'for' statement for scanning a "multidimensional" -array. There cannot be one, because, in truth, 'awk' does not have +There is no special `for' statement for scanning a "multidimensional" +array. There cannot be one, because, in truth, `awk' does not have multidimensional arrays or elements--there is only a multidimensional _way of accessing_ an array. However, if your program has an array that is always accessed as -multidimensional, you can get the effect of scanning it by combining the -scanning 'for' statement (*note Scanning an Array::) with the built-in -'split()' function (*note String Functions::). It works in the -following manner: +multidimensional, you can get the effect of scanning it by combining +the scanning `for' statement (*note Scanning an Array::) with the +built-in `split()' function (*note String Functions::). It works in +the following manner: for (combined in array) { split(combined, separate, SUBSEP) ... } -This sets the variable 'combined' to each concatenated combined index in -the array, and splits it into the individual indices by breaking it -apart where the value of 'SUBSEP' appears. The individual indices then -become the elements of the array 'separate'. +This sets the variable `combined' to each concatenated combined index +in the array, and splits it into the individual indices by breaking it +apart where the value of `SUBSEP' appears. The individual indices then +become the elements of the array `separate'. - Thus, if a value is previously stored in 'array[1, "foo"]', then an -element with index '"1\034foo"' exists in 'array'. (Recall that the -default value of 'SUBSEP' is the character with code 034.) Sooner or -later, the 'for' statement finds that index and does an iteration with -the variable 'combined' set to '"1\034foo"'. Then the 'split()' + Thus, if a value is previously stored in `array[1, "foo"]', then an +element with index `"1\034foo"' exists in `array'. (Recall that the +default value of `SUBSEP' is the character with code 034.) Sooner or +later, the `for' statement finds that index and does an iteration with +the variable `combined' set to `"1\034foo"'. Then the `split()' function is called as follows: split("1\034foo", separate, "\034") -The result is to set 'separate[1]' to '"1"' and 'separate[2]' to -'"foo"'. Presto! The original sequence of separate indices is +The result is to set `separate[1]' to `"1"' and `separate[2]' to +`"foo"'. Presto! The original sequence of separate indices is recovered.  @@ -12264,72 +11480,72 @@ File: gawk.info, Node: Arrays of Arrays, Next: Arrays Summary, Prev: Multidim 8.6 Arrays of Arrays ==================== -'gawk' goes beyond standard 'awk''s multidimensional array access and -provides true arrays of arrays. Elements of a subarray are referred to -by their own indices enclosed in square brackets, just like the elements -of the main array. For example, the following creates a two-element -subarray at index '1' of the main array 'a': +`gawk' goes beyond standard `awk''s multidimensional array access and +provides true arrays of arrays. Elements of a subarray are referred to +by their own indices enclosed in square brackets, just like the +elements of the main array. For example, the following creates a +two-element subarray at index `1' of the main array `a': a[1][1] = 1 a[1][2] = 2 - This simulates a true two-dimensional array. Each subarray element + This simulates a true two-dimensional array. Each subarray element can contain another subarray as a value, which in turn can hold other -arrays as well. In this way, you can create arrays of three or more -dimensions. The indices can be any 'awk' expression, including scalars -separated by commas (that is, a regular 'awk' simulated multidimensional -subscript). So the following is valid in 'gawk': +arrays as well. In this way, you can create arrays of three or more +dimensions. The indices can be any `awk' expression, including scalars +separated by commas (that is, a regular `awk' simulated +multidimensional subscript). So the following is valid in `gawk': a[1][3][1, "name"] = "barney" - Each subarray and the main array can be of different length. In + Each subarray and the main array can be of different length. In fact, the elements of an array or its subarray do not all have to have -the same type. This means that the main array and any of its subarrays -can be non-rectangular, or jagged in structure. One can assign a scalar -value to the index '4' of the main array 'a': +the same type. This means that the main array and any of its subarrays +can be non-rectangular, or jagged in structure. One can assign a scalar +value to the index `4' of the main array `a': a[4] = "An element in a jagged array" The terms "dimension", "row" and "column" are meaningless when applied to such an array, but we will use "dimension" henceforth to imply the maximum number of indices needed to refer to an existing -element. The type of any element that has already been assigned cannot -be changed by assigning a value of a different type. You have to first -delete the current element, which effectively makes 'gawk' forget about +element. The type of any element that has already been assigned cannot +be changed by assigning a value of a different type. You have to first +delete the current element, which effectively makes `gawk' forget about the element at that index: delete a[4] a[4][5][6][7] = "An element in a four-dimensional array" -This removes the scalar value from index '4' and then inserts a subarray -of subarray of subarray containing a scalar. You can also delete an -entire subarray or subarray of subarrays: +This removes the scalar value from index `4' and then inserts a +subarray of subarray of subarray containing a scalar. You can also +delete an entire subarray or subarray of subarrays: delete a[4][5] a[4][5] = "An element in subarray a[4]" - But recall that you can not delete the main array 'a' and then use it + But recall that you can not delete the main array `a' and then use it as a scalar. The built-in functions which take array arguments can also be used -with subarrays. For example, the following code fragment uses -'length()' (*note String Functions::) to determine the number of -elements in the main array 'a' and its subarrays: +with subarrays. For example, the following code fragment uses `length()' +(*note String Functions::) to determine the number of elements in the +main array `a' and its subarrays: print length(a), length(a[1]), length(a[1][3]) -This results in the following output for our main array 'a': +This results in the following output for our main array `a': 2, 3, 1 -The 'SUBSCRIPT in ARRAY' expression (*note Reference to Elements::) -works similarly for both regular 'awk'-style arrays and arrays of -arrays. For example, the tests '1 in a', '3 in a[1]', and '(1, "name") -in a[1][3]' all evaluate to one (true) for our array 'a'. +The `SUBSCRIPT in ARRAY' expression (*note Reference to Elements::) +works similarly for both regular `awk'-style arrays and arrays of +arrays. For example, the tests `1 in a', `3 in a[1]', and `(1, "name") +in a[1][3]' all evaluate to one (true) for our array `a'. - The 'for (item in array)' statement (*note Scanning an Array::) can + The `for (item in array)' statement (*note Scanning an Array::) can be nested to scan all the elements of an array of arrays if it is -rectangular in structure. In order to print the contents (scalar +rectangular in structure. In order to print the contents (scalar values) of a two-dimensional array of arrays (i.e., in which each first-level element is itself an array, not necessarily of the same length) you could use the following code: @@ -12338,8 +11554,8 @@ length) you could use the following code: for (j in array[i]) print array[i][j] - The 'isarray()' function (*note Type Functions::) lets you test if an -array element is itself an array: + The `isarray()' function (*note Type Functions::) lets you test if +an array element is itself an array: for (i in array) { if (isarray(array[i]) { @@ -12349,9 +11565,9 @@ array element is itself an array: } } - If the structure of a jagged array of arrays is known in advance, you -can often devise workarounds using control statements. For example, the -following code prints the elements of our main array 'a': + If the structure of a jagged array of arrays is known in advance, +you can often devise workarounds using control statements. For example, +the following code prints the elements of our main array `a': for (i in a) { for (j in a[i]) { @@ -12367,14 +11583,14 @@ following code prints the elements of our main array 'a': arbitrarily-dimensioned array of arrays. Recall that a reference to an uninitialized array element yields a -value of '""', the null string. This has one important implication when +value of `""', the null string. This has one important implication when you intend to use a subarray as an argument to a function, as illustrated by the following example: $ gawk 'BEGIN { split("a b c d", b[1]); print b[1][1] }' - error-> gawk: cmd. line:1: fatal: split: second argument is not an array + error--> gawk: cmd. line:1: fatal: split: second argument is not an array - The way to work around this is to first force 'b[1]' to be an array + The way to work around this is to first force `b[1]' to be an array by creating an arbitrary index: $ gawk 'BEGIN { b[1][1] = ""; split("a b c d", b[1]); print b[1][1] }' @@ -12386,59 +11602,60 @@ File: gawk.info, Node: Arrays Summary, Prev: Arrays of Arrays, Up: Arrays 8.7 Summary =========== - * Standard 'awk' provides one-dimensional associative arrays (arrays + * Standard `awk' provides one-dimensional associative arrays (arrays indexed by string values). All arrays are associative; numeric indices are converted automatically to strings. - * Array elements are referenced as 'ARRAY[INDX]'. Referencing an + * Array elements are referenced as `ARRAY[INDX]'. Referencing an element creates it if it did not exist previously. * The proper way to see if an array has an element with a given index - is to use the 'in' operator: 'INDX in ARRAY'. + is to use the `in' operator: `INDX in ARRAY'. - * Use 'for (INDX in ARRAY) ...' to scan through all the individual - elements of an array. In the body of the loop, INDX takes on the + * Use `for (INDX in ARRAY) ...' to scan through all the individual + elements of an array. In the body of the loop, INDX takes on the value of each element's index in turn. - * The order in which a 'for (INDX in ARRAY)' loop traverses an array - is undefined in POSIX 'awk' and varies among implementations. - 'gawk' lets you control the order by assigning special predefined - values to 'PROCINFO["sorted_in"]'. + * The order in which a `for (INDX in ARRAY)' loop traverses an array + is undefined in POSIX `awk' and varies among implementations. + `gawk' lets you control the order by assigning special predefined + values to `PROCINFO["sorted_in"]'. - * Use 'delete ARRAY[INDX]' to delete an individual element. You may - also use 'delete ARRAY' to delete all of the elements in the array. - This latter feature has been a common extension for many years and - is now standard, but may not be supported by all commercial - versions of 'awk'. + * Use `delete ARRAY[INDX]' to delete an individual element. You may + also use `delete ARRAY' to delete all of the elements in the + array. This latter feature has been a common extension for many + years and is now standard, but may not be supported by all + commercial versions of `awk'. - * Standard 'awk' simulates multidimensional arrays by separating + * Standard `awk' simulates multidimensional arrays by separating subscript values with a comma. The values are concatenated into a - single string, separated by the value of 'SUBSEP'. The fact that + single string, separated by the value of `SUBSEP'. The fact that such a subscript was created in this way is not retained; thus - changing 'SUBSEP' may have unexpected consequences. You can use - '(SUB1, SUB2, ...) in ARRAY' to see if such a multidimensional + changing `SUBSEP' may have unexpected consequences. You can use + `(SUB1, SUB2, ...) in ARRAY' to see if such a multidimensional subscript exists in ARRAY. - * 'gawk' provides true arrays of arrays. You use a separate set of + * `gawk' provides true arrays of arrays. You use a separate set of square brackets for each dimension in such an array: - 'data[row][col]', for example. Array elements may thus be either + `data[row][col]', for example. Array elements may thus be either scalar values (number or string) or another array. - * Use the 'isarray()' built-in function to determine if an array + * Use the `isarray()' built-in function to determine if an array element is itself a subarray. +  File: gawk.info, Node: Functions, Next: Library Functions, Prev: Arrays, Up: Top 9 Functions *********** -This major node describes 'awk''s built-in functions, which fall into -three categories: numeric, string, and I/O. 'gawk' provides additional +This major node describes `awk''s built-in functions, which fall into +three categories: numeric, string, and I/O. `gawk' provides additional groups of functions to work with values that represent time, do bit manipulation, sort arrays, and internationalize and localize programs. - Besides the built-in functions, 'awk' has provisions for writing new + Besides the built-in functions, `awk' has provisions for writing new functions that the rest of a program can use. The second half of this major node describes these "user-defined" functions. @@ -12455,19 +11672,19 @@ File: gawk.info, Node: Built-in, Next: User-defined, Up: Functions 9.1 Built-in Functions ====================== -"Built-in" functions are always available for your 'awk' program to -call. This minor node defines all the built-in functions in 'awk'; some -of these are mentioned in other sections but are summarized here for -your convenience. +"Built-in" functions are always available for your `awk' program to +call. This minor node defines all the built-in functions in `awk'; +some of these are mentioned in other sections but are summarized here +for your convenience. * Menu: * Calling Built-in:: How to call built-in functions. * Numeric Functions:: Functions that work with numbers, including - 'int()', 'sin()' and 'rand()'. + `int()', `sin()' and `rand()'. * String Functions:: Functions for string manipulation, such as - 'split()', 'match()' and - 'sprintf()'. + `split()', `match()' and + `sprintf()'. * I/O Functions:: Functions for files and shell commands. * Time Functions:: Functions for dealing with timestamps. * Bitwise Functions:: Functions for bitwise operations. @@ -12480,21 +11697,21 @@ File: gawk.info, Node: Calling Built-in, Next: Numeric Functions, Up: Built-i 9.1.1 Calling Built-in Functions -------------------------------- -To call one of 'awk''s built-in functions, write the name of the -function followed by arguments in parentheses. For example, 'atan2(y + -z, 1)' is a call to the function 'atan2()' and has two arguments. +To call one of `awk''s built-in functions, write the name of the +function followed by arguments in parentheses. For example, `atan2(y + +z, 1)' is a call to the function `atan2()' and has two arguments. - Whitespace is ignored between the built-in function name and the open -parenthesis, but nonetheless it is good practice to avoid using + Whitespace is ignored between the built-in function name and the +open parenthesis, but nonetheless it is good practice to avoid using whitespace there. User-defined functions do not permit whitespace in this way, and it is easier to avoid mistakes by following a simple convention that always works--no whitespace after a function name. Each built-in function accepts a certain number of arguments. In -some cases, arguments can be omitted. The defaults for omitted +some cases, arguments can be omitted. The defaults for omitted arguments vary from function to function and are described under the -individual functions. In some 'awk' implementations, extra arguments -given to built-in functions are ignored. However, in 'gawk', it is a +individual functions. In some `awk' implementations, extra arguments +given to built-in functions are ignored. However, in `gawk', it is a fatal error to give extra arguments to a built-in function. When a function is called, expressions that create the function's @@ -12504,19 +11721,19 @@ For example, in the following code fragment: i = 4 j = sqrt(i++) -the variable 'i' is incremented to the value five before 'sqrt()' is +the variable `i' is incremented to the value five before `sqrt()' is called with a value of four for its actual parameter. The order of evaluation of the expressions used for the function's parameters is -undefined. Thus, avoid writing programs that assume that parameters are -evaluated from left to right or from right to left. For example: +undefined. Thus, avoid writing programs that assume that parameters +are evaluated from left to right or from right to left. For example: i = 5 j = atan2(i++, i *= 2) - If the order of evaluation is left to right, then 'i' first becomes -6, and then 12, and 'atan2()' is called with the two arguments 6 and 12. -But if the order of evaluation is right to left, 'i' first becomes 10, -then 11, and 'atan2()' is called with the two arguments 11 and 10. + If the order of evaluation is left to right, then `i' first becomes +6, and then 12, and `atan2()' is called with the two arguments 6 and +12. But if the order of evaluation is right to left, `i' first becomes +10, then 11, and `atan2()' is called with the two arguments 11 and 10.  File: gawk.info, Node: Numeric Functions, Next: String Functions, Prev: Calling Built-in, Up: Built-in @@ -12525,49 +11742,50 @@ File: gawk.info, Node: Numeric Functions, Next: String Functions, Prev: Calli ----------------------- The following list describes all of the built-in functions that work -with numbers. Optional parameters are enclosed in square brackets ([ ]): +with numbers. Optional parameters are enclosed in square +brackets ([ ]): -'atan2(Y, X)' - Return the arctangent of 'Y / X' in radians. You can use 'pi = +`atan2(Y, X)' + Return the arctangent of `Y / X' in radians. You can use `pi = atan2(0, -1)' to retrieve the value of pi. -'cos(X)' +`cos(X)' Return the cosine of X, with X in radians. -'div(NUMERATOR, DENOMINATOR, RESULT)' +`div(NUMERATOR, DENOMINATOR, RESULT)' Perform integer division, similar to the standard C function of the - same name. First, truncate 'numerator' and 'denominator' towards - zero, creating integer values. Clear the 'result' array, and then - set 'result["quotient"]' to the result of 'numerator / + same name. First, truncate `numerator' and `denominator' towards + zero, creating integer values. Clear the `result' array, and then + set `result["quotient"]' to the result of `numerator / denominator', truncated towards zero to an integer, and set - 'result["remainder"]' to the result of 'numerator % denominator', + `result["remainder"]' to the result of `numerator % denominator', truncated towards zero to an integer. This function is primarily - intended for use with arbitrary length integers; it avoids creating - MPFR arbitrary precision floating-point values (*note Arbitrary - Precision Integers::). + intended for use with arbitrary length integers; it avoids + creating MPFR arbitrary precision floating-point values (*note + Arbitrary Precision Integers::). - This function is a 'gawk' extension. It is not available in + This function is a `gawk' extension. It is not available in compatibility mode (*note Options::). -'exp(X)' - Return the exponential of X ('e ^ X') or report an error if X is +`exp(X)' + Return the exponential of X (`e ^ X') or report an error if X is out of range. The range of values X can have depends on your machine's floating-point representation. -'int(X)' +`int(X)' Return the nearest integer to X, located between X and zero and truncated toward zero. - For example, 'int(3)' is 3, 'int(3.9)' is 3, 'int(-3.9)' is -3, and - 'int(-3)' is -3 as well. + For example, `int(3)' is 3, `int(3.9)' is 3, `int(-3.9)' is -3, + and `int(-3)' is -3 as well. -'log(X)' +`log(X)' Return the natural logarithm of X, if X is positive; otherwise, return `NaN' ("not a number") on IEEE 754 systems. Additionally, `gawk' prints a warning message when `x' is negative. -'rand()' - Return a random number. The values of 'rand()' are uniformly +`rand()' + Return a random number. The values of `rand()' are uniformly distributed between zero and one. The value could be zero but is never one.(1) @@ -12580,8 +11798,8 @@ with numbers. Optional parameters are enclosed in square brackets ([ ]): } The multiplication produces a random number greater than zero and - less than 'n'. Using 'int()', this result is made into an integer - between zero and 'n' - 1, inclusive. + less than `n'. Using `int()', this result is made into an integer + between zero and `n' - 1, inclusive. The following example uses a similar function to produce random integers between one and N. This program prints a new random @@ -12597,41 +11815,41 @@ with numbers. Optional parameters are enclosed in square brackets ([ ]): roll(6)+roll(6)+roll(6)) } - CAUTION: In most 'awk' implementations, including 'gawk', - 'rand()' starts generating numbers from the same starting - number, or "seed", each time you run 'awk'.(2) Thus, a + CAUTION: In most `awk' implementations, including `gawk', + `rand()' starts generating numbers from the same starting + number, or "seed", each time you run `awk'.(2) Thus, a program generates the same results each time you run it. The - numbers are random within one 'awk' run but predictable from + numbers are random within one `awk' run but predictable from run to run. This is convenient for debugging, but if you want a program to do different things each time it is used, you - must change the seed to a value that is different in each run. - To do this, use 'srand()'. + must change the seed to a value that is different in each + run. To do this, use `srand()'. -'sin(X)' +`sin(X)' Return the sine of X, with X in radians. -'sqrt(X)' - Return the positive square root of X. 'gawk' prints a warning - message if X is negative. Thus, 'sqrt(4)' is 2. +`sqrt(X)' + Return the positive square root of X. `gawk' prints a warning + message if X is negative. Thus, `sqrt(4)' is 2. -'srand('[X]')' +`srand('[X]`)' Set the starting point, or seed, for generating random numbers to the value X. Each seed value leads to a particular sequence of random - numbers.(3) Thus, if the seed is set to the same value a second + numbers.(3) Thus, if the seed is set to the same value a second time, the same sequence of random numbers is produced again. - CAUTION: Different 'awk' implementations use different + CAUTION: Different `awk' implementations use different random-number generators internally. Don't expect the same - 'awk' program to produce the same series of random numbers - when executed by different versions of 'awk'. + `awk' program to produce the same series of random numbers + when executed by different versions of `awk'. - If the argument X is omitted, as in 'srand()', then the current + If the argument X is omitted, as in `srand()', then the current date and time of day are used for a seed. This is the way to get random numbers that are truly unpredictable. - The return value of 'srand()' is the previous seed. This makes it + The return value of `srand()' is the previous seed. This makes it easy to keep track of the seeds in case you need to consistently reproduce sequences of random numbers. @@ -12640,19 +11858,19 @@ with numbers. Optional parameters are enclosed in square brackets ([ ]): ---------- Footnotes ---------- - (1) The C version of 'rand()' on many Unix systems is known to + (1) The C version of `rand()' on many Unix systems is known to produce fairly poor sequences of random numbers. However, nothing -requires that an 'awk' implementation use the C 'rand()' to implement -the 'awk' version of 'rand()'. In fact, 'gawk' uses the BSD 'random()' -function, which is considerably better than 'rand()', to produce random +requires that an `awk' implementation use the C `rand()' to implement +the `awk' version of `rand()'. In fact, `gawk' uses the BSD `random()' +function, which is considerably better than `rand()', to produce random numbers. - (2) 'mawk' uses a different seed each time. + (2) `mawk' uses a different seed each time. (3) Computer-generated random numbers really are not truly random. -They are technically known as "pseudorandom." This means that while the -numbers in a sequence appear to be random, you can in fact generate the -same sequence of random numbers over and over again. +They are technically known as "pseudorandom." This means that while +the numbers in a sequence appear to be random, you can in fact generate +the same sequence of random numbers over and over again.  File: gawk.info, Node: String Functions, Next: I/O Functions, Prev: Numeric Functions, Up: Built-in @@ -12663,101 +11881,102 @@ File: gawk.info, Node: String Functions, Next: I/O Functions, Prev: Numeric F The functions in this minor node look at or change the text of one or more strings. - 'gawk' understands locales (*note Locales::), and does all string + `gawk' understands locales (*note Locales::), and does all string processing in terms of _characters_, not _bytes_. This distinction is -particularly important to understand for locales where one character may -be represented by multiple bytes. Thus, for example, 'length()' returns -the number of characters in a string, and not the number of bytes used -to represent those characters. Similarly, 'index()' works with -character indices, and not byte indices. - - CAUTION: A number of functions deal with indices into strings. For - these functions, the first character of a string is at position - (index) one. This is different from C and the languages descended - from it, where the first character is at position zero. You need - to remember this when doing index calculations, particularly if you - are used to C. +particularly important to understand for locales where one character +may be represented by multiple bytes. Thus, for example, `length()' +returns the number of characters in a string, and not the number of +bytes used to represent those characters. Similarly, `index()' works +with character indices, and not byte indices. + + CAUTION: A number of functions deal with indices into strings. + For these functions, the first character of a string is at + position (index) one. This is different from C and the languages + descended from it, where the first character is at position zero. + You need to remember this when doing index calculations, + particularly if you are used to C. In the following list, optional parameters are enclosed in square -brackets ([ ]). Several functions perform string substitution; the full -discussion is provided in the description of the 'sub()' function, which -comes towards the end since the list is presented in alphabetic order. +brackets ([ ]). Several functions perform string substitution; the +full discussion is provided in the description of the `sub()' function, +which comes towards the end since the list is presented in alphabetic +order. - Those functions that are specific to 'gawk' are marked with a pound -sign ('#'). They are not available in compatibility mode (*note + Those functions that are specific to `gawk' are marked with a pound +sign (`#'). They are not available in compatibility mode (*note Options::): * Menu: -* Gory Details:: More than you want to know about '\' and - '&' with 'sub()', 'gsub()', and - 'gensub()'. +* Gory Details:: More than you want to know about `\' and + `&' with `sub()', `gsub()', and + `gensub()'. -'asort('SOURCE [',' DEST [',' HOW ] ]') #' -'asorti('SOURCE [',' DEST [',' HOW ] ]') #' +`asort('SOURCE [`,' DEST [`,' HOW ] ]`) #' +`asorti('SOURCE [`,' DEST [`,' HOW ] ]`) #' These two functions are similar in behavior, so they are described together. NOTE: The following description ignores the third argument, - HOW, since it requires understanding features that we have not - discussed yet. Thus, the discussion here is a deliberate + HOW, since it requires understanding features that we have + not discussed yet. Thus, the discussion here is a deliberate simplification. (We do provide all the details later on: *Note Array Sorting Functions::, for the full story.) Both functions return the number of elements in the array SOURCE. - For 'asort()', 'gawk' sorts the values of SOURCE and replaces the + For `asort()', `gawk' sorts the values of SOURCE and replaces the indices of the sorted values of SOURCE with sequential integers starting with one. If the optional array DEST is specified, then SOURCE is duplicated into DEST. DEST is then sorted, leaving the indices of SOURCE unchanged. - When comparing strings, 'IGNORECASE' affects the sorting (*note - Array Sorting Functions::). If the SOURCE array contains subarrays - as values (*note Arrays of Arrays::), they will come last, after - all scalar values. + When comparing strings, `IGNORECASE' affects the sorting (*note + Array Sorting Functions::). If the SOURCE array contains + subarrays as values (*note Arrays of Arrays::), they will come + last, after all scalar values. - For example, if the contents of 'a' are as follows: + For example, if the contents of `a' are as follows: a["last"] = "de" a["first"] = "sac" a["middle"] = "cul" - A call to 'asort()': + A call to `asort()': asort(a) - results in the following contents of 'a': + results in the following contents of `a': a[1] = "cul" a[2] = "de" a[3] = "sac" - The 'asorti()' function works similarly to 'asort()', however, the - _indices_ are sorted, instead of the values. Thus, in the previous + The `asorti()' function works similarly to `asort()', however, the + _indices_ are sorted, instead of the values. Thus, in the previous example, starting with the same initial set of indices and values - in 'a', calling 'asorti(a)' would yield: + in `a', calling `asorti(a)' would yield: a[1] = "first" a[2] = "last" a[3] = "middle" -'gensub(REGEXP, REPLACEMENT, HOW' [', TARGET']') #' +`gensub(REGEXP, REPLACEMENT, HOW' [`, TARGET']`) #' Search the target string TARGET for matches of the regular - expression REGEXP. If HOW is a string beginning with 'g' or 'G' + expression REGEXP. If HOW is a string beginning with `g' or `G' (short for "global"), then replace all matches of REGEXP with REPLACEMENT. Otherwise, HOW is treated as a number indicating - which match of REGEXP to replace. If no TARGET is supplied, use - '$0'. It returns the modified string as the result of the function - and the original target string is _not_ changed. + which match of REGEXP to replace. If no TARGET is supplied, use + `$0'. It returns the modified string as the result of the + function and the original target string is _not_ changed. - 'gensub()' is a general substitution function. Its purpose is to - provide more features than the standard 'sub()' and 'gsub()' + `gensub()' is a general substitution function. Its purpose is to + provide more features than the standard `sub()' and `gsub()' functions. - 'gensub()' provides an additional feature that is not available in - 'sub()' or 'gsub()': the ability to specify components of a regexp + `gensub()' provides an additional feature that is not available in + `sub()' or `gsub()': the ability to specify components of a regexp in the replacement text. This is done by using parentheses in the - regexp to mark the components and then specifying '\N' in the + regexp to mark the components and then specifying `\N' in the replacement text, where N is a digit from 1 to 9. For example: $ gawk ' @@ -12768,9 +11987,9 @@ Options::): > }' -| def abc - As with 'sub()', you must type two backslashes in order to get one - into the string. In the replacement text, the sequence '\0' - represents the entire matched text, as does the character '&'. + As with `sub()', you must type two backslashes in order to get one + into the string. In the replacement text, the sequence `\0' + represents the entire matched text, as does the character `&'. The following example shows how you can use the third argument to control which match of the regexp should be changed: @@ -12779,35 +11998,35 @@ Options::): > gawk '{ print gensub(/a/, "AA", 2) }' -| a b c AA b c - In this case, '$0' is the default target string. 'gensub()' + In this case, `$0' is the default target string. `gensub()' returns the new string as its result, which is passed directly to - 'print' for printing. + `print' for printing. - If the HOW argument is a string that does not begin with 'g' or - 'G', or if it is a number that is less than or equal to zero, only - one substitution is performed. If HOW is zero, 'gawk' issues a + If the HOW argument is a string that does not begin with `g' or + `G', or if it is a number that is less than or equal to zero, only + one substitution is performed. If HOW is zero, `gawk' issues a warning message. - If REGEXP does not match TARGET, 'gensub()''s return value is the + If REGEXP does not match TARGET, `gensub()''s return value is the original unchanged value of TARGET. -'gsub(REGEXP, REPLACEMENT' [', TARGET']')' +`gsub(REGEXP, REPLACEMENT' [`, TARGET']`)' Search TARGET for _all_ of the longest, leftmost, _nonoverlapping_ matching substrings it can find and replace them with REPLACEMENT. - The 'g' in 'gsub()' stands for "global," which means replace + The `g' in `gsub()' stands for "global," which means replace everywhere. For example: { gsub(/Britain/, "United Kingdom"); print } - replaces all occurrences of the string 'Britain' with 'United + replaces all occurrences of the string `Britain' with `United Kingdom' for all input records. - The 'gsub()' function returns the number of substitutions made. If + The `gsub()' function returns the number of substitutions made. If the variable to search and alter (TARGET) is omitted, then the - entire input record ('$0') is used. As in 'sub()', the characters - '&' and '\' are special, and the third argument must be assignable. + entire input record (`$0') is used. As in `sub()', the characters + `&' and `\' are special, and the third argument must be assignable. -'index(IN, FIND)' +`index(IN, FIND)' Search the string IN for the first occurrence of the string FIND, and return the position in characters where that occurrence begins in the string IN. Consider the following example: @@ -12815,72 +12034,72 @@ Options::): $ awk 'BEGIN { print index("peanut", "an") }' -| 3 - If FIND is not found, 'index()' returns zero. + If FIND is not found, `index()' returns zero. It is a fatal error to use a regexp constant for FIND. -'length('[STRING]')' +`length('[STRING]`)' Return the number of characters in STRING. If STRING is a number, the length of the digit string representing that number is - returned. For example, 'length("abcde")' is five. By contrast, - 'length(15 * 35)' works out to three. In this example, 15 * 35 = - 525, and 525 is then converted to the string '"525"', which has + returned. For example, `length("abcde")' is five. By contrast, + `length(15 * 35)' works out to three. In this example, 15 * 35 = + 525, and 525 is then converted to the string `"525"', which has three characters. - If no argument is supplied, 'length()' returns the length of '$0'. + If no argument is supplied, `length()' returns the length of `$0'. - NOTE: In older versions of 'awk', the 'length()' function + NOTE: In older versions of `awk', the `length()' function could be called without any parentheses. Doing so is considered poor practice, although the 2008 POSIX standard explicitly allows it, to support historical practice. For programs to be maximally portable, always supply the parentheses. - If 'length()' is called with a variable that has not been used, - 'gawk' forces the variable to be a scalar. Other implementations - of 'awk' leave the variable without a type. (d.c.) Consider: + If `length()' is called with a variable that has not been used, + `gawk' forces the variable to be a scalar. Other implementations + of `awk' leave the variable without a type. (d.c.) Consider: $ gawk 'BEGIN { print length(x) ; x[1] = 1 }' -| 0 - error-> gawk: fatal: attempt to use scalar `x' as array + error--> gawk: fatal: attempt to use scalar `x' as array $ nawk 'BEGIN { print length(x) ; x[1] = 1 }' -| 0 - If '--lint' has been specified on the command line, 'gawk' issues a + If `--lint' has been specified on the command line, `gawk' issues a warning about this. - With 'gawk' and several other 'awk' implementations, when given an - array argument, the 'length()' function returns the number of - elements in the array. (c.e.) This is less useful than it might + With `gawk' and several other `awk' implementations, when given an + array argument, the `length()' function returns the number of + elements in the array. (c.e.) This is less useful than it might seem at first, as the array is not guaranteed to be indexed from - one to the number of elements in it. If '--lint' is provided on - the command line (*note Options::), 'gawk' warns that passing an - array argument is not portable. If '--posix' is supplied, using an - array argument is a fatal error (*note Arrays::). + one to the number of elements in it. If `--lint' is provided on + the command line (*note Options::), `gawk' warns that passing an + array argument is not portable. If `--posix' is supplied, using + an array argument is a fatal error (*note Arrays::). -'match(STRING, REGEXP' [', ARRAY']')' +`match(STRING, REGEXP' [`, ARRAY']`)' Search STRING for the longest, leftmost substring matched by the regular expression, REGEXP and return the character position (index) at which that substring begins (one, if it starts at the beginning of STRING). If no match is found, return zero. - The REGEXP argument may be either a regexp constant ('/'...'/') or - a string constant ('"'...'"'). In the latter case, the string is + The REGEXP argument may be either a regexp constant (`/'...`/') or + a string constant (`"'...`"'). In the latter case, the string is treated as a regexp to be matched. *Note Computed Regexps::, for a discussion of the difference between the two forms, and the implications for writing your program correctly. The order of the first two arguments is backwards from most other string functions that work with regular expressions, such as - 'sub()' and 'gsub()'. It might help to remember that for - 'match()', the order is the same as for the '~' operator: 'STRING ~ - REGEXP'. + `sub()' and `gsub()'. It might help to remember that for + `match()', the order is the same as for the `~' operator: `STRING + ~ REGEXP'. - The 'match()' function sets the built-in variable 'RSTART' to the - index. It also sets the built-in variable 'RLENGTH' to the length + The `match()' function sets the built-in variable `RSTART' to the + index. It also sets the built-in variable `RLENGTH' to the length in characters of the matched substring. If no match is found, - 'RSTART' is set to zero, and 'RLENGTH' to -1. + `RSTART' is set to zero, and `RLENGTH' to -1. For example: @@ -12896,9 +12115,9 @@ Options::): } This program looks for lines that match the regular expression - stored in the variable 'regex'. This regular expression can be - changed. If the first word on a line is 'FIND', 'regex' is changed - to be the second word on that line. Therefore, if given: + stored in the variable `regex'. This regular expression can be + changed. If the first word on a line is `FIND', `regex' is + changed to be the second word on that line. Therefore, if given: FIND ru+n My program runs @@ -12908,16 +12127,16 @@ Options::): This line is property of Reality Engineering Co. Melvin was here. - 'awk' prints: + `awk' prints: Match of ru+n found at 12 in My program runs Match of Melvin found at 1 in Melvin was here. If ARRAY is present, it is cleared, and then the zeroth element of - ARRAY is set to the entire portion of STRING matched by REGEXP. If - REGEXP contains parentheses, the integer-indexed elements of ARRAY - are set to contain the portion of STRING matching the corresponding - parenthesized subexpression. For example: + ARRAY is set to the entire portion of STRING matched by REGEXP. + If REGEXP contains parentheses, the integer-indexed elements of + ARRAY are set to contain the portion of STRING matching the + corresponding parenthesized subexpression. For example: $ echo foooobazbarrrrr | > gawk '{ match($0, /(fo+).+(bar*)/, arr) @@ -12939,157 +12158,158 @@ Options::): There may not be subscripts for the start and index for every parenthesized subexpression, since they may not all have matched - text; thus they should be tested for with the 'in' operator (*note + text; thus they should be tested for with the `in' operator (*note Reference to Elements::). - The ARRAY argument to 'match()' is a 'gawk' extension. In + The ARRAY argument to `match()' is a `gawk' extension. In compatibility mode (*note Options::), using a third argument is a fatal error. -'patsplit(STRING, ARRAY' [', FIELDPAT' [', SEPS' ] ]') #' +`patsplit(STRING, ARRAY' [`, FIELDPAT' [`, SEPS' ] ]`) #' Divide STRING into pieces defined by FIELDPAT and store the pieces in ARRAY and the separator strings in the SEPS array. The first - piece is stored in 'ARRAY[1]', the second piece in 'ARRAY[2]', and - so forth. The third argument, FIELDPAT, is a regexp describing the - fields in STRING (just as 'FPAT' is a regexp describing the fields - in input records). It may be either a regexp constant or a string. - If FIELDPAT is omitted, the value of 'FPAT' is used. 'patsplit()' - returns the number of elements created. 'SEPS[I]' is the separator - string between 'ARRAY[I]' and 'ARRAY[I+1]'. Any leading separator - will be in 'SEPS[0]'. - - The 'patsplit()' function splits strings into pieces in a manner - similar to the way input lines are split into fields using 'FPAT' + piece is stored in `ARRAY[1]', the second piece in `ARRAY[2]', and + so forth. The third argument, FIELDPAT, is a regexp describing + the fields in STRING (just as `FPAT' is a regexp describing the + fields in input records). It may be either a regexp constant or a + string. If FIELDPAT is omitted, the value of `FPAT' is used. + `patsplit()' returns the number of elements created. `SEPS[I]' is + the separator string between `ARRAY[I]' and `ARRAY[I+1]'. Any + leading separator will be in `SEPS[0]'. + + The `patsplit()' function splits strings into pieces in a manner + similar to the way input lines are split into fields using `FPAT' (*note Splitting By Content::. - Before splitting the string, 'patsplit()' deletes any previously + Before splitting the string, `patsplit()' deletes any previously existing elements in the arrays ARRAY and SEPS. -'split(STRING, ARRAY' [', FIELDSEP' [', SEPS' ] ]')' +`split(STRING, ARRAY' [`, FIELDSEP' [`, SEPS' ] ]`)' Divide STRING into pieces separated by FIELDSEP and store the pieces in ARRAY and the separator strings in the SEPS array. The - first piece is stored in 'ARRAY[1]', the second piece in - 'ARRAY[2]', and so forth. The string value of the third argument, + first piece is stored in `ARRAY[1]', the second piece in + `ARRAY[2]', and so forth. The string value of the third argument, FIELDSEP, is a regexp describing where to split STRING (much as - 'FS' can be a regexp describing where to split input records; *note - Regexp Field Splitting::). If FIELDSEP is omitted, the value of - 'FS' is used. 'split()' returns the number of elements created. - SEPS is a 'gawk' extension with 'SEPS[I]' being the separator - string between 'ARRAY[I]' and 'ARRAY[I+1]'. If FIELDSEP is a - single space then any leading whitespace goes into 'SEPS[0]' and - any trailing whitespace goes into 'SEPS[N]' where N is the return - value of 'split()' (that is, the number of elements in ARRAY). - - The 'split()' function splits strings into pieces in a manner + `FS' can be a regexp describing where to split input records; + *note Regexp Field Splitting::). If FIELDSEP is omitted, the + value of `FS' is used. `split()' returns the number of elements + created. SEPS is a `gawk' extension with `SEPS[I]' being the + separator string between `ARRAY[I]' and `ARRAY[I+1]'. If FIELDSEP + is a single space then any leading whitespace goes into `SEPS[0]' + and any trailing whitespace goes into `SEPS[N]' where N is the + return value of `split()' (that is, the number of elements in + ARRAY). + + The `split()' function splits strings into pieces in a manner similar to the way input lines are split into fields. For example: split("cul-de-sac", a, "-", seps) - splits the string 'cul-de-sac' into three fields using '-' as the - separator. It sets the contents of the array 'a' as follows: + splits the string `cul-de-sac' into three fields using `-' as the + separator. It sets the contents of the array `a' as follows: a[1] = "cul" a[2] = "de" a[3] = "sac" - and sets the contents of the array 'seps' as follows: + and sets the contents of the array `seps' as follows: seps[1] = "-" seps[2] = "-" - The value returned by this call to 'split()' is three. + The value returned by this call to `split()' is three. - As with input field-splitting, when the value of FIELDSEP is '" "', - leading and trailing whitespace is ignored in values assigned to - the elements of ARRAY but not in SEPS, and the elements are - separated by runs of whitespace. Also as with input + As with input field-splitting, when the value of FIELDSEP is + `" "', leading and trailing whitespace is ignored in values + assigned to the elements of ARRAY but not in SEPS, and the elements + are separated by runs of whitespace. Also as with input field-splitting, if FIELDSEP is the null string, each individual character in the string is split into its own array element. (c.e.) - Note, however, that 'RS' has no effect on the way 'split()' works. - Even though 'RS = ""' causes newline to also be an input field - separator, this does not affect how 'split()' splits strings. + Note, however, that `RS' has no effect on the way `split()' works. + Even though `RS = ""' causes newline to also be an input field + separator, this does not affect how `split()' splits strings. - Modern implementations of 'awk', including 'gawk', allow the third - argument to be a regexp constant ('/abc/') as well as a string. + Modern implementations of `awk', including `gawk', allow the third + argument to be a regexp constant (`/abc/') as well as a string. (d.c.) The POSIX standard allows this as well. *Note Computed Regexps::, for a discussion of the difference between using a string constant or a regexp constant, and the implications for writing your program correctly. - Before splitting the string, 'split()' deletes any previously + Before splitting the string, `split()' deletes any previously existing elements in the arrays ARRAY and SEPS. - If STRING is null, the array has no elements. (So this is a + If STRING is null, the array has no elements. (So this is a portable way to delete an entire array with one statement. *Note Delete::.) If STRING does not match FIELDSEP at all (but is not null), ARRAY - has one element only. The value of that element is the original + has one element only. The value of that element is the original STRING. In POSIX mode (*note Options::), the fourth argument is not allowed. -'sprintf(FORMAT, EXPRESSION1, ...)' - Return (without printing) the string that 'printf' would have +`sprintf(FORMAT, EXPRESSION1, ...)' + Return (without printing) the string that `printf' would have printed out with the same arguments (*note Printf::). For example: pival = sprintf("pi = %.2f (approx.)", 22/7) - assigns the string 'pi = 3.14 (approx.)' to the variable 'pival'. + assigns the string `pi = 3.14 (approx.)' to the variable `pival'. -'strtonum(STR) #' +`strtonum(STR) #' Examine STR and return its numeric value. If STR begins with a - leading '0', 'strtonum()' assumes that STR is an octal number. If - STR begins with a leading '0x' or '0X', 'strtonum()' assumes that + leading `0', `strtonum()' assumes that STR is an octal number. If + STR begins with a leading `0x' or `0X', `strtonum()' assumes that STR is a hexadecimal number. For example: $ echo 0x11 | > gawk '{ printf "%d\n", strtonum($1) }' -| 17 - Using the 'strtonum()' function is _not_ the same as adding zero to - a string value; the automatic coercion of strings to numbers works - only for decimal data, not for octal or hexadecimal.(1) + Using the `strtonum()' function is _not_ the same as adding zero + to a string value; the automatic coercion of strings to numbers + works only for decimal data, not for octal or hexadecimal.(1) - Note also that 'strtonum()' uses the current locale's decimal point + Note also that `strtonum()' uses the current locale's decimal point for recognizing numbers (*note Locales::). -'sub(REGEXP, REPLACEMENT' [', TARGET']')' +`sub(REGEXP, REPLACEMENT' [`, TARGET']`)' Search TARGET, which is treated as a string, for the leftmost, - longest substring matched by the regular expression REGEXP. Modify - the entire string by replacing the matched text with REPLACEMENT. - The modified string becomes the new value of TARGET. Return the - number of substitutions made (zero or one). + longest substring matched by the regular expression REGEXP. + Modify the entire string by replacing the matched text with + REPLACEMENT. The modified string becomes the new value of TARGET. + Return the number of substitutions made (zero or one). - The REGEXP argument may be either a regexp constant ('/'...'/') or - a string constant ('"'...'"'). In the latter case, the string is + The REGEXP argument may be either a regexp constant (`/'...`/') or + a string constant (`"'...`"'). In the latter case, the string is treated as a regexp to be matched. *Note Computed Regexps::, for a discussion of the difference between the two forms, and the implications for writing your program correctly. This function is peculiar because TARGET is not simply used to compute a value, and not just any expression will do--it must be a - variable, field, or array element so that 'sub()' can store a + variable, field, or array element so that `sub()' can store a modified value there. If this argument is omitted, then the - default is to use and alter '$0'.(2) For example: + default is to use and alter `$0'.(2) For example: str = "water, water, everywhere" sub(/at/, "ith", str) - sets 'str' to 'wither, water, everywhere', by replacing the - leftmost longest occurrence of 'at' with 'ith'. + sets `str' to `wither, water, everywhere', by replacing the + leftmost longest occurrence of `at' with `ith'. - If the special character '&' appears in REPLACEMENT, it stands for + If the special character `&' appears in REPLACEMENT, it stands for the precise substring that was matched by REGEXP. (If the regexp can match more than one string, then this precise substring may vary.) For example: { sub(/candidate/, "& and his wife"); print } - changes the first occurrence of 'candidate' to 'candidate and his + changes the first occurrence of `candidate' to `candidate and his wife' on each input line. Here is another example: $ awk 'BEGIN { @@ -13099,30 +12319,30 @@ Options::): > }' -| dCaaCbaaa - This shows how '&' can represent a nonconstant string and also + This shows how `&' can represent a nonconstant string and also illustrates the "leftmost, longest" rule in regexp matching (*note Leftmost Longest::). - The effect of this special character ('&') can be turned off by + The effect of this special character (`&') can be turned off by putting a backslash before it in the string. As usual, to insert one backslash in the string, you must write two backslashes. - Therefore, write '\\&' in a string constant to include a literal - '&' in the replacement. For example, the following shows how to - replace the first '|' on each line with an '&': + Therefore, write `\\&' in a string constant to include a literal + `&' in the replacement. For example, the following shows how to + replace the first `|' on each line with an `&': { sub(/\|/, "\\&"); print } - As mentioned, the third argument to 'sub()' must be a variable, - field or array element. Some versions of 'awk' allow the third + As mentioned, the third argument to `sub()' must be a variable, + field or array element. Some versions of `awk' allow the third argument to be an expression that is not an lvalue. In such a - case, 'sub()' still searches for the pattern and returns zero or + case, `sub()' still searches for the pattern and returns zero or one, but the result of the substitution (if any) is thrown away - because there is no place to put it. Such versions of 'awk' accept - expressions like the following: + because there is no place to put it. Such versions of `awk' + accept expressions like the following: sub(/USA/, "United States", "the USA and Canada") - For historical compatibility, 'gawk' accepts such erroneous code. + For historical compatibility, `gawk' accepts such erroneous code. However, using any other nonchangeable object as the third parameter causes a fatal error and your program will not run. @@ -13130,35 +12350,26 @@ Options::): into a string, and then the value of that string is treated as the regexp to match. -'substr(STRING, START' [', LENGTH' ]')' +`substr(STRING, START' [`, LENGTH' ]`)' Return a LENGTH-character-long substring of STRING, starting at character number START. The first character of a string is - character number one.(3) For example, 'substr("washington", 5, 3)' - returns '"ing"'. + character number one.(3) For example, `substr("washington", 5, 3)' + returns `"ing"'. - If LENGTH is not present, 'substr()' returns the whole suffix of + If LENGTH is not present, `substr()' returns the whole suffix of STRING that begins at character number START. For example, - 'substr("washington", 5)' returns '"ington"'. The whole suffix is + `substr("washington", 5)' returns `"ington"'. The whole suffix is also returned if LENGTH is greater than the number of characters remaining in the string, counting from character START. -<<<<<<< HEAD - If START is less than one, 'substr()' treats it as if it was one. - (POSIX doesn't specify what to do in this case: Brian Kernighan's - 'awk' acts this way, and therefore 'gawk' does too.) If START is - greater than the number of characters in the string, 'substr()' - returns the null string. Similarly, if LENGTH is present but less - than or equal to zero, the null string is returned. -======= If START is less than one, `substr()' treats it as if it was one. (POSIX doesn't specify what to do in this case: BWK `awk' acts this way, and therefore `gawk' does too.) If START is greater than the number of characters in the string, `substr()' returns the null string. Similarly, if LENGTH is present but less than or equal to zero, the null string is returned. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - The string returned by 'substr()' _cannot_ be assigned. Thus, it + The string returned by `substr()' _cannot_ be assigned. Thus, it is a mistake to attempt to change a portion of a string, as shown in the following example: @@ -13166,57 +12377,52 @@ Options::): # try to get "abCDEf", won't work substr(string, 3, 3) = "CDE" - It is also a mistake to use 'substr()' as the third argument of - 'sub()' or 'gsub()': + It is also a mistake to use `substr()' as the third argument of + `sub()' or `gsub()': gsub(/xyz/, "pdq", substr($0, 5, 20)) # WRONG - (Some commercial versions of 'awk' treat 'substr()' as assignable, + (Some commercial versions of `awk' treat `substr()' as assignable, but doing so is not portable.) If you need to replace bits and pieces of a string, combine - 'substr()' with string concatenation, in the following manner: + `substr()' with string concatenation, in the following manner: string = "abcdef" ... string = substr(string, 1, 2) "CDE" substr(string, 6) -'tolower(STRING)' +`tolower(STRING)' Return a copy of STRING, with each uppercase character in the string replaced with its corresponding lowercase character. Nonalphabetic characters are left unchanged. For example, - 'tolower("MiXeD cAsE 123")' returns '"mixed case 123"'. + `tolower("MiXeD cAsE 123")' returns `"mixed case 123"'. -'toupper(STRING)' +`toupper(STRING)' Return a copy of STRING, with each lowercase character in the string replaced with its corresponding uppercase character. Nonalphabetic characters are left unchanged. For example, - 'toupper("MiXeD cAsE 123")' returns '"MIXED CASE 123"'. + `toupper("MiXeD cAsE 123")' returns `"MIXED CASE 123"'. ---------- Footnotes ---------- - (1) Unless you use the '--non-decimal-data' option, which isn't + (1) Unless you use the `--non-decimal-data' option, which isn't recommended. *Note Nondecimal Data::, for more information. (2) Note that this means that the record will first be regenerated -using the value of 'OFS' if any fields have been changed, and that the +using the value of `OFS' if any fields have been changed, and that the fields will be updated after the substitution, even if the operation is -a "no-op" such as 'sub(/^/, "")'. +a "no-op" such as `sub(/^/, "")'. - (3) This is different from C and C++, in which the first character is -number zero. + (3) This is different from C and C++, in which the first character +is number zero.  File: gawk.info, Node: Gory Details, Up: String Functions -9.1.3.1 More About '\' and '&' with 'sub()', 'gsub()', and 'gensub()' +9.1.3.1 More About `\' and `&' with `sub()', `gsub()', and `gensub()' ..................................................................... -<<<<<<< HEAD -When using 'sub()', 'gsub()', or 'gensub()', and trying to get literal -backslashes and ampersands into the replacement text, you need to -remember that there are several levels of "escape processing" going on. -======= CAUTION: This section has been known to cause headaches. You might want to skip it upon first reading. @@ -13224,44 +12430,17 @@ remember that there are several levels of "escape processing" going on. literal backslashes and ampersands into the replacement text, you need to remember that there are several levels of "escape processing" going on. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - First, there is the "lexical" level, which is when 'awk' reads your -program and builds an internal copy of it to execute. Then there is the -runtime level, which is when 'awk' actually scans the replacement string -to determine what to generate. + First, there is the "lexical" level, which is when `awk' reads your +program and builds an internal copy of it to execute. Then there is +the runtime level, which is when `awk' actually scans the replacement +string to determine what to generate. - At both levels, 'awk' looks for a defined set of characters that can + At both levels, `awk' looks for a defined set of characters that can come after a backslash. At the lexical level, it looks for the escape -sequences listed in *note Escape Sequences::. Thus, for every '\' that -'awk' processes at the runtime level, you must type two backslashes at +sequences listed in *note Escape Sequences::. Thus, for every `\' that +`awk' processes at the runtime level, you must type two backslashes at the lexical level. When a character that is not valid for an escape -<<<<<<< HEAD -sequence follows the '\', Brian Kernighan's 'awk' and 'gawk' both simply -remove the initial '\' and put the next character into the string. -Thus, for example, '"a\qb"' is treated as '"aqb"'. - - At the runtime level, the various functions handle sequences of '\' -and '&' differently. The situation is (sadly) somewhat complex. -Historically, the 'sub()' and 'gsub()' functions treated the two -character sequence '\&' specially; this sequence was replaced in the -generated text with a single '&'. Any other '\' within the REPLACEMENT -string that did not precede an '&' was passed through unchanged. This -is illustrated in *note Table 9.1: table-sub-escapes. - - You type 'sub()' sees 'sub()' generates - ----- ------- ---------- - '\&' '&' the matched text - '\\&' '\&' a literal '&' - '\\\&' '\&' a literal '&' - '\\\\&' '\\&' a literal '\&' - '\\\\\&' '\\&' a literal '\&' - '\\\\\\&' '\\\&' a literal '\\&' - '\\q' '\q' a literal '\q' - -Table 9.1: Historical Escape Sequence Processing for 'sub()' and -'gsub()' -======= sequence follows the `\', BWK `awk' and `gawk' both simply remove the initial `\' and put the next character into the string. Thus, for example, `"a\qb"' is treated as `"aqb"'. @@ -13286,63 +12465,14 @@ is illustrated in *note table-sub-escapes::. Table 9.1: Historical Escape Sequence Processing for `sub()' and `gsub()' ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac This table shows both the lexical-level processing, where an odd number of backslashes becomes an even number at the runtime level, as well as -the runtime processing done by 'sub()'. (For the sake of simplicity, +the runtime processing done by `sub()'. (For the sake of simplicity, the rest of the following tables only show the case of even numbers of backslashes entered at the lexical level.) The problem with the historical approach is that there is no way to -<<<<<<< HEAD -get a literal '\' followed by the matched text. - - The 1992 POSIX standard attempted to fix this problem. That standard -says that 'sub()' and 'gsub()' look for either a '\' or an '&' after the -'\'. If either one follows a '\', that character is output literally. -The interpretation of '\' and '&' then becomes as shown in *note Table -9.2: table-sub-posix-92. - - You type 'sub()' sees 'sub()' generates - ----- ------- ---------- - '&' '&' the matched text - '\\&' '\&' a literal '&' - '\\\\&' '\\&' a literal '\', then the matched text - '\\\\\\&' '\\\&' a literal '\&' - -Table 9.2: 1992 POSIX Rules for 'sub()' and 'gsub()' Escape Sequence -Processing - -This appears to solve the problem. Unfortunately, the phrasing of the -standard is unusual. It says, in effect, that '\' turns off the special -meaning of any following character, but for anything other than '\' and -'&', such special meaning is undefined. This wording leads to two -problems: - - * Backslashes must now be doubled in the REPLACEMENT string, breaking - historical 'awk' programs. - - * To make sure that an 'awk' program is portable, _every_ character - in the REPLACEMENT string must be preceded with a backslash.(1) - - Because of the problems just listed, in 1996, the 'gawk' maintainer -submitted proposed text for a revised standard that reverts to rules -that correspond more closely to the original existing practice. The -proposed rules have special cases that make it possible to produce a '\' -preceding the matched text. This is shown in *note Table 9.3: -table-sub-proposed. - - You type 'sub()' sees 'sub()' generates - ----- ------- ---------- - '\\\\\\&' '\\\&' a literal '\&' - '\\\\&' '\\&' a literal '\', followed by the matched text - '\\&' '\&' a literal '&' - '\\q' '\q' a literal '\q' - '\\\\' '\\' '\\' - -Table 9.3: Proposed Rules For 'sub()' And Backslash -======= get a literal `\' followed by the matched text. Several editions of the POSIX standard attempted to fix this problem @@ -13364,44 +12494,24 @@ This is shown in *note table-sub-proposed::. `\\\\' `\\' `\\' Table 9.2: GNU `awk' Rules For `sub()' And Backslash ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac In a nutshell, at the runtime level, there are now three special -sequences of characters ('\\\&', '\\&' and '\&') whereas historically -there was only one. However, as in the historical case, any '\' that is -not part of one of these three sequences is not special and appears in -the output literally. - -<<<<<<< HEAD - 'gawk' 3.0 and 3.1 follow these proposed POSIX rules for 'sub()' and -'gsub()'. The POSIX standard took much longer to be revised than was -expected in 1996. The 2001 standard does not follow the above rules. -Instead, the rules there are somewhat simpler. The results are similar -except for one case. -======= +sequences of characters (`\\\&', `\\&' and `\&') whereas historically +there was only one. However, as in the historical case, any `\' that +is not part of one of these three sequences is not special and appears +in the output literally. + `gawk' 3.0 and 3.1 follow these rules for `sub()' and `gsub()'. The POSIX standard took much longer to be revised than was expected. In addition, the `gawk' maintainer's proposal was lost during the standardization process. The final rules are somewhat simpler. The results are similar except for one case. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - - The POSIX rules state that '\&' in the replacement string produces a -literal '&', '\\' produces a literal '\', and '\' followed by anything -else is not special; the '\' is placed straight into the output. These -rules are presented in *note Table 9.4: table-posix-sub. - -<<<<<<< HEAD - You type 'sub()' sees 'sub()' generates - ----- ------- ---------- - '\\\\\\&' '\\\&' a literal '\&' - '\\\\&' '\\&' a literal '\', followed by the matched text - '\\&' '\&' a literal '&' - '\\q' '\q' a literal '\q' - '\\\\' '\\' '\' - -Table 9.4: POSIX Rules For 'sub()' And 'gsub()' -======= + + The POSIX rules state that `\&' in the replacement string produces a +literal `&', `\\' produces a literal `\', and `\' followed by anything +else is not special; the `\' is placed straight into the output. These +rules are presented in *note table-posix-sub::. + You type `sub()' sees `sub()' generates ------- --------- -------------- `\\\\\\&' `\\\&' A literal `\&' @@ -13411,23 +12521,10 @@ Table 9.4: POSIX Rules For 'sub()' And 'gsub()' `\\\\' `\\' `\' Table 9.3: POSIX Rules For `sub()' And `gsub()' ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac The only case where the difference is noticeable is the last one: -'\\\\' is seen as '\\' and produces '\' instead of '\\'. - -<<<<<<< HEAD - Starting with version 3.1.4, 'gawk' followed the POSIX rules when -'--posix' is specified (*note Options::). Otherwise, it continued to -follow the 1996 proposed rules, since that had been its behavior for -many years. - - When version 4.0.0 was released, the 'gawk' maintainer made the POSIX -rules the default, breaking well over a decade's worth of backwards -compatibility.(2) Needless to say, this was a bad idea, and as of -version 4.0.1, 'gawk' resumed its historical behavior, and only follows -the POSIX rules when '--posix' is given. -======= +`\\\\' is seen as `\\' and produces `\' instead of `\\'. + Starting with version 3.1.4, `gawk' followed the POSIX rules when `--posix' is specified (*note Options::). Otherwise, it continued to follow the proposed rules, since that had been its behavior for many @@ -13438,27 +12535,14 @@ POSIX rules the default, breaking well over a decade's worth of backwards compatibility.(1) Needless to say, this was a bad idea, and as of version 4.0.1, `gawk' resumed its historical behavior, and only follows the POSIX rules when `--posix' is given. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - The rules for 'gensub()' are considerably simpler. At the runtime -level, whenever 'gawk' sees a '\', if the following character is a + The rules for `gensub()' are considerably simpler. At the runtime +level, whenever `gawk' sees a `\', if the following character is a digit, then the text that matched the corresponding parenthesized subexpression is placed in the generated output. Otherwise, no matter -what character follows the '\', it appears in the generated text and the -'\' does not, as shown in *note Table 9.5: table-gensub-escapes. - -<<<<<<< HEAD - You type 'gensub()' sees 'gensub()' generates - ----- --------- ------------ - '&' '&' the matched text - '\\&' '\&' a literal '&' - '\\\\' '\\' a literal '\' - '\\\\&' '\\&' a literal '\', then the matched text - '\\\\\\&' '\\\&' a literal '\&' - '\\q' '\q' a literal 'q' - -Table 9.5: Escape Sequence Processing For 'gensub()' -======= +what character follows the `\', it appears in the generated text and +the `\' does not, as shown in *note table-gensub-escapes::. + You type `gensub()' sees `gensub()' generates ------- ------------ ----------------- `&' `&' The matched text @@ -13469,16 +12553,15 @@ Table 9.5: Escape Sequence Processing For 'gensub()' `\\q' `\q' A literal `q' Table 9.4: Escape Sequence Processing For `gensub()' ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Because of the complexity of the lexical and runtime level processing -and the special cases for 'sub()' and 'gsub()', we recommend the use of -'gawk' and 'gensub()' when you have to do substitutions. +and the special cases for `sub()' and `gsub()', we recommend the use of +`gawk' and `gensub()' when you have to do substitutions. Matching the Null String - In 'awk', the '*' operator can match the null string. This is -particularly important for the 'sub()', 'gsub()', and 'gensub()' + In `awk', the `*' operator can match the null string. This is +particularly important for the `sub()', `gsub()', and `gensub()' functions. For example: $ echo abc | awk '{ gsub(/m*/, "X"); print }' @@ -13498,31 +12581,31 @@ File: gawk.info, Node: I/O Functions, Next: Time Functions, Prev: String Func 9.1.4 Input/Output Functions ---------------------------- -The following functions relate to input/output (I/O). Optional +The following functions relate to input/output (I/O). Optional parameters are enclosed in square brackets ([ ]): -'close('FILENAME [',' HOW]')' - Close the file FILENAME for input or output. Alternatively, the +`close('FILENAME [`,' HOW]`)' + Close the file FILENAME for input or output. Alternatively, the argument may be a shell command that was used for creating a - coprocess, or for redirecting to or from a pipe; then the coprocess - or pipe is closed. *Note Close Files And Pipes::, for more - information. + coprocess, or for redirecting to or from a pipe; then the + coprocess or pipe is closed. *Note Close Files And Pipes::, for + more information. When closing a coprocess, it is occasionally useful to first close one end of the two-way pipe and then to close the other. This is - done by providing a second argument to 'close()'. This second - argument should be one of the two string values '"to"' or '"from"', + done by providing a second argument to `close()'. This second + argument should be one of the two string values `"to"' or `"from"', indicating which end of the pipe to close. Case in the string does not matter. *Note Two-way I/O::, which discusses this feature in more detail and gives an example. - Note that the second argument to 'close()' is a 'gawk' extension; + Note that the second argument to `close()' is a `gawk' extension; it is not available in compatibility mode (*note Options::). -'fflush('[FILENAME]')' - Flush any buffered output associated with FILENAME, which is either - a file opened for writing or a shell command for redirecting output - to a pipe or coprocess. +`fflush('[FILENAME]`)' + Flush any buffered output associated with FILENAME, which is + either a file opened for writing or a shell command for + redirecting output to a pipe or coprocess. Many utility programs "buffer" their output; i.e., they save information to write to a disk file or the screen in memory until @@ -13530,64 +12613,57 @@ parameters are enclosed in square brackets ([ ]): output device. This is often more efficient than writing every little bit of information as soon as it is ready. However, sometimes it is necessary to force a program to "flush" its - buffers; that is, write the information to its destination, even if - a buffer is not full. This is the purpose of the 'fflush()' - function--'gawk' also buffers its output and the 'fflush()' - function forces 'gawk' to flush its buffers. - -<<<<<<< HEAD - 'fflush()' was added to Brian Kernighan's 'awk' in April of 1992. - For two decades, it was not part of the POSIX standard. As of - December, 2012, it was accepted for inclusion into the POSIX - standard. See the Austin Group website -======= + buffers; that is, write the information to its destination, even + if a buffer is not full. This is the purpose of the `fflush()' + function--`gawk' also buffers its output and the `fflush()' + function forces `gawk' to flush its buffers. + `fflush()' was added to BWK `awk' in April of 1992. For two decades, it was not part of the POSIX standard. As of December, 2012, it was accepted for inclusion into the POSIX standard. See the Austin Group website ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (http://austingroupbugs.net/view.php?id=634). - POSIX standardizes 'fflush()' as follows: If there is no argument, - or if the argument is the null string ('""'), then 'awk' flushes + POSIX standardizes `fflush()' as follows: If there is no argument, + or if the argument is the null string (`""'), then `awk' flushes the buffers for _all_ open output files and pipes. - NOTE: Prior to version 4.0.2, 'gawk' would flush only the - standard output if there was no argument, and flush all output - files and pipes if the argument was the null string. This was - changed in order to be compatible with Brian Kernighan's - 'awk', in the hope that standardizing this feature in POSIX - would then be easier (which indeed helped). + NOTE: Prior to version 4.0.2, `gawk' would flush only the + standard output if there was no argument, and flush all + output files and pipes if the argument was the null string. + This was changed in order to be compatible with Brian + Kernighan's `awk', in the hope that standardizing this + feature in POSIX would then be easier (which indeed helped). - With 'gawk', you can use 'fflush("/dev/stdout")' if you wish + With `gawk', you can use `fflush("/dev/stdout")' if you wish to flush only the standard output. - 'fflush()' returns zero if the buffer is successfully flushed; - otherwise, it returns non-zero. ('gawk' returns -1.) In the case - where all buffers are flushed, the return value is zero only if all - buffers were flushed successfully. Otherwise, it is -1, and 'gawk' - warns about the problem FILENAME. + `fflush()' returns zero if the buffer is successfully flushed; + otherwise, it returns non-zero. (`gawk' returns -1.) In the case + where all buffers are flushed, the return value is zero only if + all buffers were flushed successfully. Otherwise, it is -1, and + `gawk' warns about the problem FILENAME. - 'gawk' also issues a warning message if you attempt to flush a file - or pipe that was opened for reading (such as with 'getline'), or if - FILENAME is not an open file, pipe, or coprocess. In such a case, - 'fflush()' returns -1, as well. + `gawk' also issues a warning message if you attempt to flush a + file or pipe that was opened for reading (such as with `getline'), + or if FILENAME is not an open file, pipe, or coprocess. In such a + case, `fflush()' returns -1, as well. -'system(COMMAND)' - Execute the operating-system command COMMAND and then return to the - 'awk' program. Return COMMAND's exit status. +`system(COMMAND)' + Execute the operating-system command COMMAND and then return to + the `awk' program. Return COMMAND's exit status. - For example, if the following fragment of code is put in your 'awk' + For example, if the following fragment of code is put in your `awk' program: END { system("date | mail -s 'awk run done' root") } - the system administrator is sent mail when the 'awk' program + the system administrator is sent mail when the `awk' program finishes processing input and begins its end-of-input processing. - Note that redirecting 'print' or 'printf' into a pipe is often + Note that redirecting `print' or `printf' into a pipe is often enough to accomplish your task. If you need to run many commands, it is more efficient to simply print them down a pipeline to the shell: @@ -13596,14 +12672,16 @@ parameters are enclosed in square brackets ([ ]): print COMMAND | "/bin/sh" close("/bin/sh") - However, if your 'awk' program is interactive, 'system()' is useful - for running large self-contained programs, such as a shell or an - editor. Some operating systems cannot implement the 'system()' - function. 'system()' causes a fatal error if it is not supported. + However, if your `awk' program is interactive, `system()' is + useful for running large self-contained programs, such as a shell + or an editor. Some operating systems cannot implement the + `system()' function. `system()' causes a fatal error if it is not + supported. - NOTE: When '--sandbox' is specified, the 'system()' function + NOTE: When `--sandbox' is specified, the `system()' function is disabled (*note Options::). + Interactive Versus Noninteractive Buffering As a side point, buffering issues can be even more confusing, @@ -13622,7 +12700,7 @@ the difference: -| 5 Ctrl-d -Each line of output is printed immediately. Compare that behavior with +Each line of output is printed immediately. Compare that behavior with this example: $ awk '{ print $1 + $2 }' | cat @@ -13632,30 +12710,30 @@ this example: -| 2 -| 5 -Here, no output is printed until after the 'Ctrl-d' is typed, because it -is all buffered and sent down the pipe to 'cat' in one shot. +Here, no output is printed until after the `Ctrl-d' is typed, because +it is all buffered and sent down the pipe to `cat' in one shot. - Controlling Output Buffering with 'system()' + Controlling Output Buffering with `system()' - The 'fflush()' function provides explicit control over output + The `fflush()' function provides explicit control over output buffering for individual files and pipes. However, its use is not -portable to many older 'awk' implementations. An alternative method to -flush output buffers is to call 'system()' with a null string as its +portable to many older `awk' implementations. An alternative method to +flush output buffers is to call `system()' with a null string as its argument: system("") # flush output -'gawk' treats this use of the 'system()' function as a special case and +`gawk' treats this use of the `system()' function as a special case and is smart enough not to run a shell (or other command interpreter) with -the empty command. Therefore, with 'gawk', this idiom is not only +the empty command. Therefore, with `gawk', this idiom is not only useful, it is also efficient. While this method should work with other -'awk' implementations, it does not necessarily avoid starting an +`awk' implementations, it does not necessarily avoid starting an unnecessary shell. (Other implementations may only flush the buffer associated with the standard output and not necessarily all buffered output.) If you think about what a programmer expects, it makes sense that -'system()' should flush any pending output. The following program: +`system()' should flush any pending output. The following program: BEGIN { print "first print" @@ -13675,13 +12753,13 @@ and not: first print second print - If 'awk' did not flush its buffers before calling 'system()', you + If `awk' did not flush its buffers before calling `system()', you would see the latter (undesirable) output. ---------- Footnotes ---------- - (1) A program is interactive if the standard output is connected to a -terminal device. On modern systems, this means your keyboard and + (1) A program is interactive if the standard output is connected to +a terminal device. On modern systems, this means your keyboard and screen.  @@ -13690,264 +12768,266 @@ File: gawk.info, Node: Time Functions, Next: Bitwise Functions, Prev: I/O Fun 9.1.5 Time Functions -------------------- -'awk' programs are commonly used to process log files containing +`awk' programs are commonly used to process log files containing timestamp information, indicating when a particular log record was written. Many programs log their timestamp in the form returned by the -'time()' system call, which is the number of seconds since a particular +`time()' system call, which is the number of seconds since a particular epoch. On POSIX-compliant systems, it is the number of seconds since -1970-01-01 00:00:00 UTC, not counting leap seconds.(1) All known +1970-01-01 00:00:00 UTC, not counting leap seconds.(1) All known POSIX-compliant systems support timestamps from 0 through 2^31 - 1, which is sufficient to represent times through 2038-01-19 03:14:07 UTC. Many systems support a wider range of timestamps, including negative timestamps that represent times before the epoch. In order to make it easier to process such log files and to produce -useful reports, 'gawk' provides the following functions for working with -timestamps. They are 'gawk' extensions; they are not specified in the -POSIX standard.(2) However, recent versions of 'mawk' (*note Other +useful reports, `gawk' provides the following functions for working +with timestamps. They are `gawk' extensions; they are not specified in +the POSIX standard.(2) However, recent versions of `mawk' (*note Other Versions::) also support these functions. Optional parameters are enclosed in square brackets ([ ]): -'mktime(DATESPEC)' +`mktime(DATESPEC)' Turn DATESPEC into a timestamp in the same form as is returned by - 'systime()'. It is similar to the function of the same name in ISO - C. The argument, DATESPEC, is a string of the form - '"YYYY MM DD HH MM SS [DST]"'. The string consists of six or seven - numbers representing, respectively, the full year including - century, the month from 1 to 12, the day of the month from 1 to 31, - the hour of the day from 0 to 23, the minute from 0 to 59, the + `systime()'. It is similar to the function of the same name in + ISO C. The argument, DATESPEC, is a string of the form + `"YYYY MM DD HH MM SS [DST]"'. The string consists of six or + seven numbers representing, respectively, the full year including + century, the month from 1 to 12, the day of the month from 1 to + 31, the hour of the day from 0 to 23, the minute from 0 to 59, the second from 0 to 60,(3) and an optional daylight-savings flag. The values of these numbers need not be within the ranges specified; for example, an hour of -1 means 1 hour before midnight. The origin-zero Gregorian calendar is assumed, with year 0 - preceding year 1 and year -1 preceding year 0. The time is assumed - to be in the local timezone. If the daylight-savings flag is - positive, the time is assumed to be daylight savings time; if zero, - the time is assumed to be standard time; and if negative (the - default), 'mktime()' attempts to determine whether daylight savings - time is in effect for the specified time. + preceding year 1 and year -1 preceding year 0. The time is + assumed to be in the local timezone. If the daylight-savings flag + is positive, the time is assumed to be daylight savings time; if + zero, the time is assumed to be standard time; and if negative + (the default), `mktime()' attempts to determine whether daylight + savings time is in effect for the specified time. If DATESPEC does not contain enough elements or if the resulting - time is out of range, 'mktime()' returns -1. - -'strftime(' [FORMAT [',' TIMESTAMP [',' UTC-FLAG] ] ]')' - Format the time specified by TIMESTAMP based on the contents of the - FORMAT string and return the result. It is similar to the function - of the same name in ISO C. If UTC-FLAG is present and is either - nonzero or non-null, the value is formatted as UTC (Coordinated - Universal Time, formerly GMT or Greenwich Mean Time). Otherwise, - the value is formatted for the local time zone. The TIMESTAMP is - in the same format as the value returned by the 'systime()' - function. If no TIMESTAMP argument is supplied, 'gawk' uses the - current time of day as the timestamp. If no FORMAT argument is - supplied, 'strftime()' uses the value of 'PROCINFO["strftime"]' as - the format string (*note Built-in Variables::). The default string - value is '"%a %b %e %H:%M:%S %Z %Y"'. This format string produces - output that is equivalent to that of the 'date' utility. You can - assign a new value to 'PROCINFO["strftime"]' to change the default + time is out of range, `mktime()' returns -1. + +`strftime(' [FORMAT [`,' TIMESTAMP [`,' UTC-FLAG] ] ]`)' + Format the time specified by TIMESTAMP based on the contents of + the FORMAT string and return the result. It is similar to the + function of the same name in ISO C. If UTC-FLAG is present and is + either nonzero or non-null, the value is formatted as UTC + (Coordinated Universal Time, formerly GMT or Greenwich Mean Time). + Otherwise, the value is formatted for the local time zone. The + TIMESTAMP is in the same format as the value returned by the + `systime()' function. If no TIMESTAMP argument is supplied, + `gawk' uses the current time of day as the timestamp. If no + FORMAT argument is supplied, `strftime()' uses the value of + `PROCINFO["strftime"]' as the format string (*note Built-in + Variables::). The default string value is + `"%a %b %e %H:%M:%S %Z %Y"'. This format string produces output + that is equivalent to that of the `date' utility. You can assign + a new value to `PROCINFO["strftime"]' to change the default format; see below for the various format directives. -'systime()' +`systime()' Return the current time as the number of seconds since the system epoch. On POSIX systems, this is the number of seconds since 1970-01-01 00:00:00 UTC, not counting leap seconds. It may be a different number on other systems. - The 'systime()' function allows you to compare a timestamp from a log -file with the current time of day. In particular, it is easy to + The `systime()' function allows you to compare a timestamp from a +log file with the current time of day. In particular, it is easy to determine how long ago a particular record was logged. It also allows you to produce log records using the "seconds since the epoch" format. - The 'mktime()' function allows you to convert a textual -representation of a date and time into a timestamp. This makes it easy -to do before/after comparisons of dates and times, particularly when -dealing with date and time data coming from an external source, such as -a log file. + The `mktime()' function allows you to convert a textual +representation of a date and time into a timestamp. This makes it +easy to do before/after comparisons of dates and times, particularly +when dealing with date and time data coming from an external source, +such as a log file. - The 'strftime()' function allows you to easily turn a timestamp into -human-readable information. It is similar in nature to the 'sprintf()' + The `strftime()' function allows you to easily turn a timestamp into +human-readable information. It is similar in nature to the `sprintf()' function (*note String Functions::), in that it copies nonformat specification characters verbatim to the returned string, while substituting date and time values for format specifications in the FORMAT string. - 'strftime()' is guaranteed by the 1999 ISO C standard(4) to support + `strftime()' is guaranteed by the 1999 ISO C standard(4) to support the following date format specifications: -'%a' +`%a' The locale's abbreviated weekday name. -'%A' +`%A' The locale's full weekday name. -'%b' +`%b' The locale's abbreviated month name. -'%B' +`%B' The locale's full month name. -'%c' +`%c' The locale's "appropriate" date and time representation. (This is - '%A %B %d %T %Y' in the '"C"' locale.) + `%A %B %d %T %Y' in the `"C"' locale.) -'%C' +`%C' The century part of the current year. This is the year divided by 100 and truncated to the next lower integer. -'%d' +`%d' The day of the month as a decimal number (01-31). -'%D' - Equivalent to specifying '%m/%d/%y'. +`%D' + Equivalent to specifying `%m/%d/%y'. -'%e' +`%e' The day of the month, padded with a space if it is only one digit. -'%F' - Equivalent to specifying '%Y-%m-%d'. This is the ISO 8601 date +`%F' + Equivalent to specifying `%Y-%m-%d'. This is the ISO 8601 date format. -'%g' +`%g' The year modulo 100 of the ISO 8601 week number, as a decimal number (00-99). For example, January 1, 2012 is in week 53 of - 2011. Thus, the year of its ISO 8601 week number is 2011, even - though its year is 2012. Similarly, December 31, 2012 is in week 1 - of 2013. Thus, the year of its ISO week number is 2013, even + 2011. Thus, the year of its ISO 8601 week number is 2011, even + though its year is 2012. Similarly, December 31, 2012 is in week + 1 of 2013. Thus, the year of its ISO week number is 2013, even though its year is 2012. -'%G' +`%G' The full year of the ISO week number, as a decimal number. -'%h' - Equivalent to '%b'. +`%h' + Equivalent to `%b'. -'%H' +`%H' The hour (24-hour clock) as a decimal number (00-23). -'%I' +`%I' The hour (12-hour clock) as a decimal number (01-12). -'%j' +`%j' The day of the year as a decimal number (001-366). -'%m' +`%m' The month as a decimal number (01-12). -'%M' +`%M' The minute as a decimal number (00-59). -'%n' +`%n' A newline character (ASCII LF). -'%p' - The locale's equivalent of the AM/PM designations associated with a - 12-hour clock. +`%p' + The locale's equivalent of the AM/PM designations associated with + a 12-hour clock. -'%r' - The locale's 12-hour clock time. (This is '%I:%M:%S %p' in the - '"C"' locale.) +`%r' + The locale's 12-hour clock time. (This is `%I:%M:%S %p' in the + `"C"' locale.) -'%R' - Equivalent to specifying '%H:%M'. +`%R' + Equivalent to specifying `%H:%M'. -'%S' +`%S' The second as a decimal number (00-60). -'%t' +`%t' A TAB character. -'%T' - Equivalent to specifying '%H:%M:%S'. +`%T' + Equivalent to specifying `%H:%M:%S'. -'%u' +`%u' The weekday as a decimal number (1-7). Monday is day one. -'%U' +`%U' The week number of the year (the first Sunday as the first day of week one) as a decimal number (00-53). -'%V' +`%V' The week number of the year (the first Monday as the first day of week one) as a decimal number (01-53). The method for determining the week number is as specified by ISO 8601. (To wit: if the week - containing January 1 has four or more days in the new year, then it - is week one; otherwise it is week 53 of the previous year and the - next week is week one.) + containing January 1 has four or more days in the new year, then + it is week one; otherwise it is week 53 of the previous year and + the next week is week one.) -'%w' +`%w' The weekday as a decimal number (0-6). Sunday is day zero. -'%W' +`%W' The week number of the year (the first Monday as the first day of week one) as a decimal number (00-53). -'%x' - The locale's "appropriate" date representation. (This is '%A %B %d - %Y' in the '"C"' locale.) +`%x' + The locale's "appropriate" date representation. (This is `%A %B + %d %Y' in the `"C"' locale.) -'%X' - The locale's "appropriate" time representation. (This is '%T' in - the '"C"' locale.) +`%X' + The locale's "appropriate" time representation. (This is `%T' in + the `"C"' locale.) -'%y' +`%y' The year modulo 100 as a decimal number (00-99). -'%Y' +`%Y' The full year as a decimal number (e.g., 2015). -'%z' +`%z' The timezone offset in a +HHMM format (e.g., the format necessary to produce RFC 822/RFC 1036 date headers). -'%Z' +`%Z' The time zone name or abbreviation; no characters if no time zone is determinable. -'%Ec %EC %Ex %EX %Ey %EY %Od %Oe %OH' -'%OI %Om %OM %OS %Ou %OU %OV %Ow %OW %Oy' +`%Ec %EC %Ex %EX %Ey %EY %Od %Oe %OH' +`%OI %Om %OM %OS %Ou %OU %OV %Ow %OW %Oy' "Alternate representations" for the specifications that use only - the second letter ('%c', '%C', and so on).(5) (These facilitate - compliance with the POSIX 'date' utility.) + the second letter (`%c', `%C', and so on).(5) (These facilitate + compliance with the POSIX `date' utility.) -'%%' - A literal '%'. +`%%' + A literal `%'. If a conversion specifier is not one of the above, the behavior is undefined.(6) - For systems that are not yet fully standards-compliant, 'gawk' -supplies a copy of 'strftime()' from the GNU C Library. It supports all -of the just-listed format specifications. If that version is used to -compile 'gawk' (*note Installation::), then the following additional + For systems that are not yet fully standards-compliant, `gawk' +supplies a copy of `strftime()' from the GNU C Library. It supports +all of the just-listed format specifications. If that version is used +to compile `gawk' (*note Installation::), then the following additional format specifications are available: -'%k' +`%k' The hour (24-hour clock) as a decimal number (0-23). Single-digit numbers are padded with a space. -'%l' +`%l' The hour (12-hour clock) as a decimal number (1-12). Single-digit numbers are padded with a space. -'%s' +`%s' The time as a decimal timestamp in seconds since the epoch. + Additionally, the alternate representations are recognized but their normal representations are used. - The following example is an 'awk' implementation of the POSIX 'date' -utility. Normally, the 'date' utility prints the current date and time + The following example is an `awk' implementation of the POSIX `date' +utility. Normally, the `date' utility prints the current date and time of day in a well-known format. However, if you provide an argument to -it that begins with a '+', 'date' copies nonformat specifier characters +it that begins with a `+', `date' copies nonformat specifier characters to the standard output and interprets the current time according to the format specifiers in the string. For example: $ date '+Today is %A, %B %d, %Y.' -| Today is Monday, May 05, 2014. - Here is the 'gawk' version of the 'date' utility. It has a shell -"wrapper" to handle the '-u' option, which requires that 'date' run as + Here is the `gawk' version of the `date' utility. It has a shell +"wrapper" to handle the `-u' option, which requires that `date' run as if the time zone is set to UTC: #! /bin/sh @@ -13979,14 +13059,14 @@ if the time zone is set to UTC: (1) *Note Glossary::, especially the entries "Epoch" and "UTC." - (2) The GNU 'date' utility can also do many of the things described + (2) The GNU `date' utility can also do many of the things described here. Its use may be preferable for simple time-related operations in shell scripts. (3) Occasionally there are minutes in a year with a leap second, which is why the seconds can go up to 60. - (4) Unfortunately, not every system's 'strftime()' necessarily + (4) Unfortunately, not every system's `strftime()' necessarily supports all of the conversions listed here. (5) If you don't understand any of this, don't worry about it; these @@ -13995,8 +13075,8 @@ Other internationalization features are described in *note Internationalization::. (6) This is because ISO C leaves the behavior of the C version of -'strftime()' undefined and 'gawk' uses the system's version of -'strftime()' if it's there. Typically, the conversion specifier either +`strftime()' undefined and `gawk' uses the system's version of +`strftime()' if it's there. Typically, the conversion specifier either does not appear in the returned string or appears literally.  @@ -14005,20 +13085,20 @@ File: gawk.info, Node: Bitwise Functions, Next: Type Functions, Prev: Time Fu 9.1.6 Bit-Manipulation Functions -------------------------------- - I can explain it for you, but I can't understand it for you. - -- _Anonymous_ + I can explain it for you, but I can't understand it for you. -- + Anonymous - Many languages provide the ability to perform "bitwise" operations on -two integer numbers. In other words, the operation is performed on each -successive pair of bits in the operands. Three common operations are -bitwise AND, OR, and XOR. The operations are described in *note Table -9.6: table-bitwise-ops. + Many languages provide the ability to perform "bitwise" operations +on two integer numbers. In other words, the operation is performed on +each successive pair of bits in the operands. Three common operations +are bitwise AND, OR, and XOR. The operations are described in *note +table-bitwise-ops::. Bit Operator | AND | OR | XOR |--+--+--+--+--+-- Operands | 0 | 1 | 0 | 1 | 0 | 1 - -------+--+--+--+--+--+-- + ---------+--+--+--+--+--+-- 0 | 0 0 | 0 1 | 0 1 1 | 0 1 | 1 1 | 1 0 @@ -14027,45 +13107,44 @@ Table 9.5: Bitwise Operations As you can see, the result of an AND operation is 1 only when _both_ bits are 1. The result of an OR operation is 1 if _either_ bit is 1. The result of an XOR operation is 1 if either bit is 1, but not both. -The next operation is the "complement"; the complement of 1 is 0 and the -complement of 0 is 1. Thus, this operation "flips" all the bits of a -given value. +The next operation is the "complement"; the complement of 1 is 0 and +the complement of 0 is 1. Thus, this operation "flips" all the bits of +a given value. Finally, two other common operations are to shift the bits left or -right. For example, if you have a bit string '10111001' and you shift -it right by three bits, you end up with '00010111'.(1) If you start -over again with '10111001' and shift it left by three bits, you end up -with '11001000'. 'gawk' provides built-in functions that implement the -bitwise operations just described. They are: - -'and(V1, V2 [, ...])' - Return the bitwise AND of the arguments. There must be at least +right. For example, if you have a bit string `10111001' and you shift +it right by three bits, you end up with `00010111'.(1) If you start over +again with `10111001' and shift it left by three bits, you end up with +`11001000'. `gawk' provides built-in functions that implement the +bitwise operations just described. They are: + +``and(V1, V2' [`,' ...]`)'' + Return the bitwise AND of the arguments. There must be at least two. -'compl(VAL)' +``compl(VAL)'' Return the bitwise complement of VAL. -'lshift(VAL, COUNT)' +``lshift(VAL, COUNT)'' Return the value of VAL, shifted left by COUNT bits. -'or(V1, V2 [, ...])' - Return the bitwise OR of the arguments. There must be at least - two. +``or(V1, V2' [`,' ...]`)'' + Return the bitwise OR of the arguments. There must be at least two. -'rshift(VAL, COUNT)' +``rshift(VAL, COUNT)'' Return the value of VAL, shifted right by COUNT bits. -'xor(V1, V2 [, ...])' - Return the bitwise XOR of the arguments. There must be at least +``xor(V1, V2' [`,' ...]`)'' + Return the bitwise XOR of the arguments. There must be at least two. - For all of these functions, first the double precision floating-point -value is converted to the widest C unsigned integer type, then the -bitwise operation is performed. If the result cannot be represented -exactly as a C 'double', leading nonzero bits are removed one by one -until it can be represented exactly. The result is then converted back -into a C 'double'. (If you don't understand this paragraph, don't worry -about it.) + For all of these functions, first the double precision +floating-point value is converted to the widest C unsigned integer +type, then the bitwise operation is performed. If the result cannot be +represented exactly as a C `double', leading nonzero bits are removed +one by one until it can be represented exactly. The result is then +converted back into a C `double'. (If you don't understand this +paragraph, don't worry about it.) Here is a user-defined function (*note User-defined::) that illustrates the use of these functions: @@ -14109,28 +13188,28 @@ This program produces the following output when run: -| lshift(0x99, 2) = 0x264 = 0000001001100100 -| rshift(0x99, 2) = 0x26 = 00100110 - The 'bits2str()' function turns a binary number into a string. The -number '1' represents a binary value where the rightmost bit is set to + The `bits2str()' function turns a binary number into a string. The +number `1' represents a binary value where the rightmost bit is set to 1. Using this mask, the function repeatedly checks the rightmost bit. ANDing the mask with the value indicates whether the rightmost bit is 1 -or not. If so, a '"1"' is concatenated onto the front of the string. -Otherwise, a '"0"' is added. The value is then shifted right by one bit -and the loop continues until there are no more 1 bits. +or not. If so, a `"1"' is concatenated onto the front of the string. +Otherwise, a `"0"' is added. The value is then shifted right by one +bit and the loop continues until there are no more 1 bits. - If the initial value is zero it returns a simple '"0"'. Otherwise, -at the end, it pads the value with zeros to represent multiples of 8-bit -quantities. This is typical in modern computers. + If the initial value is zero it returns a simple `"0"'. Otherwise, +at the end, it pads the value with zeros to represent multiples of +8-bit quantities. This is typical in modern computers. - The main code in the 'BEGIN' rule shows the difference between the + The main code in the `BEGIN' rule shows the difference between the decimal and octal values for the same numbers (*note Nondecimal-numbers::), and then demonstrates the results of the -'compl()', 'lshift()', and 'rshift()' functions. +`compl()', `lshift()', and `rshift()' functions. ---------- Footnotes ---------- - (1) This example shows that 0's come in on the left side. For -'gawk', this is always true, but in some languages, it's possible to -have the left side fill with 1's. Caveat emptor. + (1) This example shows that 0's come in on the left side. For +`gawk', this is always true, but in some languages, it's possible to +have the left side fill with 1's. Caveat emptor.  File: gawk.info, Node: Type Functions, Next: I18N Functions, Prev: Bitwise Functions, Up: Built-in @@ -14138,26 +13217,26 @@ File: gawk.info, Node: Type Functions, Next: I18N Functions, Prev: Bitwise Fu 9.1.7 Getting Type Information ------------------------------ -'gawk' provides a single function that lets you distinguish an array +`gawk' provides a single function that lets you distinguish an array from a scalar variable. This is necessary for writing code that traverses every element of an array of arrays. (*note Arrays of Arrays::). -'isarray(X)' - Return a true value if X is an array. Otherwise return false. +`isarray(X)' + Return a true value if X is an array. Otherwise return false. - 'isarray()' is meant for use in two circumstances. The first is when + `isarray()' is meant for use in two circumstances. The first is when traversing a multidimensional array: you can test if an element is -itself an array or not. The second is inside the body of a user-defined -function (not discussed yet; *note User-defined::), to test if a -parameter is an array or not. +itself an array or not. The second is inside the body of a +user-defined function (not discussed yet; *note User-defined::), to +test if a parameter is an array or not. - Note, however, that using 'isarray()' at the global level to test -variables makes no sense. Since you are the one writing the program, -you are supposed to know if your variables are arrays or not. And in -fact, due to the way 'gawk' works, if you pass the name of a variable -that has not been previously used to 'isarray()', 'gawk' will end up -turning it into a scalar. + Note, however, that using `isarray()' at the global level to test +variables makes no sense. Since you are the one writing the program, you +are supposed to know if your variables are arrays or not. And in fact, +due to the way `gawk' works, if you pass the name of a variable that +has not been previously used to `isarray()', `gawk' will end up turning +it into a scalar.  File: gawk.info, Node: I18N Functions, Prev: Type Functions, Up: Built-in @@ -14165,34 +13244,35 @@ File: gawk.info, Node: I18N Functions, Prev: Type Functions, Up: Built-in 9.1.8 String-Translation Functions ---------------------------------- -'gawk' provides facilities for internationalizing 'awk' programs. These -include the functions described in the following list. The descriptions -here are purposely brief. *Note Internationalization::, for the full -story. Optional parameters are enclosed in square brackets ([ ]): +`gawk' provides facilities for internationalizing `awk' programs. +These include the functions described in the following list. The +descriptions here are purposely brief. *Note Internationalization::, +for the full story. Optional parameters are enclosed in square +brackets ([ ]): -'bindtextdomain(DIRECTORY' [',' DOMAIN]')' - Set the directory in which 'gawk' will look for message translation - files, in case they will not or cannot be placed in the "standard" - locations (e.g., during testing). It returns the directory in - which DOMAIN is "bound." +`bindtextdomain(DIRECTORY' [`,' DOMAIN]`)' + Set the directory in which `gawk' will look for message + translation files, in case they will not or cannot be placed in + the "standard" locations (e.g., during testing). It returns the + directory in which DOMAIN is "bound." - The default DOMAIN is the value of 'TEXTDOMAIN'. If DIRECTORY is - the null string ('""'), then 'bindtextdomain()' returns the current - binding for the given DOMAIN. + The default DOMAIN is the value of `TEXTDOMAIN'. If DIRECTORY is + the null string (`""'), then `bindtextdomain()' returns the + current binding for the given DOMAIN. -'dcgettext(STRING' [',' DOMAIN [',' CATEGORY] ]')' +`dcgettext(STRING' [`,' DOMAIN [`,' CATEGORY] ]`)' Return the translation of STRING in text domain DOMAIN for locale category CATEGORY. The default value for DOMAIN is the current - value of 'TEXTDOMAIN'. The default value for CATEGORY is - '"LC_MESSAGES"'. + value of `TEXTDOMAIN'. The default value for CATEGORY is + `"LC_MESSAGES"'. -'dcngettext(STRING1, STRING2, NUMBER' [',' DOMAIN [',' CATEGORY] ]')' +`dcngettext(STRING1, STRING2, NUMBER' [`,' DOMAIN [`,' CATEGORY] ]`)' Return the plural form used for NUMBER of the translation of STRING1 and STRING2 in text domain DOMAIN for locale category - CATEGORY. STRING1 is the English singular variant of a message, + CATEGORY. STRING1 is the English singular variant of a message, and STRING2 the English plural variant of the same message. The - default value for DOMAIN is the current value of 'TEXTDOMAIN'. The - default value for CATEGORY is '"LC_MESSAGES"'. + default value for DOMAIN is the current value of `TEXTDOMAIN'. + The default value for CATEGORY is `"LC_MESSAGES"'.  File: gawk.info, Node: User-defined, Next: Indirect Calls, Prev: Built-in, Up: Functions @@ -14200,10 +13280,10 @@ File: gawk.info, Node: User-defined, Next: Indirect Calls, Prev: Built-in, U 9.2 User-Defined Functions ========================== -Complicated 'awk' programs can often be simplified by defining your own -functions. User-defined functions can be called just like built-in ones -(*note Function Calls::), but it is up to you to define them, i.e., to -tell 'awk' what they should do. +Complicated `awk' programs can often be simplified by defining your own +functions. User-defined functions can be called just like built-in +ones (*note Function Calls::), but it is up to you to define them, +i.e., to tell `awk' what they should do. * Menu: @@ -14220,31 +13300,26 @@ File: gawk.info, Node: Definition Syntax, Next: Function Example, Up: User-de 9.2.1 Function Definition Syntax -------------------------------- -<<<<<<< HEAD -Definitions of functions can appear anywhere between the rules of an -'awk' program. Thus, the general form of an 'awk' program is extended -======= It's entirely fair to say that the `awk' syntax for local variable definitions is appallingly awful. -- Brian Kernighan Definitions of functions can appear anywhere between the rules of an `awk' program. Thus, the general form of an `awk' program is extended ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac to include sequences of rules _and_ user-defined function definitions. There is no need to put the definition of a function before all uses of -the function. This is because 'awk' reads the entire program before +the function. This is because `awk' reads the entire program before starting to execute any of it. The definition of a function named NAME looks like this: - 'function' NAME'('[PARAMETER-LIST]')' - '{' + `function' NAME`('[PARAMETER-LIST]`)' + `{' BODY-OF-FUNCTION - '}' + `}' -Here, NAME is the name of the function to define. A valid function name -is like a valid variable name: a sequence of letters, digits, and -underscores that doesn't start with a digit. Within a single 'awk' +Here, NAME is the name of the function to define. A valid function +name is like a valid variable name: a sequence of letters, digits, and +underscores that doesn't start with a digit. Within a single `awk' program, any particular name can only be used as a variable, array, or function. @@ -14257,28 +13332,23 @@ call. have a parameter with the same name as the function itself. In addition, according to the POSIX standard, function parameters cannot have the same name as one of the special built-in variables (*note -<<<<<<< HEAD -Built-in Variables::). Not all versions of 'awk' enforce this -restriction.) -======= Built-in Variables::). Not all versions of `awk' enforce this restriction. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Local variables act like the empty string if referenced where a string value is required, and like zero if referenced where a numeric -value is required. This is the same as regular variables that have +value is required. This is the same as regular variables that have never been assigned a value. (There is more to understand about local variables; *note Dynamic Typing::.) - The BODY-OF-FUNCTION consists of 'awk' statements. It is the most + The BODY-OF-FUNCTION consists of `awk' statements. It is the most important part of the definition, because it says what the function should actually _do_. The argument names exist to give the body a way to talk about the arguments; local variables exist to give the body places to keep temporary values. Argument names are not distinguished syntactically from local -variable names. Instead, the number of arguments supplied when the +variable names. Instead, the number of arguments supplied when the function is called determines how many argument variables there are. Thus, if three argument values are given, the first three names in PARAMETER-LIST are arguments and the rest are local variables. @@ -14288,19 +13358,19 @@ calls to the function, some of the names in PARAMETER-LIST may be arguments on some occasions and local variables on others. Another way to think of this is that omitted arguments default to the null string. - Usually when you write a function, you know how many names you intend -to use for arguments and how many you intend to use as local variables. -It is conventional to place some extra space between the arguments and -the local variables, in order to document how your function is supposed -to be used. + Usually when you write a function, you know how many names you +intend to use for arguments and how many you intend to use as local +variables. It is conventional to place some extra space between the +arguments and the local variables, in order to document how your +function is supposed to be used. During execution of the function body, the arguments and local variable values hide, or "shadow", any variables of the same names used in the rest of the program. The shadowed variables are not accessible in the function definition, because there is no way to name them while their names have been taken away for the local variables. All other -variables used in the 'awk' program can be referenced or set normally in -the function's body. +variables used in the `awk' program can be referenced or set normally +in the function's body. The arguments and local variables last only as long as the function body is executing. Once the body finishes, you can once again access @@ -14312,31 +13382,32 @@ function. When this happens, we say the function is "recursive". The act of a function calling itself is called "recursion". All the built-in functions return a value to their caller. -User-defined functions can do so also, using the 'return' statement, +User-defined functions can do so also, using the `return' statement, which is described in detail in *note Return Statement::. Many of the -subsequent examples in this minor node use the 'return' statement. +subsequent examples in this minor node use the `return' statement. - In many 'awk' implementations, including 'gawk', the keyword -'function' may be abbreviated 'func'. (c.e.) However, POSIX only -specifies the use of the keyword 'function'. This actually has some -practical implications. If 'gawk' is in POSIX-compatibility mode (*note -Options::), then the following statement does _not_ define a function: + In many `awk' implementations, including `gawk', the keyword +`function' may be abbreviated `func'. (c.e.) However, POSIX only +specifies the use of the keyword `function'. This actually has some +practical implications. If `gawk' is in POSIX-compatibility mode +(*note Options::), then the following statement does _not_ define a +function: func foo() { a = sqrt($1) ; print a } Instead it defines a rule that, for each record, concatenates the value -of the variable 'func' with the return value of the function 'foo'. If +of the variable `func' with the return value of the function `foo'. If the resulting string is non-null, the action is executed. This is -probably not what is desired. ('awk' accepts this input as +probably not what is desired. (`awk' accepts this input as syntactically valid, because functions may be used before they are -defined in 'awk' programs.(1)) +defined in `awk' programs.(1)) - To ensure that your 'awk' programs are portable, always use the -keyword 'function' when defining a function. + To ensure that your `awk' programs are portable, always use the +keyword `function' when defining a function. ---------- Footnotes ---------- - (1) This program won't actually run, since 'foo()' is undefined. + (1) This program won't actually run, since `foo()' is undefined.  File: gawk.info, Node: Function Example, Next: Function Caveats, Prev: Definition Syntax, Up: User-defined @@ -14344,7 +13415,7 @@ File: gawk.info, Node: Function Example, Next: Function Caveats, Prev: Defini 9.2.2 Function Definition Examples ---------------------------------- -Here is an example of a user-defined function, called 'myprint()', that +Here is an example of a user-defined function, called `myprint()', that takes a number and prints it in a specific format: function myprint(num) @@ -14352,7 +13423,7 @@ takes a number and prints it in a specific format: printf "%6.3g\n", num } -To illustrate, here is an 'awk' rule that uses our 'myprint' function: +To illustrate, here is an `awk' rule that uses our `myprint' function: $3 > 0 { myprint($3) } @@ -14381,8 +13452,8 @@ extra whitespace signifies the start of the local variable list): When working with arrays, it is often necessary to delete all the elements in an array and start over with a new list of elements (*note Delete::). Instead of having to repeat this loop everywhere that you -need to clear out an array, your program can just call 'delarray'. -(This guarantees portability. The use of 'delete ARRAY' to delete the +need to clear out an array, your program can just call `delarray'. +(This guarantees portability. The use of `delete ARRAY' to delete the contents of an entire array is a recent(1) addition to the POSIX standard.) @@ -14400,17 +13471,17 @@ empty. return (rev(substr(str, 2)) substr(str, 1, 1)) } - If this function is in a file named 'rev.awk', it can be tested this + If this function is in a file named `rev.awk', it can be tested this way: $ echo "Don't Panic!" | > gawk -e '{ print rev($0) }' -f rev.awk -| !cinaP t'noD - The C 'ctime()' function takes a timestamp and returns it in a + The C `ctime()' function takes a timestamp and returns it in a string, formatted in a well-known fashion. The following example uses -the built-in 'strftime()' function (*note Time Functions::) to create an -'awk' version of 'ctime()': +the built-in `strftime()' function (*note Time Functions::) to create +an `awk' version of `ctime()': # ctime.awk # @@ -14451,20 +13522,20 @@ File: gawk.info, Node: Calling A Function, Next: Variable Scope, Up: Function ............................... A function call consists of the function name followed by the arguments -in parentheses. 'awk' expressions are what you write in the call for +in parentheses. `awk' expressions are what you write in the call for the arguments. Each time the call is executed, these expressions are evaluated, and the values become the actual arguments. For example, -here is a call to 'foo()' with three arguments (the first being a string -concatenation): +here is a call to `foo()' with three arguments (the first being a +string concatenation): foo(x y, "lose", 4 * z) CAUTION: Whitespace characters (spaces and TABs) are not allowed between the function name and the open-parenthesis of the argument - list. If you write whitespace by mistake, 'awk' might think that + list. If you write whitespace by mistake, `awk' might think that you mean to concatenate a variable with an expression in - parentheses. However, it notices that you used a function name and - not a variable name, and reports an error. + parentheses. However, it notices that you used a function name + and not a variable name, and reports an error.  File: gawk.info, Node: Variable Scope, Next: Pass By Value/Reference, Prev: Calling A Function, Up: Function Caveats @@ -14472,15 +13543,15 @@ File: gawk.info, Node: Variable Scope, Next: Pass By Value/Reference, Prev: C 9.2.3.2 Controlling Variable Scope .................................. -Unlike many languages, there is no way to make a variable local to a '{' -... '}' block in 'awk', but you can make a variable local to a function. -It is good practice to do so whenever a variable is needed only in that -function. +Unlike many languages, there is no way to make a variable local to a +`{' ... `}' block in `awk', but you can make a variable local to a +function. It is good practice to do so whenever a variable is needed +only in that function. To make a variable local to a function, simply declare the variable as an argument after the actual function arguments (*note Definition -Syntax::). Look at the following example where variable 'i' is a global -variable used by both functions 'foo()' and 'bar()': +Syntax::). Look at the following example where variable `i' is a +global variable used by both functions `foo()' and `bar()': function bar() { @@ -14503,8 +13574,8 @@ variable used by both functions 'foo()' and 'bar()': print "top's i=" i } - Running this script produces the following, because the 'i' in -functions 'foo()' and 'bar()' and at the top level refer to the same + Running this script produces the following, because the `i' in +functions `foo()' and `bar()' and at the top level refer to the same variable instance: top's i=10 @@ -14515,9 +13586,9 @@ variable instance: foo's i=3 top's i=3 - If you want 'i' to be local to both 'foo()' and 'bar()' do as follows -(the extra-space before 'i' is a coding convention to indicate that 'i' -is a local variable, not an argument): + If you want `i' to be local to both `foo()' and `bar()' do as +follows (the extra-space before `i' is a coding convention to indicate +that `i' is a local variable, not an argument): function bar( i) { @@ -14551,7 +13622,7 @@ is a local variable, not an argument): top's i=10 Besides scalar values (strings and numbers), you may also have local -arrays. By using a parameter name as an array, 'awk' treats it as an +arrays. By using a parameter name as an array, `awk' treats it as an array, and it is local to the function. In addition, recursive calls create new arrays. Consider this example: @@ -14592,7 +13663,7 @@ File: gawk.info, Node: Pass By Value/Reference, Prev: Variable Scope, Up: Fun 9.2.3.3 Passing Function Arguments By Value Or By Reference ........................................................... -In 'awk', when you declare a function, there is no way to declare +In `awk', when you declare a function, there is no way to declare explicitly whether the arguments are passed "by value" or "by reference". @@ -14601,6 +13672,7 @@ function is called according to the following rule: * If the argument is an array variable, then it is passed by reference, + * Otherwise the argument is passed by value. Passing an argument by value means that when a function is called, it @@ -14612,11 +13684,11 @@ example, if you write the following code: foo = "bar" z = myfunc(foo) -then you should not think of the argument to 'myfunc()' as being "the -variable 'foo'." Instead, think of the argument as the string value -'"bar"'. If the function 'myfunc()' alters the values of its local +then you should not think of the argument to `myfunc()' as being "the +variable `foo'." Instead, think of the argument as the string value +`"bar"'. If the function `myfunc()' alters the values of its local variables, this has no effect on any other variables. Thus, if -'myfunc()' does this: +`myfunc()' does this: function myfunc(str) { @@ -14625,11 +13697,11 @@ variables, this has no effect on any other variables. Thus, if print str } -to change its first argument variable 'str', it does _not_ change the -value of 'foo' in the caller. The role of 'foo' in calling 'myfunc()' -ended when its value ('"bar"') was computed. If 'str' also exists -outside of 'myfunc()', the function body cannot alter this outer value, -because it is shadowed during the execution of 'myfunc()' and cannot be +to change its first argument variable `str', it does _not_ change the +value of `foo' in the caller. The role of `foo' in calling `myfunc()' +ended when its value (`"bar"') was computed. If `str' also exists +outside of `myfunc()', the function body cannot alter this outer value, +because it is shadowed during the execution of `myfunc()' and cannot be seen or changed from there. However, when arrays are the parameters to functions, they are _not_ @@ -14653,17 +13725,12 @@ function _are_ visible outside that function. a[1], a[2], a[3] } -<<<<<<< HEAD - prints 'a[1] = 1, a[2] = two, a[3] = 3', because 'changeit' stores - '"two"' in the second element of 'a'. -======= prints `a[1] = 1, a[2] = two, a[3] = 3', because `changeit()' stores `"two"' in the second element of `a'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - Some 'awk' implementations allow you to call a function that has not -been defined. They only report a problem at runtime when the program -actually tries to call the function. For example: + Some `awk' implementations allow you to call a function that has not +been defined. They only report a problem at runtime when the program +actually tries to call the function. For example: BEGIN { if (0) @@ -14674,52 +13741,53 @@ actually tries to call the function. For example: function bar() { ... } # note that `foo' is not defined -Because the 'if' statement will never be true, it is not really a -problem that 'foo()' has not been defined. Usually, though, it is a +Because the `if' statement will never be true, it is not really a +problem that `foo()' has not been defined. Usually, though, it is a problem if a program calls an undefined function. - If '--lint' is specified (*note Options::), 'gawk' reports calls to + If `--lint' is specified (*note Options::), `gawk' reports calls to undefined functions. - Some 'awk' implementations generate a runtime error if you use either -the 'next' statement or the 'nextfile' statement (*note Next + Some `awk' implementations generate a runtime error if you use +either the `next' statement or the `nextfile' statement (*note Next Statement::, also *note Nextfile Statement::) inside a user-defined -function. 'gawk' does not have this limitation. +function. `gawk' does not have this limitation.  File: gawk.info, Node: Return Statement, Next: Dynamic Typing, Prev: Function Caveats, Up: User-defined -9.2.4 The 'return' Statement +9.2.4 The `return' Statement ---------------------------- -As seen in several earlier examples, the body of a user-defined function -can contain a 'return' statement. This statement returns control to the -calling part of the 'awk' program. It can also be used to return a -value for use in the rest of the 'awk' program. It looks like this: +As seen in several earlier examples, the body of a user-defined +function can contain a `return' statement. This statement returns +control to the calling part of the `awk' program. It can also be used +to return a value for use in the rest of the `awk' program. It looks +like this: - 'return' [EXPRESSION] + `return' [EXPRESSION] The EXPRESSION part is optional. Due most likely to an oversight, POSIX does not define what the return value is if you omit the EXPRESSION. Technically speaking, this makes the returned value undefined, and therefore, unpredictable. In practice, though, all -versions of 'awk' simply return the null string, which acts like zero if -used in a numeric context. +versions of `awk' simply return the null string, which acts like zero +if used in a numeric context. - A 'return' statement with no value expression is assumed at the end + A `return' statement with no value expression is assumed at the end of every function definition. So if control reaches the end of the function body, then technically, the function returns an unpredictable -value. In practice, it returns the empty string. 'awk' does _not_ warn -you if you use the return value of such a function. +value. In practice, it returns the empty string. `awk' does _not_ +warn you if you use the return value of such a function. Sometimes, you want to write a function for what it does, not for -what it returns. Such a function corresponds to a 'void' function in C, -C++ or Java, or to a 'procedure' in Ada. Thus, it may be appropriate to -not return any value; simply bear in mind that you should not be using -the return value of such a function. +what it returns. Such a function corresponds to a `void' function in +C, C++ or Java, or to a `procedure' in Ada. Thus, it may be +appropriate to not return any value; simply bear in mind that you +should not be using the return value of such a function. - The following is an example of a user-defined function that returns a -value for the largest number among the elements of an array: + The following is an example of a user-defined function that returns +a value for the largest number among the elements of an array: function maxelt(vec, i, ret) { @@ -14730,15 +13798,15 @@ value for the largest number among the elements of an array: return ret } -You call 'maxelt()' with one argument, which is an array name. The -local variables 'i' and 'ret' are not intended to be arguments; while +You call `maxelt()' with one argument, which is an array name. The +local variables `i' and `ret' are not intended to be arguments; while there is nothing to stop you from passing more than one argument to -'maxelt()', the results would be strange. The extra space before 'i' in -the function parameter list indicates that 'i' and 'ret' are local +`maxelt()', the results would be strange. The extra space before `i' +in the function parameter list indicates that `i' and `ret' are local variables. You should follow this convention when defining functions. - The following program uses the 'maxelt()' function. It loads an -array, calls 'maxelt()', and then reports the maximum number in that + The following program uses the `maxelt()' function. It loads an +array, calls `maxelt()', and then reports the maximum number in that array: function maxelt(vec, i, ret) @@ -14777,8 +13845,8 @@ File: gawk.info, Node: Dynamic Typing, Prev: Return Statement, Up: User-defin 9.2.5 Functions and Their Effects on Variable Typing ---------------------------------------------------- -'awk' is a very fluid language. It is possible that 'awk' can't tell if -an identifier represents a scalar variable or an array until runtime. +`awk' is a very fluid language. It is possible that `awk' can't tell +if an identifier represents a scalar variable or an array until runtime. Here is an annotated sample program: function foo(a) @@ -14794,9 +13862,9 @@ Here is an annotated sample program: x = 1 # now not allowed, runtime error } - In this example, the first call to 'foo()' generates a fatal error, -so 'awk' will not report the second error. If you comment out that -call, though, then 'awk' does report the second error. + In this example, the first call to `foo()' generates a fatal error, +so `awk' will not report the second error. If you comment out that +call, though, then `awk' does report the second error. Usually, such things aren't a big issue, but it's worth being aware of them. @@ -14807,25 +13875,21 @@ File: gawk.info, Node: Indirect Calls, Next: Functions Summary, Prev: User-de 9.3 Indirect Function Calls =========================== -<<<<<<< HEAD -This section describes a 'gawk'-specific extension. -======= This section describes an advanced, `gawk'-specific extension. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Often, you may wish to defer the choice of function to call until runtime. For example, you may have different kinds of records, each of which should be processed differently. - Normally, you would have to use a series of 'if'-'else' statements to -decide which function to call. By using "indirect" function calls, you -can specify the name of the function to call as a string variable, and -then call the function. Let's look at an example. + Normally, you would have to use a series of `if'-`else' statements +to decide which function to call. By using "indirect" function calls, +you can specify the name of the function to call as a string variable, +and then call the function. Let's look at an example. - Suppose you have a file with your test scores for the classes you are -taking. The first field is the class name. The following fields are -the functions to call to process the data, up to a "marker" field -'data:'. Following the marker, to the end of the record, are the + Suppose you have a file with your test scores for the classes you +are taking. The first field is the class name. The following fields +are the functions to call to process the data, up to a "marker" field +`data:'. Following the marker, to the end of the record, are the various numeric test scores. Here is the initial file; you wish to get the sum and the average of @@ -14849,17 +13913,12 @@ your test scores: } This style of programming works, but can be awkward. With "indirect" -<<<<<<< HEAD -function calls, you tell 'gawk' to use the _value_ of a variable as the -name of the function to call. -======= function calls, you tell `gawk' to use the _value_ of a variable as the _name_ of the function to call. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac The syntax is similar to that of a regular function call: an identifier immediately followed by a left parenthesis, any arguments, -and then a closing right parenthesis, with the addition of a leading '@' +and then a closing right parenthesis, with the addition of a leading `@' character: the_func = "sum" @@ -14893,7 +13952,7 @@ using indirect function calls. } These two functions expect to work on fields; thus the parameters -'first' and 'last' indicate where in the fields to start and end. +`first' and `last' indicate where in the fields to start and end. Otherwise they perform the expected computations and are not unusual. # For each record, print the class name and the requested statistics @@ -14917,14 +13976,14 @@ Otherwise they perform the expected computations and are not unusual. print "" } - This is the main processing for each record. It prints the class -name (with underscores replaced with spaces). It then finds the start -of the actual data, saving it in 'start'. The last part of the code -loops through each function name (from '$2' up to the marker, 'data:'), -calling the function named by the field. The indirect function call -itself occurs as a parameter in the call to 'printf'. (The 'printf' -format string uses '%s' as the format specifier so that we can use -functions that return strings, as well as numbers. Note that the result + This is the main processing for each record. It prints the class +name (with underscores replaced with spaces). It then finds the start +of the actual data, saving it in `start'. The last part of the code +loops through each function name (from `$2' up to the marker, `data:'), +calling the function named by the field. The indirect function call +itself occurs as a parameter in the call to `printf'. (The `printf' +format string uses `%s' as the format specifier so that we can use +functions that return strings, as well as numbers. Note that the result from the indirect call is concatenated with the empty string, in order to force it to be a string value.) @@ -14947,13 +14006,13 @@ to force it to be a string value.) may think at first. The C and C++ languages provide "function pointers," which are a mechanism for calling a function chosen at runtime. One of the most well-known uses of this ability is the C -'qsort()' function, which sorts an array using the famous "quick sort" +`qsort()' function, which sorts an array using the famous "quick sort" algorithm (see the Wikipedia article -(http://en.wikipedia.org/wiki/Quick_sort) for more information). To use -this function, you supply a pointer to a comparison function. This +(http://en.wikipedia.org/wiki/Quick_sort) for more information). To +use this function, you supply a pointer to a comparison function. This mechanism allows you to sort arbitrary data in an arbitrary fashion. - We can do something similar using 'gawk', like this: + We can do something similar using `gawk', like this: # quicksort.awk --- Quicksort algorithm, with user-supplied # comparison function @@ -14984,13 +14043,13 @@ mechanism allows you to sort arbitrary data in an arbitrary fashion. data[j] = temp } - The 'quicksort()' function receives the 'data' array, the starting -and ending indices to sort ('left' and 'right'), and the name of a -function that performs a "less than" comparison. It then implements the -quick sort algorithm. + The `quicksort()' function receives the `data' array, the starting +and ending indices to sort (`left' and `right'), and the name of a +function that performs a "less than" comparison. It then implements +the quick sort algorithm. To make use of the sorting function, we return to our previous -example. The first thing to do is write some comparison functions: +example. The first thing to do is write some comparison functions: # num_lt --- do a numeric less than comparison @@ -15006,15 +14065,15 @@ example. The first thing to do is write some comparison functions: return ((left + 0) >= (right + 0)) } - The 'num_ge()' function is needed to perform a descending sort; when + The `num_ge()' function is needed to perform a descending sort; when used to perform a "less than" test, it actually does the opposite (greater than or equal to), which yields data sorted in descending order. - Next comes a sorting function. It is parameterized with the starting -and ending field numbers and the comparison function. It builds an -array with the data and calls 'quicksort()' appropriately, and then -formats the results as a single string: + Next comes a sorting function. It is parameterized with the +starting and ending field numbers and the comparison function. It +builds an array with the data and calls `quicksort()' appropriately, +and then formats the results as a single string: # do_sort --- sort the data according to `compare' # and return it as a string @@ -15036,7 +14095,7 @@ formats the results as a single string: return retval } - Finally, the two sorting functions call 'do_sort()', passing in the + Finally, the two sorting functions call `do_sort()', passing in the names of the two comparison functions: # sort --- sort the data in ascending order and return it as a string @@ -15080,39 +14139,27 @@ names of the two comparison functions: -| sort: <87.1 93.4 95.6 100.0> -| rsort: <100.0 95.6 93.4 87.1> - Remember that you must supply a leading '@' in front of an indirect + Remember that you must supply a leading `@' in front of an indirect function call. -<<<<<<< HEAD - Unfortunately, indirect function calls cannot be used with the -built-in functions. However, you can generally write "wrapper" -functions which call the built-in ones, and those can be called -indirectly. (Other than, perhaps, the mathematical functions, there is -not a lot of reason to try to call the built-in functions indirectly.) -======= Starting with version 4.1.2 of `gawk', indirect function calls may also be used with built-in functions and with extension functions (*note Dynamic Extensions::). The only thing you cannot do is pass a regular expression constant to a built-in function through an indirect function call.(1) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - 'gawk' does its best to make indirect function calls efficient. For + `gawk' does its best to make indirect function calls efficient. For example, in the following case: for (i = 1; i <= n; i++) @the_func() -<<<<<<< HEAD -'gawk' will look up the actual function to call only once. -======= `gawk' looks up the actual function to call only once. ---------- Footnotes ---------- (1) This may change in a future version; recheck the documentation that comes with your version of `gawk' to see if it has. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions @@ -15120,27 +14167,27 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions 9.4 Summary =========== - * 'awk' provides built-in functions and lets you define your own + * `awk' provides built-in functions and lets you define your own functions. - * POSIX 'awk' provides three kinds of built-in functions: numeric, - string, and I/O. 'gawk' provides functions that work with values + * POSIX `awk' provides three kinds of built-in functions: numeric, + string, and I/O. `gawk' provides functions that work with values representing time, do bit manipulation, sort arrays, and - internationalize and localize programs. 'gawk' also provides + internationalize and localize programs. `gawk' also provides several extensions to some of standard functions, typically in the form of additional arguments. * Functions accept zero or more arguments and return a value. The expressions that provide the argument values are completely - evaluated before the function is called. Order of evaluation is + evaluated before the function is called. Order of evaluation is not defined. The return value can be ignored. - * The handling of backslash in 'sub()' and 'gsub()' is not simple. - It is more straightforward in 'gawk''s 'gensub()' function, but + * The handling of backslash in `sub()' and `gsub()' is not simple. + It is more straightforward in `gawk''s `gensub()' function, but that function still requires care in its use. * User-defined functions provide important capabilities but come with - some syntactic inelegancies. In a function call, there cannot be + some syntactic inelegancies. In a function call, there cannot be any space between the function name and the opening left parenthesis of the argument list. Also, there is no provision for local variables, so the convention is to add extra parameters, and @@ -15148,22 +14195,17 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions whitespace. * User-defined functions may call other user-defined (and built-in) -<<<<<<< HEAD - functions and may call themselves recursively. Function parameters - "hide" any global variables of the same names. -======= functions and may call themselves recursively. Function parameters "hide" any global variables of the same names. You cannot use the name of a reserved variable (such as `ARGC') as the name of a parameter in user-defined functions. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - * Scalar values are passed to user-defined functions by value. Array + * Scalar values are passed to user-defined functions by value. Array parameters are passed by reference; any changes made by the function to array parameters are thus visible after the function has returned. - * Use the 'return' statement to return from a user-defined function. + * Use the `return' statement to return from a user-defined function. An optional expression becomes the function's return value. Only scalar values may be returned by a function. @@ -15171,32 +14213,25 @@ File: gawk.info, Node: Functions Summary, Prev: Indirect Calls, Up: Functions function, how that function treats the variable can set its nature: either scalar or array. -<<<<<<< HEAD - * 'gawk' provides indirect function calls using a special syntax. By - setting a variable to the name of a user-defined function, you can - determine at runtime what function will be called at that point in - the program. This is equivalent to function pointers in C and C++. -======= * `gawk' provides indirect function calls using a special syntax. By setting a variable to the name of a function, you can determine at runtime what function will be called at that point in the program. This is equivalent to function pointers in C and C++. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Library Functions, Next: Sample Programs, Prev: Functions, Up: Top -10 A Library of 'awk' Functions +10 A Library of `awk' Functions ******************************* -*note User-defined::, describes how to write your own 'awk' functions. +*note User-defined::, describes how to write your own `awk' functions. Writing functions is important, because it allows you to encapsulate algorithms and program tasks in a single place. It simplifies programming, making program development more manageable, and making programs more readable. - In their seminal 1976 book, 'Software Tools',(1) Brian Kernighan and + In their seminal 1976 book, `Software Tools',(1) Brian Kernighan and P.J. Plauger wrote: Good Programming is not learned from generalities, but by seeing @@ -15208,44 +14243,38 @@ P.J. Plauger wrote: In fact, they felt this idea was so important that they placed this statement on the cover of their book. Because we believe strongly that -<<<<<<< HEAD -their statement is correct, this major node and *note Sample Programs::, -provide a good-sized body of code for you to read, and we hope, to learn -from. -======= their statement is correct, this major node and *note Sample Programs::, provide a good-sized body of code for you to read and, we hope, to learn from. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - This major node presents a library of useful 'awk' functions. Many + This major node presents a library of useful `awk' functions. Many of the sample programs presented later in this Info file use these functions. The functions are presented here in a progression from simple to complex. *note Extract Program::, presents a program that you can use to -extract the source code for these example library functions and programs -from the Texinfo source for this Info file. (This has already been done -as part of the 'gawk' distribution.) +extract the source code for these example library functions and +programs from the Texinfo source for this Info file. (This has already +been done as part of the `gawk' distribution.) - If you have written one or more useful, general-purpose 'awk' -functions and would like to contribute them to the 'awk' user community, -see *note How To Contribute::, for more information. + If you have written one or more useful, general-purpose `awk' +functions and would like to contribute them to the `awk' user +community, see *note How To Contribute::, for more information. The programs in this major node and in *note Sample Programs::, -freely use features that are 'gawk'-specific. Rewriting these programs -for different implementations of 'awk' is pretty straightforward. +freely use features that are `gawk'-specific. Rewriting these programs +for different implementations of `awk' is pretty straightforward. - * Diagnostic error messages are sent to '/dev/stderr'. Use '| "cat - 1>&2"' instead of '> "/dev/stderr"' if your system does not have a - '/dev/stderr', or if you cannot use 'gawk'. + * Diagnostic error messages are sent to `/dev/stderr'. Use `| "cat + 1>&2"' instead of `> "/dev/stderr"' if your system does not have a + `/dev/stderr', or if you cannot use `gawk'. - * A number of programs use 'nextfile' (*note Nextfile Statement::) to - skip any remaining input in the input file. + * A number of programs use `nextfile' (*note Nextfile Statement::) + to skip any remaining input in the input file. * Finally, some of the programs choose to ignore upper- and lowercase - distinctions in their input. They do so by assigning one to - 'IGNORECASE'. You can achieve almost the same effect(2) by adding + distinctions in their input. They do so by assigning one to + `IGNORECASE'. You can achieve almost the same effect(2) by adding the following rule to the beginning of the program: # ignore case @@ -15275,7 +14304,7 @@ for different implementations of 'awk' is pretty straightforward. book have yet to be learned by a vast number of practicing programmers. (2) The effects are not identical. Output of the transformed record -will be in all lowercase, while 'IGNORECASE' preserves the original +will be in all lowercase, while `IGNORECASE' preserves the original contents of the input record.  @@ -15284,49 +14313,49 @@ File: gawk.info, Node: Library Names, Next: General Functions, Up: Library Fu 10.1 Naming Library Function Global Variables ============================================= -Due to the way the 'awk' language evolved, variables are either "global" -(usable by the entire program) or "local" (usable just by a specific -function). There is no intermediate state analogous to 'static' -variables in C. +Due to the way the `awk' language evolved, variables are either +"global" (usable by the entire program) or "local" (usable just by a +specific function). There is no intermediate state analogous to +`static' variables in C. Library functions often need to have global variables that they can use to preserve state information between calls to the function--for -example, 'getopt()''s variable '_opti' (*note Getopt Function::). Such +example, `getopt()''s variable `_opti' (*note Getopt Function::). Such variables are called "private", since the only functions that need to use them are the ones in the library. When writing a library function, you should try to choose names for your private variables that will not conflict with any variables used by either another library function or a user's main program. For example, -a name like 'i' or 'j' is not a good choice, because user programs often -use variable names like these for their own purposes. +a name like `i' or `j' is not a good choice, because user programs +often use variable names like these for their own purposes. The example programs shown in this major node all start the names of -their private variables with an underscore ('_'). Users generally don't -use leading underscores in their variable names, so this convention -immediately decreases the chances that the variable name will be -accidentally shared with the user's program. +their private variables with an underscore (`_'). Users generally +don't use leading underscores in their variable names, so this +convention immediately decreases the chances that the variable name +will be accidentally shared with the user's program. In addition, several of the library functions use a prefix that helps indicate what function or set of functions use the variables--for -example, '_pw_byname()' in the user database routines (*note Passwd +example, `_pw_byname()' in the user database routines (*note Passwd Functions::). This convention is recommended, since it even further -decreases the chance of inadvertent conflict among variable names. Note -that this convention is used equally well for variable names and for -private function names.(1) +decreases the chance of inadvertent conflict among variable names. +Note that this convention is used equally well for variable names and +for private function names.(1) As a final note on variable naming, if a function makes global variables available for use by a main program, it is a good convention to start that variable's name with a capital letter--for example, -'getopt()''s 'Opterr' and 'Optind' variables (*note Getopt Function::). +`getopt()''s `Opterr' and `Optind' variables (*note Getopt Function::). The leading capital letter indicates that it is global, while the fact that the variable name is not all capital letters indicates that the -variable is not one of 'awk''s built-in variables, such as 'FS'. +variable is not one of `awk''s built-in variables, such as `FS'. It is also important that _all_ variables in library functions that -do not need to save state are, in fact, declared local.(2) If this is -not done, the variable could accidentally be used in the user's program, -leading to bugs that are very difficult to track down: +do not need to save state are, in fact, declared local.(2) If this is +not done, the variable could accidentally be used in the user's +program, leading to bugs that are very difficult to track down: function lib_func(x, y, l1, l2) { @@ -15340,22 +14369,22 @@ single associative array to hold the values needed by the library function(s), or "package." This significantly decreases the number of actual global names in use. For example, the functions described in *note Passwd Functions::, might have used array elements -'PW_data["inited"]', 'PW_data["total"]', 'PW_data["count"]', and -'PW_data["awklib"]', instead of '_pw_inited', '_pw_awklib', '_pw_total', -and '_pw_count'. +`PW_data["inited"]', `PW_data["total"]', `PW_data["count"]', and +`PW_data["awklib"]', instead of `_pw_inited', `_pw_awklib', `_pw_total', +and `_pw_count'. The conventions presented in this minor node are exactly that: -conventions. You are not required to write your programs this way--we +conventions. You are not required to write your programs this way--we merely recommend that you do so. ---------- Footnotes ---------- (1) While all the library routines could have been rewritten to use -this convention, this was not done, in order to show how our own 'awk' +this convention, this was not done, in order to show how our own `awk' programming style has evolved and to provide some basis for this discussion. - (2) 'gawk''s '--dump-variables' command-line option is useful for + (2) `gawk''s `--dump-variables' command-line option is useful for verifying this.  @@ -15370,10 +14399,10 @@ programming use. * Menu: * Strtonum Function:: A replacement for the built-in - 'strtonum()' function. -* Assert Function:: A function for assertions in 'awk' + `strtonum()' function. +* Assert Function:: A function for assertions in `awk' programs. -* Round Function:: A function for rounding if 'sprintf()' +* Round Function:: A function for rounding if `sprintf()' does not do it correctly. * Cliff Random Function:: The Cliff Random Number Generator. * Ordinal Functions:: Functions for using characters as numbers and @@ -15388,9 +14417,9 @@ File: gawk.info, Node: Strtonum Function, Next: Assert Function, Up: General 10.2.1 Converting Strings To Numbers ------------------------------------ -The 'strtonum()' function (*note String Functions::) is a 'gawk' +The `strtonum()' function (*note String Functions::) is a `gawk' extension. The following function provides an implementation for other -versions of 'awk': +versions of `awk': # mystrtonum --- convert string to number @@ -15447,24 +14476,24 @@ versions of 'awk': # } The function first looks for C-style octal numbers (base 8). If the -input string matches a regular expression describing octal numbers, then -'mystrtonum()' loops through each character in the string. It sets 'k' -to the index in '"01234567"' of the current octal digit. Since the -return value is one-based, the 'k--' adjusts 'k' so it can be used in -computing the return value. +input string matches a regular expression describing octal numbers, +then `mystrtonum()' loops through each character in the string. It +sets `k' to the index in `"01234567"' of the current octal digit. +Since the return value is one-based, the `k--' adjusts `k' so it can be +used in computing the return value. Similar logic applies to the code that checks for and converts a -hexadecimal value, which starts with '0x' or '0X'. The use of -'tolower()' simplifies the computation for finding the correct numeric +hexadecimal value, which starts with `0x' or `0X'. The use of +`tolower()' simplifies the computation for finding the correct numeric value for each hexadecimal digit. Finally, if the string matches the (rather complicated) regexp for a -regular decimal integer or floating-point number, the computation 'ret = -str + 0' lets 'awk' convert the value to a number. +regular decimal integer or floating-point number, the computation `ret += str + 0' lets `awk' convert the value to a number. - A commented-out test program is included, so that the function can be -tested with 'gawk' and the results compared to the built-in 'strtonum()' -function. + A commented-out test program is included, so that the function can +be tested with `gawk' and the results compared to the built-in +`strtonum()' function.  File: gawk.info, Node: Assert Function, Next: Round Function, Prev: Strtonum Function, Up: General Functions @@ -15472,15 +14501,15 @@ File: gawk.info, Node: Assert Function, Next: Round Function, Prev: Strtonum 10.2.2 Assertions ----------------- -When writing large programs, it is often useful to know that a condition -or set of conditions is true. Before proceeding with a particular -computation, you make a statement about what you believe to be the case. -Such a statement is known as an "assertion". The C language provides an -'' header file and corresponding 'assert()' macro that the -programmer can use to make assertions. If an assertion fails, the -'assert()' macro arranges to print a diagnostic message describing the -condition that should have been true but was not, and then it kills the -program. In C, using 'assert()' looks this: +When writing large programs, it is often useful to know that a +condition or set of conditions is true. Before proceeding with a +particular computation, you make a statement about what you believe to +be the case. Such a statement is known as an "assertion". The C +language provides an `' header file and corresponding +`assert()' macro that the programmer can use to make assertions. If an +assertion fails, the `assert()' macro arranges to print a diagnostic +message describing the condition that should have been true but was +not, and then it kills the program. In C, using `assert()' looks this: #include @@ -15496,8 +14525,8 @@ program. In C, using 'assert()' looks this: The C language makes it possible to turn the condition into a string for use in printing the diagnostic message. This is not possible in -'awk', so this 'assert()' function also requires a string version of the -condition that is being tested. Following is the function: +`awk', so this `assert()' function also requires a string version of +the condition that is being tested. Following is the function: # assert --- assert that a condition is true. Otherwise exit. @@ -15516,20 +14545,20 @@ condition that is being tested. Following is the function: exit 1 } - The 'assert()' function tests the 'condition' parameter. If it is -false, it prints a message to standard error, using the 'string' + The `assert()' function tests the `condition' parameter. If it is +false, it prints a message to standard error, using the `string' parameter to describe the failed condition. It then sets the variable -'_assert_exit' to one and executes the 'exit' statement. The 'exit' -statement jumps to the 'END' rule. If the 'END' rules finds -'_assert_exit' to be true, it exits immediately. +`_assert_exit' to one and executes the `exit' statement. The `exit' +statement jumps to the `END' rule. If the `END' rules finds +`_assert_exit' to be true, it exits immediately. - The purpose of the test in the 'END' rule is to keep any other 'END' + The purpose of the test in the `END' rule is to keep any other `END' rules from running. When an assertion fails, the program should exit -immediately. If no assertions fail, then '_assert_exit' is still false -when the 'END' rule is run normally, and the rest of the program's 'END' -rules execute. For all of this to work correctly, 'assert.awk' must be -the first source file read by 'awk'. The function can be used in a -program in the following way: +immediately. If no assertions fail, then `_assert_exit' is still false +when the `END' rule is run normally, and the rest of the program's +`END' rules execute. For all of this to work correctly, `assert.awk' +must be the first source file read by `awk'. The function can be used +in a program in the following way: function myfunc(a, b) { @@ -15541,16 +14570,16 @@ If the assertion fails, you see a message similar to the following: mydata:1357: assertion failed: a <= 5 && b >= 17.1 - There is a small problem with this version of 'assert()'. An 'END' -rule is automatically added to the program calling 'assert()'. -Normally, if a program consists of just a 'BEGIN' rule, the input files -and/or standard input are not read. However, now that the program has -an 'END' rule, 'awk' attempts to read the input data files or standard -input (*note Using BEGIN/END::), most likely causing the program to hang -as it waits for input. + There is a small problem with this version of `assert()'. An `END' +rule is automatically added to the program calling `assert()'. +Normally, if a program consists of just a `BEGIN' rule, the input files +and/or standard input are not read. However, now that the program has +an `END' rule, `awk' attempts to read the input data files or standard +input (*note Using BEGIN/END::), most likely causing the program to +hang as it waits for input. - There is a simple workaround to this: make sure that such a 'BEGIN' -rule always ends with an 'exit' statement. + There is a simple workaround to this: make sure that such a `BEGIN' +rule always ends with an `exit' statement.  File: gawk.info, Node: Round Function, Next: Cliff Random Function, Prev: Assert Function, Up: General Functions @@ -15558,15 +14587,15 @@ File: gawk.info, Node: Round Function, Next: Cliff Random Function, Prev: Ass 10.2.3 Rounding Numbers ----------------------- -The way 'printf' and 'sprintf()' (*note Printf::) perform rounding often -depends upon the system's C 'sprintf()' subroutine. On many machines, -'sprintf()' rounding is "unbiased", which means it doesn't always round -a trailing .5 up, contrary to naive expectations. In unbiased rounding, -.5 rounds to even, rather than always up, so 1.5 rounds to 2 but 4.5 -rounds to 4. This means that if you are using a format that does -rounding (e.g., '"%.0f"'), you should check what your system does. The -following function does traditional rounding; it might be useful if your -'awk''s 'printf' does unbiased rounding: +The way `printf' and `sprintf()' (*note Printf::) perform rounding +often depends upon the system's C `sprintf()' subroutine. On many +machines, `sprintf()' rounding is "unbiased", which means it doesn't +always round a trailing .5 up, contrary to naive expectations. In +unbiased rounding, .5 rounds to even, rather than always up, so 1.5 +rounds to 2 but 4.5 rounds to 4. This means that if you are using a +format that does rounding (e.g., `"%.0f"'), you should check what your +system does. The following function does traditional rounding; it +might be useful if your `awk''s `printf' does unbiased rounding: # round.awk --- do normal rounding @@ -15605,10 +14634,10 @@ File: gawk.info, Node: Cliff Random Function, Next: Ordinal Functions, Prev: ---------------------------------------- The Cliff random number generator -(http://mathworld.wolfram.com/CliffRandomNumberGenerator.html) is a very -simple random number generator that "passes the noise sphere test for -randomness by showing no structure." It is easily programmed, in less -than 10 lines of 'awk' code: +(http://mathworld.wolfram.com/CliffRandomNumberGenerator.html) is a +very simple random number generator that "passes the noise sphere test +for randomness by showing no structure." It is easily programmed, in +less than 10 lines of `awk' code: # cliff_rand.awk --- generate Cliff random numbers @@ -15624,7 +14653,7 @@ than 10 lines of 'awk' code: This algorithm requires an initial "seed" of 0.1. Each new value uses the current seed as input for the calculation. If the built-in -'rand()' function (*note Numeric Functions::) isn't random enough, you +`rand()' function (*note Numeric Functions::) isn't random enough, you might try using this function instead.  @@ -15633,15 +14662,15 @@ File: gawk.info, Node: Ordinal Functions, Next: Join Function, Prev: Cliff Ra 10.2.5 Translating Between Characters and Numbers ------------------------------------------------- -One commercial implementation of 'awk' supplies a built-in function, -'ord()', which takes a character and returns the numeric value for that +One commercial implementation of `awk' supplies a built-in function, +`ord()', which takes a character and returns the numeric value for that character in the machine's character set. If the string passed to -'ord()' has more than one character, only the first one is used. +`ord()' has more than one character, only the first one is used. - The inverse of this function is 'chr()' (from the function of the -same name in Pascal), which takes a number and returns the corresponding -character. Both functions are written very nicely in 'awk'; there is no -real reason to build them into the 'awk' interpreter: + The inverse of this function is `chr()' (from the function of the +same name in Pascal), which takes a number and returns the +corresponding character. Both functions are written very nicely in +`awk'; there is no real reason to build them into the `awk' interpreter: # ord.awk --- do ord and chr @@ -15672,16 +14701,17 @@ real reason to build them into the 'awk' interpreter: } } - Some explanation of the numbers used by '_ord_init()' is worthwhile. + Some explanation of the numbers used by `_ord_init()' is worthwhile. The most prominent character set in use today is ASCII.(1) Although an 8-bit byte can hold 256 distinct values (from 0 to 255), ASCII only -defines characters that use the values from 0 to 127.(2) In the now +defines characters that use the values from 0 to 127.(2) In the now distant past, at least one minicomputer manufacturer used ASCII, but -with mark parity, meaning that the leftmost bit in the byte is always 1. -This means that on those systems, characters have numeric values from -128 to 255. Finally, large mainframe systems use the EBCDIC character -set, which uses all 256 values. While there are other character sets in -use on some older systems, they are not really worth worrying about: +with mark parity, meaning that the leftmost bit in the byte is always +1. This means that on those systems, characters have numeric values +from 128 to 255. Finally, large mainframe systems use the EBCDIC +character set, which uses all 256 values. While there are other +character sets in use on some older systems, they are not really worth +worrying about: function ord(str, c) { @@ -15707,9 +14737,9 @@ use on some older systems, they are not really worth worrying about: # } An obvious improvement to these functions is to move the code for the -'_ord_init' function into the body of the 'BEGIN' rule. It was written +`_ord_init' function into the body of the `BEGIN' rule. It was written this way initially for ease of development. There is a "test program" -in a 'BEGIN' rule, to test the function. It is commented out for +in a `BEGIN' rule, to test the function. It is commented out for production use. ---------- Footnotes ---------- @@ -15720,8 +14750,8 @@ Unicode support, a character can occupy up to 32 bits, making simple tests such as used here prohibitively expensive. (2) ASCII has been extended in many countries to use the values from -128 to 255 for country-specific characters. If your system uses these -extensions, you can simplify '_ord_init()' to loop from 0 to 255. +128 to 255 for country-specific characters. If your system uses these +extensions, you can simplify `_ord_init()' to loop from 0 to 255.  File: gawk.info, Node: Join Function, Next: Getlocaltime Function, Prev: Ordinal Functions, Up: General Functions @@ -15731,15 +14761,15 @@ File: gawk.info, Node: Join Function, Next: Getlocaltime Function, Prev: Ordi When doing string processing, it is often useful to be able to join all the strings in an array into one long string. The following function, -'join()', accomplishes this task. It is used later in several of the +`join()', accomplishes this task. It is used later in several of the application programs (*note Sample Programs::). Good function design is important; this function needs to be general but it should also have a reasonable default behavior. It is called with an array as well as the beginning and ending indices of the -elements in the array to be merged. This assumes that the array indices -are numeric--a reasonable assumption since the array was likely created -with 'split()' (*note String Functions::): +elements in the array to be merged. This assumes that the array +indices are numeric--a reasonable assumption since the array was likely +created with `split()' (*note String Functions::): # join.awk --- join an array into a string @@ -15757,18 +14787,18 @@ with 'split()' (*note String Functions::): An optional additional argument is the separator to use when joining the strings back together. If the caller supplies a nonempty value, -'join()' uses it; if it is not supplied, it has a null value. In this -case, 'join()' uses a single space as a default separator for the -strings. If the value is equal to 'SUBSEP', then 'join()' joins the -strings with no separator between them. 'SUBSEP' serves as a "magic" +`join()' uses it; if it is not supplied, it has a null value. In this +case, `join()' uses a single space as a default separator for the +strings. If the value is equal to `SUBSEP', then `join()' joins the +strings with no separator between them. `SUBSEP' serves as a "magic" value to indicate that there should be no separation between the component strings.(1) ---------- Footnotes ---------- - (1) It would be nice if 'awk' had an assignment operator for -concatenation. The lack of an explicit operator for concatenation makes -string operations more difficult than they really need to be. + (1) It would be nice if `awk' had an assignment operator for +concatenation. The lack of an explicit operator for concatenation +makes string operations more difficult than they really need to be.  File: gawk.info, Node: Getlocaltime Function, Next: Readfile Function, Prev: Join Function, Up: General Functions @@ -15776,15 +14806,15 @@ File: gawk.info, Node: Getlocaltime Function, Next: Readfile Function, Prev: 10.2.7 Managing the Time of Day ------------------------------- -The 'systime()' and 'strftime()' functions described in *note Time +The `systime()' and `strftime()' functions described in *note Time Functions::, provide the minimum functionality necessary for dealing -with the time of day in human readable form. While 'strftime()' is +with the time of day in human readable form. While `strftime()' is extensive, the control formats are not necessarily easy to remember or intuitively obvious when reading a program. - The following function, 'getlocaltime()', populates a user-supplied + The following function, `getlocaltime()', populates a user-supplied array with preformatted time information. It returns a string with the -current time formatted in the same way as the 'date' utility: +current time formatted in the same way as the `date' utility: # getlocaltime.awk --- get the time of day in a usable format @@ -15847,9 +14877,9 @@ current time formatted in the same way as the 'date' utility: } The string indices are easier to use and read than the various -formats required by 'strftime()'. The 'alarm' program presented in +formats required by `strftime()'. The `alarm' program presented in *note Alarm Program::, uses this function. A more general design for -the 'getlocaltime()' function would have allowed the user to supply an +the `getlocaltime()' function would have allowed the user to supply an optional timestamp value to use instead of the current time.  @@ -15859,7 +14889,7 @@ File: gawk.info, Node: Readfile Function, Prev: Getlocaltime Function, Up: Ge ----------------------------------- Often, it is convenient to have the entire contents of a file available -in memory as a single string. A straightforward but naive way to do +in memory as a single string. A straightforward but naive way to do that might be as follows: function readfile(file, tmp, contents) @@ -15875,9 +14905,9 @@ that might be as follows: return contents } - This function reads from 'file' one record at a time, building up the -full contents of the file in the local variable 'contents'. It works, -but is not necessarily efficient. + This function reads from `file' one record at a time, building up +the full contents of the file in the local variable `contents'. It +works, but is not necessarily efficient. The following function, based on a suggestion by Denis Shirokov, reads the entire contents of the named file in one shot: @@ -15895,21 +14925,22 @@ reads the entire contents of the named file in one shot: return tmp } - It works by setting 'RS' to '^$', a regular expression that will -never match if the file has contents. 'gawk' reads data from the file -into 'tmp' attempting to match 'RS'. The match fails after each read, -but fails quickly, such that 'gawk' fills 'tmp' with the entire contents -of the file. (*Note Records::, for information on 'RT' and 'RS'.) + It works by setting `RS' to `^$', a regular expression that will +never match if the file has contents. `gawk' reads data from the file +into `tmp' attempting to match `RS'. The match fails after each read, +but fails quickly, such that `gawk' fills `tmp' with the entire +contents of the file. (*Note Records::, for information on `RT' and +`RS'.) - In the case that 'file' is empty, the return value is the null + In the case that `file' is empty, the return value is the null string. Thus calling code may use something like: contents = readfile("/some/path") if (length(contents) == 0) # file was empty ... - This tests the result to see if it is empty or not. An equivalent -test would be 'contents == ""'. + This tests the result to see if it is empty or not. An equivalent +test would be `contents == ""'.  File: gawk.info, Node: Data File Management, Next: Getopt Function, Prev: General Functions, Up: Library Functions @@ -15934,23 +14965,23 @@ File: gawk.info, Node: Filetrans Function, Next: Rewind Function, Up: Data Fi 10.3.1 Noting Data File Boundaries ---------------------------------- -The 'BEGIN' and 'END' rules are each executed exactly once at the -beginning and end of your 'awk' program, respectively (*note -BEGIN/END::). We (the 'gawk' authors) once had a user who mistakenly -thought that the 'BEGIN' rule is executed at the beginning of each data -file and the 'END' rule is executed at the end of each data file. +The `BEGIN' and `END' rules are each executed exactly once at the +beginning and end of your `awk' program, respectively (*note +BEGIN/END::). We (the `gawk' authors) once had a user who mistakenly +thought that the `BEGIN' rule is executed at the beginning of each data +file and the `END' rule is executed at the end of each data file. When informed that this was not the case, the user requested that we -add new special patterns to 'gawk', named 'BEGIN_FILE' and 'END_FILE', +add new special patterns to `gawk', named `BEGIN_FILE' and `END_FILE', that would have the desired behavior. He even supplied us the code to do so. - Adding these special patterns to 'gawk' wasn't necessary; the job can -be done cleanly in 'awk' itself, as illustrated by the following library -program. It arranges to call two user-supplied functions, 'beginfile()' -and 'endfile()', at the beginning and end of each data file. Besides -solving the problem in only nine(!) lines of code, it does so -_portably_; this works with any implementation of 'awk': + Adding these special patterns to `gawk' wasn't necessary; the job +can be done cleanly in `awk' itself, as illustrated by the following +library program. It arranges to call two user-supplied functions, +`beginfile()' and `endfile()', at the beginning and end of each data +file. Besides solving the problem in only nine(!) lines of code, it +does so _portably_; this works with any implementation of `awk': # transfile.awk # @@ -15973,25 +15004,25 @@ _portably_; this works with any implementation of 'awk': This file must be loaded before the user's "main" program, so that the rule it supplies is executed first. - This rule relies on 'awk''s 'FILENAME' variable that automatically + This rule relies on `awk''s `FILENAME' variable that automatically changes for each new data file. The current file name is saved in a -private variable, '_oldfilename'. If 'FILENAME' does not equal -'_oldfilename', then a new data file is being processed and it is -necessary to call 'endfile()' for the old file. Because 'endfile()' +private variable, `_oldfilename'. If `FILENAME' does not equal +`_oldfilename', then a new data file is being processed and it is +necessary to call `endfile()' for the old file. Because `endfile()' should only be called if a file has been processed, the program first -checks to make sure that '_oldfilename' is not the null string. The -program then assigns the current file name to '_oldfilename' and calls -'beginfile()' for the file. Because, like all 'awk' variables, -'_oldfilename' is initialized to the null string, this rule executes +checks to make sure that `_oldfilename' is not the null string. The +program then assigns the current file name to `_oldfilename' and calls +`beginfile()' for the file. Because, like all `awk' variables, +`_oldfilename' is initialized to the null string, this rule executes correctly even for the first data file. - The program also supplies an 'END' rule to do the final processing -for the last file. Because this 'END' rule comes before any 'END' rules -supplied in the "main" program, 'endfile()' is called first. Once again -the value of multiple 'BEGIN' and 'END' rules should be clear. + The program also supplies an `END' rule to do the final processing +for the last file. Because this `END' rule comes before any `END' rules +supplied in the "main" program, `endfile()' is called first. Once +again the value of multiple `BEGIN' and `END' rules should be clear. If the same data file occurs twice in a row on the command line, then -'endfile()' and 'beginfile()' are not executed at the end of the first +`endfile()' and `beginfile()' are not executed at the end of the first pass and at the beginning of the second pass. The following version solves the problem: @@ -16011,19 +15042,19 @@ solves the problem: *note Wc Program::, shows how this library function can be used and how it simplifies writing the main program. - So Why Does 'gawk' have 'BEGINFILE' and 'ENDFILE'? + So Why Does `gawk' have `BEGINFILE' and `ENDFILE'? - You are probably wondering, if 'beginfile()' and 'endfile()' -functions can do the job, why does 'gawk' have 'BEGINFILE' and 'ENDFILE' -patterns (*note BEGINFILE/ENDFILE::)? + You are probably wondering, if `beginfile()' and `endfile()' +functions can do the job, why does `gawk' have `BEGINFILE' and +`ENDFILE' patterns (*note BEGINFILE/ENDFILE::)? - Good question. Normally, if 'awk' cannot open a file, this causes an -immediate fatal error. In this case, there is no way for a user-defined -function to deal with the problem, since the mechanism for calling it -relies on the file being open and at the first record. Thus, the main -reason for 'BEGINFILE' is to give you a "hook" to catch files that -cannot be processed. 'ENDFILE' exists for symmetry, and because it -provides an easy way to do per-file cleanup processing. + Good question. Normally, if `awk' cannot open a file, this causes +an immediate fatal error. In this case, there is no way for a +user-defined function to deal with the problem, since the mechanism for +calling it relies on the file being open and at the first record. Thus, +the main reason for `BEGINFILE' is to give you a "hook" to catch files +that cannot be processed. `ENDFILE' exists for symmetry, and because +it provides an easy way to do per-file cleanup processing.  File: gawk.info, Node: Rewind Function, Next: File Checking, Prev: Filetrans Function, Up: Data File Management @@ -16031,15 +15062,15 @@ File: gawk.info, Node: Rewind Function, Next: File Checking, Prev: Filetrans 10.3.2 Rereading the Current File --------------------------------- -Another request for a new built-in function was for a 'rewind()' +Another request for a new built-in function was for a `rewind()' function that would make it possible to reread the current file. The -requesting user didn't want to have to use 'getline' (*note Getline::) +requesting user didn't want to have to use `getline' (*note Getline::) inside a loop. - However, as long as you are not in the 'END' rule, it is quite easy + However, as long as you are not in the `END' rule, it is quite easy to arrange to immediately close the current input file and then start over with it from the top. For lack of a better name, we'll call it -'rewind()': +`rewind()': # rewind.awk --- rewind the current file and start over @@ -16059,15 +15090,15 @@ over with it from the top. For lack of a better name, we'll call it nextfile } - This code relies on the 'ARGIND' variable (*note Auto-set::), which -is specific to 'gawk'. If you are not using 'gawk', you can use ideas -presented in *note Filetrans Function::, to either update 'ARGIND' on + This code relies on the `ARGIND' variable (*note Auto-set::), which +is specific to `gawk'. If you are not using `gawk', you can use ideas +presented in *note Filetrans Function::, to either update `ARGIND' on your own or modify this code as appropriate. - The 'rewind()' function also relies on the 'nextfile' keyword (*note + The `rewind()' function also relies on the `nextfile' keyword (*note Nextfile Statement::). Because of this, you should not call it from an -'ENDFILE' rule. (This isn't necessary anyway, since as soon as an -'ENDFILE' rule finishes 'gawk' goes to the next file!) +`ENDFILE' rule. (This isn't necessary anyway, since as soon as an +`ENDFILE' rule finishes `gawk' goes to the next file!)  File: gawk.info, Node: File Checking, Next: Empty Files, Prev: Rewind Function, Up: Data File Management @@ -16075,10 +15106,10 @@ File: gawk.info, Node: File Checking, Next: Empty Files, Prev: Rewind Functio 10.3.3 Checking for Readable Data Files --------------------------------------- -Normally, if you give 'awk' a data file that isn't readable, it stops +Normally, if you give `awk' a data file that isn't readable, it stops with a fatal error. There are times when you might want to just ignore -such files and keep going.(1) You can do this by prepending the -following program to your 'awk' program: +such files and keep going.(1) You can do this by prepending the +following program to your `awk' program: # readable.awk --- library file to skip over unreadable files @@ -16094,13 +15125,13 @@ following program to your 'awk' program: } } - This works, because the 'getline' won't be fatal. Removing the -element from 'ARGV' with 'delete' skips the file (since it's no longer + This works, because the `getline' won't be fatal. Removing the +element from `ARGV' with `delete' skips the file (since it's no longer in the list). See also *note ARGC and ARGV::. ---------- Footnotes ---------- - (1) The 'BEGINFILE' special pattern (*note BEGINFILE/ENDFILE::) + (1) The `BEGINFILE' special pattern (*note BEGINFILE/ENDFILE::) provides an alternative mechanism for dealing with files that can't be opened. However, the code here provides a portable solution. @@ -16110,19 +15141,20 @@ File: gawk.info, Node: Empty Files, Next: Ignoring Assigns, Prev: File Checki 10.3.4 Checking for Zero-length Files ------------------------------------- -All known 'awk' implementations silently skip over zero-length files. -This is a by-product of 'awk''s implicit -read-a-record-and-match-against-the-rules loop: when 'awk' tries to read -a record from an empty file, it immediately receives an end of file -indication, closes the file, and proceeds on to the next command-line -data file, _without_ executing any user-level 'awk' program code. - - Using 'gawk''s 'ARGIND' variable (*note Built-in Variables::), it is -possible to detect when an empty data file has been skipped. Similar to -the library file presented in *note Filetrans Function::, the following -library file calls a function named 'zerofile()' that the user must -provide. The arguments passed are the file name and the position in -'ARGV' where it was found: +All known `awk' implementations silently skip over zero-length files. +This is a by-product of `awk''s implicit +read-a-record-and-match-against-the-rules loop: when `awk' tries to +read a record from an empty file, it immediately receives an end of +file indication, closes the file, and proceeds on to the next +command-line data file, _without_ executing any user-level `awk' +program code. + + Using `gawk''s `ARGIND' variable (*note Built-in Variables::), it is +possible to detect when an empty data file has been skipped. Similar +to the library file presented in *note Filetrans Function::, the +following library file calls a function named `zerofile()' that the +user must provide. The arguments passed are the file name and the +position in `ARGV' where it was found: # zerofile.awk --- library file to process empty input files @@ -16141,18 +15173,18 @@ provide. The arguments passed are the file name and the position in zerofile(ARGV[Argind], Argind) } - The user-level variable 'Argind' allows the 'awk' program to track -its progress through 'ARGV'. Whenever the program detects that 'ARGIND' -is greater than 'Argind + 1', it means that one or more empty files were -skipped. The action then calls 'zerofile()' for each such file, -incrementing 'Argind' along the way. + The user-level variable `Argind' allows the `awk' program to track +its progress through `ARGV'. Whenever the program detects that +`ARGIND' is greater than `Argind + 1', it means that one or more empty +files were skipped. The action then calls `zerofile()' for each such +file, incrementing `Argind' along the way. - The 'Argind != ARGIND' rule simply keeps 'Argind' up to date in the + The `Argind != ARGIND' rule simply keeps `Argind' up to date in the normal case. - Finally, the 'END' rule catches the case of any empty files at the + Finally, the `END' rule catches the case of any empty files at the end of the command-line arguments. Note that the test in the condition -of the 'for' loop uses the '<=' operator, not '<'. +of the `for' loop uses the `<=' operator, not `<'.  File: gawk.info, Node: Ignoring Assigns, Prev: Empty Files, Up: Data File Management @@ -16160,13 +15192,13 @@ File: gawk.info, Node: Ignoring Assigns, Prev: Empty Files, Up: Data File Man 10.3.5 Treating Assignments as File Names ----------------------------------------- -Occasionally, you might not want 'awk' to process command-line variable +Occasionally, you might not want `awk' to process command-line variable assignments (*note Assignment Options::). In particular, if you have a -file name that contains an '=' character, 'awk' treats the file name as +file name that contains an `=' character, `awk' treats the file name as an assignment, and does not process it. Some users have suggested an additional command-line option for -'gawk' to disable command-line assignments. However, some simple +`gawk' to disable command-line assignments. However, some simple programming with a library file does the trick: # noassign.awk --- library file to avoid the need for a @@ -16189,10 +15221,10 @@ programming with a library file does the trick: awk -v No_command_assign=1 -f noassign.awk -f yourprog.awk * The function works by looping through the arguments. It prepends -'./' to any argument that matches the form of a variable assignment, +`./' to any argument that matches the form of a variable assignment, turning that argument into a file name. - The use of 'No_command_assign' allows you to disable command-line + The use of `No_command_assign' allows you to disable command-line assignments at invocation time, by giving the variable a true value. When not set, it is initially zero (i.e., false), so the command-line arguments are left alone. @@ -16204,32 +15236,32 @@ File: gawk.info, Node: Getopt Function, Next: Passwd Functions, Prev: Data Fi ==================================== Most utilities on POSIX compatible systems take options on the command -line that can be used to change the way a program behaves. 'awk' is an +line that can be used to change the way a program behaves. `awk' is an example of such a program (*note Options::). Often, options take "arguments"; i.e., data that the program needs to correctly obey the -command-line option. For example, 'awk''s '-F' option requires a string -to use as the field separator. The first occurrence on the command line -of either '--' or a string that does not begin with '-' ends the -options. +command-line option. For example, `awk''s `-F' option requires a +string to use as the field separator. The first occurrence on the +command line of either `--' or a string that does not begin with `-' +ends the options. - Modern Unix systems provide a C function named 'getopt()' for + Modern Unix systems provide a C function named `getopt()' for processing command-line arguments. The programmer provides a string -describing the one-letter options. If an option requires an argument, -it is followed in the string with a colon. 'getopt()' is also passed +describing the one-letter options. If an option requires an argument, +it is followed in the string with a colon. `getopt()' is also passed the count and values of the command-line arguments and is called in a -loop. 'getopt()' processes the command-line arguments for option +loop. `getopt()' processes the command-line arguments for option letters. Each time around the loop, it returns a single character -representing the next option letter that it finds, or '?' if it finds an -invalid option. When it returns -1, there are no options left on the -command line. +representing the next option letter that it finds, or `?' if it finds +an invalid option. When it returns -1, there are no options left on +the command line. - When using 'getopt()', options that do not take arguments can be -grouped together. Furthermore, options that take arguments require that -the argument be present. The argument can immediately follow the option -letter, or it can be a separate command-line argument. + When using `getopt()', options that do not take arguments can be +grouped together. Furthermore, options that take arguments require +that the argument be present. The argument can immediately follow the +option letter, or it can be a separate command-line argument. Given a hypothetical program that takes three command-line options, -'-a', '-b', and '-c', where '-b' requires an argument, all of the +`-a', `-b', and `-c', where `-b' requires an argument, all of the following are valid ways of invoking the program: prog -a -b foo -c data1 data2 data3 @@ -16238,30 +15270,30 @@ following are valid ways of invoking the program: Notice that when the argument is grouped with its option, the rest of the argument is considered to be the option's argument. In this -example, '-acbfoo' indicates that all of the '-a', '-b', and '-c' -options were supplied, and that 'foo' is the argument to the '-b' +example, `-acbfoo' indicates that all of the `-a', `-b', and `-c' +options were supplied, and that `foo' is the argument to the `-b' option. - 'getopt()' provides four external variables that the programmer can + `getopt()' provides four external variables that the programmer can use: -'optind' - The index in the argument value array ('argv') where the first +`optind' + The index in the argument value array (`argv') where the first nonoption command-line argument can be found. -'optarg' +`optarg' The string value of the argument to an option. -'opterr' - Usually 'getopt()' prints an error message when it finds an invalid - option. Setting 'opterr' to zero disables this feature. (An +`opterr' + Usually `getopt()' prints an error message when it finds an invalid + option. Setting `opterr' to zero disables this feature. (An application might want to print its own error message.) -'optopt' +`optopt' The letter representing the command-line option. - The following C fragment shows how 'getopt()' might process -command-line arguments for 'awk': + The following C fragment shows how `getopt()' might process +command-line arguments for `awk': int main(int argc, char *argv[]) @@ -16292,15 +15324,15 @@ command-line arguments for 'awk': ... } - As a side point, 'gawk' actually uses the GNU 'getopt_long()' + As a side point, `gawk' actually uses the GNU `getopt_long()' function to process both normal and GNU-style long options (*note Options::). - The abstraction provided by 'getopt()' is very useful and is quite -handy in 'awk' programs as well. Following is an 'awk' version of -'getopt()'. This function highlights one of the greatest weaknesses in -'awk', which is that it is very poor at manipulating single characters. -Repeated calls to 'substr()' are necessary for accessing individual + The abstraction provided by `getopt()' is very useful and is quite +handy in `awk' programs as well. Following is an `awk' version of +`getopt()'. This function highlights one of the greatest weaknesses in +`awk', which is that it is very poor at manipulating single characters. +Repeated calls to `substr()' are necessary for accessing individual characters (*note String Functions::).(1) The discussion that follows walks through the code a bit at a time: @@ -16321,15 +15353,15 @@ characters (*note String Functions::).(1) # Private Data: # _opti -- index in multiflag option, e.g., -abc - The function starts out with comments presenting a list of the global -variables it uses, what the return values are, what they mean, and any -global variables that are "private" to this library function. Such -documentation is essential for any program, and particularly for library -functions. + The function starts out with comments presenting a list of the +global variables it uses, what the return values are, what they mean, +and any global variables that are "private" to this library function. +Such documentation is essential for any program, and particularly for +library functions. - The 'getopt()' function first checks that it was indeed called with a -string of options (the 'options' parameter). If 'options' has a zero -length, 'getopt()' immediately returns -1: + The `getopt()' function first checks that it was indeed called with +a string of options (the `options' parameter). If `options' has a zero +length, `getopt()' immediately returns -1: function getopt(argc, argv, options, thisopt, i) { @@ -16345,16 +15377,16 @@ length, 'getopt()' immediately returns -1: return -1 } - The next thing to check for is the end of the options. A '--' ends + The next thing to check for is the end of the options. A `--' ends the command-line options, as does any command-line argument that does -not begin with a '-'. 'Optind' is used to step through the array of -command-line arguments; it retains its value across calls to 'getopt()', -because it is a global variable. +not begin with a `-'. `Optind' is used to step through the array of +command-line arguments; it retains its value across calls to +`getopt()', because it is a global variable. - The regular expression that is used, '/^-[^:[:space:]/', checks for a -'-' followed by anything that is not whitespace and not a colon. If the -current command-line argument does not match this pattern, it is not an -option, and it ends option processing. Continuing on: + The regular expression that is used, `/^-[^:[:space:]/', checks for +a `-' followed by anything that is not whitespace and not a colon. If +the current command-line argument does not match this pattern, it is +not an option, and it ends option processing. Continuing on: if (_opti == 0) _opti = 2 @@ -16372,31 +15404,31 @@ option, and it ends option processing. Continuing on: return "?" } - The '_opti' variable tracks the position in the current command-line -argument ('argv[Optind]'). If multiple options are grouped together -with one '-' (e.g., '-abx'), it is necessary to return them to the user + The `_opti' variable tracks the position in the current command-line +argument (`argv[Optind]'). If multiple options are grouped together +with one `-' (e.g., `-abx'), it is necessary to return them to the user one at a time. - If '_opti' is equal to zero, it is set to two, which is the index in -the string of the next character to look at (we skip the '-', which is -at position one). The variable 'thisopt' holds the character, obtained -with 'substr()'. It is saved in 'Optopt' for the main program to use. + If `_opti' is equal to zero, it is set to two, which is the index in +the string of the next character to look at (we skip the `-', which is +at position one). The variable `thisopt' holds the character, obtained +with `substr()'. It is saved in `Optopt' for the main program to use. - If 'thisopt' is not in the 'options' string, then it is an invalid -option. If 'Opterr' is nonzero, 'getopt()' prints an error message on + If `thisopt' is not in the `options' string, then it is an invalid +option. If `Opterr' is nonzero, `getopt()' prints an error message on the standard error that is similar to the message from the C version of -'getopt()'. +`getopt()'. - Because the option is invalid, it is necessary to skip it and move on -to the next option character. If '_opti' is greater than or equal to -the length of the current command-line argument, it is necessary to move -on to the next argument, so 'Optind' is incremented and '_opti' is reset -to zero. Otherwise, 'Optind' is left alone and '_opti' is merely + Because the option is invalid, it is necessary to skip it and move +on to the next option character. If `_opti' is greater than or equal +to the length of the current command-line argument, it is necessary to +move on to the next argument, so `Optind' is incremented and `_opti' is +reset to zero. Otherwise, `Optind' is left alone and `_opti' is merely incremented. - In any case, because the option is invalid, 'getopt()' returns '"?"'. -The main program can examine 'Optopt' if it needs to know what the -invalid option letter actually is. Continuing on: + In any case, because the option is invalid, `getopt()' returns `"?"'. +The main program can examine `Optopt' if it needs to know what the +invalid option letter actually is. Continuing on: if (substr(options, i + 1, 1) == ":") { # get option argument @@ -16409,12 +15441,12 @@ invalid option letter actually is. Continuing on: Optarg = "" If the option requires an argument, the option letter is followed by -a colon in the 'options' string. If there are remaining characters in -the current command-line argument ('argv[Optind]'), then the rest of -that string is assigned to 'Optarg'. Otherwise, the next command-line -argument is used ('-xFOO' versus '-x FOO'). In either case, '_opti' is +a colon in the `options' string. If there are remaining characters in +the current command-line argument (`argv[Optind]'), then the rest of +that string is assigned to `Optarg'. Otherwise, the next command-line +argument is used (`-xFOO' versus `-x FOO'). In either case, `_opti' is reset to zero, because there are no more characters left to examine in -the current command-line argument. Continuing: +the current command-line argument. Continuing: if (_opti == 0 || _opti >= length(argv[Optind])) { Optind++ @@ -16424,18 +15456,18 @@ the current command-line argument. Continuing: return thisopt } - Finally, if '_opti' is either zero or greater than the length of the -current command-line argument, it means this element in 'argv' is -through being processed, so 'Optind' is incremented to point to the next -element in 'argv'. If neither condition is true, then only '_opti' is -incremented, so that the next option letter can be processed on the next -call to 'getopt()'. + Finally, if `_opti' is either zero or greater than the length of the +current command-line argument, it means this element in `argv' is +through being processed, so `Optind' is incremented to point to the +next element in `argv'. If neither condition is true, then only +`_opti' is incremented, so that the next option letter can be processed +on the next call to `getopt()'. - The 'BEGIN' rule initializes both 'Opterr' and 'Optind' to one. -'Opterr' is set to one, since the default behavior is for 'getopt()' to -print a diagnostic message upon seeing an invalid option. 'Optind' is + The `BEGIN' rule initializes both `Opterr' and `Optind' to one. +`Opterr' is set to one, since the default behavior is for `getopt()' to +print a diagnostic message upon seeing an invalid option. `Optind' is set to one, since there's no reason to look at the program name, which -is in 'ARGV[0]': +is in `ARGV[0]': BEGIN { Opterr = 1 # default is to diagnose @@ -16453,7 +15485,7 @@ is in 'ARGV[0]': } } - The rest of the 'BEGIN' rule is a simple test program. Here is the + The rest of the `BEGIN' rule is a simple test program. Here is the result of two sample runs of the test program: $ awk -f getopt.awk -v _getopt_test=1 -- -a -cbARG bax -x @@ -16466,28 +15498,28 @@ result of two sample runs of the test program: $ awk -f getopt.awk -v _getopt_test=1 -- -a -x -- xyz abc -| c = , Optarg = <> - error-> x -- invalid option + error--> x -- invalid option -| c = , Optarg = <> -| non-option arguments: -| ARGV[4] = -| ARGV[5] = - In both runs, the first '--' terminates the arguments to 'awk', so -that it does not try to interpret the '-a', etc., as its own options. + In both runs, the first `--' terminates the arguments to `awk', so +that it does not try to interpret the `-a', etc., as its own options. - NOTE: After 'getopt()' is through, it is the responsibility of the - user level code to clear out all the elements of 'ARGV' from 1 to - 'Optind', so that 'awk' does not try to process the command-line + NOTE: After `getopt()' is through, it is the responsibility of the + user level code to clear out all the elements of `ARGV' from 1 to + `Optind', so that `awk' does not try to process the command-line options as file names. Several of the sample programs presented in *note Sample Programs::, -use 'getopt()' to process their arguments. +use `getopt()' to process their arguments. ---------- Footnotes ---------- - (1) This function was written before 'gawk' acquired the ability to -split strings into single characters using '""' as the separator. We -have left it alone, since using 'substr()' is more portable. + (1) This function was written before `gawk' acquired the ability to +split strings into single characters using `""' as the separator. We +have left it alone, since using `substr()' is more portable.  File: gawk.info, Node: Passwd Functions, Next: Group Functions, Prev: Getopt Function, Up: Library Functions @@ -16495,33 +15527,33 @@ File: gawk.info, Node: Passwd Functions, Next: Group Functions, Prev: Getopt 10.5 Reading the User Database ============================== -The 'PROCINFO' array (*note Built-in Variables::) provides access to the -current user's real and effective user and group ID numbers, and if +The `PROCINFO' array (*note Built-in Variables::) provides access to +the current user's real and effective user and group ID numbers, and if available, the user's supplementary group set. However, because these are numbers, they do not provide very useful information to the average user. There needs to be some way to find the user information -associated with the user and group ID numbers. This minor node presents -a suite of functions for retrieving information from the user database. -*Note Group Functions::, for a similar suite that retrieves information -from the group database. +associated with the user and group ID numbers. This minor node +presents a suite of functions for retrieving information from the user +database. *Note Group Functions::, for a similar suite that retrieves +information from the group database. The POSIX standard does not define the file where user information is -kept. Instead, it provides the '' header file and several C +kept. Instead, it provides the `' header file and several C language subroutines for obtaining user information. The primary -function is 'getpwent()', for "get password entry." The "password" -comes from the original user database file, '/etc/passwd', which stores +function is `getpwent()', for "get password entry." The "password" +comes from the original user database file, `/etc/passwd', which stores user information, along with the encrypted passwords (hence the name). - While an 'awk' program could simply read '/etc/passwd' directly, this -file may not contain complete information about the system's set of -users.(1) To be sure you are able to produce a readable and complete -version of the user database, it is necessary to write a small C program -that calls 'getpwent()'. 'getpwent()' is defined as returning a pointer -to a 'struct passwd'. Each time it is called, it returns the next entry -in the database. When there are no more entries, it returns 'NULL', the -null pointer. When this happens, the C program should call 'endpwent()' -to close the database. Following is 'pwcat', a C program that "cats" -the password database: + While an `awk' program could simply read `/etc/passwd' directly, +this file may not contain complete information about the system's set +of users.(1) To be sure you are able to produce a readable and complete +version of the user database, it is necessary to write a small C +program that calls `getpwent()'. `getpwent()' is defined as returning +a pointer to a `struct passwd'. Each time it is called, it returns the +next entry in the database. When there are no more entries, it returns +`NULL', the null pointer. When this happens, the C program should call +`endpwent()' to close the database. Following is `pwcat', a C program +that "cats" the password database: /* * pwcat.c @@ -16546,8 +15578,8 @@ the password database: } If you don't understand C, don't worry about it. The output from -'pwcat' is the user database, in the traditional '/etc/passwd' format of -colon-separated fields. The fields are: +`pwcat' is the user database, in the traditional `/etc/passwd' format +of colon-separated fields. The fields are: Login name The user's login name. @@ -16558,26 +15590,26 @@ Encrypted password User-ID The user's numeric user ID number. (On some systems it's a C - 'long', and not an 'int'. Thus we cast it to 'long' for all + `long', and not an `int'. Thus we cast it to `long' for all cases.) Group-ID - The user's numeric group ID number. (Similar comments about 'long' - vs. 'int' apply here.) + The user's numeric group ID number. (Similar comments about + `long' vs. `int' apply here.) Full name - The user's full name, and perhaps other information associated with - the user. + The user's full name, and perhaps other information associated + with the user. Home directory The user's login (or "home") directory (familiar to shell - programmers as '$HOME'). + programmers as `$HOME'). Login shell The program that is run when the user logs in. This is usually a shell, such as Bash. - A few lines representative of 'pwcat''s output are as follows: + A few lines representative of `pwcat''s output are as follows: $ pwcat -| root:3Ov02d5VaUPB6:0:1:Operator:/:/bin/sh @@ -16590,9 +15622,9 @@ Login shell -| andy:abcca2:113:10:Andy Jacobs:/home/andy:/bin/sh ... - With that introduction, following is a group of functions for getting -user information. There are several functions here, corresponding to -the C functions of the same names: + With that introduction, following is a group of functions for +getting user information. There are several functions here, +corresponding to the C functions of the same names: # passwd.awk --- access password file information @@ -16632,41 +15664,41 @@ the C functions of the same names: $0 = olddol0 } - The 'BEGIN' rule sets a private variable to the directory where -'pwcat' is stored. Because it is used to help out an 'awk' library -routine, we have chosen to put it in '/usr/local/libexec/awk'; however, + The `BEGIN' rule sets a private variable to the directory where +`pwcat' is stored. Because it is used to help out an `awk' library +routine, we have chosen to put it in `/usr/local/libexec/awk'; however, you might want it to be in a different directory on your system. - The function '_pw_init()' keeps three copies of the user information + The function `_pw_init()' keeps three copies of the user information in three associative arrays. The arrays are indexed by username -('_pw_byname'), by user ID number ('_pw_byuid'), and by order of -occurrence ('_pw_bycount'). The variable '_pw_inited' is used for -efficiency, since '_pw_init()' needs to be called only once. - - Because this function uses 'getline' to read information from -'pwcat', it first saves the values of 'FS', 'RS', and '$0'. It notes in -the variable 'using_fw' whether field splitting with 'FIELDWIDTHS' is in -effect or not. Doing so is necessary, since these functions could be -called from anywhere within a user's program, and the user may have his -or her own way of splitting records and fields. - - The 'using_fw' variable checks 'PROCINFO["FS"]', which is -'"FIELDWIDTHS"' if field splitting is being done with 'FIELDWIDTHS'. +(`_pw_byname'), by user ID number (`_pw_byuid'), and by order of +occurrence (`_pw_bycount'). The variable `_pw_inited' is used for +efficiency, since `_pw_init()' needs to be called only once. + + Because this function uses `getline' to read information from +`pwcat', it first saves the values of `FS', `RS', and `$0'. It notes +in the variable `using_fw' whether field splitting with `FIELDWIDTHS' +is in effect or not. Doing so is necessary, since these functions +could be called from anywhere within a user's program, and the user may +have his or her own way of splitting records and fields. + + The `using_fw' variable checks `PROCINFO["FS"]', which is +`"FIELDWIDTHS"' if field splitting is being done with `FIELDWIDTHS'. This makes it possible to restore the correct field-splitting mechanism -later. The test can only be true for 'gawk'. It is false if using 'FS' -or 'FPAT', or on some other 'awk' implementation. +later. The test can only be true for `gawk'. It is false if using +`FS' or `FPAT', or on some other `awk' implementation. - The code that checks for using 'FPAT', using 'using_fpat' and -'PROCINFO["FS"]', is similar. + The code that checks for using `FPAT', using `using_fpat' and +`PROCINFO["FS"]', is similar. The main part of the function uses a loop to read database lines, split the line into fields, and then store the line into each array as -necessary. When the loop is done, '_pw_init()' cleans up by closing the -pipeline, setting '_pw_inited' to one, and restoring 'FS' (and -'FIELDWIDTHS' or 'FPAT' if necessary), 'RS', and '$0'. The use of -'_pw_count' is explained shortly. +necessary. When the loop is done, `_pw_init()' cleans up by closing +the pipeline, setting `_pw_inited' to one, and restoring `FS' (and +`FIELDWIDTHS' or `FPAT' if necessary), `RS', and `$0'. The use of +`_pw_count' is explained shortly. - The 'getpwnam()' function takes a username as a string argument. If + The `getpwnam()' function takes a username as a string argument. If that user is in the database, it returns the appropriate line. Otherwise, it relies on the array reference to a nonexistent element to create the element with the null string as its value: @@ -16677,9 +15709,9 @@ create the element with the null string as its value: return _pw_byname[name] } - Similarly, the 'getpwuid()' function takes a user ID number argument. -If that user number is in the database, it returns the appropriate line. -Otherwise, it returns the null string: + Similarly, the `getpwuid()' function takes a user ID number +argument. If that user number is in the database, it returns the +appropriate line. Otherwise, it returns the null string: function getpwuid(uid) { @@ -16687,9 +15719,9 @@ Otherwise, it returns the null string: return _pw_byuid[uid] } - The 'getpwent()' function simply steps through the database, one -entry at a time. It uses '_pw_count' to track its current position in -the '_pw_bycount' array: + The `getpwent()' function simply steps through the database, one +entry at a time. It uses `_pw_count' to track its current position in +the `_pw_bycount' array: function getpwent() { @@ -16699,8 +15731,8 @@ the '_pw_bycount' array: return "" } - The 'endpwent()' function resets '_pw_count' to zero, so that -subsequent calls to 'getpwent()' start over again: + The `endpwent()' function resets `_pw_count' to zero, so that +subsequent calls to `getpwent()' start over again: function endpwent() { @@ -16708,24 +15740,24 @@ subsequent calls to 'getpwent()' start over again: } A conscious design decision in this suite is that each subroutine -calls '_pw_init()' to initialize the database arrays. The overhead of -running a separate process to generate the user database, and the I/O to -scan it, are only incurred if the user's main program actually calls one -of these functions. If this library file is loaded along with a user's -program, but none of the routines are ever called, then there is no -extra runtime overhead. (The alternative is move the body of -'_pw_init()' into a 'BEGIN' rule, which always runs 'pwcat'. This +calls `_pw_init()' to initialize the database arrays. The overhead of +running a separate process to generate the user database, and the I/O +to scan it, are only incurred if the user's main program actually calls +one of these functions. If this library file is loaded along with a +user's program, but none of the routines are ever called, then there is +no extra runtime overhead. (The alternative is move the body of +`_pw_init()' into a `BEGIN' rule, which always runs `pwcat'. This simplifies the code but runs an extra process that may never be needed.) - In turn, calling '_pw_init()' is not too expensive, because the -'_pw_inited' variable keeps the program from reading the data more than + In turn, calling `_pw_init()' is not too expensive, because the +`_pw_inited' variable keeps the program from reading the data more than once. If you are worried about squeezing every last cycle out of your -'awk' program, the check of '_pw_inited' could be moved out of -'_pw_init()' and duplicated in all the other functions. In practice, -this is not necessary, since most 'awk' programs are I/O-bound, and such -a change would clutter up the code. +`awk' program, the check of `_pw_inited' could be moved out of +`_pw_init()' and duplicated in all the other functions. In practice, +this is not necessary, since most `awk' programs are I/O-bound, and +such a change would clutter up the code. - The 'id' program in *note Id Program::, uses these functions. + The `id' program in *note Id Program::, uses these functions. ---------- Footnotes ---------- @@ -16738,14 +15770,14 @@ File: gawk.info, Node: Group Functions, Next: Walking Arrays, Prev: Passwd Fu 10.6 Reading the Group Database =============================== -Much of the discussion presented in *note Passwd Functions::, applies to -the group database as well. Although there has traditionally been a -well-known file ('/etc/group') in a well-known format, the POSIX -standard only provides a set of C library routines ('' and -'getgrent()') for accessing the information. Even though this file may +Much of the discussion presented in *note Passwd Functions::, applies +to the group database as well. Although there has traditionally been a +well-known file (`/etc/group') in a well-known format, the POSIX +standard only provides a set of C library routines (`' and +`getgrent()') for accessing the information. Even though this file may exist, it may not have complete information. Therefore, as with the user database, it is necessary to have a small C program that generates -the group database as its output. 'grcat', a C program that "cats" the +the group database as its output. `grcat', a C program that "cats" the group database, is as follows: /* @@ -16783,24 +15815,24 @@ Group Name The group's name. Group Password - The group's encrypted password. In practice, this field is never - used; it is usually empty or set to '*'. + The group's encrypted password. In practice, this field is never + used; it is usually empty or set to `*'. Group ID Number The group's numeric group ID number; the association of name to number must be unique within the file. (On some systems it's a C - 'long', and not an 'int'. Thus we cast it to 'long' for all + `long', and not an `int'. Thus we cast it to `long' for all cases.) Group Member List A comma-separated list of user names. These users are members of the group. Modern Unix systems allow users to be members of - several groups simultaneously. If your system does, then there are - elements '"group1"' through '"groupN"' in 'PROCINFO' for those - group ID numbers. (Note that 'PROCINFO' is a 'gawk' extension; + several groups simultaneously. If your system does, then there + are elements `"group1"' through `"groupN"' in `PROCINFO' for those + group ID numbers. (Note that `PROCINFO' is a `gawk' extension; *note Built-in Variables::.) - Here is what running 'grcat' might produce: + Here is what running `grcat' might produce: $ grcat -| wheel:*:0:arnold @@ -16869,23 +15901,23 @@ the same names: $0 = olddol0 } - The 'BEGIN' rule sets a private variable to the directory where -'grcat' is stored. Because it is used to help out an 'awk' library -routine, we have chosen to put it in '/usr/local/libexec/awk'. You + The `BEGIN' rule sets a private variable to the directory where +`grcat' is stored. Because it is used to help out an `awk' library +routine, we have chosen to put it in `/usr/local/libexec/awk'. You might want it to be in a different directory on your system. These routines follow the same general outline as the user database -routines (*note Passwd Functions::). The '_gr_inited' variable is used +routines (*note Passwd Functions::). The `_gr_inited' variable is used to ensure that the database is scanned no more than once. The -'_gr_init()' function first saves 'FS', 'RS', and '$0', and then sets -'FS' and 'RS' to the correct values for scanning the group information. -It also takes care to note whether 'FIELDWIDTHS' or 'FPAT' is being +`_gr_init()' function first saves `FS', `RS', and `$0', and then sets +`FS' and `RS' to the correct values for scanning the group information. +It also takes care to note whether `FIELDWIDTHS' or `FPAT' is being used, and to restore the appropriate field splitting mechanism. The group information is stored is several associative arrays. The -arrays are indexed by group name ('_gr_byname'), by group ID number -('_gr_bygid'), and by position in the database ('_gr_bycount'). There -is an additional array indexed by user name ('_gr_groupsbyuser'), which +arrays are indexed by group name (`_gr_byname'), by group ID number +(`_gr_bygid'), and by position in the database (`_gr_bycount'). There +is an additional array indexed by user name (`_gr_groupsbyuser'), which is a space-separated list of groups to which each user belongs. Unlike the user database, it is possible to have multiple records in @@ -16896,15 +15928,15 @@ following: tvpeople:*:101:johny,jay,arsenio tvpeople:*:101:david,conan,tom,joan - For this reason, '_gr_init()' looks to see if a group name or group + For this reason, `_gr_init()' looks to see if a group name or group ID number is already seen. If it is, then the user names are simply concatenated onto the previous list of users.(1) - Finally, '_gr_init()' closes the pipeline to 'grcat', restores 'FS' -(and 'FIELDWIDTHS' or 'FPAT' if necessary), 'RS', and '$0', initializes -'_gr_count' to zero (it is used later), and makes '_gr_inited' nonzero. + Finally, `_gr_init()' closes the pipeline to `grcat', restores `FS' +(and `FIELDWIDTHS' or `FPAT' if necessary), `RS', and `$0', initializes +`_gr_count' to zero (it is used later), and makes `_gr_inited' nonzero. - The 'getgrnam()' function takes a group name as its argument, and if + The `getgrnam()' function takes a group name as its argument, and if that group exists, it is returned. Otherwise, it relies on the array reference to a nonexistent element to create the element with the null string as its value: @@ -16915,7 +15947,7 @@ string as its value: return _gr_byname[group] } - The 'getgrgid()' function is similar; it takes a numeric group ID and + The `getgrgid()' function is similar; it takes a numeric group ID and looks up the information associated with that group ID: function getgrgid(gid) @@ -16924,7 +15956,7 @@ looks up the information associated with that group ID: return _gr_bygid[gid] } - The 'getgruser()' function does not have a C counterpart. It takes a + The `getgruser()' function does not have a C counterpart. It takes a user name and returns the list of groups that have the user as a member: function getgruser(user) @@ -16933,8 +15965,8 @@ user name and returns the list of groups that have the user as a member: return _gr_groupsbyuser[user] } - The 'getgrent()' function steps through the database one entry at a -time. It uses '_gr_count' to track its position in the list: + The `getgrent()' function steps through the database one entry at a +time. It uses `_gr_count' to track its position in the list: function getgrent() { @@ -16944,30 +15976,30 @@ time. It uses '_gr_count' to track its position in the list: return "" } - The 'endgrent()' function resets '_gr_count' to zero so that -'getgrent()' can start over again: + The `endgrent()' function resets `_gr_count' to zero so that +`getgrent()' can start over again: function endgrent() { _gr_count = 0 } - As with the user database routines, each function calls '_gr_init()' + As with the user database routines, each function calls `_gr_init()' to initialize the arrays. Doing so only incurs the extra overhead of -running 'grcat' if these functions are used (as opposed to moving the -body of '_gr_init()' into a 'BEGIN' rule). +running `grcat' if these functions are used (as opposed to moving the +body of `_gr_init()' into a `BEGIN' rule). Most of the work is in scanning the database and building the various associative arrays. The functions that the user calls are themselves -very simple, relying on 'awk''s associative arrays to do work. +very simple, relying on `awk''s associative arrays to do work. - The 'id' program in *note Id Program::, uses these functions. + The `id' program in *note Id Program::, uses these functions. ---------- Footnotes ---------- (1) There is actually a subtle problem with the code just presented. -Suppose that the first time there were no names. This code adds the -names with a leading comma. It also doesn't check that there is a '$4'. +Suppose that the first time there were no names. This code adds the +names with a leading comma. It also doesn't check that there is a `$4'.  File: gawk.info, Node: Walking Arrays, Next: Library Functions Summary, Prev: Group Functions, Up: Library Functions @@ -16975,13 +16007,13 @@ File: gawk.info, Node: Walking Arrays, Next: Library Functions Summary, Prev: 10.7 Traversing Arrays of Arrays ================================ -*note Arrays of Arrays::, described how 'gawk' provides arrays of +*note Arrays of Arrays::, described how `gawk' provides arrays of arrays. In particular, any element of an array may be either a scalar, -or another array. The 'isarray()' function (*note Type Functions::) +or another array. The `isarray()' function (*note Type Functions::) lets you distinguish an array from a scalar. The following function, -'walk_array()', recursively traverses an array, printing each element's -indices and value. You call it with the array and a string representing -the name of the array: +`walk_array()', recursively traverses an array, printing each element's +indices and value. You call it with the array and a string +representing the name of the array: function walk_array(arr, name, i) { @@ -16993,7 +16025,7 @@ the name of the array: } } -It works by looping over each element of the array. If any given +It works by looping over each element of the array. If any given element is itself an array, the function calls itself recursively, passing the subarray and a new string representing the current index. Otherwise, the function simply prints the element's name, index, and @@ -17036,65 +16068,67 @@ File: gawk.info, Node: Library Functions Summary, Next: Library Exercises, Pr * The functions presented here fit into the following categories: - General problems + General problems Number to string conversion, assertions, rounding, random number generation, converting characters to numbers, joining strings, getting easily usable time-of-day information, and reading a whole file in one shot. - Managing data files + Managing data files Noting data file boundaries, rereading the current file, checking for readable files, checking for zero-length files, and treating assignments as file names. - Processing command-line options - An 'awk' version of the standard C 'getopt()' function. + Processing command-line options + An `awk' version of the standard C `getopt()' function. - Reading the user and group databases + Reading the user and group databases Two sets of routines that parallel the C library versions. - Traversing arrays of arrays + Traversing arrays of arrays A simple function to traverse an array of arrays to any depth. +  File: gawk.info, Node: Library Exercises, Prev: Library Functions Summary, Up: Library Functions 10.9 Exercises ============== - 1. In *note Empty Files::, we presented the 'zerofile.awk' program, - which made use of 'gawk''s 'ARGIND' variable. Can this problem be - solved without relying on 'ARGIND'? If so, how? + 1. In *note Empty Files::, we presented the `zerofile.awk' program, + which made use of `gawk''s `ARGIND' variable. Can this problem be + solved without relying on `ARGIND'? If so, how? 2. As a related challenge, revise that code to handle the case where - an intervening value in 'ARGV' is a variable assignment. + an intervening value in `ARGV' is a variable assignment. 3. *note Walking Arrays::, presented a function that walked a multidimensional array to print it out. However, walking an array and processing each element is a general-purpose operation. - Generalize the 'walk_array()' function by adding an additional - parameter named 'process'. + Generalize the `walk_array()' function by adding an additional + parameter named `process'. Then, inside the loop, instead of printing the array element's index and value, use the indirect function call syntax (*note - Indirect Calls::) on 'process', passing it the index and the value. + Indirect Calls::) on `process', passing it the index and the value. - When calling 'walk_array()', you would pass the name of a + When calling `walk_array()', you would pass the name of a user-defined function that expects to receive an index and a value, and then processes the element. Test your new version by printing the array; you should end up with output identical to that of the original version. +  File: gawk.info, Node: Sample Programs, Next: Advanced Features, Prev: Library Functions, Up: Top -11 Practical 'awk' Programs +11 Practical `awk' Programs *************************** *note Library Functions::, presents the idea that reading programs in a language contributes to learning that language. This major node -continues that theme, presenting a potpourri of 'awk' programs for your +continues that theme, presenting a potpourri of `awk' programs for your reading enjoyment. Many of these programs use library functions presented in *note @@ -17104,7 +16138,7 @@ Library Functions::. * Running Examples:: How to run these examples. * Clones:: Clones of common utilities. -* Miscellaneous Programs:: Some interesting 'awk' programs. +* Miscellaneous Programs:: Some interesting `awk' programs. * Programs Summary:: Summary of programs. * Programs Exercises:: Exercises. @@ -17118,16 +16152,16 @@ To run a given program, you would typically do something like this: awk -f PROGRAM -- OPTIONS FILES -Here, PROGRAM is the name of the 'awk' program (such as 'cut.awk'), +Here, PROGRAM is the name of the `awk' program (such as `cut.awk'), OPTIONS are any command-line options for the program that start with a -'-', and FILES are the actual data files. +`-', and FILES are the actual data files. - If your system supports the '#!' executable interpreter mechanism + If your system supports the `#!' executable interpreter mechanism (*note Executable Scripts::), you can instead run your program directly: cut.awk -c1-8 myfiles > results - If your 'awk' is not 'gawk', you may instead need to use this: + If your `awk' is not `gawk', you may instead need to use this: cut.awk -- -c1-8 myfiles > results @@ -17138,28 +16172,28 @@ File: gawk.info, Node: Clones, Next: Miscellaneous Programs, Prev: Running Ex ========================================== This minor node presents a number of POSIX utilities implemented in -'awk'. Reinventing these programs in 'awk' is often enjoyable, because +`awk'. Reinventing these programs in `awk' is often enjoyable, because the algorithms can be very clearly expressed, and the code is usually -very concise and simple. This is true because 'awk' does so much for +very concise and simple. This is true because `awk' does so much for you. It should be noted that these programs are not necessarily intended to replace the installed versions on your system. Nor may all of these programs be fully compliant with the most recent POSIX standard. This -is not a problem; their purpose is to illustrate 'awk' language +is not a problem; their purpose is to illustrate `awk' language programming for "real world" tasks. The programs are presented in alphabetical order. * Menu: -* Cut Program:: The 'cut' utility. -* Egrep Program:: The 'egrep' utility. -* Id Program:: The 'id' utility. -* Split Program:: The 'split' utility. -* Tee Program:: The 'tee' utility. -* Uniq Program:: The 'uniq' utility. -* Wc Program:: The 'wc' utility. +* Cut Program:: The `cut' utility. +* Egrep Program:: The `egrep' utility. +* Id Program:: The `id' utility. +* Split Program:: The `split' utility. +* Tee Program:: The `tee' utility. +* Uniq Program:: The `uniq' utility. +* Wc Program:: The `wc' utility.  File: gawk.info, Node: Cut Program, Next: Egrep Program, Up: Clones @@ -17167,43 +16201,43 @@ File: gawk.info, Node: Cut Program, Next: Egrep Program, Up: Clones 11.2.1 Cutting out Fields and Columns ------------------------------------- -The 'cut' utility selects, or "cuts," characters or fields from its +The `cut' utility selects, or "cuts," characters or fields from its standard input and sends them to its standard output. Fields are separated by TABs by default, but you may supply a command-line option to change the field "delimiter" (i.e., the field-separator character). -'cut''s definition of fields is less general than 'awk''s. +`cut''s definition of fields is less general than `awk''s. - A common use of 'cut' might be to pull out just the login name of -logged-on users from the output of 'who'. For example, the following + A common use of `cut' might be to pull out just the login name of +logged-on users from the output of `who'. For example, the following pipeline generates a sorted, unique list of the logged-on users: who | cut -c1-8 | sort | uniq - The options for 'cut' are: + The options for `cut' are: -'-c LIST' +`-c LIST' Use LIST as the list of characters to cut out. Items within the list may be separated by commas, and ranges of characters can be - separated with dashes. The list '1-8,15,22-35' specifies + separated with dashes. The list `1-8,15,22-35' specifies characters 1 through 8, 15, and 22 through 35. -'-f LIST' +`-f LIST' Use LIST as the list of fields to cut out. -'-d DELIM' +`-d DELIM' Use DELIM as the field-separator character instead of the TAB character. -'-s' +`-s' Suppress printing of lines that do not contain the field delimiter. - The 'awk' implementation of 'cut' uses the 'getopt()' library -function (*note Getopt Function::) and the 'join()' library function + The `awk' implementation of `cut' uses the `getopt()' library +function (*note Getopt Function::) and the `join()' library function (*note Join Function::). The program begins with a comment describing the options, the library -functions needed, and a 'usage()' function that prints out a usage -message and exits. 'usage()' is called if invalid arguments are +functions needed, and a `usage()' function that prints out a usage +message and exits. `usage()' is called if invalid arguments are supplied: # cut.awk --- implement cut in awk @@ -17226,15 +16260,15 @@ supplied: exit 1 } -The variables 'e1' and 'e2' are used so that the function fits nicely on -the screen. +The variables `e1' and `e2' are used so that the function fits nicely +on the screen. - Next comes a 'BEGIN' rule that parses the command-line options. It -sets 'FS' to a single TAB character, because that is 'cut''s default -field separator. The rule then sets the output field separator to be -the same as the input field separator. A loop using 'getopt()' steps + Next comes a `BEGIN' rule that parses the command-line options. It +sets `FS' to a single TAB character, because that is `cut''s default +field separator. The rule then sets the output field separator to be the +same as the input field separator. A loop using `getopt()' steps through the command-line options. Exactly one of the variables -'by_fields' or 'by_chars' is set to true, to indicate that processing +`by_fields' or `by_chars' is set to true, to indicate that processing should be done by fields or by characters, respectively. When cutting by characters, the output field separator is set to the null string: @@ -17270,18 +16304,18 @@ by characters, the output field separator is set to the null string: ARGV[i] = "" The code must take special care when the field delimiter is a space. -Using a single space ('" "') for the value of 'FS' is incorrect--'awk' -would separate fields with runs of spaces, TABs, and/or newlines, and we -want them to be separated with individual spaces. Also remember that -after 'getopt()' is through (as described in *note Getopt Function::), -we have to clear out all the elements of 'ARGV' from 1 to 'Optind', so -that 'awk' does not try to process the command-line options as file -names. +Using a single space (`" "') for the value of `FS' is incorrect--`awk' +would separate fields with runs of spaces, TABs, and/or newlines, and +we want them to be separated with individual spaces. Also remember +that after `getopt()' is through (as described in *note Getopt +Function::), we have to clear out all the elements of `ARGV' from 1 to +`Optind', so that `awk' does not try to process the command-line options +as file names. After dealing with the command-line options, the program verifies -that the options make sense. Only one or the other of '-c' and '-f' +that the options make sense. Only one or the other of `-c' and `-f' should be used, and both require a field list. Then the program calls -either 'set_fieldlist()' or 'set_charlist()' to pull apart the list of +either `set_fieldlist()' or `set_charlist()' to pull apart the list of fields or characters: if (by_fields && by_chars) @@ -17301,13 +16335,13 @@ fields or characters: set_charlist() } - 'set_fieldlist()' splits the field list apart at the commas into an + `set_fieldlist()' splits the field list apart at the commas into an array. Then, for each element of the array, it looks to see if the element is actually a range, and if so, splits it apart. The function checks the range to make sure that the first number is smaller than the -second. Each number in the list is added to the 'flist' array, which -simply lists the fields that will be printed. Normal field splitting is -used. The program lets 'awk' handle the job of doing the field +second. Each number in the list is added to the `flist' array, which +simply lists the fields that will be printed. Normal field splitting +is used. The program lets `awk' handle the job of doing the field splitting: function set_fieldlist( n, m, i, j, k, f, g) @@ -17330,20 +16364,20 @@ splitting: nfields = j - 1 } - The 'set_charlist()' function is more complicated than -'set_fieldlist()'. The idea here is to use 'gawk''s 'FIELDWIDTHS' + The `set_charlist()' function is more complicated than +`set_fieldlist()'. The idea here is to use `gawk''s `FIELDWIDTHS' variable (*note Constant Size::), which describes constant-width input. When using a character list, that is exactly what we have. - Setting up 'FIELDWIDTHS' is more complicated than simply listing the + Setting up `FIELDWIDTHS' is more complicated than simply listing the fields that need to be printed. We have to keep track of the fields to print and also the intervening characters that have to be skipped. For example, suppose you wanted characters 1 through 8, 15, and 22 through -35. You would use '-c 1-8,15,22-35'. The necessary value for -'FIELDWIDTHS' is '"8 6 1 6 14"'. This yields five fields, and the -fields to print are '$1', '$3', and '$5'. The intermediate fields are -"filler", which is stuff in between the desired data. 'flist' lists the -fields to print, and 't' tracks the complete field list, including +35. You would use `-c 1-8,15,22-35'. The necessary value for +`FIELDWIDTHS' is `"8 6 1 6 14"'. This yields five fields, and the +fields to print are `$1', `$3', and `$5'. The intermediate fields are +"filler", which is stuff in between the desired data. `flist' lists +the fields to print, and `t' tracks the complete field list, including filler fields: function set_charlist( field, i, j, f, g, n, m, t, @@ -17386,15 +16420,15 @@ filler fields: nfields = j - 1 } - Next is the rule that actually processes the data. If the '-s' -option is given, then 'suppress' is true. The first 'if' statement + Next is the rule that actually processes the data. If the `-s' +option is given, then `suppress' is true. The first `if' statement makes sure that the input record does have the field separator. If -'cut' is processing fields, 'suppress' is true, and the field separator +`cut' is processing fields, `suppress' is true, and the field separator character is not in the record, then the record is skipped. - If the record is valid, then 'gawk' has split the data into fields, -either using the character in 'FS' or using fixed-length fields and -'FIELDWIDTHS'. The loop goes through the list of fields that should be + If the record is valid, then `gawk' has split the data into fields, +either using the character in `FS' or using fixed-length fields and +`FIELDWIDTHS'. The loop goes through the list of fields that should be printed. The corresponding field is printed if it contains data. If the next field also has data, then the separator character is written out between the fields: @@ -17413,10 +16447,10 @@ out between the fields: print "" } - This version of 'cut' relies on 'gawk''s 'FIELDWIDTHS' variable to do -the character-based cutting. While it is possible in other 'awk' -implementations to use 'substr()' (*note String Functions::), it is also -extremely painful. The 'FIELDWIDTHS' variable supplies an elegant + This version of `cut' relies on `gawk''s `FIELDWIDTHS' variable to +do the character-based cutting. While it is possible in other `awk' +implementations to use `substr()' (*note String Functions::), it is +also extremely painful. The `FIELDWIDTHS' variable supplies an elegant solution to the problem of picking the input line apart by characters.  @@ -17425,52 +16459,53 @@ File: gawk.info, Node: Egrep Program, Next: Id Program, Prev: Cut Program, U 11.2.2 Searching for Regular Expressions in Files ------------------------------------------------- -The 'egrep' utility searches files for patterns. It uses regular -expressions that are almost identical to those available in 'awk' (*note -Regexp::). You invoke it as follows: +The `egrep' utility searches files for patterns. It uses regular +expressions that are almost identical to those available in `awk' +(*note Regexp::). You invoke it as follows: - 'egrep' [OPTIONS] ''PATTERN'' FILES ... + `egrep' [OPTIONS] `'PATTERN'' FILES ... The PATTERN is a regular expression. In typical usage, the regular expression is quoted to prevent the shell from expanding any of the -special characters as file name wildcards. Normally, 'egrep' prints the -lines that matched. If multiple file names are provided on the command -line, each output line is preceded by the name of the file and a colon. +special characters as file name wildcards. Normally, `egrep' prints +the lines that matched. If multiple file names are provided on the +command line, each output line is preceded by the name of the file and +a colon. - The options to 'egrep' are as follows: + The options to `egrep' are as follows: -'-c' - Print out a count of the lines that matched the pattern, instead of - the lines themselves. +`-c' + Print out a count of the lines that matched the pattern, instead + of the lines themselves. -'-s' +`-s' Be silent. No output is produced and the exit value indicates whether the pattern was matched. -'-v' - Invert the sense of the test. 'egrep' prints the lines that do +`-v' + Invert the sense of the test. `egrep' prints the lines that do _not_ match the pattern and exits successfully if the pattern is not matched. -'-i' +`-i' Ignore case distinctions in both the pattern and the input data. -'-l' +`-l' Only print (list) the names of the files that matched, not the lines that matched. -'-e PATTERN' - Use PATTERN as the regexp to match. The purpose of the '-e' option - is to allow patterns that start with a '-'. +`-e PATTERN' + Use PATTERN as the regexp to match. The purpose of the `-e' + option is to allow patterns that start with a `-'. - This version uses the 'getopt()' library function (*note Getopt + This version uses the `getopt()' library function (*note Getopt Function::) and the file transition library program (*note Filetrans Function::). - The program begins with a descriptive comment and then a 'BEGIN' rule -that processes the command-line arguments with 'getopt()'. The '-i' -(ignore case) option is particularly easy with 'gawk'; we just use the -'IGNORECASE' built-in variable (*note Built-in Variables::): + The program begins with a descriptive comment and then a `BEGIN' rule +that processes the command-line arguments with `getopt()'. The `-i' +(ignore case) option is particularly easy with `gawk'; we just use the +`IGNORECASE' built-in variable (*note Built-in Variables::): # egrep.awk --- simulate egrep in awk # @@ -17502,10 +16537,10 @@ that processes the command-line arguments with 'getopt()'. The '-i' usage() } - Next comes the code that handles the 'egrep'-specific behavior. If -no pattern is supplied with '-e', the first nonoption on the command -line is used. The 'awk' command-line arguments up to 'ARGV[Optind]' are -cleared, so that 'awk' won't try to process them as files. If no files + Next comes the code that handles the `egrep'-specific behavior. If no +pattern is supplied with `-e', the first nonoption on the command line +is used. The `awk' command-line arguments up to `ARGV[Optind]' are +cleared, so that `awk' won't try to process them as files. If no files are specified, the standard input is used, and if multiple files are specified, we make sure to note this so that the file names can precede the matched lines in the output: @@ -17526,24 +16561,24 @@ the matched lines in the output: } The last two lines are commented out, since they are not needed in -'gawk'. They should be uncommented if you have to use another version -of 'awk'. +`gawk'. They should be uncommented if you have to use another version +of `awk'. The next set of lines should be uncommented if you are not using -'gawk'. This rule translates all the characters in the input line into -lowercase if the '-i' option is specified.(1) The rule is commented out -since it is not necessary with 'gawk': +`gawk'. This rule translates all the characters in the input line into +lowercase if the `-i' option is specified.(1) The rule is commented out +since it is not necessary with `gawk': #{ # if (IGNORECASE) # $0 = tolower($0) #} - The 'beginfile()' function is called by the rule in 'ftrans.awk' when -each new file is processed. In this case, it is very simple; all it -does is initialize a variable 'fcount' to zero. 'fcount' tracks how + The `beginfile()' function is called by the rule in `ftrans.awk' +when each new file is processed. In this case, it is very simple; all +it does is initialize a variable `fcount' to zero. `fcount' tracks how many lines in the current file matched the pattern. Naming the -parameter 'junk' shows we know that 'beginfile()' is called with a +parameter `junk' shows we know that `beginfile()' is called with a parameter, but that we're not interested in its value: function beginfile(junk) @@ -17551,13 +16586,13 @@ parameter, but that we're not interested in its value: fcount = 0 } - The 'endfile()' function is called after each file has been + The `endfile()' function is called after each file has been processed. It affects the output only when the user wants a count of -the number of lines that matched. 'no_print' is true only if the exit -status is desired. 'count_only' is true if line counts are desired. -'egrep' therefore only prints line counts if printing and counting are +the number of lines that matched. `no_print' is true only if the exit +status is desired. `count_only' is true if line counts are desired. +`egrep' therefore only prints line counts if printing and counting are enabled. The output format must be adjusted depending upon the number -of files to process. Finally, 'fcount' is added to 'total', so that we +of files to process. Finally, `fcount' is added to `total', so that we know the total number of lines that matched the pattern: function endfile(file) @@ -17572,25 +16607,25 @@ know the total number of lines that matched the pattern: total += fcount } - The 'BEGINFILE' and 'ENDFILE' special patterns (*note + The `BEGINFILE' and `ENDFILE' special patterns (*note BEGINFILE/ENDFILE::) could be used, but then the program would be -'gawk'-specific. Additionally, this example was written before 'gawk' -acquired 'BEGINFILE' and 'ENDFILE'. +`gawk'-specific. Additionally, this example was written before `gawk' +acquired `BEGINFILE' and `ENDFILE'. - The following rule does most of the work of matching lines. The -variable 'matches' is true if the line matched the pattern. If the user -wants lines that did not match, the sense of 'matches' is inverted using -the '!' operator. 'fcount' is incremented with the value of 'matches', -which is either one or zero, depending upon a successful or unsuccessful -match. If the line does not match, the 'next' statement just moves on -to the next record. + The following rule does most of the work of matching lines. The +variable `matches' is true if the line matched the pattern. If the user +wants lines that did not match, the sense of `matches' is inverted +using the `!' operator. `fcount' is incremented with the value of +`matches', which is either one or zero, depending upon a successful or +unsuccessful match. If the line does not match, the `next' statement +just moves on to the next record. A number of additional tests are made, but they are only done if we are not counting lines. First, if the user only wants exit status -('no_print' is true), then it is enough to know that _one_ line in this -file matched, and we can skip on to the next file with 'nextfile'. +(`no_print' is true), then it is enough to know that _one_ line in this +file matched, and we can skip on to the next file with `nextfile'. Similarly, if we are only printing file names, we can print the file -name, and then skip to the next file with 'nextfile'. Finally, each +name, and then skip to the next file with `nextfile'. Finally, each line is printed, with a leading file name and colon if necessary: { @@ -17619,14 +16654,14 @@ line is printed, with a leading file name and colon if necessary: } } - The 'END' rule takes care of producing the correct exit status. If + The `END' rule takes care of producing the correct exit status. If there are no matches, the exit status is one; otherwise it is zero: END { exit (total == 0) } - The 'usage()' function prints a usage message in case of invalid + The `usage()' function prints a usage message in case of invalid options, and then exits: function usage( e) @@ -17637,19 +16672,9 @@ options, and then exits: exit 1 } - The variable 'e' is used so that the function fits nicely on the + The variable `e' is used so that the function fits nicely on the printed page. -<<<<<<< HEAD - Just a note on programming style: you may have noticed that the 'END' -rule uses backslash continuation, with the open brace on a line by -itself. This is so that it more closely resembles the way functions are -written. Many of the examples in this major node use this style. You -can decide for yourself if you like writing your 'BEGIN' and 'END' rules -this way or not. - -======= ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac ---------- Footnotes ---------- (1) It also introduces a subtle bug; if a match happens, we output @@ -17661,29 +16686,29 @@ File: gawk.info, Node: Id Program, Next: Split Program, Prev: Egrep Program, 11.2.3 Printing out User Information ------------------------------------ -The 'id' utility lists a user's real and effective user ID numbers, real -and effective group ID numbers, and the user's group set, if any. 'id' -only prints the effective user ID and group ID if they are different -from the real ones. If possible, 'id' also supplies the corresponding -user and group names. The output might look like this: +The `id' utility lists a user's real and effective user ID numbers, +real and effective group ID numbers, and the user's group set, if any. +`id' only prints the effective user ID and group ID if they are +different from the real ones. If possible, `id' also supplies the +corresponding user and group names. The output might look like this: $ id -| uid=1000(arnold) gid=1000(arnold) groups=1000(arnold),4(adm),7(lp),27(sudo) - This information is part of what is provided by 'gawk''s 'PROCINFO' -array (*note Built-in Variables::). However, the 'id' utility provides + This information is part of what is provided by `gawk''s `PROCINFO' +array (*note Built-in Variables::). However, the `id' utility provides a more palatable output than just individual numbers. - Here is a simple version of 'id' written in 'awk'. It uses the user + Here is a simple version of `id' written in `awk'. It uses the user database library functions (*note Passwd Functions::) and the group database library functions (*note Group Functions::): The program is fairly straightforward. All the work is done in the -'BEGIN' rule. The user and group ID numbers are obtained from -'PROCINFO'. The code is repetitive. The entry in the user database for -the real user ID number is split into parts at the ':'. The name is the -first field. Similar code is used for the effective user ID number and -the group numbers: +`BEGIN' rule. The user and group ID numbers are obtained from +`PROCINFO'. The code is repetitive. The entry in the user database +for the real user ID number is split into parts at the `:'. The name is +the first field. Similar code is used for the effective user ID number +and the group numbers: # id.awk --- implement id in awk # @@ -17743,22 +16768,23 @@ the group numbers: printf("(%s)", a[1]) } - The test in the 'for' loop is worth noting. Any supplementary groups -in the 'PROCINFO' array have the indices '"group1"' through '"groupN"' -for some N, i.e., the total number of supplementary groups. However, we -don't know in advance how many of these groups there are. + The test in the `for' loop is worth noting. Any supplementary +groups in the `PROCINFO' array have the indices `"group1"' through +`"groupN"' for some N, i.e., the total number of supplementary groups. +However, we don't know in advance how many of these groups there are. This loop works by starting at one, concatenating the value with -'"group"', and then using 'in' to see if that value is in the array -(*note Reference to Elements::). Eventually, 'i' is incremented past +`"group"', and then using `in' to see if that value is in the array +(*note Reference to Elements::). Eventually, `i' is incremented past the last group in the array and the loop exits. - The loop is also correct if there are _no_ supplementary groups; then -the condition is false the first time it's tested, and the loop body -never executes. + The loop is also correct if there are _no_ supplementary groups; +then the condition is false the first time it's tested, and the loop +body never executes. - The 'pr_first_field()' function simply isolates out some code that is -used repeatedly, making the whole program slightly shorter and cleaner. + The `pr_first_field()' function simply isolates out some code that +is used repeatedly, making the whole program slightly shorter and +cleaner.  File: gawk.info, Node: Split Program, Next: Tee Program, Prev: Id Program, Up: Clones @@ -17766,29 +16792,29 @@ File: gawk.info, Node: Split Program, Next: Tee Program, Prev: Id Program, U 11.2.4 Splitting a Large File into Pieces ----------------------------------------- -The 'split' program splits large text files into smaller pieces. Usage +The `split' program splits large text files into smaller pieces. Usage is as follows:(1) - 'split' ['-COUNT'] [FILE] [PREFIX] + `split' [`-COUNT'] [FILE] [PREFIX] - By default, the output files are named 'xaa', 'xab', and so on. Each + By default, the output files are named `xaa', `xab', and so on. Each file has 1000 lines in it, with the likely exception of the last file. To change the number of lines in each file, supply a number on the -command line preceded with a minus; e.g., '-500' for files with 500 +command line preceded with a minus; e.g., `-500' for files with 500 lines in them instead of 1000. To change the name of the output files -to something like 'myfileaa', 'myfileab', and so on, supply an +to something like `myfileaa', `myfileab', and so on, supply an additional argument that specifies the file name prefix. - Here is a version of 'split' in 'awk'. It uses the 'ord()' and -'chr()' functions presented in *note Ordinal Functions::. + Here is a version of `split' in `awk'. It uses the `ord()' and +`chr()' functions presented in *note Ordinal Functions::. The program first sets its defaults, and then tests to make sure there are not too many arguments. It then looks at each argument in turn. The first argument could be a minus sign followed by a number. If it is, this happens to look like a negative number, so it is made -positive, and that is the count of lines. The data file name is skipped -over and the final argument is used as the prefix for the output file -names: +positive, and that is the count of lines. The data file name is +skipped over and the final argument is used as the prefix for the +output file names: # split.awk --- do split in awk # @@ -17819,13 +16845,13 @@ names: out = (outfile s1 s2) } - The next rule does most of the work. 'tcount' (temporary count) -tracks how many lines have been printed to the output file so far. If -it is greater than 'count', it is time to close the current file and -start a new one. 's1' and 's2' track the current suffixes for the file -name. If they are both 'z', the file is just too big. Otherwise, 's1' -moves to the next letter in the alphabet and 's2' starts over again at -'a': + The next rule does most of the work. `tcount' (temporary count) +tracks how many lines have been printed to the output file so far. If +it is greater than `count', it is time to close the current file and +start a new one. `s1' and `s2' track the current suffixes for the file +name. If they are both `z', the file is just too big. Otherwise, `s1' +moves to the next letter in the alphabet and `s2' starts over again at +`a': { if (++tcount > count) { @@ -17847,7 +16873,7 @@ moves to the next letter in the alphabet and 's2' starts over again at print > out } -The 'usage()' function simply prints an error message and exits: +The `usage()' function simply prints an error message and exits: function usage( e) { @@ -17856,16 +16882,16 @@ The 'usage()' function simply prints an error message and exits: exit 1 } -The variable 'e' is used so that the function fits nicely on the screen. +The variable `e' is used so that the function fits nicely on the screen. - This program is a bit sloppy; it relies on 'awk' to automatically -close the last file instead of doing it in an 'END' rule. It also + This program is a bit sloppy; it relies on `awk' to automatically +close the last file instead of doing it in an `END' rule. It also assumes that letters are contiguous in the character set, which isn't true for EBCDIC systems. ---------- Footnotes ---------- - (1) This is the traditional usage. The POSIX usage is different, but + (1) This is the traditional usage. The POSIX usage is different, but not relevant for what the program aims to demonstrate.  @@ -17874,25 +16900,25 @@ File: gawk.info, Node: Tee Program, Next: Uniq Program, Prev: Split Program, 11.2.5 Duplicating Output into Multiple Files --------------------------------------------- -The 'tee' program is known as a "pipe fitting." 'tee' copies its +The `tee' program is known as a "pipe fitting." `tee' copies its standard input to its standard output and also duplicates it to the files named on the command line. Its usage is as follows: - 'tee' ['-a'] FILE ... + `tee' [`-a'] FILE ... - The '-a' option tells 'tee' to append to the named files, instead of + The `-a' option tells `tee' to append to the named files, instead of truncating them and starting over. - The 'BEGIN' rule first makes a copy of all the command-line arguments -into an array named 'copy'. 'ARGV[0]' is not copied, since it is not -needed. 'tee' cannot use 'ARGV' directly, since 'awk' attempts to -process each file name in 'ARGV' as input data. + The `BEGIN' rule first makes a copy of all the command-line arguments +into an array named `copy'. `ARGV[0]' is not copied, since it is not +needed. `tee' cannot use `ARGV' directly, since `awk' attempts to +process each file name in `ARGV' as input data. - If the first argument is '-a', then the flag variable 'append' is set -to true, and both 'ARGV[1]' and 'copy[1]' are deleted. If 'ARGC' is -less than two, then no file names were supplied and 'tee' prints a usage -message and exits. Finally, 'awk' is forced to read the standard input -by setting 'ARGV[1]' to '"-"' and 'ARGC' to two: + If the first argument is `-a', then the flag variable `append' is +set to true, and both `ARGV[1]' and `copy[1]' are deleted. If `ARGC' is +less than two, then no file names were supplied and `tee' prints a +usage message and exits. Finally, `awk' is forced to read the standard +input by setting `ARGV[1]' to `"-"' and `ARGC' to two: # tee.awk --- tee in awk # @@ -17941,13 +16967,13 @@ It is also possible to write the loop this way: else print > copy[i] -This is more concise but it is also less efficient. The 'if' is tested -for each record and for each output file. By duplicating the loop body, -the 'if' is only tested once for each input record. If there are N -input records and M output files, the first method only executes N 'if' -statements, while the second executes N'*'M 'if' statements. +This is more concise but it is also less efficient. The `if' is tested +for each record and for each output file. By duplicating the loop +body, the `if' is only tested once for each input record. If there are +N input records and M output files, the first method only executes N +`if' statements, while the second executes N`*'M `if' statements. - Finally, the 'END' rule cleans up by closing all the output files: + Finally, the `END' rule cleans up by closing all the output files: END { for (i in copy) @@ -17960,64 +16986,64 @@ File: gawk.info, Node: Uniq Program, Next: Wc Program, Prev: Tee Program, Up 11.2.6 Printing Nonduplicated Lines of Text ------------------------------------------- -The 'uniq' utility reads sorted lines of data on its standard input, and -by default removes duplicate lines. In other words, it only prints -unique lines--hence the name. 'uniq' has a number of options. The +The `uniq' utility reads sorted lines of data on its standard input, +and by default removes duplicate lines. In other words, it only prints +unique lines--hence the name. `uniq' has a number of options. The usage is as follows: - 'uniq' ['-udc' ['-N']] ['+N'] [INPUTFILE [OUTPUTFILE]] + `uniq' [`-udc' [`-N']] [`+N'] [INPUTFILE [OUTPUTFILE]] - The options for 'uniq' are: + The options for `uniq' are: -'-d' +`-d' Print only repeated lines. -'-u' +`-u' Print only nonrepeated lines. -'-c' - Count lines. This option overrides '-d' and '-u'. Both repeated +`-c' + Count lines. This option overrides `-d' and `-u'. Both repeated and nonrepeated lines are counted. -'-N' +`-N' Skip N fields before comparing lines. The definition of fields is - similar to 'awk''s default: nonwhitespace characters separated by + similar to `awk''s default: nonwhitespace characters separated by runs of spaces and/or TABs. -'+N' +`+N' Skip N characters before comparing lines. Any fields specified - with '-N' are skipped first. + with `-N' are skipped first. -'INPUTFILE' - Data is read from the input file named on the command line, instead - of from the standard input. +`INPUTFILE' + Data is read from the input file named on the command line, + instead of from the standard input. -'OUTPUTFILE' +`OUTPUTFILE' The generated output is sent to the named output file, instead of to the standard output. - Normally 'uniq' behaves as if both the '-d' and '-u' options are + Normally `uniq' behaves as if both the `-d' and `-u' options are provided. - 'uniq' uses the 'getopt()' library function (*note Getopt Function::) -and the 'join()' library function (*note Join Function::). + `uniq' uses the `getopt()' library function (*note Getopt Function::) +and the `join()' library function (*note Join Function::). - The program begins with a 'usage()' function and then a brief outline -of the options and their meanings in comments. The 'BEGIN' rule deals -with the command-line arguments and options. It uses a trick to get -'getopt()' to handle options of the form '-25', treating such an option -as the option letter '2' with an argument of '5'. If indeed two or more -digits are supplied ('Optarg' looks like a number), 'Optarg' is + The program begins with a `usage()' function and then a brief +outline of the options and their meanings in comments. The `BEGIN' +rule deals with the command-line arguments and options. It uses a trick +to get `getopt()' to handle options of the form `-25', treating such an +option as the option letter `2' with an argument of `5'. If indeed two +or more digits are supplied (`Optarg' looks like a number), `Optarg' is concatenated with the option digit and then the result is added to zero to make it into a number. If there is only one digit in the option, -then 'Optarg' is not needed. In this case, 'Optind' must be decremented -so that 'getopt()' processes it next time. This code is admittedly a +then `Optarg' is not needed. In this case, `Optind' must be decremented +so that `getopt()' processes it next time. This code is admittedly a bit tricky. If no options are supplied, then the default is taken, to print both repeated and nonrepeated lines. The output file, if provided, is -assigned to 'outputfile'. Early on, 'outputfile' is initialized to the -standard output, '/dev/stdout': +assigned to `outputfile'. Early on, `outputfile' is initialized to the +standard output, `/dev/stdout': # uniq.awk --- do uniq in awk # @@ -18077,19 +17103,19 @@ standard output, '/dev/stdout': } } - The following function, 'are_equal()', compares the current line, -'$0', to the previous line, 'last'. It handles skipping fields and + The following function, `are_equal()', compares the current line, +`$0', to the previous line, `last'. It handles skipping fields and characters. If no field count and no character count are specified, -'are_equal()' simply returns one or zero depending upon the result of a -simple string comparison of 'last' and '$0'. Otherwise, things get more +`are_equal()' simply returns one or zero depending upon the result of a +simple string comparison of `last' and `$0'. Otherwise, things get more complicated. If fields have to be skipped, each line is broken into an -array using 'split()' (*note String Functions::); the desired fields are -then joined back into a line using 'join()'. The joined lines are -stored in 'clast' and 'cline'. If no fields are skipped, 'clast' and -'cline' are set to 'last' and '$0', respectively. Finally, if -characters are skipped, 'substr()' is used to strip off the leading -'charcount' characters in 'clast' and 'cline'. The two strings are then -compared and 'are_equal()' returns the result: +array using `split()' (*note String Functions::); the desired fields +are then joined back into a line using `join()'. The joined lines are +stored in `clast' and `cline'. If no fields are skipped, `clast' and +`cline' are set to `last' and `$0', respectively. Finally, if +characters are skipped, `substr()' is used to strip off the leading +`charcount' characters in `clast' and `cline'. The two strings are +then compared and `are_equal()' returns the result: function are_equal( n, m, clast, cline, alast, aline) { @@ -18114,23 +17140,23 @@ compared and 'are_equal()' returns the result: } The following two rules are the body of the program. The first one -is executed only for the very first line of data. It sets 'last' equal -to '$0', so that subsequent lines of text have something to be compared +is executed only for the very first line of data. It sets `last' equal +to `$0', so that subsequent lines of text have something to be compared to. - The second rule does the work. The variable 'equal' is one or zero, -depending upon the results of 'are_equal()''s comparison. If 'uniq' is -counting repeated lines, and the lines are equal, then it increments the -'count' variable. Otherwise, it prints the line and resets 'count', + The second rule does the work. The variable `equal' is one or zero, +depending upon the results of `are_equal()''s comparison. If `uniq' is +counting repeated lines, and the lines are equal, then it increments +the `count' variable. Otherwise, it prints the line and resets `count', since the two lines are not equal. - If 'uniq' is not counting, and if the lines are equal, 'count' is + If `uniq' is not counting, and if the lines are equal, `count' is incremented. Nothing is printed, since the point is to remove -duplicates. Otherwise, if 'uniq' is counting repeated lines and more -than one line is seen, or if 'uniq' is counting nonrepeated lines and -only one line is seen, then the line is printed, and 'count' is reset. +duplicates. Otherwise, if `uniq' is counting repeated lines and more +than one line is seen, or if `uniq' is counting nonrepeated lines and +only one line is seen, then the line is printed, and `count' is reset. - Finally, similar logic is used in the 'END' rule to print the final + Finally, similar logic is used in the `END' rule to print the final line of input data: NR == 1 { @@ -18178,44 +17204,44 @@ File: gawk.info, Node: Wc Program, Prev: Uniq Program, Up: Clones 11.2.7 Counting Things ---------------------- -The 'wc' (word count) utility counts lines, words, and characters in one -or more input files. Its usage is as follows: +The `wc' (word count) utility counts lines, words, and characters in +one or more input files. Its usage is as follows: - 'wc' ['-lwc'] [FILES ...] + `wc' [`-lwc'] [FILES ...] - If no files are specified on the command line, 'wc' reads its -standard input. If there are multiple files, it also prints total + If no files are specified on the command line, `wc' reads its +standard input. If there are multiple files, it also prints total counts for all the files. The options and their meanings are shown in the following list: -'-l' +`-l' Count only lines. -'-w' +`-w' Count only words. A "word" is a contiguous sequence of nonwhitespace characters, separated by spaces and/or TABs. - Luckily, this is the normal way 'awk' separates fields in its input - data. + Luckily, this is the normal way `awk' separates fields in its + input data. -'-c' +`-c' Count only characters. - Implementing 'wc' in 'awk' is particularly elegant, since 'awk' does + Implementing `wc' in `awk' is particularly elegant, since `awk' does a lot of the work for us; it splits lines into words (i.e., fields) and counts them, it counts lines (i.e., records), and it can easily tell us how long a line is. - This program uses the 'getopt()' library function (*note Getopt + This program uses the `getopt()' library function (*note Getopt Function::) and the file-transition functions (*note Filetrans Function::). This version has one notable difference from traditional versions of -'wc': it always prints the counts in the order lines, words, and -characters. Traditional versions note the order of the '-l', '-w', and -'-c' options on the command line, and print the counts in that order. +`wc': it always prints the counts in the order lines, words, and +characters. Traditional versions note the order of the `-l', `-w', and +`-c' options on the command line, and print the counts in that order. - The 'BEGIN' rule does the argument processing. The variable -'print_total' is true if more than one file is named on the command + The `BEGIN' rule does the argument processing. The variable +`print_total' is true if more than one file is named on the command line: # wc.awk --- count lines, words, characters @@ -18250,9 +17276,9 @@ line: print_total = (ARGC - i > 2) } - The 'beginfile()' function is simple; it just resets the counts of + The `beginfile()' function is simple; it just resets the counts of lines, words, and characters to zero, and saves the current file name in -'fname': +`fname': function beginfile(file) { @@ -18260,10 +17286,10 @@ lines, words, and characters to zero, and saves the current file name in fname = FILENAME } - The 'endfile()' function adds the current file's numbers to the + The `endfile()' function adds the current file's numbers to the running totals of lines, words, and characters. It then prints out -those numbers for the file that was just read. It relies on -'beginfile()' to reset the numbers for the following data file: +those numbers for the file that was just read. It relies on +`beginfile()' to reset the numbers for the following data file: function endfile(file) { @@ -18279,12 +17305,12 @@ those numbers for the file that was just read. It relies on printf "\t%s\n", fname } - There is one rule that is executed for each line. It adds the length -of the record, plus one, to 'chars'.(1) Adding one plus the record + There is one rule that is executed for each line. It adds the length +of the record, plus one, to `chars'.(1) Adding one plus the record length is needed because the newline character separating records (the -value of 'RS') is not part of the record itself, and thus not included -in its length. Next, 'lines' is incremented for each line read, and -'words' is incremented by the value of 'NF', which is the number of +value of `RS') is not part of the record itself, and thus not included +in its length. Next, `lines' is incremented for each line read, and +`words' is incremented by the value of `NF', which is the number of "words" on this line: # do per line @@ -18294,7 +17320,7 @@ in its length. Next, 'lines' is incremented for each line read, and words += NF } - Finally, the 'END' rule simply prints the totals for all the files: + Finally, the `END' rule simply prints the totals for all the files: END { if (print_total) { @@ -18310,13 +17336,13 @@ in its length. Next, 'lines' is incremented for each line read, and ---------- Footnotes ---------- - (1) Since 'gawk' understands multibyte locales, this code counts + (1) Since `gawk' understands multibyte locales, this code counts characters, not bytes.  File: gawk.info, Node: Miscellaneous Programs, Next: Programs Summary, Prev: Clones, Up: Sample Programs -11.3 A Grab Bag of 'awk' Programs +11.3 A Grab Bag of `awk' Programs ================================= This minor node is a large "grab bag" of miscellaneous programs. We @@ -18326,7 +17352,7 @@ hope you find them both interesting and enjoyable. * Dupword Program:: Finding duplicated words in a document. * Alarm Program:: An alarm clock. -* Translate Program:: A program similar to the 'tr' utility. +* Translate Program:: A program similar to the `tr' utility. * Labels Program:: Printing mailing labels. * Word Sorting:: A program to produce a word usage count. * History Sorting:: Eliminating duplicate entries from a history @@ -18334,7 +17360,7 @@ hope you find them both interesting and enjoyable. * Extract Program:: Pulling out programs from Texinfo source files. * Simple Sed:: A Simple Stream Editor. -* Igawk Program:: A wrapper for 'awk' that includes +* Igawk Program:: A wrapper for `awk' that includes files. * Anagram Program:: Finding anagrams from a dictionary. * Signature Program:: People do amazing things with too much time on @@ -18348,22 +17374,22 @@ File: gawk.info, Node: Dupword Program, Next: Alarm Program, Up: Miscellaneou A common error when writing large amounts of prose is to accidentally duplicate words. Typically you will see this in text as something like -"the the program does the following..." When the text is online, often +"the the program does the following..." When the text is online, often the duplicated words occur at the end of one line and the beginning of another, making them very difficult to spot. - This program, 'dupword.awk', scans through a file one line at a time + This program, `dupword.awk', scans through a file one line at a time and looks for adjacent occurrences of the same word. It also saves the -last word on a line (in the variable 'prev') for comparison with the +last word on a line (in the variable `prev') for comparison with the first word on the next line. - The first two statements make sure that the line is all lowercase, so -that, for example, "The" and "the" compare equal to each other. The + The first two statements make sure that the line is all lowercase, +so that, for example, "The" and "the" compare equal to each other. The next statement replaces nonalphanumeric and nonwhitespace characters with spaces, so that punctuation does not affect the comparison either. The characters are replaced with spaces so that formatting controls -don't create nonsense words (e.g., the Texinfo '@code{NF}' becomes -'codeNF' if punctuation is simply deleted). The record is then resplit +don't create nonsense words (e.g., the Texinfo `@code{NF}' becomes +`codeNF' if punctuation is simply deleted). The record is then resplit into fields, yielding just the actual words on the line, and ensuring that there are no empty fields. @@ -18394,30 +17420,30 @@ File: gawk.info, Node: Alarm Program, Next: Translate Program, Prev: Dupword 11.3.2 An Alarm Clock Program ----------------------------- - Nothing cures insomnia like a ringing alarm clock. - -- _Arnold Robbins_ - Sleep is for web developers. - -- _Erik Quanstrom_ + Nothing cures insomnia like a ringing alarm clock. -- Arnold + Robbins - The following program is a simple "alarm clock" program. You give it -a time of day and an optional message. At the specified time, it prints -the message on the standard output. In addition, you can give it the -number of times to repeat the message as well as a delay between + Sleep is for web developers. -- Erik Quanstrom + + The following program is a simple "alarm clock" program. You give +it a time of day and an optional message. At the specified time, it +prints the message on the standard output. In addition, you can give it +the number of times to repeat the message as well as a delay between repetitions. - This program uses the 'getlocaltime()' function from *note + This program uses the `getlocaltime()' function from *note Getlocaltime Function::. - All the work is done in the 'BEGIN' rule. The first part is argument + All the work is done in the `BEGIN' rule. The first part is argument checking and setting of defaults: the delay, the count, and the message to print. If the user supplied a message without the ASCII BEL -character (known as the "alert" character, '"\a"'), then it is added to +character (known as the "alert" character, `"\a"'), then it is added to the message. (On many systems, printing the ASCII BEL generates an -audible alert. Thus when the alarm goes off, the system calls attention +audible alert. Thus when the alarm goes off, the system calls attention to itself in case the user is not looking at the computer.) Just for a -change, this program uses a 'switch' statement (*note Switch +change, this program uses a `switch' statement (*note Switch Statement::), but the processing could be done with a series of -'if'-'else' statements instead. Here is the program: +`if'-`else' statements instead. Here is the program: # alarm.awk --- set an alarm # @@ -18465,9 +17491,10 @@ Statement::), but the processing could be done with a series of The next minor node of code turns the alarm time into hours and minutes, converts it (if necessary) to a 24-hour clock, and then turns -that time into a count of the seconds since midnight. Next it turns the -current time into a count of seconds since midnight. The difference -between the two is how long to wait before setting off the alarm: +that time into a count of the seconds since midnight. Next it turns +the current time into a count of seconds since midnight. The +difference between the two is how long to wait before setting off the +alarm: # split up alarm time split(ARGV[1], atime, ":") @@ -18497,12 +17524,12 @@ between the two is how long to wait before setting off the alarm: exit 1 } - Finally, the program uses the 'system()' function (*note I/O -Functions::) to call the 'sleep' utility. The 'sleep' utility simply + Finally, the program uses the `system()' function (*note I/O +Functions::) to call the `sleep' utility. The `sleep' utility simply pauses for the given number of seconds. If the exit status is not zero, -the program assumes that 'sleep' was interrupted and exits. If 'sleep' +the program assumes that `sleep' was interrupted and exits. If `sleep' exited with an OK status (zero), then the program prints the message in -a loop, again using 'sleep' to delay for however many seconds are +a loop, again using `sleep' to delay for however many seconds are necessary: # zzzzzz..... go away if interrupted @@ -18527,14 +17554,14 @@ File: gawk.info, Node: Translate Program, Next: Labels Program, Prev: Alarm P 11.3.3 Transliterating Characters --------------------------------- -The system 'tr' utility transliterates characters. For example, it is +The system `tr' utility transliterates characters. For example, it is often used to map uppercase letters into lowercase for further processing: GENERATE DATA | tr 'A-Z' 'a-z' | PROCESS DATA ... - 'tr' requires two lists of characters.(1) When processing the input, -the first character in the first list is replaced with the first + `tr' requires two lists of characters.(1) When processing the +input, the first character in the first list is replaced with the first character in the second list, the second character in the first list is replaced with the second character in the second list, and so on. If there are more characters in the "from" list than in the "to" list, the @@ -18542,38 +17569,38 @@ last character of the "to" list is used for the remaining characters in the "from" list. Once upon a time, a user proposed that a transliteration function -should be added to 'gawk'. The following program was written to prove -that character transliteration could be done with a user-level function. -This program is not as complete as the system 'tr' utility but it does -most of the job. - - The 'translate' program demonstrates one of the few weaknesses of -standard 'awk': dealing with individual characters is very painful, -requiring repeated use of the 'substr()', 'index()', and 'gsub()' -built-in functions (*note String Functions::).(2) There are two -functions. The first, 'stranslate()', takes three arguments: - -'from' +should be added to `gawk'. The following program was written to prove +that character transliteration could be done with a user-level +function. This program is not as complete as the system `tr' utility +but it does most of the job. + + The `translate' program demonstrates one of the few weaknesses of +standard `awk': dealing with individual characters is very painful, +requiring repeated use of the `substr()', `index()', and `gsub()' +built-in functions (*note String Functions::).(2) There are two +functions. The first, `stranslate()', takes three arguments: + +`from' A list of characters from which to translate. -'to' +`to' A list of characters to which to translate. -'target' +`target' The string on which to do the translation. - Associative arrays make the translation part fairly easy. 't_ar' + Associative arrays make the translation part fairly easy. `t_ar' holds the "to" characters, indexed by the "from" characters. Then a -simple loop goes through 'from', one character at a time. For each -character in 'from', if the character appears in 'target', it is -replaced with the corresponding 'to' character. +simple loop goes through `from', one character at a time. For each +character in `from', if the character appears in `target', it is +replaced with the corresponding `to' character. - The 'translate()' function simply calls 'stranslate()' using '$0' as -the target. The main program sets two global variables, 'FROM' and -'TO', from the command line, and then changes 'ARGV' so that 'awk' reads -from the standard input. + The `translate()' function simply calls `stranslate()' using `$0' as +the target. The main program sets two global variables, `FROM' and +`TO', from the command line, and then changes `ARGV' so that `awk' +reads from the standard input. - Finally, the processing rule simply calls 'translate()' for each + Finally, the processing rule simply calls `translate()' for each record: # translate.awk --- do tr-like stuff @@ -18624,16 +17651,16 @@ record: } While it is possible to do character transliteration in a user-level -function, it is not necessarily efficient, and we (the 'gawk' authors) +function, it is not necessarily efficient, and we (the `gawk' authors) started to consider adding a built-in function. However, shortly after writing this program, we learned that Brian Kernighan had added the -'toupper()' and 'tolower()' functions to his 'awk' (*note String +`toupper()' and `tolower()' functions to his `awk' (*note String Functions::). These functions handle the vast majority of the cases where character transliteration is necessary, and so we chose to simply -add those functions to 'gawk' as well and then leave well enough alone. +add those functions to `gawk' as well and then leave well enough alone. - An obvious improvement to this program would be to set up the 't_ar' -array only once, in a 'BEGIN' rule. However, this assumes that the + An obvious improvement to this program would be to set up the `t_ar' +array only once, in a `BEGIN' rule. However, this assumes that the "from" and "to" lists will never change throughout the lifetime of the program. @@ -18644,17 +17671,12 @@ program. ---------- Footnotes ---------- (1) On some older systems, including Solaris, the system version of -'tr' may require that the lists be written as range expressions enclosed -in square brackets ('[a-z]') and quoted, to prevent the shell from -attempting a file name expansion. This is not a feature. - -<<<<<<< HEAD - (2) This program was written before 'gawk' acquired the ability to -split each character in a string into separate array elements. -======= +`tr' may require that the lists be written as range expressions +enclosed in square brackets (`[a-z]') and quoted, to prevent the shell +from attempting a file name expansion. This is not a feature. + (2) This program was also written before `gawk' acquired the ability to split each character in a string into separate array elements. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Labels Program, Next: Word Sorting, Prev: Translate Program, Up: Miscellaneous Programs @@ -18668,25 +17690,25 @@ labels on it, two across and 10 down. The addresses are guaranteed to be no more than five lines of data. Each address is separated from the next by a blank line. - The basic idea is to read 20 labels worth of data. Each line of each -label is stored in the 'line' array. The single rule takes care of -filling the 'line' array and printing the page when 20 labels have been -read. + The basic idea is to read 20 labels worth of data. Each line of +each label is stored in the `line' array. The single rule takes care +of filling the `line' array and printing the page when 20 labels have +been read. - The 'BEGIN' rule simply sets 'RS' to the empty string, so that 'awk' -splits records at blank lines (*note Records::). It sets 'MAXLINES' to + The `BEGIN' rule simply sets `RS' to the empty string, so that `awk' +splits records at blank lines (*note Records::). It sets `MAXLINES' to 100, since 100 is the maximum number of lines on the page (20 * 5 = 100). - Most of the work is done in the 'printpage()' function. The label -lines are stored sequentially in the 'line' array. But they have to -print horizontally; 'line[1]' next to 'line[6]', 'line[2]' next to -'line[7]', and so on. Two loops are used to accomplish this. The outer -loop, controlled by 'i', steps through every 10 lines of data; this is -each row of labels. The inner loop, controlled by 'j', goes through the -lines within the row. As 'j' goes from 0 to 4, 'i+j' is the 'j'-th line -in the row, and 'i+j+5' is the entry next to it. The output ends up -looking something like this: + Most of the work is done in the `printpage()' function. The label +lines are stored sequentially in the `line' array. But they have to +print horizontally; `line[1]' next to `line[6]', `line[2]' next to +`line[7]', and so on. Two loops are used to accomplish this. The +outer loop, controlled by `i', steps through every 10 lines of data; +this is each row of labels. The inner loop, controlled by `j', goes +through the lines within the row. As `j' goes from 0 to 4, `i+j' is +the `j'-th line in the row, and `i+j+5' is the entry next to it. The +output ends up looking something like this: line 1 line 6 line 2 line 7 @@ -18695,7 +17717,7 @@ looking something like this: line 5 line 10 ... -The 'printf' format string '%-41s' left-aligns the data and prints it +The `printf' format string `%-41s' left-aligns the data and prints it within a fixed-width field. As a final note, an extra blank line is printed at lines 21 and 61, @@ -18704,7 +17726,7 @@ particular brand of labels in use when the program was written. You will also note that there are two blank lines at the top and two blank lines at the bottom. - The 'END' rule arranges to flush the final page of labels; there may + The `END' rule arranges to flush the final page of labels; there may not have been an even multiple of 20 labels in the data: # labels.awk --- print mailing labels @@ -18771,9 +17793,9 @@ File: gawk.info, Node: Word Sorting, Next: History Sorting, Prev: Labels Prog When working with large amounts of text, it can be interesting to know how often different words appear. For example, an author may overuse certain words, in which case he or she might wish to find synonyms to -substitute for words that appear too often. This node develops a -program for counting words and presenting the frequency information in a -useful format. +substitute for words that appear too often. This node develops a +program for counting words and presenting the frequency information in +a useful format. At first glance, a program like this would seem to do the job: @@ -18789,33 +17811,33 @@ useful format. printf "%s\t%d\n", word, freq[word] } - The program relies on 'awk''s default field splitting mechanism to + The program relies on `awk''s default field splitting mechanism to break each line up into "words," and uses an associative array named -'freq', indexed by each word, to count the number of times the word -occurs. In the 'END' rule, it prints the counts. +`freq', indexed by each word, to count the number of times the word +occurs. In the `END' rule, it prints the counts. This program has several problems that prevent it from being useful on real text files: - * The 'awk' language considers upper- and lowercase characters to be + * The `awk' language considers upper- and lowercase characters to be distinct. Therefore, "bartender" and "Bartender" are not treated as the same word. This is undesirable, since in normal text, words are capitalized if they begin sentences, and a frequency analyzer should not be sensitive to capitalization. - * Words are detected using the 'awk' convention that fields are + * Words are detected using the `awk' convention that fields are separated just by whitespace. Other characters in the input - (except newlines) don't have any special meaning to 'awk'. This + (except newlines) don't have any special meaning to `awk'. This means that punctuation characters count as part of words. * The output does not come out in any useful order. You're more likely to be interested in which words occur most frequently or in having an alphabetized table of how frequently each word occurs. - The first problem can be solved by using 'tolower()' to remove case -distinctions. The second problem can be solved by using 'gsub()' to + The first problem can be solved by using `tolower()' to remove case +distinctions. The second problem can be solved by using `gsub()' to remove punctuation characters. Finally, we solve the third problem by -using the system 'sort' utility to process the output of the 'awk' +using the system `sort' utility to process the output of the `awk' script. Here is the new version of the program: # wordfreq.awk --- print list of word frequencies @@ -18833,29 +17855,30 @@ script. Here is the new version of the program: printf "%s\t%d\n", word, freq[word] } - The regexp '/[^[:alnum:]_[:blank:]]/' might have been written -'/[[:punct:]]/', but then underscores would also be removed, and we want -to keep them. + The regexp `/[^[:alnum:]_[:blank:]]/' might have been written +`/[[:punct:]]/', but then underscores would also be removed, and we +want to keep them. - Assuming we have saved this program in a file named 'wordfreq.awk', -and that the data is in 'file1', the following pipeline: + Assuming we have saved this program in a file named `wordfreq.awk', +and that the data is in `file1', the following pipeline: awk -f wordfreq.awk file1 | sort -k 2nr -produces a table of the words appearing in 'file1' in order of +produces a table of the words appearing in `file1' in order of decreasing frequency. - The 'awk' program suitably massages the data and produces a word -frequency table, which is not ordered. The 'awk' script's output is -then sorted by the 'sort' utility and printed on the screen. + The `awk' program suitably massages the data and produces a word +frequency table, which is not ordered. The `awk' script's output is +then sorted by the `sort' utility and printed on the screen. - The options given to 'sort' specify a sort that uses the second field -of each input line (skipping one field), that the sort keys should be -treated as numeric quantities (otherwise '15' would come before '5'), -and that the sorting should be done in descending (reverse) order. + The options given to `sort' specify a sort that uses the second +field of each input line (skipping one field), that the sort keys +should be treated as numeric quantities (otherwise `15' would come +before `5'), and that the sorting should be done in descending +(reverse) order. - The 'sort' could even be done from within the program, by changing -the 'END' action to: + The `sort' could even be done from within the program, by changing +the `END' action to: END { sort = "sort -k 2nr" @@ -18867,7 +17890,7 @@ the 'END' action to: This way of sorting must be used on systems that do not have true pipes at the command-line (or batch-file) level. See the general operating system documentation for more information on how to use the -'sort' program. +`sort' program.  File: gawk.info, Node: History Sorting, Next: Extract Program, Prev: Word Sorting, Up: Miscellaneous Programs @@ -18875,24 +17898,24 @@ File: gawk.info, Node: History Sorting, Next: Extract Program, Prev: Word Sor 11.3.6 Removing Duplicates from Unsorted Text --------------------------------------------- -The 'uniq' program (*note Uniq Program::), removes duplicate lines from +The `uniq' program (*note Uniq Program::), removes duplicate lines from _sorted_ data. - Suppose, however, you need to remove duplicate lines from a data file -but that you want to preserve the order the lines are in. A good -example of this might be a shell history file. The history file keeps a -copy of all the commands you have entered, and it is not unusual to -repeat a command several times in a row. Occasionally you might want to -compact the history by removing duplicate entries. Yet it is desirable -to maintain the order of the original commands. - - This simple program does the job. It uses two arrays. The 'data' -array is indexed by the text of each line. For each line, 'data[$0]' is -incremented. If a particular line has not been seen before, then -'data[$0]' is zero. In this case, the text of the line is stored in -'lines[count]'. Each element of 'lines' is a unique command, and the -indices of 'lines' indicate the order in which those lines are -encountered. The 'END' rule simply prints out the lines, in order: + Suppose, however, you need to remove duplicate lines from a data +file but that you want to preserve the order the lines are in. A good +example of this might be a shell history file. The history file keeps +a copy of all the commands you have entered, and it is not unusual to +repeat a command several times in a row. Occasionally you might want +to compact the history by removing duplicate entries. Yet it is +desirable to maintain the order of the original commands. + + This simple program does the job. It uses two arrays. The `data' +array is indexed by the text of each line. For each line, `data[$0]' +is incremented. If a particular line has not been seen before, then +`data[$0]' is zero. In this case, the text of the line is stored in +`lines[count]'. Each element of `lines' is a unique command, and the +indices of `lines' indicate the order in which those lines are +encountered. The `END' rule simply prints out the lines, in order: # histsort.awk --- compact a shell history file # Thanks to Byron Rakitzis for the general idea @@ -18908,12 +17931,12 @@ encountered. The 'END' rule simply prints out the lines, in order: } This program also provides a foundation for generating other useful -information. For example, using the following 'print' statement in the -'END' rule indicates how often a particular command is used: +information. For example, using the following `print' statement in the +`END' rule indicates how often a particular command is used: print data[lines[i]], lines[i] -This works because 'data[$0]' is incremented each time a line is seen. +This works because `data[$0]' is incremented each time a line is seen.  File: gawk.info, Node: Extract Program, Next: Simple Sed, Prev: History Sorting, Up: Miscellaneous Programs @@ -18922,51 +17945,51 @@ File: gawk.info, Node: Extract Program, Next: Simple Sed, Prev: History Sorti ---------------------------------------------------- The nodes *note Library Functions::, and *note Sample Programs::, are -the top level nodes for a large number of 'awk' programs. If you want -to experiment with these programs, it is tedious to have to type them in -by hand. Here we present a program that can extract parts of a Texinfo -input file into separate files. +the top level nodes for a large number of `awk' programs. If you want +to experiment with these programs, it is tedious to have to type them +in by hand. Here we present a program that can extract parts of a +Texinfo input file into separate files. - This Info file is written in Texinfo +This Info file is written in Texinfo (http://www.gnu.org/software/texinfo/), the GNU project's document formatting language. A single Texinfo source file can be used to produce both printed and online documentation. The Texinfo language is -described fully, starting with *note (Texinfo, texinfo,Texinfo---The GNU -Documentation Format)Top::. +described fully, starting with *note (Texinfo)Top:: +texinfo,Texinfo--The GNU Documentation Format. For our purposes, it is enough to know three things about Texinfo input files: - * The "at" symbol ('@') is special in Texinfo, much as the backslash - ('\') is in C or 'awk'. Literal '@' symbols are represented in - Texinfo source files as '@@'. + * The "at" symbol (`@') is special in Texinfo, much as the backslash + (`\') is in C or `awk'. Literal `@' symbols are represented in + Texinfo source files as `@@'. - * Comments start with either '@c' or '@comment'. The file-extraction - program works by using special comments that start at the beginning - of a line. + * Comments start with either `@c' or `@comment'. The + file-extraction program works by using special comments that start + at the beginning of a line. - * Lines containing '@group' and '@end group' commands bracket example - text that should not be split across a page boundary. + * Lines containing `@group' and `@end group' commands bracket + example text that should not be split across a page boundary. (Unfortunately, TeX isn't always smart enough to do things exactly right, so we have to give it some help.) - The following program, 'extract.awk', reads through a Texinfo source + The following program, `extract.awk', reads through a Texinfo source file and does two things, based on the special comments. Upon seeing -'@c system ...', it runs a command, by extracting the command text from -the control line and passing it on to the 'system()' function (*note I/O -Functions::). Upon seeing '@c file FILENAME', each subsequent line is -sent to the file FILENAME, until '@c endfile' is encountered. The rules -in 'extract.awk' match either '@c' or '@comment' by letting the 'omment' -part be optional. Lines containing '@group' and '@end group' are simply -removed. 'extract.awk' uses the 'join()' library function (*note Join -Function::). +`@c system ...', it runs a command, by extracting the command text from +the control line and passing it on to the `system()' function (*note +I/O Functions::). Upon seeing `@c file FILENAME', each subsequent line +is sent to the file FILENAME, until `@c endfile' is encountered. The +rules in `extract.awk' match either `@c' or `@comment' by letting the +`omment' part be optional. Lines containing `@group' and `@end group' +are simply removed. `extract.awk' uses the `join()' library function +(*note Join Function::). - The example programs in the online Texinfo source for 'GAWK: -Effective AWK Programming' ('gawktexi.in') have all been bracketed -inside 'file' and 'endfile' lines. The 'gawk' distribution uses a copy -of 'extract.awk' to extract the sample programs and install many of them -in a standard directory where 'gawk' can find them. The Texinfo file -looks something like this: + The example programs in the online Texinfo source for `GAWK: +Effective AWK Programming' (`gawktexi.in') have all been bracketed +inside `file' and `endfile' lines. The `gawk' distribution uses a copy +of `extract.awk' to extract the sample programs and install many of +them in a standard directory where `gawk' can find them. The Texinfo +file looks something like this: ... This program has a @code{BEGIN} rule, @@ -18987,11 +18010,11 @@ looks something like this: @end example ... - 'extract.awk' begins by setting 'IGNORECASE' to one, so that mixed + `extract.awk' begins by setting `IGNORECASE' to one, so that mixed upper- and lowercase letters in the directives won't matter. - The first rule handles calling 'system()', checking that a command is -given ('NF' is at least three) and also checking that the command exits + The first rule handles calling `system()', checking that a command is +given (`NF' is at least three) and also checking that the command exits with a zero exit status, signifying OK: # extract.awk --- extract files and run programs @@ -19017,34 +18040,36 @@ with a zero exit status, signifying OK: } } -The variable 'e' is used so that the rule fits nicely on the screen. +The variable `e' is used so that the rule fits nicely on the screen. The second rule handles moving data into files. It verifies that a file name is given in the directive. If the file named is not the current file, then the current file is closed. Keeping the current file -open until a new file is encountered allows the use of the '>' +open until a new file is encountered allows the use of the `>' redirection for printing the contents, keeping open file management simple. - The 'for' loop does the work. It reads lines using 'getline' (*note + The `for' loop does the work. It reads lines using `getline' (*note Getline::). For an unexpected end of file, it calls the -'unexpected_eof()' function. If the line is an "endfile" line, then it -breaks out of the loop. If the line is an '@group' or '@end group' +`unexpected_eof()' function. If the line is an "endfile" line, then it +breaks out of the loop. If the line is an `@group' or `@end group' line, then it ignores it and goes on to the next line. Similarly, comments within examples are also ignored. Most of the work is in the following few lines. If the line has no -'@' symbols, the program can print it directly. Otherwise, each leading -'@' must be stripped off. To remove the '@' symbols, the line is split -into separate elements of the array 'a', using the 'split()' function -(*note String Functions::). The '@' symbol is used as the separator -character. Each element of 'a' that is empty indicates two successive -'@' symbols in the original line. For each two empty elements ('@@' in -the original file), we have to add a single '@' symbol back in. - - When the processing of the array is finished, 'join()' is called with -the value of 'SUBSEP' (*note Multidimensional::), to rejoin the pieces -back into a single line. That line is then printed to the output file: +`@' symbols, the program can print it directly. Otherwise, each +leading `@' must be stripped off. To remove the `@' symbols, the line +is split into separate elements of the array `a', using the `split()' +function (*note String Functions::). The `@' symbol is used as the +separator character. Each element of `a' that is empty indicates two +successive `@' symbols in the original line. For each two empty +elements (`@@' in the original file), we have to add a single `@' +symbol back in. + + When the processing of the array is finished, `join()' is called +with the value of `SUBSEP' (*note Multidimensional::), to rejoin the +pieces back into a single line. That line is then printed to the +output file: /^@c(omment)?[ \t]+file/ \ { @@ -19086,16 +18111,16 @@ back into a single line. That line is then printed to the output file: } } - An important thing to note is the use of the '>' redirection. Output -done with '>' only opens the file once; it stays open and subsequent -output is appended to the file (*note Redirection::). This makes it -easy to mix program text and explanatory prose for the same sample -source file (as has been done here!) without any hassle. The file is -only closed when a new data file name is encountered or at the end of -the input file. + An important thing to note is the use of the `>' redirection. +Output done with `>' only opens the file once; it stays open and +subsequent output is appended to the file (*note Redirection::). This +makes it easy to mix program text and explanatory prose for the same +sample source file (as has been done here!) without any hassle. The +file is only closed when a new data file name is encountered or at the +end of the input file. - Finally, the function 'unexpected_eof()' prints an appropriate error -message and then exits. The 'END' rule handles the final cleanup, + Finally, the function `unexpected_eof()' prints an appropriate error +message and then exits. The `END' rule handles the final cleanup, closing the open file: function unexpected_eof() @@ -19116,24 +18141,24 @@ File: gawk.info, Node: Simple Sed, Next: Igawk Program, Prev: Extract Program 11.3.8 A Simple Stream Editor ----------------------------- -The 'sed' utility is a stream editor, a program that reads a stream of +The `sed' utility is a stream editor, a program that reads a stream of data, makes changes to it, and passes it on. It is often used to make global changes to a large file or to a stream of data generated by a -pipeline of commands. While 'sed' is a complicated program in its own +pipeline of commands. While `sed' is a complicated program in its own right, its most common use is to perform global substitutions in the middle of a pipeline: command1 < orig.data | sed 's/old/new/g' | command2 > result - Here, 's/old/new/g' tells 'sed' to look for the regexp 'old' on each -input line and globally replace it with the text 'new', i.e., all the -occurrences on a line. This is similar to 'awk''s 'gsub()' function + Here, `s/old/new/g' tells `sed' to look for the regexp `old' on each +input line and globally replace it with the text `new', i.e., all the +occurrences on a line. This is similar to `awk''s `gsub()' function (*note String Functions::). - The following program, 'awksed.awk', accepts at least two + The following program, `awksed.awk', accepts at least two command-line arguments: the pattern to look for and the text to replace -it with. Any additional arguments are treated as data file names to -process. If none are provided, the standard input is used: +it with. Any additional arguments are treated as data file names to +process. If none are provided, the standard input is used: # awksed.awk --- do s/foo/bar/g using just print # Thanks to Michael Brennan for the idea @@ -19164,32 +18189,32 @@ process. If none are provided, the standard input is used: print } - The program relies on 'gawk''s ability to have 'RS' be a regexp, as -well as on the setting of 'RT' to the actual text that terminates the + The program relies on `gawk''s ability to have `RS' be a regexp, as +well as on the setting of `RT' to the actual text that terminates the record (*note Records::). - The idea is to have 'RS' be the pattern to look for. 'gawk' -automatically sets '$0' to the text between matches of the pattern. -This is text that we want to keep, unmodified. Then, by setting 'ORS' -to the replacement text, a simple 'print' statement outputs the text we + The idea is to have `RS' be the pattern to look for. `gawk' +automatically sets `$0' to the text between matches of the pattern. +This is text that we want to keep, unmodified. Then, by setting `ORS' +to the replacement text, a simple `print' statement outputs the text we want to keep, followed by the replacement text. There is one wrinkle to this scheme, which is what to do if the last -record doesn't end with text that matches 'RS'. Using a 'print' +record doesn't end with text that matches `RS'. Using a `print' statement unconditionally prints the replacement text, which is not -correct. However, if the file did not end in text that matches 'RS', -'RT' is set to the null string. In this case, we can print '$0' using -'printf' (*note Printf::). - - The 'BEGIN' rule handles the setup, checking for the right number of -arguments and calling 'usage()' if there is a problem. Then it sets -'RS' and 'ORS' from the command-line arguments and sets 'ARGV[1]' and -'ARGV[2]' to the null string, so that they are not treated as file names +correct. However, if the file did not end in text that matches `RS', +`RT' is set to the null string. In this case, we can print `$0' using +`printf' (*note Printf::). + + The `BEGIN' rule handles the setup, checking for the right number of +arguments and calling `usage()' if there is a problem. Then it sets +`RS' and `ORS' from the command-line arguments and sets `ARGV[1]' and +`ARGV[2]' to the null string, so that they are not treated as file names (*note ARGC and ARGV::). - The 'usage()' function prints an error message and exits. Finally, + The `usage()' function prints an error message and exits. Finally, the single rule handles the printing scheme outlined above, using -'print' or 'printf' as appropriate, depending upon the value of 'RT'. +`print' or `printf' as appropriate, depending upon the value of `RT'.  File: gawk.info, Node: Igawk Program, Next: Anagram Program, Prev: Simple Sed, Up: Miscellaneous Programs @@ -19197,18 +18222,18 @@ File: gawk.info, Node: Igawk Program, Next: Anagram Program, Prev: Simple Sed 11.3.9 An Easy Way to Use Library Functions ------------------------------------------- -In *note Include Files::, we saw how 'gawk' provides a built-in -file-inclusion capability. However, this is a 'gawk' extension. This +In *note Include Files::, we saw how `gawk' provides a built-in +file-inclusion capability. However, this is a `gawk' extension. This minor node provides the motivation for making file inclusion available -for standard 'awk', and shows how to do it using a combination of shell -and 'awk' programming. - - Using library functions in 'awk' can be very beneficial. It -encourages code reuse and the writing of general functions. Programs -are smaller and therefore clearer. However, using library functions is -only easy when writing 'awk' programs; it is painful when running them, -requiring multiple '-f' options. If 'gawk' is unavailable, then so too -is the 'AWKPATH' environment variable and the ability to put 'awk' +for standard `awk', and shows how to do it using a combination of shell +and `awk' programming. + + Using library functions in `awk' can be very beneficial. It +encourages code reuse and the writing of general functions. Programs are +smaller and therefore clearer. However, using library functions is +only easy when writing `awk' programs; it is painful when running them, +requiring multiple `-f' options. If `gawk' is unavailable, then so too +is the `AWKPATH' environment variable and the ability to put `awk' functions into a library directory (*note Options::). It would be nice to be able to write programs in the following manner: @@ -19224,98 +18249,93 @@ to be able to write programs in the following manner: ... } - The following program, 'igawk.sh', provides this service. It -simulates 'gawk''s searching of the 'AWKPATH' variable and also allows -"nested" includes; i.e., a file that is included with '@include' can -contain further '@include' statements. 'igawk' makes an effort to only -include files once, so that nested includes don't accidentally include a -library function twice. + The following program, `igawk.sh', provides this service. It +simulates `gawk''s searching of the `AWKPATH' variable and also allows +"nested" includes; i.e., a file that is included with `@include' can +contain further `@include' statements. `igawk' makes an effort to only +include files once, so that nested includes don't accidentally include +a library function twice. - 'igawk' should behave just like 'gawk' externally. This means it -should accept all of 'gawk''s command-line arguments, including the -ability to have multiple source files specified via '-f', and the + `igawk' should behave just like `gawk' externally. This means it +should accept all of `gawk''s command-line arguments, including the +ability to have multiple source files specified via `-f', and the ability to mix command-line and library source files. - The program is written using the POSIX Shell ('sh') command -language.(1) It works as follows: + The program is written using the POSIX Shell (`sh') command +language.(1) It works as follows: 1. Loop through the arguments, saving anything that doesn't represent - 'awk' source code for later, when the expanded program is run. + `awk' source code for later, when the expanded program is run. - 2. For any arguments that do represent 'awk' text, put the arguments + 2. For any arguments that do represent `awk' text, put the arguments into a shell variable that will be expanded. There are two cases: -<<<<<<< HEAD - a. Literal text, provided with '--source' or '--source='. This - text is just appended directly. -======= a. Literal text, provided with `-e' or `--source'. This text is just appended directly. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - b. Source file names, provided with '-f'. We use a neat trick - and append '@include FILENAME' to the shell variable's + b. Source file names, provided with `-f'. We use a neat trick + and append `@include FILENAME' to the shell variable's contents. Since the file-inclusion program works the way - 'gawk' does, this gets the text of the file included into the + `gawk' does, this gets the text of the file included into the program at the correct point. - 3. Run an 'awk' program (naturally) over the shell variable's contents - to expand '@include' statements. The expanded program is placed in - a second shell variable. + 3. Run an `awk' program (naturally) over the shell variable's + contents to expand `@include' statements. The expanded program is + placed in a second shell variable. - 4. Run the expanded program with 'gawk' and any other original + 4. Run the expanded program with `gawk' and any other original command-line arguments that the user supplied (such as the data file names). This program uses shell variables extensively: for storing -command-line arguments, the text of the 'awk' program that will expand +command-line arguments, the text of the `awk' program that will expand the user's program, for the user's original program, and for the expanded program. Doing so removes some potential problems that might arise were we to use temporary files instead, at the cost of making the script somewhat more complicated. The initial part of the program turns on shell tracing if the first -argument is 'debug'. +argument is `debug'. The next part loops through all the command-line arguments. There are several cases of interest: -'--' - This ends the arguments to 'igawk'. Anything else should be passed - on to the user's 'awk' program without being evaluated. +`--' + This ends the arguments to `igawk'. Anything else should be + passed on to the user's `awk' program without being evaluated. -'-W' - This indicates that the next option is specific to 'gawk'. To make - argument processing easier, the '-W' is appended to the front of - the remaining arguments and the loop continues. (This is an 'sh' +`-W' + This indicates that the next option is specific to `gawk'. To make + argument processing easier, the `-W' is appended to the front of + the remaining arguments and the loop continues. (This is an `sh' programming trick. Don't worry about it if you are not familiar - with 'sh'.) + with `sh'.) -'-v', '-F' - These are saved and passed on to 'gawk'. +`-v', `-F' + These are saved and passed on to `gawk'. -'-f', '--file', '--file=', '-Wfile=' - The file name is appended to the shell variable 'program' with an - '@include' statement. The 'expr' utility is used to remove the - leading option part of the argument (e.g., '--file='). (Typical - 'sh' usage would be to use the 'echo' and 'sed' utilities to do - this work. Unfortunately, some versions of 'echo' evaluate escape +`-f', `--file', `--file=', `-Wfile=' + The file name is appended to the shell variable `program' with an + `@include' statement. The `expr' utility is used to remove the + leading option part of the argument (e.g., `--file='). (Typical + `sh' usage would be to use the `echo' and `sed' utilities to do + this work. Unfortunately, some versions of `echo' evaluate escape sequences in their arguments, possibly mangling the program text. - Using 'expr' avoids this problem.) + Using `expr' avoids this problem.) -'--source', '--source=', '-Wsource=' - The source text is appended to 'program'. +`--source', `--source=', `-Wsource=' + The source text is appended to `program'. -'--version', '-Wversion' - 'igawk' prints its version number, runs 'gawk --version' to get the - 'gawk' version information, and then exits. +`--version', `-Wversion' + `igawk' prints its version number, runs `gawk --version' to get + the `gawk' version information, and then exits. - If none of the '-f', '--file', '-Wfile', '--source', or '-Wsource' + If none of the `-f', `--file', `-Wfile', `--source', or `-Wsource' arguments are supplied, then the first nonoption argument should be the -'awk' program. If there are no command-line arguments left, 'igawk' +`awk' program. If there are no command-line arguments left, `igawk' prints an error message and exits. Otherwise, the first argument is -appended to 'program'. In any case, after the arguments have been -processed, 'program' contains the complete text of the original 'awk' +appended to `program'. In any case, after the arguments have been +processed, `program' contains the complete text of the original `awk' program. The program is as follows: @@ -19396,27 +18416,27 @@ program. # At this point, `program' has the program. - The 'awk' program to process '@include' directives is stored in the -shell variable 'expand_prog'. Doing this keeps the shell script -readable. The 'awk' program reads through the user's program, one line -at a time, using 'getline' (*note Getline::). The input file names and -'@include' statements are managed using a stack. As each '@include' is + The `awk' program to process `@include' directives is stored in the +shell variable `expand_prog'. Doing this keeps the shell script +readable. The `awk' program reads through the user's program, one line +at a time, using `getline' (*note Getline::). The input file names and +`@include' statements are managed using a stack. As each `@include' is encountered, the current file name is "pushed" onto the stack and the -file named in the '@include' directive becomes the current file name. +file named in the `@include' directive becomes the current file name. As each file is finished, the stack is "popped," and the previous input file becomes the current input file again. The process is started by making the original file the first one on the stack. - The 'pathto()' function does the work of finding the full path to a -file. It simulates 'gawk''s behavior when searching the 'AWKPATH' + The `pathto()' function does the work of finding the full path to a +file. It simulates `gawk''s behavior when searching the `AWKPATH' environment variable (*note AWKPATH Variable::). If a file name has a -'/' in it, no path search is done. Similarly, if the file name is -'"-"', then that string is used as-is. Otherwise, the file name is -concatenated with the name of each directory in the path, and an attempt -is made to open the generated file name. The only way to test if a file -can be read in 'awk' is to go ahead and try to read it with 'getline'; -this is what 'pathto()' does.(2) If the file can be read, it is closed -and the file name is returned: +`/' in it, no path search is done. Similarly, if the file name is +`"-"', then that string is used as-is. Otherwise, the file name is +concatenated with the name of each directory in the path, and an +attempt is made to open the generated file name. The only way to test +if a file can be read in `awk' is to go ahead and try to read it with +`getline'; this is what `pathto()' does.(2) If the file can be read, it +is closed and the file name is returned: expand_prog=' @@ -19439,9 +18459,9 @@ and the file name is returned: return "" } - The main program is contained inside one 'BEGIN' rule. The first -thing it does is set up the 'pathlist' array that 'pathto()' uses. -After splitting the path on ':', null elements are replaced with '"."', + The main program is contained inside one `BEGIN' rule. The first +thing it does is set up the `pathlist' array that `pathto()' uses. +After splitting the path on `:', null elements are replaced with `"."', which represents the current directory: BEGIN { @@ -19452,21 +18472,21 @@ which represents the current directory: pathlist[i] = "." } - The stack is initialized with 'ARGV[1]', which will be -'"/dev/stdin"'. The main loop comes next. Input lines are read in -succession. Lines that do not start with '@include' are printed -verbatim. If the line does start with '@include', the file name is in -'$2'. 'pathto()' is called to generate the full path. If it cannot, + The stack is initialized with `ARGV[1]', which will be +`"/dev/stdin"'. The main loop comes next. Input lines are read in +succession. Lines that do not start with `@include' are printed +verbatim. If the line does start with `@include', the file name is in +`$2'. `pathto()' is called to generate the full path. If it cannot, then the program prints an error message and continues. The next thing to check is if the file is included already. The -'processed' array is indexed by the full file name of each included file -and it tracks this information for us. If the file is seen again, a -warning message is printed. Otherwise, the new file name is pushed onto -the stack and processing continues. +`processed' array is indexed by the full file name of each included +file and it tracks this information for us. If the file is seen again, +a warning message is printed. Otherwise, the new file name is pushed +onto the stack and processing continues. - Finally, when 'getline' encounters the end of the input file, the -file is closed and the stack is popped. When 'stackptr' is less than + Finally, when `getline' encounters the end of the input file, the +file is closed and the stack is popped. When `stackptr' is less than zero, the program is done: stackptr = 0 @@ -19501,75 +18521,76 @@ zero, the program is done: EOF ) - The shell construct 'COMMAND << MARKER' is called a "here document". + The shell construct `COMMAND << MARKER' is called a "here document". Everything in the shell script up to the MARKER is fed to COMMAND as input. The shell processes the contents of the here document for variable and command substitution (and possibly other things as well, depending upon the shell). - The shell construct '$(...)' is called "command substitution". The + The shell construct `$(...)' is called "command substitution". The output of the command inside the parentheses is substituted into the command line. Because the result is used in a variable assignment, it is saved as a single string, even if the results contain whitespace. - The expanded program is saved in the variable 'processed_program'. + The expanded program is saved in the variable `processed_program'. It's done in these steps: - 1. Run 'gawk' with the '@include'-processing program (the value of the - 'expand_prog' shell variable) on standard input. + 1. Run `gawk' with the `@include'-processing program (the value of + the `expand_prog' shell variable) on standard input. 2. Standard input is the contents of the user's program, from the - shell variable 'program'. Its contents are fed to 'gawk' via a + shell variable `program'. Its contents are fed to `gawk' via a here document. 3. The results of this processing are saved in the shell variable - 'processed_program' by using command substitution. + `processed_program' by using command substitution. - The last step is to call 'gawk' with the expanded program, along with -the original options and command-line arguments that the user supplied. + The last step is to call `gawk' with the expanded program, along +with the original options and command-line arguments that the user +supplied. eval gawk $opts -- '"$processed_program"' '"$@"' - The 'eval' command is a shell construct that reruns the shell's + The `eval' command is a shell construct that reruns the shell's parsing process. This keeps things properly quoted. - This version of 'igawk' represents the fifth version of this program. + This version of `igawk' represents the fifth version of this program. There are four key simplifications that make the program work better: - * Using '@include' even for the files named with '-f' makes building - the initial collected 'awk' program much simpler; all the - '@include' processing can be done once. + * Using `@include' even for the files named with `-f' makes building + the initial collected `awk' program much simpler; all the + `@include' processing can be done once. - * Not trying to save the line read with 'getline' in the 'pathto()' - function when testing for the file's accessibility for use with the - main program simplifies things considerably. + * Not trying to save the line read with `getline' in the `pathto()' + function when testing for the file's accessibility for use with + the main program simplifies things considerably. - * Using a 'getline' loop in the 'BEGIN' rule does it all in one + * Using a `getline' loop in the `BEGIN' rule does it all in one place. It is not necessary to call out to a separate loop for - processing nested '@include' statements. + processing nested `@include' statements. - * Instead of saving the expanded program in a temporary file, putting - it in a shell variable avoids some potential security problems. - This has the disadvantage that the script relies upon more features - of the 'sh' language, making it harder to follow for those who - aren't familiar with 'sh'. + * Instead of saving the expanded program in a temporary file, + putting it in a shell variable avoids some potential security + problems. This has the disadvantage that the script relies upon + more features of the `sh' language, making it harder to follow for + those who aren't familiar with `sh'. Also, this program illustrates that it is often worthwhile to combine -'sh' and 'awk' programming together. You can usually accomplish quite a -lot, without having to resort to low-level programming in C or C++, and -it is frequently easier to do certain kinds of string and argument -manipulation using the shell than it is in 'awk'. +`sh' and `awk' programming together. You can usually accomplish quite +a lot, without having to resort to low-level programming in C or C++, +and it is frequently easier to do certain kinds of string and argument +manipulation using the shell than it is in `awk'. - Finally, 'igawk' shows that it is not always necessary to add new + Finally, `igawk' shows that it is not always necessary to add new features to a program; they can often be layered on top. ---------- Footnotes ---------- - (1) Fully explaining the 'sh' language is beyond the scope of this -book. We provide some minimal explanations, but see a good shell + (1) Fully explaining the `sh' language is beyond the scope of this +book. We provide some minimal explanations, but see a good shell programming book if you wish to understand things in more depth. - (2) On some very old versions of 'awk', the test 'getline junk < t' + (2) On some very old versions of `awk', the test `getline junk < t' can loop forever if the file exists but is empty. Caveat emptor.  @@ -19579,12 +18600,12 @@ File: gawk.info, Node: Anagram Program, Next: Signature Program, Prev: Igawk ------------------------------------------ An interesting programming challenge is to search for "anagrams" in a -word list (such as '/usr/share/dict/words' on many GNU/Linux systems). +word list (such as `/usr/share/dict/words' on many GNU/Linux systems). One word is an anagram of another if both words contain the same letters (for example, "babbling" and "blabbing"). An elegant algorithm is presented in Column 2, Problem C of Jon -Bentley's 'Programming Pearls', second edition. The idea is to give +Bentley's `Programming Pearls', second edition. The idea is to give words that are anagrams a common signature, sort all the words together by their signature, and then print them. Dr. Bentley observes that taking the letters in each word and sorting them produces that common @@ -19601,17 +18622,17 @@ order. /'s$/ { next } # Skip possessives - The program starts with a header, and then a rule to skip possessives -in the dictionary file. The next rule builds up the data structure. -The first dimension of the array is indexed by the signature; the second -dimension is the word itself: + The program starts with a header, and then a rule to skip +possessives in the dictionary file. The next rule builds up the data +structure. The first dimension of the array is indexed by the +signature; the second dimension is the word itself: { key = word2key($1) # Build signature data[key][$1] = $1 # Store word with signature } - The 'word2key()' function creates the signature. It splits the word + The `word2key()' function creates the signature. It splits the word apart into individual letters, sorts the letters, and then joins them back together: @@ -19628,8 +18649,8 @@ back together: return result } - Finally, the 'END' rule traverses the array and prints out the -anagram lists. It sends the output to the system 'sort' command, since + Finally, the `END' rule traverses the array and prints out the +anagram lists. It sends the output to the system `sort' command, since otherwise the anagrams would appear in arbitrary order: END { @@ -19670,7 +18691,7 @@ File: gawk.info, Node: Signature Program, Prev: Anagram Program, Up: Miscella The following program was written by Davide Brini and is published on his website (http://backreference.org/2011/02/03/obfuscated-awk/). It -serves as his signature in the Usenet group 'comp.lang.awk'. He +serves as his signature in the Usenet group `comp.lang.awk'. He supplies the following copyright terms: Copyright (C) 2008 Davide Brini @@ -19701,24 +18722,25 @@ File: gawk.info, Node: Programs Summary, Next: Programs Exercises, Prev: Misc continue on the theme that reading programs is an excellent way to learn Good Programming. - * Using '#!' to make 'awk' programs directly runnable makes them - easier to use. Otherwise, invoke the program using 'awk -f ...'. + * Using `#!' to make `awk' programs directly runnable makes them + easier to use. Otherwise, invoke the program using `awk -f ...'. - * Reimplementing standard POSIX programs in 'awk' is a pleasant - exercise; 'awk''s expressive power lets you write such programs in + * Reimplementing standard POSIX programs in `awk' is a pleasant + exercise; `awk''s expressive power lets you write such programs in relatively few lines of code, yet they are functionally complete and usable. - * One of standard 'awk''s weaknesses is working with individual - characters. The ability to use 'split()' with the empty string as + * One of standard `awk''s weaknesses is working with individual + characters. The ability to use `split()' with the empty string as the separator can considerably simplify such tasks. * The library functions from *note Library Functions::, proved their usefulness for a number of real (if small) programs. - * Besides reinventing POSIX wheels, other programs solved a selection - of interesting problems, such as finding duplicates words in text, - printing mailing labels, and finding anagrams. + * Besides reinventing POSIX wheels, other programs solved a + selection of interesting problems, such as finding duplicates + words in text, printing mailing labels, and finding anagrams. +  File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample Programs @@ -19726,30 +18748,21 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample 11.5 Exercises ============== - 1. Rewrite 'cut.awk' (*note Cut Program::) using 'split()' with '""' + 1. Rewrite `cut.awk' (*note Cut Program::) using `split()' with `""' as the seperator. - 2. In *note Egrep Program::, we mentioned that 'egrep -i' could be - simulated in versions of 'awk' without 'IGNORECASE' by using - 'tolower()' on the line and the pattern. In a footnote there, we + 2. In *note Egrep Program::, we mentioned that `egrep -i' could be + simulated in versions of `awk' without `IGNORECASE' by using + `tolower()' on the line and the pattern. In a footnote there, we also mentioned that this solution has a bug: the translated line is output, and not the original one. Fix this problem. - 3. The POSIX version of 'id' takes options that control which - information is printed. Modify the 'awk' version (*note Id + 3. The POSIX version of `id' takes options that control which + information is printed. Modify the `awk' version (*note Id Program::) to accept the same arguments and perform in the same way. -<<<<<<< HEAD - 4. The 'split.awk' program (*note Split Program::) uses the 'chr()' - and 'ord()' functions to move through the letters of the alphabet. - Modify the program to instead use only the 'awk' built-in - functions, such as 'index()' and 'substr()'. - - 5. The 'split.awk' program (*note Split Program::) assumes that -======= 4. The `split.awk' program (*note Split Program::) assumes that ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac letters are contiguous in the character set, which isn't true for EBCDIC systems. Fix this problem. (Hint: Consider a different way to work through the alphabet, without relying on `ord()' and @@ -19765,21 +18778,21 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample where you would use this, just as fast." Rewrite the logic to follow this suggestion. - 6. Why can't the 'wc.awk' program (*note Wc Program::) just use the - value of 'FNR' in 'endfile()'? Hint: Examine the code in *note + 6. Why can't the `wc.awk' program (*note Wc Program::) just use the + value of `FNR' in `endfile()'? Hint: Examine the code in *note Filetrans Function::. - 7. Manipulation of individual characters in the 'translate' program - (*note Translate Program::) is painful using standard 'awk' - functions. Given that 'gawk' can split strings into individual - characters using '""' as the separator, how might you use this + 7. Manipulation of individual characters in the `translate' program + (*note Translate Program::) is painful using standard `awk' + functions. Given that `gawk' can split strings into individual + characters using `""' as the separator, how might you use this feature to simplify the program? - 8. The 'extract.awk' program (*note Extract Program::) was written - before 'gawk' had the 'gensub()' function. Use it to simplify the + 8. The `extract.awk' program (*note Extract Program::) was written + before `gawk' had the `gensub()' function. Use it to simplify the code. - 9. Compare the performance of the 'awksed.awk' program (*note Simple + 9. Compare the performance of the `awksed.awk' program (*note Simple Sed::) with the more straightforward: BEGIN { @@ -19790,39 +18803,41 @@ File: gawk.info, Node: Programs Exercises, Prev: Programs Summary, Up: Sample { gsub(pat, repl); print } - 10. What are the advantages and disadvantages of 'awksed.awk' versus - the real 'sed' utility? + 10. What are the advantages and disadvantages of `awksed.awk' versus + the real `sed' utility? - 11. In *note Igawk Program::, we mentioned that not trying to save the - line read with 'getline' in the 'pathto()' function when testing + 11. In *note Igawk Program::, we mentioned that not trying to save the + line read with `getline' in the `pathto()' function when testing for the file's accessibility for use with the main program simplifies things considerably. What problem does this engender though? - 12. As an additional example of the idea that it is not always + 12. As an additional example of the idea that it is not always necessary to add new features to a program, consider the idea of having two files in a directory in the search path: - 'default.awk' - This file contains a set of default library functions, such as - 'getopt()' and 'assert()'. + `default.awk' + This file contains a set of default library functions, such + as `getopt()' and `assert()'. - 'site.awk' + `site.awk' This file contains library functions that are specific to a site or installation; i.e., locally developed functions. - Having a separate file allows 'default.awk' to change with new - 'gawk' releases, without requiring the system administrator to - update it each time by adding the local functions. + Having a separate file allows `default.awk' to change with + new `gawk' releases, without requiring the system + administrator to update it each time by adding the local + functions. - One user suggested that 'gawk' be modified to automatically read + One user suggested that `gawk' be modified to automatically read these files upon startup. Instead, it would be very simple to - modify 'igawk' to do this. Since 'igawk' can process nested - '@include' directives, 'default.awk' could simply contain - '@include' statements for the desired library functions. Make this - change. + modify `igawk' to do this. Since `igawk' can process nested + `@include' directives, `default.awk' could simply contain + `@include' statements for the desired library functions. Make + this change. + + 13. Modify `anagram.awk' (*note Anagram Program::), to avoid the use + of the external `sort' utility. - 13. Modify 'anagram.awk' (*note Anagram Program::), to avoid the use - of the external 'sort' utility. ---------- Footnotes ---------- @@ -19832,38 +18847,38 @@ machine' into Google.  File: gawk.info, Node: Advanced Features, Next: Internationalization, Prev: Sample Programs, Up: Top -12 Advanced Features of 'gawk' +12 Advanced Features of `gawk' ****************************** Write documentation as if whoever reads it is a violent psychopath - who knows where you live. - -- _Steve English, as quoted by Peter Langston_ + who knows where you live. -- Steve English, as quoted by Peter + Langston - This major node discusses advanced features in 'gawk'. It's a bit of -a "grab bag" of items that are otherwise unrelated to each other. -First, a command-line option allows 'gawk' to recognize nondecimal -numbers in input data, not just in 'awk' programs. Then, 'gawk''s + This major node discusses advanced features in `gawk'. It's a bit +of a "grab bag" of items that are otherwise unrelated to each other. +First, a command-line option allows `gawk' to recognize nondecimal +numbers in input data, not just in `awk' programs. Then, `gawk''s special features for sorting arrays are presented. Next, two-way I/O, discussed briefly in earlier parts of this Info file, is described in full detail, along with the basics of TCP/IP networking. Finally, -'gawk' can "profile" an 'awk' program, making it possible to tune it for -performance. +`gawk' can "profile" an `awk' program, making it possible to tune it +for performance. A number of advanced features require separate major nodes of their own: * *note Internationalization::, discusses how to internationalize - your 'awk' programs, so that they can speak multiple national + your `awk' programs, so that they can speak multiple national languages. - * *note Debugger::, describes 'gawk''s built-in command-line debugger - for debugging 'awk' programs. + * *note Debugger::, describes `gawk''s built-in command-line + debugger for debugging `awk' programs. * *note Arbitrary Precision Arithmetic::, describes how you can use - 'gawk' to perform arbitrary-precision arithmetic. + `gawk' to perform arbitrary-precision arithmetic. * *note Dynamic Extensions::, discusses the ability to dynamically - add new built-in functions to 'gawk'. + add new built-in functions to `gawk'. * Menu: @@ -19871,8 +18886,8 @@ own: * Array Sorting:: Facilities for controlling array traversal and sorting arrays. * Two-way I/O:: Two-way communications with another process. -* TCP/IP Networking:: Using 'gawk' for network programming. -* Profiling:: Profiling your 'awk' programs. +* TCP/IP Networking:: Using `gawk' for network programming. +* Profiling:: Profiling your `awk' programs. * Advanced Features Summary:: Summary of advanced features.  @@ -19881,7 +18896,7 @@ File: gawk.info, Node: Nondecimal Data, Next: Array Sorting, Up: Advanced Fea 12.1 Allowing Nondecimal Input Data =================================== -If you run 'gawk' with the '--non-decimal-data' option, you can have +If you run `gawk' with the `--non-decimal-data' option, you can have nondecimal constants in your input data: $ echo 0123 123 0x123 | @@ -19889,16 +18904,16 @@ nondecimal constants in your input data: > $1, $2, $3 }' -| 83, 123, 291 - For this feature to work, write your program so that 'gawk' treats + For this feature to work, write your program so that `gawk' treats your data as numeric: $ echo 0123 123 0x123 | gawk '{ print $1, $2, $3 }' -| 0123 123 0x123 -The 'print' statement treats its expressions as strings. Although the +The `print' statement treats its expressions as strings. Although the fields can act as numbers when necessary, they are still strings, so -'print' does not try to treat them numerically. You need to add zero to -a field to force it to be treated as a number. For example: +`print' does not try to treat them numerically. You need to add zero +to a field to force it to be treated as a number. For example: $ echo 0123 123 0x123 | gawk --non-decimal-data ' > { print $1, $2, $3 @@ -19911,8 +18926,8 @@ because using this facility could lead to surprising results, the default is to leave it disabled. If you want it, you must explicitly request it. - CAUTION: _Use of this option is not recommended._ It can break old - programs very badly. Instead, use the 'strtonum()' function to + CAUTION: _Use of this option is not recommended._ It can break old + programs very badly. Instead, use the `strtonum()' function to convert your data (*note String Functions::). This makes your programs easier to write and easier to read, and leads to less surprising results. @@ -19923,10 +18938,10 @@ File: gawk.info, Node: Array Sorting, Next: Two-way I/O, Prev: Nondecimal Dat 12.2 Controlling Array Traversal and Array Sorting ================================================== -'gawk' lets you control the order in which a 'for (i in array)' loop +`gawk' lets you control the order in which a `for (i in array)' loop traverses an array. - In addition, two built-in functions, 'asort()' and 'asorti()', let + In addition, two built-in functions, `asort()' and `asorti()', let you sort arrays based on the array values and indices, respectively. These two functions also provide control over the sorting criteria used to order the elements during sorting. @@ -19934,7 +18949,7 @@ to order the elements during sorting. * Menu: * Controlling Array Traversal:: How to use PROCINFO["sorted_in"]. -* Array Sorting Functions:: How to use 'asort()' and 'asorti()'. +* Array Sorting Functions:: How to use `asort()' and `asorti()'.  File: gawk.info, Node: Controlling Array Traversal, Next: Array Sorting Functions, Up: Array Sorting @@ -19942,19 +18957,19 @@ File: gawk.info, Node: Controlling Array Traversal, Next: Array Sorting Functi 12.2.1 Controlling Array Traversal ---------------------------------- -By default, the order in which a 'for (i in array)' loop scans an array +By default, the order in which a `for (i in array)' loop scans an array is not defined; it is generally based upon the internal implementation -of arrays inside 'awk'. +of arrays inside `awk'. Often, though, it is desirable to be able to loop over the elements -in a particular order that you, the programmer, choose. 'gawk' lets you -do this. +in a particular order that you, the programmer, choose. `gawk' lets +you do this. *note Controlling Scanning::, describes how you can assign special, -pre-defined values to 'PROCINFO["sorted_in"]' in order to control the -order in which 'gawk' traverses an array during a 'for' loop. +pre-defined values to `PROCINFO["sorted_in"]' in order to control the +order in which `gawk' traverses an array during a `for' loop. - In addition, the value of 'PROCINFO["sorted_in"]' can be a function + In addition, the value of `PROCINFO["sorted_in"]' can be a function name. This lets you traverse an array based on any custom criterion. The array elements are ordered according to the return value of this function. The comparison function should be defined with at least four @@ -19972,14 +18987,14 @@ can be arrays if the array being traversed contains subarrays as values. (*Note Arrays of Arrays::, for more information about subarrays.) The three possible return values are interpreted as follows: -'comp_func(i1, v1, i2, v2) < 0' +`comp_func(i1, v1, i2, v2) < 0' Index I1 comes before index I2 during loop traversal. -'comp_func(i1, v1, i2, v2) == 0' - Indices I1 and I2 come together but the relative order with respect - to each other is undefined. +`comp_func(i1, v1, i2, v2) == 0' + Indices I1 and I2 come together but the relative order with + respect to each other is undefined. -'comp_func(i1, v1, i2, v2) > 0' +`comp_func(i1, v1, i2, v2) > 0' Index I1 comes after index I2 during loop traversal. Our first comparison function can be used to scan an array in @@ -20020,7 +19035,7 @@ traversal: return (v1 < v2) ? -1 : (v1 != v2) } - Here is a main program to demonstrate how 'gawk' behaves using each + Here is a main program to demonstrate how `gawk' behaves using each of the previous functions: BEGIN { @@ -20096,9 +19111,9 @@ specific field position and can be used for this purpose: } The first field in each entry of the password file is the user's -login name, and the fields are separated by colons. Each record defines -a subarray, with each field as an element in the subarray. Running the -program produces the following output: +login name, and the fields are separated by colons. Each record +defines a subarray, with each field as an element in the subarray. +Running the program produces the following output: $ gawk -v POS=1 -F: -f sort.awk /etc/passwd -| adm:x:3:4:adm:/var/adm:/sbin/nologin @@ -20125,10 +19140,10 @@ when comparing item values. The partial ordering of the equal elements may change during the next loop traversal, if other elements are added or removed from the array. One way to resolve ties when comparing elements with otherwise equal values is to include the indices in the -comparison rules. Note that doing this may make the loop traversal less -efficient, so consider it only if necessary. The following comparison -functions force a deterministic order, and are based on the fact that -the (string) indices of two elements are never equal: +comparison rules. Note that doing this may make the loop traversal +less efficient, so consider it only if necessary. The following +comparison functions force a deterministic order, and are based on the +fact that the (string) indices of two elements are never equal: function cmp_numeric(i1, v1, i2, v2) { @@ -20150,33 +19165,33 @@ such a function. When string comparisons are made during a sort, either for element values where one or both aren't numbers, or for element indices handled -as strings, the value of 'IGNORECASE' (*note Built-in Variables::) +as strings, the value of `IGNORECASE' (*note Built-in Variables::) controls whether the comparisons treat corresponding uppercase and lowercase letters as equivalent or distinct. Another point to keep in mind is that in the case of subarrays the element values can themselves be arrays; a production comparison -function should use the 'isarray()' function (*note Type Functions::), +function should use the `isarray()' function (*note Type Functions::), to check for this, and choose a defined sorting order for subarrays. - All sorting based on 'PROCINFO["sorted_in"]' is disabled in POSIX -mode, since the 'PROCINFO' array is not special in that case. + All sorting based on `PROCINFO["sorted_in"]' is disabled in POSIX +mode, since the `PROCINFO' array is not special in that case. - As a side note, sorting the array indices before traversing the array -has been reported to add 15% to 20% overhead to the execution time of -'awk' programs. For this reason, sorted array traversal is not the -default. + As a side note, sorting the array indices before traversing the +array has been reported to add 15% to 20% overhead to the execution +time of `awk' programs. For this reason, sorted array traversal is not +the default.  File: gawk.info, Node: Array Sorting Functions, Prev: Controlling Array Traversal, Up: Array Sorting -12.2.2 Sorting Array Values and Indices with 'gawk' +12.2.2 Sorting Array Values and Indices with `gawk' --------------------------------------------------- -In most 'awk' implementations, sorting an array requires writing a -'sort()' function. While this can be educational for exploring +In most `awk' implementations, sorting an array requires writing a +`sort()' function. While this can be educational for exploring different sorting algorithms, usually that's not the point of the -program. 'gawk' provides the built-in 'asort()' and 'asorti()' +program. `gawk' provides the built-in `asort()' and `asorti()' functions (*note String Functions::) for sorting arrays. For example: POPULATE THE ARRAY data @@ -20184,31 +19199,31 @@ functions (*note String Functions::) for sorting arrays. For example: for (i = 1; i <= n; i++) DO SOMETHING WITH data[i] - After the call to 'asort()', the array 'data' is indexed from 1 to -some number N, the total number of elements in 'data'. (This count is -'asort()''s return value.) 'data[1]' <= 'data[2]' <= 'data[3]', and so + After the call to `asort()', the array `data' is indexed from 1 to +some number N, the total number of elements in `data'. (This count is +`asort()''s return value.) `data[1]' <= `data[2]' <= `data[3]', and so on. The default comparison is based on the type of the elements (*note Typing and Comparison::). All numeric values come before all string values, which in turn come before all subarrays. - An important side effect of calling 'asort()' is that _the array's -original indices are irrevocably lost_. As this isn't always desirable, -'asort()' accepts a second argument: + An important side effect of calling `asort()' is that _the array's +original indices are irrevocably lost_. As this isn't always +desirable, `asort()' accepts a second argument: POPULATE THE ARRAY source n = asort(source, dest) for (i = 1; i <= n; i++) DO SOMETHING WITH dest[i] - In this case, 'gawk' copies the 'source' array into the 'dest' array -and then sorts 'dest', destroying its indices. However, the 'source' + In this case, `gawk' copies the `source' array into the `dest' array +and then sorts `dest', destroying its indices. However, the `source' array is not affected. Often, what's needed is to sort on the values of the _indices_ -instead of the values of the elements. To do that, use the 'asorti()' +instead of the values of the elements. To do that, use the `asorti()' function. The interface and behavior are identical to that of -'asort()', except that the index values are used for sorting, and become -the values of the result array: +`asort()', except that the index values are used for sorting, and +become the values of the result array: { source[$0] = some_func($0) } @@ -20223,15 +19238,15 @@ the values of the result array: } } - So far, so good. Now it starts to get interesting. Both 'asort()' -and 'asorti()' accept a third string argument to control comparison of -array elements. When we introduced 'asort()' and 'asorti()' in *note + So far, so good. Now it starts to get interesting. Both `asort()' +and `asorti()' accept a third string argument to control comparison of +array elements. When we introduced `asort()' and `asorti()' in *note String Functions::, we ignored this third argument; however, now is the time to describe how this argument affects these two functions. Basically, the third argument specifies how the array is to be -sorted. There are two possibilities. As with 'PROCINFO["sorted_in"]', -this argument may be one of the predefined names that 'gawk' provides +sorted. There are two possibilities. As with `PROCINFO["sorted_in"]', +this argument may be one of the predefined names that `gawk' provides (*note Controlling Scanning::), or it may be the name of a user-defined function (*note Controlling Array Traversal::). @@ -20239,26 +19254,26 @@ function (*note Controlling Array Traversal::). chooses_, taking into account just the indices, just the values, or both. This is extremely powerful. - Once the array is sorted, 'asort()' takes the _values_ in their final -order, and uses them to fill in the result array, whereas 'asorti()' -takes the _indices_ in their final order, and uses them to fill in the -result array. + Once the array is sorted, `asort()' takes the _values_ in their +final order, and uses them to fill in the result array, whereas +`asorti()' takes the _indices_ in their final order, and uses them to +fill in the result array. NOTE: Copying array indices and elements isn't expensive in terms - of memory. Internally, 'gawk' maintains "reference counts" to - data. For example, when 'asort()' copies the first array to the + of memory. Internally, `gawk' maintains "reference counts" to + data. For example, when `asort()' copies the first array to the second one, there is only one copy of the original array elements' data, even though both arrays use the values. - Because 'IGNORECASE' affects string comparisons, the value of -'IGNORECASE' also affects sorting for both 'asort()' and 'asorti()'. + Because `IGNORECASE' affects string comparisons, the value of +`IGNORECASE' also affects sorting for both `asort()' and `asorti()'. Note also that the locale's sorting order does _not_ come into play; -comparisons are based on character values only.(1) Caveat Emptor. +comparisons are based on character values only.(1) Caveat Emptor. ---------- Footnotes ---------- (1) This is true because locale-based comparison occurs only when in -POSIX compatibility mode, and since 'asort()' and 'asorti()' are 'gawk' +POSIX compatibility mode, and since `asort()' and `asorti()' are `gawk' extensions, they are not available in that case.  @@ -20283,17 +19298,6 @@ temporary files: close(tempfile) system("rm " tempfile) -<<<<<<< HEAD -This works, but not elegantly. Among other things, it requires that the -program be run in a directory that cannot be shared among users; for -example, '/tmp' will not do, as another user might happen to be using a -temporary file with the same name. - - However, with 'gawk', it is possible to open a _two-way_ pipe to -another process. The second process is termed a "coprocess", since it -runs in parallel with 'gawk'. The two-way connection is created using -the '|&' operator (borrowed from the Korn shell, 'ksh'):(1) -======= This works, but not elegantly. Among other things, it requires that the program be run in a directory that cannot be shared among users; for example, `/tmp' will not do, as another user might happen to be @@ -20302,7 +19306,6 @@ is possible to open a _two-way_ pipe to another process. The second process is termed a "coprocess", since it runs in parallel with `gawk'. The two-way connection is created using the `|&' operator (borrowed from the Korn shell, `ksh'):(2) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac do { print DATA |& "subprogram" @@ -20310,42 +19313,43 @@ from the Korn shell, `ksh'):(2) } while (DATA LEFT TO PROCESS) close("subprogram") - The first time an I/O operation is executed using the '|&' operator, -'gawk' creates a two-way pipeline to a child process that runs the other -program. Output created with 'print' or 'printf' is written to the -program's standard input, and output from the program's standard output -can be read by the 'gawk' program using 'getline'. As is the case with -processes started by '|', the subprogram can be any program, or pipeline -of programs, that can be started by the shell. + The first time an I/O operation is executed using the `|&' operator, +`gawk' creates a two-way pipeline to a child process that runs the +other program. Output created with `print' or `printf' is written to +the program's standard input, and output from the program's standard +output can be read by the `gawk' program using `getline'. As is the +case with processes started by `|', the subprogram can be any program, +or pipeline of programs, that can be started by the shell. There are some cautionary items to be aware of: - * As the code inside 'gawk' currently stands, the coprocess's - standard error goes to the same place that the parent 'gawk''s - standard error goes. It is not possible to read the child's + * As the code inside `gawk' currently stands, the coprocess's + standard error goes to the same place that the parent `gawk''s + standard error goes. It is not possible to read the child's standard error separately. - * I/O buffering may be a problem. 'gawk' automatically flushes all + * I/O buffering may be a problem. `gawk' automatically flushes all output down the pipe to the coprocess. However, if the coprocess - does not flush its output, 'gawk' may hang when doing a 'getline' + does not flush its output, `gawk' may hang when doing a `getline' in order to read the coprocess's results. This could lead to a situation known as "deadlock", where each process is waiting for the other one to do something. It is possible to close just one end of the two-way pipe to a -coprocess, by supplying a second argument to the 'close()' function of -either '"to"' or '"from"' (*note Close Files And Pipes::). These -strings tell 'gawk' to close the end of the pipe that sends data to the +coprocess, by supplying a second argument to the `close()' function of +either `"to"' or `"from"' (*note Close Files And Pipes::). These +strings tell `gawk' to close the end of the pipe that sends data to the coprocess or the end that reads from it, respectively. - This is particularly necessary in order to use the system 'sort' -utility as part of a coprocess; 'sort' must read _all_ of its input data -before it can produce any output. The 'sort' program does not receive -an end-of-file indication until 'gawk' closes the write end of the pipe. + This is particularly necessary in order to use the system `sort' +utility as part of a coprocess; `sort' must read _all_ of its input +data before it can produce any output. The `sort' program does not +receive an end-of-file indication until `gawk' closes the write end of +the pipe. - When you have finished writing data to the 'sort' utility, you can -close the '"to"' end of the pipe, and then start reading sorted data via -'getline'. For example: + When you have finished writing data to the `sort' utility, you can +close the `"to"' end of the pipe, and then start reading sorted data +via `getline'. For example: BEGIN { command = "LC_ALL=C sort" @@ -20361,20 +19365,20 @@ close the '"to"' end of the pipe, and then start reading sorted data via } This program writes the letters of the alphabet in reverse order, one -per line, down the two-way pipe to 'sort'. It then closes the write end -of the pipe, so that 'sort' receives an end-of-file indication. This -causes 'sort' to sort the data and write the sorted data back to the -'gawk' program. Once all of the data has been read, 'gawk' terminates -the coprocess and exits. - - As a side note, the assignment 'LC_ALL=C' in the 'sort' command -ensures traditional Unix (ASCII) sorting from 'sort'. This is not +per line, down the two-way pipe to `sort'. It then closes the write +end of the pipe, so that `sort' receives an end-of-file indication. +This causes `sort' to sort the data and write the sorted data back to +the `gawk' program. Once all of the data has been read, `gawk' +terminates the coprocess and exits. + + As a side note, the assignment `LC_ALL=C' in the `sort' command +ensures traditional Unix (ASCII) sorting from `sort'. This is not strictly necessary here, but it's good to know how to do this. - You may also use pseudo-ttys (ptys) for two-way communication instead -of pipes, if your system supports them. This is done on a per-command -basis, by setting a special element in the 'PROCINFO' array (*note -Auto-set::), like so: + You may also use pseudo-ttys (ptys) for two-way communication +instead of pipes, if your system supports them. This is done on a +per-command basis, by setting a special element in the `PROCINFO' array +(*note Auto-set::), like so: command = "sort -nr" # command, save in convenience variable PROCINFO[command, "pty"] = 1 # update PROCINFO @@ -20383,7 +19387,7 @@ Auto-set::), like so: Using ptys usually avoids the buffer deadlock issues described earlier, at some loss in performance. If your system does not have ptys, or if -all the system's ptys are in use, 'gawk' automatically falls back to +all the system's ptys are in use, `gawk' automatically falls back to using regular pipes. ---------- Footnotes ---------- @@ -20398,14 +19402,14 @@ in Bash.  File: gawk.info, Node: TCP/IP Networking, Next: Profiling, Prev: Two-way I/O, Up: Advanced Features -12.4 Using 'gawk' for Network Programming +12.4 Using `gawk' for Network Programming ========================================= - 'EMISTERED': - A host is a host from coast to coast, - and no-one can talk to host that's close, - unless the host that isn't close - is busy hung or dead. + `EMISTERED': + A host is a host from coast to coast, + and no-one can talk to host that's close, + unless the host that isn't close + is busy hung or dead. In addition to being able to open a two-way pipeline to a coprocess on the same system (*note Two-way I/O::), it is possible to make a @@ -20413,48 +19417,45 @@ two-way connection to another process on another system across an IP network connection. You can think of this as just a _very long_ two-way pipeline to a -coprocess. The way 'gawk' decides that you want to use TCP/IP +coprocess. The way `gawk' decides that you want to use TCP/IP networking is by recognizing special file names that begin with one of -<<<<<<< HEAD -'/inet/', '/inet4/' or '/inet6'. -======= `/inet/', `/inet4/' or `/inet6/'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac The full syntax of the special file name is -'/NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT'. The components -are: +`/NET-TYPE/PROTOCOL/LOCAL-PORT/REMOTE-HOST/REMOTE-PORT'. The +components are: NET-TYPE - Specifies the kind of Internet connection to make. Use '/inet4/' - to force IPv4, and '/inet6/' to force IPv6. Plain '/inet/' (which + Specifies the kind of Internet connection to make. Use `/inet4/' + to force IPv4, and `/inet6/' to force IPv6. Plain `/inet/' (which used to be the only option) uses the system default, most likely IPv4. PROTOCOL - The protocol to use over IP. This must be either 'tcp', or 'udp', + The protocol to use over IP. This must be either `tcp', or `udp', for a TCP or UDP IP connection, respectively. The use of TCP is recommended for most applications. LOCAL-PORT - The local TCP or UDP port number to use. Use a port number of '0' - when you want the system to pick a port. This is what you should - do when writing a TCP or UDP client. You may also use a well-known - service name, such as 'smtp' or 'http', in which case 'gawk' + The local TCP or UDP port number to use. Use a port number of `0' + when you want the system to pick a port. This is what you should do + when writing a TCP or UDP client. You may also use a well-known + service name, such as `smtp' or `http', in which case `gawk' attempts to determine the predefined port number using the C - 'getaddrinfo()' function. + `getaddrinfo()' function. REMOTE-HOST The IP address or fully-qualified domain name of the Internet host to which you want to connect. REMOTE-PORT - The TCP or UDP port number to use on the given REMOTE-HOST. Again, - use '0' if you don't care, or else a well-known service name. + The TCP or UDP port number to use on the given REMOTE-HOST. + Again, use `0' if you don't care, or else a well-known service + name. NOTE: Failure in opening a two-way socket will result in a - non-fatal error being returned to the calling code. The value of - 'ERRNO' indicates the error (*note Auto-set::). + non-fatal error being returned to the calling code. The value of + `ERRNO' indicates the error (*note Auto-set::). Consider the following very simple example: @@ -20466,37 +19467,38 @@ REMOTE-PORT } This program reads the current date and time from the local system's -TCP 'daytime' server. It then prints the results and closes the +TCP `daytime' server. It then prints the results and closes the connection. - Because this topic is extensive, the use of 'gawk' for TCP/IP -programming is documented separately. See *note (General Introduction, -gawkinet, TCP/IP Internetworking with 'gawk')Top::, for a much more -complete introduction and discussion, as well as extensive examples. + Because this topic is extensive, the use of `gawk' for TCP/IP +programming is documented separately. See *note (General +Introduction)Top:: gawkinet, TCP/IP Internetworking with `gawk', for a +much more complete introduction and discussion, as well as extensive +examples.  File: gawk.info, Node: Profiling, Next: Advanced Features Summary, Prev: TCP/IP Networking, Up: Advanced Features -12.5 Profiling Your 'awk' Programs +12.5 Profiling Your `awk' Programs ================================== -You may produce execution traces of your 'awk' programs. This is done -by passing the option '--profile' to 'gawk'. When 'gawk' has finished +You may produce execution traces of your `awk' programs. This is done +by passing the option `--profile' to `gawk'. When `gawk' has finished running, it creates a profile of your program in a file named -'awkprof.out'. Because it is profiling, it also executes up to 45% -slower than 'gawk' normally does. +`awkprof.out'. Because it is profiling, it also executes up to 45% +slower than `gawk' normally does. - As shown in the following example, the '--profile' option can be used -to change the name of the file where 'gawk' will write the profile: + As shown in the following example, the `--profile' option can be +used to change the name of the file where `gawk' will write the profile: gawk --profile=myprog.prof -f myprog.awk data1 data2 -In the above example, 'gawk' places the profile in 'myprog.prof' instead -of in 'awkprof.out'. +In the above example, `gawk' places the profile in `myprog.prof' +instead of in `awkprof.out'. - Here is a sample session showing a simple 'awk' program, its input -data, and the results from running 'gawk' with the '--profile' option. -First, the 'awk' program: + Here is a sample session showing a simple `awk' program, its input +data, and the results from running `gawk' with the `--profile' option. +First, the `awk' program: BEGIN { print "First BEGIN rule" } @@ -20532,9 +19534,9 @@ First, the 'awk' program: foo junk - Here is the 'awkprof.out' that results from running the 'gawk' -profiler on this program and data. (This example also illustrates that -'awk' programmers sometimes get up very early in the morning to work.) + Here is the `awkprof.out' that results from running the `gawk' +profiler on this program and data. (This example also illustrates that +`awk' programmers sometimes get up very early in the morning to work.) # gawk profile, created Thu Feb 27 05:16:21 2014 @@ -20586,61 +19588,62 @@ profiler on this program and data. (This example also illustrates that This example illustrates many of the basic features of profiling output. They are as follows: - * The program is printed in the order 'BEGIN' rules, 'BEGINFILE' - rules, pattern/action rules, 'ENDFILE' rules, 'END' rules and - functions, listed alphabetically. Multiple 'BEGIN' and 'END' rules - retain their separate identities, as do multiple 'BEGINFILE' and - 'ENDFILE' rules. + * The program is printed in the order `BEGIN' rules, `BEGINFILE' + rules, pattern/action rules, `ENDFILE' rules, `END' rules and + functions, listed alphabetically. Multiple `BEGIN' and `END' + rules retain their separate identities, as do multiple `BEGINFILE' + and `ENDFILE' rules. - * Pattern-action rules have two counts. The first count, to the left - of the rule, shows how many times the rule's pattern was _tested_. - The second count, to the right of the rule's opening left brace in - a comment, shows how many times the rule's action was _executed_. - The difference between the two indicates how many times the rule's - pattern evaluated to false. + * Pattern-action rules have two counts. The first count, to the + left of the rule, shows how many times the rule's pattern was + _tested_. The second count, to the right of the rule's opening + left brace in a comment, shows how many times the rule's action + was _executed_. The difference between the two indicates how many + times the rule's pattern evaluated to false. - * Similarly, the count for an 'if'-'else' statement shows how many + * Similarly, the count for an `if'-`else' statement shows how many times the condition was tested. To the right of the opening left - brace for the 'if''s body is a count showing how many times the - condition was true. The count for the 'else' indicates how many + brace for the `if''s body is a count showing how many times the + condition was true. The count for the `else' indicates how many times the test failed. - * The count for a loop header (such as 'for' or 'while') shows how - many times the loop test was executed. (Because of this, you can't - just look at the count on the first statement in a rule to + * The count for a loop header (such as `for' or `while') shows how + many times the loop test was executed. (Because of this, you + can't just look at the count on the first statement in a rule to determine how many times the rule was executed. If the first statement is a loop, the count is misleading.) - * For user-defined functions, the count next to the 'function' + * For user-defined functions, the count next to the `function' keyword indicates how many times the function was called. The - counts next to the statements in the body show how many times those - statements were executed. + counts next to the statements in the body show how many times + those statements were executed. - * The layout uses "K&R" style with TABs. Braces are used everywhere, - even when the body of an 'if', 'else', or loop is only a single - statement. + * The layout uses "K&R" style with TABs. Braces are used + everywhere, even when the body of an `if', `else', or loop is only + a single statement. * Parentheses are used only where needed, as indicated by the structure of the program and the precedence rules. For example, - '(3 + 5) * 4' means add three plus five, then multiply the total by - four. However, '3 + 5 * 4' has no parentheses, and means '3 + (5 * - 4)'. + `(3 + 5) * 4' means add three plus five, then multiply the total + by four. However, `3 + 5 * 4' has no parentheses, and means `3 + + (5 * 4)'. - * Parentheses are used around the arguments to 'print' and 'printf' - only when the 'print' or 'printf' statement is followed by a + * Parentheses are used around the arguments to `print' and `printf' + only when the `print' or `printf' statement is followed by a redirection. Similarly, if the target of a redirection isn't a scalar, it gets parenthesized. - * 'gawk' supplies leading comments in front of the 'BEGIN' and 'END' - rules, the 'BEGINFILE' and 'ENDFILE' rules, the pattern/action + * `gawk' supplies leading comments in front of the `BEGIN' and `END' + rules, the `BEGINFILE' and `ENDFILE' rules, the pattern/action rules, and the functions. + The profiled version of your program may not look exactly like what -you typed when you wrote it. This is because 'gawk' creates the -profiled version by "pretty printing" its internal representation of the -program. The advantage to this is that 'gawk' can produce a standard -representation. The disadvantage is that all source-code comments are -lost. Also, things such as: +you typed when you wrote it. This is because `gawk' creates the +profiled version by "pretty printing" its internal representation of +the program. The advantage to this is that `gawk' can produce a +standard representation. The disadvantage is that all source-code +comments are lost. Also, things such as: /foo/ @@ -20652,23 +19655,23 @@ come out as: which is correct, but possibly surprising. - Besides creating profiles when a program has completed, 'gawk' can -produce a profile while it is running. This is useful if your 'awk' + Besides creating profiles when a program has completed, `gawk' can +produce a profile while it is running. This is useful if your `awk' program goes into an infinite loop and you want to see what has been -executed. To use this feature, run 'gawk' with the '--profile' option +executed. To use this feature, run `gawk' with the `--profile' option in the background: $ gawk --profile -f myprog & [1] 13992 The shell prints a job number and process ID number; in this case, -13992. Use the 'kill' command to send the 'USR1' signal to 'gawk': +13992. Use the `kill' command to send the `USR1' signal to `gawk': $ kill -USR1 13992 As usual, the profiled version of the program is written to -'awkprof.out', or to a different file if one specified with the -'--profile' option. +`awkprof.out', or to a different file if one specified with the +`--profile' option. Along with the regular profile, as shown earlier, the profile file includes a trace of any active functions: @@ -20680,26 +19683,26 @@ includes a trace of any active functions: # 1. foo # -- main -- - You may send 'gawk' the 'USR1' signal as many times as you like. + You may send `gawk' the `USR1' signal as many times as you like. Each time, the profile and function call trace are appended to the output profile file. - If you use the 'HUP' signal instead of the 'USR1' signal, 'gawk' + If you use the `HUP' signal instead of the `USR1' signal, `gawk' produces the profile and the function call trace and then exits. - When 'gawk' runs on MS-Windows systems, it uses the 'INT' and 'QUIT' -signals for producing the profile and, in the case of the 'INT' signal, -'gawk' exits. This is because these systems don't support the 'kill' + When `gawk' runs on MS-Windows systems, it uses the `INT' and `QUIT' +signals for producing the profile and, in the case of the `INT' signal, +`gawk' exits. This is because these systems don't support the `kill' command, so the only signals you can deliver to a program are those -generated by the keyboard. The 'INT' signal is generated by the -'Ctrl-' or 'Ctrl-' key, while the 'QUIT' signal is generated -by the 'Ctrl-<\>' key. +generated by the keyboard. The `INT' signal is generated by the +`Ctrl-' or `Ctrl-' key, while the `QUIT' signal is generated +by the `Ctrl-<\>' key. - Finally, 'gawk' also accepts another option, '--pretty-print'. When -called this way, 'gawk' "pretty prints" the program into 'awkprof.out', + Finally, `gawk' also accepts another option, `--pretty-print'. When +called this way, `gawk' "pretty prints" the program into `awkprof.out', without any execution counts. - NOTE: Once upon a time, the '--pretty-print' option would also run + NOTE: Once upon a time, the `--pretty-print' option would also run your program. This is is no longer the case.  @@ -20708,45 +19711,46 @@ File: gawk.info, Node: Advanced Features Summary, Prev: Profiling, Up: Advanc 12.6 Summary ============ - * The '--non-decimal-data' option causes 'gawk' to treat octal- and + * The `--non-decimal-data' option causes `gawk' to treat octal- and hexadecimal-looking input data as octal and hexadecimal. This option should be used with caution or not at all; use of - 'strtonum()' is preferable. + `strtonum()' is preferable. - * You can take over complete control of sorting in 'for (INDX in - ARRAY)' array traversal by setting 'PROCINFO["sorted_in"]' to the + * You can take over complete control of sorting in `for (INDX in + ARRAY)' array traversal by setting `PROCINFO["sorted_in"]' to the name of a user-defined function that does the comparison of array elements based on index and value. * Similarly, you can supply the name of a user-defined comparison - function as the third argument to either 'asort()' or 'asorti()' to - control how those functions sort arrays. Or you may provide one of - the predefined control strings that work for - 'PROCINFO["sorted_in"]'. - - * You can use the '|&' operator to create a two-way pipe to a - co-process. You read from the co-process with 'getline' and write - to it with 'print' or 'printf'. Use 'close()' to close off the + function as the third argument to either `asort()' or `asorti()' + to control how those functions sort arrays. Or you may provide one + of the predefined control strings that work for + `PROCINFO["sorted_in"]'. + + * You can use the `|&' operator to create a two-way pipe to a + co-process. You read from the co-process with `getline' and write + to it with `print' or `printf'. Use `close()' to close off the co-process completely, or optionally, close off one side of the two-way communications. - * By using special "file names" with the '|&' operator, you can open + * By using special "file names" with the `|&' operator, you can open a TCP/IP (or UDP/IP) connection to remote hosts in the Internet. - 'gawk' supports both IPv4 an IPv6. + `gawk' supports both IPv4 an IPv6. - * You can generate statement count profiles of your program. This + * You can generate statement count profiles of your program. This can help you determine which parts of your program may be taking the most time and let you tune them more easily. Sending the - 'USR1' signal while profiling causes 'gawk' to dump the profile and - keep going, including a function call stack. + `USR1' signal while profiling causes `gawk' to dump the profile + and keep going, including a function call stack. - * You can also just "pretty print" the program. This currently also + * You can also just "pretty print" the program. This currently also runs the program, but that will change in the next major release. +  File: gawk.info, Node: Internationalization, Next: Debugger, Prev: Advanced Features, Up: Top -13 Internationalization with 'gawk' +13 Internationalization with `gawk' *********************************** Once upon a time, computer makers wrote software that worked only in @@ -20758,21 +19762,21 @@ became a common practice. For many years, the ability to provide internationalization was largely restricted to programs written in C and C++. This major node -describes the underlying library 'gawk' uses for internationalization, -as well as how 'gawk' makes internationalization features available at -the 'awk' program level. Having internationalization available at the -'awk' level gives software developers additional flexibility--they are +describes the underlying library `gawk' uses for internationalization, +as well as how `gawk' makes internationalization features available at +the `awk' program level. Having internationalization available at the +`awk' level gives software developers additional flexibility--they are no longer forced to write in C or C++ when internationalization is a requirement. * Menu: * I18N and L10N:: Internationalization and Localization. -* Explaining gettext:: How GNU 'gettext' works. +* Explaining gettext:: How GNU `gettext' works. * Programmer i18n:: Features for the programmer. * Translator i18n:: Features for the translator. * I18N Example:: A simple i18n example. -* Gawk I18N:: 'gawk' is also internationalized. +* Gawk I18N:: `gawk' is also internationalized. * I18N Summary:: Summary of I18N stuff.  @@ -20784,69 +19788,69 @@ File: gawk.info, Node: I18N and L10N, Next: Explaining gettext, Up: Internati "Internationalization" means writing (or modifying) a program once, in such a way that it can use multiple languages without requiring further source-code changes. "Localization" means providing the data necessary -for an internationalized program to work in a particular language. Most -typically, these terms refer to features such as the language used for -printing error messages, the language used to read responses, and -information related to how numerical and monetary values are printed and -read. +for an internationalized program to work in a particular language. +Most typically, these terms refer to features such as the language used +for printing error messages, the language used to read responses, and +information related to how numerical and monetary values are printed +and read.  File: gawk.info, Node: Explaining gettext, Next: Programmer i18n, Prev: I18N and L10N, Up: Internationalization -13.2 GNU 'gettext' +13.2 GNU `gettext' ================== -'gawk' uses GNU 'gettext' to provide its internationalization features. -The facilities in GNU 'gettext' focus on messages; strings printed by a -program, either directly or via formatting with 'printf' or -'sprintf()'.(1) +`gawk' uses GNU `gettext' to provide its internationalization features. +The facilities in GNU `gettext' focus on messages; strings printed by a +program, either directly or via formatting with `printf' or +`sprintf()'.(1) - When using GNU 'gettext', each application has its own "text domain". -This is a unique name, such as 'kpilot' or 'gawk', that identifies the -application. A complete application may have multiple + When using GNU `gettext', each application has its own "text +domain". This is a unique name, such as `kpilot' or `gawk', that +identifies the application. A complete application may have multiple components--programs written in C or C++, as well as scripts written in -'sh' or 'awk'. All of the components use the same text domain. +`sh' or `awk'. All of the components use the same text domain. To make the discussion concrete, assume we're writing an application -named 'guide'. Internationalization consists of the following steps, in -this order: +named `guide'. Internationalization consists of the following steps, +in this order: - 1. The programmer goes through the source for all of 'guide''s + 1. The programmer goes through the source for all of `guide''s components and marks each string that is a candidate for - translation. For example, '"`-F': option required"' is a good - candidate for translation. A table with strings of option names is - not (e.g., 'gawk''s '--profile' option should remain the same, no - matter what the local language). + translation. For example, `"`-F': option required"' is a good + candidate for translation. A table with strings of option names + is not (e.g., `gawk''s `--profile' option should remain the same, + no matter what the local language). - 2. The programmer indicates the application's text domain ('"guide"') - to the 'gettext' library, by calling the 'textdomain()' function. + 2. The programmer indicates the application's text domain (`"guide"') + to the `gettext' library, by calling the `textdomain()' function. 3. Messages from the application are extracted from the source code - and collected into a portable object template file ('guide.pot'), + and collected into a portable object template file (`guide.pot'), which lists the strings and their translations. The translations - are initially empty. The original (usually English) messages serve - as the key for lookup of the translations. + are initially empty. The original (usually English) messages + serve as the key for lookup of the translations. - 4. For each language with a translator, 'guide.pot' is copied to a - portable object file ('.po') and translations are created and + 4. For each language with a translator, `guide.pot' is copied to a + portable object file (`.po') and translations are created and shipped with the application. For example, there might be a - 'fr.po' for a French translation. + `fr.po' for a French translation. - 5. Each language's '.po' file is converted into a binary message - object ('.gmo') file. A message object file contains the original - messages and their translations in a binary format that allows fast - lookup of translations at runtime. + 5. Each language's `.po' file is converted into a binary message + object (`.gmo') file. A message object file contains the original + messages and their translations in a binary format that allows + fast lookup of translations at runtime. - 6. When 'guide' is built and installed, the binary translation files + 6. When `guide' is built and installed, the binary translation files are installed in a standard place. - 7. For testing and development, it is possible to tell 'gettext' to - use '.gmo' files in a different directory than the standard one by - using the 'bindtextdomain()' function. + 7. For testing and development, it is possible to tell `gettext' to + use `.gmo' files in a different directory than the standard one by + using the `bindtextdomain()' function. - 8. At runtime, 'guide' looks up each string via a call to 'gettext()'. - The returned string is the translated string if available, or the - original string if not. + 8. At runtime, `guide' looks up each string via a call to + `gettext()'. The returned string is the translated string if + available, or the original string if not. 9. If necessary, it is possible to access messages from a different text domain than the one belonging to the application, without @@ -20854,16 +19858,16 @@ this order: forth. In C (or C++), the string marking and dynamic translation lookup are -accomplished by wrapping each string in a call to 'gettext()': +accomplished by wrapping each string in a call to `gettext()': printf("%s", gettext("Don't Panic!\n")); - The tools that extract messages from source code pull out all strings -enclosed in calls to 'gettext()'. + The tools that extract messages from source code pull out all +strings enclosed in calls to `gettext()'. - The GNU 'gettext' developers, recognizing that typing 'gettext(...)' + The GNU `gettext' developers, recognizing that typing `gettext(...)' over and over again is both painful and ugly to look at, use the macro -'_' (an underscore) to make things easier: +`_' (an underscore) to make things easier: /* In the standard header file: */ #define _(str) gettext(str) @@ -20875,137 +19879,121 @@ This reduces the typing overhead to just three extra characters per string and is considerably easier to read as well. There are locale "categories" for different types of locale-related -information. The defined locale categories that 'gettext' knows about +information. The defined locale categories that `gettext' knows about are: -'LC_MESSAGES' - Text messages. This is the default category for 'gettext' +`LC_MESSAGES' + Text messages. This is the default category for `gettext' operations, but it is possible to supply a different one explicitly, if necessary. (It is almost never necessary to supply a different category.) -'LC_COLLATE' +`LC_COLLATE' Text-collation information; i.e., how different characters and/or groups of characters sort in a given language. -<<<<<<< HEAD -'LC_CTYPE' - Character-type information (alphabetic, digit, upper- or lowercase, - and so on). This information is accessed via the POSIX character - classes in regular expressions, such as '/[[:alnum:]]/' (*note - Regexp Operators::). -======= `LC_CTYPE' Character-type information (alphabetic, digit, upper- or lowercase, and so on) as well as character encoding. This information is accessed via the POSIX character classes in regular expressions, such as `/[[:alnum:]]/' (*note Regexp Operators::). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac -'LC_MONETARY' +`LC_MONETARY' Monetary information, such as the currency symbol, and whether the symbol goes before or after a number. -'LC_NUMERIC' +`LC_NUMERIC' Numeric information, such as which characters to use for the decimal point and the thousands separator.(2) -<<<<<<< HEAD -'LC_RESPONSE' - Response information, such as how "yes" and "no" appear in the - local language, and possibly other information as well. - -'LC_TIME' -======= `LC_TIME' ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Time- and date-related information, such as 12- or 24-hour clock, month printed before or after the day in a date, local month abbreviations, and so on. -'LC_ALL' - All of the above. (Not too useful in the context of 'gettext'.) +`LC_ALL' + All of the above. (Not too useful in the context of `gettext'.) ---------- Footnotes ---------- - (1) For some operating systems, the 'gawk' port doesn't support GNU -'gettext'. Therefore, these features are not available if you are using -one of those operating systems. Sorry. + (1) For some operating systems, the `gawk' port doesn't support GNU +`gettext'. Therefore, these features are not available if you are +using one of those operating systems. Sorry. - (2) Americans use a comma every three decimal places and a period for -the decimal point, while many Europeans do exactly the opposite: + (2) Americans use a comma every three decimal places and a period +for the decimal point, while many Europeans do exactly the opposite: 1,234.56 versus 1.234,56.  File: gawk.info, Node: Programmer i18n, Next: Translator i18n, Prev: Explaining gettext, Up: Internationalization -13.3 Internationalizing 'awk' Programs +13.3 Internationalizing `awk' Programs ====================================== -'gawk' provides the following variables and functions for +`gawk' provides the following variables and functions for internationalization: -'TEXTDOMAIN' +`TEXTDOMAIN' This variable indicates the application's text domain. For - compatibility with GNU 'gettext', the default value is - '"messages"'. + compatibility with GNU `gettext', the default value is + `"messages"'. -'_"your message here"' +`_"your message here"' String constants marked with a leading underscore are candidates for translation at runtime. String constants without a leading underscore are not translated. -'dcgettext(STRING [, DOMAIN [, CATEGORY]])' +``dcgettext(STRING' [`,' DOMAIN [`,' CATEGORY]]`)'' Return the translation of STRING in text domain DOMAIN for locale category CATEGORY. The default value for DOMAIN is the current - value of 'TEXTDOMAIN'. The default value for CATEGORY is - '"LC_MESSAGES"'. + value of `TEXTDOMAIN'. The default value for CATEGORY is + `"LC_MESSAGES"'. If you supply a value for CATEGORY, it must be a string equal to one of the known locale categories described in *note Explaining - gettext::. You must also supply a text domain. Use 'TEXTDOMAIN' + gettext::. You must also supply a text domain. Use `TEXTDOMAIN' if you want to use the current domain. - CAUTION: The order of arguments to the 'awk' version of the - 'dcgettext()' function is purposely different from the order - for the C version. The 'awk' version's order was chosen to be - simple and to allow for reasonable 'awk'-style default + CAUTION: The order of arguments to the `awk' version of the + `dcgettext()' function is purposely different from the order + for the C version. The `awk' version's order was chosen to + be simple and to allow for reasonable `awk'-style default arguments. -'dcngettext(STRING1, STRING2, NUMBER [, DOMAIN [, CATEGORY]])' +``dcngettext(STRING1, STRING2, NUMBER' [`,' DOMAIN [`,' CATEGORY]]`)'' Return the plural form used for NUMBER of the translation of STRING1 and STRING2 in text domain DOMAIN for locale category - CATEGORY. STRING1 is the English singular variant of a message, + CATEGORY. STRING1 is the English singular variant of a message, and STRING2 the English plural variant of the same message. The - default value for DOMAIN is the current value of 'TEXTDOMAIN'. The - default value for CATEGORY is '"LC_MESSAGES"'. + default value for DOMAIN is the current value of `TEXTDOMAIN'. + The default value for CATEGORY is `"LC_MESSAGES"'. - The same remarks about argument order as for the 'dcgettext()' + The same remarks about argument order as for the `dcgettext()' function apply. -'bindtextdomain(DIRECTORY [, DOMAIN ])' - Change the directory in which 'gettext' looks for '.gmo' files, in +``bindtextdomain(DIRECTORY' [`,' DOMAIN ]`)'' + Change the directory in which `gettext' looks for `.gmo' files, in case they will not or cannot be placed in the standard locations (e.g., during testing). Return the directory in which DOMAIN is "bound." - The default DOMAIN is the value of 'TEXTDOMAIN'. If DIRECTORY is - the null string ('""'), then 'bindtextdomain()' returns the current - binding for the given DOMAIN. + The default DOMAIN is the value of `TEXTDOMAIN'. If DIRECTORY is + the null string (`""'), then `bindtextdomain()' returns the + current binding for the given DOMAIN. - To use these facilities in your 'awk' program, follow the steps + To use these facilities in your `awk' program, follow the steps outlined in *note Explaining gettext::, like so: - 1. Set the variable 'TEXTDOMAIN' to the text domain of your program. - This is best done in a 'BEGIN' rule (*note BEGIN/END::), or it can - also be done via the '-v' command-line option (*note Options::): + 1. Set the variable `TEXTDOMAIN' to the text domain of your program. + This is best done in a `BEGIN' rule (*note BEGIN/END::), or it can + also be done via the `-v' command-line option (*note Options::): BEGIN { TEXTDOMAIN = "guide" ... } - 2. Mark all translatable strings with a leading underscore ('_') + 2. Mark all translatable strings with a leading underscore (`_') character. It _must_ be adjacent to the opening quote of the string. For example: @@ -21014,11 +20002,7 @@ outlined in *note Explaining gettext::, like so: printf(_"Number of users is %d\n", nusers) 3. If you are creating strings dynamically, you can still translate -<<<<<<< HEAD - them, using the 'dcgettext()' built-in function: -======= them, using the `dcgettext()' built-in function:(1) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac if (groggy) message = dcgettext("%d customers disturbing me\n", "adminprog") @@ -21026,13 +20010,10 @@ outlined in *note Explaining gettext::, like so: message = dcgettext("enjoying %d customers\n", "adminprog") printf(message, ncustomers) - Here, the call to 'dcgettext()' supplies a different text domain - ('"adminprog"') in which to find the message, but it uses the - default '"LC_MESSAGES"' category. + Here, the call to `dcgettext()' supplies a different text domain + (`"adminprog"') in which to find the message, but it uses the + default `"LC_MESSAGES"' category. -<<<<<<< HEAD - 4. During development, you might want to put the '.gmo' file in a -======= The previous example only works if `ncustomers' is greater than one. This example would be better done with `dcngettext()': @@ -21043,9 +20024,8 @@ outlined in *note Explaining gettext::, like so: printf(message, ncustomers) 4. During development, you might want to put the `.gmo' file in a ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac private directory for testing. This is done with the - 'bindtextdomain()' built-in function: + `bindtextdomain()' built-in function: BEGIN { TEXTDOMAIN = "guide" # our text domain @@ -21058,8 +20038,9 @@ outlined in *note Explaining gettext::, like so: ... } + *Note I18N Example::, for an example program showing the steps to -create and use translations from 'awk'. +create and use translations from `awk'. ---------- Footnotes ---------- @@ -21068,23 +20049,23 @@ create and use translations from 'awk'.  File: gawk.info, Node: Translator i18n, Next: I18N Example, Prev: Programmer i18n, Up: Internationalization -13.4 Translating 'awk' Programs +13.4 Translating `awk' Programs =============================== Once a program's translatable strings have been marked, they must be -extracted to create the initial '.pot' file. As part of translation, it -is often helpful to rearrange the order in which arguments to 'printf' -are output. +extracted to create the initial `.pot' file. As part of translation, +it is often helpful to rearrange the order in which arguments to +`printf' are output. - 'gawk''s '--gen-pot' command-line option extracts the messages and is -discussed next. After that, 'printf''s ability to rearrange the order -for 'printf' arguments at runtime is covered. + `gawk''s `--gen-pot' command-line option extracts the messages and +is discussed next. After that, `printf''s ability to rearrange the +order for `printf' arguments at runtime is covered. * Menu: * String Extraction:: Extracting marked strings. -* Printf Ordering:: Rearranging 'printf' arguments. -* I18N Portability:: 'awk'-level portability issues. +* Printf Ordering:: Rearranging `printf' arguments. +* I18N Portability:: `awk'-level portability issues.  File: gawk.info, Node: String Extraction, Next: Printf Ordering, Up: Translator i18n @@ -21092,22 +20073,13 @@ File: gawk.info, Node: String Extraction, Next: Printf Ordering, Up: Translat 13.4.1 Extracting Marked Strings -------------------------------- -Once your 'awk' program is working, and all the strings have been marked -and you've set (and perhaps bound) the text domain, it is time to -produce translations. First, use the '--gen-pot' command-line option to -create the initial '.pot' file: +Once your `awk' program is working, and all the strings have been +marked and you've set (and perhaps bound) the text domain, it is time +to produce translations. First, use the `--gen-pot' command-line +option to create the initial `.pot' file: $ gawk --gen-pot -f guide.awk > guide.pot -<<<<<<< HEAD - When run with '--gen-pot', 'gawk' does not execute your program. -Instead, it parses it as usual and prints all marked strings to standard -output in the format of a GNU 'gettext' Portable Object file. Also -included in the output are any constant strings that appear as the first -argument to 'dcgettext()' or as the first and second argument to -'dcngettext()'.(1) *Note I18N Example::, for the full list of steps to -go through to create and test translations for 'guide'. -======= When run with `--gen-pot', `gawk' does not execute your program. Instead, it parses it as usual and prints all marked strings to standard output in the format of a GNU `gettext' Portable Object file. @@ -21118,20 +20090,19 @@ your `awk' program; translators will eventually use it to provide you translations that you can also then distribute. *Note I18N Example::, for the full list of steps to go through to create and test translations for `guide'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac ---------- Footnotes ---------- - (1) The 'xgettext' utility that comes with GNU 'gettext' can handle -'.awk' files. + (1) The `xgettext' utility that comes with GNU `gettext' can handle +`.awk' files.  File: gawk.info, Node: Printf Ordering, Next: I18N Portability, Prev: String Extraction, Up: Translator i18n -13.4.2 Rearranging 'printf' Arguments +13.4.2 Rearranging `printf' Arguments ------------------------------------- -Format strings for 'printf' and 'sprintf()' (*note Printf::) present a +Format strings for `printf' and `sprintf()' (*note Printf::) present a special problem for translation. Consider the following:(1) printf(_"String `%s' has %d characters\n", @@ -21141,21 +20112,21 @@ special problem for translation. Consider the following:(1) "%d Zeichen lang ist die Zeichenkette `%s'\n" - The problem should be obvious: the order of the format specifications -is different from the original! Even though 'gettext()' can return the -translated string at runtime, it cannot change the argument order in the -call to 'printf'. + The problem should be obvious: the order of the format +specifications is different from the original! Even though `gettext()' +can return the translated string at runtime, it cannot change the +argument order in the call to `printf'. - To solve this problem, 'printf' format specifiers may have an + To solve this problem, `printf' format specifiers may have an additional optional element, which we call a "positional specifier". For example: "%2$d Zeichen lang ist die Zeichenkette `%1$s'\n" Here, the positional specifier consists of an integer count, which -indicates which argument to use, and a '$'. Counts are one-based, and +indicates which argument to use, and a `$'. Counts are one-based, and the format string itself is _not_ included. Thus, in the following -example, 'string' is the first argument and 'length(string)' is the +example, `string' is the first argument and `length(string)' is the second: $ gawk 'BEGIN { @@ -21178,39 +20149,39 @@ precision capability: -| hello -| hello - NOTE: When using '*' with a positional specifier, the '*' comes - first, then the integer position, and then the '$'. This is + NOTE: When using `*' with a positional specifier, the `*' comes + first, then the integer position, and then the `$'. This is somewhat counterintuitive. - 'gawk' does not allow you to mix regular format specifiers and those + `gawk' does not allow you to mix regular format specifiers and those with positional specifiers in the same string: $ gawk 'BEGIN { printf "%d %3$s\n", 1, 2, "hi" }' - error-> gawk: cmd. line:1: fatal: must use `count$' on all formats or none + error--> gawk: cmd. line:1: fatal: must use `count$' on all formats or none - NOTE: There are some pathological cases that 'gawk' may fail to + NOTE: There are some pathological cases that `gawk' may fail to diagnose. In such cases, the output may not be what you expect. - It's still a bad idea to try mixing them, even if 'gawk' doesn't + It's still a bad idea to try mixing them, even if `gawk' doesn't detect it. - Although positional specifiers can be used directly in 'awk' + Although positional specifiers can be used directly in `awk' programs, their primary purpose is to help in producing correct translations of format strings into languages different from the one in which the program is first written. ---------- Footnotes ---------- - (1) This example is borrowed from the GNU 'gettext' manual. + (1) This example is borrowed from the GNU `gettext' manual.  File: gawk.info, Node: I18N Portability, Prev: Printf Ordering, Up: Translator i18n -13.4.3 'awk' Portability Issues +13.4.3 `awk' Portability Issues ------------------------------- -'gawk''s internationalization features were purposely chosen to have as -little impact as possible on the portability of 'awk' programs that use -them to other versions of 'awk'. Consider this program: +`gawk''s internationalization features were purposely chosen to have as +little impact as possible on the portability of `awk' programs that use +them to other versions of `awk'. Consider this program: BEGIN { TEXTDOMAIN = "guide" @@ -21219,19 +20190,19 @@ them to other versions of 'awk'. Consider this program: print _"don't panic!" } -As written, it won't work on other versions of 'awk'. However, it is +As written, it won't work on other versions of `awk'. However, it is actually almost portable, requiring very little change: - * Assignments to 'TEXTDOMAIN' won't have any effect, since - 'TEXTDOMAIN' is not special in other 'awk' implementations. + * Assignments to `TEXTDOMAIN' won't have any effect, since + `TEXTDOMAIN' is not special in other `awk' implementations. - * Non-GNU versions of 'awk' treat marked strings as the concatenation - of a variable named '_' with the string following it.(1) - Typically, the variable '_' has the null string ('""') as its - value, leaving the original string constant as the result. + * Non-GNU versions of `awk' treat marked strings as the + concatenation of a variable named `_' with the string following + it.(1) Typically, the variable `_' has the null string (`""') as + its value, leaving the original string constant as the result. - * By defining "dummy" functions to replace 'dcgettext()', - 'dcngettext()' and 'bindtextdomain()', the 'awk' program can be + * By defining "dummy" functions to replace `dcgettext()', + `dcngettext()' and `bindtextdomain()', the `awk' program can be made to run, but all the messages are output in the original language. For example: @@ -21250,22 +20221,22 @@ actually almost portable, requiring very little change: return (number == 1 ? string1 : string2) } - * The use of positional specifications in 'printf' or 'sprintf()' is - _not_ portable. To support 'gettext()' at the C level, many - systems' C versions of 'sprintf()' do support positional + * The use of positional specifications in `printf' or `sprintf()' is + _not_ portable. To support `gettext()' at the C level, many + systems' C versions of `sprintf()' do support positional specifiers. But it works only if enough arguments are supplied in - the function call. Many versions of 'awk' pass 'printf' formats + the function call. Many versions of `awk' pass `printf' formats and arguments unchanged to the underlying C library version of - 'sprintf()', but only one format and argument at a time. What + `sprintf()', but only one format and argument at a time. What happens if a positional specification is used is anybody's guess. However, since the positional specifications are primarily for use - in _translated_ format strings, and since non-GNU 'awk's never + in _translated_ format strings, and since non-GNU `awk's never retrieve the translated string, this should not be a problem in practice. ---------- Footnotes ---------- - (1) This is good fodder for an "Obfuscated 'awk'" contest. + (1) This is good fodder for an "Obfuscated `awk'" contest.  File: gawk.info, Node: I18N Example, Next: Gawk I18N, Prev: Translator i18n, Up: Internationalization @@ -21274,7 +20245,7 @@ File: gawk.info, Node: I18N Example, Next: Gawk I18N, Prev: Translator i18n, ========================================== Now let's look at a step-by-step example of how to internationalize and -localize a simple 'awk' program, using 'guide.awk' as our original +localize a simple `awk' program, using `guide.awk' as our original source: BEGIN { @@ -21285,7 +20256,7 @@ source: print "Pardon me, Zaphod who?" } -Run 'gawk --gen-pot' to create the '.pot' file: +Run `gawk --gen-pot' to create the `.pot' file: $ gawk --gen-pot -f guide.awk > guide.pot @@ -21300,11 +20271,11 @@ This produces: msgstr "" This original portable object template file is saved and reused for -each language into which the application is translated. The 'msgid' is -the original string and the 'msgstr' is the translation. +each language into which the application is translated. The `msgid' is +the original string and the `msgstr' is the translation. - NOTE: Strings not marked with a leading underscore do not appear in - the 'guide.pot' file. + NOTE: Strings not marked with a leading underscore do not appear + in the `guide.pot' file. Next, the messages must be translated. Here is a translation to a hypothetical dialect of English, called "Mellow":(1) @@ -21323,17 +20294,17 @@ Following are the translations: msgstr "Like, the scoop is" The next step is to make the directory to hold the binary message -object file and then to create the 'guide.mo' file. We pretend that our -file is to be used in the 'en_US.UTF-8' locale. The directory layout -shown here is standard for GNU 'gettext' on GNU/Linux systems. Other -versions of 'gettext' may use a different layout: +object file and then to create the `guide.mo' file. We pretend that +our file is to be used in the `en_US.UTF-8' locale. The directory +layout shown here is standard for GNU `gettext' on GNU/Linux systems. +Other versions of `gettext' may use a different layout: $ mkdir en_US.UTF-8 en_US.UTF-8/LC_MESSAGES - The 'msgfmt' utility does the conversion from human-readable '.po' -file to machine-readable '.mo' file. By default, 'msgfmt' creates a -file named 'messages'. This file must be renamed and placed in the -proper directory so that 'gawk' can find it: + The `msgfmt' utility does the conversion from human-readable `.po' +file to machine-readable `.mo' file. By default, `msgfmt' creates a +file named `messages'. This file must be renamed and placed in the +proper directory so that `gawk' can find it: $ msgfmt guide-mellow.po -o en_US.UTF-8/LC_MESSAGES/guide.mo @@ -21344,9 +20315,9 @@ proper directory so that 'gawk' can find it: -| Like, the scoop is 42 -| Pardon me, Zaphod who? - If the three replacement functions for 'dcgettext()', 'dcngettext()' -and 'bindtextdomain()' (*note I18N Portability::) are in a file named -'libintl.awk', then we can run 'guide.awk' unchanged as follows: + If the three replacement functions for `dcgettext()', `dcngettext()' +and `bindtextdomain()' (*note I18N Portability::) are in a file named +`libintl.awk', then we can run `guide.awk' unchanged as follows: $ gawk --posix -f guide.awk -f libintl.awk -| Don't Panic @@ -21355,21 +20326,21 @@ and 'bindtextdomain()' (*note I18N Portability::) are in a file named ---------- Footnotes ---------- - (1) Perhaps it would be better if it were called "Hippy." Ah, well. + (1) Perhaps it would be better if it were called "Hippy." Ah, well.  File: gawk.info, Node: Gawk I18N, Next: I18N Summary, Prev: I18N Example, Up: Internationalization -13.6 'gawk' Can Speak Your Language +13.6 `gawk' Can Speak Your Language =================================== -'gawk' itself has been internationalized using the GNU 'gettext' -package. (GNU 'gettext' is described in complete detail in *note (GNU -'gettext' utilities, gettext, GNU gettext tools)Top::.) As of this -writing, the latest version of GNU 'gettext' is version 0.19.1 +`gawk' itself has been internationalized using the GNU `gettext' +package. (GNU `gettext' is described in complete detail in *note (GNU +`gettext' utilities)Top:: gettext, GNU gettext tools.) As of this +writing, the latest version of GNU `gettext' is version 0.19.1 (ftp://ftp.gnu.org/gnu/gettext/gettext-0.19.1.tar.gz). - If a translation of 'gawk''s messages exists, then 'gawk' produces + If a translation of `gawk''s messages exists, then `gawk' produces usage messages, warnings, and fatal errors in the local language.  @@ -21383,46 +20354,47 @@ File: gawk.info, Node: I18N Summary, Prev: Gawk I18N, Up: Internationalizatio Localization means providing the data necessary for an internationalized program to work in a particular language. - * 'gawk' uses GNU 'gettext' to let you internationalize and localize - 'awk' programs. A program's text domain identifies the program for - grouping all messages and other data together. + * `gawk' uses GNU `gettext' to let you internationalize and localize + `awk' programs. A program's text domain identifies the program + for grouping all messages and other data together. * You mark a program's strings for translation by preceding them with - an underscore. Once that is done, the strings are extracted into a - '.pot' file. This file is copied for each language into a '.po' - file, and the '.po' files are compiled into '.gmo' files for use at - runtime. + an underscore. Once that is done, the strings are extracted into a + `.pot' file. This file is copied for each language into a `.po' + file, and the `.po' files are compiled into `.gmo' files for use + at runtime. - * You can use position specifications with 'sprintf()' and 'printf' + * You can use position specifications with `sprintf()' and `printf' to rearrange the placement of argument values in formatted strings - and output. This is useful for the translations of format control + and output. This is useful for the translations of format control strings. * The internationalization features have been designed so that they - can be easily worked around in a standard 'awk'. + can be easily worked around in a standard `awk'. + + * `gawk' itself has been internationalized and ships with a number + of translations for its messages. - * 'gawk' itself has been internationalized and ships with a number of - translations for its messages.  File: gawk.info, Node: Debugger, Next: Arbitrary Precision Arithmetic, Prev: Internationalization, Up: Top -14 Debugging 'awk' Programs +14 Debugging `awk' Programs *************************** It would be nice if computer programs worked perfectly the first time -they were run, but in real life, this rarely happens for programs of any -complexity. Thus, most programming languages have facilities available -for "debugging" programs, and now 'awk' is no exception. +they were run, but in real life, this rarely happens for programs of +any complexity. Thus, most programming languages have facilities +available for "debugging" programs, and now `awk' is no exception. - The 'gawk' debugger is purposely modeled after the GNU Debugger (GDB) -(http://www.gnu.org/software/gdb/) command-line debugger. If you are -familiar with GDB, learning how to use 'gawk' for debugging your program -is easy. + The `gawk' debugger is purposely modeled after the GNU Debugger +(GDB) (http://www.gnu.org/software/gdb/) command-line debugger. If you +are familiar with GDB, learning how to use `gawk' for debugging your +program is easy. * Menu: -* Debugging:: Introduction to 'gawk' debugger. +* Debugging:: Introduction to `gawk' debugger. * Sample Debugging Session:: Sample debugging session. * List of Debugger Commands:: Main debugger commands. * Readline Support:: Readline support. @@ -21432,11 +20404,11 @@ is easy.  File: gawk.info, Node: Debugging, Next: Sample Debugging Session, Up: Debugger -14.1 Introduction to The 'gawk' Debugger +14.1 Introduction to The `gawk' Debugger ======================================== This minor node introduces debugging in general and begins the -discussion of debugging in 'gawk'. +discussion of debugging in `gawk'. * Menu: @@ -21451,7 +20423,7 @@ File: gawk.info, Node: Debugging Concepts, Next: Debugging Terms, Up: Debuggi --------------------------- (If you have used debuggers in other languages, you may want to skip -ahead to the next section on the specific features of the 'awk' +ahead to the next section on the specific features of the `awk' debugger.) Of course, a debugging program cannot remove bugs for you, since it @@ -21498,21 +20470,21 @@ defines terms used throughout the rest of this major node. Programs generally call functions during the course of their execution. One function can call another, or a function can call itself (recursion). You can view the chain of called functions - (main program calls A, which calls B, which calls C), as a stack of - executing functions: the currently running function is the topmost - one on the stack, and when it finishes (returns), the next one down - then becomes the active function. Such a stack is termed a "call - stack". + (main program calls A, which calls B, which calls C), as a stack + of executing functions: the currently running function is the + topmost one on the stack, and when it finishes (returns), the next + one down then becomes the active function. Such a stack is termed + a "call stack". For each function on the call stack, the system maintains a data area that contains the function's parameters, local variables, and - return value, as well as any other "bookkeeping" information needed - to manage the call stack. This data area is termed a "stack - frame". + return value, as well as any other "bookkeeping" information + needed to manage the call stack. This data area is termed a + "stack frame". - 'gawk' also follows this model, and gives you access to the call - stack and to each stack frame. You can see the call stack, as well - as from where each function on the stack was invoked. Commands + `gawk' also follows this model, and gives you access to the call + stack and to each stack frame. You can see the call stack, as well + as from where each function on the stack was invoked. Commands that print the call stack print information about each stack frame (as detailed later on). @@ -21527,14 +20499,14 @@ defines terms used throughout the rest of this major node. "Watchpoint" A watchpoint is similar to a breakpoint. The difference is that - breakpoints are oriented around the code: stop when a certain point - in the code is reached. A watchpoint, however, specifies that - program execution should stop when a _data value_ is changed. This - is useful, since sometimes it happens that a variable receives an - erroneous value, and it's hard to track down where this happens - just by looking at the code. By using a watchpoint, you can stop - whenever a variable is assigned to, and usually find the errant - code quite quickly. + breakpoints are oriented around the code: stop when a certain + point in the code is reached. A watchpoint, however, specifies + that program execution should stop when a _data value_ is changed. + This is useful, since sometimes it happens that a variable + receives an erroneous value, and it's hard to track down where + this happens just by looking at the code. By using a watchpoint, + you can stop whenever a variable is assigned to, and usually find + the errant code quite quickly.  File: gawk.info, Node: Awk Debugging, Prev: Debugging Terms, Up: Debugging @@ -21542,20 +20514,20 @@ File: gawk.info, Node: Awk Debugging, Prev: Debugging Terms, Up: Debugging 14.1.3 Awk Debugging -------------------- -Debugging an 'awk' program has some specific aspects that are not shared -with other programming languages. +Debugging an `awk' program has some specific aspects that are not +shared with other programming languages. - First of all, the fact that 'awk' programs usually take input + First of all, the fact that `awk' programs usually take input line-by-line from a file or files and operate on those lines using specific rules makes it especially useful to organize viewing the execution of the program in terms of these rules. As we will see, each -'awk' rule is treated almost like a function call, with its own specific -block of instructions. +`awk' rule is treated almost like a function call, with its own +specific block of instructions. - In addition, since 'awk' is by design a very concise language, it is + In addition, since `awk' is by design a very concise language, it is easy to lose sight of everything that is going on "inside" each line of -'awk' code. The debugger provides the opportunity to look at the -individual primitive instructions carried out by the higher-level 'awk' +`awk' code. The debugger provides the opportunity to look at the +individual primitive instructions carried out by the higher-level `awk' commands.  @@ -21564,9 +20536,9 @@ File: gawk.info, Node: Sample Debugging Session, Next: List of Debugger Comman 14.2 Sample Debugging Session ============================= -In order to illustrate the use of 'gawk' as a debugger, let's look at a -sample debugging session. We will use the 'awk' implementation of the -POSIX 'uniq' command described earlier (*note Uniq Program::) as our +In order to illustrate the use of `gawk' as a debugger, let's look at a +sample debugging session. We will use the `awk' implementation of the +POSIX `uniq' command described earlier (*note Uniq Program::) as our example. * Menu: @@ -21580,23 +20552,24 @@ File: gawk.info, Node: Debugger Invocation, Next: Finding The Bug, Up: Sample 14.2.1 How to Start the Debugger -------------------------------- -Starting the debugger is almost exactly like running 'gawk', except you -have to pass an additional option '--debug' or the corresponding short -option '-D'. The file(s) containing the program and any supporting code -are given on the command line as arguments to one or more '-f' options. -('gawk' is not designed to debug command-line programs, only programs -contained in files.) In our case, we invoke the debugger like this: +Starting the debugger is almost exactly like running `gawk', except you +have to pass an additional option `--debug' or the corresponding short +option `-D'. The file(s) containing the program and any supporting +code are given on the command line as arguments to one or more `-f' +options. (`gawk' is not designed to debug command-line programs, only +programs contained in files.) In our case, we invoke the debugger like +this: $ gawk -D -f getopt.awk -f join.awk -f uniq.awk -1 inputfile -where both 'getopt.awk' and 'uniq.awk' are in '$AWKPATH'. (Experienced +where both `getopt.awk' and `uniq.awk' are in `$AWKPATH'. (Experienced users of GDB or similar debuggers should note that this syntax is -slightly different from what they are used to. With the 'gawk' +slightly different from what they are used to. With the `gawk' debugger, you give the arguments for running the program in the command -line to the debugger rather than as part of the 'run' command at the +line to the debugger rather than as part of the `run' command at the debugger prompt.) - Instead of immediately running the program on 'inputfile', as 'gawk' + Instead of immediately running the program on `inputfile', as `gawk' would ordinarily do, the debugger merely loads all the program source files, compiles them internally, and then gives us a prompt: @@ -21612,7 +20585,7 @@ File: gawk.info, Node: Finding The Bug, Prev: Debugger Invocation, Up: Sample ---------------------- Let's say that we are having a problem using (a faulty version of) -'uniq.awk' in the "field-skipping" mode, and it doesn't seem to be +`uniq.awk' in the "field-skipping" mode, and it doesn't seem to be catching lines which should be identical when skipping the first field, such as: @@ -21634,15 +20607,15 @@ we wrote: The first thing we usually want to do when trying to investigate a problem like this is to put a breakpoint in the program so that we can watch it at work and catch what it is doing wrong. A reasonable spot -for a breakpoint in 'uniq.awk' is at the beginning of the function -'are_equal()', which compares the current line with the previous one. -To set the breakpoint, use the 'b' (breakpoint) command: +for a breakpoint in `uniq.awk' is at the beginning of the function +`are_equal()', which compares the current line with the previous one. +To set the breakpoint, use the `b' (breakpoint) command: gawk> b are_equal -| Breakpoint 1 set at file `awklib/eg/prog/uniq.awk', line 63 The debugger tells us the file and line number where the breakpoint -is. Now type 'r' or 'run' and the program runs until it hits the +is. Now type `r' or `run' and the program runs until it hits the breakpoint for the first time: gawk> r @@ -21654,39 +20627,31 @@ breakpoint for the first time: gawk> Now we can look at what's going on inside our program. First of all, -let's see how we got to where we are. At the prompt, we type 'bt' -(short for "backtrace"), and the debugger responds with a listing of the -current stack frames: +let's see how we got to where we are. At the prompt, we type `bt' +(short for "backtrace"), and the debugger responds with a listing of +the current stack frames: gawk> bt -| #0 are_equal(n, m, clast, cline, alast, aline) at `awklib/eg/prog/uniq.awk':68 -| #1 in main() at `awklib/eg/prog/uniq.awk':88 -<<<<<<< HEAD - This tells us that 'are_equal()' was called by the main program at -line 89 of 'uniq.awk'. (This is not a big surprise, since this is the -only call to 'are_equal()' in the program, but in more complex programs, -knowing who called a function and with what parameters can be the key to -finding the source of the problem.) -======= This tells us that `are_equal()' was called by the main program at line 88 of `uniq.awk'. (This is not a big surprise, since this is the only call to `are_equal()' in the program, but in more complex programs, knowing who called a function and with what parameters can be the key to finding the source of the problem.) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - Now that we're in 'are_equal()', we can start looking at the values -of some variables. Let's say we type 'p n' ('p' is short for "print"). -We would expect to see the value of 'n', a parameter to 'are_equal()'. + Now that we're in `are_equal()', we can start looking at the values +of some variables. Let's say we type `p n' (`p' is short for "print"). +We would expect to see the value of `n', a parameter to `are_equal()'. Actually, the debugger gives us: gawk> p n -| n = untyped variable -In this case, 'n' is an uninitialized local variable, since the function -was called without arguments (*note Function Calls::). +In this case, `n' is an uninitialized local variable, since the +function was called without arguments (*note Function Calls::). A more useful variable to display might be the current record: @@ -21694,14 +20659,14 @@ was called without arguments (*note Function Calls::). -| $0 = "gawk is a wonderful program!" This might be a bit puzzling at first since this is the second line of -our test input above. Let's look at 'NR': +our test input above. Let's look at `NR': gawk> p NR -| NR = 2 -So we can see that 'are_equal()' was only called for the second record +So we can see that `are_equal()' was only called for the second record of the file. Of course, this is because our program contains a rule for -'NR == 1': +`NR == 1': NR == 1 { last = $0 @@ -21714,27 +20679,19 @@ of the file. Of course, this is because our program contains a rule for -| last = "awk is a wonderful program!" Everything we have done so far has verified that the program has -worked as planned, up to and including the call to 'are_equal()', so the -problem must be inside this function. To investigate further, we must -begin "stepping through" the lines of 'are_equal()'. We start by typing -'n' (for "next"): +worked as planned, up to and including the call to `are_equal()', so +the problem must be inside this function. To investigate further, we +must begin "stepping through" the lines of `are_equal()'. We start by +typing `n' (for "next"): gawk> n -| 66 if (fcount > 0) { -<<<<<<< HEAD - This tells us that 'gawk' is now ready to execute line 67, which -decides whether to give the lines the special "field skipping" treatment -indicated by the '-f' command-line option. (Notice that we skipped from -where we were before at line 64 to here, since the condition in line 64 -'if (fcount == 0 && charcount == 0)' was false.) -======= This tells us that `gawk' is now ready to execute line 66, which decides whether to give the lines the special "field skipping" treatment indicated by the `-1' command-line option. (Notice that we skipped from where we were before at line 63 to here, since the condition in line 63 `if (fcount == 0 && charcount == 0)' was false.) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Continuing to step, we now get to the splitting of the current and last records: @@ -21753,8 +20710,8 @@ split into, so we try to look: -| alast = array, 5 elements -| aline = untyped variable -(The 'p' command can take more than one argument, similar to 'awk''s -'print' statement.) +(The `p' command can take more than one argument, similar to `awk''s +`print' statement.) This is kind of disappointing, though. All we found out is that there are five elements in `alast'; `m' and `aline' don't have values @@ -21772,7 +20729,7 @@ Oops! gawk> p alast[1] -| alast["1"] = "awk" - This would be kind of slow for a 100-member array, though, so 'gawk' + This would be kind of slow for a 100-member array, though, so `gawk' provides a shortcut (reminiscent of another language not to be mentioned): @@ -21783,7 +20740,7 @@ mentioned): -| alast["4"] = "wonderful" -| alast["5"] = "program!" - It looks like we got this far OK. Let's take another step or two: + It looks like we got this far OK. Let's take another step or two: gawk> n -| 69 clast = join(alast, fcount, n) @@ -21821,7 +20778,7 @@ File: gawk.info, Node: List of Debugger Commands, Next: Readline Support, Pre 14.3 Main Debugger Commands =========================== -The 'gawk' debugger command set can be divided into the following +The `gawk' debugger command set can be divided into the following categories: * Breakpoint control @@ -21839,10 +20796,10 @@ categories: Each of these are discussed in the following subsections. In the following descriptions, commands which may be abbreviated show the abbreviation on a second description line. A debugger command name may -also be truncated if that partial name is unambiguous. The debugger has +also be truncated if that partial name is unambiguous. The debugger has the built-in capability to automatically repeat the previous command -just by hitting . This works for the commands 'list', 'next', -'nexti', 'step', 'stepi' and 'continue' executed without any argument. +just by hitting . This works for the commands `list', `next', +`nexti', `step', `stepi' and `continue' executed without any argument. * Menu: @@ -21865,89 +20822,89 @@ session is to get your breakpoints set up, since otherwise your program will just run as if it was not under the debugger. The commands for controlling breakpoints are: -'break' [[FILENAME':']N | FUNCTION] ['"EXPRESSION"'] -'b' [[FILENAME':']N | FUNCTION] ['"EXPRESSION"'] +`break' [[FILENAME`:']N | FUNCTION] [`"EXPRESSION"'] +`b' [[FILENAME`:']N | FUNCTION] [`"EXPRESSION"'] Without any argument, set a breakpoint at the next instruction to be executed in the selected stack frame. Arguments can be one of the following: - N + N Set a breakpoint at line number N in the current source file. - FILENAME':'N + FILENAME`:'N Set a breakpoint at line number N in source file FILENAME. - FUNCTION + FUNCTION Set a breakpoint at entry to (the first instruction of) function FUNCTION. - Each breakpoint is assigned a number which can be used to delete it - from the breakpoint list using the 'delete' command. + Each breakpoint is assigned a number which can be used to delete + it from the breakpoint list using the `delete' command. With a breakpoint, you may also supply a condition. This is an - 'awk' expression (enclosed in double quotes) that the debugger - evaluates whenever the breakpoint is reached. If the condition is + `awk' expression (enclosed in double quotes) that the debugger + evaluates whenever the breakpoint is reached. If the condition is true, then the debugger stops execution and prompts for a command. Otherwise, it continues executing the program. -'clear' [[FILENAME':']N | FUNCTION] +`clear' [[FILENAME`:']N | FUNCTION] Without any argument, delete any breakpoint at the next instruction - to be executed in the selected stack frame. If the program stops - at a breakpoint, this deletes that breakpoint so that the program + to be executed in the selected stack frame. If the program stops at + a breakpoint, this deletes that breakpoint so that the program does not stop at that location again. Arguments can be one of the following: - N + N Delete breakpoint(s) set at line number N in the current source file. - FILENAME':'N + FILENAME`:'N Delete breakpoint(s) set at line number N in source file FILENAME. - FUNCTION + FUNCTION Delete breakpoint(s) set at entry to function FUNCTION. -'condition' N '"EXPRESSION"' - Add a condition to existing breakpoint or watchpoint N. The - condition is an 'awk' expression that the debugger evaluates - whenever the breakpoint or watchpoint is reached. If the condition +`condition' N `"EXPRESSION"' + Add a condition to existing breakpoint or watchpoint N. The + condition is an `awk' expression that the debugger evaluates + whenever the breakpoint or watchpoint is reached. If the condition is true, then the debugger stops execution and prompts for a - command. Otherwise, the debugger continues executing the program. + command. Otherwise, the debugger continues executing the program. If the condition expression is not specified, any existing condition is removed; i.e., the breakpoint or watchpoint is made unconditional. -'delete' [N1 N2 ...] [N-M] -'d' [N1 N2 ...] [N-M] - Delete specified breakpoints or a range of breakpoints. Deletes +`delete' [N1 N2 ...] [N-M] +`d' [N1 N2 ...] [N-M] + Delete specified breakpoints or a range of breakpoints. Deletes all defined breakpoints if no argument is supplied. -'disable' [N1 N2 ... | N-M] - Disable specified breakpoints or a range of breakpoints. Without +`disable' [N1 N2 ... | N-M] + Disable specified breakpoints or a range of breakpoints. Without any argument, disables all breakpoints. -'enable' ['del' | 'once'] [N1 N2 ...] [N-M] -'e' ['del' | 'once'] [N1 N2 ...] [N-M] - Enable specified breakpoints or a range of breakpoints. Without - any argument, enables all breakpoints. Optionally, you can specify - how to enable the breakpoint: +`enable' [`del' | `once'] [N1 N2 ...] [N-M] +`e' [`del' | `once'] [N1 N2 ...] [N-M] + Enable specified breakpoints or a range of breakpoints. Without + any argument, enables all breakpoints. Optionally, you can + specify how to enable the breakpoint: - 'del' + `del' Enable the breakpoint(s) temporarily, then delete it when the program stops at the breakpoint. - 'once' - Enable the breakpoint(s) temporarily, then disable it when the - program stops at the breakpoint. + `once' + Enable the breakpoint(s) temporarily, then disable it when + the program stops at the breakpoint. -'ignore' N COUNT +`ignore' N COUNT Ignore breakpoint number N the next COUNT times it is hit. -'tbreak' [[FILENAME':']N | FUNCTION] -'t' [[FILENAME':']N | FUNCTION] +`tbreak' [[FILENAME`:']N | FUNCTION] +`t' [[FILENAME`:']N | FUNCTION] Set a temporary breakpoint (enabled for only one stop). The - arguments are the same as for 'break'. + arguments are the same as for `break'.  File: gawk.info, Node: Debugger Execution Control, Next: Viewing And Changing Data, Prev: Breakpoint Control, Up: List of Debugger Commands @@ -21959,19 +20916,19 @@ Now that your breakpoints are ready, you can start running the program and observing its behavior. There are more commands for controlling execution of the program than we saw in our earlier example: -'commands' [N] -'silent' +`commands' [N] +`silent' ... -'end' - Set a list of commands to be executed upon stopping at a breakpoint - or watchpoint. N is the breakpoint or watchpoint number. Without - a number, the last one set is used. The actual commands follow, - starting on the next line, and terminated by the 'end' command. If - the command 'silent' is in the list, the usual messages about - stopping at a breakpoint and the source line are not printed. Any - command in the list that resumes execution (e.g., 'continue') - terminates the list (an implicit 'end'), and subsequent commands - are ignored. For example: +`end' + Set a list of commands to be executed upon stopping at a + breakpoint or watchpoint. N is the breakpoint or watchpoint number. + Without a number, the last one set is used. The actual commands + follow, starting on the next line, and terminated by the `end' + command. If the command `silent' is in the list, the usual + messages about stopping at a breakpoint and the source line are + not printed. Any command in the list that resumes execution (e.g., + `continue') terminates the list (an implicit `end'), and + subsequent commands are ignored. For example: gawk> commands > silent @@ -21982,60 +20939,60 @@ execution of the program than we saw in our earlier example: > end gawk> -'continue' [COUNT] -'c' [COUNT] - Resume program execution. If continued from a breakpoint and COUNT +`continue' [COUNT] +`c' [COUNT] + Resume program execution. If continued from a breakpoint and COUNT is specified, ignores the breakpoint at that location the next COUNT times before stopping. -'finish' - Execute until the selected stack frame returns. Print the returned - value. +`finish' + Execute until the selected stack frame returns. Print the + returned value. -'next' [COUNT] -'n' [COUNT] +`next' [COUNT] +`n' [COUNT] Continue execution to the next source line, stepping over function calls. The argument COUNT controls how many times to repeat the - action, as in 'step'. + action, as in `step'. -'nexti' [COUNT] -'ni' [COUNT] +`nexti' [COUNT] +`ni' [COUNT] Execute one (or COUNT) instruction(s), stepping over function calls. -'return' [VALUE] - Cancel execution of a function call. If VALUE (either a string or - a number) is specified, it is used as the function's return value. +`return' [VALUE] + Cancel execution of a function call. If VALUE (either a string or a + number) is specified, it is used as the function's return value. If used in a frame other than the innermost one (the currently - executing function, i.e., frame number 0), discard all inner frames - in addition to the selected one, and the caller of that frame - becomes the innermost frame. + executing function, i.e., frame number 0), discard all inner + frames in addition to the selected one, and the caller of that + frame becomes the innermost frame. -'run' -'r' - Start/restart execution of the program. When restarting, the +`run' +`r' + Start/restart execution of the program. When restarting, the debugger retains the current breakpoints, watchpoints, command history, automatic display variables, and debugger options. -'step' [COUNT] -'s' [COUNT] - Continue execution until control reaches a different source line in - the current stack frame. 'step' steps inside any function called - within the line. If the argument COUNT is supplied, steps that - many times before stopping, unless it encounters a breakpoint or - watchpoint. +`step' [COUNT] +`s' [COUNT] + Continue execution until control reaches a different source line + in the current stack frame. `step' steps inside any function + called within the line. If the argument COUNT is supplied, steps + that many times before stopping, unless it encounters a breakpoint + or watchpoint. -'stepi' [COUNT] -'si' [COUNT] +`stepi' [COUNT] +`si' [COUNT] Execute one (or COUNT) instruction(s), stepping inside function calls. (For illustration of what is meant by an "instruction" in - 'gawk', see the output shown under 'dump' in *note Miscellaneous + `gawk', see the output shown under `dump' in *note Miscellaneous Debugger Commands::.) -'until' [[FILENAME':']N | FUNCTION] -'u' [[FILENAME':']N | FUNCTION] +`until' [[FILENAME`:']N | FUNCTION] +`u' [[FILENAME`:']N | FUNCTION] Without any argument, continue execution until a line past the - current line in current stack frame is reached. With an argument, + current line in current stack frame is reached. With an argument, continue execution until the specified location is reached, or the current stack frame returns. @@ -22045,11 +21002,11 @@ File: gawk.info, Node: Viewing And Changing Data, Next: Execution Stack, Prev 14.3.3 Viewing and Changing Data -------------------------------- -The commands for viewing and changing variables inside of 'gawk' are: +The commands for viewing and changing variables inside of `gawk' are: -'display' [VAR | '$'N] - Add variable VAR (or field '$N') to the display list. The value of - the variable or field is displayed each time the program stops. +`display' [VAR | `$'N] + Add variable VAR (or field `$N') to the display list. The value + of the variable or field is displayed each time the program stops. Each variable added to the list is identified by a unique number: gawk> display x @@ -22059,107 +21016,110 @@ The commands for viewing and changing variables inside of 'gawk' are: current value. If the display variable refers to a function parameter, it is silently deleted from the list as soon as the execution reaches a context where no such variable of the given - name exists. Without argument, 'display' displays the current + name exists. Without argument, `display' displays the current values of items on the list. -'eval "AWK STATEMENTS"' - Evaluate AWK STATEMENTS in the context of the running program. You - can do anything that an 'awk' program would do: assign values to - variables, call functions, and so on. +`eval "AWK STATEMENTS"' + Evaluate AWK STATEMENTS in the context of the running program. + You can do anything that an `awk' program would do: assign values + to variables, call functions, and so on. -'eval' PARAM, ... +`eval' PARAM, ... AWK STATEMENTS -'end' - This form of 'eval' is similar, but it allows you to define "local - variables" that exist in the context of the AWK STATEMENTS, instead - of using variables or function parameters defined by the program. - -'print' VAR1[',' VAR2 ...] -'p' VAR1[',' VAR2 ...] - Print the value of a 'gawk' variable or field. Fields must be +`end' + This form of `eval' is similar, but it allows you to define "local + variables" that exist in the context of the AWK STATEMENTS, + instead of using variables or function parameters defined by the + program. + +`print' VAR1[`,' VAR2 ...] +`p' VAR1[`,' VAR2 ...] + Print the value of a `gawk' variable or field. Fields must be referenced by constants: gawk> print $3 This prints the third field in the input record (if the specified - field does not exist, it prints 'Null field'). A variable can be - an array element, with the subscripts being constant values. To + field does not exist, it prints `Null field'). A variable can be + an array element, with the subscripts being constant values. To print the contents of an array, prefix the name of the array with - the '@' symbol: + the `@' symbol: gawk> print @a This prints the indices and the corresponding values for all - elements in the array 'a'. + elements in the array `a'. -'printf' FORMAT [',' ARG ...] - Print formatted text. The FORMAT may include escape sequences, - such as '\n' (*note Escape Sequences::). No newline is printed +`printf' FORMAT [`,' ARG ...] + Print formatted text. The FORMAT may include escape sequences, + such as `\n' (*note Escape Sequences::). No newline is printed unless one is specified. -'set' VAR'='VALUE - Assign a constant (number or string) value to an 'awk' variable or +`set' VAR`='VALUE + Assign a constant (number or string) value to an `awk' variable or field. String values must be enclosed between double quotes - ('"'...'"'). + (`"'...`"'). - You can also set special 'awk' variables, such as 'FS', 'NF', 'NR', - etc. + You can also set special `awk' variables, such as `FS', `NF', + `NR', etc. -'watch' VAR | '$'N ['"EXPRESSION"'] -'w' VAR | '$'N ['"EXPRESSION"'] - Add variable VAR (or field '$N') to the watch list. The debugger +`watch' VAR | `$'N [`"EXPRESSION"'] +`w' VAR | `$'N [`"EXPRESSION"'] + Add variable VAR (or field `$N') to the watch list. The debugger then stops whenever the value of the variable or field changes. Each watched item is assigned a number which can be used to delete - it from the watch list using the 'unwatch' command. + it from the watch list using the `unwatch' command. With a watchpoint, you may also supply a condition. This is an - 'awk' expression (enclosed in double quotes) that the debugger - evaluates whenever the watchpoint is reached. If the condition is + `awk' expression (enclosed in double quotes) that the debugger + evaluates whenever the watchpoint is reached. If the condition is true, then the debugger stops execution and prompts for a command. - Otherwise, 'gawk' continues executing the program. + Otherwise, `gawk' continues executing the program. -'undisplay' [N] +`undisplay' [N] Remove item number N (or all items, if no argument) from the automatic display list. -'unwatch' [N] +`unwatch' [N] Remove item number N (or all items, if no argument) from the watch list. +  File: gawk.info, Node: Execution Stack, Next: Debugger Info, Prev: Viewing And Changing Data, Up: List of Debugger Commands 14.3.4 Dealing with the Stack ----------------------------- -Whenever you run a program which contains any function calls, 'gawk' +Whenever you run a program which contains any function calls, `gawk' maintains a stack of all of the function calls leading up to where the program is right now. You can see how you got to where you are, and also move around in the stack to see what the state of things was in the functions which called the one you are in. The commands for doing this are: -'backtrace' [COUNT] -'bt' [COUNT] +`backtrace' [COUNT] +`bt' [COUNT] Print a backtrace of all function calls (stack frames), or - innermost COUNT frames if COUNT > 0. Print the outermost COUNT - frames if COUNT < 0. The backtrace displays the name and arguments - to each function, the source file name, and the line number. + innermost COUNT frames if COUNT > 0. Print the outermost COUNT + frames if COUNT < 0. The backtrace displays the name and + arguments to each function, the source file name, and the line + number. -'down' [COUNT] +`down' [COUNT] Move COUNT (default 1) frames down the stack toward the innermost frame. Then select and print the frame. -'frame' [N] -'f' [N] +`frame' [N] +`f' [N] Select and print stack frame N. Frame 0 is the currently executing, or "innermost", frame (function call), frame 1 is the - frame that called the innermost one. The highest numbered frame is + frame that called the innermost one. The highest numbered frame is the one for the main program. The printed information consists of - the frame number, function and argument names, source file, and the - source line. + the frame number, function and argument names, source file, and + the source line. -'up' [COUNT] +`up' [COUNT] Move COUNT (default 1) frames up the stack toward the outermost frame. Then select and print the frame. @@ -22171,105 +21131,105 @@ File: gawk.info, Node: Debugger Info, Next: Miscellaneous Debugger Commands, Besides looking at the values of variables, there is often a need to get other sorts of information about the state of your program and of the -debugging environment itself. The 'gawk' debugger has one command which -provides this information, appropriately called 'info'. 'info' is used +debugging environment itself. The `gawk' debugger has one command which +provides this information, appropriately called `info'. `info' is used with one of a number of arguments that tell it exactly what you want to know: -'info' WHAT -'i' WHAT +`info' WHAT +`i' WHAT The value for WHAT should be one of the following: - 'args' + `args' Arguments of the selected frame. - 'break' + `break' List all currently set breakpoints. - 'display' + `display' List all items in the automatic display list. - 'frame' + `frame' Description of the selected stack frame. - 'functions' + `functions' List all function definitions including source file names and line numbers. - 'locals' + `locals' Local variables of the selected frame. - 'source' - The name of the current source file. Each time the program + `source' + The name of the current source file. Each time the program stops, the current source file is the file containing the current instruction. When the debugger first starts, the - current source file is the first file included via the '-f' - option. The 'list FILENAME:LINENO' command can be used at any + current source file is the first file included via the `-f' + option. The `list FILENAME:LINENO' command can be used at any time to change the current source. - 'sources' + `sources' List all program sources. - 'variables' + `variables' List all global variables. - 'watch' + `watch' List all items in the watch list. Additional commands give you control over the debugger, the ability to save the debugger's state, and the ability to run debugger commands from a file. The commands are: -'option' [NAME['='VALUE]] -'o' [NAME['='VALUE]] +`option' [NAME[`='VALUE]] +`o' [NAME[`='VALUE]] Without an argument, display the available debugger options and - their current values. 'option NAME' shows the current value of the - named option. 'option NAME=VALUE' assigns a new value to the named + their current values. `option NAME' shows the current value of the + named option. `option NAME=VALUE' assigns a new value to the named option. The available options are: - 'history_size' + `history_size' The maximum number of lines to keep in the history file - './.gawk_history'. The default is 100. + `./.gawk_history'. The default is 100. - 'listsize' - The number of lines that 'list' prints. The default is 15. + `listsize' + The number of lines that `list' prints. The default is 15. - 'outfile' - Send 'gawk' output to a file; debugger output still goes to - standard output. An empty string ('""') resets output to + `outfile' + Send `gawk' output to a file; debugger output still goes to + standard output. An empty string (`""') resets output to standard output. - 'prompt' - The debugger prompt. The default is 'gawk> '. + `prompt' + The debugger prompt. The default is `gawk> '. - 'save_history' ['on' | 'off'] - Save command history to file './.gawk_history'. The default - is 'on'. + `save_history' [`on' | `off'] + Save command history to file `./.gawk_history'. The default + is `on'. - 'save_options' ['on' | 'off'] - Save current options to file './.gawkrc' upon exit. The - default is 'on'. Options are read back in to the next session - upon startup. + `save_options' [`on' | `off'] + Save current options to file `./.gawkrc' upon exit. The + default is `on'. Options are read back in to the next + session upon startup. - 'trace' ['on' | 'off'] - Turn instruction tracing on or off. The default is 'off'. + `trace' [`on' | `off'] + Turn instruction tracing on or off. The default is `off'. -'save' FILENAME +`save' FILENAME Save the commands from the current session to the given file name, - so that they can be replayed using the 'source' command. + so that they can be replayed using the `source' command. -'source' FILENAME +`source' FILENAME Run command(s) from a file; an error in any command does not - terminate execution of subsequent commands. Comments (lines - starting with '#') are allowed in a command file. Empty lines are + terminate execution of subsequent commands. Comments (lines + starting with `#') are allowed in a command file. Empty lines are ignored; they do _not_ repeat the last command. You can't restart - the program by having more than one 'run' command in the file. - Also, the list of commands may include additional 'source' - commands; however, the 'gawk' debugger will not source the same + the program by having more than one `run' command in the file. + Also, the list of commands may include additional `source' + commands; however, the `gawk' debugger will not source the same file more than once in order to avoid infinite recursion. - In addition to, or instead of the 'source' command, you can use the - '-D FILE' or '--debug=FILE' command-line options to execute + In addition to, or instead of the `source' command, you can use + the `-D FILE' or `--debug=FILE' command-line options to execute commands from a file non-interactively (*note Options::).  @@ -22281,10 +21241,10 @@ File: gawk.info, Node: Miscellaneous Debugger Commands, Prev: Debugger Info, There are a few more commands which do not fit into the previous categories, as follows: -'dump' [FILENAME] +`dump' [FILENAME] Dump bytecode of the program to standard output or to the file named in FILENAME. This prints a representation of the internal - instructions which 'gawk' executes to implement the 'awk' commands + instructions which `gawk' executes to implement the `awk' commands in a program. This can be very enlightening, as the following partial dump of Davide Brini's obfuscated code (*note Signature Program::) demonstrates: @@ -22338,56 +21298,57 @@ categories, as follows: -| [ :0xfcc1a0] Op_after_endfile : gawk> -'help' -'h' - Print a list of all of the 'gawk' debugger commands with a short - summary of their usage. 'help COMMAND' prints the information +`help' +`h' + Print a list of all of the `gawk' debugger commands with a short + summary of their usage. `help COMMAND' prints the information about the command COMMAND. -'list' ['-' | '+' | N | FILENAME':'N | N-M | FUNCTION] -'l' ['-' | '+' | N | FILENAME':'N | N-M | FUNCTION] +`list' [`-' | `+' | N | FILENAME`:'N | N-M | FUNCTION] +`l' [`-' | `+' | N | FILENAME`:'N | N-M | FUNCTION] Print the specified lines (default 15) from the current source file - or the file named FILENAME. The possible arguments to 'list' are + or the file named FILENAME. The possible arguments to `list' are as follows: - '-' + `-' Print lines before the lines last printed. - '+' - Print lines after the lines last printed. 'list' without any + `+' + Print lines after the lines last printed. `list' without any argument does the same thing. - N + N Print lines centered around line number N. - N-M + N-M Print lines from N to M. - FILENAME':'N + FILENAME`:'N Print lines centered around line number N in source file - FILENAME. This command may change the current source file. + FILENAME. This command may change the current source file. - FUNCTION + FUNCTION Print lines centered around beginning of the function - FUNCTION. This command may change the current source file. + FUNCTION. This command may change the current source file. -'quit' -'q' +`quit' +`q' Exit the debugger. Debugging is great fun, but sometimes we all have to tend to other obligations in life, and sometimes we find the bug, and are free to go on to the next one! As we saw above, if you are running a program, the debugger warns you if you - accidentally type 'q' or 'quit', to make sure you really want to + accidentally type `q' or `quit', to make sure you really want to quit. -'trace' ['on' | 'off'] +`trace' [`on' | `off'] Turn on or off a continuous printing of instructions which are - about to be executed, along with printing the 'awk' line which they - implement. The default is 'off'. + about to be executed, along with printing the `awk' line which they + implement. The default is `off'. It is to be hoped that most of the "opcodes" in these instructions - are fairly self-explanatory, and using 'stepi' and 'nexti' while - 'trace' is on will make them into familiar friends. + are fairly self-explanatory, and using `stepi' and `nexti' while + `trace' is on will make them into familiar friends. +  File: gawk.info, Node: Readline Support, Next: Limitations, Prev: List of Debugger Commands, Up: Debugger @@ -22395,26 +21356,27 @@ File: gawk.info, Node: Readline Support, Next: Limitations, Prev: List of Deb 14.4 Readline Support ===================== -If 'gawk' is compiled with the 'readline' library +If `gawk' is compiled with the `readline' library (http://cnswww.cns.cwru.edu/php/chet/readline/readline.html), you can take advantage of that library's command completion and history -expansion features. The following types of completion are available: +expansion features. The following types of completion are available: Command completion Command names. Source file name completion - Source file names. Relevant commands are 'break', 'clear', 'list', - 'tbreak', and 'until'. + Source file names. Relevant commands are `break', `clear', `list', + `tbreak', and `until'. Argument completion - Non-numeric arguments to a command. Relevant commands are 'enable' - and 'info'. + Non-numeric arguments to a command. Relevant commands are + `enable' and `info'. Variable name completion Global variable names, and function arguments in the current - context if the program is running. Relevant commands are - 'display', 'print', 'set', and 'watch'. + context if the program is running. Relevant commands are `display', + `print', `set', and `watch'. +  File: gawk.info, Node: Limitations, Next: Debugging Summary, Prev: Readline Support, Up: Debugger @@ -22422,45 +21384,41 @@ File: gawk.info, Node: Limitations, Next: Debugging Summary, Prev: Readline S 14.5 Limitations and Future Plans ================================= -We hope you find the 'gawk' debugger useful and enjoyable to work with, +We hope you find the `gawk' debugger useful and enjoyable to work with, but as with any program, especially in its early releases, it still has some limitations. A few which are worth being aware of are: * At this point, the debugger does not give a detailed explanation of what you did wrong when you type in something it doesn't like. - Rather, it just responds 'syntax error'. When you do figure out + Rather, it just responds `syntax error'. When you do figure out what your mistake was, though, you'll feel like a real guru. * If you perused the dump of opcodes in *note Miscellaneous Debugger -<<<<<<< HEAD - Commands::, (or if you are already familiar with 'gawk' internals), -======= Commands:: (or if you are already familiar with `gawk' internals), ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac you will realize that much of the internal manipulation of data in - 'gawk', as in many interpreters, is done on a stack. 'Op_push', - 'Op_pop', etc., are the "bread and butter" of most 'gawk' code. + `gawk', as in many interpreters, is done on a stack. `Op_push', + `Op_pop', etc., are the "bread and butter" of most `gawk' code. - Unfortunately, as of now, the 'gawk' debugger does not allow you to - examine the stack's contents. That is, the intermediate results of - expression evaluation are on the stack, but cannot be printed. - Rather, only variables which are defined in the program can be - printed. Of course, a workaround for this is to use more explicit - variables at the debugging stage and then change back to obscure, - perhaps more optimal code later. + Unfortunately, as of now, the `gawk' debugger does not allow you + to examine the stack's contents. That is, the intermediate + results of expression evaluation are on the stack, but cannot be + printed. Rather, only variables which are defined in the program + can be printed. Of course, a workaround for this is to use more + explicit variables at the debugging stage and then change back to + obscure, perhaps more optimal code later. * There is no way to look "inside" the process of compiling regular - expressions to see if you got it right. As an 'awk' programmer, - you are expected to know what '/[^[:alnum:][:blank:]]/' means. + expressions to see if you got it right. As an `awk' programmer, + you are expected to know what `/[^[:alnum:][:blank:]]/' means. - * The 'gawk' debugger is designed to be used by running a program + * The `gawk' debugger is designed to be used by running a program (with all its parameters) on the command line, as described in - *note Debugger Invocation::. There is no way (as of now) to attach - or "break in" to a running program. This seems reasonable for a - language which is used mainly for quickly executing, short + *note Debugger Invocation::. There is no way (as of now) to + attach or "break in" to a running program. This seems reasonable + for a language which is used mainly for quickly executing, short programs. - * The 'gawk' debugger only accepts source supplied with the '-f' + * The `gawk' debugger only accepts source supplied with the `-f' option. Look forward to a future release when these and other missing @@ -22474,48 +21432,43 @@ File: gawk.info, Node: Debugging Summary, Prev: Limitations, Up: Debugger ============ * Programs rarely work correctly the first time. Finding bugs is - "debugging" and a program that helps you find bugs is a "debugger". - 'gawk' has a built-in debugger that works very similarly to the GNU - Debugger, GDB. + "debugging" and a program that helps you find bugs is a + "debugger". `gawk' has a built-in debugger that works very + similarly to the GNU Debugger, GDB. * Debuggers let you step through your program one statement at a -<<<<<<< HEAD - time, examine and change variable and array values, and do a number - of other things that let understand what your program is actually - doing (as opposed to what it is supposed to do). -======= time, examine and change variable and array values, and do a number of other things that let you understand what your program is actually doing (as opposed to what it is supposed to do). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - * Like most debuggers, the 'gawk' debugger works in terms of stack + * Like most debuggers, the `gawk' debugger works in terms of stack frames, and lets you set both breakpoints (stop at a point in the code) and watchpoints (stop when a data value changes). * The debugger command set is fairly complete, providing control over - breakpoints, execution, viewing and changing data, working with the - stack, getting information, and other tasks. + breakpoints, execution, viewing and changing data, working with + the stack, getting information, and other tasks. - * If the 'readline' library is available when 'gawk' is compiled, it + * If the `readline' library is available when `gawk' is compiled, it is used by the debugger to provide command-line history and editing. +  File: gawk.info, Node: Arbitrary Precision Arithmetic, Next: Dynamic Extensions, Prev: Debugger, Up: Top -15 Arithmetic and Arbitrary Precision Arithmetic with 'gawk' +15 Arithmetic and Arbitrary Precision Arithmetic with `gawk' ************************************************************ -This major node introduces some basic concepts relating to how computers -do arithmetic and briefly lists the features in 'gawk' for performing -arbitrary precision floating point computations. It then proceeds to -describe floating-point arithmetic, which is what 'awk' uses for all its -computations, including a discussion of arbitrary precision floating -point arithmetic, which is a feature available only in 'gawk'. It -continues on to present arbitrary precision integers, and concludes with -a description of some points where 'gawk' and the POSIX standard are not -quite in agreement. +This major node introduces some basic concepts relating to how +computers do arithmetic and briefly lists the features in `gawk' for +performing arbitrary precision floating point computations. It then +proceeds to describe floating-point arithmetic, which is what `awk' +uses for all its computations, including a discussion of arbitrary +precision floating point arithmetic, which is a feature available only +in `gawk'. It continues on to present arbitrary precision integers, and +concludes with a description of some points where `gawk' and the POSIX +standard are not quite in agreement. NOTE: Most users of `gawk' can safely skip this chapter. But if you want to do scientific calculations with `gawk', this is the @@ -22525,10 +21478,10 @@ quite in agreement. * Computer Arithmetic:: A quick intro to computer math. * Math Definitions:: Defining terms used. -* MPFR features:: The MPFR features in 'gawk'. +* MPFR features:: The MPFR features in `gawk'. * FP Math Caution:: Things to know. * Arbitrary Precision Integers:: Arbitrary Precision Integer Arithmetic with - 'gawk'. + `gawk'. * POSIX Floating Point Problems:: Standards Versus Existing Practice. * Floating point summary:: Summary of floating point discussion. @@ -22554,7 +21507,7 @@ that interest us are: Decimal arithmetic This is the kind of arithmetic you learned in elementary school, - using paper and pencil (and/or a calculator). In theory, numbers + using paper and pencil (and/or a calculator). In theory, numbers can have an arbitrary number of digits on either side (or both sides) of the decimal point, and the results of a computation are always exact. @@ -22564,7 +21517,7 @@ Decimal arithmetic these instructions. There are also libraries that do decimal arithmetic entirely in software. - Despite the fact that some users expect 'gawk' to be performing + Despite the fact that some users expect `gawk' to be performing decimal arithmetic,(1) it does not do so. Integer arithmetic @@ -22579,48 +21532,45 @@ Integer arithmetic to zero). In computer systems, integer arithmetic is exact, but the possible - range of values is limited. Integer arithmetic is generally faster - than floating point arithmetic. + range of values is limited. Integer arithmetic is generally + faster than floating point arithmetic. Floating point arithmetic Floating-point numbers represent what were called in school "real" numbers; i.e., those that have a fractional part, such as 3.1415927. The advantage to floating-point numbers is that they - can represent a much larger range of values than can integers. The - disadvantage is that there are numbers that they cannot represent - exactly. + can represent a much larger range of values than can integers. + The disadvantage is that there are numbers that they cannot + represent exactly. Modern systems support floating point arithmetic in hardware, with a limited range of values. There are software libraries that allow the use of arbitrary precision floating point calculations. - POSIX 'awk' uses "double precision" floating-point numbers, which + POSIX `awk' uses "double precision" floating-point numbers, which can hold more digits than "single precision" floating-point - numbers. 'gawk' has facilities for performing arbitrary precision + numbers. `gawk' has facilities for performing arbitrary precision floating point arithmetic, which we describe in more detail shortly. Computers work with integer and floating point values of different -ranges. Integer values are usually either 32 or 64 bits in size. -Single precision floating point values occupy 32 bits, whereas double -precision floating point values occupy 64 bits. Floating point values -are always signed. The possible ranges of values are shown in the -following table. +ranges. Integer values are usually either 32 or 64 bits in size. Single +precision floating point values occupy 32 bits, whereas double precision +floating point values occupy 64 bits. Floating point values are always +signed. The possible ranges of values are shown in the following table. Numeric representation Miniumum value Maximum value ---------------------------------------------------------------------------- +--------------------------------------------------------------------------- 32-bit signed integer -2,147,483,648 2,147,483,647 -32-bit unsigned 0 4,294,967,295 -integer +32-bit unsigned integer 0 4,294,967,295 64-bit signed integer -9,223,372,036,854,775,8089,223,372,036,854,775,807 -64-bit unsigned 0 18,446,744,073,709,551,615 -integer -Single precision '1.175494e-38' '3.402823e+38' -floating point -(approximate) -Double precision '2.225074e-308' '1.797693e+308' -floating point -(approximate) +64-bit unsigned integer 0 18,446,744,073,709,551,615 +Single precision `1.175494e-38' `3.402823e+38' +floating point +(approximate) +Double precision `2.225074e-308' `1.797693e+308' +floating point +(approximate) ---------- Footnotes ---------- @@ -22632,7 +21582,7 @@ File: gawk.info, Node: Math Definitions, Next: MPFR features, Prev: Computer 15.2 Other Stuff To Know ======================== -The rest of this major node uses a number of terms. Here are some +The rest of this major node uses a number of terms. Here are some informal definitions that should help you work your way through the material here. @@ -22650,15 +21600,10 @@ material here. floating-point value store the exponent. "Inf" - A special value representing infinity. Operations involving - another number and infinity produce infinity. + A special value representing infinity. Operations involving another + number and infinity produce infinity. "NaN" -<<<<<<< HEAD - "Not A Number." A special value indicating a result that can't - happen in real math, but that can happen in floating-point - computations. -======= "Not A Number."(1). A special value that results from attempting a calculation that has no answer as a real number. In such a case, programs can either receive a floating-point exception, or get @@ -22671,13 +21616,12 @@ material here. `log(-8)' -8 is out of the domain of `log()', so the result is `NaN'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac "Normalized" - How the significand (see later in this list) is usually stored. - The value is adjusted so that the first bit is one, and then that - leading one is assumed instead of physically stored. This provides - one extra bit of precision. + How the significand (see later in this list) is usually stored. The + value is adjusted so that the first bit is one, and then that + leading one is assumed instead of physically stored. This + provides one extra bit of precision. "Precision" The number of bits used to represent a floating-point number. The @@ -22694,9 +21638,9 @@ material here. are provided later. "Significand" - A floating point value consists the significand multiplied by 10 to - the power of the exponent. For example, in '1.2345e67', the - significand is '1.2345'. + A floating point value consists the significand multiplied by 10 + to the power of the exponent. For example, in `1.2345e67', the + significand is `1.2345'. "Stability" From the Wikipedia article on numerical stability @@ -22713,13 +21657,13 @@ and operations defined by the IEEE 754 standard. Three of the standard IEEE 754 types are 32-bit single precision, 64-bit double precision and 128-bit quadruple precision. The standard also specifies extended precision formats to allow greater precisions and larger exponent -ranges. ('awk' uses only the 64-bit double precision format.) +ranges. (`awk' uses only the 64-bit double precision format.) - *note Table 15.1: table-ieee-formats. lists the precision and -exponent field values for the basic IEEE 754 binary formats: + *note table-ieee-formats:: lists the precision and exponent field +values for the basic IEEE 754 binary formats: Name Total bits Precision emin emax ---------------------------------------------------------------------------- +--------------------------------------------------------------------------- Single 32 24 -126 +127 Double 64 53 -1022 +1023 Quadruple 128 113 -16382 +16383 @@ -22737,12 +21681,12 @@ paraphrased, and for the examples  File: gawk.info, Node: MPFR features, Next: FP Math Caution, Prev: Math Definitions, Up: Arbitrary Precision Arithmetic -15.3 Arbitrary Precison Arithmetic Features In 'gawk' +15.3 Arbitrary Precison Arithmetic Features In `gawk' ===================================================== -By default, 'gawk' uses the double precision floating point values +By default, `gawk' uses the double precision floating point values supplied by the hardware of the system it runs on. However, if it was -compiled to do, 'gawk' uses the GNU MPFR (http://www.mpfr.org) and GNU +compiled to do, `gawk' uses the GNU MPFR (http://www.mpfr.org) and GNU MP (http://gmplib.org) (GMP) libraries for arbitrary precision arithmetic on numbers. You can see if MPFR support is available like so: @@ -22752,28 +21696,21 @@ so: -| Copyright (C) 1989, 1991-2014 Free Software Foundation. ... -(You may see different version numbers than what's shown here. That's +(You may see different version numbers than what's shown here. That's OK; what's important is to see that GNU MPFR and GNU MP are listed in the output.) - Additionally, there are a few elements available in the 'PROCINFO' + Additionally, there are a few elements available in the `PROCINFO' array to provide information about the MPFR and GMP libraries (*note Auto-set::). The MPFR library provides precise control over precisions and rounding modes, and gives correctly rounded, reproducible, -<<<<<<< HEAD -platform-independent results. With either of the command-line options -'--bignum' or '-M', all floating-point arithmetic operators and numeric -functions can yield results to any desired precision level supported by -MPFR. -======= platform-independent results. With the `-M' command-line option, all floating-point arithmetic operators and numeric functions can yield results to any desired precision level supported by MPFR. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - Two built-in variables, 'PREC' and 'ROUNDMODE', provide control over + Two built-in variables, `PREC' and `ROUNDMODE', provide control over the working precision and the rounding mode. The precision and the rounding mode are set globally for every operation to follow. *Note Auto-set::, for more information. @@ -22784,20 +21721,16 @@ File: gawk.info, Node: FP Math Caution, Next: Arbitrary Precision Integers, P 15.4 Floating Point Arithmetic: Caveat Emptor! ============================================== -<<<<<<< HEAD - Math class is tough! - -- _Late 1980's Barbie_ -======= Math class is tough! -- Teen Talk Barbie, July 1992 ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - This minor node provides a high level overview of the issues involved -when doing lots of floating-point arithmetic.(1) The discussion applies -to both hardware and arbitrary-precision floating-point arithmetic. + This minor node provides a high level overview of the issues +involved when doing lots of floating-point arithmetic.(1) The +discussion applies to both hardware and arbitrary-precision +floating-point arithmetic. - CAUTION: The material here is purposely general. If you need to do - serious computer arithmetic, you should do some research first, and - not rely just on what we tell you. + CAUTION: The material here is purposely general. If you need to do + serious computer arithmetic, you should do some research first, + and not rely just on what we tell you. * Menu: @@ -22812,7 +21745,7 @@ to both hardware and arbitrary-precision floating-point arithmetic. (1) There is a very nice paper on floating-point arithmetic (http://www.validlab.com/goldberg/paper.pdf) by David Goldberg, "What Every Computer Scientist Should Know About Floating-point Arithmetic," -'ACM Computing Surveys' *23*, 1 (1991-03), 5-48. This is worth reading +`ACM Computing Surveys' *23*, 1 (1991-03), 5-48. This is worth reading if you are interested in the details, but it does require a background in computer science. @@ -22826,7 +21759,7 @@ Binary floating-point representations and arithmetic are inexact. Simple values like 0.1 cannot be precisely represented using binary floating-point numbers, and the limited precision of floating-point numbers means that slight changes in the order of operations or the -precision of intermediate storage can change the result. To make +precision of intermediate storage can change the result. To make matters worse, with arbitrary precision floating-point, you can set the precision before starting a computation, but then you cannot be sure of the number of significant decimal places in the final result. @@ -22844,20 +21777,20 @@ File: gawk.info, Node: Inexact representation, Next: Comparing FP Values, Up: ................................................... So, before you start to write any code, you should think about what you -really want and what's really happening. Consider the two numbers in +really want and what's really happening. Consider the two numbers in the following example: x = 0.875 # 1/2 + 1/4 + 1/8 y = 0.425 - Unlike the number in 'y', the number stored in 'x' is exactly + Unlike the number in `y', the number stored in `x' is exactly representable in binary since it can be written as a finite sum of one -or more fractions whose denominators are all powers of two. When 'gawk' -reads a floating-point number from program source, it automatically -rounds that number to whatever precision your machine supports. If you -try to print the numeric content of a variable using an output format -string of '"%.17g"', it may not produce the same number as you assigned -to it: +or more fractions whose denominators are all powers of two. When +`gawk' reads a floating-point number from program source, it +automatically rounds that number to whatever precision your machine +supports. If you try to print the numeric content of a variable using +an output format string of `"%.17g"', it may not produce the same +number as you assigned to it: $ gawk 'BEGIN { x = 0.875; y = 0.425 > printf("%0.17g, %0.17g\n", x, y) }' @@ -22865,7 +21798,7 @@ to it: Often the error is so small you do not even notice it, and if you do, you can always specify how much precision you would like in your output. -Usually this is a format string like '"%.15g"', which when used in the +Usually this is a format string like `"%.15g"', which when used in the previous example, produces an output identical to the input.  @@ -22884,8 +21817,8 @@ work like you would expect: The general wisdom when comparing floating-point values is to see if they are within some small range of each other (called a "delta", or -"tolerance"). You have to decide how small a delta is important to you. -Code to do this looks something like this: +"tolerance"). You have to decide how small a delta is important to +you. Code to do this looks something like this: delta = 0.00001 # for example difference = abs(a) - abs(b) # subtract the two values @@ -22901,7 +21834,7 @@ File: gawk.info, Node: Errors accumulate, Prev: Comparing FP Values, Up: Inex .......................... The loss of accuracy during a single computation with floating-point -numbers usually isn't enough to worry about. However, if you compute a +numbers usually isn't enough to worry about. However, if you compute a value which is the result of a sequence of floating point operations, the error can accumulate and greatly affect the computation itself. Here is an attempt to compute the value of pi using one of its many @@ -22930,7 +21863,7 @@ zero: -| 3.224515243534819 -| 2.791117213058638 -| 0.000000000000000 - error-> gawk: pi.awk:6: fatal: division by zero attempted + error--> gawk: pi.awk:6: fatal: division by zero attempted Here is an additional example where the inaccuracies in internal representations yield an unexpected result: @@ -22948,14 +21881,14 @@ File: gawk.info, Node: Getting Accuracy, Next: Try To Round, Prev: Inexactnes 15.4.2 Getting The Accuracy You Need ------------------------------------ -Can arbitrary precision arithmetic give exact results? There are no -easy answers. The standard rules of algebra often do not apply when +Can arbitrary precision arithmetic give exact results? There are no +easy answers. The standard rules of algebra often do not apply when using floating-point arithmetic. Among other things, the distributive and associative laws do not hold completely, and order of operation may -be important for your computation. Rounding error, cumulative precision +be important for your computation. Rounding error, cumulative precision loss and underflow are often troublesome. - When 'gawk' tests the expressions '0.1 + 12.2' and '12.3' for + When `gawk' tests the expressions `0.1 + 12.2' and `12.3' for equality using the machine double precision arithmetic, it decides that they are not equal! (*Note Comparing FP Values::.) You can get the result you want by increasing the precision; 56 bits in this case does @@ -22966,18 +21899,18 @@ the job: If adding more bits is good, perhaps adding even more bits of precision is better? Here is what happens if we use an even larger -value of 'PREC': +value of `PREC': $ gawk -M -v PREC=201 'BEGIN { print (0.1 + 12.2 == 12.3) }' -| 0 - This is not a bug in 'gawk' or in the MPFR library. It is easy to + This is not a bug in `gawk' or in the MPFR library. It is easy to forget that the finite number of bits used to store the value is often just an approximation after proper rounding. The test for equality succeeds if and only if _all_ bits in the two operands are exactly the -same. Since this is not necessarily true after floating-point +same. Since this is not necessarily true after floating-point computations with a particular precision and effective rounding rule, a -straight test for equality may not work. Instead, compare the two +straight test for equality may not work. Instead, compare the two numbers to see if they are within the desirable delta of each other. In applications where 15 or fewer decimal places suffice, hardware @@ -22989,7 +21922,7 @@ precision can greatly enhance the stability and the accuracy of your computation in such cases. Repeated addition is not necessarily equivalent to multiplication in -floating-point arithmetic. In the example in *note Errors accumulate::: +floating-point arithmetic. In the example in *note Errors accumulate::: $ gawk 'BEGIN { > for (d = 1.1; d <= 1.5; d += 0.1) # loop five times (?) @@ -22999,7 +21932,7 @@ floating-point arithmetic. In the example in *note Errors accumulate::: -| 4 you may or may not succeed in getting the correct result by choosing an -arbitrarily large value for 'PREC'. Reformulation of the problem at +arbitrarily large value for `PREC'. Reformulation of the problem at hand is often the correct approach in such situations.  @@ -23035,24 +21968,24 @@ File: gawk.info, Node: Setting precision, Next: Setting the rounding mode, Pr 15.4.4 Setting The Precision ---------------------------- -'gawk' uses a global working precision; it does not keep track of the -precision or accuracy of individual numbers. Performing an arithmetic +`gawk' uses a global working precision; it does not keep track of the +precision or accuracy of individual numbers. Performing an arithmetic operation or calling a built-in function rounds the result to the -current working precision. The default working precision is 53 bits, -which you can modify using the built-in variable 'PREC'. You can also -set the value to one of the predefined case-insensitive strings shown in -*note Table 15.2: table-predefined-precision-strings, to emulate an IEEE -754 binary format. - -'PREC' IEEE 754 Binary Format ---------------------------------------------------- -'"half"' 16-bit half-precision. -'"single"' Basic 32-bit single precision. -'"double"' Basic 64-bit double precision. -'"quad"' Basic 128-bit quadruple precision. -'"oct"' 256-bit octuple precision. - -Table 15.2: Predefined Precision Strings For 'PREC' +current working precision. The default working precision is 53 bits, +which you can modify using the built-in variable `PREC'. You can also +set the value to one of the predefined case-insensitive strings shown +in *note table-predefined-precision-strings::, to emulate an IEEE 754 +binary format. + +`PREC' IEEE 754 Binary Format +--------------------------------------------------- +`"half"' 16-bit half-precision. +`"single"' Basic 32-bit single precision. +`"double"' Basic 64-bit double precision. +`"quad"' Basic 128-bit quadruple precision. +`"oct"' 256-bit octuple precision. + +Table 15.2: Predefined Precision Strings For `PREC' The following example illustrates the effects of changing precision on arithmetic operations: @@ -23062,26 +21995,19 @@ on arithmetic operations: -| 1e-400 -| 0 - CAUTION: Be wary of floating-point constants! When reading a - floating-point constant from program source code, 'gawk' uses the - default precision (that of a C 'double'), unless overridden by an - assignment to the special variable 'PREC' on the command line, to - store it internally as a MPFR number. Changing the precision using - 'PREC' in the program text does _not_ change the precision of a - constant. + CAUTION: Be wary of floating-point constants! When reading a + floating-point constant from program source code, `gawk' uses the + default precision (that of a C `double'), unless overridden by an + assignment to the special variable `PREC' on the command line, to + store it internally as a MPFR number. Changing the precision + using `PREC' in the program text does _not_ change the precision + of a constant. If you need to represent a floating-point constant at a higher -<<<<<<< HEAD - precision than the default and cannot use a command line assignment - to 'PREC', you should either specify the constant as a string, or - as a rational number, whenever possible. The following example - illustrates the differences among various ways to print a -======= precision than the default and cannot use a command-line assignment to `PREC', you should either specify the constant as a string, or as a rational number, whenever possible. The following example illustrates the differences among various ways to print a ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac floating-point constant: $ gawk -M 'BEGIN { PREC = 113; printf("%0.25f\n", 0.1) }' @@ -23099,39 +22025,39 @@ File: gawk.info, Node: Setting the rounding mode, Prev: Setting precision, Up 15.4.5 Setting The Rounding Mode -------------------------------- -The 'ROUNDMODE' variable provides program level control over the -rounding mode. The correspondence between 'ROUNDMODE' and the IEEE -rounding modes is shown in *note Table 15.3: table-gawk-rounding-modes. +The `ROUNDMODE' variable provides program level control over the +rounding mode. The correspondence between `ROUNDMODE' and the IEEE +rounding modes is shown in *note table-gawk-rounding-modes::. -Rounding Mode IEEE Name 'ROUNDMODE' ---------------------------------------------------------------------------- -Round to nearest, ties to even 'roundTiesToEven' '"N"' or '"n"' -Round toward plus Infinity 'roundTowardPositive' '"U"' or '"u"' -Round toward negative Infinity 'roundTowardNegative' '"D"' or '"d"' -Round toward zero 'roundTowardZero' '"Z"' or '"z"' -Round to nearest, ties away 'roundTiesToAway' '"A"' or '"a"' -from zero +Rounding Mode IEEE Name `ROUNDMODE' +--------------------------------------------------------------------------- +Round to nearest, ties to even `roundTiesToEven' `"N"' or `"n"' +Round toward plus Infinity `roundTowardPositive' `"U"' or `"u"' +Round toward negative Infinity `roundTowardNegative' `"D"' or `"d"' +Round toward zero `roundTowardZero' `"Z"' or `"z"' +Round to nearest, ties away `roundTiesToAway' `"A"' or `"a"' +from zero -Table 15.3: 'gawk' Rounding Modes +Table 15.3: `gawk' Rounding Modes - 'ROUNDMODE' has the default value '"N"', which selects the IEEE 754 -rounding mode 'roundTiesToEven'. In *note Table 15.3: -table-gawk-rounding-modes, the value '"A"' selects 'roundTiesToAway'. + `ROUNDMODE' has the default value `"N"', which selects the IEEE 754 +rounding mode `roundTiesToEven'. In *note Table 15.3: +table-gawk-rounding-modes, the value `"A"' selects `roundTiesToAway'. This is only available if your version of the MPFR library supports it; -otherwise setting 'ROUNDMODE' to '"A"' has no effect. +otherwise setting `ROUNDMODE' to `"A"' has no effect. - The default mode 'roundTiesToEven' is the most preferred, but the -least intuitive. This method does the obvious thing for most values, by + The default mode `roundTiesToEven' is the most preferred, but the +least intuitive. This method does the obvious thing for most values, by rounding them up or down to the nearest digit. For example, rounding 1.132 to two digits yields 1.13, and rounding 1.157 yields 1.16. However, when it comes to rounding a value that is exactly halfway between, things do not work the way you probably learned in school. In -this case, the number is rounded to the nearest even digit. So rounding -0.125 to two digits rounds down to 0.12, but rounding 0.6875 to three -digits rounds up to 0.688. You probably have already encountered this -rounding mode when using 'printf' to format floating-point numbers. For -example: +this case, the number is rounded to the nearest even digit. So +rounding 0.125 to two digits rounds down to 0.12, but rounding 0.6875 +to three digits rounds up to 0.688. You probably have already +encountered this rounding mode when using `printf' to format +floating-point numbers. For example: BEGIN { x = -4.5 @@ -23153,52 +22079,42 @@ produces the following output when run on the author's system:(1) 3.5 => 4 4.5 => 4 - The theory behind 'roundTiesToEven' is that it more or less evenly + The theory behind `roundTiesToEven' is that it more or less evenly distributes upward and downward rounds of exact halves, which might -cause any accumulating round-off error to cancel itself out. This is -the default rounding mode for IEEE 754 computing functions and -operators. +cause any accumulating round-off error to cancel itself out. This is the +default rounding mode for IEEE 754 computing functions and operators. The other rounding modes are rarely used. Round toward positive -infinity ('roundTowardPositive') and round toward negative infinity -('roundTowardNegative') are often used to implement interval arithmetic, -where you adjust the rounding mode to calculate upper and lower bounds -for the range of output. The 'roundTowardZero' mode can be used for -converting floating-point numbers to integers. The rounding mode -'roundTiesToAway' rounds the result to the nearest number and selects -the number with the larger magnitude if a tie occurs. +infinity (`roundTowardPositive') and round toward negative infinity +(`roundTowardNegative') are often used to implement interval +arithmetic, where you adjust the rounding mode to calculate upper and +lower bounds for the range of output. The `roundTowardZero' mode can be +used for converting floating-point numbers to integers. The rounding +mode `roundTiesToAway' rounds the result to the nearest number and +selects the number with the larger magnitude if a tie occurs. Some numerical analysts will tell you that your choice of rounding -style has tremendous impact on the final outcome, and advise you to wait -until final output for any rounding. Instead, you can often avoid +style has tremendous impact on the final outcome, and advise you to +wait until final output for any rounding. Instead, you can often avoid round-off error problems by setting the precision initially to some value sufficiently larger than the final desired precision, so that the accumulation of round-off error does not influence the outcome. If you -suspect that results from your computation are sensitive to accumulation -of round-off error, look for a significant difference in output when you -change the rounding mode to be sure. +suspect that results from your computation are sensitive to +accumulation of round-off error, look for a significant difference in +output when you change the rounding mode to be sure. ---------- Footnotes ---------- - (1) It is possible for the output to be completely different if the C -library in your system does not use the IEEE 754 even-rounding rule to -round halfway cases for 'printf'. + (1) It is possible for the output to be completely different if the +C library in your system does not use the IEEE 754 even-rounding rule +to round halfway cases for `printf'.  File: gawk.info, Node: Arbitrary Precision Integers, Next: POSIX Floating Point Problems, Prev: FP Math Caution, Up: Arbitrary Precision Arithmetic -15.5 Arbitrary Precision Integer Arithmetic with 'gawk' +15.5 Arbitrary Precision Integer Arithmetic with `gawk' ======================================================= -<<<<<<< HEAD -When given one of the options '--bignum' or '-M', 'gawk' performs all -integer arithmetic using GMP arbitrary precision integers. Any number -that looks like an integer in a source or data file is stored as an -arbitrary precision integer. The size of the integer is limited only by -the available memory. For example, the following computes 5^4^3^2, the -result of which is beyond the limits of ordinary hardware -double-precision floating point values: -======= When given the `-M' option, `gawk' performs all integer arithmetic using GMP arbitrary precision integers. Any number that looks like an integer in a source or data file is stored as an arbitrary precision @@ -23206,7 +22122,6 @@ integer. The size of the integer is limited only by the available memory. For example, the following computes 5^4^3^2, the result of which is beyond the limits of ordinary hardware double-precision floating point values: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac $ gawk -M 'BEGIN { > x = 5^4^3^2 @@ -23217,14 +22132,14 @@ floating point values: -| 62060698786608744707 ... 92256259918212890625 If instead you were to compute the same value using arbitrary -precision floating-point values, the precision needed for correct output -(using the formula 'prec = 3.322 * dps'), would be 3.322 x 183231, or -608693. +precision floating-point values, the precision needed for correct +output (using the formula `prec = 3.322 * dps'), would be 3.322 x +183231, or 608693. The result from an arithmetic operation with an integer and a -floating-point value is a floating-point value with a precision equal to -the working precision. The following program calculates the eighth term -in Sylvester's sequence(1) using a recurrence: +floating-point value is a floating-point value with a precision equal +to the working precision. The following program calculates the eighth +term in Sylvester's sequence(1) using a recurrence: $ gawk -M 'BEGIN { > s = 2.0 @@ -23235,13 +22150,14 @@ in Sylvester's sequence(1) using a recurrence: -| 113423713055421845118910464 The output differs from the actual number, -113,423,713,055,421,844,361,000,443, because the default precision of 53 -bits is not enough to represent the floating-point results exactly. You -can either increase the precision (100 bits is enough in this case), or -replace the floating-point constant '2.0' with an integer, to perform -all computations using integer arithmetic to get the correct output. - - Sometimes 'gawk' must implicitly convert an arbitrary precision +113,423,713,055,421,844,361,000,443, because the default precision of +53 bits is not enough to represent the floating-point results exactly. +You can either increase the precision (100 bits is enough in this +case), or replace the floating-point constant `2.0' with an integer, to +perform all computations using integer arithmetic to get the correct +output. + + Sometimes `gawk' must implicitly convert an arbitrary precision integer into an arbitrary precision floating-point value. This is primarily because the MPFR library does not always provide the relevant interface to process arbitrary precision integers or mixed-mode numbers @@ -23258,18 +22174,18 @@ floating-point value to begin with: gawk -M 'BEGIN { n = 13.0; print n % 2.0 }' - Note that for the particular example above, it is likely best to just -use the following: + Note that for the particular example above, it is likely best to +just use the following: gawk -M 'BEGIN { n = 13; print n % 2 }' - When dividing two arbitrary precision integers with either '/' or -'%', the result is typically an arbitrary precision floating point value -(unless the denominator evenly divides into the numerator). In order to -do integer division or remainder with arbitrary precision integers, use -the built-in 'div()' function (*note Numeric Functions::). + When dividing two arbitrary precision integers with either `/' or +`%', the result is typically an arbitrary precision floating point +value (unless the denominator evenly divides into the numerator). In +order to do integer division or remainder with arbitrary precision +integers, use the built-in `div()' function (*note Numeric Functions::). - You can simulate the 'div()' function in standard 'awk' using this + You can simulate the `div()' function in standard `awk' using this user-defined function: # div --- do integer division @@ -23288,8 +22204,9 @@ user-defined function: ---------- Footnotes ---------- - (1) Weisstein, Eric W. 'Sylvester's Sequence'. From MathWorld--A -Wolfram Web Resource (). + (1) Weisstein, Eric W. `Sylvester's Sequence'. From MathWorld--A +Wolfram Web Resource +(`http://mathworld.wolfram.com/SylvestersSequence.html').  File: gawk.info, Node: POSIX Floating Point Problems, Next: Floating point summary, Prev: Arbitrary Precision Integers, Up: Arbitrary Precision Arithmetic @@ -23297,18 +22214,18 @@ File: gawk.info, Node: POSIX Floating Point Problems, Next: Floating point sum 15.6 Standards Versus Existing Practice ======================================= -Historically, 'awk' has converted any non-numeric looking string to the -numeric value zero, when required. Furthermore, the original definition -of the language and the original POSIX standards specified that 'awk' -only understands decimal numbers (base 10), and not octal (base 8) or -hexadecimal numbers (base 16). +Historically, `awk' has converted any non-numeric looking string to the +numeric value zero, when required. Furthermore, the original +definition of the language and the original POSIX standards specified +that `awk' only understands decimal numbers (base 10), and not octal +(base 8) or hexadecimal numbers (base 16). Changes in the language of the 2001 and 2004 POSIX standards can be -interpreted to imply that 'awk' should support additional features. +interpreted to imply that `awk' should support additional features. These features are: * Interpretation of floating point data values specified in - hexadecimal notation (e.g., '0xDEADBEEF'). (Note: data values, + hexadecimal notation (e.g., `0xDEADBEEF'). (Note: data values, _not_ source code constants.) * Support for the special IEEE 754 floating point values "Not A @@ -23316,39 +22233,40 @@ These features are: ("-inf"). In particular, the format for these values is as specified by the ISO 1999 C standard, which ignores case and can allow implementation-dependent additional characters after the - 'nan' and allow either 'inf' or 'infinity'. + `nan' and allow either `inf' or `infinity'. The first problem is that both of these are clear changes to historical practice: - * The 'gawk' maintainer feels that supporting hexadecimal floating + * The `gawk' maintainer feels that supporting hexadecimal floating point values, in particular, is ugly, and was never intended by the original designers to be part of the language. - * Allowing completely alphabetic strings to have valid numeric values - is also a very severe departure from historical practice. + * Allowing completely alphabetic strings to have valid numeric + values is also a very severe departure from historical practice. - The second problem is that the 'gawk' maintainer feels that this + The second problem is that the `gawk' maintainer feels that this interpretation of the standard, which requires a certain amount of "language lawyering" to arrive at in the first place, was not even intended by the standard developers. In other words, "we see how you got where you are, but we don't think that that's where you want to be." Recognizing the above issues, but attempting to provide compatibility -with the earlier versions of the standard, the 2008 POSIX standard added -explicit wording to allow, but not require, that 'awk' support +with the earlier versions of the standard, the 2008 POSIX standard +added explicit wording to allow, but not require, that `awk' support hexadecimal floating point values and special values for "Not A Number" and infinity. - Although the 'gawk' maintainer continues to feel that providing those -features is inadvisable, nevertheless, on systems that support IEEE -floating point, it seems reasonable to provide _some_ way to support NaN -and Infinity values. The solution implemented in 'gawk' is as follows: + Although the `gawk' maintainer continues to feel that providing +those features is inadvisable, nevertheless, on systems that support +IEEE floating point, it seems reasonable to provide _some_ way to +support NaN and Infinity values. The solution implemented in `gawk' is +as follows: - * With the '--posix' command-line option, 'gawk' becomes "hands off." - String values are passed directly to the system library's - 'strtod()' function, and if it successfully returns a numeric - value, that is what's used.(1) By definition, the results are not + * With the `--posix' command-line option, `gawk' becomes "hands + off." String values are passed directly to the system library's + `strtod()' function, and if it successfully returns a numeric + value, that is what's used.(1) By definition, the results are not portable across different systems. They are also a little surprising: @@ -23357,12 +22275,12 @@ and Infinity values. The solution implemented in 'gawk' is as follows: $ echo 0xDeadBeef | gawk --posix '{ print $1 + 0 }' -| 3735928559 - * Without '--posix', 'gawk' interprets the four strings '+inf', - '-inf', '+nan', and '-nan' specially, producing the corresponding - special numeric values. The leading sign acts a signal to 'gawk' + * Without `--posix', `gawk' interprets the four strings `+inf', + `-inf', `+nan', and `-nan' specially, producing the corresponding + special numeric values. The leading sign acts a signal to `gawk' (and the user) that the value is really numeric. Hexadecimal floating point is not supported (unless you also use - '--non-decimal-data', which is _not_ recommended). For example: + `--non-decimal-data', which is _not_ recommended). For example: $ echo nanny | gawk '{ print $1 + 0 }' -| 0 @@ -23371,8 +22289,8 @@ and Infinity values. The solution implemented in 'gawk' is as follows: $ echo 0xDeadBeef | gawk '{ print $1 + 0 }' -| 0 - 'gawk' ignores case in the four special values. Thus '+nan' and - '+NaN' are the same. + `gawk' ignores case in the four special values. Thus `+nan' and + `+NaN' are the same. ---------- Footnotes ---------- @@ -23385,23 +22303,17 @@ File: gawk.info, Node: Floating point summary, Prev: POSIX Floating Point Prob ============ * Most computer arithmetic is done using either integers or - floating-point values. The default for 'awk' is to use + floating-point values. The default for `awk' is to use double-precision floating-point values. -<<<<<<< HEAD - * In the 1980's, Barbie mistakenly said "Math class is tough!" While - math isn't tough, floating-point arithmetic isn't the same as - pencil and paper math, and care must be taken: -======= * In the early 1990's, Barbie mistakenly said "Math class is tough!" While math isn't tough, floating-point arithmetic isn't the same as pencil and paper math, and care must be taken: ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - Not all numbers can be represented exactly. - Comparing values should use a delta, instead of being done - directly with '==' and '!='. + directly with `==' and `!='. - Errors accumulate. @@ -23412,15 +22324,6 @@ File: gawk.info, Node: Floating point summary, Prev: POSIX Floating Point Prob * Often, increasing the accuracy and then rounding to the desired number of digits produces reasonable results. -<<<<<<< HEAD - * Use either '-M' or '--bignum' to enable MPFR arithmetic. Use - 'PREC' to set the precision in bits, and 'ROUNDMODE' to set the - IEEE 754 rounding mode. - - * With '-M' or '--bignum', 'gawk' performs arbitrary precision - integer arithmetic using the GMP library. This is faster and more - space efficient than using MPFR for the same calculations. -======= * Use `-M' (or `--bignum') to enable MPFR arithmetic. Use `PREC' to set the precision in bits, and `ROUNDMODE' to set the IEEE 754 rounding mode. @@ -23428,44 +22331,44 @@ File: gawk.info, Node: Floating point summary, Prev: POSIX Floating Point Prob * With `-M', `gawk' performs arbitrary precision integer arithmetic using the GMP library. This is faster and more space efficient than using MPFR for the same calculations. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * There are several "dark corners" with respect to floating-point - numbers where 'gawk' disagrees with the POSIX standard. It pays to - be aware of them. - - * Overall, there is no need to be unduly suspicious about the results - from floating-point arithmetic. The lesson to remember is that - floating-point arithmetic is always more complex than arithmetic - using pencil and paper. In order to take advantage of the power of - computer floating-point, you need to know its limitations and work - within them. For most casual use of floating-point arithmetic, you - will often get the expected result if you simply round the display - of your final results to the correct number of significant decimal - digits. + numbers where `gawk' disagrees with the POSIX standard. It pays + to be aware of them. + + * Overall, there is no need to be unduly suspicious about the + results from floating-point arithmetic. The lesson to remember is + that floating-point arithmetic is always more complex than + arithmetic using pencil and paper. In order to take advantage of + the power of computer floating-point, you need to know its + limitations and work within them. For most casual use of + floating-point arithmetic, you will often get the expected result + if you simply round the display of your final results to the + correct number of significant decimal digits. * As general advice, avoid presenting numerical data in a manner that implies better precision than is actually the case. +  File: gawk.info, Node: Dynamic Extensions, Next: Language History, Prev: Arbitrary Precision Arithmetic, Up: Top -16 Writing Extensions for 'gawk' +16 Writing Extensions for `gawk' ******************************** -It is possible to add new functions written in C or C++ to 'gawk' using -dynamically loaded libraries. This facility is available on systems -that support the C 'dlopen()' and 'dlsym()' functions. This major node +It is possible to add new functions written in C or C++ to `gawk' using +dynamically loaded libraries. This facility is available on systems +that support the C `dlopen()' and `dlsym()' functions. This major node describes how to create extensions using code written in C or C++. If you don't know anything about C programming, you can safely skip this major node, although you may wish to review the documentation on -the extensions that come with 'gawk' (*note Extension Samples::), and -the information on the 'gawkextlib' project (*note gawkextlib::). The -sample extensions are automatically built and installed when 'gawk' is. +the extensions that come with `gawk' (*note Extension Samples::), and +the information on the `gawkextlib' project (*note gawkextlib::). The +sample extensions are automatically built and installed when `gawk' is. - NOTE: When '--sandbox' is specified, extensions are disabled (*note - Options::). + NOTE: When `--sandbox' is specified, extensions are disabled + (*note Options::). * Menu: @@ -23473,11 +22376,11 @@ sample extensions are automatically built and installed when 'gawk' is. * Plugin License:: A note about licensing. * Extension Mechanism Outline:: An outline of how it works. * Extension API Description:: A full description of the API. -* Finding Extensions:: How 'gawk' finds compiled extensions. +* Finding Extensions:: How `gawk' finds compiled extensions. * Extension Example:: Example C code for an extension. * Extension Samples:: The sample extensions that ship with - 'gawk'. -* gawkextlib:: The 'gawkextlib' project. + `gawk'. +* gawkextlib:: The `gawkextlib' project. * Extension summary:: Extension summary. * Extension Exercises:: Exercises. @@ -23488,23 +22391,23 @@ File: gawk.info, Node: Extension Intro, Next: Plugin License, Up: Dynamic Ext ================= An "extension" (sometimes called a "plug-in") is a piece of external -compiled code that 'gawk' can load at runtime to provide additional -functionality, over and above the built-in capabilities described in the -rest of this Info file. +compiled code that `gawk' can load at runtime to provide additional +functionality, over and above the built-in capabilities described in +the rest of this Info file. Extensions are useful because they allow you (of course) to extend -'gawk''s functionality. For example, they can provide access to system -calls (such as 'chdir()' to change directory) and to other C library +`gawk''s functionality. For example, they can provide access to system +calls (such as `chdir()' to change directory) and to other C library routines that could be of use. As with most software, "the sky is the limit;" if you can imagine something that you might want to do and can write in C or C++, you can write an extension to do it! Extensions are written in C or C++, using the "Application -Programming Interface" (API) defined for this purpose by the 'gawk' +Programming Interface" (API) defined for this purpose by the `gawk' developers. The rest of this major node explains the facilities that the API provides and how to use them, and presents a small sample extension. In addition, it documents the sample extensions included in -the 'gawk' distribution, and describes the 'gawkextlib' project. *Note +the `gawk' distribution, and describes the `gawkextlib' project. *Note Extension Design::, for a discussion of the extension mechanism goals and design. @@ -23515,13 +22418,13 @@ File: gawk.info, Node: Plugin License, Next: Extension Mechanism Outline, Pre ======================== Every dynamic extension should define the global symbol -'plugin_is_GPL_compatible' to assert that it has been licensed under a -GPL-compatible license. If this symbol does not exist, 'gawk' emits a +`plugin_is_GPL_compatible' to assert that it has been licensed under a +GPL-compatible license. If this symbol does not exist, `gawk' emits a fatal error and exits when it tries to load your extension. - The declared type of the symbol should be 'int'. It does not need to -be in any allocated section, though. The code merely asserts that the -symbol exists in the global scope. Something like this is enough: + The declared type of the symbol should be `int'. It does not need +to be in any allocated section, though. The code merely asserts that +the symbol exists in the global scope. Something like this is enough: int plugin_is_GPL_compatible; @@ -23531,45 +22434,44 @@ File: gawk.info, Node: Extension Mechanism Outline, Next: Extension API Descri 16.3 At A High Level How It Works ================================= -Communication between 'gawk' and an extension is two-way. First, when -an extension is loaded, it is passed a pointer to a 'struct' whose -fields are function pointers. This is shown in *note Figure 16.1: -figure-load-extension. +Communication between `gawk' and an extension is two-way. First, when +an extension is loaded, it is passed a pointer to a `struct' whose +fields are function pointers. This is shown in *note +figure-load-extension::. -[image src="api-figure1.txt" alt="Loading The Extension" text=" API + API Struct +---+ | | +---+ +---------------| | | +---+ dl_load(api_p, id); - | | | ___________________ + | | | ___________________ | +---+ | | +---------| | __________________ | | | +---+ || | | | | || | | +---+ || | | +---| | || - | | | +---+ \\ || / - | | | \\ / - v v v \\/ + | | | +---+ \ || / + | | | \ / + v v v \/ +-------+-+---+-+---+-+------------------+--------------------+ | |x| |x| |x| |OOOOOOOOOOOOOOOOOOOO| | |x| |x| |x| |OOOOOOOOOOOOOOOOOOOO| | |x| |x| |x| |OOOOOOOOOOOOOOOOOOOO| +-------+-+---+-+---+-+------------------+--------------------+ - gawk Main Program Address Space Extension"] - + gawk Main Program Address Space Extension Figure 16.1: Loading The Extension - The extension can call functions inside 'gawk' through these function -pointers, at runtime, without needing (link-time) access to 'gawk''s -symbols. One of these function pointers is to a function for -"registering" new built-in functions. This is shown in *note Figure -16.2: figure-load-new-function. + The extension can call functions inside `gawk' through these +function pointers, at runtime, without needing (link-time) access to +`gawk''s symbols. One of these function pointers is to a function for +"registering" new built-in functions. This is shown in *note +figure-load-new-function::. -[image src="api-figure2.txt" alt="Loading The New Function" text=" register_ext_func({ \"chdir\", do_chdir, 1 }); + register_ext_func({ "chdir", do_chdir, 1 }); +--------------------------------------------+ | | @@ -23580,19 +22482,17 @@ symbols. One of these function pointers is to a function for | |x| |x| |x| |OOOOOOOOOOOOOO|X|OOO| +-------+-+---+-+---+-+------------------+--------------+-+---+ - gawk Main Program Address Space Extension"] - + gawk Main Program Address Space Extension Figure 16.2: Loading The New Function In the other direction, the extension registers its new functions -with 'gawk' by passing function pointers to the functions that provide -the new feature ('do_chdir()', for example). 'gawk' associates the +with `gawk' by passing function pointers to the functions that provide +the new feature (`do_chdir()', for example). `gawk' associates the function pointer with a name and can then call it, using a defined -calling convention. This is shown in *note Figure 16.3: -figure-call-new-function. +calling convention. This is shown in *note figure-call-new-function::. -[image src="api-figure3.txt" alt="Calling the new function" text=" BEGIN { - chdir(\"/path\") (*fnptr)(1); + BEGIN { + chdir("/path") (*fnptr)(1); } +--------------------------------------------+ | | @@ -23603,38 +22503,32 @@ figure-call-new-function. | |x| |x| |x| |OOOOOOOOOOOOOO|X|OOO| +-------+-+---+-+---+-+------------------+--------------+-+---+ - gawk Main Program Address Space Extension"] - + gawk Main Program Address Space Extension Figure 16.3: Calling The New Function - The 'do_XXX()' function, in turn, then uses the function pointers in -the API 'struct' to do its work, such as updating variables or arrays, -printing messages, setting 'ERRNO', and so on. + The `do_XXX()' function, in turn, then uses the function pointers in +the API `struct' to do its work, such as updating variables or arrays, +printing messages, setting `ERRNO', and so on. Convenience macros make calling through the function pointers look -like regular function calls so that extension code is quite readable and -understandable. +like regular function calls so that extension code is quite readable +and understandable. Although all of this sounds somewhat complicated, the result is that -extension code is quite straightforward to write and to read. You can -see this in the sample extensions 'filefuncs.c' (*note Extension -Example::) and also the 'testext.c' code for testing the APIs. +extension code is quite straightforward to write and to read. You can +see this in the sample extensions `filefuncs.c' (*note Extension +Example::) and also the `testext.c' code for testing the APIs. Some other bits and pieces: -<<<<<<< HEAD - * The API provides access to 'gawk''s 'do_XXX' values, reflecting - command line options, like 'do_lint', 'do_profiling' and so on -======= * The API provides access to `gawk''s `do_XXX' values, reflecting command-line options, like `do_lint', `do_profiling' and so on ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (*note Extension API Variables::). These are informational: an - extension cannot affect their values inside 'gawk'. In addition, + extension cannot affect their values inside `gawk'. In addition, attempting to assign to them produces a compile-time error. * The API also provides major and minor version numbers, so that an - extension can check if the 'gawk' it is loaded with supports the + extension can check if the `gawk' it is loaded with supports the facilities it was compiled with. (Version mismatches "shouldn't" happen, but we all know how _that_ goes.) *Note Extension Versioning::, for details. @@ -23645,10 +22539,10 @@ File: gawk.info, Node: Extension API Description, Next: Finding Extensions, P 16.4 API Description ==================== -C or C++ code for an extension must include the header file 'gawkapi.h', -which declares the functions and defines the data types used to -communicate with 'gawk'. This (rather large) minor node describes the -API in detail. +C or C++ code for an extension must include the header file +`gawkapi.h', which declares the functions and defines the data types +used to communicate with `gawk'. This (rather large) minor node +describes the API in detail. * Menu: @@ -23658,9 +22552,9 @@ API in detail. * Memory Allocation Functions:: Functions for allocating memory. * Constructor Functions:: Functions for creating values. * Registration Functions:: Functions to register things with - 'gawk'. + `gawk'. * Printing Messages:: Functions for printing messages. -* Updating 'ERRNO':: Functions for updating 'ERRNO'. +* Updating `ERRNO':: Functions for updating `ERRNO'. * Accessing Parameters:: Functions for accessing parameters. * Symbol Table Access:: Functions for accessing global variables. @@ -23674,30 +22568,35 @@ File: gawk.info, Node: Extension API Functions Introduction, Next: General Dat 16.4.1 Introduction ------------------- -Access to facilities within 'gawk' are made available by calling through -function pointers passed into your extension. +Access to facilities within `gawk' are made available by calling +through function pointers passed into your extension. API function pointers are provided for the following kinds of operations: - * Registration functions. You may register: + * Registration functions. You may register: - extension functions, + - exit callbacks, + - a version string, + - input parsers, + - output wrappers, + - and two-way processors. All of these are discussed in detail, later in this major node. * Printing fatal, warning, and "lint" warning messages. - * Updating 'ERRNO', or unsetting it. + * Updating `ERRNO', or unsetting it. * Accessing parameters, including converting an undefined parameter into an array. - * Symbol table access: retrieving a global variable, creating one, or - changing one. + * Symbol table access: retrieving a global variable, creating one, + or changing one. * Allocating, reallocating, and releasing memory. @@ -23721,56 +22620,53 @@ operations: Some points about using the API: * The following types and/or macros and/or functions are referenced - in 'gawkapi.h'. For correct use, you must therefore include the - corresponding standard header file _before_ including 'gawkapi.h': + in `gawkapi.h'. For correct use, you must therefore include the + corresponding standard header file _before_ including `gawkapi.h': C Entity Header File - ------------------------------------------- - 'EOF' '' - Values for 'errno' '' - 'FILE' '' - 'NULL' '' - 'memcpy()' '' - 'memset()' '' - 'size_t' '' - 'struct stat' '' + ------------------------------------------- + `EOF' `' + Values for `errno' `' + `FILE' `' + `NULL' `' + `memcpy()' `' + `memset()' `' + `size_t' `' + `struct stat' `' Due to portability concerns, especially to systems that are not - fully standards-compliant, it is your responsibility to include the - correct files in the correct way. This requirement is necessary in - order to keep 'gawkapi.h' clean, instead of becoming a portability - hodge-podge as can be seen in some parts of the 'gawk' source code. + fully standards-compliant, it is your responsibility to include + the correct files in the correct way. This requirement is + necessary in order to keep `gawkapi.h' clean, instead of becoming + a portability hodge-podge as can be seen in some parts of the + `gawk' source code. - * The 'gawkapi.h' file may be included more than once without ill + * The `gawkapi.h' file may be included more than once without ill effect. Doing so, however, is poor coding practice. * Although the API only uses ISO C 90 features, there is an - exception; the "constructor" functions use the 'inline' keyword. + exception; the "constructor" functions use the `inline' keyword. If your compiler does not support this keyword, you should either - place '-Dinline=''' on your command line, or use the GNU Autotools - and include a 'config.h' file in your extensions. + place `-Dinline=''' on your command line, or use the GNU Autotools + and include a `config.h' file in your extensions. -<<<<<<< HEAD - * All pointers filled in by 'gawk' are to memory managed by 'gawk' -======= * All pointers filled in by `gawk' point to memory managed by `gawk' ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac and should be treated by the extension as read-only. Memory for - _all_ strings passed into 'gawk' from the extension _must_ come - from calling the API-provided function pointers 'api_malloc()', - 'api_calloc()' or 'api_realloc()', and is managed by 'gawk' from + _all_ strings passed into `gawk' from the extension _must_ come + from calling the API-provided function pointers `api_malloc()', + `api_calloc()' or `api_realloc()', and is managed by `gawk' from then on. - * The API defines several simple 'struct's that map values as seen - from 'awk'. A value can be a 'double', a string, or an array (as + * The API defines several simple `struct's that map values as seen + from `awk'. A value can be a `double', a string, or an array (as in multidimensional arrays, or when creating a new array). String values maintain both pointer and length since embedded NUL characters are allowed. NOTE: By intent, strings are maintained using the current - multibyte encoding (as defined by 'LC_XXX' environment + multibyte encoding (as defined by `LC_XXX' environment variables) and not using wide characters. This matches how - 'gawk' stores strings internally and also how characters are + `gawk' stores strings internally and also how characters are likely to be input and output from files. * When retrieving a value (such as a parameter or that of a global @@ -23784,9 +22680,10 @@ operations: that is there, so that the extension can, e.g., print an error message (such as "scalar passed where array expected"). + While you may call the API functions by using the function pointers -directly, the interface is not so pretty. To make extension code look -more like regular code, the 'gawkapi.h' header file defines several +directly, the interface is not so pretty. To make extension code look +more like regular code, the `gawkapi.h' header file defines several macros that you should use in your code. This minor node presents the macros as if they were functions. @@ -23796,135 +22693,137 @@ File: gawk.info, Node: General Data Types, Next: Requesting Values, Prev: Ext 16.4.2 General Purpose Data Types --------------------------------- - I have a true love/hate relationship with unions. - -- _Arnold Robbins_ + I have a true love/hate relationship with unions. -- Arnold + Robbins That's the thing about unions: the compiler will arrange things so - they can accommodate both love and hate. - -- _Chet Ramey_ - - The extension API defines a number of simple types and structures for -general purpose use. Additional, more specialized, data structures are -introduced in subsequent minor nodes, together with the functions that -use them. - -'typedef void *awk_ext_id_t;' - A value of this type is received from 'gawk' when an extension is - loaded. That value must then be passed back to 'gawk' as the first - parameter of each API function. - -'#define awk_const ...' - This macro expands to 'const' when compiling an extension, and to - nothing when compiling 'gawk' itself. This makes certain fields in - the API data structures unwritable from extension code, while - allowing 'gawk' to use them as it needs to. - -'typedef enum awk_bool {' -' awk_false = 0,' -' awk_true' -'} awk_bool_t;' + they can accommodate both love and hate. -- Chet Ramey + + The extension API defines a number of simple types and structures +for general purpose use. Additional, more specialized, data structures +are introduced in subsequent minor nodes, together with the functions +that use them. + +`typedef void *awk_ext_id_t;' + A value of this type is received from `gawk' when an extension is + loaded. That value must then be passed back to `gawk' as the + first parameter of each API function. + +`#define awk_const ...' + This macro expands to `const' when compiling an extension, and to + nothing when compiling `gawk' itself. This makes certain fields + in the API data structures unwritable from extension code, while + allowing `gawk' to use them as it needs to. + +`typedef enum awk_bool {' +` awk_false = 0,' +` awk_true' +`} awk_bool_t;' A simple boolean type. -'typedef struct awk_string {' -' char *str; /* data */' -' size_t len; /* length thereof, in chars */' -'} awk_string_t;' - This represents a mutable string. 'gawk' owns the memory pointed - to if it supplied the value. Otherwise, it takes ownership of the +`typedef struct awk_string {' +` char *str; /* data */' +` size_t len; /* length thereof, in chars */' +`} awk_string_t;' + This represents a mutable string. `gawk' owns the memory pointed + to if it supplied the value. Otherwise, it takes ownership of the memory pointed to. *Such memory must come from calling the - API-provided function pointers 'api_malloc()', 'api_calloc()', or - 'api_realloc()'!* + API-provided function pointers `api_malloc()', `api_calloc()', or + `api_realloc()'!* As mentioned earlier, strings are maintained using the current multibyte encoding. -'typedef enum {' -' AWK_UNDEFINED,' -' AWK_NUMBER,' -' AWK_STRING,' -' AWK_ARRAY,' -' AWK_SCALAR, /* opaque access to a variable */' -' AWK_VALUE_COOKIE /* for updating a previously created value */' -'} awk_valtype_t;' - This 'enum' indicates the type of a value. It is used in the - following 'struct'. - -'typedef struct awk_value {' -' awk_valtype_t val_type;' -' union {' -' awk_string_t s;' -' double d;' -' awk_array_t a;' -' awk_scalar_t scl;' -' awk_value_cookie_t vc;' -' } u;' -'} awk_value_t;' - An "'awk' value." The 'val_type' member indicates what kind of - value the 'union' holds, and each member is of the appropriate +`typedef enum {' +` AWK_UNDEFINED,' +` AWK_NUMBER,' +` AWK_STRING,' +` AWK_ARRAY,' +` AWK_SCALAR, /* opaque access to a variable */' +` AWK_VALUE_COOKIE /* for updating a previously created value */' +`} awk_valtype_t;' + This `enum' indicates the type of a value. It is used in the + following `struct'. + +`typedef struct awk_value {' +` awk_valtype_t val_type;' +` union {' +` awk_string_t s;' +` double d;' +` awk_array_t a;' +` awk_scalar_t scl;' +` awk_value_cookie_t vc;' +` } u;' +`} awk_value_t;' + An "`awk' value." The `val_type' member indicates what kind of + value the `union' holds, and each member is of the appropriate type. -'#define str_value u.s' -'#define num_value u.d' -'#define array_cookie u.a' -'#define scalar_cookie u.scl' -'#define value_cookie u.vc' - These macros make accessing the fields of the 'awk_value_t' more +`#define str_value u.s' +`#define num_value u.d' +`#define array_cookie u.a' +`#define scalar_cookie u.scl' +`#define value_cookie u.vc' + These macros make accessing the fields of the `awk_value_t' more readable. -'typedef void *awk_scalar_t;' - Scalars can be represented as an opaque type. These values are - obtained from 'gawk' and then passed back into it. This is +`typedef void *awk_scalar_t;' + Scalars can be represented as an opaque type. These values are + obtained from `gawk' and then passed back into it. This is discussed in a general fashion below, and in more detail in *note Symbol table by cookie::. -'typedef void *awk_value_cookie_t;' +`typedef void *awk_value_cookie_t;' A "value cookie" is an opaque type representing a cached value. This is also discussed in a general fashion below, and in more detail in *note Cached values::. - Scalar values in 'awk' are either numbers or strings. The -'awk_value_t' struct represents values. The 'val_type' member indicates -what is in the 'union'. - Representing numbers is easy--the API uses a C 'double'. Strings -require more work. Since 'gawk' allows embedded NUL bytes in string -values, a string must be represented as a pair containing a data-pointer -and length. This is the 'awk_string_t' type. + Scalar values in `awk' are either numbers or strings. The +`awk_value_t' struct represents values. The `val_type' member +indicates what is in the `union'. + + Representing numbers is easy--the API uses a C `double'. Strings +require more work. Since `gawk' allows embedded NUL bytes in string +values, a string must be represented as a pair containing a +data-pointer and length. This is the `awk_string_t' type. Identifiers (i.e., the names of global variables) can be associated -with either scalar values or with arrays. In addition, 'gawk' provides +with either scalar values or with arrays. In addition, `gawk' provides true arrays of arrays, where any given array element can itself be an array. Discussion of arrays is delayed until *note Array Manipulation::. The various macros listed earlier make it easier to use the elements -of the 'union' as if they were fields in a 'struct'; this is a common -coding practice in C. Such code is easier to write and to read, however -it remains _your_ responsibility to make sure that the 'val_type' member -correctly reflects the type of the value in the 'awk_value_t'. - - Conceptually, the first three members of the 'union' (number, string, -and array) are all that is needed for working with 'awk' values. +of the `union' as if they were fields in a `struct'; this is a common +coding practice in C. Such code is easier to write and to read, +however it remains _your_ responsibility to make sure that the +`val_type' member correctly reflects the type of the value in the +`awk_value_t'. + + Conceptually, the first three members of the `union' (number, string, +and array) are all that is needed for working with `awk' values. However, since the API provides routines for accessing and changing the value of global scalar variables only by using the variable's name, -there is a performance penalty: 'gawk' must find the variable each time -it is accessed and changed. This turns out to be a real issue, not just -a theoretical one. +there is a performance penalty: `gawk' must find the variable each time +it is accessed and changed. This turns out to be a real issue, not +just a theoretical one. Thus, if you know that your extension will spend considerable time reading and/or changing the value of one or more scalar variables, you can obtain a "scalar cookie"(1) object for that variable, and then use the cookie for getting the variable's value or for changing the -variable's value. This is the 'awk_scalar_t' type and 'scalar_cookie' -macro. Given a scalar cookie, 'gawk' can directly retrieve or modify +variable's value. This is the `awk_scalar_t' type and `scalar_cookie' +macro. Given a scalar cookie, `gawk' can directly retrieve or modify the value, as required, without having to first find it. - The 'awk_value_cookie_t' type and 'value_cookie' macro are similar. + The `awk_value_cookie_t' type and `value_cookie' macro are similar. If you know that you wish to use the same numeric or string _value_ for -one or more variables, you can create the value once, retaining a "value -cookie" for it, and then pass in that value cookie whenever you wish to -set the value of a variable. This saves both storage space within the -running 'gawk' process as well as the time needed to create the value. +one or more variables, you can create the value once, retaining a +"value cookie" for it, and then pass in that value cookie whenever you +wish to set the value of a variable. This saves both storage space +within the running `gawk' process as well as the time needed to create +the value. ---------- Footnotes ---------- @@ -23940,29 +22839,30 @@ File: gawk.info, Node: Requesting Values, Next: Memory Allocation Functions, 16.4.3 Requesting Values ------------------------ -All of the functions that return values from 'gawk' work in the same -way. You pass in an 'awk_valtype_t' value to indicate what kind of +All of the functions that return values from `gawk' work in the same +way. You pass in an `awk_valtype_t' value to indicate what kind of value you expect. If the actual value matches what you requested, the -function returns true and fills in the 'awk_value_t' result. Otherwise, -the function returns false, and the 'val_type' member indicates the type -of the actual value. You may then print an error message, or reissue -the request for the actual value type, as appropriate. This behavior is -summarized in *note Table 16.1: table-value-types-returned. +function returns true and fills in the `awk_value_t' result. +Otherwise, the function returns false, and the `val_type' member +indicates the type of the actual value. You may then print an error +message, or reissue the request for the actual value type, as +appropriate. This behavior is summarized in *note +table-value-types-returned::. Type of Actual Value: --------------------------------------------------------------------------- +-------------------------------------------------------------------------- + String Number Array Undefined ------------------------------------------------------------------------------- +------------------------------------------------------------------------------ String String String false false - Number Number if Number false false - can be - converted, - else false + Number Number if can Number false false + be converted, + else false Type Array false false Array false Requested: Scalar Scalar Scalar false false Undefined String Number Array Undefined Value false false false false - Cookie + Cookie Table 16.1: API Value Types Returned @@ -23973,52 +22873,52 @@ File: gawk.info, Node: Memory Allocation Functions, Next: Constructor Function --------------------------------------------------------- The API provides a number of "memory allocation" functions for -allocating memory that can be passed to 'gawk', as well as a number of +allocating memory that can be passed to `gawk', as well as a number of convenience macros. -'void *gawk_malloc(size_t size);' - Call 'gawk'-provided 'api_malloc()' to allocate storage that may be - passed to 'gawk'. +`void *gawk_malloc(size_t size);' + Call `gawk'-provided `api_malloc()' to allocate storage that may + be passed to `gawk'. -'void *gawk_calloc(size_t nmemb, size_t size);' - Call 'gawk'-provided 'api_calloc()' to allocate storage that may be - passed to 'gawk'. +`void *gawk_calloc(size_t nmemb, size_t size);' + Call `gawk'-provided `api_calloc()' to allocate storage that may + be passed to `gawk'. -'void *gawk_realloc(void *ptr, size_t size);' - Call 'gawk'-provided 'api_realloc()' to allocate storage that may - be passed to 'gawk'. +`void *gawk_realloc(void *ptr, size_t size);' + Call `gawk'-provided `api_realloc()' to allocate storage that may + be passed to `gawk'. -'void gawk_free(void *ptr);' - Call 'gawk'-provided 'api_free()' to release storage that was - allocated with 'gawk_malloc()', 'gawk_calloc()' or - 'gawk_realloc()'. +`void gawk_free(void *ptr);' + Call `gawk'-provided `api_free()' to release storage that was + allocated with `gawk_malloc()', `gawk_calloc()' or + `gawk_realloc()'. The API has to provide these functions because it is possible for an -extension to be compiled and linked against a different version of the C -library than was used for the 'gawk' executable.(1) If 'gawk' were to -use its version of 'free()' when the memory came from an unrelated -version of 'malloc()', unexpected behavior would likely result. +extension to be compiled and linked against a different version of the +C library than was used for the `gawk' executable.(1) If `gawk' were to +use its version of `free()' when the memory came from an unrelated +version of `malloc()', unexpected behavior would likely result. Two convenience macros may be used for allocating storage from the -API-provided function pointers 'api_malloc()' and 'api_realloc()'. If -the allocation fails, they cause 'gawk' to exit with a fatal error +API-provided function pointers `api_malloc()' and `api_realloc()'. If +the allocation fails, they cause `gawk' to exit with a fatal error message. They should be used as if they were procedure calls that do not return a value. -'#define emalloc(pointer, type, size, message) ...' +`#define emalloc(pointer, type, size, message) ...' The arguments to this macro are as follows: - 'pointer' + `pointer' The pointer variable to point at the allocated storage. - 'type' + `type' The type of the pointer variable, used to create a cast for - the call to 'api_malloc()'. + the call to `api_malloc()'. - 'size' + `size' The total number of bytes to be allocated. - 'message' + `message' A message to be prefixed to the fatal error message. Typically this is the name of the function using the macro. @@ -24032,9 +22932,9 @@ not return a value. strcpy(message, greet); make_malloced_string(message, strlen(message), & result); -'#define erealloc(pointer, type, size, message) ...' - This is like 'emalloc()', but it calls 'api_realloc()', instead of - 'api_malloc()'. The arguments are the same as for the 'emalloc()' +`#define erealloc(pointer, type, size, message) ...' + This is like `emalloc()', but it calls `api_realloc()', instead of + `api_malloc()'. The arguments are the same as for the `emalloc()' macro. ---------- Footnotes ---------- @@ -24048,37 +22948,37 @@ File: gawk.info, Node: Constructor Functions, Next: Registration Functions, P 16.4.5 Constructor Functions ---------------------------- -The API provides a number of "constructor" functions for creating string -and numeric values, as well as a number of convenience macros. This -node presents them all as function prototypes, in the way that extension -code would use them. - -'static inline awk_value_t *' -'make_const_string(const char *string, size_t length, awk_value_t *result)' - This function creates a string value in the 'awk_value_t' variable - pointed to by 'result'. It expects 'string' to be a C string - constant (or other string data), and automatically creates a _copy_ - of the data for storage in 'result'. It returns 'result'. - -'static inline awk_value_t *' -'make_malloced_string(const char *string, size_t length, awk_value_t *result)' - This function creates a string value in the 'awk_value_t' variable - pointed to by 'result'. It expects 'string' to be a 'char *' value +The API provides a number of "constructor" functions for creating +string and numeric values, as well as a number of convenience macros. +This node presents them all as function prototypes, in the way that +extension code would use them. + +`static inline awk_value_t *' +`make_const_string(const char *string, size_t length, awk_value_t *result)' + This function creates a string value in the `awk_value_t' variable + pointed to by `result'. It expects `string' to be a C string + constant (or other string data), and automatically creates a + _copy_ of the data for storage in `result'. It returns `result'. + +`static inline awk_value_t *' +`make_malloced_string(const char *string, size_t length, awk_value_t *result)' + This function creates a string value in the `awk_value_t' variable + pointed to by `result'. It expects `string' to be a `char *' value pointing to data previously obtained from the api-provided - functions 'api_malloc()', 'api_calloc()' or 'api_realloc()'. The - idea here is that the data is passed directly to 'gawk', which - assumes responsibility for it. It returns 'result'. + functions `api_malloc()', `api_calloc()' or `api_realloc()'. The + idea here is that the data is passed directly to `gawk', which + assumes responsibility for it. It returns `result'. -'static inline awk_value_t *' -'make_null_string(awk_value_t *result)' +`static inline awk_value_t *' +`make_null_string(awk_value_t *result)' This specialized function creates a null string (the "undefined" - value) in the 'awk_value_t' variable pointed to by 'result'. It - returns 'result'. + value) in the `awk_value_t' variable pointed to by `result'. It + returns `result'. -'static inline awk_value_t *' -'make_number(double num, awk_value_t *result)' - This function simply creates a numeric value in the 'awk_value_t' - variable pointed to by 'result'. +`static inline awk_value_t *' +`make_number(double num, awk_value_t *result)' + This function simply creates a numeric value in the `awk_value_t' + variable pointed to by `result'.  File: gawk.info, Node: Registration Functions, Next: Printing Messages, Prev: Constructor Functions, Up: Extension API Description @@ -24087,7 +22987,7 @@ File: gawk.info, Node: Registration Functions, Next: Printing Messages, Prev: ----------------------------- This minor node describes the API functions for registering parts of -your extension with 'gawk'. +your extension with `gawk'. * Menu: @@ -24114,43 +23014,43 @@ Extension functions are described by the following record: The fields are: -'const char *name;' - The name of the new function. 'awk' level code calls the function +`const char *name;' + The name of the new function. `awk' level code calls the function by this name. This is a regular C string. - Function names must obey the rules for 'awk' identifiers. That is, - they must begin with either a letter or an underscore, which may be - followed by any number of letters, digits, and underscores. Letter - case in function names is significant. + Function names must obey the rules for `awk' identifiers. That is, + they must begin with either a letter or an underscore, which may + be followed by any number of letters, digits, and underscores. + Letter case in function names is significant. -'awk_value_t *(*function)(int num_actual_args, awk_value_t *result);' +`awk_value_t *(*function)(int num_actual_args, awk_value_t *result);' This is a pointer to the C function that provides the desired functionality. The function must fill in the result with either a - number or a string. 'gawk' takes ownership of any string memory. + number or a string. `gawk' takes ownership of any string memory. As mentioned earlier, string memory *must* come from the - api-provided functions 'api_malloc()', 'api_calloc()' or - 'api_realloc()'. + api-provided functions `api_malloc()', `api_calloc()' or + `api_realloc()'. - The 'num_actual_args' argument tells the C function how many actual - parameters were passed from the calling 'awk' code. + The `num_actual_args' argument tells the C function how many + actual parameters were passed from the calling `awk' code. - The function must return the value of 'result'. This is for the - convenience of the calling code inside 'gawk'. + The function must return the value of `result'. This is for the + convenience of the calling code inside `gawk'. -'size_t num_expected_args;' +`size_t num_expected_args;' This is the number of arguments the function expects to receive. Each extension function may decide what to do if the number of - arguments isn't what it expected. Following 'awk' functions, it is - likely OK to ignore extra arguments. + arguments isn't what it expected. Following `awk' functions, it + is likely OK to ignore extra arguments. Once you have a record representing your extension function, you -register it with 'gawk' using this API function: +register it with `gawk' using this API function: -'awk_bool_t add_ext_func(const char *namespace, const awk_ext_func_t *func);' +`awk_bool_t add_ext_func(const char *namespace, const awk_ext_func_t *func);' This function returns true upon success, false otherwise. The - 'namespace' parameter is currently not used; you should pass in an - empty string ('""'). The 'func' pointer is the address of a - 'struct' representing your function, as just described. + `namespace' parameter is currently not used; you should pass in an + empty string (`""'). The `func' pointer is the address of a + `struct' representing your function, as just described.  File: gawk.info, Node: Exit Callback Functions, Next: Extension Version String, Prev: Extension Functions, Up: Registration Functions @@ -24158,29 +23058,29 @@ File: gawk.info, Node: Exit Callback Functions, Next: Extension Version String 16.4.6.2 Registering An Exit Callback Function .............................................. -An "exit callback" function is a function that 'gawk' calls before it +An "exit callback" function is a function that `gawk' calls before it exits. Such functions are useful if you have general "cleanup" tasks that should be performed in your extension (such as closing database connections or other resource deallocations). You can register such a -function with 'gawk' using the following function. +function with `gawk' using the following function. -'void awk_atexit(void (*funcp)(void *data, int exit_status),' -' void *arg0);' +`void awk_atexit(void (*funcp)(void *data, int exit_status),' +` void *arg0);' The parameters are: - 'funcp' - A pointer to the function to be called before 'gawk' exits. - The 'data' parameter will be the original value of 'arg0'. - The 'exit_status' parameter is the exit status value that - 'gawk' intends to pass to the 'exit()' system call. + `funcp' + A pointer to the function to be called before `gawk' exits. + The `data' parameter will be the original value of `arg0'. + The `exit_status' parameter is the exit status value that + `gawk' intends to pass to the `exit()' system call. - 'arg0' - A pointer to private data which 'gawk' saves in order to pass - to the function pointed to by 'funcp'. + `arg0' + A pointer to private data which `gawk' saves in order to pass + to the function pointed to by `funcp'. Exit callback functions are called in Last-In-First-Out (LIFO) order--that is, in the reverse order in which they are registered with -'gawk'. +`gawk'.  File: gawk.info, Node: Extension Version String, Next: Input Parsers, Prev: Exit Callback Functions, Up: Registration Functions @@ -24189,14 +23089,14 @@ File: gawk.info, Node: Extension Version String, Next: Input Parsers, Prev: E ................................................ You can register a version string which indicates the name and version -of your extension, with 'gawk', as follows: +of your extension, with `gawk', as follows: -'void register_ext_version(const char *version);' - Register the string pointed to by 'version' with 'gawk'. 'gawk' - does _not_ copy the 'version' string, so it should not be changed. +`void register_ext_version(const char *version);' + Register the string pointed to by `version' with `gawk'. `gawk' + does _not_ copy the `version' string, so it should not be changed. - 'gawk' prints all registered extension version strings when it is -invoked with the '--version' option. + `gawk' prints all registered extension version strings when it is +invoked with the `--version' option.  File: gawk.info, Node: Input Parsers, Next: Output Wrappers, Prev: Extension Version String, Up: Registration Functions @@ -24204,37 +23104,38 @@ File: gawk.info, Node: Input Parsers, Next: Output Wrappers, Prev: Extension 16.4.6.4 Customized Input Parsers ................................. -By default, 'gawk' reads text files as its input. It uses the value of -'RS' to find the end of the record, and then uses 'FS' (or 'FIELDWIDTHS' -or 'FPAT') to split it into fields (*note Reading Files::). -Additionally, it sets the value of 'RT' (*note Built-in Variables::). +By default, `gawk' reads text files as its input. It uses the value of +`RS' to find the end of the record, and then uses `FS' (or +`FIELDWIDTHS' or `FPAT') to split it into fields (*note Reading +Files::). Additionally, it sets the value of `RT' (*note Built-in +Variables::). If you want, you can provide your own custom input parser. An input -parser's job is to return a record to the 'gawk' record processing code, -along with indicators for the value and length of the data to be used -for 'RT', if any. +parser's job is to return a record to the `gawk' record processing +code, along with indicators for the value and length of the data to be +used for `RT', if any. To provide an input parser, you must first provide two functions (where XXX is a prefix name for your extension): -'awk_bool_t XXX_can_take_file(const awk_input_buf_t *iobuf)' - This function examines the information available in 'iobuf' (which - we discuss shortly). Based on the information there, it decides if - the input parser should be used for this file. If so, it should - return true. Otherwise, it should return false. It should not - change any state (variable values, etc.) within 'gawk'. - -'awk_bool_t XXX_take_control_of(awk_input_buf_t *iobuf)' - When 'gawk' decides to hand control of the file over to the input - parser, it calls this function. This function in turn must fill in - certain fields in the 'awk_input_buf_t' structure, and ensure that - certain conditions are true. It should then return true. If an - error of some kind occurs, it should not fill in any fields, and - should return false; then 'gawk' will not use the input parser. +`awk_bool_t XXX_can_take_file(const awk_input_buf_t *iobuf)' + This function examines the information available in `iobuf' (which + we discuss shortly). Based on the information there, it decides + if the input parser should be used for this file. If so, it + should return true. Otherwise, it should return false. It should + not change any state (variable values, etc.) within `gawk'. + +`awk_bool_t XXX_take_control_of(awk_input_buf_t *iobuf)' + When `gawk' decides to hand control of the file over to the input + parser, it calls this function. This function in turn must fill + in certain fields in the `awk_input_buf_t' structure, and ensure + that certain conditions are true. It should then return true. If + an error of some kind occurs, it should not fill in any fields, + and should return false; then `gawk' will not use the input parser. The details are presented shortly. Your extension should package these functions inside an -'awk_input_parser_t', which looks like this: +`awk_input_parser_t', which looks like this: typedef struct awk_input_parser { const char *name; /* name of parser */ @@ -24245,29 +23146,29 @@ for 'RT', if any. The fields are: -'const char *name;' - The name of the input parser. This is a regular C string. +`const char *name;' + The name of the input parser. This is a regular C string. -'awk_bool_t (*can_take_file)(const awk_input_buf_t *iobuf);' - A pointer to your 'XXX_can_take_file()' function. +`awk_bool_t (*can_take_file)(const awk_input_buf_t *iobuf);' + A pointer to your `XXX_can_take_file()' function. -'awk_bool_t (*take_control_of)(awk_input_buf_t *iobuf);' - A pointer to your 'XXX_take_control_of()' function. +`awk_bool_t (*take_control_of)(awk_input_buf_t *iobuf);' + A pointer to your `XXX_take_control_of()' function. -'awk_const struct input_parser *awk_const next;' - This is for use by 'gawk'; therefore it is marked 'awk_const' so +`awk_const struct input_parser *awk_const next;' + This is for use by `gawk'; therefore it is marked `awk_const' so that the extension cannot modify it. The steps are as follows: - 1. Create a 'static awk_input_parser_t' variable and initialize it + 1. Create a `static awk_input_parser_t' variable and initialize it appropriately. 2. When your extension is loaded, register your input parser with - 'gawk' using the 'register_input_parser()' API function (described + `gawk' using the `register_input_parser()' API function (described below). - An 'awk_input_buf_t' looks like this: + An `awk_input_buf_t' looks like this: typedef struct awk_input { const char *name; /* filename */ @@ -24282,143 +23183,143 @@ for 'RT', if any. } awk_input_buf_t; The fields can be divided into two categories: those for use -(initially, at least) by 'XXX_can_take_file()', and those for use by -'XXX_take_control_of()'. The first group of fields and their uses are +(initially, at least) by `XXX_can_take_file()', and those for use by +`XXX_take_control_of()'. The first group of fields and their uses are as follows: -'const char *name;' +`const char *name;' The name of the file. -'int fd;' - A file descriptor for the file. If 'gawk' was able to open the - file, then 'fd' will _not_ be equal to 'INVALID_HANDLE'. +`int fd;' + A file descriptor for the file. If `gawk' was able to open the + file, then `fd' will _not_ be equal to `INVALID_HANDLE'. Otherwise, it will. -'struct stat sbuf;' - If the file descriptor is valid, then 'gawk' will have filled in - this structure via a call to the 'fstat()' system call. +`struct stat sbuf;' + If the file descriptor is valid, then `gawk' will have filled in + this structure via a call to the `fstat()' system call. - The 'XXX_can_take_file()' function should examine these fields and + The `XXX_can_take_file()' function should examine these fields and decide if the input parser should be used for the file. The decision -can be made based upon 'gawk' state (the value of a variable defined -previously by the extension and set by 'awk' code), the name of the +can be made based upon `gawk' state (the value of a variable defined +previously by the extension and set by `awk' code), the name of the file, whether or not the file descriptor is valid, the information in -the 'struct stat', or any combination of the above. +the `struct stat', or any combination of the above. - Once 'XXX_can_take_file()' has returned true, and 'gawk' has decided -to use your input parser, it calls 'XXX_take_control_of()'. That -function then fills one of either the 'get_record' field or the -'read_func' field in the 'awk_input_buf_t'. It must also ensure that -'fd' is _not_ set to 'INVALID_HANDLE'. All of the fields that may be -filled by 'XXX_take_control_of()' are as follows: + Once `XXX_can_take_file()' has returned true, and `gawk' has decided +to use your input parser, it calls `XXX_take_control_of()'. That +function then fills one of either the `get_record' field or the +`read_func' field in the `awk_input_buf_t'. It must also ensure that +`fd' is _not_ set to `INVALID_HANDLE'. All of the fields that may be +filled by `XXX_take_control_of()' are as follows: -'void *opaque;' +`void *opaque;' This is used to hold any state information needed by the input - parser for this file. It is "opaque" to 'gawk'. The input parser + parser for this file. It is "opaque" to `gawk'. The input parser is not required to use this pointer. -'int (*get_record)(char **out,' -' struct awk_input *iobuf,' -' int *errcode,' -' char **rt_start,' -' size_t *rt_len);' +`int (*get_record)(char **out,' +` struct awk_input *iobuf,' +` int *errcode,' +` char **rt_start,' +` size_t *rt_len);' This function pointer should point to a function that creates the - input records. Said function is the core of the input parser. Its - behavior is described below. + input records. Said function is the core of the input parser. + Its behavior is described below. -'ssize_t (*read_func)();' +`ssize_t (*read_func)();' This function pointer should point to function that has the same - behavior as the standard POSIX 'read()' system call. It is an - alternative to the 'get_record' pointer. Its behavior is also + behavior as the standard POSIX `read()' system call. It is an + alternative to the `get_record' pointer. Its behavior is also described below. -'void (*close_func)(struct awk_input *iobuf);' +`void (*close_func)(struct awk_input *iobuf);' This function pointer should point to a function that does the - "tear down." It should release any resources allocated by - 'XXX_take_control_of()'. It may also close the file. If it does - so, it should set the 'fd' field to 'INVALID_HANDLE'. + "tear down." It should release any resources allocated by + `XXX_take_control_of()'. It may also close the file. If it does + so, it should set the `fd' field to `INVALID_HANDLE'. - If 'fd' is still not 'INVALID_HANDLE' after the call to this - function, 'gawk' calls the regular 'close()' system call. + If `fd' is still not `INVALID_HANDLE' after the call to this + function, `gawk' calls the regular `close()' system call. - Having a "tear down" function is optional. If your input parser - does not need it, do not set this field. Then, 'gawk' calls the - regular 'close()' system call on the file descriptor, so it should + Having a "tear down" function is optional. If your input parser + does not need it, do not set this field. Then, `gawk' calls the + regular `close()' system call on the file descriptor, so it should be valid. - The 'XXX_get_record()' function does the work of creating input + The `XXX_get_record()' function does the work of creating input records. The parameters are as follows: -'char **out' - This is a pointer to a 'char *' variable which is set to point to - the record. 'gawk' makes its own copy of the data, so the +`char **out' + This is a pointer to a `char *' variable which is set to point to + the record. `gawk' makes its own copy of the data, so the extension must manage this storage. -'struct awk_input *iobuf' - This is the 'awk_input_buf_t' for the file. The fields should be - used for reading data ('fd') and for managing private state - ('opaque'), if any. +`struct awk_input *iobuf' + This is the `awk_input_buf_t' for the file. The fields should be + used for reading data (`fd') and for managing private state + (`opaque'), if any. -'int *errcode' - If an error occurs, '*errcode' should be set to an appropriate code - from ''. +`int *errcode' + If an error occurs, `*errcode' should be set to an appropriate + code from `'. -'char **rt_start' -'size_t *rt_len' +`char **rt_start' +`size_t *rt_len' If the concept of a "record terminator" makes sense, then - '*rt_start' should be set to point to the data to be used for 'RT', - and '*rt_len' should be set to the length of the data. Otherwise, - '*rt_len' should be set to zero. 'gawk' makes its own copy of this - data, so the extension must manage the storage. + `*rt_start' should be set to point to the data to be used for + `RT', and `*rt_len' should be set to the length of the data. + Otherwise, `*rt_len' should be set to zero. `gawk' makes its own + copy of this data, so the extension must manage the storage. - The return value is the length of the buffer pointed to by '*out', or -'EOF' if end-of-file was reached or an error occurred. + The return value is the length of the buffer pointed to by `*out', +or `EOF' if end-of-file was reached or an error occurred. - It is guaranteed that 'errcode' is a valid pointer, so there is no -need to test for a 'NULL' value. 'gawk' sets '*errcode' to zero, so + It is guaranteed that `errcode' is a valid pointer, so there is no +need to test for a `NULL' value. `gawk' sets `*errcode' to zero, so there is no need to set it unless an error occurs. - If an error does occur, the function should return 'EOF' and set -'*errcode' to a value greater than zero. In that case, if '*errcode' -does not equal zero, 'gawk' automatically updates the 'ERRNO' variable -based on the value of '*errcode'. (In general, setting '*errcode = + If an error does occur, the function should return `EOF' and set +`*errcode' to a value greater than zero. In that case, if `*errcode' +does not equal zero, `gawk' automatically updates the `ERRNO' variable +based on the value of `*errcode'. (In general, setting `*errcode = errno' should do the right thing.) As an alternative to supplying a function that returns an input record, you may instead supply a function that simply reads bytes, and -let 'gawk' parse the data into records. If you do so, the data should +let `gawk' parse the data into records. If you do so, the data should be returned in the multibyte encoding of the current locale. Such a -function should follow the same behavior as the 'read()' system call, -and you fill in the 'read_func' pointer with its address in the -'awk_input_buf_t' structure. +function should follow the same behavior as the `read()' system call, +and you fill in the `read_func' pointer with its address in the +`awk_input_buf_t' structure. - By default, 'gawk' sets the 'read_func' pointer to point to the -'read()' system call. So your extension need not set this field + By default, `gawk' sets the `read_func' pointer to point to the +`read()' system call. So your extension need not set this field explicitly. NOTE: You must choose one method or the other: either a function that returns a record, or one that returns raw data. In - particular, if you supply a function to get a record, 'gawk' will + particular, if you supply a function to get a record, `gawk' will call it, and never call the raw read function. - 'gawk' ships with a sample extension that reads directories, + `gawk' ships with a sample extension that reads directories, returning records for each entry in the directory (*note Extension Sample Readdir::). You may wish to use that code as a guide for writing your own input parser. When writing an input parser, you should think about (and document) -how it is expected to interact with 'awk' code. You may want it to -always be called, and take effect as appropriate (as the 'readdir' -extension does). Or you may want it to take effect based upon the value -of an 'awk' variable, as the XML extension from the 'gawkextlib' project -does (*note gawkextlib::). In the latter case, code in a 'BEGINFILE' -section can look at 'FILENAME' and 'ERRNO' to decide whether or not to -activate an input parser (*note BEGINFILE/ENDFILE::). +how it is expected to interact with `awk' code. You may want it to +always be called, and take effect as appropriate (as the `readdir' +extension does). Or you may want it to take effect based upon the +value of an `awk' variable, as the XML extension from the `gawkextlib' +project does (*note gawkextlib::). In the latter case, code in a +`BEGINFILE' section can look at `FILENAME' and `ERRNO' to decide +whether or not to activate an input parser (*note BEGINFILE/ENDFILE::). You register your input parser with the following function: -'void register_input_parser(awk_input_parser_t *input_parser);' - Register the input parser pointed to by 'input_parser' with 'gawk'. +`void register_input_parser(awk_input_parser_t *input_parser);' + Register the input parser pointed to by `input_parser' with `gawk'.  File: gawk.info, Node: Output Wrappers, Next: Two-way processors, Prev: Input Parsers, Up: Registration Functions @@ -24427,8 +23328,8 @@ File: gawk.info, Node: Output Wrappers, Next: Two-way processors, Prev: Input ................................... An "output wrapper" is the mirror image of an input parser. It allows -an extension to take over the output to a file opened with the '>' or -'>>' I/O redirection operators (*note Redirection::). +an extension to take over the output to a file opened with the `>' or +`>>' I/O redirection operators (*note Redirection::). The output wrapper is very similar to the input parser structure: @@ -24441,27 +23342,28 @@ an extension to take over the output to a file opened with the '>' or The members are as follows: -'const char *name;' +`const char *name;' This is the name of the output wrapper. -'awk_bool_t (*can_take_file)(const awk_output_buf_t *outbuf);' +`awk_bool_t (*can_take_file)(const awk_output_buf_t *outbuf);' This points to a function that examines the information in the - 'awk_output_buf_t' structure pointed to by 'outbuf'. It should + `awk_output_buf_t' structure pointed to by `outbuf'. It should return true if the output wrapper wants to take over the file, and false otherwise. It should not change any state (variable values, - etc.) within 'gawk'. + etc.) within `gawk'. -'awk_bool_t (*take_control_of)(awk_output_buf_t *outbuf);' - The function pointed to by this field is called when 'gawk' decides - to let the output wrapper take control of the file. It should fill - in appropriate members of the 'awk_output_buf_t' structure, as - described below, and return true if successful, false otherwise. +`awk_bool_t (*take_control_of)(awk_output_buf_t *outbuf);' + The function pointed to by this field is called when `gawk' + decides to let the output wrapper take control of the file. It + should fill in appropriate members of the `awk_output_buf_t' + structure, as described below, and return true if successful, + false otherwise. -'awk_const struct output_wrapper *awk_const next;' - This is for use by 'gawk'; therefore it is marked 'awk_const' so +`awk_const struct output_wrapper *awk_const next;' + This is for use by `gawk'; therefore it is marked `awk_const' so that the extension cannot modify it. - The 'awk_output_buf_t' structure looks like this: + The `awk_output_buf_t' structure looks like this: typedef struct awk_output_buf { const char *name; /* name of output file */ @@ -24476,55 +23378,55 @@ an extension to take over the output to a file opened with the '>' or int (*gawk_fclose)(FILE *fp, void *opaque); } awk_output_buf_t; - Here too, your extension will define 'XXX_can_take_file()' and -'XXX_take_control_of()' functions that examine and update data members -in the 'awk_output_buf_t'. The data members are as follows: + Here too, your extension will define `XXX_can_take_file()' and +`XXX_take_control_of()' functions that examine and update data members +in the `awk_output_buf_t'. The data members are as follows: -'const char *name;' +`const char *name;' The name of the output file. -'const char *mode;' +`const char *mode;' The mode string (as would be used in the second argument to - 'fopen()') with which the file was opened. + `fopen()') with which the file was opened. -'FILE *fp;' - The 'FILE' pointer from ''. 'gawk' opens the file before +`FILE *fp;' + The `FILE' pointer from `'. `gawk' opens the file before attempting to find an output wrapper. -'awk_bool_t redirected;' - This field must be set to true by the 'XXX_take_control_of()' +`awk_bool_t redirected;' + This field must be set to true by the `XXX_take_control_of()' function. -'void *opaque;' - This pointer is opaque to 'gawk'. The extension should use it to +`void *opaque;' + This pointer is opaque to `gawk'. The extension should use it to store a pointer to any private data associated with the file. -'size_t (*gawk_fwrite)(const void *buf, size_t size, size_t count,' -' FILE *fp, void *opaque);' -'int (*gawk_fflush)(FILE *fp, void *opaque);' -'int (*gawk_ferror)(FILE *fp, void *opaque);' -'int (*gawk_fclose)(FILE *fp, void *opaque);' - These pointers should be set to point to functions that perform the - equivalent function as the '' functions do, if - appropriate. 'gawk' uses these function pointers for all output. - 'gawk' initializes the pointers to point to internal, "pass - through" functions that just call the regular '' +`size_t (*gawk_fwrite)(const void *buf, size_t size, size_t count,' +` FILE *fp, void *opaque);' +`int (*gawk_fflush)(FILE *fp, void *opaque);' +`int (*gawk_ferror)(FILE *fp, void *opaque);' +`int (*gawk_fclose)(FILE *fp, void *opaque);' + These pointers should be set to point to functions that perform + the equivalent function as the `' functions do, if + appropriate. `gawk' uses these function pointers for all output. + `gawk' initializes the pointers to point to internal, "pass + through" functions that just call the regular `' functions, so an extension only needs to redefine those functions that are appropriate for what it does. - The 'XXX_can_take_file()' function should make a decision based upon -the 'name' and 'mode' fields, and any additional state (such as 'awk' + The `XXX_can_take_file()' function should make a decision based upon +the `name' and `mode' fields, and any additional state (such as `awk' variable values) that is appropriate. - When 'gawk' calls 'XXX_take_control_of()', that function should fill -in the other fields, as appropriate, except for 'fp', which it should + When `gawk' calls `XXX_take_control_of()', that function should fill +in the other fields, as appropriate, except for `fp', which it should just use normally. You register your output wrapper with the following function: -'void register_output_wrapper(awk_output_wrapper_t *output_wrapper);' - Register the output wrapper pointed to by 'output_wrapper' with - 'gawk'. +`void register_output_wrapper(awk_output_wrapper_t *output_wrapper);' + Register the output wrapper pointed to by `output_wrapper' with + `gawk'.  File: gawk.info, Node: Two-way processors, Prev: Output Wrappers, Up: Registration Functions @@ -24533,8 +23435,8 @@ File: gawk.info, Node: Two-way processors, Prev: Output Wrappers, Up: Registr ...................................... A "two-way processor" combines an input parser and an output wrapper for -two-way I/O with the '|&' operator (*note Redirection::). It makes -identical use of the 'awk_input_parser_t' and 'awk_output_buf_t' +two-way I/O with the `|&' operator (*note Redirection::). It makes +identical use of the `awk_input_parser_t' and `awk_output_buf_t' structures as described earlier. A two-way processor is represented by the following structure: @@ -24550,110 +23452,110 @@ structures as described earlier. The fields are as follows: -'const char *name;' +`const char *name;' The name of the two-way processor. -'awk_bool_t (*can_take_two_way)(const char *name);' - This function returns true if it wants to take over two-way I/O for - this file name. It should not change any state (variable values, - etc.) within 'gawk'. +`awk_bool_t (*can_take_two_way)(const char *name);' + This function returns true if it wants to take over two-way I/O + for this file name. It should not change any state (variable + values, etc.) within `gawk'. -'awk_bool_t (*take_control_of)(const char *name,' -' awk_input_buf_t *inbuf,' -' awk_output_buf_t *outbuf);' - This function should fill in the 'awk_input_buf_t' and - 'awk_outut_buf_t' structures pointed to by 'inbuf' and 'outbuf', +`awk_bool_t (*take_control_of)(const char *name,' +` awk_input_buf_t *inbuf,' +` awk_output_buf_t *outbuf);' + This function should fill in the `awk_input_buf_t' and + `awk_outut_buf_t' structures pointed to by `inbuf' and `outbuf', respectively. These structures were described earlier. -'awk_const struct two_way_processor *awk_const next;' - This is for use by 'gawk'; therefore it is marked 'awk_const' so +`awk_const struct two_way_processor *awk_const next;' + This is for use by `gawk'; therefore it is marked `awk_const' so that the extension cannot modify it. - As with the input parser and output processor, you provide "yes I can -take this" and "take over for this" functions, 'XXX_can_take_two_way()' -and 'XXX_take_control_of()'. + As with the input parser and output processor, you provide "yes I +can take this" and "take over for this" functions, +`XXX_can_take_two_way()' and `XXX_take_control_of()'. You register your two-way processor with the following function: -'void register_two_way_processor(awk_two_way_processor_t *two_way_processor);' - Register the two-way processor pointed to by 'two_way_processor' - with 'gawk'. +`void register_two_way_processor(awk_two_way_processor_t *two_way_processor);' + Register the two-way processor pointed to by `two_way_processor' + with `gawk'.  -File: gawk.info, Node: Printing Messages, Next: Updating 'ERRNO', Prev: Registration Functions, Up: Extension API Description +File: gawk.info, Node: Printing Messages, Next: Updating `ERRNO', Prev: Registration Functions, Up: Extension API Description 16.4.7 Printing Messages ------------------------ You can print different kinds of warning messages from your extension, -as described below. Note that for these functions, you must pass in the -extension id received from 'gawk' when the extension was loaded.(1) +as described below. Note that for these functions, you must pass in +the extension id received from `gawk' when the extension was loaded.(1) -'void fatal(awk_ext_id_t id, const char *format, ...);' - Print a message and then cause 'gawk' to exit immediately. +`void fatal(awk_ext_id_t id, const char *format, ...);' + Print a message and then cause `gawk' to exit immediately. -'void warning(awk_ext_id_t id, const char *format, ...);' +`void warning(awk_ext_id_t id, const char *format, ...);' Print a warning message. -'void lintwarn(awk_ext_id_t id, const char *format, ...);' +`void lintwarn(awk_ext_id_t id, const char *format, ...);' Print a "lint warning." Normally this is the same as printing a - warning message, but if 'gawk' was invoked with '--lint=fatal', + warning message, but if `gawk' was invoked with `--lint=fatal', then lint warnings become fatal error messages. - All of these functions are otherwise like the C 'printf()' family of -functions, where the 'format' parameter is a string with literal + All of these functions are otherwise like the C `printf()' family of +functions, where the `format' parameter is a string with literal characters and formatting codes intermixed. ---------- Footnotes ---------- (1) Because the API uses only ISO C 90 features, it cannot make use -of the ISO C 99 variadic macro feature to hide that parameter. More's +of the ISO C 99 variadic macro feature to hide that parameter. More's the pity.  -File: gawk.info, Node: Updating 'ERRNO', Next: Accessing Parameters, Prev: Printing Messages, Up: Extension API Description +File: gawk.info, Node: Updating `ERRNO', Next: Accessing Parameters, Prev: Printing Messages, Up: Extension API Description -16.4.8 Updating 'ERRNO' +16.4.8 Updating `ERRNO' ----------------------- -The following functions allow you to update the 'ERRNO' variable: +The following functions allow you to update the `ERRNO' variable: -'void update_ERRNO_int(int errno_val);' - Set 'ERRNO' to the string equivalent of the error code in - 'errno_val'. The value should be one of the defined error codes in - '', and 'gawk' turns it into a (possibly translated) - string using the C 'strerror()' function. +`void update_ERRNO_int(int errno_val);' + Set `ERRNO' to the string equivalent of the error code in + `errno_val'. The value should be one of the defined error codes in + `', and `gawk' turns it into a (possibly translated) + string using the C `strerror()' function. -'void update_ERRNO_string(const char *string);' - Set 'ERRNO' directly to the string value of 'ERRNO'. 'gawk' makes - a copy of the value of 'string'. +`void update_ERRNO_string(const char *string);' + Set `ERRNO' directly to the string value of `ERRNO'. `gawk' makes + a copy of the value of `string'. -'void unset_ERRNO();' - Unset 'ERRNO'. +`void unset_ERRNO();' + Unset `ERRNO'.  -File: gawk.info, Node: Accessing Parameters, Next: Symbol Table Access, Prev: Updating 'ERRNO', Up: Extension API Description +File: gawk.info, Node: Accessing Parameters, Next: Symbol Table Access, Prev: Updating `ERRNO', Up: Extension API Description 16.4.9 Accessing and Updating Parameters ---------------------------------------- Two functions give you access to the arguments (parameters) passed to -your extension function. They are: - -'awk_bool_t get_argument(size_t count,' -' awk_valtype_t wanted,' -' awk_value_t *result);' - Fill in the 'awk_value_t' structure pointed to by 'result' with the - 'count''th argument. Return true if the actual type matches - 'wanted', false otherwise. In the latter case, 'result->val_type' +your extension function. They are: + +`awk_bool_t get_argument(size_t count,' +` awk_valtype_t wanted,' +` awk_value_t *result);' + Fill in the `awk_value_t' structure pointed to by `result' with + the `count''th argument. Return true if the actual type matches + `wanted', false otherwise. In the latter case, `result->val_type' indicates the actual type (*note Table 16.1: table-value-types-returned.). Counts are zero based--the first - argument is numbered zero, the second one, and so on. 'wanted' + argument is numbered zero, the second one, and so on. `wanted' indicates the type of value expected. -'awk_bool_t set_argument(size_t count, awk_array_t array);' +`awk_bool_t set_argument(size_t count, awk_array_t array);' Convert a parameter that was undefined into an array; this provides - call-by-reference for arrays. Return false if 'count' is too big, + call-by-reference for arrays. Return false if `count' is too big, or if the argument's type is not undefined. *Note Array Manipulation::, for more information on creating arrays. @@ -24669,7 +23571,7 @@ allows you to create and release cached values. * Menu: * Symbol table by name:: Accessing variables by name. -* Symbol table by cookie:: Accessing variables by "cookie". +* Symbol table by cookie:: Accessing variables by ``cookie''. * Cached values:: Creating and using cached values.  @@ -24679,38 +23581,38 @@ File: gawk.info, Node: Symbol table by name, Next: Symbol table by cookie, Up ............................................ The following routines provide the ability to access and update global -'awk'-level variables by name. In compiler terminology, identifiers of +`awk'-level variables by name. In compiler terminology, identifiers of different kinds are termed "symbols", thus the "sym" in the routines' names. The data structure which stores information about symbols is termed a "symbol table". -'awk_bool_t sym_lookup(const char *name,' -' awk_valtype_t wanted,' -' awk_value_t *result);' - Fill in the 'awk_value_t' structure pointed to by 'result' with the - value of the variable named by the string 'name', which is a - regular C string. 'wanted' indicates the type of value expected. - Return true if the actual type matches 'wanted', false otherwise In - the latter case, 'result->val_type' indicates the actual type +`awk_bool_t sym_lookup(const char *name,' +` awk_valtype_t wanted,' +` awk_value_t *result);' + Fill in the `awk_value_t' structure pointed to by `result' with + the value of the variable named by the string `name', which is a + regular C string. `wanted' indicates the type of value expected. + Return true if the actual type matches `wanted', false otherwise + In the latter case, `result->val_type' indicates the actual type (*note Table 16.1: table-value-types-returned.). -'awk_bool_t sym_update(const char *name, awk_value_t *value);' - Update the variable named by the string 'name', which is a regular - C string. The variable is added to 'gawk''s symbol table if it is +`awk_bool_t sym_update(const char *name, awk_value_t *value);' + Update the variable named by the string `name', which is a regular + C string. The variable is added to `gawk''s symbol table if it is not there. Return true if everything worked, false otherwise. Changing types (scalar to array or vice versa) of an existing variable is _not_ allowed, nor may this routine be used to update an array. This routine cannot be used to update any of the - predefined variables (such as 'ARGC' or 'NF'). + predefined variables (such as `ARGC' or `NF'). - An extension can look up the value of 'gawk''s special variables. -However, with the exception of the 'PROCINFO' array, an extension cannot -change any of those variables. + An extension can look up the value of `gawk''s special variables. +However, with the exception of the `PROCINFO' array, an extension +cannot change any of those variables. - NOTE: It is possible for the lookup of 'PROCINFO' to fail. This - happens if the 'awk' program being run does not reference - 'PROCINFO'; in this case 'gawk' doesn't bother to create the array + NOTE: It is possible for the lookup of `PROCINFO' to fail. This + happens if the `awk' program being run does not reference + `PROCINFO'; in this case `gawk' doesn't bother to create the array and populate it.  @@ -24720,28 +23622,28 @@ File: gawk.info, Node: Symbol table by cookie, Next: Cached values, Prev: Sym .............................................. A "scalar cookie" is an opaque handle that provides access to a global -variable or array. It is an optimization that avoids looking up -variables in 'gawk''s symbol table every time access is needed. This +variable or array. It is an optimization that avoids looking up +variables in `gawk''s symbol table every time access is needed. This was discussed earlier, in *note General Data Types::. The following functions let you work with scalar cookies. -'awk_bool_t sym_lookup_scalar(awk_scalar_t cookie,' -' awk_valtype_t wanted,' -' awk_value_t *result);' +`awk_bool_t sym_lookup_scalar(awk_scalar_t cookie,' +` awk_valtype_t wanted,' +` awk_value_t *result);' Retrieve the current value of a scalar cookie. Once you have - obtained a scalar_cookie using 'sym_lookup()', you can use this + obtained a scalar_cookie using `sym_lookup()', you can use this function to get its value more efficiently. Return false if the value cannot be retrieved. -'awk_bool_t sym_update_scalar(awk_scalar_t cookie, awk_value_t *value);' +`awk_bool_t sym_update_scalar(awk_scalar_t cookie, awk_value_t *value);' Update the value associated with a scalar cookie. Return false if - the new value is not of type 'AWK_STRING' or 'AWK_NUMBER'. Here + the new value is not of type `AWK_STRING' or `AWK_NUMBER'. Here too, the built-in variables may not be updated. It is not obvious at first glance how to work with scalar cookies or -what their raison d'e^tre really is. In theory, the 'sym_lookup()' and -'sym_update()' routines are all you really need to work with variables. +what their raison d'e^tre really is. In theory, the `sym_lookup()' and +`sym_update()' routines are all you really need to work with variables. For example, you might have code that looks up the value of a variable, evaluates a condition, and then possibly changes the value of the variable based on the result of that evaluation, like so: @@ -24762,13 +23664,13 @@ variable based on the result of that evaluation, like so: return make_number(0.0, result); } -This code looks (and is) simple and straightforward. So what's the +This code looks (and is) simple and straightforward. So what's the problem? - Consider what happens if 'awk'-level code associated with your -extension calls the 'magic()' function (implemented in C by -'do_magic()'), once per record, while processing hundreds of thousands -or millions of records. The 'MAGIC_VAR' variable is looked up in the + Consider what happens if `awk'-level code associated with your +extension calls the `magic()' function (implemented in C by +`do_magic()'), once per record, while processing hundreds of thousands +or millions of records. The `MAGIC_VAR' variable is looked up in the symbol table once or twice per function call! The symbol table lookup is really pure overhead; it is considerably @@ -24776,8 +23678,8 @@ more efficient to get a cookie that represents the variable, and use that to get the variable's value and update it as needed.(1) Thus, the way to use cookies is as follows. First, install your -extension's variable in 'gawk''s symbol table using 'sym_update()', as -usual. Then get a scalar cookie for the variable using 'sym_lookup()': +extension's variable in `gawk''s symbol table using `sym_update()', as +usual. Then get a scalar cookie for the variable using `sym_lookup()': static awk_scalar_t magic_var_cookie; /* cookie for MAGIC_VAR */ @@ -24798,7 +23700,7 @@ usual. Then get a scalar cookie for the variable using 'sym_lookup()': } Next, use the routines in this section for retrieving and updating -the value through the cookie. Thus, 'do_magic()' now becomes something +the value through the cookie. Thus, `do_magic()' now becomes something like this: /* do_magic --- do something really great */ @@ -24824,7 +23726,7 @@ like this: ---------- Footnotes ---------- - (1) The difference is measurable and quite real. Trust us. + (1) The difference is measurable and quite real. Trust us.  File: gawk.info, Node: Cached values, Prev: Symbol table by cookie, Up: Symbol Table Access @@ -24834,31 +23736,31 @@ File: gawk.info, Node: Cached values, Prev: Symbol table by cookie, Up: Symbo The routines in this section allow you to create and release cached values. As with scalar cookies, in theory, cached values are not -necessary. You can create numbers and strings using the functions in -*note Constructor Functions::. You can then assign those values to -variables using 'sym_update()' or 'sym_update_scalar()', as you like. +necessary. You can create numbers and strings using the functions in +*note Constructor Functions::. You can then assign those values to +variables using `sym_update()' or `sym_update_scalar()', as you like. However, you can understand the point of cached values if you remember that _every_ string value's storage _must_ come from -'api_malloc()', 'api_calloc()' or 'api_realloc()'. If you have 20 +`api_malloc()', `api_calloc()' or `api_realloc()'. If you have 20 variables, all of which have the same string value, you must create 20 identical copies of the string.(1) It is clearly more efficient, if possible, to create a value once, -and then tell 'gawk' to reuse the value for multiple variables. That is +and then tell `gawk' to reuse the value for multiple variables. That is what the routines in this section let you do. The functions are as follows: -'awk_bool_t create_value(awk_value_t *value, awk_value_cookie_t *result);' - Create a cached string or numeric value from 'value' for efficient - later assignment. Only values of type 'AWK_NUMBER' and - 'AWK_STRING' are allowed. Any other type is rejected. While - 'AWK_UNDEFINED' could be allowed, doing so would result in inferior - performance. +`awk_bool_t create_value(awk_value_t *value, awk_value_cookie_t *result);' + Create a cached string or numeric value from `value' for efficient + later assignment. Only values of type `AWK_NUMBER' and + `AWK_STRING' are allowed. Any other type is rejected. While + `AWK_UNDEFINED' could be allowed, doing so would result in + inferior performance. -'awk_bool_t release_value(awk_value_cookie_t vc);' +`awk_bool_t release_value(awk_value_cookie_t vc);' Release the memory associated with a value cookie obtained from - 'create_value()'. + `create_value()'. You use value cookies in a fashion similar to the way you use scalar cookies. In the extension initialization routine, you create the value @@ -24901,27 +23803,27 @@ of variables: } Using value cookies in this way saves considerable storage, since all of -'VAR1' through 'VAR100' share the same value. +`VAR1' through `VAR100' share the same value. You might be wondering, "Is this sharing problematic? What happens -if 'awk' code assigns a new value to 'VAR1', are all the others be +if `awk' code assigns a new value to `VAR1', are all the others be changed too?" - That's a great question. The answer is that no, it's not a problem. -Internally, 'gawk' uses "reference-counted strings". This means that -many variables can share the same string value, and 'gawk' keeps track -of the usage. When a variable's value changes, 'gawk' simply decrements -the reference count on the old value and updates the variable to use the -new value. + That's a great question. The answer is that no, it's not a problem. +Internally, `gawk' uses "reference-counted strings". This means that +many variables can share the same string value, and `gawk' keeps track +of the usage. When a variable's value changes, `gawk' simply +decrements the reference count on the old value and updates the +variable to use the new value. Finally, as part of your cleanup action (*note Exit Callback Functions::) you should release any cached values that you created, -using 'release_value()'. +using `release_value()'. ---------- Footnotes ---------- (1) Numeric values are clearly less problematic, requiring only a C -'double' to store. +`double' to store.  File: gawk.info, Node: Array Manipulation, Next: Extension API Variables, Prev: Symbol Table Access, Up: Extension API Description @@ -24929,11 +23831,11 @@ File: gawk.info, Node: Array Manipulation, Next: Extension API Variables, Pre 16.4.11 Array Manipulation -------------------------- -The primary data structure(1) in 'awk' is the associative array (*note -Arrays::). Extensions need to be able to manipulate 'awk' arrays. The +The primary data structure(1) in `awk' is the associative array (*note +Arrays::). Extensions need to be able to manipulate `awk' arrays. The API provides a number of data structures for working with arrays, functions for working with individual elements, and functions for -working with arrays as a whole. This includes the ability to "flatten" +working with arrays as a whole. This includes the ability to "flatten" an array so that it is easy for C code to traverse every element in an array. The array data structures integrate nicely with the data structures for values to make it easy to both work with and create true @@ -24958,63 +23860,63 @@ File: gawk.info, Node: Array Data Types, Next: Array Functions, Up: Array Man The data types associated with arrays are listed below. -'typedef void *awk_array_t;' +`typedef void *awk_array_t;' If you request the value of an array variable, you get back an - 'awk_array_t' value. This value is opaque(1) to the extension; it + `awk_array_t' value. This value is opaque(1) to the extension; it uniquely identifies the array but can only be used by passing it - into API functions or receiving it from API functions. This is - very similar to way 'FILE *' values are used with the '' + into API functions or receiving it from API functions. This is + very similar to way `FILE *' values are used with the `' library routines. -'typedef struct awk_element {' -' /* convenience linked list pointer, not used by gawk */' -' struct awk_element *next;' -' enum {' -' AWK_ELEMENT_DEFAULT = 0, /* set by gawk */' -' AWK_ELEMENT_DELETE = 1 /* set by extension if should be deleted */' -' } flags;' -' awk_value_t index;' -' awk_value_t value;' -'} awk_element_t;' - The 'awk_element_t' is a "flattened" array element. 'awk' produces - an array of these inside the 'awk_flat_array_t' (see the next - item). Individual elements may be marked for deletion. New +`typedef struct awk_element {' +` /* convenience linked list pointer, not used by gawk */' +` struct awk_element *next;' +` enum {' +` AWK_ELEMENT_DEFAULT = 0, /* set by gawk */' +` AWK_ELEMENT_DELETE = 1 /* set by extension if should be deleted */' +` } flags;' +` awk_value_t index;' +` awk_value_t value;' +`} awk_element_t;' + The `awk_element_t' is a "flattened" array element. `awk' produces + an array of these inside the `awk_flat_array_t' (see the next + item). Individual elements may be marked for deletion. New elements must be added individually, one at a time, using the separate API for that purpose. The fields are as follows: - 'struct awk_element *next;' + `struct awk_element *next;' This pointer is for the convenience of extension writers. It allows an extension to create a linked list of new elements that can then be added to an array in a loop that traverses the list. - 'enum { ... } flags;' - A set of flag values that convey information between 'gawk' - and the extension. Currently there is only one: - 'AWK_ELEMENT_DELETE'. Setting it causes 'gawk' to delete the + `enum { ... } flags;' + A set of flag values that convey information between `gawk' + and the extension. Currently there is only one: + `AWK_ELEMENT_DELETE'. Setting it causes `gawk' to delete the element from the original array upon release of the flattened array. - 'index' - 'value' + `index' + `value' The index and value of the element, respectively. _All_ - memory pointed to by 'index' and 'value' belongs to 'gawk'. - -'typedef struct awk_flat_array {' -' awk_const void *awk_const opaque1; /* private data for use by gawk */' -' awk_const void *awk_const opaque2; /* private data for use by gawk */' -' awk_const size_t count; /* how many elements */' -' awk_element_t elements[1]; /* will be extended */' -'} awk_flat_array_t;' - This is a flattened array. When an extension gets one of these - from 'gawk', the 'elements' array is of actual size 'count'. The - 'opaque1' and 'opaque2' pointers are for use by 'gawk'; therefore - they are marked 'awk_const' so that the extension cannot modify + memory pointed to by `index' and `value' belongs to `gawk'. + +`typedef struct awk_flat_array {' +` awk_const void *awk_const opaque1; /* private data for use by gawk */' +` awk_const void *awk_const opaque2; /* private data for use by gawk */' +` awk_const size_t count; /* how many elements */' +` awk_element_t elements[1]; /* will be extended */' +`} awk_flat_array_t;' + This is a flattened array. When an extension gets one of these + from `gawk', the `elements' array is of actual size `count'. The + `opaque1' and `opaque2' pointers are for use by `gawk'; therefore + they are marked `awk_const' so that the extension cannot modify them. ---------- Footnotes ---------- - (1) It is also a "cookie," but the 'gawk' developers did not wish to + (1) It is also a "cookie," but the `gawk' developers did not wish to overuse this term.  @@ -25025,75 +23927,75 @@ File: gawk.info, Node: Array Functions, Next: Flattening Arrays, Prev: Array The following functions relate to individual array elements. -'awk_bool_t get_element_count(awk_array_t a_cookie, size_t *count);' - For the array represented by 'a_cookie', return in '*count' the - number of elements it contains. A subarray counts as a single +`awk_bool_t get_element_count(awk_array_t a_cookie, size_t *count);' + For the array represented by `a_cookie', return in `*count' the + number of elements it contains. A subarray counts as a single element. Return false if there is an error. -'awk_bool_t get_array_element(awk_array_t a_cookie,' -' const awk_value_t *const index,' -' awk_valtype_t wanted,' -' awk_value_t *result);' - For the array represented by 'a_cookie', return in '*result' the - value of the element whose index is 'index'. 'wanted' specifies - the type of value you wish to retrieve. Return false if 'wanted' - does not match the actual type or if 'index' is not in the array +`awk_bool_t get_array_element(awk_array_t a_cookie,' +` const awk_value_t *const index,' +` awk_valtype_t wanted,' +` awk_value_t *result);' + For the array represented by `a_cookie', return in `*result' the + value of the element whose index is `index'. `wanted' specifies + the type of value you wish to retrieve. Return false if `wanted' + does not match the actual type or if `index' is not in the array (*note Table 16.1: table-value-types-returned.). - The value for 'index' can be numeric, in which case 'gawk' converts - it to a string. Using non-integral values is possible, but + The value for `index' can be numeric, in which case `gawk' + converts it to a string. Using non-integral values is possible, but requires that you understand how such values are converted to strings (*note Conversion::); thus using integral values is safest. - As with _all_ strings passed into 'gawk' from an extension, the - string value of 'index' must come from the API-provided functions - 'api_malloc()', 'api_calloc()' or 'api_realloc()' and 'gawk' + As with _all_ strings passed into `gawk' from an extension, the + string value of `index' must come from the API-provided functions + `api_malloc()', `api_calloc()' or `api_realloc()' and `gawk' releases the storage. -'awk_bool_t set_array_element(awk_array_t a_cookie,' -' const awk_value_t *const index,' -' const awk_value_t *const value);' - In the array represented by 'a_cookie', create or modify the - element whose index is given by 'index'. The 'ARGV' and 'ENVIRON' - arrays may not be changed, although the 'PROCINFO' array can be. +`awk_bool_t set_array_element(awk_array_t a_cookie,' +` const awk_value_t *const index,' +` const awk_value_t *const value);' + In the array represented by `a_cookie', create or modify the + element whose index is given by `index'. The `ARGV' and `ENVIRON' + arrays may not be changed, although the `PROCINFO' array can be. -'awk_bool_t set_array_element_by_elem(awk_array_t a_cookie,' -' awk_element_t element);' - Like 'set_array_element()', but take the 'index' and 'value' from - 'element'. This is a convenience macro. +`awk_bool_t set_array_element_by_elem(awk_array_t a_cookie,' +` awk_element_t element);' + Like `set_array_element()', but take the `index' and `value' from + `element'. This is a convenience macro. -'awk_bool_t del_array_element(awk_array_t a_cookie,' -' const awk_value_t* const index);' +`awk_bool_t del_array_element(awk_array_t a_cookie,' +` const awk_value_t* const index);' Remove the element with the given index from the array represented - by 'a_cookie'. Return true if the element was removed, or false if - the element did not exist in the array. + by `a_cookie'. Return true if the element was removed, or false + if the element did not exist in the array. The following functions relate to arrays as a whole: -'awk_array_t create_array();' +`awk_array_t create_array();' Create a new array to which elements may be added. *Note Creating Arrays::, for a discussion of how to create a new array and add elements to it. -'awk_bool_t clear_array(awk_array_t a_cookie);' - Clear the array represented by 'a_cookie'. Return false if there +`awk_bool_t clear_array(awk_array_t a_cookie);' + Clear the array represented by `a_cookie'. Return false if there was some kind of problem, true otherwise. The array remains an - array, but after calling this function, it has no elements. This - is equivalent to using the 'delete' statement (*note Delete::). + array, but after calling this function, it has no elements. This + is equivalent to using the `delete' statement (*note Delete::). -'awk_bool_t flatten_array(awk_array_t a_cookie, awk_flat_array_t **data);' - For the array represented by 'a_cookie', create an - 'awk_flat_array_t' structure and fill it in. Set the pointer whose - address is passed as 'data' to point to this structure. Return +`awk_bool_t flatten_array(awk_array_t a_cookie, awk_flat_array_t **data);' + For the array represented by `a_cookie', create an + `awk_flat_array_t' structure and fill it in. Set the pointer whose + address is passed as `data' to point to this structure. Return true upon success, or false otherwise. *Note Flattening Arrays::, for a discussion of how to flatten an array and work with it. -'awk_bool_t release_flattened_array(awk_array_t a_cookie,' -' awk_flat_array_t *data);' +`awk_bool_t release_flattened_array(awk_array_t a_cookie,' +` awk_flat_array_t *data);' When done with a flattened array, release the storage using this - function. You must pass in both the original array cookie, and the - address of the created 'awk_flat_array_t' structure. The function - returns true upon success, false otherwise. + function. You must pass in both the original array cookie, and + the address of the created `awk_flat_array_t' structure. The + function returns true upon success, false otherwise.  File: gawk.info, Node: Flattening Arrays, Next: Creating Arrays, Prev: Array Functions, Up: Array Manipulation @@ -25103,10 +24005,10 @@ File: gawk.info, Node: Flattening Arrays, Next: Creating Arrays, Prev: Array To "flatten" an array is create a structure that represents the full array in a fashion that makes it easy for C code to traverse the entire -array. Test code in 'extension/testext.c' does this, and also serves as -a nice example showing how to use the APIs. +array. Test code in `extension/testext.c' does this, and also serves +as a nice example showing how to use the APIs. - First, the 'gawk' script that drives the test extension: + First, the `gawk' script that drives the test extension: @load "testext" BEGIN { @@ -25121,16 +24023,16 @@ a nice example showing how to use the APIs. print "" } -This code creates an array with 'split()' (*note String Functions::) and -then calls 'dump_array_and_delete()'. That function looks up the array -whose name is passed as the first argument, and deletes the element at -the index passed in the second argument. The 'awk' code then prints the -return value and checks if the element was indeed deleted. Here is the -C code that implements 'dump_array_and_delete()'. It has been edited -slightly for presentation. +This code creates an array with `split()' (*note String Functions::) +and then calls `dump_array_and_delete()'. That function looks up the +array whose name is passed as the first argument, and deletes the +element at the index passed in the second argument. The `awk' code +then prints the return value and checks if the element was indeed +deleted. Here is the C code that implements `dump_array_and_delete()'. +It has been edited slightly for presentation. The first part declares variables, sets up the default return value -in 'result', and checks that the function was called with the correct +in `result', and checks that the function was called with the correct number of arguments: static awk_value_t * @@ -25151,9 +24053,9 @@ number of arguments: goto out; } - The function then proceeds in steps, as follows. First, retrieve the -name of the array, passed as the first argument. Then retrieve the -array itself. If either operation fails, print error messages and + The function then proceeds in steps, as follows. First, retrieve the +name of the array, passed as the first argument. Then retrieve the +array itself. If either operation fails, print error messages and return: /* get argument named array as flat array and print it */ @@ -25173,7 +24075,7 @@ return: } For testing purposes and to make sure that the C code sees the same -number of elements as the 'awk' code, the second step is to get the +number of elements as the `awk' code, the second step is to get the count of elements in the array and print it: if (! get_element_count(value2.array_cookie, & count)) { @@ -25185,7 +24087,7 @@ count of elements in the array and print it: (unsigned long) count); The third step is to actually flatten the array, and then to double -check that the count in the 'awk_flat_array_t' is the same as the count +check that the count in the `awk_flat_array_t' is the same as the count just retrieved: if (! flatten_array(value2.array_cookie, & flat_array)) { @@ -25203,7 +24105,7 @@ just retrieved: The fourth step is to retrieve the index of the element to be deleted, which was passed as the second argument. Remember that -argument counts passed to 'get_argument()' are zero-based, thus the +argument counts passed to `get_argument()' are zero-based, thus the second argument is numbered one: if (! get_argument(1, AWK_STRING, & value3)) { @@ -25211,11 +24113,11 @@ second argument is numbered one: goto out; } - The fifth step is where the "real work" is done. The function loops + The fifth step is where the "real work" is done. The function loops over every element in the array, printing the index and element values. -In addition, upon finding the element with the index that is supposed to -be deleted, the function sets the 'AWK_ELEMENT_DELETE' bit in the -'flags' field of the element. When the array is released, 'gawk' +In addition, upon finding the element with the index that is supposed +to be deleted, the function sets the `AWK_ELEMENT_DELETE' bit in the +`flags' field of the element. When the array is released, `gawk' traverses the flattened array, and deletes any elements which have this flag bit set: @@ -25236,11 +24138,11 @@ flag bit set: } } - The sixth step is to release the flattened array. This tells 'gawk' + The sixth step is to release the flattened array. This tells `gawk' that the extension is no longer using the array, and that it should -delete any elements marked for deletion. 'gawk' also frees any storage -that was allocated, so you should not use the pointer ('flat_array' in -this code) once you have called 'release_flattened_array()': +delete any elements marked for deletion. `gawk' also frees any storage +that was allocated, so you should not use the pointer (`flat_array' in +this code) once you have called `release_flattened_array()': if (! release_flattened_array(value2.array_cookie, flat_array)) { printf("dump_array_and_delete: could not release flattened array\n"); @@ -25275,30 +24177,30 @@ File: gawk.info, Node: Creating Arrays, Prev: Flattening Arrays, Up: Array Ma 16.4.11.4 How To Create and Populate Arrays ........................................... -Besides working with arrays created by 'awk' code, you can create arrays -and populate them as you see fit, and then 'awk' code can access them -and manipulate them. +Besides working with arrays created by `awk' code, you can create +arrays and populate them as you see fit, and then `awk' code can access +them and manipulate them. There are two important points about creating arrays from extension code: - 1. You must install a new array into 'gawk''s symbol table immediately - upon creating it. Once you have done so, you can then populate the - array. + 1. You must install a new array into `gawk''s symbol table + immediately upon creating it. Once you have done so, you can then + populate the array. Similarly, if installing a new array as a subarray of an existing array, you must add the new array to its parent before adding any elements to it. Thus, the correct way to build an array is to work "top down." - Create the array, and immediately install it in 'gawk''s symbol - table using 'sym_update()', or install it as an element in a - previously existing array using 'set_array_element()'. We show + Create the array, and immediately install it in `gawk''s symbol + table using `sym_update()', or install it as an element in a + previously existing array using `set_array_element()'. We show example code shortly. - 2. Due to gawk internals, after using 'sym_update()' to install an - array into 'gawk', you have to retrieve the array cookie from the - value passed in to 'sym_update()' before doing anything else with + 2. Due to gawk internals, after using `sym_update()' to install an + array into `gawk', you have to retrieve the array cookie from the + value passed in to `sym_update()' before doing anything else with it, like so: awk_value_t value; @@ -25314,13 +24216,13 @@ code: new_array = val.array_cookie; /* YOU MUST DO THIS */ If installing an array as a subarray, you must also retrieve the - value of the array cookie after the call to 'set_element()'. + value of the array cookie after the call to `set_element()'. The following C code is a simple test extension to create an array -with two regular elements and with a subarray. The leading '#include' +with two regular elements and with a subarray. The leading `#include' directives and boilerplate variable declarations are omitted for -brevity. The first step is to create a new array and then install it in -the symbol table: +brevity. The first step is to create a new array and then install it +in the symbol table: /* create_new_array --- create a named array */ @@ -25339,10 +24241,10 @@ the symbol table: printf("create_new_array: sym_update(\"new_array\") failed!\n"); a_cookie = value.array_cookie; -Note how 'a_cookie' is reset from the 'array_cookie' field in the -'value' structure. +Note how `a_cookie' is reset from the `array_cookie' field in the +`value' structure. - The second step is to install two regular values into 'new_array': + The second step is to install two regular values into `new_array': (void) make_const_string("hello", 5, & index); (void) make_const_string("world", 5, & value); @@ -25405,7 +24307,7 @@ array: -| new_array["hello"] = world -| new_array["answer"] = 42 -(*Note Finding Extensions::, for more information on the 'AWKLIBPATH' +(*Note Finding Extensions::, for more information on the `AWKLIBPATH' environment variable.)  @@ -25416,14 +24318,14 @@ File: gawk.info, Node: Extension API Variables, Next: Extension API Boilerplat The API provides two sets of variables. The first provides information about the version of the API (both with which the extension was -compiled, and with which 'gawk' was compiled). The second provides -information about how 'gawk' was invoked. +compiled, and with which `gawk' was compiled). The second provides +information about how `gawk' was invoked. * Menu: * Extension Versioning:: API Version information. * Extension API Informational Variables:: Variables providing information about - 'gawk''s invocation. + `gawk''s invocation.  File: gawk.info, Node: Extension Versioning, Next: Extension API Informational Variables, Up: Extension API Variables @@ -25434,29 +24336,29 @@ File: gawk.info, Node: Extension Versioning, Next: Extension API Informational The API provides both a "major" and a "minor" version number. The API versions are available at compile time as constants: -'GAWK_API_MAJOR_VERSION' +`GAWK_API_MAJOR_VERSION' The major version of the API. -'GAWK_API_MINOR_VERSION' +`GAWK_API_MINOR_VERSION' The minor version of the API. The minor version increases when new functions are added to the API. -Such new functions are always added to the end of the API 'struct'. +Such new functions are always added to the end of the API `struct'. The major version increases (and the minor version is reset to zero) if any of the data types change size or member order, or if any of the existing functions change signature. It could happen that an extension may be compiled against one version -of the API but loaded by a version of 'gawk' using a different version. -For this reason, the major and minor API versions of the running 'gawk' -are included in the API 'struct' as read-only constant integers: +of the API but loaded by a version of `gawk' using a different version. +For this reason, the major and minor API versions of the running `gawk' +are included in the API `struct' as read-only constant integers: -'api->major_version' - The major version of the running 'gawk'. +`api->major_version' + The major version of the running `gawk'. -'api->minor_version' - The minor version of the running 'gawk'. +`api->minor_version' + The minor version of the running `gawk'. It is up to the extension to decide if there are API incompatibilities. Typically a check like this is enough: @@ -25470,8 +24372,8 @@ incompatibilities. Typically a check like this is enough: exit(1); } - Such code is included in the boilerplate 'dl_load_func()' macro -provided in 'gawkapi.h' (discussed later, in *note Extension API + Such code is included in the boilerplate `dl_load_func()' macro +provided in `gawkapi.h' (discussed later, in *note Extension API Boilerplate::).  @@ -25481,32 +24383,32 @@ File: gawk.info, Node: Extension API Informational Variables, Prev: Extension ................................. The API provides access to several variables that describe whether the -corresponding command-line options were enabled when 'gawk' was invoked. -The variables are: +corresponding command-line options were enabled when `gawk' was +invoked. The variables are: -'do_debug' - This variable is true if 'gawk' was invoked with '--debug' option. +`do_debug' + This variable is true if `gawk' was invoked with `--debug' option. -'do_lint' - This variable is true if 'gawk' was invoked with '--lint' option +`do_lint' + This variable is true if `gawk' was invoked with `--lint' option (*note Options::). -'do_mpfr' - This variable is true if 'gawk' was invoked with '--bignum' option. +`do_mpfr' + This variable is true if `gawk' was invoked with `--bignum' option. -'do_profile' - This variable is true if 'gawk' was invoked with '--profile' +`do_profile' + This variable is true if `gawk' was invoked with `--profile' option. -'do_sandbox' - This variable is true if 'gawk' was invoked with '--sandbox' +`do_sandbox' + This variable is true if `gawk' was invoked with `--sandbox' option. -'do_traditional' - This variable is true if 'gawk' was invoked with '--traditional' +`do_traditional' + This variable is true if `gawk' was invoked with `--traditional' option. - The value of 'do_lint' can change if 'awk' code modifies the 'LINT' + The value of `do_lint' can change if `awk' code modifies the `LINT' built-in variable (*note Built-in Variables::). The others should not change during execution. @@ -25517,11 +24419,11 @@ File: gawk.info, Node: Extension API Boilerplate, Prev: Extension API Variable ------------------------ As mentioned earlier (*note Extension Mechanism Outline::), the function -definitions as presented are really macros. To use these macros, your +definitions as presented are really macros. To use these macros, your extension must provide a small amount of boilerplate code (variables and functions) towards the top of your source file, using pre-defined names as described below. The boilerplate needed is also provided in comments -in the 'gawkapi.h' header file: +in the `gawkapi.h' header file: /* Boiler plate code: */ int plugin_is_GPL_compatible; @@ -25553,75 +24455,76 @@ in the 'gawkapi.h' header file: These variables and functions are as follows: -'int plugin_is_GPL_compatible;' +`int plugin_is_GPL_compatible;' This asserts that the extension is compatible with the GNU GPL - (*note Copying::). If your extension does not have this, 'gawk' + (*note Copying::). If your extension does not have this, `gawk' will not load it (*note Plugin License::). -'static gawk_api_t *const api;' - This global 'static' variable should be set to point to the - 'gawk_api_t' pointer that 'gawk' passes to your 'dl_load()' +`static gawk_api_t *const api;' + This global `static' variable should be set to point to the + `gawk_api_t' pointer that `gawk' passes to your `dl_load()' function. This variable is used by all of the macros. -'static awk_ext_id_t ext_id;' - This global static variable should be set to the 'awk_ext_id_t' - value that 'gawk' passes to your 'dl_load()' function. This +`static awk_ext_id_t ext_id;' + This global static variable should be set to the `awk_ext_id_t' + value that `gawk' passes to your `dl_load()' function. This variable is used by all of the macros. -'static const char *ext_version = NULL; /* or ... = "some string" */' - This global 'static' variable should be set either to 'NULL', or to - point to a string giving the name and version of your extension. +`static const char *ext_version = NULL; /* or ... = "some string" */' + This global `static' variable should be set either to `NULL', or + to point to a string giving the name and version of your extension. -'static awk_ext_func_t func_table[] = { ... };' - This is an array of one or more 'awk_ext_func_t' structures as +`static awk_ext_func_t func_table[] = { ... };' + This is an array of one or more `awk_ext_func_t' structures as described earlier (*note Extension Functions::). It can then be - looped over for multiple calls to 'add_ext_func()'. + looped over for multiple calls to `add_ext_func()'. -'static awk_bool_t (*init_func)(void) = NULL;' -' OR' -'static awk_bool_t init_my_module(void) { ... }' -'static awk_bool_t (*init_func)(void) = init_my_module;' +`static awk_bool_t (*init_func)(void) = NULL;' +` OR' +`static awk_bool_t init_my_module(void) { ... }' +`static awk_bool_t (*init_func)(void) = init_my_module;' If you need to do some initialization work, you should define a function that does it (creates variables, opens files, etc.) and - then define the 'init_func' pointer to point to your function. The - function should return 'awk_false' upon failure, or 'awk_true' if - everything goes well. + then define the `init_func' pointer to point to your function. + The function should return `awk_false' upon failure, or `awk_true' + if everything goes well. If you don't need to do any initialization, define the pointer and - initialize it to 'NULL'. + initialize it to `NULL'. -'dl_load_func(func_table, some_name, "name_space_in_quotes")' - This macro expands to a 'dl_load()' function that performs all the +`dl_load_func(func_table, some_name, "name_space_in_quotes")' + This macro expands to a `dl_load()' function that performs all the necessary initializations. The point of the all the variables and arrays is to let the -'dl_load()' function (from the 'dl_load_func()' macro) do all the -standard work. It does the following: +`dl_load()' function (from the `dl_load_func()' macro) do all the +standard work. It does the following: - 1. Check the API versions. If the extension major version does not - match 'gawk''s, or if the extension minor version is greater than - 'gawk''s, it prints a fatal error message and exits. + 1. Check the API versions. If the extension major version does not + match `gawk''s, or if the extension minor version is greater than + `gawk''s, it prints a fatal error message and exits. - 2. Load the functions defined in 'func_table'. If any of them fails + 2. Load the functions defined in `func_table'. If any of them fails to load, it prints a warning message but continues on. - 3. If the 'init_func' pointer is not 'NULL', call the function it - points to. If it returns 'awk_false', print a warning message. + 3. If the `init_func' pointer is not `NULL', call the function it + points to. If it returns `awk_false', print a warning message. - 4. If 'ext_version' is not 'NULL', register the version string with - 'gawk'. + 4. If `ext_version' is not `NULL', register the version string with + `gawk'.  File: gawk.info, Node: Finding Extensions, Next: Extension Example, Prev: Extension API Description, Up: Dynamic Extensions -16.5 How 'gawk' Finds Extensions +16.5 How `gawk' Finds Extensions ================================ -Compiled extensions have to be installed in a directory where 'gawk' can -find them. If 'gawk' is configured and built in the default fashion, -the directory in which to find extensions is '/usr/local/lib/gawk'. You -can also specify a search path with a list of directories to search for -compiled extensions. *Note AWKLIBPATH Variable::, for more information. +Compiled extensions have to be installed in a directory where `gawk' +can find them. If `gawk' is configured and built in the default +fashion, the directory in which to find extensions is +`/usr/local/lib/gawk'. You can also specify a search path with a list +of directories to search for compiled extensions. *Note AWKLIBPATH +Variable::, for more information.  File: gawk.info, Node: Extension Example, Next: Extension Samples, Prev: Finding Extensions, Up: Dynamic Extensions @@ -25629,13 +24532,12 @@ File: gawk.info, Node: Extension Example, Next: Extension Samples, Prev: Find 16.6 Example: Some File Functions ================================= - No matter where you go, there you are. - -- _Buckaroo Bonzai_ + No matter where you go, there you are. -- Buckaroo Bonzai - Two useful functions that are not in 'awk' are 'chdir()' (so that an -'awk' program can change its directory) and 'stat()' (so that an 'awk' + Two useful functions that are not in `awk' are `chdir()' (so that an +`awk' program can change its directory) and `stat()' (so that an `awk' program can gather information about a file). This minor node -implements these functions for 'gawk' in an extension. +implements these functions for `gawk' in an extension. * Menu: @@ -25646,12 +24548,12 @@ implements these functions for 'gawk' in an extension.  File: gawk.info, Node: Internal File Description, Next: Internal File Ops, Up: Extension Example -16.6.1 Using 'chdir()' and 'stat()' +16.6.1 Using `chdir()' and `stat()' ----------------------------------- -This minor node shows how to use the new functions at the 'awk' level -once they've been integrated into the running 'gawk' interpreter. Using -'chdir()' is very straightforward. It takes one argument, the new +This minor node shows how to use the new functions at the `awk' level +once they've been integrated into the running `gawk' interpreter. +Using `chdir()' is very straightforward. It takes one argument, the new directory to change to: @load "filefuncs" @@ -25665,12 +24567,12 @@ directory to change to: } ... - The return value is negative if the 'chdir()' failed, and 'ERRNO' + The return value is negative if the `chdir()' failed, and `ERRNO' (*note Built-in Variables::) is set to a string indicating the error. - Using 'stat()' is a bit more complicated. The C 'stat()' function + Using `stat()' is a bit more complicated. The C `stat()' function fills in a structure that has a fair amount of information. The right -way to model this in 'awk' is to fill in an associative array with the +way to model this in `awk' is to fill in an associative array with the appropriate information: file = "/home/arnold/.profile" @@ -25682,94 +24584,94 @@ appropriate information: } printf("size of %s is %d bytes\n", file, fdata["size"]) - The 'stat()' function always clears the data array, even if the -'stat()' fails. It fills in the following elements: + The `stat()' function always clears the data array, even if the +`stat()' fails. It fills in the following elements: -'"name"' - The name of the file that was 'stat()''ed. +`"name"' + The name of the file that was `stat()''ed. -'"dev"' -'"ino"' +`"dev"' +`"ino"' The file's device and inode numbers, respectively. -'"mode"' - The file's mode, as a numeric value. This includes both the file's +`"mode"' + The file's mode, as a numeric value. This includes both the file's type and its permissions. -'"nlink"' +`"nlink"' The number of hard links (directory entries) the file has. -'"uid"' -'"gid"' +`"uid"' +`"gid"' The numeric user and group ID numbers of the file's owner. -'"size"' +`"size"' The size in bytes of the file. -'"blocks"' - The number of disk blocks the file actually occupies. This may not +`"blocks"' + The number of disk blocks the file actually occupies. This may not be a function of the file's size if the file has holes. -'"atime"' -'"mtime"' -'"ctime"' +`"atime"' +`"mtime"' +`"ctime"' The file's last access, modification, and inode update times, respectively. These are numeric timestamps, suitable for - formatting with 'strftime()' (*note Time Functions::). + formatting with `strftime()' (*note Time Functions::). -'"pmode"' +`"pmode"' The file's "printable mode." This is a string representation of - the file's type and permissions, such as is produced by 'ls - -l'--for example, '"drwxr-xr-x"'. + the file's type and permissions, such as is produced by `ls + -l'--for example, `"drwxr-xr-x"'. -'"type"' - A printable string representation of the file's type. The value is - one of the following: +`"type"' + A printable string representation of the file's type. The value + is one of the following: - '"blockdev"' - '"chardev"' + `"blockdev"' + `"chardev"' The file is a block or character device ("special file"). - '"directory"' + `"directory"' The file is a directory. - '"fifo"' + `"fifo"' The file is a named-pipe (also known as a FIFO). - '"file"' + `"file"' The file is just a regular file. - '"socket"' - The file is an 'AF_UNIX' ("Unix domain") socket in the + `"socket"' + The file is an `AF_UNIX' ("Unix domain") socket in the filesystem. - '"symlink"' + `"symlink"' The file is a symbolic link. -'"devbsize"' - The size of a block for the element indexed by '"blocks"'. This - information is derived from either the 'DEV_BSIZE' constant defined - in '' on most systems, or the 'S_BLKSIZE' constant in - '' on BSD systems. For some other systems, "a priori" - knowledge is used to provide a value. Where no value can be - determined, it defaults to 512. +`"devbsize"' + The size of a block for the element indexed by `"blocks"'. This + information is derived from either the `DEV_BSIZE' constant + defined in `' on most systems, or the `S_BLKSIZE' + constant in `' on BSD systems. For some other + systems, "a priori" knowledge is used to provide a value. Where no + value can be determined, it defaults to 512. Several additional elements may be present depending upon the operating system and the type of the file. You can test for them in -your 'awk' program by using the 'in' operator (*note Reference to +your `awk' program by using the `in' operator (*note Reference to Elements::): -'"blksize"' - The preferred block size for I/O to the file. This field is not - present on all POSIX-like systems in the C 'stat' structure. +`"blksize"' + The preferred block size for I/O to the file. This field is not + present on all POSIX-like systems in the C `stat' structure. -'"linkval"' +`"linkval"' If the file is a symbolic link, this element is the name of the file the link points to (i.e., the value of the link). -'"rdev"' -'"major"' -'"minor"' +`"rdev"' +`"major"' +`"minor"' If the file is a block or character device file, then these values represent the numeric device number and the major and minor components of that number, respectively. @@ -25777,15 +24679,16 @@ Elements::):  File: gawk.info, Node: Internal File Ops, Next: Using Internal File Ops, Prev: Internal File Description, Up: Extension Example -16.6.2 C Code for 'chdir()' and 'stat()' +16.6.2 C Code for `chdir()' and `stat()' ---------------------------------------- Here is the C code for these extensions.(1) The file includes a number of standard header files, and then -includes the 'gawkapi.h' header file which provides the API definitions. -Those are followed by the necessary variable declarations to make use of -the API macros and boilerplate code (*note Extension API Boilerplate::). +includes the `gawkapi.h' header file which provides the API definitions. +Those are followed by the necessary variable declarations to make use +of the API macros and boilerplate code (*note Extension API +Boilerplate::). #ifdef HAVE_CONFIG_H #include @@ -25818,11 +24721,11 @@ the API macros and boilerplate code (*note Extension API Boilerplate::). int plugin_is_GPL_compatible; - By convention, for an 'awk' function 'foo()', the C function that -implements it is called 'do_foo()'. The function should have two -arguments: the first is an 'int' usually called 'nargs', that represents -the number of actual arguments for the function. The second is a -pointer to an 'awk_value_t', usually named 'result'. + By convention, for an `awk' function `foo()', the C function that +implements it is called `do_foo()'. The function should have two +arguments: the first is an `int' usually called `nargs', that +represents the number of actual arguments for the function. The second +is a pointer to an `awk_value_t', usually named `result'. /* do_chdir --- provide dynamically loaded chdir() builtin for gawk */ @@ -25839,12 +24742,12 @@ pointer to an 'awk_value_t', usually named 'result'. _("chdir: called with incorrect number of arguments, " "expecting 1")); - The 'newdir' variable represents the new directory to change to, -retrieved with 'get_argument()'. Note that the first argument is + The `newdir' variable represents the new directory to change to, +retrieved with `get_argument()'. Note that the first argument is numbered zero. If the argument is retrieved successfully, the function calls the -'chdir()' system call. If the 'chdir()' fails, 'ERRNO' is updated. +`chdir()' system call. If the `chdir()' fails, `ERRNO' is updated. if (get_argument(0, AWK_STRING, & newdir)) { ret = chdir(newdir.str_value.str); @@ -25852,14 +24755,14 @@ numbered zero. update_ERRNO_int(errno); } - Finally, the function returns the return value to the 'awk' level: + Finally, the function returns the return value to the `awk' level: return make_number(ret, result); } - The 'stat()' extension is more involved. First comes a function that -turns a numeric mode into a printable representation (e.g., 644 becomes -'-rw-r--r--'). This is omitted here for brevity: + The `stat()' extension is more involved. First comes a function +that turns a numeric mode into a printable representation (e.g., 644 +becomes `-rw-r--r--'). This is omitted here for brevity: /* format_mode --- turn a stat mode field into something readable */ @@ -25882,7 +24785,7 @@ omitted here for brevity: } Two helper functions simplify entering values in the array that will -contain the result of the 'stat()': +contain the result of the `stat()': /* array_set --- set an array element */ @@ -25908,9 +24811,9 @@ contain the result of the 'stat()': } The following function does most of the work to fill in the -'awk_array_t' result array with values obtained from a valid 'struct -stat'. It is done in a separate function to support the 'stat()' -function for 'gawk' and also to support the 'fts()' extension which is +`awk_array_t' result array with values obtained from a valid `struct +stat'. It is done in a separate function to support the `stat()' +function for `gawk' and also to support the `fts()' extension which is included in the same file but whose code is not shown here (*note Extension Sample File Functions::). @@ -25949,7 +24852,7 @@ table to map file types to strings: int j, k; The destination array is cleared, and then code fills in various -elements based on values in the 'struct stat': +elements based on values in the `struct stat': /* empty out the array */ clear_array(array); @@ -25979,7 +24882,7 @@ elements based on values in the 'struct stat': The latter part of the function makes selective additions to the destination array, depending upon the availability of certain members -and/or the type of the file. It then returns zero, for success: +and/or the type of the file. It then returns zero, for success: #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE array_set_numeric(array, "blksize", sbuf->st_blksize); @@ -26017,7 +24920,7 @@ and/or the type of the file. It then returns zero, for success: return 0; } - Finally, here is the 'do_stat()' function. It starts with variable + Finally, here is the `do_stat()' function. It starts with variable declarations and argument checking: /* do_stat --- provide a stat() function for gawk */ @@ -26042,14 +24945,14 @@ declarations and argument checking: return make_number(-1, result); } - The third argument to 'stat()' was not discussed previously. This -argument is optional. If present, it causes 'stat()' to use the -'stat()' system call instead of the 'lstat()' system call. + The third argument to `stat()' was not discussed previously. This +argument is optional. If present, it causes `stat()' to use the `stat()' +system call instead of the `lstat()' system call. - Then comes the actual work. First, the function gets the arguments. -Next, it gets the information for the file. The code use 'lstat()' -(instead of 'stat()') to get the file information, in case the file is a -symbolic link. If there's an error, it sets 'ERRNO' and returns: + Then comes the actual work. First, the function gets the arguments. +Next, it gets the information for the file. The code use `lstat()' +(instead of `stat()') to get the file information, in case the file is +a symbolic link. If there's an error, it sets `ERRNO' and returns: /* file is first arg, array to hold results is second */ if ( ! get_argument(0, AWK_STRING, & file_param) @@ -26075,8 +24978,8 @@ symbolic link. If there's an error, it sets 'ERRNO' and returns: return make_number(ret, result); } - The tedious work is done by 'fill_stat_array()', shown earlier. When -done, return the result from 'fill_stat_array()': + The tedious work is done by `fill_stat_array()', shown earlier. +When done, return the result from `fill_stat_array()': ret = fill_stat_array(name, array, & sbuf); @@ -26084,10 +24987,10 @@ done, return the result from 'fill_stat_array()': } Finally, it's necessary to provide the "glue" that loads the new -function(s) into 'gawk'. +function(s) into `gawk'. - The 'filefuncs' extension also provides an 'fts()' function, which we -omit here. For its sake there is an initialization function: + The `filefuncs' extension also provides an `fts()' function, which +we omit here. For its sake there is an initialization function: /* init_filefuncs --- initialization routine */ @@ -26097,8 +25000,8 @@ omit here. For its sake there is an initialization function: ... } - We are almost done. We need an array of 'awk_ext_func_t' structures -for loading each function into 'gawk': + We are almost done. We need an array of `awk_ext_func_t' structures +for loading each function into `gawk': static awk_ext_func_t func_table[] = { { "chdir", do_chdir, 1 }, @@ -26108,9 +25011,9 @@ for loading each function into 'gawk': #endif }; - Each extension must have a routine named 'dl_load()' to load + Each extension must have a routine named `dl_load()' to load everything that needs to be loaded. It is simplest to use the -'dl_load_func()' macro in 'gawkapi.h': +`dl_load_func()' macro in `gawkapi.h': /* define the dl_load() function using the boilerplate macro */ @@ -26121,7 +25024,7 @@ everything that needs to be loaded. It is simplest to use the ---------- Footnotes ---------- (1) This version is edited slightly for presentation. See -'extension/filefuncs.c' in the 'gawk' distribution for the complete +`extension/filefuncs.c' in the `gawk' distribution for the complete version.  @@ -26131,15 +25034,15 @@ File: gawk.info, Node: Using Internal File Ops, Prev: Internal File Ops, Up: --------------------------------- Now that the code is written, it must be possible to add it at runtime -to the running 'gawk' interpreter. First, the code must be compiled. -Assuming that the functions are in a file named 'filefuncs.c', and IDIR -is the location of the 'gawkapi.h' header file, the following steps(1) +to the running `gawk' interpreter. First, the code must be compiled. +Assuming that the functions are in a file named `filefuncs.c', and IDIR +is the location of the `gawkapi.h' header file, the following steps(1) create a GNU/Linux shared library: $ gcc -fPIC -shared -DHAVE_CONFIG_H -c -O -g -IIDIR filefuncs.c $ gcc -o filefuncs.so -shared filefuncs.o - Once the library exists, it is loaded by using the '@load' keyword. + Once the library exists, it is loaded by using the `@load' keyword. # file testff.awk @load "filefuncs" @@ -26168,7 +25071,7 @@ create a GNU/Linux shared library: print "JUNK modified:", strftime("%m %d %y %H:%M:%S", data["mtime"]) } - The 'AWKLIBPATH' environment variable tells 'gawk' where to find + The `AWKLIBPATH' environment variable tells `gawk' where to find extensions (*note Finding Extensions::). We set it to the current directory and run the program: @@ -26200,39 +25103,39 @@ directory and run the program: ---------- Footnotes ---------- (1) In practice, you would probably want to use the GNU -Autotools--Automake, Autoconf, Libtool, and 'gettext'--to configure and -build your libraries. Instructions for doing so are beyond the scope of -this Info file. *Note gawkextlib::, for WWW links to the tools. +Autotools--Automake, Autoconf, Libtool, and `gettext'--to configure and +build your libraries. Instructions for doing so are beyond the scope of +this Info file. *Note gawkextlib::, for WWW links to the tools.  File: gawk.info, Node: Extension Samples, Next: gawkextlib, Prev: Extension Example, Up: Dynamic Extensions -16.7 The Sample Extensions In The 'gawk' Distribution +16.7 The Sample Extensions In The `gawk' Distribution ===================================================== This minor node provides brief overviews of the sample extensions that -come in the 'gawk' distribution. Some of them are intended for -production use, such the 'filefuncs', 'readdir' and 'inplace' +come in the `gawk' distribution. Some of them are intended for +production use, such the `filefuncs', `readdir' and `inplace' extensions. Others mainly provide example code that shows how to use the extension API. * Menu: * Extension Sample File Functions:: The file functions sample. -* Extension Sample Fnmatch:: An interface to 'fnmatch()'. -* Extension Sample Fork:: An interface to 'fork()' and other +* Extension Sample Fnmatch:: An interface to `fnmatch()'. +* Extension Sample Fork:: An interface to `fork()' and other process functions. * Extension Sample Inplace:: Enabling in-place file editing. * Extension Sample Ord:: Character to value to character conversions. -* Extension Sample Readdir:: An interface to 'readdir()'. +* Extension Sample Readdir:: An interface to `readdir()'. * Extension Sample Revout:: Reversing output sample output wrapper. * Extension Sample Rev2way:: Reversing data sample two-way processor. * Extension Sample Read write array:: Serializing an array to a file. * Extension Sample Readfile:: Reading an entire file into a string. * Extension Sample API Tests:: Tests for the API. -* Extension Sample Time:: An interface to 'gettimeofday()' - and 'sleep()'. +* Extension Sample Time:: An interface to `gettimeofday()' + and `sleep()'.  File: gawk.info, Node: Extension Sample File Functions, Next: Extension Sample Fnmatch, Up: Extension Samples @@ -26240,67 +25143,69 @@ File: gawk.info, Node: Extension Sample File Functions, Next: Extension Sample 16.7.1 File Related Functions ----------------------------- -The 'filefuncs' extension provides three different functions, as +The `filefuncs' extension provides three different functions, as follows: The usage is: @load "filefuncs" This is how you load the extension. -'result = chdir("/some/directory")' - The 'chdir()' function is a direct hook to the 'chdir()' system - call to change the current directory. It returns zero upon success - or less than zero upon error. In the latter case it updates - 'ERRNO'. +`result = chdir("/some/directory")' + The `chdir()' function is a direct hook to the `chdir()' system + call to change the current directory. It returns zero upon + success or less than zero upon error. In the latter case it + updates `ERRNO'. -'result = stat("/some/path", statdata' [', follow']')' - The 'stat()' function provides a hook into the 'stat()' system +`result = stat("/some/path", statdata' [`, follow']`)' + The `stat()' function provides a hook into the `stat()' system call. It returns zero upon success or less than zero upon error. - In the latter case it updates 'ERRNO'. + In the latter case it updates `ERRNO'. - By default, it uses the 'lstat()' system call. However, if passed - a third argument, it uses 'stat()' instead. + By default, it uses the `lstat()' system call. However, if passed + a third argument, it uses `stat()' instead. - In all cases, it clears the 'statdata' array. When the call is - successful, 'stat()' fills the 'statdata' array with information + In all cases, it clears the `statdata' array. When the call is + successful, `stat()' fills the `statdata' array with information retrieved from the filesystem, as follows: - Subscript Field in 'struct stat' File type - ---------------------------------------------------------------- - '"name"' The file name All - '"dev"' 'st_dev' All - '"ino"' 'st_ino' All - '"mode"' 'st_mode' All - '"nlink"' 'st_nlink' All - '"uid"' 'st_uid' All - '"gid"' 'st_gid' All - '"size"' 'st_size' All - '"atime"' 'st_atime' All - '"mtime"' 'st_mtime' All - '"ctime"' 'st_ctime' All - '"rdev"' 'st_rdev' Device files - '"major"' 'st_major' Device files - '"minor"' 'st_minor' Device files - '"blksize"' 'st_blksize' All - '"pmode"' A human-readable version of the All - mode value, such as printed by - 'ls'. For example, '"-rwxr-xr-x"' - '"linkval"' The value of the symbolic link Symbolic - links - '"type"' The type of the file as a string. All - One of '"file"', '"blockdev"', - '"chardev"', '"directory"', - '"socket"', '"fifo"', '"symlink"', - '"door"', or '"unknown"'. Not all - systems support all file types. - -'flags = or(FTS_PHYSICAL, ...)' -'result = fts(pathlist, flags, filedata)' - Walk the file trees provided in 'pathlist' and fill in the - 'filedata' array as described below. 'flags' is the bitwise OR of + Subscript Field in `struct stat' File type + ------------------------------------------------------------ + `"name"' The file name All + `"dev"' `st_dev' All + `"ino"' `st_ino' All + `"mode"' `st_mode' All + `"nlink"' `st_nlink' All + `"uid"' `st_uid' All + `"gid"' `st_gid' All + `"size"' `st_size' All + `"atime"' `st_atime' All + `"mtime"' `st_mtime' All + `"ctime"' `st_ctime' All + `"rdev"' `st_rdev' Device files + `"major"' `st_major' Device files + `"minor"' `st_minor' Device files + `"blksize"'`st_blksize' All + `"pmode"' A human-readable version of the All + mode value, such as printed by + `ls'. For example, + `"-rwxr-xr-x"' + `"linkval"'The value of the symbolic link Symbolic + links + `"type"' The type of the file as a string. All + One of `"file"', `"blockdev"', + `"chardev"', `"directory"', + `"socket"', `"fifo"', `"symlink"', + `"door"', or `"unknown"'. Not + all systems support all file + types. + +`flags = or(FTS_PHYSICAL, ...)' +`result = fts(pathlist, flags, filedata)' + Walk the file trees provided in `pathlist' and fill in the + `filedata' array as described below. `flags' is the bitwise OR of several predefined constant values, also described below. Return zero if there were no errors, otherwise return -1. - The 'fts()' function provides a hook to the C library 'fts()' + The `fts()' function provides a hook to the C library `fts()' routines for traversing file hierarchies. Instead of returning data about one file at a time in a stream, it fills in a multidimensional array with data about each file and directory encountered in the @@ -26308,141 +25213,142 @@ requested hierarchies. The arguments are as follows: -'pathlist' +`pathlist' An array of file names. The element values are used; the index values are ignored. -'flags' +`flags' This should be the bitwise OR of one or more of the following - predefined constant flag values. At least one of 'FTS_LOGICAL' or - 'FTS_PHYSICAL' must be provided; otherwise 'fts()' returns an error - value and sets 'ERRNO'. The flags are: + predefined constant flag values. At least one of `FTS_LOGICAL' or + `FTS_PHYSICAL' must be provided; otherwise `fts()' returns an + error value and sets `ERRNO'. The flags are: - 'FTS_LOGICAL' + `FTS_LOGICAL' Do a "logical" file traversal, where the information returned for a symbolic link refers to the linked-to file, and not to the symbolic link itself. This flag is mutually exclusive - with 'FTS_PHYSICAL'. + with `FTS_PHYSICAL'. - 'FTS_PHYSICAL' - Do a "physical" file traversal, where the information returned - for a symbolic link refers to the symbolic link itself. This - flag is mutually exclusive with 'FTS_LOGICAL'. + `FTS_PHYSICAL' + Do a "physical" file traversal, where the information + returned for a symbolic link refers to the symbolic link + itself. This flag is mutually exclusive with `FTS_LOGICAL'. - 'FTS_NOCHDIR' - As a performance optimization, the C library 'fts()' routines - change directory as they traverse a file hierarchy. This flag - disables that optimization. + `FTS_NOCHDIR' + As a performance optimization, the C library `fts()' routines + change directory as they traverse a file hierarchy. This + flag disables that optimization. - 'FTS_COMFOLLOW' - Immediately follow a symbolic link named in 'pathlist', - whether or not 'FTS_LOGICAL' is set. + `FTS_COMFOLLOW' + Immediately follow a symbolic link named in `pathlist', + whether or not `FTS_LOGICAL' is set. - 'FTS_SEEDOT' - By default, the 'fts()' routines do not return entries for '.' - (dot) and '..' (dot-dot). This option causes entries for + `FTS_SEEDOT' + By default, the `fts()' routines do not return entries for + `.' (dot) and `..' (dot-dot). This option causes entries for dot-dot to also be included. (The extension always includes an entry for dot, see below.) - 'FTS_XDEV' + `FTS_XDEV' During a traversal, do not cross onto a different mounted filesystem. -'filedata' - The 'filedata' array is first cleared. Then, 'fts()' creates an - element in 'filedata' for every element in 'pathlist'. The index - is the name of the directory or file given in 'pathlist'. The +`filedata' + The `filedata' array is first cleared. Then, `fts()' creates an + element in `filedata' for every element in `pathlist'. The index + is the name of the directory or file given in `pathlist'. The element for this index is itself an array. There are two cases. - _The path is a file_ + _The path is a file_ In this case, the array contains two or three elements: - '"path"' - The full path to this file, starting from the "root" that - was given in the 'pathlist' array. + `"path"' + The full path to this file, starting from the "root" + that was given in the `pathlist' array. - '"stat"' + `"stat"' This element is itself an array, containing the same - information as provided by the 'stat()' function - described earlier for its 'statdata' argument. The - element may not be present if the 'stat()' system call + information as provided by the `stat()' function + described earlier for its `statdata' argument. The + element may not be present if the `stat()' system call for the file failed. - '"error"' + `"error"' If some kind of error was encountered, the array will - also contain an element named '"error"', which is a + also contain an element named `"error"', which is a string describing the error. - _The path is a directory_ - In this case, the array contains one element for each entry in - the directory. If an entry is a file, that element is as for - files, just described. If the entry is a directory, that + _The path is a directory_ + In this case, the array contains one element for each entry + in the directory. If an entry is a file, that element is as + for files, just described. If the entry is a directory, that element is (recursively), an array describing the - subdirectory. If 'FTS_SEEDOT' was provided in the flags, then - there will also be an element named '".."'. This element will - be an array containing the data as provided by 'stat()'. + subdirectory. If `FTS_SEEDOT' was provided in the flags, + then there will also be an element named `".."'. This + element will be an array containing the data as provided by + `stat()'. - In addition, there will be an element whose index is '"."'. + In addition, there will be an element whose index is `"."'. This element is an array containing the same two or three - elements as for a file: '"path"', '"stat"', and '"error"'. + elements as for a file: `"path"', `"stat"', and `"error"'. - The 'fts()' function returns zero if there were no errors. Otherwise -it returns -1. + The `fts()' function returns zero if there were no errors. +Otherwise it returns -1. - NOTE: The 'fts()' extension does not exactly mimic the interface of - the C library 'fts()' routines, choosing instead to provide an - interface that is based on associative arrays, which should be more - comfortable to use from an 'awk' program. This includes the lack - of a comparison function, since 'gawk' already provides powerful - array sorting facilities. While an 'fts_read()'-like interface - could have been provided, this felt less natural than simply - creating a multidimensional array to represent the file hierarchy - and its information. + NOTE: The `fts()' extension does not exactly mimic the interface + of the C library `fts()' routines, choosing instead to provide an + interface that is based on associative arrays, which should be + more comfortable to use from an `awk' program. This includes the + lack of a comparison function, since `gawk' already provides + powerful array sorting facilities. While an `fts_read()'-like + interface could have been provided, this felt less natural than + simply creating a multidimensional array to represent the file + hierarchy and its information. - See 'test/fts.awk' in the 'gawk' distribution for an example. + See `test/fts.awk' in the `gawk' distribution for an example.  File: gawk.info, Node: Extension Sample Fnmatch, Next: Extension Sample Fork, Prev: Extension Sample File Functions, Up: Extension Samples -16.7.2 Interface To 'fnmatch()' +16.7.2 Interface To `fnmatch()' ------------------------------- -This extension provides an interface to the C library 'fnmatch()' +This extension provides an interface to the C library `fnmatch()' function. The usage is: -'@load "fnmatch"' +`@load "fnmatch"' This is how you load the extension. -'result = fnmatch(pattern, string, flags)' - The return value is zero on success, 'FNM_NOMATCH' if the string +`result = fnmatch(pattern, string, flags)' + The return value is zero on success, `FNM_NOMATCH' if the string did not match the pattern, or a different non-zero value if an error occurred. - Besides the 'fnmatch()' function, the 'fnmatch' extension adds one -constant ('FNM_NOMATCH'), and an array of flag values named 'FNM'. + Besides the `fnmatch()' function, the `fnmatch' extension adds one +constant (`FNM_NOMATCH'), and an array of flag values named `FNM'. - The arguments to 'fnmatch()' are: + The arguments to `fnmatch()' are: -'pattern' +`pattern' The file name wildcard to match. -'string' +`string' The file name string. -'flag' +`flag' Either zero, or the bitwise OR of one or more of the flags in the - 'FNM' array. + `FNM' array. The flags are follows: -Array element Corresponding flag defined by 'fnmatch()' --------------------------------------------------------------------------- -'FNM["CASEFOLD"]' 'FNM_CASEFOLD' -'FNM["FILE_NAME"]' 'FNM_FILE_NAME' -'FNM["LEADING_DIR"]''FNM_LEADING_DIR' -'FNM["NOESCAPE"]' 'FNM_NOESCAPE' -'FNM["PATHNAME"]' 'FNM_PATHNAME' -'FNM["PERIOD"]' 'FNM_PERIOD' +Array element Corresponding flag defined by `fnmatch()' +-------------------------------------------------------------------------- +`FNM["CASEFOLD"]' `FNM_CASEFOLD' +`FNM["FILE_NAME"]' `FNM_FILE_NAME' +`FNM["LEADING_DIR"]'`FNM_LEADING_DIR' +`FNM["NOESCAPE"]' `FNM_NOESCAPE' +`FNM["PATHNAME"]' `FNM_PATHNAME' +`FNM["PERIOD"]' `FNM_PERIOD' Here is an example: @@ -26455,30 +25361,30 @@ Array element Corresponding flag defined by 'fnmatch()'  File: gawk.info, Node: Extension Sample Fork, Next: Extension Sample Inplace, Prev: Extension Sample Fnmatch, Up: Extension Samples -16.7.3 Interface To 'fork()', 'wait()' and 'waitpid()' +16.7.3 Interface To `fork()', `wait()' and `waitpid()' ------------------------------------------------------ -The 'fork' extension adds three functions, as follows. +The `fork' extension adds three functions, as follows. -'@load "fork"' +`@load "fork"' This is how you load the extension. -'pid = fork()' - This function creates a new process. The return value is zero in +`pid = fork()' + This function creates a new process. The return value is zero in the child and the process-ID number of the child in the parent, or - -1 upon error. In the latter case, 'ERRNO' indicates the problem. - In the child, 'PROCINFO["pid"]' and 'PROCINFO["ppid"]' are updated + -1 upon error. In the latter case, `ERRNO' indicates the problem. + In the child, `PROCINFO["pid"]' and `PROCINFO["ppid"]' are updated to reflect the correct values. -'ret = waitpid(pid)' +`ret = waitpid(pid)' This function takes a numeric argument, which is the process-ID to - wait for. The return value is that of the 'waitpid()' system call. + wait for. The return value is that of the `waitpid()' system call. -'ret = wait()' +`ret = wait()' This function waits for the first child to die. The return value - is that of the 'wait()' system call. + is that of the `wait()' system call. - There is no corresponding 'exec()' function. + There is no corresponding `exec()' function. Here is an example: @@ -26495,9 +25401,9 @@ File: gawk.info, Node: Extension Sample Inplace, Next: Extension Sample Ord, 16.7.4 Enabling In-Place File Editing ------------------------------------- -The 'inplace' extension emulates GNU 'sed''s '-i' option which performs +The `inplace' extension emulates GNU `sed''s `-i' option which performs "in place" editing of each input file. It uses the bundled -'inplace.awk' include file to invoke the extension properly: +`inplace.awk' include file to invoke the extension properly: # inplace --- load and invoke the inplace extension. @@ -26516,9 +25422,9 @@ The 'inplace' extension emulates GNU 'sed''s '-i' option which performs For each regular file that is processed, the extension redirects standard output to a temporary file configured to have the same owner -and permissions as the original. After the file has been processed, the -extension restores standard output to its original destination. If -'INPLACE_SUFFIX' is not an empty string, the original file is linked to +and permissions as the original. After the file has been processed, +the extension restores standard output to its original destination. If +`INPLACE_SUFFIX' is not an empty string, the original file is linked to a backup file name created by appending that suffix. Finally, the temporary file is renamed to the original file name. @@ -26537,21 +25443,21 @@ processing immediately without damaging the original file.  File: gawk.info, Node: Extension Sample Ord, Next: Extension Sample Readdir, Prev: Extension Sample Inplace, Up: Extension Samples -16.7.5 Character and Numeric values: 'ord()' and 'chr()' +16.7.5 Character and Numeric values: `ord()' and `chr()' -------------------------------------------------------- -The 'ordchr' extension adds two functions, named 'ord()' and 'chr()', as -follows. +The `ordchr' extension adds two functions, named `ord()' and `chr()', +as follows. -'@load "ordchr"' +`@load "ordchr"' This is how you load the extension. -'number = ord(string)' - Return the numeric value of the first character in 'string'. +`number = ord(string)' + Return the numeric value of the first character in `string'. -'char = chr(number)' +`char = chr(number)' Return a string whose first character is that represented by - 'number'. + `number'. These functions are inspired by the Pascal language functions of the same name. Here is an example: @@ -26567,42 +25473,43 @@ File: gawk.info, Node: Extension Sample Readdir, Next: Extension Sample Revout 16.7.6 Reading Directories -------------------------- -The 'readdir' extension adds an input parser for directories. The usage -is as follows: +The `readdir' extension adds an input parser for directories. The +usage is as follows: @load "readdir" When this extension is in use, instead of skipping directories named -on the command line (or with 'getline'), they are read, with each entry +on the command line (or with `getline'), they are read, with each entry returned as a record. - The record consists of three fields. The first two are the inode + The record consists of three fields. The first two are the inode number and the file name, separated by a forward slash character. On -systems where the directory entry contains the file type, the record has -a third field (also separated by a slash) which is a single letter -indicating the type of the file. The letters are file types are shown -in *note Table 16.2: table-readdir-file-types. +systems where the directory entry contains the file type, the record +has a third field (also separated by a slash) which is a single letter +indicating the type of the file. The letters are file types are shown +in *note table-readdir-file-types::. Letter File Type --------------------------------------------------------------------------- -'b' Block device -'c' Character device -'d' Directory -'f' Regular file -'l' Symbolic link -'p' Named pipe (FIFO) -'s' Socket -'u' Anything else (unknown) - -Table 16.2: File Types Returned By 'readdir()' +-------------------------------------------------------------------------- +`b' Block device +`c' Character device +`d' Directory +`f' Regular file +`l' Symbolic link +`p' Named pipe (FIFO) +`s' Socket +`u' Anything else (unknown) + +Table 16.2: File Types Returned By `readdir()' On systems without the file type information, the third field is -always 'u'. +always `u'. NOTE: On GNU/Linux systems, there are filesystems that don't - support the 'd_type' entry (see the readdir(3) manual page), and so - the file type is always 'u'. You can use the 'filefuncs' extension - to call 'stat()' in order to get correct type information. + support the `d_type' entry (see the readdir(3) manual page), and + so the file type is always `u'. You can use the `filefuncs' + extension to call `stat()' in order to get correct type + information. Here is an example: @@ -26617,8 +25524,8 @@ File: gawk.info, Node: Extension Sample Revout, Next: Extension Sample Rev2way 16.7.7 Reversing Output ----------------------- -The 'revoutput' extension adds a simple output wrapper that reverses the -characters in each output line. It's main purpose is to show how to +The `revoutput' extension adds a simple output wrapper that reverses +the characters in each output line. It's main purpose is to show how to write an output wrapper, although it may be mildly amusing for the unwary. Here is an example: @@ -26629,7 +25536,7 @@ unwary. Here is an example: print "don't panic" > "/dev/stdout" } - The output from this program is: 'cinap t'nod'. + The output from this program is: `cinap t'nod'.  File: gawk.info, Node: Extension Sample Rev2way, Next: Extension Sample Read write array, Prev: Extension Sample Revout, Up: Extension Samples @@ -26637,11 +25544,11 @@ File: gawk.info, Node: Extension Sample Rev2way, Next: Extension Sample Read w 16.7.8 Two-Way I/O Example -------------------------- -The 'revtwoway' extension adds a simple two-way processor that reverses -the characters in each line sent to it for reading back by the 'awk' -program. It's main purpose is to show how to write a two-way processor, -although it may also be mildly amusing. The following example shows how -to use it: +The `revtwoway' extension adds a simple two-way processor that reverses +the characters in each line sent to it for reading back by the `awk' +program. It's main purpose is to show how to write a two-way +processor, although it may also be mildly amusing. The following +example shows how to use it: @load "revtwoway" @@ -26653,7 +25560,7 @@ to use it: close(cmd) } - The output from this program is: 'cinap t'nod'. + The output from this program is: `cinap t'nod'.  File: gawk.info, Node: Extension Sample Read write array, Next: Extension Sample Readfile, Prev: Extension Sample Rev2way, Up: Extension Samples @@ -26661,35 +25568,35 @@ File: gawk.info, Node: Extension Sample Read write array, Next: Extension Samp 16.7.9 Dumping and Restoring An Array ------------------------------------- -The 'rwarray' extension adds two functions, named 'writea()' and -'reada()', as follows: +The `rwarray' extension adds two functions, named `writea()' and +`reada()', as follows: -'ret = writea(file, array)' +`ret = writea(file, array)' This function takes a string argument, which is the name of the - file to which to dump the array, and the array itself as the second - argument. 'writea()' understands arrays of arrays. It returns one - on success, or zero upon failure. + file to which to dump the array, and the array itself as the + second argument. `writea()' understands arrays of arrays. It + returns one on success, or zero upon failure. -'ret = reada(file, array)' - 'reada()' is the inverse of 'writea()'; it reads the file named as +`ret = reada(file, array)' + `reada()' is the inverse of `writea()'; it reads the file named as its first argument, filling in the array named as the second - argument. It clears the array first. Here too, the return value + argument. It clears the array first. Here too, the return value is one on success and zero upon failure. - The array created by 'reada()' is identical to that written by -'writea()' in the sense that the contents are the same. However, due to + The array created by `reada()' is identical to that written by +`writea()' in the sense that the contents are the same. However, due to implementation issues, the array traversal order of the recreated array is likely to be different from that of the original array. As array -traversal order in 'awk' is by default undefined, this is (technically) +traversal order in `awk' is by default undefined, this is (technically) not a problem. If you need to guarantee a particular traversal order, -use the array sorting features in 'gawk' to do so (*note Array +use the array sorting features in `gawk' to do so (*note Array Sorting::). The file contains binary data. All integral values are written in -network byte order. However, double precision floating-point values are -written as native binary data. Thus, arrays containing only string data -can theoretically be dumped on systems with one byte order and restored -on systems with a different one, but this has not been tried. +network byte order. However, double precision floating-point values +are written as native binary data. Thus, arrays containing only string +data can theoretically be dumped on systems with one byte order and +restored on systems with a different one, but this has not been tried. Here is an example: @@ -26705,21 +25612,21 @@ File: gawk.info, Node: Extension Sample Readfile, Next: Extension Sample API T 16.7.10 Reading An Entire File ------------------------------ -The 'readfile' extension adds a single function named 'readfile()', and +The `readfile' extension adds a single function named `readfile()', and an input parser: -'@load "readfile"' +`@load "readfile"' This is how you load the extension. -'result = readfile("/some/path")' +`result = readfile("/some/path")' The argument is the name of the file to read. The return value is a string containing the entire contents of the requested file. - Upon error, the function returns the empty string and sets 'ERRNO'. + Upon error, the function returns the empty string and sets `ERRNO'. -'BEGIN { PROCINFO["readfile"] = 1 }' +`BEGIN { PROCINFO["readfile"] = 1 }' In addition, the extension adds an input parser that is activated - if 'PROCINFO["readfile"]' exists. When activated, each input file - is returned in its entirety as '$0'. 'RT' is set to the null + if `PROCINFO["readfile"]' exists. When activated, each input file + is returned in its entirety as `$0'. `RT' is set to the null string. Here is an example: @@ -26738,10 +25645,10 @@ File: gawk.info, Node: Extension Sample API Tests, Next: Extension Sample Time 16.7.11 API Tests ----------------- -The 'testext' extension exercises parts of the extension API that are -not tested by the other samples. The 'extension/testext.c' file -contains both the C code for the extension and 'awk' test code inside C -comments that run the tests. The testing framework extracts the 'awk' +The `testext' extension exercises parts of the extension API that are +not tested by the other samples. The `extension/testext.c' file +contains both the C code for the extension and `awk' test code inside C +comments that run the tests. The testing framework extracts the `awk' code and runs the tests. See the source file for more information.  @@ -26750,40 +25657,40 @@ File: gawk.info, Node: Extension Sample Time, Prev: Extension Sample API Tests 16.7.12 Extension Time Functions -------------------------------- -The 'time' extension adds two functions, named 'gettimeofday()' and -'sleep()', as follows: +The `time' extension adds two functions, named `gettimeofday()' and +`sleep()', as follows: -'@load "time"' +`@load "time"' This is how you load the extension. -'the_time = gettimeofday()' - Return the time in seconds that has elapsed since 1970-01-01 UTC as - a floating point value. If the time is unavailable on this - platform, return -1 and set 'ERRNO'. The returned time should have - sub-second precision, but the actual precision may vary based on - the platform. If the standard C 'gettimeofday()' system call is - available on this platform, then it simply returns the value. +`the_time = gettimeofday()' + Return the time in seconds that has elapsed since 1970-01-01 UTC + as a floating point value. If the time is unavailable on this + platform, return -1 and set `ERRNO'. The returned time should + have sub-second precision, but the actual precision may vary based + on the platform. If the standard C `gettimeofday()' system call + is available on this platform, then it simply returns the value. Otherwise, if on MS-Windows, it tries to use - 'GetSystemTimeAsFileTime()'. + `GetSystemTimeAsFileTime()'. -'result = sleep(SECONDS)' +`result = sleep(SECONDS)' Attempt to sleep for SECONDS seconds. If SECONDS is negative, or - the attempt to sleep fails, return -1 and set 'ERRNO'. Otherwise, + the attempt to sleep fails, return -1 and set `ERRNO'. Otherwise, return zero after sleeping for the indicated amount of time. Note that SECONDS may be a floating-point (non-integral) value. Implementation details: depending on platform availability, this - function tries to use 'nanosleep()' or 'select()' to implement the + function tries to use `nanosleep()' or `select()' to implement the delay.  File: gawk.info, Node: gawkextlib, Next: Extension summary, Prev: Extension Samples, Up: Dynamic Extensions -16.8 The 'gawkextlib' Project +16.8 The `gawkextlib' Project ============================= -The 'gawkextlib' (http://sourceforge.net/projects/gawkextlib/) project -provides a number of 'gawk' extensions, including one for processing XML -files. This is the evolution of the original 'xgawk' (XML 'gawk') +The `gawkextlib' (http://sourceforge.net/projects/gawkextlib/) project +provides a number of `gawk' extensions, including one for processing +XML files. This is the evolution of the original `xgawk' (XML `gawk') project. As of this writing, there are five extensions: @@ -26798,14 +25705,14 @@ project. * GD graphics library extension. * MPFR library extension. This provides access to a number of MPFR - functions which 'gawk''s native MPFR support does not. + functions which `gawk''s native MPFR support does not. - The 'time' extension described earlier (*note Extension Sample + The `time' extension described earlier (*note Extension Sample Time::) was originally from this project but has been moved in to the -main 'gawk' distribution. +main `gawk' distribution. - You can check out the code for the 'gawkextlib' project using the Git -(http://git-scm.com) distributed source code control system. The + You can check out the code for the `gawkextlib' project using the +Git (http://git-scm.com) distributed source code control system. The command is as follows: git clone git://git.code.sf.net/p/gawkextlib/code gawkextlib-code @@ -26816,18 +25723,18 @@ parser library installed in order to build and use the XML extension. In addition, you must have the GNU Autotools installed (Autoconf (http://www.gnu.org/software/autoconf), Automake (http://www.gnu.org/software/automake), Libtool -(http://www.gnu.org/software/libtool), and GNU 'gettext' +(http://www.gnu.org/software/libtool), and GNU `gettext' (http://www.gnu.org/software/gettext)). - The simple recipe for building and testing 'gawkextlib' is as -follows. First, build and install 'gawk': + The simple recipe for building and testing `gawkextlib' is as +follows. First, build and install `gawk': cd .../path/to/gawk/code ./configure --prefix=/tmp/newgawk Install in /tmp/newgawk for now make && make check Build and check that all is OK make install Install gawk - Next, build 'gawkextlib' and test it: + Next, build `gawkextlib' and test it: cd .../path/to/gawkextlib-code ./update-autotools Generate configure, etc. @@ -26836,13 +25743,13 @@ follows. First, build and install 'gawk': make && make check Build and check that all is OK make install Install the extensions - If you have installed 'gawk' in the standard way, then you will -likely not need the '--with-gawk' option when configuring 'gawkextlib'. -You may also need to use the 'sudo' utility to install both 'gawk' and -'gawkextlib', depending upon how your system works. + If you have installed `gawk' in the standard way, then you will +likely not need the `--with-gawk' option when configuring `gawkextlib'. +You may also need to use the `sudo' utility to install both `gawk' and +`gawkextlib', depending upon how your system works. - If you write an extension that you wish to share with other 'gawk' -users, please consider doing so through the 'gawkextlib' project. See + If you write an extension that you wish to share with other `gawk' +users, please consider doing so through the `gawkextlib' project. See the project's web site for more information.  @@ -26851,40 +25758,40 @@ File: gawk.info, Node: Extension summary, Next: Extension Exercises, Prev: ga 16.9 Summary ============ - * You can write extensions (sometimes called plug-ins) for 'gawk' in + * You can write extensions (sometimes called plug-ins) for `gawk' in C or C++ using the Application Programming Interface (API) defined - by the 'gawk' developers. + by the `gawk' developers. * Extensions must have a license compatible with the GNU General - Public License (GPL), and they must assert that fact by declaring a - variable named 'plugin_is_GPL_compatible'. + Public License (GPL), and they must assert that fact by declaring + a variable named `plugin_is_GPL_compatible'. - * Communication between 'gawk' and an extension is two-way. 'gawk' - passes a 'struct' to the extension which contains various data + * Communication between `gawk' and an extension is two-way. `gawk' + passes a `struct' to the extension which contains various data fields and function pointers. The extension can then call into - 'gawk' via the supplied function pointers to accomplish certain + `gawk' via the supplied function pointers to accomplish certain tasks. * One of these tasks is to "register" the name and implementation of - a new 'awk'-level function with 'gawk'. The implementation takes + a new `awk'-level function with `gawk'. The implementation takes the form of a C function pointer with a defined signature. By - convention, implementation functions are named 'do_XXXX()' for some - 'awk'-level function 'XXXX()'. + convention, implementation functions are named `do_XXXX()' for + some `awk'-level function `XXXX()'. - * The API is defined in a header file named 'gawkpi.h'. You must + * The API is defined in a header file named `gawkpi.h'. You must include a number of standard header files _before_ including it in your source file. * API function pointers are provided for the following kinds of operations: - * Registration functions. You may register extension functions, + * Registration functions. You may register extension functions, exit callbacks, a version string, input parsers, output wrappers, and two-way processors. * Printing fatal, warning, and "lint" warning messages. - * Updating 'ERRNO', or unsetting it. + * Updating `ERRNO', or unsetting it. * Accessing parameters, including converting an undefined parameter into an array. @@ -26905,66 +25812,68 @@ File: gawk.info, Node: Extension summary, Next: Extension Exercises, Prev: ga elements * The API defines a number of standard data types for representing - 'awk' values, array elements, and arrays. + `awk' values, array elements, and arrays. * The API provide convenience functions for constructing values. It also provides memory management functions to ensure compatibility - between memory allocated by 'gawk' and memory allocated by an + between memory allocated by `gawk' and memory allocated by an extension. - * _All_ memory passed from 'gawk' to an extension must be treated as + * _All_ memory passed from `gawk' to an extension must be treated as read-only by the extension. - * _All_ memory passed from an extension to 'gawk' must come from the - API's memory allocation functions. 'gawk' takes responsibility for + * _All_ memory passed from an extension to `gawk' must come from the + API's memory allocation functions. `gawk' takes responsibility for the memory and will release it when appropriate. - * The API provides information about the running version of 'gawk' so - that an extension can make sure it is compatible with the 'gawk' + * The API provides information about the running version of `gawk' so + that an extension can make sure it is compatible with the `gawk' that loaded it. * It is easiest to start a new extension by copying the boilerplate - code described in this major node. Macros in the 'gawkapi.h' make + code described in this major node. Macros in the `gawkapi.h' make this easier to do. - * The 'gawk' distribution includes a number of small but useful - sample extensions. The 'gawkextlib' project includes several more, + * The `gawk' distribution includes a number of small but useful + sample extensions. The `gawkextlib' project includes several more, larger, extensions. If you wish to write an extension and - contribute it to the community of 'gawk' users, the 'gawkextlib' + contribute it to the community of `gawk' users, the `gawkextlib' project should be the place to do so. +  File: gawk.info, Node: Extension Exercises, Prev: Extension summary, Up: Dynamic Extensions 16.10 Exercises =============== - 1. Add functions to implement system calls such as 'chown()', - 'chmod()', and 'umask()' to the file operations extension presented - in *note Internal File Ops::. + 1. Add functions to implement system calls such as `chown()', + `chmod()', and `umask()' to the file operations extension + presented in *note Internal File Ops::. + + 2. (Hard.) How would you provide namespaces in `gawk', so that the + names of functions in different extensions don't conflict with + each other? If you come up with a really good scheme, contact the + `gawk' maintainer to tell him about it. - 2. (Hard.) How would you provide namespaces in 'gawk', so that the - names of functions in different extensions don't conflict with each - other? If you come up with a really good scheme, contact the - 'gawk' maintainer to tell him about it. + 3. Write a wrapper script that provides an interface similar to `sed + -i' for the "inplace" extension presented in *note Extension + Sample Inplace::. - 3. Write a wrapper script that provides an interface similar to 'sed - -i' for the "inplace" extension presented in *note Extension Sample - Inplace::.  File: gawk.info, Node: Language History, Next: Installation, Prev: Dynamic Extensions, Up: Top -Appendix A The Evolution of the 'awk' Language +Appendix A The Evolution of the `awk' Language ********************************************** -This Info file describes the GNU implementation of 'awk', which follows -the POSIX specification. Many long-time 'awk' users learned 'awk' -programming with the original 'awk' implementation in Version 7 Unix. -(This implementation was the basis for 'awk' in Berkeley Unix, through +This Info file describes the GNU implementation of `awk', which follows +the POSIX specification. Many long-time `awk' users learned `awk' +programming with the original `awk' implementation in Version 7 Unix. +(This implementation was the basis for `awk' in Berkeley Unix, through 4.3-Reno. Subsequent versions of Berkeley Unix, and some systems -derived from 4.4BSD-Lite, used various versions of 'gawk' for their -'awk'.) This major node briefly describes the evolution of the 'awk' +derived from 4.4BSD-Lite, used various versions of `gawk' for their +`awk'.) This major node briefly describes the evolution of the `awk' language, with cross-references to other parts of the Info file where you can find more information. @@ -26976,13 +25885,13 @@ you can find more information. and 4. * POSIX:: New features from the POSIX standard. * BTL:: New features from Brian Kernighan's version of - 'awk'. -* POSIX/GNU:: The extensions in 'gawk' not in POSIX - 'awk'. -* Feature History:: The history of the features in 'gawk'. + `awk'. +* POSIX/GNU:: The extensions in `gawk' not in POSIX + `awk'. +* Feature History:: The history of the features in `gawk'. * Common Extensions:: Common Extensions Summary. * Ranges and Locales:: How locales used to affect regexp ranges. -* Contributors:: The major contributors to 'gawk'. +* Contributors:: The major contributors to `gawk'. * History summary:: History summary.  @@ -26991,62 +25900,62 @@ File: gawk.info, Node: V7/SVR3.1, Next: SVR4, Up: Language History A.1 Major Changes Between V7 and SVR3.1 ======================================= -The 'awk' language evolved considerably between the release of Version 7 -Unix (1978) and the new version that was first made generally available -in System V Release 3.1 (1987). This minor node summarizes the changes, -with cross-references to further details: +The `awk' language evolved considerably between the release of Version +7 Unix (1978) and the new version that was first made generally +available in System V Release 3.1 (1987). This minor node summarizes +the changes, with cross-references to further details: - * The requirement for ';' to separate rules on a line (*note + * The requirement for `;' to separate rules on a line (*note Statements/Lines::). - * User-defined functions and the 'return' statement (*note + * User-defined functions and the `return' statement (*note User-defined::). - * The 'delete' statement (*note Delete::). + * The `delete' statement (*note Delete::). - * The 'do'-'while' statement (*note Do Statement::). + * The `do'-`while' statement (*note Do Statement::). - * The built-in functions 'atan2()', 'cos()', 'sin()', 'rand()', and - 'srand()' (*note Numeric Functions::). + * The built-in functions `atan2()', `cos()', `sin()', `rand()', and + `srand()' (*note Numeric Functions::). - * The built-in functions 'gsub()', 'sub()', and 'match()' (*note + * The built-in functions `gsub()', `sub()', and `match()' (*note String Functions::). - * The built-in functions 'close()' and 'system()' (*note I/O + * The built-in functions `close()' and `system()' (*note I/O Functions::). - * The 'ARGC', 'ARGV', 'FNR', 'RLENGTH', 'RSTART', and 'SUBSEP' + * The `ARGC', `ARGV', `FNR', `RLENGTH', `RSTART', and `SUBSEP' built-in variables (*note Built-in Variables::). - * Assignable '$0' (*note Changing Fields::). + * Assignable `$0' (*note Changing Fields::). - * The conditional expression using the ternary operator '?:' (*note + * The conditional expression using the ternary operator `?:' (*note Conditional Exp::). - * The expression 'INDEX-VARIABLE in ARRAY' outside of 'for' + * The expression `INDEX-VARIABLE in ARRAY' outside of `for' statements (*note Reference to Elements::). - * The exponentiation operator '^' (*note Arithmetic Ops::) and its - assignment operator form '^=' (*note Assignment Ops::). + * The exponentiation operator `^' (*note Arithmetic Ops::) and its + assignment operator form `^=' (*note Assignment Ops::). - * C-compatible operator precedence, which breaks some old 'awk' + * C-compatible operator precedence, which breaks some old `awk' programs (*note Precedence::). - * Regexps as the value of 'FS' (*note Field Separators::) and as the - third argument to the 'split()' function (*note String - Functions::), rather than using only the first character of 'FS'. + * Regexps as the value of `FS' (*note Field Separators::) and as the + third argument to the `split()' function (*note String + Functions::), rather than using only the first character of `FS'. - * Dynamic regexps as operands of the '~' and '!~' operators (*note + * Dynamic regexps as operands of the `~' and `!~' operators (*note Regexp Usage::). - * The escape sequences '\b', '\f', and '\r' (*note Escape + * The escape sequences `\b', `\f', and `\r' (*note Escape Sequences::). (Some vendors have updated their old versions of - 'awk' to recognize '\b', '\f', and '\r', but this is not something + `awk' to recognize `\b', `\f', and `\r', but this is not something you can rely on.) - * Redirection of input for the 'getline' function (*note Getline::). + * Redirection of input for the `getline' function (*note Getline::). - * Multiple 'BEGIN' and 'END' rules (*note BEGIN/END::). + * Multiple `BEGIN' and `END' rules (*note BEGIN/END::). * Multidimensional arrays (*note Multidimensional::). @@ -27056,36 +25965,36 @@ File: gawk.info, Node: SVR4, Next: POSIX, Prev: V7/SVR3.1, Up: Language Hist A.2 Changes Between SVR3.1 and SVR4 =================================== -The System V Release 4 (1989) version of Unix 'awk' added these features -(some of which originated in 'gawk'): +The System V Release 4 (1989) version of Unix `awk' added these features +(some of which originated in `gawk'): - * The 'ENVIRON' array (*note Built-in Variables::). + * The `ENVIRON' array (*note Built-in Variables::). - * Multiple '-f' options on the command line (*note Options::). + * Multiple `-f' options on the command line (*note Options::). - * The '-v' option for assigning variables before program execution + * The `-v' option for assigning variables before program execution begins (*note Options::). - * The '--' option for terminating command-line options. + * The `--' option for terminating command-line options. - * The '\a', '\v', and '\x' escape sequences (*note Escape + * The `\a', `\v', and `\x' escape sequences (*note Escape Sequences::). - * A defined return value for the 'srand()' built-in function (*note + * A defined return value for the `srand()' built-in function (*note Numeric Functions::). - * The 'toupper()' and 'tolower()' built-in string functions for case + * The `toupper()' and `tolower()' built-in string functions for case translation (*note String Functions::). - * A cleaner specification for the '%c' format-control letter in the - 'printf' function (*note Control Letters::). + * A cleaner specification for the `%c' format-control letter in the + `printf' function (*note Control Letters::). * The ability to dynamically pass the field width and precision - ('"%*.*d"') in the argument list of the 'printf' function (*note + (`"%*.*d"') in the argument list of the `printf' function (*note Control Letters::). - * The use of regexp constants, such as '/foo/', as expressions, where - they are equivalent to using the matching operator, as in '$0 ~ + * The use of regexp constants, such as `/foo/', as expressions, where + they are equivalent to using the matching operator, as in `$0 ~ /foo/' (*note Using Constant Regexps::). * Processing of escape sequences inside command-line variable @@ -27094,16 +26003,16 @@ The System V Release 4 (1989) version of Unix 'awk' added these features  File: gawk.info, Node: POSIX, Next: BTL, Prev: SVR4, Up: Language History -A.3 Changes Between SVR4 and POSIX 'awk' +A.3 Changes Between SVR4 and POSIX `awk' ======================================== -The POSIX Command Language and Utilities standard for 'awk' (1992) +The POSIX Command Language and Utilities standard for `awk' (1992) introduced the following changes into the language: - * The use of '-W' for implementation-specific options (*note + * The use of `-W' for implementation-specific options (*note Options::). - * The use of 'CONVFMT' for controlling the conversion of numbers to + * The use of `CONVFMT' for controlling the conversion of numbers to strings (*note Conversion::). * The concept of a numeric string and tighter comparison rules to go @@ -27118,88 +26027,90 @@ introduced the following changes into the language: In 2012, a number of extensions that had been commonly available for many years were finally added to POSIX. They are: - * The 'fflush()' built-in function for flushing buffered output + * The `fflush()' built-in function for flushing buffered output (*note I/O Functions::). - * The 'nextfile' statement (*note Nextfile Statement::). + * The `nextfile' statement (*note Nextfile Statement::). - * The ability to delete all of an array at once with 'delete ARRAY' + * The ability to delete all of an array at once with `delete ARRAY' (*note Delete::). + *Note Common Extensions::, for a list of common extensions not permitted by the POSIX standard. The 2008 POSIX standard can be found online at -. +`http://www.opengroup.org/onlinepubs/9699919799/'.  File: gawk.info, Node: BTL, Next: POSIX/GNU, Prev: POSIX, Up: Language History -A.4 Extensions in Brian Kernighan's 'awk' +A.4 Extensions in Brian Kernighan's `awk' ========================================= Brian Kernighan has made his version available via his home page (*note Other Versions::). This minor node describes common extensions that originally appeared -in his version of 'awk'. +in his version of `awk'. - * The '**' and '**=' operators (*note Arithmetic Ops:: and *note + * The `**' and `**=' operators (*note Arithmetic Ops:: and *note Assignment Ops::). - * The use of 'func' as an abbreviation for 'function' (*note + * The use of `func' as an abbreviation for `function' (*note Definition Syntax::). - * The 'fflush()' built-in function for flushing buffered output + * The `fflush()' built-in function for flushing buffered output (*note I/O Functions::). + *Note Common Extensions::, for a full list of the extensions -available in his 'awk'. +available in his `awk'.  File: gawk.info, Node: POSIX/GNU, Next: Feature History, Prev: BTL, Up: Language History -A.5 Extensions in 'gawk' Not in POSIX 'awk' +A.5 Extensions in `gawk' Not in POSIX `awk' =========================================== -The GNU implementation, 'gawk', adds a large number of features. They -can all be disabled with either the '--traditional' or '--posix' options +The GNU implementation, `gawk', adds a large number of features. They +can all be disabled with either the `--traditional' or `--posix' options (*note Options::). - A number of features have come and gone over the years. This minor -node summarizes the additional features over POSIX 'awk' that are in the -current version of 'gawk'. + A number of features have come and gone over the years. This minor +node summarizes the additional features over POSIX `awk' that are in +the current version of `gawk'. * Additional built-in variables: - - The 'ARGIND' 'BINMODE', 'ERRNO', 'FIELDWIDTHS', 'FPAT', - 'IGNORECASE', 'LINT', 'PROCINFO', 'RT', and 'TEXTDOMAIN' + - The `ARGIND' `BINMODE', `ERRNO', `FIELDWIDTHS', `FPAT', + `IGNORECASE', `LINT', `PROCINFO', `RT', and `TEXTDOMAIN' variables (*note Built-in Variables::). * Special files in I/O redirections: - - The '/dev/stdin', '/dev/stdout', '/dev/stderr' and '/dev/fd/N' - special file names (*note Special Files::). + - The `/dev/stdin', `/dev/stdout', `/dev/stderr' and + `/dev/fd/N' special file names (*note Special Files::). - - The '/inet', '/inet4', and '/inet6' special files for TCP/IP - networking using '|&' to specify which version of the IP + - The `/inet', `/inet4', and `/inet6' special files for TCP/IP + networking using `|&' to specify which version of the IP protocol to use. (*note TCP/IP Networking::). * Changes and/or additions to the language: - - The '\x' escape sequence (*note Escape Sequences::). + - The `\x' escape sequence (*note Escape Sequences::). - Full support for both POSIX and GNU regexps (*note Regexp::). - - The ability for 'FS' and for the third argument to 'split()' + - The ability for `FS' and for the third argument to `split()' to be null strings (*note Single Character Fields::). - - The ability for 'RS' to be a regexp (*note Records::). + - The ability for `RS' to be a regexp (*note Records::). - - The ability to use octal and hexadecimal constants in 'awk' + - The ability to use octal and hexadecimal constants in `awk' program source code (*note Nondecimal-numbers::). - - The '|&' operator for two-way I/O to a coprocess (*note + - The `|&' operator for two-way I/O to a coprocess (*note Two-way I/O::). - Indirect function calls (*note Indirect Calls::). @@ -27209,87 +26120,62 @@ current version of 'gawk'. * New keywords: - - The 'BEGINFILE' and 'ENDFILE' special patterns. (*note + - The `BEGINFILE' and `ENDFILE' special patterns. (*note BEGINFILE/ENDFILE::). - - The ability to delete all of an array at once with 'delete + - The ability to delete all of an array at once with `delete ARRAY' (*note Delete::). - - The 'nextfile' statement (*note Nextfile Statement::). + - The `nextfile' statement (*note Nextfile Statement::). - - The 'switch' statement (*note Switch Statement::). + - The `switch' statement (*note Switch Statement::). - * Changes to standard 'awk' functions: + * Changes to standard `awk' functions: - - The optional second argument to 'close()' that allows closing + - The optional second argument to `close()' that allows closing one end of a two-way pipe to a coprocess (*note Two-way I/O::). - - POSIX compliance for 'gsub()' and 'sub()'. + - POSIX compliance for `gsub()' and `sub()'. - - The 'length()' function accepts an array argument and returns + - The `length()' function accepts an array argument and returns the number of elements in the array (*note String Functions::). - - The optional third argument to the 'match()' function for + - The optional third argument to the `match()' function for capturing text-matching subexpressions within a regexp (*note String Functions::). - - Positional specifiers in 'printf' formats for making + - Positional specifiers in `printf' formats for making translations easier (*note Printf Ordering::). - - The 'split()' function's additional optional fourth argument + - The `split()' function's additional optional fourth argument which is an array to hold the text of the field separators. (*note String Functions::). - * Additional functions only in 'gawk': + * Additional functions only in `gawk': - - The 'and()', 'compl()', 'lshift()', 'or()', 'rshift()', and - 'xor()' functions for bit manipulation (*note Bitwise + - The `and()', `compl()', `lshift()', `or()', `rshift()', and + `xor()' functions for bit manipulation (*note Bitwise Functions::). - - The 'asort()' and 'asorti()' functions for sorting arrays + - The `asort()' and `asorti()' functions for sorting arrays (*note Array Sorting::). - - The 'bindtextdomain()', 'dcgettext()' and 'dcngettext()' + - The `bindtextdomain()', `dcgettext()' and `dcngettext()' functions for internationalization (*note Programmer i18n::). -<<<<<<< HEAD - - The 'fflush()' function from Brian Kernighan's version of - 'awk' (*note I/O Functions::). -======= - The `fflush()' function from BWK `awk' (*note I/O Functions::). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - - The 'gensub()', 'patsplit()', and 'strtonum()' functions for + - The `gensub()', `patsplit()', and `strtonum()' functions for more powerful text manipulation (*note String Functions::). - - The 'mktime()', 'systime()', and 'strftime()' functions for + - The `mktime()', `systime()', and `strftime()' functions for working with timestamps (*note Time Functions::). * Changes and/or additions in the command-line options: -<<<<<<< HEAD - - The 'AWKPATH' environment variable for specifying a path - search for the '-f' command-line option (*note Options::). - - - The 'AWKLIBPATH' environment variable for specifying a path - search for the '-l' command-line option (*note Options::). - - - The '-b', '-c', '-C', '-d', '-D', '-e', '-E', '-g', '-h', - '-i', '-l', '-L', '-M', '-n', '-N', '-o', '-O', '-p', '-P', - '-r', '-S', '-t', and '-V' short options. Also, the ability - to use GNU-style long-named options that start with '--' and - the '--assign', '--bignum', '--characters-as-bytes', - '--copyright', '--debug', '--dump-variables', '--execle', - '--field-separator', '--file', '--gen-pot', '--help', - '--include', '--lint', '--lint-old', '--load', - '--non-decimal-data', '--optimize', '--posix', - '--pretty-print', '--profile', '--re-interval', '--sandbox', - '--source', '--traditional', '--use-lc-numeric', and - '--version' long options (*note Options::). -======= - The `AWKPATH' environment variable for specifying a path search for the `-f' command-line option (*note Options::). @@ -27308,10 +26194,9 @@ current version of 'gawk'. `--pretty-print', `--profile', `--re-interval', `--sandbox', `--source', `--traditional', `--use-lc-numeric', and `--version' long options (*note Options::). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Support for the following obsolete systems was removed from the - code and the documentation for 'gawk' version 4.0: + code and the documentation for `gawk' version 4.0: - Amiga @@ -27337,230 +26222,218 @@ current version of 'gawk'. - GCC for VAX and Alpha has not been tested for a while. + * Support for the following obsolete systems was removed from the - code and the documentation for 'gawk' version 4.1: + code and the documentation for `gawk' version 4.1: - Ultrix -<<<<<<< HEAD -======= * Support for MirBSD was removed at `gawk' version 4.2. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  File: gawk.info, Node: Feature History, Next: Common Extensions, Prev: POSIX/GNU, Up: Language History -A.6 History of 'gawk' Features +A.6 History of `gawk' Features ============================== -This minor node describes the features in 'gawk' over and above those in -POSIX 'awk', in the order they were added to 'gawk'. +This minor node describes the features in `gawk' over and above those +in POSIX `awk', in the order they were added to `gawk'. - Version 2.10 of 'gawk' introduced the following features: + Version 2.10 of `gawk' introduced the following features: - * The 'AWKPATH' environment variable for specifying a path search for - the '-f' command-line option (*note Options::). + * The `AWKPATH' environment variable for specifying a path search for + the `-f' command-line option (*note Options::). - * The 'IGNORECASE' variable and its effects (*note + * The `IGNORECASE' variable and its effects (*note Case-sensitivity::). - * The '/dev/stdin', '/dev/stdout', '/dev/stderr' and '/dev/fd/N' + * The `/dev/stdin', `/dev/stdout', `/dev/stderr' and `/dev/fd/N' special file names (*note Special Files::). - Version 2.13 of 'gawk' introduced the following features: + Version 2.13 of `gawk' introduced the following features: - * The 'FIELDWIDTHS' variable and its effects (*note Constant Size::). + * The `FIELDWIDTHS' variable and its effects (*note Constant Size::). - * The 'systime()' and 'strftime()' built-in functions for obtaining + * The `systime()' and `strftime()' built-in functions for obtaining and printing timestamps (*note Time Functions::). * Additional command-line options (*note Options::): - - The '-W lint' option to provide error and portability checking + - The `-W lint' option to provide error and portability checking for both the source code and at runtime. - - The '-W compat' option to turn off the GNU extensions. + - The `-W compat' option to turn off the GNU extensions. - - The '-W posix' option for full POSIX compliance. + - The `-W posix' option for full POSIX compliance. - Version 2.14 of 'gawk' introduced the following feature: + Version 2.14 of `gawk' introduced the following feature: - * The 'next file' statement for skipping to the next data file (*note - Nextfile Statement::). + * The `next file' statement for skipping to the next data file + (*note Nextfile Statement::). - Version 2.15 of 'gawk' introduced the following features: + Version 2.15 of `gawk' introduced the following features: * New variables (*note Built-in Variables::): - - 'ARGIND', which tracks the movement of 'FILENAME' through - 'ARGV'. + - `ARGIND', which tracks the movement of `FILENAME' through + `ARGV'. - - 'ERRNO', which contains the system error message when - 'getline' returns -1 or 'close()' fails. + - `ERRNO', which contains the system error message when + `getline' returns -1 or `close()' fails. - * The '/dev/pid', '/dev/ppid', '/dev/pgrpid', and '/dev/user' special - file names. These have since been removed. + * The `/dev/pid', `/dev/ppid', `/dev/pgrpid', and `/dev/user' + special file names. These have since been removed. - * The ability to delete all of an array at once with 'delete ARRAY' + * The ability to delete all of an array at once with `delete ARRAY' (*note Delete::). * Command-line option changes (*note Options::): - The ability to use GNU-style long-named options that start - with '--'. + with `--'. - - The '--source' option for mixing command-line and library-file + - The `--source' option for mixing command-line and library-file source code. - Version 3.0 of 'gawk' introduced the following features: + Version 3.0 of `gawk' introduced the following features: * New or changed variables: - - 'IGNORECASE' changed, now applying to string comparison as + - `IGNORECASE' changed, now applying to string comparison as well as regexp operations (*note Case-sensitivity::). - - 'RT', which contains the input text that matched 'RS' (*note + - `RT', which contains the input text that matched `RS' (*note Records::). * Full support for both POSIX and GNU regexps (*note Regexp::). - * The 'gensub()' function for more powerful text manipulation (*note + * The `gensub()' function for more powerful text manipulation (*note String Functions::). - * The 'strftime()' function acquired a default time format, allowing + * The `strftime()' function acquired a default time format, allowing it to be called with no arguments (*note Time Functions::). - * The ability for 'FS' and for the third argument to 'split()' to be + * The ability for `FS' and for the third argument to `split()' to be null strings (*note Single Character Fields::). - * The ability for 'RS' to be a regexp (*note Records::). + * The ability for `RS' to be a regexp (*note Records::). - * The 'next file' statement became 'nextfile' (*note Nextfile + * The `next file' statement became `nextfile' (*note Nextfile Statement::). -<<<<<<< HEAD - * The 'fflush()' function from Brian Kernighan's 'awk' (then at Bell - Laboratories; *note I/O Functions::). -======= * The `fflush()' function from BWK `awk' (then at Bell Laboratories; *note I/O Functions::). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * New command-line options: - - The '--lint-old' option to warn about constructs that are not - available in the original Version 7 Unix version of 'awk' + - The `--lint-old' option to warn about constructs that are not + available in the original Version 7 Unix version of `awk' (*note V7/SVR3.1::). -<<<<<<< HEAD - - The '-m' option from Brian Kernighan's 'awk'. (He was still - at Bell Laboratories at the time.) This was later removed - from both his 'awk' and from 'gawk'. -======= - The `-m' option from BWK `awk'. (Brian was still at Bell Laboratories at the time.) This was later removed from both his `awk' and from `gawk'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - - The '--re-interval' option to provide interval expressions in + - The `--re-interval' option to provide interval expressions in regexps (*note Regexp Operators::). - - The '--traditional' option was added as a better name for - '--compat' (*note Options::). + - The `--traditional' option was added as a better name for + `--compat' (*note Options::). - * The use of GNU Autoconf to control the configuration process (*note - Quick Installation::). + * The use of GNU Autoconf to control the configuration process + (*note Quick Installation::). * Amiga support. This has since been removed. - Version 3.1 of 'gawk' introduced the following features: + + Version 3.1 of `gawk' introduced the following features: * New variables (*note Built-in Variables::): - - 'BINMODE', for non-POSIX systems, which allows binary I/O for + - `BINMODE', for non-POSIX systems, which allows binary I/O for input and/or output files (*note PC Using::). - - 'LINT', which dynamically controls lint warnings. + - `LINT', which dynamically controls lint warnings. - - 'PROCINFO', an array for providing process-related + - `PROCINFO', an array for providing process-related information. - - 'TEXTDOMAIN', for setting an application's + - `TEXTDOMAIN', for setting an application's internationalization text domain (*note Internationalization::). - * The ability to use octal and hexadecimal constants in 'awk' program - source code (*note Nondecimal-numbers::). + * The ability to use octal and hexadecimal constants in `awk' + program source code (*note Nondecimal-numbers::). - * The '|&' operator for two-way I/O to a coprocess (*note Two-way + * The `|&' operator for two-way I/O to a coprocess (*note Two-way I/O::). - * The '/inet' special files for TCP/IP networking using '|&' (*note + * The `/inet' special files for TCP/IP networking using `|&' (*note TCP/IP Networking::). - * The optional second argument to 'close()' that allows closing one + * The optional second argument to `close()' that allows closing one end of a two-way pipe to a coprocess (*note Two-way I/O::). - * The optional third argument to the 'match()' function for capturing - text-matching subexpressions within a regexp (*note String - Functions::). + * The optional third argument to the `match()' function for + capturing text-matching subexpressions within a regexp (*note + String Functions::). - * Positional specifiers in 'printf' formats for making translations + * Positional specifiers in `printf' formats for making translations easier (*note Printf Ordering::). * A number of new built-in functions: - - The 'asort()' and 'asorti()' functions for sorting arrays + - The `asort()' and `asorti()' functions for sorting arrays (*note Array Sorting::). - - The 'bindtextdomain()', 'dcgettext()' and 'dcngettext()' + - The `bindtextdomain()', `dcgettext()' and `dcngettext()' functions for internationalization (*note Programmer i18n::). - - The 'extension()' function and the ability to add new built-in - functions dynamically (*note Dynamic Extensions::). + - The `extension()' function and the ability to add new + built-in functions dynamically (*note Dynamic Extensions::). - - The 'mktime()' function for creating timestamps (*note Time + - The `mktime()' function for creating timestamps (*note Time Functions::). - - The 'and()', 'or()', 'xor()', 'compl()', 'lshift()', - 'rshift()', and 'strtonum()' functions (*note Bitwise + - The `and()', `or()', `xor()', `compl()', `lshift()', + `rshift()', and `strtonum()' functions (*note Bitwise Functions::). - * The support for 'next file' as two words was removed completely + * The support for `next file' as two words was removed completely (*note Nextfile Statement::). * Additional command-line options (*note Options::): - - The '--dump-variables' option to print a list of all global + - The `--dump-variables' option to print a list of all global variables. - - The '--exec' option, for use in CGI scripts. + - The `--exec' option, for use in CGI scripts. - - The '--gen-po' command-line option and the use of a leading + - The `--gen-po' command-line option and the use of a leading underscore to mark strings that should be translated (*note String Extraction::). - - The '--non-decimal-data' option to allow non-decimal input + - The `--non-decimal-data' option to allow non-decimal input data (*note Nondecimal Data::). - - The '--profile' option and 'pgawk', the profiling version of - 'gawk', for producing execution profiles of 'awk' programs + - The `--profile' option and `pgawk', the profiling version of + `gawk', for producing execution profiles of `awk' programs (*note Profiling::). - - The '--use-lc-numeric' option to force 'gawk' to use the + - The `--use-lc-numeric' option to force `gawk' to use the locale's decimal point for parsing input data (*note Conversion::). * The use of GNU Automake to help in standardizing the configuration process (*note Quick Installation::). - * The use of GNU 'gettext' for 'gawk''s own message output (*note + * The use of GNU `gettext' for `gawk''s own message output (*note Gawk I18N::). - * BeOS support. This was later removed. + * BeOS support. This was later removed. - * Tandem support. This was later removed. + * Tandem support. This was later removed. * The Atari port became officially unsupported and was later removed entirely. @@ -27568,130 +26441,119 @@ POSIX 'awk', in the order they were added to 'gawk'. * The source code changed to use ISO C standard-style function definitions. - * POSIX compliance for 'sub()' and 'gsub()' (*note Gory Details::). + * POSIX compliance for `sub()' and `gsub()' (*note Gory Details::). - * The 'length()' function was extended to accept an array argument + * The `length()' function was extended to accept an array argument and return the number of elements in the array (*note String Functions::). - * The 'strftime()' function acquired a third argument to enable + * The `strftime()' function acquired a third argument to enable printing times as UTC (*note Time Functions::). - Version 4.0 of 'gawk' introduced the following features: + Version 4.0 of `gawk' introduced the following features: * Variable additions: - - 'FPAT', which allows you to specify a regexp that matches the + - `FPAT', which allows you to specify a regexp that matches the fields, instead of matching the field separator (*note Splitting By Content::). - - If 'PROCINFO["sorted_in"]' exists, 'for(iggy in foo)' loops + - If `PROCINFO["sorted_in"]' exists, `for(iggy in foo)' loops sort the indices before looping over them. The value of this element provides control over how the indices are sorted before the loop traversal starts (*note Controlling Scanning::). - - 'PROCINFO["strftime"]', which holds the default format for - 'strftime()' (*note Time Functions::). + - `PROCINFO["strftime"]', which holds the default format for + `strftime()' (*note Time Functions::). - * The special files '/dev/pid', '/dev/ppid', '/dev/pgrpid' and - '/dev/user' were removed. + * The special files `/dev/pid', `/dev/ppid', `/dev/pgrpid' and + `/dev/user' were removed. - * Support for IPv6 was added via the '/inet6' special file. '/inet4' - forces IPv4 and '/inet' chooses the system default, which is - probably IPv4 (*note TCP/IP Networking::). + * Support for IPv6 was added via the `/inet6' special file. + `/inet4' forces IPv4 and `/inet' chooses the system default, which + is probably IPv4 (*note TCP/IP Networking::). - * The use of '\s' and '\S' escape sequences in regular expressions + * The use of `\s' and `\S' escape sequences in regular expressions (*note GNU Regexp Operators::). * Interval expressions became part of default regular expressions (*note Regexp Operators::). - * POSIX character classes work even with '--traditional' (*note + * POSIX character classes work even with `--traditional' (*note Regexp Operators::). - * 'break' and 'continue' became invalid outside a loop, even with - '--traditional' (*note Break Statement::, and also see *note + * `break' and `continue' became invalid outside a loop, even with + `--traditional' (*note Break Statement::, and also see *note Continue Statement::). - * 'fflush()', 'nextfile', and 'delete ARRAY' are allowed if '--posix' - or '--traditional', since they are all now part of POSIX. + * `fflush()', `nextfile', and `delete ARRAY' are allowed if + `--posix' or `--traditional', since they are all now part of POSIX. - * An optional third argument to 'asort()' and 'asorti()', specifying + * An optional third argument to `asort()' and `asorti()', specifying how to sort (*note String Functions::). -<<<<<<< HEAD - * The behavior of 'fflush()' changed to match Brian Kernighan's 'awk' - and for POSIX; now both 'fflush()' and 'fflush("")' flush all open - output redirections (*note I/O Functions::). -======= * The behavior of `fflush()' changed to match BWK `awk' and for POSIX; now both `fflush()' and `fflush("")' flush all open output redirections (*note I/O Functions::). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - * The 'isarray()' function which distinguishes if an item is an array + * The `isarray()' function which distinguishes if an item is an array or not, to make it possible to traverse arrays of arrays (*note Type Functions::). - * The 'patsplit()' function which gives the same capability as - 'FPAT', for splitting (*note String Functions::). + * The `patsplit()' function which gives the same capability as + `FPAT', for splitting (*note String Functions::). - * An optional fourth argument to the 'split()' function, which is an + * An optional fourth argument to the `split()' function, which is an array to hold the values of the separators (*note String Functions::). * Arrays of arrays (*note Arrays of Arrays::). - * The 'BEGINFILE' and 'ENDFILE' special patterns (*note + * The `BEGINFILE' and `ENDFILE' special patterns (*note BEGINFILE/ENDFILE::). * Indirect function calls (*note Indirect Calls::). - * 'switch' / 'case' are enabled by default (*note Switch + * `switch' / `case' are enabled by default (*note Switch Statement::). * Command-line option changes (*note Options::): - - The '-b' and '--characters-as-bytes' options which prevent - 'gawk' from treating input as a multibyte string. + - The `-b' and `--characters-as-bytes' options which prevent + `gawk' from treating input as a multibyte string. - - The redundant '--compat', '--copyleft', and '--usage' long + - The redundant `--compat', `--copyleft', and `--usage' long options were removed. - - The '--gen-po' option was finally renamed to the correct - '--gen-pot'. + - The `--gen-po' option was finally renamed to the correct + `--gen-pot'. - - The '--sandbox' option which disables certain features. + - The `--sandbox' option which disables certain features. - - All long options acquired corresponding short options, for use - in '#!' scripts. + - All long options acquired corresponding short options, for + use in `#!' scripts. * Directories named on the command line now produce a warning, not a -<<<<<<< HEAD - fatal error, unless '--posix' or '--traditional' are used (*note - Command line directories::). -======= fatal error, unless `--posix' or `--traditional' are used (*note Command-line directories::). ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - * The 'gawk' internals were rewritten, bringing the 'dgawk' debugger + * The `gawk' internals were rewritten, bringing the `dgawk' debugger and possibly improved performance (*note Debugger::). * Per the GNU Coding Standards, dynamic extensions must now define a - global symbol indicating that they are GPL-compatible (*note Plugin - License::). + global symbol indicating that they are GPL-compatible (*note + Plugin License::). - * In POSIX mode, string comparisons use 'strcoll()' / 'wcscoll()' + * In POSIX mode, string comparisons use `strcoll()' / `wcscoll()' (*note POSIX String Comparison::). * The option for raw sockets was removed, since it was never implemented (*note TCP/IP Networking::). - * Ranges of the form '[d-h]' are treated as if they were in the C + * Ranges of the form `[d-h]' are treated as if they were in the C locale, no matter what kind of regexp is being used, and even if - '--posix' (*note Ranges and Locales::). + `--posix' (*note Ranges and Locales::). * Support was removed for the following systems: @@ -27717,76 +26579,72 @@ POSIX 'awk', in the order they were added to 'gawk'. - Prestandard VAX C compiler for VAX/VMS - Version 4.1 of 'gawk' introduced the following features: + Version 4.1 of `gawk' introduced the following features: - * Three new arrays: 'SYMTAB', 'FUNCTAB', and - 'PROCINFO["identifiers"]' (*note Auto-set::). + * Three new arrays: `SYMTAB', `FUNCTAB', and + `PROCINFO["identifiers"]' (*note Auto-set::). -<<<<<<< HEAD - * The three executables 'gawk', 'pgawk', and 'dgawk', were merged - into one, named just 'gawk'. As a result the command line options -======= * The three executables `gawk', `pgawk', and `dgawk', were merged into one, named just `gawk'. As a result the command-line options ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac changed. * Command-line option changes (*note Options::): - - The '-D' option invokes the debugger. + - The `-D' option invokes the debugger. - - The '-i' and '--include' options load 'awk' library files. + - The `-i' and `--include' options load `awk' library files. - - The '-l' and '--load' options load compiled dynamic + - The `-l' and `--load' options load compiled dynamic extensions. - - The '-M' and '--bignum' options enable MPFR. + - The `-M' and `--bignum' options enable MPFR. - - The '-o' only does pretty-printing. + - The `-o' only does pretty-printing. - - The '-p' option is used for profiling. + - The `-p' option is used for profiling. - - The '-R' option was removed. + - The `-R' option was removed. - * Support for high precision arithmetic with MPFR. (*note Arbitrary + * Support for high precision arithmetic with MPFR. (*note Arbitrary Precision Arithmetic::). - * The 'and()', 'or()' and 'xor()' functions changed to allow any + * The `and()', `or()' and `xor()' functions changed to allow any number of arguments, with a minimum of two (*note Bitwise Functions::). * The dynamic extension interface was completely redone (*note Dynamic Extensions::). +  File: gawk.info, Node: Common Extensions, Next: Ranges and Locales, Prev: Feature History, Up: Language History A.7 Common Extensions Summary ============================= -This minor node summarizes the common extensions supported by 'gawk', -Brian Kernighan's 'awk', and 'mawk', the three most widely-used freely -available versions of 'awk' (*note Other Versions::). +This minor node summarizes the common extensions supported by `gawk', +Brian Kernighan's `awk', and `mawk', the three most widely-used freely +available versions of `awk' (*note Other Versions::). Feature BWK Awk Mawk GNU Awk --------------------------------------------------------- -'\x' Escape sequence X X X -'FS' as null string X X X -'/dev/stdin' special file X X X -'/dev/stdout' special file X X X -'/dev/stderr' special file X X X -'delete' without subscript X X X -'fflush()' function X X X -'length()' of an array X X X -'nextfile' statement X X X -'**' and '**=' operators X X -'func' keyword X X -'BINMODE' variable X X -'RS' as regexp X X +-------------------------------------------------------- +`\x' Escape sequence X X X +`FS' as null string X X X +`/dev/stdin' special file X X X +`/dev/stdout' special file X X X +`/dev/stderr' special file X X X +`delete' without subscript X X X +`fflush()' function X X X +`length()' of an array X X X +`nextfile' statement X X X +`**' and `**=' operators X X +`func' keyword X X +`BINMODE' variable X X +`RS' as regexp X X Time related functions X X - (Technically speaking, as of late 2012, 'fflush()', 'delete ARRAY', -and 'nextfile' are no longer extensions, since they have been added to + (Technically speaking, as of late 2012, `fflush()', `delete ARRAY', +and `nextfile' are no longer extensions, since they have been added to POSIX.)  @@ -27795,24 +26653,24 @@ File: gawk.info, Node: Ranges and Locales, Next: Contributors, Prev: Common E A.8 Regexp Ranges and Locales: A Long Sad Story =============================================== -This minor node describes the confusing history of ranges within regular -expressions and their interactions with locales, and how this affected -different versions of 'gawk'. +This minor node describes the confusing history of ranges within +regular expressions and their interactions with locales, and how this +affected different versions of `gawk'. The original Unix tools that worked with regular expressions defined -character ranges (such as '[a-z]') to match any character between the +character ranges (such as `[a-z]') to match any character between the first character in the range and the last character in the range, -inclusive. Ordering was based on the numeric value of each character in -the machine's native character set. Thus, on ASCII-based systems, -'[a-z]' matched all the lowercase letters, and only the lowercase -letters, since the numeric values for the letters from 'a' through 'z' -were contiguous. (On an EBCDIC system, the range '[a-z]' includes +inclusive. Ordering was based on the numeric value of each character +in the machine's native character set. Thus, on ASCII-based systems, +`[a-z]' matched all the lowercase letters, and only the lowercase +letters, since the numeric values for the letters from `a' through `z' +were contiguous. (On an EBCDIC system, the range `[a-z]' includes additional, non-alphabetic characters as well.) Almost all introductory Unix literature explained range expressions as working in this fashion, and in particular, would teach that the -"correct" way to match lowercase letters was with '[a-z]', and that -'[A-Z]' was the "correct" way to match uppercase letters. And indeed, +"correct" way to match lowercase letters was with `[a-z]', and that +`[A-Z]' was the "correct" way to match uppercase letters. And indeed, this was true.(1) The 1992 POSIX standard introduced the idea of locales (*note @@ -27823,63 +26681,63 @@ different kinds of characters besides the traditional ones in the ASCII character set. However, the standard _changed_ the interpretation of range -expressions. In the '"C"' and '"POSIX"' locales, a range expression -like '[a-dx-z]' is still equivalent to '[abcdxyz]', as in ASCII. But +expressions. In the `"C"' and `"POSIX"' locales, a range expression +like `[a-dx-z]' is still equivalent to `[abcdxyz]', as in ASCII. But outside those locales, the ordering was defined to be based on "collation order". - In many locales, 'A' and 'a' are both less than 'B'. In other words, -these locales sort characters in dictionary order, and '[a-dx-z]' is -typically not equivalent to '[abcdxyz]'; instead it might be equivalent -to '[ABCXYabcdxyz]', for example. + In many locales, `A' and `a' are both less than `B'. In other +words, these locales sort characters in dictionary order, and +`[a-dx-z]' is typically not equivalent to `[abcdxyz]'; instead it might +be equivalent to `[ABCXYabcdxyz]', for example. This point needs to be emphasized: Much literature teaches that you -should use '[a-z]' to match a lowercase character. But on systems with +should use `[a-z]' to match a lowercase character. But on systems with non-ASCII locales, this also matched all of the uppercase characters -except 'A' or 'Z'! This was a continuous cause of confusion, even well +except `A' or `Z'! This was a continuous cause of confusion, even well into the twenty-first century. - To demonstrate these issues, the following example uses the 'sub()' + To demonstrate these issues, the following example uses the `sub()' function, which does text replacement (*note String Functions::). Here, the intent is to remove trailing uppercase characters: $ echo something1234abc | gawk-3.1.8 '{ sub("[A-Z]*$", ""); print }' -| something1234a -This output is unexpected, since the 'bc' at the end of -'something1234abc' should not normally match '[A-Z]*'. This result is +This output is unexpected, since the `bc' at the end of +`something1234abc' should not normally match `[A-Z]*'. This result is due to the locale setting (and thus you may not see it on your system). - Similar considerations apply to other ranges. For example, '["-/]' + Similar considerations apply to other ranges. For example, `["-/]' is perfectly valid in ASCII, but is not valid in many Unicode locales, -such as 'en_US.UTF-8'. +such as `en_US.UTF-8'. - Early versions of 'gawk' used regexp matching code that was not + Early versions of `gawk' used regexp matching code that was not locale aware, so ranges had their traditional interpretation. - When 'gawk' switched to using locale-aware regexp matchers, the -problems began; especially as both GNU/Linux and commercial Unix vendors -started implementing non-ASCII locales, _and making them the default_. -Perhaps the most frequently asked question became something like "why -does '[A-Z]' match lowercase letters?!?" + When `gawk' switched to using locale-aware regexp matchers, the +problems began; especially as both GNU/Linux and commercial Unix +vendors started implementing non-ASCII locales, _and making them the +default_. Perhaps the most frequently asked question became something +like "why does `[A-Z]' match lowercase letters?!?" This situation existed for close to 10 years, if not more, and the -'gawk' maintainer grew weary of trying to explain that 'gawk' was being -nicely standards-compliant, and that the issue was in the user's locale. -During the development of version 4.0, he modified 'gawk' to always -treat ranges in the original, pre-POSIX fashion, unless '--posix' was -used (*note Options::).(2) +`gawk' maintainer grew weary of trying to explain that `gawk' was being +nicely standards-compliant, and that the issue was in the user's +locale. During the development of version 4.0, he modified `gawk' to +always treat ranges in the original, pre-POSIX fashion, unless +`--posix' was used (*note Options::).(2) - Fortunately, shortly before the final release of 'gawk' 4.0, the + Fortunately, shortly before the final release of `gawk' 4.0, the maintainer learned that the 2008 standard had changed the definition of -ranges, such that outside the '"C"' and '"POSIX"' locales, the meaning +ranges, such that outside the `"C"' and `"POSIX"' locales, the meaning of range expressions was _undefined_.(3) By using this lovely technical term, the standard gives license to implementors to implement ranges in whatever way they choose. The -'gawk' maintainer chose to apply the pre-POSIX meaning in all cases: the -default regexp matching; with '--traditional' and with '--posix'; in all -cases, 'gawk' remains POSIX compliant. +`gawk' maintainer chose to apply the pre-POSIX meaning in all cases: +the default regexp matching; with `--traditional' and with `--posix'; +in all cases, `gawk' remains POSIX compliant. ---------- Footnotes ---------- @@ -27898,18 +26756,17 @@ and its rationale  File: gawk.info, Node: Contributors, Next: History summary, Prev: Ranges and Locales, Up: Language History -A.9 Major Contributors to 'gawk' +A.9 Major Contributors to `gawk' ================================ - Always give credit where credit is due. - -- _Anonymous_ + Always give credit where credit is due. -- Anonymous - This minor node names the major contributors to 'gawk' and/or this + This minor node names the major contributors to `gawk' and/or this Info file, in approximate chronological order: * Dr. Alfred V. Aho, Dr. Peter J. Weinberger, and Dr. Brian W. Kernighan, all of Bell Laboratories, designed and implemented Unix - 'awk', from which 'gawk' gets the majority of its feature set. + `awk', from which `gawk' gets the majority of its feature set. * Paul Rubin did the initial design and implementation in 1986, and wrote the first draft (around 40 pages) of this Info file. @@ -27920,14 +26777,14 @@ Info file, in approximate chronological order: to around 90 pages. * Richard Stallman helped finish the implementation and the initial - draft of this Info file. He is also the founder of the FSF and the - GNU project. + draft of this Info file. He is also the founder of the FSF and + the GNU project. * John Woods contributed parts of the code (mostly fixes) in the - initial version of 'gawk'. + initial version of `gawk'. - * In 1988, David Trueman took over primary maintenance of 'gawk', - making it compatible with "new" 'awk', and greatly improving its + * In 1988, David Trueman took over primary maintenance of `gawk', + making it compatible with "new" `awk', and greatly improving its performance. * Conrad Kwok, Scott Garfinkle, and Kent Williams did the initial @@ -27935,7 +26792,7 @@ Info file, in approximate chronological order: * Pat Rankin provided the VMS port and its documentation. - * Hal Peterson provided help in porting 'gawk' to Cray systems. + * Hal Peterson provided help in porting `gawk' to Cray systems. (This is no longer supported.) * Kai Uwe Rommel provided the initial port to OS/2 and its @@ -27943,8 +26800,8 @@ Info file, in approximate chronological order: * Michal Jaegermann provided the port to Atari systems and its documentation. (This port is no longer supported.) He continues - to provide portability checking, and has done a lot of work to make - sure 'gawk' works on non-32-bit systems. + to provide portability checking, and has done a lot of work to + make sure `gawk' works on non-32-bit systems. * Fred Fish provided the port to Amiga systems and its documentation. (With Fred's sad passing, this is no longer supported.) @@ -27962,18 +26819,18 @@ Info file, in approximate chronological order: instrumental in keeping the documentation up to date for the various PC platforms. - * Christos Zoulas provided the 'extension()' built-in function for - dynamically adding new modules. (This was obsoleted at 'gawk' + * Christos Zoulas provided the `extension()' built-in function for + dynamically adding new modules. (This was obsoleted at `gawk' 4.1.) * Ju"rgen Kahrs contributed the initial version of the TCP/IP networking code and documentation, and motivated the inclusion of - the '|&' operator. + the `|&' operator. * Stephen Davies provided the initial port to Tandem systems and its documentation. (However, this is no longer supported.) He was also instrumental in the initial work to integrate the byte-code - internals into the 'gawk' code base. + internals into the `gawk' code base. * Matthew Woehlke provided improvements for Tandem's POSIX-compliant systems. @@ -27981,19 +26838,19 @@ Info file, in approximate chronological order: * Martin Brown provided the port to BeOS and its documentation. (This is no longer supported.) - * Arno Peters did the initial work to convert 'gawk' to use GNU - Automake and GNU 'gettext'. + * Arno Peters did the initial work to convert `gawk' to use GNU + Automake and GNU `gettext'. - * Alan J. Broder provided the initial version of the 'asort()' + * Alan J. Broder provided the initial version of the `asort()' function as well as the code for the optional third argument to the - 'match()' function. + `match()' function. - * Andreas Buening updated the 'gawk' port for OS/2. + * Andreas Buening updated the `gawk' port for OS/2. * Isamu Hasegawa, of IBM in Japan, contributed support for multibyte characters. - * Michael Benzinger contributed the initial code for 'switch' + * Michael Benzinger contributed the initial code for `switch' statements. * Patrick T.J. McPhee contributed the code for dynamic loading in @@ -28001,12 +26858,12 @@ Info file, in approximate chronological order: * Anders Wallin helped keep the VMS port going for several years. - * Assaf Gordon contributed the code to implement the '--sandbox' + * Assaf Gordon contributed the code to implement the `--sandbox' option. * John Haque made the following contributions: - - The modifications to convert 'gawk' into a byte-code + - The modifications to convert `gawk' into a byte-code interpreter, including the debugger. - The addition of true arrays of arrays. @@ -28016,7 +26873,7 @@ Info file, in approximate chronological order: - The initial text of *note Arbitrary Precision Arithmetic::. - - The work to merge the three versions of 'gawk' into one, for + - The work to merge the three versions of `gawk' into one, for the 4.1 release. - Improved array internals for arrays indexed by integers. @@ -28029,15 +26886,15 @@ Info file, in approximate chronological order: * Efraim Yawitz contributed the original text for *note Debugger::. - * The development of the extension API first released with 'gawk' 4.1 - was driven primarily by Arnold Robbins and Andrew Schorr, with + * The development of the extension API first released with `gawk' + 4.1 was driven primarily by Arnold Robbins and Andrew Schorr, with notable contributions from the rest of the development team. * Antonio Giovanni Colombo rewrote a number of examples in the early chapters that were severely dated, for which I am incredibly grateful. - * Arnold Robbins has been working on 'gawk' since 1988, at first + * Arnold Robbins has been working on `gawk' since 1988, at first helping David Trueman, and as the primary maintainer since around 1994. @@ -28047,61 +26904,62 @@ File: gawk.info, Node: History summary, Prev: Contributors, Up: Language Hist A.10 Summary ============ - * The 'awk' language has evolved over time. The first release was + * The `awk' language has evolved over time. The first release was with V7 Unix circa 1978. In 1987 for System V Release 3.1, major additions, including user-defined functions, were made to the language. Additional changes were made for System V Release 4, in 1989. Since then, further minor changes happen under the auspices of the POSIX standard. - * Brian Kernighan's 'awk' provides a small number of extensions that - are implemented in common with other versions of 'awk'. + * Brian Kernighan's `awk' provides a small number of extensions that + are implemented in common with other versions of `awk'. - * 'gawk' provides a large number of extensions over POSIX 'awk'. - They can be disabled with either the '--traditional' or '--posix' + * `gawk' provides a large number of extensions over POSIX `awk'. + They can be disabled with either the `--traditional' or `--posix' options. - * The interaction of POSIX locales and regexp matching in 'gawk' has - been confusing over the years. Today, 'gawk' implements Rational - Range Interpretation, where ranges of the form '[a-z]' match _only_ - the characters numerically between 'a' through 'z' in the machine's - native character set. Usually this is ASCII but it can be EBCDIC - on IBM S/390 systems. + * The interaction of POSIX locales and regexp matching in `gawk' has + been confusing over the years. Today, `gawk' implements Rational + Range Interpretation, where ranges of the form `[a-z]' match + _only_ the characters numerically between `a' through `z' in the + machine's native character set. Usually this is ASCII but it can + be EBCDIC on IBM S/390 systems. - * Many people have contributed to 'gawk' development over the years. + * Many people have contributed to `gawk' development over the years. We hope that the list provided in this major node is complete and gives the appropriate credit where credit is due. +  File: gawk.info, Node: Installation, Next: Notes, Prev: Language History, Up: Top -Appendix B Installing 'gawk' +Appendix B Installing `gawk' **************************** -This appendix provides instructions for installing 'gawk' on the various -platforms that are supported by the developers. The primary developer -supports GNU/Linux (and Unix), whereas the other ports are contributed. -*Note Bugs::, for the electronic mail addresses of the people who did -the respective ports. +This appendix provides instructions for installing `gawk' on the +various platforms that are supported by the developers. The primary +developer supports GNU/Linux (and Unix), whereas the other ports are +contributed. *Note Bugs::, for the electronic mail addresses of the +people who did the respective ports. * Menu: -* Gawk Distribution:: What is in the 'gawk' distribution. -* Unix Installation:: Installing 'gawk' under various +* Gawk Distribution:: What is in the `gawk' distribution. +* Unix Installation:: Installing `gawk' under various versions of Unix. * Non-Unix Installation:: Installation on Other Operating Systems. * Bugs:: Reporting Problems and Bugs. -* Other Versions:: Other freely available 'awk' +* Other Versions:: Other freely available `awk' implementations. * Installation summary:: Summary of installation.  File: gawk.info, Node: Gawk Distribution, Next: Unix Installation, Up: Installation -B.1 The 'gawk' Distribution +B.1 The `gawk' Distribution =========================== -This minor node describes how to get the 'gawk' distribution, how to +This minor node describes how to get the `gawk' distribution, how to extract it, and then what is in the various files and subdirectories. * Menu: @@ -28113,16 +26971,16 @@ extract it, and then what is in the various files and subdirectories.  File: gawk.info, Node: Getting, Next: Extracting, Up: Gawk Distribution -B.1.1 Getting the 'gawk' Distribution +B.1.1 Getting the `gawk' Distribution ------------------------------------- There are two ways to get GNU software: * Copy it from someone else who already has it. - * Retrieve 'gawk' from the Internet host 'ftp.gnu.org', in the - directory '/gnu/gawk'. Both anonymous 'ftp' and 'http' access are - supported. If you have the 'wget' program, you can use a command + * Retrieve `gawk' from the Internet host `ftp.gnu.org', in the + directory `/gnu/gawk'. Both anonymous `ftp' and `http' access are + supported. If you have the `wget' program, you can use a command like the following: wget http://ftp.gnu.org/gnu/gawk/gawk-4.1.1.tar.gz @@ -28139,283 +26997,285 @@ File: gawk.info, Node: Extracting, Next: Distribution contents, Prev: Getting B.1.2 Extracting the Distribution --------------------------------- -'gawk' is distributed as several 'tar' files compressed with different -compression programs: 'gzip', 'bzip2', and 'xz'. For simplicity, the +`gawk' is distributed as several `tar' files compressed with different +compression programs: `gzip', `bzip2', and `xz'. For simplicity, the rest of these instructions assume you are using the one compressed with -the GNU Zip program, 'gzip'. +the GNU Zip program, `gzip'. - Once you have the distribution (for example, 'gawk-4.1.1.tar.gz'), -use 'gzip' to expand the file and then use 'tar' to extract it. You can -use the following pipeline to produce the 'gawk' distribution: + Once you have the distribution (for example, `gawk-4.1.1.tar.gz'), +use `gzip' to expand the file and then use `tar' to extract it. You +can use the following pipeline to produce the `gawk' distribution: gzip -d -c gawk-4.1.1.tar.gz | tar -xvpf - - On a system with GNU 'tar', you can let 'tar' do the decompression + On a system with GNU `tar', you can let `tar' do the decompression for you: tar -xvpzf gawk-4.1.1.tar.gz -Extracting the archive creates a directory named 'gawk-4.1.1' in the +Extracting the archive creates a directory named `gawk-4.1.1' in the current directory. - The distribution file name is of the form 'gawk-V.R.P.tar.gz'. The V -represents the major version of 'gawk', the R represents the current -release of version V, and the P represents a "patch level", meaning that -minor bugs have been fixed in the release. The current patch level is -1, but when retrieving distributions, you should get the version with -the highest version, release, and patch level. (Note, however, that -patch levels greater than or equal to 70 denote "beta" or nonproduction -software; you might not want to retrieve such a version unless you don't -mind experimenting.) If you are not on a Unix or GNU/Linux system, you -need to make other arrangements for getting and extracting the 'gawk' -distribution. You should consult a local expert. + The distribution file name is of the form `gawk-V.R.P.tar.gz'. The +V represents the major version of `gawk', the R represents the current +release of version V, and the P represents a "patch level", meaning +that minor bugs have been fixed in the release. The current patch +level is 1, but when retrieving distributions, you should get the +version with the highest version, release, and patch level. (Note, +however, that patch levels greater than or equal to 70 denote "beta" or +nonproduction software; you might not want to retrieve such a version +unless you don't mind experimenting.) If you are not on a Unix or +GNU/Linux system, you need to make other arrangements for getting and +extracting the `gawk' distribution. You should consult a local expert.  File: gawk.info, Node: Distribution contents, Prev: Extracting, Up: Gawk Distribution -B.1.3 Contents of the 'gawk' Distribution +B.1.3 Contents of the `gawk' Distribution ----------------------------------------- -The 'gawk' distribution has a number of C source files, documentation +The `gawk' distribution has a number of C source files, documentation files, subdirectories, and files related to the configuration process (*note Unix Installation::), as well as several subdirectories related to different non-Unix operating systems: -Various '.c', '.y', and '.h' files - The actual 'gawk' source code. +Various `.c', `.y', and `.h' files + The actual `gawk' source code. -'ABOUT-NLS' - Information about GNU 'gettext' and translations. +`ABOUT-NLS' + Information about GNU `gettext' and translations. -'AUTHORS' - A file with some information about the authorship of 'gawk'. It +`AUTHORS' + A file with some information about the authorship of `gawk'. It exists only to satisfy the pedants at the Free Software Foundation. -'README' -'README_d/README.*' - Descriptive files: 'README' for 'gawk' under Unix and the rest for +`README' +`README_d/README.*' + Descriptive files: `README' for `gawk' under Unix and the rest for the various hardware and software combinations. -'INSTALL' +`INSTALL' A file providing an overview of the configuration and installation process. -'ChangeLog' +`ChangeLog' A detailed list of source code changes as bugs are fixed or improvements made. -'ChangeLog.0' +`ChangeLog.0' An older list of source code changes. -'NEWS' - A list of changes to 'gawk' since the last release or patch. +`NEWS' + A list of changes to `gawk' since the last release or patch. -'NEWS.0' - An older list of changes to 'gawk'. +`NEWS.0' + An older list of changes to `gawk'. -'COPYING' +`COPYING' The GNU General Public License. -'POSIX.STD' - A description of behaviors in the POSIX standard for 'awk' which - are left undefined, or where 'gawk' may not comply fully, as well +`POSIX.STD' + A description of behaviors in the POSIX standard for `awk' which + are left undefined, or where `gawk' may not comply fully, as well as a list of things that the POSIX standard should describe but does not. -'doc/awkforai.txt' +`doc/awkforai.txt' Pointers to the original draft of a short article describing why - 'gawk' is a good language for Artificial Intelligence (AI) + `gawk' is a good language for Artificial Intelligence (AI) programming. -'doc/bc_notes' - A brief description of 'gawk''s "byte code" internals. - -'doc/README.card' -'doc/ad.block' -'doc/awkcard.in' -'doc/cardfonts' -'doc/colors' -'doc/macros' -'doc/no.colors' -'doc/setter.outline' - The 'troff' source for a five-color 'awk' reference card. A modern - version of 'troff' such as GNU 'troff' ('groff') is needed to - produce the color version. See the file 'README.card' for - instructions if you have an older 'troff'. - -'doc/gawk.1' - The 'troff' source for a manual page describing 'gawk'. This is +`doc/bc_notes' + A brief description of `gawk''s "byte code" internals. + +`doc/README.card' +`doc/ad.block' +`doc/awkcard.in' +`doc/cardfonts' +`doc/colors' +`doc/macros' +`doc/no.colors' +`doc/setter.outline' + The `troff' source for a five-color `awk' reference card. A + modern version of `troff' such as GNU `troff' (`groff') is needed + to produce the color version. See the file `README.card' for + instructions if you have an older `troff'. + +`doc/gawk.1' + The `troff' source for a manual page describing `gawk'. This is distributed for the convenience of Unix users. -'doc/gawktexi.in' -'doc/sidebar.awk' - The Texinfo source file for this Info file. It should be processed - by 'doc/sidebar.awk' before processing with 'texi2dvi' or - 'texi2pdf' to produce a printed document, and with 'makeinfo' to - produce an Info or HTML file. The 'Makefile' takes care of this - processing and produces printable output via 'texi2dvi' or - 'texi2pdf'. +`doc/gawktexi.in' +`doc/sidebar.awk' + The Texinfo source file for this Info file. It should be + processed by `doc/sidebar.awk' before processing with `texi2dvi' + or `texi2pdf' to produce a printed document, and with `makeinfo' + to produce an Info or HTML file. The `Makefile' takes care of + this processing and produces printable output via `texi2dvi' or + `texi2pdf'. -'doc/gawk.texi' - The file produced after processing 'gawktexi.in' with - 'sidebar.awk'. +`doc/gawk.texi' + The file produced after processing `gawktexi.in' with + `sidebar.awk'. -'doc/gawk.info' +`doc/gawk.info' The generated Info file for this Info file. -'doc/gawkinet.texi' - The Texinfo source file for *note (General Introduction, gawkinet, - TCP/IP Internetworking with 'gawk')Top::. It should be processed - with TeX (via 'texi2dvi' or 'texi2pdf') to produce a printed - document and with 'makeinfo' to produce an Info or HTML file. +`doc/gawkinet.texi' + The Texinfo source file for *note (General Introduction)Top:: + gawkinet, TCP/IP Internetworking with `gawk'. It should be + processed with TeX (via `texi2dvi' or `texi2pdf') to produce a + printed document and with `makeinfo' to produce an Info or HTML + file. -'doc/gawkinet.info' - The generated Info file for 'TCP/IP Internetworking with 'gawk''. +`doc/gawkinet.info' + The generated Info file for `TCP/IP Internetworking with `gawk''. -'doc/igawk.1' - The 'troff' source for a manual page describing the 'igawk' program - presented in *note Igawk Program::. (Since 'gawk' can do its own - '@include' processing, neither 'igawk' nor 'igawk.1' are +`doc/igawk.1' + The `troff' source for a manual page describing the `igawk' + program presented in *note Igawk Program::. (Since `gawk' can do + its own `@include' processing, neither `igawk' nor `igawk.1' are installed.) -'doc/Makefile.in' +`doc/Makefile.in' The input file used during the configuration process to generate - the actual 'Makefile' for creating the documentation. + the actual `Makefile' for creating the documentation. -'Makefile.am' -'*/Makefile.am' +`Makefile.am' +`*/Makefile.am' Files used by the GNU Automake software for generating the - 'Makefile.in' files used by Autoconf and 'configure'. - -'Makefile.in' -'aclocal.m4' -'bisonfix.awk' -'config.guess' -'configh.in' -'configure.ac' -'configure' -'custom.h' -'depcomp' -'install-sh' -'missing_d/*' -'mkinstalldirs' -'m4/*' + `Makefile.in' files used by Autoconf and `configure'. + +`Makefile.in' +`aclocal.m4' +`bisonfix.awk' +`config.guess' +`configh.in' +`configure.ac' +`configure' +`custom.h' +`depcomp' +`install-sh' +`missing_d/*' +`mkinstalldirs' +`m4/*' These files and subdirectories are used when configuring and - compiling 'gawk' for various Unix systems. Most of them are - explained in *note Unix Installation::. The rest are there to + compiling `gawk' for various Unix systems. Most of them are + explained in *note Unix Installation::. The rest are there to support the main infrastructure. -'po/*' - The 'po' library contains message translations. +`po/*' + The `po' library contains message translations. -'awklib/extract.awk' -'awklib/Makefile.am' -'awklib/Makefile.in' -'awklib/eg/*' - The 'awklib' directory contains a copy of 'extract.awk' (*note +`awklib/extract.awk' +`awklib/Makefile.am' +`awklib/Makefile.in' +`awklib/eg/*' + The `awklib' directory contains a copy of `extract.awk' (*note Extract Program::), which can be used to extract the sample - programs from the Texinfo source file for this Info file. It also - contains a 'Makefile.in' file, which 'configure' uses to generate a - 'Makefile'. 'Makefile.am' is used by GNU Automake to create - 'Makefile.in'. The library functions from *note Library - Functions::, are included as ready-to-use files in the 'gawk' + programs from the Texinfo source file for this Info file. It also + contains a `Makefile.in' file, which `configure' uses to generate + a `Makefile'. `Makefile.am' is used by GNU Automake to create + `Makefile.in'. The library functions from *note Library + Functions::, are included as ready-to-use files in the `gawk' distribution. They are installed as part of the installation process. The rest of the programs in this Info file are available - in appropriate subdirectories of 'awklib/eg'. + in appropriate subdirectories of `awklib/eg'. -'extension/*' +`extension/*' The source code, manual pages, and infrastructure files for the - sample extensions included with 'gawk'. *Note Dynamic + sample extensions included with `gawk'. *Note Dynamic Extensions::, for more information. -'posix/*' - Files needed for building 'gawk' on POSIX-compliant systems. +`posix/*' + Files needed for building `gawk' on POSIX-compliant systems. -'pc/*' - Files needed for building 'gawk' under MS-Windows and OS/2 (*note +`pc/*' + Files needed for building `gawk' under MS-Windows and OS/2 (*note PC Installation::, for details). -'vms/*' - Files needed for building 'gawk' under Vax/VMS and OpenVMS (*note +`vms/*' + Files needed for building `gawk' under Vax/VMS and OpenVMS (*note VMS Installation::, for details). -'test/*' - A test suite for 'gawk'. You can use 'make check' from the - top-level 'gawk' directory to run your version of 'gawk' against - the test suite. If 'gawk' successfully passes 'make check', then +`test/*' + A test suite for `gawk'. You can use `make check' from the + top-level `gawk' directory to run your version of `gawk' against + the test suite. If `gawk' successfully passes `make check', then you can be confident of a successful port.  File: gawk.info, Node: Unix Installation, Next: Non-Unix Installation, Prev: Gawk Distribution, Up: Installation -B.2 Compiling and Installing 'gawk' on Unix-like Systems +B.2 Compiling and Installing `gawk' on Unix-like Systems ======================================================== -Usually, you can compile and install 'gawk' by typing only two commands. -However, if you use an unusual system, you may need to configure 'gawk' -for your system yourself. +Usually, you can compile and install `gawk' by typing only two +commands. However, if you use an unusual system, you may need to +configure `gawk' for your system yourself. * Menu: -* Quick Installation:: Compiling 'gawk' under Unix. +* Quick Installation:: Compiling `gawk' under Unix. * Additional Configuration Options:: Other compile-time options. * Configuration Philosophy:: How it's all supposed to work.  File: gawk.info, Node: Quick Installation, Next: Additional Configuration Options, Up: Unix Installation -B.2.1 Compiling 'gawk' for Unix-like Systems +B.2.1 Compiling `gawk' for Unix-like Systems -------------------------------------------- The normal installation steps should work on all modern commercial Unix-derived systems, GNU/Linux, BSD-based systems, and the Cygwin environment for MS-Windows. - After you have extracted the 'gawk' distribution, 'cd' to -'gawk-4.1.1'. Like most GNU software, 'gawk' is configured -automatically for your system by running the 'configure' program. This + After you have extracted the `gawk' distribution, `cd' to +`gawk-4.1.1'. Like most GNU software, `gawk' is configured +automatically for your system by running the `configure' program. This program is a Bourne shell script that is generated automatically using GNU Autoconf. (The Autoconf software is described fully starting with -*note (Autoconf, autoconf,Autoconf---Generating Automatic Configuration -Scripts)Top::.) +*note (Autoconf)Top:: autoconf,Autoconf--Generating Automatic +Configuration Scripts.) - To configure 'gawk', simply run 'configure': + To configure `gawk', simply run `configure': sh ./configure - This produces a 'Makefile' and 'config.h' tailored to your system. -The 'config.h' file describes various facts about your system. You -might want to edit the 'Makefile' to change the 'CFLAGS' variable, which -controls the command-line options that are passed to the C compiler -(such as optimization levels or compiling for debugging). + This produces a `Makefile' and `config.h' tailored to your system. +The `config.h' file describes various facts about your system. You +might want to edit the `Makefile' to change the `CFLAGS' variable, +which controls the command-line options that are passed to the C +compiler (such as optimization levels or compiling for debugging). - Alternatively, you can add your own values for most 'make' variables -on the command line, such as 'CC' and 'CFLAGS', when running -'configure': + Alternatively, you can add your own values for most `make' variables +on the command line, such as `CC' and `CFLAGS', when running +`configure': CC=cc CFLAGS=-g sh ./configure -See the file 'INSTALL' in the 'gawk' distribution for all the details. +See the file `INSTALL' in the `gawk' distribution for all the details. - After you have run 'configure' and possibly edited the 'Makefile', + After you have run `configure' and possibly edited the `Makefile', type: make -Shortly thereafter, you should have an executable version of 'gawk'. -That's all there is to it! To verify that 'gawk' is working properly, -run 'make check'. All of the tests should succeed. If these steps do -not work, or if any of the tests fail, check the files in the 'README_d' -directory to see if you've found a known problem. If the failure is not -described there, please send in a bug report (*note Bugs::). - - Of course, once you've built 'gawk', it is likely that you will wish -to install it. To do so, you need to run the command 'make install', as -a user with the appropriate permissions. How to do this varies by -system, but on many systems you can use the 'sudo' command to do so. -The command then becomes 'sudo make install'. It is likely that you +Shortly thereafter, you should have an executable version of `gawk'. +That's all there is to it! To verify that `gawk' is working properly, +run `make check'. All of the tests should succeed. If these steps do +not work, or if any of the tests fail, check the files in the +`README_d' directory to see if you've found a known problem. If the +failure is not described there, please send in a bug report (*note +Bugs::). + + Of course, once you've built `gawk', it is likely that you will wish +to install it. To do so, you need to run the command `make install', +as a user with the appropriate permissions. How to do this varies by +system, but on many systems you can use the `sudo' command to do so. +The command then becomes `sudo make install'. It is likely that you will be asked for your password, and you will have to have been set up -previously as a user who is allowed to run the 'sudo' command. +previously as a user who is allowed to run the `sudo' command.  File: gawk.info, Node: Additional Configuration Options, Next: Configuration Philosophy, Prev: Quick Installation, Up: Unix Installation @@ -28423,41 +27283,41 @@ File: gawk.info, Node: Additional Configuration Options, Next: Configuration P B.2.2 Additional Configuration Options -------------------------------------- -There are several additional options you may use on the 'configure' -command line when compiling 'gawk' from scratch, including: +There are several additional options you may use on the `configure' +command line when compiling `gawk' from scratch, including: -'--disable-extensions' +`--disable-extensions' Disable configuring and building the sample extensions in the - 'extension' directory. This is useful for cross-compiling. The + `extension' directory. This is useful for cross-compiling. The default action is to dynamically check if the extensions can be configured and compiled. -'--disable-lint' - Disable all lint checking within 'gawk'. The '--lint' and - '--lint-old' options (*note Options::) are accepted, but silently - do nothing. Similarly, setting the 'LINT' variable (*note - User-modified::) has no effect on the running 'awk' program. +`--disable-lint' + Disable all lint checking within `gawk'. The `--lint' and + `--lint-old' options (*note Options::) are accepted, but silently + do nothing. Similarly, setting the `LINT' variable (*note + User-modified::) has no effect on the running `awk' program. When used with GCC's automatic dead-code-elimination, this option - cuts almost 200K bytes off the size of the 'gawk' executable on + cuts almost 200K bytes off the size of the `gawk' executable on GNU/Linux x86 systems. Results on other systems and with other - compilers are likely to vary. Using this option may bring you some - slight performance improvement. + compilers are likely to vary. Using this option may bring you + some slight performance improvement. - Using this option will cause some of the tests in the test suite to - fail. This option may be removed at a later date. + Using this option will cause some of the tests in the test suite + to fail. This option may be removed at a later date. -'--disable-nls' +`--disable-nls' Disable all message-translation facilities. This is usually not desirable, but it may bring you some slight performance improvement. -'--with-whiny-user-strftime' - Force use of the included version of the C 'strftime()' function +`--with-whiny-user-strftime' + Force use of the included version of the C `strftime()' function for deficient systems. - Use the command './configure --help' to see the full list of options -that 'configure' supplies. + Use the command `./configure --help' to see the full list of options +that `configure' supplies.  File: gawk.info, Node: Configuration Philosophy, Prev: Additional Configuration Options, Up: Unix Installation @@ -28468,42 +27328,42 @@ B.2.3 The Configuration Process This minor node is of interest only if you know something about using the C language and Unix-like operating systems. - The source code for 'gawk' generally attempts to adhere to formal -standards wherever possible. This means that 'gawk' uses library + The source code for `gawk' generally attempts to adhere to formal +standards wherever possible. This means that `gawk' uses library routines that are specified by the ISO C standard and by the POSIX -operating system interface standard. The 'gawk' source code requires +operating system interface standard. The `gawk' source code requires using an ISO C compiler (the 1990 standard). Many Unix systems do not support all of either the ISO or the POSIX -standards. The 'missing_d' subdirectory in the 'gawk' distribution -contains replacement versions of those functions that are most likely to -be missing. +standards. The `missing_d' subdirectory in the `gawk' distribution +contains replacement versions of those functions that are most likely +to be missing. - The 'config.h' file that 'configure' creates contains definitions + The `config.h' file that `configure' creates contains definitions that describe features of the particular operating system where you are -attempting to compile 'gawk'. The three things described by this file +attempting to compile `gawk'. The three things described by this file are: what header files are available, so that they can be correctly -included, what (supposedly) standard functions are actually available in -your C libraries, and various miscellaneous facts about your operating -system. For example, there may not be an 'st_blksize' element in the -'stat' structure. In this case, 'HAVE_STRUCT_STAT_ST_BLKSIZE' is -undefined. +included, what (supposedly) standard functions are actually available +in your C libraries, and various miscellaneous facts about your +operating system. For example, there may not be an `st_blksize' +element in the `stat' structure. In this case, +`HAVE_STRUCT_STAT_ST_BLKSIZE' is undefined. - It is possible for your C compiler to lie to 'configure'. It may do + It is possible for your C compiler to lie to `configure'. It may do so by not exiting with an error when a library function is not -available. To get around this, edit the file 'custom.h'. Use an -'#ifdef' that is appropriate for your system, and either '#define' any -constants that 'configure' should have defined but didn't, or '#undef' -any constants that 'configure' defined and should not have. 'custom.h' -is automatically included by 'config.h'. +available. To get around this, edit the file `custom.h'. Use an +`#ifdef' that is appropriate for your system, and either `#define' any +constants that `configure' should have defined but didn't, or `#undef' +any constants that `configure' defined and should not have. `custom.h' +is automatically included by `config.h'. - It is also possible that the 'configure' program generated by + It is also possible that the `configure' program generated by Autoconf will not work on your system in some other fashion. If you do -have a problem, the file 'configure.ac' is the input for Autoconf. You +have a problem, the file `configure.ac' is the input for Autoconf. You may be able to change this file and generate a new version of -'configure' that works on your system (*note Bugs::, for information on -how to report problems in configuring 'gawk'). The same mechanism may -be used to send in updates to 'configure.ac' and/or 'custom.h'. +`configure' that works on your system (*note Bugs::, for information on +how to report problems in configuring `gawk'). The same mechanism may +be used to send in updates to `configure.ac' and/or `custom.h'.  File: gawk.info, Node: Non-Unix Installation, Next: Bugs, Prev: Unix Installation, Up: Installation @@ -28511,14 +27371,14 @@ File: gawk.info, Node: Non-Unix Installation, Next: Bugs, Prev: Unix Installa B.3 Installation on Other Operating Systems =========================================== -This minor node describes how to install 'gawk' on various non-Unix +This minor node describes how to install `gawk' on various non-Unix systems. * Menu: -* PC Installation:: Installing and Compiling 'gawk' on +* PC Installation:: Installing and Compiling `gawk' on MS-DOS and OS/2. -* VMS Installation:: Installing 'gawk' on VMS. +* VMS Installation:: Installing `gawk' on VMS.  File: gawk.info, Node: PC Installation, Next: VMS Installation, Up: Non-Unix Installation @@ -28526,29 +27386,29 @@ File: gawk.info, Node: PC Installation, Next: VMS Installation, Up: Non-Unix B.3.1 Installation on PC Operating Systems ------------------------------------------ -This minor node covers installation and usage of 'gawk' on x86 machines -running MS-DOS, any version of MS-Windows, or OS/2. In this minor node, -the term "Windows32" refers to any of Microsoft +This minor node covers installation and usage of `gawk' on x86 machines +running MS-DOS, any version of MS-Windows, or OS/2. In this minor +node, the term "Windows32" refers to any of Microsoft Windows-95/98/ME/NT/2000/XP/Vista/7/8. The limitations of MS-DOS (and MS-DOS shells under the other -operating systems) has meant that various "DOS extenders" are often used -with programs such as 'gawk'. The varying capabilities of Microsoft -Windows 3.1 and Windows32 can add to the confusion. For an overview of -the considerations, please refer to 'README_d/README.pc' in the -distribution. +operating systems) has meant that various "DOS extenders" are often +used with programs such as `gawk'. The varying capabilities of +Microsoft Windows 3.1 and Windows32 can add to the confusion. For an +overview of the considerations, please refer to `README_d/README.pc' in +the distribution. * Menu: * PC Binary Installation:: Installing a prepared distribution. -* PC Compiling:: Compiling 'gawk' for MS-DOS, +* PC Compiling:: Compiling `gawk' for MS-DOS, Windows32, and OS/2. -* PC Testing:: Testing 'gawk' on PC systems. -* PC Using:: Running 'gawk' on MS-DOS, Windows32 +* PC Testing:: Testing `gawk' on PC systems. +* PC Using:: Running `gawk' on MS-DOS, Windows32 and OS/2. -* Cygwin:: Building and running 'gawk' for +* Cygwin:: Building and running `gawk' for Cygwin. -* MSYS:: Using 'gawk' In The MSYS Environment. +* MSYS:: Using `gawk' In The MSYS Environment.  File: gawk.info, Node: PC Binary Installation, Next: PC Compiling, Up: PC Installation @@ -28557,30 +27417,30 @@ B.3.1.1 Installing a Prepared Distribution for PC Systems ......................................................... If you have received a binary distribution prepared by the MS-DOS -maintainers, then 'gawk' and the necessary support files appear under -the 'gnu' directory, with executables in 'gnu/bin', libraries in -'gnu/lib/awk', and manual pages under 'gnu/man'. This is designed for -easy installation to a '/gnu' directory on your drive--however, the -files can be installed anywhere provided 'AWKPATH' is set properly. -Regardless of the installation directory, the first line of 'igawk.cmd' -and 'igawk.bat' (in 'gnu/bin') may need to be edited. +maintainers, then `gawk' and the necessary support files appear under +the `gnu' directory, with executables in `gnu/bin', libraries in +`gnu/lib/awk', and manual pages under `gnu/man'. This is designed for +easy installation to a `/gnu' directory on your drive--however, the +files can be installed anywhere provided `AWKPATH' is set properly. +Regardless of the installation directory, the first line of `igawk.cmd' +and `igawk.bat' (in `gnu/bin') may need to be edited. The binary distribution contains a separate file describing the -contents. In particular, it may include more than one version of the -'gawk' executable. - - OS/2 (32 bit, EMX) binary distributions are prepared for the '/usr' -directory of your preferred drive. Set 'UNIXROOT' to your installation -drive (e.g., 'e:') if you want to install 'gawk' onto another drive than -the hardcoded default 'c:'. Executables appear in '/usr/bin', libraries -under '/usr/share/awk', manual pages under '/usr/man', Texinfo -documentation under '/usr/info', and NLS files under -'/usr/share/locale'. Note that the files can be installed anywhere -provided 'AWKPATH' is set properly. - - If you already have a file '/usr/info/dir' from another package _do -not overwrite it!_ Instead enter the following commands at your prompt -(replace 'x:' by your installation drive): +contents. In particular, it may include more than one version of the +`gawk' executable. + + OS/2 (32 bit, EMX) binary distributions are prepared for the `/usr' +directory of your preferred drive. Set `UNIXROOT' to your installation +drive (e.g., `e:') if you want to install `gawk' onto another drive +than the hardcoded default `c:'. Executables appear in `/usr/bin', +libraries under `/usr/share/awk', manual pages under `/usr/man', +Texinfo documentation under `/usr/info', and NLS files under +`/usr/share/locale'. Note that the files can be installed anywhere +provided `AWKPATH' is set properly. + + If you already have a file `/usr/info/dir' from another package _do +not overwrite it!_ Instead enter the following commands at your prompt +(replace `x:' by your installation drive): install-info --info-dir=x:/usr/info x:/usr/info/gawk.info install-info --info-dir=x:/usr/info x:/usr/info/gawkinet.info @@ -28591,40 +27451,40 @@ additional or more detailed installation instructions.  File: gawk.info, Node: PC Compiling, Next: PC Testing, Prev: PC Binary Installation, Up: PC Installation -B.3.1.2 Compiling 'gawk' for PC Operating Systems +B.3.1.2 Compiling `gawk' for PC Operating Systems ................................................. -'gawk' can be compiled for MS-DOS, Windows32, and OS/2 using the GNU +`gawk' can be compiled for MS-DOS, Windows32, and OS/2 using the GNU development tools from DJ Delorie (DJGPP: MS-DOS only), MinGW (Windows32) or Eberhard Mattes (EMX: MS-DOS, Windows32 and OS/2). The -file 'README_d/README.pc' in the 'gawk' distribution contains additional -notes, and 'pc/Makefile' contains important information on compilation -options. - - To build 'gawk' for MS-DOS and Windows32, copy the files in the 'pc' -directory (_except_ for 'ChangeLog') to the directory with the rest of -the 'gawk' sources, then invoke 'make' with the appropriate target name -as an argument to build 'gawk'. The 'Makefile' copied from the 'pc' -directory contains a configuration section with comments and may need to -be edited in order to work with your 'make' utility. - - The 'Makefile' supports a number of targets for building various +file `README_d/README.pc' in the `gawk' distribution contains +additional notes, and `pc/Makefile' contains important information on +compilation options. + +To build `gawk' for MS-DOS and Windows32, copy the files in the `pc' +directory (_except_ for `ChangeLog') to the directory with the rest of +the `gawk' sources, then invoke `make' with the appropriate target name +as an argument to build `gawk'. The `Makefile' copied from the `pc' +directory contains a configuration section with comments and may need +to be edited in order to work with your `make' utility. + + The `Makefile' supports a number of targets for building various MS-DOS and Windows32 versions. A list of targets is printed if the -'make' command is given without a target. As an example, to build -'gawk' using the DJGPP tools, enter 'make djgpp'. (The DJGPP tools +`make' command is given without a target. As an example, to build +`gawk' using the DJGPP tools, enter `make djgpp'. (The DJGPP tools needed for the build may be found at -.) To build a native -MS-Windows binary of 'gawk', type 'make mingw32'. +`ftp://ftp.delorie.com/pub/djgpp/current/v2gnu/'.) To build a native +MS-Windows binary of `gawk', type `make mingw32'. - The 32 bit EMX version of 'gawk' works "out of the box" under OS/2. + The 32 bit EMX version of `gawk' works "out of the box" under OS/2. However, it is highly recommended to use GCC 2.95.3 for the compilation. -In principle, it is possible to compile 'gawk' the following way: +In principle, it is possible to compile `gawk' the following way: $ ./configure $ make This is not recommended, though. To get an OMF executable you should -use the following commands at your 'sh' prompt: +use the following commands at your `sh' prompt: $ CFLAGS="-O2 -Zomf -Zmt" $ export CFLAGS @@ -28643,7 +27503,7 @@ other set of (self-consistent) environment variables and compiler flags. $ LIBS="-lgcc" $ export LIBS - You can also get an 'a.out' executable if you prefer: + You can also get an `a.out' executable if you prefer: $ CFLAGS="-O2 -Zmt" $ export CFLAGS @@ -28653,15 +27513,15 @@ other set of (self-consistent) environment variables and compiler flags. $ ./configure --prefix=c:/usr $ make - NOTE: Compilation of 'a.out' executables also works with GCC 3.2. + NOTE: Compilation of `a.out' executables also works with GCC 3.2. Versions later than GCC 3.2 have not been tested successfully. - 'make install' works as expected with the EMX build. + `make install' works as expected with the EMX build. - NOTE: Ancient OS/2 ports of GNU 'make' are not able to handle the + NOTE: Ancient OS/2 ports of GNU `make' are not able to handle the Makefiles of this package. If you encounter any problems with - 'make', try GNU Make 3.79.1 or later versions. You should find the - latest version on .(1) + `make', try GNU Make 3.79.1 or later versions. You should find + the latest version on `ftp://hobbes.nmsu.edu/pub/os2/'.(1) ---------- Footnotes ---------- @@ -28671,99 +27531,99 @@ not find a package for GNU Make.  File: gawk.info, Node: PC Testing, Next: PC Using, Prev: PC Compiling, Up: PC Installation -B.3.1.3 Testing 'gawk' on PC Operating Systems +B.3.1.3 Testing `gawk' on PC Operating Systems .............................................. -Using 'make' to run the standard tests and to install 'gawk' requires -additional Unix-like tools, including 'sh', 'sed', and 'cp'. In order -to run the tests, the 'test/*.ok' files may need to be converted so that -they have the usual MS-DOS-style end-of-line markers. Alternatively, -run 'make check CMP="diff -a"' to use GNU 'diff' in text mode instead of -'cmp' to compare the resulting files. +Using `make' to run the standard tests and to install `gawk' requires +additional Unix-like tools, including `sh', `sed', and `cp'. In order +to run the tests, the `test/*.ok' files may need to be converted so +that they have the usual MS-DOS-style end-of-line markers. +Alternatively, run `make check CMP="diff -a"' to use GNU `diff' in text +mode instead of `cmp' to compare the resulting files. Most of the tests work properly with Stewartson's shell along with the companion utilities or appropriate GNU utilities. However, some -editing of 'test/Makefile' is required. It is recommended that you copy -the file 'pc/Makefile.tst' over the file 'test/Makefile' as a -replacement. Details can be found in 'README_d/README.pc' and in the -file 'pc/Makefile.tst'. - - On OS/2 the 'pid' test fails because 'spawnl()' is used instead of -'fork()'/'execl()' to start child processes. Also the 'mbfw1' and -'mbprintf1' tests fail because the needed multibyte functionality is not -available. +editing of `test/Makefile' is required. It is recommended that you copy +the file `pc/Makefile.tst' over the file `test/Makefile' as a +replacement. Details can be found in `README_d/README.pc' and in the +file `pc/Makefile.tst'. + + On OS/2 the `pid' test fails because `spawnl()' is used instead of +`fork()'/`execl()' to start child processes. Also the `mbfw1' and +`mbprintf1' tests fail because the needed multibyte functionality is +not available.  File: gawk.info, Node: PC Using, Next: Cygwin, Prev: PC Testing, Up: PC Installation -B.3.1.4 Using 'gawk' on PC Operating Systems +B.3.1.4 Using `gawk' on PC Operating Systems ............................................ Under MS-DOS and MS-Windows, the Cygwin and MinGW environments support -both the '|&' operator and TCP/IP networking (*note TCP/IP -Networking::). EMX (OS/2 only) supports at least the '|&' operator. +both the `|&' operator and TCP/IP networking (*note TCP/IP +Networking::). EMX (OS/2 only) supports at least the `|&' operator. - The MS-DOS and MS-Windows versions of 'gawk' search for program files -as described in *note AWKPATH Variable::. However, semicolons (rather -than colons) separate elements in the 'AWKPATH' variable. If 'AWKPATH' -is not set or is empty, then the default search path for MS-Windows and -MS-DOS versions is '.;c:/lib/awk;c:/gnu/lib/awk'. + The MS-DOS and MS-Windows versions of `gawk' search for program +files as described in *note AWKPATH Variable::. However, semicolons +(rather than colons) separate elements in the `AWKPATH' variable. If +`AWKPATH' is not set or is empty, then the default search path for +MS-Windows and MS-DOS versions is `.;c:/lib/awk;c:/gnu/lib/awk'. The search path for OS/2 (32 bit, EMX) is determined by the prefix -directory (most likely '/usr' or 'c:/usr') that has been specified as an -option of the 'configure' script as is the case for the Unix versions. -If 'c:/usr' is the prefix directory then the default search path -contains '.' and 'c:/usr/share/awk'. Additionally, to support binary -distributions of 'gawk' for OS/2 systems whose drive 'c:' might not -support long file names or might not exist at all, there is a special -environment variable. If 'UNIXROOT' specifies a drive then this -specific drive is also searched for program files. E.g., if 'UNIXROOT' -is set to 'e:' the complete default search path is -'.;c:/usr/share/awk;e:/usr/share/awk'. - - An 'sh'-like shell (as opposed to 'command.com' under MS-DOS or -'cmd.exe' under MS-Windows or OS/2) may be useful for 'awk' programming. +directory (most likely `/usr' or `c:/usr') that has been specified as +an option of the `configure' script as is the case for the Unix +versions. If `c:/usr' is the prefix directory then the default search +path contains `.' and `c:/usr/share/awk'. Additionally, to support +binary distributions of `gawk' for OS/2 systems whose drive `c:' might +not support long file names or might not exist at all, there is a +special environment variable. If `UNIXROOT' specifies a drive then +this specific drive is also searched for program files. E.g., if +`UNIXROOT' is set to `e:' the complete default search path is +`.;c:/usr/share/awk;e:/usr/share/awk'. + + An `sh'-like shell (as opposed to `command.com' under MS-DOS or +`cmd.exe' under MS-Windows or OS/2) may be useful for `awk' programming. The DJGPP collection of tools includes an MS-DOS port of Bash, and -several shells are available for OS/2, including 'ksh'. +several shells are available for OS/2, including `ksh'. - Under MS-Windows, OS/2 and MS-DOS, 'gawk' (and many other text -programs) silently translate end-of-line '\r\n' to '\n' on input and -'\n' to '\r\n' on output. A special 'BINMODE' variable (c.e.) allows + Under MS-Windows, OS/2 and MS-DOS, `gawk' (and many other text +programs) silently translate end-of-line `\r\n' to `\n' on input and +`\n' to `\r\n' on output. A special `BINMODE' variable (c.e.) allows control over these translations and is interpreted as follows: - * If 'BINMODE' is '"r"', or one, then binary mode is set on read + * If `BINMODE' is `"r"', or one, then binary mode is set on read (i.e., no translations on reads). - * If 'BINMODE' is '"w"', or two, then binary mode is set on write + * If `BINMODE' is `"w"', or two, then binary mode is set on write (i.e., no translations on writes). - * If 'BINMODE' is '"rw"' or '"wr"' or three, binary mode is set for + * If `BINMODE' is `"rw"' or `"wr"' or three, binary mode is set for both read and write. - * 'BINMODE=NON-NULL-STRING' is the same as 'BINMODE=3' (i.e., no - translations on reads or writes). However, 'gawk' issues a warning - message if the string is not one of '"rw"' or '"wr"'. + * `BINMODE=NON-NULL-STRING' is the same as `BINMODE=3' (i.e., no + translations on reads or writes). However, `gawk' issues a warning + message if the string is not one of `"rw"' or `"wr"'. The modes for standard input and standard output are set one time only -(after the command line is read, but before processing any of the 'awk' -program). Setting 'BINMODE' for standard input or standard output is -accomplished by using an appropriate '-v BINMODE=N' option on the -command line. 'BINMODE' is set at the time a file or pipe is opened and -cannot be changed mid-stream. - - The name 'BINMODE' was chosen to match 'mawk' (*note Other -Versions::). 'mawk' and 'gawk' handle 'BINMODE' similarly; however, -'mawk' adds a '-W BINMODE=N' option and an environment variable that can -set 'BINMODE', 'RS', and 'ORS'. The files 'binmode[1-3].awk' (under -'gnu/lib/awk' in some of the prepared binary distributions) have been -chosen to match 'mawk''s '-W BINMODE=N' option. These can be changed or -discarded; in particular, the setting of 'RS' giving the fewest -"surprises" is open to debate. 'mawk' uses 'RS = "\r\n"' if binary mode -is set on read, which is appropriate for files with the MS-DOS-style -end-of-line. +(after the command line is read, but before processing any of the `awk' +program). Setting `BINMODE' for standard input or standard output is +accomplished by using an appropriate `-v BINMODE=N' option on the +command line. `BINMODE' is set at the time a file or pipe is opened +and cannot be changed mid-stream. + + The name `BINMODE' was chosen to match `mawk' (*note Other +Versions::). `mawk' and `gawk' handle `BINMODE' similarly; however, +`mawk' adds a `-W BINMODE=N' option and an environment variable that +can set `BINMODE', `RS', and `ORS'. The files `binmode[1-3].awk' +(under `gnu/lib/awk' in some of the prepared binary distributions) have +been chosen to match `mawk''s `-W BINMODE=N' option. These can be +changed or discarded; in particular, the setting of `RS' giving the +fewest "surprises" is open to debate. `mawk' uses `RS = "\r\n"' if +binary mode is set on read, which is appropriate for files with the +MS-DOS-style end-of-line. To illustrate, the following examples set binary mode on writes for -standard output and other files, and set 'ORS' as the "usual" +standard output and other files, and set `ORS' as the "usual" MS-DOS-style end-of-line: gawk -v BINMODE=2 -v ORS="\r\n" ... @@ -28772,8 +27632,8 @@ or: gawk -v BINMODE=w -f binmode2.awk ... -These give the same result as the '-W BINMODE=2' option in 'mawk'. The -following changes the record separator to '"\r\n"' and sets binary mode +These give the same result as the `-W BINMODE=2' option in `mawk'. The +following changes the record separator to `"\r\n"' and sets binary mode on reads, but does not affect the mode on standard input: gawk -v RS="\r\n" -e "BEGIN { BINMODE = 1 }" ... @@ -28782,73 +27642,73 @@ or: gawk -f binmode1.awk ... -With proper quoting, in the first example the setting of 'RS' can be -moved into the 'BEGIN' rule. +With proper quoting, in the first example the setting of `RS' can be +moved into the `BEGIN' rule.  File: gawk.info, Node: Cygwin, Next: MSYS, Prev: PC Using, Up: PC Installation -B.3.1.5 Using 'gawk' In The Cygwin Environment +B.3.1.5 Using `gawk' In The Cygwin Environment .............................................. -'gawk' can be built and used "out of the box" under MS-Windows if you +`gawk' can be built and used "out of the box" under MS-Windows if you are using the Cygwin environment (http://www.cygwin.com). This -environment provides an excellent simulation of GNU/Linux, using the GNU -tools, such as Bash, the GNU Compiler Collection (GCC), GNU Make, and -other GNU programs. Compilation and installation for Cygwin is the same -as for a Unix system: +environment provides an excellent simulation of GNU/Linux, using the +GNU tools, such as Bash, the GNU Compiler Collection (GCC), GNU Make, +and other GNU programs. Compilation and installation for Cygwin is the +same as for a Unix system: tar -xvpzf gawk-4.1.1.tar.gz cd gawk-4.1.1 ./configure make - When compared to GNU/Linux on the same system, the 'configure' step + When compared to GNU/Linux on the same system, the `configure' step on Cygwin takes considerably longer. However, it does finish, and then -the 'make' proceeds as usual. +the `make' proceeds as usual.  File: gawk.info, Node: MSYS, Prev: Cygwin, Up: PC Installation -B.3.1.6 Using 'gawk' In The MSYS Environment +B.3.1.6 Using `gawk' In The MSYS Environment ............................................ -In the MSYS environment under MS-Windows, 'gawk' automatically uses -binary mode for reading and writing files. Thus there is no need to use -the 'BINMODE' variable. +In the MSYS environment under MS-Windows, `gawk' automatically uses +binary mode for reading and writing files. Thus there is no need to +use the `BINMODE' variable. This can cause problems with other Unix-like components that have -been ported to MS-Windows that expect 'gawk' to do automatic translation -of '"\r\n"', since it won't. Caveat Emptor! +been ported to MS-Windows that expect `gawk' to do automatic +translation of `"\r\n"', since it won't. Caveat Emptor!  File: gawk.info, Node: VMS Installation, Prev: PC Installation, Up: Non-Unix Installation -B.3.2 How to Compile and Install 'gawk' on Vax/VMS and OpenVMS +B.3.2 How to Compile and Install `gawk' on Vax/VMS and OpenVMS -------------------------------------------------------------- -This node describes how to compile and install 'gawk' under VMS. The +This node describes how to compile and install `gawk' under VMS. The older designation "VMS" is used throughout to refer to OpenVMS. * Menu: -* VMS Compilation:: How to compile 'gawk' under VMS. -* VMS Dynamic Extensions:: Compiling 'gawk' dynamic extensions on +* VMS Compilation:: How to compile `gawk' under VMS. +* VMS Dynamic Extensions:: Compiling `gawk' dynamic extensions on VMS. -* VMS Installation Details:: How to install 'gawk' under VMS. -* VMS Running:: How to run 'gawk' under VMS. +* VMS Installation Details:: How to install `gawk' under VMS. +* VMS Running:: How to run `gawk' under VMS. * VMS GNV:: The VMS GNV Project. * VMS Old Gawk:: An old version comes with some VMS systems.  File: gawk.info, Node: VMS Compilation, Next: VMS Dynamic Extensions, Up: VMS Installation -B.3.2.1 Compiling 'gawk' on VMS +B.3.2.1 Compiling `gawk' on VMS ............................... -To compile 'gawk' under VMS, there is a 'DCL' command procedure that -issues all the necessary 'CC' and 'LINK' commands. There is also a -'Makefile' for use with the 'MMS' and 'MMK' utilities. From the source +To compile `gawk' under VMS, there is a `DCL' command procedure that +issues all the necessary `CC' and `LINK' commands. There is also a +`Makefile' for use with the `MMS' and `MMK' utilities. From the source directory, use either: $ @[.vms]vmsbuild.com @@ -28861,19 +27721,19 @@ or: $ MMK/DESCRIPTION=[.vms]descrip.mms gawk - 'MMK' is an open source, free, near-clone of 'MMS' and can better -handle ODS-5 volumes with upper- and lowercase file names. 'MMK' is -available from . + `MMK' is an open source, free, near-clone of `MMS' and can better +handle ODS-5 volumes with upper- and lowercase file names. `MMK' is +available from `https://github.com/endlesssoftware/mmk'. With ODS-5 volumes and extended parsing enabled, the case of the target parameter may need to be exact. - 'gawk' has been tested under VAX/VMS 7.3 and Alpha/VMS 7.3-1 using + `gawk' has been tested under VAX/VMS 7.3 and Alpha/VMS 7.3-1 using Compaq C V6.4, and Alpha/VMS 7.3, Alpha/VMS 7.3-2, and IA64/VMS 8.3. The most recent builds used HP C V7.3 on Alpha VMS 8.3 and both Alpha and IA64 VMS 8.4 used HP C 7.3.(1) - *Note VMS GNV::, for information on building 'gawk' as a PCSI kit + *Note VMS GNV::, for information on building `gawk' as a PCSI kit that is compatible with the GNV product. ---------- Footnotes ---------- @@ -28883,7 +27743,7 @@ that is compatible with the GNV product.  File: gawk.info, Node: VMS Dynamic Extensions, Next: VMS Installation Details, Prev: VMS Compilation, Up: VMS Installation -B.3.2.2 Compiling 'gawk' Dynamic Extensions on VMS +B.3.2.2 Compiling `gawk' Dynamic Extensions on VMS .................................................. The extensions that have been ported to VMS can be built using one of @@ -28895,14 +27755,15 @@ or: $ MMK/DESCRIPTION=[.vms]descrip.mms extensions - 'gawk' uses 'AWKLIBPATH' as either an environment variable or a + `gawk' uses `AWKLIBPATH' as either an environment variable or a logical name to find the dynamic extensions. - Dynamic extensions need to be compiled with the same compiler options -for floating point, pointer size, and symbol name handling as were used -to compile 'gawk' itself. Alpha and Itanium should use IEEE floating -point. The pointer size is 32 bits, and the symbol name handling should -be exact case with CRC shortening for symbols longer than 32 bits. + Dynamic extensions need to be compiled with the same compiler +options for floating point, pointer size, and symbol name handling as +were used to compile `gawk' itself. Alpha and Itanium should use IEEE +floating point. The pointer size is 32 bits, and the symbol name +handling should be exact case with CRC shortening for symbols longer +than 32 bits. For Alpha and Itanium: @@ -28931,69 +27792,70 @@ header file is included.  File: gawk.info, Node: VMS Installation Details, Next: VMS Running, Prev: VMS Dynamic Extensions, Up: VMS Installation -B.3.2.3 Installing 'gawk' on VMS +B.3.2.3 Installing `gawk' on VMS ................................ -To use 'gawk', all you need is a "foreign" command, which is a 'DCL' -symbol whose value begins with a dollar sign. For example: +To use `gawk', all you need is a "foreign" command, which is a `DCL' +symbol whose value begins with a dollar sign. For example: $ GAWK :== $disk1:[gnubin]gawk -Substitute the actual location of 'gawk.exe' for '$disk1:[gnubin]'. The -symbol should be placed in the 'login.com' of any user who wants to run -'gawk', so that it is defined every time the user logs on. -Alternatively, the symbol may be placed in the system-wide 'sylogin.com' -procedure, which allows all users to run 'gawk'. +Substitute the actual location of `gawk.exe' for `$disk1:[gnubin]'. The +symbol should be placed in the `login.com' of any user who wants to run +`gawk', so that it is defined every time the user logs on. +Alternatively, the symbol may be placed in the system-wide +`sylogin.com' procedure, which allows all users to run `gawk'. - If your 'gawk' was installed by a PCSI kit into the 'GNV$GNU:' -directory tree, the program will be known as 'GNV$GNU:[bin]gnv$gawk.exe' -and the help file will be 'GNV$GNU:[vms_help]gawk.hlp'. + If your `gawk' was installed by a PCSI kit into the `GNV$GNU:' +directory tree, the program will be known as +`GNV$GNU:[bin]gnv$gawk.exe' and the help file will be +`GNV$GNU:[vms_help]gawk.hlp'. - The PCSI kit also installs a 'GNV$GNU:[vms_bin]gawk_verb.cld' file -which can be used to add 'gawk' and 'awk' as DCL commands. + The PCSI kit also installs a `GNV$GNU:[vms_bin]gawk_verb.cld' file +which can be used to add `gawk' and `awk' as DCL commands. For just the current process you can use: $ set command gnv$gnu:[vms_bin]gawk_verb.cld - Or the system manager can use 'GNV$GNU:[vms_bin]gawk_verb.cld' to add -the 'gawk' and 'awk' to the system wide 'DCLTABLES'. + Or the system manager can use `GNV$GNU:[vms_bin]gawk_verb.cld' to +add the `gawk' and `awk' to the system wide `DCLTABLES'. - The DCL syntax is documented in the 'gawk.hlp' file. + The DCL syntax is documented in the `gawk.hlp' file. - Optionally, the 'gawk.hlp' entry can be loaded into a VMS help + Optionally, the `gawk.hlp' entry can be loaded into a VMS help library: $ LIBRARY/HELP sys$help:helplib [.vms]gawk.hlp -(You may want to substitute a site-specific help library rather than the -standard VMS library 'HELPLIB'.) After loading the help text, the +(You may want to substitute a site-specific help library rather than +the standard VMS library `HELPLIB'.) After loading the help text, the command: $ HELP GAWK -provides information about both the 'gawk' implementation and the 'awk' +provides information about both the `gawk' implementation and the `awk' programming language. - The logical name 'AWK_LIBRARY' can designate a default location for -'awk' program files. For the '-f' option, if the specified file name -has no device or directory path information in it, 'gawk' looks in the + The logical name `AWK_LIBRARY' can designate a default location for +`awk' program files. For the `-f' option, if the specified file name +has no device or directory path information in it, `gawk' looks in the current directory first, then in the directory specified by the -translation of 'AWK_LIBRARY' if the file is not found. If, after -searching in both directories, the file still is not found, 'gawk' -appends the suffix '.awk' to the file name and retries the file search. -If 'AWK_LIBRARY' has no definition, a default value of 'SYS$LIBRARY:' is -used for it. +translation of `AWK_LIBRARY' if the file is not found. If, after +searching in both directories, the file still is not found, `gawk' +appends the suffix `.awk' to the file name and retries the file search. +If `AWK_LIBRARY' has no definition, a default value of `SYS$LIBRARY:' +is used for it.  File: gawk.info, Node: VMS Running, Next: VMS GNV, Prev: VMS Installation Details, Up: VMS Installation -B.3.2.4 Running 'gawk' on VMS +B.3.2.4 Running `gawk' on VMS ............................. Command-line parsing and quoting conventions are significantly different on VMS, so examples in this Info file or from other sources often need -minor changes. They _are_ minor though, and all 'awk' programs should +minor changes. They _are_ minor though, and all `awk' programs should run correctly. Here are a couple of trivial tests: @@ -29004,50 +27866,51 @@ run correctly. Note that uppercase and mixed-case text must be quoted. - The VMS port of 'gawk' includes a 'DCL'-style interface in addition + The VMS port of `gawk' includes a `DCL'-style interface in addition to the original shell-style interface (see the help entry for details). One side effect of dual command-line parsing is that if there is only a single parameter (as in the quoted string program above), the command -becomes ambiguous. To work around this, the normally optional '--' flag -is required to force Unix-style parsing rather than 'DCL' parsing. If -any other dash-type options (or multiple parameters such as data files -to process) are present, there is no ambiguity and '--' can be omitted. +becomes ambiguous. To work around this, the normally optional `--' +flag is required to force Unix-style parsing rather than `DCL' parsing. +If any other dash-type options (or multiple parameters such as data +files to process) are present, there is no ambiguity and `--' can be +omitted. - The 'exit' value is a Unix-style value and is encoded to a VMS exit + The `exit' value is a Unix-style value and is encoded to a VMS exit status value when the program exits. - The VMS severity bits will be set based on the 'exit' value. A -failure is indicated by 1 and VMS sets the 'ERROR' status. A fatal -error is indicated by 2 and VMS will set the 'FATAL' status. All other -values will have the 'SUCCESS' status. The exit value is encoded to -comply with VMS coding standards and will have the 'C_FACILITY_NO' of -'0x350000' with the constant '0xA000' added to the number shifted over + The VMS severity bits will be set based on the `exit' value. A +failure is indicated by 1 and VMS sets the `ERROR' status. A fatal +error is indicated by 2 and VMS will set the `FATAL' status. All other +values will have the `SUCCESS' status. The exit value is encoded to +comply with VMS coding standards and will have the `C_FACILITY_NO' of +`0x350000' with the constant `0xA000' added to the number shifted over by 3 bits to make room for the severity codes. - To extract the actual 'gawk' exit code from the VMS status use: + To extract the actual `gawk' exit code from the VMS status use: unix_status = (vms_status .and. &x7f8) / 8 -A C program that uses 'exec()' to call 'gawk' will get the original +A C program that uses `exec()' to call `gawk' will get the original Unix-style exit value. - Older versions of 'gawk' treated a Unix exit code 0 as 1, a failure + Older versions of `gawk' treated a Unix exit code 0 as 1, a failure as 2, a fatal error as 4, and passed all the other numbers through. This violated the VMS exit status coding requirements. - VAX/VMS floating point uses unbiased rounding. *Note Round + VAX/VMS floating point uses unbiased rounding. *Note Round Function::. - VMS reports time values in GMT unless one of the 'SYS$TIMEZONE_RULE' -or 'TZ' logical names is set. Older versions of VMS, such as VAX/VMS + VMS reports time values in GMT unless one of the `SYS$TIMEZONE_RULE' +or `TZ' logical names is set. Older versions of VMS, such as VAX/VMS 7.3 do not set these logical names. - The default search path, when looking for 'awk' program files -specified by the '-f' option, is '"SYS$DISK:[],AWK_LIBRARY:"'. The -logical name 'AWKPATH' can be used to override this default. The format -of 'AWKPATH' is a comma-separated list of directory specifications. + The default search path, when looking for `awk' program files +specified by the `-f' option, is `"SYS$DISK:[],AWK_LIBRARY:"'. The +logical name `AWKPATH' can be used to override this default. The format +of `AWKPATH' is a comma-separated list of directory specifications. When defining it, the value should be quoted so that it retains a single -translation and not a multitranslation 'RMS' searchlist. +translation and not a multitranslation `RMS' searchlist.  File: gawk.info, Node: VMS GNV, Next: VMS Old Gawk, Prev: VMS Running, Up: VMS Installation @@ -29056,28 +27919,29 @@ B.3.2.5 The VMS GNV Project ........................... The VMS GNV package provides a build environment similar to POSIX with -ports of a collection of open source tools. The 'gawk' found in the GNV +ports of a collection of open source tools. The `gawk' found in the GNV base kit is an older port. Currently the GNV project is being -reorganized to supply individual PCSI packages for each component. See . +reorganized to supply individual PCSI packages for each component. See +`https://sourceforge.net/p/gnv/wiki/InstallingGNVPackages/'. - The normal build procedure for 'gawk' produces a program that is + The normal build procedure for `gawk' produces a program that is suitable for use with GNV. - The 'vms/gawk_build_steps.txt' in the source documents the procedure + The `vms/gawk_build_steps.txt' in the source documents the procedure for building a VMS PCSI kit that is compatible with GNV.  File: gawk.info, Node: VMS Old Gawk, Prev: VMS GNV, Up: VMS Installation -B.3.2.6 Some VMS Systems Have An Old Version of 'gawk' +B.3.2.6 Some VMS Systems Have An Old Version of `gawk' ...................................................... -Some versions of VMS have an old version of 'gawk'. To access it, +Some versions of VMS have an old version of `gawk'. To access it, define a symbol, as follows: $ gawk :== $sys$common:[syshlp.examples.tcpip.snmp]gawk.exe - This is apparently version 2.15.6, which is extremely old. We + This is apparently version 2.15.6, which is extremely old. We recommend compiling and using the current version.  @@ -29086,12 +27950,12 @@ File: gawk.info, Node: Bugs, Next: Other Versions, Prev: Non-Unix Installatio B.4 Reporting Problems and Bugs =============================== - There is nothing more dangerous than a bored archeologist. - -- _The Hitchhiker's Guide to the Galaxy_ + There is nothing more dangerous than a bored archeologist. -- The + Hitchhiker's Guide to the Galaxy - If you have problems with 'gawk' or think that you have found a bug, -please report it to the developers; we cannot promise to do anything but -we might well want to fix it. + If you have problems with `gawk' or think that you have found a bug, +please report it to the developers; we cannot promise to do anything +but we might well want to fix it. Before reporting a bug, make sure you have actually found a real bug. Carefully reread the documentation and see if it really says you can do @@ -29100,30 +27964,30 @@ to do something or not, report that too; it's a bug in the documentation! Before reporting a bug or trying to fix it yourself, try to isolate -it to the smallest possible 'awk' program and input data file that +it to the smallest possible `awk' program and input data file that reproduces the problem. Then send us the program and data file, some idea of what kind of Unix system you're using, the compiler you used to -compile 'gawk', and the exact results 'gawk' gave you. Also say what +compile `gawk', and the exact results `gawk' gave you. Also say what you expected to occur; this helps us decide whether the problem is really in the documentation. - Please include the version number of 'gawk' you are using. You can -get this information with the command 'gawk --version'. + Please include the version number of `gawk' you are using. You can +get this information with the command `gawk --version'. Once you have a precise problem, send email to . - The 'gawk' maintainers subscribe to this address and thus they will + The `gawk' maintainers subscribe to this address and thus they will receive your bug report. If necessary, the primary maintainer can be reached directly at . The bug reporting address is preferred since the email list is archived at the GNU Project. _All -email should be in English. This is the only language understood in +email should be in English. This is the only language understood in common by all the maintainers._ - CAUTION: Do _not_ try to report bugs in 'gawk' by posting to the - Usenet/Internet newsgroup 'comp.lang.awk'. While the 'gawk' + CAUTION: Do _not_ try to report bugs in `gawk' by posting to the + Usenet/Internet newsgroup `comp.lang.awk'. While the `gawk' developers do occasionally read this newsgroup, there is no - guarantee that we will see your posting. The steps described above - are the official recognized ways for reporting bugs. Really. + guarantee that we will see your posting. The steps described + above are the official recognized ways for reporting bugs. Really. NOTE: Many distributions of GNU/Linux and the various BSD-based operating systems have their own bug reporting systems. If you @@ -29132,34 +27996,30 @@ common by all the maintainers._ This is for two reasons. First, while some distributions forward bug reports "upstream" to the GNU mailing list, many don't, so - there is a good chance that the 'gawk' maintainer won't even see + there is a good chance that the `gawk' maintainer won't even see the bug report! Second, mail to the GNU list is archived, and having everything at the GNU project keeps things self-contained and not dependant on other web sites. Non-bug suggestions are always welcome as well. If you have -questions about things that are unclear in the documentation or are just -obscure features, ask me; I will try to help you out, although I may not -have the time to fix the problem. You can send me electronic mail at -the Internet address noted previously. +questions about things that are unclear in the documentation or are +just obscure features, ask me; I will try to help you out, although I +may not have the time to fix the problem. You can send me electronic +mail at the Internet address noted previously. - If you find bugs in one of the non-Unix ports of 'gawk', please send + If you find bugs in one of the non-Unix ports of `gawk', please send an electronic mail message to the person who maintains that port. They -are named in the following list, as well as in the 'README' file in the -'gawk' distribution. Information in the 'README' file should be +are named in the following list, as well as in the `README' file in the +`gawk' distribution. Information in the `README' file should be considered authoritative if it conflicts with this Info file. - The people maintaining the non-Unix ports of 'gawk' are as follows: + The people maintaining the non-Unix ports of `gawk' are as follows: MS-DOS with DJGPP Scott Deifik, . - MS-Windows with MinGW Eli Zaretskii, . - OS/2 Andreas Buening, . - VMS Pat Rankin, , and John Malmberg, . - z/OS (OS/390) Dave Pitts, . If your bug is also reproducible under Unix, please send a copy of @@ -29168,91 +28028,81 @@ your report to the email list as well.  File: gawk.info, Node: Other Versions, Next: Installation summary, Prev: Bugs, Up: Installation -B.5 Other Freely Available 'awk' Implementations +B.5 Other Freely Available `awk' Implementations ================================================ It's kind of fun to put comments like this in your awk code. - '// Do C++ comments work? answer: yes! of course' - -- _Michael Brennan_ + `// Do C++ comments work? answer: yes! of course' -- Michael + Brennan - There are a number of other freely available 'awk' implementations. + There are a number of other freely available `awk' implementations. This minor node briefly describes where to get them: -Unix 'awk' - Brian Kernighan, one of the original designers of Unix 'awk', has - made his implementation of 'awk' freely available. You can +Unix `awk' + Brian Kernighan, one of the original designers of Unix `awk', has + made his implementation of `awk' freely available. You can retrieve this version via the World Wide Web from his home page (http://www.cs.princeton.edu/~bwk). It is available in several archive formats: - Shell archive - + Shell archive + `http://www.cs.princeton.edu/~bwk/btl.mirror/awk.shar' - Compressed 'tar' file - + Compressed `tar' file + `http://www.cs.princeton.edu/~bwk/btl.mirror/awk.tar.gz' - Zip file - + Zip file + `http://www.cs.princeton.edu/~bwk/btl.mirror/awk.zip' You can also retrieve it from Git Hub: git clone git://github.com/onetrueawk/awk bwkawk The above command creates a copy of the Git - (http://www.git-scm.com) repository in a directory named 'bwkawk'. - If you leave that argument off the 'git' command line, the - repository copy is created in a directory named 'awk'. + (http://www.git-scm.com) repository in a directory named `bwkawk'. + If you leave that argument off the `git' command line, the + repository copy is created in a directory named `awk'. This version requires an ISO C (1990 standard) compiler; the C compiler from GCC (the GNU Compiler Collection) works quite nicely. - *Note Common Extensions::, for a list of extensions in this 'awk' - that are not in POSIX 'awk'. + *Note Common Extensions::, for a list of extensions in this `awk' + that are not in POSIX `awk'. -'mawk' - Michael Brennan wrote an independent implementation of 'awk', - called 'mawk'. It is available under the GPL (*note Copying::), - just as 'gawk' is. +`mawk' + Michael Brennan wrote an independent implementation of `awk', + called `mawk'. It is available under the GPL (*note Copying::), + just as `gawk' is. - The original distribution site for the 'mawk' source code no longer - has it. A copy is available at - . + The original distribution site for the `mawk' source code no + longer has it. A copy is available at + `http://www.skeeve.com/gawk/mawk1.3.3.tar.gz'. - In 2009, Thomas Dickey took on 'mawk' maintenance. Basic + In 2009, Thomas Dickey took on `mawk' maintenance. Basic information is available on the project's web page (http://www.invisible-island.net/mawk). The download URL is - . + `http://invisible-island.net/datafiles/release/mawk.tar.gz'. - Once you have it, 'gunzip' may be used to decompress this file. - Installation is similar to 'gawk''s (*note Unix Installation::). + Once you have it, `gunzip' may be used to decompress this file. + Installation is similar to `gawk''s (*note Unix Installation::). - *Note Common Extensions::, for a list of extensions in 'mawk' that - are not in POSIX 'awk'. + *Note Common Extensions::, for a list of extensions in `mawk' that + are not in POSIX `awk'. -'awka' - Written by Andrew Sumner, 'awka' translates 'awk' programs into C, +`awka' + Written by Andrew Sumner, `awka' translates `awk' programs into C, compiles them, and links them with a library of functions that - provides the core 'awk' functionality. It also has a number of + provides the core `awk' functionality. It also has a number of extensions. - The 'awk' translator is released under the GPL, and the library is + The `awk' translator is released under the GPL, and the library is under the LGPL. - To get 'awka', go to . + To get `awka', go to `http://sourceforge.net/projects/awka'. The project seems to be frozen; no new code changes have been made since approximately 2003. -<<<<<<< HEAD -'pawk' - Nelson H.F. Beebe at the University of Utah has modified Brian - Kernighan's 'awk' to provide timing and profiling information. It - is different from 'gawk' with the '--profile' option. (*note - Profiling::), in that it uses CPU-based profiling, not line-count - profiling. You may find it at either - or - . -======= `pawk' Nelson H.F. Beebe at the University of Utah has modified BWK `awk' to provide timing and profiling information. It is different from @@ -29261,25 +28111,24 @@ Unix 'awk' find it at either `ftp://ftp.math.utah.edu/pub/pawk/pawk-20030606.tar.gz' or `http://www.math.utah.edu/pub/pawk/pawk-20030606.tar.gz'. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac Busybox Awk Busybox is a GPL-licensed program providing small versions of many - applications within a single executable. It is aimed at embedded - systems. It includes a full implementation of POSIX 'awk'. When - building it, be careful not to do 'make install' as it will - overwrite copies of other applications in your '/usr/local/bin'. + applications within a single executable. It is aimed at embedded + systems. It includes a full implementation of POSIX `awk'. When + building it, be careful not to do `make install' as it will + overwrite copies of other applications in your `/usr/local/bin'. For more information, see the project's home page (http://busybox.net). -The OpenSolaris POSIX 'awk' - The versions of 'awk' in '/usr/xpg4/bin' and '/usr/xpg6/bin' on +The OpenSolaris POSIX `awk' + The versions of `awk' in `/usr/xpg4/bin' and `/usr/xpg6/bin' on Solaris are more-or-less POSIX-compliant. They are based on the - 'awk' from Mortice Kern Systems for PCs. This author was able to + `awk' from Mortice Kern Systems for PCs. This author was able to make this code compile and work under GNU/Linux with 1-2 hours of - work. Making it more generally portable (using GNU Autoconf and/or - Automake) would take more work, and this has not been done, at - least to our knowledge. + work. Making it more generally portable (using GNU Autoconf + and/or Automake) would take more work, and this has not been done, + at least to our knowledge. The source code used to be available from the OpenSolaris web site. However, that project was ended and the web site shut down. @@ -29287,42 +28136,34 @@ The OpenSolaris POSIX 'awk' (http://wiki.illumos.org/display/illumos/illumos+Home) makes this implementation available. You can view the files one at a time from - . + `https://github.com/joyent/illumos-joyent/blob/master/usr/src/cmd/awk_xpg4'. -'jawk' - This is an interpreter for 'awk' written in Java. It claims to be +`jawk' + This is an interpreter for `awk' written in Java. It claims to be a full interpreter, although because it uses Java facilities for I/O and for regexp matching, the language it supports is different - from POSIX 'awk'. More information is available on the project's + from POSIX `awk'. More information is available on the project's home page (http://jawk.sourceforge.net). Libmawk - This is an embeddable 'awk' interpreter derived from 'mawk'. For - more information see . - -<<<<<<< HEAD -'pawk' - This is a Python module that claims to bring 'awk'-like features to - Python. See for more - information. (This is not related to Nelson Beebe's modified - version of Brian Kernighan's 'awk', described earlier.) -======= + This is an embeddable `awk' interpreter derived from `mawk'. For + more information see `http://repo.hu/projects/libmawk/'. + `pawk' This is a Python module that claims to bring `awk'-like features to Python. See `https://github.com/alecthomas/pawk' for more information. (This is not related to Nelson Beebe's modified version of BWK `awk', described earlier.) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac QSE Awk - This is an embeddable 'awk' interpreter. For more information see - and . + This is an embeddable `awk' interpreter. For more information see + `http://code.google.com/p/qse/' and `http://awk.info/?tools/qse'. -'QTawk' - This is an independent implementation of 'awk' distributed under - the GPL. It has a large number of extensions over standard 'awk' +`QTawk' + This is an independent implementation of `awk' distributed under + the GPL. It has a large number of extensions over standard `awk' and may not be 100% syntactically compatible with it. See - for more information, + `http://www.quiktrim.org/QTawk.html' for more information, including the manual and a download link. The project may also be frozen; no new code changes have been made @@ -29333,32 +28174,34 @@ Other Versions (http://en.wikipedia.org/wiki/Awk_language#Versions_and_implementations), for information on additional versions. +  File: gawk.info, Node: Installation summary, Prev: Other Versions, Up: Installation B.6 Summary =========== - * The 'gawk' distribution is available from GNU project's main - distribution site, 'ftp.gnu.org'. The canonical build recipe is: + * The `gawk' distribution is available from GNU project's main + distribution site, `ftp.gnu.org'. The canonical build recipe is: wget http://ftp.gnu.org/gnu/gawk/gawk-4.1.1.tar.gz tar -xvpzf gawk-4.1.1.tar.gz cd gawk-4.1.1 ./configure && make && make check - * 'gawk' may be built on non-POSIX systems as well. The currently + * `gawk' may be built on non-POSIX systems as well. The currently supported systems are MS-Windows using DJGPP, MSYS, MinGW and - Cygwin, OS/2 using EMX, and both Vax/VMS and OpenVMS. Instructions - for each system are included in this major node. + Cygwin, OS/2 using EMX, and both Vax/VMS and OpenVMS. + Instructions for each system are included in this major node. * Bug reports should be sent via email to . Bug reports should be in English, and should include the version of - 'gawk', how it was compiled, and a short program and data file + `gawk', how it was compiled, and a short program and data file which demonstrate the problem. - * There are a number of other freely available 'awk' implementations. - Many are POSIX compliant; others are less so. + * There are a number of other freely available `awk' + implementations. Many are POSIX compliant; others are less so. +  File: gawk.info, Node: Notes, Next: Basic Concepts, Prev: Installation, Up: Top @@ -29367,14 +28210,14 @@ Appendix C Implementation Notes ******************************* This appendix contains information mainly of interest to implementers -and maintainers of 'gawk'. Everything in it applies specifically to -'gawk' and not to other implementations. +and maintainers of `gawk'. Everything in it applies specifically to +`gawk' and not to other implementations. * Menu: -* Compatibility Mode:: How to disable certain 'gawk' +* Compatibility Mode:: How to disable certain `gawk' extensions. -* Additions:: Making Additions To 'gawk'. +* Additions:: Making Additions To `gawk'. * Future Extensions:: New features that may be implemented one day. * Implementation Limitations:: Some limitations of the implementation. * Extension Design:: Design notes about the extension API. @@ -29387,43 +28230,43 @@ File: gawk.info, Node: Compatibility Mode, Next: Additions, Up: Notes C.1 Downward Compatibility and Debugging ======================================== -*Note POSIX/GNU::, for a summary of the GNU extensions to the 'awk' +*Note POSIX/GNU::, for a summary of the GNU extensions to the `awk' language and program. All of these features can be turned off by -invoking 'gawk' with the '--traditional' option or with the '--posix' +invoking `gawk' with the `--traditional' option or with the `--posix' option. - If 'gawk' is compiled for debugging with '-DDEBUG', then there is one -more option available on the command line: + If `gawk' is compiled for debugging with `-DDEBUG', then there is +one more option available on the command line: -'-Y' -'--parsedebug' +`-Y' +`--parsedebug' Print out the parse stack information as the program is being parsed. - This option is intended only for serious 'gawk' developers and not + This option is intended only for serious `gawk' developers and not for the casual user. It probably has not even been compiled into your -version of 'gawk', since it slows down execution. +version of `gawk', since it slows down execution.  File: gawk.info, Node: Additions, Next: Future Extensions, Prev: Compatibility Mode, Up: Notes -C.2 Making Additions to 'gawk' +C.2 Making Additions to `gawk' ============================== -If you find that you want to enhance 'gawk' in a significant fashion, +If you find that you want to enhance `gawk' in a significant fashion, you are perfectly free to do so. That is the point of having free software; the source code is available and you are free to change it as you want (*note Copying::). - This minor node discusses the ways you might want to change 'gawk' as -well as any considerations you should bear in mind. + This minor node discusses the ways you might want to change `gawk' +as well as any considerations you should bear in mind. * Menu: * Accessing The Source:: Accessing the Git repository. * Adding Code:: Adding code to the main body of - 'gawk'. -* New Ports:: Porting 'gawk' to a new operating + `gawk'. +* New Ports:: Porting `gawk' to a new operating system. * Derived Files:: Why derived files are kept in the Git repository. @@ -29431,34 +28274,34 @@ well as any considerations you should bear in mind.  File: gawk.info, Node: Accessing The Source, Next: Adding Code, Up: Additions -C.2.1 Accessing The 'gawk' Git Repository +C.2.1 Accessing The `gawk' Git Repository ----------------------------------------- -As 'gawk' is Free Software, the source code is always available. *note -Gawk Distribution::, describes how to get and build the formal, released -versions of 'gawk'. +As `gawk' is Free Software, the source code is always available. *note +Gawk Distribution::, describes how to get and build the formal, +released versions of `gawk'. - However, if you want to modify 'gawk' and contribute back your + However, if you want to modify `gawk' and contribute back your changes, you will probably wish to work with the development version. -To do so, you will need to access the 'gawk' source code repository. +To do so, you will need to access the `gawk' source code repository. The code is maintained using the Git distributed version control system (http://git-scm.com/). You will need to install it if your system doesn't have it. Once you have done so, use the command: git clone git://git.savannah.gnu.org/gawk.git -This clones the 'gawk' repository. If you are behind a firewall that +This clones the `gawk' repository. If you are behind a firewall that does not allow you to use the Git native protocol, you can still access the repository using: git clone http://git.savannah.gnu.org/r/gawk.git - Once you have made changes, you can use 'git diff' to produce a -patch, and send that to the 'gawk' maintainer; see *note Bugs::, for how -to do that. + Once you have made changes, you can use `git diff' to produce a +patch, and send that to the `gawk' maintainer; see *note Bugs::, for +how to do that. Once upon a time there was Git-CVS gateway for use by people who -could not install Git. However, this gateway no longer works, so you +could not install Git. However, this gateway no longer works, so you may have better luck using a more modern version control system like Bazaar, that has a Git plug-in for working with Git repositories. @@ -29468,217 +28311,217 @@ File: gawk.info, Node: Adding Code, Next: New Ports, Prev: Accessing The Sour C.2.2 Adding New Features ------------------------- -You are free to add any new features you like to 'gawk'. However, if -you want your changes to be incorporated into the 'gawk' distribution, +You are free to add any new features you like to `gawk'. However, if +you want your changes to be incorporated into the `gawk' distribution, there are several steps that you need to take in order to make it possible to include them: - 1. Before building the new feature into 'gawk' itself, consider - writing it as an extension module (*note Dynamic Extensions::). If - that's not possible, continue with the rest of the steps in this - list. + 1. Before building the new feature into `gawk' itself, consider + writing it as an extension module (*note Dynamic Extensions::). + If that's not possible, continue with the rest of the steps in + this list. 2. Be prepared to sign the appropriate paperwork. In order for the - FSF to distribute your changes, you must either place those changes - in the public domain and submit a signed statement to that effect, - or assign the copyright in your changes to the FSF. Both of these - actions are easy to do and _many_ people have done so already. If - you have questions, please contact me (*note Bugs::), or - . + FSF to distribute your changes, you must either place those + changes in the public domain and submit a signed statement to that + effect, or assign the copyright in your changes to the FSF. Both + of these actions are easy to do and _many_ people have done so + already. If you have questions, please contact me (*note Bugs::), + or . 3. Get the latest version. It is much easier for me to integrate - changes if they are relative to the most recent distributed version - of 'gawk', or better yet, relative to the latest code in the Git - repository. If your version of 'gawk' is very old, I may not be - able to integrate your changes at all. (*Note Getting::, for - information on getting the latest version of 'gawk'.) - - 4. See *note (Version, standards, GNU Coding Standards)Top::. This - document describes how GNU software should be written. If you + changes if they are relative to the most recent distributed + version of `gawk', or better yet, relative to the latest code in + the Git repository. If your version of `gawk' is very old, I may + not be able to integrate your changes at all. (*Note Getting::, + for information on getting the latest version of `gawk'.) + + 4. See *note (Version)Top:: standards, GNU Coding Standards. This + document describes how GNU software should be written. If you haven't read it, please do so, preferably _before_ starting to - modify 'gawk'. (The 'GNU Coding Standards' are available from the + modify `gawk'. (The `GNU Coding Standards' are available from the GNU Project's web site (http://www.gnu.org/prep/standards_toc.html). Texinfo, Info, and DVI versions are also available.) - 5. Use the 'gawk' coding style. The C code for 'gawk' follows the - instructions in the 'GNU Coding Standards', with minor exceptions. + 5. Use the `gawk' coding style. The C code for `gawk' follows the + instructions in the `GNU Coding Standards', with minor exceptions. The code is formatted using the traditional "K&R" style, particularly as regards to the placement of braces and the use of - TABs. In brief, the coding rules for 'gawk' are as follows: + TABs. In brief, the coding rules for `gawk' are as follows: * Use ANSI/ISO style (prototype) function headers when defining functions. * Put the name of the function at the beginning of its own line. - * Put the return type of the function, even if it is 'int', on + * Put the return type of the function, even if it is `int', on the line above the line with the name and arguments of the function. * Put spaces around parentheses used in control structures - ('if', 'while', 'for', 'do', 'switch', and 'return'). + (`if', `while', `for', `do', `switch', and `return'). * Do not put spaces in front of parentheses used in function calls. - * Put spaces around all C operators and after commas in function - calls. + * Put spaces around all C operators and after commas in + function calls. * Do not use the comma operator to produce multiple side - effects, except in 'for' loop initialization and increment + effects, except in `for' loop initialization and increment parts, and in macro bodies. * Use real TABs for indenting, not spaces. * Use the "K&R" brace layout style. - * Use comparisons against 'NULL' and ''\0'' in the conditions of - 'if', 'while', and 'for' statements, as well as in the 'case's - of 'switch' statements, instead of just the plain pointer or + * Use comparisons against `NULL' and `'\0'' in the conditions of + `if', `while', and `for' statements, as well as in the `case's + of `switch' statements, instead of just the plain pointer or character value. - * Use 'true' and 'false' for 'bool' values, the 'NULL' symbolic - constant for pointer values, and the character constant ''\0'' - where appropriate, instead of '1' and '0'. + * Use `true' and `false' for `bool' values, the `NULL' symbolic + constant for pointer values, and the character constant + `'\0'' where appropriate, instead of `1' and `0'. * Provide one-line descriptive comments for each function. - * Do not use the 'alloca()' function for allocating memory off + * Do not use the `alloca()' function for allocating memory off the stack. Its use causes more portability trouble than is worth the minor benefit of not having to free the storage. - Instead, use 'malloc()' and 'free()'. + Instead, use `malloc()' and `free()'. - * Do not use comparisons of the form '! strcmp(a, b)' or - similar. As Henry Spencer once said, "'strcmp()' is not a - boolean!" Instead, use 'strcmp(a, b) == 0'. + * Do not use comparisons of the form `! strcmp(a, b)' or + similar. As Henry Spencer once said, "`strcmp()' is not a + boolean!" Instead, use `strcmp(a, b) == 0'. * If adding new bit flag values, use explicit hexadecimal - constants ('0x001', '0x002', '0x004', and son on) instead of - shifting one left by successive amounts ('(1<<0)', '(1<<1)', + constants (`0x001', `0x002', `0x004', and son on) instead of + shifting one left by successive amounts (`(1<<0)', `(1<<1)', and so on). NOTE: If I have to reformat your code to follow the coding - style used in 'gawk', I may not bother to integrate your + style used in `gawk', I may not bother to integrate your changes at all. 6. Update the documentation. Along with your new code, please supply new sections and/or chapters for this Info file. If at all possible, please use real Texinfo, instead of just supplying unformatted ASCII text (although even that is better than no - documentation at all). Conventions to be followed in 'GAWK: - Effective AWK Programming' are provided after the '@bye' at the end - of the Texinfo source file. If possible, please update the 'man' - page as well. + documentation at all). Conventions to be followed in `GAWK: + Effective AWK Programming' are provided after the `@bye' at the + end of the Texinfo source file. If possible, please update the + `man' page as well. You will also have to sign paperwork for your documentation changes. - 7. Submit changes as unified diffs. Use 'diff -u -r -N' to compare - the original 'gawk' source tree with your version. I recommend - using the GNU version of 'diff', or best of all, 'git diff' or 'git - format-patch'. Send the output produced by 'diff' to me when you - submit your changes. (*Note Bugs::, for the electronic mail + 7. Submit changes as unified diffs. Use `diff -u -r -N' to compare + the original `gawk' source tree with your version. I recommend + using the GNU version of `diff', or best of all, `git diff' or + `git format-patch'. Send the output produced by `diff' to me when + you submit your changes. (*Note Bugs::, for the electronic mail information.) Using this format makes it easy for me to apply your changes to the - master version of the 'gawk' source code (using 'patch'). If I + master version of the `gawk' source code (using `patch'). If I have to apply the changes manually, using a text editor, I may not do so, particularly if there are lots of changes. - 8. Include an entry for the 'ChangeLog' file with your submission. - This helps further minimize the amount of work I have to do, making - it easier for me to accept patches. It is simplest if you just - make this part of your diff. + 8. Include an entry for the `ChangeLog' file with your submission. + This helps further minimize the amount of work I have to do, + making it easier for me to accept patches. It is simplest if you + just make this part of your diff. Although this sounds like a lot of work, please remember that while -you may write the new code, I have to maintain it and support it. If it +you may write the new code, I have to maintain it and support it. If it isn't possible for me to do that with a minimum of extra work, then I probably will not.  File: gawk.info, Node: New Ports, Next: Derived Files, Prev: Adding Code, Up: Additions -C.2.3 Porting 'gawk' to a New Operating System +C.2.3 Porting `gawk' to a New Operating System ---------------------------------------------- -If you want to port 'gawk' to a new operating system, there are several +If you want to port `gawk' to a new operating system, there are several steps: 1. Follow the guidelines in *note Adding Code::, concerning coding style, submission of diffs, and so on. 2. Be prepared to sign the appropriate paperwork. In order for the - FSF to distribute your code, you must either place your code in the - public domain and submit a signed statement to that effect, or - assign the copyright in your code to the FSF. Both of these actions - are easy to do and _many_ people have done so already. If you have - questions, please contact me, or . + FSF to distribute your code, you must either place your code in + the public domain and submit a signed statement to that effect, or + assign the copyright in your code to the FSF. Both of these + actions are easy to do and _many_ people have done so already. If + you have questions, please contact me, or . 3. When doing a port, bear in mind that your code must coexist - peacefully with the rest of 'gawk' and the other ports. Avoid - gratuitous changes to the system-independent parts of the code. If - at all possible, avoid sprinkling '#ifdef's just for your port + peacefully with the rest of `gawk' and the other ports. Avoid + gratuitous changes to the system-independent parts of the code. If + at all possible, avoid sprinkling `#ifdef's just for your port throughout the code. If the changes needed for a particular system affect too much of the code, I probably will not accept them. In such a case, you - can, of course, distribute your changes on your own, as long as you - comply with the GPL (*note Copying::). + can, of course, distribute your changes on your own, as long as + you comply with the GPL (*note Copying::). - 4. A number of the files that come with 'gawk' are maintained by other + 4. A number of the files that come with `gawk' are maintained by other people. Thus, you should not change them unless it is for a very - good reason; i.e., changes are not out of the question, but changes - to these files are scrutinized extra carefully. The files are - 'dfa.c', 'dfa.h', 'getopt.c', 'getopt.h', 'getopt1.c', - 'getopt_int.h', 'gettext.h', 'regcomp.c', 'regex.c', 'regex.h', - 'regex_internal.c', 'regex_internal.h', and 'regexec.c'. + good reason; i.e., changes are not out of the question, but + changes to these files are scrutinized extra carefully. The files + are `dfa.c', `dfa.h', `getopt.c', `getopt.h', `getopt1.c', + `getopt_int.h', `gettext.h', `regcomp.c', `regex.c', `regex.h', + `regex_internal.c', `regex_internal.h', and `regexec.c'. 5. A number of other files are provided by the GNU Autotools - (Autoconf, Automake, and GNU 'gettext'). You should not change - them either, unless it is for a very good reason. The files are - 'ABOUT-NLS', 'config.guess', 'config.rpath', 'config.sub', - 'depcomp', 'INSTALL', 'install-sh', 'missing', 'mkinstalldirs', - 'xalloc.h', and 'ylwrap'. + (Autoconf, Automake, and GNU `gettext'). You should not change + them either, unless it is for a very good reason. The files are + `ABOUT-NLS', `config.guess', `config.rpath', `config.sub', + `depcomp', `INSTALL', `install-sh', `missing', `mkinstalldirs', + `xalloc.h', and `ylwrap'. 6. Be willing to continue to maintain the port. Non-Unix operating - systems are supported by volunteers who maintain the code needed to - compile and run 'gawk' on their systems. If noone volunteers to + systems are supported by volunteers who maintain the code needed + to compile and run `gawk' on their systems. If noone volunteers to maintain a port, it becomes unsupported and it may be necessary to remove it from the distribution. - 7. Supply an appropriate 'gawkmisc.???' file. Each port has its own - 'gawkmisc.???' that implements certain operating system specific - functions. This is cleaner than a plethora of '#ifdef's scattered - throughout the code. The 'gawkmisc.c' in the main source directory - includes the appropriate 'gawkmisc.???' file from each + 7. Supply an appropriate `gawkmisc.???' file. Each port has its own + `gawkmisc.???' that implements certain operating system specific + functions. This is cleaner than a plethora of `#ifdef's scattered + throughout the code. The `gawkmisc.c' in the main source + directory includes the appropriate `gawkmisc.???' file from each subdirectory. Be sure to update it as well. - Each port's 'gawkmisc.???' file has a suffix reminiscent of the + Each port's `gawkmisc.???' file has a suffix reminiscent of the machine or operating system for the port--for example, - 'pc/gawkmisc.pc' and 'vms/gawkmisc.vms'. The use of separate - suffixes, instead of plain 'gawkmisc.c', makes it possible to move + `pc/gawkmisc.pc' and `vms/gawkmisc.vms'. The use of separate + suffixes, instead of plain `gawkmisc.c', makes it possible to move files from a port's subdirectory into the main subdirectory, - without accidentally destroying the real 'gawkmisc.c' file. + without accidentally destroying the real `gawkmisc.c' file. (Currently, this is only an issue for the PC operating system ports.) - 8. Supply a 'Makefile' as well as any other C source and header files - that are necessary for your operating system. All your code should - be in a separate subdirectory, with a name that is the same as, or - reminiscent of, either your operating system or the computer - system. If possible, try to structure things so that it is not - necessary to move files out of the subdirectory into the main - source directory. If that is not possible, then be sure to avoid - using names for your files that duplicate the names of files in the - main source directory. + 8. Supply a `Makefile' as well as any other C source and header files + that are necessary for your operating system. All your code + should be in a separate subdirectory, with a name that is the same + as, or reminiscent of, either your operating system or the + computer system. If possible, try to structure things so that it + is not necessary to move files out of the subdirectory into the + main source directory. If that is not possible, then be sure to + avoid using names for your files that duplicate the names of files + in the main source directory. - 9. Update the documentation. Please write a section (or sections) for - this Info file describing the installation and compilation steps - needed to compile and/or install 'gawk' for your system. + 9. Update the documentation. Please write a section (or sections) + for this Info file describing the installation and compilation + steps needed to compile and/or install `gawk' for your system. Following these steps makes it much easier to integrate your changes -into 'gawk' and have them coexist happily with other operating systems' +into `gawk' and have them coexist happily with other operating systems' code that is already there. In the code that you supply and maintain, feel free to use a coding @@ -29690,17 +28533,17 @@ File: gawk.info, Node: Derived Files, Prev: New Ports, Up: Additions C.2.4 Why Generated Files Are Kept In Git ----------------------------------------- -If you look at the 'gawk' source in the Git repository, you will notice +If you look at the `gawk' source in the Git repository, you will notice that it includes files that are automatically generated by GNU -infrastructure tools, such as 'Makefile.in' from Automake and even -'configure' from Autoconf. +infrastructure tools, such as `Makefile.in' from Automake and even +`configure' from Autoconf. This is different from many Free Software projects that do not store -the derived files, because that keeps the repository less cluttered, and -it is easier to see the substantive changes when comparing versions and -trying to understand what changed between commits. +the derived files, because that keeps the repository less cluttered, +and it is easier to see the substantive changes when comparing versions +and trying to understand what changed between commits. - However, there are two reasons why the 'gawk' maintainer likes to + However, there are two reasons why the `gawk' maintainer likes to have everything in the repository. First, because it is then easy to reproduce any given version @@ -29708,30 +28551,30 @@ completely, without relying upon the availability of (older, likely obsolete, and maybe even impossible to find) other tools. As an extreme example, if you ever even think about trying to -compile, oh, say, the V7 'awk', you will discover that not only do you -have to bootstrap the V7 'yacc' to do so, but you also need the V7 -'lex'. And the latter is pretty much impossible to bring up on a modern -GNU/Linux system.(1) - - (Or, let's say 'gawk' 1.2 required 'bison' whatever-it-was in 1989 -and that there was no 'awkgram.c' file in the repository. Is there a -guarantee that we could find that 'bison' version? Or that _it_ would +compile, oh, say, the V7 `awk', you will discover that not only do you +have to bootstrap the V7 `yacc' to do so, but you also need the V7 +`lex'. And the latter is pretty much impossible to bring up on a +modern GNU/Linux system.(1) + + (Or, let's say `gawk' 1.2 required `bison' whatever-it-was in 1989 +and that there was no `awkgram.c' file in the repository. Is there a +guarantee that we could find that `bison' version? Or that _it_ would build?) - If the repository has all the generated files, then it's easy to just -check them out and build. (Or _easier_, depending upon how far back we -go.) + If the repository has all the generated files, then it's easy to +just check them out and build. (Or _easier_, depending upon how far +back we go.) And that brings us to the second (and stronger) reason why all the files really need to be in Git. It boils down to who do you cater -to--the 'gawk' developer(s), or the user who just wants to check out a +to--the `gawk' developer(s), or the user who just wants to check out a version and try it out? - The 'gawk' maintainer wants it to be possible for any interested -'awk' user in the world to just clone the repository, check out the -branch of interest and build it. Without their having to have the -correct version(s) of the autotools.(2) That is the point of the -'bootstrap.sh' file. It touches the various other files in the right + The `gawk' maintainer wants it to be possible for any interested +`awk' user in the world to just clone the repository, check out the +branch of interest and build it. Without their having to have the +correct version(s) of the autotools.(2) That is the point of the +`bootstrap.sh' file. It touches the various other files in the right order such that # The canonical incantation for building GNU software: @@ -29739,17 +28582,17 @@ order such that will _just work_. - This is extremely important for the 'master' and 'gawk-X.Y-stable' + This is extremely important for the `master' and `gawk-X.Y-stable' branches. - Further, the 'gawk' maintainer would argue that it's also important -for the 'gawk' developers. When he tried to check out the 'xgawk' -branch(3) to build it, he couldn't. (No 'ltmain.sh' file, and he had no + Further, the `gawk' maintainer would argue that it's also important +for the `gawk' developers. When he tried to check out the `xgawk' +branch(3) to build it, he couldn't. (No `ltmain.sh' file, and he had no idea how to create it, and that was not the only problem.) He felt _extremely_ frustrated. With respect to that branch, the maintainer is no different than Jane User who wants to try to build -'gawk-4.1-stable' or 'master' from the repository. +`gawk-4.1-stable' or `master' from the repository. Thus, the maintainer thinks that it's not just important, but critical, that for any given branch, the above incantation _just works_. @@ -29762,17 +28605,17 @@ critical, that for any given branch, the above incantation _just works_. A. It's the maintainer's job to merge them and he will deal with it. - B. He is really good at 'git diff x y > /tmp/diff1 ; gvim + B. He is really good at `git diff x y > /tmp/diff1 ; gvim /tmp/diff1' to remove the diffs that aren't of interest in order to review code. 2. It would certainly help if everyone used the same versions of the GNU tools as he does, which in general are the latest released - versions of Automake, Autoconf, 'bison', and GNU 'gettext'. + versions of Automake, Autoconf, `bison', and GNU `gettext'. - Installing from source is quite easy. It's how the maintainer - worked for years (and still works). He had '/usr/local/bin' at the - front of his 'PATH' and just did: + Installing from source is quite easy. It's how the maintainer + worked for years (and still works). He had `/usr/local/bin' at + the front of his `PATH' and just did: wget http://ftp.gnu.org/gnu/PACKAGE/PACKAGE-X.Y.Z.tar.gz tar -xpzvf PACKAGE-X.Y.Z.tar.gz @@ -29780,22 +28623,23 @@ critical, that for any given branch, the above incantation _just works_. ./configure && make && make check make install # as root + Most of the above was originally written by the maintainer to other -'gawk' developers. It raised the objection from one of the developers +`gawk' developers. It raised the objection from one of the developers "... that anybody pulling down the source from Git is not an end user." - However, this is not true. There are "power 'awk' users" who can -build 'gawk' (using the magic incantation shown previously) but who -can't program in C. Thus, the major branches should be kept buildable + However, this is not true. There are "power `awk' users" who can +build `gawk' (using the magic incantation shown previously) but who +can't program in C. Thus, the major branches should be kept buildable all the time. - It was then suggested that there be a 'cron' job to create nightly + It was then suggested that there be a `cron' job to create nightly tarballs of "the source." Here, the problem is that there are source -trees, corresponding to the various branches! So, nightly tarballs -aren't the answer, especially as the repository can go for weeks without -significant change being introduced. +trees, corresponding to the various branches! So, nightly tarballs +aren't the answer, especially as the repository can go for weeks +without significant change being introduced. - Fortunately, the Git server can meet this need. For any given branch + Fortunately, the Git server can meet this need. For any given branch named BRANCHNAME, use: wget http://git.savannah.gnu.org/cgit/gawk.git/snapshot/gawk-BRANCHNAME.tar.gz @@ -29804,18 +28648,18 @@ to retrieve a snapshot of the given branch. ---------- Footnotes ---------- - (1) We tried. It was painful. + (1) We tried. It was painful. (2) There is one GNU program that is (in our opinion) severely -difficult to bootstrap from the Git repository. For example, on the +difficult to bootstrap from the Git repository. For example, on the author's old (but still working) PowerPC Macintosh with Mac OS X 10.5, it was necessary to bootstrap a ton of software, starting with Git itself, in order to try to work with the latest code. It's not pleasant, and especially on older systems, it's a big waste of time. - Starting with the latest tarball was no picnic either. The -maintainers had dropped '.gz' and '.bz2' files and only distribute -'.tar.xz' files. It was necessary to bootstrap 'xz' first! + Starting with the latest tarball was no picnic either. The +maintainers had dropped `.gz' and `.bz2' files and only distribute +`.tar.xz' files. It was necessary to bootstrap `xz' first! (3) A branch (since removed) created by one of the other developers that did not include the generated files. @@ -29827,16 +28671,15 @@ C.3 Probable Future Extensions ============================== AWK is a language similar to PERL, only considerably more elegant. - -- _Arnold Robbins_ + -- Arnold Robbins - Hey! - -- _Larry Wall_ + Hey! -- Larry Wall - The 'TODO' file in the 'master' branch of the 'gawk' Git repository + The `TODO' file in the `master' branch of the `gawk' Git repository lists possible future enhancements. Some of these relate to the source -code, and others to possible new features. Please see that file for the -list. *Note Additions::, if you are interested in tackling any of the -projects listed there. +code, and others to possible new features. Please see that file for +the list. *Note Additions::, if you are interested in tackling any of +the projects listed there.  File: gawk.info, Node: Implementation Limitations, Next: Extension Design, Prev: Future Extensions, Up: Notes @@ -29844,31 +28687,30 @@ File: gawk.info, Node: Implementation Limitations, Next: Extension Design, Pr C.4 Some Limitations of the Implementation ========================================== -This following table describes limits of 'gawk' on a Unix-like system -(although it is variable even then). Other systems may have different +This following table describes limits of `gawk' on a Unix-like system +(although it is variable even then). Other systems may have different limits. Item Limit --------------------------------------------------------------------------- +-------------------------------------------------------------------------- Characters in a character 2^(number of bits per byte) -class -Length of input record 'MAX_INT' +class +Length of input record `MAX_INT' Length of output record Unlimited Length of source line Unlimited -Number of fields in a 'MAX_LONG' -record +Number of fields in a record `MAX_LONG' Number of file redirections Unlimited -Number of input records in 'MAX_LONG' -one file -Number of input records 'MAX_LONG' -total +Number of input records in `MAX_LONG' +one file +Number of input records `MAX_LONG' +total Number of pipe redirections min(number of processes per user, number of open files) Numeric values Double-precision floating point (if not using MPFR) -Size of a field 'MAX_INT' -Size of a literal string 'MAX_INT' -Size of a printf string 'MAX_INT' +Size of a field `MAX_INT' +Size of a literal string `MAX_INT' +Size of a printf string `MAX_INT'  File: gawk.info, Node: Extension Design, Next: Old Extension Mechanism, Prev: Implementation Limitations, Up: Notes @@ -29879,15 +28721,15 @@ C.5 Extension API Design This minor node documents the design of the extension API, including a discussion of some of the history and problems that needed to be solved. - The first version of extensions for 'gawk' was developed in the -mid-1990s and released with 'gawk' 3.1 in the late 1990s. The basic + The first version of extensions for `gawk' was developed in the +mid-1990s and released with `gawk' 3.1 in the late 1990s. The basic mechanisms and design remained unchanged for close to 15 years, until 2012. - The old extension mechanism used data types and functions from 'gawk' -itself, with a "clever hack" to install extension functions. + The old extension mechanism used data types and functions from +`gawk' itself, with a "clever hack" to install extension functions. - 'gawk' included some sample extensions, of which a few were really + `gawk' included some sample extensions, of which a few were really useful. However, it was clear from the outset that the extension mechanism was bolted onto the side and was not really well thought out. @@ -29906,33 +28748,33 @@ C.5.1 Problems With The Old Mechanism The old extension mechanism had several problems: - * It depended heavily upon 'gawk' internals. Any time the 'NODE' + * It depended heavily upon `gawk' internals. Any time the `NODE' structure(1) changed, an extension would have to be recompiled. Furthermore, to really write extensions required understanding - something about 'gawk''s internal functions. There was some + something about `gawk''s internal functions. There was some documentation in this Info file, but it was quite minimal. - * Being able to call into 'gawk' from an extension required linker - facilities that are common on Unix-derived systems but that did not - work on MS-Windows systems; users wanting extensions on MS-Windows - had to statically link them into 'gawk', even though MS-Windows - supports dynamic loading of shared objects. + * Being able to call into `gawk' from an extension required linker + facilities that are common on Unix-derived systems but that did + not work on MS-Windows systems; users wanting extensions on + MS-Windows had to statically link them into `gawk', even though + MS-Windows supports dynamic loading of shared objects. - * The API would change occasionally as 'gawk' changed; no + * The API would change occasionally as `gawk' changed; no compatibility between versions was ever offered or planned for. - Despite the drawbacks, the 'xgawk' project developers forked 'gawk' -and developed several significant extensions. They also enhanced -'gawk''s facilities relating to file inclusion and shared object access. + Despite the drawbacks, the `xgawk' project developers forked `gawk' +and developed several significant extensions. They also enhanced +`gawk''s facilities relating to file inclusion and shared object access. A new API was desired for a long time, but only in 2012 did the -'gawk' maintainer and the 'xgawk' developers finally start working on it -together. More information about the 'xgawk' project is provided in +`gawk' maintainer and the `xgawk' developers finally start working on +it together. More information about the `xgawk' project is provided in *note gawkextlib::. ---------- Footnotes ---------- - (1) A critical central data structure inside 'gawk'. + (1) A critical central data structure inside `gawk'.  File: gawk.info, Node: Extension New Mechanism Goals, Next: Extension Other Design Decisions, Prev: Old Extension Problems, Up: Extension Design @@ -29942,21 +28784,21 @@ C.5.2 Goals For A New Mechanism Some goals for the new API were: - * The API should be independent of 'gawk' internals. Changes in - 'gawk' internals should not be visible to the writer of an + * The API should be independent of `gawk' internals. Changes in + `gawk' internals should not be visible to the writer of an extension function. - * The API should provide _binary_ compatibility across 'gawk' + * The API should provide _binary_ compatibility across `gawk' releases as long as the API itself does not change. * The API should enable extensions written in C or C++ to have - roughly the same "appearance" to 'awk'-level code as 'awk' - functions do. This means that extensions should have: + roughly the same "appearance" to `awk'-level code as `awk' + functions do. This means that extensions should have: - The ability to access function parameters. - - The ability to turn an undefined parameter into an array (call - by reference). + - The ability to turn an undefined parameter into an array + (call by reference). - The ability to create, access and update global variables. @@ -29964,20 +28806,20 @@ Some goals for the new API were: flattening") in order to loop over all the element in an easy fashion for C code. - - The ability to create arrays (including 'gawk''s true arrays + - The ability to create arrays (including `gawk''s true arrays of arrays). Some additional important goals were: * The API should use only features in ISO C 90, so that extensions - can be written using the widest range of C and C++ compilers. The - header should include the appropriate '#ifdef __cplusplus' and - 'extern "C"' magic so that a C++ compiler could be used. (If using - C++, the runtime system has to be smart enough to call any - constructors and destructors, as 'gawk' is a C program. As of this + can be written using the widest range of C and C++ compilers. The + header should include the appropriate `#ifdef __cplusplus' and + `extern "C"' magic so that a C++ compiler could be used. (If + using C++, the runtime system has to be smart enough to call any + constructors and destructors, as `gawk' is a C program. As of this writing, this has not been tested.) - * The API mechanism should not require access to 'gawk''s symbols(1) + * The API mechanism should not require access to `gawk''s symbols(1) by the compile-time or dynamic linker, in order to enable creation of extensions that also work on MS-Windows. @@ -29985,29 +28827,29 @@ Some goals for the new API were: that should be available to extensions, which were also subsequently provided: - * Extensions should have the ability to hook into 'gawk''s I/O - redirection mechanism. In particular, the 'xgawk' developers + * Extensions should have the ability to hook into `gawk''s I/O + redirection mechanism. In particular, the `xgawk' developers provided a so-called "open hook" to take over reading records. During development, this was generalized to allow extensions to hook into input processing, output processing, and two-way I/O. * An extension should be able to provide a "call back" function to - perform cleanup actions when 'gawk' exits. + perform cleanup actions when `gawk' exits. * An extension should be able to provide a version string so that - 'gawk''s '--version' option can provide information about + `gawk''s `--version' option can provide information about extensions as well. - The requirement to avoid access to 'gawk''s symbols is, at first + The requirement to avoid access to `gawk''s symbols is, at first glance, a difficult one to meet. One design, apparently used by Perl and Ruby and maybe others, would -be to make the mainline 'gawk' code into a library, with the 'gawk' -utility a small C 'main()' function linked against the library. +be to make the mainline `gawk' code into a library, with the `gawk' +utility a small C `main()' function linked against the library. This seemed like the tail wagging the dog, complicating build and -installation and making a simple copy of the 'gawk' executable from one -system to another (or one place to another on the same system!) into a +installation and making a simple copy of the `gawk' executable from one +system to another (or one place to another on the same system!) into a chancy operation. Pat Rankin suggested the solution that was adopted. *Note Extension @@ -30016,7 +28858,7 @@ Mechanism Outline::, for the details. ---------- Footnotes ---------- (1) The "symbols" are the variables and functions defined inside -'gawk'. Access to these symbols by code external to 'gawk' loaded +`gawk'. Access to these symbols by code external to `gawk' loaded dynamically at runtime is problematic on MS-Windows.  @@ -30026,40 +28868,40 @@ C.5.3 Other Design Decisions ---------------------------- As an arbitrary design decision, extensions can read the values of -built-in variables and arrays (such as 'ARGV' and 'FS'), but cannot -change them, with the exception of 'PROCINFO'. +built-in variables and arrays (such as `ARGV' and `FS'), but cannot +change them, with the exception of `PROCINFO'. The reason for this is to prevent an extension function from -affecting the flow of an 'awk' program outside its control. While a -real 'awk' function can do what it likes, that is at the discretion of +affecting the flow of an `awk' program outside its control. While a +real `awk' function can do what it likes, that is at the discretion of the programmer. An extension function should provide a service or make -a C API available for use within 'awk', and not mess with 'FS' or 'ARGC' -and 'ARGV'. +a C API available for use within `awk', and not mess with `FS' or +`ARGC' and `ARGV'. - In addition, it becomes easy to start down a slippery slope. How -much access to 'gawk' facilities do extensions need? Do they need -'getline'? What about calling 'gsub()' or compiling regular -expressions? What about calling into 'awk' functions? (_That_ would be + In addition, it becomes easy to start down a slippery slope. How +much access to `gawk' facilities do extensions need? Do they need +`getline'? What about calling `gsub()' or compiling regular +expressions? What about calling into `awk' functions? (_That_ would be messy.) - In order to avoid these issues, the 'gawk' developers chose to start + In order to avoid these issues, the `gawk' developers chose to start with the simplest, most basic features that are still truly useful. - Another decision is that although 'gawk' provides nice things like + Another decision is that although `gawk' provides nice things like MPFR, and arrays indexed internally by integers, these features are not being brought out to the API in order to keep things simple and close to -traditional 'awk' semantics. (In fact, arrays indexed internally by +traditional `awk' semantics. (In fact, arrays indexed internally by integers are so transparent that they aren't even documented!) - Additionally, all functions in the API check that their pointer input -parameters are not 'NULL'. If they are, they return an error. (It is a -good idea for extension code to verify that pointers received from -'gawk' are not 'NULL'. Such a thing should not happen, but the 'gawk' -developers are only human, and they have been known to occasionally make -mistakes.) + Additionally, all functions in the API check that their pointer +input parameters are not `NULL'. If they are, they return an error. +(It is a good idea for extension code to verify that pointers received +from `gawk' are not `NULL'. Such a thing should not happen, but the +`gawk' developers are only human, and they have been known to +occasionally make mistakes.) - With time, the API will undoubtedly evolve; the 'gawk' developers -expect this to be driven by user needs. For now, the current API seems + With time, the API will undoubtedly evolve; the `gawk' developers +expect this to be driven by user needs. For now, the current API seems to provide a minimal yet powerful set of features for creating extensions. @@ -30071,12 +28913,12 @@ C.5.4 Room For Future Growth The API can later be expanded, in two ways: - * 'gawk' passes an "extension id" into the extension when it first + * `gawk' passes an "extension id" into the extension when it first loads the extension. The extension then passes this id back to - 'gawk' with each function call. This mechanism allows 'gawk' to + `gawk' with each function call. This mechanism allows `gawk' to identify the extension calling into it, should it need to know. - * Similarly, the extension passes a "name space" into 'gawk' when it + * Similarly, the extension passes a "name space" into `gawk' when it registers each extension function. This accommodates a possible future mechanism for grouping extension functions and possibly avoiding name conflicts. @@ -30091,34 +28933,34 @@ C.6 Compatibility For Old Extensions ==================================== *note Dynamic Extensions::, describes the supported API and mechanisms -for writing extensions for 'gawk'. This API was introduced in version -4.1. However, for many years 'gawk' provided an extension mechanism -that required knowledge of 'gawk' internals and that was not as well +for writing extensions for `gawk'. This API was introduced in version +4.1. However, for many years `gawk' provided an extension mechanism +that required knowledge of `gawk' internals and that was not as well designed. - In order to provide a transition period, 'gawk' version 4.1 continues -to support the original extension mechanism. This will be true for the -life of exactly one major release. This support will be withdrawn, and -removed from the source code, at the next major release. + In order to provide a transition period, `gawk' version 4.1 +continues to support the original extension mechanism. This will be +true for the life of exactly one major release. This support will be +withdrawn, and removed from the source code, at the next major release. Briefly, original-style extensions should be compiled by including -the 'awk.h' header file in the extension source code. Additionally, you -must define the identifier 'GAWK' when building (use '-DGAWK' with -Unix-style compilers). Otherwise, the definitions in 'gawkapi.h' will -cause conflicts with those in 'awk.h' and your extension will not +the `awk.h' header file in the extension source code. Additionally, you +must define the identifier `GAWK' when building (use `-DGAWK' with +Unix-style compilers). Otherwise, the definitions in `gawkapi.h' will +cause conflicts with those in `awk.h' and your extension will not compile. Just as in previous versions, you load an old-style extension with -the 'extension()' built-in function (which is not otherwise documented). +the `extension()' built-in function (which is not otherwise documented). This function in turn finds and loads the shared object file containing -the extension and calls its 'dl_load()' C routine. +the extension and calls its `dl_load()' C routine. Because original-style and new-style extensions use different -initialization routines ('dl_load()' versus 'dlload()'), they may safely -be installed in the same directory (to be found by 'AWKLIBPATH') without -conflict. +initialization routines (`dl_load()' versus `dlload()'), they may safely +be installed in the same directory (to be found by `AWKLIBPATH') +without conflict. - The 'gawk' development team strongly recommends that you convert any + The `gawk' development team strongly recommends that you convert any old extensions that you may have to use the new API described in *note Dynamic Extensions::. @@ -30128,33 +28970,30 @@ File: gawk.info, Node: Notes summary, Prev: Old Extension Mechanism, Up: Note C.7 Summary =========== - * 'gawk''s extensions can be disabled with either the '--traditional' - option or with the '--posix' option. The '--parsedebug' option is - available if 'gawk' is compiled with '-DDEBUG'. + * `gawk''s extensions can be disabled with either the + `--traditional' option or with the `--posix' option. The + `--parsedebug' option is available if `gawk' is compiled with + `-DDEBUG'. -<<<<<<< HEAD - * The source code for 'gawk' is maintained in a publicly accessable - Git repository. Anyone may check it out and view the source. -======= * The source code for `gawk' is maintained in a publicly accessible Git repository. Anyone may check it out and view the source. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - * Contributions to 'gawk' are welcome. Following the steps outlined + * Contributions to `gawk' are welcome. Following the steps outlined in this major node will make it easier to integrate your - contributions into the code base. This applies both to new feature - contributions and to ports to additional operating systems. + contributions into the code base. This applies both to new + feature contributions and to ports to additional operating systems. - * 'gawk' has some limits--generally those that are imposed by the + * `gawk' has some limits--generally those that are imposed by the machine architecture. * The extension API design was intended to solve a number of problems with the previous extension mechanism, enable features needed by - the 'xgawk' project, and provide binary compatibility going + the `xgawk' project, and provide binary compatibility going forward. * The previous extension mechanism is still supported in version 4.1 - of 'gawk', but it _will_ be removed in the next major release. + of `gawk', but it _will_ be removed in the next major release. +  File: gawk.info, Node: Basic Concepts, Next: Glossary, Prev: Notes, Up: Top @@ -30164,7 +29003,7 @@ Appendix D Basic Programming Concepts This major node attempts to define some of the basic concepts and terms that are used throughout the rest of this Info file. As this Info file -is specifically about 'awk', and not about computer programming in +is specifically about `awk', and not about computer programming in general, the coverage here is by necessity fairly cursory and simplistic. (If you need more background, there are many other introductory texts that you should refer to instead.) @@ -30181,41 +29020,39 @@ D.1 What a Program Does ======================= At the most basic level, the job of a program is to process some input -data and produce results. See *note Figure D.1: figure-general-flow. +data and produce results. See *note figure-general-flow::. -[image src="general-program.txt" alt="General program flow" text=" _______ -+------+ / \\ +---------+ + _______ ++------+ / \ +---------+ | Data | -----> < Program > -----> | Results | -+------+ \\_______/ +---------+"] - ++------+ \_______/ +---------+ Figure D.1: General Program Flow - The "program" in the figure can be either a compiled program(1) (such -as 'ls'), or it may be "interpreted". In the latter case, a -machine-executable program such as 'awk' reads your program, and then + The "program" in the figure can be either a compiled program(1) +(such as `ls'), or it may be "interpreted". In the latter case, a +machine-executable program such as `awk' reads your program, and then uses the instructions in your program to process the data. When you write a program, it usually consists of the following, very -basic set of steps, as shown in *note Figure D.2: figure-process-flow.: +basic set of steps, as shown in *note figure-process-flow::: -[image src="process-flow.txt" alt="Basic Program Stages" text=" ______ -+----------------+ / More \\ No +----------+ + ______ ++----------------+ / More \ No +----------+ | Initialization | -------> < Data > -------> | Clean Up | -+----------------+ ^ \\ ? / +----------+ ++----------------+ ^ \ ? / +----------+ | +--+-+ | | Yes | | | V | +---------+ +-----+ Process | - +---------+"] - + +---------+ Figure D.2: Basic Program Steps Initialization These are the things you do before actually starting to process - data, such as checking arguments, initializing any data you need to - work with, and so on. This step corresponds to 'awk''s 'BEGIN' + data, such as checking arguments, initializing any data you need + to work with, and so on. This step corresponds to `awk''s `BEGIN' rule (*note BEGIN/END::). If you were baking a cake, this might consist of laying out all the @@ -30228,7 +29065,7 @@ Processing In most programming languages, you have to manually manage the reading of data, checking to see if there is more each time you - read a chunk. 'awk''s pattern-action paradigm (*note Getting + read a chunk. `awk''s pattern-action paradigm (*note Getting Started::) handles the mechanics of this for you. In baking a cake, the processing corresponds to the actual labor: @@ -30237,7 +29074,7 @@ Processing Clean Up Once you've processed all the data, you may have things you need to - do before exiting. This step corresponds to 'awk''s 'END' rule + do before exiting. This step corresponds to `awk''s `END' rule (*note BEGIN/END::). After the cake comes out of the oven, you still have to wrap it in @@ -30245,9 +29082,9 @@ Clean Up mixing bowls and utensils. An "algorithm" is a detailed set of instructions necessary to -accomplish a task, or process data. It is much the same as a recipe for -baking a cake. Programs implement algorithms. Often, it is up to you -to design the algorithm and implement it, simultaneously. +accomplish a task, or process data. It is much the same as a recipe +for baking a cake. Programs implement algorithms. Often, it is up to +you to design the algorithm and implement it, simultaneously. The "logical chunks" we talked about previously are called "records", similar to the records a company keeps on employees, a school keeps for @@ -30261,12 +29098,12 @@ results, not too surprisingly, is termed "output". They are often referred to together as "input/output," and even more often, as "I/O" for short. (You will also see "input" and "output" used as verbs.) - 'awk' manages the reading of data for you, as well as the breaking it -up into records and fields. Your program's job is to tell 'awk' what to -do with the data. You do this by describing "patterns" in the data to -look for, and "actions" to execute when those patterns are seen. This -"data-driven" nature of 'awk' programs usually makes them both easier to -write and easier to read. + `awk' manages the reading of data for you, as well as the breaking +it up into records and fields. Your program's job is to tell `awk' +what to do with the data. You do this by describing "patterns" in the +data to look for, and "actions" to execute when those patterns are +seen. This "data-driven" nature of `awk' programs usually makes them +both easier to write and easier to read. ---------- Footnotes ---------- @@ -30282,18 +29119,18 @@ D.2 Data Values in a Computer In a program, you keep track of information and values in things called "variables". A variable is just a name for a given value, such as -'first_name', 'last_name', 'address', and so on. 'awk' has several +`first_name', `last_name', `address', and so on. `awk' has several predefined variables, and it has special names to refer to the current input record and the fields of the record. You may also group multiple associated values under one name, as an array. - Data, particularly in 'awk', consists of either numeric values, such + Data, particularly in `awk', consists of either numeric values, such as 42 or 3.1415927, or string values. String values are essentially anything that's not a number, such as a name. Strings are sometimes referred to as "character data", since they store the individual -characters that comprise them. Individual variables, as well as numeric -and string variables, are referred to as "scalar" values. Groups of -values, such as arrays, are not scalars. +characters that comprise them. Individual variables, as well as +numeric and string variables, are referred to as "scalar" values. +Groups of values, such as arrays, are not scalars. *note Computer Arithmetic::, provided a basic introduction to numeric types (integer and floating-point) and how they are used in a computer. @@ -30303,41 +29140,41 @@ presented. While you are probably used to the idea of a number without a value (i.e., zero), it takes a bit more getting used to the idea of zero-length character data. Nevertheless, such a thing exists. It is -called the "null string". The null string is character data that has no -value. In other words, it is empty. It is written in 'awk' programs -like this: '""'. +called the "null string". The null string is character data that has +no value. In other words, it is empty. It is written in `awk' programs +like this: `""'. Humans are used to working in decimal; i.e., base 10. In base 10, numbers go from 0 to 9, and then "roll over" into the next column. -(Remember grade school? 42 = 4 x 10 + 2.) +(Remember grade school? 42 = 4 x 10 + 2.) There are other number bases though. Computers commonly use base 2 or "binary", base 8 or "octal", and base 16 or "hexadecimal". In binary, each column represents two times the value in the column to its -right. Each column may contain either a 0 or a 1. Thus, binary 1010 +right. Each column may contain either a 0 or a 1. Thus, binary 1010 represents (1 x 8) + (0 x 4) + (1 x 2) + (0 x 1), or decimal 10. Octal and hexadecimal are discussed more in *note Nondecimal-numbers::. At the very lowest level, computers store values as groups of binary digits, or "bits". Modern computers group bits into groups of eight, -called "bytes". Advanced applications sometimes have to manipulate bits -directly, and 'gawk' provides functions for doing so. +called "bytes". Advanced applications sometimes have to manipulate +bits directly, and `gawk' provides functions for doing so. Programs are written in programming languages. Hundreds, if not thousands, of programming languages exist. One of the most popular is the C programming language. The C language had a very strong influence -on the design of the 'awk' language. +on the design of the `awk' language. - There have been several versions of C. The first is often referred to -as "K&R" C, after the initials of Brian Kernighan and Dennis Ritchie, -the authors of the first book on C. (Dennis Ritchie created the -language, and Brian Kernighan was one of the creators of 'awk'.) + There have been several versions of C. The first is often referred +to as "K&R" C, after the initials of Brian Kernighan and Dennis Ritchie, +the authors of the first book on C. (Dennis Ritchie created the +language, and Brian Kernighan was one of the creators of `awk'.) In the mid-1980s, an effort began to produce an international -standard for C. This work culminated in 1989, with the production of the -ANSI standard for C. This standard became an ISO standard in 1990. In -1999, a revised ISO C standard was approved and released. Where it -makes sense, POSIX 'awk' is compatible with 1999 ISO C. +standard for C. This work culminated in 1989, with the production of +the ANSI standard for C. This standard became an ISO standard in 1990. +In 1999, a revised ISO C standard was approved and released. Where it +makes sense, POSIX `awk' is compatible with 1999 ISO C.  File: gawk.info, Node: Glossary, Next: Copying, Prev: Basic Concepts, Up: Top @@ -30346,42 +29183,42 @@ Glossary ******** Action - A series of 'awk' statements attached to a rule. If the rule's - pattern matches an input record, 'awk' executes the rule's action. + A series of `awk' statements attached to a rule. If the rule's + pattern matches an input record, `awk' executes the rule's action. Actions are always enclosed in braces. (*Note Action Overview::.) -Amazing 'awk' Assembler +Amazing `awk' Assembler Henry Spencer at the University of Toronto wrote a retargetable - assembler completely as 'sed' and 'awk' scripts. It is thousands + assembler completely as `sed' and `awk' scripts. It is thousands of lines long, including machine descriptions for several eight-bit microcomputers. It is a good example of a program that would have been better written in another language. You can get it from - . + `http://awk.info/?awk100/aaa'. Ada A programming language originally defined by the U.S. Department of - Defense for embedded programming. It was designed to enforce good + Defense for embedded programming. It was designed to enforce good Software Engineering practices. -Amazingly Workable Formatter ('awf') +Amazingly Workable Formatter (`awf') Henry Spencer at the University of Toronto wrote a formatter that - accepts a large subset of the 'nroff -ms' and 'nroff -man' - formatting commands, using 'awk' and 'sh'. It is available from - . + accepts a large subset of the `nroff -ms' and `nroff -man' + formatting commands, using `awk' and `sh'. It is available from + `http://awk.info/?tools/awf'. Anchor - The regexp metacharacters '^' and '$', which force the match to the - beginning or end of the string, respectively. + The regexp metacharacters `^' and `$', which force the match to + the beginning or end of the string, respectively. ANSI The American National Standards Institute. This organization - produces many standards, among them the standards for the C and C++ - programming languages. These standards often become international - standards as well. See also "ISO." + produces many standards, among them the standards for the C and + C++ programming languages. These standards often become + international standards as well. See also "ISO." Array A grouping of multiple values under the same name. Most languages - just provide sequential arrays. 'awk' provides associative arrays. + just provide sequential arrays. `awk' provides associative arrays. Assertion A statement in a program that a condition is true at this point in @@ -30389,7 +29226,7 @@ Assertion to behave. Assignment - An 'awk' expression that changes the value of some 'awk' variable + An `awk' expression that changes the value of some `awk' variable or data object. An object that you can assign to is called an "lvalue". The assigned values are called "rvalues". *Note Assignment Ops::. @@ -30398,29 +29235,29 @@ Associative Array Arrays in which the indices may be numbers or strings, not just sequential integers in a fixed range. -'awk' Language - The language in which 'awk' programs are written. +`awk' Language + The language in which `awk' programs are written. -'awk' Program - An 'awk' program consists of a series of "patterns" and "actions", +`awk' Program + An `awk' program consists of a series of "patterns" and "actions", collectively known as "rules". For each input record given to the - program, the program's rules are all processed in turn. 'awk' + program, the program's rules are all processed in turn. `awk' programs may also contain function definitions. -'awk' Script - Another name for an 'awk' program. +`awk' Script + Another name for an `awk' program. Bash The GNU version of the standard shell (the Bourne-Again SHell). See also "Bourne Shell." Bit - Short for "Binary Digit." All values in computer memory ultimately - reduce to binary digits: values that are either zero or one. - Groups of bits may be interpreted differently--as integers, + Short for "Binary Digit." All values in computer memory + ultimately reduce to binary digits: values that are either zero or + one. Groups of bits may be interpreted differently--as integers, floating-point numbers, character data, addresses of other memory - objects, or other data. 'awk' lets you work with floating-point - numbers and strings. 'gawk' lets you manipulate bit values with + objects, or other data. `awk' lets you work with floating-point + numbers and strings. `gawk' lets you manipulate bit values with the built-in functions described in *note Bitwise Functions::. Computers are often defined by how many bits they use to represent @@ -30429,53 +29266,53 @@ Bit essentially disappeared. Boolean Expression - Named after the English mathematician Boole. See also "Logical + Named after the English mathematician Boole. See also "Logical Expression." Bourne Shell - The standard shell ('/bin/sh') on Unix and Unix-like systems, + The standard shell (`/bin/sh') on Unix and Unix-like systems, originally written by Steven R. Bourne at Bell Laboratories. Many - shells (Bash, 'ksh', 'pdksh', 'zsh') are generally upwardly + shells (Bash, `ksh', `pdksh', `zsh') are generally upwardly compatible with the Bourne shell. Built-in Function - The 'awk' language provides built-in functions that perform various + The `awk' language provides built-in functions that perform various numerical, I/O-related, and string computations. Examples are - 'sqrt()' (for the square root of a number) and 'substr()' (for a - substring of a string). 'gawk' provides functions for timestamp + `sqrt()' (for the square root of a number) and `substr()' (for a + substring of a string). `gawk' provides functions for timestamp management, bit manipulation, array sorting, type checking, and runtime string translation. (*Note Built-in::.) Built-in Variable - 'ARGC', 'ARGV', 'CONVFMT', 'ENVIRON', 'FILENAME', 'FNR', 'FS', - 'NF', 'NR', 'OFMT', 'OFS', 'ORS', 'RLENGTH', 'RSTART', 'RS', and - 'SUBSEP' are the variables that have special meaning to 'awk'. In - addition, 'ARGIND', 'BINMODE', 'ERRNO', 'FIELDWIDTHS', 'FPAT', - 'IGNORECASE', 'LINT', 'PROCINFO', 'RT', and 'TEXTDOMAIN' are the - variables that have special meaning to 'gawk'. Changing some of - them affects 'awk''s running environment. (*Note Built-in + `ARGC', `ARGV', `CONVFMT', `ENVIRON', `FILENAME', `FNR', `FS', + `NF', `NR', `OFMT', `OFS', `ORS', `RLENGTH', `RSTART', `RS', and + `SUBSEP' are the variables that have special meaning to `awk'. In + addition, `ARGIND', `BINMODE', `ERRNO', `FIELDWIDTHS', `FPAT', + `IGNORECASE', `LINT', `PROCINFO', `RT', and `TEXTDOMAIN' are the + variables that have special meaning to `gawk'. Changing some of + them affects `awk''s running environment. (*Note Built-in Variables::.) Braces - The characters '{' and '}'. Braces are used in 'awk' for + The characters `{' and `}'. Braces are used in `awk' for delimiting actions, compound statements, and function bodies. C The system programming language that most GNU software is written - in. The 'awk' programming language has C-like syntax, and this - Info file points out similarities between 'awk' and C when + in. The `awk' programming language has C-like syntax, and this + Info file points out similarities between `awk' and C when appropriate. - In general, 'gawk' attempts to be as similar to the 1990 version of - ISO C as makes sense. + In general, `gawk' attempts to be as similar to the 1990 version + of ISO C as makes sense. C++ A popular object-oriented programming language derived from C. Character Set The set of numeric codes used by a computer system to represent the - characters (letters, numbers, punctuation, etc.) of a particular - country or place. The most common character set in use today is + characters (letters, numbers, punctuation, etc.) of a particular + country or place. The most common character set in use today is ASCII (American Standard Code for Information Interchange). Many European countries use an extension of ASCII known as ISO-8859-1 (ISO Latin-1). The Unicode character set (http://www.unicode.org) @@ -30483,14 +29320,14 @@ Character Set used on GNU/Linux systems. CHEM - A preprocessor for 'pic' that reads descriptions of molecules and - produces 'pic' input for drawing them. It was written in 'awk' by + A preprocessor for `pic' that reads descriptions of molecules and + produces `pic' input for drawing them. It was written in `awk' by Brian Kernighan and Jon Bentley, and is available from - . + `http://netlib.sandia.gov/netlib/typesetting/chem.gz'. Cookie A peculiar goodie, token, saying or remembrance produced by or - presented to a program. (With thanks to Professor Doug McIlroy.) + presented to a program. (With thanks to Professor Doug McIlroy.) Coprocess A subordinate program with which two-way communications is @@ -30502,25 +29339,25 @@ Compiler directly by the computer. See also "Interpreter." Compound Statement - A series of 'awk' statements, enclosed in curly braces. Compound + A series of `awk' statements, enclosed in curly braces. Compound statements may be nested. (*Note Statements::.) Concatenation Concatenating two strings means sticking them together, one after - another, producing a new string. For example, the string 'foo' - concatenated with the string 'bar' gives the string 'foobar'. + another, producing a new string. For example, the string `foo' + concatenated with the string `bar' gives the string `foobar'. (*Note Concatenation::.) Conditional Expression - An expression using the '?:' ternary operator, such as 'EXPR1 ? + An expression using the `?:' ternary operator, such as `EXPR1 ? EXPR2 : EXPR3'. The expression EXPR1 is evaluated; if the result is true, the value of the whole expression is the value of EXPR2; otherwise the value is EXPR3. In either case, only one of EXPR2 - and EXPR3 is evaluated. (*Note Conditional Exp::.) + and EXPR3 is evaluated. (*Note Conditional Exp::.) Comparison Expression - A relation that is either true or false, such as 'a < b'. - Comparison expressions are used in 'if', 'while', 'do', and 'for' + A relation that is either true or false, such as `a < b'. + Comparison expressions are used in `if', `while', `do', and `for' statements, and in patterns to select which input records to process. (*Note Typing and Comparison::.) @@ -30530,43 +29367,45 @@ Curly Braces Dark Corner An area in the language where specifications often were (or still are) not clear, leading to unexpected or undesirable behavior. - Such areas are marked in this Info file with "(d.c.)" in the text + Such areas are marked in this Info file with "(d.c.)" in the text and are indexed under the heading "dark corner." Data Driven - A description of 'awk' programs, where you specify the data you are - interested in processing, and what to do when that data is seen. + A description of `awk' programs, where you specify the data you + are interested in processing, and what to do when that data is + seen. Data Objects - These are numbers and strings of characters. Numbers are converted - into strings and vice versa, as needed. (*Note Conversion::.) + These are numbers and strings of characters. Numbers are + converted into strings and vice versa, as needed. (*Note + Conversion::.) Deadlock The situation in which two communicating processes are each waiting for the other to perform an action. Debugger - A program used to help developers remove "bugs" from (de-bug) their - programs. + A program used to help developers remove "bugs" from (de-bug) + their programs. Double Precision An internal representation of numbers that can have fractional parts. Double precision numbers keep track of more digits than do - single precision numbers, but operations on them are sometimes more - expensive. This is the way 'awk' stores numeric values. It is the - C type 'double'. + single precision numbers, but operations on them are sometimes + more expensive. This is the way `awk' stores numeric values. It + is the C type `double'. Dynamic Regular Expression A dynamic regular expression is a regular expression written as an ordinary expression. It could be a string constant, such as - '"foo"', but it may also be an expression whose value can vary. + `"foo"', but it may also be an expression whose value can vary. (*Note Computed Regexps::.) Environment - A collection of strings, of the form 'NAME=VAL', that each program - has available to it. Users generally place values into the + A collection of strings, of the form `NAME=VAL', that each program + has available to it. Users generally place values into the environment in order to provide information to various programs. - Typical examples are the environment variables 'HOME' and 'PATH'. + Typical examples are the environment variables `HOME' and `PATH'. Empty String See "Null String." @@ -30577,30 +29416,30 @@ Epoch with library functions available for converting these values into standard date and time formats. - The epoch on Unix and POSIX systems is 1970-01-01 00:00:00 UTC. See - also "GMT" and "UTC." + The epoch on Unix and POSIX systems is 1970-01-01 00:00:00 UTC. + See also "GMT" and "UTC." Escape Sequences A special sequence of characters used for describing nonprinting - characters, such as '\n' for newline or '\033' for the ASCII ESC - (Escape) character. (*Note Escape Sequences::.) + characters, such as `\n' for newline or `\033' for the ASCII ESC + (Escape) character. (*Note Escape Sequences::.) Extension An additional feature or change to a programming language or utility not defined by that language's or utility's standard. - 'gawk' has (too) many extensions over POSIX 'awk'. + `gawk' has (too) many extensions over POSIX `awk'. FDL See "Free Documentation License." Field - When 'awk' reads an input record, it splits the record into pieces + When `awk' reads an input record, it splits the record into pieces separated by whitespace (or by a separator regexp that you can - change by setting the built-in variable 'FS'). Such pieces are + change by setting the built-in variable `FS'). Such pieces are called fields. If the pieces are of fixed length, you can use the - built-in variable 'FIELDWIDTHS' to describe their lengths. If you + built-in variable `FIELDWIDTHS' to describe their lengths. If you wish to specify the contents of fields instead of the field - separator, you can use the built-in variable 'FPAT' to do so. + separator, you can use the built-in variable `FPAT' to do so. (*Note Field Separators::, *note Constant Size::, and *note Splitting By Content::.) @@ -30610,24 +29449,24 @@ Flag Floating-Point Number Often referred to in mathematical terms as a "rational" or real - number, this is just a number that can have a fractional part. See - also "Double Precision" and "Single Precision." + number, this is just a number that can have a fractional part. + See also "Double Precision" and "Single Precision." Format - Format strings control the appearance of output in the 'strftime()' - and 'sprintf()' functions, and in the 'printf' statement as well. - Also, data conversions from numbers to strings are controlled by - the format strings contained in the built-in variables 'CONVFMT' - and 'OFMT'. (*Note Control Letters::.) + Format strings control the appearance of output in the + `strftime()' and `sprintf()' functions, and in the `printf' + statement as well. Also, data conversions from numbers to strings + are controlled by the format strings contained in the built-in + variables `CONVFMT' and `OFMT'. (*Note Control Letters::.) Free Documentation License This document describes the terms under which this Info file is - published and may be copied. (*Note GNU Free Documentation + published and may be copied. (*Note GNU Free Documentation License::.) Function A specialized group of statements used to encapsulate general or - program-specific tasks. 'awk' has a number of built-in functions, + program-specific tasks. `awk' has a number of built-in functions, and also allows you to define your own. (*Note Functions::.) FSF @@ -30639,15 +29478,15 @@ Free Software Foundation Richard M. Stallman, the author of the original Emacs editor. GNU Emacs is the most widely used version of Emacs today. -'gawk' - The GNU implementation of 'awk'. +`gawk' + The GNU implementation of `awk'. General Public License - This document describes the terms under which 'gawk' and its source - code may be distributed. (*Note Copying::.) + This document describes the terms under which `gawk' and its source + code may be distributed. (*Note Copying::.) GMT - "Greenwich Mean Time." This is the old term for UTC. It is the + "Greenwich Mean Time." This is the old term for UTC. It is the time of day used internally for Unix and POSIX systems. See also "Epoch" and "UTC." @@ -30659,20 +29498,21 @@ GNU GNU/Linux A variant of the GNU system using the Linux kernel, instead of the Free Software Foundation's Hurd kernel. The Linux kernel is a - stable, efficient, full-featured clone of Unix that has been ported - to a variety of architectures. It is most popular on PC-class - systems, but runs well on a variety of other systems too. The - Linux kernel source code is available under the terms of the GNU - General Public License, which is perhaps its most important aspect. + stable, efficient, full-featured clone of Unix that has been + ported to a variety of architectures. It is most popular on + PC-class systems, but runs well on a variety of other systems too. + The Linux kernel source code is available under the terms of the + GNU General Public License, which is perhaps its most important + aspect. GPL See "General Public License." Hexadecimal - Base 16 notation, where the digits are '0'-'9' and 'A'-'F', with - 'A' representing 10, 'B' representing 11, and so on, up to 'F' for - 15. Hexadecimal numbers are written in C using a leading '0x', to - indicate their base. Thus, '0x12' is 18 ((1 x 16) + 2). *Note + Base 16 notation, where the digits are `0'-`9' and `A'-`F', with + `A' representing 10, `B' representing 11, and so on, up to `F' for + 15. Hexadecimal numbers are written in C using a leading `0x', to + indicate their base. Thus, `0x12' is 18 ((1 x 16) + 2). *Note Nondecimal-numbers::. I/O @@ -30680,8 +29520,9 @@ I/O out of a running program. Input Record - A single chunk of data that is read in by 'awk'. Usually, an 'awk' - input record consists of one line of text. (*Note Records::.) + A single chunk of data that is read in by `awk'. Usually, an + `awk' input record consists of one line of text. (*Note + Records::.) Integer A whole number, i.e., a number that does not have a fractional @@ -30693,23 +29534,23 @@ Internationalization Interpreter A program that reads human-readable source code directly, and uses - the instructions in it to process data and produce results. 'awk' + the instructions in it to process data and produce results. `awk' is typically (but not always) implemented as an interpreter. See also "Compiler." Interval Expression A component of a regular expression that lets you specify repeated matches of some part of the regexp. Interval expressions were not - originally available in 'awk' programs. + originally available in `awk' programs. ISO The International Organization for Standardization. This organization produces international standards for many things, including programming languages, such as C and C++. In the computer arena, important standards like those for C, C++, and - POSIX become both American national and ISO international standards - simultaneously. This Info file refers to Standard C as "ISO C" - throughout. See the ISO website + POSIX become both American national and ISO international + standards simultaneously. This Info file refers to Standard C as + "ISO C" throughout. See the ISO website (http://www.iso.org/iso/home/about.htm) for more information about the name of the organization and its language-independent three-letter acronym. @@ -30717,19 +29558,19 @@ ISO Java A modern programming language originally developed by Sun Microsystems (now Oracle) supporting Object-Oriented programming. - Although usually implemented by compiling to the instructions for a - standard virtual machine (the JVM), the language can be compiled to - native code. + Although usually implemented by compiling to the instructions for + a standard virtual machine (the JVM), the language can be compiled + to native code. Keyword - In the 'awk' language, a keyword is a word that has special + In the `awk' language, a keyword is a word that has special meaning. Keywords are reserved and may not be used as variable names. - 'gawk''s keywords are: 'BEGIN', 'BEGINFILE', 'END', 'ENDFILE', - 'break', 'case', 'continue', 'default' 'delete', 'do...while', - 'else', 'exit', 'for...in', 'for', 'function', 'func', 'if', - 'next', 'nextfile', 'switch', and 'while'. + `gawk''s keywords are: `BEGIN', `BEGINFILE', `END', `ENDFILE', + `break', `case', `continue', `default' `delete', `do...while', + `else', `exit', `for...in', `for', `function', `func', `if', + `next', `nextfile', `switch', and `while'. Lesser General Public License This document describes the terms under which binary library @@ -30748,14 +29589,14 @@ Localization Logical Expression An expression using the operators for logic, AND, OR, and NOT, - written '&&', '||', and '!' in 'awk'. Often called Boolean + written `&&', `||', and `!' in `awk'. Often called Boolean expressions, after the mathematician who pioneered this kind of mathematical logic. Lvalue An expression that can appear on the left side of an assignment operator. In most languages, lvalues can be variables or array - elements. In 'awk', a field designator can also be used as an + elements. In `awk', a field designator can also be used as an lvalue. Matching @@ -30773,42 +29614,42 @@ No-op Null String A string with no characters in it. It is represented explicitly in - 'awk' programs by placing two double quote characters next to each - other ('""'). It can appear in input data by having two successive + `awk' programs by placing two double quote characters next to each + other (`""'). It can appear in input data by having two successive occurrences of the field separator appear next to each other. Number - A numeric-valued data object. Modern 'awk' implementations use + A numeric-valued data object. Modern `awk' implementations use double precision floating-point to represent numbers. Ancient - 'awk' implementations used single precision floating-point. + `awk' implementations used single precision floating-point. Octal - Base-eight notation, where the digits are '0'-'7'. Octal numbers - are written in C using a leading '0', to indicate their base. - Thus, '013' is 11 ((1 x 8) + 3). *Note Nondecimal-numbers::. + Base-eight notation, where the digits are `0'-`7'. Octal numbers + are written in C using a leading `0', to indicate their base. + Thus, `013' is 11 ((1 x 8) + 3). *Note Nondecimal-numbers::. Pattern - Patterns tell 'awk' which input records are interesting to which + Patterns tell `awk' which input records are interesting to which rules. A pattern is an arbitrary conditional expression against which input is tested. If the condition is satisfied, the pattern is said to "match" the input record. A typical pattern might compare - the input record against a regular expression. (*Note Pattern + the input record against a regular expression. (*Note Pattern Overview::.) PEBKAC An acronym describing what is possibly the most frequent source of - computer usage problems. (Problem Exists Between Keyboard And + computer usage problems. (Problem Exists Between Keyboard And Chair.) POSIX The name for a series of standards that specify a Portable Operating System interface. The "IX" denotes the Unix heritage of - these standards. The main standard of interest for 'awk' users is - 'IEEE Standard for Information Technology, Standard 1003.1-2008'. + these standards. The main standard of interest for `awk' users is + `IEEE Standard for Information Technology, Standard 1003.1-2008'. The 2008 POSIX standard can be found online at - . + `http://www.opengroup.org/onlinepubs/9699919799/'. Precedence The order in which operations are performed when operators are used @@ -30816,14 +29657,14 @@ Precedence Private Variables and/or functions that are meant for use exclusively by - library functions and not for the main 'awk' program. Special care + library functions and not for the main `awk' program. Special care must be taken when naming such variables and functions. (*Note Library Names::.) Range (of input lines) A sequence of consecutive lines from the input file(s). A pattern - can specify ranges of input lines for 'awk' to process or it can - specify single lines. (*Note Pattern Overview::.) + can specify ranges of input lines for `awk' to process or it can + specify single lines. (*Note Pattern Overview::.) Recursion When a function calls itself, either directly or indirectly. If @@ -30832,43 +29673,43 @@ Recursion Redirection Redirection means performing input from something other than the - standard input stream, or performing output to something other than - the standard output stream. + standard input stream, or performing output to something other + than the standard output stream. - You can redirect input to the 'getline' statement using the '<', - '|', and '|&' operators. You can redirect the output of the - 'print' and 'printf' statements to a file or a system command, - using the '>', '>>', '|', and '|&' operators. (*Note Getline::, + You can redirect input to the `getline' statement using the `<', + `|', and `|&' operators. You can redirect the output of the + `print' and `printf' statements to a file or a system command, + using the `>', `>>', `|', and `|&' operators. (*Note Getline::, and *note Redirection::.) Regexp See "Regular Expression." Regular Expression - A regular expression ("regexp" for short) is a pattern that denotes - a set of strings, possibly an infinite set. For example, the - regular expression 'R.*xp' matches any string starting with the - letter 'R' and ending with the letters 'xp'. In 'awk', regular - expressions are used in patterns and in conditional expressions. - Regular expressions may contain escape sequences. (*Note - Regexp::.) + A regular expression ("regexp" for short) is a pattern that + denotes a set of strings, possibly an infinite set. For example, + the regular expression `R.*xp' matches any string starting with + the letter `R' and ending with the letters `xp'. In `awk', + regular expressions are used in patterns and in conditional + expressions. Regular expressions may contain escape sequences. + (*Note Regexp::.) Regular Expression Constant A regular expression constant is a regular expression written - within slashes, such as '/foo/'. This regular expression is chosen - when you write the 'awk' program and cannot be changed during its - execution. (*Note Regexp Usage::.) + within slashes, such as `/foo/'. This regular expression is chosen + when you write the `awk' program and cannot be changed during its + execution. (*Note Regexp Usage::.) Rule - A segment of an 'awk' program that specifies how to process single + A segment of an `awk' program that specifies how to process single input records. A rule consists of a "pattern" and an "action". - 'awk' reads an input record; then, for each rule, if the input - record satisfies the rule's pattern, 'awk' executes the rule's + `awk' reads an input record; then, for each rule, if the input + record satisfies the rule's pattern, `awk' executes the rule's action. Otherwise, the rule does nothing for that input record. Rvalue A value that can appear on the right side of an assignment - operator. In 'awk', essentially every expression has a value. + operator. In `awk', essentially every expression has a value. These values are rvalues. Scalar @@ -30876,15 +29717,15 @@ Scalar scalars; arrays and functions are not. Search Path - In 'gawk', a list of directories to search for 'awk' program source - files. In the shell, a list of directories to search for + In `gawk', a list of directories to search for `awk' program + source files. In the shell, a list of directories to search for executable programs. Seed The initial value, or starting point, for a sequence of random numbers. -'sed' +`sed' See "Stream Editor." Shell @@ -30893,7 +29734,7 @@ Shell batch files, or shell scripts. Short-Circuit - The nature of the 'awk' logical operators '&&' and '||'. If the + The nature of the `awk' logical operators `&&' and `||'. If the value of the entire expression is determinable from evaluating just the lefthand side of these operators, the righthand side is not evaluated. (*Note Boolean Ops::.) @@ -30906,19 +29747,19 @@ Side Effect Single Precision An internal representation of numbers that can have fractional - parts. Single precision numbers keep track of fewer digits than do - double precision numbers, but operations on them are sometimes less - expensive in terms of CPU time. This is the type used by some - ancient versions of 'awk' to store numeric values. It is the C - type 'float'. + parts. Single precision numbers keep track of fewer digits than + do double precision numbers, but operations on them are sometimes + less expensive in terms of CPU time. This is the type used by + some ancient versions of `awk' to store numeric values. It is the + C type `float'. Space The character generated by hitting the space bar on the keyboard. Special File - A file name interpreted internally by 'gawk', instead of being + A file name interpreted internally by `gawk', instead of being handed directly to the underlying operating system--for example, - '/dev/stderr'. (*Note Special Files::.) + `/dev/stderr'. (*Note Special Files::.) Stream Editor A program that reads records from an input stream and processes @@ -30928,13 +29769,13 @@ Stream Editor programs which require input from the user. String - A datum consisting of a sequence of characters, such as 'I am a + A datum consisting of a sequence of characters, such as `I am a string'. Constant strings are written with double quotes in the - 'awk' language and may contain escape sequences. (*Note Escape + `awk' language and may contain escape sequences. (*Note Escape Sequences::.) Tab - The character generated by hitting the 'TAB' key on the keyboard. + The character generated by hitting the `TAB' key on the keyboard. It usually expands to up to eight spaces upon output. Text Domain @@ -30943,15 +29784,15 @@ Text Domain Timestamp A value in the "seconds since the epoch" format used by Unix and - POSIX systems. Used for the 'gawk' functions 'mktime()', - 'strftime()', and 'systime()'. See also "Epoch," "GMT," and "UTC." + POSIX systems. Used for the `gawk' functions `mktime()', + `strftime()', and `systime()'. See also "Epoch," "GMT," and "UTC." Unix A computer operating system originally developed in the early 1970's at AT&T Bell Laboratories. It initially became popular in universities around the world and later moved into commercial environments as a software development system and network server - system. There are many commercial versions of Unix, as well as + system. There are many commercial versions of Unix, as well as several work-alike systems whose source code is freely available (such as GNU/Linux, NetBSD (http://www.netbsd.org), FreeBSD (http://www.freebsd.org), and OpenBSD (http://www.openbsd.org)). @@ -30959,12 +29800,12 @@ Unix UTC The accepted abbreviation for "Universal Coordinated Time." This is standard time in Greenwich, England, which is used as a - reference time for day and date calculations. See also "Epoch" and - "GMT." + reference time for day and date calculations. See also "Epoch" + and "GMT." Whitespace - A sequence of space, TAB, or newline characters occurring inside an - input record or a string. + A sequence of space, TAB, or newline characters occurring inside + an input record or a string.  File: gawk.info, Node: Copying, Next: GNU Free Documentation License, Prev: Glossary, Up: Top @@ -30973,8 +29814,7 @@ GNU General Public License ************************** Version 3, 29 June 2007 - - Copyright (C) 2007 Free Software Foundation, Inc. + Copyright (C) 2007 Free Software Foundation, Inc. `http://fsf.org/' Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. @@ -30988,11 +29828,11 @@ and other kinds of works. The licenses for most software and other practical works are designed to take away your freedom to share and change the works. By contrast, the GNU General Public License is intended to guarantee your freedom to -share and change all versions of a program--to make sure it remains free -software for all its users. We, the Free Software Foundation, use the -GNU General Public License for most of our software; it applies also to -any other work released this way by its authors. You can apply it to -your programs, too. +share and change all versions of a program--to make sure it remains +free software for all its users. We, the Free Software Foundation, use +the GNU General Public License for most of our software; it applies +also to any other work released this way by its authors. You can apply +it to your programs, too. When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you @@ -31002,9 +29842,9 @@ want it, that you can change the software or use pieces of it in new free programs, and that you know you can do these things. To protect your rights, we need to prevent others from denying you -these rights or asking you to surrender the rights. Therefore, you have -certain responsibilities if you distribute copies of the software, or if -you modify it: responsibilities to respect the freedom of others. +these rights or asking you to surrender the rights. Therefore, you +have certain responsibilities if you distribute copies of the software, +or if you modify it: responsibilities to respect the freedom of others. For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same @@ -31023,15 +29863,16 @@ changed, so that their problems will not be attributed erroneously to authors of previous versions. Some devices are designed to deny users access to install or run -modified versions of the software inside them, although the manufacturer -can do so. This is fundamentally incompatible with the aim of -protecting users' freedom to change the software. The systematic -pattern of such abuse occurs in the area of products for individuals to -use, which is precisely where it is most unacceptable. Therefore, we -have designed this version of the GPL to prohibit the practice for those -products. If such problems arise substantially in other domains, we -stand ready to extend this provision to those domains in future versions -of the GPL, as needed to protect the freedom of users. +modified versions of the software inside them, although the +manufacturer can do so. This is fundamentally incompatible with the +aim of protecting users' freedom to change the software. The +systematic pattern of such abuse occurs in the area of products for +individuals to use, which is precisely where it is most unacceptable. +Therefore, we have designed this version of the GPL to prohibit the +practice for those products. If such problems arise substantially in +other domains, we stand ready to extend this provision to those domains +in future versions of the GPL, as needed to protect the freedom of +users. Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and use of @@ -31068,8 +29909,8 @@ TERMS AND CONDITIONS To "propagate" a work means to do anything with it that, without permission, would make you directly or secondarily liable for - infringement under applicable copyright law, except executing it on - a computer or modifying a private copy. Propagation includes + infringement under applicable copyright law, except executing it + on a computer or modifying a private copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as well. @@ -31083,8 +29924,8 @@ TERMS AND CONDITIONS to the extent that it includes a convenient and prominently visible feature that (1) displays an appropriate copyright notice, and (2) tells the user that there is no warranty for the work (except to - the extent that warranties are provided), that licensees may convey - the work under this License, and how to view a copy of this + the extent that warranties are provided), that licensees may + convey the work under this License, and how to view a copy of this License. If the interface presents a list of user commands or options, such as a menu, a prominent item in the list meets this criterion. @@ -31092,8 +29933,8 @@ TERMS AND CONDITIONS 1. Source Code. The "source code" for a work means the preferred form of the work - for making modifications to it. "Object code" means any non-source - form of a work. + for making modifications to it. "Object code" means any + non-source form of a work. A "Standard Interface" means an interface that either is an official standard defined by a recognized standards body, or, in @@ -31104,10 +29945,10 @@ TERMS AND CONDITIONS The "System Libraries" of an executable work include anything, other than the work as a whole, that (a) is included in the normal form of packaging a Major Component, but which is not part of that - Major Component, and (b) serves only to enable use of the work with - that Major Component, or to implement a Standard Interface for - which an implementation is available to the public in source code - form. A "Major Component", in this context, means a major + Major Component, and (b) serves only to enable use of the work + with that Major Component, or to implement a Standard Interface + for which an implementation is available to the public in source + code form. A "Major Component", in this context, means a major essential component (kernel, window system, and so on) of the specific operating system (if any) on which the executable work runs, or a compiler used to produce the work, or an object code @@ -31115,15 +29956,15 @@ TERMS AND CONDITIONS The "Corresponding Source" for a work in object code form means all the source code needed to generate, install, and (for an executable - work) run the object code and to modify the work, including scripts - to control those activities. However, it does not include the - work's System Libraries, or general-purpose tools or generally + work) run the object code and to modify the work, including + scripts to control those activities. However, it does not include + the work's System Libraries, or general-purpose tools or generally available free programs which are used unmodified in performing those activities but which are not part of the work. For example, - Corresponding Source includes interface definition files associated - with source files for the work, and the source code for shared - libraries and dynamically linked subprograms that the work is - specifically designed to require, such as by intimate data + Corresponding Source includes interface definition files + associated with source files for the work, and the source code for + shared libraries and dynamically linked subprograms that the work + is specifically designed to require, such as by intimate data communication or control flow between those subprograms and other parts of the work. @@ -31140,22 +29981,22 @@ TERMS AND CONDITIONS copyright on the Program, and are irrevocable provided the stated conditions are met. This License explicitly affirms your unlimited permission to run the unmodified Program. The output from running - a covered work is covered by this License only if the output, given - its content, constitutes a covered work. This License acknowledges - your rights of fair use or other equivalent, as provided by - copyright law. + a covered work is covered by this License only if the output, + given its content, constitutes a covered work. This License + acknowledges your rights of fair use or other equivalent, as + provided by copyright law. You may make, run and propagate covered works that you do not convey, without conditions so long as your license otherwise remains in force. You may convey covered works to others for the - sole purpose of having them make modifications exclusively for you, - or provide you with facilities for running those works, provided - that you comply with the terms of this License in conveying all - material for which you do not control copyright. Those thus making - or running the covered works for you must do so exclusively on your - behalf, under your direction and control, on terms that prohibit - them from making any copies of your copyrighted material outside - their relationship with you. + sole purpose of having them make modifications exclusively for + you, or provide you with facilities for running those works, + provided that you comply with the terms of this License in + conveying all material for which you do not control copyright. + Those thus making or running the covered works for you must do so + exclusively on your behalf, under your direction and control, on + terms that prohibit them from making any copies of your + copyrighted material outside their relationship with you. Conveying under any other circumstances is permitted solely under the conditions stated below. Sublicensing is not allowed; section @@ -31172,8 +30013,8 @@ TERMS AND CONDITIONS When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License - with respect to the covered work, and you disclaim any intention to - limit operation or modification of the work as a means of + with respect to the covered work, and you disclaim any intention + to limit operation or modification of the work as a means of enforcing, against the work's users, your or third parties' legal rights to forbid circumvention of technological measures. @@ -31243,8 +30084,8 @@ TERMS AND CONDITIONS b. Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by a - written offer, valid for at least three years and valid for as - long as you offer spare parts or customer support for that + written offer, valid for at least three years and valid for + as long as you offer spare parts or customer support for that product model, to give anyone who possesses the object code either (1) a copy of the Corresponding Source for all the software in the product that is covered by this License, on a @@ -31254,31 +30095,32 @@ TERMS AND CONDITIONS to copy the Corresponding Source from a network server at no charge. - c. Convey individual copies of the object code with a copy of the - written offer to provide the Corresponding Source. This + c. Convey individual copies of the object code with a copy of + the written offer to provide the Corresponding Source. This alternative is allowed only occasionally and noncommercially, and only if you received the object code with such an offer, in accord with subsection 6b. d. Convey the object code by offering access from a designated - place (gratis or for a charge), and offer equivalent access to - the Corresponding Source in the same way through the same + place (gratis or for a charge), and offer equivalent access + to the Corresponding Source in the same way through the same place at no further charge. You need not require recipients to copy the Corresponding Source along with the object code. If the place to copy the object code is a network server, the - Corresponding Source may be on a different server (operated by - you or a third party) that supports equivalent copying - facilities, provided you maintain clear directions next to the - object code saying where to find the Corresponding Source. + Corresponding Source may be on a different server (operated + by you or a third party) that supports equivalent copying + facilities, provided you maintain clear directions next to + the object code saying where to find the Corresponding Source. Regardless of what server hosts the Corresponding Source, you - remain obligated to ensure that it is available for as long as - needed to satisfy these requirements. + remain obligated to ensure that it is available for as long + as needed to satisfy these requirements. e. Convey the object code using peer-to-peer transmission, provided you inform other peers where the object code and Corresponding Source of the work are being offered to the general public at no charge under subsection 6d. + A separable portion of the object code, whose source code is excluded from the Corresponding Source as a System Library, need not be included in conveying the object code work. @@ -31286,8 +30128,8 @@ TERMS AND CONDITIONS A "User Product" is either (1) a "consumer product", which means any tangible personal property which is normally used for personal, family, or household purposes, or (2) anything designed or sold for - incorporation into a dwelling. In determining whether a product is - a consumer product, doubtful cases shall be resolved in favor of + incorporation into a dwelling. In determining whether a product + is a consumer product, doubtful cases shall be resolved in favor of coverage. For a particular product received by a particular user, "normally used" refers to a typical or common use of that class of product, regardless of the status of the particular user or of the @@ -31318,11 +30160,11 @@ TERMS AND CONDITIONS The requirement to provide Installation Information does not include a requirement to continue to provide support service, - warranty, or updates for a work that has been modified or installed - by the recipient, or for the User Product in which it has been - modified or installed. Access to a network may be denied when the - modification itself materially and adversely affects the operation - of the network or violates the rules and protocols for + warranty, or updates for a work that has been modified or + installed by the recipient, or for the User Product in which it + has been modified or installed. Access to a network may be denied + when the modification itself materially and adversely affects the + operation of the network or violates the rules and protocols for communication across the network. Corresponding Source conveyed, and Installation Information @@ -31352,8 +30194,8 @@ TERMS AND CONDITIONS Notwithstanding any other provision of this License, for material you add to a covered work, you may (if authorized by the copyright - holders of that material) supplement the terms of this License with - terms: + holders of that material) supplement the terms of this License + with terms: a. Disclaiming warranty or limiting liability differently from the terms of sections 15 and 16 of this License; or @@ -31363,8 +30205,9 @@ TERMS AND CONDITIONS Legal Notices displayed by works containing it; or c. Prohibiting misrepresentation of the origin of that material, - or requiring that modified versions of such material be marked - in reasonable ways as different from the original version; or + or requiring that modified versions of such material be + marked in reasonable ways as different from the original + version; or d. Limiting the use for publicity purposes of names of licensors or authors of the material; or @@ -31383,10 +30226,11 @@ TERMS AND CONDITIONS you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term. If a license document - contains a further restriction but permits relicensing or conveying - under this License, you may add to a covered work material governed - by the terms of that license document, provided that the further - restriction does not survive such relicensing or conveying. + contains a further restriction but permits relicensing or + conveying under this License, you may add to a covered work + material governed by the terms of that license document, provided + that the further restriction does not survive such relicensing or + conveying. If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the @@ -31402,13 +30246,13 @@ TERMS AND CONDITIONS You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights - under this License (including any patent licenses granted under the - third paragraph of section 11). + under this License (including any patent licenses granted under + the third paragraph of section 11). However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) - provisionally, unless and until the copyright holder explicitly and - finally terminates your license, and (b) permanently, if the + provisionally, unless and until the copyright holder explicitly + and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. @@ -31420,10 +30264,10 @@ TERMS AND CONDITIONS after your receipt of the notice. Termination of your rights under this section does not terminate - the licenses of parties who have received copies or rights from you - under this License. If your rights have been terminated and not - permanently reinstated, you do not qualify to receive new licenses - for the same material under section 10. + the licenses of parties who have received copies or rights from + you under this License. If your rights have been terminated and + not permanently reinstated, you do not qualify to receive new + licenses for the same material under section 10. 9. Acceptance Not Required for Having Copies. @@ -31437,7 +30281,7 @@ TERMS AND CONDITIONS by modifying or propagating a covered work, you indicate your acceptance of this License to do so. - 10. Automatic Licensing of Downstream Recipients. + 10. Automatic Licensing of Downstream Recipients. Each time you convey a covered work, the recipient automatically receives a license from the original licensors, to run, modify and @@ -31451,21 +30295,21 @@ TERMS AND CONDITIONS covered work results from an entity transaction, each party to that transaction who receives a copy of the work also receives whatever licenses to the work the party's predecessor in interest had or - could give under the previous paragraph, plus a right to possession - of the Corresponding Source of the work from the predecessor in - interest, if the predecessor has it or can get it with reasonable - efforts. + could give under the previous paragraph, plus a right to + possession of the Corresponding Source of the work from the + predecessor in interest, if the predecessor has it or can get it + with reasonable efforts. You may not impose any further restrictions on the exercise of the rights granted or affirmed under this License. For example, you - may not impose a license fee, royalty, or other charge for exercise - of rights granted under this License, and you may not initiate - litigation (including a cross-claim or counterclaim in a lawsuit) - alleging that any patent claim is infringed by making, using, - selling, offering for sale, or importing the Program or any portion - of it. + may not impose a license fee, royalty, or other charge for + exercise of rights granted under this License, and you may not + initiate litigation (including a cross-claim or counterclaim in a + lawsuit) alleging that any patent claim is infringed by making, + using, selling, offering for sale, or importing the Program or any + portion of it. - 11. Patents. + 11. Patents. A "contributor" is a copyright holder who authorizes use under this License of the Program or a work on which the Program is based. @@ -31485,15 +30329,15 @@ TERMS AND CONDITIONS Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and - otherwise run, modify and propagate the contents of its contributor - version. + otherwise run, modify and propagate the contents of its + contributor version. In the following three paragraphs, a "patent license" is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a - patent or covenant not to sue for patent infringement). To "grant" - such a patent license to a party means to make such an agreement or - commitment not to enforce a patent against the party. + patent or covenant not to sue for patent infringement). To + "grant" such a patent license to a party means to make such an + agreement or commitment not to enforce a patent against the party. If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available @@ -31523,35 +30367,36 @@ TERMS AND CONDITIONS conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third - party that is in the business of distributing software, under which - you make payment to the third party based on the extent of your - activity of conveying the work, and under which the third party - grants, to any of the parties who would receive the covered work - from you, a discriminatory patent license (a) in connection with - copies of the covered work conveyed by you (or copies made from - those copies), or (b) primarily for and in connection with specific - products or compilations that contain the covered work, unless you - entered into that arrangement, or that patent license was granted, - prior to 28 March 2007. + party that is in the business of distributing software, under + which you make payment to the third party based on the extent of + your activity of conveying the work, and under which the third + party grants, to any of the parties who would receive the covered + work from you, a discriminatory patent license (a) in connection + with copies of the covered work conveyed by you (or copies made + from those copies), or (b) primarily for and in connection with + specific products or compilations that contain the covered work, + unless you entered into that arrangement, or that patent license + was granted, prior to 28 March 2007. Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law. - 12. No Surrender of Others' Freedom. + 12. No Surrender of Others' Freedom. - If conditions are imposed on you (whether by court order, agreement - or otherwise) that contradict the conditions of this License, they - do not excuse you from the conditions of this License. If you - cannot convey a covered work so as to satisfy simultaneously your - obligations under this License and any other pertinent obligations, - then as a consequence you may not convey it at all. For example, - if you agree to terms that obligate you to collect a royalty for - further conveying from those to whom you convey the Program, the - only way you could satisfy both those terms and this License would - be to refrain entirely from conveying the Program. + If conditions are imposed on you (whether by court order, + agreement or otherwise) that contradict the conditions of this + License, they do not excuse you from the conditions of this + License. If you cannot convey a covered work so as to satisfy + simultaneously your obligations under this License and any other + pertinent obligations, then as a consequence you may not convey it + at all. For example, if you agree to terms that obligate you to + collect a royalty for further conveying from those to whom you + convey the Program, the only way you could satisfy both those + terms and this License would be to refrain entirely from conveying + the Program. - 13. Use with the GNU Affero General Public License. + 13. Use with the GNU Affero General Public License. Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed @@ -31562,21 +30407,22 @@ TERMS AND CONDITIONS General Public License, section 13, concerning interaction through a network will apply to the combination as such. - 14. Revised Versions of this License. + 14. Revised Versions of this License. The Free Software Foundation may publish revised and/or new - versions of the GNU General Public License from time to time. Such - new versions will be similar in spirit to the present version, but - may differ in detail to address new problems or concerns. + versions of the GNU General Public License from time to time. + Such new versions will be similar in spirit to the present + version, but may differ in detail to address new problems or + concerns. Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License "or any later version" applies to it, you have the option of following the terms and conditions either of - that numbered version or of any later version published by the Free - Software Foundation. If the Program does not specify a version - number of the GNU General Public License, you may choose any - version ever published by the Free Software Foundation. + that numbered version or of any later version published by the + Free Software Foundation. If the Program does not specify a + version number of the GNU General Public License, you may choose + any version ever published by the Free Software Foundation. If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that @@ -31588,24 +30434,24 @@ TERMS AND CONDITIONS author or copyright holder as a result of your choosing to follow a later version. - 15. Disclaimer of Warranty. + 15. Disclaimer of Warranty. THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY - APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE + APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF - MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE + MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. - 16. Limitation of Liability. + 16. Limitation of Liability. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES - AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR - DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR + AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU + FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD @@ -31613,7 +30459,7 @@ TERMS AND CONDITIONS PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. - 17. Interpretation of Sections 15 and 16. + 17. Interpretation of Sections 15 and 16. If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, @@ -31622,6 +30468,7 @@ TERMS AND CONDITIONS connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee. + END OF TERMS AND CONDITIONS =========================== @@ -31652,7 +30499,7 @@ state the exclusion of warranty; and each file should have at least the General Public License for more details. You should have received a copy of the GNU General Public License - along with this program. If not, see . + along with this program. If not, see `http://www.gnu.org/licenses/'. Also add information on how to contact you by electronic and paper mail. @@ -31661,11 +30508,11 @@ mail. notice like this when it starts in an interactive mode: PROGRAM Copyright (C) YEAR NAME OF AUTHOR - This program comes with ABSOLUTELY NO WARRANTY; for details type 'show w'. + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it - under certain conditions; type 'show c' for details. + under certain conditions; type `show c' for details. - The hypothetical commands 'show w' and 'show c' should show the + The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an "about box". @@ -31673,14 +30520,14 @@ use an "about box". You should also get your employer (if you work as a programmer) or school, if any, to sign a "copyright disclaimer" for the program, if necessary. For more information on this, and how to apply and follow -the GNU GPL, see . +the GNU GPL, see `http://www.gnu.org/licenses/'. The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, -please read . +please read `http://www.gnu.org/philosophy/why-not-lgpl.html'.  File: gawk.info, Node: GNU Free Documentation License, Next: Index, Prev: Copying, Up: Top @@ -31689,9 +30536,8 @@ GNU Free Documentation License ****************************** Version 1.3, 3 November 2008 - Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. - + `http://fsf.org/' Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. @@ -31716,21 +30562,21 @@ GNU Free Documentation License free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless - of subject matter or whether it is published as a printed book. We - recommend this License principally for works whose purpose is + of subject matter or whether it is published as a printed book. + We recommend this License principally for works whose purpose is instruction or reference. 1. APPLICABILITY AND DEFINITIONS This License applies to any manual or other work, in any medium, - that contains a notice placed by the copyright holder saying it can - be distributed under the terms of this License. Such a notice + that contains a notice placed by the copyright holder saying it + can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The "Document", below, refers to any such manual or work. Any member - of the public is a licensee, and is addressed as "you". You accept - the license if you copy, modify or distribute the work in a way - requiring permission under copyright law. + of the public is a licensee, and is addressed as "you". You + accept the license if you copy, modify or distribute the work in a + way requiring permission under copyright law. A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with @@ -31748,12 +30594,12 @@ GNU Free Documentation License regarding them. The "Invariant Sections" are certain Secondary Sections whose - titles are designated, as being those of Invariant Sections, in the - notice that says that the Document is released under this License. - If a section does not fit the above definition of Secondary then it - is not allowed to be designated as Invariant. The Document may - contain zero Invariant Sections. If the Document does not identify - any Invariant Sections then there are none. + titles are designated, as being those of Invariant Sections, in + the notice that says that the Document is released under this + License. If a section does not fit the above definition of + Secondary then it is not allowed to be designated as Invariant. + The Document may contain zero Invariant Sections. If the Document + does not identify any Invariant Sections then there are none. The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice @@ -31764,27 +30610,27 @@ GNU Free Documentation License A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document - straightforwardly with generic text editors or (for images composed - of pixels) generic paint programs or (for drawings) some widely - available drawing editor, and that is suitable for input to text - formatters or for automatic translation to a variety of formats - suitable for input to text formatters. A copy made in an otherwise - Transparent file format whose markup, or absence of markup, has - been arranged to thwart or discourage subsequent modification by - readers is not Transparent. An image format is not Transparent if - used for any substantial amount of text. A copy that is not - "Transparent" is called "Opaque". + straightforwardly with generic text editors or (for images + composed of pixels) generic paint programs or (for drawings) some + widely available drawing editor, and that is suitable for input to + text formatters or for automatic translation to a variety of + formats suitable for input to text formatters. A copy made in an + otherwise Transparent file format whose markup, or absence of + markup, has been arranged to thwart or discourage subsequent + modification by readers is not Transparent. An image format is + not Transparent if used for any substantial amount of text. A + copy that is not "Transparent" is called "Opaque". Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, - SGML or XML using a publicly available DTD, and standard-conforming - simple HTML, PostScript or PDF designed for human modification. - Examples of transparent image formats include PNG, XCF and JPG. - Opaque formats include proprietary formats that can be read and - edited only by proprietary word processors, SGML or XML for which - the DTD and/or processing tools are not generally available, and - the machine-generated HTML, PostScript or PDF produced by some word - processors for output purposes only. + SGML or XML using a publicly available DTD, and + standard-conforming simple HTML, PostScript or PDF designed for + human modification. Examples of transparent image formats include + PNG, XCF and JPG. Opaque formats include proprietary formats that + can be read and edited only by proprietary word processors, SGML or + XML for which the DTD and/or processing tools are not generally + available, and the machine-generated HTML, PostScript or PDF + produced by some word processors for output purposes only. The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the @@ -31822,8 +30668,8 @@ GNU Free Documentation License may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you - distribute a large enough number of copies you must also follow the - conditions in section 3. + distribute a large enough number of copies you must also follow + the conditions in section 3. You may also lend copies, under the same conditions stated above, and you may publicly display copies. @@ -31837,11 +30683,12 @@ GNU Free Documentation License these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The - front cover must present the full title with all words of the title - equally prominent and visible. You may add other material on the - covers in addition. Copying with changes limited to the covers, as - long as they preserve the title of the Document and satisfy these - conditions, can be treated as verbatim copying in other respects. + front cover must present the full title with all words of the + title equally prominent and visible. You may add other material + on the covers in addition. Copying with changes limited to the + covers, as long as they preserve the title of the Document and + satisfy these conditions, can be treated as verbatim copying in + other respects. If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit @@ -31849,39 +30696,40 @@ GNU Free Documentation License adjacent pages. If you publish or distribute Opaque copies of the Document - numbering more than 100, you must either include a machine-readable - Transparent copy along with each Opaque copy, or state in or with - each Opaque copy a computer-network location from which the general - network-using public has access to download using public-standard - network protocols a complete Transparent copy of the Document, free - of added material. If you use the latter option, you must take - reasonably prudent steps, when you begin distribution of Opaque - copies in quantity, to ensure that this Transparent copy will - remain thus accessible at the stated location until at least one - year after the last time you distribute an Opaque copy (directly or - through your agents or retailers) of that edition to the public. + numbering more than 100, you must either include a + machine-readable Transparent copy along with each Opaque copy, or + state in or with each Opaque copy a computer-network location from + which the general network-using public has access to download + using public-standard network protocols a complete Transparent + copy of the Document, free of added material. If you use the + latter option, you must take reasonably prudent steps, when you + begin distribution of Opaque copies in quantity, to ensure that + this Transparent copy will remain thus accessible at the stated + location until at least one year after the last time you + distribute an Opaque copy (directly or through your agents or + retailers) of that edition to the public. It is requested, but not required, that you contact the authors of - the Document well before redistributing any large number of copies, - to give them a chance to provide you with an updated version of the - Document. + the Document well before redistributing any large number of + copies, to give them a chance to provide you with an updated + version of the Document. 4. MODIFICATIONS You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you - release the Modified Version under precisely this License, with the - Modified Version filling the role of the Document, thus licensing - distribution and modification of the Modified Version to whoever - possesses a copy of it. In addition, you must do these things in - the Modified Version: + release the Modified Version under precisely this License, with + the Modified Version filling the role of the Document, thus + licensing distribution and modification of the Modified Version to + whoever possesses a copy of it. In addition, you must do these + things in the Modified Version: A. Use in the Title Page (and on the covers, if any) a title - distinct from that of the Document, and from those of previous - versions (which should, if there were any, be listed in the - History section of the Document). You may use the same title - as a previous version if the original publisher of that - version gives permission. + distinct from that of the Document, and from those of + previous versions (which should, if there were any, be listed + in the History section of the Document). You may use the + same title as a previous version if the original publisher of + that version gives permission. B. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in @@ -31911,30 +30759,31 @@ GNU Free Documentation License I. Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new - authors, and publisher of the Modified Version as given on the - Title Page. If there is no section Entitled "History" in the - Document, create one stating the title, year, authors, and - publisher of the Document as given on its Title Page, then add - an item describing the Modified Version as stated in the - previous sentence. + authors, and publisher of the Modified Version as given on + the Title Page. If there is no section Entitled "History" in + the Document, create one stating the title, year, authors, + and publisher of the Document as given on its Title Page, + then add an item describing the Modified Version as stated in + the previous sentence. J. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for - previous versions it was based on. These may be placed in the - "History" section. You may omit a network location for a work - that was published at least four years before the Document - itself, or if the original publisher of the version it refers - to gives permission. + previous versions it was based on. These may be placed in + the "History" section. You may omit a network location for a + work that was published at least four years before the + Document itself, or if the original publisher of the version + it refers to gives permission. K. For any section Entitled "Acknowledgements" or "Dedications", - Preserve the Title of the section, and preserve in the section - all the substance and tone of each of the contributor + Preserve the Title of the section, and preserve in the + section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein. - L. Preserve all the Invariant Sections of the Document, unaltered - in their text and in their titles. Section numbers or the - equivalent are not considered part of the section titles. + L. Preserve all the Invariant Sections of the Document, + unaltered in their text and in their titles. Section numbers + or the equivalent are not considered part of the section + titles. M. Delete any section Entitled "Endorsements". Such a section may not be included in the Modified Version. @@ -31947,11 +30796,11 @@ GNU Free Documentation License If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no - material copied from the Document, you may at your option designate - some or all of these sections as invariant. To do this, add their - titles to the list of Invariant Sections in the Modified Version's - license notice. These titles must be distinct from any other - section titles. + material copied from the Document, you may at your option + designate some or all of these sections as invariant. To do this, + add their titles to the list of Invariant Sections in the Modified + Version's license notice. These titles must be distinct from any + other section titles. You may add a section Entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various @@ -31960,15 +30809,15 @@ GNU Free Documentation License definition of a standard. You may add a passage of up to five words as a Front-Cover Text, - and a passage of up to 25 words as a Back-Cover Text, to the end of - the list of Cover Texts in the Modified Version. Only one passage - of Front-Cover Text and one of Back-Cover Text may be added by (or - through arrangements made by) any one entity. If the Document - already includes a cover text for the same cover, previously added - by you or by arrangement made by the same entity you are acting on - behalf of, you may not add another; but you may replace the old - one, on explicit permission from the previous publisher that added - the old one. + and a passage of up to 25 words as a Back-Cover Text, to the end + of the list of Cover Texts in the Modified Version. Only one + passage of Front-Cover Text and one of Back-Cover Text may be + added by (or through arrangements made by) any one entity. If the + Document already includes a cover text for the same cover, + previously added by you or by arrangement made by the same entity + you are acting on behalf of, you may not add another; but you may + replace the old one, on explicit permission from the previous + publisher that added the old one. The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to @@ -31978,8 +30827,8 @@ GNU Free Documentation License You may combine the Document with other documents released under this License, under the terms defined in section 4 above for - modified versions, provided that you include in the combination all - of the Invariant Sections of all of the original documents, + modified versions, provided that you include in the combination + all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers. @@ -32006,20 +30855,20 @@ GNU Free Documentation License documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the - rules of this License for verbatim copying of each of the documents - in all other respects. + rules of this License for verbatim copying of each of the + documents in all other respects. You may extract a single document from such a collection, and distribute it individually under this License, provided you insert - a copy of this License into the extracted document, and follow this - License in all other respects regarding verbatim copying of that - document. + a copy of this License into the extracted document, and follow + this License in all other respects regarding verbatim copying of + that document. 7. AGGREGATION WITH INDEPENDENT WORKS A compilation of the Document or its derivatives with other - separate and independent documents or works, in or on a volume of a - storage or distribution medium, is called an "aggregate" if the + separate and independent documents or works, in or on a volume of + a storage or distribution medium, is called an "aggregate" if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this @@ -32064,8 +30913,8 @@ GNU Free Documentation License However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) - provisionally, unless and until the copyright holder explicitly and - finally terminates your license, and (b) permanently, if the + provisionally, unless and until the copyright holder explicitly + and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. @@ -32077,33 +30926,33 @@ GNU Free Documentation License after your receipt of the notice. Termination of your rights under this section does not terminate - the licenses of parties who have received copies or rights from you - under this License. If your rights have been terminated and not - permanently reinstated, receipt of a copy of some or all of the - same material does not give you any rights to use it. + the licenses of parties who have received copies or rights from + you under this License. If your rights have been terminated and + not permanently reinstated, receipt of a copy of some or all of + the same material does not give you any rights to use it. - 10. FUTURE REVISIONS OF THIS LICENSE + 10. FUTURE REVISIONS OF THIS LICENSE The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See - . + `http://www.gnu.org/copyleft/'. Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been - published (not as a draft) by the Free Software Foundation. If the - Document does not specify a version number of this License, you may - choose any version ever published (not as a draft) by the Free - Software Foundation. If the Document specifies that a proxy can - decide which future versions of this License can be used, that + published (not as a draft) by the Free Software Foundation. If + the Document does not specify a version number of this License, + you may choose any version ever published (not as a draft) by the + Free Software Foundation. If the Document specifies that a proxy + can decide which future versions of this License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Document. - 11. RELICENSING + 11. RELICENSING "Massive Multiauthor Collaboration Site" (or "MMC Site") means any World Wide Web server that publishes copyrightable works and also @@ -32133,6 +30982,7 @@ GNU Free Documentation License site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing. + ADDENDUM: How to use this License for your documents ==================================================== @@ -32149,7 +30999,7 @@ notices just after the title page: Free Documentation License''. If you have Invariant Sections, Front-Cover Texts and Back-Cover -Texts, replace the "with...Texts." line with this: +Texts, replace the "with...Texts." line with this: with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts @@ -32160,9 +31010,9 @@ combination of the three, merge those two alternatives to suit the situation. If your document contains nontrivial examples of program code, we -recommend releasing these examples in parallel under your choice of free -software license, such as the GNU General Public License, to permit -their use in free software. +recommend releasing these examples in parallel under your choice of +free software license, such as the GNU General Public License, to +permit their use in free software.  File: gawk.info, Node: Index, Prev: GNU Free Documentation License, Up: Top @@ -32173,33 +31023,18 @@ Index [index] * Menu: -* '!' (exclamation point), '!' operator: Boolean Ops. (line 67) -* '!' (exclamation point), '!' operator <1>: Precedence. (line 51) -* '!' (exclamation point), '!' operator <2>: Ranges. (line 47) -* '!' (exclamation point), '!' operator <3>: Egrep Program. (line 174) -* '!' (exclamation point), '!=' operator: Comparison Operators. - (line 11) -* '!' (exclamation point), '!=' operator <1>: Precedence. (line 64) -* '!' (exclamation point), '!~' operator: Regexp Usage. (line 19) -* '!' (exclamation point), '!~' operator <1>: Case-sensitivity. - (line 26) -* '!' (exclamation point), '!~' operator <2>: Computed Regexps. - (line 6) -* '!' (exclamation point), '!~' operator <3>: Regexp Constants. - (line 6) -* '!' (exclamation point), '!~' operator <4>: Comparison Operators. +* ! (exclamation point), ! operator: Boolean Ops. (line 67) +* ! (exclamation point), ! operator <1>: Egrep Program. (line 175) +* ! (exclamation point), ! operator <2>: Ranges. (line 48) +* ! (exclamation point), ! operator: Precedence. (line 52) +* ! (exclamation point), != operator <1>: Precedence. (line 65) +* ! (exclamation point), != operator: Comparison Operators. (line 11) -<<<<<<< HEAD -* '!' (exclamation point), '!~' operator <5>: Comparison Operators. - (line 98) -* '!' (exclamation point), '!~' operator <6>: Precedence. (line 79) -* '!' (exclamation point), '!~' operator <7>: Expression Patterns. +* ! (exclamation point), !~ operator <1>: Expression Patterns. (line 24) -* '"' (double quote) in shell commands: Read Terminal. (line 25) -* '"' (double quote), in regexp constants: Computed Regexps. (line 29) -* '"' (double quote), in shell commands: Quoting. (line 54) -* '#' (number sign), '#!' (executable scripts): Executable Scripts. -======= +* ! (exclamation point), !~ operator <2>: Precedence. (line 80) +* ! (exclamation point), !~ operator <3>: Comparison Operators. + (line 11) * ! (exclamation point), !~ operator <4>: Regexp Constants. (line 6) * ! (exclamation point), !~ operator <5>: Case-sensitivity. (line 26) * ! (exclamation point), !~ operator <6>: Computed Regexps. (line 6) @@ -32207,65 +31042,20 @@ Index * " (double quote), in regexp constants: Computed Regexps. (line 29) * " (double quote), in shell commands: Quoting. (line 54) * # (number sign), #! (executable scripts): Executable Scripts. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 6) -* '#' (number sign), commenting: Comments. (line 6) -* '$' (dollar sign), '$' field operator: Fields. (line 19) -* '$' (dollar sign), '$' field operator <1>: Precedence. (line 42) -* '$' (dollar sign), incrementing fields and arrays: Increment Ops. +* # (number sign), commenting: Comments. (line 6) +* $ (dollar sign), $ field operator <1>: Precedence. (line 43) +* $ (dollar sign), $ field operator: Fields. (line 19) +* $ (dollar sign), incrementing fields and arrays: Increment Ops. (line 30) -* '$' (dollar sign), regexp operator: Regexp Operators. (line 35) -* '%' (percent sign), '%' operator: Precedence. (line 54) -* '%' (percent sign), '%=' operator: Assignment Ops. (line 129) -* '%' (percent sign), '%=' operator <1>: Precedence. (line 94) -* '&' (ampersand), '&&' operator: Boolean Ops. (line 57) -* '&' (ampersand), '&&' operator <1>: Precedence. (line 85) -* '&' (ampersand), 'gsub()'/'gensub()'/'sub()' functions and: Gory Details. +* $ (dollar sign), regexp operator: Regexp Operators. (line 35) +* % (percent sign), % operator: Precedence. (line 55) +* % (percent sign), %= operator <1>: Precedence. (line 95) +* % (percent sign), %= operator: Assignment Ops. (line 130) +* & (ampersand), && operator <1>: Precedence. (line 86) +* & (ampersand), && operator: Boolean Ops. (line 57) +* & (ampersand), gsub()/gensub()/sub() functions and: Gory Details. (line 6) -<<<<<<< HEAD -* ''' (single quote): One-shot. (line 15) -* ''' (single quote) in 'gawk' command lines: Long. (line 33) -* ''' (single quote), in shell commands: Quoting. (line 48) -* ''' (single quote), vs. apostrophe: Comments. (line 27) -* ''' (single quote), with double quotes: Quoting. (line 70) -* '()' (parentheses), in a profile: Profiling. (line 146) -* '()' (parentheses), regexp operator: Regexp Operators. (line 80) -* '*' (asterisk), '*' operator, as multiplication operator: Precedence. - (line 54) -* '*' (asterisk), '*' operator, as regexp operator: Regexp Operators. - (line 88) -* '*' (asterisk), '*' operator, null strings, matching: Gory Details. - (line 164) -* '*' (asterisk), '**' operator: Arithmetic Ops. (line 81) -* '*' (asterisk), '**' operator <1>: Precedence. (line 48) -* '*' (asterisk), '**=' operator: Assignment Ops. (line 129) -* '*' (asterisk), '**=' operator <1>: Precedence. (line 94) -* '*' (asterisk), '*=' operator: Assignment Ops. (line 129) -* '*' (asterisk), '*=' operator <1>: Precedence. (line 94) -* '+' (plus sign), '+' operator: Precedence. (line 51) -* '+' (plus sign), '+' operator <1>: Precedence. (line 57) -* '+' (plus sign), '++' operator: Increment Ops. (line 11) -* '+' (plus sign), '++' operator <1>: Increment Ops. (line 40) -* '+' (plus sign), '++' operator <2>: Precedence. (line 45) -* '+' (plus sign), '+=' operator: Assignment Ops. (line 81) -* '+' (plus sign), '+=' operator <1>: Precedence. (line 94) -* '+' (plus sign), regexp operator: Regexp Operators. (line 103) -* ',' (comma), in range patterns: Ranges. (line 6) -* '-' (hyphen), '-' operator: Precedence. (line 51) -* '-' (hyphen), '-' operator <1>: Precedence. (line 57) -* '-' (hyphen), '--' operator: Increment Ops. (line 48) -* '-' (hyphen), '--' operator <1>: Precedence. (line 45) -* '-' (hyphen), '-=' operator: Assignment Ops. (line 129) -* '-' (hyphen), '-=' operator <1>: Precedence. (line 94) -* '-' (hyphen), filenames beginning with: Options. (line 60) -* '-' (hyphen), in bracket expressions: Bracket Expressions. (line 17) -* '--assign' option: Options. (line 32) -* '--bignum' option: Options. (line 203) -* '--characters-as-bytes' option: Options. (line 69) -* '--copyright' option: Options. (line 89) -* '--debug' option: Options. (line 108) -* '--disable-extensions' configuration option: Additional Configuration Options. -======= * ' (single quote): One-shot. (line 15) * ' (single quote) in gawk command lines: Long. (line 33) * ' (single quote), in shell commands: Quoting. (line 48) @@ -32305,67 +31095,49 @@ Index * --copyright option: Options. (line 88) * --debug option: Options. (line 108) * --disable-extensions configuration option: Additional Configuration Options. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 9) -* '--disable-lint' configuration option: Additional Configuration Options. +* --disable-lint configuration option: Additional Configuration Options. (line 15) -* '--disable-nls' configuration option: Additional Configuration Options. +* --disable-nls configuration option: Additional Configuration Options. (line 30) -* '--dump-variables' option: Options. (line 94) -* '--dump-variables' option, using for library functions: Library Names. +* --dump-variables option: Options. (line 93) +* --dump-variables option, using for library functions: Library Names. (line 45) -* '--exec' option: Options. (line 125) -* '--field-separator' option: Options. (line 21) -* '--file' option: Options. (line 25) -* '--gen-pot' option: Options. (line 147) -* '--gen-pot' option <1>: String Extraction. (line 6) -* '--gen-pot' option <2>: String Extraction. (line 6) -* '--help' option: Options. (line 154) -* '--include' option: Options. (line 159) -* '--lint' option: Command Line. (line 20) -* '--lint' option <1>: Options. (line 184) -* '--lint-old' option: Options. (line 290) -* '--load' option: Options. (line 172) -* '--non-decimal-data' option: Options. (line 209) -* '--non-decimal-data' option <1>: Nondecimal Data. (line 6) -* '--non-decimal-data' option, 'strtonum()' function and: Nondecimal Data. +* --exec option: Options. (line 125) +* --field-separator option: Options. (line 21) +* --file option: Options. (line 25) +* --gen-pot option <1>: String Extraction. (line 6) +* --gen-pot option: Options. (line 147) +* --help option: Options. (line 154) +* --include option: Options. (line 159) +* --lint option <1>: Options. (line 185) +* --lint option: Command Line. (line 20) +* --lint-old option: Options. (line 293) +* --load option: Options. (line 173) +* --non-decimal-data option <1>: Nondecimal Data. (line 6) +* --non-decimal-data option: Options. (line 211) +* --non-decimal-data option, strtonum() function and: Nondecimal Data. (line 36) -* '--optimize' option: Options. (line 233) -* '--posix' option: Options. (line 250) -* '--posix' option, '--traditional' option and: Options. (line 268) -* '--pretty-print' option: Options. (line 222) -* '--profile' option: Options. (line 238) -* '--profile' option <1>: Profiling. (line 12) -* '--re-interval' option: Options. (line 274) -* '--sandbox' option: Options. (line 281) -* '--sandbox' option, disabling 'system()' function: I/O Functions. - (line 98) -* '--sandbox' option, input redirection with 'getline': Getline. - (line 19) -* '--sandbox' option, output redirection with 'print', 'printf': Redirection. +* --optimize option: Options. (line 235) +* --posix option: Options. (line 252) +* --posix option, --traditional option and: Options. (line 271) +* --pretty-print option: Options. (line 224) +* --profile option <1>: Profiling. (line 12) +* --profile option: Options. (line 240) +* --re-interval option: Options. (line 277) +* --sandbox option: Options. (line 284) +* --sandbox option, disabling system() function: I/O Functions. + (line 97) +* --sandbox option, input redirection with getline: Getline. (line 19) +* --sandbox option, output redirection with print, printf: Redirection. (line 6) -* '--source' option: Options. (line 117) -* '--source' option <1>: Options. (line 331) -* '--traditional' option: Options. (line 82) -* '--traditional' option, '--posix' option and: Options. (line 268) -* '--use-lc-numeric' option: Options. (line 217) -* '--version' option: Options. (line 295) -* '--with-whiny-user-strftime' configuration option: Additional Configuration Options. +* --source option: Options. (line 117) +* --traditional option: Options. (line 81) +* --traditional option, --posix option and: Options. (line 271) +* --use-lc-numeric option: Options. (line 219) +* --version option: Options. (line 298) +* --with-whiny-user-strftime configuration option: Additional Configuration Options. (line 35) -<<<<<<< HEAD -* '-b' option: Options. (line 69) -* '-c' option: Options. (line 82) -* '-C' option: Options. (line 89) -* '-d' option: Options. (line 94) -* '-D' option: Options. (line 108) -* '-e' option: Options. (line 117) -* '-E' option: Options. (line 125) -* '-f' option: Long. (line 12) -* '-F' option: Options. (line 21) -* '-f' option <1>: Options. (line 25) -* '-F' option, '-Ft' sets 'FS' to TAB: Options. (line 303) -* '-F' option, command line: Command Line Field Separator. -======= * -b option: Options. (line 68) * -C option: Options. (line 88) * -c option: Options. (line 81) @@ -32379,109 +31151,73 @@ Index * -f option: Long. (line 12) * -F option, -Ft sets FS to TAB: Options. (line 306) * -F option, command-line: Command Line Field Separator. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 6) -* '-f' option, multiple uses: Options. (line 308) -* '-g' option: Options. (line 147) -* '-h' option: Options. (line 154) -* '-i' option: Options. (line 159) -* '-l' option: Options. (line 172) -* '-l' option <1>: Options. (line 184) -* '-L' option: Options. (line 290) -* '-M' option: Options. (line 203) -* '-n' option: Options. (line 209) -* '-N' option: Options. (line 217) -* '-o' option: Options. (line 222) -* '-O' option: Options. (line 233) -* '-p' option: Options. (line 238) -* '-P' option: Options. (line 250) -* '-r' option: Options. (line 274) -* '-S' option: Options. (line 281) -* '-v' option: Options. (line 32) -* '-V' option: Options. (line 295) -* '-v' option <1>: Assignment Options. (line 12) -* '-W' option: Options. (line 47) -* '.' (period), regexp operator: Regexp Operators. (line 44) -* '.gmo' files: Explaining gettext. (line 42) -* '.gmo' files, specifying directory of: Explaining gettext. (line 54) -* '.gmo' files, specifying directory of <1>: Programmer i18n. (line 47) -* '.mo' files, converting from '.po': I18N Example. (line 63) -* '.po' files: Explaining gettext. (line 37) -* '.po' files <1>: Translator i18n. (line 6) -* '.po' files, converting to '.mo': I18N Example. (line 63) -* '.pot' files: Explaining gettext. (line 31) -* '/' (forward slash) to enclose regular expressions: Regexp. (line 10) -* '/' (forward slash), '/' operator: Precedence. (line 54) -* '/' (forward slash), '/=' operator: Assignment Ops. (line 129) -* '/' (forward slash), '/=' operator <1>: Precedence. (line 94) -* '/' (forward slash), '/=' operator, vs. '/=.../' regexp constant: Assignment Ops. - (line 149) -* '/' (forward slash), patterns and: Expression Patterns. (line 24) -* '/=' operator vs. '/=.../' regexp constant: Assignment Ops. (line 149) -* '/dev/...' special files: Special FD. (line 46) -* '/dev/fd/N' special files ('gawk'): Special FD. (line 46) -* '/inet/...' special files ('gawk'): TCP/IP Networking. (line 6) -* '/inet4/...' special files ('gawk'): TCP/IP Networking. (line 6) -* '/inet6/...' special files ('gawk'): TCP/IP Networking. (line 6) -* ';' (semicolon), 'AWKPATH' variable and: PC Using. (line 10) -* ';' (semicolon), separating statements in actions: Statements/Lines. - (line 90) -* ';' (semicolon), separating statements in actions <1>: Action Overview. - (line 19) -* ';' (semicolon), separating statements in actions <2>: Statements. +* -f option, multiple uses: Options. (line 311) +* -g option: Options. (line 147) +* -h option: Options. (line 154) +* -i option: Options. (line 159) +* -L option: Options. (line 293) +* -l option: Options. (line 173) +* -M option: Options. (line 205) +* -N option: Options. (line 219) +* -n option: Options. (line 211) +* -O option: Options. (line 235) +* -o option: Options. (line 224) +* -P option: Options. (line 252) +* -p option: Options. (line 240) +* -r option: Options. (line 277) +* -S option: Options. (line 284) +* -v option: Assignment Options. (line 12) +* -V option: Options. (line 298) +* -v option: Options. (line 32) +* -W option: Options. (line 46) +* . (period), regexp operator: Regexp Operators. (line 44) +* .gmo files: Explaining gettext. (line 42) +* .gmo files, specifying directory of <1>: Programmer i18n. (line 47) +* .gmo files, specifying directory of: Explaining gettext. (line 54) +* .mo files, converting from .po: I18N Example. (line 63) +* .po files <1>: Translator i18n. (line 6) +* .po files: Explaining gettext. (line 37) +* .po files, converting to .mo: I18N Example. (line 63) +* .pot files: Explaining gettext. (line 31) +* / (forward slash) to enclose regular expressions: Regexp. (line 10) +* / (forward slash), / operator: Precedence. (line 55) +* / (forward slash), /= operator <1>: Precedence. (line 95) +* / (forward slash), /= operator: Assignment Ops. (line 130) +* / (forward slash), /= operator, vs. /=.../ regexp constant: Assignment Ops. + (line 148) +* / (forward slash), patterns and: Expression Patterns. (line 24) +* /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) +* /dev/... special files: Special FD. (line 46) +* /dev/fd/N special files (gawk): Special FD. (line 46) +* /inet/... special files (gawk): TCP/IP Networking. (line 6) +* /inet4/... special files (gawk): TCP/IP Networking. (line 6) +* /inet6/... special files (gawk): TCP/IP Networking. (line 6) +* ; (semicolon), AWKPATH variable and: PC Using. (line 10) +* ; (semicolon), separating statements in actions <1>: Statements. (line 10) -* '<' (left angle bracket), '<' operator: Comparison Operators. +* ; (semicolon), separating statements in actions <2>: Action Overview. + (line 19) +* ; (semicolon), separating statements in actions: Statements/Lines. + (line 91) +* < (left angle bracket), < operator <1>: Precedence. (line 65) +* < (left angle bracket), < operator: Comparison Operators. (line 11) -* '<' (left angle bracket), '<' operator <1>: Precedence. (line 64) -* '<' (left angle bracket), '<' operator (I/O): Getline/File. (line 6) -* '<' (left angle bracket), '<=' operator: Comparison Operators. +* < (left angle bracket), < operator (I/O): Getline/File. (line 6) +* < (left angle bracket), <= operator <1>: Precedence. (line 65) +* < (left angle bracket), <= operator: Comparison Operators. (line 11) -* '<' (left angle bracket), '<=' operator <1>: Precedence. (line 64) -* '=' (equals sign), '=' operator: Assignment Ops. (line 6) -* '=' (equals sign), '==' operator: Comparison Operators. +* = (equals sign), = operator: Assignment Ops. (line 6) +* = (equals sign), == operator <1>: Precedence. (line 65) +* = (equals sign), == operator: Comparison Operators. (line 11) -* '=' (equals sign), '==' operator <1>: Precedence. (line 64) -* '>' (right angle bracket), '>' operator: Comparison Operators. +* > (right angle bracket), > operator <1>: Precedence. (line 65) +* > (right angle bracket), > operator: Comparison Operators. (line 11) -* '>' (right angle bracket), '>' operator <1>: Precedence. (line 64) -* '>' (right angle bracket), '>' operator (I/O): Redirection. (line 22) -* '>' (right angle bracket), '>=' operator: Comparison Operators. +* > (right angle bracket), > operator (I/O): Redirection. (line 22) +* > (right angle bracket), >= operator <1>: Precedence. (line 65) +* > (right angle bracket), >= operator: Comparison Operators. (line 11) -<<<<<<< HEAD -* '>' (right angle bracket), '>=' operator <1>: Precedence. (line 64) -* '>' (right angle bracket), '>>' operator (I/O): Redirection. - (line 50) -* '>' (right angle bracket), '>>' operator (I/O) <1>: Precedence. - (line 64) -* '?' (question mark), '?:' operator: Precedence. (line 91) -* '?' (question mark), regexp operator: Regexp Operators. (line 112) -* '?' (question mark), regexp operator <1>: GNU Regexp Operators. - (line 62) -* '[]' (square brackets), regexp operator: Regexp Operators. (line 56) -* '\' (backslash): Comments. (line 50) -* '\' (backslash) in shell commands: Read Terminal. (line 25) -* '\' (backslash), as field separator: Command Line Field Separator. - (line 27) -* '\' (backslash), continuing lines and: Statements/Lines. (line 19) -* '\' (backslash), continuing lines and <1>: Egrep Program. (line 222) -* '\' (backslash), continuing lines and, comments and: Statements/Lines. - (line 75) -* '\' (backslash), continuing lines and, in 'csh': Statements/Lines. - (line 43) -* '\' (backslash), 'gsub()'/'gensub()'/'sub()' functions and: Gory Details. - (line 6) -* '\' (backslash), in bracket expressions: Bracket Expressions. - (line 17) -* '\' (backslash), in escape sequences: Escape Sequences. (line 6) -* '\' (backslash), in escape sequences <1>: Escape Sequences. (line 93) -* '\' (backslash), in escape sequences, POSIX and: Escape Sequences. - (line 111) -* '\' (backslash), in regexp constants: Computed Regexps. (line 29) -* '\' (backslash), in shell commands: Quoting. (line 48) -* '\' (backslash), regexp operator: Regexp Operators. (line 18) -* '\' (backslash), '\"' escape sequence: Escape Sequences. (line 76) -* '\' (backslash), '\'' operator ('gawk'): GNU Regexp Operators. -======= * > (right angle bracket), >> operator (I/O) <1>: Precedence. (line 65) * > (right angle bracket), >> operator (I/O): Redirection. (line 50) * ? (question mark), ?: operator: Precedence. (line 92) @@ -32546,114 +31282,44 @@ Index * ^ (caret), ^= operator: Assignment Ops. (line 130) * ^ (caret), in bracket expressions: Bracket Expressions. (line 17) * ^ (caret), in FS: Regexp Field Splitting. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 59) -* '\' (backslash), '\/' escape sequence: Escape Sequences. (line 69) -* '\' (backslash), '\<' operator ('gawk'): GNU Regexp Operators. - (line 33) -* '\' (backslash), '\>' operator ('gawk'): GNU Regexp Operators. - (line 37) -* '\' (backslash), '\a' escape sequence: Escape Sequences. (line 34) -* '\' (backslash), '\b' escape sequence: Escape Sequences. (line 38) -* '\' (backslash), '\B' operator ('gawk'): GNU Regexp Operators. - (line 46) -* '\' (backslash), '\f' escape sequence: Escape Sequences. (line 41) -* '\' (backslash), '\n' escape sequence: Escape Sequences. (line 44) -* '\' (backslash), '\'NNN escape sequence: Escape Sequences. (line 56) -* '\' (backslash), '\r' escape sequence: Escape Sequences. (line 47) -* '\' (backslash), '\s' operator ('gawk'): GNU Regexp Operators. - (line 13) -* '\' (backslash), '\S' operator ('gawk'): GNU Regexp Operators. - (line 17) -* '\' (backslash), '\t' escape sequence: Escape Sequences. (line 50) -* '\' (backslash), '\v' escape sequence: Escape Sequences. (line 53) -* '\' (backslash), '\w' operator ('gawk'): GNU Regexp Operators. - (line 22) -* '\' (backslash), '\W' operator ('gawk'): GNU Regexp Operators. - (line 28) -* '\' (backslash), '\x' escape sequence: Escape Sequences. (line 61) -* '\' (backslash), '\y' operator ('gawk'): GNU Regexp Operators. - (line 41) -* '\' (backslash), '\`' operator ('gawk'): GNU Regexp Operators. - (line 57) -* '^' (caret), in bracket expressions: Bracket Expressions. (line 17) -* '^' (caret), in 'FS': Regexp Field Splitting. +* ^ (caret), regexp operator <1>: GNU Regexp Operators. (line 59) -* '^' (caret), regexp operator: Regexp Operators. (line 22) -* '^' (caret), regexp operator <1>: GNU Regexp Operators. - (line 62) -* '^' (caret), '^' operator: Precedence. (line 48) -* '^' (caret), '^=' operator: Assignment Ops. (line 129) -* '^' (caret), '^=' operator <1>: Precedence. (line 94) -* '_' (underscore), C macro: Explaining gettext. (line 71) -* '_' (underscore), in names of private variables: Library Names. +* ^ (caret), regexp operator: Regexp Operators. (line 22) +* _ (underscore), C macro: Explaining gettext. (line 71) +* _ (underscore), in names of private variables: Library Names. (line 29) -* '_' (underscore), translatable string: Programmer i18n. (line 69) -* '_gr_init()' user-defined function: Group Functions. (line 83) -* '_ord_init()' user-defined function: Ordinal Functions. (line 16) -* '_pw_init()' user-defined function: Passwd Functions. (line 105) -* '{}' (braces): Profiling. (line 142) -* '{}' (braces), actions and: Action Overview. (line 19) -* '{}' (braces), statements, grouping: Statements. (line 10) -* '|' (vertical bar): Regexp Operators. (line 70) -* '|' (vertical bar), '|' operator (I/O): Getline/Pipe. (line 10) -* '|' (vertical bar), '|' operator (I/O) <1>: Redirection. (line 57) -* '|' (vertical bar), '|' operator (I/O) <2>: Precedence. (line 64) -* '|' (vertical bar), '|&' operator (I/O): Getline/Coprocess. (line 6) -* '|' (vertical bar), '|&' operator (I/O) <1>: Redirection. (line 102) -* '|' (vertical bar), '|&' operator (I/O) <2>: Precedence. (line 64) -* '|' (vertical bar), '|&' operator (I/O) <3>: Two-way I/O. (line 44) -* '|' (vertical bar), '|&' operator (I/O), pipes, closing: Close Files And Pipes. - (line 119) -* '|' (vertical bar), '||' operator: Boolean Ops. (line 57) -* '|' (vertical bar), '||' operator <1>: Precedence. (line 88) -* '~' (tilde), '~' operator: Regexp Usage. (line 19) -* '~' (tilde), '~' operator <1>: Case-sensitivity. (line 26) -* '~' (tilde), '~' operator <2>: Computed Regexps. (line 6) -* '~' (tilde), '~' operator <3>: Regexp Constants. (line 6) -* '~' (tilde), '~' operator <4>: Comparison Operators. - (line 11) -* '~' (tilde), '~' operator <5>: Comparison Operators. - (line 98) -* '~' (tilde), '~' operator <6>: Precedence. (line 79) -* '~' (tilde), '~' operator <7>: Expression Patterns. (line 24) +* _ (underscore), translatable string: Programmer i18n. (line 69) +* _gr_init() user-defined function: Group Functions. (line 83) +* _ord_init() user-defined function: Ordinal Functions. (line 16) +* _pw_init() user-defined function: Passwd Functions. (line 105) * accessing fields: Fields. (line 6) * accessing global variables from extensions: Symbol Table Access. (line 6) -* account information: Passwd Functions. (line 16) * account information <1>: Group Functions. (line 6) +* account information: Passwd Functions. (line 16) * actions: Action Overview. (line 6) * actions, control statements in: Statements. (line 6) * actions, default: Very Simple. (line 34) * actions, empty: Very Simple. (line 39) * Ada programming language: Glossary. (line 19) -* adding, features to 'gawk': Adding Code. (line 6) +* adding, features to gawk: Adding Code. (line 6) * adding, fields: Changing Fields. (line 53) * advanced features, fixed-width data: Constant Size. (line 10) -* advanced features, 'gawk': Advanced Features. (line 6) +* advanced features, gawk: Advanced Features. (line 6) * advanced features, network programming: TCP/IP Networking. (line 6) * advanced features, nondecimal input data: Nondecimal Data. (line 6) * advanced features, processes, communicating with: Two-way I/O. (line 6) * advanced features, specifying field content: Splitting By Content. (line 10) +* Aho, Alfred <1>: Contributors. (line 11) * Aho, Alfred: History. (line 17) -* Aho, Alfred <1>: Contributors. (line 12) * alarm clock example program: Alarm Program. (line 11) -* 'alarm.awk' program: Alarm Program. (line 31) -* algorithms: Basic High Level. (line 57) +* alarm.awk program: Alarm Program. (line 31) +* algorithms: Basic High Level. (line 68) * allocating memory for extensions: Memory Allocation Functions. (line 6) -<<<<<<< HEAD -* Alpha (DEC): Manual History. (line 28) -* amazing 'awk' assembler ('aaa'): Glossary. (line 11) -* amazingly workable formatter ('awf'): Glossary. (line 24) -* ambiguity, syntactic: '/=' operator vs. '/=.../' regexp constant: Assignment Ops. - (line 149) -* ampersand ('&'), '&&' operator: Boolean Ops. (line 57) -* ampersand ('&'), '&&' operator <1>: Precedence. (line 85) -* ampersand ('&'), 'gsub()'/'gensub()'/'sub()' functions and: Gory Details. -======= * amazing awk assembler (aaa): Glossary. (line 11) * amazingly workable formatter (awf): Glossary. (line 24) * ambiguity, syntactic: /= operator vs. /=.../ regexp constant: Assignment Ops. @@ -32661,11 +31327,10 @@ Index * ampersand (&), && operator <1>: Precedence. (line 86) * ampersand (&), && operator: Boolean Ops. (line 57) * ampersand (&), gsub()/gensub()/sub() functions and: Gory Details. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 6) -* 'anagram.awk' program: Anagram Program. (line 22) +* anagram.awk program: Anagram Program. (line 22) * anagrams, finding: Anagram Program. (line 6) -* 'and': Bitwise Functions. (line 39) +* and: Bitwise Functions. (line 39) * AND bitwise operation: Bitwise Functions. (line 6) * and Boolean-logic operator: Boolean Ops. (line 6) * ANSI: Glossary. (line 34) @@ -32678,31 +31343,21 @@ Index * arbitrary precision integers: Arbitrary Precision Integers. (line 6) * archeologists: Bugs. (line 6) -* arctangent: Numeric Functions. (line 10) -* 'ARGC'/'ARGV' variables: Auto-set. (line 15) -* 'ARGC'/'ARGV' variables, command-line arguments: Other Arguments. +* arctangent: Numeric Functions. (line 11) +* ARGC/ARGV variables: Auto-set. (line 15) +* ARGC/ARGV variables, command-line arguments: Other Arguments. (line 12) -<<<<<<< HEAD -* 'ARGC'/'ARGV' variables, how to use: ARGC and ARGV. (line 6) -* 'ARGC'/'ARGV' variables, portability and: Executable Scripts. - (line 42) -* 'ARGIND' variable: Auto-set. (line 44) -* 'ARGIND' variable, command-line arguments: Other Arguments. (line 12) -======= * ARGC/ARGV variables, how to use: ARGC and ARGV. (line 6) * ARGC/ARGV variables, portability and: Executable Scripts. (line 59) * ARGIND variable: Auto-set. (line 44) * ARGIND variable, command-line arguments: Other Arguments. (line 12) * arguments, command-line <1>: ARGC and ARGV. (line 6) * arguments, command-line <2>: Auto-set. (line 15) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * arguments, command-line: Other Arguments. (line 6) -* arguments, command-line <1>: Auto-set. (line 15) -* arguments, command-line <2>: ARGC and ARGV. (line 6) -* arguments, command-line, invoking 'awk': Command Line. (line 6) +* arguments, command-line, invoking awk: Command Line. (line 6) * arguments, in function calls: Function Calls. (line 18) * arguments, processing: Getopt Function. (line 6) -* 'ARGV' array, indexing into: Other Arguments. (line 12) +* ARGV array, indexing into: Other Arguments. (line 12) * arithmetic operators: Arithmetic Ops. (line 6) * array manipulation in extensions: Array Manipulation. (line 6) * array members: Reference to Elements. @@ -32713,25 +31368,21 @@ Index * arrays: Arrays. (line 6) * arrays of arrays: Arrays of Arrays. (line 6) * arrays, an example of using: Array Example. (line 6) -<<<<<<< HEAD -* arrays, and 'IGNORECASE' variable: Array Intro. (line 91) -======= * arrays, and IGNORECASE variable: Array Intro. (line 94) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * arrays, as parameters to functions: Pass By Value/Reference. - (line 46) -* arrays, associative: Array Intro. (line 48) + (line 47) +* arrays, associative: Array Intro. (line 50) * arrays, associative, library functions and: Library Names. (line 57) * arrays, deleting entire contents: Delete. (line 39) * arrays, elements that don't exist: Reference to Elements. (line 23) * arrays, elements, assigning values: Assigning Elements. (line 6) * arrays, elements, deleting: Delete. (line 6) -* arrays, elements, order of access by 'in' operator: Scanning an Array. +* arrays, elements, order of access by in operator: Scanning an Array. (line 48) * arrays, elements, retrieving number of: String Functions. (line 42) -* arrays, 'for' statement and: Scanning an Array. (line 20) -* arrays, indexing: Array Intro. (line 48) +* arrays, for statement and: Scanning an Array. (line 20) +* arrays, indexing: Array Intro. (line 50) * arrays, merging into strings: Join Function. (line 6) * arrays, multidimensional: Multidimensional. (line 10) * arrays, multidimensional, scanning: Multiscanning. (line 11) @@ -32743,108 +31394,36 @@ Index * arrays, scanning: Scanning an Array. (line 6) * arrays, sorting: Array Sorting Functions. (line 6) -* arrays, sorting, and 'IGNORECASE' variable: Array Sorting Functions. +* arrays, sorting, and IGNORECASE variable: Array Sorting Functions. (line 83) -<<<<<<< HEAD -* arrays, sparse: Array Intro. (line 70) -======= * arrays, sparse: Array Intro. (line 72) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * arrays, subscripts, uninitialized variables as: Uninitialized Subscripts. (line 6) * arrays, unassigned elements: Reference to Elements. (line 18) -* artificial intelligence, 'gawk' and: Distribution contents. +* artificial intelligence, gawk and: Distribution contents. (line 52) -* ASCII: Ordinal Functions. (line 45) * ASCII <1>: Glossary. (line 133) -* 'asort': String Functions. (line 42) -* 'asort' <1>: Array Sorting Functions. +* ASCII: Ordinal Functions. (line 45) +* asort <1>: Array Sorting Functions. (line 6) -* 'asort()' function ('gawk'), arrays, sorting: Array Sorting Functions. +* asort: String Functions. (line 42) +* asort() function (gawk), arrays, sorting: Array Sorting Functions. (line 6) -* 'asorti': String Functions. (line 42) -* 'asorti' <1>: Array Sorting Functions. +* asorti <1>: Array Sorting Functions. (line 6) -* 'asorti()' function ('gawk'), arrays, sorting: Array Sorting Functions. +* asorti: String Functions. (line 42) +* asorti() function (gawk), arrays, sorting: Array Sorting Functions. (line 6) -* 'assert()' function (C library): Assert Function. (line 6) -* 'assert()' user-defined function: Assert Function. (line 28) +* assert() function (C library): Assert Function. (line 6) +* assert() user-defined function: Assert Function. (line 28) * assertions: Assert Function. (line 6) * assign values to variables, in debugger: Viewing And Changing Data. - (line 58) + (line 59) * assignment operators: Assignment Ops. (line 6) -* assignment operators, evaluation order: Assignment Ops. (line 110) -* assignment operators, lvalues/rvalues: Assignment Ops. (line 31) +* assignment operators, evaluation order: Assignment Ops. (line 111) +* assignment operators, lvalues/rvalues: Assignment Ops. (line 32) * assignments as filenames: Ignoring Assigns. (line 6) -<<<<<<< HEAD -* associative arrays: Array Intro. (line 48) -* asterisk ('*'), '*' operator, as multiplication operator: Precedence. - (line 54) -* asterisk ('*'), '*' operator, as regexp operator: Regexp Operators. - (line 88) -* asterisk ('*'), '*' operator, null strings, matching: Gory Details. - (line 164) -* asterisk ('*'), '**' operator: Arithmetic Ops. (line 81) -* asterisk ('*'), '**' operator <1>: Precedence. (line 48) -* asterisk ('*'), '**=' operator: Assignment Ops. (line 129) -* asterisk ('*'), '**=' operator <1>: Precedence. (line 94) -* asterisk ('*'), '*=' operator: Assignment Ops. (line 129) -* asterisk ('*'), '*=' operator <1>: Precedence. (line 94) -* 'atan2': Numeric Functions. (line 10) -* automatic displays, in debugger: Debugger Info. (line 24) -* 'awf' (amazingly workable formatter) program: Glossary. (line 24) -* 'awk' debugging, enabling: Options. (line 108) -* 'awk' language, POSIX version: Assignment Ops. (line 138) -* 'awk' profiling, enabling: Options. (line 238) -* 'awk' programs: Getting Started. (line 12) -* 'awk' programs <1>: Executable Scripts. (line 6) -* 'awk' programs <2>: Two Rules. (line 6) -* 'awk' programs, complex: When. (line 29) -* 'awk' programs, documenting: Comments. (line 6) -* 'awk' programs, documenting <1>: Library Names. (line 6) -* 'awk' programs, examples of: Sample Programs. (line 6) -* 'awk' programs, execution of: Next Statement. (line 16) -* 'awk' programs, internationalizing: I18N Functions. (line 6) -* 'awk' programs, internationalizing <1>: Programmer i18n. (line 6) -* 'awk' programs, lengthy: Long. (line 6) -* 'awk' programs, lengthy, assertions: Assert Function. (line 6) -* 'awk' programs, location of: Options. (line 25) -* 'awk' programs, location of <1>: Options. (line 125) -* 'awk' programs, location of <2>: Options. (line 159) -* 'awk' programs, one-line examples: Very Simple. (line 45) -* 'awk' programs, profiling: Profiling. (line 6) -* 'awk' programs, running: Running gawk. (line 6) -* 'awk' programs, running <1>: Long. (line 6) -* 'awk' programs, running, from shell scripts: One-shot. (line 22) -* 'awk' programs, running, without input files: Read Terminal. - (line 17) -* 'awk' programs, shell variables in: Using Shell Variables. - (line 6) -* 'awk', function of: Getting Started. (line 6) -* 'awk', 'gawk' and: Preface. (line 23) -* 'awk', 'gawk' and <1>: This Manual. (line 14) -* 'awk', history of: History. (line 17) -* 'awk', implementation issues, pipes: Redirection. (line 134) -* 'awk', implementations: Other Versions. (line 6) -* 'awk', implementations, limits: Getline Notes. (line 14) -* 'awk', invoking: Command Line. (line 6) -* 'awk', new vs. old: Names. (line 6) -* 'awk', new vs. old, 'OFMT' variable: Strings And Numbers. (line 56) -* 'awk', POSIX and: Preface. (line 23) -* 'awk', POSIX and, See Also POSIX 'awk': Preface. (line 23) -* 'awk', regexp constants and: Comparison Operators. - (line 103) -* 'awk', See Also 'gawk': Preface. (line 36) -* 'awk', terms describing: This Manual. (line 6) -* 'awk', uses for: Preface. (line 23) -* 'awk', uses for <1>: Getting Started. (line 12) -* 'awk', uses for <2>: When. (line 6) -* 'awk', versions of: Names. (line 10) -* 'awk', versions of <1>: V7/SVR3.1. (line 6) -* 'awk', versions of, changes between SVR3.1 and SVR4: SVR4. (line 6) -* 'awk', versions of, changes between SVR4 and POSIX 'awk': POSIX. -======= * associative arrays: Array Intro. (line 50) * asterisk (*), * operator, as multiplication operator: Precedence. (line 55) @@ -32907,33 +31486,10 @@ Index * awk, versions of: V7/SVR3.1. (line 6) * awk, versions of, changes between SVR3.1 and SVR4: SVR4. (line 6) * awk, versions of, changes between SVR4 and POSIX awk: POSIX. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac - (line 6) -* 'awk', versions of, changes between V7 and SVR3.1: V7/SVR3.1. (line 6) -* 'awk', versions of, See Also Brian Kernighan's 'awk': BTL. (line 6) -* 'awk', versions of, See Also Brian Kernighan's 'awk' <1>: Other Versions. +* awk, versions of, changes between V7 and SVR3.1: V7/SVR3.1. (line 6) +* awk, versions of, See Also Brian Kernighan's awk <1>: Other Versions. (line 13) -<<<<<<< HEAD -* 'awka' compiler for 'awk': Other Versions. (line 64) -* 'AWKLIBPATH' environment variable: AWKLIBPATH Variable. (line 6) -* 'AWKPATH' environment variable: AWKPATH Variable. (line 6) -* 'AWKPATH' environment variable <1>: PC Using. (line 10) -* 'awkprof.out' file: Profiling. (line 6) -* 'awksed.awk' program: Simple Sed. (line 25) -* 'awkvars.out' file: Options. (line 94) -* 'b' debugger command (alias for 'break'): Breakpoint Control. - (line 11) -* backslash ('\'): Comments. (line 50) -* backslash ('\') in shell commands: Read Terminal. (line 25) -* backslash ('\'), as field separator: Command Line Field Separator. - (line 27) -* backslash ('\'), continuing lines and: Statements/Lines. (line 19) -* backslash ('\'), continuing lines and <1>: Egrep Program. (line 222) -* backslash ('\'), continuing lines and, comments and: Statements/Lines. - (line 75) -* backslash ('\'), continuing lines and, in 'csh': Statements/Lines. -======= * awk, versions of, See Also Brian Kernighan's awk: BTL. (line 6) * awka compiler for awk: Other Versions. (line 64) * AWKLIBPATH environment variable: AWKLIBPATH Variable. (line 6) @@ -32957,53 +31513,15 @@ Index * backslash (\), \a escape sequence: Escape Sequences. (line 34) * backslash (\), \b escape sequence: Escape Sequences. (line 38) * backslash (\), \B operator (gawk): GNU Regexp Operators. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 43) -* backslash ('\'), 'gsub()'/'gensub()'/'sub()' functions and: Gory Details. - (line 6) -* backslash ('\'), in bracket expressions: Bracket Expressions. +* backslash (\), \f escape sequence: Escape Sequences. (line 41) +* backslash (\), \n escape sequence: Escape Sequences. (line 44) +* backslash (\), \NNN escape sequence: Escape Sequences. (line 56) +* backslash (\), \r escape sequence: Escape Sequences. (line 47) +* backslash (\), \S operator (gawk): GNU Regexp Operators. (line 17) -* backslash ('\'), in escape sequences: Escape Sequences. (line 6) -* backslash ('\'), in escape sequences <1>: Escape Sequences. (line 93) -* backslash ('\'), in escape sequences, POSIX and: Escape Sequences. - (line 111) -* backslash ('\'), in regexp constants: Computed Regexps. (line 29) -* backslash ('\'), in shell commands: Quoting. (line 48) -* backslash ('\'), regexp operator: Regexp Operators. (line 18) -* backslash ('\'), '\"' escape sequence: Escape Sequences. (line 76) -* backslash ('\'), '\'' operator ('gawk'): GNU Regexp Operators. - (line 59) -* backslash ('\'), '\/' escape sequence: Escape Sequences. (line 69) -* backslash ('\'), '\<' operator ('gawk'): GNU Regexp Operators. - (line 33) -* backslash ('\'), '\>' operator ('gawk'): GNU Regexp Operators. - (line 37) -* backslash ('\'), '\a' escape sequence: Escape Sequences. (line 34) -* backslash ('\'), '\b' escape sequence: Escape Sequences. (line 38) -* backslash ('\'), '\B' operator ('gawk'): GNU Regexp Operators. - (line 46) -* backslash ('\'), '\f' escape sequence: Escape Sequences. (line 41) -* backslash ('\'), '\n' escape sequence: Escape Sequences. (line 44) -* backslash ('\'), '\'NNN escape sequence: Escape Sequences. (line 56) -* backslash ('\'), '\r' escape sequence: Escape Sequences. (line 47) -* backslash ('\'), '\s' operator ('gawk'): GNU Regexp Operators. +* backslash (\), \s operator (gawk): GNU Regexp Operators. (line 13) -<<<<<<< HEAD -* backslash ('\'), '\S' operator ('gawk'): GNU Regexp Operators. - (line 17) -* backslash ('\'), '\t' escape sequence: Escape Sequences. (line 50) -* backslash ('\'), '\v' escape sequence: Escape Sequences. (line 53) -* backslash ('\'), '\w' operator ('gawk'): GNU Regexp Operators. - (line 22) -* backslash ('\'), '\W' operator ('gawk'): GNU Regexp Operators. - (line 28) -* backslash ('\'), '\x' escape sequence: Escape Sequences. (line 61) -* backslash ('\'), '\y' operator ('gawk'): GNU Regexp Operators. - (line 41) -* backslash ('\'), '\`' operator ('gawk'): GNU Regexp Operators. - (line 57) -* 'backtrace' debugger command: Execution Stack. (line 13) -======= * backslash (\), \t escape sequence: Escape Sequences. (line 50) * backslash (\), \v escape sequence: Escape Sequences. (line 53) * backslash (\), \W operator (gawk): GNU Regexp Operators. @@ -33031,60 +31549,50 @@ Index * backslash (\), regexp operator: Regexp Operators. (line 18) * backtrace debugger command: Execution Stack. (line 13) * Beebe, Nelson H.F. <1>: Other Versions. (line 78) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Beebe, Nelson H.F.: Acknowledgments. (line 60) -* Beebe, Nelson H.F. <1>: Other Versions. (line 78) -* 'BEGIN' pattern: Field Separators. (line 44) -* 'BEGIN' pattern <1>: BEGIN/END. (line 6) -* 'BEGIN' pattern <2>: Using BEGIN/END. (line 6) -* 'BEGIN' pattern, and profiling: Profiling. (line 62) -* 'BEGIN' pattern, 'assert()' user-defined function and: Assert Function. +* BEGIN pattern <1>: Using BEGIN/END. (line 6) +* BEGIN pattern <2>: BEGIN/END. (line 6) +* BEGIN pattern: Field Separators. (line 45) +* BEGIN pattern, and profiling: Profiling. (line 62) +* BEGIN pattern, assert() user-defined function and: Assert Function. (line 83) -* 'BEGIN' pattern, Boolean patterns and: Expression Patterns. (line 70) -* 'BEGIN' pattern, 'exit' statement and: Exit Statement. (line 12) -* 'BEGIN' pattern, 'getline' and: Getline Notes. (line 19) -* 'BEGIN' pattern, headings, adding: Print Examples. (line 42) -* 'BEGIN' pattern, 'next'/'nextfile' statements and: I/O And BEGIN/END. - (line 36) -* 'BEGIN' pattern, 'next'/'nextfile' statements and <1>: Next Statement. +* BEGIN pattern, Boolean patterns and: Expression Patterns. (line 70) +* BEGIN pattern, exit statement and: Exit Statement. (line 12) +* BEGIN pattern, getline and: Getline Notes. (line 19) +* BEGIN pattern, headings, adding: Print Examples. (line 43) +* BEGIN pattern, next/nextfile statements and <1>: Next Statement. (line 45) -<<<<<<< HEAD -* 'BEGIN' pattern, 'OFS'/'ORS' variables, assigning values to: Output Separators. -======= * BEGIN pattern, next/nextfile statements and: I/O And BEGIN/END. (line 36) * BEGIN pattern, OFS/ORS variables, assigning values to: Output Separators. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 20) -* 'BEGIN' pattern, operators and: Using BEGIN/END. (line 17) -* 'BEGIN' pattern, 'print' statement and: I/O And BEGIN/END. (line 15) -* 'BEGIN' pattern, 'pwcat' program: Passwd Functions. (line 143) -* 'BEGIN' pattern, running 'awk' programs and: Cut Program. (line 68) -* 'BEGIN' pattern, 'TEXTDOMAIN' variable and: Programmer i18n. - (line 60) -* 'BEGINFILE' pattern: BEGINFILE/ENDFILE. (line 6) -* 'BEGINFILE' pattern, Boolean patterns and: Expression Patterns. +* BEGIN pattern, operators and: Using BEGIN/END. (line 17) +* BEGIN pattern, print statement and: I/O And BEGIN/END. (line 16) +* BEGIN pattern, pwcat program: Passwd Functions. (line 143) +* BEGIN pattern, running awk programs and: Cut Program. (line 68) +* BEGIN pattern, TEXTDOMAIN variable and: Programmer i18n. (line 60) +* BEGINFILE pattern: BEGINFILE/ENDFILE. (line 6) +* BEGINFILE pattern, Boolean patterns and: Expression Patterns. (line 70) -* 'beginfile()' user-defined function: Filetrans Function. (line 62) +* beginfile() user-defined function: Filetrans Function. (line 62) * Bentley, Jon: Glossary. (line 143) -* Benzinger, Michael: Contributors. (line 98) -* Berry, Karl: Acknowledgments. (line 33) +* Benzinger, Michael: Contributors. (line 97) * Berry, Karl <1>: Ranges and Locales. (line 74) +* Berry, Karl: Acknowledgments. (line 33) * binary input/output: User-modified. (line 15) -* 'bindtextdomain': I18N Functions. (line 11) -* 'bindtextdomain' <1>: Programmer i18n. (line 47) -* 'bindtextdomain()' function (C library): Explaining gettext. - (line 50) -* 'bindtextdomain()' function ('gawk'), portability and: I18N Portability. +* bindtextdomain <1>: Programmer i18n. (line 47) +* bindtextdomain: I18N Functions. (line 12) +* bindtextdomain() function (C library): Explaining gettext. (line 50) +* bindtextdomain() function (gawk), portability and: I18N Portability. (line 33) -* 'BINMODE' variable: User-modified. (line 15) -* 'BINMODE' variable <1>: PC Using. (line 33) +* BINMODE variable <1>: PC Using. (line 33) +* BINMODE variable: User-modified. (line 15) * bit-manipulation functions: Bitwise Functions. (line 6) -* 'bits2str()' user-defined function: Bitwise Functions. (line 71) +* bits2str() user-defined function: Bitwise Functions. (line 70) * bitwise AND: Bitwise Functions. (line 39) * bitwise complement: Bitwise Functions. (line 43) * bitwise OR: Bitwise Functions. (line 49) -* bitwise XOR: Bitwise Functions. (line 56) +* bitwise XOR: Bitwise Functions. (line 55) * bitwise, complement: Bitwise Functions. (line 25) * bitwise, operations: Bitwise Functions. (line 6) * bitwise, shift: Bitwise Functions. (line 32) @@ -33094,23 +31602,14 @@ Index * Boolean expressions, as patterns: Expression Patterns. (line 39) * Boolean operators, See Boolean expressions: Boolean Ops. (line 6) * Bourne shell, quoting rules for: Quoting. (line 18) -* braces ('{}'): Profiling. (line 142) -* braces ('{}'), actions and: Action Overview. (line 19) -* braces ('{}'), statements, grouping: Statements. (line 10) -* bracket expressions: Regexp Operators. (line 56) +* braces ({}): Profiling. (line 142) +* braces ({}), actions and: Action Overview. (line 19) +* braces ({}), statements, grouping: Statements. (line 10) * bracket expressions <1>: Bracket Expressions. (line 6) +* bracket expressions: Regexp Operators. (line 56) * bracket expressions, character classes: Bracket Expressions. (line 32) * bracket expressions, collating elements: Bracket Expressions. -<<<<<<< HEAD - (line 76) -* bracket expressions, collating symbols: Bracket Expressions. - (line 83) -* bracket expressions, complemented: Regexp Operators. (line 64) -* bracket expressions, equivalence classes: Bracket Expressions. - (line 89) -* bracket expressions, non-ASCII: Bracket Expressions. (line 76) -======= (line 79) * bracket expressions, collating symbols: Bracket Expressions. (line 86) @@ -33118,11 +31617,10 @@ Index * bracket expressions, equivalence classes: Bracket Expressions. (line 92) * bracket expressions, non-ASCII: Bracket Expressions. (line 79) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * bracket expressions, range expressions: Bracket Expressions. (line 6) -* 'break' debugger command: Breakpoint Control. (line 11) -* 'break' statement: Break Statement. (line 6) +* break debugger command: Breakpoint Control. (line 11) +* break statement: Break Statement. (line 6) * breakpoint: Debugging Terms. (line 33) * breakpoint at location, how to delete: Breakpoint Control. (line 36) * breakpoint commands: Debugger Execution Control. @@ -33131,33 +31629,6 @@ Index * breakpoint, delete by number: Breakpoint Control. (line 64) * breakpoint, how to disable or enable: Breakpoint Control. (line 69) * breakpoint, setting: Breakpoint Control. (line 11) -<<<<<<< HEAD -* Brennan, Michael: Foreword. (line 83) -* Brennan, Michael <1>: Delete. (line 56) -* Brennan, Michael <2>: Simple Sed. (line 25) -* Brennan, Michael <3>: Two-way I/O. (line 6) -* Brennan, Michael <4>: Other Versions. (line 6) -* Brennan, Michael <5>: Other Versions. (line 44) -* Brian Kernighan's 'awk': Preface. (line 15) -* Brian Kernighan's 'awk' <1>: When. (line 21) -* Brian Kernighan's 'awk' <2>: Escape Sequences. (line 115) -* Brian Kernighan's 'awk' <3>: GNU Regexp Operators. - (line 86) -* Brian Kernighan's 'awk' <4>: Regexp Field Splitting. - (line 67) -* Brian Kernighan's 'awk' <5>: Getline/Pipe. (line 62) -* Brian Kernighan's 'awk' <6>: Concatenation. (line 36) -* Brian Kernighan's 'awk' <7>: I/O And BEGIN/END. (line 15) -* Brian Kernighan's 'awk' <8>: Break Statement. (line 51) -* Brian Kernighan's 'awk' <9>: Continue Statement. (line 43) -* Brian Kernighan's 'awk' <10>: Nextfile Statement. (line 46) -* Brian Kernighan's 'awk' <11>: Delete. (line 48) -* Brian Kernighan's 'awk' <12>: String Functions. (line 489) -* Brian Kernighan's 'awk' <13>: Gory Details. (line 15) -* Brian Kernighan's 'awk' <14>: I/O Functions. (line 43) -* Brian Kernighan's 'awk', extensions: BTL. (line 6) -* Brian Kernighan's 'awk', source code: Other Versions. (line 13) -======= * Brennan, Michael <1>: Other Versions. (line 6) * Brennan, Michael <2>: Simple Sed. (line 25) * Brennan, Michael <3>: Delete. (line 56) @@ -33181,106 +31652,84 @@ Index * Brian Kernighan's awk: When. (line 21) * Brian Kernighan's awk, extensions: BTL. (line 6) * Brian Kernighan's awk, source code: Other Versions. (line 13) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Brini, Davide: Signature Program. (line 6) * Brink, Jeroen: DOS Quoting. (line 10) -* Broder, Alan J.: Contributors. (line 89) -* Brown, Martin: Contributors. (line 83) -* BSD-based operating systems: Glossary. (line 607) -* 'bt' debugger command (alias for 'backtrace'): Execution Stack. - (line 13) +* Broder, Alan J.: Contributors. (line 88) +* Brown, Martin: Contributors. (line 82) +* BSD-based operating systems: Glossary. (line 611) +* bt debugger command (alias for backtrace): Execution Stack. (line 13) +* Buening, Andreas <1>: Bugs. (line 71) +* Buening, Andreas <2>: Contributors. (line 92) * Buening, Andreas: Acknowledgments. (line 60) -<<<<<<< HEAD -* Buening, Andreas <1>: Contributors. (line 93) -* Buening, Andreas <2>: Bugs. (line 71) -* buffering, input/output: I/O Functions. (line 139) -* buffering, input/output <1>: Two-way I/O. (line 70) -* buffering, interactive vs. noninteractive: I/O Functions. (line 108) -======= * buffering, input/output <1>: Two-way I/O. (line 52) * buffering, input/output: I/O Functions. (line 140) * buffering, interactive vs. noninteractive: I/O Functions. (line 109) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * buffers, flushing: I/O Functions. (line 32) -* buffers, flushing <1>: I/O Functions. (line 139) * buffers, operators for: GNU Regexp Operators. - (line 51) -* bug reports, email address, 'bug-gawk@gnu.org': Bugs. (line 30) -* 'bug-gawk@gnu.org' bug reporting address: Bugs. (line 30) + (line 48) +* bug reports, email address, bug-gawk@gnu.org: Bugs. (line 30) +* bug-gawk@gnu.org bug reporting address: Bugs. (line 30) * built-in functions: Functions. (line 6) * built-in functions, evaluation order: Calling Built-in. (line 30) * built-in variables: Built-in Variables. (line 6) -* built-in variables, '-v' option, setting with: Options. (line 41) +* built-in variables, -v option, setting with: Options. (line 40) * built-in variables, conveying information: Auto-set. (line 6) * built-in variables, user-modifiable: User-modified. (line 6) * Busybox Awk: Other Versions. (line 88) * c.e., See common extensions: Conventions. (line 51) * call by reference: Pass By Value/Reference. - (line 46) + (line 47) * call by value: Pass By Value/Reference. - (line 17) + (line 18) * call stack, display in debugger: Execution Stack. (line 13) -* caret ('^'), in bracket expressions: Bracket Expressions. (line 17) -* caret ('^'), regexp operator: Regexp Operators. (line 22) -* caret ('^'), regexp operator <1>: GNU Regexp Operators. - (line 62) -* caret ('^'), '^' operator: Precedence. (line 48) -* caret ('^'), '^=' operator: Assignment Ops. (line 129) -* caret ('^'), '^=' operator <1>: Precedence. (line 94) -* 'case' keyword: Switch Statement. (line 6) +* caret (^), ^ operator: Precedence. (line 49) +* caret (^), ^= operator <1>: Precedence. (line 95) +* caret (^), ^= operator: Assignment Ops. (line 130) +* caret (^), in bracket expressions: Bracket Expressions. (line 17) +* caret (^), regexp operator <1>: GNU Regexp Operators. + (line 59) +* caret (^), regexp operator: Regexp Operators. (line 22) +* case keyword: Switch Statement. (line 6) * case sensitivity, and regexps: User-modified. (line 76) * case sensitivity, and string comparisons: User-modified. (line 76) -<<<<<<< HEAD -* case sensitivity, array indices and: Array Intro. (line 91) -* case sensitivity, converting case: String Functions. (line 519) -======= * case sensitivity, array indices and: Array Intro. (line 94) * case sensitivity, converting case: String Functions. (line 520) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * case sensitivity, example programs: Library Functions. (line 53) -* case sensitivity, 'gawk': Case-sensitivity. (line 26) +* case sensitivity, gawk: Case-sensitivity. (line 26) * case sensitivity, regexps and: Case-sensitivity. (line 6) -* CGI, 'awk' scripts for: Options. (line 125) +* CGI, awk scripts for: Options. (line 125) * character classes, See bracket expressions: Regexp Operators. (line 56) * character lists in regular expression: Bracket Expressions. (line 6) * character lists, See bracket expressions: Regexp Operators. (line 56) +* character sets (machine character encodings) <1>: Glossary. (line 133) * character sets (machine character encodings): Ordinal Functions. (line 45) -* character sets (machine character encodings) <1>: Glossary. (line 133) * character sets, See Also bracket expressions: Regexp Operators. (line 56) * characters, counting: Wc Program. (line 6) * characters, transliterating: Translate Program. (line 6) * characters, values of as numbers: Ordinal Functions. (line 6) * Chassell, Robert J.: Acknowledgments. (line 33) -* 'chdir()' extension function: Extension Sample File Functions. +* chdir() extension function: Extension Sample File Functions. (line 12) -* 'chem' utility: Glossary. (line 143) -* 'chr()' extension function: Extension Sample Ord. +* chem utility: Glossary. (line 143) +* chr() extension function: Extension Sample Ord. (line 15) -* 'chr()' user-defined function: Ordinal Functions. (line 16) -* 'clear' debugger command: Breakpoint Control. (line 36) +* chr() user-defined function: Ordinal Functions. (line 16) +* clear debugger command: Breakpoint Control. (line 36) * Cliff random numbers: Cliff Random Function. (line 6) -* 'cliff_rand()' user-defined function: Cliff Random Function. +* cliff_rand() user-defined function: Cliff Random Function. (line 12) -* 'close': Close Files And Pipes. +* close <1>: I/O Functions. (line 10) +* close: Close Files And Pipes. (line 18) -* 'close' <1>: I/O Functions. (line 10) * close file or coprocess: I/O Functions. (line 10) -* 'close()' function, portability: Close Files And Pipes. +* close() function, portability: Close Files And Pipes. (line 81) -* 'close()' function, return value: Close Files And Pipes. +* close() function, return value: Close Files And Pipes. (line 131) -<<<<<<< HEAD -* 'close()' function, two-way pipes and: Two-way I/O. (line 77) -* Close, Diane: Manual History. (line 41) -* Close, Diane <1>: Contributors. (line 21) -* Collado, Manuel: Acknowledgments. (line 60) -* collating elements: Bracket Expressions. (line 76) -* collating symbols: Bracket Expressions. (line 83) -======= * close() function, two-way pipes and: Two-way I/O. (line 59) * Close, Diane <1>: Contributors. (line 20) * Close, Diane: Manual History. (line 34) @@ -33288,50 +31737,31 @@ Index * collating elements: Bracket Expressions. (line 79) * collating symbols: Bracket Expressions. (line 86) * Colombo, Antonio <1>: Contributors. (line 137) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Colombo, Antonio: Acknowledgments. (line 60) -* Colombo, Antonio <1>: Contributors. (line 138) -* columns, aligning: Print Examples. (line 69) +* columns, aligning: Print Examples. (line 70) * columns, cutting: Cut Program. (line 6) -* comma (','), in range patterns: Ranges. (line 6) +* comma (,), in range patterns: Ranges. (line 6) * command completion, in debugger: Readline Support. (line 6) +* command line, arguments <1>: ARGC and ARGV. (line 6) +* command line, arguments <2>: Auto-set. (line 15) * command line, arguments: Other Arguments. (line 6) -<<<<<<< HEAD -* command line, arguments <1>: Auto-set. (line 15) -* command line, arguments <2>: ARGC and ARGV. (line 6) -* command line, directories on: Command line directories. -======= * command line, directories on: Command-line directories. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 6) * command line, formats: Running gawk. (line 12) -* command line, 'FS' on, setting: Command Line Field Separator. +* command line, FS on, setting: Command Line Field Separator. (line 6) -* command line, invoking 'awk' from: Command Line. (line 6) -* command line, option '-f': Long. (line 12) +* command line, invoking awk from: Command Line. (line 6) +* command line, option -f: Long. (line 12) * command line, options: Options. (line 6) -* command line, options, end of: Options. (line 55) +* command line, options, end of: Options. (line 54) * command line, variables, assigning on: Assignment Options. (line 6) * command-line options, processing: Getopt Function. (line 6) * command-line options, string extraction: String Extraction. (line 6) -* 'commands' debugger command: Debugger Execution Control. +* commands debugger command: Debugger Execution Control. (line 10) * commands to execute at breakpoint: Debugger Execution Control. (line 10) * commenting: Comments. (line 6) -<<<<<<< HEAD -* commenting, backslash continuation and: Statements/Lines. (line 75) -* common extensions, '**' operator: Arithmetic Ops. (line 30) -* common extensions, '**=' operator: Assignment Ops. (line 138) -* common extensions, '/dev/stderr' special file: Special FD. (line 46) -* common extensions, '/dev/stdin' special file: Special FD. (line 46) -* common extensions, '/dev/stdout' special file: Special FD. (line 46) -* common extensions, 'BINMODE' variable: PC Using. (line 33) -* common extensions, 'delete' to delete entire arrays: Delete. - (line 39) -* common extensions, 'func' keyword: Definition Syntax. (line 89) -* common extensions, 'length()' applied to an array: String Functions. -======= * commenting, backslash continuation and: Statements/Lines. (line 76) * common extensions, ** operator: Arithmetic Ops. (line 30) * common extensions, **= operator: Assignment Ops. (line 137) @@ -33343,46 +31773,44 @@ Index * common extensions, delete to delete entire arrays: Delete. (line 39) * common extensions, func keyword: Definition Syntax. (line 92) * common extensions, length() applied to an array: String Functions. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 197) -* common extensions, 'RS' as a regexp: gawk split records. (line 6) +* common extensions, RS as a regexp: gawk split records. (line 6) * common extensions, single character fields: Single Character Fields. (line 6) -* common extensions, '\x' escape sequence: Escape Sequences. (line 61) -* 'comp.lang.awk' newsgroup: Bugs. (line 39) +* comp.lang.awk newsgroup: Bugs. (line 39) * comparison expressions: Typing and Comparison. (line 9) * comparison expressions, as patterns: Expression Patterns. (line 14) * comparison expressions, string vs. regexp: Comparison Operators. - (line 79) -* compatibility mode ('gawk'), extensions: POSIX/GNU. (line 6) -* compatibility mode ('gawk'), file names: Special Caveats. (line 9) -* compatibility mode ('gawk'), hexadecimal numbers: Nondecimal-numbers. - (line 59) -* compatibility mode ('gawk'), octal numbers: Nondecimal-numbers. - (line 59) -* compatibility mode ('gawk'), specifying: Options. (line 82) -* compiled programs: Basic High Level. (line 13) + (line 78) +* compatibility mode (gawk), extensions: POSIX/GNU. (line 6) +* compatibility mode (gawk), file names: Special Caveats. (line 9) +* compatibility mode (gawk), hexadecimal numbers: Nondecimal-numbers. + (line 60) +* compatibility mode (gawk), octal numbers: Nondecimal-numbers. + (line 60) +* compatibility mode (gawk), specifying: Options. (line 81) * compiled programs <1>: Glossary. (line 157) -* compiling 'gawk' for Cygwin: Cygwin. (line 6) -* compiling 'gawk' for MS-DOS and MS-Windows: PC Compiling. (line 13) -* compiling 'gawk' for VMS: VMS Compilation. (line 6) -* compiling 'gawk' with EMX for OS/2: PC Compiling. (line 28) -* 'compl': Bitwise Functions. (line 43) +* compiled programs: Basic High Level. (line 15) +* compiling gawk for Cygwin: Cygwin. (line 6) +* compiling gawk for MS-DOS and MS-Windows: PC Compiling. (line 13) +* compiling gawk for VMS: VMS Compilation. (line 6) +* compiling gawk with EMX for OS/2: PC Compiling. (line 28) +* compl: Bitwise Functions. (line 43) * complement, bitwise: Bitwise Functions. (line 25) * compound statements, control statements and: Statements. (line 10) -* concatenating: Concatenation. (line 9) -* 'condition' debugger command: Breakpoint Control. (line 54) +* concatenating: Concatenation. (line 8) +* condition debugger command: Breakpoint Control. (line 54) * conditional expressions: Conditional Exp. (line 6) -* configuration option, '--disable-extensions': Additional Configuration Options. +* configuration option, --disable-extensions: Additional Configuration Options. (line 9) -* configuration option, '--disable-lint': Additional Configuration Options. +* configuration option, --disable-lint: Additional Configuration Options. (line 15) -* configuration option, '--disable-nls': Additional Configuration Options. +* configuration option, --disable-nls: Additional Configuration Options. (line 30) -* configuration option, '--with-whiny-user-strftime': Additional Configuration Options. +* configuration option, --with-whiny-user-strftime: Additional Configuration Options. (line 35) -* configuration options, 'gawk': Additional Configuration Options. +* configuration options, gawk: Additional Configuration Options. (line 6) * constant regexps: Regexp Usage. (line 57) * constants, nondecimal: Nondecimal Data. (line 6) @@ -33390,69 +31818,44 @@ Index * constants, types of: Constants. (line 6) * continue program, in debugger: Debugger Execution Control. (line 33) -* 'continue' statement: Continue Statement. (line 6) +* continue statement: Continue Statement. (line 6) * control statements: Statements. (line 6) * controlling array scanning order: Controlling Scanning. (line 14) -* convert string to lower case: String Functions. (line 520) -* convert string to number: String Functions. (line 387) -* convert string to upper case: String Functions. (line 526) +* convert string to lower case: String Functions. (line 521) +* convert string to number: String Functions. (line 388) +* convert string to upper case: String Functions. (line 527) * converting integer array subscripts: Numeric Array Subscripts. (line 31) -* converting, dates to timestamps: Time Functions. (line 75) +* converting, dates to timestamps: Time Functions. (line 76) +* converting, numbers to strings <1>: Bitwise Functions. (line 109) * converting, numbers to strings: Strings And Numbers. (line 6) -* converting, numbers to strings <1>: Bitwise Functions. (line 110) +* converting, strings to numbers <1>: Bitwise Functions. (line 109) * converting, strings to numbers: Strings And Numbers. (line 6) -* converting, strings to numbers <1>: Bitwise Functions. (line 110) -* 'CONVFMT' variable: Strings And Numbers. (line 29) -* 'CONVFMT' variable <1>: User-modified. (line 30) -* 'CONVFMT' variable, and array subscripts: Numeric Array Subscripts. +* CONVFMT variable <1>: User-modified. (line 30) +* CONVFMT variable: Strings And Numbers. (line 29) +* CONVFMT variable, and array subscripts: Numeric Array Subscripts. (line 6) * cookie: Glossary. (line 149) -<<<<<<< HEAD -======= * coprocesses <1>: Two-way I/O. (line 25) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * coprocesses: Redirection. (line 102) -* coprocesses <1>: Two-way I/O. (line 44) * coprocesses, closing: Close Files And Pipes. (line 6) -* coprocesses, 'getline' from: Getline/Coprocess. (line 6) -* 'cos': Numeric Functions. (line 14) -* cosine: Numeric Functions. (line 14) +* coprocesses, getline from: Getline/Coprocess. (line 6) +* cos: Numeric Functions. (line 15) +* cosine: Numeric Functions. (line 15) * counting: Wc Program. (line 6) -<<<<<<< HEAD -* 'csh' utility: Statements/Lines. (line 43) -* 'csh' utility, 'POSIXLY_CORRECT' environment variable: Options. - (line 350) -* 'csh' utility, '|&' operator, comparison with: Two-way I/O. (line 44) -* 'ctime()' user-defined function: Function Example. (line 73) -======= * csh utility: Statements/Lines. (line 44) * csh utility, POSIXLY_CORRECT environment variable: Options. (line 351) * csh utility, |& operator, comparison with: Two-way I/O. (line 25) * ctime() user-defined function: Function Example. (line 74) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * currency symbols, localization: Explaining gettext. (line 104) -* current system time: Time Functions. (line 65) -* 'custom.h' file: Configuration Philosophy. +* current system time: Time Functions. (line 66) +* custom.h file: Configuration Philosophy. (line 30) * customized input parser: Input Parsers. (line 6) * customized output wrapper: Output Wrappers. (line 6) * customized two-way processor: Two-way processors. (line 6) -<<<<<<< HEAD -* 'cut' utility: Cut Program. (line 6) -* 'cut' utility <1>: Cut Program. (line 6) -* 'cut.awk' program: Cut Program. (line 45) -* 'd' debugger command (alias for 'delete'): Breakpoint Control. - (line 64) -* d.c., See dark corner: Conventions. (line 38) -* dark corner: Conventions. (line 38) -* dark corner <1>: Glossary. (line 188) -* dark corner, '"0"' is actually true: Truth Values. (line 24) -* dark corner, '/=' operator vs. '/=.../' regexp constant: Assignment Ops. - (line 149) -======= * cut utility: Cut Program. (line 6) * cut.awk program: Cut Program. (line 45) * d debugger command (alias for delete): Breakpoint Control. (line 64) @@ -33464,26 +31867,12 @@ Index (line 148) * dark corner, ^, in FS: Regexp Field Splitting. (line 59) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * dark corner, array subscripts: Uninitialized Subscripts. (line 43) -* dark corner, 'break' statement: Break Statement. (line 51) -* dark corner, 'close()' function: Close Files And Pipes. +* dark corner, break statement: Break Statement. (line 51) +* dark corner, close() function: Close Files And Pipes. (line 131) * dark corner, command-line arguments: Assignment Options. (line 43) -<<<<<<< HEAD -* dark corner, 'continue' statement: Continue Statement. (line 43) -* dark corner, 'CONVFMT' variable: Strings And Numbers. (line 39) -* dark corner, escape sequences: Other Arguments. (line 31) -* dark corner, escape sequences, for metacharacters: Escape Sequences. - (line 133) -* dark corner, 'exit' statement: Exit Statement. (line 30) -* dark corner, field separators: Field Splitting Summary. - (line 45) -* dark corner, 'FILENAME' variable: Getline Notes. (line 19) -* dark corner, 'FILENAME' variable <1>: Auto-set. (line 98) -* dark corner, 'FNR'/'NR' variables: Auto-set. (line 309) -======= * dark corner, continue statement: Continue Statement. (line 44) * dark corner, CONVFMT variable: Strings And Numbers. (line 40) * dark corner, escape sequences: Other Arguments. (line 35) @@ -33495,47 +31884,34 @@ Index * dark corner, FILENAME variable <1>: Auto-set. (line 98) * dark corner, FILENAME variable: Getline Notes. (line 19) * dark corner, FNR/NR variables: Auto-set. (line 313) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * dark corner, format-control characters: Control Letters. (line 18) -* dark corner, format-control characters <1>: Control Letters. - (line 93) -* dark corner, 'FS' as null string: Single Character Fields. +* dark corner, FS as null string: Single Character Fields. (line 20) -* dark corner, input files: awk split records. (line 109) -* dark corner, invoking 'awk': Command Line. (line 16) -* dark corner, 'length()' function: String Functions. (line 183) +* dark corner, input files: awk split records. (line 110) +* dark corner, invoking awk: Command Line. (line 16) +* dark corner, length() function: String Functions. (line 183) * dark corner, locale's decimal point character: Locale influences conversions. (line 17) * dark corner, multiline records: Multiple Line. (line 35) -* dark corner, 'NF' variable, decrementing: Changing Fields. (line 107) -* dark corner, 'OFMT' variable: OFMT. (line 27) +* dark corner, NF variable, decrementing: Changing Fields. (line 107) +* dark corner, OFMT variable: OFMT. (line 27) * dark corner, regexp constants: Using Constant Regexps. (line 6) -* dark corner, regexp constants, '/=' operator and: Assignment Ops. - (line 149) +* dark corner, regexp constants, /= operator and: Assignment Ops. + (line 148) * dark corner, regexp constants, as arguments to user-defined functions: Using Constant Regexps. (line 43) -* dark corner, 'split()' function: String Functions. (line 358) -* dark corner, strings, storing: gawk split records. (line 82) -* dark corner, value of 'ARGV[0]': Auto-set. (line 39) -* dark corner, '^', in 'FS': Regexp Field Splitting. - (line 59) +* dark corner, split() function: String Functions. (line 359) +* dark corner, strings, storing: gawk split records. (line 83) +* dark corner, value of ARGV[0]: Auto-set. (line 39) * data, fixed-width: Constant Size. (line 10) -* data-driven languages: Basic High Level. (line 74) +* data-driven languages: Basic High Level. (line 85) * database, group, reading: Group Functions. (line 6) * database, users, reading: Passwd Functions. (line 6) -* 'date' utility, GNU: Time Functions. (line 17) -* 'date' utility, POSIX: Time Functions. (line 252) -* dates, converting to timestamps: Time Functions. (line 75) +* date utility, GNU: Time Functions. (line 17) +* date utility, POSIX: Time Functions. (line 254) +* dates, converting to timestamps: Time Functions. (line 76) * dates, information related to, localization: Explaining gettext. -<<<<<<< HEAD - (line 116) -* Davies, Stephen: Acknowledgments. (line 60) -* Davies, Stephen <1>: Contributors. (line 75) -* 'dcgettext': I18N Functions. (line 21) -* 'dcgettext' <1>: Programmer i18n. (line 19) -* 'dcgettext()' function ('gawk'), portability and: I18N Portability. -======= (line 112) * Davies, Stephen <1>: Contributors. (line 74) * Davies, Stephen: Acknowledgments. (line 60) @@ -33543,118 +31919,108 @@ Index * dcgettext <1>: Programmer i18n. (line 19) * dcgettext: I18N Functions. (line 22) * dcgettext() function (gawk), portability and: I18N Portability. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 33) -* 'dcngettext': I18N Functions. (line 27) -* 'dcngettext' <1>: Programmer i18n. (line 36) -* 'dcngettext()' function ('gawk'), portability and: I18N Portability. +* dcngettext <1>: Programmer i18n. (line 36) +* dcngettext: I18N Functions. (line 28) +* dcngettext() function (gawk), portability and: I18N Portability. (line 33) -<<<<<<< HEAD -* deadlocks: Two-way I/O. (line 70) -* debugger commands, 'b' ('break'): Breakpoint Control. (line 11) -* debugger commands, 'backtrace': Execution Stack. (line 13) -* debugger commands, 'break': Breakpoint Control. (line 11) -* debugger commands, 'bt' ('backtrace'): Execution Stack. (line 13) -* debugger commands, 'c' ('continue'): Debugger Execution Control. -======= * deadlocks: Two-way I/O. (line 52) * debugger commands, b (break): Breakpoint Control. (line 11) * debugger commands, backtrace: Execution Stack. (line 13) * debugger commands, break: Breakpoint Control. (line 11) * debugger commands, bt (backtrace): Execution Stack. (line 13) * debugger commands, c (continue): Debugger Execution Control. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 33) -* debugger commands, 'clear': Breakpoint Control. (line 36) -* debugger commands, 'commands': Debugger Execution Control. +* debugger commands, clear: Breakpoint Control. (line 36) +* debugger commands, commands: Debugger Execution Control. (line 10) -* debugger commands, 'condition': Breakpoint Control. (line 54) -* debugger commands, 'continue': Debugger Execution Control. +* debugger commands, condition: Breakpoint Control. (line 54) +* debugger commands, continue: Debugger Execution Control. (line 33) -* debugger commands, 'd' ('delete'): Breakpoint Control. (line 64) -* debugger commands, 'delete': Breakpoint Control. (line 64) -* debugger commands, 'disable': Breakpoint Control. (line 69) -* debugger commands, 'display': Viewing And Changing Data. +* debugger commands, d (delete): Breakpoint Control. (line 64) +* debugger commands, delete: Breakpoint Control. (line 64) +* debugger commands, disable: Breakpoint Control. (line 69) +* debugger commands, display: Viewing And Changing Data. (line 8) -* debugger commands, 'down': Execution Stack. (line 20) -* debugger commands, 'dump': Miscellaneous Debugger Commands. +* debugger commands, down: Execution Stack. (line 21) +* debugger commands, dump: Miscellaneous Debugger Commands. (line 9) -* debugger commands, 'e' ('enable'): Breakpoint Control. (line 73) -* debugger commands, 'enable': Breakpoint Control. (line 73) -* debugger commands, 'end': Debugger Execution Control. +* debugger commands, e (enable): Breakpoint Control. (line 73) +* debugger commands, enable: Breakpoint Control. (line 73) +* debugger commands, end: Debugger Execution Control. (line 10) -* debugger commands, 'eval': Viewing And Changing Data. +* debugger commands, eval: Viewing And Changing Data. (line 23) -* debugger commands, 'f' ('frame'): Execution Stack. (line 24) -* debugger commands, 'finish': Debugger Execution Control. +* debugger commands, f (frame): Execution Stack. (line 25) +* debugger commands, finish: Debugger Execution Control. (line 39) -* debugger commands, 'frame': Execution Stack. (line 24) -* debugger commands, 'h' ('help'): Miscellaneous Debugger Commands. +* debugger commands, frame: Execution Stack. (line 25) +* debugger commands, h (help): Miscellaneous Debugger Commands. (line 66) -* debugger commands, 'help': Miscellaneous Debugger Commands. +* debugger commands, help: Miscellaneous Debugger Commands. (line 66) -* debugger commands, 'i' ('info'): Debugger Info. (line 13) -* debugger commands, 'ignore': Breakpoint Control. (line 87) -* debugger commands, 'info': Debugger Info. (line 13) -* debugger commands, 'l' ('list'): Miscellaneous Debugger Commands. +* debugger commands, i (info): Debugger Info. (line 13) +* debugger commands, ignore: Breakpoint Control. (line 87) +* debugger commands, info: Debugger Info. (line 13) +* debugger commands, l (list): Miscellaneous Debugger Commands. (line 72) -* debugger commands, 'list': Miscellaneous Debugger Commands. +* debugger commands, list: Miscellaneous Debugger Commands. (line 72) -* debugger commands, 'n' ('next'): Debugger Execution Control. +* debugger commands, n (next): Debugger Execution Control. (line 43) -* debugger commands, 'next': Debugger Execution Control. +* debugger commands, next: Debugger Execution Control. (line 43) -* debugger commands, 'nexti': Debugger Execution Control. +* debugger commands, nexti: Debugger Execution Control. (line 49) -* debugger commands, 'ni' ('nexti'): Debugger Execution Control. +* debugger commands, ni (nexti): Debugger Execution Control. (line 49) -* debugger commands, 'o' ('option'): Debugger Info. (line 57) -* debugger commands, 'option': Debugger Info. (line 57) -* debugger commands, 'p' ('print'): Viewing And Changing Data. - (line 35) -* debugger commands, 'print': Viewing And Changing Data. - (line 35) -* debugger commands, 'printf': Viewing And Changing Data. - (line 53) -* debugger commands, 'q' ('quit'): Miscellaneous Debugger Commands. +* debugger commands, o (option): Debugger Info. (line 57) +* debugger commands, option: Debugger Info. (line 57) +* debugger commands, p (print): Viewing And Changing Data. + (line 36) +* debugger commands, print: Viewing And Changing Data. + (line 36) +* debugger commands, printf: Viewing And Changing Data. + (line 54) +* debugger commands, q (quit): Miscellaneous Debugger Commands. (line 99) -* debugger commands, 'quit': Miscellaneous Debugger Commands. +* debugger commands, quit: Miscellaneous Debugger Commands. (line 99) -* debugger commands, 'r' ('run'): Debugger Execution Control. +* debugger commands, r (run): Debugger Execution Control. (line 62) -* debugger commands, 'return': Debugger Execution Control. +* debugger commands, return: Debugger Execution Control. (line 54) -* debugger commands, 'run': Debugger Execution Control. +* debugger commands, run: Debugger Execution Control. (line 62) -* debugger commands, 's' ('step'): Debugger Execution Control. +* debugger commands, s (step): Debugger Execution Control. (line 68) -* debugger commands, 'set': Viewing And Changing Data. - (line 58) -* debugger commands, 'si' ('stepi'): Debugger Execution Control. +* debugger commands, set: Viewing And Changing Data. + (line 59) +* debugger commands, si (stepi): Debugger Execution Control. (line 76) -* debugger commands, 'silent': Debugger Execution Control. +* debugger commands, silent: Debugger Execution Control. (line 10) -* debugger commands, 'step': Debugger Execution Control. +* debugger commands, step: Debugger Execution Control. (line 68) -* debugger commands, 'stepi': Debugger Execution Control. +* debugger commands, stepi: Debugger Execution Control. (line 76) -* debugger commands, 't' ('tbreak'): Breakpoint Control. (line 90) -* debugger commands, 'tbreak': Breakpoint Control. (line 90) -* debugger commands, 'trace': Miscellaneous Debugger Commands. +* debugger commands, t (tbreak): Breakpoint Control. (line 90) +* debugger commands, tbreak: Breakpoint Control. (line 90) +* debugger commands, trace: Miscellaneous Debugger Commands. (line 108) -* debugger commands, 'u' ('until'): Debugger Execution Control. +* debugger commands, u (until): Debugger Execution Control. (line 83) -* debugger commands, 'undisplay': Viewing And Changing Data. - (line 79) -* debugger commands, 'until': Debugger Execution Control. +* debugger commands, undisplay: Viewing And Changing Data. + (line 80) +* debugger commands, until: Debugger Execution Control. (line 83) -* debugger commands, 'unwatch': Viewing And Changing Data. - (line 83) -* debugger commands, 'up': Execution Stack. (line 33) -* debugger commands, 'w' ('watch'): Viewing And Changing Data. - (line 66) -* debugger commands, 'watch': Viewing And Changing Data. - (line 66) +* debugger commands, unwatch: Viewing And Changing Data. + (line 84) +* debugger commands, up: Execution Stack. (line 34) +* debugger commands, w (watch): Viewing And Changing Data. + (line 67) +* debugger commands, watch: Viewing And Changing Data. + (line 67) * debugger default list amount: Debugger Info. (line 69) * debugger history file: Debugger Info. (line 80) * debugger history size: Debugger Info. (line 65) @@ -33662,129 +32028,85 @@ Index * debugger prompt: Debugger Info. (line 77) * debugger, how to start: Debugger Invocation. (line 6) * debugger, read commands from a file: Debugger Info. (line 96) -* debugging 'awk' programs: Debugger. (line 6) -* debugging 'gawk', bug reports: Bugs. (line 9) -* decimal point character, locale specific: Options. (line 265) +* debugging awk programs: Debugger. (line 6) +* debugging gawk, bug reports: Bugs. (line 9) +* decimal point character, locale specific: Options. (line 268) * decrement operators: Increment Ops. (line 35) -* 'default' keyword: Switch Statement. (line 6) +* default keyword: Switch Statement. (line 6) +* Deifik, Scott <1>: Bugs. (line 71) +* Deifik, Scott <2>: Contributors. (line 53) * Deifik, Scott: Acknowledgments. (line 60) -* Deifik, Scott <1>: Contributors. (line 54) -* Deifik, Scott <2>: Bugs. (line 71) -* 'delete' ARRAY: Delete. (line 39) +* delete ARRAY: Delete. (line 39) * delete breakpoint at location: Breakpoint Control. (line 36) * delete breakpoint by number: Breakpoint Control. (line 64) -* 'delete' debugger command: Breakpoint Control. (line 64) -* 'delete' statement: Delete. (line 6) +* delete debugger command: Breakpoint Control. (line 64) +* delete statement: Delete. (line 6) * delete watchpoint: Viewing And Changing Data. - (line 83) + (line 84) * deleting elements in arrays: Delete. (line 6) * deleting entire arrays: Delete. (line 39) * Demaille, Akim: Acknowledgments. (line 60) * describe call stack frame, in debugger: Debugger Info. (line 27) -<<<<<<< HEAD -* differences between 'gawk' and 'awk': String Functions. (line 197) -* differences in 'awk' and 'gawk', 'ARGC'/'ARGV' variables: ARGC and ARGV. - (line 88) -* differences in 'awk' and 'gawk', 'ARGIND' variable: Auto-set. - (line 44) -* differences in 'awk' and 'gawk', array elements, deleting: Delete. -======= * differences between gawk and awk: String Functions. (line 197) * differences in awk and gawk, ARGC/ARGV variables: ARGC and ARGV. (line 90) * differences in awk and gawk, ARGIND variable: Auto-set. (line 44) * differences in awk and gawk, array elements, deleting: Delete. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 39) -* differences in 'awk' and 'gawk', 'AWKLIBPATH' environment variable: AWKLIBPATH Variable. +* differences in awk and gawk, AWKLIBPATH environment variable: AWKLIBPATH Variable. (line 6) -* differences in 'awk' and 'gawk', 'AWKPATH' environment variable: AWKPATH Variable. +* differences in awk and gawk, AWKPATH environment variable: AWKPATH Variable. (line 6) -* differences in 'awk' and 'gawk', 'BEGIN'/'END' patterns: I/O And BEGIN/END. - (line 15) -* differences in 'awk' and 'gawk', 'BEGINFILE'/'ENDFILE' patterns: BEGINFILE/ENDFILE. +* differences in awk and gawk, BEGIN/END patterns: I/O And BEGIN/END. + (line 16) +* differences in awk and gawk, BEGINFILE/ENDFILE patterns: BEGINFILE/ENDFILE. (line 6) -* differences in 'awk' and 'gawk', 'BINMODE' variable: User-modified. - (line 15) -* differences in 'awk' and 'gawk', 'BINMODE' variable <1>: PC Using. +* differences in awk and gawk, BINMODE variable <1>: PC Using. (line 33) -* differences in 'awk' and 'gawk', 'close()' function: Close Files And Pipes. +* differences in awk and gawk, BINMODE variable: User-modified. + (line 15) +* differences in awk and gawk, close() function: Close Files And Pipes. (line 81) -<<<<<<< HEAD -* differences in 'awk' and 'gawk', 'close()' function <1>: Close Files And Pipes. - (line 131) -* differences in 'awk' and 'gawk', command line directories: Command line directories. -======= * differences in awk and gawk, command-line directories: Command-line directories. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 6) -* differences in 'awk' and 'gawk', 'ERRNO' variable: Auto-set. - (line 82) -* differences in 'awk' and 'gawk', error messages: Special FD. - (line 16) -* differences in 'awk' and 'gawk', 'FIELDWIDTHS' variable: User-modified. +* differences in awk and gawk, ERRNO variable: Auto-set. (line 82) +* differences in awk and gawk, error messages: Special FD. (line 16) +* differences in awk and gawk, FIELDWIDTHS variable: User-modified. (line 37) -* differences in 'awk' and 'gawk', 'FPAT' variable: User-modified. - (line 43) -* differences in 'awk' and 'gawk', 'FUNCTAB' variable: Auto-set. - (line 123) -* differences in 'awk' and 'gawk', function arguments ('gawk'): Calling Built-in. +* differences in awk and gawk, FPAT variable: User-modified. (line 43) +* differences in awk and gawk, FUNCTAB variable: Auto-set. (line 123) +* differences in awk and gawk, function arguments (gawk): Calling Built-in. (line 16) -* differences in 'awk' and 'gawk', 'getline' command: Getline. - (line 19) -* differences in 'awk' and 'gawk', 'IGNORECASE' variable: User-modified. +* differences in awk and gawk, getline command: Getline. (line 19) +* differences in awk and gawk, IGNORECASE variable: User-modified. (line 76) -* differences in 'awk' and 'gawk', implementation limitations: Getline Notes. +* differences in awk and gawk, implementation limitations <1>: Redirection. + (line 135) +* differences in awk and gawk, implementation limitations: Getline Notes. (line 14) -* differences in 'awk' and 'gawk', implementation limitations <1>: Redirection. - (line 134) -* differences in 'awk' and 'gawk', indirect function calls: Indirect Calls. - (line 6) -* differences in 'awk' and 'gawk', input/output operators: Getline/Coprocess. +* differences in awk and gawk, indirect function calls: Indirect Calls. (line 6) -* differences in 'awk' and 'gawk', input/output operators <1>: Redirection. +* differences in awk and gawk, input/output operators <1>: Redirection. (line 102) -* differences in 'awk' and 'gawk', line continuations: Conditional Exp. +* differences in awk and gawk, input/output operators: Getline/Coprocess. + (line 6) +* differences in awk and gawk, line continuations: Conditional Exp. (line 34) -* differences in 'awk' and 'gawk', 'LINT' variable: User-modified. - (line 88) -* differences in 'awk' and 'gawk', 'match()' function: String Functions. +* differences in awk and gawk, LINT variable: User-modified. (line 88) +* differences in awk and gawk, match() function: String Functions. (line 260) -* differences in 'awk' and 'gawk', 'print'/'printf' statements: Format Modifiers. +* differences in awk and gawk, print/printf statements: Format Modifiers. (line 13) -<<<<<<< HEAD -* differences in 'awk' and 'gawk', 'PROCINFO' array: Auto-set. - (line 136) -* differences in 'awk' and 'gawk', read timeouts: Read Timeout. - (line 6) -* differences in 'awk' and 'gawk', record separators: awk split records. - (line 123) -* differences in 'awk' and 'gawk', regexp constants: Using Constant Regexps. -======= * differences in awk and gawk, PROCINFO array: Auto-set. (line 137) * differences in awk and gawk, read timeouts: Read Timeout. (line 6) * differences in awk and gawk, record separators: awk split records. (line 124) * differences in awk and gawk, regexp constants: Using Constant Regexps. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 43) -* differences in 'awk' and 'gawk', regular expressions: Case-sensitivity. +* differences in awk and gawk, regular expressions: Case-sensitivity. (line 26) -* differences in 'awk' and 'gawk', 'RS'/'RT' variables: gawk split records. +* differences in awk and gawk, RS/RT variables: gawk split records. (line 58) -<<<<<<< HEAD -* differences in 'awk' and 'gawk', 'RT' variable: Auto-set. (line 265) -* differences in 'awk' and 'gawk', single-character fields: Single Character Fields. - (line 6) -* differences in 'awk' and 'gawk', 'split()' function: String Functions. - (line 346) -* differences in 'awk' and 'gawk', strings: Scalar Constants. (line 20) -* differences in 'awk' and 'gawk', strings, storing: gawk split records. - (line 76) -* differences in 'awk' and 'gawk', 'SYMTAB' variable: Auto-set. - (line 269) -* differences in 'awk' and 'gawk', 'TEXTDOMAIN' variable: User-modified. -======= * differences in awk and gawk, RT variable: Auto-set. (line 269) * differences in awk and gawk, single-character fields: Single Character Fields. (line 6) @@ -33795,9 +32117,8 @@ Index (line 77) * differences in awk and gawk, SYMTAB variable: Auto-set. (line 273) * differences in awk and gawk, TEXTDOMAIN variable: User-modified. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 152) -* differences in 'awk' and 'gawk', trunc-mod operation: Arithmetic Ops. +* differences in awk and gawk, trunc-mod operation: Arithmetic Ops. (line 66) * directories, command-line: Command-line directories. (line 6) @@ -33806,100 +32127,63 @@ Index (line 6) * directories, searching for source files: AWKPATH Variable. (line 6) * disable breakpoint: Breakpoint Control. (line 69) -* 'disable' debugger command: Breakpoint Control. (line 69) -* 'display' debugger command: Viewing And Changing Data. +* disable debugger command: Breakpoint Control. (line 69) +* display debugger command: Viewing And Changing Data. (line 8) * display debugger options: Debugger Info. (line 57) -* 'div': Numeric Functions. (line 17) -* div: Numeric Functions. (line 17) +* div: Numeric Functions. (line 18) * division: Arithmetic Ops. (line 44) -* 'do'-'while' statement: Do Statement. (line 6) -* 'do'-'while' statement, use of regexps in: Regexp Usage. (line 19) -* documentation, of 'awk' programs: Library Names. (line 6) +* do-while statement: Do Statement. (line 6) +* do-while statement, use of regexps in: Regexp Usage. (line 19) +* documentation, of awk programs: Library Names. (line 6) * documentation, online: Manual History. (line 11) * documents, searching: Dupword Program. (line 6) -* dollar sign ('$'), '$' field operator: Fields. (line 19) -* dollar sign ('$'), '$' field operator <1>: Precedence. (line 42) -* dollar sign ('$'), incrementing fields and arrays: Increment Ops. +* dollar sign ($), $ field operator <1>: Precedence. (line 43) +* dollar sign ($), $ field operator: Fields. (line 19) +* dollar sign ($), incrementing fields and arrays: Increment Ops. (line 30) -<<<<<<< HEAD -* dollar sign ('$'), regexp operator: Regexp Operators. (line 35) -* double quote ('"') in shell commands: Read Terminal. (line 25) -* double quote ('"'), in regexp constants: Computed Regexps. (line 29) -* double quote ('"'), in shell commands: Quoting. (line 54) -* 'down' debugger command: Execution Stack. (line 20) -======= * dollar sign ($), regexp operator: Regexp Operators. (line 35) * double quote ("), in regexp constants: Computed Regexps. (line 29) * double quote ("), in shell commands: Quoting. (line 54) * down debugger command: Execution Stack. (line 21) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Drepper, Ulrich: Acknowledgments. (line 52) -* dump all variables of a program: Options. (line 94) -* 'dump' debugger command: Miscellaneous Debugger Commands. +* dump all variables of a program: Options. (line 93) +* dump debugger command: Miscellaneous Debugger Commands. (line 9) -* 'dupword.awk' program: Dupword Program. (line 31) -* dynamic profiling: Profiling. (line 178) +* dupword.awk program: Dupword Program. (line 31) +* dynamic profiling: Profiling. (line 179) * dynamically loaded extensions: Dynamic Extensions. (line 6) -* 'e' debugger command (alias for 'enable'): Breakpoint Control. - (line 73) +* e debugger command (alias for enable): Breakpoint Control. (line 73) * EBCDIC: Ordinal Functions. (line 45) -<<<<<<< HEAD -* effective group ID of 'gawk' user: Auto-set. (line 141) -* effective user ID of 'gawk' user: Auto-set. (line 145) -* 'egrep' utility: Bracket Expressions. (line 24) -* 'egrep' utility <1>: Egrep Program. (line 6) -* 'egrep.awk' program: Egrep Program. (line 53) -======= * effective group ID of gawk user: Auto-set. (line 142) * effective user ID of gawk user: Auto-set. (line 146) * egrep utility <1>: Egrep Program. (line 6) * egrep utility: Bracket Expressions. (line 26) * egrep.awk program: Egrep Program. (line 54) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * elements in arrays, assigning values: Assigning Elements. (line 6) * elements in arrays, deleting: Delete. (line 6) -* elements in arrays, order of access by 'in' operator: Scanning an Array. +* elements in arrays, order of access by in operator: Scanning an Array. (line 48) * elements in arrays, scanning: Scanning an Array. (line 6) * elements of arrays: Reference to Elements. (line 6) -* email address for bug reports, 'bug-gawk@gnu.org': Bugs. (line 30) -* 'EMISTERED': TCP/IP Networking. (line 6) +* email address for bug reports, bug-gawk@gnu.org: Bugs. (line 30) +* EMISTERED: TCP/IP Networking. (line 6) * empty array elements: Reference to Elements. (line 18) * empty pattern: Empty. (line 6) -* empty strings: awk split records. (line 113) +* empty strings: awk split records. (line 114) * empty strings, See null strings: Regexp Field Splitting. (line 43) * enable breakpoint: Breakpoint Control. (line 73) -* 'enable' debugger command: Breakpoint Control. (line 73) -* 'end' debugger command: Debugger Execution Control. +* enable debugger command: Breakpoint Control. (line 73) +* end debugger command: Debugger Execution Control. (line 10) -* 'END' pattern: BEGIN/END. (line 6) -* 'END' pattern <1>: Using BEGIN/END. (line 6) -* 'END' pattern, and profiling: Profiling. (line 62) -* 'END' pattern, 'assert()' user-defined function and: Assert Function. +* END pattern <1>: Using BEGIN/END. (line 6) +* END pattern: BEGIN/END. (line 6) +* END pattern, and profiling: Profiling. (line 62) +* END pattern, assert() user-defined function and: Assert Function. (line 75) -<<<<<<< HEAD -* 'END' pattern, backslash continuation and: Egrep Program. (line 222) -* 'END' pattern, Boolean patterns and: Expression Patterns. (line 70) -* 'END' pattern, 'exit' statement and: Exit Statement. (line 12) -* 'END' pattern, 'next'/'nextfile' statements and: I/O And BEGIN/END. - (line 36) -* 'END' pattern, 'next'/'nextfile' statements and <1>: Next Statement. - (line 45) -* 'END' pattern, operators and: Using BEGIN/END. (line 17) -* 'END' pattern, 'print' statement and: I/O And BEGIN/END. (line 15) -* 'ENDFILE' pattern: BEGINFILE/ENDFILE. (line 6) -* 'ENDFILE' pattern, Boolean patterns and: Expression Patterns. - (line 70) -* 'endfile()' user-defined function: Filetrans Function. (line 62) -* 'endgrent()' function (C library): Group Functions. (line 213) -* 'endgrent()' user-defined function: Group Functions. (line 216) -* 'endpwent()' function (C library): Passwd Functions. (line 210) -* 'endpwent()' user-defined function: Passwd Functions. (line 213) -======= * END pattern, Boolean patterns and: Expression Patterns. (line 70) * END pattern, exit statement and: Exit Statement. (line 12) * END pattern, next/nextfile statements and <1>: Next Statement. @@ -33915,40 +32199,30 @@ Index * endgrent() user-defined function: Group Functions. (line 215) * endpwent() function (C library): Passwd Functions. (line 210) * endpwent() user-defined function: Passwd Functions. (line 213) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * English, Steve: Advanced Features. (line 6) -* 'ENVIRON' array: Auto-set. (line 59) -* environment variables used by 'gawk': Environment Variables. +* ENVIRON array: Auto-set. (line 60) +* environment variables used by gawk: Environment Variables. (line 6) -* environment variables, in 'ENVIRON' array: Auto-set. (line 59) -* epoch, definition of: Glossary. (line 232) -* equals sign ('='), '=' operator: Assignment Ops. (line 6) -* equals sign ('='), '==' operator: Comparison Operators. +* environment variables, in ENVIRON array: Auto-set. (line 60) +* epoch, definition of: Glossary. (line 234) +* equals sign (=), = operator: Assignment Ops. (line 6) +* equals sign (=), == operator <1>: Precedence. (line 65) +* equals sign (=), == operator: Comparison Operators. (line 11) -<<<<<<< HEAD -* equals sign ('='), '==' operator <1>: Precedence. (line 64) -* EREs (Extended Regular Expressions): Bracket Expressions. (line 24) -* 'ERRNO' variable: Auto-set. (line 82) -* 'ERRNO' variable <1>: TCP/IP Networking. (line 53) -* 'ERRNO' variable, with 'BEGINFILE' pattern: BEGINFILE/ENDFILE. - (line 26) -* 'ERRNO' variable, with 'close()' function: Close Files And Pipes. -======= * EREs (Extended Regular Expressions): Bracket Expressions. (line 26) * ERRNO variable <1>: TCP/IP Networking. (line 54) * ERRNO variable: Auto-set. (line 82) * ERRNO variable, with BEGINFILE pattern: BEGINFILE/ENDFILE. (line 26) * ERRNO variable, with close() function: Close Files And Pipes. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 139) -* 'ERRNO' variable, with 'getline' command: Getline. (line 19) +* ERRNO variable, with getline command: Getline. (line 19) * error handling: Special FD. (line 16) -* error handling, 'ERRNO' variable and: Auto-set. (line 82) +* error handling, ERRNO variable and: Auto-set. (line 82) * error output: Special FD. (line 6) -* escape processing, 'gsub()'/'gensub()'/'sub()' functions: Gory Details. +* escape processing, gsub()/gensub()/sub() functions: Gory Details. (line 6) * escape sequences, in strings: Escape Sequences. (line 6) -* 'eval' debugger command: Viewing And Changing Data. +* eval debugger command: Viewing And Changing Data. (line 23) * evaluate expressions, in debugger: Viewing And Changing Data. (line 23) @@ -33956,35 +32230,17 @@ Index * evaluation order, concatenation: Concatenation. (line 41) * evaluation order, functions: Calling Built-in. (line 30) * examining fields: Fields. (line 6) -* exclamation point ('!'), '!' operator: Boolean Ops. (line 67) -* exclamation point ('!'), '!' operator <1>: Precedence. (line 51) -* exclamation point ('!'), '!' operator <2>: Egrep Program. (line 174) -* exclamation point ('!'), '!=' operator: Comparison Operators. - (line 11) -* exclamation point ('!'), '!=' operator <1>: Precedence. (line 64) -* exclamation point ('!'), '!~' operator: Regexp Usage. (line 19) -* exclamation point ('!'), '!~' operator <1>: Case-sensitivity. - (line 26) -* exclamation point ('!'), '!~' operator <2>: Computed Regexps. - (line 6) -* exclamation point ('!'), '!~' operator <3>: Regexp Constants. - (line 6) -* exclamation point ('!'), '!~' operator <4>: Comparison Operators. +* exclamation point (!), ! operator <1>: Egrep Program. (line 175) +* exclamation point (!), ! operator <2>: Precedence. (line 52) +* exclamation point (!), ! operator: Boolean Ops. (line 67) +* exclamation point (!), != operator <1>: Precedence. (line 65) +* exclamation point (!), != operator: Comparison Operators. (line 11) -<<<<<<< HEAD -* exclamation point ('!'), '!~' operator <5>: Comparison Operators. - (line 98) -* exclamation point ('!'), '!~' operator <6>: Precedence. (line 79) -* exclamation point ('!'), '!~' operator <7>: Expression Patterns. +* exclamation point (!), !~ operator <1>: Expression Patterns. (line 24) -* 'exit' statement: Exit Statement. (line 6) -* exit status, of 'gawk': Exit Status. (line 6) -* exit status, of VMS: VMS Running. (line 28) -* exit the debugger: Miscellaneous Debugger Commands. - (line 99) -* 'exp': Numeric Functions. (line 32) -* 'expand' utility: Very Simple. (line 69) -======= +* exclamation point (!), !~ operator <2>: Precedence. (line 80) +* exclamation point (!), !~ operator <3>: Comparison Operators. + (line 11) * exclamation point (!), !~ operator <4>: Regexp Constants. (line 6) * exclamation point (!), !~ operator <5>: Case-sensitivity. (line 26) * exclamation point (!), !~ operator <6>: Computed Regexps. (line 6) @@ -33996,9 +32252,8 @@ Index (line 99) * exp: Numeric Functions. (line 33) * expand utility: Very Simple. (line 72) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Expat XML parser library: gawkextlib. (line 35) -* exponent: Numeric Functions. (line 32) +* exponent: Numeric Functions. (line 33) * expressions: Expressions. (line 6) * expressions, as patterns: Expression Patterns. (line 6) * expressions, assignment: Assignment Ops. (line 6) @@ -34021,24 +32276,9 @@ Index * extension registration: Registration Functions. (line 6) * extension search path: Finding Extensions. (line 6) -* extensions distributed with 'gawk': Extension Samples. (line 6) +* extensions distributed with gawk: Extension Samples. (line 6) * extensions, allocating memory: Memory Allocation Functions. (line 6) -<<<<<<< HEAD -* extensions, Brian Kernighan's 'awk': BTL. (line 6) -* extensions, Brian Kernighan's 'awk' <1>: Common Extensions. (line 6) -* extensions, common, '**' operator: Arithmetic Ops. (line 30) -* extensions, common, '**=' operator: Assignment Ops. (line 138) -* extensions, common, '/dev/stderr' special file: Special FD. (line 46) -* extensions, common, '/dev/stdin' special file: Special FD. (line 46) -* extensions, common, '/dev/stdout' special file: Special FD. (line 46) -* extensions, common, 'BINMODE' variable: PC Using. (line 33) -* extensions, common, 'delete' to delete entire arrays: Delete. - (line 39) -* extensions, common, 'fflush()' function: I/O Functions. (line 43) -* extensions, common, 'func' keyword: Definition Syntax. (line 89) -* extensions, common, 'length()' applied to an array: String Functions. -======= * extensions, Brian Kernighan's awk <1>: Common Extensions. (line 6) * extensions, Brian Kernighan's awk: BTL. (line 6) * extensions, common, ** operator: Arithmetic Ops. (line 30) @@ -34052,110 +32292,86 @@ Index * extensions, common, fflush() function: I/O Functions. (line 43) * extensions, common, func keyword: Definition Syntax. (line 92) * extensions, common, length() applied to an array: String Functions. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 197) -* extensions, common, 'RS' as a regexp: gawk split records. (line 6) +* extensions, common, RS as a regexp: gawk split records. (line 6) * extensions, common, single character fields: Single Character Fields. (line 6) -<<<<<<< HEAD -* extensions, common, '\x' escape sequence: Escape Sequences. (line 61) -* extensions, in 'gawk', not in POSIX 'awk': POSIX/GNU. (line 6) -* extensions, 'mawk': Common Extensions. (line 6) -======= * extensions, in gawk, not in POSIX awk: POSIX/GNU. (line 6) * extensions, loading, @load directive: Loading Shared Libraries. (line 8) * extensions, mawk: Common Extensions. (line 6) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * extensions, where to find: gawkextlib. (line 6) -* 'extract.awk' program: Extract Program. (line 79) +* extract.awk program: Extract Program. (line 79) * extraction, of marked strings (internationalization): String Extraction. (line 6) -* 'f' debugger command (alias for 'frame'): Execution Stack. (line 24) +* f debugger command (alias for frame): Execution Stack. (line 25) * false, logical: Truth Values. (line 6) * FDL (Free Documentation License): GNU Free Documentation License. - (line 8) -* features, adding to 'gawk': Adding Code. (line 6) + (line 7) +* features, adding to gawk: Adding Code. (line 6) * features, deprecated: Obsolete. (line 6) * features, undocumented: Undocumented. (line 6) +* Fenlason, Jay <1>: Contributors. (line 18) * Fenlason, Jay: History. (line 30) -* Fenlason, Jay <1>: Contributors. (line 19) -* 'fflush': I/O Functions. (line 28) +* fflush: I/O Functions. (line 28) * field numbers: Nonconstant Fields. (line 6) -* field operator '$': Fields. (line 19) +* field operator $: Fields. (line 19) * field operators, dollar sign as: Fields. (line 19) * field separator, in multiline records: Multiple Line. (line 41) * field separator, on command line: Command Line Field Separator. (line 6) * field separator, POSIX and: Field Splitting Summary. - (line 39) -* field separators: Field Separators. (line 15) + (line 40) * field separators <1>: User-modified. (line 50) -* field separators <2>: User-modified. (line 113) -* field separators, choice of: Field Separators. (line 50) -* field separators, 'FIELDWIDTHS' variable and: User-modified. - (line 37) -* field separators, 'FPAT' variable and: User-modified. (line 43) +* field separators: Field Separators. (line 15) +* field separators, choice of: Field Separators. (line 51) +* field separators, FIELDWIDTHS variable and: User-modified. (line 37) +* field separators, FPAT variable and: User-modified. (line 43) * field separators, POSIX and: Fields. (line 6) -* field separators, regular expressions as: Field Separators. (line 50) * field separators, regular expressions as <1>: Regexp Field Splitting. (line 6) -<<<<<<< HEAD -* field separators, See Also 'OFS': Changing Fields. (line 64) -* field separators, spaces as: Cut Program. (line 109) -======= * field separators, regular expressions as: Field Separators. (line 51) * field separators, See Also OFS: Changing Fields. (line 64) * field separators, spaces as: Cut Program. (line 108) * fields <1>: Basic High Level. (line 73) * fields <2>: Fields. (line 6) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * fields: Reading Files. (line 14) -* fields <1>: Fields. (line 6) -* fields <2>: Basic High Level. (line 62) * fields, adding: Changing Fields. (line 53) * fields, changing contents of: Changing Fields. (line 6) * fields, cutting: Cut Program. (line 6) * fields, examining: Fields. (line 6) * fields, number of: Fields. (line 33) * fields, numbers: Nonconstant Fields. (line 6) -* fields, printing: Print Examples. (line 20) +* fields, printing: Print Examples. (line 21) * fields, separating: Field Separators. (line 15) -* fields, separating <1>: Field Separators. (line 15) * fields, single-character: Single Character Fields. (line 6) -* 'FIELDWIDTHS' variable: Constant Size. (line 23) -* 'FIELDWIDTHS' variable <1>: User-modified. (line 37) +* FIELDWIDTHS variable <1>: User-modified. (line 37) +* FIELDWIDTHS variable: Constant Size. (line 23) * file descriptors: Special FD. (line 6) -<<<<<<< HEAD -* file names, distinguishing: Auto-set. (line 55) -======= * file inclusion, @include directive: Include Files. (line 8) * file names, distinguishing: Auto-set. (line 56) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * file names, in compatibility mode: Special Caveats. (line 9) -* file names, standard streams in 'gawk': Special FD. (line 46) -* 'FILENAME' variable: Reading Files. (line 6) -* 'FILENAME' variable <1>: Auto-set. (line 98) -* 'FILENAME' variable, 'getline', setting with: Getline Notes. - (line 19) +* file names, standard streams in gawk: Special FD. (line 46) +* FILENAME variable <1>: Auto-set. (line 98) +* FILENAME variable: Reading Files. (line 6) +* FILENAME variable, getline, setting with: Getline Notes. (line 19) * filenames, assignments as: Ignoring Assigns. (line 6) -* files, '.gmo': Explaining gettext. (line 42) -* files, '.gmo', specifying directory of: Explaining gettext. (line 54) -* files, '.gmo', specifying directory of <1>: Programmer i18n. - (line 47) -* files, '.mo', converting from '.po': I18N Example. (line 63) -* files, '.po': Explaining gettext. (line 37) -* files, '.po' <1>: Translator i18n. (line 6) -* files, '.po', converting to '.mo': I18N Example. (line 63) -* files, '.pot': Explaining gettext. (line 31) -* files, '/dev/...' special files: Special FD. (line 46) -* files, '/inet/...' ('gawk'): TCP/IP Networking. (line 6) -* files, '/inet4/...' ('gawk'): TCP/IP Networking. (line 6) -* files, '/inet6/...' ('gawk'): TCP/IP Networking. (line 6) -* files, 'awk' programs in: Long. (line 6) -* files, 'awkprof.out': Profiling. (line 6) -* files, 'awkvars.out': Options. (line 94) +* files, .gmo: Explaining gettext. (line 42) +* files, .gmo, specifying directory of <1>: Programmer i18n. (line 47) +* files, .gmo, specifying directory of: Explaining gettext. (line 54) +* files, .mo, converting from .po: I18N Example. (line 63) +* files, .po <1>: Translator i18n. (line 6) +* files, .po: Explaining gettext. (line 37) +* files, .po, converting to .mo: I18N Example. (line 63) +* files, .pot: Explaining gettext. (line 31) +* files, /dev/... special files: Special FD. (line 46) +* files, /inet/... (gawk): TCP/IP Networking. (line 6) +* files, /inet4/... (gawk): TCP/IP Networking. (line 6) +* files, /inet6/... (gawk): TCP/IP Networking. (line 6) +* files, awk programs in: Long. (line 6) +* files, awkprof.out: Profiling. (line 6) +* files, awkvars.out: Options. (line 93) * files, closing: I/O Functions. (line 10) * files, descriptors, See file descriptors: Special FD. (line 6) * files, group: Group Functions. (line 6) @@ -34168,26 +32384,22 @@ Index * files, message object: Explaining gettext. (line 42) * files, message object, converting from portable object files: I18N Example. (line 63) -* files, message object, specifying directory of: Explaining gettext. - (line 54) -<<<<<<< HEAD * files, message object, specifying directory of <1>: Programmer i18n. (line 47) -* files, multiple passes over: Other Arguments. (line 49) -======= +* files, message object, specifying directory of: Explaining gettext. + (line 54) * files, multiple passes over: Other Arguments. (line 53) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * files, multiple, duplicating output into: Tee Program. (line 6) * files, output, See output files: Close Files And Pipes. (line 6) * files, password: Passwd Functions. (line 16) -* files, portable object: Explaining gettext. (line 37) * files, portable object <1>: Translator i18n. (line 6) +* files, portable object: Explaining gettext. (line 37) * files, portable object template: Explaining gettext. (line 31) * files, portable object, converting to message object files: I18N Example. (line 63) * files, portable object, generating: Options. (line 147) -* files, processing, 'ARGIND' variable and: Auto-set. (line 50) +* files, processing, ARGIND variable and: Auto-set. (line 51) * files, reading: Rewind Function. (line 6) * files, reading, multiline records: Multiple Line. (line 6) * files, searching for regular expressions: Egrep Program. (line 6) @@ -34197,91 +32409,80 @@ Index * files, Texinfo, extracting programs from: Extract Program. (line 6) * find substring in string: String Functions. (line 155) * finding extensions: Finding Extensions. (line 6) -* 'finish' debugger command: Debugger Execution Control. +* finish debugger command: Debugger Execution Control. (line 39) -* Fish, Fred: Contributors. (line 51) +* Fish, Fred: Contributors. (line 50) * fixed-width data: Constant Size. (line 10) -* flag variables: Boolean Ops. (line 67) * flag variables <1>: Tee Program. (line 20) +* flag variables: Boolean Ops. (line 67) * floating-point, numbers, arbitrary precision: Arbitrary Precision Arithmetic. (line 6) -* floating-point, VAX/VMS: VMS Running. (line 50) +* floating-point, VAX/VMS: VMS Running. (line 51) * flush buffered output: I/O Functions. (line 28) -* 'fnmatch()' extension function: Extension Sample Fnmatch. +* fnmatch() extension function: Extension Sample Fnmatch. (line 12) -<<<<<<< HEAD -* 'FNR' variable: Records. (line 6) -* 'FNR' variable <1>: Auto-set. (line 108) -* 'FNR' variable, changing: Auto-set. (line 309) -* 'for' statement: For Statement. (line 6) -* 'for' statement, looping over arrays: Scanning an Array. (line 20) -* 'fork()' extension function: Extension Sample Fork. -======= * FNR variable <1>: Auto-set. (line 107) * FNR variable: Records. (line 6) * FNR variable, changing: Auto-set. (line 313) * for statement: For Statement. (line 6) * for statement, looping over arrays: Scanning an Array. (line 20) * fork() extension function: Extension Sample Fork. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 11) * format specifiers: Basic Printf. (line 15) * format specifiers, mixing regular with positional specifiers: Printf Ordering. (line 57) -* format specifiers, 'printf' statement: Control Letters. (line 6) -* format specifiers, 'strftime()' function ('gawk'): Time Functions. - (line 88) +* format specifiers, printf statement: Control Letters. (line 6) +* format specifiers, strftime() function (gawk): Time Functions. + (line 89) * format time string: Time Functions. (line 48) * formats, numeric output: OFMT. (line 6) * formatting output: Printf. (line 6) -* formatting strings: String Functions. (line 380) -* forward slash ('/') to enclose regular expressions: Regexp. (line 10) -* forward slash ('/'), '/' operator: Precedence. (line 54) -* forward slash ('/'), '/=' operator: Assignment Ops. (line 129) -* forward slash ('/'), '/=' operator <1>: Precedence. (line 94) -* forward slash ('/'), '/=' operator, vs. '/=.../' regexp constant: Assignment Ops. - (line 149) -* forward slash ('/'), patterns and: Expression Patterns. (line 24) -* 'FPAT' variable: Splitting By Content. +* formatting strings: String Functions. (line 381) +* forward slash (/) to enclose regular expressions: Regexp. (line 10) +* forward slash (/), / operator: Precedence. (line 55) +* forward slash (/), /= operator <1>: Precedence. (line 95) +* forward slash (/), /= operator: Assignment Ops. (line 130) +* forward slash (/), /= operator, vs. /=.../ regexp constant: Assignment Ops. + (line 148) +* forward slash (/), patterns and: Expression Patterns. (line 24) +* FPAT variable <1>: User-modified. (line 43) +* FPAT variable: Splitting By Content. (line 27) -* 'FPAT' variable <1>: User-modified. (line 43) -* 'frame' debugger command: Execution Stack. (line 24) +* frame debugger command: Execution Stack. (line 25) * Free Documentation License (FDL): GNU Free Documentation License. - (line 8) + (line 7) +* Free Software Foundation (FSF) <1>: Glossary. (line 296) +* Free Software Foundation (FSF) <2>: Getting. (line 10) * Free Software Foundation (FSF): Manual History. (line 6) -* Free Software Foundation (FSF) <1>: Getting. (line 10) -* Free Software Foundation (FSF) <2>: Glossary. (line 294) -* Free Software Foundation (FSF) <3>: Glossary. (line 312) -* FreeBSD: Glossary. (line 607) -* 'FS' variable: Field Separators. (line 15) -* 'FS' variable <1>: User-modified. (line 50) -* 'FS' variable, '--field-separator' option and: Options. (line 21) -* 'FS' variable, as null string: Single Character Fields. +* FreeBSD: Glossary. (line 611) +* FS variable <1>: User-modified. (line 50) +* FS variable: Field Separators. (line 15) +* FS variable, --field-separator option and: Options. (line 21) +* FS variable, as null string: Single Character Fields. (line 20) -* 'FS' variable, as TAB character: Options. (line 262) -* 'FS' variable, changing value of: Field Separators. (line 34) -* 'FS' variable, running 'awk' programs and: Cut Program. (line 68) -* 'FS' variable, setting from command line: Command Line Field Separator. +* FS variable, as TAB character: Options. (line 264) +* FS variable, changing value of: Field Separators. (line 35) +* FS variable, running awk programs and: Cut Program. (line 68) +* FS variable, setting from command line: Command Line Field Separator. (line 6) -* 'FS', containing '^': Regexp Field Splitting. +* FS, containing ^: Regexp Field Splitting. (line 59) -* 'FS', in multiline records: Multiple Line. (line 41) +* FS, in multiline records: Multiple Line. (line 41) +* FSF (Free Software Foundation) <1>: Glossary. (line 296) +* FSF (Free Software Foundation) <2>: Getting. (line 10) * FSF (Free Software Foundation): Manual History. (line 6) -* FSF (Free Software Foundation) <1>: Getting. (line 10) -* FSF (Free Software Foundation) <2>: Glossary. (line 294) -* FSF (Free Software Foundation) <3>: Glossary. (line 312) -* 'fts()' extension function: Extension Sample File Functions. - (line 59) -* 'FUNCTAB' array: Auto-set. (line 123) +* fts() extension function: Extension Sample File Functions. + (line 61) +* FUNCTAB array: Auto-set. (line 123) * function calls: Function Calls. (line 6) * function calls, indirect: Indirect Calls. (line 6) * function calls, indirect, @-notation for: Indirect Calls. (line 47) * function definition example: Function Example. (line 6) * function pointers: Indirect Calls. (line 6) * functions, arrays as parameters to: Pass By Value/Reference. - (line 46) -* functions, built-in: Function Calls. (line 10) + (line 47) * functions, built-in <1>: Functions. (line 6) +* functions, built-in: Function Calls. (line 10) * functions, built-in, evaluation order: Calling Built-in. (line 30) * functions, defining: Definition Syntax. (line 9) * functions, library: Library Functions. (line 6) @@ -34306,45 +32507,20 @@ Index * functions, library, rounding numbers: Round Function. (line 6) * functions, library, user database, reading: Passwd Functions. (line 6) -<<<<<<< HEAD -* functions, names of: Arrays. (line 18) -* functions, names of <1>: Definition Syntax. (line 20) -* functions, recursive: Definition Syntax. (line 79) -======= * functions, names of <1>: Definition Syntax. (line 23) * functions, names of: Arrays. (line 18) * functions, recursive: Definition Syntax. (line 82) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * functions, string-translation: I18N Functions. (line 6) * functions, undefined: Pass By Value/Reference. - (line 70) + (line 71) * functions, user-defined: User-defined. (line 6) * functions, user-defined, calling: Function Caveats. (line 6) * functions, user-defined, counts, in a profile: Profiling. (line 137) * functions, user-defined, library of: Library Functions. (line 6) -* functions, user-defined, 'next'/'nextfile' statements and: Next Statement. +* functions, user-defined, next/nextfile statements and <1>: Nextfile Statement. + (line 47) +* functions, user-defined, next/nextfile statements and: Next Statement. (line 45) -<<<<<<< HEAD -* functions, user-defined, 'next'/'nextfile' statements and <1>: Nextfile Statement. - (line 46) -* G-d: Acknowledgments. (line 82) -* Garfinkle, Scott: Contributors. (line 35) -* 'gawk' program, dynamic profiling: Profiling. (line 178) -* 'gawk' version: Auto-set. (line 207) -* 'gawk', 'ARGIND' variable in: Other Arguments. (line 12) -* 'gawk', 'awk' and: Preface. (line 23) -* 'gawk', 'awk' and <1>: This Manual. (line 14) -* 'gawk', bitwise operations in: Bitwise Functions. (line 39) -* 'gawk', 'break' statement in: Break Statement. (line 51) -* 'gawk', built-in variables and: Built-in Variables. (line 14) -* 'gawk', character classes and: Bracket Expressions. (line 97) -* 'gawk', coding style in: Adding Code. (line 39) -* 'gawk', command-line options, and regular expressions: GNU Regexp Operators. - (line 73) -* 'gawk', comparison operators and: Comparison Operators. - (line 51) -* 'gawk', configuring: Configuration Philosophy. -======= * G-d: Acknowledgments. (line 92) * Garfinkle, Scott: Contributors. (line 34) * gawk program, dynamic profiling: Profiling. (line 179) @@ -34362,37 +32538,17 @@ Index * gawk, comparison operators and: Comparison Operators. (line 50) * gawk, configuring: Configuration Philosophy. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 6) -* 'gawk', configuring, options: Additional Configuration Options. +* gawk, configuring, options: Additional Configuration Options. (line 6) -<<<<<<< HEAD -* 'gawk', 'continue' statement in: Continue Statement. (line 43) -* 'gawk', distribution: Distribution contents. -======= * gawk, continue statement in: Continue Statement. (line 44) * gawk, distribution: Distribution contents. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 6) -* 'gawk', 'ERRNO' variable in: Getline. (line 19) -* 'gawk', 'ERRNO' variable in <1>: Close Files And Pipes. +* gawk, ERRNO variable in <1>: TCP/IP Networking. (line 54) +* gawk, ERRNO variable in <2>: Auto-set. (line 82) +* gawk, ERRNO variable in <3>: BEGINFILE/ENDFILE. (line 26) +* gawk, ERRNO variable in <4>: Close Files And Pipes. (line 139) -<<<<<<< HEAD -* 'gawk', 'ERRNO' variable in <2>: BEGINFILE/ENDFILE. (line 26) -* 'gawk', 'ERRNO' variable in <3>: Auto-set. (line 82) -* 'gawk', 'ERRNO' variable in <4>: TCP/IP Networking. (line 53) -* 'gawk', escape sequences: Escape Sequences. (line 123) -* 'gawk', extensions, disabling: Options. (line 250) -* 'gawk', features, adding: Adding Code. (line 6) -* 'gawk', features, advanced: Advanced Features. (line 6) -* 'gawk', field separators and: User-modified. (line 71) -* 'gawk', 'FIELDWIDTHS' variable in: Constant Size. (line 23) -* 'gawk', 'FIELDWIDTHS' variable in <1>: User-modified. (line 37) -* 'gawk', file names in: Special Files. (line 6) -* 'gawk', format-control characters: Control Letters. (line 18) -* 'gawk', format-control characters <1>: Control Letters. (line 93) -* 'gawk', 'FPAT' variable in: Splitting By Content. -======= * gawk, ERRNO variable in: Getline. (line 19) * gawk, escape sequences: Escape Sequences. (line 132) * gawk, extensions, disabling: Options. (line 252) @@ -34405,24 +32561,12 @@ Index * gawk, format-control characters: Control Letters. (line 18) * gawk, FPAT variable in <1>: User-modified. (line 43) * gawk, FPAT variable in: Splitting By Content. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 27) -* 'gawk', 'FPAT' variable in <1>: User-modified. (line 43) -* 'gawk', 'FUNCTAB' array in: Auto-set. (line 123) -* 'gawk', function arguments and: Calling Built-in. (line 16) -* 'gawk', hexadecimal numbers and: Nondecimal-numbers. (line 41) -* 'gawk', 'IGNORECASE' variable in: Case-sensitivity. (line 26) -* 'gawk', 'IGNORECASE' variable in <1>: User-modified. (line 76) -* 'gawk', 'IGNORECASE' variable in <2>: Array Intro. (line 91) -* 'gawk', 'IGNORECASE' variable in <3>: String Functions. (line 58) -* 'gawk', 'IGNORECASE' variable in <4>: Array Sorting Functions. +* gawk, FUNCTAB array in: Auto-set. (line 123) +* gawk, function arguments and: Calling Built-in. (line 16) +* gawk, hexadecimal numbers and: Nondecimal-numbers. (line 42) +* gawk, IGNORECASE variable in <1>: Array Sorting Functions. (line 83) -<<<<<<< HEAD -* 'gawk', implementation issues: Notes. (line 6) -* 'gawk', implementation issues, debugging: Compatibility Mode. - (line 6) -* 'gawk', implementation issues, downward compatibility: Compatibility Mode. -======= * gawk, IGNORECASE variable in <2>: String Functions. (line 58) * gawk, IGNORECASE variable in <3>: Array Intro. (line 94) * gawk, IGNORECASE variable in <4>: User-modified. (line 76) @@ -34430,31 +32574,14 @@ Index * gawk, implementation issues: Notes. (line 6) * gawk, implementation issues, debugging: Compatibility Mode. (line 6) * gawk, implementation issues, downward compatibility: Compatibility Mode. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 6) -* 'gawk', implementation issues, limits: Getline Notes. (line 14) -* 'gawk', implementation issues, pipes: Redirection. (line 134) -* 'gawk', installing: Installation. (line 6) -* 'gawk', internationalization and, See internationalization: Internationalization. +* gawk, implementation issues, limits: Getline Notes. (line 14) +* gawk, implementation issues, pipes: Redirection. (line 135) +* gawk, installing: Installation. (line 6) +* gawk, internationalization and, See internationalization: Internationalization. (line 13) -* 'gawk', interpreter, adding code to: Using Internal File Ops. +* gawk, interpreter, adding code to: Using Internal File Ops. (line 6) -<<<<<<< HEAD -* 'gawk', interval expressions and: Regexp Operators. (line 140) -* 'gawk', line continuation in: Conditional Exp. (line 34) -* 'gawk', 'LINT' variable in: User-modified. (line 88) -* 'gawk', list of contributors to: Contributors. (line 6) -* 'gawk', MS-DOS version of: PC Using. (line 10) -* 'gawk', MS-Windows version of: PC Using. (line 10) -* 'gawk', newlines in: Statements/Lines. (line 12) -* 'gawk', octal numbers and: Nondecimal-numbers. (line 41) -* 'gawk', OS/2 version of: PC Using. (line 16) -* 'gawk', 'PROCINFO' array in: Auto-set. (line 136) -* 'gawk', 'PROCINFO' array in <1>: Auto-set. (line 242) -* 'gawk', 'PROCINFO' array in <2>: Time Functions. (line 47) -* 'gawk', 'PROCINFO' array in <3>: Two-way I/O. (line 116) -* 'gawk', regexp constants and: Using Constant Regexps. -======= * gawk, interval expressions and: Regexp Operators. (line 139) * gawk, line continuation in: Conditional Exp. (line 34) * gawk, LINT variable in: User-modified. (line 88) @@ -34468,33 +32595,11 @@ Index * gawk, PROCINFO array in <2>: Time Functions. (line 47) * gawk, PROCINFO array in: Auto-set. (line 137) * gawk, regexp constants and: Using Constant Regexps. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 28) -* 'gawk', regular expressions, case sensitivity: Case-sensitivity. +* gawk, regular expressions, case sensitivity: Case-sensitivity. (line 26) -* 'gawk', regular expressions, operators: GNU Regexp Operators. +* gawk, regular expressions, operators: GNU Regexp Operators. (line 6) -<<<<<<< HEAD -* 'gawk', regular expressions, precedence: Regexp Operators. (line 162) -* 'gawk', 'RT' variable in: awk split records. (line 123) -* 'gawk', 'RT' variable in <1>: Multiple Line. (line 129) -* 'gawk', 'RT' variable in <2>: Auto-set. (line 265) -* 'gawk', See Also 'awk': Preface. (line 36) -* 'gawk', source code, obtaining: Getting. (line 6) -* 'gawk', splitting fields and: Constant Size. (line 87) -* 'gawk', string-translation functions: I18N Functions. (line 6) -* 'gawk', 'SYMTAB' array in: Auto-set. (line 269) -* 'gawk', 'TEXTDOMAIN' variable in: User-modified. (line 152) -* 'gawk', timestamps: Time Functions. (line 6) -* 'gawk', uses for: Preface. (line 36) -* 'gawk', versions of, information about, printing: Options. (line 295) -* 'gawk', VMS version of: VMS Installation. (line 6) -* 'gawk', word-boundary operator: GNU Regexp Operators. - (line 66) -* 'gawkextlib': gawkextlib. (line 6) -* 'gawkextlib' project: gawkextlib. (line 6) -* General Public License (GPL): Glossary. (line 303) -======= * gawk, regular expressions, precedence: Regexp Operators. (line 161) * gawk, RT variable in <1>: Auto-set. (line 269) * gawk, RT variable in <2>: Multiple Line. (line 129) @@ -34514,29 +32619,11 @@ Index * gawkextlib: gawkextlib. (line 6) * gawkextlib project: gawkextlib. (line 6) * General Public License (GPL): Glossary. (line 305) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * General Public License, See GPL: Manual History. (line 11) * generate time values: Time Functions. (line 25) -* 'gensub': Using Constant Regexps. +* gensub <1>: String Functions. (line 89) +* gensub: Using Constant Regexps. (line 43) -<<<<<<< HEAD -* 'gensub' <1>: String Functions. (line 89) -* 'gensub()' function ('gawk'), escape processing: Gory Details. - (line 6) -* 'getaddrinfo()' function (C library): TCP/IP Networking. (line 38) -* 'getgrent()' function (C library): Group Functions. (line 6) -* 'getgrent()' function (C library) <1>: Group Functions. (line 202) -* 'getgrent()' user-defined function: Group Functions. (line 6) -* 'getgrent()' user-defined function <1>: Group Functions. (line 205) -* 'getgrgid()' function (C library): Group Functions. (line 184) -* 'getgrgid()' user-defined function: Group Functions. (line 187) -* 'getgrnam()' function (C library): Group Functions. (line 173) -* 'getgrnam()' user-defined function: Group Functions. (line 178) -* 'getgruser()' function (C library): Group Functions. (line 193) -* 'getgruser()' function, user-defined: Group Functions. (line 196) -* 'getline' command: Reading Files. (line 20) -* 'getline' command, coprocesses, using from: Getline/Coprocess. -======= * gensub() function (gawk), escape processing: Gory Details. (line 6) * getaddrinfo() function (C library): TCP/IP Networking. (line 38) * getgrent() function (C library): Group Functions. (line 6) @@ -34552,23 +32639,9 @@ Index (line 83) * getline command, _pw_init() function: Passwd Functions. (line 154) * getline command, coprocesses, using from <1>: Close Files And Pipes. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 6) -* 'getline' command, coprocesses, using from <1>: Close Files And Pipes. +* getline command, coprocesses, using from: Getline/Coprocess. (line 6) -<<<<<<< HEAD -* 'getline' command, deadlock and: Two-way I/O. (line 70) -* 'getline' command, explicit input with: Getline. (line 6) -* 'getline' command, 'FILENAME' variable and: Getline Notes. (line 19) -* 'getline' command, return values: Getline. (line 19) -* 'getline' command, variants: Getline Summary. (line 6) -* 'getline' command, '_gr_init()' user-defined function: Group Functions. - (line 83) -* 'getline' command, '_pw_init()' function: Passwd Functions. (line 154) -* 'getline' from a file: Getline/File. (line 6) -* 'getline' into a variable: Getline/Variable. (line 6) -* 'getline' statement, 'BEGINFILE'/'ENDFILE' patterns and: BEGINFILE/ENDFILE. -======= * getline command, deadlock and: Two-way I/O. (line 52) * getline command, explicit input with: Getline. (line 6) * getline command, FILENAME variable and: Getline Notes. (line 19) @@ -34577,136 +32650,107 @@ Index * getline from a file: Getline/File. (line 6) * getline into a variable: Getline/Variable. (line 6) * getline statement, BEGINFILE/ENDFILE patterns and: BEGINFILE/ENDFILE. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 54) -* 'getlocaltime()' user-defined function: Getlocaltime Function. +* getlocaltime() user-defined function: Getlocaltime Function. (line 16) -* 'getopt()' function (C library): Getopt Function. (line 15) -* 'getopt()' user-defined function: Getopt Function. (line 108) -* 'getopt()' user-defined function <1>: Getopt Function. (line 134) -* 'getpwent()' function (C library): Passwd Functions. (line 16) -* 'getpwent()' function (C library) <1>: Passwd Functions. (line 198) -* 'getpwent()' user-defined function: Passwd Functions. (line 16) -* 'getpwent()' user-defined function <1>: Passwd Functions. (line 202) -* 'getpwnam()' function (C library): Passwd Functions. (line 177) -* 'getpwnam()' user-defined function: Passwd Functions. (line 182) -* 'getpwuid()' function (C library): Passwd Functions. (line 188) -* 'getpwuid()' user-defined function: Passwd Functions. (line 192) -* 'gettext' library: Explaining gettext. (line 6) -* 'gettext' library, locale categories: Explaining gettext. (line 81) -* 'gettext()' function (C library): Explaining gettext. (line 63) -* 'gettimeofday()' extension function: Extension Sample Time. +* getopt() function (C library): Getopt Function. (line 15) +* getopt() user-defined function: Getopt Function. (line 108) +* getpwent() function (C library): Passwd Functions. (line 16) +* getpwent() user-defined function: Passwd Functions. (line 16) +* getpwnam() function (C library): Passwd Functions. (line 177) +* getpwnam() user-defined function: Passwd Functions. (line 182) +* getpwuid() function (C library): Passwd Functions. (line 188) +* getpwuid() user-defined function: Passwd Functions. (line 192) +* gettext library: Explaining gettext. (line 6) +* gettext library, locale categories: Explaining gettext. (line 81) +* gettext() function (C library): Explaining gettext. (line 63) +* gettimeofday() extension function: Extension Sample Time. (line 12) -* 'git' utility: gawkextlib. (line 29) -* 'git' utility <1>: Other Versions. (line 29) -* 'git' utility <2>: Accessing The Source. +* git utility <1>: Adding Code. (line 112) +* git utility <2>: Accessing The Source. (line 10) -* 'git' utility <3>: Adding Code. (line 112) -* Git, use of for 'gawk' source code: Derived Files. (line 6) +* git utility <3>: Other Versions. (line 29) +* git utility: gawkextlib. (line 29) +* Git, use of for gawk source code: Derived Files. (line 6) * GNITS mailing list: Acknowledgments. (line 52) -<<<<<<< HEAD -* GNU 'awk', See 'gawk': Preface. (line 53) -======= * GNU awk, See gawk: Preface. (line 51) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * GNU Free Documentation License: GNU Free Documentation License. - (line 8) -* GNU General Public License: Glossary. (line 303) -* GNU Lesser General Public License: Glossary. (line 392) -* GNU long options: Command Line. (line 13) + (line 7) +* GNU General Public License: Glossary. (line 305) +* GNU Lesser General Public License: Glossary. (line 396) * GNU long options <1>: Options. (line 6) +* GNU long options: Command Line. (line 13) * GNU long options, printing list of: Options. (line 154) +* GNU Project <1>: Glossary. (line 314) * GNU Project: Manual History. (line 11) -* GNU Project <1>: Glossary. (line 312) +* GNU/Linux <1>: Glossary. (line 611) +* GNU/Linux <2>: I18N Example. (line 55) * GNU/Linux: Manual History. (line 28) -* GNU/Linux <1>: I18N Example. (line 55) -* GNU/Linux <2>: Glossary. (line 607) -* Gordon, Assaf: Contributors. (line 106) +* Gordon, Assaf: Contributors. (line 105) +* GPL (General Public License) <1>: Glossary. (line 305) * GPL (General Public License): Manual History. (line 11) -* GPL (General Public License) <1>: Glossary. (line 303) -* GPL (General Public License), printing: Options. (line 89) -* 'grcat' program: Group Functions. (line 16) -* Grigera, Juan: Contributors. (line 58) +* GPL (General Public License), printing: Options. (line 88) +* grcat program: Group Functions. (line 16) +* Grigera, Juan: Contributors. (line 57) * group database, reading: Group Functions. (line 6) * group file: Group Functions. (line 6) -<<<<<<< HEAD -* group ID of 'gawk' user: Auto-set. (line 180) -======= * group ID of gawk user: Auto-set. (line 184) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * groups, information about: Group Functions. (line 6) -* 'gsub': Using Constant Regexps. +* gsub <1>: String Functions. (line 139) +* gsub: Using Constant Regexps. (line 43) -* 'gsub' <1>: String Functions. (line 139) -* 'gsub()' function, arguments of: String Functions. (line 459) -* 'gsub()' function, escape processing: Gory Details. (line 6) -* 'h' debugger command (alias for 'help'): Miscellaneous Debugger Commands. +* gsub() function, arguments of: String Functions. (line 460) +* gsub() function, escape processing: Gory Details. (line 6) +* h debugger command (alias for help): Miscellaneous Debugger Commands. (line 66) +* Hankerson, Darrel <1>: Contributors. (line 60) * Hankerson, Darrel: Acknowledgments. (line 60) -* Hankerson, Darrel <1>: Contributors. (line 61) -* Haque, John: Contributors. (line 109) +* Haque, John: Contributors. (line 108) * Hartholz, Elaine: Acknowledgments. (line 38) * Hartholz, Marshall: Acknowledgments. (line 38) -* Hasegawa, Isamu: Contributors. (line 95) -* 'help' debugger command: Miscellaneous Debugger Commands. +* Hasegawa, Isamu: Contributors. (line 94) +* help debugger command: Miscellaneous Debugger Commands. (line 66) * hexadecimal numbers: Nondecimal-numbers. (line 6) -* hexadecimal values, enabling interpretation of: Options. (line 209) +* hexadecimal values, enabling interpretation of: Options. (line 211) * history expansion, in debugger: Readline Support. (line 6) -* 'histsort.awk' program: History Sorting. (line 25) +* histsort.awk program: History Sorting. (line 25) * Hughes, Phil: Acknowledgments. (line 43) -* 'HUP' signal, for dynamic profiling: Profiling. (line 210) -* hyphen ('-'), '-' operator: Precedence. (line 51) -* hyphen ('-'), '-' operator <1>: Precedence. (line 57) -* hyphen ('-'), '--' operator: Increment Ops. (line 48) -* hyphen ('-'), '--' operator <1>: Precedence. (line 45) -* hyphen ('-'), '-=' operator: Assignment Ops. (line 129) -* hyphen ('-'), '-=' operator <1>: Precedence. (line 94) -* hyphen ('-'), filenames beginning with: Options. (line 60) -* hyphen ('-'), in bracket expressions: Bracket Expressions. (line 17) -* 'i' debugger command (alias for 'info'): Debugger Info. (line 13) -* 'id' utility: Id Program. (line 6) -* 'id.awk' program: Id Program. (line 30) -* 'if' statement: If Statement. (line 6) -* 'if' statement, actions, changing: Ranges. (line 25) -* 'if' statement, use of regexps in: Regexp Usage. (line 19) -* 'igawk.sh' program: Igawk Program. (line 124) +* HUP signal, for dynamic profiling: Profiling. (line 211) +* hyphen (-), - operator: Precedence. (line 52) +* hyphen (-), -- operator <1>: Precedence. (line 46) +* hyphen (-), -- operator: Increment Ops. (line 48) +* hyphen (-), -= operator <1>: Precedence. (line 95) +* hyphen (-), -= operator: Assignment Ops. (line 130) +* hyphen (-), filenames beginning with: Options. (line 59) +* hyphen (-), in bracket expressions: Bracket Expressions. (line 17) +* i debugger command (alias for info): Debugger Info. (line 13) +* id utility: Id Program. (line 6) +* id.awk program: Id Program. (line 30) +* if statement: If Statement. (line 6) +* if statement, actions, changing: Ranges. (line 25) +* if statement, use of regexps in: Regexp Usage. (line 19) +* igawk.sh program: Igawk Program. (line 124) * ignore breakpoint: Breakpoint Control. (line 87) -<<<<<<< HEAD -* 'ignore' debugger command: Breakpoint Control. (line 87) -* 'IGNORECASE' variable: User-modified. (line 76) -* 'IGNORECASE' variable, and array indices: Array Intro. (line 91) -* 'IGNORECASE' variable, and array sorting functions: Array Sorting Functions. -======= * ignore debugger command: Breakpoint Control. (line 87) * IGNORECASE variable: User-modified. (line 76) * IGNORECASE variable, and array indices: Array Intro. (line 94) * IGNORECASE variable, and array sorting functions: Array Sorting Functions. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 83) -* 'IGNORECASE' variable, in example programs: Library Functions. +* IGNORECASE variable, in example programs: Library Functions. (line 53) -* 'IGNORECASE' variable, with '~' and '!~' operators: Case-sensitivity. +* IGNORECASE variable, with ~ and !~ operators: Case-sensitivity. (line 26) * Illumos: Other Versions. (line 105) -* Illumos, POSIX-compliant 'awk': Other Versions. (line 105) -* implementation issues, 'gawk': Notes. (line 6) -* implementation issues, 'gawk', debugging: Compatibility Mode. - (line 6) -* implementation issues, 'gawk', limits: Getline Notes. (line 14) -* implementation issues, 'gawk', limits <1>: Redirection. (line 134) -* 'in' operator: Comparison Operators. +* Illumos, POSIX-compliant awk: Other Versions. (line 105) +* implementation issues, gawk: Notes. (line 6) +* implementation issues, gawk, debugging: Compatibility Mode. (line 6) +* implementation issues, gawk, limits <1>: Redirection. (line 135) +* implementation issues, gawk, limits: Getline Notes. (line 14) +* in operator <1>: For Statement. (line 75) +* in operator <2>: Precedence. (line 83) +* in operator: Comparison Operators. (line 11) -<<<<<<< HEAD -* 'in' operator <1>: Precedence. (line 82) -* 'in' operator <2>: For Statement. (line 75) -* 'in' operator, index existence in multidimensional arrays: Multidimensional. - (line 41) -* 'in' operator, order of array access: Scanning an Array. (line 48) -* 'in' operator, testing if array element exists: Reference to Elements. - (line 37) -* 'in' operator, use in loops: Scanning an Array. (line 17) -======= * in operator, index existence in multidimensional arrays: Multidimensional. (line 43) * in operator, order of array access: Scanning an Array. (line 48) @@ -34714,17 +32758,16 @@ Index (line 38) * in operator, use in loops: Scanning an Array. (line 17) * including files, @include directive: Include Files. (line 8) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * increment operators: Increment Ops. (line 6) -* 'index': String Functions. (line 155) -* indexing arrays: Array Intro. (line 48) +* index: String Functions. (line 155) +* indexing arrays: Array Intro. (line 50) * indirect function calls: Indirect Calls. (line 6) * indirect function calls, @-notation: Indirect Calls. (line 47) * infinite precision: Arbitrary Precision Arithmetic. (line 6) -* 'info' debugger command: Debugger Info. (line 13) -* initialization, automatic: More Complex. (line 39) -* 'inplace' extension: Extension Sample Inplace. +* info debugger command: Debugger Info. (line 13) +* initialization, automatic: More Complex. (line 38) +* inplace extension: Extension Sample Inplace. (line 6) * input files: Reading Files. (line 6) * input files, closing: Close Files And Pipes. @@ -34732,16 +32775,9 @@ Index * input files, counting elements in: Wc Program. (line 6) * input files, examples: Sample Data Files. (line 6) * input files, reading: Reading Files. (line 6) -<<<<<<< HEAD -* input files, running 'awk' without: Read Terminal. (line 6) -* input files, running 'awk' without <1>: Read Terminal. (line 17) -* input files, variable assignments and: Other Arguments. (line 19) -* input pipeline: Getline/Pipe. (line 10) -======= * input files, running awk without: Read Terminal. (line 6) * input files, variable assignments and: Other Arguments. (line 23) * input pipeline: Getline/Pipe. (line 9) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * input record, length of: String Functions. (line 174) * input redirection: Getline/File. (line 6) * input, data, nondecimal: Nondecimal Data. (line 6) @@ -34749,42 +32785,32 @@ Index * input, files, See input files: Multiple Line. (line 6) * input, multiline records: Multiple Line. (line 6) * input, splitting into records: Records. (line 6) -* input, standard: Read Terminal. (line 6) * input, standard <1>: Special FD. (line 6) +* input, standard: Read Terminal. (line 6) * input/output functions: I/O Functions. (line 6) * input/output, binary: User-modified. (line 15) -<<<<<<< HEAD -* input/output, from 'BEGIN' and 'END': I/O And BEGIN/END. (line 6) -* input/output, two-way: Two-way I/O. (line 44) -======= * input/output, from BEGIN and END: I/O And BEGIN/END. (line 6) * input/output, two-way: Two-way I/O. (line 25) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * insomnia, cure for: Alarm Program. (line 6) * installation, VMS: VMS Installation. (line 6) -* installing 'gawk': Installation. (line 6) +* installing gawk: Installation. (line 6) * instruction tracing, in debugger: Debugger Info. (line 89) -* 'int': Numeric Functions. (line 37) -* 'INT' signal (MS-Windows): Profiling. (line 213) +* int: Numeric Functions. (line 38) +* INT signal (MS-Windows): Profiling. (line 214) * integer array indices: Numeric Array Subscripts. (line 31) * integers, arbitrary precision: Arbitrary Precision Integers. (line 6) * integers, unsigned: Computer Arithmetic. (line 41) -* interacting with other programs: I/O Functions. (line 76) -* internationalization: I18N Functions. (line 6) +* interacting with other programs: I/O Functions. (line 75) * internationalization <1>: I18N and L10N. (line 6) -* internationalization, localization: User-modified. (line 152) +* internationalization: I18N Functions. (line 6) * internationalization, localization <1>: Internationalization. (line 13) +* internationalization, localization: User-modified. (line 152) * internationalization, localization, character classes: Bracket Expressions. -<<<<<<< HEAD - (line 97) -* internationalization, localization, 'gawk' and: Internationalization. -======= (line 100) * internationalization, localization, gawk and: Internationalization. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 13) * internationalization, localization, locale categories: Explaining gettext. (line 81) @@ -34793,15 +32819,6 @@ Index * internationalization, localization, portability and: I18N Portability. (line 6) * internationalizing a program: Explaining gettext. (line 6) -<<<<<<< HEAD -* interpreted programs: Basic High Level. (line 13) -* interpreted programs <1>: Glossary. (line 352) -* interval expressions, regexp operator: Regexp Operators. (line 117) -* 'inventory-shipped' file: Sample Data Files. (line 32) -* invoke shell command: I/O Functions. (line 76) -* 'isarray': Type Functions. (line 11) -* ISO: Glossary. (line 363) -======= * interpreted programs <1>: Glossary. (line 356) * interpreted programs: Basic High Level. (line 15) * interval expressions, regexp operator: Regexp Operators. (line 116) @@ -34809,24 +32826,21 @@ Index * invoke shell command: I/O Functions. (line 75) * isarray: Type Functions. (line 11) * ISO: Glossary. (line 367) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * ISO 8859-1: Glossary. (line 133) * ISO Latin-1: Glossary. (line 133) * Jacobs, Andrew: Passwd Functions. (line 90) +* Jaegermann, Michal <1>: Contributors. (line 45) * Jaegermann, Michal: Acknowledgments. (line 60) -* Jaegermann, Michal <1>: Contributors. (line 46) -* Java implementation of 'awk': Other Versions. (line 113) -* Java programming language: Glossary. (line 375) -* 'jawk': Other Versions. (line 113) +* Java implementation of awk: Other Versions. (line 113) +* Java programming language: Glossary. (line 379) +* jawk: Other Versions. (line 113) * Jedi knights: Undocumented. (line 6) * Johansen, Chris: Signature Program. (line 25) -* 'join()' user-defined function: Join Function. (line 18) +* join() user-defined function: Join Function. (line 18) +* Kahrs, Ju"rgen <1>: Contributors. (line 70) * Kahrs, Ju"rgen: Acknowledgments. (line 60) -* Kahrs, Ju"rgen <1>: Contributors. (line 71) * Kasal, Stepan: Acknowledgments. (line 60) * Kenobi, Obi-Wan: Undocumented. (line 6) -<<<<<<< HEAD -======= * Kernighan, Brian <1>: Glossary. (line 143) * Kernighan, Brian <2>: Basic Data Typing. (line 54) * Kernighan, Brian <3>: Other Versions. (line 13) @@ -34837,39 +32851,14 @@ Index * Kernighan, Brian <8>: Getline/Pipe. (line 6) * Kernighan, Brian <9>: Acknowledgments. (line 76) * Kernighan, Brian <10>: Conventions. (line 38) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Kernighan, Brian: History. (line 17) -* Kernighan, Brian <1>: Conventions. (line 34) -* Kernighan, Brian <2>: Acknowledgments. (line 76) -* Kernighan, Brian <3>: Getline/Pipe. (line 6) -* Kernighan, Brian <4>: Concatenation. (line 6) -* Kernighan, Brian <5>: Library Functions. (line 12) -* Kernighan, Brian <6>: BTL. (line 6) -* Kernighan, Brian <7>: Contributors. (line 12) -* Kernighan, Brian <8>: Other Versions. (line 13) -* Kernighan, Brian <9>: Basic Data Typing. (line 54) -* Kernighan, Brian <10>: Glossary. (line 143) -* 'kill' command, dynamic profiling: Profiling. (line 187) +* kill command, dynamic profiling: Profiling. (line 188) * Knights, jedi: Undocumented. (line 6) -* Kwok, Conrad: Contributors. (line 35) -* 'l' debugger command (alias for 'list'): Miscellaneous Debugger Commands. +* Kwok, Conrad: Contributors. (line 34) +* l debugger command (alias for list): Miscellaneous Debugger Commands. (line 72) -* 'labels.awk' program: Labels Program. (line 51) +* labels.awk program: Labels Program. (line 51) * Langston, Peter: Advanced Features. (line 6) -<<<<<<< HEAD -* languages, data-driven: Basic High Level. (line 74) -* 'LC_ALL' locale category: Explaining gettext. (line 121) -* 'LC_COLLATE' locale category: Explaining gettext. (line 94) -* 'LC_CTYPE' locale category: Explaining gettext. (line 98) -* 'LC_MESSAGES' locale category: Explaining gettext. (line 88) -* 'LC_MESSAGES' locale category, 'bindtextdomain()' function ('gawk'): Programmer i18n. - (line 88) -* 'LC_MONETARY' locale category: Explaining gettext. (line 104) -* 'LC_NUMERIC' locale category: Explaining gettext. (line 108) -* 'LC_RESPONSE' locale category: Explaining gettext. (line 112) -* 'LC_TIME' locale category: Explaining gettext. (line 116) -* left angle bracket ('<'), '<' operator: Comparison Operators. -======= * languages, data-driven: Basic High Level. (line 85) * LC_ALL locale category: Explaining gettext. (line 117) * LC_COLLATE locale category: Explaining gettext. (line 94) @@ -34882,49 +32871,47 @@ Index * LC_TIME locale category: Explaining gettext. (line 112) * left angle bracket (<), < operator <1>: Precedence. (line 65) * left angle bracket (<), < operator: Comparison Operators. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 11) -* left angle bracket ('<'), '<' operator <1>: Precedence. (line 64) -* left angle bracket ('<'), '<' operator (I/O): Getline/File. (line 6) -* left angle bracket ('<'), '<=' operator: Comparison Operators. +* left angle bracket (<), < operator (I/O): Getline/File. (line 6) +* left angle bracket (<), <= operator <1>: Precedence. (line 65) +* left angle bracket (<), <= operator: Comparison Operators. (line 11) -* left angle bracket ('<'), '<=' operator <1>: Precedence. (line 64) * left shift: Bitwise Functions. (line 46) * left shift, bitwise: Bitwise Functions. (line 32) * leftmost longest match: Multiple Line. (line 26) -* 'length': String Functions. (line 167) +* length: String Functions. (line 167) * length of input record: String Functions. (line 174) * length of string: String Functions. (line 167) -* Lesser General Public License (LGPL): Glossary. (line 392) -* LGPL (Lesser General Public License): Glossary. (line 392) +* Lesser General Public License (LGPL): Glossary. (line 396) +* LGPL (Lesser General Public License): Glossary. (line 396) * libmawk: Other Versions. (line 121) -* libraries of 'awk' functions: Library Functions. (line 6) -* libraries of 'awk' functions, assertions: Assert Function. (line 6) -* libraries of 'awk' functions, associative arrays and: Library Names. +* libraries of awk functions: Library Functions. (line 6) +* libraries of awk functions, assertions: Assert Function. (line 6) +* libraries of awk functions, associative arrays and: Library Names. (line 57) -* libraries of 'awk' functions, character values as numbers: Ordinal Functions. +* libraries of awk functions, character values as numbers: Ordinal Functions. (line 6) -* libraries of 'awk' functions, command-line options: Getopt Function. +* libraries of awk functions, command-line options: Getopt Function. (line 6) -* libraries of 'awk' functions, example program for using: Igawk Program. +* libraries of awk functions, example program for using: Igawk Program. (line 6) -* libraries of 'awk' functions, group database, reading: Group Functions. +* libraries of awk functions, group database, reading: Group Functions. (line 6) -* libraries of 'awk' functions, managing, data files: Data File Management. +* libraries of awk functions, managing, data files: Data File Management. (line 6) -* libraries of 'awk' functions, managing, time: Getlocaltime Function. +* libraries of awk functions, managing, time: Getlocaltime Function. (line 6) -* libraries of 'awk' functions, merging arrays into strings: Join Function. +* libraries of awk functions, merging arrays into strings: Join Function. (line 6) -* libraries of 'awk' functions, rounding numbers: Round Function. +* libraries of awk functions, rounding numbers: Round Function. (line 6) -* libraries of 'awk' functions, user database, reading: Passwd Functions. +* libraries of awk functions, user database, reading: Passwd Functions. (line 6) * line breaks: Statements/Lines. (line 6) * line continuations: Boolean Ops. (line 62) -* line continuations, 'gawk': Conditional Exp. (line 34) -* line continuations, in 'print' statement: Print Examples. (line 75) -* line continuations, with C shell: More Complex. (line 31) +* line continuations, gawk: Conditional Exp. (line 34) +* line continuations, in print statement: Print Examples. (line 76) +* line continuations, with C shell: More Complex. (line 30) * lines, blank, printing: Print. (line 22) * lines, counting: Wc Program. (line 6) * lines, duplicate, removing: History Sorting. (line 6) @@ -34935,85 +32922,66 @@ Index * lint checking, array subscripts: Uninitialized Subscripts. (line 43) * lint checking, empty programs: Command Line. (line 16) -<<<<<<< HEAD -* lint checking, issuing warnings: Options. (line 184) -* lint checking, 'POSIXLY_CORRECT' environment variable: Options. - (line 335) -======= * lint checking, issuing warnings: Options. (line 185) * lint checking, POSIXLY_CORRECT environment variable: Options. (line 336) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * lint checking, undefined functions: Pass By Value/Reference. - (line 87) -* 'LINT' variable: User-modified. (line 88) + (line 88) +* LINT variable: User-modified. (line 88) +* Linux <1>: Glossary. (line 611) +* Linux <2>: I18N Example. (line 55) * Linux: Manual History. (line 28) -* Linux <1>: I18N Example. (line 55) -* Linux <2>: Glossary. (line 607) * list all global variables, in debugger: Debugger Info. (line 48) -* 'list' debugger command: Miscellaneous Debugger Commands. +* list debugger command: Miscellaneous Debugger Commands. (line 72) * list function definitions, in debugger: Debugger Info. (line 30) -<<<<<<< HEAD -* loading, extensions: Options. (line 172) -======= * loading extensions, @load directive: Loading Shared Libraries. (line 8) * loading, extensions: Options. (line 173) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * local variables, in a function: Variable Scope. (line 6) * locale categories: Explaining gettext. (line 81) -* locale decimal point character: Options. (line 265) +* locale decimal point character: Options. (line 268) * locale, definition of: Locales. (line 6) * localization: I18N and L10N. (line 6) * localization, See internationalization, localization: I18N and L10N. (line 6) -* 'log': Numeric Functions. (line 44) +* log: Numeric Functions. (line 45) * log files, timestamps in: Time Functions. (line 6) -* logarithm: Numeric Functions. (line 44) +* logarithm: Numeric Functions. (line 45) * logical false/true: Truth Values. (line 6) * logical operators, See Boolean expressions: Boolean Ops. (line 6) * login information: Passwd Functions. (line 16) * long options: Command Line. (line 13) * loops: While Statement. (line 6) -* loops, 'break' statement and: Break Statement. (line 6) -* loops, 'continue' statements and: For Statement. (line 64) +* loops, break statement and: Break Statement. (line 6) +* loops, continue statements and: For Statement. (line 64) * loops, count for header, in a profile: Profiling. (line 131) -* loops, 'do'-'while': Do Statement. (line 6) +* loops, do-while: Do Statement. (line 6) * loops, exiting: Break Statement. (line 6) -* loops, 'for', array scanning: Scanning an Array. (line 6) -* loops, 'for', iterative: For Statement. (line 6) -* loops, See Also 'while' statement: While Statement. (line 6) -* loops, 'while': While Statement. (line 6) -* 'ls' utility: More Complex. (line 15) -* 'lshift': Bitwise Functions. (line 46) -* lvalues/rvalues: Assignment Ops. (line 31) -* 'mail-list' file: Sample Data Files. (line 6) +* loops, for, array scanning: Scanning an Array. (line 6) +* loops, for, iterative: For Statement. (line 6) +* loops, See Also while statement: While Statement. (line 6) +* loops, while: While Statement. (line 6) +* ls utility: More Complex. (line 15) +* lshift: Bitwise Functions. (line 46) +* lvalues/rvalues: Assignment Ops. (line 32) +* mail-list file: Sample Data Files. (line 6) * mailing labels, printing: Labels Program. (line 6) * mailing list, GNITS: Acknowledgments. (line 52) -* Malmberg, John: Acknowledgments. (line 60) * Malmberg, John <1>: Bugs. (line 71) +* Malmberg, John: Acknowledgments. (line 60) * mark parity: Ordinal Functions. (line 45) * marked string extraction (internationalization): String Extraction. (line 6) * marked strings, extracting: String Extraction. (line 6) * Marx, Groucho: Increment Ops. (line 60) -* 'match': String Functions. (line 207) +* match: String Functions. (line 207) * match regexp in string: String Functions. (line 207) -* 'match()' function, 'RSTART'/'RLENGTH' variables: String Functions. +* match() function, RSTART/RLENGTH variables: String Functions. (line 224) * matching, expressions, See comparison expressions: Typing and Comparison. (line 9) * matching, leftmost longest: Multiple Line. (line 26) -<<<<<<< HEAD -* matching, null strings: Gory Details. (line 164) -* 'mawk' utility: Escape Sequences. (line 123) -* 'mawk' utility <1>: Getline/Pipe. (line 62) -* 'mawk' utility <2>: Concatenation. (line 36) -* 'mawk' utility <3>: Nextfile Statement. (line 46) -* 'mawk' utility <4>: Other Versions. (line 44) -* maximum precision supported by MPFR library: Auto-set. (line 221) -======= * matching, null strings: Gory Details. (line 143) * mawk utility <1>: Other Versions. (line 44) * mawk utility <2>: Nextfile Statement. (line 47) @@ -35021,85 +32989,53 @@ Index * mawk utility <4>: Getline/Pipe. (line 62) * mawk utility: Escape Sequences. (line 132) * maximum precision supported by MPFR library: Auto-set. (line 225) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * McIlroy, Doug: Glossary. (line 149) -* McPhee, Patrick: Contributors. (line 101) +* McPhee, Patrick: Contributors. (line 100) * message object files: Explaining gettext. (line 42) * message object files, converting from portable object files: I18N Example. (line 63) -* message object files, specifying directory of: Explaining gettext. - (line 54) * message object files, specifying directory of <1>: Programmer i18n. (line 47) +* message object files, specifying directory of: Explaining gettext. + (line 54) * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) -<<<<<<< HEAD -* metacharacters, escape sequences for: Escape Sequences. (line 129) -* minimum precision supported by MPFR library: Auto-set. (line 224) -* 'mktime': Time Functions. (line 25) -======= * metacharacters, escape sequences for: Escape Sequences. (line 138) * minimum precision supported by MPFR library: Auto-set. (line 228) * mktime: Time Functions. (line 25) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * modifiers, in format specifiers: Format Modifiers. (line 6) * monetary information, localization: Explaining gettext. (line 104) * Moore, Duncan: Getline Notes. (line 40) -* 'msgfmt' utility: I18N Example. (line 63) +* msgfmt utility: I18N Example. (line 63) * multiple precision: Arbitrary Precision Arithmetic. (line 6) * multiple-line records: Multiple Line. (line 6) -* 'n' debugger command (alias for 'next'): Debugger Execution Control. +* n debugger command (alias for next): Debugger Execution Control. (line 43) -* names, arrays/variables: Arrays. (line 18) -<<<<<<< HEAD * names, arrays/variables <1>: Library Names. (line 6) -* names, functions: Definition Syntax. (line 20) -* names, functions <1>: Library Names. (line 6) -* namespace issues: Arrays. (line 18) -* namespace issues <1>: Library Names. (line 6) -* namespace issues, functions: Definition Syntax. (line 20) -* 'nawk' utility: Names. (line 10) -* NetBSD: Glossary. (line 607) -======= +* names, arrays/variables: Arrays. (line 18) * names, functions <1>: Library Names. (line 6) * names, functions: Definition Syntax. (line 23) * namespace issues <1>: Library Names. (line 6) * namespace issues: Arrays. (line 18) * namespace issues, functions: Definition Syntax. (line 23) * NetBSD: Glossary. (line 611) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * networks, programming: TCP/IP Networking. (line 6) * networks, support for: Special Network. (line 6) +* newlines <1>: Boolean Ops. (line 67) +* newlines <2>: Options. (line 258) * newlines: Statements/Lines. (line 6) -* newlines <1>: Options. (line 256) -* newlines <2>: Boolean Ops. (line 67) * newlines, as field separators: Default Field Splitting. (line 6) * newlines, as record separators: awk split records. (line 12) * newlines, in dynamic regexps: Computed Regexps. (line 59) * newlines, in regexp constants: Computed Regexps. (line 69) -* newlines, printing: Print Examples. (line 11) +* newlines, printing: Print Examples. (line 12) +* newlines, separating statements in actions <1>: Statements. (line 10) * newlines, separating statements in actions: Action Overview. (line 19) -* newlines, separating statements in actions <1>: Statements. (line 10) -* 'next' debugger command: Debugger Execution Control. +* next debugger command: Debugger Execution Control. (line 43) -<<<<<<< HEAD -* 'next file' statement: Feature History. (line 168) -* 'next' statement: Boolean Ops. (line 85) -* 'next' statement <1>: Next Statement. (line 6) -* 'next' statement, 'BEGIN'/'END' patterns and: I/O And BEGIN/END. - (line 36) -* 'next' statement, 'BEGINFILE'/'ENDFILE' patterns and: BEGINFILE/ENDFILE. - (line 49) -* 'next' statement, user-defined functions and: Next Statement. - (line 45) -* 'nextfile' statement: Nextfile Statement. (line 6) -* 'nextfile' statement, 'BEGIN'/'END' patterns and: I/O And BEGIN/END. - (line 36) -* 'nextfile' statement, 'BEGINFILE'/'ENDFILE' patterns and: BEGINFILE/ENDFILE. -======= * next file statement: Feature History. (line 169) * next statement <1>: Next Statement. (line 6) * next statement: Boolean Ops. (line 93) @@ -35111,64 +33047,48 @@ Index * nextfile statement, BEGIN/END patterns and: I/O And BEGIN/END. (line 36) * nextfile statement, BEGINFILE/ENDFILE patterns and: BEGINFILE/ENDFILE. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 26) -* 'nextfile' statement, user-defined functions and: Nextfile Statement. - (line 46) -* 'nexti' debugger command: Debugger Execution Control. +* nextfile statement, user-defined functions and: Nextfile Statement. + (line 47) +* nexti debugger command: Debugger Execution Control. (line 49) -* 'NF' variable: Fields. (line 33) -* 'NF' variable <1>: Auto-set. (line 113) -* 'NF' variable, decrementing: Changing Fields. (line 107) -* 'ni' debugger command (alias for 'nexti'): Debugger Execution Control. +* NF variable <1>: Auto-set. (line 112) +* NF variable: Fields. (line 33) +* NF variable, decrementing: Changing Fields. (line 107) +* ni debugger command (alias for nexti): Debugger Execution Control. (line 49) -* 'noassign.awk' program: Ignoring Assigns. (line 15) +* noassign.awk program: Ignoring Assigns. (line 15) * non-existent array elements: Reference to Elements. (line 23) * not Boolean-logic operator: Boolean Ops. (line 6) -<<<<<<< HEAD -* 'NR' variable: Records. (line 6) -* 'NR' variable <1>: Auto-set. (line 131) -* 'NR' variable, changing: Auto-set. (line 309) -* null strings: awk split records. (line 113) -* null strings <1>: Regexp Field Splitting. -======= * NR variable <1>: Auto-set. (line 132) * NR variable: Records. (line 6) * NR variable, changing: Auto-set. (line 313) * null strings <1>: Basic Data Typing. (line 26) * null strings <2>: Truth Values. (line 6) * null strings <3>: Regexp Field Splitting. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 43) -* null strings <2>: Truth Values. (line 6) -* null strings <3>: Basic Data Typing. (line 26) -* null strings in 'gawk' arguments, quoting and: Quoting. (line 79) +* null strings: awk split records. (line 114) +* null strings in gawk arguments, quoting and: Quoting. (line 79) * null strings, and deleting array elements: Delete. (line 27) * null strings, as array subscripts: Uninitialized Subscripts. (line 43) * null strings, converting numbers to strings: Strings And Numbers. (line 21) -<<<<<<< HEAD -* null strings, matching: Gory Details. (line 164) -* number as string of bits: Bitwise Functions. (line 110) -======= * null strings, matching: Gory Details. (line 143) * number as string of bits: Bitwise Functions. (line 109) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * number of array elements: String Functions. (line 197) -* number sign ('#'), '#!' (executable scripts): Executable Scripts. +* number sign (#), #! (executable scripts): Executable Scripts. (line 6) -* number sign ('#'), commenting: Comments. (line 6) +* number sign (#), commenting: Comments. (line 6) * numbers, as array subscripts: Numeric Array Subscripts. (line 6) * numbers, as values of characters: Ordinal Functions. (line 6) * numbers, Cliff random: Cliff Random Function. (line 6) +* numbers, converting <1>: Bitwise Functions. (line 109) * numbers, converting: Strings And Numbers. (line 6) -* numbers, converting <1>: Bitwise Functions. (line 110) * numbers, converting, to strings: User-modified. (line 30) -* numbers, converting, to strings <1>: User-modified. (line 105) * numbers, hexadecimal: Nondecimal-numbers. (line 6) * numbers, octal: Nondecimal-numbers. (line 6) * numbers, rounding: Round Function. (line 6) @@ -35176,112 +33096,92 @@ Index * numeric functions: Numeric Functions. (line 6) * numeric, output format: OFMT. (line 6) * numeric, strings: Variable Typing. (line 6) -<<<<<<< HEAD -* 'o' debugger command (alias for 'option'): Debugger Info. (line 57) -* 'oawk' utility: Names. (line 10) -======= * o debugger command (alias for option): Debugger Info. (line 57) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * obsolete features: Obsolete. (line 6) * octal numbers: Nondecimal-numbers. (line 6) -* octal values, enabling interpretation of: Options. (line 209) -* 'OFMT' variable: OFMT. (line 15) -* 'OFMT' variable <1>: Strings And Numbers. (line 56) -* 'OFMT' variable <2>: User-modified. (line 105) -* 'OFMT' variable, POSIX 'awk' and: OFMT. (line 27) -* 'OFS' variable: Changing Fields. (line 64) -* 'OFS' variable <1>: Output Separators. (line 6) -* 'OFS' variable <2>: User-modified. (line 113) -* OpenBSD: Glossary. (line 607) +* octal values, enabling interpretation of: Options. (line 211) +* OFMT variable <1>: User-modified. (line 105) +* OFMT variable <2>: Strings And Numbers. (line 57) +* OFMT variable: OFMT. (line 15) +* OFMT variable, POSIX awk and: OFMT. (line 27) +* OFS variable <1>: User-modified. (line 114) +* OFS variable <2>: Output Separators. (line 6) +* OFS variable: Changing Fields. (line 64) +* OpenBSD: Glossary. (line 611) * OpenSolaris: Other Versions. (line 96) * operating systems, BSD-based: Manual History. (line 28) -* operating systems, PC, 'gawk' on: PC Using. (line 6) -* operating systems, PC, 'gawk' on, installing: PC Installation. +* operating systems, PC, gawk on: PC Using. (line 6) +* operating systems, PC, gawk on, installing: PC Installation. (line 6) -* operating systems, porting 'gawk' to: New Ports. (line 6) +* operating systems, porting gawk to: New Ports. (line 6) * operating systems, See Also GNU/Linux, PC operating systems, Unix: Installation. (line 6) * operations, bitwise: Bitwise Functions. (line 6) * operators, arithmetic: Arithmetic Ops. (line 6) * operators, assignment: Assignment Ops. (line 6) -* operators, assignment <1>: Assignment Ops. (line 31) -* operators, assignment, evaluation order: Assignment Ops. (line 110) +* operators, assignment, evaluation order: Assignment Ops. (line 111) * operators, Boolean, See Boolean expressions: Boolean Ops. (line 6) * operators, decrement/increment: Increment Ops. (line 6) * operators, GNU-specific: GNU Regexp Operators. (line 6) +* operators, input/output <1>: Precedence. (line 65) +* operators, input/output <2>: Redirection. (line 22) +* operators, input/output <3>: Getline/Coprocess. (line 6) +* operators, input/output <4>: Getline/Pipe. (line 9) * operators, input/output: Getline/File. (line 6) -* operators, input/output <1>: Getline/Pipe. (line 10) -* operators, input/output <2>: Getline/Coprocess. (line 6) -* operators, input/output <3>: Redirection. (line 22) -* operators, input/output <4>: Redirection. (line 102) -* operators, input/output <5>: Precedence. (line 64) -* operators, input/output <6>: Precedence. (line 64) -* operators, input/output <7>: Precedence. (line 64) * operators, logical, See Boolean expressions: Boolean Ops. (line 6) -* operators, precedence: Increment Ops. (line 60) * operators, precedence <1>: Precedence. (line 6) +* operators, precedence: Increment Ops. (line 60) * operators, relational, See operators, comparison: Typing and Comparison. (line 9) * operators, short-circuit: Boolean Ops. (line 57) -* operators, string: Concatenation. (line 9) +* operators, string: Concatenation. (line 8) * operators, string-matching: Regexp Usage. (line 19) * operators, string-matching, for buffers: GNU Regexp Operators. - (line 51) -* operators, word-boundary ('gawk'): GNU Regexp Operators. - (line 66) -* 'option' debugger command: Debugger Info. (line 57) + (line 48) +* operators, word-boundary (gawk): GNU Regexp Operators. + (line 63) +* option debugger command: Debugger Info. (line 57) * options, command-line: Options. (line 6) -* options, command-line, end of: Options. (line 55) -* options, command-line, invoking 'awk': Command Line. (line 6) +* options, command-line, end of: Options. (line 54) +* options, command-line, invoking awk: Command Line. (line 6) * options, command-line, processing: Getopt Function. (line 6) * options, deprecated: Obsolete. (line 6) -* options, long: Command Line. (line 13) * options, long <1>: Options. (line 6) +* options, long: Command Line. (line 13) * options, printing list of: Options. (line 154) -* 'or': Bitwise Functions. (line 49) +* or: Bitwise Functions. (line 49) * OR bitwise operation: Bitwise Functions. (line 6) * or Boolean-logic operator: Boolean Ops. (line 6) -* 'ord()' extension function: Extension Sample Ord. +* ord() extension function: Extension Sample Ord. (line 12) -* 'ord()' user-defined function: Ordinal Functions. (line 16) +* ord() user-defined function: Ordinal Functions. (line 16) * order of evaluation, concatenation: Concatenation. (line 41) -* 'ORS' variable: Output Separators. (line 20) -* 'ORS' variable <1>: User-modified. (line 119) -* output field separator, See 'OFS' variable: Changing Fields. - (line 64) -* output record separator, See 'ORS' variable: Output Separators. +* ORS variable <1>: User-modified. (line 119) +* ORS variable: Output Separators. (line 20) +* output field separator, See OFS variable: Changing Fields. (line 64) +* output record separator, See ORS variable: Output Separators. (line 20) * output redirection: Redirection. (line 6) * output wrapper: Output Wrappers. (line 6) * output, buffering: I/O Functions. (line 32) -* output, buffering <1>: I/O Functions. (line 139) * output, duplicating into files: Tee Program. (line 6) * output, files, closing: Close Files And Pipes. (line 6) -* output, format specifier, 'OFMT': OFMT. (line 15) +* output, format specifier, OFMT: OFMT. (line 15) * output, formatted: Printf. (line 6) * output, pipes: Redirection. (line 57) * output, printing, See printing: Printing. (line 6) * output, records: Output Separators. (line 20) * output, standard: Special FD. (line 6) -<<<<<<< HEAD -* 'p' debugger command (alias for 'print'): Viewing And Changing Data. - (line 35) -* Papadopoulos, Panos: Contributors. (line 129) -* parent process ID of 'gawk' process: Auto-set. (line 189) -* parentheses '()', in a profile: Profiling. (line 146) -* parentheses '()', regexp operator: Regexp Operators. (line 80) -======= * p debugger command (alias for print): Viewing And Changing Data. (line 36) * Papadopoulos, Panos: Contributors. (line 128) * parent process ID of gawk process: Auto-set. (line 193) * parentheses (), in a profile: Profiling. (line 146) * parentheses (), regexp operator: Regexp Operators. (line 81) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * password file: Passwd Functions. (line 16) -* 'patsplit': String Functions. (line 294) +* patsplit: String Functions. (line 294) * patterns: Patterns and Actions. (line 6) * patterns, comparison expressions as: Expression Patterns. (line 14) @@ -35292,47 +33192,26 @@ Index * patterns, ranges in: Ranges. (line 6) * patterns, regexp constants as: Expression Patterns. (line 34) * patterns, types of: Pattern Overview. (line 15) -* 'pawk' (profiling version of Brian Kernighan's 'awk'): Other Versions. +* pawk (profiling version of Brian Kernighan's awk): Other Versions. (line 78) -* 'pawk', 'awk'-like facilities for Python: Other Versions. (line 125) -* PC operating systems, 'gawk' on: PC Using. (line 6) -* PC operating systems, 'gawk' on, installing: PC Installation. - (line 6) -* percent sign ('%'), '%' operator: Precedence. (line 54) -* percent sign ('%'), '%=' operator: Assignment Ops. (line 129) -* percent sign ('%'), '%=' operator <1>: Precedence. (line 94) -* period ('.'), regexp operator: Regexp Operators. (line 44) +* pawk, awk-like facilities for Python: Other Versions. (line 125) +* PC operating systems, gawk on: PC Using. (line 6) +* PC operating systems, gawk on, installing: PC Installation. (line 6) +* percent sign (%), % operator: Precedence. (line 55) +* percent sign (%), %= operator <1>: Precedence. (line 95) +* percent sign (%), %= operator: Assignment Ops. (line 130) +* period (.), regexp operator: Regexp Operators. (line 44) * Perl: Future Extensions. (line 6) -* Peters, Arno: Contributors. (line 86) -* Peterson, Hal: Contributors. (line 40) +* Peters, Arno: Contributors. (line 85) +* Peterson, Hal: Contributors. (line 39) * pipe, closing: Close Files And Pipes. (line 6) -* pipe, input: Getline/Pipe. (line 10) +* pipe, input: Getline/Pipe. (line 9) * pipe, output: Redirection. (line 57) -* Pitts, Dave: Acknowledgments. (line 60) * Pitts, Dave <1>: Bugs. (line 71) +* Pitts, Dave: Acknowledgments. (line 60) * Plauger, P.J.: Library Functions. (line 12) * plug-in: Extension Intro. (line 6) -<<<<<<< HEAD -* plus sign ('+'), '+' operator: Precedence. (line 51) -* plus sign ('+'), '+' operator <1>: Precedence. (line 57) -* plus sign ('+'), '++' operator: Increment Ops. (line 11) -* plus sign ('+'), '++' operator <1>: Increment Ops. (line 40) -* plus sign ('+'), '++' operator <2>: Precedence. (line 45) -* plus sign ('+'), '+=' operator: Assignment Ops. (line 81) -* plus sign ('+'), '+=' operator <1>: Precedence. (line 94) -* plus sign ('+'), regexp operator: Regexp Operators. (line 103) -* pointers to functions: Indirect Calls. (line 6) -* portability: Escape Sequences. (line 93) -* portability, '#!' (executable scripts): Executable Scripts. (line 33) -* portability, '**' operator and: Arithmetic Ops. (line 81) -* portability, '**=' operator and: Assignment Ops. (line 144) -* portability, 'ARGV' variable: Executable Scripts. (line 42) -* portability, backslash continuation and: Statements/Lines. (line 30) -* portability, backslash in escape sequences: Escape Sequences. - (line 111) -* portability, 'close()' function and: Close Files And Pipes. -======= * plus sign (+), + operator: Precedence. (line 52) * plus sign (+), ++ operator <1>: Precedence. (line 46) * plus sign (+), ++ operator: Increment Ops. (line 11) @@ -35349,112 +33228,36 @@ Index * portability, backslash in escape sequences: Escape Sequences. (line 120) * portability, close() function and: Close Files And Pipes. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 81) * portability, data files as single record: gawk split records. (line 65) * portability, deleting array elements: Delete. (line 56) * portability, example programs: Library Functions. (line 42) -<<<<<<< HEAD -* portability, functions, defining: Definition Syntax. (line 104) -* portability, 'gawk': New Ports. (line 6) -* portability, 'gettext' library and: Explaining gettext. (line 11) -======= * portability, functions, defining: Definition Syntax. (line 108) * portability, gawk: New Ports. (line 6) * portability, gettext library and: Explaining gettext. (line 11) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * portability, internationalization and: I18N Portability. (line 6) -* portability, 'length()' function: String Functions. (line 176) -* portability, new 'awk' vs. old 'awk': Strings And Numbers. (line 56) -* portability, 'next' statement in user-defined functions: Pass By Value/Reference. - (line 90) -* portability, 'NF' variable, decrementing: Changing Fields. (line 115) +* portability, length() function: String Functions. (line 176) +* portability, new awk vs. old awk: Strings And Numbers. (line 57) +* portability, next statement in user-defined functions: Pass By Value/Reference. + (line 91) +* portability, NF variable, decrementing: Changing Fields. (line 115) * portability, operators: Increment Ops. (line 60) -<<<<<<< HEAD -* portability, operators, not in POSIX 'awk': Precedence. (line 97) -* portability, 'POSIXLY_CORRECT' environment variable: Options. - (line 355) -* portability, 'substr()' function: String Functions. (line 509) -======= * portability, operators, not in POSIX awk: Precedence. (line 98) * portability, POSIXLY_CORRECT environment variable: Options. (line 356) * portability, substr() function: String Functions. (line 510) * portable object files <1>: Translator i18n. (line 6) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * portable object files: Explaining gettext. (line 37) -* portable object files <1>: Translator i18n. (line 6) * portable object files, converting to message object files: I18N Example. (line 63) * portable object files, generating: Options. (line 147) * portable object template files: Explaining gettext. (line 31) -* porting 'gawk': New Ports. (line 6) -* positional specifiers, 'printf' statement: Format Modifiers. - (line 13) -* positional specifiers, 'printf' statement <1>: Printf Ordering. +* porting gawk: New Ports. (line 6) +* positional specifiers, printf statement <1>: Printf Ordering. (line 6) -* positional specifiers, 'printf' statement, mixing with regular formats: Printf Ordering. +* positional specifiers, printf statement: Format Modifiers. (line 13) +* positional specifiers, printf statement, mixing with regular formats: Printf Ordering. (line 57) -<<<<<<< HEAD -* POSIX 'awk': This Manual. (line 14) -* POSIX 'awk' <1>: Assignment Ops. (line 138) -* POSIX 'awk', '**' operator and: Precedence. (line 97) -* POSIX 'awk', '**=' operator and: Assignment Ops. (line 144) -* POSIX 'awk', '<' operator and: Getline/File. (line 26) -* POSIX 'awk', arithmetic operators and: Arithmetic Ops. (line 30) -* POSIX 'awk', backslashes in string constants: Escape Sequences. - (line 111) -* POSIX 'awk', 'BEGIN'/'END' patterns: I/O And BEGIN/END. (line 15) -* POSIX 'awk', bracket expressions and: Bracket Expressions. (line 24) -* POSIX 'awk', bracket expressions and, character classes: Bracket Expressions. - (line 30) -* POSIX 'awk', bracket expressions and, character classes <1>: Bracket Expressions. - (line 97) -* POSIX 'awk', 'break' statement and: Break Statement. (line 51) -* POSIX 'awk', changes in 'awk' versions: POSIX. (line 6) -* POSIX 'awk', 'continue' statement and: Continue Statement. (line 43) -* POSIX 'awk', 'CONVFMT' variable and: User-modified. (line 30) -* POSIX 'awk', 'date' utility and: Time Functions. (line 252) -* POSIX 'awk', field separators and: Fields. (line 6) -* POSIX 'awk', field separators and <1>: Field Splitting Summary. - (line 39) -* POSIX 'awk', 'FS' variable and: User-modified. (line 60) -* POSIX 'awk', 'function' keyword in: Definition Syntax. (line 89) -* POSIX 'awk', functions and, 'gsub()'/'sub()': Gory Details. (line 54) -* POSIX 'awk', functions and, 'length()': String Functions. (line 176) -* POSIX 'awk', GNU long options and: Options. (line 15) -* POSIX 'awk', interval expressions in: Regexp Operators. (line 136) -* POSIX 'awk', 'next'/'nextfile' statements and: Next Statement. - (line 45) -* POSIX 'awk', numeric strings and: Variable Typing. (line 6) -* POSIX 'awk', 'OFMT' variable and: OFMT. (line 27) -* POSIX 'awk', 'OFMT' variable and <1>: Strings And Numbers. (line 56) -* POSIX 'awk', period ('.'), using: Regexp Operators. (line 51) -* POSIX 'awk', 'printf' format strings and: Format Modifiers. (line 158) -* POSIX 'awk', regular expressions and: Regexp Operators. (line 162) -* POSIX 'awk', timestamps and: Time Functions. (line 6) -* POSIX 'awk', '|' I/O operator and: Getline/Pipe. (line 56) -* POSIX mode: Options. (line 250) -* POSIX mode <1>: Options. (line 335) -* POSIX, 'awk' and: Preface. (line 23) -* POSIX, 'gawk' extensions not included in: POSIX/GNU. (line 6) -* POSIX, programs, implementing in 'awk': Clones. (line 6) -* 'POSIXLY_CORRECT' environment variable: Options. (line 335) -* 'PREC' variable: User-modified. (line 124) -* precedence: Increment Ops. (line 60) -* precedence <1>: Precedence. (line 6) -* precedence, regexp operators: Regexp Operators. (line 157) -* 'print' debugger command: Viewing And Changing Data. - (line 35) -* 'print' statement: Printing. (line 16) -* 'print' statement, 'BEGIN'/'END' patterns and: I/O And BEGIN/END. - (line 15) -* 'print' statement, commas, omitting: Print Examples. (line 30) -* 'print' statement, I/O operators in: Precedence. (line 70) -* 'print' statement, line continuations and: Print Examples. (line 75) -* 'print' statement, 'OFMT' variable and: User-modified. (line 113) -* 'print' statement, See Also redirection, of output: Redirection. -======= * POSIX awk <1>: Assignment Ops. (line 137) * POSIX awk: This Manual. (line 14) * POSIX awk, ** operator and: Precedence. (line 98) @@ -35508,32 +33311,28 @@ Index * print statement, line continuations and: Print Examples. (line 76) * print statement, OFMT variable and: User-modified. (line 114) * print statement, See Also redirection, of output: Redirection. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 17) -* 'print' statement, 'sprintf()' function and: Round Function. - (line 6) +* print statement, sprintf() function and: Round Function. (line 6) * print variables, in debugger: Viewing And Changing Data. - (line 35) -* 'printf' debugger command: Viewing And Changing Data. - (line 53) -* 'printf' statement: Printing. (line 16) -* 'printf' statement <1>: Printf. (line 6) -* 'printf' statement, columns, aligning: Print Examples. (line 69) -* 'printf' statement, format-control characters: Control Letters. + (line 36) +* printf debugger command: Viewing And Changing Data. + (line 54) +* printf statement <1>: Printf. (line 6) +* printf statement: Printing. (line 16) +* printf statement, columns, aligning: Print Examples. (line 70) +* printf statement, format-control characters: Control Letters. (line 6) -* 'printf' statement, I/O operators in: Precedence. (line 70) -* 'printf' statement, modifiers: Format Modifiers. (line 6) -* 'printf' statement, positional specifiers: Format Modifiers. - (line 13) -* 'printf' statement, positional specifiers <1>: Printf Ordering. +* printf statement, I/O operators in: Precedence. (line 71) +* printf statement, modifiers: Format Modifiers. (line 6) +* printf statement, positional specifiers <1>: Printf Ordering. (line 6) -* 'printf' statement, positional specifiers, mixing with regular formats: Printf Ordering. +* printf statement, positional specifiers: Format Modifiers. (line 13) +* printf statement, positional specifiers, mixing with regular formats: Printf Ordering. (line 57) -* 'printf' statement, See Also redirection, of output: Redirection. +* printf statement, See Also redirection, of output: Redirection. (line 17) -* 'printf' statement, 'sprintf()' function and: Round Function. - (line 6) -* 'printf' statement, syntax of: Basic Printf. (line 6) +* printf statement, sprintf() function and: Round Function. (line 6) +* printf statement, syntax of: Basic Printf. (line 6) * printing: Printing. (line 6) * printing messages from extensions: Printing Messages. (line 6) * printing, list of options: Options. (line 154) @@ -35541,30 +33340,6 @@ Index * printing, unduplicated lines of text: Uniq Program. (line 6) * printing, user information: Id Program. (line 6) * private variables: Library Names. (line 11) -<<<<<<< HEAD -* process group idIDof 'gawk' process: Auto-set. (line 183) -* process ID of 'gawk' process: Auto-set. (line 186) -* processes, two-way communications with: Two-way I/O. (line 23) -* processing data: Basic High Level. (line 6) -* 'PROCINFO' array: Auto-set. (line 136) -* 'PROCINFO' array <1>: Time Functions. (line 47) -* 'PROCINFO' array <2>: Passwd Functions. (line 6) -* 'PROCINFO' array, and communications via ptys: Two-way I/O. (line 116) -* 'PROCINFO' array, and group membership: Group Functions. (line 6) -* 'PROCINFO' array, and user and group ID numbers: Id Program. - (line 15) -* 'PROCINFO' array, testing the field splitting: Passwd Functions. - (line 161) -* 'PROCINFO' array, uses: Auto-set. (line 242) -* 'PROCINFO', values of 'sorted_in': Controlling Scanning. - (line 26) -* profiling 'awk' programs: Profiling. (line 6) -* profiling 'awk' programs, dynamically: Profiling. (line 178) -* program identifiers: Auto-set. (line 154) -* program, definition of: Getting Started. (line 21) -* programmers, attractiveness of: Two-way I/O. (line 6) -* programming conventions, '--non-decimal-data' option: Nondecimal Data. -======= * process group idIDof gawk process: Auto-set. (line 187) * process ID of gawk process: Auto-set. (line 190) * processes, two-way communications with: Two-way I/O. (line 6) @@ -35585,237 +33360,162 @@ Index * program identifiers: Auto-set. (line 155) * program, definition of: Getting Started. (line 21) * programming conventions, --non-decimal-data option: Nondecimal Data. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 36) -* programming conventions, 'ARGC'/'ARGV' variables: Auto-set. (line 35) -* programming conventions, 'exit' statement: Exit Statement. (line 38) +* programming conventions, ARGC/ARGV variables: Auto-set. (line 35) +* programming conventions, exit statement: Exit Statement. (line 38) * programming conventions, function parameters: Return Statement. - (line 44) + (line 45) * programming conventions, functions, calling: Calling Built-in. (line 10) * programming conventions, functions, writing: Definition Syntax. -<<<<<<< HEAD - (line 61) -* programming conventions, 'gawk' extensions: Internal File Ops. - (line 44) -======= (line 64) * programming conventions, gawk extensions: Internal File Ops. (line 45) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * programming conventions, private variable names: Library Names. (line 23) * programming language, recipe for: History. (line 6) * programming languages, Ada: Glossary. (line 19) * programming languages, data-driven vs. procedural: Getting Started. (line 12) -* programming languages, Java: Glossary. (line 375) -* programming, basic steps: Basic High Level. (line 18) +* programming languages, Java: Glossary. (line 379) +* programming, basic steps: Basic High Level. (line 20) * programming, concepts: Basic Concepts. (line 6) -* programming, concepts <1>: Basic Concepts. (line 6) -* 'pwcat' program: Passwd Functions. (line 23) -* 'q' debugger command (alias for 'quit'): Miscellaneous Debugger Commands. +* pwcat program: Passwd Functions. (line 23) +* q debugger command (alias for quit): Miscellaneous Debugger Commands. (line 99) * QSE Awk: Other Versions. (line 131) * Quanstrom, Erik: Alarm Program. (line 8) -<<<<<<< HEAD -* question mark ('?'), '?:' operator: Precedence. (line 91) -* question mark ('?'), regexp operator: Regexp Operators. (line 112) -* question mark ('?'), regexp operator <1>: GNU Regexp Operators. - (line 62) -======= * question mark (?), ?: operator: Precedence. (line 92) * question mark (?), regexp operator <1>: GNU Regexp Operators. (line 59) * question mark (?), regexp operator: Regexp Operators. (line 111) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * QuikTrim Awk: Other Versions. (line 135) -* 'quit' debugger command: Miscellaneous Debugger Commands. +* quit debugger command: Miscellaneous Debugger Commands. (line 99) -* 'QUIT' signal (MS-Windows): Profiling. (line 213) -* quoting in 'gawk' command lines: Long. (line 26) -* quoting in 'gawk' command lines, tricks for: Quoting. (line 88) +* QUIT signal (MS-Windows): Profiling. (line 214) +* quoting in gawk command lines: Long. (line 26) +* quoting in gawk command lines, tricks for: Quoting. (line 88) * quoting, for small awk programs: Comments. (line 27) -* 'r' debugger command (alias for 'run'): Debugger Execution Control. +* r debugger command (alias for run): Debugger Execution Control. (line 62) * Rakitzis, Byron: History Sorting. (line 25) -* Ramey, Chet: Acknowledgments. (line 60) -<<<<<<< HEAD * Ramey, Chet <1>: General Data Types. (line 6) -* 'rand': Numeric Functions. (line 48) -* random numbers, Cliff: Cliff Random Function. - (line 6) -* random numbers, 'rand()'/'srand()' functions: Numeric Functions. - (line 48) -* random numbers, seed of: Numeric Functions. (line 78) -======= +* Ramey, Chet: Acknowledgments. (line 60) * rand: Numeric Functions. (line 50) * random numbers, Cliff: Cliff Random Function. (line 6) * random numbers, rand()/srand() functions: Numeric Functions. (line 50) * random numbers, seed of: Numeric Functions. (line 80) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * range expressions (regexps): Bracket Expressions. (line 6) * range patterns: Ranges. (line 6) -* range patterns, line continuation and: Ranges. (line 64) +* range patterns, line continuation and: Ranges. (line 65) +* Rankin, Pat <1>: Bugs. (line 71) +* Rankin, Pat <2>: Contributors. (line 37) +* Rankin, Pat <3>: Assignment Ops. (line 100) * Rankin, Pat: Acknowledgments. (line 60) -* Rankin, Pat <1>: Assignment Ops. (line 99) -* Rankin, Pat <2>: Contributors. (line 38) -* Rankin, Pat <3>: Bugs. (line 71) -* 'reada()' extension function: Extension Sample Read write array. +* reada() extension function: Extension Sample Read write array. (line 15) * readable data files, checking: File Checking. (line 6) -* 'readable.awk' program: File Checking. (line 11) -* 'readdir' extension: Extension Sample Readdir. +* readable.awk program: File Checking. (line 11) +* readdir extension: Extension Sample Readdir. (line 9) -* 'readfile()' extension function: Extension Sample Readfile. +* readfile() extension function: Extension Sample Readfile. (line 12) -* 'readfile()' user-defined function: Readfile Function. (line 30) +* readfile() user-defined function: Readfile Function. (line 30) * reading input files: Reading Files. (line 6) * recipe for a programming language: History. (line 6) -* record separators: awk split records. (line 6) * record separators <1>: User-modified. (line 133) +* record separators: awk split records. (line 6) * record separators, changing: awk split records. (line 85) * record separators, regular expressions as: awk split records. - (line 123) + (line 124) * record separators, with multiline records: Multiple Line. (line 10) +* records <1>: Basic High Level. (line 73) * records: Reading Files. (line 14) -* records <1>: Basic High Level. (line 62) * records, multiline: Multiple Line. (line 6) * records, printing: Print. (line 22) * records, splitting input into: Records. (line 6) -<<<<<<< HEAD -* records, terminating: awk split records. (line 123) -* records, treating files as: gawk split records. (line 91) -* recursive functions: Definition Syntax. (line 79) -* redirect 'gawk' output, in debugger: Debugger Info. (line 72) -======= * records, terminating: awk split records. (line 124) * records, treating files as: gawk split records. (line 92) * recursive functions: Definition Syntax. (line 82) * redirect gawk output, in debugger: Debugger Info. (line 72) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * redirection of input: Getline/File. (line 6) * redirection of output: Redirection. (line 6) * reference counting, sorting arrays: Array Sorting Functions. (line 77) * regexp: Regexp. (line 6) +* regexp constants <1>: Comparison Operators. + (line 102) +* regexp constants <2>: Regexp Constants. (line 6) * regexp constants: Regexp Usage. (line 57) -* regexp constants <1>: Regexp Constants. (line 6) -* regexp constants <2>: Comparison Operators. - (line 103) -* regexp constants, '/=.../', '/=' operator and: Assignment Ops. - (line 149) +* regexp constants, /=.../, /= operator and: Assignment Ops. (line 148) * regexp constants, as patterns: Expression Patterns. (line 34) -* regexp constants, in 'gawk': Using Constant Regexps. +* regexp constants, in gawk: Using Constant Regexps. (line 28) * regexp constants, slashes vs. quotes: Computed Regexps. (line 29) * regexp constants, vs. string constants: Computed Regexps. (line 39) * register extension: Registration Functions. (line 6) * regular expressions: Regexp. (line 6) -* regular expressions as field separators: Field Separators. (line 50) +* regular expressions as field separators: Field Separators. (line 51) * regular expressions, anchors in: Regexp Operators. (line 22) * regular expressions, as field separators: Regexp Field Splitting. (line 6) -* regular expressions, as patterns: Regexp Usage. (line 6) * regular expressions, as patterns <1>: Regexp Patterns. (line 6) +* regular expressions, as patterns: Regexp Usage. (line 6) * regular expressions, as record separators: awk split records. - (line 123) -* regular expressions, case sensitivity: Case-sensitivity. (line 6) + (line 124) * regular expressions, case sensitivity <1>: User-modified. (line 76) +* regular expressions, case sensitivity: Case-sensitivity. (line 6) * regular expressions, computed: Computed Regexps. (line 6) * regular expressions, constants, See regexp constants: Regexp Usage. (line 57) * regular expressions, dynamic: Computed Regexps. (line 6) * regular expressions, dynamic, with embedded newlines: Computed Regexps. (line 59) -* regular expressions, 'gawk', command-line options: GNU Regexp Operators. - (line 73) -* regular expressions, interval expressions and: Options. (line 274) +* regular expressions, gawk, command-line options: GNU Regexp Operators. + (line 70) +* regular expressions, interval expressions and: Options. (line 277) * regular expressions, leftmost longest match: Leftmost Longest. (line 6) -* regular expressions, operators: Regexp Usage. (line 19) * regular expressions, operators <1>: Regexp Operators. (line 6) +* regular expressions, operators: Regexp Usage. (line 19) * regular expressions, operators, for buffers: GNU Regexp Operators. - (line 51) + (line 48) * regular expressions, operators, for words: GNU Regexp Operators. (line 6) -* regular expressions, operators, 'gawk': GNU Regexp Operators. +* regular expressions, operators, gawk: GNU Regexp Operators. (line 6) * regular expressions, operators, precedence of: Regexp Operators. (line 156) * regular expressions, searching for: Egrep Program. (line 6) * relational operators, See comparison operators: Typing and Comparison. (line 9) -* replace in string: String Functions. (line 405) -* 'return' debugger command: Debugger Execution Control. +* replace in string: String Functions. (line 406) +* return debugger command: Debugger Execution Control. (line 54) -* 'return' statement, user-defined functions: Return Statement. - (line 6) -* return value, 'close()' function: Close Files And Pipes. +* return statement, user-defined functions: Return Statement. (line 6) +* return value, close() function: Close Files And Pipes. (line 131) -<<<<<<< HEAD -* 'rev()' user-defined function: Function Example. (line 53) -* 'revoutput' extension: Extension Sample Revout. -======= * rev() user-defined function: Function Example. (line 54) * revoutput extension: Extension Sample Revout. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 11) -* 'revtwoway' extension: Extension Sample Rev2way. +* revtwoway extension: Extension Sample Rev2way. (line 12) -* 'rewind()' user-defined function: Rewind Function. (line 16) -* right angle bracket ('>'), '>' operator: Comparison Operators. +* rewind() user-defined function: Rewind Function. (line 16) +* right angle bracket (>), > operator <1>: Precedence. (line 65) +* right angle bracket (>), > operator: Comparison Operators. (line 11) -* right angle bracket ('>'), '>' operator <1>: Precedence. (line 64) -* right angle bracket ('>'), '>' operator (I/O): Redirection. (line 22) -* right angle bracket ('>'), '>=' operator: Comparison Operators. +* right angle bracket (>), > operator (I/O): Redirection. (line 22) +* right angle bracket (>), >= operator <1>: Precedence. (line 65) +* right angle bracket (>), >= operator: Comparison Operators. (line 11) -* right angle bracket ('>'), '>=' operator <1>: Precedence. (line 64) -* right angle bracket ('>'), '>>' operator (I/O): Redirection. - (line 50) -* right angle bracket ('>'), '>>' operator (I/O) <1>: Precedence. - (line 64) -* right shift: Bitwise Functions. (line 53) +* right angle bracket (>), >> operator (I/O) <1>: Precedence. (line 65) +* right angle bracket (>), >> operator (I/O): Redirection. (line 50) +* right shift: Bitwise Functions. (line 52) * right shift, bitwise: Bitwise Functions. (line 32) * Ritchie, Dennis: Basic Data Typing. (line 54) -<<<<<<< HEAD -* 'RLENGTH' variable: Auto-set. (line 252) -* 'RLENGTH' variable, 'match()' function and: String Functions. - (line 224) -* Robbins, Arnold: Command Line Field Separator. - (line 73) -* Robbins, Arnold <1>: Getline/Pipe. (line 40) -* Robbins, Arnold <2>: Passwd Functions. (line 90) -* Robbins, Arnold <3>: Alarm Program. (line 6) -* Robbins, Arnold <4>: General Data Types. (line 6) -* Robbins, Arnold <5>: Contributors. (line 142) -* Robbins, Arnold <6>: Bugs. (line 32) -* Robbins, Arnold <7>: Future Extensions. (line 6) -* Robbins, Bill: Getline/Pipe. (line 40) -* Robbins, Harry: Acknowledgments. (line 82) -* Robbins, Jean: Acknowledgments. (line 82) -* Robbins, Miriam: Acknowledgments. (line 82) -* Robbins, Miriam <1>: Getline/Pipe. (line 40) -* Robbins, Miriam <2>: Passwd Functions. (line 90) -* Rommel, Kai Uwe: Contributors. (line 43) -* round to nearest integer: Numeric Functions. (line 37) -* 'round()' user-defined function: Round Function. (line 16) -* rounding numbers: Round Function. (line 6) -* 'ROUNDMODE' variable: User-modified. (line 128) -* 'RS' variable: awk split records. (line 12) -* 'RS' variable <1>: User-modified. (line 133) -* 'RS' variable, multiline records and: Multiple Line. (line 17) -* 'rshift': Bitwise Functions. (line 53) -* 'RSTART' variable: Auto-set. (line 258) -* 'RSTART' variable, 'match()' function and: String Functions. - (line 224) -* 'RT' variable: awk split records. (line 123) -* 'RT' variable <1>: Multiple Line. (line 129) -* 'RT' variable <2>: Auto-set. (line 265) -======= * RLENGTH variable: Auto-set. (line 256) * RLENGTH variable, match() function and: String Functions. (line 224) * Robbins, Arnold <1>: Future Extensions. (line 6) @@ -35848,41 +33548,28 @@ Index * RT variable <2>: Multiple Line. (line 129) * RT variable: awk split records. (line 124) * Rubin, Paul <1>: Contributors. (line 15) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Rubin, Paul: History. (line 30) -* Rubin, Paul <1>: Contributors. (line 16) * rule, definition of: Getting Started. (line 21) -* 'run' debugger command: Debugger Execution Control. +* run debugger command: Debugger Execution Control. (line 62) -* rvalues/lvalues: Assignment Ops. (line 31) -* 's' debugger command (alias for 'step'): Debugger Execution Control. +* rvalues/lvalues: Assignment Ops. (line 32) +* s debugger command (alias for step): Debugger Execution Control. (line 68) * sample debugging session: Sample Debugging Session. (line 6) -* sandbox mode: Options. (line 281) +* sandbox mode: Options. (line 284) * save debugger options: Debugger Info. (line 84) * scalar or array: Type Functions. (line 11) * scalar values: Basic Data Typing. (line 13) * scanning arrays: Scanning an Array. (line 6) * scanning multidimensional arrays: Multiscanning. (line 11) -<<<<<<< HEAD -======= * Schorr, Andrew <1>: Contributors. (line 133) * Schorr, Andrew <2>: Auto-set. (line 296) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Schorr, Andrew: Acknowledgments. (line 60) -* Schorr, Andrew <1>: Auto-set. (line 292) -* Schorr, Andrew <2>: Contributors. (line 134) * Schreiber, Bert: Acknowledgments. (line 38) * Schreiber, Rita: Acknowledgments. (line 38) * search and replace in strings: String Functions. (line 89) * search in string: String Functions. (line 155) -<<<<<<< HEAD -* search paths: Programs Exercises. (line 63) -* search paths <1>: PC Using. (line 10) -* search paths <2>: VMS Running. (line 57) -* search paths, for loadable extensions: AWKLIBPATH Variable. (line 6) -======= * search paths <1>: VMS Running. (line 58) * search paths <2>: PC Using. (line 10) * search paths: Programs Exercises. (line 70) @@ -35890,24 +33577,9 @@ Index * search paths, for source files <1>: VMS Running. (line 58) * search paths, for source files <2>: PC Using. (line 10) * search paths, for source files <3>: Programs Exercises. (line 70) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * search paths, for source files: AWKPATH Variable. (line 6) -* search paths, for source files <1>: Programs Exercises. (line 63) -* search paths, for source files <2>: PC Using. (line 10) -* search paths, for source files <3>: VMS Running. (line 57) * searching, files for regular expressions: Egrep Program. (line 6) * searching, for words: Dupword Program. (line 6) -<<<<<<< HEAD -* 'sed' utility: Field Splitting Summary. - (line 45) -* 'sed' utility <1>: Simple Sed. (line 6) -* 'sed' utility <2>: Glossary. (line 11) -* seeding random number generator: Numeric Functions. (line 78) -* semicolon (';'), 'AWKPATH' variable and: PC Using. (line 10) -* semicolon (';'), separating statements in actions: Statements/Lines. - (line 90) -* semicolon (';'), separating statements in actions <1>: Action Overview. -======= * sed utility <1>: Glossary. (line 11) * sed utility <2>: Simple Sed. (line 6) * sed utility: Field Splitting Summary. @@ -35917,43 +33589,33 @@ Index * semicolon (;), separating statements in actions <1>: Statements. (line 10) * semicolon (;), separating statements in actions <2>: Action Overview. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 19) -* semicolon (';'), separating statements in actions <2>: Statements. - (line 10) +* semicolon (;), separating statements in actions: Statements/Lines. + (line 91) * separators, field: User-modified. (line 50) -* separators, field <1>: User-modified. (line 113) -* separators, field, 'FIELDWIDTHS' variable and: User-modified. - (line 37) -* separators, field, 'FPAT' variable and: User-modified. (line 43) +* separators, field, FIELDWIDTHS variable and: User-modified. (line 37) +* separators, field, FPAT variable and: User-modified. (line 43) * separators, field, POSIX and: Fields. (line 6) +* separators, for records <1>: User-modified. (line 133) * separators, for records: awk split records. (line 6) -* separators, for records <1>: awk split records. (line 85) -* separators, for records <2>: User-modified. (line 133) * separators, for records, regular expressions as: awk split records. - (line 123) + (line 124) * separators, for statements in actions: Action Overview. (line 19) * separators, subscript: User-modified. (line 146) * set breakpoint: Breakpoint Control. (line 11) -* 'set' debugger command: Viewing And Changing Data. - (line 58) -* set directory of message catalogs: I18N Functions. (line 11) +* set debugger command: Viewing And Changing Data. + (line 59) +* set directory of message catalogs: I18N Functions. (line 12) * set watchpoint: Viewing And Changing Data. -<<<<<<< HEAD - (line 66) -* shadowing of variable values: Definition Syntax. (line 67) -* shell quoting, double quote: Read Terminal. (line 25) -======= (line 67) * shadowing of variable values: Definition Syntax. (line 70) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * shell quoting, rules for: Quoting. (line 6) -* shells, piping commands into: Redirection. (line 141) +* shells, piping commands into: Redirection. (line 142) * shells, quoting: Using Shell Variables. (line 12) * shells, quoting, rules for: Quoting. (line 18) * shells, scripts: One-shot. (line 22) -* shells, sea: Undocumented. (line 9) +* shells, sea: Undocumented. (line 8) * shells, variables: Using Shell Variables. (line 6) * shift, bitwise: Bitwise Functions. (line 32) @@ -35965,50 +33627,24 @@ Index * show name of current source file, in debugger: Debugger Info. (line 37) * show watchpoints: Debugger Info. (line 51) -* 'si' debugger command (alias for 'stepi'): Debugger Execution Control. +* si debugger command (alias for stepi): Debugger Execution Control. (line 76) -* side effects: Concatenation. (line 41) * side effects <1>: Increment Ops. (line 11) -* side effects <2>: Increment Ops. (line 75) +* side effects: Concatenation. (line 41) * side effects, array indexing: Reference to Elements. -<<<<<<< HEAD - (line 42) -* side effects, 'asort()' function: Array Sorting Functions. -======= (line 43) * side effects, asort() function: Array Sorting Functions. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 24) -* side effects, assignment expressions: Assignment Ops. (line 22) +* side effects, assignment expressions: Assignment Ops. (line 23) * side effects, Boolean operators: Boolean Ops. (line 30) * side effects, conditional expressions: Conditional Exp. (line 22) * side effects, decrement/increment operators: Increment Ops. (line 11) -* side effects, 'FILENAME' variable: Getline Notes. (line 19) +* side effects, FILENAME variable: Getline Notes. (line 19) * side effects, function calls: Function Calls. (line 57) * side effects, statements: Action Overview. (line 32) * sidebar, A Constant's Base Does Not Affect Its Value: Nondecimal-numbers. - (line 63) + (line 64) * sidebar, Backslash Before Regular Characters: Escape Sequences. -<<<<<<< HEAD - (line 109) -* sidebar, Changing 'FS' Does Not Affect the Fields: Field Splitting Summary. - (line 37) -* sidebar, Changing 'NR' and 'FNR': Auto-set. (line 307) -* sidebar, Controlling Output Buffering with 'system()': I/O Functions. - (line 137) -* sidebar, Escape Sequences for Metacharacters: Escape Sequences. - (line 127) -* sidebar, 'FS' and 'IGNORECASE': Field Splitting Summary. - (line 63) -* sidebar, Interactive Versus Noninteractive Buffering: I/O Functions. - (line 106) -* sidebar, Matching the Null String: Gory Details. (line 162) -* sidebar, Operator Evaluation Order: Increment Ops. (line 58) -* sidebar, Piping into 'sh': Redirection. (line 139) -* sidebar, Portability Issues with '#!': Executable Scripts. (line 31) -* sidebar, Pre-POSIX 'awk' Used 'OFMT' For String Conversion: Strings And Numbers. - (line 54) -======= (line 118) * sidebar, Changing FS Does Not Affect the Fields: Field Splitting Summary. (line 38) @@ -36026,17 +33662,10 @@ Index * sidebar, Piping into sh: Redirection. (line 140) * sidebar, Pre-POSIX awk Used OFMT For String Conversion: Strings And Numbers. (line 55) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * sidebar, Recipe For A Programming Language: History. (line 6) -* sidebar, 'RS = "\0"' Is Not Portable: gawk split records. (line 63) -* sidebar, So Why Does 'gawk' have 'BEGINFILE' and 'ENDFILE'?: Filetrans Function. +* sidebar, RS = "\0" Is Not Portable: gawk split records. (line 63) +* sidebar, So Why Does gawk have BEGINFILE and ENDFILE?: Filetrans Function. (line 83) -<<<<<<< HEAD -* sidebar, Syntactic Ambiguities Between '/=' and Regular Expressions: Assignment Ops. - (line 147) -* sidebar, Understanding '$0': Changing Fields. (line 134) -* sidebar, Using 'close()''s Return Value: Close Files And Pipes. -======= * sidebar, Syntactic Ambiguities Between /= and Regular Expressions: Assignment Ops. (line 146) * sidebar, Understanding #!: Executable Scripts. (line 31) @@ -36044,30 +33673,18 @@ Index * sidebar, Using \n in Bracket Expressions of Dynamic Regexps: Computed Regexps. (line 57) * sidebar, Using close()'s Return Value: Close Files And Pipes. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 129) -* sidebar, Using '\n' in Bracket Expressions of Dynamic Regexps: Computed Regexps. - (line 57) -* 'SIGHUP' signal, for dynamic profiling: Profiling. (line 210) -* 'SIGINT' signal (MS-Windows): Profiling. (line 213) -* signals, 'HUP'/'SIGHUP', for profiling: Profiling. (line 210) -* signals, 'INT'/'SIGINT' (MS-Windows): Profiling. (line 213) -* signals, 'QUIT'/'SIGQUIT' (MS-Windows): Profiling. (line 213) -* signals, 'USR1'/'SIGUSR1', for profiling: Profiling. (line 187) +* SIGHUP signal, for dynamic profiling: Profiling. (line 211) +* SIGINT signal (MS-Windows): Profiling. (line 214) +* signals, HUP/SIGHUP, for profiling: Profiling. (line 211) +* signals, INT/SIGINT (MS-Windows): Profiling. (line 214) +* signals, QUIT/SIGQUIT (MS-Windows): Profiling. (line 214) +* signals, USR1/SIGUSR1, for profiling: Profiling. (line 188) * signature program: Signature Program. (line 6) -* 'SIGQUIT' signal (MS-Windows): Profiling. (line 213) -* 'SIGUSR1' signal, for dynamic profiling: Profiling. (line 187) -* 'silent' debugger command: Debugger Execution Control. +* SIGQUIT signal (MS-Windows): Profiling. (line 214) +* SIGUSR1 signal, for dynamic profiling: Profiling. (line 188) +* silent debugger command: Debugger Execution Control. (line 10) -<<<<<<< HEAD -* 'sin': Numeric Functions. (line 89) -* sine: Numeric Functions. (line 89) -* single quote ('''): One-shot. (line 15) -* single quote (''') in 'gawk' command lines: Long. (line 33) -* single quote ('''), in shell commands: Quoting. (line 48) -* single quote ('''), vs. apostrophe: Comments. (line 27) -* single quote ('''), with double quotes: Quoting. (line 70) -======= * sin: Numeric Functions. (line 91) * sine: Numeric Functions. (line 91) * single quote ('): One-shot. (line 15) @@ -36075,120 +33692,95 @@ Index * single quote ('), in shell commands: Quoting. (line 48) * single quote ('), vs. apostrophe: Comments. (line 27) * single quote ('), with double quotes: Quoting. (line 70) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * single-character fields: Single Character Fields. (line 6) * single-step execution, in the debugger: Debugger Execution Control. (line 43) * Skywalker, Luke: Undocumented. (line 6) -<<<<<<< HEAD -* 'sleep' utility: Alarm Program. (line 110) -* 'sleep()' extension function: Extension Sample Time. -======= * sleep utility: Alarm Program. (line 110) * sleep() extension function: Extension Sample Time. ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac (line 22) -* Solaris, POSIX-compliant 'awk': Other Versions. (line 96) +* Solaris, POSIX-compliant awk: Other Versions. (line 96) * sort array: String Functions. (line 42) * sort array indices: String Functions. (line 42) * sort function, arrays, sorting: Array Sorting Functions. (line 6) -<<<<<<< HEAD -* 'sort' utility: Word Sorting. (line 50) -* 'sort' utility, coprocesses and: Two-way I/O. (line 83) -======= * sort utility: Word Sorting. (line 50) * sort utility, coprocesses and: Two-way I/O. (line 65) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * sorting characters in different languages: Explaining gettext. (line 94) -* source code, 'awka': Other Versions. (line 64) -* source code, Brian Kernighan's 'awk': Other Versions. (line 13) +* source code, awka: Other Versions. (line 64) +* source code, Brian Kernighan's awk: Other Versions. (line 13) * source code, Busybox Awk: Other Versions. (line 88) -* source code, 'gawk': Gawk Distribution. (line 6) -* source code, Illumos 'awk': Other Versions. (line 105) -* source code, 'jawk': Other Versions. (line 113) +* source code, gawk: Gawk Distribution. (line 6) +* source code, Illumos awk: Other Versions. (line 105) +* source code, jawk: Other Versions. (line 113) * source code, libmawk: Other Versions. (line 121) -* source code, 'mawk': Other Versions. (line 44) +* source code, mawk: Other Versions. (line 44) * source code, mixing: Options. (line 117) -* source code, 'pawk': Other Versions. (line 78) -* source code, 'pawk' (Python version): Other Versions. (line 125) +* source code, pawk: Other Versions. (line 78) +* source code, pawk (Python version): Other Versions. (line 125) * source code, QSE Awk: Other Versions. (line 131) * source code, QuikTrim Awk: Other Versions. (line 135) -<<<<<<< HEAD -* source code, Solaris 'awk': Other Versions. (line 96) -* source files, search path for: Programs Exercises. (line 63) -* sparse arrays: Array Intro. (line 70) -======= * source code, Solaris awk: Other Versions. (line 96) * source files, search path for: Programs Exercises. (line 70) * sparse arrays: Array Intro. (line 72) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Spencer, Henry: Glossary. (line 11) -* 'split': String Functions. (line 313) +* split: String Functions. (line 313) * split string into array: String Functions. (line 294) -* 'split' utility: Split Program. (line 6) -* 'split()' function, array elements, deleting: Delete. (line 61) -* 'split.awk' program: Split Program. (line 30) -* 'sprintf': OFMT. (line 15) -* 'sprintf' <1>: String Functions. (line 380) -* 'sprintf()' function, 'OFMT' variable and: User-modified. (line 113) -* 'sprintf()' function, 'print'/'printf' statements and: Round Function. +* split utility: Split Program. (line 6) +* split() function, array elements, deleting: Delete. (line 61) +* split.awk program: Split Program. (line 30) +* sprintf <1>: String Functions. (line 381) +* sprintf: OFMT. (line 15) +* sprintf() function, OFMT variable and: User-modified. (line 114) +* sprintf() function, print/printf statements and: Round Function. (line 6) -<<<<<<< HEAD -* 'sqrt': Numeric Functions. (line 92) -* square brackets ('[]'), regexp operator: Regexp Operators. (line 56) -* square root: Numeric Functions. (line 92) -* 'srand': Numeric Functions. (line 96) -======= * sqrt: Numeric Functions. (line 94) * square brackets ([]), regexp operator: Regexp Operators. (line 56) * square root: Numeric Functions. (line 94) * srand: Numeric Functions. (line 98) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * stack frame: Debugging Terms. (line 10) +* Stallman, Richard <1>: Glossary. (line 296) +* Stallman, Richard <2>: Contributors. (line 23) +* Stallman, Richard <3>: Acknowledgments. (line 18) * Stallman, Richard: Manual History. (line 6) -* Stallman, Richard <1>: Acknowledgments. (line 18) -* Stallman, Richard <2>: Contributors. (line 24) -* Stallman, Richard <3>: Glossary. (line 294) * standard error: Special FD. (line 6) -* standard input: Read Terminal. (line 6) * standard input <1>: Special FD. (line 6) +* standard input: Read Terminal. (line 6) * standard output: Special FD. (line 6) * starting the debugger: Debugger Invocation. (line 6) -* 'stat()' extension function: Extension Sample File Functions. +* stat() extension function: Extension Sample File Functions. (line 18) * statements, compound, control statements and: Statements. (line 10) * statements, control, in actions: Statements. (line 6) -* statements, multiple: Statements/Lines. (line 90) -* 'step' debugger command: Debugger Execution Control. +* statements, multiple: Statements/Lines. (line 91) +* step debugger command: Debugger Execution Control. (line 68) -* 'stepi' debugger command: Debugger Execution Control. +* stepi debugger command: Debugger Execution Control. (line 76) * stop automatic display, in debugger: Viewing And Changing Data. - (line 79) -* stream editors: Field Splitting Summary. - (line 45) + (line 80) * stream editors <1>: Simple Sed. (line 6) -* 'strftime': Time Functions. (line 48) +* stream editors: Field Splitting Summary. + (line 46) +* strftime: Time Functions. (line 48) * string constants: Scalar Constants. (line 15) * string constants, vs. regexp constants: Computed Regexps. (line 39) * string extraction (internationalization): String Extraction. (line 6) * string length: String Functions. (line 167) -* string operators: Concatenation. (line 9) +* string operators: Concatenation. (line 8) * string, regular expression match: String Functions. (line 207) * string-manipulation functions: String Functions. (line 6) * string-matching operators: Regexp Usage. (line 19) * string-translation functions: I18N Functions. (line 6) -* strings splitting, example: String Functions. (line 332) +* strings splitting, example: String Functions. (line 333) +* strings, converting <1>: Bitwise Functions. (line 109) * strings, converting: Strings And Numbers. (line 6) -* strings, converting <1>: Bitwise Functions. (line 110) -* strings, converting letter case: String Functions. (line 519) +* strings, converting letter case: String Functions. (line 520) * strings, converting, numbers to: User-modified. (line 30) -* strings, converting, numbers to <1>: User-modified. (line 105) -* strings, empty, See null strings: awk split records. (line 113) +* strings, empty, See null strings: awk split records. (line 114) * strings, extracting: String Extraction. (line 6) * strings, for localization: Programmer i18n. (line 14) * strings, length limitations: Scalar Constants. (line 20) @@ -36196,14 +33788,14 @@ Index * strings, null: Regexp Field Splitting. (line 43) * strings, numeric: Variable Typing. (line 6) -* 'strtonum': String Functions. (line 387) -* 'strtonum()' function ('gawk'), '--non-decimal-data' option and: Nondecimal Data. +* strtonum: String Functions. (line 388) +* strtonum() function (gawk), --non-decimal-data option and: Nondecimal Data. (line 36) -* 'sub': Using Constant Regexps. +* sub <1>: String Functions. (line 406) +* sub: Using Constant Regexps. (line 43) -* 'sub' <1>: String Functions. (line 405) -* 'sub()' function, arguments of: String Functions. (line 459) -* 'sub()' function, escape processing: Gory Details. (line 6) +* sub() function, arguments of: String Functions. (line 460) +* sub() function, escape processing: Gory Details. (line 6) * subscript separators: User-modified. (line 146) * subscripts in arrays, multidimensional: Multidimensional. (line 10) * subscripts in arrays, multidimensional, scanning: Multiscanning. @@ -36212,25 +33804,13 @@ Index (line 6) * subscripts in arrays, uninitialized variables as: Uninitialized Subscripts. (line 6) -* 'SUBSEP' variable: User-modified. (line 146) -* 'SUBSEP' variable, and multidimensional arrays: Multidimensional. +* SUBSEP variable: User-modified. (line 146) +* SUBSEP variable, and multidimensional arrays: Multidimensional. (line 16) * substitute in string: String Functions. (line 89) -* 'substr': String Functions. (line 478) -* substring: String Functions. (line 478) +* substr: String Functions. (line 479) +* substring: String Functions. (line 479) * Sumner, Andrew: Other Versions. (line 64) -<<<<<<< HEAD -* supplementary groups of 'gawk' process: Auto-set. (line 237) -* 'switch' statement: Switch Statement. (line 6) -* 'SYMTAB' array: Auto-set. (line 269) -* syntactic ambiguity: '/=' operator vs. '/=.../' regexp constant: Assignment Ops. - (line 149) -* 'system': I/O Functions. (line 76) -* 'systime': Time Functions. (line 65) -* 't' debugger command (alias for 'tbreak'): Breakpoint Control. - (line 90) -* 'tbreak' debugger command: Breakpoint Control. (line 90) -======= * supplementary groups of gawk process: Auto-set. (line 241) * switch statement: Switch Statement. (line 6) * SYMTAB array: Auto-set. (line 273) @@ -36240,52 +33820,41 @@ Index * systime: Time Functions. (line 66) * t debugger command (alias for tbreak): Breakpoint Control. (line 90) * tbreak debugger command: Breakpoint Control. (line 90) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Tcl: Library Names. (line 57) * TCP/IP: TCP/IP Networking. (line 6) * TCP/IP, support for: Special Network. (line 6) -* 'tee' utility: Tee Program. (line 6) -* 'tee.awk' program: Tee Program. (line 26) +* tee utility: Tee Program. (line 6) +* tee.awk program: Tee Program. (line 26) * temporary breakpoint: Breakpoint Control. (line 90) -* terminating records: awk split records. (line 123) -* 'testbits.awk' program: Bitwise Functions. (line 71) -* 'testext' extension: Extension Sample API Tests. +* terminating records: awk split records. (line 124) +* testbits.awk program: Bitwise Functions. (line 70) +* testext extension: Extension Sample API Tests. (line 6) -* Texinfo: Conventions. (line 6) -* Texinfo <1>: Library Functions. (line 33) -* Texinfo <2>: Dupword Program. (line 17) -* Texinfo <3>: Extract Program. (line 12) -* Texinfo <4>: Distribution contents. +* Texinfo <1>: Adding Code. (line 100) +* Texinfo <2>: Distribution contents. (line 77) -* Texinfo <5>: Adding Code. (line 100) +* Texinfo <3>: Extract Program. (line 12) +* Texinfo <4>: Dupword Program. (line 17) +* Texinfo <5>: Library Functions. (line 33) +* Texinfo: Conventions. (line 6) * Texinfo, chapter beginnings in files: Regexp Operators. (line 22) * Texinfo, extracting programs from source files: Extract Program. (line 6) * text, printing: Print. (line 22) * text, printing, unduplicated lines of: Uniq Program. (line 6) -* 'TEXTDOMAIN' variable: User-modified. (line 152) -* 'TEXTDOMAIN' variable <1>: Programmer i18n. (line 9) -* 'TEXTDOMAIN' variable, 'BEGIN' pattern and: Programmer i18n. - (line 60) -* 'TEXTDOMAIN' variable, portability and: I18N Portability. (line 20) -* 'textdomain()' function (C library): Explaining gettext. (line 28) -* tilde ('~'), '~' operator: Regexp Usage. (line 19) -* tilde ('~'), '~' operator <1>: Case-sensitivity. (line 26) -* tilde ('~'), '~' operator <2>: Computed Regexps. (line 6) -* tilde ('~'), '~' operator <3>: Regexp Constants. (line 6) -* tilde ('~'), '~' operator <4>: Comparison Operators. +* TEXTDOMAIN variable <1>: Programmer i18n. (line 9) +* TEXTDOMAIN variable: User-modified. (line 152) +* TEXTDOMAIN variable, BEGIN pattern and: Programmer i18n. (line 60) +* TEXTDOMAIN variable, portability and: I18N Portability. (line 20) +* textdomain() function (C library): Explaining gettext. (line 28) +* tilde (~), ~ operator <1>: Expression Patterns. (line 24) +* tilde (~), ~ operator <2>: Precedence. (line 80) +* tilde (~), ~ operator <3>: Comparison Operators. (line 11) -<<<<<<< HEAD -* tilde ('~'), '~' operator <5>: Comparison Operators. - (line 98) -* tilde ('~'), '~' operator <6>: Precedence. (line 79) -* tilde ('~'), '~' operator <7>: Expression Patterns. (line 24) -======= * tilde (~), ~ operator <4>: Regexp Constants. (line 6) * tilde (~), ~ operator <5>: Case-sensitivity. (line 26) * tilde (~), ~ operator <6>: Computed Regexps. (line 6) * tilde (~), ~ operator: Regexp Usage. (line 19) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * time functions: Time Functions. (line 6) * time, alarm clock example program: Alarm Program. (line 11) * time, localization and: Explaining gettext. (line 112) @@ -36294,95 +33863,75 @@ Index * time, retrieving: Time Functions. (line 17) * timeout, reading input: Read Timeout. (line 6) * timestamps: Time Functions. (line 6) -* timestamps <1>: Time Functions. (line 65) -* timestamps, converting dates to: Time Functions. (line 75) +* timestamps, converting dates to: Time Functions. (line 76) * timestamps, formatted: Getlocaltime Function. (line 6) -* 'tolower': String Functions. (line 520) -* 'toupper': String Functions. (line 526) -* 'tr' utility: Translate Program. (line 6) -* 'trace' debugger command: Miscellaneous Debugger Commands. +* tolower: String Functions. (line 521) +* toupper: String Functions. (line 527) +* tr utility: Translate Program. (line 6) +* trace debugger command: Miscellaneous Debugger Commands. (line 108) * traceback, display in debugger: Execution Stack. (line 13) -* translate string: I18N Functions. (line 21) -* 'translate.awk' program: Translate Program. (line 55) -* treating files, as single records: gawk split records. (line 91) -* troubleshooting, '--non-decimal-data' option: Options. (line 209) -* troubleshooting, '==' operator: Comparison Operators. - (line 38) -* troubleshooting, 'awk' uses 'FS' not 'IFS': Field Separators. - (line 29) +* translate string: I18N Functions. (line 22) +* translate.awk program: Translate Program. (line 55) +* treating files, as single records: gawk split records. (line 92) +* troubleshooting, --non-decimal-data option: Options. (line 211) +* troubleshooting, == operator: Comparison Operators. + (line 37) +* troubleshooting, awk uses FS not IFS: Field Separators. (line 30) * troubleshooting, backslash before nonspecial character: Escape Sequences. -<<<<<<< HEAD - (line 111) -======= (line 120) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * troubleshooting, division: Arithmetic Ops. (line 44) * troubleshooting, fatal errors, field widths, specifying: Constant Size. (line 23) -* troubleshooting, fatal errors, 'printf' format strings: Format Modifiers. - (line 158) -* troubleshooting, 'fflush()' function: I/O Functions. (line 64) +* troubleshooting, fatal errors, printf format strings: Format Modifiers. + (line 159) +* troubleshooting, fflush() function: I/O Functions. (line 63) * troubleshooting, function call syntax: Function Calls. (line 30) -* troubleshooting, 'gawk': Compatibility Mode. (line 6) -* troubleshooting, 'gawk', bug reports: Bugs. (line 9) -* troubleshooting, 'gawk', fatal errors, function arguments: Calling Built-in. +* troubleshooting, gawk: Compatibility Mode. (line 6) +* troubleshooting, gawk, bug reports: Bugs. (line 9) +* troubleshooting, gawk, fatal errors, function arguments: Calling Built-in. (line 16) -* troubleshooting, 'getline' function: File Checking. (line 25) -* troubleshooting, 'gsub()'/'sub()' functions: String Functions. - (line 469) -* troubleshooting, 'match()' function: String Functions. (line 289) -* troubleshooting, 'print' statement, omitting commas: Print Examples. - (line 30) +* troubleshooting, getline function: File Checking. (line 25) +* troubleshooting, gsub()/sub() functions: String Functions. (line 470) +* troubleshooting, match() function: String Functions. (line 289) +* troubleshooting, print statement, omitting commas: Print Examples. + (line 31) * troubleshooting, printing: Redirection. (line 118) * troubleshooting, quotes with file names: Special FD. (line 68) * troubleshooting, readable data files: File Checking. (line 6) * troubleshooting, regexp constants vs. string constants: Computed Regexps. (line 39) -* troubleshooting, string concatenation: Concatenation. (line 27) -* troubleshooting, 'substr()' function: String Functions. (line 496) -* troubleshooting, 'system()' function: I/O Functions. (line 98) +* troubleshooting, string concatenation: Concatenation. (line 26) +* troubleshooting, substr() function: String Functions. (line 497) +* troubleshooting, system() function: I/O Functions. (line 97) * troubleshooting, typographical errors, global variables: Options. - (line 99) + (line 98) * true, logical: Truth Values. (line 6) +* Trueman, David <1>: Contributors. (line 30) +* Trueman, David <2>: Acknowledgments. (line 47) * Trueman, David: History. (line 30) -* Trueman, David <1>: Acknowledgments. (line 47) -* Trueman, David <2>: Contributors. (line 31) * trunc-mod operation: Arithmetic Ops. (line 66) * truth values: Truth Values. (line 6) * type conversion: Strings And Numbers. (line 21) -* 'u' debugger command (alias for 'until'): Debugger Execution Control. +* u debugger command (alias for until): Debugger Execution Control. (line 83) * unassigned array elements: Reference to Elements. (line 18) * undefined functions: Pass By Value/Reference. - (line 70) -* underscore ('_'), C macro: Explaining gettext. (line 71) -* underscore ('_'), in names of private variables: Library Names. + (line 71) +* underscore (_), C macro: Explaining gettext. (line 71) +* underscore (_), in names of private variables: Library Names. (line 29) -* underscore ('_'), translatable string: Programmer i18n. (line 69) -* 'undisplay' debugger command: Viewing And Changing Data. - (line 79) +* underscore (_), translatable string: Programmer i18n. (line 69) +* undisplay debugger command: Viewing And Changing Data. + (line 80) * undocumented features: Undocumented. (line 6) +* Unicode <1>: Glossary. (line 133) +* Unicode <2>: Ranges and Locales. (line 61) * Unicode: Ordinal Functions. (line 45) -* Unicode <1>: Ranges and Locales. (line 61) -* Unicode <2>: Glossary. (line 133) * uninitialized variables, as array subscripts: Uninitialized Subscripts. (line 6) -<<<<<<< HEAD -* 'uniq' utility: Uniq Program. (line 6) -* 'uniq.awk' program: Uniq Program. (line 65) -* Unix: Glossary. (line 607) -* Unix 'awk', backslashes in escape sequences: Escape Sequences. - (line 123) -* Unix 'awk', 'close()' function and: Close Files And Pipes. - (line 131) -* Unix 'awk', password files, field separators and: Command Line Field Separator. - (line 64) -* Unix, 'awk' scripts and: Executable Scripts. (line 6) -* 'UNIXROOT' variable, on OS/2 systems: PC Using. (line 16) -======= * uniq utility: Uniq Program. (line 6) * uniq.awk program: Uniq Program. (line 65) * Unix: Glossary. (line 611) @@ -36394,13 +33943,12 @@ Index (line 65) * Unix, awk scripts and: Executable Scripts. (line 6) * UNIXROOT variable, on OS/2 systems: PC Using. (line 16) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * unsigned integers: Computer Arithmetic. (line 41) -* 'until' debugger command: Debugger Execution Control. +* until debugger command: Debugger Execution Control. (line 83) -* 'unwatch' debugger command: Viewing And Changing Data. - (line 83) -* 'up' debugger command: Execution Stack. (line 33) +* unwatch debugger command: Viewing And Changing Data. + (line 84) +* up debugger command: Execution Stack. (line 34) * user database, reading: Passwd Functions. (line 6) * user-defined functions: User-defined. (line 6) * user-defined, functions, counts, in a profile: Profiling. (line 137) @@ -36408,60 +33956,41 @@ Index * user-modifiable variables: User-modified. (line 6) * users, information about, printing: Id Program. (line 6) * users, information about, retrieving: Passwd Functions. (line 16) -* 'USR1' signal, for dynamic profiling: Profiling. (line 187) +* USR1 signal, for dynamic profiling: Profiling. (line 188) * values, numeric: Basic Data Typing. (line 13) * values, string: Basic Data Typing. (line 13) * variable assignments and input files: Other Arguments. (line 23) * variable typing: Typing and Comparison. (line 9) -* variables: Other Features. (line 6) * variables <1>: Basic Data Typing. (line 6) +* variables: Other Features. (line 6) * variables, assigning on command line: Assignment Options. (line 6) -* variables, built-in: Using Variables. (line 20) * variables, built-in <1>: Built-in Variables. (line 6) -* variables, built-in, '-v' option, setting with: Options. (line 41) +* variables, built-in: Using Variables. (line 20) +* variables, built-in, -v option, setting with: Options. (line 40) * variables, built-in, conveying information: Auto-set. (line 6) * variables, flag: Boolean Ops. (line 67) -* variables, 'getline' command into, using: Getline/Variable. (line 6) -* variables, 'getline' command into, using <1>: Getline/Variable/File. +* variables, getline command into, using <1>: Getline/Variable/Coprocess. (line 6) -* variables, 'getline' command into, using <2>: Getline/Variable/Pipe. +* variables, getline command into, using <2>: Getline/Variable/Pipe. (line 6) -* variables, 'getline' command into, using <3>: Getline/Variable/Coprocess. +* variables, getline command into, using <3>: Getline/Variable/File. (line 6) +* variables, getline command into, using: Getline/Variable. (line 6) * variables, global, for library functions: Library Names. (line 11) -* variables, global, printing list of: Options. (line 94) +* variables, global, printing list of: Options. (line 93) * variables, initializing: Using Variables. (line 20) * variables, local to a function: Variable Scope. (line 6) * variables, names of: Arrays. (line 18) * variables, private: Library Names. (line 11) * variables, setting: Options. (line 32) -<<<<<<< HEAD -* variables, shadowing: Definition Syntax. (line 67) -* variables, types of: Assignment Ops. (line 39) -======= * variables, shadowing: Definition Syntax. (line 70) * variables, types of: Assignment Ops. (line 40) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * variables, types of, comparison expressions and: Typing and Comparison. (line 9) * variables, uninitialized, as array subscripts: Uninitialized Subscripts. (line 6) * variables, user-defined: Variables. (line 6) -<<<<<<< HEAD -* version of 'gawk': Auto-set. (line 207) -* version of 'gawk' extension API: Auto-set. (line 232) -* version of GNU MP library: Auto-set. (line 218) -* version of GNU MPFR library: Auto-set. (line 214) -* vertical bar ('|'): Regexp Operators. (line 70) -* vertical bar ('|'), '|' operator (I/O): Getline/Pipe. (line 10) -* vertical bar ('|'), '|' operator (I/O) <1>: Precedence. (line 64) -* vertical bar ('|'), '|&' operator (I/O): Getline/Coprocess. (line 6) -* vertical bar ('|'), '|&' operator (I/O) <1>: Precedence. (line 64) -* vertical bar ('|'), '|&' operator (I/O) <2>: Two-way I/O. (line 44) -* vertical bar ('|'), '||' operator: Boolean Ops. (line 57) -* vertical bar ('|'), '||' operator <1>: Precedence. (line 88) -======= * version of gawk: Auto-set. (line 211) * version of gawk extension API: Auto-set. (line 236) * version of GNU MP library: Auto-set. (line 222) @@ -36474,59 +34003,54 @@ Index * vertical bar (|), |& operator (I/O): Getline/Coprocess. (line 6) * vertical bar (|), || operator <1>: Precedence. (line 89) * vertical bar (|), || operator: Boolean Ops. (line 57) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac * Vinschen, Corinna: Acknowledgments. (line 60) -* 'w' debugger command (alias for 'watch'): Viewing And Changing Data. - (line 66) -* 'w' utility: Constant Size. (line 23) -* 'wait()' extension function: Extension Sample Fork. +* w debugger command (alias for watch): Viewing And Changing Data. + (line 67) +* w utility: Constant Size. (line 23) +* wait() extension function: Extension Sample Fork. (line 22) -* 'waitpid()' extension function: Extension Sample Fork. +* waitpid() extension function: Extension Sample Fork. (line 18) -* 'walk_array()' user-defined function: Walking Arrays. (line 14) -* Wall, Larry: Array Intro. (line 6) +* walk_array() user-defined function: Walking Arrays. (line 14) * Wall, Larry <1>: Future Extensions. (line 6) -* Wallin, Anders: Contributors. (line 104) -* warnings, issuing: Options. (line 184) -* 'watch' debugger command: Viewing And Changing Data. - (line 66) +* Wall, Larry: Array Intro. (line 6) +* Wallin, Anders: Contributors. (line 103) +* warnings, issuing: Options. (line 185) +* watch debugger command: Viewing And Changing Data. + (line 67) * watchpoint: Debugging Terms. (line 42) -* 'wc' utility: Wc Program. (line 6) -* 'wc.awk' program: Wc Program. (line 46) +* wc utility: Wc Program. (line 6) +* wc.awk program: Wc Program. (line 46) +* Weinberger, Peter <1>: Contributors. (line 11) * Weinberger, Peter: History. (line 17) -* Weinberger, Peter <1>: Contributors. (line 12) -* 'while' statement: While Statement. (line 6) -* 'while' statement, use of regexps in: Regexp Usage. (line 19) +* while statement: While Statement. (line 6) +* while statement, use of regexps in: Regexp Usage. (line 19) * whitespace, as field separators: Default Field Splitting. (line 6) * whitespace, functions, calling: Calling Built-in. (line 10) -* whitespace, newlines as: Options. (line 256) -* Williams, Kent: Contributors. (line 35) -* Woehlke, Matthew: Contributors. (line 80) -* Woods, John: Contributors. (line 28) +* whitespace, newlines as: Options. (line 258) +* Williams, Kent: Contributors. (line 34) +* Woehlke, Matthew: Contributors. (line 79) +* Woods, John: Contributors. (line 27) * word boundaries, matching: GNU Regexp Operators. - (line 41) + (line 38) * word, regexp definition of: GNU Regexp Operators. (line 6) -* word-boundary operator ('gawk'): GNU Regexp Operators. - (line 66) -* 'wordfreq.awk' program: Word Sorting. (line 56) +* word-boundary operator (gawk): GNU Regexp Operators. + (line 63) +* wordfreq.awk program: Word Sorting. (line 56) * words, counting: Wc Program. (line 6) * words, duplicate, searching for: Dupword Program. (line 6) * words, usage counts, generating: Word Sorting. (line 6) -* 'writea()' extension function: Extension Sample Read write array. +* writea() extension function: Extension Sample Read write array. (line 9) -* 'xgettext' utility: String Extraction. (line 13) -* 'xor': Bitwise Functions. (line 56) +* xgettext utility: String Extraction. (line 13) +* xor: Bitwise Functions. (line 55) * XOR bitwise operation: Bitwise Functions. (line 6) -* Yawitz, Efraim: Contributors. (line 132) +* Yawitz, Efraim: Contributors. (line 131) +* Zaretskii, Eli <1>: Bugs. (line 71) +* Zaretskii, Eli <2>: Contributors. (line 55) * Zaretskii, Eli: Acknowledgments. (line 60) -<<<<<<< HEAD -* Zaretskii, Eli <1>: Contributors. (line 56) -* Zaretskii, Eli <2>: Bugs. (line 71) -* 'zerofile.awk' program: Empty Files. (line 20) -* Zoulas, Christos: Contributors. (line 67) -======= * zerofile.awk program: Empty Files. (line 21) * Zoulas, Christos: Contributors. (line 66) * {} (braces): Profiling. (line 142) @@ -36552,561 +34076,10 @@ Index * ~ (tilde), ~ operator <5>: Case-sensitivity. (line 26) * ~ (tilde), ~ operator <6>: Computed Regexps. (line 6) * ~ (tilde), ~ operator: Regexp Usage. (line 19) ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  Tag Table: -<<<<<<< HEAD -Node: Top1200 -Node: Foreword41842 -Node: Preface46186 -Ref: Preface-Footnote-149331 -Ref: Preface-Footnote-249438 -Node: History49671 -Node: Names52046 -Ref: Names-Footnote-153512 -Node: This Manual53585 -Ref: This Manual-Footnote-159367 -Node: Conventions59467 -Node: Manual History61640 -Ref: Manual History-Footnote-165081 -Ref: Manual History-Footnote-265122 -Node: How To Contribute65196 -Node: Acknowledgments66435 -Node: Getting Started70730 -Node: Running gawk73164 -Node: One-shot74354 -Node: Read Terminal75578 -Ref: Read Terminal-Footnote-177228 -Ref: Read Terminal-Footnote-277504 -Node: Long77675 -Node: Executable Scripts79051 -Ref: Executable Scripts-Footnote-180886 -Ref: Executable Scripts-Footnote-280988 -Node: Comments81537 -Node: Quoting84011 -Node: DOS Quoting89327 -Node: Sample Data Files90002 -Node: Very Simple92517 -Node: Two Rules97156 -Node: More Complex99050 -Ref: More Complex-Footnote-1101985 -Node: Statements/Lines102070 -Ref: Statements/Lines-Footnote-1106530 -Node: Other Features106795 -Node: When107724 -Node: Intro Summary109894 -Node: Invoking Gawk110660 -Node: Command Line112175 -Node: Options112966 -Ref: Options-Footnote-1128650 -Node: Other Arguments128675 -Node: Naming Standard Input131335 -Node: Environment Variables132429 -Node: AWKPATH Variable132987 -Ref: AWKPATH Variable-Footnote-1135859 -Ref: AWKPATH Variable-Footnote-2135904 -Node: AWKLIBPATH Variable136165 -Node: Other Environment Variables136924 -Node: Exit Status140380 -Node: Include Files141055 -Node: Loading Shared Libraries144639 -Node: Obsolete146024 -Node: Undocumented146721 -Node: Invoking Summary147017 -Node: Regexp148593 -Node: Regexp Usage150043 -Node: Escape Sequences152076 -Node: Regexp Operators157742 -Ref: Regexp Operators-Footnote-1165228 -Ref: Regexp Operators-Footnote-2165375 -Node: Bracket Expressions165473 -Ref: table-char-classes167371 -Node: GNU Regexp Operators170315 -Node: Case-sensitivity174045 -Ref: Case-sensitivity-Footnote-1176939 -Ref: Case-sensitivity-Footnote-2177174 -Node: Leftmost Longest177282 -Node: Computed Regexps178484 -Node: Regexp Summary181854 -Node: Reading Files183324 -Node: Records185417 -Node: awk split records186160 -Node: gawk split records191021 -Ref: gawk split records-Footnote-1195546 -Node: Fields195583 -Ref: Fields-Footnote-1198548 -Node: Nonconstant Fields198634 -Ref: Nonconstant Fields-Footnote-1200863 -Node: Changing Fields201066 -Node: Field Separators207019 -Node: Default Field Splitting209716 -Node: Regexp Field Splitting210834 -Node: Single Character Fields214176 -Node: Command Line Field Separator215236 -Node: Full Line Fields218579 -Ref: Full Line Fields-Footnote-1219087 -Node: Field Splitting Summary219133 -Ref: Field Splitting Summary-Footnote-1222231 -Node: Constant Size222332 -Node: Splitting By Content226939 -Ref: Splitting By Content-Footnote-1230696 -Node: Multiple Line230736 -Ref: Multiple Line-Footnote-1236594 -Node: Getline236773 -Node: Plain Getline238987 -Node: Getline/Variable241081 -Node: Getline/File242228 -Node: Getline/Variable/File243613 -Ref: Getline/Variable/File-Footnote-1245213 -Node: Getline/Pipe245301 -Node: Getline/Variable/Pipe248026 -Node: Getline/Coprocess249134 -Node: Getline/Variable/Coprocess250387 -Node: Getline Notes251125 -Node: Getline Summary253930 -Ref: table-getline-variants254348 -Node: Read Timeout255179 -Ref: Read Timeout-Footnote-1259010 -Node: Command line directories259068 -Node: Input Summary259972 -Node: Input Exercises262928 -Node: Printing263660 -Node: Print265382 -Node: Print Examples266723 -Node: Output Separators269503 -Node: OFMT271519 -Node: Printf272878 -Node: Basic Printf273784 -Node: Control Letters275324 -Node: Format Modifiers279318 -Node: Printf Examples285354 -Node: Redirection287818 -Node: Special Files294794 -Node: Special FD295325 -Ref: Special FD-Footnote-1298951 -Node: Special Network299025 -Node: Special Caveats299873 -Node: Close Files And Pipes300669 -Ref: Close Files And Pipes-Footnote-1307832 -Ref: Close Files And Pipes-Footnote-2307980 -Node: Output Summary308131 -Node: Output exercises309128 -Node: Expressions309807 -Node: Values310991 -Node: Constants311668 -Node: Scalar Constants312348 -Ref: Scalar Constants-Footnote-1313209 -Node: Nondecimal-numbers313459 -Node: Regexp Constants316462 -Node: Using Constant Regexps316937 -Node: Variables320007 -Node: Using Variables320662 -Node: Assignment Options322387 -Node: Conversion324261 -Node: Strings And Numbers324785 -Ref: Strings And Numbers-Footnote-1327845 -Node: Locale influences conversions327954 -Ref: table-locale-affects330683 -Node: All Operators331297 -Node: Arithmetic Ops331927 -Node: Concatenation334433 -Ref: Concatenation-Footnote-1337256 -Node: Assignment Ops337376 -Ref: table-assign-ops342372 -Node: Increment Ops343685 -Node: Truth Values and Conditions347150 -Node: Truth Values348224 -Node: Typing and Comparison349272 -Node: Variable Typing350077 -Ref: Variable Typing-Footnote-1353933 -Node: Comparison Operators354055 -Ref: table-relational-ops354474 -Node: POSIX String Comparison358043 -Ref: POSIX String Comparison-Footnote-1359128 -Node: Boolean Ops359266 -Ref: Boolean Ops-Footnote-1363340 -Node: Conditional Exp363432 -Node: Function Calls365157 -Node: Precedence369037 -Node: Locales372705 -Node: Expressions Summary374336 -Node: Patterns and Actions376879 -Node: Pattern Overview377995 -Node: Regexp Patterns379670 -Node: Expression Patterns380212 -Node: Ranges383994 -Node: BEGIN/END387101 -Node: Using BEGIN/END387863 -Ref: Using BEGIN/END-Footnote-1390600 -Node: I/O And BEGIN/END390706 -Node: BEGINFILE/ENDFILE392992 -Node: Empty395924 -Node: Using Shell Variables396241 -Node: Action Overview398525 -Node: Statements400851 -Node: If Statement402699 -Node: While Statement404197 -Node: Do Statement406241 -Node: For Statement407397 -Node: Switch Statement410550 -Node: Break Statement412657 -Node: Continue Statement414711 -Node: Next Statement416504 -Node: Nextfile Statement418896 -Node: Exit Statement421554 -Node: Built-in Variables423952 -Node: User-modified425079 -Ref: User-modified-Footnote-1432758 -Node: Auto-set432820 -Ref: Auto-set-Footnote-1445763 -Ref: Auto-set-Footnote-2445969 -Node: ARGC and ARGV446025 -Node: Pattern Action Summary449880 -Node: Arrays452106 -Node: Array Basics453655 -Node: Array Intro454481 -Ref: figure-array-elements456492 -Node: Reference to Elements458977 -Node: Assigning Elements461250 -Node: Array Example461741 -Node: Scanning an Array463473 -Node: Controlling Scanning466489 -Ref: Controlling Scanning-Footnote-1471667 -Node: Delete471983 -Ref: Delete-Footnote-1474752 -Node: Numeric Array Subscripts474809 -Node: Uninitialized Subscripts476991 -Node: Multidimensional478618 -Node: Multiscanning481709 -Node: Arrays of Arrays483300 -Node: Arrays Summary487977 -Node: Functions490083 -Node: Built-in490955 -Node: Calling Built-in492033 -Node: Numeric Functions494021 -Ref: Numeric Functions-Footnote-1498657 -Ref: Numeric Functions-Footnote-2499014 -Ref: Numeric Functions-Footnote-3499062 -Node: String Functions499331 -Ref: String Functions-Footnote-1522348 -Ref: String Functions-Footnote-2522477 -Ref: String Functions-Footnote-3522725 -Node: Gory Details522812 -Ref: table-sub-escapes524490 -Ref: table-sub-posix-92525846 -Ref: table-sub-proposed527201 -Ref: table-posix-sub528556 -Ref: table-gensub-escapes530105 -Ref: Gory Details-Footnote-1531270 -Ref: Gory Details-Footnote-2531321 -Node: I/O Functions531472 -Ref: I/O Functions-Footnote-1538590 -Node: Time Functions538738 -Ref: Time Functions-Footnote-1549199 -Ref: Time Functions-Footnote-2549267 -Ref: Time Functions-Footnote-3549425 -Ref: Time Functions-Footnote-4549536 -Ref: Time Functions-Footnote-5549648 -Ref: Time Functions-Footnote-6549875 -Node: Bitwise Functions550141 -Ref: table-bitwise-ops550734 -Ref: Bitwise Functions-Footnote-1554966 -Node: Type Functions555152 -Node: I18N Functions556298 -Node: User-defined557946 -Node: Definition Syntax558750 -Ref: Definition Syntax-Footnote-1563931 -Node: Function Example564000 -Ref: Function Example-Footnote-1566644 -Node: Function Caveats566666 -Node: Calling A Function567184 -Node: Variable Scope568139 -Node: Pass By Value/Reference571127 -Node: Return Statement574636 -Node: Dynamic Typing577620 -Node: Indirect Calls578550 -Node: Functions Summary588271 -Node: Library Functions590809 -Ref: Library Functions-Footnote-1594428 -Ref: Library Functions-Footnote-2594571 -Node: Library Names594742 -Ref: Library Names-Footnote-1598218 -Ref: Library Names-Footnote-2598438 -Node: General Functions598524 -Node: Strtonum Function599552 -Node: Assert Function602333 -Node: Round Function605661 -Node: Cliff Random Function607202 -Node: Ordinal Functions608218 -Ref: Ordinal Functions-Footnote-1611295 -Ref: Ordinal Functions-Footnote-2611547 -Node: Join Function611757 -Ref: Join Function-Footnote-1613528 -Node: Getlocaltime Function613728 -Node: Readfile Function617464 -Node: Data File Management619305 -Node: Filetrans Function619937 -Node: Rewind Function624006 -Node: File Checking625564 -Ref: File Checking-Footnote-1626697 -Node: Empty Files626898 -Node: Ignoring Assigns628877 -Node: Getopt Function630431 -Ref: Getopt Function-Footnote-1641740 -Node: Passwd Functions641943 -Ref: Passwd Functions-Footnote-1650923 -Node: Group Functions651011 -Ref: Group Functions-Footnote-1658954 -Node: Walking Arrays659169 -Node: Library Functions Summary660774 -Node: Library exercises662166 -Node: Sample Programs663445 -Node: Running Examples664215 -Node: Clones664943 -Node: Cut Program666167 -Node: Egrep Program676036 -Ref: Egrep Program-Footnote-1684017 -Node: Id Program684127 -Node: Split Program687794 -Ref: Split Program-Footnote-1691337 -Node: Tee Program691466 -Node: Uniq Program694274 -Node: Wc Program701711 -Ref: Wc Program-Footnote-1705981 -Node: Miscellaneous Programs706073 -Node: Dupword Program707286 -Node: Alarm Program709316 -Node: Translate Program714179 -Ref: Translate Program-Footnote-1718572 -Ref: Translate Program-Footnote-2718842 -Node: Labels Program718976 -Ref: Labels Program-Footnote-1722347 -Node: Word Sorting722431 -Node: History Sorting726476 -Node: Extract Program728312 -Node: Simple Sed735855 -Node: Igawk Program738921 -Ref: Igawk Program-Footnote-1753237 -Ref: Igawk Program-Footnote-2753439 -Node: Anagram Program753577 -Node: Signature Program756646 -Node: Programs Summary757893 -Node: Programs Exercises759107 -Node: Advanced Features762755 -Node: Nondecimal Data764710 -Node: Array Sorting766288 -Node: Controlling Array Traversal766985 -Node: Array Sorting Functions775267 -Ref: Array Sorting Functions-Footnote-1779176 -Node: Two-way I/O779370 -Ref: Two-way I/O-Footnote-1784888 -Node: TCP/IP Networking784970 -Node: Profiling787828 -Node: Advanced Features Summary795378 -Node: Internationalization797245 -Node: I18N and L10N798725 -Node: Explaining gettext799412 -Ref: Explaining gettext-Footnote-1804550 -Ref: Explaining gettext-Footnote-2804735 -Node: Programmer i18n804900 -Node: Translator i18n809104 -Node: String Extraction809898 -Ref: String Extraction-Footnote-1810861 -Node: Printf Ordering810947 -Ref: Printf Ordering-Footnote-1813729 -Node: I18N Portability813793 -Ref: I18N Portability-Footnote-1816242 -Node: I18N Example816305 -Ref: I18N Example-Footnote-1819028 -Node: Gawk I18N819101 -Node: I18N Summary819740 -Node: Debugger821080 -Node: Debugging822102 -Node: Debugging Concepts822543 -Node: Debugging Terms824399 -Node: Awk Debugging826999 -Node: Sample Debugging Session827891 -Node: Debugger Invocation828411 -Node: Finding The Bug829744 -Node: List of Debugger Commands836225 -Node: Breakpoint Control837558 -Node: Debugger Execution Control841238 -Node: Viewing And Changing Data844607 -Node: Execution Stack847964 -Node: Debugger Info849474 -Node: Miscellaneous Debugger Commands853494 -Node: Readline Support858686 -Node: Limitations859580 -Node: Debugging Summary861853 -Node: Arbitrary Precision Arithmetic863015 -Node: Computer Arithmetic864345 -Ref: Computer Arithmetic-Footnote-1868604 -Node: Math Definitions868661 -Ref: table-ieee-formats871560 -Node: MPFR features872063 -Node: FP Math Caution873706 -Ref: FP Math Caution-Footnote-1874773 -Node: Inexactness of computations875142 -Node: Inexact representation876091 -Node: Comparing FP Values877448 -Node: Errors accumulate878412 -Node: Getting Accuracy879845 -Node: Try To Round882511 -Node: Setting precision883410 -Ref: table-predefined-precision-strings884105 -Node: Setting the rounding mode885899 -Ref: table-gawk-rounding-modes886273 -Ref: Setting the rounding mode-Footnote-1889683 -Node: Arbitrary Precision Integers889862 -Ref: Arbitrary Precision Integers-Footnote-1893658 -Node: POSIX Floating Point Problems893807 -Ref: POSIX Floating Point Problems-Footnote-1897686 -Node: Floating point summary897724 -Node: Dynamic Extensions899945 -Node: Extension Intro901498 -Node: Plugin License902764 -Node: Extension Mechanism Outline903449 -Ref: figure-load-extension903884 -Ref: figure-load-new-function905454 -Ref: figure-call-new-function906542 -Node: Extension API Description908602 -Node: Extension API Functions Introduction910052 -Node: General Data Types914908 -Ref: General Data Types-Footnote-1920654 -Node: Requesting Values920953 -Ref: table-value-types-returned921702 -Node: Memory Allocation Functions922586 -Ref: Memory Allocation Functions-Footnote-1925339 -Node: Constructor Functions925435 -Node: Registration Functions927199 -Node: Extension Functions927884 -Node: Exit Callback Functions930189 -Node: Extension Version String931440 -Node: Input Parsers932090 -Node: Output Wrappers941914 -Node: Two-way processors946429 -Node: Printing Messages948634 -Ref: Printing Messages-Footnote-1949711 -Node: Updating 'ERRNO'949864 -Node: Accessing Parameters950604 -Node: Symbol Table Access951836 -Node: Symbol table by name952348 -Node: Symbol table by cookie954325 -Ref: Symbol table by cookie-Footnote-1958462 -Node: Cached values958526 -Ref: Cached values-Footnote-1962035 -Node: Array Manipulation962126 -Ref: Array Manipulation-Footnote-1963225 -Node: Array Data Types963264 -Ref: Array Data Types-Footnote-1965971 -Node: Array Functions966063 -Node: Flattening Arrays969942 -Node: Creating Arrays976801 -Node: Extension API Variables981533 -Node: Extension Versioning982169 -Node: Extension API Informational Variables984070 -Node: Extension API Boilerplate985155 -Node: Finding Extensions988964 -Node: Extension Example989524 -Node: Internal File Description990279 -Node: Internal File Ops994383 -Ref: Internal File Ops-Footnote-11005826 -Node: Using Internal File Ops1005966 -Ref: Using Internal File Ops-Footnote-11008313 -Node: Extension Samples1008583 -Node: Extension Sample File Functions1010108 -Node: Extension Sample Fnmatch1017619 -Node: Extension Sample Fork1019100 -Node: Extension Sample Inplace1020316 -Node: Extension Sample Ord1021991 -Node: Extension Sample Readdir1022827 -Ref: table-readdir-file-types1023695 -Node: Extension Sample Revout1024488 -Node: Extension Sample Rev2way1025079 -Node: Extension Sample Read write array1025820 -Node: Extension Sample Readfile1027701 -Node: Extension Sample API Tests1028801 -Node: Extension Sample Time1029327 -Node: gawkextlib1030642 -Node: Extension summary1033455 -Node: Extension Exercises1037151 -Node: Language History1037872 -Node: V7/SVR3.11039515 -Node: SVR41041835 -Node: POSIX1043277 -Node: BTL1044662 -Node: POSIX/GNU1045395 -Node: Feature History1051138 -Node: Common Extensions1064269 -Node: Ranges and Locales1065580 -Ref: Ranges and Locales-Footnote-11070194 -Ref: Ranges and Locales-Footnote-21070221 -Ref: Ranges and Locales-Footnote-31070455 -Node: Contributors1070676 -Node: History summary1076129 -Node: Installation1077499 -Node: Gawk Distribution1078449 -Node: Getting1078933 -Node: Extracting1079757 -Node: Distribution contents1081400 -Node: Unix Installation1087169 -Node: Quick Installation1087785 -Node: Additional Configuration Options1090230 -Node: Configuration Philosophy1091969 -Node: Non-Unix Installation1094321 -Node: PC Installation1094779 -Node: PC Binary Installation1096090 -Node: PC Compiling1097942 -Ref: PC Compiling-Footnote-11100944 -Node: PC Testing1101049 -Node: PC Using1102229 -Node: Cygwin1106386 -Node: MSYS1107195 -Node: VMS Installation1107709 -Node: VMS Compilation1108504 -Ref: VMS Compilation-Footnote-11109727 -Node: VMS Dynamic Extensions1109785 -Node: VMS Installation Details1111158 -Node: VMS Running1113412 -Node: VMS GNV1116248 -Node: VMS Old Gawk1116971 -Node: Bugs1117442 -Node: Other Versions1121556 -Node: Installation summary1127846 -Node: Notes1128901 -Node: Compatibility Mode1129766 -Node: Additions1130548 -Node: Accessing The Source1131473 -Node: Adding Code1132910 -Node: New Ports1139092 -Node: Derived Files1143579 -Ref: Derived Files-Footnote-11148668 -Ref: Derived Files-Footnote-21148703 -Ref: Derived Files-Footnote-31149301 -Node: Future Extensions1149415 -Node: Implementation Limitations1150071 -Node: Extension Design1151254 -Node: Old Extension Problems1152408 -Ref: Old Extension Problems-Footnote-11153926 -Node: Extension New Mechanism Goals1153983 -Ref: Extension New Mechanism Goals-Footnote-11157347 -Node: Extension Other Design Decisions1157536 -Node: Extension Future Growth1159647 -Node: Old Extension Mechanism1160483 -Node: Notes summary1162246 -Node: Basic Concepts1163428 -Node: Basic High Level1164109 -Ref: figure-general-flow1164391 -Ref: figure-process-flow1165076 -Ref: Basic High Level-Footnote-11168377 -Node: Basic Data Typing1168562 -Node: Glossary1171890 -Node: Copying1197041 -Node: GNU Free Documentation License1234579 -Node: Index1259696 -======= Node: Top1204 Node: Foreword41858 Node: Preface46203 @@ -37656,6 +34629,5 @@ Node: Glossary1174392 Node: Copying1199544 Node: GNU Free Documentation License1237100 Node: Index1262236 ->>>>>>> ca9f23d6c33c4b5cb3786d480948a42988ca99ac  End Tag Table -- cgit v1.2.3 From 8a1df492afae19d544fa5e5b636ed427b2d1c3f5 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Sun, 14 Sep 2014 19:28:50 +0300 Subject: Doc edits. --- doc/gawk.info | 746 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 376 insertions(+), 370 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index 1ae776a6..bd9ddbab 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -9827,9 +9827,8 @@ complicating the rest of the program, write a "weed out" rule near the beginning, in the following manner: NF != 4 { - err = sprintf("%s:%d: skipped: NF != 4\n", FILENAME, FNR) - print err > "/dev/stderr" - next + printf("%s:%d: skipped: NF != 4\n", FILENAME, FNR) > "/dev/stderr" + next } Because of the `next' statement, the program's subsequent rules won't @@ -14413,8 +14412,8 @@ versions of `awk': ret = 0 for (i = 1; i <= n; i++) { c = substr(str, i, 1) - # index() returns 0 if c not in string, - # includes c == "0" + # index() returns 0 if c not in string, + # includes c == "0" k = index("1234567", c) ret = ret * 8 + k @@ -14427,8 +14426,8 @@ versions of `awk': for (i = 1; i <= n; i++) { c = substr(str, i, 1) c = tolower(c) - # index() returns 0 if c not in string, - # includes c == "0" + # index() returns 0 if c not in string, + # includes c == "0" k = index("123456789abcdef", c) ret = ret * 16 + k @@ -28499,8 +28498,8 @@ the derived files, because that keeps the repository less cluttered, and it is easier to see the substantive changes when comparing versions and trying to understand what changed between commits. - However, there are two reasons why the `gawk' maintainer likes to -have everything in the repository. + However, there are several reasons why the `gawk' maintainer likes +to have everything in the repository. First, because it is then easy to reproduce any given version completely, without relying upon the availability of (older, likely @@ -28553,6 +28552,13 @@ maintainer is no different than Jane User who wants to try to build Thus, the maintainer thinks that it's not just important, but critical, that for any given branch, the above incantation _just works_. + A third reason to have all the files is that without them, using `git +bisect' to try to find the commit that introduced a bug is exceedingly +difficult. The maintainer tried to do that on another project that +requires running bootstrapping scripts just to create `configure' and +so on; it was really painful. When the repository is self-contained, +using `git bisect' in it is very easy. + What are some of the consequences and/or actions to take? 1. We don't mind that there are differing files in the different @@ -31517,7 +31523,7 @@ Index * BEGIN pattern, getline and: Getline Notes. (line 19) * BEGIN pattern, headings, adding: Print Examples. (line 43) * BEGIN pattern, next/nextfile statements and <1>: Next Statement. - (line 45) + (line 44) * BEGIN pattern, next/nextfile statements and: I/O And BEGIN/END. (line 36) * BEGIN pattern, OFS/ORS variables, assigning values to: Output Separators. @@ -32142,7 +32148,7 @@ Index * END pattern, Boolean patterns and: Expression Patterns. (line 70) * END pattern, exit statement and: Exit Statement. (line 12) * END pattern, next/nextfile statements and <1>: Next Statement. - (line 45) + (line 44) * END pattern, next/nextfile statements and: I/O And BEGIN/END. (line 36) * END pattern, operators and: Using BEGIN/END. (line 17) @@ -32475,7 +32481,7 @@ Index * functions, user-defined, next/nextfile statements and <1>: Nextfile Statement. (line 47) * functions, user-defined, next/nextfile statements and: Next Statement. - (line 45) + (line 44) * G-d: Acknowledgments. (line 92) * Garfinkle, Scott: Contributors. (line 34) * gawk program, dynamic profiling: Profiling. (line 179) @@ -32997,7 +33003,7 @@ Index * next statement, BEGIN/END patterns and: I/O And BEGIN/END. (line 36) * next statement, BEGINFILE/ENDFILE patterns and: BEGINFILE/ENDFILE. (line 49) -* next statement, user-defined functions and: Next Statement. (line 45) +* next statement, user-defined functions and: Next Statement. (line 44) * nextfile statement: Nextfile Statement. (line 6) * nextfile statement, BEGIN/END patterns and: I/O And BEGIN/END. (line 36) @@ -33239,7 +33245,7 @@ Index * POSIX awk, functions and, length(): String Functions. (line 176) * POSIX awk, GNU long options and: Options. (line 15) * POSIX awk, interval expressions in: Regexp Operators. (line 135) -* POSIX awk, next/nextfile statements and: Next Statement. (line 45) +* POSIX awk, next/nextfile statements and: Next Statement. (line 44) * POSIX awk, numeric strings and: Variable Typing. (line 6) * POSIX awk, OFMT variable and <1>: Strings And Numbers. (line 57) * POSIX awk, OFMT variable and: OFMT. (line 27) @@ -34228,361 +34234,361 @@ Node: Switch Statement412792 Node: Break Statement415180 Node: Continue Statement417221 Node: Next Statement419046 -Node: Nextfile Statement421436 -Node: Exit Statement424093 -Node: Built-in Variables426497 -Node: User-modified427624 -Ref: User-modified-Footnote-1435313 -Node: Auto-set435375 -Ref: Auto-set-Footnote-1448057 -Ref: Auto-set-Footnote-2448262 -Node: ARGC and ARGV448318 -Node: Pattern Action Summary452222 -Node: Arrays454445 -Node: Array Basics455994 -Node: Array Intro456820 -Ref: figure-array-elements458793 -Ref: Array Intro-Footnote-1461317 -Node: Reference to Elements461445 -Node: Assigning Elements463895 -Node: Array Example464386 -Node: Scanning an Array466118 -Node: Controlling Scanning469119 -Ref: Controlling Scanning-Footnote-1474292 -Node: Delete474608 -Ref: Delete-Footnote-1477359 -Node: Numeric Array Subscripts477416 -Node: Uninitialized Subscripts479599 -Node: Multidimensional481226 -Node: Multiscanning484339 -Node: Arrays of Arrays485928 -Node: Arrays Summary490591 -Node: Functions492696 -Node: Built-in493569 -Node: Calling Built-in494647 -Node: Numeric Functions496635 -Ref: Numeric Functions-Footnote-1500669 -Ref: Numeric Functions-Footnote-2501026 -Ref: Numeric Functions-Footnote-3501074 -Node: String Functions501343 -Ref: String Functions-Footnote-1524340 -Ref: String Functions-Footnote-2524469 -Ref: String Functions-Footnote-3524717 -Node: Gory Details524804 -Ref: table-sub-escapes526577 -Ref: table-sub-proposed528097 -Ref: table-posix-sub529461 -Ref: table-gensub-escapes531001 -Ref: Gory Details-Footnote-1532177 -Node: I/O Functions532328 -Ref: I/O Functions-Footnote-1539438 -Node: Time Functions539585 -Ref: Time Functions-Footnote-1550049 -Ref: Time Functions-Footnote-2550117 -Ref: Time Functions-Footnote-3550275 -Ref: Time Functions-Footnote-4550386 -Ref: Time Functions-Footnote-5550498 -Ref: Time Functions-Footnote-6550725 -Node: Bitwise Functions550991 -Ref: table-bitwise-ops551553 -Ref: Bitwise Functions-Footnote-1555798 -Node: Type Functions555982 -Node: I18N Functions557124 -Node: User-defined558769 -Node: Definition Syntax559573 -Ref: Definition Syntax-Footnote-1564886 -Node: Function Example564955 -Ref: Function Example-Footnote-1567595 -Node: Function Caveats567617 -Node: Calling A Function568135 -Node: Variable Scope569090 -Node: Pass By Value/Reference572078 -Node: Return Statement575588 -Node: Dynamic Typing578572 -Node: Indirect Calls579501 -Ref: Indirect Calls-Footnote-1589217 -Node: Functions Summary589345 -Node: Library Functions591995 -Ref: Library Functions-Footnote-1595613 -Ref: Library Functions-Footnote-2595756 -Node: Library Names595927 -Ref: Library Names-Footnote-1599400 -Ref: Library Names-Footnote-2599620 -Node: General Functions599706 -Node: Strtonum Function600734 -Node: Assert Function603608 -Node: Round Function606934 -Node: Cliff Random Function608475 -Node: Ordinal Functions609491 -Ref: Ordinal Functions-Footnote-1612556 -Ref: Ordinal Functions-Footnote-2612808 -Node: Join Function613019 -Ref: Join Function-Footnote-1614790 -Node: Getlocaltime Function614990 -Node: Readfile Function618726 -Node: Data File Management620565 -Node: Filetrans Function621197 -Node: Rewind Function625266 -Node: File Checking626824 -Ref: File Checking-Footnote-1627956 -Node: Empty Files628157 -Node: Ignoring Assigns630136 -Node: Getopt Function631690 -Ref: Getopt Function-Footnote-1642954 -Node: Passwd Functions643157 -Ref: Passwd Functions-Footnote-1652136 -Node: Group Functions652224 -Ref: Group Functions-Footnote-1660155 -Node: Walking Arrays660368 -Node: Library Functions Summary661971 -Node: Library Exercises663359 -Node: Sample Programs664639 -Node: Running Examples665409 -Node: Clones666137 -Node: Cut Program667361 -Node: Egrep Program677219 -Ref: Egrep Program-Footnote-1684806 -Node: Id Program684916 -Node: Split Program688570 -Ref: Split Program-Footnote-1692108 -Node: Tee Program692236 -Node: Uniq Program695023 -Node: Wc Program702446 -Ref: Wc Program-Footnote-1706711 -Node: Miscellaneous Programs706803 -Node: Dupword Program708016 -Node: Alarm Program710047 -Node: Translate Program714851 -Ref: Translate Program-Footnote-1719424 -Ref: Translate Program-Footnote-2719694 -Node: Labels Program719833 -Ref: Labels Program-Footnote-1723194 -Node: Word Sorting723278 -Node: History Sorting727321 -Node: Extract Program729157 -Node: Simple Sed736693 -Node: Igawk Program739755 -Ref: Igawk Program-Footnote-1754059 -Ref: Igawk Program-Footnote-2754260 -Node: Anagram Program754398 -Node: Signature Program757466 -Node: Programs Summary758713 -Node: Programs Exercises759928 -Ref: Programs Exercises-Footnote-1764059 -Node: Advanced Features764150 -Node: Nondecimal Data766098 -Node: Array Sorting767675 -Node: Controlling Array Traversal768372 -Node: Array Sorting Functions776652 -Ref: Array Sorting Functions-Footnote-1780559 -Node: Two-way I/O780753 -Ref: Two-way I/O-Footnote-1785697 -Ref: Two-way I/O-Footnote-2785876 -Node: TCP/IP Networking785958 -Node: Profiling788803 -Node: Advanced Features Summary796345 -Node: Internationalization798209 -Node: I18N and L10N799689 -Node: Explaining gettext800375 -Ref: Explaining gettext-Footnote-1805401 -Ref: Explaining gettext-Footnote-2805585 -Node: Programmer i18n805750 -Ref: Programmer i18n-Footnote-1810544 -Node: Translator i18n810593 -Node: String Extraction811387 -Ref: String Extraction-Footnote-1812520 -Node: Printf Ordering812606 -Ref: Printf Ordering-Footnote-1815388 -Node: I18N Portability815452 -Ref: I18N Portability-Footnote-1817901 -Node: I18N Example817964 -Ref: I18N Example-Footnote-1820670 -Node: Gawk I18N820742 -Node: I18N Summary821380 -Node: Debugger822719 -Node: Debugging823741 -Node: Debugging Concepts824182 -Node: Debugging Terms826038 -Node: Awk Debugging828635 -Node: Sample Debugging Session829527 -Node: Debugger Invocation830047 -Node: Finding The Bug831383 -Node: List of Debugger Commands837862 -Node: Breakpoint Control839194 -Node: Debugger Execution Control842858 -Node: Viewing And Changing Data846218 -Node: Execution Stack849576 -Node: Debugger Info851089 -Node: Miscellaneous Debugger Commands855083 -Node: Readline Support860267 -Node: Limitations861159 -Node: Debugging Summary863432 -Node: Arbitrary Precision Arithmetic864600 -Node: Computer Arithmetic866087 -Ref: Computer Arithmetic-Footnote-1870474 -Node: Math Definitions870531 -Ref: table-ieee-formats873820 -Ref: Math Definitions-Footnote-1874360 -Node: MPFR features874463 -Node: FP Math Caution876080 -Ref: FP Math Caution-Footnote-1877130 -Node: Inexactness of computations877499 -Node: Inexact representation878447 -Node: Comparing FP Values879802 -Node: Errors accumulate880766 -Node: Getting Accuracy882199 -Node: Try To Round884858 -Node: Setting precision885757 -Ref: table-predefined-precision-strings886439 -Node: Setting the rounding mode888232 -Ref: table-gawk-rounding-modes888596 -Ref: Setting the rounding mode-Footnote-1892050 -Node: Arbitrary Precision Integers892229 -Ref: Arbitrary Precision Integers-Footnote-1895210 -Node: POSIX Floating Point Problems895359 -Ref: POSIX Floating Point Problems-Footnote-1899235 -Node: Floating point summary899273 -Node: Dynamic Extensions901477 -Node: Extension Intro903029 -Node: Plugin License904294 -Node: Extension Mechanism Outline904979 -Ref: figure-load-extension905403 -Ref: figure-load-new-function906888 -Ref: figure-call-new-function907890 -Node: Extension API Description909874 -Node: Extension API Functions Introduction911324 -Node: General Data Types916191 -Ref: General Data Types-Footnote-1921884 -Node: Requesting Values922183 -Ref: table-value-types-returned922920 -Node: Memory Allocation Functions923878 -Ref: Memory Allocation Functions-Footnote-1926625 -Node: Constructor Functions926721 -Node: Registration Functions928479 -Node: Extension Functions929164 -Node: Exit Callback Functions931466 -Node: Extension Version String932714 -Node: Input Parsers933364 -Node: Output Wrappers943178 -Node: Two-way processors947694 -Node: Printing Messages949898 -Ref: Printing Messages-Footnote-1950975 -Node: Updating `ERRNO'951127 -Node: Accessing Parameters951866 -Node: Symbol Table Access953096 -Node: Symbol table by name953610 -Node: Symbol table by cookie955586 -Ref: Symbol table by cookie-Footnote-1959719 -Node: Cached values959782 -Ref: Cached values-Footnote-1963286 -Node: Array Manipulation963377 -Ref: Array Manipulation-Footnote-1964475 -Node: Array Data Types964514 -Ref: Array Data Types-Footnote-1967217 -Node: Array Functions967309 -Node: Flattening Arrays971183 -Node: Creating Arrays978035 -Node: Extension API Variables982766 -Node: Extension Versioning983402 -Node: Extension API Informational Variables985303 -Node: Extension API Boilerplate986389 -Node: Finding Extensions990193 -Node: Extension Example990753 -Node: Internal File Description991483 -Node: Internal File Ops995574 -Ref: Internal File Ops-Footnote-11007006 -Node: Using Internal File Ops1007146 -Ref: Using Internal File Ops-Footnote-11009493 -Node: Extension Samples1009761 -Node: Extension Sample File Functions1011285 -Node: Extension Sample Fnmatch1018853 -Node: Extension Sample Fork1020335 -Node: Extension Sample Inplace1021548 -Node: Extension Sample Ord1023223 -Node: Extension Sample Readdir1024059 -Ref: table-readdir-file-types1024915 -Node: Extension Sample Revout1025714 -Node: Extension Sample Rev2way1026305 -Node: Extension Sample Read write array1027046 -Node: Extension Sample Readfile1028925 -Node: Extension Sample API Tests1030025 -Node: Extension Sample Time1030550 -Node: gawkextlib1031865 -Node: Extension summary1034678 -Node: Extension Exercises1038371 -Node: Language History1039093 -Node: V7/SVR3.11040736 -Node: SVR41043056 -Node: POSIX1044498 -Node: BTL1045884 -Node: POSIX/GNU1046618 -Node: Feature History1052334 -Node: Common Extensions1065425 -Node: Ranges and Locales1066737 -Ref: Ranges and Locales-Footnote-11071354 -Ref: Ranges and Locales-Footnote-21071381 -Ref: Ranges and Locales-Footnote-31071615 -Node: Contributors1071836 -Node: History summary1077261 -Node: Installation1078630 -Node: Gawk Distribution1079581 -Node: Getting1080065 -Node: Extracting1080889 -Node: Distribution contents1082531 -Node: Unix Installation1088248 -Node: Quick Installation1088865 -Node: Additional Configuration Options1091307 -Node: Configuration Philosophy1093045 -Node: Non-Unix Installation1095396 -Node: PC Installation1095854 -Node: PC Binary Installation1097165 -Node: PC Compiling1099013 -Ref: PC Compiling-Footnote-11102012 -Node: PC Testing1102117 -Node: PC Using1103293 -Node: Cygwin1107445 -Node: MSYS1108254 -Node: VMS Installation1108768 -Node: VMS Compilation1109564 -Ref: VMS Compilation-Footnote-11110786 -Node: VMS Dynamic Extensions1110844 -Node: VMS Installation Details1112217 -Node: VMS Running1114469 -Node: VMS GNV1117303 -Node: VMS Old Gawk1118026 -Node: Bugs1118496 -Node: Other Versions1122500 -Node: Installation summary1128727 -Node: Notes1129783 -Node: Compatibility Mode1130648 -Node: Additions1131430 -Node: Accessing The Source1132355 -Node: Adding Code1133791 -Node: New Ports1139969 -Node: Derived Files1144450 -Ref: Derived Files-Footnote-11149531 -Ref: Derived Files-Footnote-21149565 -Ref: Derived Files-Footnote-31150161 -Node: Future Extensions1150275 -Node: Implementation Limitations1150881 -Node: Extension Design1152129 -Node: Old Extension Problems1153283 -Ref: Old Extension Problems-Footnote-11154800 -Node: Extension New Mechanism Goals1154857 -Ref: Extension New Mechanism Goals-Footnote-11158217 -Node: Extension Other Design Decisions1158406 -Node: Extension Future Growth1160512 -Node: Old Extension Mechanism1161348 -Node: Notes summary1163110 -Node: Basic Concepts1164296 -Node: Basic High Level1164977 -Ref: figure-general-flow1165249 -Ref: figure-process-flow1165848 -Ref: Basic High Level-Footnote-11169077 -Node: Basic Data Typing1169262 -Node: Glossary1172590 -Node: Copying1197742 -Node: GNU Free Documentation License1235298 -Node: Index1260434 +Node: Nextfile Statement421416 +Node: Exit Statement424073 +Node: Built-in Variables426477 +Node: User-modified427604 +Ref: User-modified-Footnote-1435293 +Node: Auto-set435355 +Ref: Auto-set-Footnote-1448037 +Ref: Auto-set-Footnote-2448242 +Node: ARGC and ARGV448298 +Node: Pattern Action Summary452202 +Node: Arrays454425 +Node: Array Basics455974 +Node: Array Intro456800 +Ref: figure-array-elements458773 +Ref: Array Intro-Footnote-1461297 +Node: Reference to Elements461425 +Node: Assigning Elements463875 +Node: Array Example464366 +Node: Scanning an Array466098 +Node: Controlling Scanning469099 +Ref: Controlling Scanning-Footnote-1474272 +Node: Delete474588 +Ref: Delete-Footnote-1477339 +Node: Numeric Array Subscripts477396 +Node: Uninitialized Subscripts479579 +Node: Multidimensional481206 +Node: Multiscanning484319 +Node: Arrays of Arrays485908 +Node: Arrays Summary490571 +Node: Functions492676 +Node: Built-in493549 +Node: Calling Built-in494627 +Node: Numeric Functions496615 +Ref: Numeric Functions-Footnote-1500649 +Ref: Numeric Functions-Footnote-2501006 +Ref: Numeric Functions-Footnote-3501054 +Node: String Functions501323 +Ref: String Functions-Footnote-1524320 +Ref: String Functions-Footnote-2524449 +Ref: String Functions-Footnote-3524697 +Node: Gory Details524784 +Ref: table-sub-escapes526557 +Ref: table-sub-proposed528077 +Ref: table-posix-sub529441 +Ref: table-gensub-escapes530981 +Ref: Gory Details-Footnote-1532157 +Node: I/O Functions532308 +Ref: I/O Functions-Footnote-1539418 +Node: Time Functions539565 +Ref: Time Functions-Footnote-1550029 +Ref: Time Functions-Footnote-2550097 +Ref: Time Functions-Footnote-3550255 +Ref: Time Functions-Footnote-4550366 +Ref: Time Functions-Footnote-5550478 +Ref: Time Functions-Footnote-6550705 +Node: Bitwise Functions550971 +Ref: table-bitwise-ops551533 +Ref: Bitwise Functions-Footnote-1555778 +Node: Type Functions555962 +Node: I18N Functions557104 +Node: User-defined558749 +Node: Definition Syntax559553 +Ref: Definition Syntax-Footnote-1564866 +Node: Function Example564935 +Ref: Function Example-Footnote-1567575 +Node: Function Caveats567597 +Node: Calling A Function568115 +Node: Variable Scope569070 +Node: Pass By Value/Reference572058 +Node: Return Statement575568 +Node: Dynamic Typing578552 +Node: Indirect Calls579481 +Ref: Indirect Calls-Footnote-1589197 +Node: Functions Summary589325 +Node: Library Functions591975 +Ref: Library Functions-Footnote-1595593 +Ref: Library Functions-Footnote-2595736 +Node: Library Names595907 +Ref: Library Names-Footnote-1599380 +Ref: Library Names-Footnote-2599600 +Node: General Functions599686 +Node: Strtonum Function600714 +Node: Assert Function603616 +Node: Round Function606942 +Node: Cliff Random Function608483 +Node: Ordinal Functions609499 +Ref: Ordinal Functions-Footnote-1612564 +Ref: Ordinal Functions-Footnote-2612816 +Node: Join Function613027 +Ref: Join Function-Footnote-1614798 +Node: Getlocaltime Function614998 +Node: Readfile Function618734 +Node: Data File Management620573 +Node: Filetrans Function621205 +Node: Rewind Function625274 +Node: File Checking626832 +Ref: File Checking-Footnote-1627964 +Node: Empty Files628165 +Node: Ignoring Assigns630144 +Node: Getopt Function631698 +Ref: Getopt Function-Footnote-1642962 +Node: Passwd Functions643165 +Ref: Passwd Functions-Footnote-1652144 +Node: Group Functions652232 +Ref: Group Functions-Footnote-1660163 +Node: Walking Arrays660376 +Node: Library Functions Summary661979 +Node: Library Exercises663367 +Node: Sample Programs664647 +Node: Running Examples665417 +Node: Clones666145 +Node: Cut Program667369 +Node: Egrep Program677227 +Ref: Egrep Program-Footnote-1684814 +Node: Id Program684924 +Node: Split Program688578 +Ref: Split Program-Footnote-1692116 +Node: Tee Program692244 +Node: Uniq Program695031 +Node: Wc Program702454 +Ref: Wc Program-Footnote-1706719 +Node: Miscellaneous Programs706811 +Node: Dupword Program708024 +Node: Alarm Program710055 +Node: Translate Program714859 +Ref: Translate Program-Footnote-1719432 +Ref: Translate Program-Footnote-2719702 +Node: Labels Program719841 +Ref: Labels Program-Footnote-1723202 +Node: Word Sorting723286 +Node: History Sorting727329 +Node: Extract Program729165 +Node: Simple Sed736701 +Node: Igawk Program739763 +Ref: Igawk Program-Footnote-1754067 +Ref: Igawk Program-Footnote-2754268 +Node: Anagram Program754406 +Node: Signature Program757474 +Node: Programs Summary758721 +Node: Programs Exercises759936 +Ref: Programs Exercises-Footnote-1764067 +Node: Advanced Features764158 +Node: Nondecimal Data766106 +Node: Array Sorting767683 +Node: Controlling Array Traversal768380 +Node: Array Sorting Functions776660 +Ref: Array Sorting Functions-Footnote-1780567 +Node: Two-way I/O780761 +Ref: Two-way I/O-Footnote-1785705 +Ref: Two-way I/O-Footnote-2785884 +Node: TCP/IP Networking785966 +Node: Profiling788811 +Node: Advanced Features Summary796353 +Node: Internationalization798217 +Node: I18N and L10N799697 +Node: Explaining gettext800383 +Ref: Explaining gettext-Footnote-1805409 +Ref: Explaining gettext-Footnote-2805593 +Node: Programmer i18n805758 +Ref: Programmer i18n-Footnote-1810552 +Node: Translator i18n810601 +Node: String Extraction811395 +Ref: String Extraction-Footnote-1812528 +Node: Printf Ordering812614 +Ref: Printf Ordering-Footnote-1815396 +Node: I18N Portability815460 +Ref: I18N Portability-Footnote-1817909 +Node: I18N Example817972 +Ref: I18N Example-Footnote-1820678 +Node: Gawk I18N820750 +Node: I18N Summary821388 +Node: Debugger822727 +Node: Debugging823749 +Node: Debugging Concepts824190 +Node: Debugging Terms826046 +Node: Awk Debugging828643 +Node: Sample Debugging Session829535 +Node: Debugger Invocation830055 +Node: Finding The Bug831391 +Node: List of Debugger Commands837870 +Node: Breakpoint Control839202 +Node: Debugger Execution Control842866 +Node: Viewing And Changing Data846226 +Node: Execution Stack849584 +Node: Debugger Info851097 +Node: Miscellaneous Debugger Commands855091 +Node: Readline Support860275 +Node: Limitations861167 +Node: Debugging Summary863440 +Node: Arbitrary Precision Arithmetic864608 +Node: Computer Arithmetic866095 +Ref: Computer Arithmetic-Footnote-1870482 +Node: Math Definitions870539 +Ref: table-ieee-formats873828 +Ref: Math Definitions-Footnote-1874368 +Node: MPFR features874471 +Node: FP Math Caution876088 +Ref: FP Math Caution-Footnote-1877138 +Node: Inexactness of computations877507 +Node: Inexact representation878455 +Node: Comparing FP Values879810 +Node: Errors accumulate880774 +Node: Getting Accuracy882207 +Node: Try To Round884866 +Node: Setting precision885765 +Ref: table-predefined-precision-strings886447 +Node: Setting the rounding mode888240 +Ref: table-gawk-rounding-modes888604 +Ref: Setting the rounding mode-Footnote-1892058 +Node: Arbitrary Precision Integers892237 +Ref: Arbitrary Precision Integers-Footnote-1895218 +Node: POSIX Floating Point Problems895367 +Ref: POSIX Floating Point Problems-Footnote-1899243 +Node: Floating point summary899281 +Node: Dynamic Extensions901485 +Node: Extension Intro903037 +Node: Plugin License904302 +Node: Extension Mechanism Outline904987 +Ref: figure-load-extension905411 +Ref: figure-load-new-function906896 +Ref: figure-call-new-function907898 +Node: Extension API Description909882 +Node: Extension API Functions Introduction911332 +Node: General Data Types916199 +Ref: General Data Types-Footnote-1921892 +Node: Requesting Values922191 +Ref: table-value-types-returned922928 +Node: Memory Allocation Functions923886 +Ref: Memory Allocation Functions-Footnote-1926633 +Node: Constructor Functions926729 +Node: Registration Functions928487 +Node: Extension Functions929172 +Node: Exit Callback Functions931474 +Node: Extension Version String932722 +Node: Input Parsers933372 +Node: Output Wrappers943186 +Node: Two-way processors947702 +Node: Printing Messages949906 +Ref: Printing Messages-Footnote-1950983 +Node: Updating `ERRNO'951135 +Node: Accessing Parameters951874 +Node: Symbol Table Access953104 +Node: Symbol table by name953618 +Node: Symbol table by cookie955594 +Ref: Symbol table by cookie-Footnote-1959727 +Node: Cached values959790 +Ref: Cached values-Footnote-1963294 +Node: Array Manipulation963385 +Ref: Array Manipulation-Footnote-1964483 +Node: Array Data Types964522 +Ref: Array Data Types-Footnote-1967225 +Node: Array Functions967317 +Node: Flattening Arrays971191 +Node: Creating Arrays978043 +Node: Extension API Variables982774 +Node: Extension Versioning983410 +Node: Extension API Informational Variables985311 +Node: Extension API Boilerplate986397 +Node: Finding Extensions990201 +Node: Extension Example990761 +Node: Internal File Description991491 +Node: Internal File Ops995582 +Ref: Internal File Ops-Footnote-11007014 +Node: Using Internal File Ops1007154 +Ref: Using Internal File Ops-Footnote-11009501 +Node: Extension Samples1009769 +Node: Extension Sample File Functions1011293 +Node: Extension Sample Fnmatch1018861 +Node: Extension Sample Fork1020343 +Node: Extension Sample Inplace1021556 +Node: Extension Sample Ord1023231 +Node: Extension Sample Readdir1024067 +Ref: table-readdir-file-types1024923 +Node: Extension Sample Revout1025722 +Node: Extension Sample Rev2way1026313 +Node: Extension Sample Read write array1027054 +Node: Extension Sample Readfile1028933 +Node: Extension Sample API Tests1030033 +Node: Extension Sample Time1030558 +Node: gawkextlib1031873 +Node: Extension summary1034686 +Node: Extension Exercises1038379 +Node: Language History1039101 +Node: V7/SVR3.11040744 +Node: SVR41043064 +Node: POSIX1044506 +Node: BTL1045892 +Node: POSIX/GNU1046626 +Node: Feature History1052342 +Node: Common Extensions1065433 +Node: Ranges and Locales1066745 +Ref: Ranges and Locales-Footnote-11071362 +Ref: Ranges and Locales-Footnote-21071389 +Ref: Ranges and Locales-Footnote-31071623 +Node: Contributors1071844 +Node: History summary1077269 +Node: Installation1078638 +Node: Gawk Distribution1079589 +Node: Getting1080073 +Node: Extracting1080897 +Node: Distribution contents1082539 +Node: Unix Installation1088256 +Node: Quick Installation1088873 +Node: Additional Configuration Options1091315 +Node: Configuration Philosophy1093053 +Node: Non-Unix Installation1095404 +Node: PC Installation1095862 +Node: PC Binary Installation1097173 +Node: PC Compiling1099021 +Ref: PC Compiling-Footnote-11102020 +Node: PC Testing1102125 +Node: PC Using1103301 +Node: Cygwin1107453 +Node: MSYS1108262 +Node: VMS Installation1108776 +Node: VMS Compilation1109572 +Ref: VMS Compilation-Footnote-11110794 +Node: VMS Dynamic Extensions1110852 +Node: VMS Installation Details1112225 +Node: VMS Running1114477 +Node: VMS GNV1117311 +Node: VMS Old Gawk1118034 +Node: Bugs1118504 +Node: Other Versions1122508 +Node: Installation summary1128735 +Node: Notes1129791 +Node: Compatibility Mode1130656 +Node: Additions1131438 +Node: Accessing The Source1132363 +Node: Adding Code1133799 +Node: New Ports1139977 +Node: Derived Files1144458 +Ref: Derived Files-Footnote-11149933 +Ref: Derived Files-Footnote-21149967 +Ref: Derived Files-Footnote-31150563 +Node: Future Extensions1150677 +Node: Implementation Limitations1151283 +Node: Extension Design1152531 +Node: Old Extension Problems1153685 +Ref: Old Extension Problems-Footnote-11155202 +Node: Extension New Mechanism Goals1155259 +Ref: Extension New Mechanism Goals-Footnote-11158619 +Node: Extension Other Design Decisions1158808 +Node: Extension Future Growth1160914 +Node: Old Extension Mechanism1161750 +Node: Notes summary1163512 +Node: Basic Concepts1164698 +Node: Basic High Level1165379 +Ref: figure-general-flow1165651 +Ref: figure-process-flow1166250 +Ref: Basic High Level-Footnote-11169479 +Node: Basic Data Typing1169664 +Node: Glossary1172992 +Node: Copying1198144 +Node: GNU Free Documentation License1235700 +Node: Index1260836  End Tag Table -- cgit v1.2.3 From 3fcce8a32e825dd10384d5276c420c2514442fe2 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Mon, 15 Sep 2014 19:47:03 +0300 Subject: Finish excising isalpha and isalnum. Document. --- doc/gawk.info | 909 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 458 insertions(+), 451 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index bd9ddbab..d94ea8bf 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -7437,8 +7437,11 @@ File: gawk.info, Node: Using Variables, Next: Assignment Options, Up: Variabl Variables let you give names to values and refer to them later. Variables have already been used in many of the examples. The name of a variable must be a sequence of letters, digits, or underscores, and -it may not begin with a digit. Case is significant in variable names; -`a' and `A' are distinct variables. +it may not begin with a digit. Here, a "letter" is any one of the 52 +upper- and lowercase English letters. Other characters that may be +defined as letters in non-English locales are not valid in variable +names. Case is significant in variable names; `a' and `A' are distinct +variables. A variable name is a valid expression by itself; it represents the variable's current value. Variables are given new values with @@ -10299,8 +10302,11 @@ Options::), they are not special. `PROCINFO["identifiers"]' A subarray, indexed by the names of all identifiers used in - the text of the AWK program. For each identifier, the value - of the element is one of the following: + the text of the AWK program. An "identifier" is simply the + name of a variable (be it scalar or array), built-in + function, user-defined function, or extension function. For + each identifier, the value of the element is one of the + following: `"array"' The identifier is an array. @@ -13300,9 +13306,10 @@ starting to execute any of it. Here, NAME is the name of the function to define. A valid function name is like a valid variable name: a sequence of letters, digits, and -underscores that doesn't start with a digit. Within a single `awk' -program, any particular name can only be used as a variable, array, or -function. +underscores that doesn't start with a digit. Here too, only the 52 +upper- and lowercase English letters may be used in a function name. +Within a single `awk' program, any particular name can only be used as +a variable, array, or function. PARAMETER-LIST is an optional list of the function's arguments and local variable names, separated by commas. When the function is called, @@ -31733,7 +31740,7 @@ Index * common extensions, \x escape sequence: Escape Sequences. (line 61) * common extensions, BINMODE variable: PC Using. (line 33) * common extensions, delete to delete entire arrays: Delete. (line 39) -* common extensions, func keyword: Definition Syntax. (line 92) +* common extensions, func keyword: Definition Syntax. (line 93) * common extensions, length() applied to an array: String Functions. (line 197) * common extensions, RS as a regexp: gawk split records. (line 6) @@ -31845,7 +31852,7 @@ Index (line 46) * dark corner, FILENAME variable <1>: Auto-set. (line 90) * dark corner, FILENAME variable: Getline Notes. (line 19) -* dark corner, FNR/NR variables: Auto-set. (line 305) +* dark corner, FNR/NR variables: Auto-set. (line 308) * dark corner, format-control characters: Control Letters. (line 18) * dark corner, FS as null string: Single Character Fields. (line 20) @@ -32069,7 +32076,7 @@ Index (line 26) * differences in awk and gawk, RS/RT variables: gawk split records. (line 58) -* differences in awk and gawk, RT variable: Auto-set. (line 261) +* differences in awk and gawk, RT variable: Auto-set. (line 264) * differences in awk and gawk, single-character fields: Single Character Fields. (line 6) * differences in awk and gawk, split() function: String Functions. @@ -32077,7 +32084,7 @@ Index * differences in awk and gawk, strings: Scalar Constants. (line 20) * differences in awk and gawk, strings, storing: gawk split records. (line 77) -* differences in awk and gawk, SYMTAB variable: Auto-set. (line 265) +* differences in awk and gawk, SYMTAB variable: Auto-set. (line 268) * differences in awk and gawk, TEXTDOMAIN variable: User-modified. (line 152) * differences in awk and gawk, trunc-mod operation: Arithmetic Ops. @@ -32232,7 +32239,7 @@ Index (line 6) * extension API version: Extension Versioning. (line 6) -* extension API, version number: Auto-set. (line 228) +* extension API, version number: Auto-set. (line 231) * extension example: Extension Example. (line 6) * extension registration: Registration Functions. (line 6) @@ -32251,7 +32258,7 @@ Index * extensions, common, BINMODE variable: PC Using. (line 33) * extensions, common, delete to delete entire arrays: Delete. (line 39) * extensions, common, fflush() function: I/O Functions. (line 43) -* extensions, common, func keyword: Definition Syntax. (line 92) +* extensions, common, func keyword: Definition Syntax. (line 93) * extensions, common, length() applied to an array: String Functions. (line 197) * extensions, common, RS as a regexp: gawk split records. (line 6) @@ -32384,7 +32391,7 @@ Index (line 12) * FNR variable <1>: Auto-set. (line 99) * FNR variable: Records. (line 6) -* FNR variable, changing: Auto-set. (line 305) +* FNR variable, changing: Auto-set. (line 308) * for statement: For Statement. (line 6) * for statement, looping over arrays: Scanning an Array. (line 20) * fork() extension function: Extension Sample Fork. @@ -32470,7 +32477,7 @@ Index (line 6) * functions, names of <1>: Definition Syntax. (line 23) * functions, names of: Arrays. (line 18) -* functions, recursive: Definition Syntax. (line 82) +* functions, recursive: Definition Syntax. (line 83) * functions, string-translation: I18N Functions. (line 6) * functions, undefined: Pass By Value/Reference. (line 71) @@ -32485,7 +32492,7 @@ Index * G-d: Acknowledgments. (line 92) * Garfinkle, Scott: Contributors. (line 34) * gawk program, dynamic profiling: Profiling. (line 179) -* gawk version: Auto-set. (line 203) +* gawk version: Auto-set. (line 206) * gawk, ARGIND variable in: Other Arguments. (line 12) * gawk, awk and <1>: This Manual. (line 14) * gawk, awk and: Preface. (line 21) @@ -32562,14 +32569,14 @@ Index * gawk, regular expressions, operators: GNU Regexp Operators. (line 6) * gawk, regular expressions, precedence: Regexp Operators. (line 161) -* gawk, RT variable in <1>: Auto-set. (line 261) +* gawk, RT variable in <1>: Auto-set. (line 264) * gawk, RT variable in <2>: Multiple Line. (line 129) * gawk, RT variable in: awk split records. (line 124) * gawk, See Also awk: Preface. (line 34) * gawk, source code, obtaining: Getting. (line 6) * gawk, splitting fields and: Constant Size. (line 88) * gawk, string-translation functions: I18N Functions. (line 6) -* gawk, SYMTAB array in: Auto-set. (line 265) +* gawk, SYMTAB array in: Auto-set. (line 268) * gawk, TEXTDOMAIN variable in: User-modified. (line 152) * gawk, timestamps: Time Functions. (line 6) * gawk, uses for: Preface. (line 34) @@ -32655,7 +32662,7 @@ Index * Grigera, Juan: Contributors. (line 57) * group database, reading: Group Functions. (line 6) * group file: Group Functions. (line 6) -* group ID of gawk user: Auto-set. (line 176) +* group ID of gawk user: Auto-set. (line 179) * groups, information about: Group Functions. (line 6) * gsub <1>: String Functions. (line 139) * gsub: Using Constant Regexps. @@ -32949,7 +32956,7 @@ Index * mawk utility <3>: Concatenation. (line 36) * mawk utility <4>: Getline/Pipe. (line 62) * mawk utility: Escape Sequences. (line 130) -* maximum precision supported by MPFR library: Auto-set. (line 217) +* maximum precision supported by MPFR library: Auto-set. (line 220) * McIlroy, Doug: Glossary. (line 149) * McPhee, Patrick: Contributors. (line 100) * message object files: Explaining gettext. (line 42) @@ -32962,7 +32969,7 @@ Index * messages from extensions: Printing Messages. (line 6) * metacharacters in regular expressions: Regexp Operators. (line 6) * metacharacters, escape sequences for: Escape Sequences. (line 136) -* minimum precision supported by MPFR library: Auto-set. (line 220) +* minimum precision supported by MPFR library: Auto-set. (line 223) * mktime: Time Functions. (line 25) * modifiers, in format specifiers: Format Modifiers. (line 6) * monetary information, localization: Explaining gettext. (line 104) @@ -33024,7 +33031,7 @@ Index * not Boolean-logic operator: Boolean Ops. (line 6) * NR variable <1>: Auto-set. (line 124) * NR variable: Records. (line 6) -* NR variable, changing: Auto-set. (line 305) +* NR variable, changing: Auto-set. (line 308) * null strings <1>: Basic Data Typing. (line 26) * null strings <2>: Truth Values. (line 6) * null strings <3>: Regexp Field Splitting. @@ -33138,7 +33145,7 @@ Index * p debugger command (alias for print): Viewing And Changing Data. (line 36) * Papadopoulos, Panos: Contributors. (line 128) -* parent process ID of gawk process: Auto-set. (line 185) +* parent process ID of gawk process: Auto-set. (line 188) * parentheses (), in a profile: Profiling. (line 146) * parentheses (), regexp operator: Regexp Operators. (line 81) * password file: Passwd Functions. (line 16) @@ -33194,7 +33201,7 @@ Index (line 65) * portability, deleting array elements: Delete. (line 56) * portability, example programs: Library Functions. (line 42) -* portability, functions, defining: Definition Syntax. (line 108) +* portability, functions, defining: Definition Syntax. (line 109) * portability, gawk: New Ports. (line 6) * portability, gettext library and: Explaining gettext. (line 11) * portability, internationalization and: I18N Portability. (line 6) @@ -33240,7 +33247,7 @@ Index (line 40) * POSIX awk, field separators and: Fields. (line 6) * POSIX awk, FS variable and: User-modified. (line 60) -* POSIX awk, function keyword in: Definition Syntax. (line 92) +* POSIX awk, function keyword in: Definition Syntax. (line 93) * POSIX awk, functions and, gsub()/sub(): Gory Details. (line 90) * POSIX awk, functions and, length(): String Functions. (line 176) * POSIX awk, GNU long options and: Options. (line 15) @@ -33301,8 +33308,8 @@ Index * printing, unduplicated lines of text: Uniq Program. (line 6) * printing, user information: Id Program. (line 6) * private variables: Library Names. (line 11) -* process group idIDof gawk process: Auto-set. (line 179) -* process ID of gawk process: Auto-set. (line 182) +* process group idIDof gawk process: Auto-set. (line 182) +* process ID of gawk process: Auto-set. (line 185) * processes, two-way communications with: Two-way I/O. (line 6) * processing data: Basic High Level. (line 6) * PROCINFO array <1>: Passwd Functions. (line 6) @@ -33313,7 +33320,7 @@ Index * PROCINFO array, and user and group ID numbers: Id Program. (line 15) * PROCINFO array, testing the field splitting: Passwd Functions. (line 161) -* PROCINFO array, uses: Auto-set. (line 238) +* PROCINFO array, uses: Auto-set. (line 241) * PROCINFO, values of sorted_in: Controlling Scanning. (line 26) * profiling awk programs: Profiling. (line 6) @@ -33329,7 +33336,7 @@ Index * programming conventions, functions, calling: Calling Built-in. (line 10) * programming conventions, functions, writing: Definition Syntax. - (line 64) + (line 65) * programming conventions, gawk extensions: Internal File Ops. (line 45) * programming conventions, private variable names: Library Names. @@ -33399,7 +33406,7 @@ Index * records, splitting input into: Records. (line 6) * records, terminating: awk split records. (line 124) * records, treating files as: gawk split records. (line 92) -* recursive functions: Definition Syntax. (line 82) +* recursive functions: Definition Syntax. (line 83) * redirect gawk output, in debugger: Debugger Info. (line 72) * redirection of input: Getline/File. (line 6) * redirection of output: Redirection. (line 6) @@ -33477,7 +33484,7 @@ Index * right shift: Bitwise Functions. (line 52) * right shift, bitwise: Bitwise Functions. (line 32) * Ritchie, Dennis: Basic Data Typing. (line 54) -* RLENGTH variable: Auto-set. (line 248) +* RLENGTH variable: Auto-set. (line 251) * RLENGTH variable, match() function and: String Functions. (line 224) * Robbins, Arnold <1>: Future Extensions. (line 6) * Robbins, Arnold <2>: Bugs. (line 32) @@ -33503,9 +33510,9 @@ Index * RS variable: awk split records. (line 12) * RS variable, multiline records and: Multiple Line. (line 17) * rshift: Bitwise Functions. (line 52) -* RSTART variable: Auto-set. (line 254) +* RSTART variable: Auto-set. (line 257) * RSTART variable, match() function and: String Functions. (line 224) -* RT variable <1>: Auto-set. (line 261) +* RT variable <1>: Auto-set. (line 264) * RT variable <2>: Multiple Line. (line 129) * RT variable: awk split records. (line 124) * Rubin, Paul <1>: Contributors. (line 15) @@ -33525,7 +33532,7 @@ Index * scanning arrays: Scanning an Array. (line 6) * scanning multidimensional arrays: Multiscanning. (line 11) * Schorr, Andrew <1>: Contributors. (line 133) -* Schorr, Andrew <2>: Auto-set. (line 288) +* Schorr, Andrew <2>: Auto-set. (line 291) * Schorr, Andrew: Acknowledgments. (line 60) * Schreiber, Bert: Acknowledgments. (line 38) * Schreiber, Rita: Acknowledgments. (line 38) @@ -33569,7 +33576,7 @@ Index * set directory of message catalogs: I18N Functions. (line 12) * set watchpoint: Viewing And Changing Data. (line 67) -* shadowing of variable values: Definition Syntax. (line 70) +* shadowing of variable values: Definition Syntax. (line 71) * shell quoting, rules for: Quoting. (line 6) * shells, piping commands into: Redirection. (line 142) * shells, quoting: Using Shell Variables. @@ -33609,7 +33616,7 @@ Index (line 116) * sidebar, Changing FS Does Not Affect the Fields: Field Splitting Summary. (line 38) -* sidebar, Changing NR and FNR: Auto-set. (line 303) +* sidebar, Changing NR and FNR: Auto-set. (line 306) * sidebar, Controlling Output Buffering with system(): I/O Functions. (line 138) * sidebar, Escape Sequences for Metacharacters: Escape Sequences. @@ -33772,9 +33779,9 @@ Index * substr: String Functions. (line 479) * substring: String Functions. (line 479) * Sumner, Andrew: Other Versions. (line 64) -* supplementary groups of gawk process: Auto-set. (line 233) +* supplementary groups of gawk process: Auto-set. (line 236) * switch statement: Switch Statement. (line 6) -* SYMTAB array: Auto-set. (line 265) +* SYMTAB array: Auto-set. (line 268) * syntactic ambiguity: /= operator vs. /=.../ regexp constant: Assignment Ops. (line 148) * system: I/O Functions. (line 75) @@ -33927,7 +33934,7 @@ Index * variables: Other Features. (line 6) * variables, assigning on command line: Assignment Options. (line 6) * variables, built-in <1>: Built-in Variables. (line 6) -* variables, built-in: Using Variables. (line 20) +* variables, built-in: Using Variables. (line 23) * variables, built-in, -v option, setting with: Options. (line 40) * variables, built-in, conveying information: Auto-set. (line 6) * variables, flag: Boolean Ops. (line 67) @@ -33940,22 +33947,22 @@ Index * variables, getline command into, using: Getline/Variable. (line 6) * variables, global, for library functions: Library Names. (line 11) * variables, global, printing list of: Options. (line 93) -* variables, initializing: Using Variables. (line 20) +* variables, initializing: Using Variables. (line 23) * variables, local to a function: Variable Scope. (line 6) * variables, names of: Arrays. (line 18) * variables, private: Library Names. (line 11) * variables, setting: Options. (line 32) -* variables, shadowing: Definition Syntax. (line 70) +* variables, shadowing: Definition Syntax. (line 71) * variables, types of: Assignment Ops. (line 40) * variables, types of, comparison expressions and: Typing and Comparison. (line 9) * variables, uninitialized, as array subscripts: Uninitialized Subscripts. (line 6) * variables, user-defined: Variables. (line 6) -* version of gawk: Auto-set. (line 203) -* version of gawk extension API: Auto-set. (line 228) -* version of GNU MP library: Auto-set. (line 214) -* version of GNU MPFR library: Auto-set. (line 210) +* version of gawk: Auto-set. (line 206) +* version of gawk extension API: Auto-set. (line 231) +* version of GNU MP library: Auto-set. (line 217) +* version of GNU MPFR library: Auto-set. (line 213) * vertical bar (|): Regexp Operators. (line 70) * vertical bar (|), | operator (I/O) <1>: Precedence. (line 65) * vertical bar (|), | operator (I/O): Getline/Pipe. (line 9) @@ -34184,411 +34191,411 @@ Node: Regexp Constants318867 Node: Using Constant Regexps319392 Node: Variables322464 Node: Using Variables323119 -Node: Assignment Options324843 -Node: Conversion326718 -Node: Strings And Numbers327242 -Ref: Strings And Numbers-Footnote-1330304 -Node: Locale influences conversions330413 -Ref: table-locale-affects333130 -Node: All Operators333718 -Node: Arithmetic Ops334348 -Node: Concatenation336853 -Ref: Concatenation-Footnote-1339672 -Node: Assignment Ops339778 -Ref: table-assign-ops344761 -Node: Increment Ops346064 -Node: Truth Values and Conditions349502 -Node: Truth Values350585 -Node: Typing and Comparison351634 -Node: Variable Typing352427 -Node: Comparison Operators356079 -Ref: table-relational-ops356489 -Node: POSIX String Comparison360039 -Ref: POSIX String Comparison-Footnote-1361123 -Node: Boolean Ops361261 -Ref: Boolean Ops-Footnote-1365600 -Node: Conditional Exp365691 -Node: Function Calls367418 -Node: Precedence371298 -Node: Locales374967 -Node: Expressions Summary376598 -Node: Patterns and Actions379139 -Node: Pattern Overview380255 -Node: Regexp Patterns381932 -Node: Expression Patterns382475 -Node: Ranges386255 -Node: BEGIN/END389361 -Node: Using BEGIN/END390123 -Ref: Using BEGIN/END-Footnote-1392859 -Node: I/O And BEGIN/END392965 -Node: BEGINFILE/ENDFILE395236 -Node: Empty398167 -Node: Using Shell Variables398484 -Node: Action Overview400767 -Node: Statements403094 -Node: If Statement404942 -Node: While Statement406440 -Node: Do Statement408484 -Node: For Statement409640 -Node: Switch Statement412792 -Node: Break Statement415180 -Node: Continue Statement417221 -Node: Next Statement419046 -Node: Nextfile Statement421416 -Node: Exit Statement424073 -Node: Built-in Variables426477 -Node: User-modified427604 -Ref: User-modified-Footnote-1435293 -Node: Auto-set435355 -Ref: Auto-set-Footnote-1448037 -Ref: Auto-set-Footnote-2448242 -Node: ARGC and ARGV448298 -Node: Pattern Action Summary452202 -Node: Arrays454425 -Node: Array Basics455974 -Node: Array Intro456800 -Ref: figure-array-elements458773 -Ref: Array Intro-Footnote-1461297 -Node: Reference to Elements461425 -Node: Assigning Elements463875 -Node: Array Example464366 -Node: Scanning an Array466098 -Node: Controlling Scanning469099 -Ref: Controlling Scanning-Footnote-1474272 -Node: Delete474588 -Ref: Delete-Footnote-1477339 -Node: Numeric Array Subscripts477396 -Node: Uninitialized Subscripts479579 -Node: Multidimensional481206 -Node: Multiscanning484319 -Node: Arrays of Arrays485908 -Node: Arrays Summary490571 -Node: Functions492676 -Node: Built-in493549 -Node: Calling Built-in494627 -Node: Numeric Functions496615 -Ref: Numeric Functions-Footnote-1500649 -Ref: Numeric Functions-Footnote-2501006 -Ref: Numeric Functions-Footnote-3501054 -Node: String Functions501323 -Ref: String Functions-Footnote-1524320 -Ref: String Functions-Footnote-2524449 -Ref: String Functions-Footnote-3524697 -Node: Gory Details524784 -Ref: table-sub-escapes526557 -Ref: table-sub-proposed528077 -Ref: table-posix-sub529441 -Ref: table-gensub-escapes530981 -Ref: Gory Details-Footnote-1532157 -Node: I/O Functions532308 -Ref: I/O Functions-Footnote-1539418 -Node: Time Functions539565 -Ref: Time Functions-Footnote-1550029 -Ref: Time Functions-Footnote-2550097 -Ref: Time Functions-Footnote-3550255 -Ref: Time Functions-Footnote-4550366 -Ref: Time Functions-Footnote-5550478 -Ref: Time Functions-Footnote-6550705 -Node: Bitwise Functions550971 -Ref: table-bitwise-ops551533 -Ref: Bitwise Functions-Footnote-1555778 -Node: Type Functions555962 -Node: I18N Functions557104 -Node: User-defined558749 -Node: Definition Syntax559553 -Ref: Definition Syntax-Footnote-1564866 -Node: Function Example564935 -Ref: Function Example-Footnote-1567575 -Node: Function Caveats567597 -Node: Calling A Function568115 -Node: Variable Scope569070 -Node: Pass By Value/Reference572058 -Node: Return Statement575568 -Node: Dynamic Typing578552 -Node: Indirect Calls579481 -Ref: Indirect Calls-Footnote-1589197 -Node: Functions Summary589325 -Node: Library Functions591975 -Ref: Library Functions-Footnote-1595593 -Ref: Library Functions-Footnote-2595736 -Node: Library Names595907 -Ref: Library Names-Footnote-1599380 -Ref: Library Names-Footnote-2599600 -Node: General Functions599686 -Node: Strtonum Function600714 -Node: Assert Function603616 -Node: Round Function606942 -Node: Cliff Random Function608483 -Node: Ordinal Functions609499 -Ref: Ordinal Functions-Footnote-1612564 -Ref: Ordinal Functions-Footnote-2612816 -Node: Join Function613027 -Ref: Join Function-Footnote-1614798 -Node: Getlocaltime Function614998 -Node: Readfile Function618734 -Node: Data File Management620573 -Node: Filetrans Function621205 -Node: Rewind Function625274 -Node: File Checking626832 -Ref: File Checking-Footnote-1627964 -Node: Empty Files628165 -Node: Ignoring Assigns630144 -Node: Getopt Function631698 -Ref: Getopt Function-Footnote-1642962 -Node: Passwd Functions643165 -Ref: Passwd Functions-Footnote-1652144 -Node: Group Functions652232 -Ref: Group Functions-Footnote-1660163 -Node: Walking Arrays660376 -Node: Library Functions Summary661979 -Node: Library Exercises663367 -Node: Sample Programs664647 -Node: Running Examples665417 -Node: Clones666145 -Node: Cut Program667369 -Node: Egrep Program677227 -Ref: Egrep Program-Footnote-1684814 -Node: Id Program684924 -Node: Split Program688578 -Ref: Split Program-Footnote-1692116 -Node: Tee Program692244 -Node: Uniq Program695031 -Node: Wc Program702454 -Ref: Wc Program-Footnote-1706719 -Node: Miscellaneous Programs706811 -Node: Dupword Program708024 -Node: Alarm Program710055 -Node: Translate Program714859 -Ref: Translate Program-Footnote-1719432 -Ref: Translate Program-Footnote-2719702 -Node: Labels Program719841 -Ref: Labels Program-Footnote-1723202 -Node: Word Sorting723286 -Node: History Sorting727329 -Node: Extract Program729165 -Node: Simple Sed736701 -Node: Igawk Program739763 -Ref: Igawk Program-Footnote-1754067 -Ref: Igawk Program-Footnote-2754268 -Node: Anagram Program754406 -Node: Signature Program757474 -Node: Programs Summary758721 -Node: Programs Exercises759936 -Ref: Programs Exercises-Footnote-1764067 -Node: Advanced Features764158 -Node: Nondecimal Data766106 -Node: Array Sorting767683 -Node: Controlling Array Traversal768380 -Node: Array Sorting Functions776660 -Ref: Array Sorting Functions-Footnote-1780567 -Node: Two-way I/O780761 -Ref: Two-way I/O-Footnote-1785705 -Ref: Two-way I/O-Footnote-2785884 -Node: TCP/IP Networking785966 -Node: Profiling788811 -Node: Advanced Features Summary796353 -Node: Internationalization798217 -Node: I18N and L10N799697 -Node: Explaining gettext800383 -Ref: Explaining gettext-Footnote-1805409 -Ref: Explaining gettext-Footnote-2805593 -Node: Programmer i18n805758 -Ref: Programmer i18n-Footnote-1810552 -Node: Translator i18n810601 -Node: String Extraction811395 -Ref: String Extraction-Footnote-1812528 -Node: Printf Ordering812614 -Ref: Printf Ordering-Footnote-1815396 -Node: I18N Portability815460 -Ref: I18N Portability-Footnote-1817909 -Node: I18N Example817972 -Ref: I18N Example-Footnote-1820678 -Node: Gawk I18N820750 -Node: I18N Summary821388 -Node: Debugger822727 -Node: Debugging823749 -Node: Debugging Concepts824190 -Node: Debugging Terms826046 -Node: Awk Debugging828643 -Node: Sample Debugging Session829535 -Node: Debugger Invocation830055 -Node: Finding The Bug831391 -Node: List of Debugger Commands837870 -Node: Breakpoint Control839202 -Node: Debugger Execution Control842866 -Node: Viewing And Changing Data846226 -Node: Execution Stack849584 -Node: Debugger Info851097 -Node: Miscellaneous Debugger Commands855091 -Node: Readline Support860275 -Node: Limitations861167 -Node: Debugging Summary863440 -Node: Arbitrary Precision Arithmetic864608 -Node: Computer Arithmetic866095 -Ref: Computer Arithmetic-Footnote-1870482 -Node: Math Definitions870539 -Ref: table-ieee-formats873828 -Ref: Math Definitions-Footnote-1874368 -Node: MPFR features874471 -Node: FP Math Caution876088 -Ref: FP Math Caution-Footnote-1877138 -Node: Inexactness of computations877507 -Node: Inexact representation878455 -Node: Comparing FP Values879810 -Node: Errors accumulate880774 -Node: Getting Accuracy882207 -Node: Try To Round884866 -Node: Setting precision885765 -Ref: table-predefined-precision-strings886447 -Node: Setting the rounding mode888240 -Ref: table-gawk-rounding-modes888604 -Ref: Setting the rounding mode-Footnote-1892058 -Node: Arbitrary Precision Integers892237 -Ref: Arbitrary Precision Integers-Footnote-1895218 -Node: POSIX Floating Point Problems895367 -Ref: POSIX Floating Point Problems-Footnote-1899243 -Node: Floating point summary899281 -Node: Dynamic Extensions901485 -Node: Extension Intro903037 -Node: Plugin License904302 -Node: Extension Mechanism Outline904987 -Ref: figure-load-extension905411 -Ref: figure-load-new-function906896 -Ref: figure-call-new-function907898 -Node: Extension API Description909882 -Node: Extension API Functions Introduction911332 -Node: General Data Types916199 -Ref: General Data Types-Footnote-1921892 -Node: Requesting Values922191 -Ref: table-value-types-returned922928 -Node: Memory Allocation Functions923886 -Ref: Memory Allocation Functions-Footnote-1926633 -Node: Constructor Functions926729 -Node: Registration Functions928487 -Node: Extension Functions929172 -Node: Exit Callback Functions931474 -Node: Extension Version String932722 -Node: Input Parsers933372 -Node: Output Wrappers943186 -Node: Two-way processors947702 -Node: Printing Messages949906 -Ref: Printing Messages-Footnote-1950983 -Node: Updating `ERRNO'951135 -Node: Accessing Parameters951874 -Node: Symbol Table Access953104 -Node: Symbol table by name953618 -Node: Symbol table by cookie955594 -Ref: Symbol table by cookie-Footnote-1959727 -Node: Cached values959790 -Ref: Cached values-Footnote-1963294 -Node: Array Manipulation963385 -Ref: Array Manipulation-Footnote-1964483 -Node: Array Data Types964522 -Ref: Array Data Types-Footnote-1967225 -Node: Array Functions967317 -Node: Flattening Arrays971191 -Node: Creating Arrays978043 -Node: Extension API Variables982774 -Node: Extension Versioning983410 -Node: Extension API Informational Variables985311 -Node: Extension API Boilerplate986397 -Node: Finding Extensions990201 -Node: Extension Example990761 -Node: Internal File Description991491 -Node: Internal File Ops995582 -Ref: Internal File Ops-Footnote-11007014 -Node: Using Internal File Ops1007154 -Ref: Using Internal File Ops-Footnote-11009501 -Node: Extension Samples1009769 -Node: Extension Sample File Functions1011293 -Node: Extension Sample Fnmatch1018861 -Node: Extension Sample Fork1020343 -Node: Extension Sample Inplace1021556 -Node: Extension Sample Ord1023231 -Node: Extension Sample Readdir1024067 -Ref: table-readdir-file-types1024923 -Node: Extension Sample Revout1025722 -Node: Extension Sample Rev2way1026313 -Node: Extension Sample Read write array1027054 -Node: Extension Sample Readfile1028933 -Node: Extension Sample API Tests1030033 -Node: Extension Sample Time1030558 -Node: gawkextlib1031873 -Node: Extension summary1034686 -Node: Extension Exercises1038379 -Node: Language History1039101 -Node: V7/SVR3.11040744 -Node: SVR41043064 -Node: POSIX1044506 -Node: BTL1045892 -Node: POSIX/GNU1046626 -Node: Feature History1052342 -Node: Common Extensions1065433 -Node: Ranges and Locales1066745 -Ref: Ranges and Locales-Footnote-11071362 -Ref: Ranges and Locales-Footnote-21071389 -Ref: Ranges and Locales-Footnote-31071623 -Node: Contributors1071844 -Node: History summary1077269 -Node: Installation1078638 -Node: Gawk Distribution1079589 -Node: Getting1080073 -Node: Extracting1080897 -Node: Distribution contents1082539 -Node: Unix Installation1088256 -Node: Quick Installation1088873 -Node: Additional Configuration Options1091315 -Node: Configuration Philosophy1093053 -Node: Non-Unix Installation1095404 -Node: PC Installation1095862 -Node: PC Binary Installation1097173 -Node: PC Compiling1099021 -Ref: PC Compiling-Footnote-11102020 -Node: PC Testing1102125 -Node: PC Using1103301 -Node: Cygwin1107453 -Node: MSYS1108262 -Node: VMS Installation1108776 -Node: VMS Compilation1109572 -Ref: VMS Compilation-Footnote-11110794 -Node: VMS Dynamic Extensions1110852 -Node: VMS Installation Details1112225 -Node: VMS Running1114477 -Node: VMS GNV1117311 -Node: VMS Old Gawk1118034 -Node: Bugs1118504 -Node: Other Versions1122508 -Node: Installation summary1128735 -Node: Notes1129791 -Node: Compatibility Mode1130656 -Node: Additions1131438 -Node: Accessing The Source1132363 -Node: Adding Code1133799 -Node: New Ports1139977 -Node: Derived Files1144458 -Ref: Derived Files-Footnote-11149933 -Ref: Derived Files-Footnote-21149967 -Ref: Derived Files-Footnote-31150563 -Node: Future Extensions1150677 -Node: Implementation Limitations1151283 -Node: Extension Design1152531 -Node: Old Extension Problems1153685 -Ref: Old Extension Problems-Footnote-11155202 -Node: Extension New Mechanism Goals1155259 -Ref: Extension New Mechanism Goals-Footnote-11158619 -Node: Extension Other Design Decisions1158808 -Node: Extension Future Growth1160914 -Node: Old Extension Mechanism1161750 -Node: Notes summary1163512 -Node: Basic Concepts1164698 -Node: Basic High Level1165379 -Ref: figure-general-flow1165651 -Ref: figure-process-flow1166250 -Ref: Basic High Level-Footnote-11169479 -Node: Basic Data Typing1169664 -Node: Glossary1172992 -Node: Copying1198144 -Node: GNU Free Documentation License1235700 -Node: Index1260836 +Node: Assignment Options325025 +Node: Conversion326900 +Node: Strings And Numbers327424 +Ref: Strings And Numbers-Footnote-1330486 +Node: Locale influences conversions330595 +Ref: table-locale-affects333312 +Node: All Operators333900 +Node: Arithmetic Ops334530 +Node: Concatenation337035 +Ref: Concatenation-Footnote-1339854 +Node: Assignment Ops339960 +Ref: table-assign-ops344943 +Node: Increment Ops346246 +Node: Truth Values and Conditions349684 +Node: Truth Values350767 +Node: Typing and Comparison351816 +Node: Variable Typing352609 +Node: Comparison Operators356261 +Ref: table-relational-ops356671 +Node: POSIX String Comparison360221 +Ref: POSIX String Comparison-Footnote-1361305 +Node: Boolean Ops361443 +Ref: Boolean Ops-Footnote-1365782 +Node: Conditional Exp365873 +Node: Function Calls367600 +Node: Precedence371480 +Node: Locales375149 +Node: Expressions Summary376780 +Node: Patterns and Actions379321 +Node: Pattern Overview380437 +Node: Regexp Patterns382114 +Node: Expression Patterns382657 +Node: Ranges386437 +Node: BEGIN/END389543 +Node: Using BEGIN/END390305 +Ref: Using BEGIN/END-Footnote-1393041 +Node: I/O And BEGIN/END393147 +Node: BEGINFILE/ENDFILE395418 +Node: Empty398349 +Node: Using Shell Variables398666 +Node: Action Overview400949 +Node: Statements403276 +Node: If Statement405124 +Node: While Statement406622 +Node: Do Statement408666 +Node: For Statement409822 +Node: Switch Statement412974 +Node: Break Statement415362 +Node: Continue Statement417403 +Node: Next Statement419228 +Node: Nextfile Statement421598 +Node: Exit Statement424255 +Node: Built-in Variables426659 +Node: User-modified427786 +Ref: User-modified-Footnote-1435475 +Node: Auto-set435537 +Ref: Auto-set-Footnote-1448389 +Ref: Auto-set-Footnote-2448594 +Node: ARGC and ARGV448650 +Node: Pattern Action Summary452554 +Node: Arrays454777 +Node: Array Basics456326 +Node: Array Intro457152 +Ref: figure-array-elements459125 +Ref: Array Intro-Footnote-1461649 +Node: Reference to Elements461777 +Node: Assigning Elements464227 +Node: Array Example464718 +Node: Scanning an Array466450 +Node: Controlling Scanning469451 +Ref: Controlling Scanning-Footnote-1474624 +Node: Delete474940 +Ref: Delete-Footnote-1477691 +Node: Numeric Array Subscripts477748 +Node: Uninitialized Subscripts479931 +Node: Multidimensional481558 +Node: Multiscanning484671 +Node: Arrays of Arrays486260 +Node: Arrays Summary490923 +Node: Functions493028 +Node: Built-in493901 +Node: Calling Built-in494979 +Node: Numeric Functions496967 +Ref: Numeric Functions-Footnote-1501001 +Ref: Numeric Functions-Footnote-2501358 +Ref: Numeric Functions-Footnote-3501406 +Node: String Functions501675 +Ref: String Functions-Footnote-1524672 +Ref: String Functions-Footnote-2524801 +Ref: String Functions-Footnote-3525049 +Node: Gory Details525136 +Ref: table-sub-escapes526909 +Ref: table-sub-proposed528429 +Ref: table-posix-sub529793 +Ref: table-gensub-escapes531333 +Ref: Gory Details-Footnote-1532509 +Node: I/O Functions532660 +Ref: I/O Functions-Footnote-1539770 +Node: Time Functions539917 +Ref: Time Functions-Footnote-1550381 +Ref: Time Functions-Footnote-2550449 +Ref: Time Functions-Footnote-3550607 +Ref: Time Functions-Footnote-4550718 +Ref: Time Functions-Footnote-5550830 +Ref: Time Functions-Footnote-6551057 +Node: Bitwise Functions551323 +Ref: table-bitwise-ops551885 +Ref: Bitwise Functions-Footnote-1556130 +Node: Type Functions556314 +Node: I18N Functions557456 +Node: User-defined559101 +Node: Definition Syntax559905 +Ref: Definition Syntax-Footnote-1565309 +Node: Function Example565378 +Ref: Function Example-Footnote-1568018 +Node: Function Caveats568040 +Node: Calling A Function568558 +Node: Variable Scope569513 +Node: Pass By Value/Reference572501 +Node: Return Statement576011 +Node: Dynamic Typing578995 +Node: Indirect Calls579924 +Ref: Indirect Calls-Footnote-1589640 +Node: Functions Summary589768 +Node: Library Functions592418 +Ref: Library Functions-Footnote-1596036 +Ref: Library Functions-Footnote-2596179 +Node: Library Names596350 +Ref: Library Names-Footnote-1599823 +Ref: Library Names-Footnote-2600043 +Node: General Functions600129 +Node: Strtonum Function601157 +Node: Assert Function604059 +Node: Round Function607385 +Node: Cliff Random Function608926 +Node: Ordinal Functions609942 +Ref: Ordinal Functions-Footnote-1613007 +Ref: Ordinal Functions-Footnote-2613259 +Node: Join Function613470 +Ref: Join Function-Footnote-1615241 +Node: Getlocaltime Function615441 +Node: Readfile Function619177 +Node: Data File Management621016 +Node: Filetrans Function621648 +Node: Rewind Function625717 +Node: File Checking627275 +Ref: File Checking-Footnote-1628407 +Node: Empty Files628608 +Node: Ignoring Assigns630587 +Node: Getopt Function632141 +Ref: Getopt Function-Footnote-1643405 +Node: Passwd Functions643608 +Ref: Passwd Functions-Footnote-1652587 +Node: Group Functions652675 +Ref: Group Functions-Footnote-1660606 +Node: Walking Arrays660819 +Node: Library Functions Summary662422 +Node: Library Exercises663810 +Node: Sample Programs665090 +Node: Running Examples665860 +Node: Clones666588 +Node: Cut Program667812 +Node: Egrep Program677670 +Ref: Egrep Program-Footnote-1685257 +Node: Id Program685367 +Node: Split Program689021 +Ref: Split Program-Footnote-1692559 +Node: Tee Program692687 +Node: Uniq Program695474 +Node: Wc Program702897 +Ref: Wc Program-Footnote-1707162 +Node: Miscellaneous Programs707254 +Node: Dupword Program708467 +Node: Alarm Program710498 +Node: Translate Program715302 +Ref: Translate Program-Footnote-1719875 +Ref: Translate Program-Footnote-2720145 +Node: Labels Program720284 +Ref: Labels Program-Footnote-1723645 +Node: Word Sorting723729 +Node: History Sorting727772 +Node: Extract Program729608 +Node: Simple Sed737144 +Node: Igawk Program740206 +Ref: Igawk Program-Footnote-1754510 +Ref: Igawk Program-Footnote-2754711 +Node: Anagram Program754849 +Node: Signature Program757917 +Node: Programs Summary759164 +Node: Programs Exercises760379 +Ref: Programs Exercises-Footnote-1764510 +Node: Advanced Features764601 +Node: Nondecimal Data766549 +Node: Array Sorting768126 +Node: Controlling Array Traversal768823 +Node: Array Sorting Functions777103 +Ref: Array Sorting Functions-Footnote-1781010 +Node: Two-way I/O781204 +Ref: Two-way I/O-Footnote-1786148 +Ref: Two-way I/O-Footnote-2786327 +Node: TCP/IP Networking786409 +Node: Profiling789254 +Node: Advanced Features Summary796796 +Node: Internationalization798660 +Node: I18N and L10N800140 +Node: Explaining gettext800826 +Ref: Explaining gettext-Footnote-1805852 +Ref: Explaining gettext-Footnote-2806036 +Node: Programmer i18n806201 +Ref: Programmer i18n-Footnote-1810995 +Node: Translator i18n811044 +Node: String Extraction811838 +Ref: String Extraction-Footnote-1812971 +Node: Printf Ordering813057 +Ref: Printf Ordering-Footnote-1815839 +Node: I18N Portability815903 +Ref: I18N Portability-Footnote-1818352 +Node: I18N Example818415 +Ref: I18N Example-Footnote-1821121 +Node: Gawk I18N821193 +Node: I18N Summary821831 +Node: Debugger823170 +Node: Debugging824192 +Node: Debugging Concepts824633 +Node: Debugging Terms826489 +Node: Awk Debugging829086 +Node: Sample Debugging Session829978 +Node: Debugger Invocation830498 +Node: Finding The Bug831834 +Node: List of Debugger Commands838313 +Node: Breakpoint Control839645 +Node: Debugger Execution Control843309 +Node: Viewing And Changing Data846669 +Node: Execution Stack850027 +Node: Debugger Info851540 +Node: Miscellaneous Debugger Commands855534 +Node: Readline Support860718 +Node: Limitations861610 +Node: Debugging Summary863883 +Node: Arbitrary Precision Arithmetic865051 +Node: Computer Arithmetic866538 +Ref: Computer Arithmetic-Footnote-1870925 +Node: Math Definitions870982 +Ref: table-ieee-formats874271 +Ref: Math Definitions-Footnote-1874811 +Node: MPFR features874914 +Node: FP Math Caution876531 +Ref: FP Math Caution-Footnote-1877581 +Node: Inexactness of computations877950 +Node: Inexact representation878898 +Node: Comparing FP Values880253 +Node: Errors accumulate881217 +Node: Getting Accuracy882650 +Node: Try To Round885309 +Node: Setting precision886208 +Ref: table-predefined-precision-strings886890 +Node: Setting the rounding mode888683 +Ref: table-gawk-rounding-modes889047 +Ref: Setting the rounding mode-Footnote-1892501 +Node: Arbitrary Precision Integers892680 +Ref: Arbitrary Precision Integers-Footnote-1895661 +Node: POSIX Floating Point Problems895810 +Ref: POSIX Floating Point Problems-Footnote-1899686 +Node: Floating point summary899724 +Node: Dynamic Extensions901928 +Node: Extension Intro903480 +Node: Plugin License904745 +Node: Extension Mechanism Outline905430 +Ref: figure-load-extension905854 +Ref: figure-load-new-function907339 +Ref: figure-call-new-function908341 +Node: Extension API Description910325 +Node: Extension API Functions Introduction911775 +Node: General Data Types916642 +Ref: General Data Types-Footnote-1922335 +Node: Requesting Values922634 +Ref: table-value-types-returned923371 +Node: Memory Allocation Functions924329 +Ref: Memory Allocation Functions-Footnote-1927076 +Node: Constructor Functions927172 +Node: Registration Functions928930 +Node: Extension Functions929615 +Node: Exit Callback Functions931917 +Node: Extension Version String933165 +Node: Input Parsers933815 +Node: Output Wrappers943629 +Node: Two-way processors948145 +Node: Printing Messages950349 +Ref: Printing Messages-Footnote-1951426 +Node: Updating `ERRNO'951578 +Node: Accessing Parameters952317 +Node: Symbol Table Access953547 +Node: Symbol table by name954061 +Node: Symbol table by cookie956037 +Ref: Symbol table by cookie-Footnote-1960170 +Node: Cached values960233 +Ref: Cached values-Footnote-1963737 +Node: Array Manipulation963828 +Ref: Array Manipulation-Footnote-1964926 +Node: Array Data Types964965 +Ref: Array Data Types-Footnote-1967668 +Node: Array Functions967760 +Node: Flattening Arrays971634 +Node: Creating Arrays978486 +Node: Extension API Variables983217 +Node: Extension Versioning983853 +Node: Extension API Informational Variables985754 +Node: Extension API Boilerplate986840 +Node: Finding Extensions990644 +Node: Extension Example991204 +Node: Internal File Description991934 +Node: Internal File Ops996025 +Ref: Internal File Ops-Footnote-11007457 +Node: Using Internal File Ops1007597 +Ref: Using Internal File Ops-Footnote-11009944 +Node: Extension Samples1010212 +Node: Extension Sample File Functions1011736 +Node: Extension Sample Fnmatch1019304 +Node: Extension Sample Fork1020786 +Node: Extension Sample Inplace1021999 +Node: Extension Sample Ord1023674 +Node: Extension Sample Readdir1024510 +Ref: table-readdir-file-types1025366 +Node: Extension Sample Revout1026165 +Node: Extension Sample Rev2way1026756 +Node: Extension Sample Read write array1027497 +Node: Extension Sample Readfile1029376 +Node: Extension Sample API Tests1030476 +Node: Extension Sample Time1031001 +Node: gawkextlib1032316 +Node: Extension summary1035129 +Node: Extension Exercises1038822 +Node: Language History1039544 +Node: V7/SVR3.11041187 +Node: SVR41043507 +Node: POSIX1044949 +Node: BTL1046335 +Node: POSIX/GNU1047069 +Node: Feature History1052785 +Node: Common Extensions1065876 +Node: Ranges and Locales1067188 +Ref: Ranges and Locales-Footnote-11071805 +Ref: Ranges and Locales-Footnote-21071832 +Ref: Ranges and Locales-Footnote-31072066 +Node: Contributors1072287 +Node: History summary1077712 +Node: Installation1079081 +Node: Gawk Distribution1080032 +Node: Getting1080516 +Node: Extracting1081340 +Node: Distribution contents1082982 +Node: Unix Installation1088699 +Node: Quick Installation1089316 +Node: Additional Configuration Options1091758 +Node: Configuration Philosophy1093496 +Node: Non-Unix Installation1095847 +Node: PC Installation1096305 +Node: PC Binary Installation1097616 +Node: PC Compiling1099464 +Ref: PC Compiling-Footnote-11102463 +Node: PC Testing1102568 +Node: PC Using1103744 +Node: Cygwin1107896 +Node: MSYS1108705 +Node: VMS Installation1109219 +Node: VMS Compilation1110015 +Ref: VMS Compilation-Footnote-11111237 +Node: VMS Dynamic Extensions1111295 +Node: VMS Installation Details1112668 +Node: VMS Running1114920 +Node: VMS GNV1117754 +Node: VMS Old Gawk1118477 +Node: Bugs1118947 +Node: Other Versions1122951 +Node: Installation summary1129178 +Node: Notes1130234 +Node: Compatibility Mode1131099 +Node: Additions1131881 +Node: Accessing The Source1132806 +Node: Adding Code1134242 +Node: New Ports1140420 +Node: Derived Files1144901 +Ref: Derived Files-Footnote-11150376 +Ref: Derived Files-Footnote-21150410 +Ref: Derived Files-Footnote-31151006 +Node: Future Extensions1151120 +Node: Implementation Limitations1151726 +Node: Extension Design1152974 +Node: Old Extension Problems1154128 +Ref: Old Extension Problems-Footnote-11155645 +Node: Extension New Mechanism Goals1155702 +Ref: Extension New Mechanism Goals-Footnote-11159062 +Node: Extension Other Design Decisions1159251 +Node: Extension Future Growth1161357 +Node: Old Extension Mechanism1162193 +Node: Notes summary1163955 +Node: Basic Concepts1165141 +Node: Basic High Level1165822 +Ref: figure-general-flow1166094 +Ref: figure-process-flow1166693 +Ref: Basic High Level-Footnote-11169922 +Node: Basic Data Typing1170107 +Node: Glossary1173435 +Node: Copying1198587 +Node: GNU Free Documentation License1236143 +Node: Index1261279  End Tag Table -- cgit v1.2.3 From 3c1052d3020c5b3ac7361ab7a706bcb83af05b30 Mon Sep 17 00:00:00 2001 From: "Arnold D. Robbins" Date: Thu, 18 Sep 2014 20:44:49 +0300 Subject: Minor doc updates. --- doc/gawk.info | 420 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 210 insertions(+), 210 deletions(-) (limited to 'doc/gawk.info') diff --git a/doc/gawk.info b/doc/gawk.info index d94ea8bf..42465c42 100644 --- a/doc/gawk.info +++ b/doc/gawk.info @@ -19399,10 +19399,10 @@ File: gawk.info, Node: TCP/IP Networking, Next: Profiling, Prev: Two-way I/O, unless the host that isn't close is busy hung or dead. - In addition to being able to open a two-way pipeline to a coprocess -on the same system (*note Two-way I/O::), it is possible to make a -two-way connection to another process on another system across an IP -network connection. +In addition to being able to open a two-way pipeline to a coprocess on +the same system (*note Two-way I/O::), it is possible to make a two-way +connection to another process on another system across an IP network +connection. You can think of this as just a _very long_ two-way pipeline to a coprocess. The way `gawk' decides that you want to use TCP/IP @@ -27997,7 +27997,7 @@ B.5 Other Freely Available `awk' Implementations `// Do C++ comments work? answer: yes! of course' -- Michael Brennan - There are a number of other freely available `awk' implementations. +There are a number of other freely available `awk' implementations. This minor node briefly describes where to get them: Unix `awk' @@ -34392,210 +34392,210 @@ Node: Two-way I/O781204 Ref: Two-way I/O-Footnote-1786148 Ref: Two-way I/O-Footnote-2786327 Node: TCP/IP Networking786409 -Node: Profiling789254 -Node: Advanced Features Summary796796 -Node: Internationalization798660 -Node: I18N and L10N800140 -Node: Explaining gettext800826 -Ref: Explaining gettext-Footnote-1805852 -Ref: Explaining gettext-Footnote-2806036 -Node: Programmer i18n806201 -Ref: Programmer i18n-Footnote-1810995 -Node: Translator i18n811044 -Node: String Extraction811838 -Ref: String Extraction-Footnote-1812971 -Node: Printf Ordering813057 -Ref: Printf Ordering-Footnote-1815839 -Node: I18N Portability815903 -Ref: I18N Portability-Footnote-1818352 -Node: I18N Example818415 -Ref: I18N Example-Footnote-1821121 -Node: Gawk I18N821193 -Node: I18N Summary821831 -Node: Debugger823170 -Node: Debugging824192 -Node: Debugging Concepts824633 -Node: Debugging Terms826489 -Node: Awk Debugging829086 -Node: Sample Debugging Session829978 -Node: Debugger Invocation830498 -Node: Finding The Bug831834 -Node: List of Debugger Commands838313 -Node: Breakpoint Control839645 -Node: Debugger Execution Control843309 -Node: Viewing And Changing Data846669 -Node: Execution Stack850027 -Node: Debugger Info851540 -Node: Miscellaneous Debugger Commands855534 -Node: Readline Support860718 -Node: Limitations861610 -Node: Debugging Summary863883 -Node: Arbitrary Precision Arithmetic865051 -Node: Computer Arithmetic866538 -Ref: Computer Arithmetic-Footnote-1870925 -Node: Math Definitions870982 -Ref: table-ieee-formats874271 -Ref: Math Definitions-Footnote-1874811 -Node: MPFR features874914 -Node: FP Math Caution876531 -Ref: FP Math Caution-Footnote-1877581 -Node: Inexactness of computations877950 -Node: Inexact representation878898 -Node: Comparing FP Values880253 -Node: Errors accumulate881217 -Node: Getting Accuracy882650 -Node: Try To Round885309 -Node: Setting precision886208 -Ref: table-predefined-precision-strings886890 -Node: Setting the rounding mode888683 -Ref: table-gawk-rounding-modes889047 -Ref: Setting the rounding mode-Footnote-1892501 -Node: Arbitrary Precision Integers892680 -Ref: Arbitrary Precision Integers-Footnote-1895661 -Node: POSIX Floating Point Problems895810 -Ref: POSIX Floating Point Problems-Footnote-1899686 -Node: Floating point summary899724 -Node: Dynamic Extensions901928 -Node: Extension Intro903480 -Node: Plugin License904745 -Node: Extension Mechanism Outline905430 -Ref: figure-load-extension905854 -Ref: figure-load-new-function907339 -Ref: figure-call-new-function908341 -Node: Extension API Description910325 -Node: Extension API Functions Introduction911775 -Node: General Data Types916642 -Ref: General Data Types-Footnote-1922335 -Node: Requesting Values922634 -Ref: table-value-types-returned923371 -Node: Memory Allocation Functions924329 -Ref: Memory Allocation Functions-Footnote-1927076 -Node: Constructor Functions927172 -Node: Registration Functions928930 -Node: Extension Functions929615 -Node: Exit Callback Functions931917 -Node: Extension Version String933165 -Node: Input Parsers933815 -Node: Output Wrappers943629 -Node: Two-way processors948145 -Node: Printing Messages950349 -Ref: Printing Messages-Footnote-1951426 -Node: Updating `ERRNO'951578 -Node: Accessing Parameters952317 -Node: Symbol Table Access953547 -Node: Symbol table by name954061 -Node: Symbol table by cookie956037 -Ref: Symbol table by cookie-Footnote-1960170 -Node: Cached values960233 -Ref: Cached values-Footnote-1963737 -Node: Array Manipulation963828 -Ref: Array Manipulation-Footnote-1964926 -Node: Array Data Types964965 -Ref: Array Data Types-Footnote-1967668 -Node: Array Functions967760 -Node: Flattening Arrays971634 -Node: Creating Arrays978486 -Node: Extension API Variables983217 -Node: Extension Versioning983853 -Node: Extension API Informational Variables985754 -Node: Extension API Boilerplate986840 -Node: Finding Extensions990644 -Node: Extension Example991204 -Node: Internal File Description991934 -Node: Internal File Ops996025 -Ref: Internal File Ops-Footnote-11007457 -Node: Using Internal File Ops1007597 -Ref: Using Internal File Ops-Footnote-11009944 -Node: Extension Samples1010212 -Node: Extension Sample File Functions1011736 -Node: Extension Sample Fnmatch1019304 -Node: Extension Sample Fork1020786 -Node: Extension Sample Inplace1021999 -Node: Extension Sample Ord1023674 -Node: Extension Sample Readdir1024510 -Ref: table-readdir-file-types1025366 -Node: Extension Sample Revout1026165 -Node: Extension Sample Rev2way1026756 -Node: Extension Sample Read write array1027497 -Node: Extension Sample Readfile1029376 -Node: Extension Sample API Tests1030476 -Node: Extension Sample Time1031001 -Node: gawkextlib1032316 -Node: Extension summary1035129 -Node: Extension Exercises1038822 -Node: Language History1039544 -Node: V7/SVR3.11041187 -Node: SVR41043507 -Node: POSIX1044949 -Node: BTL1046335 -Node: POSIX/GNU1047069 -Node: Feature History1052785 -Node: Common Extensions1065876 -Node: Ranges and Locales1067188 -Ref: Ranges and Locales-Footnote-11071805 -Ref: Ranges and Locales-Footnote-21071832 -Ref: Ranges and Locales-Footnote-31072066 -Node: Contributors1072287 -Node: History summary1077712 -Node: Installation1079081 -Node: Gawk Distribution1080032 -Node: Getting1080516 -Node: Extracting1081340 -Node: Distribution contents1082982 -Node: Unix Installation1088699 -Node: Quick Installation1089316 -Node: Additional Configuration Options1091758 -Node: Configuration Philosophy1093496 -Node: Non-Unix Installation1095847 -Node: PC Installation1096305 -Node: PC Binary Installation1097616 -Node: PC Compiling1099464 -Ref: PC Compiling-Footnote-11102463 -Node: PC Testing1102568 -Node: PC Using1103744 -Node: Cygwin1107896 -Node: MSYS1108705 -Node: VMS Installation1109219 -Node: VMS Compilation1110015 -Ref: VMS Compilation-Footnote-11111237 -Node: VMS Dynamic Extensions1111295 -Node: VMS Installation Details1112668 -Node: VMS Running1114920 -Node: VMS GNV1117754 -Node: VMS Old Gawk1118477 -Node: Bugs1118947 -Node: Other Versions1122951 -Node: Installation summary1129178 -Node: Notes1130234 -Node: Compatibility Mode1131099 -Node: Additions1131881 -Node: Accessing The Source1132806 -Node: Adding Code1134242 -Node: New Ports1140420 -Node: Derived Files1144901 -Ref: Derived Files-Footnote-11150376 -Ref: Derived Files-Footnote-21150410 -Ref: Derived Files-Footnote-31151006 -Node: Future Extensions1151120 -Node: Implementation Limitations1151726 -Node: Extension Design1152974 -Node: Old Extension Problems1154128 -Ref: Old Extension Problems-Footnote-11155645 -Node: Extension New Mechanism Goals1155702 -Ref: Extension New Mechanism Goals-Footnote-11159062 -Node: Extension Other Design Decisions1159251 -Node: Extension Future Growth1161357 -Node: Old Extension Mechanism1162193 -Node: Notes summary1163955 -Node: Basic Concepts1165141 -Node: Basic High Level1165822 -Ref: figure-general-flow1166094 -Ref: figure-process-flow1166693 -Ref: Basic High Level-Footnote-11169922 -Node: Basic Data Typing1170107 -Node: Glossary1173435 -Node: Copying1198587 -Node: GNU Free Documentation License1236143 -Node: Index1261279 +Node: Profiling789251 +Node: Advanced Features Summary796793 +Node: Internationalization798657 +Node: I18N and L10N800137 +Node: Explaining gettext800823 +Ref: Explaining gettext-Footnote-1805849 +Ref: Explaining gettext-Footnote-2806033 +Node: Programmer i18n806198 +Ref: Programmer i18n-Footnote-1810992 +Node: Translator i18n811041 +Node: String Extraction811835 +Ref: String Extraction-Footnote-1812968 +Node: Printf Ordering813054 +Ref: Printf Ordering-Footnote-1815836 +Node: I18N Portability815900 +Ref: I18N Portability-Footnote-1818349 +Node: I18N Example818412 +Ref: I18N Example-Footnote-1821118 +Node: Gawk I18N821190 +Node: I18N Summary821828 +Node: Debugger823167 +Node: Debugging824189 +Node: Debugging Concepts824630 +Node: Debugging Terms826486 +Node: Awk Debugging829083 +Node: Sample Debugging Session829975 +Node: Debugger Invocation830495 +Node: Finding The Bug831831 +Node: List of Debugger Commands838310 +Node: Breakpoint Control839642 +Node: Debugger Execution Control843306 +Node: Viewing And Changing Data846666 +Node: Execution Stack850024 +Node: Debugger Info851537 +Node: Miscellaneous Debugger Commands855531 +Node: Readline Support860715 +Node: Limitations861607 +Node: Debugging Summary863880 +Node: Arbitrary Precision Arithmetic865048 +Node: Computer Arithmetic866535 +Ref: Computer Arithmetic-Footnote-1870922 +Node: Math Definitions870979 +Ref: table-ieee-formats874268 +Ref: Math Definitions-Footnote-1874808 +Node: MPFR features874911 +Node: FP Math Caution876528 +Ref: FP Math Caution-Footnote-1877578 +Node: Inexactness of computations877947 +Node: Inexact representation878895 +Node: Comparing FP Values880250 +Node: Errors accumulate881214 +Node: Getting Accuracy882647 +Node: Try To Round885306 +Node: Setting precision886205 +Ref: table-predefined-precision-strings886887 +Node: Setting the rounding mode888680 +Ref: table-gawk-rounding-modes889044 +Ref: Setting the rounding mode-Footnote-1892498 +Node: Arbitrary Precision Integers892677 +Ref: Arbitrary Precision Integers-Footnote-1895658 +Node: POSIX Floating Point Problems895807 +Ref: POSIX Floating Point Problems-Footnote-1899683 +Node: Floating point summary899721 +Node: Dynamic Extensions901925 +Node: Extension Intro903477 +Node: Plugin License904742 +Node: Extension Mechanism Outline905427 +Ref: figure-load-extension905851 +Ref: figure-load-new-function907336 +Ref: figure-call-new-function908338 +Node: Extension API Description910322 +Node: Extension API Functions Introduction911772 +Node: General Data Types916639 +Ref: General Data Types-Footnote-1922332 +Node: Requesting Values922631 +Ref: table-value-types-returned923368 +Node: Memory Allocation Functions924326 +Ref: Memory Allocation Functions-Footnote-1927073 +Node: Constructor Functions927169 +Node: Registration Functions928927 +Node: Extension Functions929612 +Node: Exit Callback Functions931914 +Node: Extension Version String933162 +Node: Input Parsers933812 +Node: Output Wrappers943626 +Node: Two-way processors948142 +Node: Printing Messages950346 +Ref: Printing Messages-Footnote-1951423 +Node: Updating `ERRNO'951575 +Node: Accessing Parameters952314 +Node: Symbol Table Access953544 +Node: Symbol table by name954058 +Node: Symbol table by cookie956034 +Ref: Symbol table by cookie-Footnote-1960167 +Node: Cached values960230 +Ref: Cached values-Footnote-1963734 +Node: Array Manipulation963825 +Ref: Array Manipulation-Footnote-1964923 +Node: Array Data Types964962 +Ref: Array Data Types-Footnote-1967665 +Node: Array Functions967757 +Node: Flattening Arrays971631 +Node: Creating Arrays978483 +Node: Extension API Variables983214 +Node: Extension Versioning983850 +Node: Extension API Informational Variables985751 +Node: Extension API Boilerplate986837 +Node: Finding Extensions990641 +Node: Extension Example991201 +Node: Internal File Description991931 +Node: Internal File Ops996022 +Ref: Internal File Ops-Footnote-11007454 +Node: Using Internal File Ops1007594 +Ref: Using Internal File Ops-Footnote-11009941 +Node: Extension Samples1010209 +Node: Extension Sample File Functions1011733 +Node: Extension Sample Fnmatch1019301 +Node: Extension Sample Fork1020783 +Node: Extension Sample Inplace1021996 +Node: Extension Sample Ord1023671 +Node: Extension Sample Readdir1024507 +Ref: table-readdir-file-types1025363 +Node: Extension Sample Revout1026162 +Node: Extension Sample Rev2way1026753 +Node: Extension Sample Read write array1027494 +Node: Extension Sample Readfile1029373 +Node: Extension Sample API Tests1030473 +Node: Extension Sample Time1030998 +Node: gawkextlib1032313 +Node: Extension summary1035126 +Node: Extension Exercises1038819 +Node: Language History1039541 +Node: V7/SVR3.11041184 +Node: SVR41043504 +Node: POSIX1044946 +Node: BTL1046332 +Node: POSIX/GNU1047066 +Node: Feature History1052782 +Node: Common Extensions1065873 +Node: Ranges and Locales1067185 +Ref: Ranges and Locales-Footnote-11071802 +Ref: Ranges and Locales-Footnote-21071829 +Ref: Ranges and Locales-Footnote-31072063 +Node: Contributors1072284 +Node: History summary1077709 +Node: Installation1079078 +Node: Gawk Distribution1080029 +Node: Getting1080513 +Node: Extracting1081337 +Node: Distribution contents1082979 +Node: Unix Installation1088696 +Node: Quick Installation1089313 +Node: Additional Configuration Options1091755 +Node: Configuration Philosophy1093493 +Node: Non-Unix Installation1095844 +Node: PC Installation1096302 +Node: PC Binary Installation1097613 +Node: PC Compiling1099461 +Ref: PC Compiling-Footnote-11102460 +Node: PC Testing1102565 +Node: PC Using1103741 +Node: Cygwin1107893 +Node: MSYS1108702 +Node: VMS Installation1109216 +Node: VMS Compilation1110012 +Ref: VMS Compilation-Footnote-11111234 +Node: VMS Dynamic Extensions1111292 +Node: VMS Installation Details1112665 +Node: VMS Running1114917 +Node: VMS GNV1117751 +Node: VMS Old Gawk1118474 +Node: Bugs1118944 +Node: Other Versions1122948 +Node: Installation summary1129172 +Node: Notes1130228 +Node: Compatibility Mode1131093 +Node: Additions1131875 +Node: Accessing The Source1132800 +Node: Adding Code1134236 +Node: New Ports1140414 +Node: Derived Files1144895 +Ref: Derived Files-Footnote-11150370 +Ref: Derived Files-Footnote-21150404 +Ref: Derived Files-Footnote-31151000 +Node: Future Extensions1151114 +Node: Implementation Limitations1151720 +Node: Extension Design1152968 +Node: Old Extension Problems1154122 +Ref: Old Extension Problems-Footnote-11155639 +Node: Extension New Mechanism Goals1155696 +Ref: Extension New Mechanism Goals-Footnote-11159056 +Node: Extension Other Design Decisions1159245 +Node: Extension Future Growth1161351 +Node: Old Extension Mechanism1162187 +Node: Notes summary1163949 +Node: Basic Concepts1165135 +Node: Basic High Level1165816 +Ref: figure-general-flow1166088 +Ref: figure-process-flow1166687 +Ref: Basic High Level-Footnote-11169916 +Node: Basic Data Typing1170101 +Node: Glossary1173429 +Node: Copying1198581 +Node: GNU Free Documentation License1236137 +Node: Index1261273  End Tag Table -- cgit v1.2.3